parisc: implement atomic64_dec_if_positive()

	select BUG

	select HAVE_PERF_EVENTS

	select GENERIC_ATOMIC64 if !64BIT

	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE

	select HAVE_GENERIC_HARDIRQS

	select BROKEN_RODATA

	select GENERIC_IRQ_PROBE

#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)

/*

 * atomic64_dec_if_positive - decrement by 1 if old value positive

 * @v: pointer of type atomic_t

 *

 * The function returns the old value of *v minus 1, even if

 * the atomic variable, v, was not decremented.

 */

static inline long atomic64_dec_if_positive(atomic64_t *v)

{

	long c, old, dec;

	c = atomic64_read(v);

	for (;;) {

		dec = c - 1;

		if (unlikely(dec < 0))

			break;

		old = atomic64_cmpxchg((v), c, dec);

		if (likely(old == c))

			break;

		c = old;

	}

	return dec;

}

#endif /* !CONFIG_64BIT */