QP_LINKS
val = ntb_spad_read(nt->ndev, QP_LINKS);
ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
val = ntb_spad_read(qp->ndev, QP_LINKS);
ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));