source: mainline/arch/mips/src/interrupt.c@ e41c47e

/*
 * Copyright (C) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch/interrupt.h>
#include <arch/types.h>
#include <arch.h>
#include <arch/cp0.h>
#include <time/clock.h>
#include <panic.h>

pri_t cpu_priority_high(void)
{
    pri_t pri = (pri_t) cp0_status_read();
    cp0_status_write(pri & ~cp0_status_ie_enabled_bit);
    return pri;
}

pri_t cpu_priority_low(void)
{
    pri_t pri = (pri_t) cp0_status_read();
    cp0_status_write(pri | cp0_status_ie_enabled_bit);
    return pri;
}

void cpu_priority_restore(pri_t pri)
{
    cp0_status_write(cp0_status_read() | (pri & cp0_status_ie_enabled_bit));
}

pri_t cpu_priority_read(void)
{
    return cp0_status_read();
}


void interrupt(void)
{
        __u32 cause;
        int i;
        
        /* decode interrupt number and process the interrupt */
        cause = (cp0_cause_read() >> 8) &0xff;
        
        for (i = 0; i < 8; i++) {
                if (cause & (1 << i)) {
                        switch (i) {
                                case 0: /* SW0 - Software interrupt 0 */
                                        cp0_cause_write(cause & ~(1 << 8)); /* clear SW0 interrupt */
                                        break;
                                case 1: /* SW1 - Software interrupt 1 */
                                        cp0_cause_write(cause & ~(1 << 9)); /* clear SW1 interrupt */
                                        break;
                                case 2: /* IRQ0 */
                                case 3: /* IRQ1 */
                                case 4: /* IRQ2 */
                                case 5: /* IRQ3 */
                                case 6: /* IRQ4 */
                                        panic("unhandled interrupt %d\n", i);
                                        break;
                                case 7: /* Timer Interrupt */
                                        cp0_compare_write(cp0_compare_value); /* clear timer interrupt */
                                    /* start counting over again */
                                        cp0_count_write(0);                                 
                                        clock();
                                        break;
                        }
                }
        }

}