diff --git a/include/linux/io.h b/include/linux/io.h
index d5fc9b8d8b03..fa02e55e5a2e 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -61,9 +61,9 @@ static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
 #define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
 
 void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
-			    unsigned long size);
+			   resource_size_t size);
 void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
-				    unsigned long size);
+				   resource_size_t size);
 void devm_iounmap(struct device *dev, void __iomem *addr);
 int check_signature(const volatile void __iomem *io_addr,
 			const unsigned char *signature, int length);
diff --git a/lib/devres.c b/lib/devres.c
index f4a195a6efe4..0f1dd2e9d2c1 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -23,7 +23,7 @@ static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
  * Managed ioremap().  Map is automatically unmapped on driver detach.
  */
 void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
-			   unsigned long size)
+			   resource_size_t size)
 {
 	void __iomem **ptr, *addr;
 
@@ -52,7 +52,7 @@ EXPORT_SYMBOL(devm_ioremap);
  * detach.
  */
 void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
-				   unsigned long size)
+				   resource_size_t size)
 {
 	void __iomem **ptr, *addr;