From: "Rob Herring (Arm)" <robh@kernel.org> mainline inclusion from mainline-v6.12-rc1 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/9066 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ----------------------------------------------- Xscale and Armv6 PMUs defined the cycle counter at 0 and event counters starting at 1 and had 1:1 event index to counter numbering. On Armv7 and later, this changed the cycle counter to 31 and event counters start at 0. The drivers for Armv7 and PMUv3 kept the old event index numbering and introduced an event index to counter conversion. The conversion uses masking to convert from event index to a counter number. This operation relies on having at most 32 counters so that the cycle counter index 0 can be transformed to counter number 31. Armv9.4 adds support for an additional fixed function counter (instructions) which increases possible counters to more than 32, and the conversion won't work anymore as a simple subtract and mask. The primary reason for the translation (other than history) seems to be to have a contiguous mask of counters 0-N. Keeping that would result in more complicated index to counter conversions. Instead, store a mask of available counters rather than just number of events. That provides more information in addition to the number of events. No (intended) functional changes. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Tested-by: James Clark <james.clark@linaro.org> Link: https://lore.kernel.org/r/20240731-arm-pmu-3-9-icntr-v3-1-280a8d7ff465@kerne... Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Yushan Wang <wangyushan12@huawei.com> Signed-off-by: Ying Jiang <jiangying44@h-partners.com> --- arch/arm64/kvm/pmu-emul.c | 6 ++-- drivers/perf/apple_m1_cpu_pmu.c | 4 +-- drivers/perf/arm_pmu.c | 11 +++--- drivers/perf/arm_pmuv3.c | 61 ++++++++++++--------------------- include/linux/perf/arm_pmu.h | 2 +- include/linux/perf/arm_pmuv3.h | 1 + 6 files changed, 34 insertions(+), 51 deletions(-) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 2cf3c4462b64..d86c7a585f99 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -941,10 +941,10 @@ u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm) return kvm_realm_max_pmu_counters(); /* - * The arm_pmu->num_events considers the cycle counter as well. - * Ignore that and return only the general-purpose counters. + * The arm_pmu->cntr_mask considers the fixed counter(s) as well. + * Ignore those and return only the general-purpose counters. */ - return arm_pmu->num_events - 1; + return bitmap_weight(arm_pmu->cntr_mask, ARMV8_PMU_MAX_GENERAL_COUNTERS); } static int kvm_arm_pmu_v3_set_pmu(struct kvm_vcpu *vcpu, int pmu_id) diff --git a/drivers/perf/apple_m1_cpu_pmu.c b/drivers/perf/apple_m1_cpu_pmu.c index f322e5ca1114..c8f607912567 100644 --- a/drivers/perf/apple_m1_cpu_pmu.c +++ b/drivers/perf/apple_m1_cpu_pmu.c @@ -400,7 +400,7 @@ static irqreturn_t m1_pmu_handle_irq(struct arm_pmu *cpu_pmu) regs = get_irq_regs(); - for (idx = 0; idx < cpu_pmu->num_events; idx++) { + for_each_set_bit(idx, cpu_pmu->cntr_mask, M1_PMU_NR_COUNTERS) { struct perf_event *event = cpuc->events[idx]; struct perf_sample_data data; @@ -560,7 +560,7 @@ static int m1_pmu_init(struct arm_pmu *cpu_pmu, u32 flags) cpu_pmu->reset = m1_pmu_reset; cpu_pmu->set_event_filter = m1_pmu_set_event_filter; - cpu_pmu->num_events = M1_PMU_NR_COUNTERS; + bitmap_set(cpu_pmu->cntr_mask, 0, M1_PMU_NR_COUNTERS); cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_EVENTS] = &m1_pmu_events_attr_group; cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_FORMATS] = &m1_pmu_format_attr_group; return 0; diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index ea9a8d0c0b21..801a93b16ac3 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -566,7 +566,7 @@ static void armpmu_enable(struct pmu *pmu) { struct arm_pmu *armpmu = to_arm_pmu(pmu); struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); - bool enabled = !bitmap_empty(hw_events->used_mask, armpmu->num_events); + bool enabled = !bitmap_empty(hw_events->used_mask, ARMPMU_MAX_HWEVENTS); /* For task-bound events we may be called on other CPUs */ if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) @@ -801,7 +801,7 @@ static void cpu_pm_pmu_setup(struct arm_pmu *armpmu, unsigned long cmd) struct perf_event *event; int idx; - for (idx = 0; idx < armpmu->num_events; idx++) { + for_each_set_bit(idx, armpmu->cntr_mask, ARMPMU_MAX_HWEVENTS) { event = hw_events->events[idx]; if (!event) continue; @@ -831,7 +831,7 @@ static int cpu_pm_pmu_notify(struct notifier_block *b, unsigned long cmd, { struct arm_pmu *armpmu = container_of(b, struct arm_pmu, cpu_pm_nb); struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); - bool enabled = !bitmap_empty(hw_events->used_mask, armpmu->num_events); + bool enabled = !bitmap_empty(hw_events->used_mask, ARMPMU_MAX_HWEVENTS); if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) return NOTIFY_DONE; @@ -991,8 +991,9 @@ int armpmu_register(struct arm_pmu *pmu) if (ret) goto out_destroy; - pr_info("enabled with %s PMU driver, %d counters available%s\n", - pmu->name, pmu->num_events, + pr_info("enabled with %s PMU driver, %d (%*pb) counters available%s\n", + pmu->name, bitmap_weight(pmu->cntr_mask, ARMPMU_MAX_HWEVENTS), + ARMPMU_MAX_HWEVENTS, &pmu->cntr_mask, has_nmi ? ", using NMIs" : ""); kvm_host_pmu_init(pmu); diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c index 5d750678a70e..ee56bde77ef5 100644 --- a/drivers/perf/arm_pmuv3.c +++ b/drivers/perf/arm_pmuv3.c @@ -508,9 +508,8 @@ static const struct attribute_group armv8_pmuv3_caps_attr_group = { /* * Perf Events' indices */ -#define ARMV8_IDX_CYCLE_COUNTER 0 +#define ARMV8_IDX_CYCLE_COUNTER 31 #define ARMV8_IDX_COUNTER0 1 -#define ARMV8_IDX_CYCLE_COUNTER_USER 32 /* * We unconditionally enable ARMv8.5-PMU long event counter support @@ -543,19 +542,12 @@ static bool armv8pmu_event_is_chained(struct perf_event *event) return !armv8pmu_event_has_user_read(event) && armv8pmu_event_is_64bit(event) && !armv8pmu_has_long_event(cpu_pmu) && - (idx != ARMV8_IDX_CYCLE_COUNTER); + (idx < ARMV8_PMU_MAX_GENERAL_COUNTERS); } /* * ARMv8 low level PMU access */ - -/* - * Perf Event to low level counters mapping - */ -#define ARMV8_IDX_TO_COUNTER(x) \ - (((x) - ARMV8_IDX_COUNTER0) & ARMV8_PMU_COUNTER_MASK) - static u64 armv8pmu_pmcr_read(void) { return read_pmcr(); @@ -575,14 +567,12 @@ static int armv8pmu_has_overflowed(u32 pmovsr) static int armv8pmu_counter_has_overflowed(u32 pmnc, int idx) { - return pmnc & BIT(ARMV8_IDX_TO_COUNTER(idx)); + return pmnc & BIT(idx); } static u64 armv8pmu_read_evcntr(int idx) { - u32 counter = ARMV8_IDX_TO_COUNTER(idx); - - return read_pmevcntrn(counter); + return read_pmevcntrn(idx); } static u64 armv8pmu_read_hw_counter(struct perf_event *event) @@ -611,7 +601,7 @@ static bool armv8pmu_event_needs_bias(struct perf_event *event) return false; if (armv8pmu_has_long_event(cpu_pmu) || - idx == ARMV8_IDX_CYCLE_COUNTER) + idx >= ARMV8_PMU_MAX_GENERAL_COUNTERS) return true; return false; @@ -649,9 +639,7 @@ static u64 armv8pmu_read_counter(struct perf_event *event) static void armv8pmu_write_evcntr(int idx, u64 value) { - u32 counter = ARMV8_IDX_TO_COUNTER(idx); - - write_pmevcntrn(counter, value); + write_pmevcntrn(idx, value); } #ifdef CONFIG_HISILICON_HW_METRIC @@ -722,7 +710,6 @@ static void armv8pmu_write_counter(struct perf_event *event, u64 value) static void armv8pmu_write_evtype(int idx, unsigned long val) { - u32 counter = ARMV8_IDX_TO_COUNTER(idx); unsigned long mask = ARMV8_PMU_EVTYPE_EVENT | ARMV8_PMU_INCLUDE_EL2 | ARMV8_PMU_EXCLUDE_EL0 | @@ -732,7 +719,7 @@ static void armv8pmu_write_evtype(int idx, unsigned long val) mask |= ARMV8_PMU_EVTYPE_TC | ARMV8_PMU_EVTYPE_TH; val &= mask; - write_pmevtypern(counter, val); + write_pmevtypern(idx, val); } static void armv8pmu_write_event_type(struct perf_event *event) @@ -761,7 +748,7 @@ static void armv8pmu_write_event_type(struct perf_event *event) static u32 armv8pmu_event_cnten_mask(struct perf_event *event) { - int counter = ARMV8_IDX_TO_COUNTER(event->hw.idx); + int counter = event->hw.idx; u32 mask = BIT(counter); if (armv8pmu_event_is_chained(event)) @@ -864,8 +851,7 @@ static void armv8pmu_enable_intens(u32 mask) static void armv8pmu_enable_event_irq(struct perf_event *event) { - u32 counter = ARMV8_IDX_TO_COUNTER(event->hw.idx); - armv8pmu_enable_intens(BIT(counter)); + armv8pmu_enable_intens(BIT(event->hw.idx)); } static void armv8pmu_disable_intens(u32 mask) @@ -879,8 +865,7 @@ static void armv8pmu_disable_intens(u32 mask) static void armv8pmu_disable_event_irq(struct perf_event *event) { - u32 counter = ARMV8_IDX_TO_COUNTER(event->hw.idx); - armv8pmu_disable_intens(BIT(counter)); + armv8pmu_disable_intens(BIT(event->hw.idx)); } static u32 armv8pmu_getreset_flags(void) @@ -924,7 +909,8 @@ static void armv8pmu_enable_user_access(struct arm_pmu *cpu_pmu) struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events); /* Clear any unused counters to avoid leaking their contents */ - for_each_clear_bit(i, cpuc->used_mask, cpu_pmu->num_events) { + for_each_andnot_bit(i, cpu_pmu->cntr_mask, cpuc->used_mask, + ARMPMU_MAX_HWEVENTS) { if (i == ARMV8_IDX_CYCLE_COUNTER) write_pmccntr(0); else @@ -1064,7 +1050,7 @@ static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu) * to prevent skews in group events. */ armv8pmu_stop(cpu_pmu); - for (idx = 0; idx < cpu_pmu->num_events; ++idx) { + for_each_set_bit(idx, cpu_pmu->cntr_mask, ARMPMU_MAX_HWEVENTS) { struct perf_event *event = cpuc->events[idx]; struct hw_perf_event *hwc; @@ -1112,7 +1098,7 @@ static int armv8pmu_get_single_idx(struct pmu_hw_events *cpuc, { int idx; - for (idx = ARMV8_IDX_COUNTER0; idx < cpu_pmu->num_events; idx++) { + for_each_set_bit(idx, cpu_pmu->cntr_mask, ARMV8_PMU_MAX_GENERAL_COUNTERS) { if (!test_and_set_bit(idx, cpuc->used_mask)) return idx; } @@ -1128,7 +1114,9 @@ static int armv8pmu_get_chain_idx(struct pmu_hw_events *cpuc, * Chaining requires two consecutive event counters, where * the lower idx must be even. */ - for (idx = ARMV8_IDX_COUNTER0 + 1; idx < cpu_pmu->num_events; idx += 2) { + for_each_set_bit(idx, cpu_pmu->cntr_mask, ARMV8_PMU_MAX_GENERAL_COUNTERS) { + if (!(idx & 0x1)) + continue; if (!test_and_set_bit(idx, cpuc->used_mask)) { /* Check if the preceding even counter is available */ if (!test_and_set_bit(idx - 1, cpuc->used_mask)) @@ -1271,15 +1259,7 @@ static int armv8pmu_user_event_idx(struct perf_event *event) if (!sysctl_perf_user_access || !armv8pmu_event_has_user_read(event)) return 0; - /* - * We remap the cycle counter index to 32 to - * match the offset applied to the rest of - * the counter indices. - */ - if (event->hw.idx == ARMV8_IDX_CYCLE_COUNTER) - return ARMV8_IDX_CYCLE_COUNTER_USER; - - return event->hw.idx; + return event->hw.idx + 1; } static bool armv8pmu_branch_stack_init(struct perf_event *event) @@ -1546,10 +1526,11 @@ static void __armv8pmu_probe_pmu(void *info) probe->present = true; /* Read the nb of CNTx counters supported from PMNC */ - cpu_pmu->num_events = FIELD_GET(ARMV8_PMU_PMCR_N, armv8pmu_pmcr_read()); + bitmap_set(cpu_pmu->cntr_mask, + 0, FIELD_GET(ARMV8_PMU_PMCR_N, armv8pmu_pmcr_read())); /* Add the CPU cycles counter */ - cpu_pmu->num_events += 1; + set_bit(ARMV8_IDX_CYCLE_COUNTER, cpu_pmu->cntr_mask); pmceid[0] = pmceid_raw[0] = read_pmceid0(); pmceid[1] = pmceid_raw[1] = read_pmceid1(); diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index 850f363cac87..84679844592f 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -131,7 +131,7 @@ struct arm_pmu { void (*branch_stack_add)(struct perf_event *event, struct pmu_hw_events *cpuc); void (*branch_stack_del)(struct perf_event *event, struct pmu_hw_events *cpuc); void (*branch_stack_reset)(void); - int num_events; + DECLARE_BITMAP(cntr_mask, ARMPMU_MAX_HWEVENTS); unsigned int secure_access : 1, /* 32-bit ARM only */ has_branch_stack: 1, /* 64-bit ARM only */ reserved : 30; diff --git a/include/linux/perf/arm_pmuv3.h b/include/linux/perf/arm_pmuv3.h index 46377e134d67..96cbb85d19b7 100644 --- a/include/linux/perf/arm_pmuv3.h +++ b/include/linux/perf/arm_pmuv3.h @@ -6,6 +6,7 @@ #ifndef __PERF_ARM_PMUV3_H #define __PERF_ARM_PMUV3_H +#define ARMV8_PMU_MAX_GENERAL_COUNTERS 31 #define ARMV8_PMU_MAX_COUNTERS 32 #define ARMV8_PMU_COUNTER_MASK (ARMV8_PMU_MAX_COUNTERS - 1) -- 2.33.0