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>
19 #include <asm/system.h>
20 #include <asm/atomic.h>
25 wait_queue_head_t wait;
32 # define __SEM_DEBUG_INIT(name) \
33 , (int)&(name).__magic
35 # define __SEM_DEBUG_INIT(name)
38 #define __SEMAPHORE_INITIALIZER(name,count) \
39 { ATOMIC_INIT(count), 0, __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
40 __SEM_DEBUG_INIT(name) }
42 #define __MUTEX_INITIALIZER(name) \
43 __SEMAPHORE_INITIALIZER(name,1)
45 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
46 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
48 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
49 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
51 static inline void sema_init (struct semaphore *sem, int val)
54 * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
56 * i'd rather use the more flexible initialization above, but sadly
57 * GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well.
59 atomic_set(&sem->count, val);
61 init_waitqueue_head(&sem->wait);
63 sem->__magic = (int)&sem->__magic;
67 static inline void init_MUTEX (struct semaphore *sem)
72 static inline void init_MUTEX_LOCKED (struct semaphore *sem)
78 asmlinkage void __down_failed(void /* special register calling convention */);
79 asmlinkage int __down_failed_interruptible(void /* params in registers */);
80 asmlinkage int __down_failed_trylock(void /* params in registers */);
81 asmlinkage void __up_wakeup(void /* special register calling convention */);
84 asmlinkage void __down(struct semaphore * sem);
85 asmlinkage int __down_interruptible(struct semaphore * sem);
86 asmlinkage int __down_trylock(struct semaphore * sem);
87 asmlinkage void __up(struct semaphore * sem);
89 extern spinlock_t semaphore_wake_lock;
91 static inline void down(struct semaphore * sem)
94 CHECK_MAGIC(sem->__magic);
97 if (atomic_dec_return(&sem->count) < 0)
101 static inline int down_interruptible(struct semaphore * sem)
105 CHECK_MAGIC(sem->__magic);
108 if (atomic_dec_return(&sem->count) < 0)
109 ret = __down_interruptible(sem);
113 static inline int down_trylock(struct semaphore * sem)
117 CHECK_MAGIC(sem->__magic);
120 if (atomic_dec_return(&sem->count) < 0)
121 ret = __down_trylock(sem);
126 * Note! This is subtle. We jump to wake people up only if
127 * the semaphore was negative (== somebody was waiting on it).
129 static inline void up(struct semaphore * sem)
132 CHECK_MAGIC(sem->__magic);
134 if (atomic_inc_return(&sem->count) <= 0)
138 static inline int sem_getcount(struct semaphore *sem)
140 return atomic_read(&sem->count);
144 #endif /* __ASM_SH_SEMAPHORE_H */