From c7107750b2ffaa4950faa53f84f9c9aa2caac89a Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Sat, 25 May 2024 23:08:43 +0800 Subject: [PATCH] x86/cpufeatures: Add AMD FAST CPPC feature flag Some AMD Zen 4 processors support a new feature FAST CPPC which allows for a faster CPPC loop due to internal architectural enhancements. The goal of this faster loop is higher performance at the same power consumption. Reference: See the page 99 of PPR for AMD Family 19h Model 61h rev.B1, docID 56713 Signed-off-by: Perry Yuan Signed-off-by: Xiaojian Du Reviewed-by: Borislav Petkov (AMD) --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/scattered.c | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 3c7434329661..6c128d463a14 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -470,6 +470,7 @@ #define X86_FEATURE_BHI_CTRL (21*32+ 2) /* "" BHI_DIS_S HW control available */ #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_FAST_CPPC (21*32 + 5) /* "" AMD Fast CPPC */ /* * BUG word(s) diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index af5aa2c754c2..c84c30188fdf 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_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 }, { X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 }, { X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 }, + { X86_FEATURE_FAST_CPPC, CPUID_EDX, 15, 0x80000007, 0 }, { X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 }, { X86_FEATURE_SMBA, CPUID_EBX, 2, 0x80000020, 0 }, { X86_FEATURE_BMEC, CPUID_EBX, 3, 0x80000020, 0 }, -- 2.49.0