kernel/irq/chip.c - LeafOS-Devices/android_kernel_samsung_exynos9820 - Gitiles

 /*
  * 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/DocBook/genericirq
  */

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

 #include "internals.h"

 /**
  *	dynamic_irq_init - initialize a dynamically allocated irq
  *	@irq:	irq number to initialize
  */
 void dynamic_irq_init(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
 		return;
 	}

 	/* Ensure we don't have left over values from a previous use of this irq */
 	spin_lock_irqsave(&desc->lock, flags);
 	desc->status = IRQ_DISABLED;
 	desc->chip = &no_irq_chip;
 	desc->handle_irq = handle_bad_irq;
 	desc->depth = 1;
 	desc->msi_desc = NULL;
 	desc->handler_data = NULL;
 	desc->chip_data = NULL;
 	desc->action = NULL;
 	desc->irq_count = 0;
 	desc->irqs_unhandled = 0;
 #ifdef CONFIG_SMP
 	cpus_setall(desc->affinity);
 #endif
 	spin_unlock_irqrestore(&desc->lock, flags);
 }

 /**
  *	dynamic_irq_cleanup - cleanup a dynamically allocated irq
  *	@irq:	irq number to initialize
  */
 void dynamic_irq_cleanup(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
 		return;
 	}

 	spin_lock_irqsave(&desc->lock, flags);
 	if (desc->action) {
 		spin_unlock_irqrestore(&desc->lock, flags);
 		WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
 			irq);
 		return;
 	}
 	desc->msi_desc = NULL;
 	desc->handler_data = NULL;
 	desc->chip_data = NULL;
 	desc->handle_irq = handle_bad_irq;
 	desc->chip = &no_irq_chip;
 	desc->name = NULL;
 	spin_unlock_irqrestore(&desc->lock, flags);
 }


 /**
  *	set_irq_chip - set the irq chip for an irq
  *	@irq:	irq number
  *	@chip:	pointer to irq chip description structure
  */
 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
 		return -EINVAL;
 	}

 	if (!chip)
 		chip = &no_irq_chip;

 	spin_lock_irqsave(&desc->lock, flags);
 	irq_chip_set_defaults(chip);
 	desc->chip = chip;
 	spin_unlock_irqrestore(&desc->lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL(set_irq_chip);

 /**
  *	set_irq_type - set the irq trigger type for an irq
  *	@irq:	irq number
  *	@type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
  */
 int set_irq_type(unsigned int irq, unsigned int type)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;
 	int ret = -ENXIO;

 	if (!desc) {
 		printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
 		return -ENODEV;
 	}

 	if (type == IRQ_TYPE_NONE)
 		return 0;

 	spin_lock_irqsave(&desc->lock, flags);
 	ret = __irq_set_trigger(desc, irq, type);
 	spin_unlock_irqrestore(&desc->lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(set_irq_type);

 /**
  *	set_irq_data - set irq type data for an irq
  *	@irq:	Interrupt number
  *	@data:	Pointer to interrupt specific data
  *
  *	Set the hardware irq controller data for an irq
  */
 int set_irq_data(unsigned int irq, void *data)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		printk(KERN_ERR
 		       "Trying to install controller data for IRQ%d\n", irq);
 		return -EINVAL;
 	}

 	spin_lock_irqsave(&desc->lock, flags);
 	desc->handler_data = data;
 	spin_unlock_irqrestore(&desc->lock, flags);
 	return 0;
 }
 EXPORT_SYMBOL(set_irq_data);

 /**
  *	set_irq_data - set irq type data for an irq
  *	@irq:	Interrupt number
  *	@entry:	Pointer to MSI descriptor data
  *
  *	Set the hardware irq controller data for an irq
  */
 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		printk(KERN_ERR
 		       "Trying to install msi data for IRQ%d\n", irq);
 		return -EINVAL;
 	}

 	spin_lock_irqsave(&desc->lock, flags);
 	desc->msi_desc = entry;
 	if (entry)
 		entry->irq = irq;
 	spin_unlock_irqrestore(&desc->lock, flags);
 	return 0;
 }

 /**
  *	set_irq_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 set_irq_chip_data(unsigned int irq, void *data)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		printk(KERN_ERR
 		       "Trying to install chip data for IRQ%d\n", irq);
 		return -EINVAL;
 	}

 	if (!desc->chip) {
 		printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
 		return -EINVAL;
 	}

 	spin_lock_irqsave(&desc->lock, flags);
 	desc->chip_data = data;
 	spin_unlock_irqrestore(&desc->lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL(set_irq_chip_data);

 /*
  * default enable function
  */
 static void default_enable(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);

 	desc->chip->unmask(irq);
 	desc->status &= ~IRQ_MASKED;
 }

 /*
  * default disable function
  */
 static void default_disable(unsigned int irq)
 {
 }

 /*
  * default startup function
  */
 static unsigned int default_startup(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);

 	desc->chip->enable(irq);
 	return 0;
 }

 /*
  * default shutdown function
  */
 static void default_shutdown(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);

 	desc->chip->mask(irq);
 	desc->status |= IRQ_MASKED;
 }

 /*
  * Fixup enable/disable function pointers
  */
 void irq_chip_set_defaults(struct irq_chip *chip)
 {
 	if (!chip->enable)
 		chip->enable = default_enable;
 	if (!chip->disable)
 		chip->disable = default_disable;
 	if (!chip->startup)
 		chip->startup = default_startup;
 	/*
 	 * We use chip->disable, when the user provided its own. When
 	 * we have default_disable set for chip->disable, then we need
 	 * to use default_shutdown, otherwise the irq line is not
 	 * disabled on free_irq():
 	 */
 	if (!chip->shutdown)
 		chip->shutdown = chip->disable != default_disable ?
 			chip->disable : default_shutdown;
 	if (!chip->name)
 		chip->name = chip->typename;
 	if (!chip->end)
 		chip->end = dummy_irq_chip.end;
 }

 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
 {
 	if (desc->chip->mask_ack)
 		desc->chip->mask_ack(irq);
 	else {
 		desc->chip->mask(irq);
 		desc->chip->ack(irq);
 	}
 }

 /**
  *	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)
 {
 	struct irqaction *action;
 	irqreturn_t action_ret;

 	spin_lock(&desc->lock);

 	if (unlikely(desc->status & IRQ_INPROGRESS))
 		goto out_unlock;
 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 	kstat_incr_irqs_this_cpu(irq, desc);

 	action = desc->action;
 	if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 		goto out_unlock;

 	desc->status |= IRQ_INPROGRESS;
 	spin_unlock(&desc->lock);

 	action_ret = handle_IRQ_event(irq, action);
 	if (!noirqdebug)
 		note_interrupt(irq, desc, action_ret);

 	spin_lock(&desc->lock);
 	desc->status &= ~IRQ_INPROGRESS;
 out_unlock:
 	spin_unlock(&desc->lock);
 }

 /**
  *	handle_level_irq - Level type irq handler
  *	@irq:	the interrupt number
  *	@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(unsigned int irq, struct irq_desc *desc)
 {
 	struct irqaction *action;
 	irqreturn_t action_ret;

 	spin_lock(&desc->lock);
 	mask_ack_irq(desc, irq);

 	if (unlikely(desc->status & IRQ_INPROGRESS))
 		goto out_unlock;
 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 	kstat_incr_irqs_this_cpu(irq, desc);

 	/*
 	 * If its disabled or no action available
 	 * keep it masked and get out of here
 	 */
 	action = desc->action;
 	if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 		goto out_unlock;

 	desc->status |= IRQ_INPROGRESS;
 	spin_unlock(&desc->lock);

 	action_ret = handle_IRQ_event(irq, action);
 	if (!noirqdebug)
 		note_interrupt(irq, desc, action_ret);

 	spin_lock(&desc->lock);
 	desc->status &= ~IRQ_INPROGRESS;
 	if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
 		desc->chip->unmask(irq);
 out_unlock:
 	spin_unlock(&desc->lock);
 }

 /**
  *	handle_fasteoi_irq - irq handler for transparent controllers
  *	@irq:	the interrupt number
  *	@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(unsigned int irq, struct irq_desc *desc)
 {
 	struct irqaction *action;
 	irqreturn_t action_ret;

 	spin_lock(&desc->lock);

 	if (unlikely(desc->status & IRQ_INPROGRESS))
 		goto out;

 	desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 	kstat_incr_irqs_this_cpu(irq, desc);

 	/*
 	 * If its disabled or no action available
 	 * then mask it and get out of here:
 	 */
 	action = desc->action;
 	if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 		desc->status |= IRQ_PENDING;
 		if (desc->chip->mask)
 			desc->chip->mask(irq);
 		goto out;
 	}

 	desc->status |= IRQ_INPROGRESS;
 	desc->status &= ~IRQ_PENDING;
 	spin_unlock(&desc->lock);

 	action_ret = handle_IRQ_event(irq, action);
 	if (!noirqdebug)
 		note_interrupt(irq, desc, action_ret);

 	spin_lock(&desc->lock);
 	desc->status &= ~IRQ_INPROGRESS;
 out:
 	desc->chip->eoi(irq);

 	spin_unlock(&desc->lock);
 }

 /**
  *	handle_edge_irq - edge type IRQ handler
  *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  *	Interrupt occures on the falling and/or rising edge of a hardware
  *	signal. The occurence 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 assosiacted 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(unsigned int irq, struct irq_desc *desc)
 {
 	spin_lock(&desc->lock);

 	desc->status &= ~(IRQ_REPLAY | IRQ_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((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 		    !desc->action)) {
 		desc->status |= (IRQ_PENDING | IRQ_MASKED);
 		mask_ack_irq(desc, irq);
 		goto out_unlock;
 	}
 	kstat_incr_irqs_this_cpu(irq, desc);

 	/* Start handling the irq */
 	desc->chip->ack(irq);

 	/* Mark the IRQ currently in progress.*/
 	desc->status |= IRQ_INPROGRESS;

 	do {
 		struct irqaction *action = desc->action;
 		irqreturn_t action_ret;

 		if (unlikely(!action)) {
 			desc->chip->mask(irq);
 			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->status &
 			       (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 			      (IRQ_PENDING | IRQ_MASKED))) {
 			desc->chip->unmask(irq);
 			desc->status &= ~IRQ_MASKED;
 		}

 		desc->status &= ~IRQ_PENDING;
 		spin_unlock(&desc->lock);
 		action_ret = handle_IRQ_event(irq, action);
 		if (!noirqdebug)
 			note_interrupt(irq, desc, action_ret);
 		spin_lock(&desc->lock);

 	} while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);

 	desc->status &= ~IRQ_INPROGRESS;
 out_unlock:
 	spin_unlock(&desc->lock);
 }

 /**
  *	handle_percpu_IRQ - Per CPU local irq handler
  *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  *	Per CPU interrupts on SMP machines without locking requirements
  */
 void
 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 {
 	irqreturn_t action_ret;

 	kstat_incr_irqs_this_cpu(irq, desc);

 	if (desc->chip->ack)
 		desc->chip->ack(irq);

 	action_ret = handle_IRQ_event(irq, desc->action);
 	if (!noirqdebug)
 		note_interrupt(irq, desc, action_ret);

 	if (desc->chip->eoi)
 		desc->chip->eoi(irq);
 }

 void
 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 		  const char *name)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		printk(KERN_ERR
 		       "Trying to install type control for IRQ%d\n", irq);
 		return;
 	}

 	if (!handle)
 		handle = handle_bad_irq;
 	else if (desc->chip == &no_irq_chip) {
 		printk(KERN_WARNING "Trying to install %sinterrupt handler "
 		       "for IRQ%d\n", is_chained ? "chained " : "", irq);
 		/*
 		 * Some ARM implementations install a handler for really dumb
 		 * interrupt hardware without setting an irq_chip. This worked
 		 * with the ARM no_irq_chip but the check in setup_irq would
 		 * prevent us to setup the interrupt at all. Switch it to
 		 * dummy_irq_chip for easy transition.
 		 */
 		desc->chip = &dummy_irq_chip;
 	}

 	spin_lock_irqsave(&desc->lock, flags);

 	/* Uninstall? */
 	if (handle == handle_bad_irq) {
 		if (desc->chip != &no_irq_chip)
 			mask_ack_irq(desc, irq);
 		desc->status |= IRQ_DISABLED;
 		desc->depth = 1;
 	}
 	desc->handle_irq = handle;
 	desc->name = name;

 	if (handle != handle_bad_irq && is_chained) {
 		desc->status &= ~IRQ_DISABLED;
 		desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 		desc->depth = 0;
 		desc->chip->startup(irq);
 	}
 	spin_unlock_irqrestore(&desc->lock, flags);
 }

 void
 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 			 irq_flow_handler_t handle)
 {
 	set_irq_chip(irq, chip);
 	__set_irq_handler(irq, handle, 0, NULL);
 }

 void
 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 			      irq_flow_handler_t handle, const char *name)
 {
 	set_irq_chip(irq, chip);
 	__set_irq_handler(irq, handle, 0, name);
 }

 void __init set_irq_noprobe(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
 		return;
 	}

 	spin_lock_irqsave(&desc->lock, flags);
 	desc->status |= IRQ_NOPROBE;
 	spin_unlock_irqrestore(&desc->lock, flags);
 }

 void __init set_irq_probe(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 	unsigned long flags;

 	if (!desc) {
 		printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
 		return;
 	}

 	spin_lock_irqsave(&desc->lock, flags);
 	desc->status &= ~IRQ_NOPROBE;
 	spin_unlock_irqrestore(&desc->lock, flags);
 }
	/*
	* 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/DocBook/genericirq
	*/

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

	#include "internals.h"

	/**
	* dynamic_irq_init - initialize a dynamically allocated irq
	* @irq: irq number to initialize
	*/
	void dynamic_irq_init(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
	return;
	}

	/* Ensure we don't have left over values from a previous use of this irq */
	spin_lock_irqsave(&desc->lock, flags);
	desc->status = IRQ_DISABLED;
	desc->chip = &no_irq_chip;
	desc->handle_irq = handle_bad_irq;
	desc->depth = 1;
	desc->msi_desc = NULL;
	desc->handler_data = NULL;
	desc->chip_data = NULL;
	desc->action = NULL;
	desc->irq_count = 0;
	desc->irqs_unhandled = 0;
	#ifdef CONFIG_SMP
	cpus_setall(desc->affinity);
	#endif
	spin_unlock_irqrestore(&desc->lock, flags);
	}

	/**
	* dynamic_irq_cleanup - cleanup a dynamically allocated irq
	* @irq: irq number to initialize
	*/
	void dynamic_irq_cleanup(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
	return;
	}

	spin_lock_irqsave(&desc->lock, flags);
	if (desc->action) {
	spin_unlock_irqrestore(&desc->lock, flags);
	WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
	irq);
	return;
	}
	desc->msi_desc = NULL;
	desc->handler_data = NULL;
	desc->chip_data = NULL;
	desc->handle_irq = handle_bad_irq;
	desc->chip = &no_irq_chip;
	desc->name = NULL;
	spin_unlock_irqrestore(&desc->lock, flags);
	}


	/**
	* set_irq_chip - set the irq chip for an irq
	* @irq: irq number
	* @chip: pointer to irq chip description structure
	*/
	int set_irq_chip(unsigned int irq, struct irq_chip *chip)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
	return -EINVAL;
	}

	if (!chip)
	chip = &no_irq_chip;

	spin_lock_irqsave(&desc->lock, flags);
	irq_chip_set_defaults(chip);
	desc->chip = chip;
	spin_unlock_irqrestore(&desc->lock, flags);

	return 0;
	}
	EXPORT_SYMBOL(set_irq_chip);

	/**
	* set_irq_type - set the irq trigger type for an irq
	* @irq: irq number
	* @type: IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
	*/
	int set_irq_type(unsigned int irq, unsigned int type)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;
	int ret = -ENXIO;

	if (!desc) {
	printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
	return -ENODEV;
	}

	if (type == IRQ_TYPE_NONE)
	return 0;

	spin_lock_irqsave(&desc->lock, flags);
	ret = __irq_set_trigger(desc, irq, type);
	spin_unlock_irqrestore(&desc->lock, flags);
	return ret;
	}
	EXPORT_SYMBOL(set_irq_type);

	/**
	* set_irq_data - set irq type data for an irq
	* @irq: Interrupt number
	* @data: Pointer to interrupt specific data
	*
	* Set the hardware irq controller data for an irq
	*/
	int set_irq_data(unsigned int irq, void *data)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	printk(KERN_ERR
	"Trying to install controller data for IRQ%d\n", irq);
	return -EINVAL;
	}

	spin_lock_irqsave(&desc->lock, flags);
	desc->handler_data = data;
	spin_unlock_irqrestore(&desc->lock, flags);
	return 0;
	}
	EXPORT_SYMBOL(set_irq_data);

	/**
	* set_irq_data - set irq type data for an irq
	* @irq: Interrupt number
	* @entry: Pointer to MSI descriptor data
	*
	* Set the hardware irq controller data for an irq
	*/
	int set_irq_msi(unsigned int irq, struct msi_desc *entry)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	printk(KERN_ERR
	"Trying to install msi data for IRQ%d\n", irq);
	return -EINVAL;
	}

	spin_lock_irqsave(&desc->lock, flags);
	desc->msi_desc = entry;
	if (entry)
	entry->irq = irq;
	spin_unlock_irqrestore(&desc->lock, flags);
	return 0;
	}

	/**
	* set_irq_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 set_irq_chip_data(unsigned int irq, void *data)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	printk(KERN_ERR
	"Trying to install chip data for IRQ%d\n", irq);
	return -EINVAL;
	}

	if (!desc->chip) {
	printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
	return -EINVAL;
	}

	spin_lock_irqsave(&desc->lock, flags);
	desc->chip_data = data;
	spin_unlock_irqrestore(&desc->lock, flags);

	return 0;
	}
	EXPORT_SYMBOL(set_irq_chip_data);

	/*
	* default enable function
	*/
	static void default_enable(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);

	desc->chip->unmask(irq);
	desc->status &= ~IRQ_MASKED;
	}

	/*
	* default disable function
	*/
	static void default_disable(unsigned int irq)
	{
	}

	/*
	* default startup function
	*/
	static unsigned int default_startup(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);

	desc->chip->enable(irq);
	return 0;
	}

	/*
	* default shutdown function
	*/
	static void default_shutdown(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);

	desc->chip->mask(irq);
	desc->status \|= IRQ_MASKED;
	}

	/*
	* Fixup enable/disable function pointers
	*/
	void irq_chip_set_defaults(struct irq_chip *chip)
	{
	if (!chip->enable)
	chip->enable = default_enable;
	if (!chip->disable)
	chip->disable = default_disable;
	if (!chip->startup)
	chip->startup = default_startup;
	/*
	* We use chip->disable, when the user provided its own. When
	* we have default_disable set for chip->disable, then we need
	* to use default_shutdown, otherwise the irq line is not
	* disabled on free_irq():
	*/
	if (!chip->shutdown)
	chip->shutdown = chip->disable != default_disable ?
	chip->disable : default_shutdown;
	if (!chip->name)
	chip->name = chip->typename;
	if (!chip->end)
	chip->end = dummy_irq_chip.end;
	}

	static inline void mask_ack_irq(struct irq_desc *desc, int irq)
	{
	if (desc->chip->mask_ack)
	desc->chip->mask_ack(irq);
	else {
	desc->chip->mask(irq);
	desc->chip->ack(irq);
	}
	}

	/**
	* 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)
	{
	struct irqaction *action;
	irqreturn_t action_ret;

	spin_lock(&desc->lock);

	if (unlikely(desc->status & IRQ_INPROGRESS))
	goto out_unlock;
	desc->status &= ~(IRQ_REPLAY \| IRQ_WAITING);
	kstat_incr_irqs_this_cpu(irq, desc);

	action = desc->action;
	if (unlikely(!action \|\| (desc->status & IRQ_DISABLED)))
	goto out_unlock;

	desc->status \|= IRQ_INPROGRESS;
	spin_unlock(&desc->lock);

	action_ret = handle_IRQ_event(irq, action);
	if (!noirqdebug)
	note_interrupt(irq, desc, action_ret);

	spin_lock(&desc->lock);
	desc->status &= ~IRQ_INPROGRESS;
	out_unlock:
	spin_unlock(&desc->lock);
	}

	/**
	* handle_level_irq - Level type irq handler
	* @irq: the interrupt number
	* @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(unsigned int irq, struct irq_desc *desc)
	{
	struct irqaction *action;
	irqreturn_t action_ret;

	spin_lock(&desc->lock);
	mask_ack_irq(desc, irq);

	if (unlikely(desc->status & IRQ_INPROGRESS))
	goto out_unlock;
	desc->status &= ~(IRQ_REPLAY \| IRQ_WAITING);
	kstat_incr_irqs_this_cpu(irq, desc);

	/*
	* If its disabled or no action available
	* keep it masked and get out of here
	*/
	action = desc->action;
	if (unlikely(!action \|\| (desc->status & IRQ_DISABLED)))
	goto out_unlock;

	desc->status \|= IRQ_INPROGRESS;
	spin_unlock(&desc->lock);

	action_ret = handle_IRQ_event(irq, action);
	if (!noirqdebug)
	note_interrupt(irq, desc, action_ret);

	spin_lock(&desc->lock);
	desc->status &= ~IRQ_INPROGRESS;
	if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
	desc->chip->unmask(irq);
	out_unlock:
	spin_unlock(&desc->lock);
	}

	/**
	* handle_fasteoi_irq - irq handler for transparent controllers
	* @irq: the interrupt number
	* @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(unsigned int irq, struct irq_desc *desc)
	{
	struct irqaction *action;
	irqreturn_t action_ret;

	spin_lock(&desc->lock);

	if (unlikely(desc->status & IRQ_INPROGRESS))
	goto out;

	desc->status &= ~(IRQ_REPLAY \| IRQ_WAITING);
	kstat_incr_irqs_this_cpu(irq, desc);

	/*
	* If its disabled or no action available
	* then mask it and get out of here:
	*/
	action = desc->action;
	if (unlikely(!action \|\| (desc->status & IRQ_DISABLED))) {
	desc->status \|= IRQ_PENDING;
	if (desc->chip->mask)
	desc->chip->mask(irq);
	goto out;
	}

	desc->status \|= IRQ_INPROGRESS;
	desc->status &= ~IRQ_PENDING;
	spin_unlock(&desc->lock);

	action_ret = handle_IRQ_event(irq, action);
	if (!noirqdebug)
	note_interrupt(irq, desc, action_ret);

	spin_lock(&desc->lock);
	desc->status &= ~IRQ_INPROGRESS;
	out:
	desc->chip->eoi(irq);

	spin_unlock(&desc->lock);
	}

	/**
	* handle_edge_irq - edge type IRQ handler
	* @irq: the interrupt number
	* @desc: the interrupt description structure for this irq
	*
	* Interrupt occures on the falling and/or rising edge of a hardware
	* signal. The occurence 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 assosiacted 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(unsigned int irq, struct irq_desc *desc)
	{
	spin_lock(&desc->lock);

	desc->status &= ~(IRQ_REPLAY \| IRQ_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((desc->status & (IRQ_INPROGRESS \| IRQ_DISABLED)) \|\|
	!desc->action)) {
	desc->status \|= (IRQ_PENDING \| IRQ_MASKED);
	mask_ack_irq(desc, irq);
	goto out_unlock;
	}
	kstat_incr_irqs_this_cpu(irq, desc);

	/* Start handling the irq */
	desc->chip->ack(irq);

	/* Mark the IRQ currently in progress.*/
	desc->status \|= IRQ_INPROGRESS;

	do {
	struct irqaction *action = desc->action;
	irqreturn_t action_ret;

	if (unlikely(!action)) {
	desc->chip->mask(irq);
	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->status &
	(IRQ_PENDING \| IRQ_MASKED \| IRQ_DISABLED)) ==
	(IRQ_PENDING \| IRQ_MASKED))) {
	desc->chip->unmask(irq);
	desc->status &= ~IRQ_MASKED;
	}

	desc->status &= ~IRQ_PENDING;
	spin_unlock(&desc->lock);
	action_ret = handle_IRQ_event(irq, action);
	if (!noirqdebug)
	note_interrupt(irq, desc, action_ret);
	spin_lock(&desc->lock);

	} while ((desc->status & (IRQ_PENDING \| IRQ_DISABLED)) == IRQ_PENDING);

	desc->status &= ~IRQ_INPROGRESS;
	out_unlock:
	spin_unlock(&desc->lock);
	}

	/**
	* handle_percpu_IRQ - Per CPU local irq handler
	* @irq: the interrupt number
	* @desc: the interrupt description structure for this irq
	*
	* Per CPU interrupts on SMP machines without locking requirements
	*/
	void
	handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
	{
	irqreturn_t action_ret;

	kstat_incr_irqs_this_cpu(irq, desc);

	if (desc->chip->ack)
	desc->chip->ack(irq);

	action_ret = handle_IRQ_event(irq, desc->action);
	if (!noirqdebug)
	note_interrupt(irq, desc, action_ret);

	if (desc->chip->eoi)
	desc->chip->eoi(irq);
	}

	void
	__set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
	const char *name)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	printk(KERN_ERR
	"Trying to install type control for IRQ%d\n", irq);
	return;
	}

	if (!handle)
	handle = handle_bad_irq;
	else if (desc->chip == &no_irq_chip) {
	printk(KERN_WARNING "Trying to install %sinterrupt handler "
	"for IRQ%d\n", is_chained ? "chained " : "", irq);
	/*
	* Some ARM implementations install a handler for really dumb
	* interrupt hardware without setting an irq_chip. This worked
	* with the ARM no_irq_chip but the check in setup_irq would
	* prevent us to setup the interrupt at all. Switch it to
	* dummy_irq_chip for easy transition.
	*/
	desc->chip = &dummy_irq_chip;
	}

	spin_lock_irqsave(&desc->lock, flags);

	/* Uninstall? */
	if (handle == handle_bad_irq) {
	if (desc->chip != &no_irq_chip)
	mask_ack_irq(desc, irq);
	desc->status \|= IRQ_DISABLED;
	desc->depth = 1;
	}
	desc->handle_irq = handle;
	desc->name = name;

	if (handle != handle_bad_irq && is_chained) {
	desc->status &= ~IRQ_DISABLED;
	desc->status \|= IRQ_NOREQUEST \| IRQ_NOPROBE;
	desc->depth = 0;
	desc->chip->startup(irq);
	}
	spin_unlock_irqrestore(&desc->lock, flags);
	}

	void
	set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
	irq_flow_handler_t handle)
	{
	set_irq_chip(irq, chip);
	__set_irq_handler(irq, handle, 0, NULL);
	}

	void
	set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
	irq_flow_handler_t handle, const char *name)
	{
	set_irq_chip(irq, chip);
	__set_irq_handler(irq, handle, 0, name);
	}

	void __init set_irq_noprobe(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
	return;
	}

	spin_lock_irqsave(&desc->lock, flags);
	desc->status \|= IRQ_NOPROBE;
	spin_unlock_irqrestore(&desc->lock, flags);
	}

	void __init set_irq_probe(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	if (!desc) {
	printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
	return;
	}

	spin_lock_irqsave(&desc->lock, flags);
	desc->status &= ~IRQ_NOPROBE;
	spin_unlock_irqrestore(&desc->lock, flags);
	}