include/linux/hardirq.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef LINUX_HARDIRQ_H
   3 #define LINUX_HARDIRQ_H
   4
   5 #include <linux/preempt.h>
   6 #include <linux/lockdep.h>
   7 #include <linux/ftrace_irq.h>
   8 #include <linux/vtime.h>
   9 #include <asm/hardirq.h>
  10
  11
  12 extern void synchronize_irq(unsigned int irq);
  13 extern bool synchronize_hardirq(unsigned int irq);
  14
  15 #if defined(CONFIG_TINY_RCU)
  16
  17 static inline void rcu_nmi_enter(void)
  18 {
  19 }
  20
  21 static inline void rcu_nmi_exit(void)
  22 {
  23 }
  24
  25 #else
  26 extern void rcu_nmi_enter(void);
  27 extern void rcu_nmi_exit(void);
  28 #endif
  29
  30 /*
  31  * It is safe to do non-atomic ops on ->hardirq_context,
  32  * because NMI handlers may not preempt and the ops are
  33  * always balanced, so the interrupted value of ->hardirq_context
  34  * will always be restored.
  35  */
  36 #define __irq_enter()                                   \
  37         do {                                            \
  38                 account_irq_enter_time(current);        \
  39                 preempt_count_add(HARDIRQ_OFFSET);      \
  40                 trace_hardirq_enter();                  \
  41         } while (0)
  42
  43 /*
  44  * Enter irq context (on NO_HZ, update jiffies):
  45  */
  46 extern void irq_enter(void);
  47
  48 /*
  49  * Exit irq context without processing softirqs:
  50  */
  51 #define __irq_exit()                                    \
  52         do {                                            \
  53                 trace_hardirq_exit();                   \
  54                 account_irq_exit_time(current);         \
  55                 preempt_count_sub(HARDIRQ_OFFSET);      \
  56         } while (0)
  57
  58 /*
  59  * Exit irq context and process softirqs if needed:
  60  */
  61 extern void irq_exit(void);
  62
  63 #ifndef arch_nmi_enter
  64 #define arch_nmi_enter()        do { } while (0)
  65 #define arch_nmi_exit()         do { } while (0)
  66 #endif
  67
  68 #define nmi_enter()                                             \
  69         do {                                                    \
  70                 arch_nmi_enter();                               \
  71                 printk_nmi_enter();                             \
  72                 lockdep_off();                                  \
  73                 ftrace_nmi_enter();                             \
  74                 BUG_ON(in_nmi());                               \
  75                 preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
  76                 rcu_nmi_enter();                                \
  77                 trace_hardirq_enter();                          \
  78         } while (0)
  79
  80 #define nmi_exit()                                              \
  81         do {                                                    \
  82                 trace_hardirq_exit();                           \
  83                 rcu_nmi_exit();                                 \
  84                 BUG_ON(!in_nmi());                              \
  85                 preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \
  86                 ftrace_nmi_exit();                              \
  87                 lockdep_on();                                   \
  88                 printk_nmi_exit();                              \
  89                 arch_nmi_exit();                                \
  90         } while (0)
  91
  92 #endif /* LINUX_HARDIRQ_H */