diff --git a/include/linux/io.h b/include/linux/io.h
index 3a03a36..6c7f0ba 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -65,5 +65,6 @@
 void devm_iounmap(struct device *dev, void __iomem *addr);
 int check_signature(const volatile void __iomem *io_addr,
 			const unsigned char *signature, int length);
+void devm_ioremap_release(struct device *dev, void *res);
 
 #endif /* _LINUX_IO_H */