Merge branches 'release', 'idle', 'redhat-bugzilla-436589', 'sbs' and 'video' into...

[safe/jmp/linux-2.6] / include / linux / hardirq.h

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 50d8b57..4982998 100644 (file)
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -28,11 +28,16 @@
 
 #ifndef HARDIRQ_BITS
 #define HARDIRQ_BITS   12
+
+#ifndef MAX_HARDIRQS_PER_CPU
+#define MAX_HARDIRQS_PER_CPU NR_IRQS
+#endif
+
 /*
  * The hardirq mask has to be large enough to have space for potentially
  * all IRQ sources in the system nesting on a single CPU.
  */
-#if (1 << HARDIRQ_BITS) < NR_IRQS
+#if (1 << HARDIRQ_BITS) < MAX_HARDIRQS_PER_CPU
 # error HARDIRQ_BITS is too low!
 #endif
 #endif
@@ -67,12 +72,21 @@
 #define in_softirq()           (softirq_count())
 #define in_interrupt()         (irq_count())
 
-#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
-# define in_atomic()   ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
+#define in_atomic()            ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
+
+#ifdef CONFIG_PREEMPT
+# define PREEMPT_CHECK_OFFSET 1
 #else
-# define in_atomic()   ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
+# define PREEMPT_CHECK_OFFSET 0
 #endif
 
+/*
+ * Check whether we were atomic before we did preempt_disable():
+ * (used by the scheduler)
+ */
+#define in_atomic_preempt_off() \
+               ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
+
 #ifdef CONFIG_PREEMPT
 # define preemptible() (preempt_count() == 0 && !irqs_disabled())
 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
@@ -95,20 +109,34 @@ 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
  * always balanced, so the interrupted value of ->hardirq_context
  * will always be restored.
  */
-#define irq_enter()                                    \
+#define __irq_enter()                                  \
        do {                                            \
+               rcu_irq_enter();                        \
                account_system_vtime(current);          \
                add_preempt_count(HARDIRQ_OFFSET);      \
                trace_hardirq_enter();                  \
        } while (0)
 
 /*
+ * Enter irq context (on NO_HZ, update jiffies):
+ */
+extern void irq_enter(void);
+
+/*
  * Exit irq context without processing softirqs:
  */
 #define __irq_exit()                                   \
@@ -116,6 +144,7 @@ static inline void account_system_vtime(struct task_struct *tsk)
                trace_hardirq_exit();                   \
                account_system_vtime(current);          \
                sub_preempt_count(HARDIRQ_OFFSET);      \
+               rcu_irq_exit();                         \
        } while (0)
 
 /*
@@ -123,7 +152,7 @@ static inline void account_system_vtime(struct task_struct *tsk)
  */
 extern void irq_exit(void);
 
-#define nmi_enter()            do { lockdep_off(); irq_enter(); } while (0)
+#define nmi_enter()            do { lockdep_off(); __irq_enter(); } while (0)
 #define nmi_exit()             do { __irq_exit(); lockdep_on(); } while (0)
 
 #endif /* LINUX_HARDIRQ_H */