diff options
| 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 /arch/x86/events/amd/core.c | |
| parent | 21d59e3e2c403c83ba196a5857d517054124168e (diff) | |
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
Diffstat (limited to 'arch/x86/events/amd/core.c')
| -rw-r--r-- | arch/x86/events/amd/core.c | 6 |
1 files changed, 6 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; } |