#ifndef __ASM_SPINLOCK_H#define __ASM_SPINLOCK_H #include <asm/system.h>#include <asm/processor.h>#include <asm/spinlock_types.h> static inline int __raw_spin_is_locked(raw_spinlock_t *x){	volatile unsigned int *a = __ldcw_align(x);	return *a == 0;} #define __raw_spin_lock(lock) __raw_spin_lock_flags(lock, 0)#define __raw_spin_unlock_wait(x) \		do { cpu_relax(); } while (__raw_spin_is_locked(x)) static inline void __raw_spin_lock_flags(raw_spinlock_t *x,					 unsigned long flags){	volatile unsigned int *a; 	mb();	a = __ldcw_align(x);	while (__ldcw(a) == 0)		while (*a == 0)			if (flags & PSW_SM_I) {				local_irq_enable();				cpu_relax();				local_irq_disable();			} else				cpu_relax();	mb();} static inline void __raw_spin_unlock(raw_spinlock_t *x){	volatile unsigned int *a;	mb();	a = __ldcw_align(x);	*a = 1;	mb();} static inline int __raw_spin_trylock(raw_spinlock_t *x){	volatile unsigned int *a;	int ret; 	mb();	a = __ldcw_align(x);        ret = __ldcw(a) != 0;	mb(); 	return ret;} /* * Read-write spinlocks, allowing multiple readers * but only one writer. */ #define __raw_read_trylock(lock) generic__raw_read_trylock(lock) /* read_lock, read_unlock are pretty straightforward.  Of course it somehow * sucks we end up saving/restoring flags twice for read_lock_irqsave aso. */ static  __inline__ void __raw_read_lock(raw_rwlock_t *rw){	__raw_spin_lock(&rw->lock); 	rw->counter++; 	__raw_spin_unlock(&rw->lock);} static  __inline__ void __raw_read_unlock(raw_rwlock_t *rw){	__raw_spin_lock(&rw->lock); 	rw->counter--; 	__raw_spin_unlock(&rw->lock);} /* write_lock is less trivial.  We optimistically grab the lock and check * if we surprised any readers.  If so we release the lock and wait till * they're all gone before trying again * * Also note that we don't use the _irqsave / _irqrestore suffixes here. * If we're called with interrupts enabled and we've got readers (or other * writers) in interrupt handlers someone fucked up and we'd dead-lock * sooner or later anyway.   prumpf */ static  __inline__ void __raw_write_lock(raw_rwlock_t *rw){retry:	__raw_spin_lock(&rw->lock); 	if(rw->counter != 0) {		/* this basically never happens */		__raw_spin_unlock(&rw->lock); 		while (rw->counter != 0)			cpu_relax(); 		goto retry;	} 	/* got it.  now leave without unlocking */	rw->counter = -1; /* remember we are locked */} /* write_unlock is absolutely trivial - we don't have to wait for anything */ static  __inline__ void __raw_write_unlock(raw_rwlock_t *rw){	rw->counter = 0;	__raw_spin_unlock(&rw->lock);} static  __inline__ int __raw_write_trylock(raw_rwlock_t *rw){	__raw_spin_lock(&rw->lock);	if (rw->counter != 0) {		/* this basically never happens */		__raw_spin_unlock(&rw->lock); 		return 0;	} 	/* got it.  now leave without unlocking */	rw->counter = -1; /* remember we are locked */	return 1;} /* * read_can_lock - would read_trylock() succeed? * @lock: the rwlock in question. */static __inline__ int __raw_read_can_lock(raw_rwlock_t *rw){	return rw->counter >= 0;} /* * write_can_lock - would write_trylock() succeed? * @lock: the rwlock in question. */static __inline__ int __raw_write_can_lock(raw_rwlock_t *rw){	return !rw->counter;} #endif /* __ASM_SPINLOCK_H */