PG_CMASK
npte = *ptep & ~PG_CMASK;
(set & PG_CMASK) ||
(mask & PG_CMASK) == 0)) {
*pte = (*pte & ~PG_CMASK) | PG_CI;
protopte &= ~PG_CMASK;
protopte &= ~PG_CMASK;
protopte &= ~PG_CMASK;