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1da177e4 LT |
1 | #ifndef _M68K_SEMAPHORE_HELPER_H |
2 | #define _M68K_SEMAPHORE_HELPER_H | |
3 | ||
4 | /* | |
5 | * SMP- and interrupt-safe semaphores helper functions. | |
6 | * | |
7 | * (C) Copyright 1996 Linus Torvalds | |
8 | * | |
9 | * m68k version by Andreas Schwab | |
10 | */ | |
11 | ||
1da177e4 LT |
12 | |
13 | /* | |
14 | * These two _must_ execute atomically wrt each other. | |
15 | */ | |
16 | static inline void wake_one_more(struct semaphore * sem) | |
17 | { | |
18 | atomic_inc(&sem->waking); | |
19 | } | |
20 | ||
21 | static inline int waking_non_zero(struct semaphore *sem) | |
22 | { | |
23 | int ret; | |
24 | unsigned long flags; | |
25 | ||
26 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
27 | ret = 0; | |
28 | if (atomic_read(&sem->waking) > 0) { | |
29 | atomic_dec(&sem->waking); | |
30 | ret = 1; | |
31 | } | |
32 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
33 | return ret; | |
34 | } | |
35 | ||
36 | /* | |
37 | * waking_non_zero_interruptible: | |
38 | * 1 got the lock | |
39 | * 0 go to sleep | |
40 | * -EINTR interrupted | |
41 | */ | |
42 | static inline int waking_non_zero_interruptible(struct semaphore *sem, | |
43 | struct task_struct *tsk) | |
44 | { | |
45 | int ret; | |
46 | unsigned long flags; | |
47 | ||
48 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
49 | ret = 0; | |
50 | if (atomic_read(&sem->waking) > 0) { | |
51 | atomic_dec(&sem->waking); | |
52 | ret = 1; | |
53 | } else if (signal_pending(tsk)) { | |
54 | atomic_inc(&sem->count); | |
55 | ret = -EINTR; | |
56 | } | |
57 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
58 | return ret; | |
59 | } | |
60 | ||
61 | /* | |
62 | * waking_non_zero_trylock: | |
63 | * 1 failed to lock | |
64 | * 0 got the lock | |
65 | */ | |
66 | static inline int waking_non_zero_trylock(struct semaphore *sem) | |
67 | { | |
68 | int ret; | |
69 | unsigned long flags; | |
70 | ||
71 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
72 | ret = 1; | |
73 | if (atomic_read(&sem->waking) > 0) { | |
74 | atomic_dec(&sem->waking); | |
75 | ret = 0; | |
76 | } else | |
77 | atomic_inc(&sem->count); | |
78 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
79 | return ret; | |
80 | } | |
81 | ||
82 | #endif |