qt_cdata
struct qt_cdata *sc_ib; /* virt address of ctrl block */
struct qt_cdata *sc_pib; /* phys address of ctrl block */
sc->sc_ui.ui_size = sizeof(struct qt_cdata);
sc->sc_ib = (struct qt_cdata *)sc->sc_ui.ui_vaddr;
sc->sc_pib = (struct qt_cdata *)sc->sc_ui.ui_baddr;
memset(sc->sc_ib, 0, sizeof(struct qt_cdata));