X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=include%2Flinux%2Fhardirq.h;h=897f723bd222f73a9c9e72519fe4b8cd14e40f14;hb=95dfec6ae1cb8c03406aac612a5642cbddb676b3;hp=2961ec788046627c823feb291d7d522f15982fbf;hpb=99f1c97dbdb30e958edfd1ced0ae43df62504e07;p=linux-2.6-omap-h63xx.git

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 2961ec78804..897f723bd22 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -72,6 +72,13 @@
 #define in_softirq()		(softirq_count())
 #define in_interrupt()		(irq_count())
 
+/*
+ * Are we running in atomic context?  WARNING: this macro cannot
+ * always detect atomic context; in particular, it cannot know about
+ * held spinlocks in non-preemptible kernels.  Thus it should not be
+ * used in the general case to determine whether sleeping is possible.
+ * Do not use in_atomic() in driver code.
+ */
 #define in_atomic()		((preempt_count() & ~PREEMPT_ACTIVE) != 0)
 
 #ifdef CONFIG_PREEMPT
@@ -109,6 +116,14 @@ static inline void account_system_vtime(struct task_struct *tsk)
 }
 #endif
 
+#if defined(CONFIG_PREEMPT_RCU) && defined(CONFIG_NO_HZ)
+extern void rcu_irq_enter(void);
+extern void rcu_irq_exit(void);
+#else
+# define rcu_irq_enter() do { } while (0)
+# define rcu_irq_exit() do { } while (0)
+#endif /* CONFIG_PREEMPT_RCU */
+
 /*
  * It is safe to do non-atomic ops on ->hardirq_context,
  * because NMI handlers may not preempt and the ops are
@@ -117,6 +132,7 @@ static inline void account_system_vtime(struct task_struct *tsk)
  */
 #define __irq_enter()					\
 	do {						\
+		rcu_irq_enter();			\
 		account_system_vtime(current);		\
 		add_preempt_count(HARDIRQ_OFFSET);	\
 		trace_hardirq_enter();			\
@@ -135,6 +151,7 @@ extern void irq_enter(void);
 		trace_hardirq_exit();			\
 		account_system_vtime(current);		\
 		sub_preempt_count(HARDIRQ_OFFSET);	\
+		rcu_irq_exit();				\
 	} while (0)
 
 /*