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/page.h b/include/asm-x86/page.h
index e99fb9f..6c84622 100644
--- a/include/asm-x86/page.h
+++ b/include/asm-x86/page.h
@@ -21,6 +21,9 @@
 /* PTE_PFN_MASK extracts the PFN from a (pte|pmd|pud|pgd)val_t */
 #define PTE_PFN_MASK		((pteval_t)PHYSICAL_PAGE_MASK)
 
+/* PTE_FLAGS_MASK extracts the flags from a (pte|pmd|pud|pgd)val_t */
+#define PTE_FLAGS_MASK		(~PTE_PFN_MASK)
+
 #define PMD_PAGE_SIZE		(_AC(1, UL) << PMD_SHIFT)
 #define PMD_PAGE_MASK		(~(PMD_PAGE_SIZE-1))
 
@@ -146,7 +149,7 @@
 
 static inline pteval_t native_pte_flags(pte_t pte)
 {
-	return native_pte_val(pte) & ~PTE_PFN_MASK;
+	return native_pte_val(pte) & PTE_FLAGS_MASK;
 }
 
 #define pgprot_val(x)	((x).pgprot)