* [tip:x86/asm] x86: Require MOVBE feature in cpuid when we use it
[not found] <1359395390.3529.65.camel@shinybook.infradead.org>
@ 2013-01-29 9:07 ` tip-bot for David Woodhouse
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From: tip-bot for David Woodhouse @ 2013-01-29 9:07 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, dwmw2, tglx, hpa, David.Woodhouse
Commit-ID: 2b9b6d8c715b23fa119261c32ad360681f4464a9
Gitweb: http://git.kernel.org/tip/2b9b6d8c715b23fa119261c32ad360681f4464a9
Author: David Woodhouse <dwmw2@infradead.org>
AuthorDate: Mon, 28 Jan 2013 17:49:50 +0000
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 28 Jan 2013 16:59:55 -0800
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 <David.Woodhouse@intel.com>
Link: http://lkml.kernel.org/r/1359395390.3529.65.camel@shinybook.infradead.org
[ hpa: added a patch description ]
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
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
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