_pmap_remove_pv
opv = _pmap_remove_pv(opp, pm, va, opte);
opv = _pmap_remove_pv(pp, pm, trunc_page(pv->pv_va), pte);
opv = _pmap_remove_pv(pp, pm, va, pte);
pvtmp = _pmap_remove_pv(pp, pm, va, opte);