x86/asm: Use alternative_2() in rdtsc_barrier()
authorBorislav Petkov <bp@suse.de>
Sun, 18 Jan 2015 14:19:55 +0000 (15:19 +0100)
committerBorislav Petkov <bp@suse.de>
Mon, 23 Feb 2015 12:44:17 +0000 (13:44 +0100)
... now that we have it.

Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Borislav Petkov <bp@suse.de>
arch/x86/include/asm/barrier.h
arch/x86/um/asm/barrier.h

index 2ab1eb3..959e45b 100644 (file)
@@ -95,13 +95,11 @@ do {                                                                        \
  * Stop RDTSC speculation. This is needed when you need to use RDTSC
  * (or get_cycles or vread that possibly accesses the TSC) in a defined
  * code region.
- *
- * (Could use an alternative three way for this if there was one.)
  */
 static __always_inline void rdtsc_barrier(void)
 {
-       alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);
-       alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
+       alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC,
+                         "lfence", X86_FEATURE_LFENCE_RDTSC);
 }
 
 #endif /* _ASM_X86_BARRIER_H */
index 2d7d9a1..8ffd214 100644 (file)
@@ -64,8 +64,8 @@
  */
 static inline void rdtsc_barrier(void)
 {
-       alternative(ASM_NOP3, "mfence", X86_FEATURE_MFENCE_RDTSC);
-       alternative(ASM_NOP3, "lfence", X86_FEATURE_LFENCE_RDTSC);
+       alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC,
+                         "lfence", X86_FEATURE_LFENCE_RDTSC);
 }
 
 #endif