/*-
 * Copyright (c) 1995 Per Fogelstrom
 * Copyright (c) 1993, 1994 Charles M. Hannum.
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz and Don Ahn.
 *
 * 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.
 *
 *	$NetBSD: extintr.c,v 1.12 2000/02/14 12:45:52 tsubai Exp $
 *	@(#)isa.c	7.2 (Berkeley) 5/12/91
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/interrupt.h>
#include <sys/malloc.h>
#include <sys/kernel.h>

#include <vm/vm.h>
#include <vm/vm_kern.h>

#if 0 /* XXX: Not used yet and may never be. */
#include <machine/autoconf.h>
#endif

#include <machine/intr.h>
#include <machine/psl.h>
#include <machine/pio.h>

#include <machine/openpicreg.h>

#include <dev/ofw/openfirm.h>

#define	NIRQ		32
#define	HWIRQ_MAX	(NIRQ - 4 - 1)
#define	HWIRQ_MASK	0x0fffffff

void	intr_calculatemasks(void);
char	*intr_typename(int);
int	fakeintr(void *);

static __inline int	cntlzw(int);
static __inline int	read_irq(void);
static __inline int	mapirq(int);
static void		enable_irq(int);

static __inline u_int	openpic_read(int);
static __inline void	openpic_write(int, u_int);
void			openpic_enable_irq(int);
void			openpic_disable_irq(int);
void			openpic_set_priority(int, int);
static __inline int	openpic_read_irq(int);
static __inline void	openpic_eoi(int);

unsigned int	imen = 0xffffffff;
u_int		cpl, ipending, tickspending;
int		imask[NIPL];

int		intrtype[NIRQ], intrmask[NIRQ], intrlevel[NIRQ];
struct intrhand	*intrhand[NIRQ];

static u_char	hwirq[NIRQ], virq[ICU_LEN];
static int	virq_max = 0;

static u_char	*obio_base, *openpic_base;

#if 0 /* XXX */
extern u_int	*heathrow_FCR;
#endif

extern void	install_extint(void (*)(void));

#define interrupt_reg	(obio_base + 0x10)

#define	INT_STATE_REG_H		(interrupt_reg + 0x00)
#define	INT_ENABLE_REG_H	(interrupt_reg + 0x04)
#define	INT_CLEAR_REG_H		(interrupt_reg + 0x08)
#define	INT_LEVEL_REG_H		(interrupt_reg + 0x0c)
#define	INT_STATE_REG_L		(interrupt_reg + 0x10)
#define	INT_ENABLE_REG_L	(interrupt_reg + 0x14)
#define	INT_CLEAR_REG_L		(interrupt_reg + 0x18)
#define	INT_LEVEL_REG_L		(interrupt_reg + 0x1c)

#define	have_openpic	(openpic_base != NULL)

/*
 * Map 64 irqs into 32 (bits).
 */
int
mapirq(irq)
	int	irq;
{
	int	v;

	if (irq < 0 || irq >= ICU_LEN)
		panic("invalid irq");
	if (virq[irq])
		return virq[irq];

	virq_max++;
	v = virq_max;
	if (v > HWIRQ_MAX)
		panic("virq overflow");

	hwirq[v] = irq;
	virq[irq] = v;

	return v;
}

/*
 * Count leading zeros.
 */
static __inline int
cntlzw(x)
	int	x;
{
	int	a;

	__asm __volatile ("cntlzw %0,%1" : "=r"(a) : "r"(x));

	return a;
}

int
read_irq()
{
	int	rv, lo, hi, p;

	rv = 0;
	lo = in32rb(INT_STATE_REG_L);
	if (lo)
		out32rb(INT_CLEAR_REG_L, lo);
	while (lo) {
		p = 31 - cntlzw(lo);
		rv |= 1 << virq[p];
		lo &= ~(1 << p);
	}

#if 0 /* XXX */
	if (heathrow_FCR)			/* has heathrow? */
		hi = in32rb(INT_STATE_REG_H);
	else
#endif
		hi = 0;

	if (hi)
		out32rb(INT_CLEAR_REG_H, hi);
	while (hi) {
		p = 31 - cntlzw(hi);
		rv |= 1 << virq[p + 32];
		hi &= ~(1 << p);
	}

	/* 1 << 0 is invalid. */
	return rv & ~1;
}

void
enable_irq(x)
	int	x;
{
	int	lo, hi, v, irq;

	x &= HWIRQ_MASK;	/* XXX Higher bits are software interrupts. */

	lo = hi = 0;
	while (x) {
		v = 31 - cntlzw(x);
		irq = hwirq[v];
		if (irq < 32)
			lo |= 1 << irq;
		else
			hi |= 1 << (irq - 32);
		x &= ~(1 << v);
	}

	out32rb(INT_ENABLE_REG_L, lo);
#if 0 /* XXX */
	if (heathrow_FCR)
		out32rb(INT_ENABLE_REG_H, hi);
#endif
}

u_int
openpic_read(reg)
	int	reg;
{
	char	*addr;

	addr = openpic_base + reg;

	return in32rb(addr);
}

void
openpic_write(reg, val)
	int	reg;
	u_int	val;
{
	char	*addr;

	addr = openpic_base + reg;

	out32rb(addr, val);
}

void
openpic_enable_irq(irq)
	int	irq;
{
	u_int	x;

	x = openpic_read(OPENPIC_SRC_VECTOR(irq));
	x &= ~OPENPIC_IMASK;
	openpic_write(OPENPIC_SRC_VECTOR(irq), x);
}

void
openpic_disable_irq(irq)
	int	irq;
{
	u_int	x;

	x = openpic_read(OPENPIC_SRC_VECTOR(irq));
	x |= OPENPIC_IMASK;
	openpic_write(OPENPIC_SRC_VECTOR(irq), x);
}

void
openpic_set_priority(cpu, pri)
	int	cpu, pri;
{
	u_int	x;

	x = openpic_read(OPENPIC_CPU_PRIORITY(cpu));
	x &= ~OPENPIC_CPU_PRIORITY_MASK;
	x |= pri;
	openpic_write(OPENPIC_CPU_PRIORITY(cpu), x);
}

int
openpic_read_irq(cpu)
	int	cpu;
{
	return openpic_read(OPENPIC_IACK(cpu)) & OPENPIC_VECTOR_MASK;
}

void
openpic_eoi(cpu)
	int	cpu;
{
	openpic_write(OPENPIC_EOI(cpu), 0);
	openpic_read(OPENPIC_EOI(cpu));
}

/*
 * Recalculate the interrupt masks from scratch.
 * We could code special registry and deregistry versions of this function that
 * would be faster, but the code would be nastier, and we don't expect this to
 * happen very much anyway.
 */
void
intr_calculatemasks()
{
	int	irq, level, irqs;
	struct intrhand	*q;

	irqs = 0;

	/* First, figure out which levels each IRQ uses. */
#if 0 /* XXX */
	for (irq = 0; irq < NIRQ; irq++) {
		register int levels = 0;
		for (q = intrhand[irq]; q; q = q->ih_next)
			levels |= 1 << q->ih_level;
		intrlevel[irq] = levels;
	}
#endif

	/* Then figure out which IRQs use each level. */
	for (level = 0; level < NIPL; level++) {
		register int irqs = 0;
		for (irq = 0; irq < NIRQ; irq++)
			if (intrlevel[irq] & (1 << level))
				irqs |= 1 << irq;
		imask[level] = irqs;
	}

	/*
	 * IPL_CLOCK should mask clock interrupt even if interrupt handler
	 * is not registered.
	 */
	imask[IPL_CLOCK] |= 1 << SPL_CLOCK;

	/*
	 * Initialize soft interrupt masks to block themselves.
	 */
	imask[IPL_SOFTCLOCK] = 1 << SIR_CLOCK;
	imask[IPL_SOFTNET] = 1 << SIR_NET;
	imask[IPL_SOFTSERIAL] = 1 << SIR_SERIAL;

	/*
	 * IPL_NONE is used for hardware interrupts that are never blocked,
	 * and do not block anything else.
	 */
	imask[IPL_NONE] = 0;

	/*
	 * Enforce a hierarchy that gives slow devices a better chance at not
	 * dropping data.
	 */
	imask[IPL_SOFTCLOCK] |= imask[IPL_NONE];
	imask[IPL_SOFTNET] |= imask[IPL_SOFTCLOCK];
	imask[IPL_BIO] |= imask[IPL_SOFTNET];
	imask[IPL_NET] |= imask[IPL_BIO];
	imask[IPL_SOFTSERIAL] |= imask[IPL_NET];
	imask[IPL_TTY] |= imask[IPL_SOFTSERIAL];

	/*
	 * There are tty, network and disk drivers that use free() at interrupt
	 * time, so imp > (tty | net | bio).
	 */
	imask[IPL_IMP] |= imask[IPL_TTY];

	imask[IPL_AUDIO] |= imask[IPL_IMP];

	/*
	 * Since run queues may be manipulated by both the statclock and tty,
	 * network, and disk drivers, clock > imp.
	 */
	imask[IPL_CLOCK] |= imask[IPL_AUDIO];

	/*
	 * IPL_HIGH must block everything that can manipulate a run queue.
	 */
	imask[IPL_HIGH] |= imask[IPL_CLOCK];

	/*
	 * We need serial drivers to run at the absolute highest priority to
	 * avoid overruns, so serial > high.
	 */
	imask[IPL_SERIAL] |= imask[IPL_HIGH];

	/* And eventually calculate the complete masks. */
#if 0 /* XXX */
	for (irq = 0; irq < NIRQ; irq++) {
		register int irqs = 1 << irq;
		for (q = intrhand[irq]; q; q = q->ih_next)
			irqs |= imask[q->ih_level];
		intrmask[irq] = irqs;
	}
#endif

	/* Lastly, determine which IRQs are actually in use. */
	for (irq = 0; irq < NIRQ; irq++)
		if (intrhand[irq])
			irqs |= 1 << irq;

	if (have_openpic) {
		for (irq = 0; irq < NIRQ; irq++) {
			if (irqs & (1 << irq))
				openpic_enable_irq(hwirq[irq]);
			else
				openpic_disable_irq(hwirq[irq]);
		}
	} else {
		imen = ~irqs;
		enable_irq(~imen);
	}
}

int
fakeintr(arg)
	void *arg;
{

	return 0;
}

#define	LEGAL_IRQ(x)	((x) >= 0 && (x) < NIRQ)

char *
intr_typename(type)
	int	type;
{

	switch (type) {
        case IST_NONE :
		return ("none");
        case IST_PULSE:
		return ("pulsed");
        case IST_EDGE:
		return ("edge-triggered");
        case IST_LEVEL:
		return ("level-triggered");
	default:
		panic("intr_typename: invalid type %d", type);
#if 1 /* XXX */
		return ("unknown");
#endif
	}
}

/*
 * Register an interrupt handler.
 */
void *
intr_establish(int irq, int type, int level, int (*ih_fun)(void *),
    void *ih_arg)
{
	struct intrhand		**p, *q, *ih;
	static struct intrhand	fakehand = {fakeintr};

	irq = mapirq(irq);

	/* no point in sleeping unless someone can free memory. */
	ih = malloc(sizeof *ih, M_DEVBUF, cold ? M_NOWAIT : M_WAITOK);
	if (ih == NULL)
		panic("intr_establish: can't malloc handler info");

	if (!LEGAL_IRQ(irq) || type == IST_NONE)
		panic("intr_establish: bogus irq or type");

	switch (intrtype[irq]) {
	case IST_NONE:
		intrtype[irq] = type;
		break;
	case IST_EDGE:
	case IST_LEVEL:
		if (type == intrtype[irq])
			break;
	case IST_PULSE:
		if (type != IST_NONE)
			panic("intr_establish: can't share %s with %s",
			    intr_typename(intrtype[irq]),
			    intr_typename(type));
		break;
	}

	/*
	 * Figure out where to put the handler.
	 * This is O(N^2), but we want to preserve the order, and N is
	 * generally small.
	 */
#if 0 /* XXX */
	for (p = &intrhand[irq]; (q = *p) != NULL; p = &q->ih_next)
		;
#endif

	/*
	 * Actually install a fake handler momentarily, since we might be doing
	 * this with interrupts enabled and don't want the real routine called
	 * until masking is set up.
	 */
#if 0 /* XXX */
	fakehand.ih_level = level;
#endif
	*p = &fakehand;

	intr_calculatemasks();

	/*
	 * Poke the real handler in now.
	 */
#if 0
	ih->ih_fun = ih_fun;
	ih->ih_arg = ih_arg;
	ih->ih_count = 0;
	ih->ih_next = NULL;
	ih->ih_level = level;
	ih->ih_irq = irq;
#endif
	*p = ih;

	return (ih);
}

/*
 * Deregister an interrupt handler.
 */
void
intr_disestablish(void *arg)
{
	struct intrhand	*ih, **p, *q;
	int		irq;

#if 0 /* XXX */
	irq = ih->ih_irq;
#endif

	ih = arg;

	if (!LEGAL_IRQ(irq))
		panic("intr_disestablish: bogus irq");

	/*
	 * Remove the handler from the chain.
	 * This is O(n^2), too.
	 */
	for (p = &intrhand[irq]; (q = *p) != NULL && q != ih; p = &q->ih_next)
		;
	if (q)
#if 0 /* XXX */
		*p = q->ih_next;
#else
		p = p;
#endif
	else
		panic("intr_disestablish: handler not registered");
	free((void *)ih, M_DEVBUF);

	intr_calculatemasks();

	if (intrhand[irq] == NULL)
		intrtype[irq] = IST_NONE;
}

/*
 * external interrupt handler
 */
void
ext_intr(void)
{
	int		irq;
	int		o_imen, r_imen;
	int		pcpl;
	struct intrhand	*ih;
	volatile unsigned long	int_state;

	pcpl = splhigh();	/* Turn off all */

	int_state = read_irq();
	if (int_state == 0)
		goto out;

start:
	irq = 31 - cntlzw(int_state);

	o_imen = imen;
	r_imen = 1 << irq;

	if ((pcpl & r_imen) != 0) {
		ipending |= r_imen;	/* Masked! Mark this as pending */
		imen |= r_imen;
		enable_irq(~imen);
	} else {
		ih = intrhand[irq];
		while (ih) {
#if 0 /* XXX */
			(*ih->ih_fun)(ih->ih_arg);
			ih = ih->ih_next;
#endif
		}

		intrcnt[hwirq[irq]]++;
	}

	int_state &= ~r_imen;
	if (int_state)
		goto start;

out:
	splx(pcpl);	/* Process pendings. */
}

void
ext_intr_openpic()
{
	int		irq, realirq;
	int		r_imen;
	int		pcpl;
	struct intrhand	*ih;

	pcpl = splhigh();	/* Turn off all */

	realirq = openpic_read_irq(0);
	if (realirq == 255) {
		printf("sprious interrupt\n");
		goto out;
	}

start:
	irq = virq[realirq];

	/* XXX check range */

	r_imen = 1 << irq;

	if ((pcpl & r_imen) != 0) {
		ipending |= r_imen;	/* Masked! Mark this as pending */
		openpic_disable_irq(realirq);
	} else {
		ih = intrhand[irq];
		while (ih) {
#if 0 /* XXX */
			(*ih->ih_fun)(ih->ih_arg);
			ih = ih->ih_next;
#endif
		}

		intrcnt[hwirq[irq]]++;
	}

	openpic_eoi(0);

	realirq = openpic_read_irq(0);
	if (realirq != 255)
		goto start;

out:
	splx(pcpl);	/* Process pendings. */
}

void
do_pending_int()
{
	struct intrhand	*ih;
	int		irq;
	int		pcpl;
	int		hwpend;
	int		emsr, dmsr;
	static int	processing;

	return;	/* XXX */

	if (processing)
		return;

	processing = 1;
	emsr = mfmsr();
	dmsr = emsr & ~PSL_EE;
	mtmsr(dmsr);

	pcpl = splhigh();		/* Turn off all */
	hwpend = ipending & ~pcpl;	/* Do now unmasked pendings */
	if (!have_openpic) {
		imen &= ~hwpend;
		enable_irq(~imen);
	}
	hwpend &= HWIRQ_MASK;
	while (hwpend) {
		irq = 31 - cntlzw(hwpend);
		hwpend &= ~(1L << irq);
		ih = intrhand[irq];
		while(ih) {
#if 0 /* XXX */
			(*ih->ih_fun)(ih->ih_arg);
			ih = ih->ih_next;
#endif
		}

		intrcnt[hwirq[irq]]++;
		if (have_openpic)
			openpic_enable_irq(hwirq[irq]);
	}

	/*out32rb(INT_ENABLE_REG, ~imen);*/

	if ((ipending & ~pcpl) & (1 << SIR_CLOCK)) {
		ipending &= ~(1 << SIR_CLOCK);
		softclock(NULL);
		intrcnt[CNT_SOFTCLOCK]++;
	}
#if 0 /* XXX */
	if ((ipending & ~pcpl) & (1 << SIR_NET)) {
		ipending &= ~(1 << SIR_NET);
		softnet();
		intrcnt[CNT_SOFTNET]++;
	}
	if ((ipending & ~pcpl) & (1 << SIR_SERIAL)) {
		ipending &= ~(1 << SIR_SERIAL);
		softserial();
		intrcnt[CNT_SOFTSERIAL]++;
	}
#endif
	ipending &= pcpl;
	cpl = pcpl;	/* Don't use splx... we are here already! */
	mtmsr(emsr);
	processing = 0;
}

void
openpic_init(void)
{
	int	irq;
	u_int	x;

	/* disable all interrupts */
	for (irq = 0; irq < 256; irq++)
		openpic_write(OPENPIC_SRC_VECTOR(irq), OPENPIC_IMASK);

	openpic_set_priority(0, 15);

	/* we don't need 8259 pass through mode */
	x = openpic_read(OPENPIC_CONFIG);
	x |= OPENPIC_CONFIG_8259_PASSTHRU_DISABLE;
	openpic_write(OPENPIC_CONFIG, x);

	/* send all interrupts to cpu 0 */
	for (irq = 0; irq < ICU_LEN; irq++)
		openpic_write(OPENPIC_IDEST(irq), 1 << 0);

	for (irq = 0; irq < ICU_LEN; irq++) {
		x = irq;
		x |= OPENPIC_IMASK;
		x |= OPENPIC_POLARITY_POSITIVE;
		x |= OPENPIC_SENSE_LEVEL;
		x |= 8 << OPENPIC_PRIORITY_SHIFT;
		openpic_write(OPENPIC_SRC_VECTOR(irq), x);
	}

	/* XXX set spurious intr vector */

	openpic_set_priority(0, 0);

	/* clear all pending interrunts */
	for (irq = 0; irq < 256; irq++) {
		openpic_read_irq(0);
		openpic_eoi(0);
	}

	for (irq = 0; irq < ICU_LEN; irq++)
		openpic_disable_irq(irq);

	install_extint(ext_intr_openpic);
}

void
legacy_int_init(void)
{
	out32rb(INT_ENABLE_REG_L, 0);		/* disable all intr. */
	out32rb(INT_CLEAR_REG_L, 0xffffffff);	/* clear pending intr. */

	install_extint(ext_intr);
}

#define HEATHROW_FCR_OFFSET	0x38		/* XXX should not here */
#define GC_OBIO_BASE		0xf3000000

void
init_interrupt(void)
{
	int	chosen;
	int	mac_io, reg[5];
	int32_t	ictlr;
	char	type[32];

	openpic_base = NULL;

	mac_io = OF_finddevice("mac-io");
	if (mac_io == -1)
		mac_io = OF_finddevice("/pci/mac-io");

	if (mac_io == -1) {
		/*
		 * No mac-io.  Assume Grand-Central or OHare.
		 */
		obio_base = (void *)GC_OBIO_BASE;
		legacy_int_init();
		return;
	}

	if (OF_getprop(mac_io, "assigned-addresses", reg, sizeof(reg)) < 20)
		goto failed;

	obio_base = (void *)reg[2];
#if 0 /* XXX */
	heathrow_FCR = (void *)(obio_base + HEATHROW_FCR_OFFSET);
#endif

	bzero(type, sizeof(type));
	chosen = OF_finddevice("/chosen");
	if (OF_getprop(chosen, "interrupt-controller", &ictlr, 4) == 4)
		OF_getprop(ictlr, "device_type", type, sizeof(type));

	if (strcmp(type, "open-pic") != 0) {
		/*
		 * Not an open-pic.  Must be a Heathrow (compatible).
		 */
		legacy_int_init();
		return;
	} else {
		/*
		 * We have an Open PIC.
		 */
		if (OF_getprop(ictlr, "reg", reg, sizeof(reg)) < 8)
			goto failed;

		openpic_base = (void *)(obio_base + reg[0]);
		openpic_init();
		return;
	}

	printf("unknown interrupt controller\n");
failed:
	panic("init_interrupt: failed to initialize interrupt controller");
}