From 257449c6a50298bd21dcabd644f66a0296b78532 Mon Sep 17 00:00:00 2001 From: Sandipan Das Date: Thu, 11 Aug 2022 17:59:52 +0530 Subject: 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 Signed-off-by: Peter Zijlstra (Intel) Acked-by: Borislav Petkov Link: https://lore.kernel.org/r/172d2b0df39306ed77221c45ee1aa62e8ae0548d.1660211399.git.sandipan.das@amd.com --- arch/x86/kernel/cpu/scattered.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/kernel/cpu/scattered.c') 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 } }; -- cgit