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Diffstat (limited to 'include/asm-generic/mutex-dec.h')
-rw-r--r-- | include/asm-generic/mutex-dec.h | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/include/asm-generic/mutex-dec.h b/include/asm-generic/mutex-dec.h deleted file mode 100644 index c54829d3de37..000000000000 --- a/include/asm-generic/mutex-dec.h +++ /dev/null @@ -1,88 +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, void (*fail_fn)(atomic_t *)) -{ - if (unlikely(atomic_dec_return_acquire(count) < 0)) - fail_fn(count); -} - -/** - * __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 - * - * Change the count from 1 to a value lower than 1. This function returns 0 - * if the fastpath succeeds, or -1 otherwise. - */ -static inline int -__mutex_fastpath_lock_retval(atomic_t *count) -{ - if (unlikely(atomic_dec_return_acquire(count) < 0)) - return -1; - 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, void (*fail_fn)(atomic_t *)) -{ - if (unlikely(atomic_inc_return_release(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 *)) -{ - if (likely(atomic_read(count) == 1 && atomic_cmpxchg_acquire(count, 1, 0) == 1)) - return 1; - return 0; -} - -#endif |