1 #ifndef _ALPHA_SEMAPHORE_H
2 #define _ALPHA_SEMAPHORE_H
5 * SMP- and interrupt-safe semaphores..
7 * (C) Copyright 1996 Linus Torvalds
8 * (C) Copyright 1996, 2000 Richard Henderson
11 #include <asm/current.h>
12 #include <asm/system.h>
13 #include <asm/atomic.h>
14 #include <linux/compiler.h>
15 #include <linux/wait.h>
16 #include <linux/rwsem.h>
20 wait_queue_head_t wait;
21 #ifdef WAITQUEUE_DEBUG
26 #ifdef WAITQUEUE_DEBUG
27 # define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
29 # define __SEM_DEBUG_INIT(name)
32 #define __SEMAPHORE_INITIALIZER(name,count) \
33 { ATOMIC_INIT(count), \
34 __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
35 __SEM_DEBUG_INIT(name) }
37 #define __MUTEX_INITIALIZER(name) \
38 __SEMAPHORE_INITIALIZER(name,1)
40 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
41 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
43 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
44 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
46 static inline void sema_init(struct semaphore *sem, int val)
50 * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
51 * except that gcc produces better initializing by parts yet.
54 atomic_set(&sem->count, val);
55 init_waitqueue_head(&sem->wait);
56 #ifdef WAITQUEUE_DEBUG
57 sem->__magic = (long)&sem->__magic;
61 static inline void init_MUTEX (struct semaphore *sem)
66 static inline void init_MUTEX_LOCKED (struct semaphore *sem)
71 extern void down(struct semaphore *);
72 extern void __down_failed(struct semaphore *);
73 extern int down_interruptible(struct semaphore *);
74 extern int __down_failed_interruptible(struct semaphore *);
75 extern int down_trylock(struct semaphore *);
76 extern void up(struct semaphore *);
77 extern void __up_wakeup(struct semaphore *);
80 * Hidden out of line code is fun, but extremely messy. Rely on newer
81 * compilers to do a respectable job with this. The contention cases
82 * are handled out of line in arch/alpha/kernel/semaphore.c.
85 static inline void __down(struct semaphore *sem)
89 count = atomic_dec_return(&sem->count);
90 if (unlikely(count < 0))
94 static inline int __down_interruptible(struct semaphore *sem)
98 count = atomic_dec_return(&sem->count);
99 if (unlikely(count < 0))
100 return __down_failed_interruptible(sem);
105 * down_trylock returns 0 on success, 1 if we failed to get the lock.
108 static inline int __down_trylock(struct semaphore *sem)
122 __asm__ __volatile__(
133 : "=&r" (ret), "=m" (sem->count)
139 static inline void __up(struct semaphore *sem)
141 if (unlikely(atomic_inc_return(&sem->count) <= 0))
145 #if !defined(WAITQUEUE_DEBUG) && !defined(CONFIG_DEBUG_SEMAPHORE)
146 extern inline void down(struct semaphore *sem)
150 extern inline int down_interruptible(struct semaphore *sem)
152 return __down_interruptible(sem);
154 extern inline int down_trylock(struct semaphore *sem)
156 return __down_trylock(sem);
158 extern inline void up(struct semaphore *sem)