/* This is a version of ip_compute_csum() optimized for IP headers, which always checksum on 4 octet boundaries.  */
__sum16 ip_fast_csum(const void *iph, unsigned int ihl)
/* This is a version of ip_compute_csum() optimized for IP headers, which always checksum on 4 octet boundaries.  */
__sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
	return (__force __sum16)~do_csum(iph,ihl*4);
}