__PHYSICAL_MASK    19 include/asm-x86/page.h #define PHYSICAL_PAGE_MASK	(((signed long)PAGE_MASK) & __PHYSICAL_MASK)
__PHYSICAL_MASK   226 include/asm-x86/pgtable_64.h #define pmd_pfn(x)  ((pmd_val((x)) & __PHYSICAL_MASK) >> PAGE_SHIFT)