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x86/asm: Use alternative_2() in rdtsc_barrier() 

... 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>
hifive-unleashed-5.1
Borislav Petkov 2015-01-18 15:19:55 +01:00
parent 6620ef28c8
commit c70e1b475f
2 changed files with 4 additions and 6 deletions
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6
arch/x86/include/asm/barrier.h
View 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 */

4
arch/x86/um/asm/barrier.h
View 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