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author | Ingo Molnar <mingo@elte.hu> | 2009-01-18 18:37:14 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-01-18 18:37:14 +0100 |
commit | b2b062b8163391c42b3219d466ca1ac9742b9c7b (patch) | |
tree | f3f920c09b8de694b1bc1d4b878cfd2b0b98c913 /arch/blackfin/include/asm/mutex.h | |
parent | a9de18eb761f7c1c860964b2e5addc1a35c7e861 (diff) | |
parent | 99937d6455cea95405ac681c86a857d0fcd530bd (diff) | |
download | op-kernel-dev-b2b062b8163391c42b3219d466ca1ac9742b9c7b.zip op-kernel-dev-b2b062b8163391c42b3219d466ca1ac9742b9c7b.tar.gz |
Merge branch 'core/percpu' into stackprotector
Conflicts:
arch/x86/include/asm/pda.h
arch/x86/include/asm/system.h
Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/blackfin/include/asm/mutex.h')
-rw-r--r-- | arch/blackfin/include/asm/mutex.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/mutex.h b/arch/blackfin/include/asm/mutex.h index 458c1f7..5d39925 100644 --- a/arch/blackfin/include/asm/mutex.h +++ b/arch/blackfin/include/asm/mutex.h @@ -6,4 +6,67 @@ * implementation. (see asm-generic/mutex-xchg.h for details) */ +#ifndef _ASM_MUTEX_H +#define _ASM_MUTEX_H + +#ifndef CONFIG_SMP #include <asm-generic/mutex-dec.h> +#else + +static inline void +__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + if (unlikely(atomic_dec_return(count) < 0)) + fail_fn(count); + else + smp_mb(); +} + +static inline int +__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + if (unlikely(atomic_dec_return(count) < 0)) + return fail_fn(count); + else { + smp_mb(); + return 0; + } +} + +static inline void +__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + smp_mb(); + if (unlikely(atomic_inc_return(count) <= 0)) + fail_fn(count); +} + +#define __mutex_slowpath_needs_to_unlock() 1 + +static inline int +__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + /* + * We have two variants here. The cmpxchg based one is the best one + * because it never induce a false contention state. It is included + * here because architectures using the inc/dec algorithms over the + * xchg ones are much more likely to support cmpxchg natively. + * + * If not we fall back to the spinlock based variant - that is + * just as efficient (and simpler) as a 'destructive' probing of + * the mutex state would be. + */ +#ifdef __HAVE_ARCH_CMPXCHG + if (likely(atomic_cmpxchg(count, 1, 0) == 1)) { + smp_mb(); + return 1; + } + return 0; +#else + return fail_fn(count); +#endif +} + +#endif + +#endif |