_PAGE_HGLOBAL_SHIFT
#define _PAGE_HGLOBAL (_ULCAST_(1) << _PAGE_HGLOBAL_SHIFT)
((pmd_val(pmd) & _PAGE_GLOBAL) << (_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT));
(_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT));