fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / include / asm-blackfin / semaphore.h
blob533f90fb2e4e6a99eb75d9077a1d860a3f3c4688
1 #ifndef _BFIN_SEMAPHORE_H
2 #define _BFIN_SEMAPHORE_H
4 #ifndef __ASSEMBLY__
6 #include <linux/linkage.h>
7 #include <linux/wait.h>
8 #include <linux/spinlock.h>
9 #include <linux/rwsem.h>
10 #include <asm/atomic.h>
13 * Interrupt-safe semaphores..
15 * (C) Copyright 1996 Linus Torvalds
17 * BFIN version by akbar hussain Lineo Inc April 2001
21 struct semaphore {
22 atomic_t count;
23 int sleepers;
24 wait_queue_head_t wait;
27 #define __SEMAPHORE_INITIALIZER(name, n) \
28 { \
29 .count = ATOMIC_INIT(n), \
30 .sleepers = 0, \
31 .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
34 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
35 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
37 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
39 static inline void sema_init(struct semaphore *sem, int val)
41 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
44 static inline void init_MUTEX(struct semaphore *sem)
46 sema_init(sem, 1);
49 static inline void init_MUTEX_LOCKED(struct semaphore *sem)
51 sema_init(sem, 0);
54 asmlinkage void __down(struct semaphore *sem);
55 asmlinkage int __down_interruptible(struct semaphore *sem);
56 asmlinkage int __down_trylock(struct semaphore *sem);
57 asmlinkage void __up(struct semaphore *sem);
59 extern spinlock_t semaphore_wake_lock;
62 * This is ugly, but we want the default case to fall through.
63 * "down_failed" is a special asm handler that calls the C
64 * routine that actually waits.
66 static inline void down(struct semaphore *sem)
68 might_sleep();
69 if (atomic_dec_return(&sem->count) < 0)
70 __down(sem);
73 static inline int down_interruptible(struct semaphore *sem)
75 int ret = 0;
77 might_sleep();
78 if (atomic_dec_return(&sem->count) < 0)
79 ret = __down_interruptible(sem);
80 return (ret);
83 static inline int down_trylock(struct semaphore *sem)
85 int ret = 0;
87 if (atomic_dec_return(&sem->count) < 0)
88 ret = __down_trylock(sem);
89 return ret;
93 * Note! This is subtle. We jump to wake people up only if
94 * the semaphore was negative (== somebody was waiting on it).
95 * The default case (no contention) will result in NO
96 * jumps for both down() and up().
98 static inline void up(struct semaphore *sem)
100 if (atomic_inc_return(&sem->count) <= 0)
101 __up(sem);
104 #endif /* __ASSEMBLY__ */
105 #endif /* _BFIN_SEMAPHORE_H */