MIPS: mm: add page valid judgement in function pte_modify

If original PTE has _PAGE_ACCESSED bit set, and new pte has no
_PAGE_NO_READ bit set, we can add _PAGE_SILENT_READ bit to enable
page valid bit.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index d9772af..85b39c9 100644 (file)
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -532,8 +532,11 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 #else
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
-       return __pte((pte_val(pte) & _PAGE_CHG_MASK) |
-                    (pgprot_val(newprot) & ~_PAGE_CHG_MASK));
+       pte_val(pte) &= _PAGE_CHG_MASK;
+       pte_val(pte) |= pgprot_val(newprot) & ~_PAGE_CHG_MASK;
+       if ((pte_val(pte) & _PAGE_ACCESSED) && !(pte_val(pte) & _PAGE_NO_READ))
+               pte_val(pte) |= _PAGE_SILENT_READ;
+       return pte;
 }
 #endif