From: Maciej Wieczor-Retman maciej.wieczor-retman@intel.com
The setting for non-contiguous 1s support in Intel CAT is hardcoded to false. On these systems, writing non-contiguous 1s into the schemata file will fail before resctrl passes the value to the hardware.
In Intel CAT CPUID.0x10.1:ECX[3] and CPUID.0x10.2:ECX[3] stopped being reserved and now carry information about non-contiguous 1s value support for L3 and L2 cache respectively. The CAT capacity bitmask (CBM) supports a non-contiguous 1s value if the bit is set.
The exception are Haswell systems where non-contiguous 1s value support needs to stay disabled since they can't make use of CPUID for Cache allocation.
Originally-by: Fenghua Yu fenghua.yu@intel.com Signed-off-by: Maciej Wieczor-Retman maciej.wieczor-retman@intel.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Reviewed-by: Peter Newman peternewman@google.com Reviewed-by: Reinette Chatre reinette.chatre@intel.com Reviewed-by: Babu Moger babu.moger@amd.com Tested-by: Peter Newman peternewman@google.com Link: https://lore.kernel.org/r/1849b487256fe4de40b30f88450cba3d9abc9171.169693409... --- arch/x86/kernel/cpu/resctrl/core.c | 9 ++++++--- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 10 ++++++---- arch/x86/kernel/cpu/resctrl/internal.h | 9 +++++++++ 3 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index c09e4fdded3c..19e0681f0435 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -152,6 +152,7 @@ static inline void cache_alloc_hsw_probe(void) r->cache.cbm_len = 20; r->cache.shareable_bits = 0xc0000; r->cache.min_cbm_bits = 2; + r->cache.arch_has_sparse_bitmasks = false; r->alloc_capable = true;
rdt_alloc_capable = true; @@ -267,15 +268,18 @@ static void rdt_get_cache_alloc_cfg(int idx, struct rdt_resource *r) { struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); union cpuid_0x10_1_eax eax; + union cpuid_0x10_x_ecx ecx; union cpuid_0x10_x_edx edx; - u32 ebx, ecx; + u32 ebx;
- cpuid_count(0x00000010, idx, &eax.full, &ebx, &ecx, &edx.full); + cpuid_count(0x00000010, idx, &eax.full, &ebx, &ecx.full, &edx.full); hw_res->num_closid = edx.split.cos_max + 1; r->cache.cbm_len = eax.split.cbm_len + 1; r->default_ctrl = BIT_MASK(eax.split.cbm_len + 1) - 1; r->cache.shareable_bits = ebx & r->default_ctrl; r->data_width = (r->cache.cbm_len + 3) / 4; + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) + r->cache.arch_has_sparse_bitmasks = ecx.split.noncont; r->alloc_capable = true; }
@@ -872,7 +876,6 @@ static __init void rdt_init_res_defs_intel(void)
if (r->rid == RDT_RESOURCE_L3 || r->rid == RDT_RESOURCE_L2) { - r->cache.arch_has_sparse_bitmasks = false; r->cache.arch_has_per_cpu_cfg = false; r->cache.min_cbm_bits = 1; } else if (r->rid == RDT_RESOURCE_MBA) { diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index ab45012288bb..beccb0e87ba7 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -87,10 +87,12 @@ int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s,
/* * Check whether a cache bit mask is valid. - * For Intel the SDM says: - * Please note that all (and only) contiguous '1' combinations - * are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.). - * Additionally Haswell requires at least two bits set. + * 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) diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 85ceaf9a31ac..c47ef2f13e8e 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -492,6 +492,15 @@ union cpuid_0x10_3_eax { unsigned int full; };
+/* CPUID.(EAX=10H, ECX=ResID).ECX */ +union cpuid_0x10_x_ecx { + struct { + unsigned int reserved:3; + unsigned int noncont:1; + } split; + unsigned int full; +}; + /* CPUID.(EAX=10H, ECX=ResID).EDX */ union cpuid_0x10_x_edx { struct {