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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 | #ifndef _PPC_SEMAPHORE_H #define _PPC_SEMAPHORE_H /* * Swiped from asm-sparc/semaphore.h and modified * -- Cort (cort@cs.nmt.edu) */ #ifdef __KERNEL__ #include <asm/atomic.h> #include <linux/wait.h> struct semaphore { atomic_t count; atomic_t waking; wait_queue_head_t wait; #if WAITQUEUE_DEBUG long __magic; #endif }; #if WAITQUEUE_DEBUG # define __SEM_DEBUG_INIT(name) \ , (long)&(name).__magic #else # define __SEM_DEBUG_INIT(name) #endif #define __SEMAPHORE_INITIALIZER(name,count) \ { ATOMIC_INIT(count), ATOMIC_INIT(0), __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ __SEM_DEBUG_INIT(name) } #define __MUTEX_INITIALIZER(name) \ __SEMAPHORE_INITIALIZER(name,1) #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) extern inline void sema_init (struct semaphore *sem, int val) { atomic_set(&sem->count, val); atomic_set(&sem->waking, 0); init_waitqueue_head(&sem->wait); #if WAITQUEUE_DEBUG sem->__magic = (long)&sem->__magic; #endif } static inline void init_MUTEX (struct semaphore *sem) { sema_init(sem, 1); } static inline void init_MUTEX_LOCKED (struct semaphore *sem) { sema_init(sem, 0); } extern void __down(struct semaphore * sem); extern int __down_interruptible(struct semaphore * sem); extern int __down_trylock(struct semaphore * sem); extern void __up(struct semaphore * sem); extern inline void down(struct semaphore * sem) { if (atomic_dec_return(&sem->count) >= 0) wmb(); else __down(sem); } extern inline int down_interruptible(struct semaphore * sem) { int ret = 0; if (atomic_dec_return(&sem->count) >= 0) wmb(); else ret = __down_interruptible(sem); return ret; } extern inline int down_trylock(struct semaphore * sem) { int ret = 0; if (atomic_dec_return(&sem->count) >= 0) wmb(); else ret = __down_trylock(sem); return ret; } extern inline void up(struct semaphore * sem) { mb(); if (atomic_inc_return(&sem->count) <= 0) __up(sem); } #endif /* __KERNEL__ */ #endif /* !(_PPC_SEMAPHORE_H) */ |