pmd_mkyoung
entry = pmd_mkyoung(entry);
pmd = pmd_mkyoung(pmd);
WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
pmd = pmd_mkyoung(pmd);
entry = pmd_mkyoung(*pmd);
entry = pmd_mkyoung(pmd_mkdirty(entry));
entry = pmd_mkyoung(*pmd);
entry = pmd_mkyoung(orig_pmd);
pmd = pmd_mkyoung(pmd);