diff --git a/[refs] b/[refs]
index 9d322196caa1..2e40a2002fbb 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 89e09f5ebba4bcde9852e4be4af536d5b691f20a
+refs/heads/master: e63f8f439de010b6227c0c9c6f56e2c44dbe5dae
diff --git a/trunk/include/asm-ppc64/processor.h b/trunk/include/asm-ppc64/processor.h
index eb33d33cfd6d..cae65b30adb8 100644
--- a/trunk/include/asm-ppc64/processor.h
+++ b/trunk/include/asm-ppc64/processor.h
@@ -642,11 +642,17 @@ static inline unsigned long __pack_fe01(unsigned int fpmode)
 
 static inline void prefetch(const void *x)
 {
+	if (unlikely(!x))
+		return;
+
 	__asm__ __volatile__ ("dcbt 0,%0" : : "r" (x));
 }
 
 static inline void prefetchw(const void *x)
 {
+	if (unlikely(!x))
+		return;
+
 	__asm__ __volatile__ ("dcbtst 0,%0" : : "r" (x));
 }