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Commit 5958f1d5 authored by Borislav Petkov's avatar Borislav Petkov Committed by H. Peter Anvin
Browse files

x86, cpu: Add AMD core boosting feature flag to /proc/cpuinfo 



By semi-popular demand, this adds the Core Performance Boost feature
flag to /proc/cpuinfo. Possible use case for this is userspace tools
like cpufreq-aperf, for example, so that they don't have to jump through
hoops of accessing "/dev/cpu/%d/cpuid" in order to check for CPB hw
support, or call cpuid from userspace.

Signed-off-by: default avatarBorislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1270065406-1814-2-git-send-email-bp@amd64.org>
Reviewed-by: default avatarThomas Renninger <trenn@suse.de>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 2eaa9cfd

arch/x86/include/asm/cpufeature.h

+1 −0
Original line number Diff line number Diff line
@@ -161,6 +161,7 @@ 
 */

#define X86_FEATURE_IDA		(7*32+ 0) /* Intel Dynamic Acceleration */

#define X86_FEATURE_ARAT	(7*32+ 1) /* Always Running APIC Timer */

#define X86_FEATURE_CPB		(7*32+ 2) /* AMD Core Performance Boost */



/* Virtualization flags: Linux defined */

#define X86_FEATURE_TPR_SHADOW  (8*32+ 0) /* Intel TPR Shadow */

arch/x86/kernel/cpu/addon_cpuid_features.c

+3 −2
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c) 
	static const struct cpuid_bit __cpuinitconst cpuid_bits[] = {

		{ X86_FEATURE_IDA,   CR_EAX, 1, 0x00000006 },

		{ X86_FEATURE_ARAT,  CR_EAX, 2, 0x00000006 },

		{ X86_FEATURE_CPB,   CR_EDX, 9, 0x80000007 },

		{ X86_FEATURE_NPT,   CR_EDX, 0, 0x8000000a },

		{ X86_FEATURE_LBRV,  CR_EDX, 1, 0x8000000a },

		{ X86_FEATURE_SVML,  CR_EDX, 2, 0x8000000a },