diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 22d94c3e6fc4..d0f0a514b04e 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -560,12 +560,12 @@ subsys_initcall(add_system_ram_resources);
  */
 int devmem_is_allowed(unsigned long pfn)
 {
+	if (page_is_rtas_user_buf(pfn))
+		return 1;
 	if (iomem_is_exclusive(PFN_PHYS(pfn)))
 		return 0;
 	if (!page_is_ram(pfn))
 		return 1;
-	if (page_is_rtas_user_buf(pfn))
-		return 1;
 	return 0;
 }
 #endif /* CONFIG_STRICT_DEVMEM */