Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755776Ab3F1Qls (ORCPT ); Fri, 28 Jun 2013 12:41:48 -0400 Received: from mail.skyhub.de ([78.46.96.112]:49272 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754695Ab3F1Qlr (ORCPT ); Fri, 28 Jun 2013 12:41:47 -0400 From: Borislav Petkov To: "H. Peter Anvin" Cc: X86 ML , Wedson Almeida Filho , Linus Torvalds , Andrew Morton , Peter Zijlstra , LKML , Borislav Petkov Subject: [PATCH] x86, cpufeature: Use new CC_HAVE_ASM_GOTO Date: Fri, 28 Jun 2013 18:41:41 +0200 Message-Id: <1372437701-13351-1-git-send-email-bp@alien8.de> X-Mailer: git-send-email 1.8.3 In-Reply-To: <51CD99C2.9040109@zytor.com> References: <51CD99C2.9040109@zytor.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2926 Lines: 91 From: Borislav Petkov ... 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 --- 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 47538a61c91b..d3f5c63078d8 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) \ -- 1.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/