pte_prot
const pt_entry_t bits = pte_prot(pmap, prot);
npte = ((pa >> PGSHIFT) << PG_SHIFT) | pte_prot(pmap, prot) | PG_V;
((pa >> PGSHIFT) << PG_SHIFT) | pte_prot(pmap_kernel(), prot) |
isro = pte_prot(pmap, prot);
npte = pa | pte_prot(pmap, prot) | (*pte & (PG_M|PG_U)) | PG_V;
npte = pa | pte_prot(pmap, prot) | PG_V | PG_W;