wb_data
f->wb_data = VTOPHYS(mtod(m, vaddr_t));
f->wb_data = VTOPHYS(mtod(m_new, caddr_t));
f->wb_data = VTOPHYS(&sc->wb_cdata.wb_pad);
c->wb_ptr->wb_data = VTOPHYS(c->wb_buf + sizeof(u_int64_t));
#define WB_TXDATA(x) x->wb_ptr->wb_frag[x->wb_lastdesc].wb_data
u_int32_t wb_data[1024];