[PATCH] x86: more asm cleanups
Some more assembler cleanups I noticed along the way.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-i386/msr.h b/include/asm-i386/msr.h
index c76fce8..62b76cd 100644
--- a/include/asm-i386/msr.h
+++ b/include/asm-i386/msr.h
@@ -47,6 +47,21 @@
: "c" (msr), "0" (a), "d" (b), "i" (-EFAULT));\
ret__; })
+/* rdmsr with exception handling */
+#define rdmsr_safe(msr,a,b) ({ int ret__; \
+ asm volatile("2: rdmsr ; xorl %0,%0\n" \
+ "1:\n\t" \
+ ".section .fixup,\"ax\"\n\t" \
+ "3: movl %4,%0 ; jmp 1b\n\t" \
+ ".previous\n\t" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 4\n\t" \
+ " .long 2b,3b\n\t" \
+ ".previous" \
+ : "=r" (ret__), "=a" (*(a)), "=d" (*(b)) \
+ : "c" (msr), "i" (-EFAULT));\
+ ret__; })
+
#define rdtsc(low,high) \
__asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high))