diff --git a/include/asm-sh/io.h b/include/asm-sh/io.h
index 03427ad..51fd10b 100644
--- a/include/asm-sh/io.h
+++ b/include/asm-sh/io.h
@@ -227,5 +227,32 @@
 static inline void sync(void)
 {
 }
+
+/*
+ * Given a physical address and a length, return a virtual address
+ * that can be used to access the memory range with the caching
+ * properties specified by "flags".
+ */
+typedef unsigned long phys_addr_t;
+
+#define MAP_NOCACHE     (0)
+#define MAP_WRCOMBINE   (0)
+#define MAP_WRBACK      (0)
+#define MAP_WRTHROUGH   (0)
+
+static inline void *
+map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
+{
+	return (void *)paddr;
+}
+
+/*
+ * Take down a mapping set up by map_physmem().
+ */
+static inline void unmap_physmem(void *vaddr, unsigned long flags)
+{
+
+}
+
 #endif	/* __KERNEL__ */
 #endif	/* __ASM_SH_IO_H */