include/linux/hardirq.h

   1 #ifndef LINUX_HARDIRQ_H
   2 #define LINUX_HARDIRQ_H
   3
   4 #include <linux/preempt.h>
   5 #include <linux/lockdep.h>
   6 #include <linux/ftrace_irq.h>
   7 #include <linux/vtime.h>
   8 #include <asm/hardirq.h>
   9
  10
  11 extern void synchronize_irq(unsigned int irq);
  12 extern bool synchronize_hardirq(unsigned int irq);
  13
  14 #if defined(CONFIG_TINY_RCU)
  15
  16 static inline void rcu_nmi_enter(void)
  17 {
  18 }
  19
  20 static inline void rcu_nmi_exit(void)
  21 {
  22 }
  23
  24 #else
  25 extern void rcu_nmi_enter(void);
  26 extern void rcu_nmi_exit(void);
  27 #endif
  28
  29 /*
  30  * It is safe to do non-atomic ops on ->hardirq_context,
  31  * because NMI handlers may not preempt and the ops are
  32  * always balanced, so the interrupted value of ->hardirq_context
  33  * will always be restored.
  34  */
  35 #define __irq_enter()                                   \
  36         do {                                            \
  37                 account_irq_enter_time(current);        \
  38                 preempt_count_add(HARDIRQ_OFFSET);      \
  39                 trace_hardirq_enter();                  \
  40         } while (0)
  41
  42 /*
  43  * Enter irq context (on NO_HZ, update jiffies):
  44  */
  45 extern void irq_enter(void);
  46
  47 /*
  48  * Exit irq context without processing softirqs:
  49  */
  50 #define __irq_exit()                                    \
  51         do {                                            \
  52                 trace_hardirq_exit();                   \
  53                 account_irq_exit_time(current);         \
  54                 preempt_count_sub(HARDIRQ_OFFSET);      \
  55         } while (0)
  56
  57 /*
  58  * Exit irq context and process softirqs if needed:
  59  */
  60 extern void irq_exit(void);
  61
  62 #define nmi_enter()                                             \
  63         do {                                                    \
  64                 lockdep_off();                                  \
  65                 ftrace_nmi_enter();                             \
  66                 BUG_ON(in_nmi());                               \
  67                 preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
  68                 rcu_nmi_enter();                                \
  69                 trace_hardirq_enter();                          \
  70         } while (0)
  71
  72 #define nmi_exit()                                              \
  73         do {                                                    \
  74                 trace_hardirq_exit();                           \
  75                 rcu_nmi_exit();                                 \
  76                 BUG_ON(!in_nmi());                              \
  77                 preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \
  78                 ftrace_nmi_exit();                              \
  79                 lockdep_on();                                   \
  80         } while (0)
  81
  82 #endif /* LINUX_HARDIRQ_H */