diff --git a/[refs] b/[refs]
index 735142647957..91a8e600181f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e1fa2e136ff64a3814a98c03d46320b9e80d29c8
+refs/heads/master: 2d3fbbb391e280724f7f7804ab00ff61cf1b6a4c
diff --git a/trunk/include/linux/interrupt.h b/trunk/include/linux/interrupt.h
index f7b01b9a35b3..5323f6275854 100644
--- a/trunk/include/linux/interrupt.h
+++ b/trunk/include/linux/interrupt.h
@@ -241,6 +241,16 @@ static inline void __deprecated save_and_cli(unsigned long *x)
 #define save_and_cli(x)	save_and_cli(&x)
 #endif /* CONFIG_SMP */
 
+/* Some architectures might implement lazy enabling/disabling of
+ * interrupts. In some cases, such as stop_machine, we might want
+ * to ensure that after a local_irq_disable(), interrupts have
+ * really been disabled in hardware. Such architectures need to
+ * implement the following hook.
+ */
+#ifndef hard_irq_disable
+#define hard_irq_disable()	do { } while(0)
+#endif
+
 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
    frequency threaded job scheduling. For almost all the purposes
    tasklets are more than enough. F.e. all serial device BHs et