x86: add PTE_FLAGS_MASK

PTE_PFN_MASK was getting lonely, so I made it a friend.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h
index 525b53e..5c3b265 100644
--- a/include/asm-x86/pgtable_32.h
+++ b/include/asm-x86/pgtable_32.h
@@ -88,7 +88,7 @@
 /* To avoid harmful races, pmd_none(x) should check only the lower when PAE */
 #define pmd_none(x)	(!(unsigned long)pmd_val((x)))
 #define pmd_present(x)	(pmd_val((x)) & _PAGE_PRESENT)
-#define pmd_bad(x) ((pmd_val(x) & (~PTE_PFN_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+#define pmd_bad(x) ((pmd_val(x) & (PTE_FLAGS_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 
 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))