From 34ef29430b9a217ef0811f218b8f86c631d6c574 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Fri, 25 Oct 2024 12:14:56 -0500 Subject: x86/cpufeatures: Add feature bits for AMD heterogeneous processor CPUID leaf 0x80000026 advertises core types with different efficiency rankings. Bit 30 indicates the heterogeneous core topology feature, if the bit set, it means not all instances at the current hierarchical level have the same core topology. This is described in the AMD64 Architecture Programmers Manual Volume 2 and 3, doc ID #25493 and #25494. Signed-off-by: Perry Yuan Co-developed-by: Mario Limonciello Signed-off-by: Mario Limonciello --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/scattered.c | 1 + 2 files changed, 2 insertions(+) --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -474,6 +474,7 @@ #define X86_FEATURE_CLEAR_BHB_HW (21*32+ 3) /* BHI_DIS_S HW control enabled */ #define X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT (21*32+ 4) /* Clear branch history at vmexit using SW loop */ #define X86_FEATURE_AMD_FAST_CPPC (21*32 + 5) /* Fast CPPC */ +#define X86_FEATURE_AMD_HETEROGENEOUS_CORES (21*32 + 6) /* Heterogeneous Core Topology */ /* * BUG word(s) --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -52,6 +52,7 @@ static const struct cpuid_bit cpuid_bits { X86_FEATURE_PERFMON_V2, CPUID_EAX, 0, 0x80000022, 0 }, { X86_FEATURE_AMD_LBR_V2, CPUID_EAX, 1, 0x80000022, 0 }, { X86_FEATURE_AMD_LBR_PMC_FREEZE, CPUID_EAX, 2, 0x80000022, 0 }, + { X86_FEATURE_AMD_HETEROGENEOUS_CORES, CPUID_EAX, 30, 0x80000026, 0 }, { 0, 0, 0, 0, 0 } };