/*
   * linux/kernel/irq/chip.c
   *
   * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   *
   * This file contains the core interrupt handling code, for irq-chip
   * based architectures.
   *

   * Detailed information is available in Documentation/core-api/genericirq.rst

   */
  
  #include <linux/irq.h>

  #include <linux/msi.h>

  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/kernel_stat.h>

  #include <linux/irqdomain.h>

  #include <trace/events/irq.h>

  #include "internals.h"

  static irqreturn_t bad_chained_irq(int irq, void *dev_id)
  {
  	WARN_ONCE(1, "Chained irq %d should not call an action
  ", irq);
  	return IRQ_NONE;
  }
  
  /*
   * Chained handlers should never call action on their IRQ. This default
   * action will emit warning if such thing happens.
   */
  struct irqaction chained_action = {
  	.handler = bad_chained_irq,
  };

  /**

   *	irq_set_chip - set the irq chip for an irq

   *	@irq:	irq number
   *	@chip:	pointer to irq chip description structure
   */

  int irq_set_chip(unsigned int irq, struct irq_chip *chip)

  {

  	unsigned long flags;

  	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);

  	if (!desc)

  		return -EINVAL;

  
  	if (!chip)
  		chip = &no_irq_chip;

  	desc->irq_data.chip = chip;

  	irq_put_desc_unlock(desc, flags);

  	/*
  	 * For !CONFIG_SPARSE_IRQ make the irq show up in

  	 * allocated_irqs.

  	 */

  	irq_mark_irq(irq);

  	return 0;
  }

  EXPORT_SYMBOL(irq_set_chip);

  
  /**

   *	irq_set_type - set the irq trigger type for an irq

   *	@irq:	irq number

   *	@type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h

   */

  int irq_set_irq_type(unsigned int irq, unsigned int type)

  {

  	unsigned long flags;

  	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);

  	int ret = 0;

  	if (!desc)
  		return -EINVAL;

  	ret = __irq_set_trigger(desc, type);

  	irq_put_desc_busunlock(desc, flags);

  	return ret;
  }

  EXPORT_SYMBOL(irq_set_irq_type);

  
  /**

   *	irq_set_handler_data - set irq handler data for an irq

   *	@irq:	Interrupt number
   *	@data:	Pointer to interrupt specific data
   *
   *	Set the hardware irq controller data for an irq
   */

  int irq_set_handler_data(unsigned int irq, void *data)

  {

  	unsigned long flags;

  	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);

  	if (!desc)

  		return -EINVAL;

  	desc->irq_common_data.handler_data = data;

  	irq_put_desc_unlock(desc, flags);

  	return 0;
  }

  EXPORT_SYMBOL(irq_set_handler_data);

  
  /**

   *	irq_set_msi_desc_off - set MSI descriptor data for an irq at offset
   *	@irq_base:	Interrupt number base
   *	@irq_offset:	Interrupt number offset
   *	@entry:		Pointer to MSI descriptor data

   *

   *	Set the MSI descriptor entry for an irq at offset

   */

  int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset,
  			 struct msi_desc *entry)

  {

  	unsigned long flags;

  	struct irq_desc *desc = irq_get_desc_lock(irq_base + irq_offset, &flags, IRQ_GET_DESC_CHECK_GLOBAL);

  	if (!desc)

  		return -EINVAL;

  	desc->irq_common_data.msi_desc = entry;

  	if (entry && !irq_offset)
  		entry->irq = irq_base;

  	irq_put_desc_unlock(desc, flags);

  	return 0;
  }
  
  /**

   *	irq_set_msi_desc - set MSI descriptor data for an irq
   *	@irq:	Interrupt number
   *	@entry:	Pointer to MSI descriptor data
   *
   *	Set the MSI descriptor entry for an irq
   */
  int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
  {
  	return irq_set_msi_desc_off(irq, 0, entry);
  }
  
  /**

   *	irq_set_chip_data - set irq chip data for an irq

   *	@irq:	Interrupt number
   *	@data:	Pointer to chip specific data
   *
   *	Set the hardware irq chip data for an irq
   */

  int irq_set_chip_data(unsigned int irq, void *data)

  {

  	unsigned long flags;

  	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);

  	if (!desc)

  		return -EINVAL;

  	desc->irq_data.chip_data = data;

  	irq_put_desc_unlock(desc, flags);

  	return 0;
  }

  EXPORT_SYMBOL(irq_set_chip_data);

  struct irq_data *irq_get_irq_data(unsigned int irq)
  {
  	struct irq_desc *desc = irq_to_desc(irq);
  
  	return desc ? &desc->irq_data : NULL;
  }
  EXPORT_SYMBOL_GPL(irq_get_irq_data);

  static void irq_state_clr_disabled(struct irq_desc *desc)
  {

  	irqd_clear(&desc->irq_data, IRQD_IRQ_DISABLED);

  }

  static void irq_state_clr_masked(struct irq_desc *desc)
  {

  	irqd_clear(&desc->irq_data, IRQD_IRQ_MASKED);

  }

  static void irq_state_clr_started(struct irq_desc *desc)
  {
  	irqd_clear(&desc->irq_data, IRQD_IRQ_STARTED);
  }
  
  static void irq_state_set_started(struct irq_desc *desc)
  {
  	irqd_set(&desc->irq_data, IRQD_IRQ_STARTED);
  }

  enum {
  	IRQ_STARTUP_NORMAL,
  	IRQ_STARTUP_MANAGED,
  	IRQ_STARTUP_ABORT,
  };
  
  #ifdef CONFIG_SMP
  static int
  __irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
  {
  	struct irq_data *d = irq_desc_get_irq_data(desc);
  
  	if (!irqd_affinity_is_managed(d))
  		return IRQ_STARTUP_NORMAL;
  
  	irqd_clr_managed_shutdown(d);

  	if (cpumask_any_and(aff, cpu_online_mask) >= nr_cpu_ids) {

  		/*
  		 * Catch code which fiddles with enable_irq() on a managed
  		 * and potentially shutdown IRQ. Chained interrupt
  		 * installment or irq auto probing should not happen on
  		 * managed irqs either. Emit a warning, break the affinity
  		 * and start it up as a normal interrupt.
  		 */
  		if (WARN_ON_ONCE(force))
  			return IRQ_STARTUP_NORMAL;
  		/*
  		 * The interrupt was requested, but there is no online CPU
  		 * in it's affinity mask. Put it into managed shutdown
  		 * state and let the cpu hotplug mechanism start it up once
  		 * a CPU in the mask becomes available.
  		 */
  		irqd_set_managed_shutdown(d);
  		return IRQ_STARTUP_ABORT;
  	}
  	return IRQ_STARTUP_MANAGED;
  }
  #else

  static __always_inline int

  __irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force)
  {
  	return IRQ_STARTUP_NORMAL;
  }
  #endif

  static int __irq_startup(struct irq_desc *desc)
  {
  	struct irq_data *d = irq_desc_get_irq_data(desc);
  	int ret = 0;
  
  	irq_domain_activate_irq(d);
  	if (d->chip->irq_startup) {
  		ret = d->chip->irq_startup(d);
  		irq_state_clr_disabled(desc);
  		irq_state_clr_masked(desc);
  	} else {
  		irq_enable(desc);
  	}
  	irq_state_set_started(desc);
  	return ret;
  }

  int irq_startup(struct irq_desc *desc, bool resend, bool force)

  {

  	struct irq_data *d = irq_desc_get_irq_data(desc);
  	struct cpumask *aff = irq_data_get_affinity_mask(d);

  	int ret = 0;

  	desc->depth = 0;

  	if (irqd_is_started(d)) {

  		irq_enable(desc);

  	} else {

  		switch (__irq_startup_managed(desc, aff, force)) {
  		case IRQ_STARTUP_NORMAL:
  			ret = __irq_startup(desc);
  			irq_setup_affinity(desc);
  			break;
  		case IRQ_STARTUP_MANAGED:

  			irq_do_set_affinity(d, aff, false);

  			ret = __irq_startup(desc);

  			break;
  		case IRQ_STARTUP_ABORT:
  			return 0;
  		}

  	}

  	if (resend)

  		check_irq_resend(desc);

  	return ret;

  }

  static void __irq_disable(struct irq_desc *desc, bool mask);

  void irq_shutdown(struct irq_desc *desc)
  {

  	if (irqd_is_started(&desc->irq_data)) {
  		desc->depth = 1;
  		if (desc->irq_data.chip->irq_shutdown) {
  			desc->irq_data.chip->irq_shutdown(&desc->irq_data);
  			irq_state_set_disabled(desc);
  			irq_state_set_masked(desc);
  		} else {
  			__irq_disable(desc, true);
  		}
  		irq_state_clr_started(desc);
  	}
  	/*
  	 * This must be called even if the interrupt was never started up,
  	 * because the activation can happen before the interrupt is
  	 * available for request/startup. It has it's own state tracking so
  	 * it's safe to call it unconditionally.
  	 */

  	irq_domain_deactivate_irq(&desc->irq_data);

  }

  void irq_enable(struct irq_desc *desc)
  {

  	if (!irqd_irq_disabled(&desc->irq_data)) {
  		unmask_irq(desc);
  	} else {
  		irq_state_clr_disabled(desc);
  		if (desc->irq_data.chip->irq_enable) {
  			desc->irq_data.chip->irq_enable(&desc->irq_data);
  			irq_state_clr_masked(desc);
  		} else {
  			unmask_irq(desc);
  		}
  	}

  }

  static void __irq_disable(struct irq_desc *desc, bool mask)
  {

  	if (irqd_irq_disabled(&desc->irq_data)) {
  		if (mask)
  			mask_irq(desc);
  	} else {
  		irq_state_set_disabled(desc);
  		if (desc->irq_data.chip->irq_disable) {
  			desc->irq_data.chip->irq_disable(&desc->irq_data);
  			irq_state_set_masked(desc);
  		} else if (mask) {
  			mask_irq(desc);
  		}

  	}
  }

  /**

   * irq_disable - Mark interrupt disabled

   * @desc:	irq descriptor which should be disabled
   *
   * If the chip does not implement the irq_disable callback, we
   * use a lazy disable approach. That means we mark the interrupt
   * disabled, but leave the hardware unmasked. That's an
   * optimization because we avoid the hardware access for the
   * common case where no interrupt happens after we marked it
   * disabled. If an interrupt happens, then the interrupt flow
   * handler masks the line at the hardware level and marks it
   * pending.

   *
   * If the interrupt chip does not implement the irq_disable callback,
   * a driver can disable the lazy approach for a particular irq line by
   * calling 'irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY)'. This can
   * be used for devices which cannot disable the interrupt at the
   * device level under certain circumstances and have to use
   * disable_irq[_nosync] instead.

   */

  void irq_disable(struct irq_desc *desc)

  {

  	__irq_disable(desc, irq_settings_disable_unlazy(desc));

  }

  void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu)
  {
  	if (desc->irq_data.chip->irq_enable)
  		desc->irq_data.chip->irq_enable(&desc->irq_data);
  	else
  		desc->irq_data.chip->irq_unmask(&desc->irq_data);
  	cpumask_set_cpu(cpu, desc->percpu_enabled);
  }
  
  void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu)
  {
  	if (desc->irq_data.chip->irq_disable)
  		desc->irq_data.chip->irq_disable(&desc->irq_data);
  	else
  		desc->irq_data.chip->irq_mask(&desc->irq_data);
  	cpumask_clear_cpu(cpu, desc->percpu_enabled);
  }

  static inline void mask_ack_irq(struct irq_desc *desc)

  {

  	if (desc->irq_data.chip->irq_mask_ack) {

  		desc->irq_data.chip->irq_mask_ack(&desc->irq_data);

  		irq_state_set_masked(desc);
  	} else {
  		mask_irq(desc);

  		if (desc->irq_data.chip->irq_ack)
  			desc->irq_data.chip->irq_ack(&desc->irq_data);

  	}

  }

  void mask_irq(struct irq_desc *desc)

  {

  	if (irqd_irq_masked(&desc->irq_data))
  		return;

  	if (desc->irq_data.chip->irq_mask) {
  		desc->irq_data.chip->irq_mask(&desc->irq_data);

  		irq_state_set_masked(desc);

  	}
  }

  void unmask_irq(struct irq_desc *desc)

  {

  	if (!irqd_irq_masked(&desc->irq_data))
  		return;

  	if (desc->irq_data.chip->irq_unmask) {
  		desc->irq_data.chip->irq_unmask(&desc->irq_data);

  		irq_state_clr_masked(desc);

  	}

  }

  void unmask_threaded_irq(struct irq_desc *desc)
  {
  	struct irq_chip *chip = desc->irq_data.chip;
  
  	if (chip->flags & IRQCHIP_EOI_THREADED)
  		chip->irq_eoi(&desc->irq_data);

  	unmask_irq(desc);

  }

  /*
   *	handle_nested_irq - Handle a nested irq from a irq thread
   *	@irq:	the interrupt number
   *
   *	Handle interrupts which are nested into a threaded interrupt
   *	handler. The handler function is called inside the calling
   *	threads context.
   */
  void handle_nested_irq(unsigned int irq)
  {
  	struct irq_desc *desc = irq_to_desc(irq);
  	struct irqaction *action;
  	irqreturn_t action_ret;
  
  	might_sleep();

  	raw_spin_lock_irq(&desc->lock);

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

  
  	action = desc->action;

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

  		goto out_unlock;

  	}

  	kstat_incr_irqs_this_cpu(desc);

  	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);

  	raw_spin_unlock_irq(&desc->lock);

  	action_ret = IRQ_NONE;
  	for_each_action_of_desc(desc, action)
  		action_ret |= action->thread_fn(action->irq, action->dev_id);

  	if (!noirqdebug)

  		note_interrupt(desc, action_ret);

  	raw_spin_lock_irq(&desc->lock);

  	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);

  
  out_unlock:

  	raw_spin_unlock_irq(&desc->lock);

  }
  EXPORT_SYMBOL_GPL(handle_nested_irq);

  static bool irq_check_poll(struct irq_desc *desc)
  {

  	if (!(desc->istate & IRQS_POLL_INPROGRESS))

  		return false;
  	return irq_wait_for_poll(desc);
  }

  static bool irq_may_run(struct irq_desc *desc)
  {

  	unsigned int mask = IRQD_IRQ_INPROGRESS | IRQD_WAKEUP_ARMED;
  
  	/*
  	 * If the interrupt is not in progress and is not an armed
  	 * wakeup interrupt, proceed.
  	 */
  	if (!irqd_has_set(&desc->irq_data, mask))

  		return true;

  
  	/*
  	 * If the interrupt is an armed wakeup source, mark it pending
  	 * and suspended, disable it and notify the pm core about the
  	 * event.
  	 */
  	if (irq_pm_check_wakeup(desc))
  		return false;
  
  	/*
  	 * Handle a potential concurrent poll on a different core.
  	 */

  	return irq_check_poll(desc);
  }

  /**
   *	handle_simple_irq - Simple and software-decoded IRQs.

   *	@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(struct irq_desc *desc)

  {

  	raw_spin_lock(&desc->lock);

  	if (!irq_may_run(desc))
  		goto out_unlock;

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

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

  		goto out_unlock;

  	}

  	kstat_incr_irqs_this_cpu(desc);

  	handle_irq_event(desc);

  out_unlock:

  	raw_spin_unlock(&desc->lock);

  }

  EXPORT_SYMBOL_GPL(handle_simple_irq);

  /**
   *	handle_untracked_irq - Simple and software-decoded IRQs.
   *	@desc:	the interrupt description structure for this irq
   *
   *	Untracked interrupts are sent from a demultiplexing interrupt
   *	handler when the demultiplexer does not know which device it its
   *	multiplexed irq domain generated the interrupt. IRQ's handled
   *	through here are not subjected to stats tracking, randomness, or
   *	spurious interrupt detection.
   *
   *	Note: Like handle_simple_irq, the caller is expected to handle
   *	the ack, clear, mask and unmask issues if necessary.
   */
  void handle_untracked_irq(struct irq_desc *desc)
  {
  	unsigned int flags = 0;
  
  	raw_spin_lock(&desc->lock);
  
  	if (!irq_may_run(desc))
  		goto out_unlock;
  
  	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
  
  	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
  		desc->istate |= IRQS_PENDING;
  		goto out_unlock;
  	}
  
  	desc->istate &= ~IRQS_PENDING;
  	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
  	raw_spin_unlock(&desc->lock);
  
  	__handle_irq_event_percpu(desc, &flags);
  
  	raw_spin_lock(&desc->lock);
  	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
  
  out_unlock:
  	raw_spin_unlock(&desc->lock);
  }
  EXPORT_SYMBOL_GPL(handle_untracked_irq);

  /*
   * Called unconditionally from handle_level_irq() and only for oneshot
   * interrupts from handle_fasteoi_irq()
   */
  static void cond_unmask_irq(struct irq_desc *desc)
  {
  	/*
  	 * We need to unmask in the following cases:
  	 * - Standard level irq (IRQF_ONESHOT is not set)
  	 * - Oneshot irq which did not wake the thread (caused by a
  	 *   spurious interrupt or a primary handler handling it
  	 *   completely).
  	 */
  	if (!irqd_irq_disabled(&desc->irq_data) &&
  	    irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot)
  		unmask_irq(desc);
  }

  /**
   *	handle_level_irq - Level type irq handler

   *	@desc:	the interrupt description structure for this irq

   *
   *	Level type interrupts are active as long as the hardware line has
   *	the active level. This may require to mask the interrupt and unmask
   *	it after the associated handler has acknowledged the device, so the
   *	interrupt line is back to inactive.
   */

  void handle_level_irq(struct irq_desc *desc)

  {

  	raw_spin_lock(&desc->lock);

  	mask_ack_irq(desc);

  	if (!irq_may_run(desc))
  		goto out_unlock;

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

  
  	/*
  	 * If its disabled or no action available
  	 * keep it masked and get out of here
  	 */

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

  		goto out_unlock;

  	}

  	kstat_incr_irqs_this_cpu(desc);

  	handle_irq_event(desc);

  	cond_unmask_irq(desc);

  out_unlock:

  	raw_spin_unlock(&desc->lock);

  }

  EXPORT_SYMBOL_GPL(handle_level_irq);

  #ifdef CONFIG_IRQ_PREFLOW_FASTEOI
  static inline void preflow_handler(struct irq_desc *desc)
  {
  	if (desc->preflow_handler)
  		desc->preflow_handler(&desc->irq_data);
  }
  #else
  static inline void preflow_handler(struct irq_desc *desc) { }
  #endif

  static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
  {
  	if (!(desc->istate & IRQS_ONESHOT)) {
  		chip->irq_eoi(&desc->irq_data);
  		return;
  	}
  	/*
  	 * We need to unmask in the following cases:
  	 * - Oneshot irq which did not wake the thread (caused by a
  	 *   spurious interrupt or a primary handler handling it
  	 *   completely).
  	 */
  	if (!irqd_irq_disabled(&desc->irq_data) &&
  	    irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {
  		chip->irq_eoi(&desc->irq_data);
  		unmask_irq(desc);
  	} else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {
  		chip->irq_eoi(&desc->irq_data);
  	}
  }

  /**

   *	handle_fasteoi_irq - irq handler for transparent controllers

   *	@desc:	the interrupt description structure for this irq

   *

   *	Only a single callback will be issued to the chip: an ->eoi()

   *	call when the interrupt has been serviced. This enables support
   *	for modern forms of interrupt handlers, which handle the flow
   *	details in hardware, transparently.
   */

  void handle_fasteoi_irq(struct irq_desc *desc)

  {

  	struct irq_chip *chip = desc->irq_data.chip;

  	raw_spin_lock(&desc->lock);

  	if (!irq_may_run(desc))
  		goto out;

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

  
  	/*
  	 * If its disabled or no action available

  	 * then mask it and get out of here:

  	 */

  	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {

  		desc->istate |= IRQS_PENDING;

  		mask_irq(desc);

  		goto out;

  	}

  	kstat_incr_irqs_this_cpu(desc);

  	if (desc->istate & IRQS_ONESHOT)
  		mask_irq(desc);

  	preflow_handler(desc);

  	handle_irq_event(desc);

  	cond_unmask_eoi_irq(desc, chip);

  	raw_spin_unlock(&desc->lock);

  	return;
  out:

  	if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
  		chip->irq_eoi(&desc->irq_data);
  	raw_spin_unlock(&desc->lock);

  }

  EXPORT_SYMBOL_GPL(handle_fasteoi_irq);

  
  /**
   *	handle_edge_irq - edge type IRQ handler

   *	@desc:	the interrupt description structure for this irq

   *
   *	Interrupt occures on the falling and/or rising edge of a hardware

   *	signal. The occurrence is latched into the irq controller hardware

   *	and must be acked in order to be reenabled. After the ack another
   *	interrupt can happen on the same source even before the first one

   *	is handled by the associated event handler. If this happens it

   *	might be necessary to disable (mask) the interrupt depending on the
   *	controller hardware. This requires to reenable the interrupt inside
   *	of the loop which handles the interrupts which have arrived while
   *	the handler was running. If all pending interrupts are handled, the
   *	loop is left.
   */

  void handle_edge_irq(struct irq_desc *desc)

  {

  	raw_spin_lock(&desc->lock);

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

  	if (!irq_may_run(desc)) {
  		desc->istate |= IRQS_PENDING;
  		mask_ack_irq(desc);
  		goto out_unlock;

  	}

  	/*

  	 * 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;
  		mask_ack_irq(desc);
  		goto out_unlock;

  	}

  	kstat_incr_irqs_this_cpu(desc);

  
  	/* Start handling the irq */

  	desc->irq_data.chip->irq_ack(&desc->irq_data);

  	do {

  		if (unlikely(!desc->action)) {

  			mask_irq(desc);

  			goto out_unlock;
  		}
  
  		/*
  		 * When another irq arrived while we were handling
  		 * one, we could have masked the irq.
  		 * Renable it, if it was not disabled in meantime.
  		 */

  		if (unlikely(desc->istate & IRQS_PENDING)) {

  			if (!irqd_irq_disabled(&desc->irq_data) &&
  			    irqd_irq_masked(&desc->irq_data))

  				unmask_irq(desc);

  		}

  		handle_irq_event(desc);

  	} while ((desc->istate & IRQS_PENDING) &&

  		 !irqd_irq_disabled(&desc->irq_data));

  out_unlock:

  	raw_spin_unlock(&desc->lock);

  }

  EXPORT_SYMBOL(handle_edge_irq);

  #ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
  /**
   *	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);
  }
  #endif

  /**

   *	handle_percpu_irq - Per CPU local irq handler

   *	@desc:	the interrupt description structure for this irq

   *
   *	Per CPU interrupts on SMP machines without locking requirements
   */

  void handle_percpu_irq(struct irq_desc *desc)

  {

  	struct irq_chip *chip = irq_desc_get_chip(desc);

  	kstat_incr_irqs_this_cpu(desc);

  	if (chip->irq_ack)
  		chip->irq_ack(&desc->irq_data);

  	handle_irq_event_percpu(desc);

  	if (chip->irq_eoi)
  		chip->irq_eoi(&desc->irq_data);

  }

  /**
   * handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids

   * @desc:	the interrupt description structure for this irq
   *
   * Per CPU interrupts on SMP machines without locking requirements. Same as
   * handle_percpu_irq() above but with the following extras:
   *
   * action->percpu_dev_id is a pointer to percpu variables which
   * contain the real device id for the cpu on which this handler is
   * called
   */

  void handle_percpu_devid_irq(struct irq_desc *desc)

  {
  	struct irq_chip *chip = irq_desc_get_chip(desc);
  	struct irqaction *action = desc->action;

  	unsigned int irq = irq_desc_get_irq(desc);

  	irqreturn_t res;

  	kstat_incr_irqs_this_cpu(desc);

  
  	if (chip->irq_ack)
  		chip->irq_ack(&desc->irq_data);

  	if (likely(action)) {
  		trace_irq_handler_entry(irq, action);
  		res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
  		trace_irq_handler_exit(irq, action, res);
  	} else {
  		unsigned int cpu = smp_processor_id();
  		bool enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
  
  		if (enabled)
  			irq_percpu_disable(desc, cpu);
  
  		pr_err_once("Spurious%s percpu IRQ%u on CPU%u
  ",
  			    enabled ? " and unmasked" : "", irq, cpu);
  	}

  
  	if (chip->irq_eoi)
  		chip->irq_eoi(&desc->irq_data);
  }

  static void

  __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
  		     int is_chained, const char *name)

  {

  	if (!handle) {

  		handle = handle_bad_irq;

  	} else {

  		struct irq_data *irq_data = &desc->irq_data;
  #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
  		/*
  		 * With hierarchical domains we might run into a
  		 * situation where the outermost chip is not yet set
  		 * up, but the inner chips are there.  Instead of
  		 * bailing we install the handler, but obviously we
  		 * cannot enable/startup the interrupt at this point.
  		 */
  		while (irq_data) {
  			if (irq_data->chip != &no_irq_chip)
  				break;
  			/*
  			 * Bail out if the outer chip is not set up
  			 * and the interrrupt supposed to be started
  			 * right away.
  			 */
  			if (WARN_ON(is_chained))

  				return;

  			/* Try the parent */
  			irq_data = irq_data->parent_data;
  		}
  #endif
  		if (WARN_ON(!irq_data || irq_data->chip == &no_irq_chip))

  			return;

  	}

  	/* Uninstall? */
  	if (handle == handle_bad_irq) {

  		if (desc->irq_data.chip != &no_irq_chip)

  			mask_ack_irq(desc);

  		irq_state_set_disabled(desc);

  		if (is_chained)
  			desc->action = NULL;

  		desc->depth = 1;
  	}
  	desc->handle_irq = handle;

  	desc->name = name;

  
  	if (handle != handle_bad_irq && is_chained) {

  		unsigned int type = irqd_get_trigger_type(&desc->irq_data);

  		/*
  		 * We're about to start this interrupt immediately,
  		 * hence the need to set the trigger configuration.
  		 * But the .set_type callback may have overridden the
  		 * flow handler, ignoring that we're dealing with a
  		 * chained interrupt. Reset it immediately because we
  		 * do know better.
  		 */

  		if (type != IRQ_TYPE_NONE) {
  			__irq_set_trigger(desc, type);
  			desc->handle_irq = handle;
  		}

  		irq_settings_set_noprobe(desc);
  		irq_settings_set_norequest(desc);

  		irq_settings_set_nothread(desc);

  		desc->action = &chained_action;

  		irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);

  	}

  }
  
  void
  __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
  		  const char *name)
  {
  	unsigned long flags;
  	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
  
  	if (!desc)
  		return;
  
  	__irq_do_set_handler(desc, handle, is_chained, name);

  	irq_put_desc_busunlock(desc, flags);

  }

  EXPORT_SYMBOL_GPL(__irq_set_handler);

  
  void

  irq_set_chained_handler_and_data(unsigned int irq, irq_flow_handler_t handle,
  				 void *data)
  {
  	unsigned long flags;
  	struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
  
  	if (!desc)
  		return;

  	desc->irq_common_data.handler_data = data;

  	__irq_do_set_handler(desc, handle, 1, NULL);

  
  	irq_put_desc_busunlock(desc, flags);
  }
  EXPORT_SYMBOL_GPL(irq_set_chained_handler_and_data);
  
  void

  irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,

  			      irq_flow_handler_t handle, const char *name)

  {

  	irq_set_chip(irq, chip);

  	__irq_set_handler(irq, handle, 0, name);

  }

  EXPORT_SYMBOL_GPL(irq_set_chip_and_handler_name);

  void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)

  {

  	unsigned long flags, trigger, tmp;

  	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);

  	if (!desc)

  		return;

  
  	/*
  	 * Warn when a driver sets the no autoenable flag on an already
  	 * active interrupt.
  	 */
  	WARN_ON_ONCE(!desc->depth && (set & _IRQ_NOAUTOEN));

  	irq_settings_clr_and_set(desc, clr, set);

  	trigger = irqd_get_trigger_type(&desc->irq_data);

  	irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |

  		   IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);

  	if (irq_settings_has_no_balance_set(desc))
  		irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
  	if (irq_settings_is_per_cpu(desc))
  		irqd_set(&desc->irq_data, IRQD_PER_CPU);

  	if (irq_settings_can_move_pcntxt(desc))
  		irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);

  	if (irq_settings_is_level(desc))
  		irqd_set(&desc->irq_data, IRQD_LEVEL);

  	tmp = irq_settings_get_trigger_mask(desc);
  	if (tmp != IRQ_TYPE_NONE)
  		trigger = tmp;
  
  	irqd_set(&desc->irq_data, trigger);

  	irq_put_desc_unlock(desc, flags);

  }

  EXPORT_SYMBOL_GPL(irq_modify_status);

  
  /**
   *	irq_cpu_online - Invoke all irq_cpu_online functions.
   *
   *	Iterate through all irqs and invoke the chip.irq_cpu_online()
   *	for each.
   */
  void irq_cpu_online(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_online &&
  		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||

  		     !irqd_irq_disabled(&desc->irq_data)))

  			chip->irq_cpu_online(&desc->irq_data);
  
  		raw_spin_unlock_irqrestore(&desc->lock, flags);
  	}
  }
  
  /**
   *	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);
  	}
  }

  
  #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY

  
  #ifdef CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS
  /**
   *	handle_fasteoi_ack_irq - irq handler for edge hierarchy
   *	stacked on transparent controllers
   *
   *	@desc:	the interrupt description structure for this irq
   *
   *	Like handle_fasteoi_irq(), but for use with hierarchy where
   *	the irq_chip also needs to have its ->irq_ack() function
   *	called.
   */
  void handle_fasteoi_ack_irq(struct irq_desc *desc)
  {
  	struct irq_chip *chip = desc->irq_data.chip;
  
  	raw_spin_lock(&desc->lock);
  
  	if (!irq_may_run(desc))
  		goto out;
  
  	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
  
  	/*
  	 * If its disabled or no action available
  	 * then mask it and get out of here:
  	 */
  	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
  		desc->istate |= IRQS_PENDING;
  		mask_irq(desc);
  		goto out;
  	}
  
  	kstat_incr_irqs_this_cpu(desc);
  	if (desc->istate & IRQS_ONESHOT)
  		mask_irq(desc);
  
  	/* Start handling the irq */
  	desc->irq_data.chip->irq_ack(&desc->irq_data);
  
  	preflow_handler(desc);
  	handle_irq_event(desc);
  
  	cond_unmask_eoi_irq(desc, chip);
  
  	raw_spin_unlock(&desc->lock);
  	return;
  out:
  	if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
  		chip->irq_eoi(&desc->irq_data);
  	raw_spin_unlock(&desc->lock);
  }
  EXPORT_SYMBOL_GPL(handle_fasteoi_ack_irq);
  
  /**
   *	handle_fasteoi_mask_irq - irq handler for level hierarchy
   *	stacked on transparent controllers
   *
   *	@desc:	the interrupt description structure for this irq
   *
   *	Like handle_fasteoi_irq(), but for use with hierarchy where
   *	the irq_chip also needs to have its ->irq_mask_ack() function
   *	called.
   */
  void handle_fasteoi_mask_irq(struct irq_desc *desc)
  {
  	struct irq_chip *chip = desc->irq_data.chip;
  
  	raw_spin_lock(&desc->lock);
  	mask_ack_irq(desc);
  
  	if (!irq_may_run(desc))
  		goto out;
  
  	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
  
  	/*
  	 * If its disabled or no action available
  	 * then mask it and get out of here:
  	 */
  	if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
  		desc->istate |= IRQS_PENDING;
  		mask_irq(desc);
  		goto out;
  	}
  
  	kstat_incr_irqs_this_cpu(desc);
  	if (desc->istate & IRQS_ONESHOT)
  		mask_irq(desc);
  
  	preflow_handler(desc);
  	handle_irq_event(desc);
  
  	cond_unmask_eoi_irq(desc, chip);
  
  	raw_spin_unlock(&desc->lock);
  	return;
  out:
  	if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
  		chip->irq_eoi(&desc->irq_data);
  	raw_spin_unlock(&desc->lock);
  }
  EXPORT_SYMBOL_GPL(handle_fasteoi_mask_irq);
  
  #endif /* CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS */

  /**

   * irq_chip_enable_parent - Enable the parent interrupt (defaults to unmask if
   * NULL)
   * @data:	Pointer to interrupt specific data
   */
  void irq_chip_enable_parent(struct irq_data *data)
  {
  	data = data->parent_data;
  	if (data->chip->irq_enable)
  		data->chip->irq_enable(data);
  	else
  		data->chip->irq_unmask(data);
  }

  EXPORT_SYMBOL_GPL(irq_chip_enable_parent);

  
  /**
   * irq_chip_disable_parent - Disable the parent interrupt (defaults to mask if
   * NULL)
   * @data:	Pointer to interrupt specific data
   */
  void irq_chip_disable_parent(struct irq_data *data)
  {
  	data = data->parent_data;
  	if (data->chip->irq_disable)
  		data->chip->irq_disable(data);
  	else
  		data->chip->irq_mask(data);
  }

  EXPORT_SYMBOL_GPL(irq_chip_disable_parent);

  
  /**

   * irq_chip_ack_parent - Acknowledge the parent interrupt
   * @data:	Pointer to interrupt specific data
   */
  void irq_chip_ack_parent(struct irq_data *data)
  {
  	data = data->parent_data;
  	data->chip->irq_ack(data);
  }

  EXPORT_SYMBOL_GPL(irq_chip_ack_parent);

  
  /**

   * irq_chip_mask_parent - Mask the parent interrupt
   * @data:	Pointer to interrupt specific data
   */
  void irq_chip_mask_parent(struct irq_data *data)
  {
  	data = data->parent_data;
  	data->chip->irq_mask(data);
  }

  EXPORT_SYMBOL_GPL(irq_chip_mask_parent);

  
  /**
   * irq_chip_unmask_parent - Unmask the parent interrupt
   * @data:	Pointer to interrupt specific data
   */
  void irq_chip_unmask_parent(struct irq_data *data)
  {
  	data = data->parent_data;
  	data->chip->irq_unmask(data);
  }

  EXPORT_SYMBOL_GPL(irq_chip_unmask_parent);

  
  /**
   * irq_chip_eoi_parent - Invoke EOI on the parent interrupt
   * @data:	Pointer to interrupt specific data
   */
  void irq_chip_eoi_parent(struct irq_data *data)
  {
  	data = data->parent_data;
  	data->chip->irq_eoi(data);
  }

  EXPORT_SYMBOL_GPL(irq_chip_eoi_parent);

  
  /**
   * irq_chip_set_affinity_parent - Set affinity on the parent interrupt
   * @data:	Pointer to interrupt specific data
   * @dest:	The affinity mask to set
   * @force:	Flag to enforce setting (disable online checks)
   *
   * Conditinal, as the underlying parent chip might not implement it.
   */
  int irq_chip_set_affinity_parent(struct irq_data *data,
  				 const struct cpumask *dest, bool force)
  {
  	data = data->parent_data;
  	if (data->chip->irq_set_affinity)
  		return data->chip->irq_set_affinity(data, dest, force);

  
  	return -ENOSYS;
  }

  EXPORT_SYMBOL_GPL(irq_chip_set_affinity_parent);

  
  /**
   * irq_chip_set_type_parent - Set IRQ type on the parent interrupt
   * @data:	Pointer to interrupt specific data
   * @type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
   *
   * Conditional, as the underlying parent chip might not implement it.
   */
  int irq_chip_set_type_parent(struct irq_data *data, unsigned int type)
  {
  	data = data->parent_data;
  
  	if (data->chip->irq_set_type)
  		return data->chip->irq_set_type(data, type);

  
  	return -ENOSYS;
  }

  EXPORT_SYMBOL_GPL(irq_chip_set_type_parent);

  
  /**

   * irq_chip_retrigger_hierarchy - Retrigger an interrupt in hardware
   * @data:	Pointer to interrupt specific data
   *
   * Iterate through the domain hierarchy of the interrupt and check
   * whether a hw retrigger function exists. If yes, invoke it.
   */
  int irq_chip_retrigger_hierarchy(struct irq_data *data)
  {
  	for (data = data->parent_data; data; data = data->parent_data)
  		if (data->chip && data->chip->irq_retrigger)
  			return data->chip->irq_retrigger(data);

  	return 0;

  }

  
  /**

   * irq_chip_set_vcpu_affinity_parent - Set vcpu affinity on the parent interrupt
   * @data:	Pointer to interrupt specific data

   * @vcpu_info:	The vcpu affinity information

   */
  int irq_chip_set_vcpu_affinity_parent(struct irq_data *data, void *vcpu_info)
  {
  	data = data->parent_data;
  	if (data->chip->irq_set_vcpu_affinity)
  		return data->chip->irq_set_vcpu_affinity(data, vcpu_info);
  
  	return -ENOSYS;
  }
  
  /**

   * irq_chip_set_wake_parent - Set/reset wake-up on the parent interrupt
   * @data:	Pointer to interrupt specific data
   * @on:		Whether to set or reset the wake-up capability of this irq
   *
   * Conditional, as the underlying parent chip might not implement it.
   */
  int irq_chip_set_wake_parent(struct irq_data *data, unsigned int on)
  {
  	data = data->parent_data;
  	if (data->chip->irq_set_wake)
  		return data->chip->irq_set_wake(data, on);
  
  	return -ENOSYS;
  }

  #endif

  
  /**
   * irq_chip_compose_msi_msg - Componse msi message for a irq chip
   * @data:	Pointer to interrupt specific data
   * @msg:	Pointer to the MSI message
   *
   * For hierarchical domains we find the first chip in the hierarchy
   * which implements the irq_compose_msi_msg callback. For non
   * hierarchical we use the top level chip.
   */
  int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
  {
  	struct irq_data *pos = NULL;
  
  #ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
  	for (; data; data = data->parent_data)
  #endif
  		if (data->chip && data->chip->irq_compose_msi_msg)
  			pos = data;
  	if (!pos)
  		return -ENOSYS;
  
  	pos->chip->irq_compose_msi_msg(pos, msg);
  
  	return 0;
  }

  
  /**
   * irq_chip_pm_get - Enable power for an IRQ chip
   * @data:	Pointer to interrupt specific data
   *
   * Enable the power to the IRQ chip referenced by the interrupt data
   * structure.
   */
  int irq_chip_pm_get(struct irq_data *data)
  {
  	int retval;
  
  	if (IS_ENABLED(CONFIG_PM) && data->chip->parent_device) {
  		retval = pm_runtime_get_sync(data->chip->parent_device);
  		if (retval < 0) {
  			pm_runtime_put_noidle(data->chip->parent_device);
  			return retval;
  		}
  	}
  
  	return 0;
  }
  
  /**
   * irq_chip_pm_put - Disable power for an IRQ chip
   * @data:	Pointer to interrupt specific data
   *
   * Disable the power to the IRQ chip referenced by the interrupt data
   * structure, belongs. Note that power will only be disabled, once this
   * function has been called for all IRQs that have called irq_chip_pm_get().
   */
  int irq_chip_pm_put(struct irq_data *data)
  {
  	int retval = 0;
  
  	if (IS_ENABLED(CONFIG_PM) && data->chip->parent_device)
  		retval = pm_runtime_put(data->chip->parent_device);
  
  	return (retval < 0) ? retval : 0;
  }