2 * linux/include/asm-arm/semaphore.h
4 #ifndef __ASM_ARM_SEMAPHORE_H
5 #define __ASM_ARM_SEMAPHORE_H
7 #include <linux/linkage.h>
8 #include <linux/spinlock.h>
9 #include <linux/wait.h>
10 #include <linux/rwsem.h>
12 #include <asm/atomic.h>
13 #include <asm/locks.h>
18 wait_queue_head_t wait;
25 # define __SEM_DEBUG_INIT(name) \
26 , (long)&(name).__magic
28 # define __SEM_DEBUG_INIT(name)
31 #define __SEMAPHORE_INIT(name,count) \
32 { ATOMIC_INIT(count), 0, \
33 __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
34 __SEM_DEBUG_INIT(name) }
36 #define __MUTEX_INITIALIZER(name) \
37 __SEMAPHORE_INIT(name,1)
39 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
40 struct semaphore name = __SEMAPHORE_INIT(name,count)
42 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
43 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
45 static inline void sema_init(struct semaphore *sem, int val)
47 atomic_set(&sem->count, val);
49 init_waitqueue_head(&sem->wait);
51 sem->__magic = (long)&sem->__magic;
55 static inline void init_MUTEX(struct semaphore *sem)
60 static inline void init_MUTEX_LOCKED(struct semaphore *sem)
66 * special register calling convention
68 asmlinkage void __down_failed(void);
69 asmlinkage int __down_interruptible_failed(void);
70 asmlinkage int __down_trylock_failed(void);
71 asmlinkage void __up_wakeup(void);
73 extern void __down(struct semaphore * sem);
74 extern int __down_interruptible(struct semaphore * sem);
75 extern int __down_trylock(struct semaphore * sem);
76 extern void __up(struct semaphore * sem);
79 * This is ugly, but we want the default case to fall through.
80 * "__down" is the actual routine that waits...
82 static inline void down(struct semaphore * sem)
85 CHECK_MAGIC(sem->__magic);
88 __down_op(sem, __down_failed);
92 * This is ugly, but we want the default case to fall through.
93 * "__down_interruptible" is the actual routine that waits...
95 static inline int down_interruptible (struct semaphore * sem)
98 CHECK_MAGIC(sem->__magic);
101 return __down_op_ret(sem, __down_interruptible_failed);
104 static inline int down_trylock(struct semaphore *sem)
107 CHECK_MAGIC(sem->__magic);
110 return __down_op_ret(sem, __down_trylock_failed);
114 * Note! This is subtle. We jump to wake people up only if
115 * the semaphore was negative (== somebody was waiting on it).
116 * The default case (no contention) will result in NO
117 * jumps for both down() and up().
119 static inline void up(struct semaphore * sem)
122 CHECK_MAGIC(sem->__magic);
125 __up_op(sem, __up_wakeup);