x86: add pmd_[dirty|mkclean] for THP

MADV_FREE needs pmd_dirty and pmd_mkclean for detecting recent overwrite
of the contents since MADV_FREE syscall is called for THP page.

This patch adds pmd_dirty and pmd_mkclean for THP page MADV_FREE
support.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index fe57e7a98839801ce76a6a33c0f3a7552e5d292a..6caf13453b0383a5889e9129d5f698d48ffae4b1 100644 (file)
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -110,6 +110,11 @@ static inline int pmd_young(pmd_t pmd)
        return pmd_flags(pmd) & _PAGE_ACCESSED;
 }
 
+static inline int pmd_dirty(pmd_t pmd)
+{
+       return pmd_flags(pmd) & _PAGE_DIRTY;
+}
+
 static inline int pte_write(pte_t pte)
 {
        return pte_flags(pte) & _PAGE_RW;
@@ -267,6 +272,11 @@ static inline pmd_t pmd_mkold(pmd_t pmd)
        return pmd_clear_flags(pmd, _PAGE_ACCESSED);
 }
 
+static inline pmd_t pmd_mkclean(pmd_t pmd)
+{
+       return pmd_clear_flags(pmd, _PAGE_DIRTY);
+}
+
 static inline pmd_t pmd_wrprotect(pmd_t pmd)
 {
        return pmd_clear_flags(pmd, _PAGE_RW);