1 #ifndef __ASM_SH_SEMAPHORE_H
2 #define __ASM_SH_SEMAPHORE_H
4 #include <linux/linkage.h>
8 * SMP- and interrupt-safe semaphores.
10 * (C) Copyright 1996 Linus Torvalds
12 * SuperH verison by Niibe Yutaka
13 * (Currently no asm implementation but generic C code...)
16 #include <linux/spinlock.h>
17 #include <linux/rwsem.h>
18 #include <linux/wait.h>
20 #include <asm/system.h>
21 #include <asm/atomic.h>
26 wait_queue_head_t wait;
27 #ifdef WAITQUEUE_DEBUG
32 #ifdef WAITQUEUE_DEBUG
33 # define __SEM_DEBUG_INIT(name) \
34 , (int)&(name).__magic
36 # define __SEM_DEBUG_INIT(name)
39 #define __SEMAPHORE_INITIALIZER(name,count) \
40 { ATOMIC_INIT(count), 0, __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
41 __SEM_DEBUG_INIT(name) }
43 #define __MUTEX_INITIALIZER(name) \
44 __SEMAPHORE_INITIALIZER(name,1)
46 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
47 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
49 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
50 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
52 static inline void sema_init (struct semaphore *sem, int val)
55 * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
57 * i'd rather use the more flexible initialization above, but sadly
58 * GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well.
60 atomic_set(&sem->count, val);
62 init_waitqueue_head(&sem->wait);
63 #ifdef WAITQUEUE_DEBUG
64 sem->__magic = (int)&sem->__magic;
68 static inline void init_MUTEX (struct semaphore *sem)
73 static inline void init_MUTEX_LOCKED (struct semaphore *sem)
79 asmlinkage void __down_failed(void /* special register calling convention */);
80 asmlinkage int __down_failed_interruptible(void /* params in registers */);
81 asmlinkage int __down_failed_trylock(void /* params in registers */);
82 asmlinkage void __up_wakeup(void /* special register calling convention */);
85 asmlinkage void __down(struct semaphore * sem);
86 asmlinkage int __down_interruptible(struct semaphore * sem);
87 asmlinkage int __down_trylock(struct semaphore * sem);
88 asmlinkage void __up(struct semaphore * sem);
90 extern spinlock_t semaphore_wake_lock;
92 static inline void down(struct semaphore * sem)
94 #ifdef WAITQUEUE_DEBUG
95 CHECK_MAGIC(sem->__magic);
99 if (atomic_dec_return(&sem->count) < 0)
103 static inline int down_interruptible(struct semaphore * sem)
106 #ifdef WAITQUEUE_DEBUG
107 CHECK_MAGIC(sem->__magic);
111 if (atomic_dec_return(&sem->count) < 0)
112 ret = __down_interruptible(sem);
116 static inline int down_trylock(struct semaphore * sem)
119 #ifdef WAITQUEUE_DEBUG
120 CHECK_MAGIC(sem->__magic);
123 if (atomic_dec_return(&sem->count) < 0)
124 ret = __down_trylock(sem);
129 * Note! This is subtle. We jump to wake people up only if
130 * the semaphore was negative (== somebody was waiting on it).
132 static inline void up(struct semaphore * sem)
134 #ifdef WAITQUEUE_DEBUG
135 CHECK_MAGIC(sem->__magic);
137 if (atomic_inc_return(&sem->count) <= 0)
142 #endif /* __ASM_SH_SEMAPHORE_H */