diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index d42b933..513c26b 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -27,6 +27,7 @@
 #include <linux/vmalloc.h>
 #include <linux/io.h>
 #include <linux/sizes.h>
+#include <linux/memblock.h>
 
 #include <asm/cp15.h>
 #include <asm/cputype.h>
@@ -301,7 +302,8 @@
 	 * Don't allow RAM to be mapped with mismatched attributes - this
 	 * causes problems with ARMv6+
 	 */
-	if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW))
+	if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) &&
+		    mtype != MT_MEMORY_RW))
 		return NULL;
 
 	area = get_vm_area_caller(size, VM_IOREMAP, caller);