From 06325190bd577e11429444d54f454b9d13f560c9 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 27 Feb 2014 08:47:02 +0000 Subject: [PATCH] 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 Link: http://lkml.kernel.org/r/530F0996020000780011FBE7@nat28.tlf.novell.com Cc: Francesco Fusco Cc: Thomas Graf Cc: David S. Miller Acked-by: Daniel Borkmann Signed-off-by: H. Peter Anvin Cc: # v3.14 --- arch/x86/Makefile | 1 + arch/x86/lib/hash.c | 4 ++++ 2 files changed, 5 insertions(+) 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; } -- 2.39.2