[deliverable/linux.git] / arch / alpha / lib / dec_and_lock.c

/*
 * arch/alpha/lib/dec_and_lock.c
 *
 * ll/sc version of atomic_dec_and_lock()
 * 
 */

#include <linux/spinlock.h>
#include <linux/atomic.h>
#include <linux/export.h>

  asm (".text					\n\
	.global _atomic_dec_and_lock		\n\
	.ent _atomic_dec_and_lock		\n\
	.align	4				\n\
_atomic_dec_and_lock:				\n\
	.prologue 0				\n\
1:	ldl_l	$1, 0($16)			\n\
	subl	$1, 1, $1			\n\
	beq	$1, 2f				\n\
	stl_c	$1, 0($16)			\n\
	beq	$1, 4f				\n\
	mb					\n\
	clr	$0				\n\
	ret					\n\
2:	br	$29, 3f				\n\
3:	ldgp	$29, 0($29)			\n\
	br	$atomic_dec_and_lock_1..ng	\n\
	.subsection 2				\n\
4:	br	1b				\n\
	.previous				\n\
	.end _atomic_dec_and_lock");

static int __used atomic_dec_and_lock_1(atomic_t *atomic, spinlock_t *lock)
{
	/* Slow path */
	spin_lock(lock);
	if (atomic_dec_and_test(atomic))
		return 1;
	spin_unlock(lock);
	return 0;
}
EXPORT_SYMBOL(_atomic_dec_and_lock);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/alpha/lib/dec_and_lock.c
	3	*
	4	* ll/sc version of atomic_dec_and_lock()
	5	*
	6	*/
	7
	8	#include <linux/spinlock.h>
60063497	9	#include <linux/atomic.h>
00fc0e0d	10	#include <linux/export.h>
1da177e4 LT	11
	12	asm (".text \n\
	13	.global _atomic_dec_and_lock \n\
	14	.ent _atomic_dec_and_lock \n\
	15	.align 4 \n\
	16	_atomic_dec_and_lock: \n\
	17	.prologue 0 \n\
	18	1: ldl_l $1, 0($16) \n\
	19	subl $1, 1, $1 \n\
	20	beq $1, 2f \n\
	21	stl_c $1, 0($16) \n\
	22	beq $1, 4f \n\
	23	mb \n\
	24	clr $0 \n\
	25	ret \n\
	26	2: br $29, 3f \n\
	27	3: ldgp $29, 0($29) \n\
	28	br $atomic_dec_and_lock_1..ng \n\
	29	.subsection 2 \n\
	30	4: br 1b \n\
	31	.previous \n\
	32	.end _atomic_dec_and_lock");
	33
3ff6eecc	34	static int __used atomic_dec_and_lock_1(atomic_t atomic, spinlock_t lock)
1da177e4 LT	35	{
	36	/* Slow path */
	37	spin_lock(lock);
	38	if (atomic_dec_and_test(atomic))
	39	return 1;
	40	spin_unlock(lock);
	41	return 0;
	42	}
00fc0e0d	43	EXPORT_SYMBOL(_atomic_dec_and_lock);