/* shorter and faster modulo function, only works when v < 2N.  */
static int mod_s(struct bch_control *bch, unsigned int v)
/* shorter and faster modulo function, only works when v < 2N.  */
static int mod_s(struct bch_control *bch, unsigned int v)
{
	const unsigned int n = GF_N(bch);
	return (v < n) ? v : v-n;
}