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Linux kernel mirror (for testing)
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kernel
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linux
1#ifndef __V850_SEMAPHORE_H__
2#define __V850_SEMAPHORE_H__
3
4#include <linux/linkage.h>
5#include <linux/spinlock.h>
6#include <linux/wait.h>
7#include <linux/rwsem.h>
8
9#include <asm/atomic.h>
10
11struct semaphore {
12 atomic_t count;
13 int sleepers;
14 wait_queue_head_t wait;
15};
16
17#define __SEMAPHORE_INITIALIZER(name,count) \
18 { ATOMIC_INIT (count), 0, \
19 __WAIT_QUEUE_HEAD_INITIALIZER ((name).wait) }
20
21#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
22 struct semaphore name = __SEMAPHORE_INITIALIZER (name,count)
23
24#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC (name,1)
25
26static inline void sema_init (struct semaphore *sem, int val)
27{
28 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
29}
30
31static inline void init_MUTEX (struct semaphore *sem)
32{
33 sema_init (sem, 1);
34}
35
36static inline void init_MUTEX_LOCKED (struct semaphore *sem)
37{
38 sema_init (sem, 0);
39}
40
41/*
42 * special register calling convention
43 */
44asmlinkage void __down_failed (void);
45asmlinkage int __down_interruptible_failed (void);
46asmlinkage int __down_trylock_failed (void);
47asmlinkage void __up_wakeup (void);
48
49extern void __down (struct semaphore * sem);
50extern int __down_interruptible (struct semaphore * sem);
51extern int __down_trylock (struct semaphore * sem);
52extern void __up (struct semaphore * sem);
53
54static inline void down (struct semaphore * sem)
55{
56 might_sleep();
57 if (atomic_dec_return (&sem->count) < 0)
58 __down (sem);
59}
60
61static inline int down_interruptible (struct semaphore * sem)
62{
63 int ret = 0;
64 might_sleep();
65 if (atomic_dec_return (&sem->count) < 0)
66 ret = __down_interruptible (sem);
67 return ret;
68}
69
70static inline int down_trylock (struct semaphore *sem)
71{
72 int ret = 0;
73 if (atomic_dec_return (&sem->count) < 0)
74 ret = __down_trylock (sem);
75 return ret;
76}
77
78static inline void up (struct semaphore * sem)
79{
80 if (atomic_inc_return (&sem->count) <= 0)
81 __up (sem);
82}
83
84#endif /* __V850_SEMAPHORE_H__ */