thp: add pmd_modify

Add pmd_modify() for use with mprotect() on huge pmds. Signed-off-by: Johannes Weiner <[email protected]> Signed-off-by: Andrea Arcangeli <[email protected]> Reviewed-by: Rik van Riel <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · Jan 14, 2011 · c489f12 · c489f12
1 parent 0ca1634
commit c489f12
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diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
@@ -325,6 +325,16 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 	return __pte(val);
 }
 
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+	pmdval_t val = pmd_val(pmd);
+
+	val &= _HPAGE_CHG_MASK;
+	val |= massage_pgprot(newprot) & ~_HPAGE_CHG_MASK;
+
+	return __pmd(val);
+}
+
 /* mprotect needs to preserve PAT bits when updating vm_page_prot */
 #define pgprot_modify pgprot_modify
 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)

diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
@@ -72,6 +72,7 @@
 /* Set of bits not changed in pte_modify */
 #define _PAGE_CHG_MASK	(PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT |		\
 			 _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE)
 
 #define _PAGE_CACHE_MASK	(_PAGE_PCD | _PAGE_PWT)
 #define _PAGE_CACHE_WB		(0)