diff --git a/arch/arm/cpu/armv7m/cache.c b/arch/arm/cpu/armv7m/cache.c
index b6d08b7..8e7db73 100644
--- a/arch/arm/cpu/armv7m/cache.c
+++ b/arch/arm/cpu/armv7m/cache.c
@@ -11,6 +11,7 @@
 #include <asm/cache.h>
 #include <asm/io.h>
 #include <linux/bitops.h>
+#include <linux/errno.h>
 
 /* Cache maintenance operation registers */
 
@@ -370,3 +371,8 @@
 	dcache_enable();
 #endif
 }
+
+int __weak pgprot_set_attrs(phys_addr_t addr, size_t size, enum pgprot_attrs perm)
+{
+	return -ENOSYS;
+}