Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * linux/kernel/irq/resend.c

 *

 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar

 * Copyright (C) 2005-2006, Thomas Gleixner

 *

 * This file contains the IRQ-resend code

 *

 * If the interrupt is waiting to be processed, we try to re-run it.

 * We can't directly run it from here since the caller might be in an

 * interrupt-protected region. Not all irq controller chips can

 * retrigger interrupts at the hardware level, so in those cases

 * we allow the resending of IRQs via a tasklet.

 */

#include <linux/irq.h>

#include <linux/module.h>

#include <linux/random.h>

#include <linux/interrupt.h>

#include "internals.h"

#ifdef CONFIG_HARDIRQS_SW_RESEND

/* Bitmap to handle software resend of interrupts: */

static DECLARE_BITMAP(irqs_resend, NR_IRQS);

/*

 * Run software resends of IRQ's

 */

static void resend_irqs(unsigned long arg)

{

        struct irq_desc *desc;

        int irq;

        while (!bitmap_empty(irqs_resend, NR_IRQS)) {

                irq = find_first_bit(irqs_resend, NR_IRQS);

                clear_bit(irq, irqs_resend);

                desc = irq_desc + irq;

                local_irq_disable();

                desc->handle_irq(irq, desc);

                local_irq_enable();

        }

}

/* Tasklet to handle resend: */

static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);

#endif

/*

 * IRQ resend

 *

 * Is called with interrupts disabled and desc->lock held.

 */

void check_irq_resend(struct irq_desc *desc, unsigned int irq)

{

        unsigned int status = desc->status;

        /*

         * Make sure the interrupt is enabled, before resending it:

         */

        desc->chip->enable(irq);

        /*

         * We do not resend level type interrupts. Level type

         * interrupts are resent by hardware when they are still

         * active.

         */

        if ((status & (IRQ_LEVEL | IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {

                desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;

                if (!desc->chip || !desc->chip->retrigger ||

                                        !desc->chip->retrigger(irq)) {

#ifdef CONFIG_HARDIRQS_SW_RESEND

                        /* Set it pending and activate the softirq: */

                        set_bit(irq, irqs_resend);

                        tasklet_schedule(&resend_tasklet);

#endif

                }

        }

}