/*
 * linux/kernel/irq/handle.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.
 *
 * Detailed information is available in Documentation/DocBook/genericirq
 *
 */

#include <linux/irq.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>

#include <trace/events/irq.h>

#include "internals.h"

void handle_bad_irq(unsigned int irq, struct irq_desc *desc)
{
	print_irq_desc(irq, desc);
	kstat_incr_irqs_this_cpu(irq, desc);
	ack_bad_irq(irq);
}

irqreturn_t no_action(int cpl, void *dev_id)
{
	return IRQ_NONE;
}

static void warn_no_thread(unsigned int irq, struct irqaction *action)
{
	if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags))
		return;

	printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD "
	       "but no thread function available.", irq, action->name);
}

static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
{
	if (action->thread->flags & PF_EXITING)
		return;

	if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))
		return;

	desc->threads_oneshot |= action->thread_mask;

	atomic_inc(&desc->threads_active);

	wake_up_process(action->thread);
}

irqreturn_t
handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
{
	irqreturn_t retval = IRQ_NONE;
	unsigned int flags = 0, irq = desc->irq_data.irq;

	do {
		irqreturn_t res;

		trace_irq_handler_entry(irq, action);
		res = action->handler(irq, action->dev_id);
		trace_irq_handler_exit(irq, action, res);

		if (WARN_ONCE(!irqs_disabled(),"irq %u handler %pF enabled interrupts\n",
			      irq, action->handler))
			local_irq_disable();

		switch (res) {
		case IRQ_WAKE_THREAD:
			if (unlikely(!action->thread_fn)) {
				warn_no_thread(irq, action);
				break;
			}

			irq_wake_thread(desc, action);

			
		case IRQ_HANDLED:
			flags |= action->flags;
			break;

		default:
			break;
		}

		retval |= res;
		action = action->next;
	} while (action);

	add_interrupt_randomness(irq, flags);

	if (!noirqdebug)
		note_interrupt(irq, desc, retval);
	return retval;
}

irqreturn_t handle_irq_event(struct irq_desc *desc)
{
	struct irqaction *action = desc->action;
	irqreturn_t ret;

	desc->istate &= ~IRQS_PENDING;
	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
	raw_spin_unlock(&desc->lock);

	ret = handle_irq_event_percpu(desc, action);

	raw_spin_lock(&desc->lock);
	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
	return ret;
}