diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bdb7eb2..94725ae 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5631,10 +5631,11 @@ static void __meminit zone_init_free_lists(struct zone *zone)
 	}
 }
 
-#ifndef __HAVE_ARCH_MEMMAP_INIT
-#define memmap_init(size, nid, zone, start_pfn) \
-	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY, NULL)
-#endif
+void __meminit __weak memmap_init(unsigned long size, int nid,
+				  unsigned long zone, unsigned long start_pfn)
+{
+	memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY, NULL);
+}
 
 static int zone_batchsize(struct zone *zone)
 {