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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
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 __MUTEX_INITIALIZER(name) \
22 __SEMAPHORE_INITIALIZER (name,1)
23
24#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
25 struct semaphore name = __SEMAPHORE_INITIALIZER (name,count)
26
27#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC (name,1)
28#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC (name,0)
29
30extern inline void sema_init (struct semaphore *sem, int val)
31{
32 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
33}
34
35static inline void init_MUTEX (struct semaphore *sem)
36{
37 sema_init (sem, 1);
38}
39
40static inline void init_MUTEX_LOCKED (struct semaphore *sem)
41{
42 sema_init (sem, 0);
43}
44
45/*
46 * special register calling convention
47 */
48asmlinkage void __down_failed (void);
49asmlinkage int __down_interruptible_failed (void);
50asmlinkage int __down_trylock_failed (void);
51asmlinkage void __up_wakeup (void);
52
53extern void __down (struct semaphore * sem);
54extern int __down_interruptible (struct semaphore * sem);
55extern int __down_trylock (struct semaphore * sem);
56extern void __up (struct semaphore * sem);
57
58extern inline void down (struct semaphore * sem)
59{
60 might_sleep();
61 if (atomic_dec_return (&sem->count) < 0)
62 __down (sem);
63}
64
65extern inline int down_interruptible (struct semaphore * sem)
66{
67 int ret = 0;
68 might_sleep();
69 if (atomic_dec_return (&sem->count) < 0)
70 ret = __down_interruptible (sem);
71 return ret;
72}
73
74extern inline int down_trylock (struct semaphore *sem)
75{
76 int ret = 0;
77 if (atomic_dec_return (&sem->count) < 0)
78 ret = __down_trylock (sem);
79 return ret;
80}
81
82extern inline void up (struct semaphore * sem)
83{
84 if (atomic_inc_return (&sem->count) <= 0)
85 __up (sem);
86}
87
88#endif /* __V850_SEMAPHORE_H__ */