From 2b9b6d8c715b23fa119261c32ad360681f4464a9 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Mon, 28 Jan 2013 17:49:50 +0000 Subject: [PATCH] x86: Require MOVBE feature in cpuid when we use it Add MOVBE to asm/required-features.h so we check for it during startup and don't bother checking for it later. CONFIG_MATOM is used because it corresponds to -march=atom in the Makefiles. If the rules get more complicated it may be necessary to make this an explicit Kconfig option which uses -mmovbe/-mno-movbe to control the use of this instruction explicitly. Signed-off-by: David Woodhouse Link: http://lkml.kernel.org/r/1359395390.3529.65.camel@shinybook.infradead.org [ hpa: added a patch description ] Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/required-features.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h index 6c7fc25..5c6e4fb 100644 --- a/arch/x86/include/asm/required-features.h +++ b/arch/x86/include/asm/required-features.h @@ -47,6 +47,12 @@ # define NEED_NOPL 0 #endif +#ifdef CONFIG_MATOM +# define NEED_MOVBE (1<<(X86_FEATURE_MOVBE & 31)) +#else +# define NEED_MOVBE 0 +#endif + #ifdef CONFIG_X86_64 #ifdef CONFIG_PARAVIRT /* Paravirtualized systems may not have PSE or PGE available */ @@ -80,7 +86,7 @@ #define REQUIRED_MASK2 0 #define REQUIRED_MASK3 (NEED_NOPL) -#define REQUIRED_MASK4 0 +#define REQUIRED_MASK4 (NEED_MOVBE) #define REQUIRED_MASK5 0 #define REQUIRED_MASK6 0 #define REQUIRED_MASK7 0 -- 2.7.4