| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |