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| author | Sandipan Das <sandipan.das@amd.com> | 2022-04-21 11:16:56 +0530 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-05-04 11:18:26 +0200 |
| commit | 56e026a7ca3f92b8e44359e1f705febd1833f701 (patch) | |
| tree | cd1ae6fe5665a3a3ca8114eb1aff6b458274a641 | |
| parent | 21d59e3e2c403c83ba196a5857d517054124168e (diff) | |
| download | linux-56e026a7ca3f92b8e44359e1f705febd1833f701.tar.bz2 | |
perf/x86/amd/core: Detect available counters
If AMD Performance Monitoring Version 2 (PerfMonV2) is
supported, use CPUID leaf 0x80000022 EBX to detect the
number of Core PMCs. This offers more flexibility if the
counts change in later processor families.
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/68a6d9688df189267db26530378870edd34f7b06.1650515382.git.sandipan.das@amd.com
| -rw-r--r-- | arch/x86/events/amd/core.c | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/perf_event.h | 17 |
2 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index b70dfa028ba5..52fd7941a724 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -1186,6 +1186,7 @@ static const struct attribute_group *amd_attr_update[] = { static int __init amd_core_pmu_init(void) { + union cpuid_0x80000022_ebx ebx; u64 even_ctr_mask = 0ULL; int i; @@ -1206,9 +1207,14 @@ static int __init amd_core_pmu_init(void) /* Check for Performance Monitoring v2 support */ if (boot_cpu_has(X86_FEATURE_PERFMON_V2)) { + ebx.full = cpuid_ebx(EXT_PERFMON_DEBUG_FEATURES); + /* Update PMU version for later usage */ x86_pmu.version = 2; + /* Find the number of available Core PMCs */ + x86_pmu.num_counters = ebx.split.num_core_pmc; + amd_pmu_global_cntr_mask = (1ULL << x86_pmu.num_counters) - 1; } diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index 8199fc5a37ea..c6cc07f46556 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -186,6 +186,18 @@ union cpuid28_ecx { unsigned int full; }; +/* + * AMD "Extended Performance Monitoring and Debug" CPUID + * detection/enumeration details: + */ +union cpuid_0x80000022_ebx { + struct { + /* Number of Core Performance Counters */ + unsigned int num_core_pmc:4; + } split; + unsigned int full; +}; + struct x86_pmu_capability { int version; int num_counters_gp; @@ -368,6 +380,11 @@ struct pebs_xmm { }; /* + * AMD Extended Performance Monitoring and Debug cpuid feature detection + */ +#define EXT_PERFMON_DEBUG_FEATURES 0x80000022 + +/* * IBS cpuid feature detection */ |