/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_HARDIRQ_H
#define LINUX_HARDIRQ_H

#include <linux/context_tracking_state.h>
#include <linux/preempt.h>
#include <linux/lockdep.h>
#include <linux/ftrace_irq.h>
#include <linux/sched.h>
#include <linux/vtime.h>
#include <asm/hardirq.h>

extern void synchronize_irq(unsigned int irq);
extern bool synchronize_hardirq(unsigned int irq);

#ifdef CONFIG_NO_HZ_FULL
void __rcu_irq_enter_check_tick(void);
#else
static inline void __rcu_irq_enter_check_tick(void) { }
#endif

static __always_inline void rcu_irq_enter_check_tick(void)
{
        if (context_tracking_enabled())
                __rcu_irq_enter_check_tick();
}

/*
 * It is safe to do non-atomic ops on ->hardirq_context,
 * because NMI handlers may not preempt and the ops are
 * always balanced, so the interrupted value of ->hardirq_context
 * will always be restored.
 */
#define __irq_enter()                                   \
        do {                                            \
                preempt_count_add(HARDIRQ_OFFSET);      \
                lockdep_hardirq_enter();                \
                account_hardirq_enter(current);         \
        } while (0)

/*
 * Like __irq_enter() without time accounting for fast
 * interrupts, e.g. reschedule IPI where time accounting
 * is more expensive than the actual interrupt.
 */
#define __irq_enter_raw()                               \
        do {                                            \
                preempt_count_add(HARDIRQ_OFFSET);      \
                lockdep_hardirq_enter();                \
        } while (0)

/*
 * Enter irq context (on NO_HZ, update jiffies):
 */
void irq_enter(void);
/*
 * Like irq_enter(), but RCU is already watching.
 */
void irq_enter_rcu(void);

/*
 * Exit irq context without processing softirqs:
 */
#define __irq_exit()                                    \
        do {                                            \
                account_hardirq_exit(current);          \
                lockdep_hardirq_exit();                 \
                preempt_count_sub(HARDIRQ_OFFSET);      \
        } while (0)

/*
 * Like __irq_exit() without time accounting
 */
#define __irq_exit_raw()                                \
        do {                                            \
                lockdep_hardirq_exit();                 \
                preempt_count_sub(HARDIRQ_OFFSET);      \
        } while (0)

/*
 * Exit irq context and process softirqs if needed:
 */
void irq_exit(void);

/*
 * Like irq_exit(), but return with RCU watching.
 */
void irq_exit_rcu(void);

#ifndef arch_nmi_enter
#define arch_nmi_enter()        do { } while (0)
#define arch_nmi_exit()         do { } while (0)
#endif

/*
 * NMI vs Tracing
 * --------------
 *
 * We must not land in a tracer until (or after) we've changed preempt_count
 * such that in_nmi() becomes true. To that effect all NMI C entry points must
 * be marked 'notrace' and call nmi_enter() as soon as possible.
 */

/*
 * nmi_enter() can nest up to 15 times; see NMI_BITS.
 */
#define __nmi_enter()                                           \
        do {                                                    \
                lockdep_off();                                  \
                arch_nmi_enter();                               \
                BUG_ON(in_nmi() == NMI_MASK);                   \
                __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET);       \
        } while (0)

#define nmi_enter()                                             \
        do {                                                    \
                __nmi_enter();                                  \
                lockdep_hardirq_enter();                        \
                ct_nmi_enter();                         \
                instrumentation_begin();                        \
                ftrace_nmi_enter();                             \
                instrumentation_end();                          \
        } while (0)

#define __nmi_exit()                                            \
        do {                                                    \
                BUG_ON(!in_nmi());                              \
                __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET);       \
                arch_nmi_exit();                                \
                lockdep_on();                                   \
        } while (0)

#define nmi_exit()                                              \
        do {                                                    \
                instrumentation_begin();                        \
                ftrace_nmi_exit();                              \
                instrumentation_end();                          \
                ct_nmi_exit();                                  \
                lockdep_hardirq_exit();                         \
                __nmi_exit();                                   \
        } while (0)

#endif /* LINUX_HARDIRQ_H */