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1da177e4 LT |
1 | #ifndef _H8300_SEMAPHORE_HELPER_H |
2 | #define _H8300_SEMAPHORE_HELPER_H | |
3 | ||
4 | /* | |
5 | * SMP- and interrupt-safe semaphores helper functions. | |
6 | * | |
7 | * (C) Copyright 1996 Linus Torvalds | |
8 | * | |
9 | * based on | |
10 | * m68k version by Andreas Schwab | |
11 | */ | |
12 | ||
1da177e4 LT |
13 | #include <linux/errno.h> |
14 | ||
15 | /* | |
16 | * These two _must_ execute atomically wrt each other. | |
17 | */ | |
18 | static inline void wake_one_more(struct semaphore * sem) | |
19 | { | |
20 | atomic_inc((atomic_t *)&sem->sleepers); | |
21 | } | |
22 | ||
23 | static inline int waking_non_zero(struct semaphore *sem) | |
24 | { | |
25 | int ret; | |
26 | unsigned long flags; | |
27 | ||
28 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
29 | ret = 0; | |
30 | if (sem->sleepers > 0) { | |
31 | sem->sleepers--; | |
32 | ret = 1; | |
33 | } | |
34 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
35 | return ret; | |
36 | } | |
37 | ||
38 | /* | |
39 | * waking_non_zero_interruptible: | |
40 | * 1 got the lock | |
41 | * 0 go to sleep | |
42 | * -EINTR interrupted | |
43 | */ | |
44 | static inline int waking_non_zero_interruptible(struct semaphore *sem, | |
45 | struct task_struct *tsk) | |
46 | { | |
47 | int ret; | |
48 | unsigned long flags; | |
49 | ||
50 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
51 | ret = 0; | |
52 | if (sem->sleepers > 0) { | |
53 | sem->sleepers--; | |
54 | ret = 1; | |
55 | } else if (signal_pending(tsk)) { | |
56 | atomic_inc(&sem->count); | |
57 | ret = -EINTR; | |
58 | } | |
59 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
60 | return ret; | |
61 | } | |
62 | ||
63 | /* | |
64 | * waking_non_zero_trylock: | |
65 | * 1 failed to lock | |
66 | * 0 got the lock | |
67 | */ | |
68 | static inline int waking_non_zero_trylock(struct semaphore *sem) | |
69 | { | |
70 | int ret; | |
71 | unsigned long flags; | |
72 | ||
73 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
74 | ret = 1; | |
75 | if (sem->sleepers <= 0) | |
76 | atomic_inc(&sem->count); | |
77 | else { | |
78 | sem->sleepers--; | |
79 | ret = 0; | |
80 | } | |
81 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
82 | return ret; | |
83 | } | |
84 | ||
85 | #endif |