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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-30 15:10:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-30 15:10:40 -0700 |
| commit | 84d88d5d4efc37dfb8a93a4a58d8a227ee86ffa4 (patch) | |
| tree | 8dc2761f3111a7dfee01f290f2659faaa24ec06e /arch/x86/include/asm/cmpxchg_32.h | |
| parent | Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus (diff) | |
| parent | sched_clock: Fix atomicity/continuity bug by using cmpxchg64() (diff) | |
| download | linux-dev-84d88d5d4efc37dfb8a93a4a58d8a227ee86ffa4.tar.xz linux-dev-84d88d5d4efc37dfb8a93a4a58d8a227ee86ffa4.zip | |
Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched_clock: Fix atomicity/continuity bug by using cmpxchg64()
x86: Provide an alternative() based cmpxchg64()
Diffstat (limited to 'arch/x86/include/asm/cmpxchg_32.h')
| -rw-r--r-- | arch/x86/include/asm/cmpxchg_32.h | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index 82ceb788a981..ee1931be6593 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -312,19 +312,23 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old, extern unsigned long long cmpxchg_486_u64(volatile void *, u64, u64); -#define cmpxchg64(ptr, o, n) \ -({ \ - __typeof__(*(ptr)) __ret; \ - if (likely(boot_cpu_data.x86 > 4)) \ - __ret = (__typeof__(*(ptr)))__cmpxchg64((ptr), \ - (unsigned long long)(o), \ - (unsigned long long)(n)); \ - else \ - __ret = (__typeof__(*(ptr)))cmpxchg_486_u64((ptr), \ - (unsigned long long)(o), \ - (unsigned long long)(n)); \ - __ret; \ -}) +#define cmpxchg64(ptr, o, n) \ +({ \ + __typeof__(*(ptr)) __ret; \ + __typeof__(*(ptr)) __old = (o); \ + __typeof__(*(ptr)) __new = (n); \ + alternative_io("call cmpxchg8b_emu", \ + "lock; cmpxchg8b (%%esi)" , \ + X86_FEATURE_CX8, \ + "=A" (__ret), \ + "S" ((ptr)), "0" (__old), \ + "b" ((unsigned int)__new), \ + "c" ((unsigned int)(__new>>32)) \ + : "memory"); \ + __ret; }) + + + #define cmpxchg64_local(ptr, o, n) \ ({ \ __typeof__(*(ptr)) __ret; \ |