1 files changed, 31 insertions, 7 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index dff711509661..8c1335f3c3a3 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -35,13 +35,37 @@
  */
 #define PAGE_ALLOC_COSTLY_ORDER 3
 
-#define MIGRATE_UNMOVABLE     0
-#define MIGRATE_RECLAIMABLE   1
-#define MIGRATE_MOVABLE       2
-#define MIGRATE_PCPTYPES      3 /* the number of types on the pcp lists */
-#define MIGRATE_RESERVE       3
-#define MIGRATE_ISOLATE       4 /* can't allocate from here */
-#define MIGRATE_TYPES         5
+enum {
+        MIGRATE_UNMOVABLE,
+        MIGRATE_RECLAIMABLE,
+        MIGRATE_MOVABLE,
+        MIGRATE_PCPTYPES,       /* the number of types on the pcp lists */
+        MIGRATE_RESERVE = MIGRATE_PCPTYPES,
+#ifdef CONFIG_CMA
+        /*
+         * MIGRATE_CMA migration type is designed to mimic the way
+         * ZONE_MOVABLE works.  Only movable pages can be allocated
+         * from MIGRATE_CMA pageblocks and page allocator never
+         * implicitly change migration type of MIGRATE_CMA pageblock.
+         *
+         * The way to use it is to change migratetype of a range of
+         * pageblocks to MIGRATE_CMA which can be done by
+         * __free_pageblock_cma() function.  What is important though
+         * is that a range of pageblocks must be aligned to
+         * MAX_ORDER_NR_PAGES should biggest page be bigger then
+         * a single pageblock.
+         */
+        MIGRATE_CMA,
+#endif
+        MIGRATE_ISOLATE,        /* can't allocate from here */
+        MIGRATE_TYPES
+};
+
+#ifdef CONFIG_CMA
+#  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
+#else
+#  define is_migrate_cma(migratetype) false
+#endif
 
 #define for_each_migratetype_order(order, type) \
         for (order = 0; order < MAX_ORDER; order++) \