mirror of
https://github.com/torvalds/linux.git
synced 2024-12-24 20:01:55 +00:00
44 lines
874 B
C
44 lines
874 B
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);
|