2 * x86 version of "atomic_dec_and_lock()" using
3 * the atomic "cmpxchg" instruction.
5 * (For CPU's lacking cmpxchg, we use the slow
6 * generic version, and this one never even gets
10 #include <linux/spinlock.h>
11 #include <asm/atomic.h>
13 int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
19 counter = atomic_read(atomic);
25 asm volatile("lock; cmpxchgl %1,%2"
27 :"r" (newcount), "m" (atomic->counter), "0" (counter));
29 /* If the above failed, "eax" will have changed */
30 if (newcount != counter)
36 if (atomic_dec_and_test(atomic))