diff options
Diffstat (limited to 'include/asm-avr32/semaphore.h')
-rw-r--r-- | include/asm-avr32/semaphore.h | 109 |
1 files changed, 1 insertions, 108 deletions
diff --git a/include/asm-avr32/semaphore.h b/include/asm-avr32/semaphore.h index feaf1d453386..d9b2034ed1d2 100644 --- a/include/asm-avr32/semaphore.h +++ b/include/asm-avr32/semaphore.h | |||
@@ -1,108 +1 @@ | |||
1 | /* | #include <linux/semaphore.h> | |
2 | * SMP- and interrupt-safe semaphores. | ||
3 | * | ||
4 | * Copyright (C) 2006 Atmel Corporation | ||
5 | * | ||
6 | * Based on include/asm-i386/semaphore.h | ||
7 | * Copyright (C) 1996 Linus Torvalds | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or modify | ||
10 | * it under the terms of the GNU General Public License version 2 as | ||
11 | * published by the Free Software Foundation. | ||
12 | */ | ||
13 | #ifndef __ASM_AVR32_SEMAPHORE_H | ||
14 | #define __ASM_AVR32_SEMAPHORE_H | ||
15 | |||
16 | #include <linux/linkage.h> | ||
17 | |||
18 | #include <asm/system.h> | ||
19 | #include <asm/atomic.h> | ||
20 | #include <linux/wait.h> | ||
21 | #include <linux/rwsem.h> | ||
22 | |||
23 | struct semaphore { | ||
24 | atomic_t count; | ||
25 | int sleepers; | ||
26 | wait_queue_head_t wait; | ||
27 | }; | ||
28 | |||
29 | #define __SEMAPHORE_INITIALIZER(name, n) \ | ||
30 | { \ | ||
31 | .count = ATOMIC_INIT(n), \ | ||
32 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | ||
33 | } | ||
34 | |||
35 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ | ||
36 | struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) | ||
37 | |||
38 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) | ||
39 | |||
40 | static inline void sema_init (struct semaphore *sem, int val) | ||
41 | { | ||
42 | atomic_set(&sem->count, val); | ||
43 | sem->sleepers = 0; | ||
44 | init_waitqueue_head(&sem->wait); | ||
45 | } | ||
46 | |||
47 | static inline void init_MUTEX (struct semaphore *sem) | ||
48 | { | ||
49 | sema_init(sem, 1); | ||
50 | } | ||
51 | |||
52 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | ||
53 | { | ||
54 | sema_init(sem, 0); | ||
55 | } | ||
56 | |||
57 | void __down(struct semaphore * sem); | ||
58 | int __down_interruptible(struct semaphore * sem); | ||
59 | void __up(struct semaphore * sem); | ||
60 | |||
61 | /* | ||
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. See arch/i386/kernel/semaphore.c | ||
65 | */ | ||
66 | static inline void down(struct semaphore * sem) | ||
67 | { | ||
68 | might_sleep(); | ||
69 | if (unlikely(atomic_dec_return (&sem->count) < 0)) | ||
70 | __down (sem); | ||
71 | } | ||
72 | |||
73 | /* | ||
74 | * Interruptible try to acquire a semaphore. If we obtained | ||
75 | * it, return zero. If we were interrupted, returns -EINTR | ||
76 | */ | ||
77 | static inline int down_interruptible(struct semaphore * sem) | ||
78 | { | ||
79 | int ret = 0; | ||
80 | |||
81 | might_sleep(); | ||
82 | if (unlikely(atomic_dec_return (&sem->count) < 0)) | ||
83 | ret = __down_interruptible (sem); | ||
84 | return ret; | ||
85 | } | ||
86 | |||
87 | /* | ||
88 | * Non-blockingly attempt to down() a semaphore. | ||
89 | * Returns zero if we acquired it | ||
90 | */ | ||
91 | static inline int down_trylock(struct semaphore * sem) | ||
92 | { | ||
93 | return atomic_dec_if_positive(&sem->count) < 0; | ||
94 | } | ||
95 | |||
96 | /* | ||
97 | * Note! This is subtle. We jump to wake people up only if | ||
98 | * the semaphore was negative (== somebody was waiting on it). | ||
99 | * The default case (no contention) will result in NO | ||
100 | * jumps for both down() and up(). | ||
101 | */ | ||
102 | static inline void up(struct semaphore * sem) | ||
103 | { | ||
104 | if (unlikely(atomic_inc_return (&sem->count) <= 0)) | ||
105 | __up (sem); | ||
106 | } | ||
107 | |||
108 | #endif /*__ASM_AVR32_SEMAPHORE_H */ | ||