s390/checksum: use register pair instead of register asm

 */

static inline __wsum csum_partial(const void *buff, int len, __wsum sum)

{

	register unsigned long reg2 asm("2") = (unsigned long) buff;

	register unsigned long reg3 asm("3") = (unsigned long) len;

	union register_pair rp = {

		.even = (unsigned long) buff,

		.odd = (unsigned long) len,

	};

	asm volatile(

		"0:	cksm	%0,%1\n"	/* do checksum on longs */

		"0:	cksm	%[sum],%[rp]\n"

		"	jo	0b\n"

		: "+d" (sum), "+d" (reg2), "+d" (reg3) : : "cc", "memory");

		: [sum] "+&d" (sum), [rp] "+&d" (rp.pair) : : "cc", "memory");

	return sum;

}