Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Copyright (C) 1999, 2005 MIPS Technologies, Inc.  All rights reserved.

 *

 *  This program is free software; you can distribute 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 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, write to the Free Software Foundation, Inc.,

 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.

 *

 */

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/interrupt.h>

#include <linux/kernel_stat.h>

#include <asm/mips-boards/simint.h>

#include <asm/irq_cpu.h>

static inline int clz(unsigned long x)

{

        __asm__(

        "       .set    push                                    \n"

        "       .set    mips32                                  \n"

        "       clz     %0, %1                                  \n"

        "       .set    pop                                     \n"

        : "=r" (x)

        : "r" (x));

        return x;

}

/*

 * Version of ffs that only looks at bits 12..15.

 */

static inline unsigned int irq_ffs(unsigned int pending)

{

#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)

        return -clz(pending) + 31 - CAUSEB_IP;

#else

        unsigned int a0 = 7;

        unsigned int t0;

        t0 = s0 & 0xf000;

        t0 = t0 < 1;

        t0 = t0 << 2;

        a0 = a0 - t0;

        s0 = s0 << t0;

        t0 = s0 & 0xc000;

        t0 = t0 < 1;

        t0 = t0 << 1;

        a0 = a0 - t0;

        s0 = s0 << t0;

        t0 = s0 & 0x8000;

        t0 = t0 < 1;

        /* t0 = t0 << 2; */

        a0 = a0 - t0;

        /* s0 = s0 << t0; */

        return a0;

#endif

}

asmlinkage void plat_irq_dispatch(void)

{

        unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;

        int irq;

        irq = irq_ffs(pending);

        if (irq > 0)

                do_IRQ(MIPS_CPU_IRQ_BASE + irq);

        else

                spurious_interrupt();

}

void __init arch_init_irq(void)

{

        mips_cpu_irq_init();

}