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1 | #ifndef _ASM_IA64_SEMAPHORE_H |
2 | #define _ASM_IA64_SEMAPHORE_H | |
3 | ||
4 | /* | |
5 | * Copyright (C) 1998-2000 Hewlett-Packard Co | |
6 | * Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com> | |
7 | */ | |
8 | ||
9 | #include <linux/wait.h> | |
10 | #include <linux/rwsem.h> | |
11 | ||
12 | #include <asm/atomic.h> | |
13 | ||
14 | struct semaphore { | |
15 | atomic_t count; | |
16 | int sleepers; | |
17 | wait_queue_head_t wait; | |
18 | }; | |
19 | ||
20 | #define __SEMAPHORE_INITIALIZER(name, n) \ | |
21 | { \ | |
22 | .count = ATOMIC_INIT(n), \ | |
23 | .sleepers = 0, \ | |
24 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | |
25 | } | |
26 | ||
27 | #define __MUTEX_INITIALIZER(name) __SEMAPHORE_INITIALIZER(name,1) | |
28 | ||
29 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ | |
30 | struct semaphore name = __SEMAPHORE_INITIALIZER(name, count) | |
31 | ||
32 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1) | |
33 | #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name, 0) | |
34 | ||
35 | static inline void | |
36 | sema_init (struct semaphore *sem, int val) | |
37 | { | |
38 | *sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val); | |
39 | } | |
40 | ||
41 | static inline void | |
42 | init_MUTEX (struct semaphore *sem) | |
43 | { | |
44 | sema_init(sem, 1); | |
45 | } | |
46 | ||
47 | static inline void | |
48 | init_MUTEX_LOCKED (struct semaphore *sem) | |
49 | { | |
50 | sema_init(sem, 0); | |
51 | } | |
52 | ||
53 | extern void __down (struct semaphore * sem); | |
54 | extern int __down_interruptible (struct semaphore * sem); | |
55 | extern int __down_trylock (struct semaphore * sem); | |
56 | extern void __up (struct semaphore * sem); | |
57 | ||
58 | /* | |
59 | * Atomically decrement the semaphore's count. If it goes negative, | |
60 | * block the calling thread in the TASK_UNINTERRUPTIBLE state. | |
61 | */ | |
62 | static inline void | |
63 | down (struct semaphore *sem) | |
64 | { | |
65 | might_sleep(); | |
66 | if (atomic_dec_return(&sem->count) < 0) | |
67 | __down(sem); | |
68 | } | |
69 | ||
70 | /* | |
71 | * Atomically decrement the semaphore's count. If it goes negative, | |
72 | * block the calling thread in the TASK_INTERRUPTIBLE state. | |
73 | */ | |
74 | static inline int | |
75 | down_interruptible (struct semaphore * sem) | |
76 | { | |
77 | int ret = 0; | |
78 | ||
79 | might_sleep(); | |
80 | if (atomic_dec_return(&sem->count) < 0) | |
81 | ret = __down_interruptible(sem); | |
82 | return ret; | |
83 | } | |
84 | ||
85 | static inline int | |
86 | down_trylock (struct semaphore *sem) | |
87 | { | |
88 | int ret = 0; | |
89 | ||
90 | if (atomic_dec_return(&sem->count) < 0) | |
91 | ret = __down_trylock(sem); | |
92 | return ret; | |
93 | } | |
94 | ||
95 | static inline void | |
96 | up (struct semaphore * sem) | |
97 | { | |
98 | if (atomic_inc_return(&sem->count) <= 0) | |
99 | __up(sem); | |
100 | } | |
101 | ||
102 | #endif /* _ASM_IA64_SEMAPHORE_H */ |