Messages in this thread Patch in this message | | | Date | Wed, 19 Mar 2014 16:54:26 -0700 | From | tip-bot for Jan Beulich <> | Subject | [tip:x86/hash] x86, hash: Fix build failure with older binutils |
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Commit-ID: 06325190bd577e11429444d54f454b9d13f560c9 Gitweb: http://git.kernel.org/tip/06325190bd577e11429444d54f454b9d13f560c9 Author: Jan Beulich <JBeulich@suse.com> AuthorDate: Thu, 27 Feb 2014 08:47:02 +0000 Committer: H. Peter Anvin <hpa@linux.intel.com> CommitDate: Wed, 19 Mar 2014 16:51:04 -0700
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 <jbeulich@suse.com> Link: http://lkml.kernel.org/r/530F0996020000780011FBE7@nat28.tlf.novell.com Cc: Francesco Fusco <ffusco@redhat.com> Cc: Thomas Graf <tgraf@redhat.com> Cc: David S. Miller <davem@davemloft.net> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org> # 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 eeda43a..f8842c4 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 3056702..060cc44 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; }
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