MASK_XENCONS_IDX
ifp->out[MASK_XENCONS_IDX(prod++, ifp->out)] = c;
xcp->pollbuf[0] = ifp->in[MASK_XENCONS_IDX(cons++, ifp->in)];
(ix) : MASK_XENCONS_IDX((ix), (ifp)->in))
ifp->out[MASK_XENCONS_IDX(prod++, ifp->out)] =
cons_ifp->out[MASK_XENCONS_IDX(cons_ifp->out_prod, cons_ifp->out)] =
c = cons_ifp->in[MASK_XENCONS_IDX(cons_ifp->in_cons, cons_ifp->in)];