NetBSD/sys/arch/i386/isa/intr.c

/*-
 * Copyright (c) 1993, 1994 Charles Hannum.
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *	from: @(#)isa.c	7.2 (Berkeley) 5/13/91
 *	$Id: intr.c,v 1.19 1994/04/25 22:12:14 mycroft Exp $
 */

#include <sys/param.h>
#include <sys/syslog.h>
#include <sys/device.h>

#include <machine/pio.h>
#include <machine/cpufunc.h>

#include <i386/isa/isareg.h>
#include <i386/isa/isavar.h>
#include <i386/isa/icu.h>

#define	IDTVEC(name)	__CONCAT(X,name)
/* default interrupt vector table entries */
extern IDTVEC(wild), IDTVEC(intr)[], IDTVEC(fast)[];

/*
 * Fill in default interrupt table (in case of spuruious interrupt
 * during configuration of kernel, setup interrupt control unit
 */
void
isa_defaultirq()
{
	int i;

	imask[IPL_BIO] |= SIR_CLOCKMASK;
	imask[IPL_NET] |= SIR_NETMASK;
	imask[IPL_TTY] |= SIR_TTYMASK;
	imask[IPL_CLOCK] |= SIR_CLOCKMASK;

	/* out of range vectors */
	for (i = NRSVIDT; i < NIDT; i++)
		setidt(i, &IDTVEC(wild), SDT_SYS386IGT, SEL_KPL);

	/* icu vectors */
	for (i = 0; i < ICU_LEN; i++)
		setidt(ICU_OFFSET + i, IDTVEC(intr)[i],  SDT_SYS386IGT, SEL_KPL);
  
	/* initialize 8259's */
	outb(IO_ICU1, 0x11);		/* reset; program device, four bytes */
	outb(IO_ICU1+1, ICU_OFFSET);	/* starting at this vector index */
	outb(IO_ICU1+1, IRQ_SLAVE);	/* slave on line 2 */
#ifdef AUTO_EOI_1
	outb(IO_ICU1+1, 2 | 1);		/* auto EOI, 8086 mode */
#else
	outb(IO_ICU1+1, 1);		/* 8086 mode */
#endif
	outb(IO_ICU1+1, 0xff);		/* leave interrupts masked */
	outb(IO_ICU1, 0x68);		/* special mask mode (if available) */
#ifdef REORDER_IRQ
	outb(IO_ICU1, 0xc0 | (3 - 1));	/* pri order 3-7, 0-2 (com2 first) */
#endif

	outb(IO_ICU2, 0x11);		/* reset; program device, four bytes */
	outb(IO_ICU2+1, ICU_OFFSET+8);	/* staring at this vector index */
	outb(IO_ICU2+1, ffs(IRQ_SLAVE)-1);
#ifdef AUTO_EOI_2
	outb(IO_ICU2+1, 2 | 1);		/* auto EOI, 8086 mode */
#else
	outb(IO_ICU2+1, 1);		/* 8086 mode */
#endif
	outb(IO_ICU2+1, 0xff);		/* leave interrupts masked */
	outb(IO_ICU2, 0x68);		/* special mask mode (if available) */

	splhigh();
	enable_intr();
}

/*
 * Handle a NMI, possibly a machine check.
 * return true to panic system, false to ignore.
 */
int
isa_nmi()
{

	log(LOG_CRIT, "NMI port 61 %x, port 70 %x\n", inb(0x61), inb(0x70));
	return(0);
}

/*
 * Caught a stray interrupt, notify
 */
void
isa_strayintr(irq)
	int irq;
{
	static u_long strays, wilds;

        /*
         * Stray interrupts on irq 7 occur when an interrupt line is raised
         * and then lowered before the CPU acknowledges it.  This generally
         * means either the device is screwed or something is cli'ing too
         * long and it's timing out.
         *
         * -1 is passed by the generic handler for out of range exceptions,
         * since we don't really want 208 little vectors just to get the
	 * message right.  (It wouldn't be all that much code, but why bother?)
         */
	if (irq == -1) {
		++wilds;
		log(LOG_ERR, "wild interrupt\n");
	} else {
		if (++strays <= 5)
			log(LOG_ERR, "stray interrupt %d%s\n", irq,
			    strays >= 5 ? "; stopped logging" : "");
	}
}

int fastvec;
int intrmask[ICU_LEN], intrlevel[ICU_LEN];
struct intrhand *intrhand[ICU_LEN];

void
intr_establish(mask, ih)
	int mask;
	struct intrhand *ih;
{
	int n, irq;
	struct intrhand **p, *q;

	irq = ffs(mask) - 1;

	if (irq < 0 || irq > ICU_LEN)
		panic("intr_establish: bogus irq");
	if (fastvec & mask)
		panic("intr_establish: irq is already fast vector");

	if (ih->ih_level != IPL_NONE) {
		imask[ih->ih_level] |= mask;
		for (n = 0; n < ICU_LEN; n++)
			if (intrlevel[n] & (1 << ih->ih_level))
				intrmask[n] |= mask;
		intrlevel[irq] |= 1 << ih->ih_level;
		intrmask[irq] |= imask[ih->ih_level];
	} else
		intrmask[irq] |= mask;

	ih->ih_count = 0;
	ih->ih_next = NULL;

	/*
	 * This is O(N^2), but we want to preserve the order, and N is
	 * generally small.
	 */
	for (p = &intrhand[irq]; (q = *p) != NULL; p = &q->ih_next)
		;
	*p = ih;

	if (irq >= 8)
		mask |= IRQ_SLAVE;
	INTREN(mask);
}

void
intr_disestablish(mask, ih)
	int mask;
	struct intrhand *ih;
{
	int n, irq, maxirq;
	struct intrhand **p, *q;

	irq = ffs(mask) - 1;

	if (irq < 0 || irq > ICU_LEN)
		panic("intr_disestablish: bogus irq");
	if (fastvec & mask)
		fastvec &= ~mask;

	/* Remove the handler from the chain. */
	for (p = &intrhand[irq]; (q = *p) != NULL && q != ih; p = &q->ih_next)
		;
	if (q)
		*p = q->ih_next;
	else
		panic("intr_disestablish: handler not registered");

	/* See if there are still any handlers with the same level. */
	for (q = intrhand[irq]; q; q = q->ih_next)
		if (q->ih_level == ih->ih_level)
			break;
	/* If so, we're done. */
	if (q)
		return;

	/*
	 * Remove the IRQ from any interrupt masks with the old IPL, and remove
	 * anu IRQs which no longer share a common level from this IRQ's mask.
	 */
	if (ih->ih_level != IPL_NONE) {
		intrlevel[irq] &= ~(1 << ih->ih_level);
		for (n = 0; n < ICU_LEN; n++)
			if ((intrlevel[n] & (1 << ih->ih_level)) &&
			    (intrlevel[n] & intrlevel[irq]) == 0) {
				intrmask[n] &= ~mask;
				intrmask[irq] &= ~(1 << n);
			}
	}

	/* If there are more handlers on this IRQ, we're done. */
	if (intrhand[irq])
		return;

	/* Figure out if we should deactivate the slave IRQ. */
	maxirq = 7;
	for (n = 8; n < ICU_LEN; n++)
		if (intrhand[n]) {
			maxirq = n;
			break;
		}
	if (maxirq < 8)
		mask |= IRQ_SLAVE;

	/* Deactivate the interrupt. */
	INTRDIS(mask);
}