lib/raid6: Add AVX2 optimized recovery functions
Optimize RAID6 recovery functions to take advantage of
the 256-bit YMM integer instructions introduced in AVX2.
The patch was tested and benchmarked before submission.
However hardware is not yet released so benchmark numbers
cannot be reported.
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/lib/raid6/x86.h b/lib/raid6/x86.h
index d55d632..b759548 100644
--- a/lib/raid6/x86.h
+++ b/lib/raid6/x86.h
@@ -45,19 +45,23 @@
#define X86_FEATURE_XMM3 (4*32+ 0) /* "pni" SSE-3 */
#define X86_FEATURE_SSSE3 (4*32+ 9) /* Supplemental SSE-3 */
#define X86_FEATURE_AVX (4*32+28) /* Advanced Vector Extensions */
+#define X86_FEATURE_AVX2 (9*32+ 5) /* AVX2 instructions */
#define X86_FEATURE_MMXEXT (1*32+22) /* AMD MMX extensions */
/* Should work well enough on modern CPUs for testing */
static inline int boot_cpu_has(int flag)
{
- u32 eax = (flag & 0x20) ? 0x80000001 : 1;
- u32 ecx, edx;
+ u32 eax, ebx, ecx, edx;
+
+ eax = (flag & 0x100) ? 7 :
+ (flag & 0x20) ? 0x80000001 : 1;
+ ecx = 0;
asm volatile("cpuid"
- : "+a" (eax), "=d" (edx), "=c" (ecx)
- : : "ebx");
+ : "+a" (eax), "=b" (ebx), "=d" (edx), "+c" (ecx));
- return ((flag & 0x80 ? ecx : edx) >> (flag & 31)) & 1;
+ return ((flag & 0x100 ? ebx :
+ (flag & 0x80) ? ecx : edx) >> (flag & 31)) & 1;
}
#endif /* ndef __KERNEL__ */