Commit 1ad46670 authored by Perry Yuan's avatar Perry Yuan Committed by Borislav Petkov (AMD)
Browse files

x86/cpufeatures: Add X86_FEATURE_AMD_HETEROGENEOUS_CORES 



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: default avatarPerry Yuan <perry.yuan@amd.com>
Co-developed-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20241025171459.1093-3-mario.limonciello@amd.com
parent 104edc6e

arch/x86/include/asm/cpufeatures.h

+1 −0
Original line number Diff line number Diff line
@@ -473,6 +473,7 @@ 
#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)

arch/x86/kernel/cpu/scattered.c

+1 −0
Original line number Diff line number Diff line
@@ -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 }

};