[PATCH] sha: Enable cpuid check for Intel SHA extensions implementations

[Tim Chen]

The Intel Secure Hash Algorithm Extensions are designed to improve the performance
of SHA-1 and SHA-256. This patch adds the check for X86_FEATURE_SHA_NI bit.

The SHA extension guide is found in chapter 8 of the Intel
Architecture Instruction Set Extensions Programming reference:
https://software.intel.com/sites/default/files/managed/07/b7/319433-023.pdf

Signed-off-by: Chandramouli Narayanan <mouli@xxxxxxxxxxxxxxx>
Signed-off-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/cpufeature.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 3d6606f..7f85580 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -239,6 +239,7 @@
 #define X86_FEATURE_AVX512PF	( 9*32+26) /* AVX-512 Prefetch */
 #define X86_FEATURE_AVX512ER	( 9*32+27) /* AVX-512 Exponential and Reciprocal */
 #define X86_FEATURE_AVX512CD	( 9*32+28) /* AVX-512 Conflict Detection */
+#define X86_FEATURE_SHA_NI	( 9*32+29) /* SHA1/SHA256 Instruction Extensions */
 
 /* Extended state features, CPUID level 0x0000000d:1 (eax), word 10 */
 #define X86_FEATURE_XSAVEOPT	(10*32+ 0) /* XSAVEOPT */
@@ -401,6 +402,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 #define cpu_has_eager_fpu	boot_cpu_has(X86_FEATURE_EAGER_FPU)
 #define cpu_has_topoext		boot_cpu_has(X86_FEATURE_TOPOEXT)
 #define cpu_has_bpext		boot_cpu_has(X86_FEATURE_BPEXT)
+#define cpu_has_sha_ni		boot_cpu_has(X86_FEATURE_SHA_NI)
 
 #if __GNUC__ >= 4
 extern void warn_pre_alternatives(void);
-- 
1.8.3.1


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