sparc64/sparc64/clock.c

/*	$OpenBSD: clock.c,v 1.67 2020/10/20 15:59:17 cheloha Exp $	*/
/*	$NetBSD: clock.c,v 1.41 2001/07/24 19:29:25 eeh Exp $ */

/*
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1994 Gordon W. Ross
 * Copyright (c) 1993 Adam Glass
 * Copyright (c) 1996 Paul Kranenburg
 * Copyright (c) 1996
 * 	The President and Fellows of Harvard College. All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * All advertising materials mentioning features or use of this software
 * must display the following acknowledgement:
 *	This product includes software developed by Harvard University.
 *	This product includes software developed by the University of
 *	California, Lawrence Berkeley Laboratory.
 *
 * 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.
 *	This product includes software developed by Paul Kranenburg.
 *	This product includes software developed by Harvard University.
 * 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.
 *
 *	@(#)clock.c	8.1 (Berkeley) 6/11/93
 *
 */

/*
 * Clock driver.  This is the id prom and eeprom driver as well
 * and includes the timer register functions too.
 */

/* Define this for a 1/4s clock to ease debugging */
/* #define INTR_DEBUG */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#ifdef GPROF
#include <sys/gmon.h>
#endif
#include <sys/sched.h>
#include <sys/timetc.h>
#include <sys/atomic.h>

#include <machine/bus.h>
#include <machine/autoconf.h>
#include <machine/cpu.h>
#include <machine/idprom.h>

#include <dev/clock_subr.h>
#include <dev/ic/mk48txxreg.h>

#include <sparc64/sparc64/intreg.h>
#include <sparc64/sparc64/timerreg.h>
#include <sparc64/dev/iommureg.h>
#include <sparc64/dev/sbusreg.h>
#include <dev/sbus/sbusvar.h>
#include <sparc64/dev/ebusreg.h>
#include <sparc64/dev/ebusvar.h>
#include <sparc64/dev/fhcvar.h>

extern u_int64_t cpu_clockrate;

struct clock_wenable_info {
	bus_space_tag_t		cwi_bt;
	bus_space_handle_t	cwi_bh;
	bus_size_t		cwi_size;
};

struct cfdriver clock_cd = {
	NULL, "clock", DV_DULL
};

u_int tick_get_timecount(struct timecounter *);

struct timecounter tick_timecounter = {
	tick_get_timecount, NULL, ~0u, 0, "tick", 0,
	NULL, TC_TICK
};

u_int sys_tick_get_timecount(struct timecounter *);

struct timecounter sys_tick_timecounter = {
	sys_tick_get_timecount, NULL, ~0u, 0, "sys_tick", 1000,
	NULL, TC_SYS_TICK
};

/*
 * Statistics clock interval and variance, in usec.  Variance must be a
 * power of two.  Since this gives us an even number, not an odd number,
 * we discard one case and compensate.  That is, a variance of 1024 would
 * give us offsets in [0..1023].  Instead, we take offsets in [1..1023].
 * This is symmetric about the point 512, or statvar/2, and thus averages
 * to that value (assuming uniform random numbers).
 */
/* XXX fix comment to match value */
int statvar = 8192;
int statmin;			/* statclock interval - 1/2*variance */

static long tick_increment;

void	tick_start(void);
void	sys_tick_start(void);
void	stick_start(void);

int	tickintr(void *);
int	sys_tickintr(void *);
int	stickintr(void *);
int	schedintr(void *);

static struct intrhand level10 = { clockintr };
static struct intrhand level0 = { tickintr };
static struct intrhand level14 = { statintr };
static struct intrhand schedint = { schedintr };

/*
 * clock (eeprom) attaches at the sbus or the ebus (PCI)
 */
static int	clockmatch_sbus(struct device *, void *, void *);
static void	clockattach_sbus(struct device *, struct device *, void *);
static int	clockmatch_ebus(struct device *, void *, void *);
static void	clockattach_ebus(struct device *, struct device *, void *);
static int	clockmatch_fhc(struct device *, void *, void *);
static void	clockattach_fhc(struct device *, struct device *, void *);
static void	clockattach(int, bus_space_tag_t, bus_space_handle_t);

struct cfattach clock_sbus_ca = {
	sizeof(struct device), clockmatch_sbus, clockattach_sbus
};

struct cfattach clock_ebus_ca = {
	sizeof(struct device), clockmatch_ebus, clockattach_ebus
};

struct cfattach clock_fhc_ca = {
	sizeof(struct device), clockmatch_fhc, clockattach_fhc
};

/* Global TOD clock handle & idprom pointer */
extern todr_chip_handle_t todr_handle;
static struct idprom *idprom;

static int	timermatch(struct device *, void *, void *);
static void	timerattach(struct device *, struct device *, void *);

struct timerreg_4u	timerreg_4u;	/* XXX - need more cleanup */

struct cfattach timer_ca = {
	sizeof(struct device), timermatch, timerattach
};

struct cfdriver timer_cd = {
	NULL, "timer", DV_DULL
};

int clock_bus_wenable(struct todr_chip_handle *, int);
struct chiptime;
void myetheraddr(u_char *);
struct idprom *getidprom(void);
int chiptotime(int, int, int, int, int, int);
void timetochip(struct chiptime *);
void stopcounter(struct timer_4u *);

int timerblurb = 10; /* Guess a value; used before clock is attached */

/*
 * The OPENPROM calls the clock the "eeprom", so we have to have our
 * own special match function to call it the "clock".
 */
static int
clockmatch_sbus(parent, cf, aux)
	struct device *parent;
	void *cf;
	void *aux;
{
	struct sbus_attach_args *sa = aux;

	return (strcmp("eeprom", sa->sa_name) == 0);
}

static int
clockmatch_ebus(parent, cf, aux)
	struct device *parent;
	void *cf;
	void *aux;
{
	struct ebus_attach_args *ea = aux;

	return (strcmp("eeprom", ea->ea_name) == 0);
}

static int
clockmatch_fhc(parent, cf, aux)
	struct device *parent;
	void *cf;
	void *aux;
{
	struct fhc_attach_args *fa = aux;

	return (strcmp("eeprom", fa->fa_name) == 0);
}

/*
 * Attach a clock (really `eeprom') to the sbus or ebus.
 *
 * We ignore any existing virtual address as we need to map
 * this read-only and make it read-write only temporarily,
 * whenever we read or write the clock chip.  The clock also
 * contains the ID ``PROM'', and I have already had the pleasure
 * of reloading the cpu type, Ethernet address, etc, by hand from
 * the console FORTH interpreter.  I intend not to enjoy it again.
 *
 * the MK48T02 is 2K.  the MK48T08 is 8K, and the MK48T59 is
 * supposed to be identical to it.
 *
 * This is *UGLY*!  We probably have multiple mappings.  But I do
 * know that this all fits inside an 8K page, so I'll just map in
 * once.
 *
 * What we really need is some way to record the bus attach args
 * so we can call *_bus_map() later with BUS_SPACE_MAP_READONLY
 * or not to write enable/disable the device registers.  This is
 * a non-trivial operation.
 */

/* ARGSUSED */
static void
clockattach_sbus(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct sbus_attach_args *sa = aux;
	bus_space_tag_t bt = sa->sa_bustag;
	int sz;
	static struct clock_wenable_info cwi;

	/* use sa->sa_regs[0].size? */
	sz = 8192;

	if (sbus_bus_map(bt,
			 sa->sa_slot,
			 (sa->sa_offset & ~NBPG),
			 sz,
			 BUS_SPACE_MAP_LINEAR | BUS_SPACE_MAP_READONLY,
			 0, &cwi.cwi_bh) != 0) {
		printf("%s: can't map register\n", self->dv_xname);
		return;
	}
	clockattach(sa->sa_node, bt, cwi.cwi_bh);

	/* Save info for the clock wenable call. */
	cwi.cwi_bt = bt;
	cwi.cwi_size = sz;
	todr_handle->bus_cookie = &cwi;
	todr_handle->todr_setwen = clock_bus_wenable;
}

/*
 * Write en/dis-able clock registers.  We coordinate so that several
 * writers can run simultaneously.
 * XXX There is still a race here.  The page change and the "writers"
 * change are not atomic.
 */
int
clock_bus_wenable(handle, onoff)
	struct todr_chip_handle *handle;
	int onoff;
{
	int s, err = 0;
	int prot; /* nonzero => change prot */
	volatile static int writers;
	struct clock_wenable_info *cwi = handle->bus_cookie;

	s = splhigh();
	if (onoff)
		prot = writers++ == 0 ? 1 : 0;
	else
		prot = --writers == 0 ? 1 : 0;
	splx(s);

	if (prot) {
		err = bus_space_protect(cwi->cwi_bt, cwi->cwi_bh, cwi->cwi_size,
		    onoff ? 0 : BUS_SPACE_MAP_READONLY);
		if (err)
			printf("clock_wenable_info: WARNING -- cannot %s "
			    "page protection\n", onoff ? "disable" : "enable");
	}
	return (err);
}

/* ARGSUSED */
static void
clockattach_ebus(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct ebus_attach_args *ea = aux;
	bus_space_tag_t bt;
	int sz;
	static struct clock_wenable_info cwi;

	/* hard code to 8K? */
	sz = ea->ea_regs[0].size;

	if (ea->ea_nvaddrs) {
		if (bus_space_map(ea->ea_memtag, ea->ea_vaddrs[0], 0,
		    BUS_SPACE_MAP_PROMADDRESS, &cwi.cwi_bh) != 0) {
			printf("%s: can't map register\n", self->dv_xname);
			return;
		}
		bt = ea->ea_memtag;
	} else if (ebus_bus_map(ea->ea_iotag, 0,
	    EBUS_PADDR_FROM_REG(&ea->ea_regs[0]), sz, 0, 0, &cwi.cwi_bh) == 0) {
		bt = ea->ea_iotag;
	} else if (ebus_bus_map(ea->ea_memtag, 0,
	    EBUS_PADDR_FROM_REG(&ea->ea_regs[0]), sz,
	    BUS_SPACE_MAP_LINEAR | BUS_SPACE_MAP_READONLY,
	    0, &cwi.cwi_bh) == 0) {
		bt = ea->ea_memtag;
	} else {
		printf("%s: can't map register\n", self->dv_xname);
		return;
	}

	clockattach(ea->ea_node, bt, cwi.cwi_bh);

	/* Save info for the clock wenable call. */
	cwi.cwi_bt = bt;
	cwi.cwi_size = sz;
	todr_handle->bus_cookie = &cwi;
	todr_handle->todr_setwen = (ea->ea_memtag == bt) ?
	    clock_bus_wenable : NULL;
}

static void
clockattach_fhc(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct fhc_attach_args *fa = aux;
	bus_space_tag_t bt = fa->fa_bustag;
	int sz;
	static struct clock_wenable_info cwi;

	/* use sa->sa_regs[0].size? */
	sz = 8192;

	if (fhc_bus_map(bt, fa->fa_reg[0].fbr_slot,
	    (fa->fa_reg[0].fbr_offset & ~NBPG), fa->fa_reg[0].fbr_size,
	    BUS_SPACE_MAP_LINEAR | BUS_SPACE_MAP_READONLY, &cwi.cwi_bh) != 0) {
		printf("%s: can't map register\n", self->dv_xname);
		return;
	}

	clockattach(fa->fa_node, bt, cwi.cwi_bh);

	/* Save info for the clock wenable call. */
	cwi.cwi_bt = bt;
	cwi.cwi_size = sz;
	todr_handle->bus_cookie = &cwi;
	todr_handle->todr_setwen = clock_bus_wenable;
}

static void
clockattach(node, bt, bh)
	int node;
	bus_space_tag_t bt;
	bus_space_handle_t bh;
{
	char *model;
	struct idprom *idp;
	int h;

	model = getpropstring(node, "model");

#ifdef DIAGNOSTIC
	if (model == NULL)
		panic("clockattach: no model property");
#endif

	/* Our TOD clock year 0 is 1968 */
	if ((todr_handle = mk48txx_attach(bt, bh, model, 1968)) == NULL)
		panic("Can't attach %s tod clock", model);

#define IDPROM_OFFSET (8*1024 - 40)	/* XXX - get nvram sz from driver */
	if (idprom == NULL) {
		idp = getidprom();
		if (idp == NULL)
			idp = (struct idprom *)(bus_space_vaddr(bt, bh) +
			    IDPROM_OFFSET);
		idprom = idp;
	} else
		idp = idprom;
	h = idp->id_machine << 24;
	h |= idp->id_hostid[0] << 16;
	h |= idp->id_hostid[1] << 8;
	h |= idp->id_hostid[2];
	hostid = h;
	printf("\n");
}

struct idprom *
getidprom(void)
{
	struct idprom *idp = NULL;
	int node, n;

	node = findroot();
	if (getprop(node, "idprom", sizeof(*idp), &n, (void **)&idp) != 0)
		return (NULL);
	if (n != 1) {
		free(idp, M_DEVBUF, 0);
		return (NULL);
	}
	return (idp);
}

/*
 * The sun4u OPENPROMs call the timer the "counter-timer", except for
 * the lame UltraSPARC IIi PCI machines that don't have them.
 */
static int
timermatch(parent, cf, aux)
	struct device *parent;
	void *cf;
	void *aux;
{
#ifndef MULTIPROCESSOR
	struct mainbus_attach_args *ma = aux;

	if (!timerreg_4u.t_timer || !timerreg_4u.t_clrintr)
		return (strcmp("counter-timer", ma->ma_name) == 0);
	else
#endif
		return (0);
}

static void
timerattach(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct mainbus_attach_args *ma = aux;
	u_int *va = ma->ma_address;

	/*
	 * What we should have are 3 sets of registers that reside on
	 * different parts of SYSIO or PSYCHO.  We'll use the prom
	 * mappings cause we can't get rid of them and set up appropriate
	 * pointers on the timerreg_4u structure.
	 */
	timerreg_4u.t_timer = (struct timer_4u *)(u_long)va[0];
	timerreg_4u.t_clrintr = (int64_t *)(u_long)va[1];
	timerreg_4u.t_mapintr = (int64_t *)(u_long)va[2];

	/* Install the appropriate interrupt vector here */
	level10.ih_number = INTVEC(ma->ma_interrupts[0]);
	level10.ih_clr = (void *)&timerreg_4u.t_clrintr[0];
	level10.ih_map = (void *)&timerreg_4u.t_mapintr[0];
	strlcpy(level10.ih_name, "clock", sizeof(level10.ih_name));
	intr_establish(10, &level10);

	level14.ih_number = INTVEC(ma->ma_interrupts[1]);
	level14.ih_clr = (void *)&timerreg_4u.t_clrintr[1];
	level14.ih_map = (void *)&timerreg_4u.t_mapintr[1];
	strlcpy(level14.ih_name, "prof", sizeof(level14.ih_name));
	intr_establish(14, &level14);

	printf(" ivec 0x%llx, 0x%llx\n", INTVEC(level10.ih_number),
	    INTVEC(level14.ih_number));
}

void
stopcounter(creg)
	struct timer_4u *creg;
{
	/* Stop the clock */
	volatile int discard;
	discard = creg->t_limit;
	creg->t_limit = 0;
}

/*
 * XXX this belongs elsewhere
 */
void
myetheraddr(cp)
	u_char *cp;
{
	struct idprom *idp;

	if ((idp = idprom) == NULL) {
		int node, n;

		node = findroot();
		if (getprop(node, "idprom", sizeof *idp, &n, (void **)&idp) ||
		    n != 1) {
			printf("\nmyetheraddr: clock not setup yet, "
			       "and no idprom property in /\n");
			return;
		}
	}

	cp[0] = idp->id_ether[0];
	cp[1] = idp->id_ether[1];
	cp[2] = idp->id_ether[2];
	cp[3] = idp->id_ether[3];
	cp[4] = idp->id_ether[4];
	cp[5] = idp->id_ether[5];
	if (idprom == NULL)
		free(idp, M_DEVBUF, 0);
}

/*
 * Set up the real-time and statistics clocks.  Leave stathz 0 only if
 * no alternative timer is available.
 *
 * The frequencies of these clocks must be an even number of microseconds.
 */
void
cpu_initclocks(void)
{
	int statint, minint;
#ifdef DEBUG
	extern int intrdebug;
#endif
	u_int sys_tick_rate;
	int impl = 0;

#ifdef DEBUG
	/* Set a 1s clock */
	if (intrdebug) {
		hz = 1;
		tick = 1000000 / hz;
		tick_nsec = 1000000000 / hz;
		printf("intrdebug set: 1Hz clock\n");
	}
#endif

	if (1000000 % hz) {
		printf("cannot get %d Hz clock; using 100 Hz\n", hz);
		hz = 100;
		tick = 1000000 / hz;
		tick_nsec = 1000000000 / hz;
	}

	/* Make sure we have a sane cpu_clockrate -- we'll need it */
	if (!cpu_clockrate)
		/* Default to 200MHz clock XXXXX */
		cpu_clockrate = 200000000;

	tick_timecounter.tc_frequency = cpu_clockrate;
	tc_init(&tick_timecounter);

	/*
	 * UltraSPARC IIe processors do have a STICK register, but it
	 * lives on the PCI host bridge and isn't accessable through
	 * ASR24.
	 */
	if (CPU_ISSUN4U || CPU_ISSUN4US)
		impl = (getver() & VER_IMPL) >> VER_IMPL_SHIFT;

	sys_tick_rate = getpropint(findroot(), "stick-frequency", 0);
	if (sys_tick_rate > 0 && impl != IMPL_HUMMINGBIRD) {
		sys_tick_timecounter.tc_frequency = sys_tick_rate;
		tc_init(&sys_tick_timecounter);
	}

	/*
	 * Now handle machines w/o counter-timers.
	 */

	if (!timerreg_4u.t_timer || !timerreg_4u.t_clrintr) {
		struct cpu_info *ci;

		/* We don't have a counter-timer -- use %tick */
		level0.ih_clr = 0;

		/*
		 * Establish a level 10 interrupt handler
		 *
		 * We will have a conflict with the softint handler,
		 * so we set the ih_number to 1.
		 */
		level0.ih_number = 1;
		strlcpy(level0.ih_name, "clock", sizeof(level0.ih_name));
		intr_establish(10, &level0);

		/* We only have one timer so we have no statclock */
		stathz = 0;

		if (sys_tick_rate > 0) {
			tick_increment = sys_tick_rate / hz;
			if (impl == IMPL_HUMMINGBIRD) {
				level0.ih_fun = stickintr;
				cpu_start_clock = stick_start;
			} else {
				level0.ih_fun = sys_tickintr;
				cpu_start_clock = sys_tick_start;
			}
		} else {
			/* set the next interrupt time */
			tick_increment = cpu_clockrate / hz;
			level0.ih_fun = tickintr;
			cpu_start_clock = tick_start;
		}

		for (ci = cpus; ci != NULL; ci = ci->ci_next)
			memcpy(&ci->ci_tickintr, &level0, sizeof(level0));

		cpu_start_clock();

		return;
	}

	if (stathz == 0)
		stathz = hz;
	if (1000000 % stathz) {
		printf("cannot get %d Hz statclock; using 100 Hz\n", stathz);
		stathz = 100;
	}

	profhz = stathz;		/* always */

	statint = 1000000 / stathz;
	minint = statint / 2 + 100;
	while (statvar > minint)
		statvar >>= 1;

	/*
	 * Establish scheduler softint.
	 */
	schedint.ih_pil = PIL_SCHED;
	schedint.ih_clr = NULL;
	schedint.ih_arg = 0;
	schedint.ih_pending = 0;
	schedhz = stathz/4;

	/*
	 * Enable timers
	 *
	 * Also need to map the interrupts cause we're not a child of the sbus.
	 * N.B. By default timer[0] is disabled and timer[1] is enabled.
	 */
	stxa((vaddr_t)&timerreg_4u.t_timer[0].t_limit, ASI_NUCLEUS,
	     tmr_ustolim(tick)|TMR_LIM_IEN|TMR_LIM_PERIODIC|TMR_LIM_RELOAD);
	stxa((vaddr_t)&timerreg_4u.t_mapintr[0], ASI_NUCLEUS,
	     timerreg_4u.t_mapintr[0]|INTMAP_V);

#ifdef DEBUG
	if (intrdebug)
		/* Neglect to enable timer */
		stxa((vaddr_t)&timerreg_4u.t_timer[1].t_limit, ASI_NUCLEUS,
		     tmr_ustolim(statint)|TMR_LIM_RELOAD);
	else
#endif
		stxa((vaddr_t)&timerreg_4u.t_timer[1].t_limit, ASI_NUCLEUS,
		     tmr_ustolim(statint)|TMR_LIM_IEN|TMR_LIM_RELOAD);
	stxa((vaddr_t)&timerreg_4u.t_mapintr[1], ASI_NUCLEUS,
	     timerreg_4u.t_mapintr[1]|INTMAP_V);

	statmin = statint - (statvar >> 1);

	tick_enable();
}

/*
 * Dummy setstatclockrate(), since we know profhz==hz.
 */
/* ARGSUSED */
void
setstatclockrate(newhz)
	int newhz;
{
	/* nothing */
}

/*
 * Level 10 (clock) interrupts.  If we are using the FORTH PROM for
 * console input, we need to check for that here as well, and generate
 * a software interrupt to read it.
 */
#ifdef	DEBUG
static int clockcheck = 0;
#endif
int
clockintr(cap)
	void *cap;
{
#ifdef DEBUG
	static int64_t tick_base = 0;
	struct timeval ctime;
	int64_t t;

	t = tick() & TICK_TICKS;

	microtime(&ctime);
	if (!tick_base) {
		tick_base = (ctime.tv_sec * 1000000LL + ctime.tv_usec)
			* 1000000LL / cpu_clockrate;
		tick_base -= t;
	} else if (clockcheck) {
		int64_t tk = t;
		int64_t clk = (ctime.tv_sec * 1000000LL + ctime.tv_usec);
		t -= tick_base;
		t = t * 1000000LL / cpu_clockrate;
		if (t - clk > hz) {
			printf("Clock lost an interrupt!\n");
			printf("Actual: %llx Expected: %llx tick %llx "
			    "tick_base %llx\n", (long long)t, (long long)clk,
			    (long long)tk, (long long)tick_base);
#ifdef DDB
			db_enter();
#endif
			tick_base = 0;
		}
	}
#endif
	/* Let locore.s clear the interrupt for us. */
	hardclock((struct clockframe *)cap);

	return (1);
}

/*
 * Level 10 (clock) interrupts.  If we are using the FORTH PROM for
 * console input, we need to check for that here as well, and generate
 * a software interrupt to read it.
 *
 * %tick is really a level-14 interrupt.  We need to remap this in
 * locore.s to a level 10.
 */
int
tickintr(cap)
	void *cap;
{
	struct cpu_info *ci = curcpu();
	u_int64_t s;

	/*
	 * No need to worry about overflow; %tick is architecturally
	 * defined not to do that for at least 10 years.
	 */
	while (ci->ci_tick < tick()) {
		ci->ci_tick += tick_increment;
		hardclock((struct clockframe *)cap);
		atomic_add_long((unsigned long *)&level0.ih_count.ec_count, 1);
	}

	/* Reset the interrupt. */
	s = intr_disable();
	tickcmpr_set(ci->ci_tick);
	intr_restore(s);

	return (1);
}

int
sys_tickintr(cap)
	void *cap;
{
	struct cpu_info *ci = curcpu();
	u_int64_t s;

	/*
	 * Do we need to worry about overflow here?
	 */
	while (ci->ci_tick < sys_tick()) {
		ci->ci_tick += tick_increment;
		hardclock((struct clockframe *)cap);
		atomic_add_long((unsigned long *)&level0.ih_count.ec_count, 1);
	}

	/* Reset the interrupt. */
	s = intr_disable();
	sys_tickcmpr_set(ci->ci_tick);
	intr_restore(s);

	return (1);
}

int
stickintr(cap)
	void *cap;
{
	struct cpu_info *ci = curcpu();
	u_int64_t s;

	/*
	 * Do we need to worry about overflow here?
	 */
	while (ci->ci_tick < stick()) {
		ci->ci_tick += tick_increment;
		hardclock((struct clockframe *)cap);
		atomic_add_long((unsigned long *)&level0.ih_count.ec_count, 1);
	}

	/* Reset the interrupt. */
	s = intr_disable();
	stickcmpr_set(ci->ci_tick);
	intr_restore(s);

	return (1);
}

/*
 * Level 14 (stat clock) interrupt handler.
 */
int
statintr(cap)
	void *cap;
{
	u_long newint, r, var;
	struct cpu_info *ci = curcpu();

#ifdef NOT_DEBUG
	printf("statclock: count %x:%x, limit %x:%x\n",
	       timerreg_4u.t_timer[1].t_count, timerreg_4u.t_timer[1].t_limit);
#endif
#ifdef NOT_DEBUG
	prom_printf("!");
#endif
	statclock((struct clockframe *)cap);
#ifdef NOTDEF_DEBUG
	/* Don't re-schedule the IRQ */
	return 1;
#endif
	/*
	 * Compute new randomized interval.  The intervals are uniformly
	 * distributed on [statint - statvar / 2, statint + statvar / 2],
	 * and therefore have mean statint, giving a stathz frequency clock.
	 */
	var = statvar;
	do {
		r = random() & (var - 1);
	} while (r == 0);
	newint = statmin + r;

	if (schedhz)
		if ((++ci->ci_schedstate.spc_schedticks & 3) == 0)
			send_softint(-1, PIL_SCHED, &schedint);
	stxa((vaddr_t)&timerreg_4u.t_timer[1].t_limit, ASI_NUCLEUS,
	     tmr_ustolim(newint)|TMR_LIM_IEN|TMR_LIM_RELOAD);

	return (1);
}

int
schedintr(arg)
	void *arg;
{
	if (curproc)
		schedclock(curproc);
	return (1);
}

void
tick_start(void)
{
	struct cpu_info *ci = curcpu();
	u_int64_t s;

	tick_enable();

	/*
	 * Try to make the tick interrupts as synchronously as possible on
	 * all CPUs to avoid inaccuracies for migrating processes.
	 */

	s = intr_disable();
	ci->ci_tick = roundup(tick(), tick_increment);
	tickcmpr_set(ci->ci_tick);
	intr_restore(s);
}

void
sys_tick_start(void)
{
	struct cpu_info *ci = curcpu();
	u_int64_t s;

	if (CPU_ISSUN4U || CPU_ISSUN4US) {
		tick_enable();
		sys_tick_enable();
	}

	/*
	 * Try to make the tick interrupts as synchronously as possible on
	 * all CPUs to avoid inaccuracies for migrating processes.
	 */

	s = intr_disable();
	ci->ci_tick = roundup(sys_tick(), tick_increment);
	sys_tickcmpr_set(ci->ci_tick);
	intr_restore(s);
}

void
stick_start(void)
{
	struct cpu_info *ci = curcpu();
	u_int64_t s;

	tick_enable();

	/*
	 * Try to make the tick interrupts as synchronously as possible on
	 * all CPUs to avoid inaccuracies for migrating processes.
	 */

	s = intr_disable();
	ci->ci_tick = roundup(stick(), tick_increment);
	stickcmpr_set(ci->ci_tick);
	intr_restore(s);
}

u_int
tick_get_timecount(struct timecounter *tc)
{
	u_int64_t tick;

	__asm volatile("rd %%tick, %0" : "=r" (tick));

	return (tick & ~0u);
}

u_int
sys_tick_get_timecount(struct timecounter *tc)
{
	u_int64_t tick;

	__asm volatile("rd %%sys_tick, %0" : "=r" (tick));

	return (tick & ~0u);
}