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/*
 96 * NMI vs Tracing
 97 * --------------
 98 *
 99 * We must not land in a tracer until (or after) we've changed preempt_count
100 * such that in_nmi() becomes true. To that effect all NMI C entry points must
101 * be marked 'notrace' and call nmi_enter() as soon as possible.
102 */
103
104/*
105 * nmi_enter() can nest up to 15 times; see NMI_BITS.
106 */
107#define __nmi_enter()						\
108	do {							\
109		lockdep_off();					\
110		arch_nmi_enter();				\
111		BUG_ON(in_nmi() == NMI_MASK);			\
112		__preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET);	\
113	} while (0)
114
115#define nmi_enter()						\
116	do {							\
117		__nmi_enter();					\
118		lockdep_hardirq_enter();			\
119		ct_nmi_enter();				\
120		instrumentation_begin();			\
121		ftrace_nmi_enter();				\
122		instrumentation_end();				\
123	} while (0)
124
125#define __nmi_exit()						\
126	do {							\
127		BUG_ON(!in_nmi());				\
128		__preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET);	\
129		arch_nmi_exit();				\
130		lockdep_on();					\
131	} while (0)
132
133#define nmi_exit()						\
134	do {							\
135		instrumentation_begin();			\
136		ftrace_nmi_exit();				\
137		instrumentation_end();				\
138		ct_nmi_exit();					\
139		lockdep_hardirq_exit();				\
140		__nmi_exit();					\
141	} while (0)
142
143#endif /* LINUX_HARDIRQ_H */