diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index cc28d207a06106fec1e375fb92e74639857ab606..affd21e9c20b42b749eefdfa9765932fe0245d47 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -554,6 +554,7 @@ extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
  * access
  */
 #define xlate_dev_mem_ptr(p)	__va(p)
+#define unxlate_dev_mem_ptr(p, v) do { } while (0)
 
 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
 
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index f494d31f2b9835b951f5f303194655308526430d..94eff6a2a7b6dbae1e6ae754a19e007ce5e22d02 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -90,13 +90,6 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 }
 #endif
 
-#ifndef unxlate_dev_mem_ptr
-#define unxlate_dev_mem_ptr unxlate_dev_mem_ptr
-void __weak unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
-{
-}
-#endif
-
 static inline bool should_stop_iteration(void)
 {
 	if (need_resched())