LXR linux/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/context_tracking_state.h>
   6#include <linux/preempt.h>
   7#include <linux/lockdep.h>
   8#include <linux/ftrace_irq.h>
   9#include <linux/sched.h>
  10#include <linux/vtime.h>
  11#include <asm/hardirq.h>
  12
  13extern void synchronize_irq(unsigned int irq);
  14extern bool synchronize_hardirq(unsigned int irq);
  15
  16#ifdef CONFIG_NO_HZ_FULL
  17void __rcu_irq_enter_check_tick(void);
  18#else
  19static inline void __rcu_irq_enter_check_tick(void) { }
  20#endif
  21
  22static __always_inline void rcu_irq_enter_check_tick(void)
  23{
  24        if (context_tracking_enabled())
  25                __rcu_irq_enter_check_tick();
  26}
  27
  28/*
  29 * It is safe to do non-atomic ops on ->hardirq_context,
  30 * because NMI handlers may not preempt and the ops are
  31 * always balanced, so the interrupted value of ->hardirq_context
  32 * will always be restored.
  33 */
  34#define __irq_enter()                                   \
  35        do {                                            \
  36                preempt_count_add(HARDIRQ_OFFSET);      \
  37                lockdep_hardirq_enter();                \
  38                account_hardirq_enter(current);         \
  39        } while (0)
  40
  41/*
  42 * Like __irq_enter() without time accounting for fast
  43 * interrupts, e.g. reschedule IPI where time accounting
  44 * is more expensive than the actual interrupt.
  45 */
  46#define __irq_enter_raw()                               \
  47        do {                                            \
  48                preempt_count_add(HARDIRQ_OFFSET);      \
  49                lockdep_hardirq_enter();                \
  50        } while (0)
  51
  52/*
  53 * Enter irq context (on NO_HZ, update jiffies):
  54 */
  55void irq_enter(void);
  56/*
  57 * Like irq_enter(), but RCU is already watching.
  58 */
  59void irq_enter_rcu(void);
  60
  61/*
  62 * Exit irq context without processing softirqs:
  63 */
  64#define __irq_exit()                                    \
  65        do {                                            \
  66                account_hardirq_exit(current);          \
  67                lockdep_hardirq_exit();                 \
  68                preempt_count_sub(HARDIRQ_OFFSET);      \
  69        } while (0)
  70
  71/*
  72 * Like __irq_exit() without time accounting
  73 */
  74#define __irq_exit_raw()                                \
  75        do {                                            \
  76                lockdep_hardirq_exit();                 \
  77                preempt_count_sub(HARDIRQ_OFFSET);      \
  78        } while (0)
  79
  80/*
  81 * Exit irq context and process softirqs if needed:
  82 */
  83void irq_exit(void);
  84
  85/*
  86 * Like irq_exit(), but return with RCU watching.
  87 */
  88void irq_exit_rcu(void);
  89
  90#ifndef arch_nmi_enter
  91#define arch_nmi_enter()        do { } while (0)
  92#define arch_nmi_exit()         do { } while (0)
  93#endif
  94
  95#ifdef CONFIG_TINY_RCU
  96static inline void rcu_nmi_enter(void) { }
  97static inline void rcu_nmi_exit(void) { }
  98#else
  99extern void rcu_nmi_enter(void);
 100extern void rcu_nmi_exit(void);
 101#endif
 102
 103/*
 104 * NMI vs Tracing
 105 * --------------
 106 *
 107 * We must not land in a tracer until (or after) we've changed preempt_count
 108 * such that in_nmi() becomes true. To that effect all NMI C entry points must
 109 * be marked 'notrace' and call nmi_enter() as soon as possible.
 110 */
 111
 112/*
 113 * nmi_enter() can nest up to 15 times; see NMI_BITS.
 114 */
 115#define __nmi_enter()                                           \
 116        do {                                                    \
 117                lockdep_off();                                  \
 118                arch_nmi_enter();                               \
 119                BUG_ON(in_nmi() == NMI_MASK);                   \
 120                __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET);       \
 121        } while (0)
 122
 123#define nmi_enter()                                             \
 124        do {                                                    \
 125                __nmi_enter();                                  \
 126                lockdep_hardirq_enter();                        \
 127                rcu_nmi_enter();                                \
 128                instrumentation_begin();                        \
 129                ftrace_nmi_enter();                             \
 130                instrumentation_end();                          \
 131        } while (0)
 132
 133#define __nmi_exit()                                            \
 134        do {                                                    \
 135                BUG_ON(!in_nmi());                              \
 136                __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET);       \
 137                arch_nmi_exit();                                \
 138                lockdep_on();                                   \
 139        } while (0)
 140
 141#define nmi_exit()                                              \
 142        do {                                                    \
 143                instrumentation_begin();                        \
 144                ftrace_nmi_exit();                              \
 145                instrumentation_end();                          \
 146                rcu_nmi_exit();                                 \
 147                lockdep_hardirq_exit();                         \
 148                __nmi_exit();                                   \
 149        } while (0)
 150
 151#endif /* LINUX_HARDIRQ_H */
 152