C++ raw_spin_unlock函数代码示例

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);
	restart = fn(timer);
	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()
	 */
	if (restart != HRTIMER_NORESTART) {
		BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
		enqueue_hrtimer(timer, base);
	}

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

	timer->state &= ~HRTIMER_STATE_CALLBACK;
}

/*
 * Retrigger next event is called after clock was set
 *
 * Called with interrupts disabled via on_each_cpu()
 */
static void retrigger_next_event(void *arg)
{
	struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
	struct timespec realtime_offset, xtim, wtm, sleep;

	if (!hrtimer_hres_active())
		return;

	/* Optimized out for !HIGH_RES */
	get_xtime_and_monotonic_and_sleep_offset(&xtim, &wtm, &sleep);
	set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec);

	/* Adjust CLOCK_REALTIME offset */
	raw_spin_lock(&base->lock);
	base->clock_base[HRTIMER_BASE_REALTIME].offset =
		timespec_to_ktime(realtime_offset);
	base->clock_base[HRTIMER_BASE_BOOTTIME].offset =
		timespec_to_ktime(sleep);

	hrtimer_force_reprogram(base, 0);
	raw_spin_unlock(&base->lock);
}

static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
	unsigned long timeout;

	/*
	 * set synchronisation state between this boot processor
	 * and the secondary one
	 */
	raw_spin_lock(&boot_lock);

	/*
	 * The secondary processor is waiting to be released from
	 * the holding pen - release it, then wait for it to flag
	 * that it has been released by resetting pen_release.
	 *
	 * Note that "pen_release" is the hardware CPU ID, whereas
	 * "cpu" is Linux's internal ID.
	 */
	pen_release = cpu;
	flush_cache_all();
	outer_flush_all();

	timeout = jiffies + (1 * HZ);
	while (time_before(jiffies, timeout)) {
		smp_rmb();
		if (pen_release == -1)
			break;

		udelay(10);
	}

	/*
	 * now the secondary core is starting up let it run its
	 * calibrations, then wait for it to finish
	 */
	raw_spin_unlock(&boot_lock);

	return pen_release != -1 ? -ENOSYS : 0;
}

/*
 * The current CPU has been marked offline.  Migrate IRQs off this CPU.
 * If the affinity settings do not allow other CPUs, force them onto any
 * available CPU.
 *
 * Note: we must iterate over all IRQs, whether they have an attached
 * action structure or not, as we need to get chained interrupts too.
 */
void migrate_irqs(void)
{
	unsigned int i;
	struct irq_desc *desc;
	unsigned long flags;

	local_irq_save(flags);

	for_each_irq_desc(i, desc) {
		bool affinity_broken = false;

		if (!desc)
			continue;

		raw_spin_lock(&desc->lock);
		affinity_broken = migrate_one_irq(desc);
		raw_spin_unlock(&desc->lock);

		if (affinity_broken && printk_ratelimit())
			pr_warning("IRQ%u no longer affine to CPU%u\n", i,
				smp_processor_id());
	}

void handle_level_irq(unsigned int irq, struct irq_desc *desc)
{
    raw_spin_lock(&desc->lock);
	mask_ack_irq(desc);

	if (irqd_irq_inprogress(&desc->irq_data))
		if (!irq_check_poll(desc))
			goto out_unlock;

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	/* kstat_incr_irqs_this_cpu(irq, desc); */

	if (!desc->action || irqd_irq_disabled(&desc->irq_data))
		goto out_unlock;

	handle_irq_event(desc);

	if (!irqd_irq_disabled(&desc->irq_data) && !(desc->istate & IRQS_ONESHOT))
		unmask_irq(desc);
out_unlock:
	raw_spin_unlock(&desc->lock);
}

/**
 *	handle_simple_irq - Simple and software-decoded IRQs.
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 *	Simple interrupts are either sent from a demultiplexing interrupt
 *	handler or come from hardware, where no interrupt hardware control
 *	is necessary.
 *
 *	Note: The caller is expected to handle the ack, clear, mask and
 *	unmask issues if necessary.
 */
void
handle_simple_irq(unsigned int irq, struct irq_desc *desc)
{
	raw_spin_lock(&desc->lock);

	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
		if (!irq_check_poll(desc))
			goto out_unlock;

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	kstat_incr_irqs_this_cpu(irq, desc);

	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
		desc->istate |= IRQS_PENDING;
		goto out_unlock;
	}

	handle_irq_event(desc);

out_unlock:
	raw_spin_unlock(&desc->lock);
}

static unsigned int steal_context_smp(unsigned int id)
{
	struct mm_struct *mm;
	unsigned int cpu, max, i;

	max = last_context - first_context;

	
	while (max--) {
		
		mm = context_mm[id];

		if (mm->context.active) {
			id++;
			if (id > last_context)
				id = first_context;
			continue;
		}
		pr_hardcont(" | steal %d from 0x%p", id, mm);

		
		mm->context.id = MMU_NO_CONTEXT;

		for_each_cpu(cpu, mm_cpumask(mm)) {
			for (i = cpu_first_thread_sibling(cpu);
			     i <= cpu_last_thread_sibling(cpu); i++)
				__set_bit(id, stale_map[i]);
			cpu = i - 1;
		}
		return id;
	}

	raw_spin_unlock(&context_lock);
	cpu_relax();
	raw_spin_lock(&context_lock);

	
	return MMU_NO_CONTEXT;
}

asmlinkage int vstlog(const char *fmt, va_list args)
{
	static char textbuf[RINGBUF_LINE_MAX];
	char *text = textbuf;
	size_t text_len;
	enum ringbuf_flags lflags = 0;
	unsigned long flags;
	int this_cpu;
	int printed_len = 0;
	bool stored = false;

	local_irq_save(flags);
	this_cpu = smp_processor_id();

	lockdep_off();
	raw_spin_lock(&ringbuf_lock);
	ringbuf_cpu = this_cpu;

	text_len = vscnprintf(text, sizeof(textbuf), fmt, args);


	/* mark and strip a trailing newline */
	if (text_len && text[text_len-1] == '\n') {
		text_len--;
		lflags |= RINGBUF_NEWLINE;
	}

	if (!stored)
		ringbuf_store(lflags,text, text_len, ringbuf_cpu, current);

	printed_len += text_len;

	raw_spin_unlock(&ringbuf_lock);
	local_irq_restore(flags);


	return printed_len;
}

/**
 * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
 * @lock:		 the rt_mutex to take
 * @state:		 the state the task should block in (TASK_INTERRUPTIBLE
 * 			 or TASK_UNINTERRUPTIBLE)
 * @timeout:		 the pre-initialized and started timer, or NULL for none
 * @waiter:		 the pre-initialized rt_mutex_waiter
 *
 * lock->wait_lock must be held by the caller.
 */
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
		    struct hrtimer_sleeper *timeout,
		    struct rt_mutex_waiter *waiter)
{
	int ret = 0;

	for (;;) {
		/* Try to acquire the lock: */
		if (try_to_take_rt_mutex(lock, current, waiter))
			break;

		/*
		 * TASK_INTERRUPTIBLE checks for signals and
		 * timeout. Ignored otherwise.
		 */
		if (unlikely(state == TASK_INTERRUPTIBLE)) {
			/* Signal pending? */
			if (signal_pending(current))
				ret = -EINTR;
			if (timeout && !timeout->task)
				ret = -ETIMEDOUT;
			if (ret)
				break;
		}

		raw_spin_unlock(&lock->wait_lock);

		debug_rt_mutex_print_deadlock(waiter);

		schedule_rt_mutex(lock);

		raw_spin_lock(&lock->wait_lock);
		set_current_state(state);
	}

	return ret;
}

/**
 * irq_migrate_all_off_this_cpu - Migrate irqs away from offline cpu
 *
 * The current CPU has been marked offline.  Migrate IRQs off this CPU.
 * If the affinity settings do not allow other CPUs, force them onto any
 * available CPU.
 *
 * Note: we must iterate over all IRQs, whether they have an attached
 * action structure or not, as we need to get chained interrupts too.
 */
void irq_migrate_all_off_this_cpu(void)
{
	unsigned int irq;
	struct irq_desc *desc;
	unsigned long flags;

	local_irq_save(flags);

	for_each_active_irq(irq) {
		bool affinity_broken;

		desc = irq_to_desc(irq);
		raw_spin_lock(&desc->lock);
		affinity_broken = migrate_one_irq(desc);
		raw_spin_unlock(&desc->lock);

		if (affinity_broken)
			pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
					    irq, smp_processor_id());
	}

	local_irq_restore(flags);
}

/**
 * rt_mutex_finish_proxy_lock() - Complete lock acquisition
 * @lock:		the rt_mutex we were woken on
 * @to:			the timeout, null if none. hrtimer should already have
 * 			been started.
 * @waiter:		the pre-initialized rt_mutex_waiter
 * @detect_deadlock:	perform deadlock detection (1) or not (0)
 *
 * Complete the lock acquisition started our behalf by another thread.
 *
 * Returns:
 *  0 - success
 * <0 - error, one of -EINTR, -ETIMEDOUT, or -EDEADLK
 *
 * Special API call for PI-futex requeue support
 */
int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
			       struct hrtimer_sleeper *to,
			       struct rt_mutex_waiter *waiter,
			       int detect_deadlock)
{
	int ret;

	raw_spin_lock(&lock->wait_lock);

	set_current_state(TASK_INTERRUPTIBLE);

	ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter,
				  detect_deadlock);

	set_current_state(TASK_RUNNING);

	if (unlikely(waiter->task))
		remove_waiter(lock, waiter);

	/*
	 * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
	 * have to fix that up.
	 */
	fixup_rt_mutex_waiters(lock);

	raw_spin_unlock(&lock->wait_lock);

	/*
	 * Readjust priority, when we did not get the lock. We might have been
	 * the pending owner and boosted. Since we did not take the lock, the
	 * PI boost has to go.
	 */
	if (unlikely(ret))
		rt_mutex_adjust_prio(current);

	return ret;
}

static int panic_flush(struct notifier_block *nb,
				   unsigned long l, void *buf)
{
	int i;

	raw_spin_lock(&panic_lock);
	pr_emerg("EMMD: ready to perform memory dump\n");

	for (i = 0; i < nr_cpu_ids; i++)
		coresight_dump_pcsr(i);

	set_emmd_indicator();
	ramtag_setup();

	kmsg_dump(KMSG_DUMP_PANIC);
	dump_task_info();

#ifdef CONFIG_PXA_RAMDUMP
	ramdump_panic();
#endif

#ifdef CONFIG_REGDUMP
	dump_reg_to_console();
#endif

	pr_emerg("EMMD: done\n");
	arm_machine_flush_console();

	flush_cache_all();
#ifdef CONFIG_ARM
	outer_flush_all();
#endif
	drain_mc_buffer();
	raw_spin_unlock(&panic_lock);

	return NOTIFY_DONE;
}

/**
 *	handle_edge_eoi_irq - edge eoi type IRQ handler
 *	@irq:	the interrupt number
 *	@desc:	the interrupt description structure for this irq
 *
 * Similar as the above handle_edge_irq, but using eoi and w/o the
 * mask/unmask logic.
 */
bool handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
{
	bool handled = false;
	struct irq_chip *chip = irq_desc_get_chip(desc);

	raw_spin_lock(&desc->lock);

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
	/*
	 * If we're currently running this IRQ, or its disabled,
	 * we shouldn't process the IRQ. Mark it pending, handle
	 * the necessary masking and go out
	 */
	if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
		     irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
		if (!irq_check_poll(desc)) {
			desc->istate |= IRQS_PENDING;
			goto out_eoi;
		}
	}
	kstat_incr_irqs_this_cpu(irq, desc);

	do {
		if (unlikely(!desc->action))
			goto out_eoi;

		handle_irq_event(desc);
		handled = true;

	} while ((desc->istate & IRQS_PENDING) &&
		 !irqd_irq_disabled(&desc->irq_data));

out_eoi:
	chip->irq_eoi(&desc->irq_data);
	raw_spin_unlock(&desc->lock);
	return handled;
}

/**
 *	handle_edge_eoi_irq - edge eoi type IRQ handler
 *	@desc:	the interrupt description structure for this irq
 *
 * Similar as the above handle_edge_irq, but using eoi and w/o the
 * mask/unmask logic.
 */
void handle_edge_eoi_irq(struct irq_desc *desc)
{
	struct irq_chip *chip = irq_desc_get_chip(desc);

	raw_spin_lock(&desc->lock);

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);

	if (!irq_may_run(desc)) {
		desc->istate |= IRQS_PENDING;
		goto out_eoi;
	}

	/*
	 * If its disabled or no action available then mask it and get
	 * out of here.
	 */
	if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
		desc->istate |= IRQS_PENDING;
		goto out_eoi;
	}

	kstat_incr_irqs_this_cpu(desc);

	do {
		if (unlikely(!desc->action))
			goto out_eoi;

		handle_irq_event(desc);

	} while ((desc->istate & IRQS_PENDING) &&
		 !irqd_irq_disabled(&desc->irq_data));

out_eoi:
	chip->irq_eoi(&desc->irq_data);
	raw_spin_unlock(&desc->lock);
}

static int allocate_gic_irq(struct irq_domain *domain, unsigned virq,
			    irq_hw_number_t hwirq)
{
	struct irq_fwspec fwspec;
	int i;
	int err;

	if (!irq_domain_get_of_node(domain->parent))
		return -EINVAL;

	raw_spin_lock(&cb->lock);
	for (i = cb->int_max - 1; i >= 0; i--) {
		if (cb->irq_map[i] == IRQ_FREE) {
			cb->irq_map[i] = hwirq;
			break;
		}
	}
	raw_spin_unlock(&cb->lock);

	if (i < 0)
		return -ENODEV;

	fwspec.fwnode = domain->parent->fwnode;
	fwspec.param_count = 3;
	fwspec.param[0] = 0;	/* SPI */
	fwspec.param[1] = i;
	fwspec.param[2] = IRQ_TYPE_LEVEL_HIGH;

	err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
	if (err)
		cb->irq_map[i] = IRQ_FREE;
	else
		cb->write(i, hwirq);

	return err;
}