PHYSICAL_PAGE_MASK  136 arch/x86/include/asm/pgtable_64.h #define pte_to_pgoff(pte) ((pte_val((pte)) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT)
PHYSICAL_PAGE_MASK  236 arch/x86/include/asm/pgtable_types.h #define PTE_PFN_MASK		((pteval_t)PHYSICAL_PAGE_MASK)