Commit-ID: 62122fd7dadac09704782d8bc051fb898a0272bd Gitweb: http://git.kernel.org/tip/62122fd7dadac09704782d8bc051fb898a0272bd Author: Borislav Petkov <b...@suse.de> AuthorDate: Fri, 28 Jun 2013 18:41:41 +0200 Committer: H. Peter Anvin <h...@linux.intel.com> CommitDate: Fri, 28 Jun 2013 15:26:48 -0700
x86, cpufeature: Use new CC_HAVE_ASM_GOTO ... for checking for "asm goto" compiler support. It is more explicit this way and we cover the cases where distros have backported that support even to gcc versions < 4.5. Signed-off-by: Borislav Petkov <b...@suse.de> Link: http://lkml.kernel.org/r/1372437701-13351-1-git-send-email...@alien8.de Signed-off-by: H. Peter Anvin <h...@linux.intel.com> --- arch/x86/include/asm/cpufeature.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 47538a6..d3f5c63 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -366,9 +366,10 @@ extern bool __static_cpu_has_safe(u16 bit); */ static __always_inline __pure bool __static_cpu_has(u16 bit) { -#if __GNUC__ > 4 || __GNUC_MINOR__ >= 5 +#ifdef CC_HAVE_ASM_GOTO #ifdef CONFIG_X86_DEBUG_STATIC_CPU_HAS + /* * Catch too early usage of this before alternatives * have run. @@ -384,6 +385,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit) ".previous\n" /* skipping size check since replacement size = 0 */ : : "i" (X86_FEATURE_ALWAYS) : : t_warn); + #endif asm goto("1: jmp %l[t_no]\n" @@ -406,7 +408,9 @@ static __always_inline __pure bool __static_cpu_has(u16 bit) warn_pre_alternatives(); return false; #endif -#else /* GCC_VERSION >= 40500 */ + +#else /* CC_HAVE_ASM_GOTO */ + u8 flag; /* Open-coded due to __stringify() in ALTERNATIVE() */ asm volatile("1: movb $0,%0\n" @@ -427,7 +431,8 @@ static __always_inline __pure bool __static_cpu_has(u16 bit) ".previous\n" : "=qm" (flag) : "i" (bit)); return flag; -#endif + +#endif /* CC_HAVE_ASM_GOTO */ } #define static_cpu_has(bit) \ @@ -441,7 +446,7 @@ static __always_inline __pure bool __static_cpu_has(u16 bit) static __always_inline __pure bool _static_cpu_has_safe(u16 bit) { -#if __GNUC__ > 4 || __GNUC_MINOR__ >= 5 +#ifdef CC_HAVE_ASM_GOTO /* * We need to spell the jumps to the compiler because, depending on the offset, * the replacement jump can be bigger than the original jump, and this we cannot @@ -475,7 +480,7 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit) return false; t_dynamic: return __static_cpu_has_safe(bit); -#else /* GCC_VERSION >= 40500 */ +#else u8 flag; /* Open-coded due to __stringify() in ALTERNATIVE() */ asm volatile("1: movb $2,%0\n" @@ -511,7 +516,7 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit) : "=qm" (flag) : "i" (bit), "i" (X86_FEATURE_ALWAYS)); return (flag == 2 ? __static_cpu_has_safe(bit) : flag); -#endif +#endif /* CC_HAVE_ASM_GOTO */ } #define static_cpu_has_safe(bit) \ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
