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1da177e4 LT |
1 | /* |
2 | * linux/include/asm-arm/semaphore.h | |
3 | */ | |
4 | #ifndef __ASM_ARM_SEMAPHORE_H | |
5 | #define __ASM_ARM_SEMAPHORE_H | |
6 | ||
7 | #include <linux/linkage.h> | |
8 | #include <linux/spinlock.h> | |
9 | #include <linux/wait.h> | |
10 | #include <linux/rwsem.h> | |
11 | ||
12 | #include <asm/atomic.h> | |
13 | #include <asm/locks.h> | |
14 | ||
15 | struct semaphore { | |
16 | atomic_t count; | |
17 | int sleepers; | |
18 | wait_queue_head_t wait; | |
19 | }; | |
20 | ||
21 | #define __SEMAPHORE_INIT(name, n) \ | |
22 | { \ | |
23 | .count = ATOMIC_INIT(n), \ | |
24 | .sleepers = 0, \ | |
25 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \ | |
26 | } | |
27 | ||
1da177e4 LT |
28 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ |
29 | struct semaphore name = __SEMAPHORE_INIT(name,count) | |
30 | ||
31 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) | |
32 | #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) | |
33 | ||
34 | static inline void sema_init(struct semaphore *sem, int val) | |
35 | { | |
36 | atomic_set(&sem->count, val); | |
37 | sem->sleepers = 0; | |
38 | init_waitqueue_head(&sem->wait); | |
39 | } | |
40 | ||
41 | static inline void init_MUTEX(struct semaphore *sem) | |
42 | { | |
43 | sema_init(sem, 1); | |
44 | } | |
45 | ||
46 | static inline void init_MUTEX_LOCKED(struct semaphore *sem) | |
47 | { | |
48 | sema_init(sem, 0); | |
49 | } | |
50 | ||
51 | /* | |
52 | * special register calling convention | |
53 | */ | |
54 | asmlinkage void __down_failed(void); | |
55 | asmlinkage int __down_interruptible_failed(void); | |
56 | asmlinkage int __down_trylock_failed(void); | |
57 | asmlinkage void __up_wakeup(void); | |
58 | ||
59 | extern void __down(struct semaphore * sem); | |
60 | extern int __down_interruptible(struct semaphore * sem); | |
61 | extern int __down_trylock(struct semaphore * sem); | |
62 | extern void __up(struct semaphore * sem); | |
63 | ||
64 | /* | |
65 | * This is ugly, but we want the default case to fall through. | |
66 | * "__down" is the actual routine that waits... | |
67 | */ | |
68 | static inline void down(struct semaphore * sem) | |
69 | { | |
70 | might_sleep(); | |
71 | __down_op(sem, __down_failed); | |
72 | } | |
73 | ||
74 | /* | |
75 | * This is ugly, but we want the default case to fall through. | |
76 | * "__down_interruptible" is the actual routine that waits... | |
77 | */ | |
78 | static inline int down_interruptible (struct semaphore * sem) | |
79 | { | |
80 | might_sleep(); | |
81 | return __down_op_ret(sem, __down_interruptible_failed); | |
82 | } | |
83 | ||
84 | static inline int down_trylock(struct semaphore *sem) | |
85 | { | |
86 | return __down_op_ret(sem, __down_trylock_failed); | |
87 | } | |
88 | ||
89 | /* | |
90 | * Note! This is subtle. We jump to wake people up only if | |
91 | * the semaphore was negative (== somebody was waiting on it). | |
92 | * The default case (no contention) will result in NO | |
93 | * jumps for both down() and up(). | |
94 | */ | |
95 | static inline void up(struct semaphore * sem) | |
96 | { | |
97 | __up_op(sem, __up_wakeup); | |
98 | } | |
99 | ||
100 | #endif |