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>

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.

mm/migrate.c

@@ -115,11 +115,6 @@ int putback_lru_pages(struct list_head *l)
 	return count;
 }
 
-static inline int is_swap_pte(pte_t pte)
-{
-	return !pte_none(pte) && !pte_present(pte) && !pte_file(pte);
-}
-
 /*
  * Restore a potential migration pte to a working pte entry
  */