/*
 * We're finished using the context for an address space.
 */
void destroy_context(struct mm_struct *mm)
{
	unsigned long flags;
	unsigned int id;

	if (mm->context.id == MMU_NO_CONTEXT)
		return;

	WARN_ON(mm->context.active != 0);

	raw_spin_lock_irqsave(&context_lock, flags);
	id = mm->context.id;
	if (id != MMU_NO_CONTEXT) {
		__clear_bit(id, context_map);
		mm->context.id = MMU_NO_CONTEXT;
#ifdef DEBUG_MAP_CONSISTENCY
		mm->context.active = 0;
#endif
		context_mm[id] = NULL;
		nr_free_contexts++;
	}
	raw_spin_unlock_irqrestore(&context_lock, flags);
}

/*
 * mt65xx_mon_enable: Enable hardware monitors.
 * Return 0.
 */
int mt65xx_mon_enable(void)
{
    unsigned long flags;
    p_pmu->reset();

    // enable & start ARM performance monitors
    p_pmu->enable();
    p_pmu->start();

    // reset and enable L2C event counters
    raw_spin_lock_irqsave(&l2x0_lock, flags); 
    __raw_writel(7, PL310_BASE + L2X0_EVENT_CNT_CTRL);
    dsb();
    raw_spin_unlock_irqrestore(&l2x0_lock, flags);

    // stopping EMI monitors will reset all counters
    BM_Enable(0);

    // start EMI monitor counting
    BM_Enable(1);
    
    return 0;
}

static void armv8pmu_disable_event(struct perf_event *event)
{
	unsigned long flags;
	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);

	/*
	 * Disable counter and interrupt
	 */
	raw_spin_lock_irqsave(&events->pmu_lock, flags);

	/*
	 * Disable counter
	 */
	armv8pmu_disable_event_counter(event);

	/*
	 * Disable interrupt for this counter
	 */
	armv8pmu_disable_event_irq(event);

	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}

/**
 * down_interruptible - acquire the semaphore unless interrupted
 * @sem: the semaphore to be acquired
 *
 * Attempts to acquire the semaphore.  If no more tasks are allowed to
 * acquire the semaphore, calling this function will put the task to sleep.
 * If the sleep is interrupted by a signal, this function will return -EINTR.
 * If the semaphore is successfully acquired, this function returns 0.
 */
int down_interruptible(struct semaphore *sem)
{
	unsigned long flags;
	int result = 0;

	raw_spin_lock_irqsave(&sem->lock, flags);
#ifdef CONFIG_ILOCKDEP
	ilockdep_acquire(&sem->idep_map, _RET_IP_, (void *)sem);
#endif
	if (likely(sem->count > 0))
		sem->count--;
	else
		result = __down_interruptible(sem);
#ifdef CONFIG_ILOCKDEP
	if (result)
		ilockdep_clear_locking(current);
	else
		ilockdep_acquired(&sem->idep_map, _RET_IP_, (void *)sem);
#endif
	raw_spin_unlock_irqrestore(&sem->lock, flags);

	return result;
}

/**
 *	irq_cpu_offline - Invoke all irq_cpu_offline functions.
 *
 *	Iterate through all irqs and invoke the chip.irq_cpu_offline()
 *	for each.
 */
void irq_cpu_offline(void)
{
	struct irq_desc *desc;
	struct irq_chip *chip;
	unsigned long flags;
	unsigned int irq;

	for_each_active_irq(irq) {
		desc = irq_to_desc(irq);
		if (!desc)
			continue;

		raw_spin_lock_irqsave(&desc->lock, flags);

		chip = irq_data_get_irq_chip(&desc->irq_data);
		if (chip && chip->irq_cpu_offline &&
		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
		     !irqd_irq_disabled(&desc->irq_data)))
			chip->irq_cpu_offline(&desc->irq_data);

		raw_spin_unlock_irqrestore(&desc->lock, flags);
	}
}

static cycle_t em_sti_set_next(struct em_sti_priv *p, cycle_t next)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&p->lock, flags);

	/* mask compare A interrupt */
	em_sti_write(p, STI_INTENCLR, 1);

	/* update compare A value */
	em_sti_write(p, STI_COMPA_H, next >> 32);
	em_sti_write(p, STI_COMPA_L, next & 0xffffffff);

	/* clear compare A interrupt source */
	em_sti_write(p, STI_INTFFCLR, 1);

	/* unmask compare A interrupt */
	em_sti_write(p, STI_INTENSET, 1);

	raw_spin_unlock_irqrestore(&p->lock, flags);

	return next;
}

static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
	unsigned long *mask, unsigned long *bits)
{
	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
	unsigned int i;
	const unsigned int gpio_reg_size = 8;
	unsigned int port;
	unsigned int out_port;
	unsigned int bitmask;
	unsigned long flags;

	/* set bits are evaluated a gpio register size at a time */
	for (i = 0; i < chip->ngpio; i += gpio_reg_size) {
		/* no more set bits in this mask word; skip to the next word */
		if (!mask[BIT_WORD(i)]) {
			i = (BIT_WORD(i) + 1) * BITS_PER_LONG - gpio_reg_size;
			continue;
		}

		port = i / gpio_reg_size;
		out_port = (port > 2) ? port + 1 : port;
		bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)];

		raw_spin_lock_irqsave(&dio48egpio->lock, flags);

		/* update output state data and set device gpio register */
		dio48egpio->out_state[port] &= ~mask[BIT_WORD(i)];
		dio48egpio->out_state[port] |= bitmask;
		outb(dio48egpio->out_state[port], dio48egpio->base + out_port);

		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);

		/* prepare for next gpio register set */
		mask[BIT_WORD(i)] >>= gpio_reg_size;
		bits[BIT_WORD(i)] >>= gpio_reg_size;
	}
}

static void mcip_ipi_clear(int irq)
{
	unsigned int cpu, c;
	unsigned long flags;
	unsigned int __maybe_unused copy;

	if (unlikely(irq == SOFTIRQ_IRQ)) {
		arc_softirq_clear(irq);
		return;
	}

	raw_spin_lock_irqsave(&mcip_lock, flags);

	/* Who sent the IPI */
	__mcip_cmd(CMD_INTRPT_CHECK_SOURCE, 0);

	copy = cpu = read_aux_reg(ARC_REG_MCIP_READBACK);	/* 1,2,4,8... */

	/*
	 * In rare case, multiple concurrent IPIs sent to same target can
	 * possibly be coalesced by MCIP into 1 asserted IRQ, so @cpus can be
	 * "vectored" (multiple bits sets) as opposed to typical single bit
	 */
	do {
		c = __ffs(cpu);			/* 0,1,2,3 */
		__mcip_cmd(CMD_INTRPT_GENERATE_ACK, c);
		cpu &= ~(1U << c);
	} while (cpu);

	raw_spin_unlock_irqrestore(&mcip_lock, flags);

#ifdef CONFIG_ARC_IPI_DBG
	if (c != __ffs(copy))
		pr_info("IPIs from %x coalesced to %x\n",
			copy, raw_smp_processor_id());
#endif
}

int show_interrupts(struct seq_file *p, void *v)
{
	int i = *(loff_t *) v, j;
	struct irqaction * action;
	unsigned long flags;

	if (i == 0) {
		seq_printf(p, "           ");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%d       ",j);
		seq_putc(p, '\n');
	}

	if (i < NR_IRQS) {
		raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
		action = irq_desc[i].action;
		if (!action)
			goto skip;
		seq_printf(p, "%3d: ",i);
#ifndef CONFIG_SMP
		seq_printf(p, "%10u ", kstat_irqs(i));
#else
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
#endif
		seq_printf(p, " %14s", irq_desc[i].chip->name);
		seq_printf(p, "  %s", action->name);

		for (action=action->next; action; action = action->next)
			seq_printf(p, ", %s", action->name);

		seq_putc(p, '\n');
skip:
		raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	}
	return 0;
}

static void dio48e_irq_mask(struct irq_data *data)
{
	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
	struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
	const unsigned long offset = irqd_to_hwirq(data);
	unsigned long flags;

	/* only bit 3 on each respective Port C supports interrupts */
	if (offset != 19 && offset != 43)
		return;

	raw_spin_lock_irqsave(&dio48egpio->lock, flags);

	if (offset == 19)
		dio48egpio->irq_mask &= ~BIT(0);
	else
		dio48egpio->irq_mask &= ~BIT(1);

	if (!dio48egpio->irq_mask)
		/* disable interrupts */
		inb(dio48egpio->base + 0xB);

	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
}

/*
 * cpudl_set - update the cpudl max-heap
 * @cp: the cpudl max-heap context
 * @cpu: the target cpu
 * @dl: the new earliest deadline for this cpu
 *
 * Notes: assumes cpu_rq(cpu)->lock is locked
 *
 * Returns: (void)
 */
void cpudl_set(struct cpudl *cp, int cpu, u64 dl)
{
	int old_idx;
	unsigned long flags;

	WARN_ON(!cpu_present(cpu));

	raw_spin_lock_irqsave(&cp->lock, flags);

	old_idx = cp->elements[cpu].idx;
	if (old_idx == IDX_INVALID) {
		int new_idx = cp->size++;
		cp->elements[new_idx].dl = dl;
		cp->elements[new_idx].cpu = cpu;
		cp->elements[cpu].idx = new_idx;
		cpudl_heapify_up(cp, new_idx);
		cpumask_clear_cpu(cpu, cp->free_cpus);
	} else {
		cp->elements[old_idx].dl = dl;
		cpudl_heapify(cp, old_idx);
	}

	raw_spin_unlock_irqrestore(&cp->lock, flags);
}

static void armv8pmu_enable_event(struct perf_event *event)
{
	unsigned long flags;
	struct hw_perf_event *hwc = &event->hw;
	struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
	struct pmu_hw_events *events = this_cpu_ptr(cpu_pmu->hw_events);
	int idx = hwc->idx;

	/*
	 * Enable counter and interrupt, and set the counter to count
	 * the event that we're interested in.
	 */
	raw_spin_lock_irqsave(&events->pmu_lock, flags);

	/*
	 * Disable counter
	 */
	armv8pmu_disable_counter(idx);

	/*
	 * Set event (if destined for PMNx counters).
	 */
	armv8pmu_write_evtype(idx, hwc->config_base);

	/*
	 * Enable interrupt for this counter
	 */
	armv8pmu_enable_intens(idx);

	/*
	 * Enable counter
	 */
	armv8pmu_enable_counter(idx);

	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}

void rq_attach_root(struct rq *rq, struct root_domain *rd)
{
	struct root_domain *old_rd = NULL;
	unsigned long flags;

	raw_spin_lock_irqsave(&rq->lock, flags);

	if (rq->rd) {
		old_rd = rq->rd;

		if (cpumask_test_cpu(rq->cpu, old_rd->online))
			set_rq_offline(rq);

		cpumask_clear_cpu(rq->cpu, old_rd->span);

		/*
		 * If we dont want to free the old_rd yet then
		 * set old_rd to NULL to skip the freeing later
		 * in this function:
		 */
		if (!atomic_dec_and_test(&old_rd->refcount))
			old_rd = NULL;
	}

	atomic_inc(&rd->refcount);
	rq->rd = rd;

	cpumask_set_cpu(rq->cpu, rd->span);
	if (cpumask_test_cpu(rq->cpu, cpu_active_mask))
		set_rq_online(rq);

	raw_spin_unlock_irqrestore(&rq->lock, flags);

	if (old_rd)
		call_rcu_sched(&old_rd->rcu, free_rootdomain);
}

/*
 * Check, if the new registered device should be used.
 */
static int tick_check_new_device(struct clock_event_device *newdev)
{
	struct clock_event_device *curdev;
	struct tick_device *td;
	int cpu, ret = NOTIFY_OK;
	unsigned long flags;

	raw_spin_lock_irqsave(&tick_device_lock, flags);

	cpu = smp_processor_id();
	if (!cpumask_test_cpu(cpu, newdev->cpumask))
		goto out_bc;

	td = &per_cpu(tick_cpu_device, cpu);
	curdev = td->evtdev;

	/* cpu local device ? */
	if (!cpumask_equal(newdev->cpumask, cpumask_of(cpu))) {

		/*
		 * If the cpu affinity of the device interrupt can not
		 * be set, ignore it.
		 */
		if (!irq_can_set_affinity(newdev->irq))
			goto out_bc;

		/*
		 * If we have a cpu local device already, do not replace it
		 * by a non cpu local device
		 */
		if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
			goto out_bc;
	}

	/*
	 * If we have an active device, then check the rating and the oneshot
	 * feature.
	 */
	if (curdev) {
		/*
		 * Prefer one shot capable devices !
		 */
		if ((curdev->features & CLOCK_EVT_FEAT_ONESHOT) &&
		    !(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
			goto out_bc;
		/*
		 * Check the rating
		 */
		if (curdev->rating >= newdev->rating)
			goto out_bc;
	}

	/*
	 * Replace the eventually existing device by the new
	 * device. If the current device is the broadcast device, do
	 * not give it back to the clockevents layer !
	 */
	if (tick_is_broadcast_device(curdev)) {
		clockevents_shutdown(curdev);
		curdev = NULL;
	}
	clockevents_exchange_device(curdev, newdev);
	tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
	if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
		tick_oneshot_notify();

	raw_spin_unlock_irqrestore(&tick_device_lock, flags);
	return NOTIFY_STOP;

out_bc:
	/*
	 * Can the new device be used as a broadcast device ?
	 */
	if (tick_check_broadcast_device(newdev))
		ret = NOTIFY_STOP;

	raw_spin_unlock_irqrestore(&tick_device_lock, flags);

	return ret;
}

/*
 * Counterpart to lock_hrtimer_base above:
 */
static inline
void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
{
	raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
}

void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
{
	raw_spin_unlock_irqrestore(&desc->lock, flags);
	if (bus)
		chip_bus_sync_unlock(desc);
}

/*
 * Task blocks on lock.
 *
 * Prepare waiter and propagate pi chain
 *
 * This must be called with lock->wait_lock held.
 */
static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
				   struct rt_mutex_waiter *waiter,
				   struct task_struct *task,
				   int detect_deadlock)
{
	struct task_struct *owner = rt_mutex_owner(lock);
	struct rt_mutex_waiter *top_waiter = waiter;
	unsigned long flags;
	int chain_walk = 0, res;

	raw_spin_lock_irqsave(&task->pi_lock, flags);
	__rt_mutex_adjust_prio(task);
	waiter->task = task;
	waiter->lock = lock;
	plist_node_init(&waiter->list_entry, task->prio);
	plist_node_init(&waiter->pi_list_entry, task->prio);

	/* Get the top priority waiter on the lock */
	if (rt_mutex_has_waiters(lock))
		top_waiter = rt_mutex_top_waiter(lock);
	plist_add(&waiter->list_entry, &lock->wait_list);

	task->pi_blocked_on = waiter;

	raw_spin_unlock_irqrestore(&task->pi_lock, flags);

	if (!owner)
		return 0;

	if (waiter == rt_mutex_top_waiter(lock)) {
		raw_spin_lock_irqsave(&owner->pi_lock, flags);
		plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
		plist_add(&waiter->pi_list_entry, &owner->pi_waiters);

		__rt_mutex_adjust_prio(owner);
		if (owner->pi_blocked_on)
			chain_walk = 1;
		raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
	}
	else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock))
		chain_walk = 1;

	if (!chain_walk)
		return 0;

	/*
	 * The owner can't disappear while holding a lock,
	 * so the owner struct is protected by wait_lock.
	 * Gets dropped in rt_mutex_adjust_prio_chain()!
	 */
	get_task_struct(owner);

	raw_spin_unlock(&lock->wait_lock);

	res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
					 task);

	raw_spin_lock(&lock->wait_lock);

	return res;
}

/*
 * Try to take an rt-mutex
 *
 * Must be called with lock->wait_lock held.
 *
 * @lock:   the lock to be acquired.
 * @task:   the task which wants to acquire the lock
 * @waiter: the waiter that is queued to the lock's wait list. (could be NULL)
 */
static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
		struct rt_mutex_waiter *waiter)
{
	/*
	 * We have to be careful here if the atomic speedups are
	 * enabled, such that, when
	 *  - no other waiter is on the lock
	 *  - the lock has been released since we did the cmpxchg
	 * the lock can be released or taken while we are doing the
	 * checks and marking the lock with RT_MUTEX_HAS_WAITERS.
	 *
	 * The atomic acquire/release aware variant of
	 * mark_rt_mutex_waiters uses a cmpxchg loop. After setting
	 * the WAITERS bit, the atomic release / acquire can not
	 * happen anymore and lock->wait_lock protects us from the
	 * non-atomic case.
	 *
	 * Note, that this might set lock->owner =
	 * RT_MUTEX_HAS_WAITERS in the case the lock is not contended
	 * any more. This is fixed up when we take the ownership.
	 * This is the transitional state explained at the top of this file.
	 */
	mark_rt_mutex_waiters(lock);

	if (rt_mutex_owner(lock))
		return 0;

	/*
	 * It will get the lock because of one of these conditions:
	 * 1) there is no waiter
	 * 2) higher priority than waiters
	 * 3) it is top waiter
	 */
	if (rt_mutex_has_waiters(lock)) {
		if (task->prio >= rt_mutex_top_waiter(lock)->list_entry.prio) {
			if (!waiter || waiter != rt_mutex_top_waiter(lock))
				return 0;
		}
	}

	if (waiter || rt_mutex_has_waiters(lock)) {
		unsigned long flags;
		struct rt_mutex_waiter *top;

		raw_spin_lock_irqsave(&task->pi_lock, flags);

		/* remove the queued waiter. */
		if (waiter) {
			plist_del(&waiter->list_entry, &lock->wait_list);
			task->pi_blocked_on = NULL;
		}

		/*
		 * We have to enqueue the top waiter(if it exists) into
		 * task->pi_waiters list.
		 */
		if (rt_mutex_has_waiters(lock)) {
			top = rt_mutex_top_waiter(lock);
			top->pi_list_entry.prio = top->list_entry.prio;
			plist_add(&top->pi_list_entry, &task->pi_waiters);
		}
		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
	}

	/* We got the lock. */
	debug_rt_mutex_lock(lock);

	rt_mutex_set_owner(lock, task);

	rt_mutex_deadlock_account_lock(lock, task);

	return 1;
}

/*
 * Adjust the priority chain. Also used for deadlock detection.
 * Decreases task's usage by one - may thus free the task.
 * Returns 0 or -EDEADLK.
 */
static int rt_mutex_adjust_prio_chain(struct task_struct *task,
				      int deadlock_detect,
				      struct rt_mutex *orig_lock,
				      struct rt_mutex_waiter *orig_waiter,
				      struct task_struct *top_task)
{
	struct rt_mutex *lock;
	struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter;
	int detect_deadlock, ret = 0, depth = 0;
	unsigned long flags;

	detect_deadlock = debug_rt_mutex_detect_deadlock(orig_waiter,
							 deadlock_detect);

	/*
	 * The (de)boosting is a step by step approach with a lot of
	 * pitfalls. We want this to be preemptible and we want hold a
	 * maximum of two locks per step. So we have to check
	 * carefully whether things change under us.
	 */
 again:
	if (++depth > max_lock_depth) {
		static int prev_max;

		/*
		 * Print this only once. If the admin changes the limit,
		 * print a new message when reaching the limit again.
		 */
		if (prev_max != max_lock_depth) {
			prev_max = max_lock_depth;
			printk(KERN_WARNING "Maximum lock depth %d reached "
			       "task: %s (%d)\n", max_lock_depth,
			       top_task->comm, task_pid_nr(top_task));
		}
		put_task_struct(task);

		return deadlock_detect ? -EDEADLK : 0;
	}
 retry:
	/*
	 * Task can not go away as we did a get_task() before !
	 */
	raw_spin_lock_irqsave(&task->pi_lock, flags);

	waiter = task->pi_blocked_on;
	/*
	 * Check whether the end of the boosting chain has been
	 * reached or the state of the chain has changed while we
	 * dropped the locks.
	 */
	if (!waiter)
		goto out_unlock_pi;

	/*
	 * Check the orig_waiter state. After we dropped the locks,
	 * the previous owner of the lock might have released the lock.
	 */
	if (orig_waiter && !rt_mutex_owner(orig_lock))
		goto out_unlock_pi;

	/*
	 * Drop out, when the task has no waiters. Note,
	 * top_waiter can be NULL, when we are in the deboosting
	 * mode!
	 */
	if (top_waiter && (!task_has_pi_waiters(task) ||
			   top_waiter != task_top_pi_waiter(task)))
		goto out_unlock_pi;

	/*
	 * When deadlock detection is off then we check, if further
	 * priority adjustment is necessary.
	 */
	if (!detect_deadlock && waiter->list_entry.prio == task->prio)
		goto out_unlock_pi;

	lock = waiter->lock;
	if (!raw_spin_trylock(&lock->wait_lock)) {
		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
		cpu_relax();
		goto retry;
	}

	/* Deadlock detection */
	if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
		debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
		raw_spin_unlock(&lock->wait_lock);
		ret = deadlock_detect ? -EDEADLK : 0;
		goto out_unlock_pi;
	}

	top_waiter = rt_mutex_top_waiter(lock);

	/* Requeue the waiter */
	plist_del(&waiter->list_entry, &lock->wait_list);
//.........这里部分代码省略.........

/**
 * tick_broadcast_control - Enable/disable or force broadcast mode
 * @mode:	The selected broadcast mode
 *
 * Called when the system enters a state where affected tick devices
 * might stop. Note: TICK_BROADCAST_FORCE cannot be undone.
 */
void tick_broadcast_control(enum tick_broadcast_mode mode)
{
	struct clock_event_device *bc, *dev;
	struct tick_device *td;
	int cpu, bc_stopped;
	unsigned long flags;

	/* Protects also the local clockevent device. */
	raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
	td = this_cpu_ptr(&tick_cpu_device);
	dev = td->evtdev;

	/*
	 * Is the device not affected by the powerstate ?
	 */
	if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP))
		goto out;

	if (!tick_device_is_functional(dev))
		goto out;

	cpu = smp_processor_id();
	bc = tick_broadcast_device.evtdev;
	bc_stopped = cpumask_empty(tick_broadcast_mask);

	switch (mode) {
	case TICK_BROADCAST_FORCE:
		tick_broadcast_forced = 1;
	case TICK_BROADCAST_ON:
		cpumask_set_cpu(cpu, tick_broadcast_on);
		if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_mask)) {
			/*
			 * Only shutdown the cpu local device, if:
			 *
			 * - the broadcast device exists
			 * - the broadcast device is not a hrtimer based one
			 * - the broadcast device is in periodic mode to
			 *   avoid a hickup during switch to oneshot mode
			 */
			if (bc && !(bc->features & CLOCK_EVT_FEAT_HRTIMER) &&
			    tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
				clockevents_shutdown(dev);
		}
		break;

	case TICK_BROADCAST_OFF:
		if (tick_broadcast_forced)
			break;
		cpumask_clear_cpu(cpu, tick_broadcast_on);
		if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_mask)) {
			if (tick_broadcast_device.mode ==
			    TICKDEV_MODE_PERIODIC)
				tick_setup_periodic(dev, 0);
		}
		break;
	}

	if (bc) {
		if (cpumask_empty(tick_broadcast_mask)) {
			if (!bc_stopped)
				clockevents_shutdown(bc);
		} else if (bc_stopped) {
			if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
				tick_broadcast_start_periodic(bc);
			else
				tick_broadcast_setup_oneshot(bc);
		}
	}
out:
	raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}