diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index da0af631ded5b651d549e03d805d0da1e8083ab4..9c4ed2c4b45cc4f1795eaeb2b231ae132cbb6241 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -65,13 +65,16 @@ extern void irq_exit(void);
 #define arch_nmi_exit()		do { } while (0)
 #endif
 
+/*
+ * nmi_enter() can nest up to 15 times; see NMI_BITS.
+ */
 #define nmi_enter()						\
 	do {							\
 		arch_nmi_enter();				\
 		printk_nmi_enter();				\
 		lockdep_off();					\
 		ftrace_nmi_enter();				\
-		BUG_ON(in_nmi());				\
+		BUG_ON(in_nmi() == NMI_MASK);			\
 		preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET);	\
 		rcu_nmi_enter();				\
 		trace_hardirq_enter();				\
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index c01813c3fbe9336ed69a54a0296ed7bb69186a5f..f10333a2b676857e7b18e8ad00b882bcc05f08ce 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -26,13 +26,13 @@
  *         PREEMPT_MASK:	0x000000ff
  *         SOFTIRQ_MASK:	0x0000ff00
  *         HARDIRQ_MASK:	0x000f0000
- *             NMI_MASK:	0x00100000
+ *             NMI_MASK:	0x00f00000
  * PREEMPT_NEED_RESCHED:	0x80000000
  */
 #define PREEMPT_BITS	8
 #define SOFTIRQ_BITS	8
 #define HARDIRQ_BITS	4
-#define NMI_BITS	1
+#define NMI_BITS	4
 
 #define PREEMPT_SHIFT	0
 #define SOFTIRQ_SHIFT	(PREEMPT_SHIFT + PREEMPT_BITS)