include/linux/hardirq.h

   1 #ifndef LINUX_HARDIRQ_H
   2 #define LINUX_HARDIRQ_H
   3
   4 #include <linux/preempt_mask.h>
   5 #include <linux/lockdep.h>
   6 #include <linux/ftrace_irq.h>
   7 #include <linux/vtime.h>
   8
   9
  10 #if defined(CONFIG_SMP) || defined(CONFIG_GENERIC_HARDIRQS)
  11 extern void synchronize_irq(unsigned int irq);
  12 #else
  13 # define synchronize_irq(irq)   barrier()
  14 #endif
  15
  16 #if defined(CONFIG_TINY_RCU)
  17
  18 static inline void rcu_nmi_enter(void)
  19 {
  20 }
  21
  22 static inline void rcu_nmi_exit(void)
  23 {
  24 }
  25
  26 #else
  27 extern void rcu_nmi_enter(void);
  28 extern void rcu_nmi_exit(void);
  29 #endif
  30
  31 /*
  32  * It is safe to do non-atomic ops on ->hardirq_context,
  33  * because NMI handlers may not preempt and the ops are
  34  * always balanced, so the interrupted value of ->hardirq_context
  35  * will always be restored.
  36  */
  37 #define __irq_enter()                                   \
  38         do {                                            \
  39                 account_irq_enter_time(current);        \
  40                 add_preempt_count(HARDIRQ_OFFSET);      \
  41                 trace_hardirq_enter();                  \
  42         } while (0)
  43
  44 /*
  45  * Enter irq context (on NO_HZ, update jiffies):
  46  */
  47 extern void irq_enter(void);
  48
  49 /*
  50  * Exit irq context without processing softirqs:
  51  */
  52 #define __irq_exit()                                    \
  53         do {                                            \
  54                 trace_hardirq_exit();                   \
  55                 account_irq_exit_time(current);         \
  56                 sub_preempt_count(HARDIRQ_OFFSET);      \
  57         } while (0)
  58
  59 /*
  60  * Exit irq context and process softirqs if needed:
  61  */
  62 extern void irq_exit(void);
  63
  64 #define nmi_enter()                                             \
  65         do {                                                    \
  66                 lockdep_off();                                  \
  67                 ftrace_nmi_enter();                             \
  68                 BUG_ON(in_nmi());                               \
  69                 add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
  70                 rcu_nmi_enter();                                \
  71                 trace_hardirq_enter();                          \
  72         } while (0)
  73
  74 #define nmi_exit()                                              \
  75         do {                                                    \
  76                 trace_hardirq_exit();                           \
  77                 rcu_nmi_exit();                                 \
  78                 BUG_ON(!in_nmi());                              \
  79                 sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
  80                 ftrace_nmi_exit();                              \
  81                 lockdep_on();                                   \
  82         } while (0)
  83
  84 #endif /* LINUX_HARDIRQ_H */