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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 | #ifndef _ASM_IA64_SEMAPHORE_H #define _ASM_IA64_SEMAPHORE_H /* * Copyright (C) 1998-2000 Hewlett-Packard Co * Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com> */ #include <linux/wait.h> #include <linux/rwsem.h> #include <asm/atomic.h> struct semaphore { atomic_t count; int sleepers; wait_queue_head_t wait; #if WAITQUEUE_DEBUG long __magic; /* initialized by __SEM_DEBUG_INIT() */ #endif }; #if WAITQUEUE_DEBUG # define __SEM_DEBUG_INIT(name) , (long) &(name).__magic #else # define __SEM_DEBUG_INIT(name) #endif #define __SEMAPHORE_INITIALIZER(name,count) \ { \ ATOMIC_INIT(count), 0, __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ __SEM_DEBUG_INIT(name) \ } #define __MUTEX_INITIALIZER(name) __SEMAPHORE_INITIALIZER(name,1) #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ struct semaphore name = __SEMAPHORE_INITIALIZER(name, count) #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1) #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name, 0) static inline void sema_init (struct semaphore *sem, int val) { *sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val); } static inline void init_MUTEX (struct semaphore *sem) { sema_init(sem, 1); } static inline void init_MUTEX_LOCKED (struct semaphore *sem) { sema_init(sem, 0); } extern void __down (struct semaphore * sem); extern int __down_interruptible (struct semaphore * sem); extern int __down_trylock (struct semaphore * sem); extern void __up (struct semaphore * sem); /* * Atomically decrement the semaphore's count. If it goes negative, * block the calling thread in the TASK_UNINTERRUPTIBLE state. */ static inline void down (struct semaphore *sem) { #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif if (atomic_dec_return(&sem->count) < 0) __down(sem); } /* * Atomically decrement the semaphore's count. If it goes negative, * block the calling thread in the TASK_INTERRUPTIBLE state. */ static inline int down_interruptible (struct semaphore * sem) { int ret = 0; #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif if (atomic_dec_return(&sem->count) < 0) ret = __down_interruptible(sem); return ret; } static inline int down_trylock (struct semaphore *sem) { int ret = 0; #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif if (atomic_dec_return(&sem->count) < 0) ret = __down_trylock(sem); return ret; } static inline void up (struct semaphore * sem) { #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif if (atomic_inc_return(&sem->count) <= 0) __up(sem); } #endif /* _ASM_IA64_SEMAPHORE_H */ |