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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 | ||
13 | #include <linux/config.h> | |
14 | #include <linux/errno.h> | |
15 | ||
16 | /* | |
17 | * These two _must_ execute atomically wrt each other. | |
18 | */ | |
19 | static inline void wake_one_more(struct semaphore * sem) | |
20 | { | |
21 | atomic_inc((atomic_t *)&sem->sleepers); | |
22 | } | |
23 | ||
24 | static inline int waking_non_zero(struct semaphore *sem) | |
25 | { | |
26 | int ret; | |
27 | unsigned long flags; | |
28 | ||
29 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
30 | ret = 0; | |
31 | if (sem->sleepers > 0) { | |
32 | sem->sleepers--; | |
33 | ret = 1; | |
34 | } | |
35 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
36 | return ret; | |
37 | } | |
38 | ||
39 | /* | |
40 | * waking_non_zero_interruptible: | |
41 | * 1 got the lock | |
42 | * 0 go to sleep | |
43 | * -EINTR interrupted | |
44 | */ | |
45 | static inline int waking_non_zero_interruptible(struct semaphore *sem, | |
46 | struct task_struct *tsk) | |
47 | { | |
48 | int ret; | |
49 | unsigned long flags; | |
50 | ||
51 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
52 | ret = 0; | |
53 | if (sem->sleepers > 0) { | |
54 | sem->sleepers--; | |
55 | ret = 1; | |
56 | } else if (signal_pending(tsk)) { | |
57 | atomic_inc(&sem->count); | |
58 | ret = -EINTR; | |
59 | } | |
60 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
61 | return ret; | |
62 | } | |
63 | ||
64 | /* | |
65 | * waking_non_zero_trylock: | |
66 | * 1 failed to lock | |
67 | * 0 got the lock | |
68 | */ | |
69 | static inline int waking_non_zero_trylock(struct semaphore *sem) | |
70 | { | |
71 | int ret; | |
72 | unsigned long flags; | |
73 | ||
74 | spin_lock_irqsave(&semaphore_wake_lock, flags); | |
75 | ret = 1; | |
76 | if (sem->sleepers <= 0) | |
77 | atomic_inc(&sem->count); | |
78 | else { | |
79 | sem->sleepers--; | |
80 | ret = 0; | |
81 | } | |
82 | spin_unlock_irqrestore(&semaphore_wake_lock, flags); | |
83 | return ret; | |
84 | } | |
85 | ||
86 | #endif |