x86: unify pgtable accessors which use, #2

based on:

 Subject: x86: unify pgtable accessors which use supported_pte_mask
 From: Jeremy Fitzhardinge <jeremy@goop.org>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h
index b29a122fc1f..6452286e71a 100644
--- a/include/asm-x86/pgtable.h
+++ b/include/asm-x86/pgtable.h
@@ -155,6 +155,21 @@ static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
                       pgprot_val(pgprot)) & __supported_pte_mask);
 }
 
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+        pteval_t val = pte_val(pte);
+
+        /*
+         * Chop off the NX bit (if present), and add the NX portion of
+         * the newprot (if present):
+         */
+        val &= _PAGE_CHG_MASK & ~_PAGE_NX;
+        val |= pgprot_val(newprot) & __supported_pte_mask;
+
+        return __pte(val);
+}
+
+
 #endif  /* __ASSEMBLY__ */
 
 #ifdef CONFIG_X86_32