Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...

[linux-2.6.git] / include / linux / hardirq.h

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index ebc712e..50d8b57 100644 (file)
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -1,8 +1,9 @@
 #ifndef LINUX_HARDIRQ_H
 #define LINUX_HARDIRQ_H
 
-#include <linux/config.h>
+#include <linux/preempt.h>
 #include <linux/smp_lock.h>
+#include <linux/lockdep.h>
 #include <asm/hardirq.h>
 #include <asm/system.h>
 
@@ -43,13 +44,17 @@
 #define __IRQ_MASK(x)  ((1UL << (x))-1)
 
 #define PREEMPT_MASK   (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
-#define HARDIRQ_MASK   (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
 #define SOFTIRQ_MASK   (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
+#define HARDIRQ_MASK   (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
 
 #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
 #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
 #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
 
+#if PREEMPT_ACTIVE < (1 << (HARDIRQ_SHIFT + HARDIRQ_BITS))
+#error PREEMPT_ACTIVE is too low!
+#endif
+
 #define hardirq_count()        (preempt_count() & HARDIRQ_MASK)
 #define softirq_count()        (preempt_count() & SOFTIRQ_MASK)
 #define irq_count()    (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
@@ -82,25 +87,43 @@ extern void synchronize_irq(unsigned int irq);
 # define synchronize_irq(irq)  barrier()
 #endif
 
-#define nmi_enter()            irq_enter()
-#define nmi_exit()             sub_preempt_count(HARDIRQ_OFFSET)
+struct task_struct;
 
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
-static inline void account_user_vtime(struct task_struct *tsk)
-{
-}
-
 static inline void account_system_vtime(struct task_struct *tsk)
 {
 }
 #endif
 
+/*
+ * 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()                                    \
        do {                                            \
                account_system_vtime(current);          \
                add_preempt_count(HARDIRQ_OFFSET);      \
+               trace_hardirq_enter();                  \
        } while (0)
 
+/*
+ * Exit irq context without processing softirqs:
+ */
+#define __irq_exit()                                   \
+       do {                                            \
+               trace_hardirq_exit();                   \
+               account_system_vtime(current);          \
+               sub_preempt_count(HARDIRQ_OFFSET);      \
+       } while (0)
+
+/*
+ * Exit irq context and process softirqs if needed:
+ */
 extern void irq_exit(void);
 
+#define nmi_enter()            do { lockdep_off(); irq_enter(); } while (0)
+#define nmi_exit()             do { __irq_exit(); lockdep_on(); } while (0)
+
 #endif /* LINUX_HARDIRQ_H */