From bd657aa3dd8514e62486ce7f90b5e484c18d684d Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Fri, 3 Jul 2020 05:49:07 -0700 Subject: [PATCH] x86/cpufeatures: Add Architectural LBRs feature bit CPUID.(EAX=07H, ECX=0):EDX[19] indicates whether an Intel CPU supports Architectural LBRs. The "X86_FEATURE_..., word 18" is already mirrored from CPUID "0x00000007:0 (EDX)". Add X86_FEATURE_ARCH_LBR under the "word 18" section. The feature will appear as "arch_lbr" in /proc/cpuinfo. The Architectural Last Branch Records (LBR) feature enables recording of software path history by logging taken branches and other control flows. The feature will be supported in the perf_events subsystem. Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Dave Hansen Link: https://lkml.kernel.org/r/1593780569-62993-2-git-send-email-kan.liang@linux.intel.com --- arch/x86/include/asm/cpufeatures.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 02dabc9e77b0..72ba4c59ad05 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -366,6 +366,7 @@ #define X86_FEATURE_MD_CLEAR (18*32+10) /* VERW clears CPU buffers */ #define X86_FEATURE_TSX_FORCE_ABORT (18*32+13) /* "" TSX_FORCE_ABORT */ #define X86_FEATURE_PCONFIG (18*32+18) /* Intel PCONFIG */ +#define X86_FEATURE_ARCH_LBR (18*32+19) /* Intel ARCH LBR */ #define X86_FEATURE_SPEC_CTRL (18*32+26) /* "" Speculation Control (IBRS + IBPB) */ #define X86_FEATURE_INTEL_STIBP (18*32+27) /* "" Single Thread Indirect Branch Predictors */ #define X86_FEATURE_FLUSH_L1D (18*32+28) /* Flush L1D cache */