root/include/linux/hardirq.h

INCLUDED FROM

DEFINITIONS

1. rcu_nmi_enter
2. rcu_nmi_exit

#ifndef LINUX_HARDIRQ_H
#define LINUX_HARDIRQ_H

#include <linux/preempt_mask.h>
#include <linux/lockdep.h>
#include <linux/ftrace_irq.h>
#include <linux/vtime.h>
#include <asm/hardirq.h>


extern void synchronize_irq(unsigned int irq);
extern void synchronize_hardirq(unsigned int irq);

#if defined(CONFIG_TINY_RCU)

static inline void rcu_nmi_enter(void)
{
}

static inline void rcu_nmi_exit(void)
{
}

#else
extern void rcu_nmi_enter(void);
extern void rcu_nmi_exit(void);
#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_irq_enter_time(current);        \
                preempt_count_add(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()                                    \
        do {                                            \
                trace_hardirq_exit();                   \
                account_irq_exit_time(current);         \
                preempt_count_sub(HARDIRQ_OFFSET);      \
        } while (0)

/*
 * Exit irq context and process softirqs if needed:
 */
extern void irq_exit(void);

#define nmi_enter()                                             \
        do {                                                    \
                lockdep_off();                                  \
                ftrace_nmi_enter();                             \
                BUG_ON(in_nmi());                               \
                preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
                rcu_nmi_enter();                                \
                trace_hardirq_enter();                          \
        } while (0)

#define nmi_exit()                                              \
        do {                                                    \
                trace_hardirq_exit();                           \
                rcu_nmi_exit();                                 \
                BUG_ON(!in_nmi());                              \
                preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \
                ftrace_nmi_exit();                              \
                lockdep_on();                                   \
        } while (0)

#endif /* LINUX_HARDIRQ_H */