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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 | ||
12 | #include <linux/config.h> | |
13 | ||
14 | /* | |
15 | * These two _must_ execute atomically wrt each other. | |
16 | */ | |
17 | static inline void wake_one_more(struct semaphore * sem) | |
18 | { | |
19 | atomic_inc(&sem->waking); | |
20 | } | |
21 | ||
22 | static inline int waking_non_zero(struct semaphore *sem) | |
23 | { | |
24 | int ret; | |
25 | unsigned long flags; | |
26 | ||
27 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
28 | ret = 0; | |
29 | if (atomic_read(&sem->waking) > 0) { | |
30 | atomic_dec(&sem->waking); | |
31 | ret = 1; | |
32 | } | |
33 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
34 | return ret; | |
35 | } | |
36 | ||
37 | /* | |
38 | * waking_non_zero_interruptible: | |
39 | * 1 got the lock | |
40 | * 0 go to sleep | |
41 | * -EINTR interrupted | |
42 | */ | |
43 | static inline int waking_non_zero_interruptible(struct semaphore *sem, | |
44 | struct task_struct *tsk) | |
45 | { | |
46 | int ret; | |
47 | unsigned long flags; | |
48 | ||
49 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
50 | ret = 0; | |
51 | if (atomic_read(&sem->waking) > 0) { | |
52 | atomic_dec(&sem->waking); | |
53 | ret = 1; | |
54 | } else if (signal_pending(tsk)) { | |
55 | atomic_inc(&sem->count); | |
56 | ret = -EINTR; | |
57 | } | |
58 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
59 | return ret; | |
60 | } | |
61 | ||
62 | /* | |
63 | * waking_non_zero_trylock: | |
64 | * 1 failed to lock | |
65 | * 0 got the lock | |
66 | */ | |
67 | static inline int waking_non_zero_trylock(struct semaphore *sem) | |
68 | { | |
69 | int ret; | |
70 | unsigned long flags; | |
71 | ||
72 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
73 | ret = 1; | |
74 | if (atomic_read(&sem->waking) > 0) { | |
75 | atomic_dec(&sem->waking); | |
76 | ret = 0; | |
77 | } else | |
78 | atomic_inc(&sem->count); | |
79 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | #endif |