mac_hwrings_get
hw_rh_cnt = mac_hwrings_get(port->lp_mch, NULL, hw_rh,
extern int mac_hwrings_get(mac_client_handle_t, mac_group_handle_t *,
hw_ring_cnt = mac_hwrings_get(vnetp->hio_mch, &vnetp->rx_hwgh, hw_rh,
hw_ring_cnt = mac_hwrings_get(vnetp->hio_mch, &vnetp->tx_hwgh, hw_rh,