diff options
| author | Sandipan Das <sandipan.das@amd.com> | 2022-08-11 17:59:52 +0530 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-08-27 00:05:42 +0200 |
| commit | 257449c6a50298bd21dcabd644f66a0296b78532 (patch) | |
| tree | d57328fb393b04e488c73f45df80e81a57bf4d74 /arch/x86/kernel | |
| parent | 706460a96fc654e80b6bed1f562b00d2ce9f2f4d (diff) | |
x86/cpufeatures: Add LbrExtV2 feature bit
CPUID leaf 0x80000022 i.e. ExtPerfMonAndDbg advertises some new performance
monitoring features for AMD processors.
Bit 1 of EAX indicates support for Last Branch Record Extension Version 2
(LbrExtV2) features. If found to be set during PMU initialization, the EBX
bits of the same leaf can be used to determine the number of available LBR
entries.
For better utilization of feature words, LbrExtV2 is added as a scattered
feature bit.
[peterz: Rename to AMD_LBR_V2]
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/172d2b0df39306ed77221c45ee1aa62e8ae0548d.1660211399.git.sandipan.das@amd.com
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/scattered.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index fd44b54c90d5..fc01f81f6e2a 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -45,6 +45,7 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 }, { X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 }, { X86_FEATURE_PERFMON_V2, CPUID_EAX, 0, 0x80000022, 0 }, + { X86_FEATURE_AMD_LBR_V2, CPUID_EAX, 1, 0x80000022, 0 }, { 0, 0, 0, 0, 0 } }; |