/*
 * remove hrtimer, called with base lock held
 */
static inline int
remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
{
	if (hrtimer_is_queued(timer)) {
		unsigned long state;
		int reprogram;

		/*
		 * Remove the timer and force reprogramming when high
		 * resolution mode is active and the timer is on the current
		 * CPU. If we remove a timer on another CPU, reprogramming is
		 * skipped. The interrupt event on this CPU is fired and
		 * reprogramming happens in the interrupt handler. This is a
		 * rare case and less expensive than a smp call.
		 */
		debug_deactivate(timer);
		timer_stats_hrtimer_clear_start_info(timer);
		reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
		/*
		 * We must preserve the CALLBACK state flag here,
		 * otherwise we could move the timer base in
		 * switch_hrtimer_base.
		 */
		state = timer->state & HRTIMER_STATE_CALLBACK;
		__remove_hrtimer(timer, base, state, reprogram);
		return 1;
	}
	return 0;
}

/*
 * remove hrtimer, called with base lock held
 */
static inline int
remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, bool restart)
{
	if (hrtimer_is_queued(timer)) {
		u8 state = timer->state;
		int reprogram;

		/*
		 * Remove the timer and force reprogramming when high
		 * resolution mode is active and the timer is on the current
		 * CPU. If we remove a timer on another CPU, reprogramming is
		 * skipped. The interrupt event on this CPU is fired and
		 * reprogramming happens in the interrupt handler. This is a
		 * rare case and less expensive than a smp call.
		 */
		debug_deactivate(timer);
		timer_stats_hrtimer_clear_start_info(timer);
		reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);

		if (!restart)
			state = HRTIMER_STATE_INACTIVE;

		__remove_hrtimer(timer, base, state, reprogram);
		return 1;
	}
	return 0;
}

static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
				struct hrtimer_clock_base *new_base)
{
	struct hrtimer *timer;
	struct timerqueue_node *node;

	while ((node = timerqueue_getnext(&old_base->active))) {
		timer = container_of(node, struct hrtimer, node);
		BUG_ON(hrtimer_callback_running(timer));
		debug_deactivate(timer);

		/*
		 * Mark it as STATE_MIGRATE not INACTIVE otherwise the
		 * timer could be seen as !active and just vanish away
		 * under us on another CPU
		 */
		__remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
		timer->base = new_base;
		/*
		 * Enqueue the timers on the new cpu. This does not
		 * reprogram the event device in case the timer
		 * expires before the earliest on this CPU, but we run
		 * hrtimer_interrupt after we migrated everything to
		 * sort out already expired timers and reprogram the
		 * event device.
		 */
		enqueue_hrtimer(timer, new_base);

		/* Clear the migration state bit */
		timer->state &= ~HRTIMER_STATE_MIGRATE;
	}
}

static inline void detach_timer(struct tti_timer_list *timer,
				int clear_pending)
{
	struct list_head *entry = &timer->entry;

    debug_deactivate(timer);

    __list_del(entry->prev, entry->next);
	if (clear_pending)
		entry->next = NULL;
	entry->prev = LIST_POISON2;
}

static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
{
	struct hrtimer_clock_base *base = timer->base;
	struct hrtimer_cpu_base *cpu_base = base->cpu_base;
	enum hrtimer_restart (*fn)(struct hrtimer *);
	int restart;

	WARN_ON(!irqs_disabled());

	debug_deactivate(timer);
	__remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
	timer_stats_account_hrtimer(timer);
	fn = timer->function;

	/*
	 * Because we run timers from hardirq context, there is no chance
	 * they get migrated to another cpu, therefore its safe to unlock
	 * the timer base.
	 */
	raw_spin_unlock(&cpu_base->lock);
	trace_hrtimer_expire_entry(timer, now);
#ifdef CONFIG_SEC_DEBUG
	secdbg_msg("hrtimer %pS entry", fn);
#endif
	restart = fn(timer);
#ifdef CONFIG_SEC_DEBUG
	secdbg_msg("hrtimer %pS exit", fn);
#endif
	trace_hrtimer_expire_exit(timer);
	raw_spin_lock(&cpu_base->lock);

	/*
	 * Note: We clear the CALLBACK bit after enqueue_hrtimer and
	 * we do not reprogramm the event hardware. Happens either in
	 * hrtimer_start_range_ns() or in hrtimer_interrupt()
	 *
	 * Note: Because we dropped the cpu_base->lock above,
	 * hrtimer_start_range_ns() can have popped in and enqueued the timer
	 * for us already.
	 */
	if (restart != HRTIMER_NORESTART &&
	    !(timer->state & HRTIMER_STATE_ENQUEUED))
		enqueue_hrtimer(timer, base);

	WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK));

	timer->state &= ~HRTIMER_STATE_CALLBACK;
}

static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
			  struct hrtimer_clock_base *base,
			  struct hrtimer *timer, ktime_t *now)
{
	enum hrtimer_restart (*fn)(struct hrtimer *);
	int restart;

	lockdep_assert_held(&cpu_base->lock);

	debug_deactivate(timer);
	cpu_base->running = timer;

	/*
	 * Separate the ->running assignment from the ->state assignment.
	 *
	 * As with a regular write barrier, this ensures the read side in
	 * hrtimer_active() cannot observe cpu_base->running == NULL &&
	 * timer->state == INACTIVE.
	 */
	raw_write_seqcount_barrier(&cpu_base->seq);

	__remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, 0);
	timer_stats_account_hrtimer(timer);
	fn = timer->function;

	/*
	 * Clear the 'is relative' flag for the TIME_LOW_RES case. If the
	 * timer is restarted with a period then it becomes an absolute
	 * timer. If its not restarted it does not matter.
	 */
	if (IS_ENABLED(CONFIG_TIME_LOW_RES))
		timer->is_rel = false;

	/*
	 * Because we run timers from hardirq context, there is no chance
	 * they get migrated to another cpu, therefore its safe to unlock
	 * the timer base.
	 */
	raw_spin_unlock(&cpu_base->lock);
	trace_hrtimer_expire_entry(timer, now);
	restart = fn(timer);
	trace_hrtimer_expire_exit(timer);
	raw_spin_lock(&cpu_base->lock);

	/*
	 * Note: We clear the running state after enqueue_hrtimer and
	 * we do not reprogramm the event hardware. Happens either in
	 * hrtimer_start_range_ns() or in hrtimer_interrupt()
	 *
	 * Note: Because we dropped the cpu_base->lock above,
	 * hrtimer_start_range_ns() can have popped in and enqueued the timer
	 * for us already.
	 */
	if (restart != HRTIMER_NORESTART &&
	    !(timer->state & HRTIMER_STATE_ENQUEUED))
		enqueue_hrtimer(timer, base);

	/*
	 * Separate the ->running assignment from the ->state assignment.
	 *
	 * As with a regular write barrier, this ensures the read side in
	 * hrtimer_active() cannot observe cpu_base->running == NULL &&
	 * timer->state == INACTIVE.
	 */
	raw_write_seqcount_barrier(&cpu_base->seq);

	WARN_ON_ONCE(cpu_base->running != timer);
	cpu_base->running = NULL;
}