/* | |
* arch/alpha/lib/dec_and_lock.c | |
* | |
* ll/sc version of atomic_dec_and_lock() | |
* | |
*/ | |
#include <linux/spinlock.h> | |
#include <linux/atomic.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; | |
} |