diff options
| author | Jan Beulich <[email protected]> | 2014-02-27 08:47:02 +0000 |
|---|---|---|
| committer | H. Peter Anvin <[email protected]> | 2014-03-19 16:51:04 -0700 |
| commit | 06325190bd577e11429444d54f454b9d13f560c9 (patch) | |
| tree | 2bf84044b54c0651d589656ac9cf2c3d11618c51 | |
| parent | dcb99fd9b08cfe1afe426af4d8d3cbc429190f15 (diff) | |
x86, hash: Fix build failure with older binutils
Just like for other ISA extension instruction uses we should check
whether the assembler actually supports them. The fallback here simply
is to encode an instruction with fixed operands (%eax and %ecx).
[ hpa: tagging for -stable as a build fix ]
Signed-off-by: Jan Beulich <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Cc: Francesco Fusco <[email protected]>
Cc: Thomas Graf <[email protected]>
Cc: David S. Miller <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
Cc: <[email protected]> # v3.14
| -rw-r--r-- | arch/x86/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/lib/hash.c | 4 |
2 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile index eeda43abed6e..f8842c444560 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -152,6 +152,7 @@ cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTI # does binutils support specific instructions? asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1) +asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1) avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1) avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1) diff --git a/arch/x86/lib/hash.c b/arch/x86/lib/hash.c index 3056702e81fb..060cc4415bd9 100644 --- a/arch/x86/lib/hash.c +++ b/arch/x86/lib/hash.c @@ -39,7 +39,11 @@ static inline u32 crc32_u32(u32 crc, u32 val) { +#ifdef CONFIG_AS_CRC32 asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val)); +#else + asm (".byte 0xf2, 0x0f, 0x38, 0xf1, 0xc1" : "+a" (crc) : "c" (val)); +#endif return crc; } |