diff --git a/arch/powerpc/lib/cache.c b/arch/powerpc/lib/cache.c
index a9cd7b8..e4d9546 100644
--- a/arch/powerpc/lib/cache.c
+++ b/arch/powerpc/lib/cache.c
@@ -8,6 +8,7 @@
 #include <stdio.h>
 #include <asm/cache.h>
 #include <watchdog.h>
+#include <linux/errno.h>
 
 static ulong maybe_watchdog_reset(ulong flushed)
 {
@@ -58,3 +59,8 @@
 {
 	puts("No arch specific invalidate_icache_all available!\n");
 }
+
+int __weak pgprot_set_attrs(phys_addr_t addr, size_t size, enum pgprot_attrs perm)
+{
+	return -ENOSYS;
+}