x86, cpufeature: Add CPU feature bit for enhanced REP MOVSB/STOSB
authorFenghua Yu <fenghua.yu@intel.com>
Tue, 17 May 2011 22:29:10 +0000 (15:29 -0700)
committerH. Peter Anvin <hpa@linux.intel.com>
Tue, 17 May 2011 21:56:36 +0000 (14:56 -0700)
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@intel.com>
Link: http://lkml.kernel.org/r/1305671358-14478-2-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
arch/x86/include/asm/cpufeature.h

index 91f3e087cf21817704c68f24379edc4cf31a6885..7f2f7b12329301a5f62fb4f15b4201ba236f4c00 100644 (file)
 
 /* 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__)