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1da177e4 LT |
1 | #ifndef __ASM_SH64_SEMAPHORE_H |
2 | #define __ASM_SH64_SEMAPHORE_H | |
3 | ||
4 | /* | |
5 | * This file is subject to the terms and conditions of the GNU General Public | |
6 | * License. See the file "COPYING" in the main directory of this archive | |
7 | * for more details. | |
8 | * | |
9 | * include/asm-sh64/semaphore.h | |
10 | * | |
11 | * Copyright (C) 2000, 2001 Paolo Alberelli | |
12 | * | |
13 | * SMP- and interrupt-safe semaphores. | |
14 | * | |
15 | * (C) Copyright 1996 Linus Torvalds | |
16 | * | |
17 | * SuperH verison by Niibe Yutaka | |
18 | * (Currently no asm implementation but generic C code...) | |
19 | * | |
20 | */ | |
21 | ||
22 | #include <linux/linkage.h> | |
23 | #include <linux/spinlock.h> | |
24 | #include <linux/wait.h> | |
25 | #include <linux/rwsem.h> | |
26 | ||
27 | #include <asm/system.h> | |
28 | #include <asm/atomic.h> | |
29 | ||
30 | struct semaphore { | |
31 | atomic_t count; | |
32 | int sleepers; | |
33 | wait_queue_head_t wait; | |
34 | }; | |
35 | ||
36 | #define __SEMAPHORE_INITIALIZER(name, n) \ | |
37 | { \ | |
38 | .count = ATOMIC_INIT(n), \ | |
39 | .sleepers = 0, \ | |
40 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | |
41 | } | |
42 | ||
1da177e4 LT |
43 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ |
44 | struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) | |
45 | ||
46 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) | |
1da177e4 LT |
47 | |
48 | static inline void sema_init (struct semaphore *sem, int val) | |
49 | { | |
50 | /* | |
51 | * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); | |
52 | * | |
53 | * i'd rather use the more flexible initialization above, but sadly | |
54 | * GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well. | |
55 | */ | |
56 | atomic_set(&sem->count, val); | |
57 | sem->sleepers = 0; | |
58 | init_waitqueue_head(&sem->wait); | |
59 | } | |
60 | ||
61 | static inline void init_MUTEX (struct semaphore *sem) | |
62 | { | |
63 | sema_init(sem, 1); | |
64 | } | |
65 | ||
66 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | |
67 | { | |
68 | sema_init(sem, 0); | |
69 | } | |
70 | ||
71 | #if 0 | |
72 | asmlinkage void __down_failed(void /* special register calling convention */); | |
73 | asmlinkage int __down_failed_interruptible(void /* params in registers */); | |
74 | asmlinkage int __down_failed_trylock(void /* params in registers */); | |
75 | asmlinkage void __up_wakeup(void /* special register calling convention */); | |
76 | #endif | |
77 | ||
78 | asmlinkage void __down(struct semaphore * sem); | |
79 | asmlinkage int __down_interruptible(struct semaphore * sem); | |
80 | asmlinkage int __down_trylock(struct semaphore * sem); | |
81 | asmlinkage void __up(struct semaphore * sem); | |
82 | ||
83 | extern spinlock_t semaphore_wake_lock; | |
84 | ||
85 | static inline void down(struct semaphore * sem) | |
86 | { | |
87 | if (atomic_dec_return(&sem->count) < 0) | |
88 | __down(sem); | |
89 | } | |
90 | ||
91 | static inline int down_interruptible(struct semaphore * sem) | |
92 | { | |
93 | int ret = 0; | |
94 | ||
95 | if (atomic_dec_return(&sem->count) < 0) | |
96 | ret = __down_interruptible(sem); | |
97 | return ret; | |
98 | } | |
99 | ||
100 | static inline int down_trylock(struct semaphore * sem) | |
101 | { | |
102 | int ret = 0; | |
103 | ||
104 | if (atomic_dec_return(&sem->count) < 0) | |
105 | ret = __down_trylock(sem); | |
106 | return ret; | |
107 | } | |
108 | ||
109 | /* | |
110 | * Note! This is subtle. We jump to wake people up only if | |
111 | * the semaphore was negative (== somebody was waiting on it). | |
112 | */ | |
113 | static inline void up(struct semaphore * sem) | |
114 | { | |
115 | if (atomic_inc_return(&sem->count) <= 0) | |
116 | __up(sem); | |
117 | } | |
118 | ||
119 | #endif /* __ASM_SH64_SEMAPHORE_H */ |