diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index d02806513670..bf8204de3a48 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -935,18 +935,7 @@ static inline void *phys_to_virt(unsigned long address)
  * defined your own ioremap_*() variant you must then declare your own
  * ioremap_*() variant as defined to itself to avoid the default NULL return.
  */
-
-#ifdef CONFIG_MMU
-
-#ifndef ioremap_uc
-#define ioremap_uc ioremap_uc
-static inline void __iomem *ioremap_uc(phys_addr_t offset, size_t size)
-{
-	return NULL;
-}
-#endif
-
-#else /* !CONFIG_MMU */
+#ifndef CONFIG_MMU
 
 /*
  * Change "struct page" to physical address.
@@ -980,14 +969,6 @@ static inline void __iomem *ioremap_nocache(phys_addr_t offset, size_t size)
 }
 #endif
 
-#ifndef ioremap_uc
-#define ioremap_uc ioremap_uc
-static inline void __iomem *ioremap_uc(phys_addr_t offset, size_t size)
-{
-	return ioremap_nocache(offset, size);
-}
-#endif
-
 #ifndef ioremap_wc
 #define ioremap_wc ioremap_wc
 static inline void __iomem *ioremap_wc(phys_addr_t offset, size_t size)
@@ -1004,6 +985,21 @@ static inline void __iomem *ioremap_wt(phys_addr_t offset, size_t size)
 }
 #endif
 
+/*
+ * ioremap_uc is special in that we do require an explicit architecture
+ * implementation.  In general you do not want to use this function in a
+ * driver and use plain ioremap, which is uncached by default.  Similarly
+ * architectures should not implement it unless they have a very good
+ * reason.
+ */
+#ifndef ioremap_uc
+#define ioremap_uc ioremap_uc
+static inline void __iomem *ioremap_uc(phys_addr_t offset, size_t size)
+{
+	return NULL;
+}
+#endif
+
 #ifdef CONFIG_HAS_IOPORT_MAP
 #ifndef CONFIG_GENERIC_IOMAP
 #ifndef ioport_map