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// SPDX-License-Identifier: GPL-2.0
/*
* 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);
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