maps4: move is_swap_pte

Move is_swap_pte helper function to swapops.h for use by pagemap code

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index ceb6cc5ceebb..7bf2d149d209 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -42,6 +42,12 @@ static inline pgoff_t swp_offset(swp_entry_t entry)
         return entry.val & SWP_OFFSET_MASK(entry);
 }
 
+/* check whether a pte points to a swap entry */
+static inline int is_swap_pte(pte_t pte)
+{
+        return !pte_none(pte) && !pte_present(pte) && !pte_file(pte);
+}
+
 /*
  * Convert the arch-dependent pte representation of a swp_entry_t into an
  * arch-independent swp_entry_t.