X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=include%2Fasm-cris%2Fsemaphore.h;h=d9b2034ed1d2ecd24bf648b333c8ad68e0d878d5;hb=92760499d01ef91518119908eb9b8798b6c9bd3f;hp=31a4ac448195e640931b58eb4cc8089079b9605f;hpb=4c5cdb1e1f2a502069f57a60b5c6b97b8106c73c;p=linux-2.6-omap-h63xx.git diff --git a/include/asm-cris/semaphore.h b/include/asm-cris/semaphore.h index 31a4ac44819..d9b2034ed1d 100644 --- a/include/asm-cris/semaphore.h +++ b/include/asm-cris/semaphore.h @@ -1,133 +1 @@ -/* $Id: semaphore.h,v 1.3 2001/05/08 13:54:09 bjornw Exp $ */ - -/* On the i386 these are coded in asm, perhaps we should as well. Later.. */ - -#ifndef _CRIS_SEMAPHORE_H -#define _CRIS_SEMAPHORE_H - -#define RW_LOCK_BIAS 0x01000000 - -#include -#include -#include - -#include -#include - -/* - * CRIS semaphores, implemented in C-only so far. - */ - -struct semaphore { - atomic_t count; - atomic_t waking; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INITIALIZER(name, n) \ -{ \ - .count = ATOMIC_INIT(n), \ - .waking = ATOMIC_INIT(0), \ - .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ -} - -#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ - struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) - -#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) - -static inline void sema_init(struct semaphore *sem, int val) -{ - *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); -} - -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); - -/* notice - we probably can do cli/sti here instead of saving */ - -static inline void down(struct semaphore * sem) -{ - unsigned long flags; - int failed; - - might_sleep(); - - /* atomically decrement the semaphores count, and if its negative, we wait */ - cris_atomic_save(sem, flags); - failed = --(sem->count.counter) < 0; - cris_atomic_restore(sem, flags); - if(failed) { - __down(sem); - } -} - -/* - * This version waits in interruptible state so that the waiting - * process can be killed. The down_interruptible routine - * returns negative for signalled and zero for semaphore acquired. - */ - -static inline int down_interruptible(struct semaphore * sem) -{ - unsigned long flags; - int failed; - - might_sleep(); - - /* atomically decrement the semaphores count, and if its negative, we wait */ - cris_atomic_save(sem, flags); - failed = --(sem->count.counter) < 0; - cris_atomic_restore(sem, flags); - if(failed) - failed = __down_interruptible(sem); - return(failed); -} - -static inline int down_trylock(struct semaphore * sem) -{ - unsigned long flags; - int failed; - - cris_atomic_save(sem, flags); - failed = --(sem->count.counter) < 0; - cris_atomic_restore(sem, flags); - if(failed) - failed = __down_trylock(sem); - return(failed); - -} - -/* - * Note! This is subtle. We jump to wake people up only if - * the semaphore was negative (== somebody was waiting on it). - * The default case (no contention) will result in NO - * jumps for both down() and up(). - */ -static inline void up(struct semaphore * sem) -{ - unsigned long flags; - int wakeup; - - /* atomically increment the semaphores count, and if it was negative, we wake people */ - cris_atomic_save(sem, flags); - wakeup = ++(sem->count.counter) <= 0; - cris_atomic_restore(sem, flags); - if(wakeup) { - __up(sem); - } -} - -#endif +#include