pmap_inval_loadandclear
vpte_t pmap_inval_loadandclear(volatile vpte_t *ptep, struct pmap *pmap, vm_offset_t va);
oldpte = pmap_inval_loadandclear(ptq, pmap, va);
tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);
tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);
origpte = pmap_inval_loadandclear(pte, pmap, va);
tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);