#include <linux/module.h>#include <linux/spinlock.h>#include <asm/atomic.h>/* * This is an architecture-neutral, but slow, * implementation of the notion of "decrement * a reference count, and return locked if it * decremented to zero". * * NOTE NOTE NOTE! This is _not_ equivalent to * *	if (atomic_dec_and_test(&atomic)) { *		spin_lock(&lock); *		return 1; *	} *	return 0; * * because the spin-lock and the decrement must be * "atomic". * * This slow version gets the spinlock unconditionally, * and releases it if it isn't needed. Architectures * are encouraged to come up with better approaches, * this is trivially done efficiently using a load-locked * store-conditional approach, for example. */#ifndef ATOMIC_DEC_AND_LOCKint atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock){	spin_lock(lock);	if (atomic_dec_and_test(atomic))		return 1;	spin_unlock(lock);	return 0;}EXPORT_SYMBOL(atomic_dec_and_lock);#endif