[mirror_ubuntu-bionic-kernel.git] / include / asm-sparc64 / rwsem.h

/* $Id: rwsem.h,v 1.5 2001/11/18 00:12:56 davem Exp $
 * rwsem.h: R/W semaphores implemented using CAS
 *
 * Written by David S. Miller (davem@redhat.com), 2001.
 * Derived from asm-i386/rwsem.h
 */
#ifndef _SPARC64_RWSEM_H
#define _SPARC64_RWSEM_H

#ifndef _LINUX_RWSEM_H
#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
#endif

#ifdef __KERNEL__

#include <linux/list.h>
#include <linux/spinlock.h>
#include <asm/rwsem-const.h>

struct rwsem_waiter;

struct rw_semaphore {
	signed int count;
	spinlock_t		wait_lock;
	struct list_head	wait_list;
};

#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) }

#define DECLARE_RWSEM(name) \
	struct rw_semaphore name = __RWSEM_INITIALIZER(name)

static __inline__ void init_rwsem(struct rw_semaphore *sem)
{
	sem->count = RWSEM_UNLOCKED_VALUE;
	spin_lock_init(&sem->wait_lock);
	INIT_LIST_HEAD(&sem->wait_list);
}

extern void __down_read(struct rw_semaphore *sem);
extern int __down_read_trylock(struct rw_semaphore *sem);
extern void __down_write(struct rw_semaphore *sem);
extern int __down_write_trylock(struct rw_semaphore *sem);
extern void __up_read(struct rw_semaphore *sem);
extern void __up_write(struct rw_semaphore *sem);
extern void __downgrade_write(struct rw_semaphore *sem);

static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
{
	return atomic_add_return(delta, (atomic_t *)(&sem->count));
}

static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
{
	atomic_add(delta, (atomic_t *)(&sem->count));
}

#endif /* __KERNEL__ */

#endif /* _SPARC64_RWSEM_H */
Commit	Line	Data
1da177e4 LT	1	/* $Id: rwsem.h,v 1.5 2001/11/18 00:12:56 davem Exp $
	2	* rwsem.h: R/W semaphores implemented using CAS
	3	*
	4	* Written by David S. Miller (davem@redhat.com), 2001.
	5	* Derived from asm-i386/rwsem.h
	6	*/
	7	#ifndef _SPARC64_RWSEM_H
	8	#define _SPARC64_RWSEM_H
	9
	10	#ifndef _LINUX_RWSEM_H
	11	#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
	12	#endif
	13
	14	#ifdef __KERNEL__
	15
	16	#include <linux/list.h>
	17	#include <linux/spinlock.h>
	18	#include <asm/rwsem-const.h>
	19
	20	struct rwsem_waiter;
	21
	22	struct rw_semaphore {
	23	signed int count;
	24	spinlock_t wait_lock;
	25	struct list_head wait_list;
	26	};
	27
	28	#define __RWSEM_INITIALIZER(name) \
	29	{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) }
	30
	31	#define DECLARE_RWSEM(name) \
	32	struct rw_semaphore name = __RWSEM_INITIALIZER(name)
	33
	34	static __inline__ void init_rwsem(struct rw_semaphore *sem)
	35	{
	36	sem->count = RWSEM_UNLOCKED_VALUE;
	37	spin_lock_init(&sem->wait_lock);
	38	INIT_LIST_HEAD(&sem->wait_list);
	39	}
	40
	41	extern void __down_read(struct rw_semaphore *sem);
	42	extern int __down_read_trylock(struct rw_semaphore *sem);
	43	extern void __down_write(struct rw_semaphore *sem);
	44	extern int __down_write_trylock(struct rw_semaphore *sem);
	45	extern void __up_read(struct rw_semaphore *sem);
	46	extern void __up_write(struct rw_semaphore *sem);
	47	extern void __downgrade_write(struct rw_semaphore *sem);
	48
620de546	49	static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
1da177e4	50	{
620de546	51	return atomic_add_return(delta, (atomic_t *)(&sem->count));
1da177e4 LT	52	}
1da177e4 LT	53
620de546	54	static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
1da177e4	55	{
620de546	56	atomic_add(delta, (atomic_t *)(&sem->count));
1da177e4 LT	57	}
	58
	59	#endif /* __KERNEL__ */
	60
	61	#endif /* _SPARC64_RWSEM_H */