diff options
Diffstat (limited to 'include/asm-x86_64/mutex.h')
-rw-r--r-- | include/asm-x86_64/mutex.h | 105 |
1 files changed, 0 insertions, 105 deletions
diff --git a/include/asm-x86_64/mutex.h b/include/asm-x86_64/mutex.h deleted file mode 100644 index 6c2949a3c67..00000000000 --- a/include/asm-x86_64/mutex.h +++ /dev/null @@ -1,105 +0,0 @@ -/* - * Assembly implementation of the mutex fastpath, based on atomic - * decrement/increment. - * - * started by Ingo Molnar: - * - * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> - */ -#ifndef _ASM_MUTEX_H -#define _ASM_MUTEX_H - -/** - * __mutex_fastpath_lock - decrement and call function if negative - * @v: pointer of type atomic_t - * @fail_fn: function to call if the result is negative - * - * Atomically decrements @v and calls <fail_fn> if the result is negative. - */ -#define __mutex_fastpath_lock(v, fail_fn) \ -do { \ - unsigned long dummy; \ - \ - typecheck(atomic_t *, v); \ - typecheck_fn(void (*)(atomic_t *), fail_fn); \ - \ - __asm__ __volatile__( \ - LOCK_PREFIX " decl (%%rdi) \n" \ - " jns 1f \n" \ - " call "#fail_fn" \n" \ - "1:" \ - \ - :"=D" (dummy) \ - : "D" (v) \ - : "rax", "rsi", "rdx", "rcx", \ - "r8", "r9", "r10", "r11", "memory"); \ -} while (0) - -/** - * __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, - int (*fail_fn)(atomic_t *)) -{ - if (unlikely(atomic_dec_return(count) < 0)) - return fail_fn(count); - else - return 0; -} - -/** - * __mutex_fastpath_unlock - increment and call function if nonpositive - * @v: pointer of type atomic_t - * @fail_fn: function to call if the result is nonpositive - * - * Atomically increments @v and calls <fail_fn> if the result is nonpositive. - */ -#define __mutex_fastpath_unlock(v, fail_fn) \ -do { \ - unsigned long dummy; \ - \ - typecheck(atomic_t *, v); \ - typecheck_fn(void (*)(atomic_t *), fail_fn); \ - \ - __asm__ __volatile__( \ - LOCK_PREFIX " incl (%%rdi) \n" \ - " jg 1f \n" \ - " call "#fail_fn" \n" \ - "1: " \ - \ - :"=D" (dummy) \ - : "D" (v) \ - : "rax", "rsi", "rdx", "rcx", \ - "r8", "r9", "r10", "r11", "memory"); \ -} while (0) - -#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 0 and return 1 (success), or return 0 (failure) - * if it wasn't 1 originally. [the fallback function is never used on - * x86_64, because all x86_64 CPUs have a CMPXCHG instruction.] - */ -static inline int -__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) -{ - if (likely(atomic_cmpxchg(count, 1, 0) == 1)) - return 1; - else - return 0; -} - -#endif |