2 files changed, 29 insertions, 0 deletions

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 79dd9eca054f..d9524c49d767 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -259,6 +259,7 @@ static inline void remove_memory(int nid, u64 start, u64 size) {}
 extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
                 void *arg, int (*func)(struct memory_block *, void *));
 extern int add_memory(int nid, u64 start, u64 size);
+extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default);
 extern int arch_add_memory(int nid, u64 start, u64 size);
 extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
 extern bool is_memblock_offlined(struct memory_block *mem);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a3797d3fd8a4..2ff8c2325e96 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1159,6 +1159,34 @@ static int check_hotplug_memory_range(u64 start, u64 size)
         return 0;
 }
 
+/*
+ * If movable zone has already been setup, newly added memory should be check.
+ * If its address is higher than movable zone, it should be added as movable.
+ * Without this check, movable zone may overlap with other zone.
+ */
+static int should_add_memory_movable(int nid, u64 start, u64 size)
+{
+        unsigned long start_pfn = start >> PAGE_SHIFT;
+        pg_data_t *pgdat = NODE_DATA(nid);
+        struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE;
+
+        if (zone_is_empty(movable_zone))
+                return 0;
+
+        if (movable_zone->zone_start_pfn <= start_pfn)
+                return 1;
+
+        return 0;
+}
+
+int zone_for_memory(int nid, u64 start, u64 size, int zone_default)
+{
+        if (should_add_memory_movable(nid, start, size))
+                return ZONE_MOVABLE;
+
+        return zone_default;
+}
+
 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
 int __ref add_memory(int nid, u64 start, u64 size)
 {