diff --git a/arch/sh/cpu/sh4/cache.c b/arch/sh/cpu/sh4/cache.c
index 99acc59..56161ee 100644
--- a/arch/sh/cpu/sh4/cache.c
+++ b/arch/sh/cpu/sh4/cache.c
@@ -11,6 +11,7 @@
 #include <asm/io.h>
 #include <asm/processor.h>
 #include <asm/system.h>
+#include <linux/errno.h>
 
 #define CACHE_VALID       1
 #define CACHE_UPDATED     2
@@ -126,3 +127,8 @@
 {
 	return 0;
 }
+
+int __weak pgprot_set_attrs(phys_addr_t addr, size_t size, enum pgprot_attrs perm)
+{
+	return -ENOSYS;
+}