[PATCH OLK-6.6 064/123] x86/resctrl: Move the filesystem portions of resctrl to live in '/fs/'

From: James Morse james.morse@arm.com

Move the parts of resctrl that aren't archictecture specific to live in /fs/.

This lets other architectures implement resctrl too.

Signed-off-by: James Morse james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/core.c | 15 - arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 506 --- arch/x86/kernel/cpu/resctrl/internal.h | 282 -- arch/x86/kernel/cpu/resctrl/monitor.c | 837 ---- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 1105 ------ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4289 +-------------------- fs/resctrl/ctrlmondata.c | 528 +++ fs/resctrl/internal.h | 313 ++ fs/resctrl/monitor.c | 859 +++++ fs/resctrl/psuedo_lock.c | 1134 ++++++ fs/resctrl/rdtgroup.c | 4014 +++++++++++++++++++ 11 files changed, 6995 insertions(+), 6887 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 9ca3a39de912..46411c9afd5c 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -164,21 +164,6 @@ static inline void cache_alloc_hsw_probe(void) rdt_alloc_capable = true; }

-bool is_mba_sc(struct rdt_resource *r) -{ - if (!r) - r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - - /* - * The software controller support is only applicable to MBA resource. - * Make sure to check for resource type. - */ - if (r->rid != RDT_RESOURCE_MBA) - return false; - - return r->membw.mba_sc; -} - /* * rdt_get_mb_table() - get a mapping of bandwidth(b/w) percentage values * exposed to user interface and the h/w understandable delay values. diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 6b31e6c97c20..c5c3eaea27b6 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -23,261 +23,6 @@

#include "internal.h"

-struct rdt_parse_data { - struct rdtgroup *rdtgrp; - char *buf; -}; - -typedef int (ctrlval_parser_t)(struct rdt_parse_data *data, - struct resctrl_schema *s, - struct rdt_domain *d); - -/* - * Check whether MBA bandwidth percentage value is correct. The value is - * checked against the minimum and max bandwidth values specified by the - * hardware. The allocated bandwidth percentage is rounded to the next - * control step available on the hardware. - */ -static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r) -{ - unsigned long bw; - int ret; - - /* - * Only linear delay values is supported for current Intel SKUs. - */ - if (!r->membw.delay_linear && r->membw.arch_needs_linear) { - rdt_last_cmd_puts("No support for non-linear MB domains\n"); - return false; - } - - ret = kstrtoul(buf, 10, &bw); - if (ret) { - rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf); - return false; - } - - if ((bw < r->membw.min_bw || bw > r->default_ctrl) && - !is_mba_sc(r)) { - rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw, - r->membw.min_bw, r->default_ctrl); - return false; - } - - *data = roundup(bw, (unsigned long)r->membw.bw_gran); - return true; -} - -static int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, - struct rdt_domain *d) -{ - struct resctrl_staged_config *cfg; - u32 closid = data->rdtgrp->closid; - struct rdt_resource *r = s->res; - unsigned long bw_val; - - cfg = &d->staged_config[s->conf_type]; - if (cfg->have_new_ctrl) { - rdt_last_cmd_printf("Duplicate domain %d\n", d->id); - return -EINVAL; - } - - if (!bw_validate(data->buf, &bw_val, r)) - return -EINVAL; - - if (is_mba_sc(r)) { - d->mbps_val[closid] = bw_val; - return 0; - } - - cfg->new_ctrl = bw_val; - cfg->have_new_ctrl = true; - - return 0; -} - -/* - * Check whether a cache bit mask is valid. - * On Intel CPUs, non-contiguous 1s value support is indicated by CPUID: - * - CPUID.0x10.1:ECX[3]: L3 non-contiguous 1s value supported if 1 - * - CPUID.0x10.2:ECX[3]: L2 non-contiguous 1s value supported if 1 - * - * Haswell does not support a non-contiguous 1s value and additionally - * requires at least two bits set. - * AMD allows non-contiguous bitmasks. - */ -static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r) -{ - unsigned long first_bit, zero_bit, val; - unsigned int cbm_len = r->cache.cbm_len; - int ret; - - ret = kstrtoul(buf, 16, &val); - if (ret) { - rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf); - return false; - } - - if ((r->cache.min_cbm_bits > 0 && val == 0) || val > r->default_ctrl) { - rdt_last_cmd_puts("Mask out of range\n"); - return false; - } - - first_bit = find_first_bit(&val, cbm_len); - zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); - - /* Are non-contiguous bitmasks allowed? */ - if (!r->cache.arch_has_sparse_bitmasks && - (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) { - rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val); - return false; - } - - if ((zero_bit - first_bit) < r->cache.min_cbm_bits) { - rdt_last_cmd_printf("Need at least %d bits in the mask\n", - r->cache.min_cbm_bits); - return false; - } - - *data = val; - return true; -} - -/* - * Read one cache bit mask (hex). Check that it is valid for the current - * resource type. - */ -static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s, - struct rdt_domain *d) -{ - struct rdtgroup *rdtgrp = data->rdtgrp; - struct resctrl_staged_config *cfg; - struct rdt_resource *r = s->res; - u32 cbm_val; - - cfg = &d->staged_config[s->conf_type]; - if (cfg->have_new_ctrl) { - rdt_last_cmd_printf("Duplicate domain %d\n", d->id); - return -EINVAL; - } - - /* - * Cannot set up more than one pseudo-locked region in a cache - * hierarchy. - */ - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && - rdtgroup_pseudo_locked_in_hierarchy(d)) { - rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n"); - return -EINVAL; - } - - if (!cbm_validate(data->buf, &cbm_val, r)) - return -EINVAL; - - if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) && - (rdtgrp->mode == RDT_MODE_EXCLUSIVE || - rdtgrp->mode == RDT_MODE_SHAREABLE) && - rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) { - rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n"); - return -EINVAL; - } - - /* - * The CBM may not overlap with the CBM of another closid if - * either is exclusive. - */ - if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) { - rdt_last_cmd_puts("Overlaps with exclusive group\n"); - return -EINVAL; - } - - if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) { - if (rdtgrp->mode == RDT_MODE_EXCLUSIVE || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - rdt_last_cmd_puts("Overlaps with other group\n"); - return -EINVAL; - } - } - - cfg->new_ctrl = cbm_val; - cfg->have_new_ctrl = true; - - return 0; -} - -static ctrlval_parser_t *get_parser(struct rdt_resource *res) -{ - if (res->fflags & RFTYPE_RES_CACHE) - return &parse_cbm; - else - return &parse_bw; -} - -/* - * For each domain in this resource we expect to find a series of: - * id=mask - * separated by ";". The "id" is in decimal, and must match one of - * the "id"s for this resource. - */ -static int parse_line(char *line, struct resctrl_schema *s, - struct rdtgroup *rdtgrp) -{ - ctrlval_parser_t *parse_ctrlval = get_parser(s->res); - enum resctrl_conf_type t = s->conf_type; - struct resctrl_staged_config *cfg; - struct rdt_resource *r = s->res; - struct rdt_parse_data data; - char *dom = NULL, *id; - struct rdt_domain *d; - unsigned long dom_id; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && - (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) { - rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n"); - return -EINVAL; - } - -next: - if (!line || line[0] == '\0') - return 0; - dom = strsep(&line, ";"); - id = strsep(&dom, "="); - if (!dom || kstrtoul(id, 10, &dom_id)) { - rdt_last_cmd_puts("Missing '=' or non-numeric domain\n"); - return -EINVAL; - } - dom = strim(dom); - list_for_each_entry(d, &r->domains, list) { - if (d->id == dom_id) { - data.buf = dom; - data.rdtgrp = rdtgrp; - if (parse_ctrlval(&data, s, d)) - return -EINVAL; - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - cfg = &d->staged_config[t]; - /* - * In pseudo-locking setup mode and just - * parsed a valid CBM that should be - * pseudo-locked. Only one locked region per - * resource group and domain so just do - * the required initialization for single - * region and return. - */ - rdtgrp->plr->s = s; - rdtgrp->plr->d = d; - rdtgrp->plr->cbm = cfg->new_ctrl; - d->plr = rdtgrp->plr; - return 0; - } - goto next; - } - } - return -EINVAL; -} - static bool apply_config(struct rdt_hw_domain *hw_dom, struct resctrl_staged_config *cfg, u32 idx, cpumask_var_t cpu_mask) @@ -366,100 +111,6 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) return 0; }

-static int rdtgroup_parse_resource(char *resname, char *tok, - struct rdtgroup *rdtgrp) -{ - struct resctrl_schema *s; - - list_for_each_entry(s, &resctrl_schema_all, list) { - if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid) - return parse_line(tok, s, rdtgrp); - } - rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname); - return -EINVAL; -} - -ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct resctrl_schema *s; - struct rdtgroup *rdtgrp; - struct rdt_resource *r; - char *tok, *resname; - int ret = 0; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - buf[nbytes - 1] = '\0'; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - rdt_last_cmd_clear(); - - /* - * No changes to pseudo-locked region allowed. It has to be removed - * and re-created instead. - */ - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - ret = -EINVAL; - rdt_last_cmd_puts("Resource group is pseudo-locked\n"); - goto out; - } - - rdt_staged_configs_clear(); - - while ((tok = strsep(&buf, "\n")) != NULL) { - resname = strim(strsep(&tok, ":")); - if (!tok) { - rdt_last_cmd_puts("Missing ':'\n"); - ret = -EINVAL; - goto out; - } - if (tok[0] == '\0') { - rdt_last_cmd_printf("Missing '%s' value\n", resname); - ret = -EINVAL; - goto out; - } - ret = rdtgroup_parse_resource(resname, tok, rdtgrp); - if (ret) - goto out; - } - - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - - /* - * Writes to mba_sc resources update the software controller, - * not the control MSR. - */ - if (is_mba_sc(r)) - continue; - - ret = resctrl_arch_update_domains(r, rdtgrp->closid); - if (ret) - goto out; - } - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - /* - * If pseudo-locking fails we keep the resource group in - * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service - * active and updated for just the domain the pseudo-locked - * region was requested for. - */ - ret = rdtgroup_pseudo_lock_create(rdtgrp); - } - -out: - rdt_staged_configs_clear(); - rdtgroup_kn_unlock(of->kn); - return ret ?: nbytes; -} - u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type type) { @@ -468,160 +119,3 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,

return hw_dom->ctrl_val[idx]; } - -static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid) -{ - struct rdt_resource *r = schema->res; - struct rdt_domain *dom; - bool sep = false; - u32 ctrl_val; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - seq_printf(s, "%*s:", max_name_width, schema->name); - list_for_each_entry(dom, &r->domains, list) { - if (sep) - seq_puts(s, ";"); - - if (is_mba_sc(r)) - ctrl_val = dom->mbps_val[closid]; - else - ctrl_val = resctrl_arch_get_config(r, dom, closid, - schema->conf_type); - - seq_printf(s, r->format_str, dom->id, max_data_width, - ctrl_val); - sep = true; - } - seq_puts(s, "\n"); -} - -int rdtgroup_schemata_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct resctrl_schema *schema; - struct rdtgroup *rdtgrp; - int ret = 0; - u32 closid; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - list_for_each_entry(schema, &resctrl_schema_all, list) { - seq_printf(s, "%s:uninitialized\n", schema->name); - } - } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - if (!rdtgrp->plr->d) { - rdt_last_cmd_clear(); - rdt_last_cmd_puts("Cache domain offline\n"); - ret = -ENODEV; - } else { - seq_printf(s, "%s:%d=%x\n", - rdtgrp->plr->s->res->name, - rdtgrp->plr->d->id, - rdtgrp->plr->cbm); - } - } else { - closid = rdtgrp->closid; - list_for_each_entry(schema, &resctrl_schema_all, list) { - if (closid < schema->num_closid) - show_doms(s, schema, closid); - } - } - } else { - ret = -ENOENT; - } - rdtgroup_kn_unlock(of->kn); - return ret; -} - -static int smp_mon_event_count(void *arg) -{ - mon_event_count(arg); - - return 0; -} - -void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, - struct rdt_domain *d, struct rdtgroup *rdtgrp, - int evtid, int first) -{ - int cpu; - - /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - /* - * Setup the parameters to pass to mon_event_count() to read the data. - */ - rr->rgrp = rdtgrp; - rr->evtid = evtid; - rr->r = r; - rr->d = d; - rr->val = 0; - rr->first = first; - rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid); - if (IS_ERR(rr->arch_mon_ctx)) { - rr->err = -EINVAL; - return; - } - - cpu = cpumask_any_housekeeping(&d->cpu_mask, RESCTRL_PICK_ANY_CPU); - - /* - * cpumask_any_housekeeping() prefers housekeeping CPUs, but - * are all the CPUs nohz_full? If yes, pick a CPU to IPI. - * MPAM's resctrl_arch_rmid_read() is unable to read the - * counters on some platforms if its called in irq context. - */ - if (tick_nohz_full_cpu(cpu)) - smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1); - else - smp_call_on_cpu(cpu, smp_mon_event_count, rr, false); - - resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx); -} - -int rdtgroup_mondata_show(struct seq_file *m, void *arg) -{ - struct kernfs_open_file *of = m->private; - u32 resid, evtid, domid; - struct rdtgroup *rdtgrp; - struct rdt_resource *r; - union mon_data_bits md; - struct rdt_domain *d; - struct rmid_read rr; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - ret = -ENOENT; - goto out; - } - - md.priv = of->kn->priv; - resid = md.u.rid; - domid = md.u.domid; - evtid = md.u.evtid; - - r = resctrl_arch_get_resource(resid); - d = resctrl_arch_find_domain(r, domid); - if (IS_ERR_OR_NULL(d)) { - ret = -ENOENT; - goto out; - } - - mon_event_read(&rr, r, d, rdtgrp, evtid, false); - - if (rr.err == -EIO) - seq_puts(m, "Error\n"); - else if (rr.err == -EINVAL) - seq_puts(m, "Unavailable\n"); - else - seq_printf(m, "%llu\n", rr.val); - -out: - rdtgroup_kn_unlock(of->kn); - return ret; -} diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 8803640d017f..d7b8762716f2 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -27,231 +27,6 @@ */ #define MBM_CNTR_WIDTH_OFFSET_MAX (62 - MBM_CNTR_WIDTH_BASE)

-/** - * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that - * aren't marked nohz_full - * @mask: The mask to pick a CPU from. - * @exclude_cpu:The CPU to avoid picking. - * - * Returns a CPU from @mask, but not @exclude_cpu. If there are housekeeping - * CPUs that don't use nohz_full, these are preferred. Pass - * RESCTRL_PICK_ANY_CPU to avoid excluding any CPUs. - * - * When a CPU is excluded, returns >= nr_cpu_ids if no CPUs are available. - */ -static inline unsigned int -cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu) -{ - unsigned int cpu, hk_cpu; - - if (exclude_cpu == RESCTRL_PICK_ANY_CPU) - cpu = cpumask_any(mask); - else - cpu = cpumask_any_but(mask, exclude_cpu); - - if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) - return cpu; - - /* If the CPU picked isn't marked nohz_full nothing more needs doing. */ - if (cpu < nr_cpu_ids && !tick_nohz_full_cpu(cpu)) - return cpu; - - /* Try to find a CPU that isn't nohz_full to use in preference */ - hk_cpu = cpumask_nth_andnot(0, mask, tick_nohz_full_mask); - if (hk_cpu == exclude_cpu) - hk_cpu = cpumask_nth_andnot(1, mask, tick_nohz_full_mask); - - if (hk_cpu < nr_cpu_ids) - cpu = hk_cpu; - - return cpu; -} - -struct rdt_fs_context { - struct kernfs_fs_context kfc; - bool enable_cdpl2; - bool enable_cdpl3; - bool enable_mba_mbps; - bool enable_debug; -}; - -static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) -{ - struct kernfs_fs_context *kfc = fc->fs_private; - - return container_of(kfc, struct rdt_fs_context, kfc); -} - -/** - * struct mon_evt - Entry in the event list of a resource - * @evtid: event id - * @name: name of the event - * @configurable: true if the event is configurable - * @list: entry in &rdt_resource->evt_list - */ -struct mon_evt { - enum resctrl_event_id evtid; - char *name; - bool configurable; - struct list_head list; -}; - -/** - * union mon_data_bits - Monitoring details for each event file - * @priv: Used to store monitoring event data in @u - * as kernfs private data - * @rid: Resource id associated with the event file - * @evtid: Event id associated with the event file - * @domid: The domain to which the event file belongs - * @u: Name of the bit fields struct - */ -union mon_data_bits { - void *priv; - struct { - unsigned int rid : 10; - enum resctrl_event_id evtid : 8; - unsigned int domid : 14; - } u; -}; - -struct rmid_read { - struct rdtgroup *rgrp; - struct rdt_resource *r; - struct rdt_domain *d; - enum resctrl_event_id evtid; - bool first; - int err; - u64 val; - void *arch_mon_ctx; -}; - -extern struct list_head resctrl_schema_all; -extern bool resctrl_mounted; - -enum rdt_group_type { - RDTCTRL_GROUP = 0, - RDTMON_GROUP, - RDT_NUM_GROUP, -}; - -/** - * enum rdtgrp_mode - Mode of a RDT resource group - * @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations - * @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed - * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking - * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations - * allowed AND the allocations are Cache Pseudo-Locked - * @RDT_NUM_MODES: Total number of modes - * - * The mode of a resource group enables control over the allowed overlap - * between allocations associated with different resource groups (classes - * of service). User is able to modify the mode of a resource group by - * writing to the "mode" resctrl file associated with the resource group. - * - * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by - * writing the appropriate text to the "mode" file. A resource group enters - * "pseudo-locked" mode after the schemata is written while the resource - * group is in "pseudo-locksetup" mode. - */ -enum rdtgrp_mode { - RDT_MODE_SHAREABLE = 0, - RDT_MODE_EXCLUSIVE, - RDT_MODE_PSEUDO_LOCKSETUP, - RDT_MODE_PSEUDO_LOCKED, - - /* Must be last */ - RDT_NUM_MODES, -}; - -/** - * struct mongroup - store mon group's data in resctrl fs. - * @mon_data_kn: kernfs node for the mon_data directory - * @parent: parent rdtgrp - * @crdtgrp_list: child rdtgroup node list - * @rmid: rmid for this rdtgroup - */ -struct mongroup { - struct kernfs_node *mon_data_kn; - struct rdtgroup *parent; - struct list_head crdtgrp_list; - u32 rmid; -}; - -/** - * struct rdtgroup - store rdtgroup's data in resctrl file system. - * @kn: kernfs node - * @rdtgroup_list: linked list for all rdtgroups - * @closid: closid for this rdtgroup - * @cpu_mask: CPUs assigned to this rdtgroup - * @flags: status bits - * @waitcount: how many cpus expect to find this - * group when they acquire rdtgroup_mutex - * @type: indicates type of this rdtgroup - either - * monitor only or ctrl_mon group - * @mon: mongroup related data - * @mode: mode of resource group - * @plr: pseudo-locked region - */ -struct rdtgroup { - struct kernfs_node *kn; - struct list_head rdtgroup_list; - u32 closid; - struct cpumask cpu_mask; - int flags; - atomic_t waitcount; - enum rdt_group_type type; - struct mongroup mon; - enum rdtgrp_mode mode; - struct pseudo_lock_region *plr; -}; - -/* List of all resource groups */ -extern struct list_head rdt_all_groups; - -extern int max_name_width, max_data_width; - -/** - * struct rftype - describe each file in the resctrl file system - * @name: File name - * @mode: Access mode - * @kf_ops: File operations - * @flags: File specific RFTYPE_FLAGS_* flags - * @fflags: File specific RFTYPE_* flags - * @seq_show: Show content of the file - * @write: Write to the file - */ -struct rftype { - char *name; - umode_t mode; - const struct kernfs_ops *kf_ops; - unsigned long flags; - unsigned long fflags; - - int (*seq_show)(struct kernfs_open_file *of, - struct seq_file *sf, void *v); - /* - * write() is the generic write callback which maps directly to - * kernfs write operation and overrides all other operations. - * Maximum write size is determined by ->max_write_len. - */ - ssize_t (*write)(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off); -}; - -/** - * struct mbm_state - status for each MBM counter in each domain - * @prev_bw_bytes: Previous bytes value read for bandwidth calculation - * @prev_bw: The most recent bandwidth in MBps - * @delta_bw: Difference between the current and previous bandwidth - * @delta_comp: Indicates whether to compute the delta_bw - */ -struct mbm_state { - u64 prev_bw_bytes; - u32 prev_bw; - u32 delta_bw; - bool delta_comp; -}; - /** * struct arch_mbm_state - values used to compute resctrl_arch_rmid_read()s * return value. @@ -343,11 +118,7 @@ static inline struct rdt_hw_resource *resctrl_to_arch_res(struct rdt_resource *r return container_of(r, struct rdt_hw_resource, r_resctrl); }

-extern struct mutex rdtgroup_mutex; - extern struct rdt_hw_resource rdt_resources_all[]; -extern struct rdtgroup rdtgroup_default; -extern struct dentry *debugfs_resctrl;

static inline struct rdt_resource *resctrl_inc(struct rdt_resource *res) { @@ -411,62 +182,9 @@ union cpuid_0x10_x_edx { unsigned int full; };

-void rdt_last_cmd_clear(void); -void rdt_last_cmd_puts(const char *s); -__printf(1, 2) -void rdt_last_cmd_printf(const char *fmt, ...); - void rdt_ctrl_update(void *arg); -struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn); -void rdtgroup_kn_unlock(struct kernfs_node *kn); -int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name); -int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, - umode_t mask); -ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off); -int rdtgroup_schemata_show(struct kernfs_open_file *of, - struct seq_file *s, void *v); -bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_domain *d, - unsigned long cbm, int closid, bool exclusive); -unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_domain *d, - unsigned long cbm); -enum rdtgrp_mode rdtgroup_mode_by_closid(int closid); -int rdtgroup_tasks_assigned(struct rdtgroup *r); -int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp); -int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp); -bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_domain *d, unsigned long cbm); -bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d); -int rdt_pseudo_lock_init(void); -void rdt_pseudo_lock_release(void); -int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp); -void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp); -int closids_supported(void); -void closid_free(int closid); -int alloc_rmid(u32 closid); -void free_rmid(u32 closid, u32 rmid); int rdt_get_mon_l3_config(struct rdt_resource *r); -void resctrl_mon_resource_exit(void); -void mon_event_count(void *info); -int rdtgroup_mondata_show(struct seq_file *m, void *arg); -void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, - struct rdt_domain *d, struct rdtgroup *rdtgrp, - int evtid, int first); -int resctrl_mon_resource_init(void); -void mbm_setup_overflow_handler(struct rdt_domain *dom, - unsigned long delay_ms, - int exclude_cpu); -void mbm_handle_overflow(struct work_struct *work); void __init intel_rdt_mbm_apply_quirk(void); -bool is_mba_sc(struct rdt_resource *r); -void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms, - int exclude_cpu); -void cqm_handle_limbo(struct work_struct *work); -bool has_busy_rmid(struct rdt_domain *d); -void __check_limbo(struct rdt_domain *d, bool force_free); void rdt_domain_reconfigure_cdp(struct rdt_resource *r); -void mbm_config_rftype_init(const char *config); -void rdt_staged_configs_clear(void); -bool closid_allocated(unsigned int closid); -int resctrl_find_cleanest_closid(void);

#endif /* _ASM_X86_RESCTRL_INTERNAL_H */ diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 507145fdd79a..54cf311b6de4 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -25,53 +25,6 @@

#include "internal.h"

-/** - * struct rmid_entry - dirty tracking for all RMID. - * @closid: The CLOSID for this entry. - * @rmid: The RMID for this entry. - * @busy: The number of domains with cached data using this RMID. - * @list: Member of the rmid_free_lru list when busy == 0. - * - * Depending on the architecture the correct monitor is accessed using - * both @closid and @rmid, or @rmid only. - * - * Take the rdtgroup_mutex when accessing. - */ -struct rmid_entry { - u32 closid; - u32 rmid; - int busy; - struct list_head list; -}; - -/* - * @rmid_free_lru - A least recently used list of free RMIDs - * These RMIDs are guaranteed to have an occupancy less than the - * threshold occupancy - */ -static LIST_HEAD(rmid_free_lru); - -/* - * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has. - * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined. - * Indexed by CLOSID. Protected by rdtgroup_mutex. - */ -static u32 *closid_num_dirty_rmid; - -/* - * @rmid_limbo_count - count of currently unused but (potentially) - * dirty RMIDs. - * This counts RMIDs that no one is currently using but that - * may have a occupancy value > resctrl_rmid_realloc_threshold. User can - * change the threshold occupancy value. - */ -static unsigned int rmid_limbo_count; - -/* - * @rmid_entry - The entry in the limbo and free lists. - */ -static struct rmid_entry *rmid_ptrs; - /* * Global boolean for rdt_monitor which is true if any * resource monitoring is enabled. @@ -83,17 +36,6 @@ bool rdt_mon_capable; */ unsigned int rdt_mon_features;

-/* - * This is the threshold cache occupancy in bytes at which we will consider an - * RMID available for re-allocation. - */ -unsigned int resctrl_rmid_realloc_threshold; - -/* - * This is the maximum value for the reallocation threshold, in bytes. - */ -unsigned int resctrl_rmid_realloc_limit; - #define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5))

/* @@ -157,33 +99,6 @@ static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val) return val; }

-/* - * x86 and arm64 differ in their handling of monitoring. - * x86's RMID are independent numbers, there is only one source of traffic - * with an RMID value of '1'. - * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of - * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID - * value is no longer unique. - * To account for this, resctrl uses an index. On x86 this is just the RMID, - * on arm64 it encodes the CLOSID and RMID. This gives a unique number. - * - * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code - * must accept an attempt to read every index. - */ -static inline struct rmid_entry *__rmid_entry(u32 idx) -{ - struct rmid_entry *entry; - u32 closid, rmid; - - entry = &rmid_ptrs[idx]; - resctrl_arch_rmid_idx_decode(idx, &closid, &rmid); - - WARN_ON_ONCE(entry->closid != closid); - WARN_ON_ONCE(entry->rmid != rmid); - - return entry; -} - static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) { u64 msr_val; @@ -302,751 +217,6 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, return 0; }

-static void limbo_release_entry(struct rmid_entry *entry) -{ - lockdep_assert_held(&rdtgroup_mutex); - - rmid_limbo_count--; - list_add_tail(&entry->list, &rmid_free_lru); - - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) - closid_num_dirty_rmid[entry->closid]--; -} - -/* - * Check the RMIDs that are marked as busy for this domain. If the - * reported LLC occupancy is below the threshold clear the busy bit and - * decrement the count. If the busy count gets to zero on an RMID, we - * free the RMID - */ -void __check_limbo(struct rdt_domain *d, bool force_free) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - struct rmid_entry *entry; - u32 idx, cur_idx = 1; - void *arch_mon_ctx; - bool rmid_dirty; - u64 val = 0; - - arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID); - if (IS_ERR(arch_mon_ctx)) { - pr_warn_ratelimited("Failed to allocate monitor context: %ld", - PTR_ERR(arch_mon_ctx)); - return; - } - - /* - * Skip RMID 0 and start from RMID 1 and check all the RMIDs that - * are marked as busy for occupancy < threshold. If the occupancy - * is less than the threshold decrement the busy counter of the - * RMID and move it to the free list when the counter reaches 0. - */ - for (;;) { - idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx); - if (idx >= idx_limit) - break; - - entry = __rmid_entry(idx); - if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, - QOS_L3_OCCUP_EVENT_ID, &val, - arch_mon_ctx)) { - rmid_dirty = true; - } else { - rmid_dirty = (val >= resctrl_rmid_realloc_threshold); - } - - if (force_free || !rmid_dirty) { - clear_bit(idx, d->rmid_busy_llc); - if (!--entry->busy) - limbo_release_entry(entry); - } - cur_idx = idx + 1; - } - - resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx); -} - -bool has_busy_rmid(struct rdt_domain *d) -{ - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - - return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit; -} - -static struct rmid_entry *resctrl_find_free_rmid(u32 closid) -{ - struct rmid_entry *itr; - u32 itr_idx, cmp_idx; - - if (list_empty(&rmid_free_lru)) - return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC); - - list_for_each_entry(itr, &rmid_free_lru, list) { - /* - * Get the index of this free RMID, and the index it would need - * to be if it were used with this CLOSID. - * If the CLOSID is irrelevant on this architecture, the two - * index values are always the same on every entry and thus the - * very first entry will be returned. - */ - itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid); - cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid); - - if (itr_idx == cmp_idx) - return itr; - } - - return ERR_PTR(-ENOSPC); -} - -/** - * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated - * RMID are clean, or the CLOSID that has - * the most clean RMID. - * - * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID - * may not be able to allocate clean RMID. To avoid this the allocator will - * choose the CLOSID with the most clean RMID. - * - * When the CLOSID and RMID are independent numbers, the first free CLOSID will - * be returned. - */ -int resctrl_find_cleanest_closid(void) -{ - u32 cleanest_closid = ~0; - int i = 0; - - lockdep_assert_held(&rdtgroup_mutex); - - if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) - return -EIO; - - for (i = 0; i < closids_supported(); i++) { - int num_dirty; - - if (closid_allocated(i)) - continue; - - num_dirty = closid_num_dirty_rmid[i]; - if (num_dirty == 0) - return i; - - if (cleanest_closid == ~0) - cleanest_closid = i; - - if (num_dirty < closid_num_dirty_rmid[cleanest_closid]) - cleanest_closid = i; - } - - if (cleanest_closid == ~0) - return -ENOSPC; - - return cleanest_closid; -} - -/* - * For MPAM the RMID value is not unique, and has to be considered with - * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which - * allows all domains to be managed by a single free list. - * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler. - */ -int alloc_rmid(u32 closid) -{ - struct rmid_entry *entry; - - lockdep_assert_held(&rdtgroup_mutex); - - entry = resctrl_find_free_rmid(closid); - if (IS_ERR(entry)) - return PTR_ERR(entry); - - list_del(&entry->list); - return entry->rmid; -} - -static void add_rmid_to_limbo(struct rmid_entry *entry) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - struct rdt_domain *d; - u32 idx; - - lockdep_assert_held(&rdtgroup_mutex); - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid); - - entry->busy = 0; - list_for_each_entry(d, &r->domains, list) { - /* - * For the first limbo RMID in the domain, - * setup up the limbo worker. - */ - if (!has_busy_rmid(d)) - cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL, - RESCTRL_PICK_ANY_CPU); - set_bit(idx, d->rmid_busy_llc); - entry->busy++; - } - - rmid_limbo_count++; - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) - closid_num_dirty_rmid[entry->closid]++; -} - -void free_rmid(u32 closid, u32 rmid) -{ - u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); - struct rmid_entry *entry; - - lockdep_assert_held(&rdtgroup_mutex); - - /* - * Do not allow the default rmid to be free'd. Comparing by index - * allows architectures that ignore the closid parameter to avoid an - * unnecessary check. - */ - if (idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, - RESCTRL_RESERVED_RMID)) - return; - - entry = __rmid_entry(idx); - - if (resctrl_arch_is_llc_occupancy_enabled()) - add_rmid_to_limbo(entry); - else - list_add_tail(&entry->list, &rmid_free_lru); -} - -static struct mbm_state *get_mbm_state(struct rdt_domain *d, u32 closid, - u32 rmid, enum resctrl_event_id evtid) -{ - u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); - - switch (evtid) { - case QOS_L3_MBM_TOTAL_EVENT_ID: - return &d->mbm_total[idx]; - case QOS_L3_MBM_LOCAL_EVENT_ID: - return &d->mbm_local[idx]; - default: - return NULL; - } -} - -static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) -{ - struct mbm_state *m; - u64 tval = 0; - - if (rr->first) { - resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid); - m = get_mbm_state(rr->d, closid, rmid, rr->evtid); - if (m) - memset(m, 0, sizeof(struct mbm_state)); - return 0; - } - - rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid, rr->evtid, - &tval, rr->arch_mon_ctx); - if (rr->err) - return rr->err; - - rr->val += tval; - - return 0; -} - -/* - * mbm_bw_count() - Update bw count from values previously read by - * __mon_event_count(). - * @closid: The closid used to identify the cached mbm_state. - * @rmid: The rmid used to identify the cached mbm_state. - * @rr: The struct rmid_read populated by __mon_event_count(). - * - * Supporting function to calculate the memory bandwidth - * and delta bandwidth in MBps. The chunks value previously read by - * __mon_event_count() is compared with the chunks value from the previous - * invocation. This must be called once per second to maintain values in MBps. - */ -static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr) -{ - u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); - struct mbm_state *m = &rr->d->mbm_local[idx]; - u64 cur_bw, bytes, cur_bytes; - - cur_bytes = rr->val; - bytes = cur_bytes - m->prev_bw_bytes; - m->prev_bw_bytes = cur_bytes; - - cur_bw = bytes / SZ_1M; - - if (m->delta_comp) - m->delta_bw = abs(cur_bw - m->prev_bw); - m->delta_comp = false; - m->prev_bw = cur_bw; -} - -/* - * This is scheduled by mon_event_read() to read the CQM/MBM counters - * on a domain. - */ -void mon_event_count(void *info) -{ - struct rdtgroup *rdtgrp, *entry; - struct rmid_read *rr = info; - struct list_head *head; - int ret; - - rdtgrp = rr->rgrp; - - ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr); - - /* - * For Ctrl groups read data from child monitor groups and - * add them together. Count events which are read successfully. - * Discard the rmid_read's reporting errors. - */ - head = &rdtgrp->mon.crdtgrp_list; - - if (rdtgrp->type == RDTCTRL_GROUP) { - list_for_each_entry(entry, head, mon.crdtgrp_list) { - if (__mon_event_count(entry->closid, entry->mon.rmid, - rr) == 0) - ret = 0; - } - } - - /* - * __mon_event_count() calls for newly created monitor groups may - * report -EINVAL/Unavailable if the monitor hasn't seen any traffic. - * Discard error if any of the monitor event reads succeeded. - */ - if (ret == 0) - rr->err = 0; -} - -/* - * Feedback loop for MBA software controller (mba_sc) - * - * mba_sc is a feedback loop where we periodically read MBM counters and - * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so - * that: - * - * current bandwidth(cur_bw) < user specified bandwidth(user_bw) - * - * This uses the MBM counters to measure the bandwidth and MBA throttle - * MSRs to control the bandwidth for a particular rdtgrp. It builds on the - * fact that resctrl rdtgroups have both monitoring and control. - * - * The frequency of the checks is 1s and we just tag along the MBM overflow - * timer. Having 1s interval makes the calculation of bandwidth simpler. - * - * Although MBA's goal is to restrict the bandwidth to a maximum, there may - * be a need to increase the bandwidth to avoid unnecessarily restricting - * the L2 <-> L3 traffic. - * - * Since MBA controls the L2 external bandwidth where as MBM measures the - * L3 external bandwidth the following sequence could lead to such a - * situation. - * - * Consider an rdtgroup which had high L3 <-> memory traffic in initial - * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but - * after some time rdtgroup has mostly L2 <-> L3 traffic. - * - * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its - * throttle MSRs already have low percentage values. To avoid - * unnecessarily restricting such rdtgroups, we also increase the bandwidth. - */ -static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm) -{ - u32 closid, rmid, cur_msr_val, new_msr_val; - struct mbm_state *pmbm_data, *cmbm_data; - u32 cur_bw, delta_bw, user_bw, idx; - struct rdt_resource *r_mba; - struct rdt_domain *dom_mba; - struct list_head *head; - struct rdtgroup *entry; - - if (!resctrl_arch_is_mbm_local_enabled()) - return; - - r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - - closid = rgrp->closid; - rmid = rgrp->mon.rmid; - idx = resctrl_arch_rmid_idx_encode(closid, rmid); - pmbm_data = &dom_mbm->mbm_local[idx]; - - dom_mba = resctrl_get_domain_from_cpu(smp_processor_id(), r_mba); - if (!dom_mba) { - pr_warn_once("Failure to get domain for MBA update\n"); - return; - } - - cur_bw = pmbm_data->prev_bw; - user_bw = dom_mba->mbps_val[closid]; - delta_bw = pmbm_data->delta_bw; - - /* MBA resource doesn't support CDP */ - cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE); - - /* - * For Ctrl groups read data from child monitor groups. - */ - head = &rgrp->mon.crdtgrp_list; - list_for_each_entry(entry, head, mon.crdtgrp_list) { - cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid]; - cur_bw += cmbm_data->prev_bw; - delta_bw += cmbm_data->delta_bw; - } - - /* - * Scale up/down the bandwidth linearly for the ctrl group. The - * bandwidth step is the bandwidth granularity specified by the - * hardware. - * - * The delta_bw is used when increasing the bandwidth so that we - * dont alternately increase and decrease the control values - * continuously. - * - * For ex: consider cur_bw = 90MBps, user_bw = 100MBps and if - * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep - * switching between 90 and 110 continuously if we only check - * cur_bw < user_bw. - */ - if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) { - new_msr_val = cur_msr_val - r_mba->membw.bw_gran; - } else if (cur_msr_val < MAX_MBA_BW && - (user_bw > (cur_bw + delta_bw))) { - new_msr_val = cur_msr_val + r_mba->membw.bw_gran; - } else { - return; - } - - resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val); - - /* - * Delta values are updated dynamically package wise for each - * rdtgrp every time the throttle MSR changes value. - * - * This is because (1)the increase in bandwidth is not perfectly - * linear and only "approximately" linear even when the hardware - * says it is linear.(2)Also since MBA is a core specific - * mechanism, the delta values vary based on number of cores used - * by the rdtgrp. - */ - pmbm_data->delta_comp = true; - list_for_each_entry(entry, head, mon.crdtgrp_list) { - cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid]; - cmbm_data->delta_comp = true; - } -} - -static void mbm_update(struct rdt_resource *r, struct rdt_domain *d, - u32 closid, u32 rmid) -{ - struct rmid_read rr; - - rr.first = false; - rr.r = r; - rr.d = d; - - /* - * This is protected from concurrent reads from user - * as both the user and we hold the global mutex. - */ - if (resctrl_arch_is_mbm_total_enabled()) { - rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID; - rr.val = 0; - rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); - if (IS_ERR(rr.arch_mon_ctx)) { - pr_warn_ratelimited("Failed to allocate monitor context: %ld", - PTR_ERR(rr.arch_mon_ctx)); - return; - } - - __mon_event_count(closid, rmid, &rr); - - resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); - } - if (resctrl_arch_is_mbm_local_enabled()) { - rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID; - rr.val = 0; - rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); - if (IS_ERR(rr.arch_mon_ctx)) { - pr_warn_ratelimited("Failed to allocate monitor context: %ld", - PTR_ERR(rr.arch_mon_ctx)); - return; - } - - __mon_event_count(closid, rmid, &rr); - - /* - * Call the MBA software controller only for the - * control groups and when user has enabled - * the software controller explicitly. - */ - if (is_mba_sc(NULL)) - mbm_bw_count(closid, rmid, &rr); - - resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); - } -} - -/* - * Handler to scan the limbo list and move the RMIDs - * to free list whose occupancy < threshold_occupancy. - */ -void cqm_handle_limbo(struct work_struct *work) -{ - unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL); - struct rdt_domain *d; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - d = container_of(work, struct rdt_domain, cqm_limbo.work); - - __check_limbo(d, false); - - if (has_busy_rmid(d)) { - d->cqm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask, - RESCTRL_PICK_ANY_CPU); - schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo, - delay); - } - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); -} - -/** - * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this - * domain. - * @dom: The domain the limbo handler should run for. - * @delay_ms: How far in the future the handler should run. - * @exclude_cpu: Which CPU the handler should not run on, - * RESCTRL_PICK_ANY_CPU to pick any CPU. - */ -void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms, - int exclude_cpu) -{ - unsigned long delay = msecs_to_jiffies(delay_ms); - int cpu; - - cpu = cpumask_any_housekeeping(&dom->cpu_mask, exclude_cpu); - dom->cqm_work_cpu = cpu; - - if (cpu < nr_cpu_ids) - schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay); -} - -void mbm_handle_overflow(struct work_struct *work) -{ - unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL); - struct rdtgroup *prgrp, *crgrp; - struct list_head *head; - struct rdt_resource *r; - struct rdt_domain *d; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - /* - * If the filesystem has been unmounted this work no longer needs to - * run. - */ - if (!resctrl_mounted || !resctrl_arch_mon_capable()) - goto out_unlock; - - r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - d = container_of(work, struct rdt_domain, mbm_over.work); - - list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { - mbm_update(r, d, prgrp->closid, prgrp->mon.rmid); - - head = &prgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) - mbm_update(r, d, crgrp->closid, crgrp->mon.rmid); - - if (is_mba_sc(NULL)) - update_mba_bw(prgrp, d); - } - - /* - * Re-check for housekeeping CPUs. This allows the overflow handler to - * move off a nohz_full CPU quickly. - */ - d->mbm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask, - RESCTRL_PICK_ANY_CPU); - schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay); - -out_unlock: - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); -} - -/** - * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this - * domain. - * @dom: The domain the overflow handler should run for. - * @delay_ms: How far in the future the handler should run. - * @exclude_cpu: Which CPU the handler should not run on, - * RESCTRL_PICK_ANY_CPU to pick any CPU. - */ -void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms, - int exclude_cpu) -{ - unsigned long delay = msecs_to_jiffies(delay_ms); - int cpu; - - /* - * When a domain comes online there is no guarantee the filesystem is - * mounted. If not, there is no need to catch counter overflow. - */ - if (!resctrl_mounted || !resctrl_arch_mon_capable()) - return; - cpu = cpumask_any_housekeeping(&dom->cpu_mask, exclude_cpu); - dom->mbm_work_cpu = cpu; - - if (cpu < nr_cpu_ids) - schedule_delayed_work_on(cpu, &dom->mbm_over, delay); -} - -static int dom_data_init(struct rdt_resource *r) -{ - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - u32 num_closid = resctrl_arch_get_num_closid(r); - struct rmid_entry *entry = NULL; - int err = 0, i; - u32 idx; - - mutex_lock(&rdtgroup_mutex); - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { - u32 *tmp; - - tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL); - if (!tmp) { - err = -ENOMEM; - goto out_unlock; - } - - closid_num_dirty_rmid = tmp; - } - - rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL); - if (!rmid_ptrs) { - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { - kfree(closid_num_dirty_rmid); - closid_num_dirty_rmid = NULL; - } - err = -ENOMEM; - goto out_unlock; - } - - for (i = 0; i < idx_limit; i++) { - entry = &rmid_ptrs[i]; - INIT_LIST_HEAD(&entry->list); - - resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid); - list_add_tail(&entry->list, &rmid_free_lru); - } - - /* - * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and - * are always allocated. These are used for the rdtgroup_default - * control group, which will be setup later in rdtgroup_init(). - */ - idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, - RESCTRL_RESERVED_RMID); - entry = __rmid_entry(idx); - list_del(&entry->list); - -out_unlock: - mutex_unlock(&rdtgroup_mutex); - - return err; -} - -static void dom_data_exit(struct rdt_resource *r) -{ - if (!r->mon_capable) - return; - - mutex_lock(&rdtgroup_mutex); - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { - kfree(closid_num_dirty_rmid); - closid_num_dirty_rmid = NULL; - } - - kfree(rmid_ptrs); - rmid_ptrs = NULL; - - mutex_unlock(&rdtgroup_mutex); -} - -static struct mon_evt llc_occupancy_event = { - .name = "llc_occupancy", - .evtid = QOS_L3_OCCUP_EVENT_ID, -}; - -static struct mon_evt mbm_total_event = { - .name = "mbm_total_bytes", - .evtid = QOS_L3_MBM_TOTAL_EVENT_ID, -}; - -static struct mon_evt mbm_local_event = { - .name = "mbm_local_bytes", - .evtid = QOS_L3_MBM_LOCAL_EVENT_ID, -}; - -/* - * Initialize the event list for the resource. - * - * Note that MBM events are also part of RDT_RESOURCE_L3 resource - * because as per the SDM the total and local memory bandwidth - * are enumerated as part of L3 monitoring. - */ -static void l3_mon_evt_init(struct rdt_resource *r) -{ - INIT_LIST_HEAD(&r->evt_list); - - if (resctrl_arch_is_llc_occupancy_enabled()) - list_add_tail(&llc_occupancy_event.list, &r->evt_list); - if (resctrl_arch_is_mbm_total_enabled()) - list_add_tail(&mbm_total_event.list, &r->evt_list); - if (resctrl_arch_is_mbm_local_enabled()) - list_add_tail(&mbm_local_event.list, &r->evt_list); -} - -int resctrl_mon_resource_init(void) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - int ret; - - ret = dom_data_init(r); - if (ret) - return ret; - - if (!r->mon_capable) - return 0; - - l3_mon_evt_init(r); - - if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) { - mbm_total_event.configurable = true; - mbm_config_rftype_init("mbm_total_bytes_config"); - } - if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) { - mbm_local_event.configurable = true; - mbm_config_rftype_init("mbm_local_bytes_config"); - } - - return 0; -} - int __init rdt_get_mon_l3_config(struct rdt_resource *r) { unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset; @@ -1084,13 +254,6 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) return 0; }

-void resctrl_mon_resource_exit(void) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); - - dom_data_exit(r); -} - void __init intel_rdt_mbm_apply_quirk(void) { int cf_index; diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c index 85536566d7f5..ba1596afee10 100644 --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c @@ -39,28 +39,6 @@ */ static u64 prefetch_disable_bits;

-/* - * Major number assigned to and shared by all devices exposing - * pseudo-locked regions. - */ -static unsigned int pseudo_lock_major; -static unsigned long pseudo_lock_minor_avail = GENMASK(MINORBITS, 0); - -static char *pseudo_lock_devnode(const struct device *dev, umode_t *mode) -{ - const struct rdtgroup *rdtgrp; - - rdtgrp = dev_get_drvdata(dev); - if (mode) - *mode = 0600; - return kasprintf(GFP_KERNEL, "pseudo_lock/%s", rdtgrp->kn->name); -} - -static const struct class pseudo_lock_class = { - .name = "pseudo_lock", - .devnode = pseudo_lock_devnode, -}; - /** * resctrl_arch_get_prefetch_disable_bits - prefetch disable bits of supported * platforms @@ -121,299 +99,6 @@ u64 resctrl_arch_get_prefetch_disable_bits(void) return prefetch_disable_bits; }

-/** - * pseudo_lock_minor_get - Obtain available minor number - * @minor: Pointer to where new minor number will be stored - * - * A bitmask is used to track available minor numbers. Here the next free - * minor number is marked as unavailable and returned. - * - * Return: 0 on success, <0 on failure. - */ -static int pseudo_lock_minor_get(unsigned int *minor) -{ - unsigned long first_bit; - - first_bit = find_first_bit(&pseudo_lock_minor_avail, MINORBITS); - - if (first_bit == MINORBITS) - return -ENOSPC; - - __clear_bit(first_bit, &pseudo_lock_minor_avail); - *minor = first_bit; - - return 0; -} - -/** - * pseudo_lock_minor_release - Return minor number to available - * @minor: The minor number made available - */ -static void pseudo_lock_minor_release(unsigned int minor) -{ - __set_bit(minor, &pseudo_lock_minor_avail); -} - -/** - * region_find_by_minor - Locate a pseudo-lock region by inode minor number - * @minor: The minor number of the device representing pseudo-locked region - * - * When the character device is accessed we need to determine which - * pseudo-locked region it belongs to. This is done by matching the minor - * number of the device to the pseudo-locked region it belongs. - * - * Minor numbers are assigned at the time a pseudo-locked region is associated - * with a cache instance. - * - * Return: On success return pointer to resource group owning the pseudo-locked - * region, NULL on failure. - */ -static struct rdtgroup *region_find_by_minor(unsigned int minor) -{ - struct rdtgroup *rdtgrp, *rdtgrp_match = NULL; - - list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { - if (rdtgrp->plr && rdtgrp->plr->minor == minor) { - rdtgrp_match = rdtgrp; - break; - } - } - return rdtgrp_match; -} - -/** - * struct pseudo_lock_pm_req - A power management QoS request list entry - * @list: Entry within the @pm_reqs list for a pseudo-locked region - * @req: PM QoS request - */ -struct pseudo_lock_pm_req { - struct list_head list; - struct dev_pm_qos_request req; -}; - -static void pseudo_lock_cstates_relax(struct pseudo_lock_region *plr) -{ - struct pseudo_lock_pm_req *pm_req, *next; - - list_for_each_entry_safe(pm_req, next, &plr->pm_reqs, list) { - dev_pm_qos_remove_request(&pm_req->req); - list_del(&pm_req->list); - kfree(pm_req); - } -} - -/** - * pseudo_lock_cstates_constrain - Restrict cores from entering C6 - * @plr: Pseudo-locked region - * - * To prevent the cache from being affected by power management entering - * C6 has to be avoided. This is accomplished by requesting a latency - * requirement lower than lowest C6 exit latency of all supported - * platforms as found in the cpuidle state tables in the intel_idle driver. - * At this time it is possible to do so with a single latency requirement - * for all supported platforms. - * - * Since Goldmont is supported, which is affected by X86_BUG_MONITOR, - * the ACPI latencies need to be considered while keeping in mind that C2 - * may be set to map to deeper sleep states. In this case the latency - * requirement needs to prevent entering C2 also. - * - * Return: 0 on success, <0 on failure - */ -static int pseudo_lock_cstates_constrain(struct pseudo_lock_region *plr) -{ - struct pseudo_lock_pm_req *pm_req; - int cpu; - int ret; - - for_each_cpu(cpu, &plr->d->cpu_mask) { - pm_req = kzalloc(sizeof(*pm_req), GFP_KERNEL); - if (!pm_req) { - rdt_last_cmd_puts("Failure to allocate memory for PM QoS\n"); - ret = -ENOMEM; - goto out_err; - } - ret = dev_pm_qos_add_request(get_cpu_device(cpu), - &pm_req->req, - DEV_PM_QOS_RESUME_LATENCY, - 30); - if (ret < 0) { - rdt_last_cmd_printf("Failed to add latency req CPU%d\n", - cpu); - kfree(pm_req); - ret = -1; - goto out_err; - } - list_add(&pm_req->list, &plr->pm_reqs); - } - - return 0; - -out_err: - pseudo_lock_cstates_relax(plr); - return ret; -} - -/** - * pseudo_lock_region_clear - Reset pseudo-lock region data - * @plr: pseudo-lock region - * - * All content of the pseudo-locked region is reset - any memory allocated - * freed. - * - * Return: void - */ -static void pseudo_lock_region_clear(struct pseudo_lock_region *plr) -{ - plr->size = 0; - plr->line_size = 0; - kfree(plr->kmem); - plr->kmem = NULL; - plr->s = NULL; - if (plr->d) - plr->d->plr = NULL; - plr->d = NULL; - plr->cbm = 0; - plr->debugfs_dir = NULL; -} - -/** - * pseudo_lock_region_init - Initialize pseudo-lock region information - * @plr: pseudo-lock region - * - * Called after user provided a schemata to be pseudo-locked. From the - * schemata the &struct pseudo_lock_region is on entry already initialized - * with the resource, domain, and capacity bitmask. Here the information - * required for pseudo-locking is deduced from this data and &struct - * pseudo_lock_region initialized further. This information includes: - * - size in bytes of the region to be pseudo-locked - * - cache line size to know the stride with which data needs to be accessed - * to be pseudo-locked - * - a cpu associated with the cache instance on which the pseudo-locking - * flow can be executed - * - * Return: 0 on success, <0 on failure. Descriptive error will be written - * to last_cmd_status buffer. - */ -static int pseudo_lock_region_init(struct pseudo_lock_region *plr) -{ - struct cpu_cacheinfo *ci; - int ret; - int i; - - /* Pick the first cpu we find that is associated with the cache. */ - plr->cpu = cpumask_first(&plr->d->cpu_mask); - - if (!cpu_online(plr->cpu)) { - rdt_last_cmd_printf("CPU %u associated with cache not online\n", - plr->cpu); - ret = -ENODEV; - goto out_region; - } - - ci = get_cpu_cacheinfo(plr->cpu); - - plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm); - - for (i = 0; i < ci->num_leaves; i++) { - if (ci->info_list[i].level == plr->s->res->cache_level) { - plr->line_size = ci->info_list[i].coherency_line_size; - return 0; - } - } - - ret = -1; - rdt_last_cmd_puts("Unable to determine cache line size\n"); -out_region: - pseudo_lock_region_clear(plr); - return ret; -} - -/** - * pseudo_lock_init - Initialize a pseudo-lock region - * @rdtgrp: resource group to which new pseudo-locked region will belong - * - * A pseudo-locked region is associated with a resource group. When this - * association is created the pseudo-locked region is initialized. The - * details of the pseudo-locked region are not known at this time so only - * allocation is done and association established. - * - * Return: 0 on success, <0 on failure - */ -static int pseudo_lock_init(struct rdtgroup *rdtgrp) -{ - struct pseudo_lock_region *plr; - - plr = kzalloc(sizeof(*plr), GFP_KERNEL); - if (!plr) - return -ENOMEM; - - init_waitqueue_head(&plr->lock_thread_wq); - INIT_LIST_HEAD(&plr->pm_reqs); - rdtgrp->plr = plr; - return 0; -} - -/** - * pseudo_lock_region_alloc - Allocate kernel memory that will be pseudo-locked - * @plr: pseudo-lock region - * - * Initialize the details required to set up the pseudo-locked region and - * allocate the contiguous memory that will be pseudo-locked to the cache. - * - * Return: 0 on success, <0 on failure. Descriptive error will be written - * to last_cmd_status buffer. - */ -static int pseudo_lock_region_alloc(struct pseudo_lock_region *plr) -{ - int ret; - - ret = pseudo_lock_region_init(plr); - if (ret < 0) - return ret; - - /* - * We do not yet support contiguous regions larger than - * KMALLOC_MAX_SIZE. - */ - if (plr->size > KMALLOC_MAX_SIZE) { - rdt_last_cmd_puts("Requested region exceeds maximum size\n"); - ret = -E2BIG; - goto out_region; - } - - plr->kmem = kzalloc(plr->size, GFP_KERNEL); - if (!plr->kmem) { - rdt_last_cmd_puts("Unable to allocate memory\n"); - ret = -ENOMEM; - goto out_region; - } - - ret = 0; - goto out; -out_region: - pseudo_lock_region_clear(plr); -out: - return ret; -} - -/** - * pseudo_lock_free - Free a pseudo-locked region - * @rdtgrp: resource group to which pseudo-locked region belonged - * - * The pseudo-locked region's resources have already been released, or not - * yet created at this point. Now it can be freed and disassociated from the - * resource group. - * - * Return: void - */ -static void pseudo_lock_free(struct rdtgroup *rdtgrp) -{ - pseudo_lock_region_clear(rdtgrp->plr); - kfree(rdtgrp->plr); - rdtgrp->plr = NULL; -} - /** * resctrl_arch_pseudo_lock_fn - Load kernel memory into cache * @_plr: the pseudo-lock region descriptor @@ -543,351 +228,6 @@ int resctrl_arch_pseudo_lock_fn(void *_plr) return 0; }

-/** - * rdtgroup_monitor_in_progress - Test if monitoring in progress - * @rdtgrp: resource group being queried - * - * Return: 1 if monitor groups have been created for this resource - * group, 0 otherwise. - */ -static int rdtgroup_monitor_in_progress(struct rdtgroup *rdtgrp) -{ - return !list_empty(&rdtgrp->mon.crdtgrp_list); -} - -/** - * rdtgroup_locksetup_user_restrict - Restrict user access to group - * @rdtgrp: resource group needing access restricted - * - * A resource group used for cache pseudo-locking cannot have cpus or tasks - * assigned to it. This is communicated to the user by restricting access - * to all the files that can be used to make such changes. - * - * Permissions restored with rdtgroup_locksetup_user_restore() - * - * Return: 0 on success, <0 on failure. If a failure occurs during the - * restriction of access an attempt will be made to restore permissions but - * the state of the mode of these files will be uncertain when a failure - * occurs. - */ -static int rdtgroup_locksetup_user_restrict(struct rdtgroup *rdtgrp) -{ - int ret; - - ret = rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); - if (ret) - return ret; - - ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); - if (ret) - goto err_tasks; - - ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); - if (ret) - goto err_cpus; - - if (resctrl_arch_mon_capable()) { - ret = rdtgroup_kn_mode_restrict(rdtgrp, "mon_groups"); - if (ret) - goto err_cpus_list; - } - - ret = 0; - goto out; - -err_cpus_list: - rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); -err_cpus: - rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); -err_tasks: - rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); -out: - return ret; -} - -/** - * rdtgroup_locksetup_user_restore - Restore user access to group - * @rdtgrp: resource group needing access restored - * - * Restore all file access previously removed using - * rdtgroup_locksetup_user_restrict() - * - * Return: 0 on success, <0 on failure. If a failure occurs during the - * restoration of access an attempt will be made to restrict permissions - * again but the state of the mode of these files will be uncertain when - * a failure occurs. - */ -static int rdtgroup_locksetup_user_restore(struct rdtgroup *rdtgrp) -{ - int ret; - - ret = rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); - if (ret) - return ret; - - ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); - if (ret) - goto err_tasks; - - ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); - if (ret) - goto err_cpus; - - if (resctrl_arch_mon_capable()) { - ret = rdtgroup_kn_mode_restore(rdtgrp, "mon_groups", 0777); - if (ret) - goto err_cpus_list; - } - - ret = 0; - goto out; - -err_cpus_list: - rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); -err_cpus: - rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); -err_tasks: - rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); -out: - return ret; -} - -/** - * rdtgroup_locksetup_enter - Resource group enters locksetup mode - * @rdtgrp: resource group requested to enter locksetup mode - * - * A resource group enters locksetup mode to reflect that it would be used - * to represent a pseudo-locked region and is in the process of being set - * up to do so. A resource group used for a pseudo-locked region would - * lose the closid associated with it so we cannot allow it to have any - * tasks or cpus assigned nor permit tasks or cpus to be assigned in the - * future. Monitoring of a pseudo-locked region is not allowed either. - * - * The above and more restrictions on a pseudo-locked region are checked - * for and enforced before the resource group enters the locksetup mode. - * - * Returns: 0 if the resource group successfully entered locksetup mode, <0 - * on failure. On failure the last_cmd_status buffer is updated with text to - * communicate details of failure to the user. - */ -int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) -{ - int ret; - - /* - * The default resource group can neither be removed nor lose the - * default closid associated with it. - */ - if (rdtgrp == &rdtgroup_default) { - rdt_last_cmd_puts("Cannot pseudo-lock default group\n"); - return -EINVAL; - } - - /* - * Cache Pseudo-locking not supported when CDP is enabled. - * - * Some things to consider if you would like to enable this - * support (using L3 CDP as example): - * - When CDP is enabled two separate resources are exposed, - * L3DATA and L3CODE, but they are actually on the same cache. - * The implication for pseudo-locking is that if a - * pseudo-locked region is created on a domain of one - * resource (eg. L3CODE), then a pseudo-locked region cannot - * be created on that same domain of the other resource - * (eg. L3DATA). This is because the creation of a - * pseudo-locked region involves a call to wbinvd that will - * affect all cache allocations on particular domain. - * - Considering the previous, it may be possible to only - * expose one of the CDP resources to pseudo-locking and - * hide the other. For example, we could consider to only - * expose L3DATA and since the L3 cache is unified it is - * still possible to place instructions there are execute it. - * - If only one region is exposed to pseudo-locking we should - * still keep in mind that availability of a portion of cache - * for pseudo-locking should take into account both resources. - * Similarly, if a pseudo-locked region is created in one - * resource, the portion of cache used by it should be made - * unavailable to all future allocations from both resources. - */ - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3) || - resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) { - rdt_last_cmd_puts("CDP enabled\n"); - return -EINVAL; - } - - /* - * Not knowing the bits to disable prefetching implies that this - * platform does not support Cache Pseudo-Locking. - */ - if (resctrl_arch_get_prefetch_disable_bits() == 0) { - rdt_last_cmd_puts("Pseudo-locking not supported\n"); - return -EINVAL; - } - - if (rdtgroup_monitor_in_progress(rdtgrp)) { - rdt_last_cmd_puts("Monitoring in progress\n"); - return -EINVAL; - } - - if (rdtgroup_tasks_assigned(rdtgrp)) { - rdt_last_cmd_puts("Tasks assigned to resource group\n"); - return -EINVAL; - } - - if (!cpumask_empty(&rdtgrp->cpu_mask)) { - rdt_last_cmd_puts("CPUs assigned to resource group\n"); - return -EINVAL; - } - - if (rdtgroup_locksetup_user_restrict(rdtgrp)) { - rdt_last_cmd_puts("Unable to modify resctrl permissions\n"); - return -EIO; - } - - ret = pseudo_lock_init(rdtgrp); - if (ret) { - rdt_last_cmd_puts("Unable to init pseudo-lock region\n"); - goto out_release; - } - - /* - * If this system is capable of monitoring a rmid would have been - * allocated when the control group was created. This is not needed - * anymore when this group would be used for pseudo-locking. This - * is safe to call on platforms not capable of monitoring. - */ - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - - ret = 0; - goto out; - -out_release: - rdtgroup_locksetup_user_restore(rdtgrp); -out: - return ret; -} - -/** - * rdtgroup_locksetup_exit - resource group exist locksetup mode - * @rdtgrp: resource group - * - * When a resource group exits locksetup mode the earlier restrictions are - * lifted. - * - * Return: 0 on success, <0 on failure - */ -int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp) -{ - int ret; - - if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) - return -EOPNOTSUPP; - - if (resctrl_arch_mon_capable()) { - ret = alloc_rmid(rdtgrp->closid); - if (ret < 0) { - rdt_last_cmd_puts("Out of RMIDs\n"); - return ret; - } - rdtgrp->mon.rmid = ret; - } - - ret = rdtgroup_locksetup_user_restore(rdtgrp); - if (ret) { - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - return ret; - } - - pseudo_lock_free(rdtgrp); - return 0; -} - -/** - * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked - * @d: RDT domain - * @cbm: CBM to test - * - * @d represents a cache instance and @cbm a capacity bitmask that is - * considered for it. Determine if @cbm overlaps with any existing - * pseudo-locked region on @d. - * - * @cbm is unsigned long, even if only 32 bits are used, to make the - * bitmap functions work correctly. - * - * Return: true if @cbm overlaps with pseudo-locked region on @d, false - * otherwise. - */ -bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_domain *d, unsigned long cbm) -{ - unsigned int cbm_len; - unsigned long cbm_b; - - if (d->plr) { - cbm_len = d->plr->s->res->cache.cbm_len; - cbm_b = d->plr->cbm; - if (bitmap_intersects(&cbm, &cbm_b, cbm_len)) - return true; - } - return false; -} - -/** - * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy - * @d: RDT domain under test - * - * The setup of a pseudo-locked region affects all cache instances within - * the hierarchy of the region. It is thus essential to know if any - * pseudo-locked regions exist within a cache hierarchy to prevent any - * attempts to create new pseudo-locked regions in the same hierarchy. - * - * Return: true if a pseudo-locked region exists in the hierarchy of @d or - * if it is not possible to test due to memory allocation issue, - * false otherwise. - */ -bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d) -{ - cpumask_var_t cpu_with_psl; - enum resctrl_res_level i; - struct rdt_resource *r; - struct rdt_domain *d_i; - bool ret = false; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) - return -EOPNOTSUPP; - - if (!zalloc_cpumask_var(&cpu_with_psl, GFP_KERNEL)) - return true; - - /* - * First determine which cpus have pseudo-locked regions - * associated with them. - */ - for (i = 0; i < RDT_NUM_RESOURCES; i++) { - r = resctrl_arch_get_resource(i); - if (!r->alloc_capable) - continue; - - list_for_each_entry(d_i, &r->domains, list) { - if (d_i->plr) - cpumask_or(cpu_with_psl, cpu_with_psl, - &d_i->cpu_mask); - } - } - - /* - * Next test if new pseudo-locked region would intersect with - * existing region. - */ - if (cpumask_intersects(&d->cpu_mask, cpu_with_psl)) - ret = true; - - free_cpumask_var(cpu_with_psl); - return ret; -} - /** * resctrl_arch_measure_cycles_lat_fn - Measure cycle latency to read * pseudo-locked memory @@ -1180,448 +520,3 @@ int resctrl_arch_measure_l3_residency(void *_plr) wake_up_interruptible(&plr->lock_thread_wq); return 0; } - -/** - * pseudo_lock_measure_cycles - Trigger latency measure to pseudo-locked region - * @rdtgrp: Resource group to which the pseudo-locked region belongs. - * @sel: Selector of which measurement to perform on a pseudo-locked region. - * - * The measurement of latency to access a pseudo-locked region should be - * done from a cpu that is associated with that pseudo-locked region. - * Determine which cpu is associated with this region and start a thread on - * that cpu to perform the measurement, wait for that thread to complete. - * - * Return: 0 on success, <0 on failure - */ -static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel) -{ - struct pseudo_lock_region *plr = rdtgrp->plr; - struct task_struct *thread; - unsigned int cpu; - int ret = -1; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - if (rdtgrp->flags & RDT_DELETED) { - ret = -ENODEV; - goto out; - } - - if (!plr->d) { - ret = -ENODEV; - goto out; - } - - plr->thread_done = 0; - cpu = cpumask_first(&plr->d->cpu_mask); - if (!cpu_online(cpu)) { - ret = -ENODEV; - goto out; - } - - plr->cpu = cpu; - - if (sel == 1) - thread = kthread_create_on_node(resctrl_arch_measure_cycles_lat_fn, - plr, cpu_to_node(cpu), - "pseudo_lock_measure/%u", - cpu); - else if (sel == 2) - thread = kthread_create_on_node(resctrl_arch_measure_l2_residency, - plr, cpu_to_node(cpu), - "pseudo_lock_measure/%u", - cpu); - else if (sel == 3) - thread = kthread_create_on_node(resctrl_arch_measure_l3_residency, - plr, cpu_to_node(cpu), - "pseudo_lock_measure/%u", - cpu); - else - goto out; - - if (IS_ERR(thread)) { - ret = PTR_ERR(thread); - goto out; - } - kthread_bind(thread, cpu); - wake_up_process(thread); - - ret = wait_event_interruptible(plr->lock_thread_wq, - plr->thread_done == 1); - if (ret < 0) - goto out; - - ret = 0; - -out: - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - return ret; -} - -static ssize_t pseudo_lock_measure_trigger(struct file *file, - const char __user *user_buf, - size_t count, loff_t *ppos) -{ - struct rdtgroup *rdtgrp = file->private_data; - size_t buf_size; - char buf[32]; - int ret; - int sel; - - buf_size = min(count, (sizeof(buf) - 1)); - if (copy_from_user(buf, user_buf, buf_size)) - return -EFAULT; - - buf[buf_size] = '\0'; - ret = kstrtoint(buf, 10, &sel); - if (ret == 0) { - if (sel != 1 && sel != 2 && sel != 3) - return -EINVAL; - ret = debugfs_file_get(file->f_path.dentry); - if (ret) - return ret; - ret = pseudo_lock_measure_cycles(rdtgrp, sel); - if (ret == 0) - ret = count; - debugfs_file_put(file->f_path.dentry); - } - - return ret; -} - -static const struct file_operations pseudo_measure_fops = { - .write = pseudo_lock_measure_trigger, - .open = simple_open, - .llseek = default_llseek, -}; - -/** - * rdtgroup_pseudo_lock_create - Create a pseudo-locked region - * @rdtgrp: resource group to which pseudo-lock region belongs - * - * Called when a resource group in the pseudo-locksetup mode receives a - * valid schemata that should be pseudo-locked. Since the resource group is - * in pseudo-locksetup mode the &struct pseudo_lock_region has already been - * allocated and initialized with the essential information. If a failure - * occurs the resource group remains in the pseudo-locksetup mode with the - * &struct pseudo_lock_region associated with it, but cleared from all - * information and ready for the user to re-attempt pseudo-locking by - * writing the schemata again. - * - * Return: 0 if the pseudo-locked region was successfully pseudo-locked, <0 - * on failure. Descriptive error will be written to last_cmd_status buffer. - */ -int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp) -{ - struct pseudo_lock_region *plr = rdtgrp->plr; - struct task_struct *thread; - unsigned int new_minor; - struct device *dev; - int ret; - - if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) - return -EOPNOTSUPP; - - ret = pseudo_lock_region_alloc(plr); - if (ret < 0) - return ret; - - ret = pseudo_lock_cstates_constrain(plr); - if (ret < 0) { - ret = -EINVAL; - goto out_region; - } - - plr->thread_done = 0; - - plr->closid = rdtgrp->closid; - thread = kthread_create_on_node(resctrl_arch_pseudo_lock_fn, plr, - cpu_to_node(plr->cpu), - "pseudo_lock/%u", plr->cpu); - if (IS_ERR(thread)) { - ret = PTR_ERR(thread); - rdt_last_cmd_printf("Locking thread returned error %d\n", ret); - goto out_cstates; - } - - kthread_bind(thread, plr->cpu); - wake_up_process(thread); - - ret = wait_event_interruptible(plr->lock_thread_wq, - plr->thread_done == 1); - if (ret < 0) { - /* - * If the thread does not get on the CPU for whatever - * reason and the process which sets up the region is - * interrupted then this will leave the thread in runnable - * state and once it gets on the CPU it will dereference - * the cleared, but not freed, plr struct resulting in an - * empty pseudo-locking loop. - */ - rdt_last_cmd_puts("Locking thread interrupted\n"); - goto out_cstates; - } - - ret = pseudo_lock_minor_get(&new_minor); - if (ret < 0) { - rdt_last_cmd_puts("Unable to obtain a new minor number\n"); - goto out_cstates; - } - - /* - * Unlock access but do not release the reference. The - * pseudo-locked region will still be here on return. - * - * The mutex has to be released temporarily to avoid a potential - * deadlock with the mm->mmap_lock which is obtained in the - * device_create() and debugfs_create_dir() callpath below as well as - * before the mmap() callback is called. - */ - mutex_unlock(&rdtgroup_mutex); - - if (!IS_ERR_OR_NULL(debugfs_resctrl)) { - plr->debugfs_dir = debugfs_create_dir(rdtgrp->kn->name, - debugfs_resctrl); - if (!IS_ERR_OR_NULL(plr->debugfs_dir)) - debugfs_create_file("pseudo_lock_measure", 0200, - plr->debugfs_dir, rdtgrp, - &pseudo_measure_fops); - } - - dev = device_create(&pseudo_lock_class, NULL, - MKDEV(pseudo_lock_major, new_minor), - rdtgrp, "%s", rdtgrp->kn->name); - - mutex_lock(&rdtgroup_mutex); - - if (IS_ERR(dev)) { - ret = PTR_ERR(dev); - rdt_last_cmd_printf("Failed to create character device: %d\n", - ret); - goto out_debugfs; - } - - /* We released the mutex - check if group was removed while we did so */ - if (rdtgrp->flags & RDT_DELETED) { - ret = -ENODEV; - goto out_device; - } - - plr->minor = new_minor; - - rdtgrp->mode = RDT_MODE_PSEUDO_LOCKED; - closid_free(rdtgrp->closid); - rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0444); - rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0444); - - ret = 0; - goto out; - -out_device: - device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, new_minor)); -out_debugfs: - debugfs_remove_recursive(plr->debugfs_dir); - pseudo_lock_minor_release(new_minor); -out_cstates: - pseudo_lock_cstates_relax(plr); -out_region: - pseudo_lock_region_clear(plr); -out: - return ret; -} - -/** - * rdtgroup_pseudo_lock_remove - Remove a pseudo-locked region - * @rdtgrp: resource group to which the pseudo-locked region belongs - * - * The removal of a pseudo-locked region can be initiated when the resource - * group is removed from user space via a "rmdir" from userspace or the - * unmount of the resctrl filesystem. On removal the resource group does - * not go back to pseudo-locksetup mode before it is removed, instead it is - * removed directly. There is thus asymmetry with the creation where the - * &struct pseudo_lock_region is removed here while it was not created in - * rdtgroup_pseudo_lock_create(). - * - * Return: void - */ -void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) -{ - struct pseudo_lock_region *plr = rdtgrp->plr; - - if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) - return; - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - /* - * Default group cannot be a pseudo-locked region so we can - * free closid here. - */ - closid_free(rdtgrp->closid); - goto free; - } - - pseudo_lock_cstates_relax(plr); - debugfs_remove_recursive(rdtgrp->plr->debugfs_dir); - device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, plr->minor)); - pseudo_lock_minor_release(plr->minor); - -free: - pseudo_lock_free(rdtgrp); -} - -static int pseudo_lock_dev_open(struct inode *inode, struct file *filp) -{ - struct rdtgroup *rdtgrp; - - mutex_lock(&rdtgroup_mutex); - - rdtgrp = region_find_by_minor(iminor(inode)); - if (!rdtgrp) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - - filp->private_data = rdtgrp; - atomic_inc(&rdtgrp->waitcount); - /* Perform a non-seekable open - llseek is not supported */ - filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); - - mutex_unlock(&rdtgroup_mutex); - - return 0; -} - -static int pseudo_lock_dev_release(struct inode *inode, struct file *filp) -{ - struct rdtgroup *rdtgrp; - - mutex_lock(&rdtgroup_mutex); - rdtgrp = filp->private_data; - WARN_ON(!rdtgrp); - if (!rdtgrp) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - filp->private_data = NULL; - atomic_dec(&rdtgrp->waitcount); - mutex_unlock(&rdtgroup_mutex); - return 0; -} - -static int pseudo_lock_dev_mremap(struct vm_area_struct *area) -{ - /* Not supported */ - return -EINVAL; -} - -static const struct vm_operations_struct pseudo_mmap_ops = { - .mremap = pseudo_lock_dev_mremap, -}; - -static int pseudo_lock_dev_mmap(struct file *filp, struct vm_area_struct *vma) -{ - unsigned long vsize = vma->vm_end - vma->vm_start; - unsigned long off = vma->vm_pgoff << PAGE_SHIFT; - struct pseudo_lock_region *plr; - struct rdtgroup *rdtgrp; - unsigned long physical; - unsigned long psize; - - mutex_lock(&rdtgroup_mutex); - - rdtgrp = filp->private_data; - WARN_ON(!rdtgrp); - if (!rdtgrp) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - - plr = rdtgrp->plr; - - if (!plr->d) { - mutex_unlock(&rdtgroup_mutex); - return -ENODEV; - } - - /* - * Task is required to run with affinity to the cpus associated - * with the pseudo-locked region. If this is not the case the task - * may be scheduled elsewhere and invalidate entries in the - * pseudo-locked region. - */ - if (!cpumask_subset(current->cpus_ptr, &plr->d->cpu_mask)) { - mutex_unlock(&rdtgroup_mutex); - return -EINVAL; - } - - physical = __pa(plr->kmem) >> PAGE_SHIFT; - psize = plr->size - off; - - if (off > plr->size) { - mutex_unlock(&rdtgroup_mutex); - return -ENOSPC; - } - - /* - * Ensure changes are carried directly to the memory being mapped, - * do not allow copy-on-write mapping. - */ - if (!(vma->vm_flags & VM_SHARED)) { - mutex_unlock(&rdtgroup_mutex); - return -EINVAL; - } - - if (vsize > psize) { - mutex_unlock(&rdtgroup_mutex); - return -ENOSPC; - } - - memset(plr->kmem + off, 0, vsize); - - if (remap_pfn_range(vma, vma->vm_start, physical + vma->vm_pgoff, - vsize, vma->vm_page_prot)) { - mutex_unlock(&rdtgroup_mutex); - return -EAGAIN; - } - vma->vm_ops = &pseudo_mmap_ops; - mutex_unlock(&rdtgroup_mutex); - return 0; -} - -static const struct file_operations pseudo_lock_dev_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .read = NULL, - .write = NULL, - .open = pseudo_lock_dev_open, - .release = pseudo_lock_dev_release, - .mmap = pseudo_lock_dev_mmap, -}; - -int rdt_pseudo_lock_init(void) -{ - int ret; - - ret = register_chrdev(0, "pseudo_lock", &pseudo_lock_dev_fops); - if (ret < 0) - return ret; - - pseudo_lock_major = ret; - - ret = class_register(&pseudo_lock_class); - if (ret) { - unregister_chrdev(pseudo_lock_major, "pseudo_lock"); - return ret; - } - - return 0; -} - -void rdt_pseudo_lock_release(void) -{ - class_unregister(&pseudo_lock_class); - unregister_chrdev(pseudo_lock_major, "pseudo_lock"); - pseudo_lock_major = 0; -} diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 253f5fbd8e1c..10bd76e1d0d5 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -12,22 +12,8 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

-#include <linux/cacheinfo.h> #include <linux/cpu.h> -#include <linux/debugfs.h> -#include <linux/fs.h> -#include <linux/fs_parser.h> -#include <linux/sysfs.h> -#include <linux/kernfs.h> -#include <linux/seq_buf.h> -#include <linux/seq_file.h> -#include <linux/sched/signal.h> -#include <linux/sched/task.h> #include <linux/slab.h> -#include <linux/task_work.h> -#include <linux/user_namespace.h> - -#include <uapi/linux/magic.h>

#include <asm/resctrl.h> #include "internal.h" @@ -36,4220 +22,239 @@ DEFINE_STATIC_KEY_FALSE(rdt_enable_key); DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key); DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);

-/* Mutex to protect rdtgroup access. */ -DEFINE_MUTEX(rdtgroup_mutex); - -static struct kernfs_root *rdt_root; -struct rdtgroup rdtgroup_default; -LIST_HEAD(rdt_all_groups); - -/* list of entries for the schemata file */ -LIST_HEAD(resctrl_schema_all); - -/* The filesystem can only be mounted once. */ -bool resctrl_mounted; - -/* Kernel fs node for "info" directory under root */ -static struct kernfs_node *kn_info; - -/* Kernel fs node for "mon_groups" directory under root */ -static struct kernfs_node *kn_mongrp; - -/* Kernel fs node for "mon_data" directory under root */ -static struct kernfs_node *kn_mondata; - /* - * Used to store the max resource name width and max resource data width - * to display the schemata in a tabular format + * This is safe against resctrl_sched_in() called from __switch_to() + * because __switch_to() is executed with interrupts disabled. A local call + * from update_closid_rmid() is protected against __switch_to() because + * preemption is disabled. */ -int max_name_width, max_data_width; - -static struct seq_buf last_cmd_status; -static char last_cmd_status_buf[512]; - -static int rdtgroup_setup_root(struct rdt_fs_context *ctx); -static void rdtgroup_destroy_root(void); - -struct dentry *debugfs_resctrl; - -static bool resctrl_debug; - -void rdt_last_cmd_clear(void) -{ - lockdep_assert_held(&rdtgroup_mutex); - seq_buf_clear(&last_cmd_status); -} - -void rdt_last_cmd_puts(const char *s) -{ - lockdep_assert_held(&rdtgroup_mutex); - seq_buf_puts(&last_cmd_status, s); -} - -void rdt_last_cmd_printf(const char *fmt, ...) -{ - va_list ap; - - va_start(ap, fmt); - lockdep_assert_held(&rdtgroup_mutex); - seq_buf_vprintf(&last_cmd_status, fmt, ap); - va_end(ap); -} - -void rdt_staged_configs_clear(void) +void resctrl_arch_sync_cpu_defaults(void *info) { - struct rdt_resource *r; - struct rdt_domain *dom; - int i; - - lockdep_assert_held(&rdtgroup_mutex); - - for (i = 0; i < RDT_NUM_RESOURCES; i++) { - r = resctrl_arch_get_resource(i); - if (!r->alloc_capable) - continue; + struct resctrl_cpu_sync *r = info;

- list_for_each_entry(dom, &r->domains, list) - memset(dom->staged_config, 0, sizeof(dom->staged_config)); + if (r) { + this_cpu_write(pqr_state.default_closid, r->closid); + this_cpu_write(pqr_state.default_rmid, r->rmid); } -}

-static bool resctrl_is_mbm_enabled(void) -{ - return (resctrl_arch_is_mbm_total_enabled() || - resctrl_arch_is_mbm_local_enabled()); + /* + * We cannot unconditionally write the MSR because the current + * executing task might have its own closid selected. Just reuse + * the context switch code. + */ + resctrl_sched_in(current); }

-static bool resctrl_is_mbm_event(int e) -{ - return (e >= QOS_L3_MBM_TOTAL_EVENT_ID && - e <= QOS_L3_MBM_LOCAL_EVENT_ID); -} +#define INVALID_CONFIG_INDEX UINT_MAX

-/* - * Trivial allocator for CLOSIDs. Since h/w only supports a small number, - * we can keep a bitmap of free CLOSIDs in a single integer. +/** + * mon_event_config_index_get - get the hardware index for the + * configurable event + * @evtid: event id. * - * Using a global CLOSID across all resources has some advantages and - * some drawbacks: - * + We can simply set current's closid to assign a task to a resource - * group. - * + Context switch code can avoid extra memory references deciding which - * CLOSID to load into the PQR_ASSOC MSR - * - We give up some options in configuring resource groups across multi-socket - * systems. - * - Our choices on how to configure each resource become progressively more - * limited as the number of resources grows. + * Return: 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID + * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID + * INVALID_CONFIG_INDEX for invalid evtid */ -static unsigned long closid_free_map; -static int closid_free_map_len; - -int closids_supported(void) -{ - return closid_free_map_len; -} - -static void closid_init(void) +static inline unsigned int mon_event_config_index_get(u32 evtid) { - struct resctrl_schema *s; - u32 rdt_min_closid = 32; - - /* Compute rdt_min_closid across all resources */ - list_for_each_entry(s, &resctrl_schema_all, list) - rdt_min_closid = min(rdt_min_closid, s->num_closid); - - closid_free_map = BIT_MASK(rdt_min_closid) - 1; - - /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */ - __clear_bit(RESCTRL_RESERVED_CLOSID, &closid_free_map); - closid_free_map_len = rdt_min_closid; + switch (evtid) { + case QOS_L3_MBM_TOTAL_EVENT_ID: + return 0; + case QOS_L3_MBM_LOCAL_EVENT_ID: + return 1; + default: + /* Should never reach here */ + return INVALID_CONFIG_INDEX; + } }

-static int closid_alloc(void) +void resctrl_arch_mon_event_config_read(void *info) { - int cleanest_closid; - u32 closid; - - lockdep_assert_held(&rdtgroup_mutex); + struct resctrl_mon_config_info *mon_info = info; + unsigned int index; + u64 msrval;

- if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { - cleanest_closid = resctrl_find_cleanest_closid(); - if (cleanest_closid < 0) - return cleanest_closid; - closid = cleanest_closid; - } else { - closid = ffs(closid_free_map); - if (closid == 0) - return -ENOSPC; - closid--; + index = mon_event_config_index_get(mon_info->evtid); + if (index == INVALID_CONFIG_INDEX) { + pr_warn_once("Invalid event id %d\n", mon_info->evtid); + return; } - __clear_bit(closid, &closid_free_map); + rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval);

- return closid; + /* Report only the valid event configuration bits */ + mon_info->mon_config = msrval & MAX_EVT_CONFIG_BITS; }

-void closid_free(int closid) +void resctrl_arch_mon_event_config_write(void *info) { - lockdep_assert_held(&rdtgroup_mutex); - - __set_bit(closid, &closid_free_map); -} + struct resctrl_mon_config_info *mon_info = info; + unsigned int index;

-/** - * closid_allocated - test if provided closid is in use - * @closid: closid to be tested - * - * Return: true if @closid is currently associated with a resource group, - * false if @closid is free - */ -bool closid_allocated(unsigned int closid) -{ - lockdep_assert_held(&rdtgroup_mutex); + index = mon_event_config_index_get(mon_info->evtid); + if (index == INVALID_CONFIG_INDEX) { + pr_warn_once("Invalid event id %d\n", mon_info->evtid); + mon_info->err = -EINVAL; + return; + } + wrmsr(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config, 0);

- return !test_bit(closid, &closid_free_map); + mon_info->err = 0; }

-/** - * rdtgroup_mode_by_closid - Return mode of resource group with closid - * @closid: closid if the resource group - * - * Each resource group is associated with a @closid. Here the mode - * of a resource group can be queried by searching for it using its closid. - * - * Return: mode as &enum rdtgrp_mode of resource group with closid @closid - */ -enum rdtgrp_mode rdtgroup_mode_by_closid(int closid) +static void l3_qos_cfg_update(void *arg) { - struct rdtgroup *rdtgrp; - - list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { - if (rdtgrp->closid == closid) - return rdtgrp->mode; - } + bool *enable = arg;

- return RDT_NUM_MODES; + wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL); }

-static const char * const rdt_mode_str[] = { - [RDT_MODE_SHAREABLE] = "shareable", - [RDT_MODE_EXCLUSIVE] = "exclusive", - [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup", - [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked", -}; - -/** - * rdtgroup_mode_str - Return the string representation of mode - * @mode: the resource group mode as &enum rdtgroup_mode - * - * Return: string representation of valid mode, "unknown" otherwise - */ -static const char *rdtgroup_mode_str(enum rdtgrp_mode mode) +static void l2_qos_cfg_update(void *arg) { - if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES) - return "unknown"; + bool *enable = arg;

- return rdt_mode_str[mode]; + wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL); }

-/* set uid and gid of rdtgroup dirs and files to that of the creator */ -static int rdtgroup_kn_set_ugid(struct kernfs_node *kn) +static int set_cache_qos_cfg(int level, bool enable) { - struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID, - .ia_uid = current_fsuid(), - .ia_gid = current_fsgid(), }; - - if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) && - gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID)) - return 0; + void (*update)(void *arg); + struct rdt_resource *r_l; + cpumask_var_t cpu_mask; + struct rdt_domain *d; + int cpu;

- return kernfs_setattr(kn, &iattr); -} + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held();

-static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft) -{ - struct kernfs_node *kn; - int ret; + if (level == RDT_RESOURCE_L3) + update = l3_qos_cfg_update; + else if (level == RDT_RESOURCE_L2) + update = l2_qos_cfg_update; + else + return -EINVAL;

- kn = __kernfs_create_file(parent_kn, rft->name, rft->mode, - GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, - 0, rft->kf_ops, rft, NULL, NULL); - if (IS_ERR(kn)) - return PTR_ERR(kn); + if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) + return -ENOMEM;

- ret = rdtgroup_kn_set_ugid(kn); - if (ret) { - kernfs_remove(kn); - return ret; + r_l = &rdt_resources_all[level].r_resctrl; + list_for_each_entry(d, &r_l->domains, list) { + if (r_l->cache.arch_has_per_cpu_cfg) + /* Pick all the CPUs in the domain instance */ + for_each_cpu(cpu, &d->cpu_mask) + cpumask_set_cpu(cpu, cpu_mask); + else + /* Pick one CPU from each domain instance to update MSR */ + cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); }

- return 0; -} + /* Update QOS_CFG MSR on all the CPUs in cpu_mask */ + on_each_cpu_mask(cpu_mask, update, &enable, 1);

-static int rdtgroup_seqfile_show(struct seq_file *m, void *arg) -{ - struct kernfs_open_file *of = m->private; - struct rftype *rft = of->kn->priv; + free_cpumask_var(cpu_mask);

- if (rft->seq_show) - return rft->seq_show(of, m, arg); return 0; }

-static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf, - size_t nbytes, loff_t off) +/* Restore the qos cfg state when a domain comes online */ +void rdt_domain_reconfigure_cdp(struct rdt_resource *r) { - struct rftype *rft = of->kn->priv; - - if (rft->write) - return rft->write(of, buf, nbytes, off); - - return -EINVAL; -} - -static const struct kernfs_ops rdtgroup_kf_single_ops = { - .atomic_write_len = PAGE_SIZE, - .write = rdtgroup_file_write, - .seq_show = rdtgroup_seqfile_show, -}; + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);

-static const struct kernfs_ops kf_mondata_ops = { - .atomic_write_len = PAGE_SIZE, - .seq_show = rdtgroup_mondata_show, -}; + if (!r->cdp_capable) + return;

-static bool is_cpu_list(struct kernfs_open_file *of) -{ - struct rftype *rft = of->kn->priv; + if (r->rid == RDT_RESOURCE_L2) + l2_qos_cfg_update(&hw_res->cdp_enabled);

- return rft->flags & RFTYPE_FLAGS_CPUS_LIST; + if (r->rid == RDT_RESOURCE_L3) + l3_qos_cfg_update(&hw_res->cdp_enabled); }

-static int rdtgroup_cpus_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) +static int cdp_enable(int level) { - struct rdtgroup *rdtgrp; - struct cpumask *mask; - int ret = 0; + struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl; + int ret;

- rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!r_l->alloc_capable) + return -EINVAL;

- if (rdtgrp) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - if (!rdtgrp->plr->d) { - rdt_last_cmd_clear(); - rdt_last_cmd_puts("Cache domain offline\n"); - ret = -ENODEV; - } else { - mask = &rdtgrp->plr->d->cpu_mask; - seq_printf(s, is_cpu_list(of) ? - "%*pbl\n" : "%*pb\n", - cpumask_pr_args(mask)); - } - } else { - seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n", - cpumask_pr_args(&rdtgrp->cpu_mask)); - } - } else { - ret = -ENOENT; - } - rdtgroup_kn_unlock(of->kn); + ret = set_cache_qos_cfg(level, true); + if (!ret) + rdt_resources_all[level].cdp_enabled = true;

return ret; }

-/* - * This is safe against resctrl_sched_in() called from __switch_to() - * because __switch_to() is executed with interrupts disabled. A local call - * from update_closid_rmid() is protected against __switch_to() because - * preemption is disabled. - */ -void resctrl_arch_sync_cpu_defaults(void *info) -{ - struct resctrl_cpu_sync *r = info; - - if (r) { - this_cpu_write(pqr_state.default_closid, r->closid); - this_cpu_write(pqr_state.default_rmid, r->rmid); - } - - /* - * We cannot unconditionally write the MSR because the current - * executing task might have its own closid selected. Just reuse - * the context switch code. - */ - resctrl_sched_in(current); -} - -/* - * Update the PGR_ASSOC MSR on all cpus in @cpu_mask, - * - * Per task closids/rmids must have been set up before calling this function. - * @r may be NULL. - */ -static void -update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r) +static void cdp_disable(int level) { - struct resctrl_cpu_sync defaults; - struct resctrl_cpu_sync *defaults_p = NULL; + struct rdt_hw_resource *r_hw = &rdt_resources_all[level];

- if (r) { - defaults.closid = r->closid; - defaults.rmid = r->mon.rmid; - defaults_p = &defaults; + if (r_hw->cdp_enabled) { + set_cache_qos_cfg(level, false); + r_hw->cdp_enabled = false; } - - on_each_cpu_mask(cpu_mask, resctrl_arch_sync_cpu_defaults, defaults_p, - 1); }

-static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, - cpumask_var_t tmpmask) +int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable) { - struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp; - struct list_head *head; + struct rdt_hw_resource *hw_res = &rdt_resources_all[l];

- /* Check whether cpus belong to parent ctrl group */ - cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask); - if (!cpumask_empty(tmpmask)) { - rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n"); + if (!hw_res->r_resctrl.cdp_capable) return -EINVAL; - } - - /* Check whether cpus are dropped from this group */ - cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); - if (!cpumask_empty(tmpmask)) { - /* Give any dropped cpus to parent rdtgroup */ - cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask); - update_closid_rmid(tmpmask, prgrp); - }

- /* - * If we added cpus, remove them from previous group that owned them - * and update per-cpu rmid - */ - cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); - if (!cpumask_empty(tmpmask)) { - head = &prgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) { - if (crgrp == rdtgrp) - continue; - cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask, - tmpmask); - } - update_closid_rmid(tmpmask, rdtgrp); - } + if (enable) + return cdp_enable(l);

- /* Done pushing/pulling - update this group with new mask */ - cpumask_copy(&rdtgrp->cpu_mask, newmask); + cdp_disable(l);

return 0; }

-static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m) +static int reset_all_ctrls(struct rdt_resource *r) { - struct rdtgroup *crgrp; - - cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m); - /* update the child mon group masks as well*/ - list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list) - cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask); -} + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); + struct rdt_hw_domain *hw_dom; + struct msr_param msr_param; + cpumask_var_t cpu_mask; + struct rdt_domain *d; + int i;

-static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, - cpumask_var_t tmpmask, cpumask_var_t tmpmask1) -{ - struct rdtgroup *r, *crgrp; - struct list_head *head; + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held();

- /* Check whether cpus are dropped from this group */ - cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); - if (!cpumask_empty(tmpmask)) { - /* Can't drop from default group */ - if (rdtgrp == &rdtgroup_default) { - rdt_last_cmd_puts("Can't drop CPUs from default group\n"); - return -EINVAL; - } + if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) + return -ENOMEM;

- /* Give any dropped cpus to rdtgroup_default */ - cpumask_or(&rdtgroup_default.cpu_mask, - &rdtgroup_default.cpu_mask, tmpmask); - update_closid_rmid(tmpmask, &rdtgroup_default); - } + msr_param.res = r; + msr_param.low = 0; + msr_param.high = hw_res->num_closid;

/* - * If we added cpus, remove them from previous group and - * the prev group's child groups that owned them - * and update per-cpu closid/rmid. + * Disable resource control for this resource by setting all + * CBMs in all domains to the maximum mask value. Pick one CPU + * from each domain to update the MSRs below. */ - cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); - if (!cpumask_empty(tmpmask)) { - list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) { - if (r == rdtgrp) - continue; - cpumask_and(tmpmask1, &r->cpu_mask, tmpmask); - if (!cpumask_empty(tmpmask1)) - cpumask_rdtgrp_clear(r, tmpmask1); - } - update_closid_rmid(tmpmask, rdtgrp); + list_for_each_entry(d, &r->domains, list) { + hw_dom = resctrl_to_arch_dom(d); + cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); + + for (i = 0; i < hw_res->num_closid; i++) + hw_dom->ctrl_val[i] = r->default_ctrl; }

- /* Done pushing/pulling - update this group with new mask */ - cpumask_copy(&rdtgrp->cpu_mask, newmask); + /* Update CBM on all the CPUs in cpu_mask */ + on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1);

- /* - * Clear child mon group masks since there is a new parent mask - * now and update the rmid for the cpus the child lost. - */ - head = &rdtgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) { - cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask); - update_closid_rmid(tmpmask, rdtgrp); - cpumask_clear(&crgrp->cpu_mask); - } + free_cpumask_var(cpu_mask);

return 0; }

-static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) +void resctrl_arch_reset_resources(void) { - cpumask_var_t tmpmask, newmask, tmpmask1; - struct rdtgroup *rdtgrp; - int ret; - - if (!buf) - return -EINVAL; - - if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) - return -ENOMEM; - if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) { - free_cpumask_var(tmpmask); - return -ENOMEM; - } - if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) { - free_cpumask_var(tmpmask); - free_cpumask_var(newmask); - return -ENOMEM; - } - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - ret = -ENOENT; - goto unlock; - } - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = -EINVAL; - rdt_last_cmd_puts("Pseudo-locking in progress\n"); - goto unlock; - } - - if (is_cpu_list(of)) - ret = cpulist_parse(buf, newmask); - else - ret = cpumask_parse(buf, newmask); - - if (ret) { - rdt_last_cmd_puts("Bad CPU list/mask\n"); - goto unlock; - } - - /* check that user didn't specify any offline cpus */ - cpumask_andnot(tmpmask, newmask, cpu_online_mask); - if (!cpumask_empty(tmpmask)) { - ret = -EINVAL; - rdt_last_cmd_puts("Can only assign online CPUs\n"); - goto unlock; - } - - if (rdtgrp->type == RDTCTRL_GROUP) - ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1); - else if (rdtgrp->type == RDTMON_GROUP) - ret = cpus_mon_write(rdtgrp, newmask, tmpmask); - else - ret = -EINVAL; - -unlock: - rdtgroup_kn_unlock(of->kn); - free_cpumask_var(tmpmask); - free_cpumask_var(newmask); - free_cpumask_var(tmpmask1); - - return ret ?: nbytes; -} - -/** - * rdtgroup_remove - the helper to remove resource group safely - * @rdtgrp: resource group to remove - * - * On resource group creation via a mkdir, an extra kernfs_node reference is - * taken to ensure that the rdtgroup structure remains accessible for the - * rdtgroup_kn_unlock() calls where it is removed. - * - * Drop the extra reference here, then free the rdtgroup structure. - * - * Return: void - */ -static void rdtgroup_remove(struct rdtgroup *rdtgrp) -{ - kernfs_put(rdtgrp->kn); - kfree(rdtgrp); -} - -static void _update_task_closid_rmid(void *task) -{ - /* - * If the task is still current on this CPU, update PQR_ASSOC MSR. - * Otherwise, the MSR is updated when the task is scheduled in. - */ - if (task == current) - resctrl_sched_in(task); -} - -static void update_task_closid_rmid(struct task_struct *t) -{ - if (IS_ENABLED(CONFIG_SMP) && task_curr(t)) - smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1); - else - _update_task_closid_rmid(t); -} - -static bool task_in_rdtgroup(struct task_struct *tsk, struct rdtgroup *rdtgrp) -{ - u32 closid, rmid = rdtgrp->mon.rmid; - - if (rdtgrp->type == RDTCTRL_GROUP) - closid = rdtgrp->closid; - else if (rdtgrp->type == RDTMON_GROUP) - closid = rdtgrp->mon.parent->closid; - else - return false; - - return resctrl_arch_match_closid(tsk, closid) && - resctrl_arch_match_rmid(tsk, closid, rmid); -} - -static int __rdtgroup_move_task(struct task_struct *tsk, - struct rdtgroup *rdtgrp) -{ - /* If the task is already in rdtgrp, no need to move the task. */ - if (task_in_rdtgroup(tsk, rdtgrp)) - return 0; - - /* - * Set the task's closid/rmid before the PQR_ASSOC MSR can be - * updated by them. - * - * For ctrl_mon groups, move both closid and rmid. - * For monitor groups, can move the tasks only from - * their parent CTRL group. - */ - if (rdtgrp->type == RDTMON_GROUP && - !resctrl_arch_match_closid(tsk, rdtgrp->mon.parent->closid)) { - rdt_last_cmd_puts("Can't move task to different control group\n"); - return -EINVAL; - } - - if (rdtgrp->type == RDTMON_GROUP) - resctrl_arch_set_closid_rmid(tsk, rdtgrp->mon.parent->closid, - rdtgrp->mon.rmid); - else - resctrl_arch_set_closid_rmid(tsk, rdtgrp->closid, - rdtgrp->mon.rmid); - - /* - * Ensure the task's closid and rmid are written before determining if - * the task is current that will decide if it will be interrupted. - * This pairs with the full barrier between the rq->curr update and - * resctrl_sched_in() during context switch. - */ - smp_mb(); - - /* - * By now, the task's closid and rmid are set. If the task is current - * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource - * group go into effect. If the task is not current, the MSR will be - * updated when the task is scheduled in. - */ - update_task_closid_rmid(tsk); - - return 0; -} - -static bool is_closid_match(struct task_struct *t, struct rdtgroup *r) -{ - return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) && - resctrl_arch_match_closid(t, r->closid)); -} - -static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r) -{ - return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) && - resctrl_arch_match_rmid(t, r->mon.parent->closid, - r->mon.rmid)); -} - -/** - * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group - * @r: Resource group - * - * Return: 1 if tasks have been assigned to @r, 0 otherwise - */ -int rdtgroup_tasks_assigned(struct rdtgroup *r) -{ - struct task_struct *p, *t; - int ret = 0; - - lockdep_assert_held(&rdtgroup_mutex); - - rcu_read_lock(); - for_each_process_thread(p, t) { - if (is_closid_match(t, r) || is_rmid_match(t, r)) { - ret = 1; - break; - } - } - rcu_read_unlock(); - - return ret; -} - -static int rdtgroup_task_write_permission(struct task_struct *task, - struct kernfs_open_file *of) -{ - const struct cred *tcred = get_task_cred(task); - const struct cred *cred = current_cred(); - int ret = 0; - - /* - * Even if we're attaching all tasks in the thread group, we only - * need to check permissions on one of them. - */ - if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) && - !uid_eq(cred->euid, tcred->uid) && - !uid_eq(cred->euid, tcred->suid)) { - rdt_last_cmd_printf("No permission to move task %d\n", task->pid); - ret = -EPERM; - } - - put_cred(tcred); - return ret; -} - -static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp, - struct kernfs_open_file *of) -{ - struct task_struct *tsk; - int ret; - - rcu_read_lock(); - if (pid) { - tsk = find_task_by_vpid(pid); - if (!tsk) { - rcu_read_unlock(); - rdt_last_cmd_printf("No task %d\n", pid); - return -ESRCH; - } - } else { - tsk = current; - } - - get_task_struct(tsk); - rcu_read_unlock(); - - ret = rdtgroup_task_write_permission(tsk, of); - if (!ret) - ret = __rdtgroup_move_task(tsk, rdtgrp); - - put_task_struct(tsk); - return ret; -} - -static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct rdtgroup *rdtgrp; - char *pid_str; - int ret = 0; - pid_t pid; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - rdt_last_cmd_clear(); - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = -EINVAL; - rdt_last_cmd_puts("Pseudo-locking in progress\n"); - goto unlock; - } - - while (buf && buf[0] != '\0' && buf[0] != '\n') { - pid_str = strim(strsep(&buf, ",")); - - if (kstrtoint(pid_str, 0, &pid)) { - rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str); - ret = -EINVAL; - break; - } - - if (pid < 0) { - rdt_last_cmd_printf("Invalid pid %d\n", pid); - ret = -EINVAL; - break; - } - - ret = rdtgroup_move_task(pid, rdtgrp, of); - if (ret) { - rdt_last_cmd_printf("Error while processing task %d\n", pid); - break; - } - } - -unlock: - rdtgroup_kn_unlock(of->kn); - - return ret ?: nbytes; -} - -static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s) -{ - struct task_struct *p, *t; - pid_t pid; - - rcu_read_lock(); - for_each_process_thread(p, t) { - if (is_closid_match(t, r) || is_rmid_match(t, r)) { - pid = task_pid_vnr(t); - if (pid) - seq_printf(s, "%d\n", pid); - } - } - rcu_read_unlock(); -} - -static int rdtgroup_tasks_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) - show_rdt_tasks(rdtgrp, s); - else - ret = -ENOENT; - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -static int rdtgroup_closid_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) - seq_printf(s, "%u\n", rdtgrp->closid); - else - ret = -ENOENT; - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -static int rdtgroup_rmid_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - int ret = 0; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (rdtgrp) - seq_printf(s, "%u\n", rdtgrp->mon.rmid); - else - ret = -ENOENT; - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -#ifdef CONFIG_PROC_CPU_RESCTRL - -/* - * A task can only be part of one resctrl control group and of one monitor - * group which is associated to that control group. - * - * 1) res: - * mon: - * - * resctrl is not available. - * - * 2) res:/ - * mon: - * - * Task is part of the root resctrl control group, and it is not associated - * to any monitor group. - * - * 3) res:/ - * mon:mon0 - * - * Task is part of the root resctrl control group and monitor group mon0. - * - * 4) res:group0 - * mon: - * - * Task is part of resctrl control group group0, and it is not associated - * to any monitor group. - * - * 5) res:group0 - * mon:mon1 - * - * Task is part of resctrl control group group0 and monitor group mon1. - */ -int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns, - struct pid *pid, struct task_struct *tsk) -{ - struct rdtgroup *rdtg; - int ret = 0; - - mutex_lock(&rdtgroup_mutex); - - /* Return empty if resctrl has not been mounted. */ - if (!resctrl_mounted) { - seq_puts(s, "res:\nmon:\n"); - goto unlock; - } - - list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) { - struct rdtgroup *crg; - - /* - * Task information is only relevant for shareable - * and exclusive groups. - */ - if (rdtg->mode != RDT_MODE_SHAREABLE && - rdtg->mode != RDT_MODE_EXCLUSIVE) - continue; - - if (!resctrl_arch_match_closid(tsk, rdtg->closid)) - continue; - - seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "", - rdtg->kn->name); - seq_puts(s, "mon:"); - list_for_each_entry(crg, &rdtg->mon.crdtgrp_list, - mon.crdtgrp_list) { - if (!resctrl_arch_match_rmid(tsk, crg->mon.parent->closid, - crg->mon.rmid)) - continue; - seq_printf(s, "%s", crg->kn->name); - break; - } - seq_putc(s, '\n'); - goto unlock; - } - /* - * The above search should succeed. Otherwise return - * with an error. - */ - ret = -ENOENT; -unlock: - mutex_unlock(&rdtgroup_mutex); - - return ret; -} -#endif - -static int rdt_last_cmd_status_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - int len; - - mutex_lock(&rdtgroup_mutex); - len = seq_buf_used(&last_cmd_status); - if (len) - seq_printf(seq, "%.*s", len, last_cmd_status_buf); - else - seq_puts(seq, "ok\n"); - mutex_unlock(&rdtgroup_mutex); - return 0; -} - -static int rdt_num_closids_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - - seq_printf(seq, "%u\n", s->num_closid); - return 0; -} - -static int rdt_default_ctrl_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - seq_printf(seq, "%x\n", r->default_ctrl); - return 0; -} - -static int rdt_min_cbm_bits_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->cache.min_cbm_bits); - return 0; -} - -static int rdt_shareable_bits_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - seq_printf(seq, "%x\n", r->cache.shareable_bits); - return 0; -} - -/* - * rdt_bit_usage_show - Display current usage of resources - * - * A domain is a shared resource that can now be allocated differently. Here - * we display the current regions of the domain as an annotated bitmask. - * For each domain of this resource its allocation bitmask - * is annotated as below to indicate the current usage of the corresponding bit: - * 0 - currently unused - * X - currently available for sharing and used by software and hardware - * H - currently used by hardware only but available for software use - * S - currently used and shareable by software only - * E - currently used exclusively by one resource group - * P - currently pseudo-locked by one resource group - */ -static int rdt_bit_usage_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - /* - * Use unsigned long even though only 32 bits are used to ensure - * test_bit() is used safely. - */ - unsigned long sw_shareable = 0, hw_shareable = 0; - unsigned long exclusive = 0, pseudo_locked = 0; - struct rdt_resource *r = s->res; - struct rdt_domain *dom; - int i, hwb, swb, excl, psl; - enum rdtgrp_mode mode; - bool sep = false; - u32 ctrl_val; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - hw_shareable = r->cache.shareable_bits; - list_for_each_entry(dom, &r->domains, list) { - if (sep) - seq_putc(seq, ';'); - sw_shareable = 0; - exclusive = 0; - seq_printf(seq, "%d=", dom->id); - for (i = 0; i < closids_supported(); i++) { - if (!closid_allocated(i)) - continue; - ctrl_val = resctrl_arch_get_config(r, dom, i, - s->conf_type); - mode = rdtgroup_mode_by_closid(i); - switch (mode) { - case RDT_MODE_SHAREABLE: - sw_shareable |= ctrl_val; - break; - case RDT_MODE_EXCLUSIVE: - exclusive |= ctrl_val; - break; - case RDT_MODE_PSEUDO_LOCKSETUP: - /* - * RDT_MODE_PSEUDO_LOCKSETUP is possible - * here but not included since the CBM - * associated with this CLOSID in this mode - * is not initialized and no task or cpu can be - * assigned this CLOSID. - */ - break; - case RDT_MODE_PSEUDO_LOCKED: - case RDT_NUM_MODES: - WARN(1, - "invalid mode for closid %d\n", i); - break; - } - } - for (i = r->cache.cbm_len - 1; i >= 0; i--) { - pseudo_locked = dom->plr ? dom->plr->cbm : 0; - hwb = test_bit(i, &hw_shareable); - swb = test_bit(i, &sw_shareable); - excl = test_bit(i, &exclusive); - psl = test_bit(i, &pseudo_locked); - if (hwb && swb) - seq_putc(seq, 'X'); - else if (hwb && !swb) - seq_putc(seq, 'H'); - else if (!hwb && swb) - seq_putc(seq, 'S'); - else if (excl) - seq_putc(seq, 'E'); - else if (psl) - seq_putc(seq, 'P'); - else /* Unused bits remain */ - seq_putc(seq, '0'); - } - sep = true; - } - seq_putc(seq, '\n'); - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - return 0; -} - -static int rdt_min_bw_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->membw.min_bw); - return 0; -} - -static int rdt_num_rmids_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = of->kn->parent->priv; - - seq_printf(seq, "%d\n", r->num_rmid); - - return 0; -} - -static int rdt_mon_features_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = of->kn->parent->priv; - struct mon_evt *mevt; - - list_for_each_entry(mevt, &r->evt_list, list) { - seq_printf(seq, "%s\n", mevt->name); - if (mevt->configurable) - seq_printf(seq, "%s_config\n", mevt->name); - } - - return 0; -} - -static int rdt_bw_gran_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->membw.bw_gran); - return 0; -} - -static int rdt_delay_linear_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->membw.delay_linear); - return 0; -} - -static int max_threshold_occ_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - seq_printf(seq, "%u\n", resctrl_rmid_realloc_threshold); - - return 0; -} - -static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD) - seq_puts(seq, "per-thread\n"); - else - seq_puts(seq, "max\n"); - - return 0; -} - -static ssize_t max_threshold_occ_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - unsigned int bytes; - int ret; - - ret = kstrtouint(buf, 0, &bytes); - if (ret) - return ret; - - if (bytes > resctrl_rmid_realloc_limit) - return -EINVAL; - - resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes); - - return nbytes; -} - -/* - * rdtgroup_mode_show - Display mode of this resource group - */ -static int rdtgroup_mode_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct rdtgroup *rdtgrp; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - - seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode)); - - rdtgroup_kn_unlock(of->kn); - return 0; -} - -static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type) -{ - switch (my_type) { - case CDP_CODE: - return CDP_DATA; - case CDP_DATA: - return CDP_CODE; - default: - case CDP_NONE: - return CDP_NONE; - } -} - -static int rdt_has_sparse_bitmasks_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct resctrl_schema *s = of->kn->parent->priv; - struct rdt_resource *r = s->res; - - seq_printf(seq, "%u\n", r->cache.arch_has_sparse_bitmasks); - - return 0; -} - -/** - * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other - * @r: Resource to which domain instance @d belongs. - * @d: The domain instance for which @closid is being tested. - * @cbm: Capacity bitmask being tested. - * @closid: Intended closid for @cbm. - * @type: CDP type of @r. - * @exclusive: Only check if overlaps with exclusive resource groups - * - * Checks if provided @cbm intended to be used for @closid on domain - * @d overlaps with any other closids or other hardware usage associated - * with this domain. If @exclusive is true then only overlaps with - * resource groups in exclusive mode will be considered. If @exclusive - * is false then overlaps with any resource group or hardware entities - * will be considered. - * - * @cbm is unsigned long, even if only 32 bits are used, to make the - * bitmap functions work correctly. - * - * Return: false if CBM does not overlap, true if it does. - */ -static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d, - unsigned long cbm, int closid, - enum resctrl_conf_type type, bool exclusive) -{ - enum rdtgrp_mode mode; - unsigned long ctrl_b; - int i; - - /* Check for any overlap with regions used by hardware directly */ - if (!exclusive) { - ctrl_b = r->cache.shareable_bits; - if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) - return true; - } - - /* Check for overlap with other resource groups */ - for (i = 0; i < closids_supported(); i++) { - ctrl_b = resctrl_arch_get_config(r, d, i, type); - mode = rdtgroup_mode_by_closid(i); - if (closid_allocated(i) && i != closid && - mode != RDT_MODE_PSEUDO_LOCKSETUP) { - if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) { - if (exclusive) { - if (mode == RDT_MODE_EXCLUSIVE) - return true; - continue; - } - return true; - } - } - } - - return false; -} - -/** - * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware - * @s: Schema for the resource to which domain instance @d belongs. - * @d: The domain instance for which @closid is being tested. - * @cbm: Capacity bitmask being tested. - * @closid: Intended closid for @cbm. - * @exclusive: Only check if overlaps with exclusive resource groups - * - * Resources that can be allocated using a CBM can use the CBM to control - * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test - * for overlap. Overlap test is not limited to the specific resource for - * which the CBM is intended though - when dealing with CDP resources that - * share the underlying hardware the overlap check should be performed on - * the CDP resource sharing the hardware also. - * - * Refer to description of __rdtgroup_cbm_overlaps() for the details of the - * overlap test. - * - * Return: true if CBM overlap detected, false if there is no overlap - */ -bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_domain *d, - unsigned long cbm, int closid, bool exclusive) -{ - enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); - struct rdt_resource *r = s->res; - - if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type, - exclusive)) - return true; - - if (!resctrl_arch_get_cdp_enabled(r->rid)) - return false; - return __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive); -} - -/** - * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive - * @rdtgrp: Resource group identified through its closid. - * - * An exclusive resource group implies that there should be no sharing of - * its allocated resources. At the time this group is considered to be - * exclusive this test can determine if its current schemata supports this - * setting by testing for overlap with all other resource groups. - * - * Return: true if resource group can be exclusive, false if there is overlap - * with allocations of other resource groups and thus this resource group - * cannot be exclusive. - */ -static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp) -{ - int closid = rdtgrp->closid; - struct resctrl_schema *s; - struct rdt_resource *r; - bool has_cache = false; - struct rdt_domain *d; - u32 ctrl; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA) - continue; - has_cache = true; - list_for_each_entry(d, &r->domains, list) { - ctrl = resctrl_arch_get_config(r, d, closid, - s->conf_type); - if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) { - rdt_last_cmd_puts("Schemata overlaps\n"); - return false; - } - } - } - - if (!has_cache) { - rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n"); - return false; - } - - return true; -} - -/* - * rdtgroup_mode_write - Modify the resource group's mode - */ -static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct rdtgroup *rdtgrp; - enum rdtgrp_mode mode; - int ret = 0; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - buf[nbytes - 1] = '\0'; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - - rdt_last_cmd_clear(); - - mode = rdtgrp->mode; - - if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) || - (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) || - (!strcmp(buf, "pseudo-locksetup") && - mode == RDT_MODE_PSEUDO_LOCKSETUP) || - (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED)) - goto out; - - if (mode == RDT_MODE_PSEUDO_LOCKED) { - rdt_last_cmd_puts("Cannot change pseudo-locked group\n"); - ret = -EINVAL; - goto out; - } - - if (!strcmp(buf, "shareable")) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = rdtgroup_locksetup_exit(rdtgrp); - if (ret) - goto out; - } - rdtgrp->mode = RDT_MODE_SHAREABLE; - } else if (!strcmp(buf, "exclusive")) { - if (!rdtgroup_mode_test_exclusive(rdtgrp)) { - ret = -EINVAL; - goto out; - } - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - ret = rdtgroup_locksetup_exit(rdtgrp); - if (ret) - goto out; - } - rdtgrp->mode = RDT_MODE_EXCLUSIVE; - } else if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) && - !strcmp(buf, "pseudo-locksetup")) { - ret = rdtgroup_locksetup_enter(rdtgrp); - if (ret) - goto out; - rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP; - } else { - rdt_last_cmd_puts("Unknown or unsupported mode\n"); - ret = -EINVAL; - } - -out: - rdtgroup_kn_unlock(of->kn); - return ret ?: nbytes; -} - -/** - * rdtgroup_cbm_to_size - Translate CBM to size in bytes - * @r: RDT resource to which @d belongs. - * @d: RDT domain instance. - * @cbm: bitmask for which the size should be computed. - * - * The bitmask provided associated with the RDT domain instance @d will be - * translated into how many bytes it represents. The size in bytes is - * computed by first dividing the total cache size by the CBM length to - * determine how many bytes each bit in the bitmask represents. The result - * is multiplied with the number of bits set in the bitmask. - * - * @cbm is unsigned long, even if only 32 bits are used to make the - * bitmap functions work correctly. - */ -unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, - struct rdt_domain *d, unsigned long cbm) -{ - struct cpu_cacheinfo *ci; - unsigned int size = 0; - int num_b, i; - - num_b = bitmap_weight(&cbm, r->cache.cbm_len); - ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask)); - for (i = 0; i < ci->num_leaves; i++) { - if (ci->info_list[i].level == r->cache_level) { - size = ci->info_list[i].size / r->cache.cbm_len * num_b; - break; - } - } - - return size; -} - -/* - * rdtgroup_size_show - Display size in bytes of allocated regions - * - * The "size" file mirrors the layout of the "schemata" file, printing the - * size in bytes of each region instead of the capacity bitmask. - */ -static int rdtgroup_size_show(struct kernfs_open_file *of, - struct seq_file *s, void *v) -{ - struct resctrl_schema *schema; - enum resctrl_conf_type type; - struct rdtgroup *rdtgrp; - struct rdt_resource *r; - struct rdt_domain *d; - unsigned int size; - int ret = 0; - u32 closid; - bool sep; - u32 ctrl; - - rdtgrp = rdtgroup_kn_lock_live(of->kn); - if (!rdtgrp) { - rdtgroup_kn_unlock(of->kn); - return -ENOENT; - } - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - if (!rdtgrp->plr->d) { - rdt_last_cmd_clear(); - rdt_last_cmd_puts("Cache domain offline\n"); - ret = -ENODEV; - } else { - seq_printf(s, "%*s:", max_name_width, - rdtgrp->plr->s->name); - size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res, - rdtgrp->plr->d, - rdtgrp->plr->cbm); - seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size); - } - goto out; - } - - closid = rdtgrp->closid; - - list_for_each_entry(schema, &resctrl_schema_all, list) { - r = schema->res; - type = schema->conf_type; - sep = false; - seq_printf(s, "%*s:", max_name_width, schema->name); - list_for_each_entry(d, &r->domains, list) { - if (sep) - seq_putc(s, ';'); - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { - size = 0; - } else { - if (is_mba_sc(r)) - ctrl = d->mbps_val[closid]; - else - ctrl = resctrl_arch_get_config(r, d, - closid, - type); - if (r->rid == RDT_RESOURCE_MBA || - r->rid == RDT_RESOURCE_SMBA) - size = ctrl; - else - size = rdtgroup_cbm_to_size(r, d, ctrl); - } - seq_printf(s, "%d=%u", d->id, size); - sep = true; - } - seq_putc(s, '\n'); - } - -out: - rdtgroup_kn_unlock(of->kn); - - return ret; -} - -#define INVALID_CONFIG_INDEX UINT_MAX - -/** - * mon_event_config_index_get - get the hardware index for the - * configurable event - * @evtid: event id. - * - * Return: 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID - * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID - * INVALID_CONFIG_INDEX for invalid evtid - */ -static inline unsigned int mon_event_config_index_get(u32 evtid) -{ - switch (evtid) { - case QOS_L3_MBM_TOTAL_EVENT_ID: - return 0; - case QOS_L3_MBM_LOCAL_EVENT_ID: - return 1; - default: - /* Should never reach here */ - return INVALID_CONFIG_INDEX; - } -} - -void resctrl_arch_mon_event_config_read(void *info) -{ - struct resctrl_mon_config_info *mon_info = info; - unsigned int index; - u64 msrval; - - index = mon_event_config_index_get(mon_info->evtid); - if (index == INVALID_CONFIG_INDEX) { - pr_warn_once("Invalid event id %d\n", mon_info->evtid); - return; - } - rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval); - - /* Report only the valid event configuration bits */ - mon_info->mon_config = msrval & MAX_EVT_CONFIG_BITS; -} - -static void mondata_config_read(struct resctrl_mon_config_info *mon_info) -{ - smp_call_function_any(&mon_info->d->cpu_mask, - resctrl_arch_mon_event_config_read, mon_info, 1); -} - -static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid) -{ - struct resctrl_mon_config_info mon_info = {0}; - struct rdt_domain *dom; - bool sep = false; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - list_for_each_entry(dom, &r->domains, list) { - if (sep) - seq_puts(s, ";"); - - memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info)); - mon_info.r = r; - mon_info.d = dom; - mon_info.evtid = evtid; - mondata_config_read(&mon_info); - - seq_printf(s, "%d=0x%02x", dom->id, mon_info.mon_config); - sep = true; - } - seq_puts(s, "\n"); - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - return 0; -} - -static int mbm_total_bytes_config_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = of->kn->parent->priv; - - mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID); - - return 0; -} - -static int mbm_local_bytes_config_show(struct kernfs_open_file *of, - struct seq_file *seq, void *v) -{ - struct rdt_resource *r = of->kn->parent->priv; - - mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID); - - return 0; -} - -void resctrl_arch_mon_event_config_write(void *info) -{ - struct resctrl_mon_config_info *mon_info = info; - unsigned int index; - - index = mon_event_config_index_get(mon_info->evtid); - if (index == INVALID_CONFIG_INDEX) { - pr_warn_once("Invalid event id %d\n", mon_info->evtid); - mon_info->err = -EINVAL; - return; - } - wrmsr(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config, 0); - - mon_info->err = 0; -} - -static int mbm_config_write_domain(struct rdt_resource *r, - struct rdt_domain *d, u32 evtid, u32 val) -{ - struct resctrl_mon_config_info mon_info = {0}; - - /* mon_config cannot be more than the supported set of events */ - if (val > MAX_EVT_CONFIG_BITS) { - rdt_last_cmd_puts("Invalid event configuration\n"); - return -EINVAL; - } - - /* - * Read the current config value first. If both are the same then - * no need to write it again. - */ - mon_info.r = r; - mon_info.d = d; - mon_info.evtid = evtid; - mondata_config_read(&mon_info); - if (mon_info.mon_config == val) - goto out; - - mon_info.mon_config = val; - - /* - * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the - * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE - * are scoped at the domain level. Writing any of these MSRs - * on one CPU is observed by all the CPUs in the domain. - */ - smp_call_function_any(&d->cpu_mask, resctrl_arch_mon_event_config_write, - &mon_info, 1); - if (mon_info.err) { - rdt_last_cmd_puts("Invalid event configuration\n"); - goto out; - } - - /* - * When an Event Configuration is changed, the bandwidth counters - * for all RMIDs and Events will be cleared by the hardware. The - * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for - * every RMID on the next read to any event for every RMID. - * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62) - * cleared while it is tracked by the hardware. Clear the - * mbm_local and mbm_total counts for all the RMIDs. - */ - resctrl_arch_reset_rmid_all(r, d); - -out: - return mon_info.err; -} - -static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid) -{ - char *dom_str = NULL, *id_str; - unsigned long dom_id, val; - struct rdt_domain *d; - int ret = 0; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - -next: - if (!tok || tok[0] == '\0') - return 0; - - /* Start processing the strings for each domain */ - dom_str = strim(strsep(&tok, ";")); - id_str = strsep(&dom_str, "="); - - if (!id_str || kstrtoul(id_str, 10, &dom_id)) { - rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n"); - return -EINVAL; - } - - if (!dom_str || kstrtoul(dom_str, 16, &val)) { - rdt_last_cmd_puts("Non-numeric event configuration value\n"); - return -EINVAL; - } - - list_for_each_entry(d, &r->domains, list) { - if (d->id == dom_id) { - ret = mbm_config_write_domain(r, d, evtid, val); - if (ret) - return -EINVAL; - goto next; - } - } - - return -EINVAL; -} - -static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, - loff_t off) -{ - struct rdt_resource *r = of->kn->parent->priv; - int ret; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - rdt_last_cmd_clear(); - - buf[nbytes - 1] = '\0'; - - ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID); - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - return ret ?: nbytes; -} - -static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, - loff_t off) -{ - struct rdt_resource *r = of->kn->parent->priv; - int ret; - - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') - return -EINVAL; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - rdt_last_cmd_clear(); - - buf[nbytes - 1] = '\0'; - - ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID); - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - return ret ?: nbytes; -} - -/* rdtgroup information files for one cache resource. */ -static struct rftype res_common_files[] = { - { - .name = "last_cmd_status", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_last_cmd_status_show, - .fflags = RFTYPE_TOP_INFO, - }, - { - .name = "num_closids", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_num_closids_show, - .fflags = RFTYPE_CTRL_INFO, - }, - { - .name = "mon_features", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_mon_features_show, - .fflags = RFTYPE_MON_INFO, - }, - { - .name = "num_rmids", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_num_rmids_show, - .fflags = RFTYPE_MON_INFO, - }, - { - .name = "cbm_mask", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_default_ctrl_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "min_cbm_bits", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_min_cbm_bits_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "shareable_bits", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_shareable_bits_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "bit_usage", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_bit_usage_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "min_bandwidth", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_min_bw_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, - }, - { - .name = "bandwidth_gran", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_bw_gran_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, - }, - { - .name = "delay_linear", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_delay_linear_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, - }, - /* - * Platform specific which (if any) capabilities are provided by - * thread_throttle_mode. Defer "fflags" initialization to platform - * discovery. - */ - { - .name = "thread_throttle_mode", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_thread_throttle_mode_show, - }, - { - .name = "max_threshold_occupancy", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = max_threshold_occ_write, - .seq_show = max_threshold_occ_show, - .fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "mbm_total_bytes_config", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = mbm_total_bytes_config_show, - .write = mbm_total_bytes_config_write, - }, - { - .name = "mbm_local_bytes_config", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = mbm_local_bytes_config_show, - .write = mbm_local_bytes_config_write, - }, - { - .name = "cpus", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_cpus_write, - .seq_show = rdtgroup_cpus_show, - .fflags = RFTYPE_BASE, - }, - { - .name = "cpus_list", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_cpus_write, - .seq_show = rdtgroup_cpus_show, - .flags = RFTYPE_FLAGS_CPUS_LIST, - .fflags = RFTYPE_BASE, - }, - { - .name = "tasks", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_tasks_write, - .seq_show = rdtgroup_tasks_show, - .fflags = RFTYPE_BASE, - }, - { - .name = "mon_hw_id", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdtgroup_rmid_show, - .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG, - }, - { - .name = "schemata", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_schemata_write, - .seq_show = rdtgroup_schemata_show, - .fflags = RFTYPE_CTRL_BASE, - }, - { - .name = "mode", - .mode = 0644, - .kf_ops = &rdtgroup_kf_single_ops, - .write = rdtgroup_mode_write, - .seq_show = rdtgroup_mode_show, - .fflags = RFTYPE_CTRL_BASE, - }, - { - .name = "size", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdtgroup_size_show, - .fflags = RFTYPE_CTRL_BASE, - }, - { - .name = "sparse_masks", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdt_has_sparse_bitmasks_show, - .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, - }, - { - .name = "ctrl_hw_id", - .mode = 0444, - .kf_ops = &rdtgroup_kf_single_ops, - .seq_show = rdtgroup_closid_show, - .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG, - }, - -}; - -static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags) -{ - struct rftype *rfts, *rft; - int ret, len; - - rfts = res_common_files; - len = ARRAY_SIZE(res_common_files); - - lockdep_assert_held(&rdtgroup_mutex); - - if (resctrl_debug) - fflags |= RFTYPE_DEBUG; - - for (rft = rfts; rft < rfts + len; rft++) { - if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) { - ret = rdtgroup_add_file(kn, rft); - if (ret) - goto error; - } - } - - return 0; -error: - pr_warn("Failed to add %s, err=%d\n", rft->name, ret); - while (--rft >= rfts) { - if ((fflags & rft->fflags) == rft->fflags) - kernfs_remove_by_name(kn, rft->name); - } - return ret; -} - -static struct rftype *rdtgroup_get_rftype_by_name(const char *name) -{ - struct rftype *rfts, *rft; - int len; - - rfts = res_common_files; - len = ARRAY_SIZE(res_common_files); - - for (rft = rfts; rft < rfts + len; rft++) { - if (!strcmp(rft->name, name)) - return rft; - } - - return NULL; -} - -static void thread_throttle_mode_init(void) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - struct rftype *rft; - - if (!r->alloc_capable || - r->membw.throttle_mode == THREAD_THROTTLE_UNDEFINED) - return; - - rft = rdtgroup_get_rftype_by_name("thread_throttle_mode"); - if (!rft) - return; - - rft->fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB; -} - -void mbm_config_rftype_init(const char *config) -{ - struct rftype *rft; - - rft = rdtgroup_get_rftype_by_name(config); - if (rft) - rft->fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE; -} - -/** - * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file - * @r: The resource group with which the file is associated. - * @name: Name of the file - * - * The permissions of named resctrl file, directory, or link are modified - * to not allow read, write, or execute by any user. - * - * WARNING: This function is intended to communicate to the user that the - * resctrl file has been locked down - that it is not relevant to the - * particular state the system finds itself in. It should not be relied - * on to protect from user access because after the file's permissions - * are restricted the user can still change the permissions using chmod - * from the command line. - * - * Return: 0 on success, <0 on failure. - */ -int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name) -{ - struct iattr iattr = {.ia_valid = ATTR_MODE,}; - struct kernfs_node *kn; - int ret = 0; - - kn = kernfs_find_and_get_ns(r->kn, name, NULL); - if (!kn) - return -ENOENT; - - switch (kernfs_type(kn)) { - case KERNFS_DIR: - iattr.ia_mode = S_IFDIR; - break; - case KERNFS_FILE: - iattr.ia_mode = S_IFREG; - break; - case KERNFS_LINK: - iattr.ia_mode = S_IFLNK; - break; - } - - ret = kernfs_setattr(kn, &iattr); - kernfs_put(kn); - return ret; -} - -/** - * rdtgroup_kn_mode_restore - Restore user access to named resctrl file - * @r: The resource group with which the file is associated. - * @name: Name of the file - * @mask: Mask of permissions that should be restored - * - * Restore the permissions of the named file. If @name is a directory the - * permissions of its parent will be used. - * - * Return: 0 on success, <0 on failure. - */ -int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, - umode_t mask) -{ - struct iattr iattr = {.ia_valid = ATTR_MODE,}; - struct kernfs_node *kn, *parent; - struct rftype *rfts, *rft; - int ret, len; - - rfts = res_common_files; - len = ARRAY_SIZE(res_common_files); - - for (rft = rfts; rft < rfts + len; rft++) { - if (!strcmp(rft->name, name)) - iattr.ia_mode = rft->mode & mask; - } - - kn = kernfs_find_and_get_ns(r->kn, name, NULL); - if (!kn) - return -ENOENT; - - switch (kernfs_type(kn)) { - case KERNFS_DIR: - parent = kernfs_get_parent(kn); - if (parent) { - iattr.ia_mode |= parent->mode; - kernfs_put(parent); - } - iattr.ia_mode |= S_IFDIR; - break; - case KERNFS_FILE: - iattr.ia_mode |= S_IFREG; - break; - case KERNFS_LINK: - iattr.ia_mode |= S_IFLNK; - break; - } - - ret = kernfs_setattr(kn, &iattr); - kernfs_put(kn); - return ret; -} - -static int rdtgroup_mkdir_info_resdir(void *priv, char *name, - unsigned long fflags) -{ - struct kernfs_node *kn_subdir; - int ret; - - kn_subdir = kernfs_create_dir(kn_info, name, - kn_info->mode, priv); - if (IS_ERR(kn_subdir)) - return PTR_ERR(kn_subdir); - - ret = rdtgroup_kn_set_ugid(kn_subdir); - if (ret) - return ret; - - ret = rdtgroup_add_files(kn_subdir, fflags); - if (!ret) - kernfs_activate(kn_subdir); - - return ret; -} - -static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn) -{ - enum resctrl_res_level i; - struct resctrl_schema *s; - struct rdt_resource *r; - unsigned long fflags; - char name[32]; - int ret; - - /* create the directory */ - kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL); - if (IS_ERR(kn_info)) - return PTR_ERR(kn_info); - - ret = rdtgroup_add_files(kn_info, RFTYPE_TOP_INFO); - if (ret) - goto out_destroy; - - /* loop over enabled controls, these are all alloc_capable */ - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - fflags = r->fflags | RFTYPE_CTRL_INFO; - ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags); - if (ret) - goto out_destroy; - } - - for (i = 0; i < RDT_NUM_RESOURCES; i++) { - r = resctrl_arch_get_resource(i); - if (!r->mon_capable) - continue; - - fflags = r->fflags | RFTYPE_MON_INFO; - sprintf(name, "%s_MON", r->name); - ret = rdtgroup_mkdir_info_resdir(r, name, fflags); - if (ret) - goto out_destroy; - } - - ret = rdtgroup_kn_set_ugid(kn_info); - if (ret) - goto out_destroy; - - kernfs_activate(kn_info); - - return 0; - -out_destroy: - kernfs_remove(kn_info); - return ret; -} - -static int -mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp, - char *name, struct kernfs_node **dest_kn) -{ - struct kernfs_node *kn; - int ret; - - /* create the directory */ - kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); - if (IS_ERR(kn)) - return PTR_ERR(kn); - - if (dest_kn) - *dest_kn = kn; - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) - goto out_destroy; - - kernfs_activate(kn); - - return 0; - -out_destroy: - kernfs_remove(kn); - return ret; -} - -static void l3_qos_cfg_update(void *arg) -{ - bool *enable = arg; - - wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL); -} - -static void l2_qos_cfg_update(void *arg) -{ - bool *enable = arg; - - wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL); -} - -static inline bool is_mba_linear(void) -{ - return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear; -} - -static int set_cache_qos_cfg(int level, bool enable) -{ - void (*update)(void *arg); - struct rdt_resource *r_l; - cpumask_var_t cpu_mask; - struct rdt_domain *d; - int cpu; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - if (level == RDT_RESOURCE_L3) - update = l3_qos_cfg_update; - else if (level == RDT_RESOURCE_L2) - update = l2_qos_cfg_update; - else - return -EINVAL; - - if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) - return -ENOMEM; - - r_l = &rdt_resources_all[level].r_resctrl; - list_for_each_entry(d, &r_l->domains, list) { - if (r_l->cache.arch_has_per_cpu_cfg) - /* Pick all the CPUs in the domain instance */ - for_each_cpu(cpu, &d->cpu_mask) - cpumask_set_cpu(cpu, cpu_mask); - else - /* Pick one CPU from each domain instance to update MSR */ - cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); - } - - /* Update QOS_CFG MSR on all the CPUs in cpu_mask */ - on_each_cpu_mask(cpu_mask, update, &enable, 1); - - free_cpumask_var(cpu_mask); - - return 0; -} - -/* Restore the qos cfg state when a domain comes online */ -void rdt_domain_reconfigure_cdp(struct rdt_resource *r) -{ - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); - - if (!r->cdp_capable) - return; - - if (r->rid == RDT_RESOURCE_L2) - l2_qos_cfg_update(&hw_res->cdp_enabled); - - if (r->rid == RDT_RESOURCE_L3) - l3_qos_cfg_update(&hw_res->cdp_enabled); -} - -static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_domain *d) -{ - u32 num_closid = resctrl_arch_get_num_closid(r); - int cpu = cpumask_any(&d->cpu_mask); - int i; - - d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val), - GFP_KERNEL, cpu_to_node(cpu)); - if (!d->mbps_val) - return -ENOMEM; - - for (i = 0; i < num_closid; i++) - d->mbps_val[i] = MBA_MAX_MBPS; - - return 0; -} - -static void mba_sc_domain_destroy(struct rdt_resource *r, - struct rdt_domain *d) -{ - kfree(d->mbps_val); - d->mbps_val = NULL; -} - -/* - * MBA software controller is supported only if - * MBM is supported and MBA is in linear scale. - */ -static bool supports_mba_mbps(void) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - - return (resctrl_arch_is_mbm_local_enabled() && - r->alloc_capable && is_mba_linear()); -} - -/* - * Enable or disable the MBA software controller - * which helps user specify bandwidth in MBps. - */ -static int set_mba_sc(bool mba_sc) -{ - struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); - u32 num_closid = resctrl_arch_get_num_closid(r); - struct rdt_domain *d; - int i; - - if (!supports_mba_mbps() || mba_sc == is_mba_sc(r)) - return -EINVAL; - - r->membw.mba_sc = mba_sc; - - list_for_each_entry(d, &r->domains, list) { - for (i = 0; i < num_closid; i++) - d->mbps_val[i] = MBA_MAX_MBPS; - } - - return 0; -} - -static int cdp_enable(int level) -{ - struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl; - int ret; - - if (!r_l->alloc_capable) - return -EINVAL; - - ret = set_cache_qos_cfg(level, true); - if (!ret) - rdt_resources_all[level].cdp_enabled = true; - - return ret; -} - -static void cdp_disable(int level) -{ - struct rdt_hw_resource *r_hw = &rdt_resources_all[level]; - - if (r_hw->cdp_enabled) { - set_cache_qos_cfg(level, false); - r_hw->cdp_enabled = false; - } -} - -int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable) -{ - struct rdt_hw_resource *hw_res = &rdt_resources_all[l]; - - if (!hw_res->r_resctrl.cdp_capable) - return -EINVAL; - - if (enable) - return cdp_enable(l); - - cdp_disable(l); - - return 0; -} - -/* - * We don't allow rdtgroup directories to be created anywhere - * except the root directory. Thus when looking for the rdtgroup - * structure for a kernfs node we are either looking at a directory, - * in which case the rdtgroup structure is pointed at by the "priv" - * field, otherwise we have a file, and need only look to the parent - * to find the rdtgroup. - */ -static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn) -{ - if (kernfs_type(kn) == KERNFS_DIR) { - /* - * All the resource directories use "kn->priv" - * to point to the "struct rdtgroup" for the - * resource. "info" and its subdirectories don't - * have rdtgroup structures, so return NULL here. - */ - if (kn == kn_info || kn->parent == kn_info) - return NULL; - else - return kn->priv; - } else { - return kn->parent->priv; - } -} - -static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *kn) -{ - atomic_inc(&rdtgrp->waitcount); - kernfs_break_active_protection(kn); -} - -static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *kn) -{ - if (atomic_dec_and_test(&rdtgrp->waitcount) && - (rdtgrp->flags & RDT_DELETED)) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) - rdtgroup_pseudo_lock_remove(rdtgrp); - kernfs_unbreak_active_protection(kn); - rdtgroup_remove(rdtgrp); - } else { - kernfs_unbreak_active_protection(kn); - } -} - -struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn) -{ - struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); - - if (!rdtgrp) - return NULL; - - rdtgroup_kn_get(rdtgrp, kn); - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - /* Was this group deleted while we waited? */ - if (rdtgrp->flags & RDT_DELETED) - return NULL; - - return rdtgrp; -} - -void rdtgroup_kn_unlock(struct kernfs_node *kn) -{ - struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); - - if (!rdtgrp) - return; - - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - - rdtgroup_kn_put(rdtgrp, kn); -} - -static int mkdir_mondata_all(struct kernfs_node *parent_kn, - struct rdtgroup *prgrp, - struct kernfs_node **mon_data_kn); - -static void rdt_disable_ctx(void) -{ - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); - set_mba_sc(false); - - resctrl_debug = false; -} - -static int rdt_enable_ctx(struct rdt_fs_context *ctx) -{ - int ret = 0; - - if (ctx->enable_cdpl2) { - ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true); - if (ret) - goto out_done; - } - - if (ctx->enable_cdpl3) { - ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true); - if (ret) - goto out_cdpl2; - } - - if (ctx->enable_mba_mbps) { - ret = set_mba_sc(true); - if (ret) - goto out_cdpl3; - } - - if (ctx->enable_debug) - resctrl_debug = true; - - return 0; - -out_cdpl3: - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); -out_cdpl2: - resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); -out_done: - return ret; -} - -static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type) -{ - struct resctrl_schema *s; - const char *suffix = ""; - int ret, cl; - - s = kzalloc(sizeof(*s), GFP_KERNEL); - if (!s) - return -ENOMEM; - - s->res = r; - s->num_closid = resctrl_arch_get_num_closid(r); - if (resctrl_arch_get_cdp_enabled(r->rid)) - s->num_closid /= 2; - - s->conf_type = type; - switch (type) { - case CDP_CODE: - suffix = "CODE"; - break; - case CDP_DATA: - suffix = "DATA"; - break; - case CDP_NONE: - suffix = ""; - break; - } - - ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix); - if (ret >= sizeof(s->name)) { - kfree(s); - return -EINVAL; - } - - cl = strlen(s->name); - - /* - * If CDP is supported by this resource, but not enabled, - * include the suffix. This ensures the tabular format of the - * schemata file does not change between mounts of the filesystem. - */ - if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid)) - cl += 4; - - if (cl > max_name_width) - max_name_width = cl; - - /* - * Choose a width for the resource data based on the resource that has - * widest name and cbm. - */ - max_data_width = max(max_data_width, r->data_width); - - INIT_LIST_HEAD(&s->list); - list_add(&s->list, &resctrl_schema_all); - - return 0; -} - -static int schemata_list_create(void) -{ - enum resctrl_res_level i; - struct rdt_resource *r; - int ret = 0; - - for (i = 0; i < RDT_NUM_RESOURCES; i++) { - r = resctrl_arch_get_resource(i); - if (!r->alloc_capable) - continue; - - if (resctrl_arch_get_cdp_enabled(r->rid)) { - ret = schemata_list_add(r, CDP_CODE); - if (ret) - break; - - ret = schemata_list_add(r, CDP_DATA); - } else { - ret = schemata_list_add(r, CDP_NONE); - } - - if (ret) - break; - } - - return ret; -} - -static void schemata_list_destroy(void) -{ - struct resctrl_schema *s, *tmp; - - list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) { - list_del(&s->list); - kfree(s); - } -} - -static int rdt_get_tree(struct fs_context *fc) -{ - struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3); - struct rdt_fs_context *ctx = rdt_fc2context(fc); - unsigned long flags = RFTYPE_CTRL_BASE; - struct rdt_domain *dom; - int ret; - - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - /* - * resctrl file system can only be mounted once. - */ - if (resctrl_mounted) { - ret = -EBUSY; - goto out; - } - - ret = rdtgroup_setup_root(ctx); - if (ret) - goto out; - - ret = rdt_enable_ctx(ctx); - if (ret) - goto out_root; - - ret = schemata_list_create(); - if (ret) { - schemata_list_destroy(); - goto out_ctx; - } - - closid_init(); - - if (resctrl_arch_mon_capable()) - flags |= RFTYPE_MON; - - ret = rdtgroup_add_files(rdtgroup_default.kn, flags); - if (ret) - goto out_schemata_free; - - kernfs_activate(rdtgroup_default.kn); - - ret = rdtgroup_create_info_dir(rdtgroup_default.kn); - if (ret < 0) - goto out_schemata_free; - - if (resctrl_arch_mon_capable()) { - ret = mongroup_create_dir(rdtgroup_default.kn, - &rdtgroup_default, "mon_groups", - &kn_mongrp); - if (ret < 0) - goto out_info; - - ret = mkdir_mondata_all(rdtgroup_default.kn, - &rdtgroup_default, &kn_mondata); - if (ret < 0) - goto out_mongrp; - rdtgroup_default.mon.mon_data_kn = kn_mondata; - } - - if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) { - ret = rdt_pseudo_lock_init(); - if (ret) - goto out_mondata; - } - - ret = kernfs_get_tree(fc); - if (ret < 0) - goto out_psl; - - if (resctrl_arch_alloc_capable()) - resctrl_arch_enable_alloc(); - if (resctrl_arch_mon_capable()) - resctrl_arch_enable_mon(); - - if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable()) - resctrl_mounted = true; - - if (resctrl_is_mbm_enabled()) { - list_for_each_entry(dom, &l3->domains, list) - mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL, - RESCTRL_PICK_ANY_CPU); - } - - goto out; - -out_psl: - if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) - rdt_pseudo_lock_release(); -out_mondata: - if (resctrl_arch_mon_capable()) - kernfs_remove(kn_mondata); -out_mongrp: - if (resctrl_arch_mon_capable()) - kernfs_remove(kn_mongrp); -out_info: - kernfs_remove(kn_info); -out_schemata_free: - schemata_list_destroy(); -out_ctx: - rdt_disable_ctx(); -out_root: - rdtgroup_destroy_root(); -out: - rdt_last_cmd_clear(); - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); - return ret; -} - -enum rdt_param { - Opt_cdp, - Opt_cdpl2, - Opt_mba_mbps, - Opt_debug, - nr__rdt_params -}; - -static const struct fs_parameter_spec rdt_fs_parameters[] = { - fsparam_flag("cdp", Opt_cdp), - fsparam_flag("cdpl2", Opt_cdpl2), - fsparam_flag("mba_MBps", Opt_mba_mbps), - fsparam_flag("debug", Opt_debug), - {} -}; - -static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) -{ - struct rdt_fs_context *ctx = rdt_fc2context(fc); - struct fs_parse_result result; - int opt; - - opt = fs_parse(fc, rdt_fs_parameters, param, &result); - if (opt < 0) - return opt; - - switch (opt) { - case Opt_cdp: - ctx->enable_cdpl3 = true; - return 0; - case Opt_cdpl2: - ctx->enable_cdpl2 = true; - return 0; - case Opt_mba_mbps: - if (!supports_mba_mbps()) - return -EINVAL; - ctx->enable_mba_mbps = true; - return 0; - case Opt_debug: - ctx->enable_debug = true; - return 0; - } - - return -EINVAL; -} - -static void rdt_fs_context_free(struct fs_context *fc) -{ - struct rdt_fs_context *ctx = rdt_fc2context(fc); - - kernfs_free_fs_context(fc); - kfree(ctx); -} - -static const struct fs_context_operations rdt_fs_context_ops = { - .free = rdt_fs_context_free, - .parse_param = rdt_parse_param, - .get_tree = rdt_get_tree, -}; - -static int rdt_init_fs_context(struct fs_context *fc) -{ - struct rdt_fs_context *ctx; - - ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL); - if (!ctx) - return -ENOMEM; - - ctx->kfc.magic = RDTGROUP_SUPER_MAGIC; - fc->fs_private = &ctx->kfc; - fc->ops = &rdt_fs_context_ops; - put_user_ns(fc->user_ns); - fc->user_ns = get_user_ns(&init_user_ns); - fc->global = true; - return 0; -} - -static int reset_all_ctrls(struct rdt_resource *r) -{ - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); - struct rdt_hw_domain *hw_dom; - struct msr_param msr_param; - cpumask_var_t cpu_mask; - struct rdt_domain *d; - int i; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) - return -ENOMEM; - - msr_param.res = r; - msr_param.low = 0; - msr_param.high = hw_res->num_closid; - - /* - * Disable resource control for this resource by setting all - * CBMs in all domains to the maximum mask value. Pick one CPU - * from each domain to update the MSRs below. - */ - list_for_each_entry(d, &r->domains, list) { - hw_dom = resctrl_to_arch_dom(d); - cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); - - for (i = 0; i < hw_res->num_closid; i++) - hw_dom->ctrl_val[i] = r->default_ctrl; - } - - /* Update CBM on all the CPUs in cpu_mask */ - on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1); - - free_cpumask_var(cpu_mask); - - return 0; -} - -void resctrl_arch_reset_resources(void) -{ - struct rdt_resource *r; - - for_each_capable_rdt_resource(r) - reset_all_ctrls(r); -} - -/* - * Move tasks from one to the other group. If @from is NULL, then all tasks - * in the systems are moved unconditionally (used for teardown). - * - * If @mask is not NULL the cpus on which moved tasks are running are set - * in that mask so the update smp function call is restricted to affected - * cpus. - */ -static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, - struct cpumask *mask) -{ - struct task_struct *p, *t; - - read_lock(&tasklist_lock); - for_each_process_thread(p, t) { - if (!from || is_closid_match(t, from) || - is_rmid_match(t, from)) { - resctrl_arch_set_closid_rmid(t, to->closid, - to->mon.rmid); - - /* - * Order the closid/rmid stores above before the loads - * in task_curr(). This pairs with the full barrier - * between the rq->curr update and resctrl_sched_in() - * during context switch. - */ - smp_mb(); - - /* - * If the task is on a CPU, set the CPU in the mask. - * The detection is inaccurate as tasks might move or - * schedule before the smp function call takes place. - * In such a case the function call is pointless, but - * there is no other side effect. - */ - if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t)) - cpumask_set_cpu(task_cpu(t), mask); - } - } - read_unlock(&tasklist_lock); -} - -static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp) -{ - struct rdtgroup *sentry, *stmp; - struct list_head *head; - - head = &rdtgrp->mon.crdtgrp_list; - list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) { - free_rmid(sentry->closid, sentry->mon.rmid); - list_del(&sentry->mon.crdtgrp_list); - - if (atomic_read(&sentry->waitcount) != 0) - sentry->flags = RDT_DELETED; - else - rdtgroup_remove(sentry); - } -} - -/* - * Forcibly remove all of subdirectories under root. - */ -static void rmdir_all_sub(void) -{ - struct rdtgroup *rdtgrp, *tmp; - - /* Move all tasks to the default resource group */ - rdt_move_group_tasks(NULL, &rdtgroup_default, NULL); - - list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) { - /* Free any child rmids */ - free_all_child_rdtgrp(rdtgrp); - - /* Remove each rdtgroup other than root */ - if (rdtgrp == &rdtgroup_default) - continue; - - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) - rdtgroup_pseudo_lock_remove(rdtgrp); - - /* - * Give any CPUs back to the default group. We cannot copy - * cpu_online_mask because a CPU might have executed the - * offline callback already, but is still marked online. - */ - cpumask_or(&rdtgroup_default.cpu_mask, - &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); - - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - - kernfs_remove(rdtgrp->kn); - list_del(&rdtgrp->rdtgroup_list); - - if (atomic_read(&rdtgrp->waitcount) != 0) - rdtgrp->flags = RDT_DELETED; - else - rdtgroup_remove(rdtgrp); - } - /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */ - update_closid_rmid(cpu_online_mask, &rdtgroup_default); - - kernfs_remove(kn_info); - kernfs_remove(kn_mongrp); - kernfs_remove(kn_mondata); -} - -static void rdt_kill_sb(struct super_block *sb) -{ - cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - rdt_disable_ctx(); - - /* Put everything back to default values. */ - resctrl_arch_reset_resources(); - - rmdir_all_sub(); - if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) - rdt_pseudo_lock_release(); - rdtgroup_default.mode = RDT_MODE_SHAREABLE; - schemata_list_destroy(); - rdtgroup_destroy_root(); - if (resctrl_arch_alloc_capable()) - resctrl_arch_disable_alloc(); - if (resctrl_arch_mon_capable()) - resctrl_arch_disable_mon(); - resctrl_mounted = false; - kernfs_kill_sb(sb); - mutex_unlock(&rdtgroup_mutex); - cpus_read_unlock(); -} - -static struct file_system_type rdt_fs_type = { - .name = "resctrl", - .init_fs_context = rdt_init_fs_context, - .parameters = rdt_fs_parameters, - .kill_sb = rdt_kill_sb, -}; - -static int mon_addfile(struct kernfs_node *parent_kn, const char *name, - void *priv) -{ - struct kernfs_node *kn; - int ret = 0; - - kn = __kernfs_create_file(parent_kn, name, 0444, - GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0, - &kf_mondata_ops, priv, NULL, NULL); - if (IS_ERR(kn)) - return PTR_ERR(kn); - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) { - kernfs_remove(kn); - return ret; - } - - return ret; -} - -/* - * Remove all subdirectories of mon_data of ctrl_mon groups - * and monitor groups with given domain id. - */ -static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, - unsigned int dom_id) -{ - struct rdtgroup *prgrp, *crgrp; - char name[32]; - - list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { - sprintf(name, "mon_%s_%02d", r->name, dom_id); - kernfs_remove_by_name(prgrp->mon.mon_data_kn, name); - - list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list) - kernfs_remove_by_name(crgrp->mon.mon_data_kn, name); - } -} - -static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, - struct rdt_domain *d, - struct rdt_resource *r, struct rdtgroup *prgrp) -{ - union mon_data_bits priv; - struct kernfs_node *kn; - struct mon_evt *mevt; - struct rmid_read rr; - char name[32]; - int ret; - - sprintf(name, "mon_%s_%02d", r->name, d->id); - /* create the directory */ - kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); - if (IS_ERR(kn)) - return PTR_ERR(kn); - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) - goto out_destroy; - - if (WARN_ON(list_empty(&r->evt_list))) { - ret = -EPERM; - goto out_destroy; - } - - priv.u.rid = r->rid; - priv.u.domid = d->id; - list_for_each_entry(mevt, &r->evt_list, list) { - priv.u.evtid = mevt->evtid; - ret = mon_addfile(kn, mevt->name, priv.priv); - if (ret) - goto out_destroy; - - if (resctrl_is_mbm_event(mevt->evtid)) - mon_event_read(&rr, r, d, prgrp, mevt->evtid, true); - } - kernfs_activate(kn); - return 0; - -out_destroy: - kernfs_remove(kn); - return ret; -} - -/* - * Add all subdirectories of mon_data for "ctrl_mon" groups - * and "monitor" groups with given domain id. - */ -static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, - struct rdt_domain *d) -{ - struct kernfs_node *parent_kn; - struct rdtgroup *prgrp, *crgrp; - struct list_head *head; - - list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { - parent_kn = prgrp->mon.mon_data_kn; - mkdir_mondata_subdir(parent_kn, d, r, prgrp); - - head = &prgrp->mon.crdtgrp_list; - list_for_each_entry(crgrp, head, mon.crdtgrp_list) { - parent_kn = crgrp->mon.mon_data_kn; - mkdir_mondata_subdir(parent_kn, d, r, crgrp); - } - } -} - -static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn, - struct rdt_resource *r, - struct rdtgroup *prgrp) -{ - struct rdt_domain *dom; - int ret; - - /* Walking r->domains, ensure it can't race with cpuhp */ - lockdep_assert_cpus_held(); - - list_for_each_entry(dom, &r->domains, list) { - ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp); - if (ret) - return ret; - } - - return 0; -} - -/* - * This creates a directory mon_data which contains the monitored data. - * - * mon_data has one directory for each domain which are named - * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data - * with L3 domain looks as below: - * ./mon_data: - * mon_L3_00 - * mon_L3_01 - * mon_L3_02 - * ... - * - * Each domain directory has one file per event: - * ./mon_L3_00/: - * llc_occupancy - * - */ -static int mkdir_mondata_all(struct kernfs_node *parent_kn, - struct rdtgroup *prgrp, - struct kernfs_node **dest_kn) -{ - enum resctrl_res_level i; - struct rdt_resource *r; - struct kernfs_node *kn; - int ret; - - /* - * Create the mon_data directory first. - */ - ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn); - if (ret) - return ret; - - if (dest_kn) - *dest_kn = kn; - - /* - * Create the subdirectories for each domain. Note that all events - * in a domain like L3 are grouped into a resource whose domain is L3 - */ - for (i = 0; i < RDT_NUM_RESOURCES; i++) { - r = resctrl_arch_get_resource(i); - if (!r->mon_capable) - continue; - - ret = mkdir_mondata_subdir_alldom(kn, r, prgrp); - if (ret) - goto out_destroy; - } - - return 0; - -out_destroy: - kernfs_remove(kn); - return ret; -} - -/** - * cbm_ensure_valid - Enforce validity on provided CBM - * @_val: Candidate CBM - * @r: RDT resource to which the CBM belongs - * - * The provided CBM represents all cache portions available for use. This - * may be represented by a bitmap that does not consist of contiguous ones - * and thus be an invalid CBM. - * Here the provided CBM is forced to be a valid CBM by only considering - * the first set of contiguous bits as valid and clearing all bits. - * The intention here is to provide a valid default CBM with which a new - * resource group is initialized. The user can follow this with a - * modification to the CBM if the default does not satisfy the - * requirements. - */ -static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r) -{ - unsigned int cbm_len = r->cache.cbm_len; - unsigned long first_bit, zero_bit; - unsigned long val = _val; - - if (!val) - return 0; - - first_bit = find_first_bit(&val, cbm_len); - zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); - - /* Clear any remaining bits to ensure contiguous region */ - bitmap_clear(&val, zero_bit, cbm_len - zero_bit); - return (u32)val; -} - -/* - * Initialize cache resources per RDT domain - * - * Set the RDT domain up to start off with all usable allocations. That is, - * all shareable and unused bits. All-zero CBM is invalid. - */ -static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s, - u32 closid) -{ - enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); - enum resctrl_conf_type t = s->conf_type; - struct resctrl_staged_config *cfg; - struct rdt_resource *r = s->res; - u32 used_b = 0, unused_b = 0; - unsigned long tmp_cbm; - enum rdtgrp_mode mode; - u32 peer_ctl, ctrl_val; - int i; - - cfg = &d->staged_config[t]; - cfg->have_new_ctrl = false; - cfg->new_ctrl = r->cache.shareable_bits; - used_b = r->cache.shareable_bits; - for (i = 0; i < closids_supported(); i++) { - if (closid_allocated(i) && i != closid) { - mode = rdtgroup_mode_by_closid(i); - if (mode == RDT_MODE_PSEUDO_LOCKSETUP) - /* - * ctrl values for locksetup aren't relevant - * until the schemata is written, and the mode - * becomes RDT_MODE_PSEUDO_LOCKED. - */ - continue; - /* - * If CDP is active include peer domain's - * usage to ensure there is no overlap - * with an exclusive group. - */ - if (resctrl_arch_get_cdp_enabled(r->rid)) - peer_ctl = resctrl_arch_get_config(r, d, i, - peer_type); - else - peer_ctl = 0; - ctrl_val = resctrl_arch_get_config(r, d, i, - s->conf_type); - used_b |= ctrl_val | peer_ctl; - if (mode == RDT_MODE_SHAREABLE) - cfg->new_ctrl |= ctrl_val | peer_ctl; - } - } - if (d->plr && d->plr->cbm > 0) - used_b |= d->plr->cbm; - unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1); - unused_b &= BIT_MASK(r->cache.cbm_len) - 1; - cfg->new_ctrl |= unused_b; - /* - * Force the initial CBM to be valid, user can - * modify the CBM based on system availability. - */ - cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r); - /* - * Assign the u32 CBM to an unsigned long to ensure that - * bitmap_weight() does not access out-of-bound memory. - */ - tmp_cbm = cfg->new_ctrl; - if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) { - rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->id); - return -ENOSPC; - } - cfg->have_new_ctrl = true; - - return 0; -} - -/* - * Initialize cache resources with default values. - * - * A new RDT group is being created on an allocation capable (CAT) - * supporting system. Set this group up to start off with all usable - * allocations. - * - * If there are no more shareable bits available on any domain then - * the entire allocation will fail. - */ -static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid) -{ - struct rdt_domain *d; - int ret; - - list_for_each_entry(d, &s->res->domains, list) { - ret = __init_one_rdt_domain(d, s, closid); - if (ret < 0) - return ret; - } - - return 0; -} - -/* Initialize MBA resource with default values. */ -static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid) -{ - struct resctrl_staged_config *cfg; - struct rdt_domain *d; - - list_for_each_entry(d, &r->domains, list) { - if (is_mba_sc(r)) { - d->mbps_val[closid] = MBA_MAX_MBPS; - continue; - } - - cfg = &d->staged_config[CDP_NONE]; - cfg->new_ctrl = r->default_ctrl; - cfg->have_new_ctrl = true; - } -} - -/* Initialize the RDT group's allocations. */ -static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) -{ - struct resctrl_schema *s; - struct rdt_resource *r; - int ret = 0; - - rdt_staged_configs_clear(); - - list_for_each_entry(s, &resctrl_schema_all, list) { - r = s->res; - if (r->rid == RDT_RESOURCE_MBA || - r->rid == RDT_RESOURCE_SMBA) { - rdtgroup_init_mba(r, rdtgrp->closid); - if (is_mba_sc(r)) - continue; - } else { - ret = rdtgroup_init_cat(s, rdtgrp->closid); - if (ret < 0) - goto out; - } - - ret = resctrl_arch_update_domains(r, rdtgrp->closid); - if (ret < 0) { - rdt_last_cmd_puts("Failed to initialize allocations\n"); - goto out; - } - - } - - rdtgrp->mode = RDT_MODE_SHAREABLE; - -out: - rdt_staged_configs_clear(); - return ret; -} - -static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp) -{ - int ret; - - if (!resctrl_arch_mon_capable()) - return 0; - - ret = alloc_rmid(rdtgrp->closid); - if (ret < 0) { - rdt_last_cmd_puts("Out of RMIDs\n"); - return ret; - } - rdtgrp->mon.rmid = ret; - - ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn); - if (ret) { - rdt_last_cmd_puts("kernfs subdir error\n"); - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - return ret; - } - - return 0; -} - -static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp) -{ - if (resctrl_arch_mon_capable()) - free_rmid(rgrp->closid, rgrp->mon.rmid); -} - -static int mkdir_rdt_prepare(struct kernfs_node *parent_kn, - const char *name, umode_t mode, - enum rdt_group_type rtype, struct rdtgroup **r) -{ - struct rdtgroup *prdtgrp, *rdtgrp; - unsigned long files = 0; - struct kernfs_node *kn; - int ret; - - prdtgrp = rdtgroup_kn_lock_live(parent_kn); - if (!prdtgrp) { - ret = -ENODEV; - goto out_unlock; - } - - if (rtype == RDTMON_GROUP && - (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) { - ret = -EINVAL; - rdt_last_cmd_puts("Pseudo-locking in progress\n"); - goto out_unlock; - } - - /* allocate the rdtgroup. */ - rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL); - if (!rdtgrp) { - ret = -ENOSPC; - rdt_last_cmd_puts("Kernel out of memory\n"); - goto out_unlock; - } - *r = rdtgrp; - rdtgrp->mon.parent = prdtgrp; - rdtgrp->type = rtype; - INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list); - - /* kernfs creates the directory for rdtgrp */ - kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp); - if (IS_ERR(kn)) { - ret = PTR_ERR(kn); - rdt_last_cmd_puts("kernfs create error\n"); - goto out_free_rgrp; - } - rdtgrp->kn = kn; - - /* - * kernfs_remove() will drop the reference count on "kn" which - * will free it. But we still need it to stick around for the - * rdtgroup_kn_unlock(kn) call. Take one extra reference here, - * which will be dropped by kernfs_put() in rdtgroup_remove(). - */ - kernfs_get(kn); - - ret = rdtgroup_kn_set_ugid(kn); - if (ret) { - rdt_last_cmd_puts("kernfs perm error\n"); - goto out_destroy; - } - - if (rtype == RDTCTRL_GROUP) { - files = RFTYPE_BASE | RFTYPE_CTRL; - if (resctrl_arch_mon_capable()) - files |= RFTYPE_MON; - } else { - files = RFTYPE_BASE | RFTYPE_MON; - } - - ret = rdtgroup_add_files(kn, files); - if (ret) { - rdt_last_cmd_puts("kernfs fill error\n"); - goto out_destroy; - } - - /* - * The caller unlocks the parent_kn upon success. - */ - return 0; - -out_destroy: - kernfs_put(rdtgrp->kn); - kernfs_remove(rdtgrp->kn); -out_free_rgrp: - kfree(rdtgrp); -out_unlock: - rdtgroup_kn_unlock(parent_kn); - return ret; -} - -static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp) -{ - kernfs_remove(rgrp->kn); - rdtgroup_remove(rgrp); -} - -/* - * Create a monitor group under "mon_groups" directory of a control - * and monitor group(ctrl_mon). This is a resource group - * to monitor a subset of tasks and cpus in its parent ctrl_mon group. - */ -static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn, - const char *name, umode_t mode) -{ - struct rdtgroup *rdtgrp, *prgrp; - int ret; - - ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp); - if (ret) - return ret; - - prgrp = rdtgrp->mon.parent; - rdtgrp->closid = prgrp->closid; - - ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); - if (ret) { - mkdir_rdt_prepare_clean(rdtgrp); - goto out_unlock; - } - - kernfs_activate(rdtgrp->kn); - - /* - * Add the rdtgrp to the list of rdtgrps the parent - * ctrl_mon group has to track. - */ - list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list); - -out_unlock: - rdtgroup_kn_unlock(parent_kn); - return ret; -} - -/* - * These are rdtgroups created under the root directory. Can be used - * to allocate and monitor resources. - */ -static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn, - const char *name, umode_t mode) -{ - struct rdtgroup *rdtgrp; - struct kernfs_node *kn; - u32 closid; - int ret; - - ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp); - if (ret) - return ret; - - kn = rdtgrp->kn; - ret = closid_alloc(); - if (ret < 0) { - rdt_last_cmd_puts("Out of CLOSIDs\n"); - goto out_common_fail; - } - closid = ret; - ret = 0; - - rdtgrp->closid = closid; - - ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); - if (ret) - goto out_closid_free; - - kernfs_activate(rdtgrp->kn); - - ret = rdtgroup_init_alloc(rdtgrp); - if (ret < 0) - goto out_rmid_free; - - list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups); - - if (resctrl_arch_mon_capable()) { - /* - * Create an empty mon_groups directory to hold the subset - * of tasks and cpus to monitor. - */ - ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL); - if (ret) { - rdt_last_cmd_puts("kernfs subdir error\n"); - goto out_del_list; - } - } - - goto out_unlock; - -out_del_list: - list_del(&rdtgrp->rdtgroup_list); -out_rmid_free: - mkdir_rdt_prepare_rmid_free(rdtgrp); -out_closid_free: - closid_free(closid); -out_common_fail: - mkdir_rdt_prepare_clean(rdtgrp); -out_unlock: - rdtgroup_kn_unlock(parent_kn); - return ret; -} - -/* - * We allow creating mon groups only with in a directory called "mon_groups" - * which is present in every ctrl_mon group. Check if this is a valid - * "mon_groups" directory. - * - * 1. The directory should be named "mon_groups". - * 2. The mon group itself should "not" be named "mon_groups". - * This makes sure "mon_groups" directory always has a ctrl_mon group - * as parent. - */ -static bool is_mon_groups(struct kernfs_node *kn, const char *name) -{ - return (!strcmp(kn->name, "mon_groups") && - strcmp(name, "mon_groups")); -} - -static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name, - umode_t mode) -{ - /* Do not accept '\n' to avoid unparsable situation. */ - if (strchr(name, '\n')) - return -EINVAL; - - /* - * If the parent directory is the root directory and RDT - * allocation is supported, add a control and monitoring - * subdirectory - */ - if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn) - return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode); - - /* - * If RDT monitoring is supported and the parent directory is a valid - * "mon_groups" directory, add a monitoring subdirectory. - */ - if (resctrl_arch_mon_capable() && is_mon_groups(parent_kn, name)) - return rdtgroup_mkdir_mon(parent_kn, name, mode); - - return -EPERM; -} - -static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) -{ - struct rdtgroup *prdtgrp = rdtgrp->mon.parent; - int cpu; - - /* Give any tasks back to the parent group */ - rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask); - - /* Update per cpu rmid of the moved CPUs first */ - for_each_cpu(cpu, &rdtgrp->cpu_mask) - resctrl_arch_set_cpu_default_closid_rmid(cpu, rdtgrp->closid, - prdtgrp->mon.rmid); - - /* - * Update the MSR on moved CPUs and CPUs which have moved - * task running on them. - */ - cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); - update_closid_rmid(tmpmask, NULL); - - rdtgrp->flags = RDT_DELETED; - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - - /* - * Remove the rdtgrp from the parent ctrl_mon group's list - */ - WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); - list_del(&rdtgrp->mon.crdtgrp_list); - - kernfs_remove(rdtgrp->kn); - - return 0; -} - -static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp) -{ - rdtgrp->flags = RDT_DELETED; - list_del(&rdtgrp->rdtgroup_list); - - kernfs_remove(rdtgrp->kn); - return 0; -} - -static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) -{ - u32 closid, rmid; - int cpu; - - /* Give any tasks back to the default group */ - rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask); - - /* Give any CPUs back to the default group */ - cpumask_or(&rdtgroup_default.cpu_mask, - &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); - - /* Update per cpu closid and rmid of the moved CPUs first */ - closid = rdtgroup_default.closid; - rmid = rdtgroup_default.mon.rmid; - for_each_cpu(cpu, &rdtgrp->cpu_mask) - resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid); - - /* - * Update the MSR on moved CPUs and CPUs which have moved - * task running on them. - */ - cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); - update_closid_rmid(tmpmask, NULL); - - free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); - closid_free(rdtgrp->closid); - - rdtgroup_ctrl_remove(rdtgrp); - - /* - * Free all the child monitor group rmids. - */ - free_all_child_rdtgrp(rdtgrp); - - return 0; -} - -static int rdtgroup_rmdir(struct kernfs_node *kn) -{ - struct kernfs_node *parent_kn = kn->parent; - struct rdtgroup *rdtgrp; - cpumask_var_t tmpmask; - int ret = 0; - - if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) - return -ENOMEM; - - rdtgrp = rdtgroup_kn_lock_live(kn); - if (!rdtgrp) { - ret = -EPERM; - goto out; - } - - /* - * If the rdtgroup is a ctrl_mon group and parent directory - * is the root directory, remove the ctrl_mon group. - * - * If the rdtgroup is a mon group and parent directory - * is a valid "mon_groups" directory, remove the mon group. - */ - if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn && - rdtgrp != &rdtgroup_default) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - ret = rdtgroup_ctrl_remove(rdtgrp); - } else { - ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask); - } - } else if (rdtgrp->type == RDTMON_GROUP && - is_mon_groups(parent_kn, kn->name)) { - ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask); - } else { - ret = -EPERM; - } - -out: - rdtgroup_kn_unlock(kn); - free_cpumask_var(tmpmask); - return ret; -} - -/** - * mongrp_reparent() - replace parent CTRL_MON group of a MON group - * @rdtgrp: the MON group whose parent should be replaced - * @new_prdtgrp: replacement parent CTRL_MON group for @rdtgrp - * @cpus: cpumask provided by the caller for use during this call - * - * Replaces the parent CTRL_MON group for a MON group, resulting in all member - * tasks' CLOSID immediately changing to that of the new parent group. - * Monitoring data for the group is unaffected by this operation. - */ -static void mongrp_reparent(struct rdtgroup *rdtgrp, - struct rdtgroup *new_prdtgrp, - cpumask_var_t cpus) -{ - struct rdtgroup *prdtgrp = rdtgrp->mon.parent; - - WARN_ON(rdtgrp->type != RDTMON_GROUP); - WARN_ON(new_prdtgrp->type != RDTCTRL_GROUP); - - /* Nothing to do when simply renaming a MON group. */ - if (prdtgrp == new_prdtgrp) - return; - - WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); - list_move_tail(&rdtgrp->mon.crdtgrp_list, - &new_prdtgrp->mon.crdtgrp_list); - - rdtgrp->mon.parent = new_prdtgrp; - rdtgrp->closid = new_prdtgrp->closid; - - /* Propagate updated closid to all tasks in this group. */ - rdt_move_group_tasks(rdtgrp, rdtgrp, cpus); - - update_closid_rmid(cpus, NULL); -} - -static int rdtgroup_rename(struct kernfs_node *kn, - struct kernfs_node *new_parent, const char *new_name) -{ - struct rdtgroup *new_prdtgrp; - struct rdtgroup *rdtgrp; - cpumask_var_t tmpmask; - int ret; - - rdtgrp = kernfs_to_rdtgroup(kn); - new_prdtgrp = kernfs_to_rdtgroup(new_parent); - if (!rdtgrp || !new_prdtgrp) - return -ENOENT; - - /* Release both kernfs active_refs before obtaining rdtgroup mutex. */ - rdtgroup_kn_get(rdtgrp, kn); - rdtgroup_kn_get(new_prdtgrp, new_parent); - - mutex_lock(&rdtgroup_mutex); - - rdt_last_cmd_clear(); - - /* - * Don't allow kernfs_to_rdtgroup() to return a parent rdtgroup if - * either kernfs_node is a file. - */ - if (kernfs_type(kn) != KERNFS_DIR || - kernfs_type(new_parent) != KERNFS_DIR) { - rdt_last_cmd_puts("Source and destination must be directories"); - ret = -EPERM; - goto out; - } - - if ((rdtgrp->flags & RDT_DELETED) || (new_prdtgrp->flags & RDT_DELETED)) { - ret = -ENOENT; - goto out; - } - - if (rdtgrp->type != RDTMON_GROUP || !kn->parent || - !is_mon_groups(kn->parent, kn->name)) { - rdt_last_cmd_puts("Source must be a MON group\n"); - ret = -EPERM; - goto out; - } - - if (!is_mon_groups(new_parent, new_name)) { - rdt_last_cmd_puts("Destination must be a mon_groups subdirectory\n"); - ret = -EPERM; - goto out; - } - - /* - * If the MON group is monitoring CPUs, the CPUs must be assigned to the - * current parent CTRL_MON group and therefore cannot be assigned to - * the new parent, making the move illegal. - */ - if (!cpumask_empty(&rdtgrp->cpu_mask) && - rdtgrp->mon.parent != new_prdtgrp) { - rdt_last_cmd_puts("Cannot move a MON group that monitors CPUs\n"); - ret = -EPERM; - goto out; - } - - /* - * Allocate the cpumask for use in mongrp_reparent() to avoid the - * possibility of failing to allocate it after kernfs_rename() has - * succeeded. - */ - if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) { - ret = -ENOMEM; - goto out; - } - - /* - * Perform all input validation and allocations needed to ensure - * mongrp_reparent() will succeed before calling kernfs_rename(), - * otherwise it would be necessary to revert this call if - * mongrp_reparent() failed. - */ - ret = kernfs_rename(kn, new_parent, new_name); - if (!ret) - mongrp_reparent(rdtgrp, new_prdtgrp, tmpmask); - - free_cpumask_var(tmpmask); - -out: - mutex_unlock(&rdtgroup_mutex); - rdtgroup_kn_put(rdtgrp, kn); - rdtgroup_kn_put(new_prdtgrp, new_parent); - return ret; -} - -static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) -{ - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3)) - seq_puts(seq, ",cdp"); - - if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) - seq_puts(seq, ",cdpl2"); - - if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA))) - seq_puts(seq, ",mba_MBps"); - - if (resctrl_debug) - seq_puts(seq, ",debug"); - - return 0; -} - -static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { - .mkdir = rdtgroup_mkdir, - .rmdir = rdtgroup_rmdir, - .rename = rdtgroup_rename, - .show_options = rdtgroup_show_options, -}; - -static int rdtgroup_setup_root(struct rdt_fs_context *ctx) -{ - rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops, - KERNFS_ROOT_CREATE_DEACTIVATED | - KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK, - &rdtgroup_default); - if (IS_ERR(rdt_root)) - return PTR_ERR(rdt_root); - - ctx->kfc.root = rdt_root; - rdtgroup_default.kn = kernfs_root_to_node(rdt_root); - - return 0; -} - -static void rdtgroup_destroy_root(void) -{ - kernfs_destroy_root(rdt_root); - rdtgroup_default.kn = NULL; -} - -static void __init rdtgroup_setup_default(void) -{ - mutex_lock(&rdtgroup_mutex); - - rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID; - rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID; - rdtgroup_default.type = RDTCTRL_GROUP; - INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list); - - list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); - - mutex_unlock(&rdtgroup_mutex); -} - -static void domain_destroy_mon_state(struct rdt_domain *d) -{ - bitmap_free(d->rmid_busy_llc); - kfree(d->mbm_total); - kfree(d->mbm_local); -} - -void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d) -{ - mutex_lock(&rdtgroup_mutex); - - if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) - mba_sc_domain_destroy(r, d); - - if (!r->mon_capable) - goto out_unlock; - - /* - * If resctrl is mounted, remove all the - * per domain monitor data directories. - */ - if (resctrl_mounted && resctrl_arch_mon_capable()) - rmdir_mondata_subdir_allrdtgrp(r, d->id); - - if (resctrl_is_mbm_enabled()) - cancel_delayed_work(&d->mbm_over); - if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) { - /* - * When a package is going down, forcefully - * decrement rmid->ebusy. There is no way to know - * that the L3 was flushed and hence may lead to - * incorrect counts in rare scenarios, but leaving - * the RMID as busy creates RMID leaks if the - * package never comes back. - */ - __check_limbo(d, true); - cancel_delayed_work(&d->cqm_limbo); - } - - domain_destroy_mon_state(d); - -out_unlock: - mutex_unlock(&rdtgroup_mutex); -} - -static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_domain *d) -{ - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - size_t tsize; - - if (resctrl_arch_is_llc_occupancy_enabled()) { - d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL); - if (!d->rmid_busy_llc) - return -ENOMEM; - } - if (resctrl_arch_is_mbm_total_enabled()) { - tsize = sizeof(*d->mbm_total); - d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL); - if (!d->mbm_total) { - bitmap_free(d->rmid_busy_llc); - return -ENOMEM; - } - } - if (resctrl_arch_is_mbm_local_enabled()) { - tsize = sizeof(*d->mbm_local); - d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL); - if (!d->mbm_local) { - bitmap_free(d->rmid_busy_llc); - kfree(d->mbm_total); - return -ENOMEM; - } - } - - return 0; -} - -int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d) -{ - int err = 0; - - mutex_lock(&rdtgroup_mutex); - - if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) { - /* RDT_RESOURCE_MBA is never mon_capable */ - err = mba_sc_domain_allocate(r, d); - goto out_unlock; - } - - if (!r->mon_capable) - goto out_unlock; - - err = domain_setup_mon_state(r, d); - if (err) - goto out_unlock; - - if (resctrl_is_mbm_enabled()) { - INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow); - mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL, - RESCTRL_PICK_ANY_CPU); - } - - if (resctrl_arch_is_llc_occupancy_enabled()) - INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo); - - /* - * If the filesystem is not mounted then only the default resource group - * exists. Creation of its directories is deferred until mount time - * by rdt_get_tree() calling mkdir_mondata_all(). - * If resctrl is mounted, add per domain monitor data directories. - */ - if (resctrl_mounted && resctrl_arch_mon_capable()) - mkdir_mondata_subdir_allrdtgrp(r, d); - -out_unlock: - mutex_unlock(&rdtgroup_mutex); - - return err; -} - -void resctrl_online_cpu(unsigned int cpu) -{ - mutex_lock(&rdtgroup_mutex); - /* The CPU is set in default rdtgroup after online. */ - cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask); - mutex_unlock(&rdtgroup_mutex); -} - -static void clear_childcpus(struct rdtgroup *r, unsigned int cpu) -{ - struct rdtgroup *cr; - - list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) { - if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask)) - break; - } -} - -void resctrl_offline_cpu(unsigned int cpu) -{ - struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3); - struct rdtgroup *rdtgrp; - struct rdt_domain *d; - - mutex_lock(&rdtgroup_mutex); - list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { - if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) { - clear_childcpus(rdtgrp, cpu); - break; - } - } - - if (!l3->mon_capable) - goto out_unlock; - - d = resctrl_get_domain_from_cpu(cpu, l3); - if (d) { - if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) { - cancel_delayed_work(&d->mbm_over); - mbm_setup_overflow_handler(d, 0, cpu); - } - if (resctrl_arch_is_llc_occupancy_enabled() && - cpu == d->cqm_work_cpu && has_busy_rmid(d)) { - cancel_delayed_work(&d->cqm_limbo); - cqm_setup_limbo_handler(d, 0, cpu); - } - } - -out_unlock: - mutex_unlock(&rdtgroup_mutex); -} - -/* - * resctrl_init - resctrl filesystem initialization - * - * Setup resctrl file system including set up root, create mount point, - * register resctrl filesystem, and initialize files under root directory. - * - * Return: 0 on success or -errno - */ -int resctrl_init(void) -{ - int ret = 0; - - seq_buf_init(&last_cmd_status, last_cmd_status_buf, - sizeof(last_cmd_status_buf)); - - rdtgroup_setup_default(); - - thread_throttle_mode_init(); - - ret = resctrl_mon_resource_init(); - if (ret) - return ret; - - ret = sysfs_create_mount_point(fs_kobj, "resctrl"); - if (ret) - return ret; - - ret = register_filesystem(&rdt_fs_type); - if (ret) - goto cleanup_mountpoint; - - /* - * Adding the resctrl debugfs directory here may not be ideal since - * it would let the resctrl debugfs directory appear on the debugfs - * filesystem before the resctrl filesystem is mounted. - * It may also be ok since that would enable debugging of RDT before - * resctrl is mounted. - * The reason why the debugfs directory is created here and not in - * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and - * during the debugfs directory creation also &sb->s_type->i_mutex_key - * (the lockdep class of inode->i_rwsem). Other filesystem - * interactions (eg. SyS_getdents) have the lock ordering: - * &sb->s_type->i_mutex_key --> &mm->mmap_lock - * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex - * is taken, thus creating dependency: - * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause - * issues considering the other two lock dependencies. - * By creating the debugfs directory here we avoid a dependency - * that may cause deadlock (even though file operations cannot - * occur until the filesystem is mounted, but I do not know how to - * tell lockdep that). - */ - debugfs_resctrl = debugfs_create_dir("resctrl", NULL); - - return 0; - -cleanup_mountpoint: - sysfs_remove_mount_point(fs_kobj, "resctrl"); - - return ret; -} - -void resctrl_exit(void) -{ - debugfs_remove_recursive(debugfs_resctrl); - unregister_filesystem(&rdt_fs_type); - sysfs_remove_mount_point(fs_kobj, "resctrl"); + struct rdt_resource *r;

- resctrl_mon_resource_exit(); + for_each_capable_rdt_resource(r) + reset_all_ctrls(r); } diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index e69de29bb2d1..62a6a67f1192 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -0,0 +1,528 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Resource Director Technology(RDT) + * - Cache Allocation code. + * + * Copyright (C) 2016 Intel Corporation + * + * Authors: + * Fenghua Yu fenghua.yu@intel.com + * Tony Luck tony.luck@intel.com + * + * More information about RDT be found in the Intel (R) x86 Architecture + * Software Developer Manual June 2016, volume 3, section 17.17. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cpu.h> +#include <linux/kernfs.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include "internal.h" + +struct rdt_parse_data { + struct rdtgroup *rdtgrp; + char *buf; +}; + +typedef int (ctrlval_parser_t)(struct rdt_parse_data *data, + struct resctrl_schema *s, + struct rdt_domain *d); + +/* + * Check whether MBA bandwidth percentage value is correct. The value is + * checked against the minimum and max bandwidth values specified by the + * hardware. The allocated bandwidth percentage is rounded to the next + * control step available on the hardware. + */ +static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r) +{ + unsigned long bw; + int ret; + + /* + * Only linear delay values is supported for current Intel SKUs. + */ + if (!r->membw.delay_linear && r->membw.arch_needs_linear) { + rdt_last_cmd_puts("No support for non-linear MB domains\n"); + return false; + } + + ret = kstrtoul(buf, 10, &bw); + if (ret) { + rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf); + return false; + } + + if ((bw < r->membw.min_bw || bw > r->default_ctrl) && + !is_mba_sc(r)) { + rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw, + r->membw.min_bw, r->default_ctrl); + return false; + } + + *data = roundup(bw, (unsigned long)r->membw.bw_gran); + return true; +} + +static int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, + struct rdt_domain *d) +{ + struct resctrl_staged_config *cfg; + u32 closid = data->rdtgrp->closid; + struct rdt_resource *r = s->res; + unsigned long bw_val; + + cfg = &d->staged_config[s->conf_type]; + if (cfg->have_new_ctrl) { + rdt_last_cmd_printf("Duplicate domain %d\n", d->id); + return -EINVAL; + } + + if (!bw_validate(data->buf, &bw_val, r)) + return -EINVAL; + + if (is_mba_sc(r)) { + d->mbps_val[closid] = bw_val; + return 0; + } + + cfg->new_ctrl = bw_val; + cfg->have_new_ctrl = true; + + return 0; +} + +/* + * Check whether a cache bit mask is valid. + * On Intel CPUs, non-contiguous 1s value support is indicated by CPUID: + * - CPUID.0x10.1:ECX[3]: L3 non-contiguous 1s value supported if 1 + * - CPUID.0x10.2:ECX[3]: L2 non-contiguous 1s value supported if 1 + * + * Haswell does not support a non-contiguous 1s value and additionally + * requires at least two bits set. + * AMD allows non-contiguous bitmasks. + */ +static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r) +{ + unsigned long first_bit, zero_bit, val; + unsigned int cbm_len = r->cache.cbm_len; + int ret; + + ret = kstrtoul(buf, 16, &val); + if (ret) { + rdt_last_cmd_printf("Non-hex character in the mask %s\n", buf); + return false; + } + + if ((r->cache.min_cbm_bits > 0 && val == 0) || val > r->default_ctrl) { + rdt_last_cmd_puts("Mask out of range\n"); + return false; + } + + first_bit = find_first_bit(&val, cbm_len); + zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); + + /* Are non-contiguous bitmasks allowed? */ + if (!r->cache.arch_has_sparse_bitmasks && + (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)) { + rdt_last_cmd_printf("The mask %lx has non-consecutive 1-bits\n", val); + return false; + } + + if ((zero_bit - first_bit) < r->cache.min_cbm_bits) { + rdt_last_cmd_printf("Need at least %d bits in the mask\n", + r->cache.min_cbm_bits); + return false; + } + + *data = val; + return true; +} + +/* + * Read one cache bit mask (hex). Check that it is valid for the current + * resource type. + */ +static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s, + struct rdt_domain *d) +{ + struct rdtgroup *rdtgrp = data->rdtgrp; + struct resctrl_staged_config *cfg; + struct rdt_resource *r = s->res; + u32 cbm_val; + + cfg = &d->staged_config[s->conf_type]; + if (cfg->have_new_ctrl) { + rdt_last_cmd_printf("Duplicate domain %d\n", d->id); + return -EINVAL; + } + + /* + * Cannot set up more than one pseudo-locked region in a cache + * hierarchy. + */ + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && + rdtgroup_pseudo_locked_in_hierarchy(d)) { + rdt_last_cmd_puts("Pseudo-locked region in hierarchy\n"); + return -EINVAL; + } + + if (!cbm_validate(data->buf, &cbm_val, r)) + return -EINVAL; + + if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) && + (rdtgrp->mode == RDT_MODE_EXCLUSIVE || + rdtgrp->mode == RDT_MODE_SHAREABLE) && + rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) { + rdt_last_cmd_puts("CBM overlaps with pseudo-locked region\n"); + return -EINVAL; + } + + /* + * The CBM may not overlap with the CBM of another closid if + * either is exclusive. + */ + if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, true)) { + rdt_last_cmd_puts("Overlaps with exclusive group\n"); + return -EINVAL; + } + + if (rdtgroup_cbm_overlaps(s, d, cbm_val, rdtgrp->closid, false)) { + if (rdtgrp->mode == RDT_MODE_EXCLUSIVE || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + rdt_last_cmd_puts("Overlaps with other group\n"); + return -EINVAL; + } + } + + cfg->new_ctrl = cbm_val; + cfg->have_new_ctrl = true; + + return 0; +} + +static ctrlval_parser_t *get_parser(struct rdt_resource *res) +{ + if (res->fflags & RFTYPE_RES_CACHE) + return &parse_cbm; + else + return &parse_bw; +} + +/* + * For each domain in this resource we expect to find a series of: + * id=mask + * separated by ";". The "id" is in decimal, and must match one of + * the "id"s for this resource. + */ +static int parse_line(char *line, struct resctrl_schema *s, + struct rdtgroup *rdtgrp) +{ + ctrlval_parser_t *parse_ctrlval = get_parser(s->res); + enum resctrl_conf_type t = s->conf_type; + struct resctrl_staged_config *cfg; + struct rdt_resource *r = s->res; + struct rdt_parse_data data; + char *dom = NULL, *id; + struct rdt_domain *d; + unsigned long dom_id; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP && + (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) { + rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n"); + return -EINVAL; + } + +next: + if (!line || line[0] == '\0') + return 0; + dom = strsep(&line, ";"); + id = strsep(&dom, "="); + if (!dom || kstrtoul(id, 10, &dom_id)) { + rdt_last_cmd_puts("Missing '=' or non-numeric domain\n"); + return -EINVAL; + } + dom = strim(dom); + list_for_each_entry(d, &r->domains, list) { + if (d->id == dom_id) { + data.buf = dom; + data.rdtgrp = rdtgrp; + if (parse_ctrlval(&data, s, d)) + return -EINVAL; + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + cfg = &d->staged_config[t]; + /* + * In pseudo-locking setup mode and just + * parsed a valid CBM that should be + * pseudo-locked. Only one locked region per + * resource group and domain so just do + * the required initialization for single + * region and return. + */ + rdtgrp->plr->s = s; + rdtgrp->plr->d = d; + rdtgrp->plr->cbm = cfg->new_ctrl; + d->plr = rdtgrp->plr; + return 0; + } + goto next; + } + } + return -EINVAL; +} + +static int rdtgroup_parse_resource(char *resname, char *tok, + struct rdtgroup *rdtgrp) +{ + struct resctrl_schema *s; + + list_for_each_entry(s, &resctrl_schema_all, list) { + if (!strcmp(resname, s->name) && rdtgrp->closid < s->num_closid) + return parse_line(tok, s, rdtgrp); + } + rdt_last_cmd_printf("Unknown or unsupported resource name '%s'\n", resname); + return -EINVAL; +} + +ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct resctrl_schema *s; + struct rdtgroup *rdtgrp; + struct rdt_resource *r; + char *tok, *resname; + int ret = 0; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + buf[nbytes - 1] = '\0'; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + rdt_last_cmd_clear(); + + /* + * No changes to pseudo-locked region allowed. It has to be removed + * and re-created instead. + */ + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + ret = -EINVAL; + rdt_last_cmd_puts("Resource group is pseudo-locked\n"); + goto out; + } + + rdt_staged_configs_clear(); + + while ((tok = strsep(&buf, "\n")) != NULL) { + resname = strim(strsep(&tok, ":")); + if (!tok) { + rdt_last_cmd_puts("Missing ':'\n"); + ret = -EINVAL; + goto out; + } + if (tok[0] == '\0') { + rdt_last_cmd_printf("Missing '%s' value\n", resname); + ret = -EINVAL; + goto out; + } + ret = rdtgroup_parse_resource(resname, tok, rdtgrp); + if (ret) + goto out; + } + + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + + /* + * Writes to mba_sc resources update the software controller, + * not the control MSR. + */ + if (is_mba_sc(r)) + continue; + + ret = resctrl_arch_update_domains(r, rdtgrp->closid); + if (ret) + goto out; + } + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + /* + * If pseudo-locking fails we keep the resource group in + * mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service + * active and updated for just the domain the pseudo-locked + * region was requested for. + */ + ret = rdtgroup_pseudo_lock_create(rdtgrp); + } + +out: + rdt_staged_configs_clear(); + rdtgroup_kn_unlock(of->kn); + return ret ?: nbytes; +} + +static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid) +{ + struct rdt_resource *r = schema->res; + struct rdt_domain *dom; + bool sep = false; + u32 ctrl_val; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + seq_printf(s, "%*s:", max_name_width, schema->name); + list_for_each_entry(dom, &r->domains, list) { + if (sep) + seq_puts(s, ";"); + + if (is_mba_sc(r)) + ctrl_val = dom->mbps_val[closid]; + else + ctrl_val = resctrl_arch_get_config(r, dom, closid, + schema->conf_type); + + seq_printf(s, r->format_str, dom->id, max_data_width, + ctrl_val); + sep = true; + } + seq_puts(s, "\n"); +} + +int rdtgroup_schemata_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct resctrl_schema *schema; + struct rdtgroup *rdtgrp; + int ret = 0; + u32 closid; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + list_for_each_entry(schema, &resctrl_schema_all, list) { + seq_printf(s, "%s:uninitialized\n", schema->name); + } + } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + seq_printf(s, "%s:%d=%x\n", + rdtgrp->plr->s->res->name, + rdtgrp->plr->d->id, + rdtgrp->plr->cbm); + } + } else { + closid = rdtgrp->closid; + list_for_each_entry(schema, &resctrl_schema_all, list) { + if (closid < schema->num_closid) + show_doms(s, schema, closid); + } + } + } else { + ret = -ENOENT; + } + rdtgroup_kn_unlock(of->kn); + return ret; +} + +static int smp_mon_event_count(void *arg) +{ + mon_event_count(arg); + + return 0; +} + +void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, + struct rdt_domain *d, struct rdtgroup *rdtgrp, + int evtid, int first) +{ + int cpu; + + /* When picking a CPU from cpu_mask, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + /* + * Setup the parameters to pass to mon_event_count() to read the data. + */ + rr->rgrp = rdtgrp; + rr->evtid = evtid; + rr->r = r; + rr->d = d; + rr->val = 0; + rr->first = first; + rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid); + if (IS_ERR(rr->arch_mon_ctx)) { + rr->err = -EINVAL; + return; + } + + cpu = cpumask_any_housekeeping(&d->cpu_mask, RESCTRL_PICK_ANY_CPU); + + /* + * cpumask_any_housekeeping() prefers housekeeping CPUs, but + * are all the CPUs nohz_full? If yes, pick a CPU to IPI. + * MPAM's resctrl_arch_rmid_read() is unable to read the + * counters on some platforms if its called in irq context. + */ + if (tick_nohz_full_cpu(cpu)) + smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1); + else + smp_call_on_cpu(cpu, smp_mon_event_count, rr, false); + + resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx); +} + +int rdtgroup_mondata_show(struct seq_file *m, void *arg) +{ + struct kernfs_open_file *of = m->private; + u32 resid, evtid, domid; + struct rdtgroup *rdtgrp; + struct rdt_resource *r; + union mon_data_bits md; + struct rdt_domain *d; + struct rmid_read rr; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + ret = -ENOENT; + goto out; + } + + md.priv = of->kn->priv; + resid = md.u.rid; + domid = md.u.domid; + evtid = md.u.evtid; + + r = resctrl_arch_get_resource(resid); + d = resctrl_arch_find_domain(r, domid); + if (IS_ERR_OR_NULL(d)) { + ret = -ENOENT; + goto out; + } + + mon_event_read(&rr, r, d, rdtgrp, evtid, false); + + if (rr.err == -EIO) + seq_puts(m, "Error\n"); + else if (rr.err == -EINVAL) + seq_puts(m, "Unavailable\n"); + else + seq_printf(m, "%llu\n", rr.val); + +out: + rdtgroup_kn_unlock(of->kn); + return ret; +} diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h index e69de29bb2d1..7a6f46b4edd0 100644 --- a/fs/resctrl/internal.h +++ b/fs/resctrl/internal.h @@ -0,0 +1,313 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _FS_RESCTRL_INTERNAL_H +#define _FS_RESCTRL_INTERNAL_H + +#include <linux/resctrl.h> +#include <linux/sched.h> +#include <linux/kernfs.h> +#include <linux/fs_context.h> +#include <linux/jump_label.h> +#include <linux/tick.h> + +#include <asm/resctrl.h> + +/** + * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that + * aren't marked nohz_full + * @mask: The mask to pick a CPU from. + * @exclude_cpu:The CPU to avoid picking. + * + * Returns a CPU from @mask, but not @exclude_cpu. If there are housekeeping + * CPUs that don't use nohz_full, these are preferred. Pass + * RESCTRL_PICK_ANY_CPU to avoid excluding any CPUs. + * + * When a CPU is excluded, returns >= nr_cpu_ids if no CPUs are available. + */ +static inline unsigned int +cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu) +{ + unsigned int cpu, hk_cpu; + + if (exclude_cpu == RESCTRL_PICK_ANY_CPU) + cpu = cpumask_any(mask); + else + cpu = cpumask_any_but(mask, exclude_cpu); + + if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) + return cpu; + + /* If the CPU picked isn't marked nohz_full nothing more needs doing. */ + if (cpu < nr_cpu_ids && !tick_nohz_full_cpu(cpu)) + return cpu; + + /* Try to find a CPU that isn't nohz_full to use in preference */ + hk_cpu = cpumask_nth_andnot(0, mask, tick_nohz_full_mask); + if (hk_cpu == exclude_cpu) + hk_cpu = cpumask_nth_andnot(1, mask, tick_nohz_full_mask); + + if (hk_cpu < nr_cpu_ids) + cpu = hk_cpu; + + return cpu; +} + +struct rdt_fs_context { + struct kernfs_fs_context kfc; + bool enable_cdpl2; + bool enable_cdpl3; + bool enable_mba_mbps; + bool enable_debug; +}; + +static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) +{ + struct kernfs_fs_context *kfc = fc->fs_private; + + return container_of(kfc, struct rdt_fs_context, kfc); +} + +/** + * struct mon_evt - Entry in the event list of a resource + * @evtid: event id + * @name: name of the event + * @configurable: true if the event is configurable + * @list: entry in &rdt_resource->evt_list + */ +struct mon_evt { + enum resctrl_event_id evtid; + char *name; + bool configurable; + struct list_head list; +}; + +/** + * union mon_data_bits - Monitoring details for each event file + * @priv: Used to store monitoring event data in @u + * as kernfs private data + * @rid: Resource id associated with the event file + * @evtid: Event id associated with the event file + * @domid: The domain to which the event file belongs + * @u: Name of the bit fields struct + */ +union mon_data_bits { + void *priv; + struct { + unsigned int rid : 10; + enum resctrl_event_id evtid : 8; + unsigned int domid : 14; + } u; +}; + +struct rmid_read { + struct rdtgroup *rgrp; + struct rdt_resource *r; + struct rdt_domain *d; + enum resctrl_event_id evtid; + bool first; + int err; + u64 val; + void *arch_mon_ctx; +}; + +extern struct list_head resctrl_schema_all; +extern bool resctrl_mounted; + +enum rdt_group_type { + RDTCTRL_GROUP = 0, + RDTMON_GROUP, + RDT_NUM_GROUP, +}; + +/** + * enum rdtgrp_mode - Mode of a RDT resource group + * @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations + * @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed + * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking + * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations + * allowed AND the allocations are Cache Pseudo-Locked + * @RDT_NUM_MODES: Total number of modes + * + * The mode of a resource group enables control over the allowed overlap + * between allocations associated with different resource groups (classes + * of service). User is able to modify the mode of a resource group by + * writing to the "mode" resctrl file associated with the resource group. + * + * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by + * writing the appropriate text to the "mode" file. A resource group enters + * "pseudo-locked" mode after the schemata is written while the resource + * group is in "pseudo-locksetup" mode. + */ +enum rdtgrp_mode { + RDT_MODE_SHAREABLE = 0, + RDT_MODE_EXCLUSIVE, + RDT_MODE_PSEUDO_LOCKSETUP, + RDT_MODE_PSEUDO_LOCKED, + + /* Must be last */ + RDT_NUM_MODES, +}; + +/** + * struct mongroup - store mon group's data in resctrl fs. + * @mon_data_kn: kernfs node for the mon_data directory + * @parent: parent rdtgrp + * @crdtgrp_list: child rdtgroup node list + * @rmid: rmid for this rdtgroup + */ +struct mongroup { + struct kernfs_node *mon_data_kn; + struct rdtgroup *parent; + struct list_head crdtgrp_list; + u32 rmid; +}; + +/** + * struct rdtgroup - store rdtgroup's data in resctrl file system. + * @kn: kernfs node + * @rdtgroup_list: linked list for all rdtgroups + * @closid: closid for this rdtgroup + * @cpu_mask: CPUs assigned to this rdtgroup + * @flags: status bits + * @waitcount: how many cpus expect to find this + * group when they acquire rdtgroup_mutex + * @type: indicates type of this rdtgroup - either + * monitor only or ctrl_mon group + * @mon: mongroup related data + * @mode: mode of resource group + * @plr: pseudo-locked region + */ +struct rdtgroup { + struct kernfs_node *kn; + struct list_head rdtgroup_list; + u32 closid; + struct cpumask cpu_mask; + int flags; + atomic_t waitcount; + enum rdt_group_type type; + struct mongroup mon; + enum rdtgrp_mode mode; + struct pseudo_lock_region *plr; +}; + +/* List of all resource groups */ +extern struct list_head rdt_all_groups; + +extern int max_name_width, max_data_width; + +/** + * struct rftype - describe each file in the resctrl file system + * @name: File name + * @mode: Access mode + * @kf_ops: File operations + * @flags: File specific RFTYPE_FLAGS_* flags + * @fflags: File specific RFTYPE_* flags + * @seq_show: Show content of the file + * @write: Write to the file + */ +struct rftype { + char *name; + umode_t mode; + const struct kernfs_ops *kf_ops; + unsigned long flags; + unsigned long fflags; + + int (*seq_show)(struct kernfs_open_file *of, + struct seq_file *sf, void *v); + /* + * write() is the generic write callback which maps directly to + * kernfs write operation and overrides all other operations. + * Maximum write size is determined by ->max_write_len. + */ + ssize_t (*write)(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); +}; + +/** + * struct mbm_state - status for each MBM counter in each domain + * @prev_bw_bytes: Previous bytes value read for bandwidth calculation + * @prev_bw: The most recent bandwidth in MBps + * @delta_bw: Difference between the current and previous bandwidth + * @delta_comp: Indicates whether to compute the delta_bw + */ +struct mbm_state { + u64 prev_bw_bytes; + u32 prev_bw; + u32 delta_bw; + bool delta_comp; +}; + +static inline bool is_mba_sc(struct rdt_resource *r) +{ + if (!r) + r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + + /* + * The software controller support is only applicable to MBA resource. + * Make sure to check for resource type. + */ + if (r->rid != RDT_RESOURCE_MBA) + return false; + + return r->membw.mba_sc; +} + +extern struct mutex rdtgroup_mutex; +extern struct rdtgroup rdtgroup_default; +extern struct dentry *debugfs_resctrl; + +void rdt_last_cmd_clear(void); +void rdt_last_cmd_puts(const char *s); +__printf(1, 2) +void rdt_last_cmd_printf(const char *fmt, ...); + +struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn); +void rdtgroup_kn_unlock(struct kernfs_node *kn); +int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name); +int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, + umode_t mask); +ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); +int rdtgroup_schemata_show(struct kernfs_open_file *of, + struct seq_file *s, void *v); +bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_domain *d, + unsigned long cbm, int closid, bool exclusive); +unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_domain *d, + unsigned long cbm); +enum rdtgrp_mode rdtgroup_mode_by_closid(int closid); +int rdtgroup_tasks_assigned(struct rdtgroup *r); +int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp); +int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp); +bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_domain *d, unsigned long cbm); +bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d); +int rdt_pseudo_lock_init(void); +void rdt_pseudo_lock_release(void); +int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp); +void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp); +int closids_supported(void); +bool closid_allocated(unsigned int closid); +bool resctrl_closid_is_dirty(u32 closid); +void closid_free(int closid); +int alloc_rmid(u32 closid); +void free_rmid(u32 closid, u32 rmid); +void resctrl_mon_resource_exit(void); +void mon_event_count(void *info); +int rdtgroup_mondata_show(struct seq_file *m, void *arg); +void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, + struct rdt_domain *d, struct rdtgroup *rdtgrp, + int evtid, int first); +int resctrl_mon_resource_init(void); +void mbm_setup_overflow_handler(struct rdt_domain *dom, + unsigned long delay_ms, + int exclude_cpu); +void mbm_handle_overflow(struct work_struct *work); +void setup_default_ctrlval(struct rdt_resource *r, u32 *dc); +void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms, + int exclude_cpu); +void cqm_handle_limbo(struct work_struct *work); +bool has_busy_rmid(struct rdt_domain *d); +void __check_limbo(struct rdt_domain *d, bool force_free); +void mbm_config_rftype_init(const char *config); +void rdt_staged_configs_clear(void); +int resctrl_find_cleanest_closid(void); + +#endif /* _FS_RESCTRL_INTERNAL_H */ diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index e69de29bb2d1..fcf2ab18966f 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -0,0 +1,859 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Resource Director Technology(RDT) + * - Monitoring code + * + * Copyright (C) 2017 Intel Corporation + * + * Author: + * Vikas Shivappa vikas.shivappa@intel.com + * + * This replaces the cqm.c based on perf but we reuse a lot of + * code and datastructures originally from Peter Zijlstra and Matt Fleming. + * + * More information about RDT be found in the Intel (R) x86 Architecture + * Software Developer Manual June 2016, volume 3, section 17.17. + */ + +#include <linux/cpu.h> +#include <linux/module.h> +#include <linux/sizes.h> +#include <linux/slab.h> +#include "internal.h" + +/* + * struct rmid_entry - dirty tracking for all RMID. + * @closid: The CLOSID for this entry. + * @rmid: The RMID for this entry. + * @busy: The number of domains with cached data using this RMID. + * @list: Member of the rmid_free_lru list when busy == 0. + * + * Depending on the architecture the correct monitor is accessed using + * both @closid and @rmid, or @rmid only. + * + * Take the rdtgroup_mutex when accessing. + */ +struct rmid_entry { + u32 closid; + u32 rmid; + int busy; + struct list_head list; +}; + +/* + * @rmid_free_lru - A least recently used list of free RMIDs + * These RMIDs are guaranteed to have an occupancy less than the + * threshold occupancy + */ +static LIST_HEAD(rmid_free_lru); + +/** + * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has. + * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined. + * Indexed by CLOSID. Protected by rdtgroup_mutex. + */ +static u32 *closid_num_dirty_rmid; + +/* + * @rmid_limbo_count - count of currently unused but (potentially) + * dirty RMIDs. + * This counts RMIDs that no one is currently using but that + * may have a occupancy value > resctrl_rmid_realloc_threshold. User can + * change the threshold occupancy value. + */ +static unsigned int rmid_limbo_count; + +/* + * @rmid_entry - The entry in the limbo and free lists. + */ +static struct rmid_entry *rmid_ptrs; + +/* + * This is the threshold cache occupancy in bytes at which we will consider an + * RMID available for re-allocation. + */ +unsigned int resctrl_rmid_realloc_threshold; + +/* + * This is the maximum value for the reallocation threshold, in bytes. + */ +unsigned int resctrl_rmid_realloc_limit; + +/* + * x86 and arm64 differ in their handling of monitoring. + * x86's RMID are independent numbers, there is only one source of traffic + * with an RMID value of '1'. + * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of + * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID + * value is no longer unique. + * To account for this, resctrl uses an index. On x86 this is just the RMID, + * on arm64 it encodes the CLOSID and RMID. This gives a unique number. + * + * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code + * must accept an attempt to read every index. + */ +static inline struct rmid_entry *__rmid_entry(u32 idx) +{ + struct rmid_entry *entry; + u32 closid, rmid; + + entry = &rmid_ptrs[idx]; + resctrl_arch_rmid_idx_decode(idx, &closid, &rmid); + + WARN_ON_ONCE(entry->closid != closid); + WARN_ON_ONCE(entry->rmid != rmid); + + return entry; +} + +static void limbo_release_entry(struct rmid_entry *entry) +{ + lockdep_assert_held(&rdtgroup_mutex); + + rmid_limbo_count--; + list_add_tail(&entry->list, &rmid_free_lru); + + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + closid_num_dirty_rmid[entry->closid]--; +} + +/* + * Check the RMIDs that are marked as busy for this domain. If the + * reported LLC occupancy is below the threshold clear the busy bit and + * decrement the count. If the busy count gets to zero on an RMID, we + * free the RMID + */ +void __check_limbo(struct rdt_domain *d, bool force_free) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + struct rmid_entry *entry; + u32 idx, cur_idx = 1; + void *arch_mon_ctx; + bool rmid_dirty; + u64 val = 0; + + arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID); + if (IS_ERR(arch_mon_ctx)) { + pr_warn_ratelimited("Failed to allocate monitor context: %ld", + PTR_ERR(arch_mon_ctx)); + return; + } + + /* + * Skip RMID 0 and start from RMID 1 and check all the RMIDs that + * are marked as busy for occupancy < threshold. If the occupancy + * is less than the threshold decrement the busy counter of the + * RMID and move it to the free list when the counter reaches 0. + */ + for (;;) { + idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx); + if (idx >= idx_limit) + break; + + entry = __rmid_entry(idx); + if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, + QOS_L3_OCCUP_EVENT_ID, &val, + arch_mon_ctx)) { + rmid_dirty = true; + } else { + rmid_dirty = (val >= resctrl_rmid_realloc_threshold); + } + + if (force_free || !rmid_dirty) { + clear_bit(idx, d->rmid_busy_llc); + if (!--entry->busy) + limbo_release_entry(entry); + } + cur_idx = idx + 1; + } + + resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx); +} + +bool has_busy_rmid(struct rdt_domain *d) +{ + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + + return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit; +} + +static struct rmid_entry *resctrl_find_free_rmid(u32 closid) +{ + struct rmid_entry *itr; + u32 itr_idx, cmp_idx; + + if (list_empty(&rmid_free_lru)) + return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC); + + list_for_each_entry(itr, &rmid_free_lru, list) { + /* + * Get the index of this free RMID, and the index it would need + * to be if it were used with this CLOSID. + * If the CLOSID is irrelevant on this architecture, the two + * index values are always the same on every entry and thus the + * very first entry will be returned. + */ + itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid); + cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid); + + if (itr_idx == cmp_idx) + return itr; + } + + return ERR_PTR(-ENOSPC); +} + +/** + * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated + * RMID are clean, or the CLOSID that has + * the most clean RMID. + * + * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID + * may not be able to allocate clean RMID. To avoid this the allocator will + * choose the CLOSID with the most clean RMID. + * + * When the CLOSID and RMID are independent numbers, the first free CLOSID will + * be returned. + */ +int resctrl_find_cleanest_closid(void) +{ + u32 cleanest_closid = ~0; + int i = 0; + + lockdep_assert_held(&rdtgroup_mutex); + + if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + return -EIO; + + for (i = 0; i < closids_supported(); i++) { + int num_dirty; + + if (closid_allocated(i)) + continue; + + num_dirty = closid_num_dirty_rmid[i]; + if (num_dirty == 0) + return i; + + if (cleanest_closid == ~0) + cleanest_closid = i; + + if (num_dirty < closid_num_dirty_rmid[cleanest_closid]) + cleanest_closid = i; + } + + if (cleanest_closid == ~0) + return -ENOSPC; + + return cleanest_closid; +} + +/* + * For MPAM the RMID value is not unique, and has to be considered with + * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which + * allows all domains to be managed by a single free list. + * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler. + */ +int alloc_rmid(u32 closid) +{ + struct rmid_entry *entry; + + lockdep_assert_held(&rdtgroup_mutex); + + entry = resctrl_find_free_rmid(closid); + if (IS_ERR(entry)) + return PTR_ERR(entry); + + list_del(&entry->list); + return entry->rmid; +} + +static void add_rmid_to_limbo(struct rmid_entry *entry) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdt_domain *d; + u32 idx; + + lockdep_assert_held(&rdtgroup_mutex); + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid); + + entry->busy = 0; + list_for_each_entry(d, &r->domains, list) { + /* + * For the first limbo RMID in the domain, + * setup up the limbo worker. + */ + if (!has_busy_rmid(d)) + cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL, + RESCTRL_PICK_ANY_CPU); + set_bit(idx, d->rmid_busy_llc); + entry->busy++; + } + + rmid_limbo_count++; + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + closid_num_dirty_rmid[entry->closid]++; +} + +void free_rmid(u32 closid, u32 rmid) +{ + u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); + struct rmid_entry *entry; + + lockdep_assert_held(&rdtgroup_mutex); + + /* + * Do not allow the default rmid to be free'd. Comparing by index + * allows architectures that ignore the closid parameter to avoid an + * unnecessary check. + */ + if (idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, + RESCTRL_RESERVED_RMID)) + return; + + entry = __rmid_entry(idx); + + if (resctrl_arch_is_llc_occupancy_enabled()) + add_rmid_to_limbo(entry); + else + list_add_tail(&entry->list, &rmid_free_lru); +} + +static struct mbm_state *get_mbm_state(struct rdt_domain *d, u32 closid, + u32 rmid, enum resctrl_event_id evtid) +{ + u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); + + switch (evtid) { + case QOS_L3_MBM_TOTAL_EVENT_ID: + return &d->mbm_total[idx]; + case QOS_L3_MBM_LOCAL_EVENT_ID: + return &d->mbm_local[idx]; + default: + return NULL; + } +} + +static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) +{ + struct mbm_state *m; + u64 tval = 0; + + if (rr->first) { + resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid); + m = get_mbm_state(rr->d, closid, rmid, rr->evtid); + if (m) + memset(m, 0, sizeof(struct mbm_state)); + return 0; + } + + rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid, rr->evtid, + &tval, rr->arch_mon_ctx); + if (rr->err) + return rr->err; + + rr->val += tval; + + return 0; +} + +/* + * mbm_bw_count() - Update bw count from values previously read by + * __mon_event_count(). + * @closid: The closid used to identify the cached mbm_state. + * @rmid: The rmid used to identify the cached mbm_state. + * @rr: The struct rmid_read populated by __mon_event_count(). + * + * Supporting function to calculate the memory bandwidth + * and delta bandwidth in MBps. The chunks value previously read by + * __mon_event_count() is compared with the chunks value from the previous + * invocation. This must be called once per second to maintain values in MBps. + */ +static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr) +{ + u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); + struct mbm_state *m = &rr->d->mbm_local[idx]; + u64 cur_bw, bytes, cur_bytes; + + cur_bytes = rr->val; + bytes = cur_bytes - m->prev_bw_bytes; + m->prev_bw_bytes = cur_bytes; + + cur_bw = bytes / SZ_1M; + + if (m->delta_comp) + m->delta_bw = abs(cur_bw - m->prev_bw); + m->delta_comp = false; + m->prev_bw = cur_bw; +} + +/* + * This is scheduled by mon_event_read() to read the CQM/MBM counters + * on a domain. + */ +void mon_event_count(void *info) +{ + struct rdtgroup *rdtgrp, *entry; + struct rmid_read *rr = info; + struct list_head *head; + int ret; + + rdtgrp = rr->rgrp; + + ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr); + + /* + * For Ctrl groups read data from child monitor groups and + * add them together. Count events which are read successfully. + * Discard the rmid_read's reporting errors. + */ + head = &rdtgrp->mon.crdtgrp_list; + + if (rdtgrp->type == RDTCTRL_GROUP) { + list_for_each_entry(entry, head, mon.crdtgrp_list) { + if (__mon_event_count(entry->closid, entry->mon.rmid, + rr) == 0) + ret = 0; + } + } + + /* + * __mon_event_count() calls for newly created monitor groups may + * report -EINVAL/Unavailable if the monitor hasn't seen any traffic. + * Discard error if any of the monitor event reads succeeded. + */ + if (ret == 0) + rr->err = 0; +} + +/* + * Feedback loop for MBA software controller (mba_sc) + * + * mba_sc is a feedback loop where we periodically read MBM counters and + * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so + * that: + * + * current bandwidth(cur_bw) < user specified bandwidth(user_bw) + * + * This uses the MBM counters to measure the bandwidth and MBA throttle + * MSRs to control the bandwidth for a particular rdtgrp. It builds on the + * fact that resctrl rdtgroups have both monitoring and control. + * + * The frequency of the checks is 1s and we just tag along the MBM overflow + * timer. Having 1s interval makes the calculation of bandwidth simpler. + * + * Although MBA's goal is to restrict the bandwidth to a maximum, there may + * be a need to increase the bandwidth to avoid unnecessarily restricting + * the L2 <-> L3 traffic. + * + * Since MBA controls the L2 external bandwidth where as MBM measures the + * L3 external bandwidth the following sequence could lead to such a + * situation. + * + * Consider an rdtgroup which had high L3 <-> memory traffic in initial + * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but + * after some time rdtgroup has mostly L2 <-> L3 traffic. + * + * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its + * throttle MSRs already have low percentage values. To avoid + * unnecessarily restricting such rdtgroups, we also increase the bandwidth. + */ +static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm) +{ + u32 closid, rmid, cur_msr_val, new_msr_val; + struct mbm_state *pmbm_data, *cmbm_data; + u32 cur_bw, delta_bw, user_bw, idx; + struct rdt_resource *r_mba; + struct rdt_domain *dom_mba; + struct list_head *head; + struct rdtgroup *entry; + + if (!resctrl_arch_is_mbm_local_enabled()) + return; + + r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + + closid = rgrp->closid; + rmid = rgrp->mon.rmid; + idx = resctrl_arch_rmid_idx_encode(closid, rmid); + pmbm_data = &dom_mbm->mbm_local[idx]; + + dom_mba = resctrl_get_domain_from_cpu(smp_processor_id(), r_mba); + if (!dom_mba) { + pr_warn_once("Failure to get domain for MBA update\n"); + return; + } + + cur_bw = pmbm_data->prev_bw; + user_bw = dom_mba->mbps_val[closid]; + delta_bw = pmbm_data->delta_bw; + + /* MBA resource doesn't support CDP */ + cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE); + + /* + * For Ctrl groups read data from child monitor groups. + */ + head = &rgrp->mon.crdtgrp_list; + list_for_each_entry(entry, head, mon.crdtgrp_list) { + cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid]; + cur_bw += cmbm_data->prev_bw; + delta_bw += cmbm_data->delta_bw; + } + + /* + * Scale up/down the bandwidth linearly for the ctrl group. The + * bandwidth step is the bandwidth granularity specified by the + * hardware. + * + * The delta_bw is used when increasing the bandwidth so that we + * dont alternately increase and decrease the control values + * continuously. + * + * For ex: consider cur_bw = 90MBps, user_bw = 100MBps and if + * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep + * switching between 90 and 110 continuously if we only check + * cur_bw < user_bw. + */ + if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) { + new_msr_val = cur_msr_val - r_mba->membw.bw_gran; + } else if (cur_msr_val < MAX_MBA_BW && + (user_bw > (cur_bw + delta_bw))) { + new_msr_val = cur_msr_val + r_mba->membw.bw_gran; + } else { + return; + } + + resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val); + + /* + * Delta values are updated dynamically package wise for each + * rdtgrp every time the throttle MSR changes value. + * + * This is because (1)the increase in bandwidth is not perfectly + * linear and only "approximately" linear even when the hardware + * says it is linear.(2)Also since MBA is a core specific + * mechanism, the delta values vary based on number of cores used + * by the rdtgrp. + */ + pmbm_data->delta_comp = true; + list_for_each_entry(entry, head, mon.crdtgrp_list) { + cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid]; + cmbm_data->delta_comp = true; + } +} + +static void mbm_update(struct rdt_resource *r, struct rdt_domain *d, + u32 closid, u32 rmid) +{ + struct rmid_read rr; + + rr.first = false; + rr.r = r; + rr.d = d; + + /* + * This is protected from concurrent reads from user + * as both the user and we hold the global mutex. + */ + if (resctrl_arch_is_mbm_total_enabled()) { + rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID; + rr.val = 0; + rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); + if (IS_ERR(rr.arch_mon_ctx)) { + pr_warn_ratelimited("Failed to allocate monitor context: %ld", + PTR_ERR(rr.arch_mon_ctx)); + return; + } + + __mon_event_count(closid, rmid, &rr); + + resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); + } + if (resctrl_arch_is_mbm_local_enabled()) { + rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID; + rr.val = 0; + rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); + if (IS_ERR(rr.arch_mon_ctx)) { + pr_warn_ratelimited("Failed to allocate monitor context: %ld", + PTR_ERR(rr.arch_mon_ctx)); + return; + } + + __mon_event_count(closid, rmid, &rr); + + /* + * Call the MBA software controller only for the + * control groups and when user has enabled + * the software controller explicitly. + */ + if (is_mba_sc(NULL)) + mbm_bw_count(closid, rmid, &rr); + + resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); + } +} + +/* + * Handler to scan the limbo list and move the RMIDs + * to free list whose occupancy < threshold_occupancy. + */ +void cqm_handle_limbo(struct work_struct *work) +{ + unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL); + struct rdt_domain *d; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + d = container_of(work, struct rdt_domain, cqm_limbo.work); + + __check_limbo(d, false); + + if (has_busy_rmid(d)) { + d->cqm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask, + RESCTRL_PICK_ANY_CPU); + schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo, + delay); + } + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); +} + +/** + * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this + * domain. + * @dom: The domain the limbo handler should run for. + * @delay_ms: How far in the future the handler should run. + * @exclude_cpu: Which CPU the handler should not run on, + * RESCTRL_PICK_ANY_CPU to pick any CPU. + */ +void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms, + int exclude_cpu) +{ + unsigned long delay = msecs_to_jiffies(delay_ms); + int cpu; + + cpu = cpumask_any_housekeeping(&dom->cpu_mask, exclude_cpu); + dom->cqm_work_cpu = cpu; + + if (cpu < nr_cpu_ids) + schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay); +} + +void mbm_handle_overflow(struct work_struct *work) +{ + unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL); + struct rdtgroup *prgrp, *crgrp; + struct list_head *head; + struct rdt_resource *r; + struct rdt_domain *d; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + /* + * If the filesystem has been unmounted this work no longer needs to + * run. + */ + if (!resctrl_mounted || !resctrl_arch_mon_capable()) + goto out_unlock; + + r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + d = container_of(work, struct rdt_domain, mbm_over.work); + + list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { + mbm_update(r, d, prgrp->closid, prgrp->mon.rmid); + + head = &prgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) + mbm_update(r, d, crgrp->closid, crgrp->mon.rmid); + + if (is_mba_sc(NULL)) + update_mba_bw(prgrp, d); + } + + /* + * Re-check for housekeeping CPUs. This allows the overflow handler to + * move off a nohz_full CPU quickly. + */ + d->mbm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask, + RESCTRL_PICK_ANY_CPU); + schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay); + +out_unlock: + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); +} + +/** + * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this + * domain. + * @dom: The domain the overflow handler should run for. + * @delay_ms: How far in the future the handler should run. + * @exclude_cpu: Which CPU the handler should not run on, + * RESCTRL_PICK_ANY_CPU to pick any CPU. + */ +void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms, + int exclude_cpu) +{ + unsigned long delay = msecs_to_jiffies(delay_ms); + int cpu; + + /* + * When a domain comes online there is no guarantee the filesystem is + * mounted. If not, there is no need to catch counter overflow. + */ + if (!resctrl_mounted || !resctrl_arch_mon_capable()) + return; + cpu = cpumask_any_housekeeping(&dom->cpu_mask, exclude_cpu); + dom->mbm_work_cpu = cpu; + + if (cpu < nr_cpu_ids) + schedule_delayed_work_on(cpu, &dom->mbm_over, delay); +} + +static int dom_data_init(struct rdt_resource *r) +{ + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + u32 num_closid = resctrl_arch_get_num_closid(r); + struct rmid_entry *entry = NULL; + int err = 0, i; + u32 idx; + + mutex_lock(&rdtgroup_mutex); + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + u32 *tmp; + + tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL); + if (!tmp) { + err = -ENOMEM; + goto out_unlock; + } + + closid_num_dirty_rmid = tmp; + } + + rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL); + if (!rmid_ptrs) { + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + kfree(closid_num_dirty_rmid); + closid_num_dirty_rmid = NULL; + } + err = -ENOMEM; + goto out_unlock; + } + + for (i = 0; i < idx_limit; i++) { + entry = &rmid_ptrs[i]; + INIT_LIST_HEAD(&entry->list); + + resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid); + list_add_tail(&entry->list, &rmid_free_lru); + } + + /* + * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and + * are always allocated. These are used for the rdtgroup_default + * control group, which will be setup later in rdtgroup_init(). + */ + idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, + RESCTRL_RESERVED_RMID); + entry = __rmid_entry(idx); + list_del(&entry->list); + +out_unlock: + mutex_unlock(&rdtgroup_mutex); + + return err; +} + +static void dom_data_exit(struct rdt_resource *r) +{ + if (!r->mon_capable) + return; + + mutex_lock(&rdtgroup_mutex); + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + kfree(closid_num_dirty_rmid); + closid_num_dirty_rmid = NULL; + } + + kfree(rmid_ptrs); + rmid_ptrs = NULL; + + mutex_unlock(&rdtgroup_mutex); +} + +static struct mon_evt llc_occupancy_event = { + .name = "llc_occupancy", + .evtid = QOS_L3_OCCUP_EVENT_ID, +}; + +static struct mon_evt mbm_total_event = { + .name = "mbm_total_bytes", + .evtid = QOS_L3_MBM_TOTAL_EVENT_ID, +}; + +static struct mon_evt mbm_local_event = { + .name = "mbm_local_bytes", + .evtid = QOS_L3_MBM_LOCAL_EVENT_ID, +}; + +/* + * Initialize the event list for the resource. + * + * Note that MBM events are also part of RDT_RESOURCE_L3 resource + * because as per the SDM the total and local memory bandwidth + * are enumerated as part of L3 monitoring. + */ +static void l3_mon_evt_init(struct rdt_resource *r) +{ + INIT_LIST_HEAD(&r->evt_list); + + if (resctrl_arch_is_llc_occupancy_enabled()) + list_add_tail(&llc_occupancy_event.list, &r->evt_list); + if (resctrl_arch_is_mbm_total_enabled()) + list_add_tail(&mbm_total_event.list, &r->evt_list); + if (resctrl_arch_is_mbm_local_enabled()) + list_add_tail(&mbm_local_event.list, &r->evt_list); +} + +int resctrl_mon_resource_init(void) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + int ret; + + ret = dom_data_init(r); + if (ret) + return ret; + + if (!r->mon_capable) + return 0; + + l3_mon_evt_init(r); + + if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) { + mbm_total_event.configurable = true; + mbm_config_rftype_init("mbm_total_bytes_config"); + } + if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) { + mbm_local_event.configurable = true; + mbm_config_rftype_init("mbm_local_bytes_config"); + } + + return 0; +} + +void resctrl_mon_resource_exit(void) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + + dom_data_exit(r); +} diff --git a/fs/resctrl/psuedo_lock.c b/fs/resctrl/psuedo_lock.c index e69de29bb2d1..2fa42d0a33ea 100644 --- a/fs/resctrl/psuedo_lock.c +++ b/fs/resctrl/psuedo_lock.c @@ -0,0 +1,1134 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Resource Director Technology (RDT) + * + * Pseudo-locking support built on top of Cache Allocation Technology (CAT) + * + * Copyright (C) 2018 Intel Corporation + * + * Author: Reinette Chatre reinette.chatre@intel.com + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cacheinfo.h> +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/debugfs.h> +#include <linux/kthread.h> +#include <linux/mman.h> +#include <linux/perf_event.h> +#include <linux/pm_qos.h> +#include <linux/slab.h> +#include <linux/uaccess.h> + +#include <asm/cacheflush.h> +#include <asm/resctrl.h> +#include <asm/perf_event.h> + +#include "internal.h" + +/* + * Major number assigned to and shared by all devices exposing + * pseudo-locked regions. + */ +static unsigned int pseudo_lock_major; +static unsigned long pseudo_lock_minor_avail = GENMASK(MINORBITS, 0); + +static char *pseudo_lock_devnode(const struct device *dev, umode_t *mode) +{ + const struct rdtgroup *rdtgrp; + + rdtgrp = dev_get_drvdata(dev); + if (mode) + *mode = 0600; + return kasprintf(GFP_KERNEL, "pseudo_lock/%s", rdtgrp->kn->name); +} + +static const struct class pseudo_lock_class = { + .name = "pseudo_lock", + .devnode = pseudo_lock_devnode, +}; + +/** + * pseudo_lock_minor_get - Obtain available minor number + * @minor: Pointer to where new minor number will be stored + * + * A bitmask is used to track available minor numbers. Here the next free + * minor number is marked as unavailable and returned. + * + * Return: 0 on success, <0 on failure. + */ +static int pseudo_lock_minor_get(unsigned int *minor) +{ + unsigned long first_bit; + + first_bit = find_first_bit(&pseudo_lock_minor_avail, MINORBITS); + + if (first_bit == MINORBITS) + return -ENOSPC; + + __clear_bit(first_bit, &pseudo_lock_minor_avail); + *minor = first_bit; + + return 0; +} + +/** + * pseudo_lock_minor_release - Return minor number to available + * @minor: The minor number made available + */ +static void pseudo_lock_minor_release(unsigned int minor) +{ + __set_bit(minor, &pseudo_lock_minor_avail); +} + +/** + * region_find_by_minor - Locate a pseudo-lock region by inode minor number + * @minor: The minor number of the device representing pseudo-locked region + * + * When the character device is accessed we need to determine which + * pseudo-locked region it belongs to. This is done by matching the minor + * number of the device to the pseudo-locked region it belongs. + * + * Minor numbers are assigned at the time a pseudo-locked region is associated + * with a cache instance. + * + * Return: On success return pointer to resource group owning the pseudo-locked + * region, NULL on failure. + */ +static struct rdtgroup *region_find_by_minor(unsigned int minor) +{ + struct rdtgroup *rdtgrp, *rdtgrp_match = NULL; + + list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { + if (rdtgrp->plr && rdtgrp->plr->minor == minor) { + rdtgrp_match = rdtgrp; + break; + } + } + return rdtgrp_match; +} + +/** + * struct pseudo_lock_pm_req - A power management QoS request list entry + * @list: Entry within the @pm_reqs list for a pseudo-locked region + * @req: PM QoS request + */ +struct pseudo_lock_pm_req { + struct list_head list; + struct dev_pm_qos_request req; +}; + +static void pseudo_lock_cstates_relax(struct pseudo_lock_region *plr) +{ + struct pseudo_lock_pm_req *pm_req, *next; + + list_for_each_entry_safe(pm_req, next, &plr->pm_reqs, list) { + dev_pm_qos_remove_request(&pm_req->req); + list_del(&pm_req->list); + kfree(pm_req); + } +} + +/** + * pseudo_lock_cstates_constrain - Restrict cores from entering C6 + * @plr: Pseudo-locked region + * + * To prevent the cache from being affected by power management entering + * C6 has to be avoided. This is accomplished by requesting a latency + * requirement lower than lowest C6 exit latency of all supported + * platforms as found in the cpuidle state tables in the intel_idle driver. + * At this time it is possible to do so with a single latency requirement + * for all supported platforms. + * + * Since Goldmont is supported, which is affected by X86_BUG_MONITOR, + * the ACPI latencies need to be considered while keeping in mind that C2 + * may be set to map to deeper sleep states. In this case the latency + * requirement needs to prevent entering C2 also. + * + * Return: 0 on success, <0 on failure + */ +static int pseudo_lock_cstates_constrain(struct pseudo_lock_region *plr) +{ + struct pseudo_lock_pm_req *pm_req; + int cpu; + int ret; + + for_each_cpu(cpu, &plr->d->cpu_mask) { + pm_req = kzalloc(sizeof(*pm_req), GFP_KERNEL); + if (!pm_req) { + rdt_last_cmd_puts("Failure to allocate memory for PM QoS\n"); + ret = -ENOMEM; + goto out_err; + } + ret = dev_pm_qos_add_request(get_cpu_device(cpu), + &pm_req->req, + DEV_PM_QOS_RESUME_LATENCY, + 30); + if (ret < 0) { + rdt_last_cmd_printf("Failed to add latency req CPU%d\n", + cpu); + kfree(pm_req); + ret = -1; + goto out_err; + } + list_add(&pm_req->list, &plr->pm_reqs); + } + + return 0; + +out_err: + pseudo_lock_cstates_relax(plr); + return ret; +} + +/** + * pseudo_lock_region_clear - Reset pseudo-lock region data + * @plr: pseudo-lock region + * + * All content of the pseudo-locked region is reset - any memory allocated + * freed. + * + * Return: void + */ +static void pseudo_lock_region_clear(struct pseudo_lock_region *plr) +{ + plr->size = 0; + plr->line_size = 0; + kfree(plr->kmem); + plr->kmem = NULL; + plr->s = NULL; + if (plr->d) + plr->d->plr = NULL; + plr->d = NULL; + plr->cbm = 0; + plr->debugfs_dir = NULL; +} + +/** + * pseudo_lock_region_init - Initialize pseudo-lock region information + * @plr: pseudo-lock region + * + * Called after user provided a schemata to be pseudo-locked. From the + * schemata the &struct pseudo_lock_region is on entry already initialized + * with the resource, domain, and capacity bitmask. Here the information + * required for pseudo-locking is deduced from this data and &struct + * pseudo_lock_region initialized further. This information includes: + * - size in bytes of the region to be pseudo-locked + * - cache line size to know the stride with which data needs to be accessed + * to be pseudo-locked + * - a cpu associated with the cache instance on which the pseudo-locking + * flow can be executed + * + * Return: 0 on success, <0 on failure. Descriptive error will be written + * to last_cmd_status buffer. + */ +static int pseudo_lock_region_init(struct pseudo_lock_region *plr) +{ + struct cpu_cacheinfo *ci; + int ret; + int i; + + /* Pick the first cpu we find that is associated with the cache. */ + plr->cpu = cpumask_first(&plr->d->cpu_mask); + + if (!cpu_online(plr->cpu)) { + rdt_last_cmd_printf("CPU %u associated with cache not online\n", + plr->cpu); + ret = -ENODEV; + goto out_region; + } + + ci = get_cpu_cacheinfo(plr->cpu); + + plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm); + + for (i = 0; i < ci->num_leaves; i++) { + if (ci->info_list[i].level == plr->s->res->cache_level) { + plr->line_size = ci->info_list[i].coherency_line_size; + return 0; + } + } + + ret = -1; + rdt_last_cmd_puts("Unable to determine cache line size\n"); +out_region: + pseudo_lock_region_clear(plr); + return ret; +} + +/** + * pseudo_lock_init - Initialize a pseudo-lock region + * @rdtgrp: resource group to which new pseudo-locked region will belong + * + * A pseudo-locked region is associated with a resource group. When this + * association is created the pseudo-locked region is initialized. The + * details of the pseudo-locked region are not known at this time so only + * allocation is done and association established. + * + * Return: 0 on success, <0 on failure + */ +static int pseudo_lock_init(struct rdtgroup *rdtgrp) +{ + struct pseudo_lock_region *plr; + + plr = kzalloc(sizeof(*plr), GFP_KERNEL); + if (!plr) + return -ENOMEM; + + init_waitqueue_head(&plr->lock_thread_wq); + INIT_LIST_HEAD(&plr->pm_reqs); + rdtgrp->plr = plr; + return 0; +} + +/** + * pseudo_lock_region_alloc - Allocate kernel memory that will be pseudo-locked + * @plr: pseudo-lock region + * + * Initialize the details required to set up the pseudo-locked region and + * allocate the contiguous memory that will be pseudo-locked to the cache. + * + * Return: 0 on success, <0 on failure. Descriptive error will be written + * to last_cmd_status buffer. + */ +static int pseudo_lock_region_alloc(struct pseudo_lock_region *plr) +{ + int ret; + + ret = pseudo_lock_region_init(plr); + if (ret < 0) + return ret; + + /* + * We do not yet support contiguous regions larger than + * KMALLOC_MAX_SIZE. + */ + if (plr->size > KMALLOC_MAX_SIZE) { + rdt_last_cmd_puts("Requested region exceeds maximum size\n"); + ret = -E2BIG; + goto out_region; + } + + plr->kmem = kzalloc(plr->size, GFP_KERNEL); + if (!plr->kmem) { + rdt_last_cmd_puts("Unable to allocate memory\n"); + ret = -ENOMEM; + goto out_region; + } + + ret = 0; + goto out; +out_region: + pseudo_lock_region_clear(plr); +out: + return ret; +} + +/** + * pseudo_lock_free - Free a pseudo-locked region + * @rdtgrp: resource group to which pseudo-locked region belonged + * + * The pseudo-locked region's resources have already been released, or not + * yet created at this point. Now it can be freed and disassociated from the + * resource group. + * + * Return: void + */ +static void pseudo_lock_free(struct rdtgroup *rdtgrp) +{ + pseudo_lock_region_clear(rdtgrp->plr); + kfree(rdtgrp->plr); + rdtgrp->plr = NULL; +} + +/** + * rdtgroup_monitor_in_progress - Test if monitoring in progress + * @rdtgrp: resource group being queried + * + * Return: 1 if monitor groups have been created for this resource + * group, 0 otherwise. + */ +static int rdtgroup_monitor_in_progress(struct rdtgroup *rdtgrp) +{ + return !list_empty(&rdtgrp->mon.crdtgrp_list); +} + +/** + * rdtgroup_locksetup_user_restrict - Restrict user access to group + * @rdtgrp: resource group needing access restricted + * + * A resource group used for cache pseudo-locking cannot have cpus or tasks + * assigned to it. This is communicated to the user by restricting access + * to all the files that can be used to make such changes. + * + * Permissions restored with rdtgroup_locksetup_user_restore() + * + * Return: 0 on success, <0 on failure. If a failure occurs during the + * restriction of access an attempt will be made to restore permissions but + * the state of the mode of these files will be uncertain when a failure + * occurs. + */ +static int rdtgroup_locksetup_user_restrict(struct rdtgroup *rdtgrp) +{ + int ret; + + ret = rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); + if (ret) + return ret; + + ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); + if (ret) + goto err_tasks; + + ret = rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); + if (ret) + goto err_cpus; + + if (resctrl_arch_mon_capable()) { + ret = rdtgroup_kn_mode_restrict(rdtgrp, "mon_groups"); + if (ret) + goto err_cpus_list; + } + + ret = 0; + goto out; + +err_cpus_list: + rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); +err_cpus: + rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); +err_tasks: + rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); +out: + return ret; +} + +/** + * rdtgroup_locksetup_user_restore - Restore user access to group + * @rdtgrp: resource group needing access restored + * + * Restore all file access previously removed using + * rdtgroup_locksetup_user_restrict() + * + * Return: 0 on success, <0 on failure. If a failure occurs during the + * restoration of access an attempt will be made to restrict permissions + * again but the state of the mode of these files will be uncertain when + * a failure occurs. + */ +static int rdtgroup_locksetup_user_restore(struct rdtgroup *rdtgrp) +{ + int ret; + + ret = rdtgroup_kn_mode_restore(rdtgrp, "tasks", 0777); + if (ret) + return ret; + + ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0777); + if (ret) + goto err_tasks; + + ret = rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0777); + if (ret) + goto err_cpus; + + if (resctrl_arch_mon_capable()) { + ret = rdtgroup_kn_mode_restore(rdtgrp, "mon_groups", 0777); + if (ret) + goto err_cpus_list; + } + + ret = 0; + goto out; + +err_cpus_list: + rdtgroup_kn_mode_restrict(rdtgrp, "cpus_list"); +err_cpus: + rdtgroup_kn_mode_restrict(rdtgrp, "cpus"); +err_tasks: + rdtgroup_kn_mode_restrict(rdtgrp, "tasks"); +out: + return ret; +} + +/** + * rdtgroup_locksetup_enter - Resource group enters locksetup mode + * @rdtgrp: resource group requested to enter locksetup mode + * + * A resource group enters locksetup mode to reflect that it would be used + * to represent a pseudo-locked region and is in the process of being set + * up to do so. A resource group used for a pseudo-locked region would + * lose the closid associated with it so we cannot allow it to have any + * tasks or cpus assigned nor permit tasks or cpus to be assigned in the + * future. Monitoring of a pseudo-locked region is not allowed either. + * + * The above and more restrictions on a pseudo-locked region are checked + * for and enforced before the resource group enters the locksetup mode. + * + * Returns: 0 if the resource group successfully entered locksetup mode, <0 + * on failure. On failure the last_cmd_status buffer is updated with text to + * communicate details of failure to the user. + */ +int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) +{ + int ret; + + /* + * The default resource group can neither be removed nor lose the + * default closid associated with it. + */ + if (rdtgrp == &rdtgroup_default) { + rdt_last_cmd_puts("Cannot pseudo-lock default group\n"); + return -EINVAL; + } + + /* + * Cache Pseudo-locking not supported when CDP is enabled. + * + * Some things to consider if you would like to enable this + * support (using L3 CDP as example): + * - When CDP is enabled two separate resources are exposed, + * L3DATA and L3CODE, but they are actually on the same cache. + * The implication for pseudo-locking is that if a + * pseudo-locked region is created on a domain of one + * resource (eg. L3CODE), then a pseudo-locked region cannot + * be created on that same domain of the other resource + * (eg. L3DATA). This is because the creation of a + * pseudo-locked region involves a call to wbinvd that will + * affect all cache allocations on particular domain. + * - Considering the previous, it may be possible to only + * expose one of the CDP resources to pseudo-locking and + * hide the other. For example, we could consider to only + * expose L3DATA and since the L3 cache is unified it is + * still possible to place instructions there are execute it. + * - If only one region is exposed to pseudo-locking we should + * still keep in mind that availability of a portion of cache + * for pseudo-locking should take into account both resources. + * Similarly, if a pseudo-locked region is created in one + * resource, the portion of cache used by it should be made + * unavailable to all future allocations from both resources. + */ + if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3) || + resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) { + rdt_last_cmd_puts("CDP enabled\n"); + return -EINVAL; + } + + /* + * Not knowing the bits to disable prefetching implies that this + * platform does not support Cache Pseudo-Locking. + */ + if (resctrl_arch_get_prefetch_disable_bits() == 0) { + rdt_last_cmd_puts("Pseudo-locking not supported\n"); + return -EINVAL; + } + + if (rdtgroup_monitor_in_progress(rdtgrp)) { + rdt_last_cmd_puts("Monitoring in progress\n"); + return -EINVAL; + } + + if (rdtgroup_tasks_assigned(rdtgrp)) { + rdt_last_cmd_puts("Tasks assigned to resource group\n"); + return -EINVAL; + } + + if (!cpumask_empty(&rdtgrp->cpu_mask)) { + rdt_last_cmd_puts("CPUs assigned to resource group\n"); + return -EINVAL; + } + + if (rdtgroup_locksetup_user_restrict(rdtgrp)) { + rdt_last_cmd_puts("Unable to modify resctrl permissions\n"); + return -EIO; + } + + ret = pseudo_lock_init(rdtgrp); + if (ret) { + rdt_last_cmd_puts("Unable to init pseudo-lock region\n"); + goto out_release; + } + + /* + * If this system is capable of monitoring a rmid would have been + * allocated when the control group was created. This is not needed + * anymore when this group would be used for pseudo-locking. This + * is safe to call on platforms not capable of monitoring. + */ + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + + ret = 0; + goto out; + +out_release: + rdtgroup_locksetup_user_restore(rdtgrp); +out: + return ret; +} + +/** + * rdtgroup_locksetup_exit - resource group exist locksetup mode + * @rdtgrp: resource group + * + * When a resource group exits locksetup mode the earlier restrictions are + * lifted. + * + * Return: 0 on success, <0 on failure + */ +int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp) +{ + int ret; + + if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) + return -EOPNOTSUPP; + + if (resctrl_arch_mon_capable()) { + ret = alloc_rmid(rdtgrp->closid); + if (ret < 0) { + rdt_last_cmd_puts("Out of RMIDs\n"); + return ret; + } + rdtgrp->mon.rmid = ret; + } + + ret = rdtgroup_locksetup_user_restore(rdtgrp); + if (ret) { + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + return ret; + } + + pseudo_lock_free(rdtgrp); + return 0; +} + +/** + * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked + * @d: RDT domain + * @cbm: CBM to test + * + * @d represents a cache instance and @cbm a capacity bitmask that is + * considered for it. Determine if @cbm overlaps with any existing + * pseudo-locked region on @d. + * + * @cbm is unsigned long, even if only 32 bits are used, to make the + * bitmap functions work correctly. + * + * Return: true if @cbm overlaps with pseudo-locked region on @d, false + * otherwise. + */ +bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_domain *d, unsigned long cbm) +{ + unsigned int cbm_len; + unsigned long cbm_b; + + if (d->plr) { + cbm_len = d->plr->s->res->cache.cbm_len; + cbm_b = d->plr->cbm; + if (bitmap_intersects(&cbm, &cbm_b, cbm_len)) + return true; + } + return false; +} + +/** + * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy + * @d: RDT domain under test + * + * The setup of a pseudo-locked region affects all cache instances within + * the hierarchy of the region. It is thus essential to know if any + * pseudo-locked regions exist within a cache hierarchy to prevent any + * attempts to create new pseudo-locked regions in the same hierarchy. + * + * Return: true if a pseudo-locked region exists in the hierarchy of @d or + * if it is not possible to test due to memory allocation issue, + * false otherwise. + */ +bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d) +{ + cpumask_var_t cpu_with_psl; + enum resctrl_res_level i; + struct rdt_resource *r; + struct rdt_domain *d_i; + bool ret = false; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) + return -EOPNOTSUPP; + + if (!zalloc_cpumask_var(&cpu_with_psl, GFP_KERNEL)) + return true; + + /* + * First determine which cpus have pseudo-locked regions + * associated with them. + */ + for (i = 0; i < RDT_NUM_RESOURCES; i++) { + r = resctrl_arch_get_resource(i); + if (!r->alloc_capable) + continue; + + list_for_each_entry(d_i, &r->domains, list) { + if (d_i->plr) + cpumask_or(cpu_with_psl, cpu_with_psl, + &d_i->cpu_mask); + } + } + + /* + * Next test if new pseudo-locked region would intersect with + * existing region. + */ + if (cpumask_intersects(&d->cpu_mask, cpu_with_psl)) + ret = true; + + free_cpumask_var(cpu_with_psl); + return ret; +} + +/** + * pseudo_lock_measure_cycles - Trigger latency measure to pseudo-locked region + * @rdtgrp: Resource group to which the pseudo-locked region belongs. + * @sel: Selector of which measurement to perform on a pseudo-locked region. + * + * The measurement of latency to access a pseudo-locked region should be + * done from a cpu that is associated with that pseudo-locked region. + * Determine which cpu is associated with this region and start a thread on + * that cpu to perform the measurement, wait for that thread to complete. + * + * Return: 0 on success, <0 on failure + */ +static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel) +{ + struct pseudo_lock_region *plr = rdtgrp->plr; + struct task_struct *thread; + unsigned int cpu; + int ret = -1; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + if (rdtgrp->flags & RDT_DELETED) { + ret = -ENODEV; + goto out; + } + + if (!plr->d) { + ret = -ENODEV; + goto out; + } + + plr->thread_done = 0; + cpu = cpumask_first(&plr->d->cpu_mask); + if (!cpu_online(cpu)) { + ret = -ENODEV; + goto out; + } + + plr->cpu = cpu; + + if (sel == 1) + thread = kthread_create_on_node(resctrl_arch_measure_cycles_lat_fn, + plr, cpu_to_node(cpu), + "pseudo_lock_measure/%u", + cpu); + else if (sel == 2) + thread = kthread_create_on_node(resctrl_arch_measure_l2_residency, + plr, cpu_to_node(cpu), + "pseudo_lock_measure/%u", + cpu); + else if (sel == 3) + thread = kthread_create_on_node(resctrl_arch_measure_l3_residency, + plr, cpu_to_node(cpu), + "pseudo_lock_measure/%u", + cpu); + else + goto out; + + if (IS_ERR(thread)) { + ret = PTR_ERR(thread); + goto out; + } + kthread_bind(thread, cpu); + wake_up_process(thread); + + ret = wait_event_interruptible(plr->lock_thread_wq, + plr->thread_done == 1); + if (ret < 0) + goto out; + + ret = 0; + +out: + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + return ret; +} + +static ssize_t pseudo_lock_measure_trigger(struct file *file, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct rdtgroup *rdtgrp = file->private_data; + size_t buf_size; + char buf[32]; + int ret; + int sel; + + buf_size = min(count, (sizeof(buf) - 1)); + if (copy_from_user(buf, user_buf, buf_size)) + return -EFAULT; + + buf[buf_size] = '\0'; + ret = kstrtoint(buf, 10, &sel); + if (ret == 0) { + if (sel != 1 && sel != 2 && sel != 3) + return -EINVAL; + ret = debugfs_file_get(file->f_path.dentry); + if (ret) + return ret; + ret = pseudo_lock_measure_cycles(rdtgrp, sel); + if (ret == 0) + ret = count; + debugfs_file_put(file->f_path.dentry); + } + + return ret; +} + +static const struct file_operations pseudo_measure_fops = { + .write = pseudo_lock_measure_trigger, + .open = simple_open, + .llseek = default_llseek, +}; + +/** + * rdtgroup_pseudo_lock_create - Create a pseudo-locked region + * @rdtgrp: resource group to which pseudo-lock region belongs + * + * Called when a resource group in the pseudo-locksetup mode receives a + * valid schemata that should be pseudo-locked. Since the resource group is + * in pseudo-locksetup mode the &struct pseudo_lock_region has already been + * allocated and initialized with the essential information. If a failure + * occurs the resource group remains in the pseudo-locksetup mode with the + * &struct pseudo_lock_region associated with it, but cleared from all + * information and ready for the user to re-attempt pseudo-locking by + * writing the schemata again. + * + * Return: 0 if the pseudo-locked region was successfully pseudo-locked, <0 + * on failure. Descriptive error will be written to last_cmd_status buffer. + */ +int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp) +{ + struct pseudo_lock_region *plr = rdtgrp->plr; + struct task_struct *thread; + unsigned int new_minor; + struct device *dev; + int ret; + + if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) + return -EOPNOTSUPP; + + ret = pseudo_lock_region_alloc(plr); + if (ret < 0) + return ret; + + ret = pseudo_lock_cstates_constrain(plr); + if (ret < 0) { + ret = -EINVAL; + goto out_region; + } + + plr->thread_done = 0; + + plr->closid = rdtgrp->closid; + thread = kthread_create_on_node(resctrl_arch_pseudo_lock_fn, plr, + cpu_to_node(plr->cpu), + "pseudo_lock/%u", plr->cpu); + if (IS_ERR(thread)) { + ret = PTR_ERR(thread); + rdt_last_cmd_printf("Locking thread returned error %d\n", ret); + goto out_cstates; + } + + kthread_bind(thread, plr->cpu); + wake_up_process(thread); + + ret = wait_event_interruptible(plr->lock_thread_wq, + plr->thread_done == 1); + if (ret < 0) { + /* + * If the thread does not get on the CPU for whatever + * reason and the process which sets up the region is + * interrupted then this will leave the thread in runnable + * state and once it gets on the CPU it will dereference + * the cleared, but not freed, plr struct resulting in an + * empty pseudo-locking loop. + */ + rdt_last_cmd_puts("Locking thread interrupted\n"); + goto out_cstates; + } + + ret = pseudo_lock_minor_get(&new_minor); + if (ret < 0) { + rdt_last_cmd_puts("Unable to obtain a new minor number\n"); + goto out_cstates; + } + + /* + * Unlock access but do not release the reference. The + * pseudo-locked region will still be here on return. + * + * The mutex has to be released temporarily to avoid a potential + * deadlock with the mm->mmap_lock which is obtained in the + * device_create() and debugfs_create_dir() callpath below as well as + * before the mmap() callback is called. + */ + mutex_unlock(&rdtgroup_mutex); + + if (!IS_ERR_OR_NULL(debugfs_resctrl)) { + plr->debugfs_dir = debugfs_create_dir(rdtgrp->kn->name, + debugfs_resctrl); + if (!IS_ERR_OR_NULL(plr->debugfs_dir)) + debugfs_create_file("pseudo_lock_measure", 0200, + plr->debugfs_dir, rdtgrp, + &pseudo_measure_fops); + } + + dev = device_create(&pseudo_lock_class, NULL, + MKDEV(pseudo_lock_major, new_minor), + rdtgrp, "%s", rdtgrp->kn->name); + + mutex_lock(&rdtgroup_mutex); + + if (IS_ERR(dev)) { + ret = PTR_ERR(dev); + rdt_last_cmd_printf("Failed to create character device: %d\n", + ret); + goto out_debugfs; + } + + /* We released the mutex - check if group was removed while we did so */ + if (rdtgrp->flags & RDT_DELETED) { + ret = -ENODEV; + goto out_device; + } + + plr->minor = new_minor; + + rdtgrp->mode = RDT_MODE_PSEUDO_LOCKED; + closid_free(rdtgrp->closid); + rdtgroup_kn_mode_restore(rdtgrp, "cpus", 0444); + rdtgroup_kn_mode_restore(rdtgrp, "cpus_list", 0444); + + ret = 0; + goto out; + +out_device: + device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, new_minor)); +out_debugfs: + debugfs_remove_recursive(plr->debugfs_dir); + pseudo_lock_minor_release(new_minor); +out_cstates: + pseudo_lock_cstates_relax(plr); +out_region: + pseudo_lock_region_clear(plr); +out: + return ret; +} + +/** + * rdtgroup_pseudo_lock_remove - Remove a pseudo-locked region + * @rdtgrp: resource group to which the pseudo-locked region belongs + * + * The removal of a pseudo-locked region can be initiated when the resource + * group is removed from user space via a "rmdir" from userspace or the + * unmount of the resctrl filesystem. On removal the resource group does + * not go back to pseudo-locksetup mode before it is removed, instead it is + * removed directly. There is thus asymmetry with the creation where the + * &struct pseudo_lock_region is removed here while it was not created in + * rdtgroup_pseudo_lock_create(). + * + * Return: void + */ +void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) +{ + struct pseudo_lock_region *plr = rdtgrp->plr; + + if (!IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) + return; + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + /* + * Default group cannot be a pseudo-locked region so we can + * free closid here. + */ + closid_free(rdtgrp->closid); + goto free; + } + + pseudo_lock_cstates_relax(plr); + debugfs_remove_recursive(rdtgrp->plr->debugfs_dir); + device_destroy(&pseudo_lock_class, MKDEV(pseudo_lock_major, plr->minor)); + pseudo_lock_minor_release(plr->minor); + +free: + pseudo_lock_free(rdtgrp); +} + +static int pseudo_lock_dev_open(struct inode *inode, struct file *filp) +{ + struct rdtgroup *rdtgrp; + + mutex_lock(&rdtgroup_mutex); + + rdtgrp = region_find_by_minor(iminor(inode)); + if (!rdtgrp) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + + filp->private_data = rdtgrp; + atomic_inc(&rdtgrp->waitcount); + /* Perform a non-seekable open - llseek is not supported */ + filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); + + mutex_unlock(&rdtgroup_mutex); + + return 0; +} + +static int pseudo_lock_dev_release(struct inode *inode, struct file *filp) +{ + struct rdtgroup *rdtgrp; + + mutex_lock(&rdtgroup_mutex); + rdtgrp = filp->private_data; + WARN_ON(!rdtgrp); + if (!rdtgrp) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + filp->private_data = NULL; + atomic_dec(&rdtgrp->waitcount); + mutex_unlock(&rdtgroup_mutex); + return 0; +} + +static int pseudo_lock_dev_mremap(struct vm_area_struct *area) +{ + /* Not supported */ + return -EINVAL; +} + +static const struct vm_operations_struct pseudo_mmap_ops = { + .mremap = pseudo_lock_dev_mremap, +}; + +static int pseudo_lock_dev_mmap(struct file *filp, struct vm_area_struct *vma) +{ + unsigned long vsize = vma->vm_end - vma->vm_start; + unsigned long off = vma->vm_pgoff << PAGE_SHIFT; + struct pseudo_lock_region *plr; + struct rdtgroup *rdtgrp; + unsigned long physical; + unsigned long psize; + + mutex_lock(&rdtgroup_mutex); + + rdtgrp = filp->private_data; + WARN_ON(!rdtgrp); + if (!rdtgrp) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + + plr = rdtgrp->plr; + + if (!plr->d) { + mutex_unlock(&rdtgroup_mutex); + return -ENODEV; + } + + /* + * Task is required to run with affinity to the cpus associated + * with the pseudo-locked region. If this is not the case the task + * may be scheduled elsewhere and invalidate entries in the + * pseudo-locked region. + */ + if (!cpumask_subset(current->cpus_ptr, &plr->d->cpu_mask)) { + mutex_unlock(&rdtgroup_mutex); + return -EINVAL; + } + + physical = __pa(plr->kmem) >> PAGE_SHIFT; + psize = plr->size - off; + + if (off > plr->size) { + mutex_unlock(&rdtgroup_mutex); + return -ENOSPC; + } + + /* + * Ensure changes are carried directly to the memory being mapped, + * do not allow copy-on-write mapping. + */ + if (!(vma->vm_flags & VM_SHARED)) { + mutex_unlock(&rdtgroup_mutex); + return -EINVAL; + } + + if (vsize > psize) { + mutex_unlock(&rdtgroup_mutex); + return -ENOSPC; + } + + memset(plr->kmem + off, 0, vsize); + + if (remap_pfn_range(vma, vma->vm_start, physical + vma->vm_pgoff, + vsize, vma->vm_page_prot)) { + mutex_unlock(&rdtgroup_mutex); + return -EAGAIN; + } + vma->vm_ops = &pseudo_mmap_ops; + mutex_unlock(&rdtgroup_mutex); + return 0; +} + +static const struct file_operations pseudo_lock_dev_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .read = NULL, + .write = NULL, + .open = pseudo_lock_dev_open, + .release = pseudo_lock_dev_release, + .mmap = pseudo_lock_dev_mmap, +}; + +int rdt_pseudo_lock_init(void) +{ + int ret; + + ret = register_chrdev(0, "pseudo_lock", &pseudo_lock_dev_fops); + if (ret < 0) + return ret; + + pseudo_lock_major = ret; + + ret = class_register(&pseudo_lock_class); + if (ret) { + unregister_chrdev(pseudo_lock_major, "pseudo_lock"); + return ret; + } + + return 0; +} + +void rdt_pseudo_lock_release(void) +{ + class_unregister(&pseudo_lock_class); + unregister_chrdev(pseudo_lock_major, "pseudo_lock"); + pseudo_lock_major = 0; +} diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index e69de29bb2d1..0a3b99ca3b48 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -0,0 +1,4014 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * User interface for Resource Allocation in Resource Director Technology(RDT) + * + * Copyright (C) 2016 Intel Corporation + * + * Author: Fenghua Yu fenghua.yu@intel.com + * + * More information about RDT be found in the Intel (R) x86 Architecture + * Software Developer Manual. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cacheinfo.h> +#include <linux/cpu.h> +#include <linux/debugfs.h> +#include <linux/fs.h> +#include <linux/fs_parser.h> +#include <linux/sysfs.h> +#include <linux/kernfs.h> +#include <linux/seq_buf.h> +#include <linux/seq_file.h> +#include <linux/sched/signal.h> +#include <linux/sched/task.h> +#include <linux/slab.h> +#include <linux/task_work.h> +#include <linux/user_namespace.h> + +#include <uapi/linux/magic.h> + +#include <asm/resctrl.h> +#include "internal.h" + +/* Mutex to protect rdtgroup access. */ +DEFINE_MUTEX(rdtgroup_mutex); + +static struct kernfs_root *rdt_root; +struct rdtgroup rdtgroup_default; +LIST_HEAD(rdt_all_groups); + +/* list of entries for the schemata file */ +LIST_HEAD(resctrl_schema_all); + +/* The filesystem can only be mounted once. */ +bool resctrl_mounted; + +/* Kernel fs node for "info" directory under root */ +static struct kernfs_node *kn_info; + +/* Kernel fs node for "mon_groups" directory under root */ +static struct kernfs_node *kn_mongrp; + +/* Kernel fs node for "mon_data" directory under root */ +static struct kernfs_node *kn_mondata; + +/* + * Used to store the max resource name width and max resource data width + * to display the schemata in a tabular format + */ +int max_name_width, max_data_width; + +static struct seq_buf last_cmd_status; +static char last_cmd_status_buf[512]; + +static int rdtgroup_setup_root(struct rdt_fs_context *ctx); +static void rdtgroup_destroy_root(void); + +struct dentry *debugfs_resctrl; + +static bool resctrl_debug; + +void rdt_last_cmd_clear(void) +{ + lockdep_assert_held(&rdtgroup_mutex); + seq_buf_clear(&last_cmd_status); +} + +void rdt_last_cmd_puts(const char *s) +{ + lockdep_assert_held(&rdtgroup_mutex); + seq_buf_puts(&last_cmd_status, s); +} + +void rdt_last_cmd_printf(const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + lockdep_assert_held(&rdtgroup_mutex); + seq_buf_vprintf(&last_cmd_status, fmt, ap); + va_end(ap); +} + +void rdt_staged_configs_clear(void) +{ + struct rdt_resource *r; + struct rdt_domain *dom; + int i; + + lockdep_assert_held(&rdtgroup_mutex); + + for (i = 0; i < RDT_NUM_RESOURCES; i++) { + r = resctrl_arch_get_resource(i); + if (!r->alloc_capable) + continue; + + list_for_each_entry(dom, &r->domains, list) + memset(dom->staged_config, 0, sizeof(dom->staged_config)); + } +} + +static bool resctrl_is_mbm_enabled(void) +{ + return (resctrl_arch_is_mbm_total_enabled() || + resctrl_arch_is_mbm_local_enabled()); +} + +static bool resctrl_is_mbm_event(int e) +{ + return (e >= QOS_L3_MBM_TOTAL_EVENT_ID && + e <= QOS_L3_MBM_LOCAL_EVENT_ID); +} + +/* + * Trivial allocator for CLOSIDs. Since h/w only supports a small number, + * we can keep a bitmap of free CLOSIDs in a single integer. + * + * Using a global CLOSID across all resources has some advantages and + * some drawbacks: + * + We can simply set current's closid to assign a task to a resource + * group. + * + Context switch code can avoid extra memory references deciding which + * CLOSID to load into the PQR_ASSOC MSR + * - We give up some options in configuring resource groups across multi-socket + * systems. + * - Our choices on how to configure each resource become progressively more + * limited as the number of resources grows. + */ +static unsigned long closid_free_map; +static int closid_free_map_len; + +int closids_supported(void) +{ + return closid_free_map_len; +} + +static void closid_init(void) +{ + struct resctrl_schema *s; + u32 rdt_min_closid = 32; + + /* Compute rdt_min_closid across all resources */ + list_for_each_entry(s, &resctrl_schema_all, list) + rdt_min_closid = min(rdt_min_closid, s->num_closid); + + closid_free_map = BIT_MASK(rdt_min_closid) - 1; + + /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */ + __clear_bit(RESCTRL_RESERVED_CLOSID, &closid_free_map); + closid_free_map_len = rdt_min_closid; +} + +static int closid_alloc(void) +{ + int cleanest_closid; + u32 closid; + + lockdep_assert_held(&rdtgroup_mutex); + + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + cleanest_closid = resctrl_find_cleanest_closid(); + if (cleanest_closid < 0) + return cleanest_closid; + closid = cleanest_closid; + } else { + closid = ffs(closid_free_map); + if (closid == 0) + return -ENOSPC; + closid--; + } + __clear_bit(closid, &closid_free_map); + + return closid; +} + +void closid_free(int closid) +{ + lockdep_assert_held(&rdtgroup_mutex); + + __set_bit(closid, &closid_free_map); +} + +/** + * closid_allocated - test if provided closid is in use + * @closid: closid to be tested + * + * Return: true if @closid is currently associated with a resource group, + * false if @closid is free + */ +bool closid_allocated(unsigned int closid) +{ + lockdep_assert_held(&rdtgroup_mutex); + + return !test_bit(closid, &closid_free_map); +} + +/** + * rdtgroup_mode_by_closid - Return mode of resource group with closid + * @closid: closid if the resource group + * + * Each resource group is associated with a @closid. Here the mode + * of a resource group can be queried by searching for it using its closid. + * + * Return: mode as &enum rdtgrp_mode of resource group with closid @closid + */ +enum rdtgrp_mode rdtgroup_mode_by_closid(int closid) +{ + struct rdtgroup *rdtgrp; + + list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { + if (rdtgrp->closid == closid) + return rdtgrp->mode; + } + + return RDT_NUM_MODES; +} + +static const char * const rdt_mode_str[] = { + [RDT_MODE_SHAREABLE] = "shareable", + [RDT_MODE_EXCLUSIVE] = "exclusive", + [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup", + [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked", +}; + +/** + * rdtgroup_mode_str - Return the string representation of mode + * @mode: the resource group mode as &enum rdtgroup_mode + * + * Return: string representation of valid mode, "unknown" otherwise + */ +static const char *rdtgroup_mode_str(enum rdtgrp_mode mode) +{ + if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES) + return "unknown"; + + return rdt_mode_str[mode]; +} + +/* set uid and gid of rdtgroup dirs and files to that of the creator */ +static int rdtgroup_kn_set_ugid(struct kernfs_node *kn) +{ + struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID, + .ia_uid = current_fsuid(), + .ia_gid = current_fsgid(), }; + + if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) && + gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID)) + return 0; + + return kernfs_setattr(kn, &iattr); +} + +static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft) +{ + struct kernfs_node *kn; + int ret; + + kn = __kernfs_create_file(parent_kn, rft->name, rft->mode, + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, + 0, rft->kf_ops, rft, NULL, NULL); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) { + kernfs_remove(kn); + return ret; + } + + return 0; +} + +static int rdtgroup_seqfile_show(struct seq_file *m, void *arg) +{ + struct kernfs_open_file *of = m->private; + struct rftype *rft = of->kn->priv; + + if (rft->seq_show) + return rft->seq_show(of, m, arg); + return 0; +} + +static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + struct rftype *rft = of->kn->priv; + + if (rft->write) + return rft->write(of, buf, nbytes, off); + + return -EINVAL; +} + +static const struct kernfs_ops rdtgroup_kf_single_ops = { + .atomic_write_len = PAGE_SIZE, + .write = rdtgroup_file_write, + .seq_show = rdtgroup_seqfile_show, +}; + +static const struct kernfs_ops kf_mondata_ops = { + .atomic_write_len = PAGE_SIZE, + .seq_show = rdtgroup_mondata_show, +}; + +static bool is_cpu_list(struct kernfs_open_file *of) +{ + struct rftype *rft = of->kn->priv; + + return rft->flags & RFTYPE_FLAGS_CPUS_LIST; +} + +static int rdtgroup_cpus_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + struct cpumask *mask; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + + if (rdtgrp) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + mask = &rdtgrp->plr->d->cpu_mask; + seq_printf(s, is_cpu_list(of) ? + "%*pbl\n" : "%*pb\n", + cpumask_pr_args(mask)); + } + } else { + seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n", + cpumask_pr_args(&rdtgrp->cpu_mask)); + } + } else { + ret = -ENOENT; + } + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +/* + * Update the PGR_ASSOC MSR on all cpus in @cpu_mask, + * + * Per task closids/rmids must have been set up before calling this function. + * @r may be NULL. + */ +static void +update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r) +{ + struct resctrl_cpu_sync defaults; + struct resctrl_cpu_sync *defaults_p = NULL; + + if (r) { + defaults.closid = r->closid; + defaults.rmid = r->mon.rmid; + defaults_p = &defaults; + } + + on_each_cpu_mask(cpu_mask, resctrl_arch_sync_cpu_defaults, defaults_p, + 1); +} + +static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, + cpumask_var_t tmpmask) +{ + struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp; + struct list_head *head; + + /* Check whether cpus belong to parent ctrl group */ + cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask); + if (!cpumask_empty(tmpmask)) { + rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n"); + return -EINVAL; + } + + /* Check whether cpus are dropped from this group */ + cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); + if (!cpumask_empty(tmpmask)) { + /* Give any dropped cpus to parent rdtgroup */ + cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask); + update_closid_rmid(tmpmask, prgrp); + } + + /* + * If we added cpus, remove them from previous group that owned them + * and update per-cpu rmid + */ + cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); + if (!cpumask_empty(tmpmask)) { + head = &prgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) { + if (crgrp == rdtgrp) + continue; + cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask, + tmpmask); + } + update_closid_rmid(tmpmask, rdtgrp); + } + + /* Done pushing/pulling - update this group with new mask */ + cpumask_copy(&rdtgrp->cpu_mask, newmask); + + return 0; +} + +static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m) +{ + struct rdtgroup *crgrp; + + cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m); + /* update the child mon group masks as well*/ + list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list) + cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask); +} + +static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask, + cpumask_var_t tmpmask, cpumask_var_t tmpmask1) +{ + struct rdtgroup *r, *crgrp; + struct list_head *head; + + /* Check whether cpus are dropped from this group */ + cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); + if (!cpumask_empty(tmpmask)) { + /* Can't drop from default group */ + if (rdtgrp == &rdtgroup_default) { + rdt_last_cmd_puts("Can't drop CPUs from default group\n"); + return -EINVAL; + } + + /* Give any dropped cpus to rdtgroup_default */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, tmpmask); + update_closid_rmid(tmpmask, &rdtgroup_default); + } + + /* + * If we added cpus, remove them from previous group and + * the prev group's child groups that owned them + * and update per-cpu closid/rmid. + */ + cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); + if (!cpumask_empty(tmpmask)) { + list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) { + if (r == rdtgrp) + continue; + cpumask_and(tmpmask1, &r->cpu_mask, tmpmask); + if (!cpumask_empty(tmpmask1)) + cpumask_rdtgrp_clear(r, tmpmask1); + } + update_closid_rmid(tmpmask, rdtgrp); + } + + /* Done pushing/pulling - update this group with new mask */ + cpumask_copy(&rdtgrp->cpu_mask, newmask); + + /* + * Clear child mon group masks since there is a new parent mask + * now and update the rmid for the cpus the child lost. + */ + head = &rdtgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) { + cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask); + update_closid_rmid(tmpmask, rdtgrp); + cpumask_clear(&crgrp->cpu_mask); + } + + return 0; +} + +static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + cpumask_var_t tmpmask, newmask, tmpmask1; + struct rdtgroup *rdtgrp; + int ret; + + if (!buf) + return -EINVAL; + + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; + if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) { + free_cpumask_var(tmpmask); + return -ENOMEM; + } + if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) { + free_cpumask_var(tmpmask); + free_cpumask_var(newmask); + return -ENOMEM; + } + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + ret = -ENOENT; + goto unlock; + } + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = -EINVAL; + rdt_last_cmd_puts("Pseudo-locking in progress\n"); + goto unlock; + } + + if (is_cpu_list(of)) + ret = cpulist_parse(buf, newmask); + else + ret = cpumask_parse(buf, newmask); + + if (ret) { + rdt_last_cmd_puts("Bad CPU list/mask\n"); + goto unlock; + } + + /* check that user didn't specify any offline cpus */ + cpumask_andnot(tmpmask, newmask, cpu_online_mask); + if (!cpumask_empty(tmpmask)) { + ret = -EINVAL; + rdt_last_cmd_puts("Can only assign online CPUs\n"); + goto unlock; + } + + if (rdtgrp->type == RDTCTRL_GROUP) + ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1); + else if (rdtgrp->type == RDTMON_GROUP) + ret = cpus_mon_write(rdtgrp, newmask, tmpmask); + else + ret = -EINVAL; + +unlock: + rdtgroup_kn_unlock(of->kn); + free_cpumask_var(tmpmask); + free_cpumask_var(newmask); + free_cpumask_var(tmpmask1); + + return ret ?: nbytes; +} + +/** + * rdtgroup_remove - the helper to remove resource group safely + * @rdtgrp: resource group to remove + * + * On resource group creation via a mkdir, an extra kernfs_node reference is + * taken to ensure that the rdtgroup structure remains accessible for the + * rdtgroup_kn_unlock() calls where it is removed. + * + * Drop the extra reference here, then free the rdtgroup structure. + * + * Return: void + */ +static void rdtgroup_remove(struct rdtgroup *rdtgrp) +{ + kernfs_put(rdtgrp->kn); + kfree(rdtgrp); +} + +static void _update_task_closid_rmid(void *task) +{ + /* + * If the task is still current on this CPU, update PQR_ASSOC MSR. + * Otherwise, the MSR is updated when the task is scheduled in. + */ + if (task == current) + resctrl_sched_in(task); +} + +static void update_task_closid_rmid(struct task_struct *t) +{ + if (IS_ENABLED(CONFIG_SMP) && task_curr(t)) + smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1); + else + _update_task_closid_rmid(t); +} + +static bool task_in_rdtgroup(struct task_struct *tsk, struct rdtgroup *rdtgrp) +{ + u32 closid, rmid = rdtgrp->mon.rmid; + + if (rdtgrp->type == RDTCTRL_GROUP) + closid = rdtgrp->closid; + else if (rdtgrp->type == RDTMON_GROUP) + closid = rdtgrp->mon.parent->closid; + else + return false; + + return resctrl_arch_match_closid(tsk, closid) && + resctrl_arch_match_rmid(tsk, closid, rmid); +} + +static int __rdtgroup_move_task(struct task_struct *tsk, + struct rdtgroup *rdtgrp) +{ + /* If the task is already in rdtgrp, no need to move the task. */ + if (task_in_rdtgroup(tsk, rdtgrp)) + return 0; + + /* + * Set the task's closid/rmid before the PQR_ASSOC MSR can be + * updated by them. + * + * For ctrl_mon groups, move both closid and rmid. + * For monitor groups, can move the tasks only from + * their parent CTRL group. + */ + if (rdtgrp->type == RDTMON_GROUP && + !resctrl_arch_match_closid(tsk, rdtgrp->mon.parent->closid)) { + rdt_last_cmd_puts("Can't move task to different control group\n"); + return -EINVAL; + } + + if (rdtgrp->type == RDTMON_GROUP) + resctrl_arch_set_closid_rmid(tsk, rdtgrp->mon.parent->closid, + rdtgrp->mon.rmid); + else + resctrl_arch_set_closid_rmid(tsk, rdtgrp->closid, + rdtgrp->mon.rmid); + + /* + * Ensure the task's closid and rmid are written before determining if + * the task is current that will decide if it will be interrupted. + * This pairs with the full barrier between the rq->curr update and + * resctrl_sched_in() during context switch. + */ + smp_mb(); + + /* + * By now, the task's closid and rmid are set. If the task is current + * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource + * group go into effect. If the task is not current, the MSR will be + * updated when the task is scheduled in. + */ + update_task_closid_rmid(tsk); + + return 0; +} + +static bool is_closid_match(struct task_struct *t, struct rdtgroup *r) +{ + return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) && + resctrl_arch_match_closid(t, r->closid)); +} + +static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r) +{ + return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) && + resctrl_arch_match_rmid(t, r->mon.parent->closid, + r->mon.rmid)); +} + +/** + * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group + * @r: Resource group + * + * Return: 1 if tasks have been assigned to @r, 0 otherwise + */ +int rdtgroup_tasks_assigned(struct rdtgroup *r) +{ + struct task_struct *p, *t; + int ret = 0; + + lockdep_assert_held(&rdtgroup_mutex); + + rcu_read_lock(); + for_each_process_thread(p, t) { + if (is_closid_match(t, r) || is_rmid_match(t, r)) { + ret = 1; + break; + } + } + rcu_read_unlock(); + + return ret; +} + +static int rdtgroup_task_write_permission(struct task_struct *task, + struct kernfs_open_file *of) +{ + const struct cred *tcred = get_task_cred(task); + const struct cred *cred = current_cred(); + int ret = 0; + + /* + * Even if we're attaching all tasks in the thread group, we only + * need to check permissions on one of them. + */ + if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) && + !uid_eq(cred->euid, tcred->uid) && + !uid_eq(cred->euid, tcred->suid)) { + rdt_last_cmd_printf("No permission to move task %d\n", task->pid); + ret = -EPERM; + } + + put_cred(tcred); + return ret; +} + +static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp, + struct kernfs_open_file *of) +{ + struct task_struct *tsk; + int ret; + + rcu_read_lock(); + if (pid) { + tsk = find_task_by_vpid(pid); + if (!tsk) { + rcu_read_unlock(); + rdt_last_cmd_printf("No task %d\n", pid); + return -ESRCH; + } + } else { + tsk = current; + } + + get_task_struct(tsk); + rcu_read_unlock(); + + ret = rdtgroup_task_write_permission(tsk, of); + if (!ret) + ret = __rdtgroup_move_task(tsk, rdtgrp); + + put_task_struct(tsk); + return ret; +} + +static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct rdtgroup *rdtgrp; + char *pid_str; + int ret = 0; + pid_t pid; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + rdt_last_cmd_clear(); + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = -EINVAL; + rdt_last_cmd_puts("Pseudo-locking in progress\n"); + goto unlock; + } + + while (buf && buf[0] != '\0' && buf[0] != '\n') { + pid_str = strim(strsep(&buf, ",")); + + if (kstrtoint(pid_str, 0, &pid)) { + rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str); + ret = -EINVAL; + break; + } + + if (pid < 0) { + rdt_last_cmd_printf("Invalid pid %d\n", pid); + ret = -EINVAL; + break; + } + + ret = rdtgroup_move_task(pid, rdtgrp, of); + if (ret) { + rdt_last_cmd_printf("Error while processing task %d\n", pid); + break; + } + } + +unlock: + rdtgroup_kn_unlock(of->kn); + + return ret ?: nbytes; +} + +static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s) +{ + struct task_struct *p, *t; + pid_t pid; + + rcu_read_lock(); + for_each_process_thread(p, t) { + if (is_closid_match(t, r) || is_rmid_match(t, r)) { + pid = task_pid_vnr(t); + if (pid) + seq_printf(s, "%d\n", pid); + } + } + rcu_read_unlock(); +} + +static int rdtgroup_tasks_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) + show_rdt_tasks(rdtgrp, s); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +static int rdtgroup_closid_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) + seq_printf(s, "%u\n", rdtgrp->closid); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +static int rdtgroup_rmid_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) + seq_printf(s, "%u\n", rdtgrp->mon.rmid); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +#ifdef CONFIG_PROC_CPU_RESCTRL + +/* + * A task can only be part of one resctrl control group and of one monitor + * group which is associated to that control group. + * + * 1) res: + * mon: + * + * resctrl is not available. + * + * 2) res:/ + * mon: + * + * Task is part of the root resctrl control group, and it is not associated + * to any monitor group. + * + * 3) res:/ + * mon:mon0 + * + * Task is part of the root resctrl control group and monitor group mon0. + * + * 4) res:group0 + * mon: + * + * Task is part of resctrl control group group0, and it is not associated + * to any monitor group. + * + * 5) res:group0 + * mon:mon1 + * + * Task is part of resctrl control group group0 and monitor group mon1. + */ +int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns, + struct pid *pid, struct task_struct *tsk) +{ + struct rdtgroup *rdtg; + int ret = 0; + + mutex_lock(&rdtgroup_mutex); + + /* Return empty if resctrl has not been mounted. */ + if (!resctrl_mounted) { + seq_puts(s, "res:\nmon:\n"); + goto unlock; + } + + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) { + struct rdtgroup *crg; + + /* + * Task information is only relevant for shareable + * and exclusive groups. + */ + if (rdtg->mode != RDT_MODE_SHAREABLE && + rdtg->mode != RDT_MODE_EXCLUSIVE) + continue; + + if (!resctrl_arch_match_closid(tsk, rdtg->closid)) + continue; + + seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "", + rdtg->kn->name); + seq_puts(s, "mon:"); + list_for_each_entry(crg, &rdtg->mon.crdtgrp_list, + mon.crdtgrp_list) { + if (!resctrl_arch_match_rmid(tsk, crg->mon.parent->closid, + crg->mon.rmid)) + continue; + seq_printf(s, "%s", crg->kn->name); + break; + } + seq_putc(s, '\n'); + goto unlock; + } + /* + * The above search should succeed. Otherwise return + * with an error. + */ + ret = -ENOENT; +unlock: + mutex_unlock(&rdtgroup_mutex); + + return ret; +} +#endif + +static int rdt_last_cmd_status_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + int len; + + mutex_lock(&rdtgroup_mutex); + len = seq_buf_used(&last_cmd_status); + if (len) + seq_printf(seq, "%.*s", len, last_cmd_status_buf); + else + seq_puts(seq, "ok\n"); + mutex_unlock(&rdtgroup_mutex); + return 0; +} + +static int rdt_num_closids_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + + seq_printf(seq, "%u\n", s->num_closid); + return 0; +} + +static int rdt_default_ctrl_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + seq_printf(seq, "%x\n", r->default_ctrl); + return 0; +} + +static int rdt_min_cbm_bits_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->cache.min_cbm_bits); + return 0; +} + +static int rdt_shareable_bits_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + seq_printf(seq, "%x\n", r->cache.shareable_bits); + return 0; +} + +/* + * rdt_bit_usage_show - Display current usage of resources + * + * A domain is a shared resource that can now be allocated differently. Here + * we display the current regions of the domain as an annotated bitmask. + * For each domain of this resource its allocation bitmask + * is annotated as below to indicate the current usage of the corresponding bit: + * 0 - currently unused + * X - currently available for sharing and used by software and hardware + * H - currently used by hardware only but available for software use + * S - currently used and shareable by software only + * E - currently used exclusively by one resource group + * P - currently pseudo-locked by one resource group + */ +static int rdt_bit_usage_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + /* + * Use unsigned long even though only 32 bits are used to ensure + * test_bit() is used safely. + */ + unsigned long sw_shareable = 0, hw_shareable = 0; + unsigned long exclusive = 0, pseudo_locked = 0; + struct rdt_resource *r = s->res; + struct rdt_domain *dom; + int i, hwb, swb, excl, psl; + enum rdtgrp_mode mode; + bool sep = false; + u32 ctrl_val; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + hw_shareable = r->cache.shareable_bits; + list_for_each_entry(dom, &r->domains, list) { + if (sep) + seq_putc(seq, ';'); + sw_shareable = 0; + exclusive = 0; + seq_printf(seq, "%d=", dom->id); + for (i = 0; i < closids_supported(); i++) { + if (!closid_allocated(i)) + continue; + ctrl_val = resctrl_arch_get_config(r, dom, i, + s->conf_type); + mode = rdtgroup_mode_by_closid(i); + switch (mode) { + case RDT_MODE_SHAREABLE: + sw_shareable |= ctrl_val; + break; + case RDT_MODE_EXCLUSIVE: + exclusive |= ctrl_val; + break; + case RDT_MODE_PSEUDO_LOCKSETUP: + /* + * RDT_MODE_PSEUDO_LOCKSETUP is possible + * here but not included since the CBM + * associated with this CLOSID in this mode + * is not initialized and no task or cpu can be + * assigned this CLOSID. + */ + break; + case RDT_MODE_PSEUDO_LOCKED: + case RDT_NUM_MODES: + WARN(1, + "invalid mode for closid %d\n", i); + break; + } + } + for (i = r->cache.cbm_len - 1; i >= 0; i--) { + pseudo_locked = dom->plr ? dom->plr->cbm : 0; + hwb = test_bit(i, &hw_shareable); + swb = test_bit(i, &sw_shareable); + excl = test_bit(i, &exclusive); + psl = test_bit(i, &pseudo_locked); + if (hwb && swb) + seq_putc(seq, 'X'); + else if (hwb && !swb) + seq_putc(seq, 'H'); + else if (!hwb && swb) + seq_putc(seq, 'S'); + else if (excl) + seq_putc(seq, 'E'); + else if (psl) + seq_putc(seq, 'P'); + else /* Unused bits remain */ + seq_putc(seq, '0'); + } + sep = true; + } + seq_putc(seq, '\n'); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + return 0; +} + +static int rdt_min_bw_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->membw.min_bw); + return 0; +} + +static int rdt_num_rmids_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = of->kn->parent->priv; + + seq_printf(seq, "%d\n", r->num_rmid); + + return 0; +} + +static int rdt_mon_features_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = of->kn->parent->priv; + struct mon_evt *mevt; + + list_for_each_entry(mevt, &r->evt_list, list) { + seq_printf(seq, "%s\n", mevt->name); + if (mevt->configurable) + seq_printf(seq, "%s_config\n", mevt->name); + } + + return 0; +} + +static int rdt_bw_gran_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->membw.bw_gran); + return 0; +} + +static int rdt_delay_linear_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->membw.delay_linear); + return 0; +} + +static int max_threshold_occ_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + seq_printf(seq, "%u\n", resctrl_rmid_realloc_threshold); + + return 0; +} + +static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD) + seq_puts(seq, "per-thread\n"); + else + seq_puts(seq, "max\n"); + + return 0; +} + +static ssize_t max_threshold_occ_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + unsigned int bytes; + int ret; + + ret = kstrtouint(buf, 0, &bytes); + if (ret) + return ret; + + if (bytes > resctrl_rmid_realloc_limit) + return -EINVAL; + + resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes); + + return nbytes; +} + +/* + * rdtgroup_mode_show - Display mode of this resource group + */ +static int rdtgroup_mode_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + + seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode)); + + rdtgroup_kn_unlock(of->kn); + return 0; +} + +static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type) +{ + switch (my_type) { + case CDP_CODE: + return CDP_DATA; + case CDP_DATA: + return CDP_CODE; + default: + case CDP_NONE: + return CDP_NONE; + } +} + +static int rdt_has_sparse_bitmasks_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct resctrl_schema *s = of->kn->parent->priv; + struct rdt_resource *r = s->res; + + seq_printf(seq, "%u\n", r->cache.arch_has_sparse_bitmasks); + + return 0; +} + +/** + * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other + * @r: Resource to which domain instance @d belongs. + * @d: The domain instance for which @closid is being tested. + * @cbm: Capacity bitmask being tested. + * @closid: Intended closid for @cbm. + * @type: CDP type of @r. + * @exclusive: Only check if overlaps with exclusive resource groups + * + * Checks if provided @cbm intended to be used for @closid on domain + * @d overlaps with any other closids or other hardware usage associated + * with this domain. If @exclusive is true then only overlaps with + * resource groups in exclusive mode will be considered. If @exclusive + * is false then overlaps with any resource group or hardware entities + * will be considered. + * + * @cbm is unsigned long, even if only 32 bits are used, to make the + * bitmap functions work correctly. + * + * Return: false if CBM does not overlap, true if it does. + */ +static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d, + unsigned long cbm, int closid, + enum resctrl_conf_type type, bool exclusive) +{ + enum rdtgrp_mode mode; + unsigned long ctrl_b; + int i; + + /* Check for any overlap with regions used by hardware directly */ + if (!exclusive) { + ctrl_b = r->cache.shareable_bits; + if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) + return true; + } + + /* Check for overlap with other resource groups */ + for (i = 0; i < closids_supported(); i++) { + ctrl_b = resctrl_arch_get_config(r, d, i, type); + mode = rdtgroup_mode_by_closid(i); + if (closid_allocated(i) && i != closid && + mode != RDT_MODE_PSEUDO_LOCKSETUP) { + if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) { + if (exclusive) { + if (mode == RDT_MODE_EXCLUSIVE) + return true; + continue; + } + return true; + } + } + } + + return false; +} + +/** + * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware + * @s: Schema for the resource to which domain instance @d belongs. + * @d: The domain instance for which @closid is being tested. + * @cbm: Capacity bitmask being tested. + * @closid: Intended closid for @cbm. + * @exclusive: Only check if overlaps with exclusive resource groups + * + * Resources that can be allocated using a CBM can use the CBM to control + * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test + * for overlap. Overlap test is not limited to the specific resource for + * which the CBM is intended though - when dealing with CDP resources that + * share the underlying hardware the overlap check should be performed on + * the CDP resource sharing the hardware also. + * + * Refer to description of __rdtgroup_cbm_overlaps() for the details of the + * overlap test. + * + * Return: true if CBM overlap detected, false if there is no overlap + */ +bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_domain *d, + unsigned long cbm, int closid, bool exclusive) +{ + enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); + struct rdt_resource *r = s->res; + + if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type, + exclusive)) + return true; + + if (!resctrl_arch_get_cdp_enabled(r->rid)) + return false; + return __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive); +} + +/** + * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive + * @rdtgrp: Resource group identified through its closid. + * + * An exclusive resource group implies that there should be no sharing of + * its allocated resources. At the time this group is considered to be + * exclusive this test can determine if its current schemata supports this + * setting by testing for overlap with all other resource groups. + * + * Return: true if resource group can be exclusive, false if there is overlap + * with allocations of other resource groups and thus this resource group + * cannot be exclusive. + */ +static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp) +{ + int closid = rdtgrp->closid; + struct resctrl_schema *s; + struct rdt_resource *r; + bool has_cache = false; + struct rdt_domain *d; + u32 ctrl; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA) + continue; + has_cache = true; + list_for_each_entry(d, &r->domains, list) { + ctrl = resctrl_arch_get_config(r, d, closid, + s->conf_type); + if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) { + rdt_last_cmd_puts("Schemata overlaps\n"); + return false; + } + } + } + + if (!has_cache) { + rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n"); + return false; + } + + return true; +} + +/* + * rdtgroup_mode_write - Modify the resource group's mode + */ +static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct rdtgroup *rdtgrp; + enum rdtgrp_mode mode; + int ret = 0; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + buf[nbytes - 1] = '\0'; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + + rdt_last_cmd_clear(); + + mode = rdtgrp->mode; + + if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) || + (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) || + (!strcmp(buf, "pseudo-locksetup") && + mode == RDT_MODE_PSEUDO_LOCKSETUP) || + (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED)) + goto out; + + if (mode == RDT_MODE_PSEUDO_LOCKED) { + rdt_last_cmd_puts("Cannot change pseudo-locked group\n"); + ret = -EINVAL; + goto out; + } + + if (!strcmp(buf, "shareable")) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = rdtgroup_locksetup_exit(rdtgrp); + if (ret) + goto out; + } + rdtgrp->mode = RDT_MODE_SHAREABLE; + } else if (!strcmp(buf, "exclusive")) { + if (!rdtgroup_mode_test_exclusive(rdtgrp)) { + ret = -EINVAL; + goto out; + } + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + ret = rdtgroup_locksetup_exit(rdtgrp); + if (ret) + goto out; + } + rdtgrp->mode = RDT_MODE_EXCLUSIVE; + } else if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) && + !strcmp(buf, "pseudo-locksetup")) { + ret = rdtgroup_locksetup_enter(rdtgrp); + if (ret) + goto out; + rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP; + } else { + rdt_last_cmd_puts("Unknown or unsupported mode\n"); + ret = -EINVAL; + } + +out: + rdtgroup_kn_unlock(of->kn); + return ret ?: nbytes; +} + +/** + * rdtgroup_cbm_to_size - Translate CBM to size in bytes + * @r: RDT resource to which @d belongs. + * @d: RDT domain instance. + * @cbm: bitmask for which the size should be computed. + * + * The bitmask provided associated with the RDT domain instance @d will be + * translated into how many bytes it represents. The size in bytes is + * computed by first dividing the total cache size by the CBM length to + * determine how many bytes each bit in the bitmask represents. The result + * is multiplied with the number of bits set in the bitmask. + * + * @cbm is unsigned long, even if only 32 bits are used to make the + * bitmap functions work correctly. + */ +unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, + struct rdt_domain *d, unsigned long cbm) +{ + struct cpu_cacheinfo *ci; + unsigned int size = 0; + int num_b, i; + + num_b = bitmap_weight(&cbm, r->cache.cbm_len); + ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask)); + for (i = 0; i < ci->num_leaves; i++) { + if (ci->info_list[i].level == r->cache_level) { + size = ci->info_list[i].size / r->cache.cbm_len * num_b; + break; + } + } + + return size; +} + +/* + * rdtgroup_size_show - Display size in bytes of allocated regions + * + * The "size" file mirrors the layout of the "schemata" file, printing the + * size in bytes of each region instead of the capacity bitmask. + */ +static int rdtgroup_size_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct resctrl_schema *schema; + enum resctrl_conf_type type; + struct rdtgroup *rdtgrp; + struct rdt_resource *r; + struct rdt_domain *d; + unsigned int size; + int ret = 0; + u32 closid; + bool sep; + u32 ctrl; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + rdtgroup_kn_unlock(of->kn); + return -ENOENT; + } + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + seq_printf(s, "%*s:", max_name_width, + rdtgrp->plr->s->name); + size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res, + rdtgrp->plr->d, + rdtgrp->plr->cbm); + seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size); + } + goto out; + } + + closid = rdtgrp->closid; + + list_for_each_entry(schema, &resctrl_schema_all, list) { + r = schema->res; + type = schema->conf_type; + sep = false; + seq_printf(s, "%*s:", max_name_width, schema->name); + list_for_each_entry(d, &r->domains, list) { + if (sep) + seq_putc(s, ';'); + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { + size = 0; + } else { + if (is_mba_sc(r)) + ctrl = d->mbps_val[closid]; + else + ctrl = resctrl_arch_get_config(r, d, + closid, + type); + if (r->rid == RDT_RESOURCE_MBA || + r->rid == RDT_RESOURCE_SMBA) + size = ctrl; + else + size = rdtgroup_cbm_to_size(r, d, ctrl); + } + seq_printf(s, "%d=%u", d->id, size); + sep = true; + } + seq_putc(s, '\n'); + } + +out: + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +static void mondata_config_read(struct resctrl_mon_config_info *mon_info) +{ + smp_call_function_any(&mon_info->d->cpu_mask, + resctrl_arch_mon_event_config_read, mon_info, 1); +} + +static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid) +{ + struct resctrl_mon_config_info mon_info = {0}; + struct rdt_domain *dom; + bool sep = false; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + list_for_each_entry(dom, &r->domains, list) { + if (sep) + seq_puts(s, ";"); + + memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info)); + mon_info.r = r; + mon_info.d = dom; + mon_info.evtid = evtid; + mondata_config_read(&mon_info); + + seq_printf(s, "%d=0x%02x", dom->id, mon_info.mon_config); + sep = true; + } + seq_puts(s, "\n"); + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + return 0; +} + +static int mbm_total_bytes_config_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = of->kn->parent->priv; + + mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID); + + return 0; +} + +static int mbm_local_bytes_config_show(struct kernfs_open_file *of, + struct seq_file *seq, void *v) +{ + struct rdt_resource *r = of->kn->parent->priv; + + mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID); + + return 0; +} + +static int mbm_config_write_domain(struct rdt_resource *r, + struct rdt_domain *d, u32 evtid, u32 val) +{ + struct resctrl_mon_config_info mon_info = {0}; + + /* mon_config cannot be more than the supported set of events */ + if (val > MAX_EVT_CONFIG_BITS) { + rdt_last_cmd_puts("Invalid event configuration\n"); + return -EINVAL; + } + + /* + * Read the current config value first. If both are the same then + * no need to write it again. + */ + mon_info.r = r; + mon_info.d = d; + mon_info.evtid = evtid; + mondata_config_read(&mon_info); + if (mon_info.mon_config == val) + goto out; + + mon_info.mon_config = val; + + /* + * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the + * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE + * are scoped at the domain level. Writing any of these MSRs + * on one CPU is observed by all the CPUs in the domain. + */ + smp_call_function_any(&d->cpu_mask, resctrl_arch_mon_event_config_write, + &mon_info, 1); + if (mon_info.err) { + rdt_last_cmd_puts("Invalid event configuration\n"); + goto out; + } + + /* + * When an Event Configuration is changed, the bandwidth counters + * for all RMIDs and Events will be cleared by the hardware. The + * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for + * every RMID on the next read to any event for every RMID. + * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62) + * cleared while it is tracked by the hardware. Clear the + * mbm_local and mbm_total counts for all the RMIDs. + */ + resctrl_arch_reset_rmid_all(r, d); + +out: + return mon_info.err; +} + +static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid) +{ + char *dom_str = NULL, *id_str; + unsigned long dom_id, val; + struct rdt_domain *d; + int ret = 0; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + +next: + if (!tok || tok[0] == '\0') + return 0; + + /* Start processing the strings for each domain */ + dom_str = strim(strsep(&tok, ";")); + id_str = strsep(&dom_str, "="); + + if (!id_str || kstrtoul(id_str, 10, &dom_id)) { + rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n"); + return -EINVAL; + } + + if (!dom_str || kstrtoul(dom_str, 16, &val)) { + rdt_last_cmd_puts("Non-numeric event configuration value\n"); + return -EINVAL; + } + + list_for_each_entry(d, &r->domains, list) { + if (d->id == dom_id) { + ret = mbm_config_write_domain(r, d, evtid, val); + if (ret) + return -EINVAL; + goto next; + } + } + + return -EINVAL; +} + +static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, + loff_t off) +{ + struct rdt_resource *r = of->kn->parent->priv; + int ret; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + rdt_last_cmd_clear(); + + buf[nbytes - 1] = '\0'; + + ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID); + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + return ret ?: nbytes; +} + +static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, + loff_t off) +{ + struct rdt_resource *r = of->kn->parent->priv; + int ret; + + /* Valid input requires a trailing newline */ + if (nbytes == 0 || buf[nbytes - 1] != '\n') + return -EINVAL; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + rdt_last_cmd_clear(); + + buf[nbytes - 1] = '\0'; + + ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID); + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + return ret ?: nbytes; +} + +/* rdtgroup information files for one cache resource. */ +static struct rftype res_common_files[] = { + { + .name = "last_cmd_status", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_last_cmd_status_show, + .fflags = RFTYPE_TOP_INFO, + }, + { + .name = "num_closids", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_num_closids_show, + .fflags = RFTYPE_CTRL_INFO, + }, + { + .name = "mon_features", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_mon_features_show, + .fflags = RFTYPE_MON_INFO, + }, + { + .name = "num_rmids", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_num_rmids_show, + .fflags = RFTYPE_MON_INFO, + }, + { + .name = "cbm_mask", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_default_ctrl_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "min_cbm_bits", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_min_cbm_bits_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "shareable_bits", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_shareable_bits_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "bit_usage", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_bit_usage_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "min_bandwidth", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_min_bw_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, + }, + { + .name = "bandwidth_gran", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_bw_gran_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, + }, + { + .name = "delay_linear", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_delay_linear_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB, + }, + /* + * Platform specific which (if any) capabilities are provided by + * thread_throttle_mode. Defer "fflags" initialization to platform + * discovery. + */ + { + .name = "thread_throttle_mode", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_thread_throttle_mode_show, + }, + { + .name = "max_threshold_occupancy", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = max_threshold_occ_write, + .seq_show = max_threshold_occ_show, + .fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "mbm_total_bytes_config", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = mbm_total_bytes_config_show, + .write = mbm_total_bytes_config_write, + }, + { + .name = "mbm_local_bytes_config", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = mbm_local_bytes_config_show, + .write = mbm_local_bytes_config_write, + }, + { + .name = "cpus", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_cpus_write, + .seq_show = rdtgroup_cpus_show, + .fflags = RFTYPE_BASE, + }, + { + .name = "cpus_list", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_cpus_write, + .seq_show = rdtgroup_cpus_show, + .flags = RFTYPE_FLAGS_CPUS_LIST, + .fflags = RFTYPE_BASE, + }, + { + .name = "tasks", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_tasks_write, + .seq_show = rdtgroup_tasks_show, + .fflags = RFTYPE_BASE, + }, + { + .name = "mon_hw_id", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdtgroup_rmid_show, + .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG, + }, + { + .name = "schemata", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_schemata_write, + .seq_show = rdtgroup_schemata_show, + .fflags = RFTYPE_CTRL_BASE, + }, + { + .name = "mode", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_mode_write, + .seq_show = rdtgroup_mode_show, + .fflags = RFTYPE_CTRL_BASE, + }, + { + .name = "size", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdtgroup_size_show, + .fflags = RFTYPE_CTRL_BASE, + }, + { + .name = "sparse_masks", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdt_has_sparse_bitmasks_show, + .fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE, + }, + { + .name = "ctrl_hw_id", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdtgroup_closid_show, + .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG, + }, + +}; + +static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags) +{ + struct rftype *rfts, *rft; + int ret, len; + + rfts = res_common_files; + len = ARRAY_SIZE(res_common_files); + + lockdep_assert_held(&rdtgroup_mutex); + + if (resctrl_debug) + fflags |= RFTYPE_DEBUG; + + for (rft = rfts; rft < rfts + len; rft++) { + if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) { + ret = rdtgroup_add_file(kn, rft); + if (ret) + goto error; + } + } + + return 0; +error: + pr_warn("Failed to add %s, err=%d\n", rft->name, ret); + while (--rft >= rfts) { + if ((fflags & rft->fflags) == rft->fflags) + kernfs_remove_by_name(kn, rft->name); + } + return ret; +} + +static struct rftype *rdtgroup_get_rftype_by_name(const char *name) +{ + struct rftype *rfts, *rft; + int len; + + rfts = res_common_files; + len = ARRAY_SIZE(res_common_files); + + for (rft = rfts; rft < rfts + len; rft++) { + if (!strcmp(rft->name, name)) + return rft; + } + + return NULL; +} + +static void thread_throttle_mode_init(void) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + struct rftype *rft; + + if (!r->alloc_capable || + r->membw.throttle_mode == THREAD_THROTTLE_UNDEFINED) + return; + + rft = rdtgroup_get_rftype_by_name("thread_throttle_mode"); + if (!rft) + return; + + rft->fflags = RFTYPE_CTRL_INFO | RFTYPE_RES_MB; +} + +void mbm_config_rftype_init(const char *config) +{ + struct rftype *rft; + + rft = rdtgroup_get_rftype_by_name(config); + if (rft) + rft->fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE; +} + +/** + * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file + * @r: The resource group with which the file is associated. + * @name: Name of the file + * + * The permissions of named resctrl file, directory, or link are modified + * to not allow read, write, or execute by any user. + * + * WARNING: This function is intended to communicate to the user that the + * resctrl file has been locked down - that it is not relevant to the + * particular state the system finds itself in. It should not be relied + * on to protect from user access because after the file's permissions + * are restricted the user can still change the permissions using chmod + * from the command line. + * + * Return: 0 on success, <0 on failure. + */ +int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name) +{ + struct iattr iattr = {.ia_valid = ATTR_MODE,}; + struct kernfs_node *kn; + int ret = 0; + + kn = kernfs_find_and_get_ns(r->kn, name, NULL); + if (!kn) + return -ENOENT; + + switch (kernfs_type(kn)) { + case KERNFS_DIR: + iattr.ia_mode = S_IFDIR; + break; + case KERNFS_FILE: + iattr.ia_mode = S_IFREG; + break; + case KERNFS_LINK: + iattr.ia_mode = S_IFLNK; + break; + } + + ret = kernfs_setattr(kn, &iattr); + kernfs_put(kn); + return ret; +} + +/** + * rdtgroup_kn_mode_restore - Restore user access to named resctrl file + * @r: The resource group with which the file is associated. + * @name: Name of the file + * @mask: Mask of permissions that should be restored + * + * Restore the permissions of the named file. If @name is a directory the + * permissions of its parent will be used. + * + * Return: 0 on success, <0 on failure. + */ +int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name, + umode_t mask) +{ + struct iattr iattr = {.ia_valid = ATTR_MODE,}; + struct kernfs_node *kn, *parent; + struct rftype *rfts, *rft; + int ret, len; + + rfts = res_common_files; + len = ARRAY_SIZE(res_common_files); + + for (rft = rfts; rft < rfts + len; rft++) { + if (!strcmp(rft->name, name)) + iattr.ia_mode = rft->mode & mask; + } + + kn = kernfs_find_and_get_ns(r->kn, name, NULL); + if (!kn) + return -ENOENT; + + switch (kernfs_type(kn)) { + case KERNFS_DIR: + parent = kernfs_get_parent(kn); + if (parent) { + iattr.ia_mode |= parent->mode; + kernfs_put(parent); + } + iattr.ia_mode |= S_IFDIR; + break; + case KERNFS_FILE: + iattr.ia_mode |= S_IFREG; + break; + case KERNFS_LINK: + iattr.ia_mode |= S_IFLNK; + break; + } + + ret = kernfs_setattr(kn, &iattr); + kernfs_put(kn); + return ret; +} + +static int rdtgroup_mkdir_info_resdir(void *priv, char *name, + unsigned long fflags) +{ + struct kernfs_node *kn_subdir; + int ret; + + kn_subdir = kernfs_create_dir(kn_info, name, + kn_info->mode, priv); + if (IS_ERR(kn_subdir)) + return PTR_ERR(kn_subdir); + + ret = rdtgroup_kn_set_ugid(kn_subdir); + if (ret) + return ret; + + ret = rdtgroup_add_files(kn_subdir, fflags); + if (!ret) + kernfs_activate(kn_subdir); + + return ret; +} + +static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn) +{ + enum resctrl_res_level i; + struct resctrl_schema *s; + struct rdt_resource *r; + unsigned long fflags; + char name[32]; + int ret; + + /* create the directory */ + kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL); + if (IS_ERR(kn_info)) + return PTR_ERR(kn_info); + + ret = rdtgroup_add_files(kn_info, RFTYPE_TOP_INFO); + if (ret) + goto out_destroy; + + /* loop over enabled controls, these are all alloc_capable */ + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + fflags = r->fflags | RFTYPE_CTRL_INFO; + ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags); + if (ret) + goto out_destroy; + } + + for (i = 0; i < RDT_NUM_RESOURCES; i++) { + r = resctrl_arch_get_resource(i); + if (!r->mon_capable) + continue; + + fflags = r->fflags | RFTYPE_MON_INFO; + sprintf(name, "%s_MON", r->name); + ret = rdtgroup_mkdir_info_resdir(r, name, fflags); + if (ret) + goto out_destroy; + } + + ret = rdtgroup_kn_set_ugid(kn_info); + if (ret) + goto out_destroy; + + kernfs_activate(kn_info); + + return 0; + +out_destroy: + kernfs_remove(kn_info); + return ret; +} + +static int +mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp, + char *name, struct kernfs_node **dest_kn) +{ + struct kernfs_node *kn; + int ret; + + /* create the directory */ + kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + if (dest_kn) + *dest_kn = kn; + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) + goto out_destroy; + + kernfs_activate(kn); + + return 0; + +out_destroy: + kernfs_remove(kn); + return ret; +} + +static inline bool is_mba_linear(void) +{ + return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear; +} + +static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_domain *d) +{ + u32 num_closid = resctrl_arch_get_num_closid(r); + int cpu = cpumask_any(&d->cpu_mask); + int i; + + d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val), + GFP_KERNEL, cpu_to_node(cpu)); + if (!d->mbps_val) + return -ENOMEM; + + for (i = 0; i < num_closid; i++) + d->mbps_val[i] = MBA_MAX_MBPS; + + return 0; +} + +static void mba_sc_domain_destroy(struct rdt_resource *r, + struct rdt_domain *d) +{ + kfree(d->mbps_val); + d->mbps_val = NULL; +} + +/* + * MBA software controller is supported only if + * MBM is supported and MBA is in linear scale. + */ +static bool supports_mba_mbps(void) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + + return (resctrl_arch_is_mbm_local_enabled() && + r->alloc_capable && is_mba_linear()); +} + +/* + * Enable or disable the MBA software controller + * which helps user specify bandwidth in MBps. + */ +static int set_mba_sc(bool mba_sc) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA); + u32 num_closid = resctrl_arch_get_num_closid(r); + struct rdt_domain *d; + int i; + + if (!supports_mba_mbps() || mba_sc == is_mba_sc(r)) + return -EINVAL; + + r->membw.mba_sc = mba_sc; + + list_for_each_entry(d, &r->domains, list) { + for (i = 0; i < num_closid; i++) + d->mbps_val[i] = MBA_MAX_MBPS; + } + + return 0; +} + +/* + * We don't allow rdtgroup directories to be created anywhere + * except the root directory. Thus when looking for the rdtgroup + * structure for a kernfs node we are either looking at a directory, + * in which case the rdtgroup structure is pointed at by the "priv" + * field, otherwise we have a file, and need only look to the parent + * to find the rdtgroup. + */ +static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn) +{ + if (kernfs_type(kn) == KERNFS_DIR) { + /* + * All the resource directories use "kn->priv" + * to point to the "struct rdtgroup" for the + * resource. "info" and its subdirectories don't + * have rdtgroup structures, so return NULL here. + */ + if (kn == kn_info || kn->parent == kn_info) + return NULL; + else + return kn->priv; + } else { + return kn->parent->priv; + } +} + +static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *kn) +{ + atomic_inc(&rdtgrp->waitcount); + kernfs_break_active_protection(kn); +} + +static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *kn) +{ + if (atomic_dec_and_test(&rdtgrp->waitcount) && + (rdtgrp->flags & RDT_DELETED)) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) + rdtgroup_pseudo_lock_remove(rdtgrp); + kernfs_unbreak_active_protection(kn); + rdtgroup_remove(rdtgrp); + } else { + kernfs_unbreak_active_protection(kn); + } +} + +struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn) +{ + struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); + + if (!rdtgrp) + return NULL; + + rdtgroup_kn_get(rdtgrp, kn); + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + /* Was this group deleted while we waited? */ + if (rdtgrp->flags & RDT_DELETED) + return NULL; + + return rdtgrp; +} + +void rdtgroup_kn_unlock(struct kernfs_node *kn) +{ + struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn); + + if (!rdtgrp) + return; + + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + + rdtgroup_kn_put(rdtgrp, kn); +} + +static int mkdir_mondata_all(struct kernfs_node *parent_kn, + struct rdtgroup *prgrp, + struct kernfs_node **mon_data_kn); + +static void rdt_disable_ctx(void) +{ + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); + set_mba_sc(false); + + resctrl_debug = false; +} + +static int rdt_enable_ctx(struct rdt_fs_context *ctx) +{ + int ret = 0; + + if (ctx->enable_cdpl2) { + ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true); + if (ret) + goto out_done; + } + + if (ctx->enable_cdpl3) { + ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true); + if (ret) + goto out_cdpl2; + } + + if (ctx->enable_mba_mbps) { + ret = set_mba_sc(true); + if (ret) + goto out_cdpl3; + } + + if (ctx->enable_debug) + resctrl_debug = true; + + return 0; + +out_cdpl3: + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false); +out_cdpl2: + resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false); +out_done: + return ret; +} + +static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type) +{ + struct resctrl_schema *s; + const char *suffix = ""; + int ret, cl; + + s = kzalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + s->res = r; + s->num_closid = resctrl_arch_get_num_closid(r); + if (resctrl_arch_get_cdp_enabled(r->rid)) + s->num_closid /= 2; + + s->conf_type = type; + switch (type) { + case CDP_CODE: + suffix = "CODE"; + break; + case CDP_DATA: + suffix = "DATA"; + break; + case CDP_NONE: + suffix = ""; + break; + } + + ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix); + if (ret >= sizeof(s->name)) { + kfree(s); + return -EINVAL; + } + + cl = strlen(s->name); + + /* + * If CDP is supported by this resource, but not enabled, + * include the suffix. This ensures the tabular format of the + * schemata file does not change between mounts of the filesystem. + */ + if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid)) + cl += 4; + + if (cl > max_name_width) + max_name_width = cl; + + /* + * Choose a width for the resource data based on the resource that has + * widest name and cbm. + */ + max_data_width = max(max_data_width, r->data_width); + + INIT_LIST_HEAD(&s->list); + list_add(&s->list, &resctrl_schema_all); + + return 0; +} + +static int schemata_list_create(void) +{ + enum resctrl_res_level i; + struct rdt_resource *r; + int ret = 0; + + for (i = 0; i < RDT_NUM_RESOURCES; i++) { + r = resctrl_arch_get_resource(i); + if (!r->alloc_capable) + continue; + + if (resctrl_arch_get_cdp_enabled(r->rid)) { + ret = schemata_list_add(r, CDP_CODE); + if (ret) + break; + + ret = schemata_list_add(r, CDP_DATA); + } else { + ret = schemata_list_add(r, CDP_NONE); + } + + if (ret) + break; + } + + return ret; +} + +static void schemata_list_destroy(void) +{ + struct resctrl_schema *s, *tmp; + + list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) { + list_del(&s->list); + kfree(s); + } +} + +static int rdt_get_tree(struct fs_context *fc) +{ + struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdt_fs_context *ctx = rdt_fc2context(fc); + unsigned long flags = RFTYPE_CTRL_BASE; + struct rdt_domain *dom; + int ret; + + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + /* + * resctrl file system can only be mounted once. + */ + if (resctrl_mounted) { + ret = -EBUSY; + goto out; + } + + ret = rdtgroup_setup_root(ctx); + if (ret) + goto out; + + ret = rdt_enable_ctx(ctx); + if (ret) + goto out_root; + + ret = schemata_list_create(); + if (ret) { + schemata_list_destroy(); + goto out_ctx; + } + + closid_init(); + + if (resctrl_arch_mon_capable()) + flags |= RFTYPE_MON; + + ret = rdtgroup_add_files(rdtgroup_default.kn, flags); + if (ret) + goto out_schemata_free; + + kernfs_activate(rdtgroup_default.kn); + + ret = rdtgroup_create_info_dir(rdtgroup_default.kn); + if (ret < 0) + goto out_schemata_free; + + if (resctrl_arch_mon_capable()) { + ret = mongroup_create_dir(rdtgroup_default.kn, + &rdtgroup_default, "mon_groups", + &kn_mongrp); + if (ret < 0) + goto out_info; + + ret = mkdir_mondata_all(rdtgroup_default.kn, + &rdtgroup_default, &kn_mondata); + if (ret < 0) + goto out_mongrp; + rdtgroup_default.mon.mon_data_kn = kn_mondata; + } + + if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) { + ret = rdt_pseudo_lock_init(); + if (ret) + goto out_mondata; + } + + ret = kernfs_get_tree(fc); + if (ret < 0) + goto out_psl; + + if (resctrl_arch_alloc_capable()) + resctrl_arch_enable_alloc(); + if (resctrl_arch_mon_capable()) + resctrl_arch_enable_mon(); + + if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable()) + resctrl_mounted = true; + + if (resctrl_is_mbm_enabled()) { + list_for_each_entry(dom, &l3->domains, list) + mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL, + RESCTRL_PICK_ANY_CPU); + } + + goto out; + +out_psl: + if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) + rdt_pseudo_lock_release(); +out_mondata: + if (resctrl_arch_mon_capable()) + kernfs_remove(kn_mondata); +out_mongrp: + if (resctrl_arch_mon_capable()) + kernfs_remove(kn_mongrp); +out_info: + kernfs_remove(kn_info); +out_schemata_free: + schemata_list_destroy(); +out_ctx: + rdt_disable_ctx(); +out_root: + rdtgroup_destroy_root(); +out: + rdt_last_cmd_clear(); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); + return ret; +} + +enum rdt_param { + Opt_cdp, + Opt_cdpl2, + Opt_mba_mbps, + Opt_debug, + nr__rdt_params +}; + +static const struct fs_parameter_spec rdt_fs_parameters[] = { + fsparam_flag("cdp", Opt_cdp), + fsparam_flag("cdpl2", Opt_cdpl2), + fsparam_flag("mba_MBps", Opt_mba_mbps), + fsparam_flag("debug", Opt_debug), + {} +}; + +static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); + struct fs_parse_result result; + int opt; + + opt = fs_parse(fc, rdt_fs_parameters, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_cdp: + ctx->enable_cdpl3 = true; + return 0; + case Opt_cdpl2: + ctx->enable_cdpl2 = true; + return 0; + case Opt_mba_mbps: + if (!supports_mba_mbps()) + return -EINVAL; + ctx->enable_mba_mbps = true; + return 0; + case Opt_debug: + ctx->enable_debug = true; + return 0; + } + + return -EINVAL; +} + +static void rdt_fs_context_free(struct fs_context *fc) +{ + struct rdt_fs_context *ctx = rdt_fc2context(fc); + + kernfs_free_fs_context(fc); + kfree(ctx); +} + +static const struct fs_context_operations rdt_fs_context_ops = { + .free = rdt_fs_context_free, + .parse_param = rdt_parse_param, + .get_tree = rdt_get_tree, +}; + +static int rdt_init_fs_context(struct fs_context *fc) +{ + struct rdt_fs_context *ctx; + + ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->kfc.magic = RDTGROUP_SUPER_MAGIC; + fc->fs_private = &ctx->kfc; + fc->ops = &rdt_fs_context_ops; + put_user_ns(fc->user_ns); + fc->user_ns = get_user_ns(&init_user_ns); + fc->global = true; + return 0; +} + +/* + * Move tasks from one to the other group. If @from is NULL, then all tasks + * in the systems are moved unconditionally (used for teardown). + * + * If @mask is not NULL the cpus on which moved tasks are running are set + * in that mask so the update smp function call is restricted to affected + * cpus. + */ +static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to, + struct cpumask *mask) +{ + struct task_struct *p, *t; + + read_lock(&tasklist_lock); + for_each_process_thread(p, t) { + if (!from || is_closid_match(t, from) || + is_rmid_match(t, from)) { + resctrl_arch_set_closid_rmid(t, to->closid, + to->mon.rmid); + + /* + * Order the closid/rmid stores above before the loads + * in task_curr(). This pairs with the full barrier + * between the rq->curr update and resctrl_sched_in() + * during context switch. + */ + smp_mb(); + + /* + * If the task is on a CPU, set the CPU in the mask. + * The detection is inaccurate as tasks might move or + * schedule before the smp function call takes place. + * In such a case the function call is pointless, but + * there is no other side effect. + */ + if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t)) + cpumask_set_cpu(task_cpu(t), mask); + } + } + read_unlock(&tasklist_lock); +} + +static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp) +{ + struct rdtgroup *sentry, *stmp; + struct list_head *head; + + head = &rdtgrp->mon.crdtgrp_list; + list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) { + free_rmid(sentry->closid, sentry->mon.rmid); + list_del(&sentry->mon.crdtgrp_list); + + if (atomic_read(&sentry->waitcount) != 0) + sentry->flags = RDT_DELETED; + else + rdtgroup_remove(sentry); + } +} + +/* + * Forcibly remove all of subdirectories under root. + */ +static void rmdir_all_sub(void) +{ + struct rdtgroup *rdtgrp, *tmp; + + /* Move all tasks to the default resource group */ + rdt_move_group_tasks(NULL, &rdtgroup_default, NULL); + + list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) { + /* Free any child rmids */ + free_all_child_rdtgrp(rdtgrp); + + /* Remove each rdtgroup other than root */ + if (rdtgrp == &rdtgroup_default) + continue; + + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) + rdtgroup_pseudo_lock_remove(rdtgrp); + + /* + * Give any CPUs back to the default group. We cannot copy + * cpu_online_mask because a CPU might have executed the + * offline callback already, but is still marked online. + */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); + + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + + kernfs_remove(rdtgrp->kn); + list_del(&rdtgrp->rdtgroup_list); + + if (atomic_read(&rdtgrp->waitcount) != 0) + rdtgrp->flags = RDT_DELETED; + else + rdtgroup_remove(rdtgrp); + } + /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */ + update_closid_rmid(cpu_online_mask, &rdtgroup_default); + + kernfs_remove(kn_info); + kernfs_remove(kn_mongrp); + kernfs_remove(kn_mondata); +} + +static void rdt_kill_sb(struct super_block *sb) +{ + cpus_read_lock(); + mutex_lock(&rdtgroup_mutex); + + rdt_disable_ctx(); + + /* Put everything back to default values. */ + resctrl_arch_reset_resources(); + + rmdir_all_sub(); + if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK)) + rdt_pseudo_lock_release(); + rdtgroup_default.mode = RDT_MODE_SHAREABLE; + schemata_list_destroy(); + rdtgroup_destroy_root(); + if (resctrl_arch_alloc_capable()) + resctrl_arch_disable_alloc(); + if (resctrl_arch_mon_capable()) + resctrl_arch_disable_mon(); + resctrl_mounted = false; + kernfs_kill_sb(sb); + mutex_unlock(&rdtgroup_mutex); + cpus_read_unlock(); +} + +static struct file_system_type rdt_fs_type = { + .name = "resctrl", + .init_fs_context = rdt_init_fs_context, + .parameters = rdt_fs_parameters, + .kill_sb = rdt_kill_sb, +}; + +static int mon_addfile(struct kernfs_node *parent_kn, const char *name, + void *priv) +{ + struct kernfs_node *kn; + int ret = 0; + + kn = __kernfs_create_file(parent_kn, name, 0444, + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0, + &kf_mondata_ops, priv, NULL, NULL); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) { + kernfs_remove(kn); + return ret; + } + + return ret; +} + +/* + * Remove all subdirectories of mon_data of ctrl_mon groups + * and monitor groups with given domain id. + */ +static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, + unsigned int dom_id) +{ + struct rdtgroup *prgrp, *crgrp; + char name[32]; + + list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { + sprintf(name, "mon_%s_%02d", r->name, dom_id); + kernfs_remove_by_name(prgrp->mon.mon_data_kn, name); + + list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list) + kernfs_remove_by_name(crgrp->mon.mon_data_kn, name); + } +} + +static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, + struct rdt_domain *d, + struct rdt_resource *r, struct rdtgroup *prgrp) +{ + union mon_data_bits priv; + struct kernfs_node *kn; + struct mon_evt *mevt; + struct rmid_read rr; + char name[32]; + int ret; + + sprintf(name, "mon_%s_%02d", r->name, d->id); + /* create the directory */ + kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) + goto out_destroy; + + if (WARN_ON(list_empty(&r->evt_list))) { + ret = -EPERM; + goto out_destroy; + } + + priv.u.rid = r->rid; + priv.u.domid = d->id; + list_for_each_entry(mevt, &r->evt_list, list) { + priv.u.evtid = mevt->evtid; + ret = mon_addfile(kn, mevt->name, priv.priv); + if (ret) + goto out_destroy; + + if (resctrl_is_mbm_event(mevt->evtid)) + mon_event_read(&rr, r, d, prgrp, mevt->evtid, true); + } + kernfs_activate(kn); + return 0; + +out_destroy: + kernfs_remove(kn); + return ret; +} + +/* + * Add all subdirectories of mon_data for "ctrl_mon" groups + * and "monitor" groups with given domain id. + */ +static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, + struct rdt_domain *d) +{ + struct kernfs_node *parent_kn; + struct rdtgroup *prgrp, *crgrp; + struct list_head *head; + + list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { + parent_kn = prgrp->mon.mon_data_kn; + mkdir_mondata_subdir(parent_kn, d, r, prgrp); + + head = &prgrp->mon.crdtgrp_list; + list_for_each_entry(crgrp, head, mon.crdtgrp_list) { + parent_kn = crgrp->mon.mon_data_kn; + mkdir_mondata_subdir(parent_kn, d, r, crgrp); + } + } +} + +static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn, + struct rdt_resource *r, + struct rdtgroup *prgrp) +{ + struct rdt_domain *dom; + int ret; + + /* Walking r->domains, ensure it can't race with cpuhp */ + lockdep_assert_cpus_held(); + + list_for_each_entry(dom, &r->domains, list) { + ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp); + if (ret) + return ret; + } + + return 0; +} + +/* + * This creates a directory mon_data which contains the monitored data. + * + * mon_data has one directory for each domain which are named + * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data + * with L3 domain looks as below: + * ./mon_data: + * mon_L3_00 + * mon_L3_01 + * mon_L3_02 + * ... + * + * Each domain directory has one file per event: + * ./mon_L3_00/: + * llc_occupancy + * + */ +static int mkdir_mondata_all(struct kernfs_node *parent_kn, + struct rdtgroup *prgrp, + struct kernfs_node **dest_kn) +{ + enum resctrl_res_level i; + struct rdt_resource *r; + struct kernfs_node *kn; + int ret; + + /* + * Create the mon_data directory first. + */ + ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn); + if (ret) + return ret; + + if (dest_kn) + *dest_kn = kn; + + /* + * Create the subdirectories for each domain. Note that all events + * in a domain like L3 are grouped into a resource whose domain is L3 + */ + for (i = 0; i < RDT_NUM_RESOURCES; i++) { + r = resctrl_arch_get_resource(i); + if (!r->mon_capable) + continue; + + ret = mkdir_mondata_subdir_alldom(kn, r, prgrp); + if (ret) + goto out_destroy; + } + + return 0; + +out_destroy: + kernfs_remove(kn); + return ret; +} + +/** + * cbm_ensure_valid - Enforce validity on provided CBM + * @_val: Candidate CBM + * @r: RDT resource to which the CBM belongs + * + * The provided CBM represents all cache portions available for use. This + * may be represented by a bitmap that does not consist of contiguous ones + * and thus be an invalid CBM. + * Here the provided CBM is forced to be a valid CBM by only considering + * the first set of contiguous bits as valid and clearing all bits. + * The intention here is to provide a valid default CBM with which a new + * resource group is initialized. The user can follow this with a + * modification to the CBM if the default does not satisfy the + * requirements. + */ +static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r) +{ + unsigned int cbm_len = r->cache.cbm_len; + unsigned long first_bit, zero_bit; + unsigned long val = _val; + + if (!val) + return 0; + + first_bit = find_first_bit(&val, cbm_len); + zero_bit = find_next_zero_bit(&val, cbm_len, first_bit); + + /* Clear any remaining bits to ensure contiguous region */ + bitmap_clear(&val, zero_bit, cbm_len - zero_bit); + return (u32)val; +} + +/* + * Initialize cache resources per RDT domain + * + * Set the RDT domain up to start off with all usable allocations. That is, + * all shareable and unused bits. All-zero CBM is invalid. + */ +static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s, + u32 closid) +{ + enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type); + enum resctrl_conf_type t = s->conf_type; + struct resctrl_staged_config *cfg; + struct rdt_resource *r = s->res; + u32 used_b = 0, unused_b = 0; + unsigned long tmp_cbm; + enum rdtgrp_mode mode; + u32 peer_ctl, ctrl_val; + int i; + + cfg = &d->staged_config[t]; + cfg->have_new_ctrl = false; + cfg->new_ctrl = r->cache.shareable_bits; + used_b = r->cache.shareable_bits; + for (i = 0; i < closids_supported(); i++) { + if (closid_allocated(i) && i != closid) { + mode = rdtgroup_mode_by_closid(i); + if (mode == RDT_MODE_PSEUDO_LOCKSETUP) + /* + * ctrl values for locksetup aren't relevant + * until the schemata is written, and the mode + * becomes RDT_MODE_PSEUDO_LOCKED. + */ + continue; + /* + * If CDP is active include peer domain's + * usage to ensure there is no overlap + * with an exclusive group. + */ + if (resctrl_arch_get_cdp_enabled(r->rid)) + peer_ctl = resctrl_arch_get_config(r, d, i, + peer_type); + else + peer_ctl = 0; + ctrl_val = resctrl_arch_get_config(r, d, i, + s->conf_type); + used_b |= ctrl_val | peer_ctl; + if (mode == RDT_MODE_SHAREABLE) + cfg->new_ctrl |= ctrl_val | peer_ctl; + } + } + if (d->plr && d->plr->cbm > 0) + used_b |= d->plr->cbm; + unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1); + unused_b &= BIT_MASK(r->cache.cbm_len) - 1; + cfg->new_ctrl |= unused_b; + /* + * Force the initial CBM to be valid, user can + * modify the CBM based on system availability. + */ + cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r); + /* + * Assign the u32 CBM to an unsigned long to ensure that + * bitmap_weight() does not access out-of-bound memory. + */ + tmp_cbm = cfg->new_ctrl; + if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) { + rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->id); + return -ENOSPC; + } + cfg->have_new_ctrl = true; + + return 0; +} + +/* + * Initialize cache resources with default values. + * + * A new RDT group is being created on an allocation capable (CAT) + * supporting system. Set this group up to start off with all usable + * allocations. + * + * If there are no more shareable bits available on any domain then + * the entire allocation will fail. + */ +static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid) +{ + struct rdt_domain *d; + int ret; + + list_for_each_entry(d, &s->res->domains, list) { + ret = __init_one_rdt_domain(d, s, closid); + if (ret < 0) + return ret; + } + + return 0; +} + +/* Initialize MBA resource with default values. */ +static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid) +{ + struct resctrl_staged_config *cfg; + struct rdt_domain *d; + + list_for_each_entry(d, &r->domains, list) { + if (is_mba_sc(r)) { + d->mbps_val[closid] = MBA_MAX_MBPS; + continue; + } + + cfg = &d->staged_config[CDP_NONE]; + cfg->new_ctrl = r->default_ctrl; + cfg->have_new_ctrl = true; + } +} + +/* Initialize the RDT group's allocations. */ +static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) +{ + struct resctrl_schema *s; + struct rdt_resource *r; + int ret = 0; + + rdt_staged_configs_clear(); + + list_for_each_entry(s, &resctrl_schema_all, list) { + r = s->res; + if (r->rid == RDT_RESOURCE_MBA || + r->rid == RDT_RESOURCE_SMBA) { + rdtgroup_init_mba(r, rdtgrp->closid); + if (is_mba_sc(r)) + continue; + } else { + ret = rdtgroup_init_cat(s, rdtgrp->closid); + if (ret < 0) + goto out; + } + + ret = resctrl_arch_update_domains(r, rdtgrp->closid); + if (ret < 0) { + rdt_last_cmd_puts("Failed to initialize allocations\n"); + goto out; + } + + } + + rdtgrp->mode = RDT_MODE_SHAREABLE; + +out: + rdt_staged_configs_clear(); + return ret; +} + +static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp) +{ + int ret; + + if (!resctrl_arch_mon_capable()) + return 0; + + ret = alloc_rmid(rdtgrp->closid); + if (ret < 0) { + rdt_last_cmd_puts("Out of RMIDs\n"); + return ret; + } + rdtgrp->mon.rmid = ret; + + ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn); + if (ret) { + rdt_last_cmd_puts("kernfs subdir error\n"); + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + return ret; + } + + return 0; +} + +static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp) +{ + if (resctrl_arch_mon_capable()) + free_rmid(rgrp->closid, rgrp->mon.rmid); +} + +static int mkdir_rdt_prepare(struct kernfs_node *parent_kn, + const char *name, umode_t mode, + enum rdt_group_type rtype, struct rdtgroup **r) +{ + struct rdtgroup *prdtgrp, *rdtgrp; + unsigned long files = 0; + struct kernfs_node *kn; + int ret; + + prdtgrp = rdtgroup_kn_lock_live(parent_kn); + if (!prdtgrp) { + ret = -ENODEV; + goto out_unlock; + } + + if (rtype == RDTMON_GROUP && + (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) { + ret = -EINVAL; + rdt_last_cmd_puts("Pseudo-locking in progress\n"); + goto out_unlock; + } + + /* allocate the rdtgroup. */ + rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL); + if (!rdtgrp) { + ret = -ENOSPC; + rdt_last_cmd_puts("Kernel out of memory\n"); + goto out_unlock; + } + *r = rdtgrp; + rdtgrp->mon.parent = prdtgrp; + rdtgrp->type = rtype; + INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list); + + /* kernfs creates the directory for rdtgrp */ + kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp); + if (IS_ERR(kn)) { + ret = PTR_ERR(kn); + rdt_last_cmd_puts("kernfs create error\n"); + goto out_free_rgrp; + } + rdtgrp->kn = kn; + + /* + * kernfs_remove() will drop the reference count on "kn" which + * will free it. But we still need it to stick around for the + * rdtgroup_kn_unlock(kn) call. Take one extra reference here, + * which will be dropped by kernfs_put() in rdtgroup_remove(). + */ + kernfs_get(kn); + + ret = rdtgroup_kn_set_ugid(kn); + if (ret) { + rdt_last_cmd_puts("kernfs perm error\n"); + goto out_destroy; + } + + if (rtype == RDTCTRL_GROUP) { + files = RFTYPE_BASE | RFTYPE_CTRL; + if (resctrl_arch_mon_capable()) + files |= RFTYPE_MON; + } else { + files = RFTYPE_BASE | RFTYPE_MON; + } + + ret = rdtgroup_add_files(kn, files); + if (ret) { + rdt_last_cmd_puts("kernfs fill error\n"); + goto out_destroy; + } + + /* + * The caller unlocks the parent_kn upon success. + */ + return 0; + +out_destroy: + kernfs_put(rdtgrp->kn); + kernfs_remove(rdtgrp->kn); +out_free_rgrp: + kfree(rdtgrp); +out_unlock: + rdtgroup_kn_unlock(parent_kn); + return ret; +} + +static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp) +{ + kernfs_remove(rgrp->kn); + rdtgroup_remove(rgrp); +} + +/* + * Create a monitor group under "mon_groups" directory of a control + * and monitor group(ctrl_mon). This is a resource group + * to monitor a subset of tasks and cpus in its parent ctrl_mon group. + */ +static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn, + const char *name, umode_t mode) +{ + struct rdtgroup *rdtgrp, *prgrp; + int ret; + + ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp); + if (ret) + return ret; + + prgrp = rdtgrp->mon.parent; + rdtgrp->closid = prgrp->closid; + + ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); + if (ret) { + mkdir_rdt_prepare_clean(rdtgrp); + goto out_unlock; + } + + kernfs_activate(rdtgrp->kn); + + /* + * Add the rdtgrp to the list of rdtgrps the parent + * ctrl_mon group has to track. + */ + list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list); + +out_unlock: + rdtgroup_kn_unlock(parent_kn); + return ret; +} + +/* + * These are rdtgroups created under the root directory. Can be used + * to allocate and monitor resources. + */ +static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn, + const char *name, umode_t mode) +{ + struct rdtgroup *rdtgrp; + struct kernfs_node *kn; + u32 closid; + int ret; + + ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp); + if (ret) + return ret; + + kn = rdtgrp->kn; + ret = closid_alloc(); + if (ret < 0) { + rdt_last_cmd_puts("Out of CLOSIDs\n"); + goto out_common_fail; + } + closid = ret; + ret = 0; + + rdtgrp->closid = closid; + + ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp); + if (ret) + goto out_closid_free; + + kernfs_activate(rdtgrp->kn); + + ret = rdtgroup_init_alloc(rdtgrp); + if (ret < 0) + goto out_rmid_free; + + list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups); + + if (resctrl_arch_mon_capable()) { + /* + * Create an empty mon_groups directory to hold the subset + * of tasks and cpus to monitor. + */ + ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL); + if (ret) { + rdt_last_cmd_puts("kernfs subdir error\n"); + goto out_del_list; + } + } + + goto out_unlock; + +out_del_list: + list_del(&rdtgrp->rdtgroup_list); +out_rmid_free: + mkdir_rdt_prepare_rmid_free(rdtgrp); +out_closid_free: + closid_free(closid); +out_common_fail: + mkdir_rdt_prepare_clean(rdtgrp); +out_unlock: + rdtgroup_kn_unlock(parent_kn); + return ret; +} + +/* + * We allow creating mon groups only with in a directory called "mon_groups" + * which is present in every ctrl_mon group. Check if this is a valid + * "mon_groups" directory. + * + * 1. The directory should be named "mon_groups". + * 2. The mon group itself should "not" be named "mon_groups". + * This makes sure "mon_groups" directory always has a ctrl_mon group + * as parent. + */ +static bool is_mon_groups(struct kernfs_node *kn, const char *name) +{ + return (!strcmp(kn->name, "mon_groups") && + strcmp(name, "mon_groups")); +} + +static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name, + umode_t mode) +{ + /* Do not accept '\n' to avoid unparsable situation. */ + if (strchr(name, '\n')) + return -EINVAL; + + /* + * If the parent directory is the root directory and RDT + * allocation is supported, add a control and monitoring + * subdirectory + */ + if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn) + return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode); + + /* + * If RDT monitoring is supported and the parent directory is a valid + * "mon_groups" directory, add a monitoring subdirectory. + */ + if (resctrl_arch_mon_capable() && is_mon_groups(parent_kn, name)) + return rdtgroup_mkdir_mon(parent_kn, name, mode); + + return -EPERM; +} + +static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) +{ + struct rdtgroup *prdtgrp = rdtgrp->mon.parent; + int cpu; + + /* Give any tasks back to the parent group */ + rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask); + + /* Update per cpu rmid of the moved CPUs first */ + for_each_cpu(cpu, &rdtgrp->cpu_mask) + resctrl_arch_set_cpu_default_closid_rmid(cpu, rdtgrp->closid, + prdtgrp->mon.rmid); + + /* + * Update the MSR on moved CPUs and CPUs which have moved + * task running on them. + */ + cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); + update_closid_rmid(tmpmask, NULL); + + rdtgrp->flags = RDT_DELETED; + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + + /* + * Remove the rdtgrp from the parent ctrl_mon group's list + */ + WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); + list_del(&rdtgrp->mon.crdtgrp_list); + + kernfs_remove(rdtgrp->kn); + + return 0; +} + +static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp) +{ + rdtgrp->flags = RDT_DELETED; + list_del(&rdtgrp->rdtgroup_list); + + kernfs_remove(rdtgrp->kn); + return 0; +} + +static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask) +{ + u32 closid, rmid; + int cpu; + + /* Give any tasks back to the default group */ + rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask); + + /* Give any CPUs back to the default group */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); + + /* Update per cpu closid and rmid of the moved CPUs first */ + closid = rdtgroup_default.closid; + rmid = rdtgroup_default.mon.rmid; + for_each_cpu(cpu, &rdtgrp->cpu_mask) + resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid); + + /* + * Update the MSR on moved CPUs and CPUs which have moved + * task running on them. + */ + cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask); + update_closid_rmid(tmpmask, NULL); + + free_rmid(rdtgrp->closid, rdtgrp->mon.rmid); + closid_free(rdtgrp->closid); + + rdtgroup_ctrl_remove(rdtgrp); + + /* + * Free all the child monitor group rmids. + */ + free_all_child_rdtgrp(rdtgrp); + + return 0; +} + +static int rdtgroup_rmdir(struct kernfs_node *kn) +{ + struct kernfs_node *parent_kn = kn->parent; + struct rdtgroup *rdtgrp; + cpumask_var_t tmpmask; + int ret = 0; + + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; + + rdtgrp = rdtgroup_kn_lock_live(kn); + if (!rdtgrp) { + ret = -EPERM; + goto out; + } + + /* + * If the rdtgroup is a ctrl_mon group and parent directory + * is the root directory, remove the ctrl_mon group. + * + * If the rdtgroup is a mon group and parent directory + * is a valid "mon_groups" directory, remove the mon group. + */ + if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn && + rdtgrp != &rdtgroup_default) { + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + ret = rdtgroup_ctrl_remove(rdtgrp); + } else { + ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask); + } + } else if (rdtgrp->type == RDTMON_GROUP && + is_mon_groups(parent_kn, kn->name)) { + ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask); + } else { + ret = -EPERM; + } + +out: + rdtgroup_kn_unlock(kn); + free_cpumask_var(tmpmask); + return ret; +} + +/** + * mongrp_reparent() - replace parent CTRL_MON group of a MON group + * @rdtgrp: the MON group whose parent should be replaced + * @new_prdtgrp: replacement parent CTRL_MON group for @rdtgrp + * @cpus: cpumask provided by the caller for use during this call + * + * Replaces the parent CTRL_MON group for a MON group, resulting in all member + * tasks' CLOSID immediately changing to that of the new parent group. + * Monitoring data for the group is unaffected by this operation. + */ +static void mongrp_reparent(struct rdtgroup *rdtgrp, + struct rdtgroup *new_prdtgrp, + cpumask_var_t cpus) +{ + struct rdtgroup *prdtgrp = rdtgrp->mon.parent; + + WARN_ON(rdtgrp->type != RDTMON_GROUP); + WARN_ON(new_prdtgrp->type != RDTCTRL_GROUP); + + /* Nothing to do when simply renaming a MON group. */ + if (prdtgrp == new_prdtgrp) + return; + + WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list)); + list_move_tail(&rdtgrp->mon.crdtgrp_list, + &new_prdtgrp->mon.crdtgrp_list); + + rdtgrp->mon.parent = new_prdtgrp; + rdtgrp->closid = new_prdtgrp->closid; + + /* Propagate updated closid to all tasks in this group. */ + rdt_move_group_tasks(rdtgrp, rdtgrp, cpus); + + update_closid_rmid(cpus, NULL); +} + +static int rdtgroup_rename(struct kernfs_node *kn, + struct kernfs_node *new_parent, const char *new_name) +{ + struct rdtgroup *new_prdtgrp; + struct rdtgroup *rdtgrp; + cpumask_var_t tmpmask; + int ret; + + rdtgrp = kernfs_to_rdtgroup(kn); + new_prdtgrp = kernfs_to_rdtgroup(new_parent); + if (!rdtgrp || !new_prdtgrp) + return -ENOENT; + + /* Release both kernfs active_refs before obtaining rdtgroup mutex. */ + rdtgroup_kn_get(rdtgrp, kn); + rdtgroup_kn_get(new_prdtgrp, new_parent); + + mutex_lock(&rdtgroup_mutex); + + rdt_last_cmd_clear(); + + /* + * Don't allow kernfs_to_rdtgroup() to return a parent rdtgroup if + * either kernfs_node is a file. + */ + if (kernfs_type(kn) != KERNFS_DIR || + kernfs_type(new_parent) != KERNFS_DIR) { + rdt_last_cmd_puts("Source and destination must be directories"); + ret = -EPERM; + goto out; + } + + if ((rdtgrp->flags & RDT_DELETED) || (new_prdtgrp->flags & RDT_DELETED)) { + ret = -ENOENT; + goto out; + } + + if (rdtgrp->type != RDTMON_GROUP || !kn->parent || + !is_mon_groups(kn->parent, kn->name)) { + rdt_last_cmd_puts("Source must be a MON group\n"); + ret = -EPERM; + goto out; + } + + if (!is_mon_groups(new_parent, new_name)) { + rdt_last_cmd_puts("Destination must be a mon_groups subdirectory\n"); + ret = -EPERM; + goto out; + } + + /* + * If the MON group is monitoring CPUs, the CPUs must be assigned to the + * current parent CTRL_MON group and therefore cannot be assigned to + * the new parent, making the move illegal. + */ + if (!cpumask_empty(&rdtgrp->cpu_mask) && + rdtgrp->mon.parent != new_prdtgrp) { + rdt_last_cmd_puts("Cannot move a MON group that monitors CPUs\n"); + ret = -EPERM; + goto out; + } + + /* + * Allocate the cpumask for use in mongrp_reparent() to avoid the + * possibility of failing to allocate it after kernfs_rename() has + * succeeded. + */ + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) { + ret = -ENOMEM; + goto out; + } + + /* + * Perform all input validation and allocations needed to ensure + * mongrp_reparent() will succeed before calling kernfs_rename(), + * otherwise it would be necessary to revert this call if + * mongrp_reparent() failed. + */ + ret = kernfs_rename(kn, new_parent, new_name); + if (!ret) + mongrp_reparent(rdtgrp, new_prdtgrp, tmpmask); + + free_cpumask_var(tmpmask); + +out: + mutex_unlock(&rdtgroup_mutex); + rdtgroup_kn_put(rdtgrp, kn); + rdtgroup_kn_put(new_prdtgrp, new_parent); + return ret; +} + +static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) +{ + if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3)) + seq_puts(seq, ",cdp"); + + if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) + seq_puts(seq, ",cdpl2"); + + if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA))) + seq_puts(seq, ",mba_MBps"); + + if (resctrl_debug) + seq_puts(seq, ",debug"); + + return 0; +} + +static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { + .mkdir = rdtgroup_mkdir, + .rmdir = rdtgroup_rmdir, + .rename = rdtgroup_rename, + .show_options = rdtgroup_show_options, +}; + +static int rdtgroup_setup_root(struct rdt_fs_context *ctx) +{ + rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops, + KERNFS_ROOT_CREATE_DEACTIVATED | + KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK, + &rdtgroup_default); + if (IS_ERR(rdt_root)) + return PTR_ERR(rdt_root); + + ctx->kfc.root = rdt_root; + rdtgroup_default.kn = kernfs_root_to_node(rdt_root); + + return 0; +} + +static void rdtgroup_destroy_root(void) +{ + kernfs_destroy_root(rdt_root); + rdtgroup_default.kn = NULL; +} + +static void __init rdtgroup_setup_default(void) +{ + mutex_lock(&rdtgroup_mutex); + + rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID; + rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID; + rdtgroup_default.type = RDTCTRL_GROUP; + INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list); + + list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); + + mutex_unlock(&rdtgroup_mutex); +} + +static void domain_destroy_mon_state(struct rdt_domain *d) +{ + bitmap_free(d->rmid_busy_llc); + kfree(d->mbm_total); + kfree(d->mbm_local); +} + +void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d) +{ + mutex_lock(&rdtgroup_mutex); + + if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) + mba_sc_domain_destroy(r, d); + + if (!r->mon_capable) + goto out_unlock; + + /* + * If resctrl is mounted, remove all the + * per domain monitor data directories. + */ + if (resctrl_mounted && resctrl_arch_mon_capable()) + rmdir_mondata_subdir_allrdtgrp(r, d->id); + + if (resctrl_is_mbm_enabled()) + cancel_delayed_work(&d->mbm_over); + if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) { + /* + * When a package is going down, forcefully + * decrement rmid->ebusy. There is no way to know + * that the L3 was flushed and hence may lead to + * incorrect counts in rare scenarios, but leaving + * the RMID as busy creates RMID leaks if the + * package never comes back. + */ + __check_limbo(d, true); + cancel_delayed_work(&d->cqm_limbo); + } + + domain_destroy_mon_state(d); + +out_unlock: + mutex_unlock(&rdtgroup_mutex); +} + +static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_domain *d) +{ + u32 idx_limit = resctrl_arch_system_num_rmid_idx(); + size_t tsize; + + if (resctrl_arch_is_llc_occupancy_enabled()) { + d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL); + if (!d->rmid_busy_llc) + return -ENOMEM; + } + if (resctrl_arch_is_mbm_total_enabled()) { + tsize = sizeof(*d->mbm_total); + d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL); + if (!d->mbm_total) { + bitmap_free(d->rmid_busy_llc); + return -ENOMEM; + } + } + if (resctrl_arch_is_mbm_local_enabled()) { + tsize = sizeof(*d->mbm_local); + d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL); + if (!d->mbm_local) { + bitmap_free(d->rmid_busy_llc); + kfree(d->mbm_total); + return -ENOMEM; + } + } + + return 0; +} + +int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d) +{ + int err = 0; + + mutex_lock(&rdtgroup_mutex); + + if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) { + /* RDT_RESOURCE_MBA is never mon_capable */ + err = mba_sc_domain_allocate(r, d); + goto out_unlock; + } + + if (!r->mon_capable) + goto out_unlock; + + err = domain_setup_mon_state(r, d); + if (err) + goto out_unlock; + + if (resctrl_is_mbm_enabled()) { + INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow); + mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL, + RESCTRL_PICK_ANY_CPU); + } + + if (resctrl_arch_is_llc_occupancy_enabled()) + INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo); + + /* + * If the filesystem is not mounted then only the default resource group + * exists. Creation of its directories is deferred until mount time + * by rdt_get_tree() calling mkdir_mondata_all(). + * If resctrl is mounted, add per domain monitor data directories. + */ + if (resctrl_mounted && resctrl_arch_mon_capable()) + mkdir_mondata_subdir_allrdtgrp(r, d); + +out_unlock: + mutex_unlock(&rdtgroup_mutex); + + return err; +} + +void resctrl_online_cpu(unsigned int cpu) +{ + mutex_lock(&rdtgroup_mutex); + /* The CPU is set in default rdtgroup after online. */ + cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask); + mutex_unlock(&rdtgroup_mutex); +} + +static void clear_childcpus(struct rdtgroup *r, unsigned int cpu) +{ + struct rdtgroup *cr; + + list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) { + if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask)) + break; + } +} + +void resctrl_offline_cpu(unsigned int cpu) +{ + struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdtgroup *rdtgrp; + struct rdt_domain *d; + + mutex_lock(&rdtgroup_mutex); + list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) { + if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) { + clear_childcpus(rdtgrp, cpu); + break; + } + } + + if (!l3->mon_capable) + goto out_unlock; + + d = resctrl_get_domain_from_cpu(cpu, l3); + if (d) { + if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) { + cancel_delayed_work(&d->mbm_over); + mbm_setup_overflow_handler(d, 0, cpu); + } + if (resctrl_arch_is_llc_occupancy_enabled() && + cpu == d->cqm_work_cpu && has_busy_rmid(d)) { + cancel_delayed_work(&d->cqm_limbo); + cqm_setup_limbo_handler(d, 0, cpu); + } + } + +out_unlock: + mutex_unlock(&rdtgroup_mutex); +} + +/* + * resctrl_init - resctrl filesystem initialization + * + * Setup resctrl file system including set up root, create mount point, + * register resctrl filesystem, and initialize files under root directory. + * + * Return: 0 on success or -errno + */ +int resctrl_init(void) +{ + int ret = 0; + + seq_buf_init(&last_cmd_status, last_cmd_status_buf, + sizeof(last_cmd_status_buf)); + + rdtgroup_setup_default(); + + thread_throttle_mode_init(); + + ret = resctrl_mon_resource_init(); + if (ret) + return ret; + + ret = sysfs_create_mount_point(fs_kobj, "resctrl"); + if (ret) + return ret; + + ret = register_filesystem(&rdt_fs_type); + if (ret) + goto cleanup_mountpoint; + + /* + * Adding the resctrl debugfs directory here may not be ideal since + * it would let the resctrl debugfs directory appear on the debugfs + * filesystem before the resctrl filesystem is mounted. + * It may also be ok since that would enable debugging of RDT before + * resctrl is mounted. + * The reason why the debugfs directory is created here and not in + * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and + * during the debugfs directory creation also &sb->s_type->i_mutex_key + * (the lockdep class of inode->i_rwsem). Other filesystem + * interactions (eg. SyS_getdents) have the lock ordering: + * &sb->s_type->i_mutex_key --> &mm->mmap_lock + * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex + * is taken, thus creating dependency: + * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause + * issues considering the other two lock dependencies. + * By creating the debugfs directory here we avoid a dependency + * that may cause deadlock (even though file operations cannot + * occur until the filesystem is mounted, but I do not know how to + * tell lockdep that). + */ + debugfs_resctrl = debugfs_create_dir("resctrl", NULL); + + return 0; + +cleanup_mountpoint: + sysfs_remove_mount_point(fs_kobj, "resctrl"); + + return ret; +} + +void resctrl_exit(void) +{ + debugfs_remove_recursive(debugfs_resctrl); + unregister_filesystem(&rdt_fs_type); + sysfs_remove_mount_point(fs_kobj, "resctrl"); + + resctrl_mon_resource_exit(); +}