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authorAndi Kleen <ak@suse.de>2007-05-02 19:27:20 +0200
committerAndi Kleen <andi@basil.nowhere.org>2007-05-02 19:27:20 +0200
commite859dc553c857f4672b3bbb73ee9170a901f8712 (patch)
treeb71603823255c6eadfb8edbe66c8e8f4bb9caefe
parent[PATCH] i386: Evaluate constant cpu features at runtime (diff)
downloadlinux-dev-e859dc553c857f4672b3bbb73ee9170a901f8712.tar.xz
linux-dev-e859dc553c857f4672b3bbb73ee9170a901f8712.zip
[PATCH] i386: Implement alternative_io for i386
Ported from x86-64. Signed-off-by: Andi Kleen <ak@suse.de>
-rw-r--r--include/asm-i386/alternative.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h
index 277467329583..0f70b379b029 100644
--- a/include/asm-i386/alternative.h
+++ b/include/asm-i386/alternative.h
@@ -82,6 +82,21 @@ static inline void alternatives_smp_switch(int smp) {}
"663:\n\t" newinstr "\n664:\n" /* replacement */\
".previous" :: "i" (feature), ##input)
+/* Like alternative_input, but with a single output argument */
+#define alternative_io(oldinstr, newinstr, feature, output, input...) \
+ asm volatile ("661:\n\t" oldinstr "\n662:\n" \
+ ".section .altinstructions,\"a\"\n" \
+ " .align 4\n" \
+ " .long 661b\n" /* label */ \
+ " .long 663f\n" /* new instruction */ \
+ " .byte %c[feat]\n" /* feature bit */ \
+ " .byte 662b-661b\n" /* sourcelen */ \
+ " .byte 664f-663f\n" /* replacementlen */ \
+ ".previous\n" \
+ ".section .altinstr_replacement,\"ax\"\n" \
+ "663:\n\t" newinstr "\n664:\n" /* replacement */ \
+ ".previous" : output : [feat] "i" (feature), ##input)
+
/*
* Alternative inline assembly for SMP.
*