irq.c

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/*
 * Based on arch/arm/kernel/irq.c
 *
 * Copyright (C) 1992 Linus Torvalds
 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
 * Dynamic Tick Timer written by Tony Lindgren <[email protected]> and
 * Tuukka Tikkanen <[email protected]>.
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel_stat.h>
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/of_irq.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>

unsigned long irq_err_count;

int arch_show_interrupts(struct seq_file *p, int prec)
{
#ifdef CONFIG_SMP
    show_ipi_list(p, prec);
#endif
    seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
    return 0;
}

/*
 * handle_IRQ handles all hardware IRQ's.  Decoded IRQs should
 * not come via this function.  Instead, they should provide their
 * own 'handler'.  Used by platform code implementing C-based 1st
 * level decoding.
 */
void handle_IRQ(unsigned int irq, struct pt_regs *regs)
{
    struct pt_regs *old_regs = set_irq_regs(regs);

    irq_enter();

    /*
     * Some hardware gives randomly wrong interrupts.  Rather
     * than crashing, do something sensible.
     */
    if (unlikely(irq >= nr_irqs)) {
        pr_warn_ratelimited("Bad IRQ%u\n", irq);
        ack_bad_irq(irq);
    } else {
        generic_handle_irq(irq);
    }

    irq_exit();
    set_irq_regs(old_regs);
}

/*
 * Interrupt controllers supported by the kernel.
 */
static const struct of_device_id intctrl_of_match[] __initconst = {
    /* IRQ controllers { .compatible, .data } info to go here */
    {}
};

void __init init_IRQ(void)
{
    of_irq_init(intctrl_of_match);

    if (!handle_arch_irq)
        panic("No interrupt controller found.");
}