[PATCH 1/9] x86, cpu: Enable enhanced REP MOVSB/STOSB feature

From: Fenghua Yu
Date: Tue May 17 2011 - 18:43:41 EST


From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

Intel processors are adding enhancements to REP MOVSB/STOSB and the use of
REP MOVSB/STOSB for optimal memcpy/memset or similar functions is recommended.
Enhancement availability is indicated by CPUID.7.0.EBX[9] (Enhanced REP MOVSB/
STOSB).

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
arch/x86/include/asm/cpufeature.h | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 50c0d30..30afb46 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -195,6 +195,7 @@

/* Intel-defined CPU features, CPUID level 0x00000007:0 (ebx), word 9 */
#define X86_FEATURE_FSGSBASE (9*32+ 0) /* {RD/WR}{FS/GS}BASE instructions*/
+#define X86_FEATURE_ERMS (9*32+ 9) /* Enhanced REP MOVSB/STOSB */

#if defined(__KERNEL__) && !defined(__ASSEMBLY__)

--
1.7.2

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