[PATCH] x86_64: Support alternative() with a output argument.
Needed for follow on patches
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-x86_64/system.h b/include/asm-x86_64/system.h
index a3bca755..8027219 100644
--- a/include/asm-x86_64/system.h
+++ b/include/asm-x86_64/system.h
@@ -137,6 +137,21 @@
"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 8\n" \
+ " .quad 661b\n" /* label */ \
+ " .quad 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)
+
/*
* Clear and set 'TS' bit respectively
*/
