PG_NV
PMAP_SET_PTE(pte, PG_NV);
PMAP_SET_PTE(pte, PG_NV);
PMAP_SET_PTE(pte, PG_NV);
tlb_flush(pmap, va, PG_NV);
tlb_flush(pmap, va, PG_NV);
tlb_kflush(va, PG_NV);
oldpte = PG_NV;
*pte++ = PG_NV;
*pte++ = PG_NV;
*pte = PG_NV | PG_G;
if (pte[k] != PG_NV)
*pte = PG_NV | PG_G;
*pte = PG_NV;