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| /*
| * 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);
|
|
