diff options
| -rw-r--r-- | arch/blackfin/include/asm/mutex-dec.h | 112 |
1 files changed, 0 insertions, 112 deletions
diff --git a/arch/blackfin/include/asm/mutex-dec.h b/arch/blackfin/include/asm/mutex-dec.h deleted file mode 100644 index 0134151656a..00000000000 --- a/arch/blackfin/include/asm/mutex-dec.h +++ /dev/null @@ -1,112 +0,0 @@ -/* - * include/asm-generic/mutex-dec.h - * - * Generic implementation of the mutex fastpath, based on atomic - * decrement/increment. - */ -#ifndef _ASM_GENERIC_MUTEX_DEC_H -#define _ASM_GENERIC_MUTEX_DEC_H - -/** - * __mutex_fastpath_lock - try to take the lock by moving the count - * from 1 to a 0 value - * @count: pointer of type atomic_t - * @fail_fn: function to call if the original value was not 1 - * - * Change the count from 1 to a value lower than 1, and call <fail_fn> if - * it wasn't 1 originally. This function MUST leave the value lower than - * 1 even when the "1" assertion wasn't true. - */ -static inline void -__mutex_fastpath_lock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *)) -{ - if (unlikely(atomic_dec_return(count) < 0)) - fail_fn(count); - else - smp_mb(); -} - -/** - * __mutex_fastpath_lock_retval - try to take the lock by moving the count - * from 1 to a 0 value - * @count: pointer of type atomic_t - * @fail_fn: function to call if the original value was not 1 - * - * Change the count from 1 to a value lower than 1, and call <fail_fn> if - * it wasn't 1 originally. This function returns 0 if the fastpath succeeds, - * or anything the slow path function returns. - */ -static inline int -__mutex_fastpath_lock_retval(atomic_t *count, fastcall int (*fail_fn)(atomic_t *)) -{ - if (unlikely(atomic_dec_return(count) < 0)) - return fail_fn(count); - else { - smp_mb(); - return 0; - } -} - -/** - * __mutex_fastpath_unlock - try to promote the count from 0 to 1 - * @count: pointer of type atomic_t - * @fail_fn: function to call if the original value was not 0 - * - * Try to promote the count from 0 to 1. If it wasn't 0, call <fail_fn>. - * In the failure case, this function is allowed to either set the value to - * 1, or to set it to a value lower than 1. - * - * If the implementation sets it to a value of lower than 1, then the - * __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs - * to return 0 otherwise. - */ -static inline void -__mutex_fastpath_unlock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *)) -{ - smp_mb(); - if (unlikely(atomic_inc_return(count) <= 0)) - fail_fn(count); -} - -#define __mutex_slowpath_needs_to_unlock() 1 - -/** - * __mutex_fastpath_trylock - try to acquire the mutex, without waiting - * - * @count: pointer of type atomic_t - * @fail_fn: fallback function - * - * Change the count from 1 to a value lower than 1, and return 0 (failure) - * if it wasn't 1 originally, or return 1 (success) otherwise. This function - * MUST leave the value lower than 1 even when the "1" assertion wasn't true. - * Additionally, if the value was < 0 originally, this function must not leave - * it to 0 on failure. - * - * If the architecture has no effective trylock variant, it should call the - * <fail_fn> spinlock-based trylock variant unconditionally. - */ -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 |