freebsd-dev/sys/ia64/ia64/clock.c

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department and Ralph Campbell.
 *
 * 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: Utah Hdr: clock.c 1.18 91/01/21
 *
 *	@(#)clock.c	8.1 (Berkeley) 6/10/93
 */
/* $NetBSD: clock.c,v 1.20 1998/01/31 10:32:47 ross Exp $ */

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

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/queue.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/timetc.h>
#include <sys/pcpu.h>

#include <machine/clock.h>
#include <machine/clockvar.h>
#include <machine/cpu.h>

#define	SECMIN	((unsigned)60)			/* seconds per minute */
#define	SECHOUR	((unsigned)(60*SECMIN))		/* seconds per hour */
#define	SECDAY	((unsigned)(24*SECHOUR))	/* seconds per day */
#define	SECYR	((unsigned)(365*SECDAY))	/* seconds per common year */

/*
 * 32-bit time_t's can't reach leap years before 1904 or after 2036, so we
 * can use a simple formula for leap years.
 * XXX time_t is 64-bits on ia64.
 */
#define	LEAPYEAR(y)	(((y) % 4) == 0)

static int sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS);

int disable_rtc_set;	/* disable resettodr() if != 0 */
SYSCTL_INT(_machdep, CPU_DISRTCSET, disable_rtc_set,
	CTLFLAG_RW, &disable_rtc_set, 0, "");

int wall_cmos_clock;	/* wall	CMOS clock assumed if != 0 */
SYSCTL_INT(_machdep, CPU_WALLCLOCK, wall_cmos_clock,
	CTLFLAG_RW, &wall_cmos_clock, 0, "");

int	adjkerntz;		/* local offset	from GMT in seconds */
SYSCTL_PROC(_machdep, CPU_ADJKERNTZ, adjkerntz, CTLTYPE_INT|CTLFLAG_RW,
	&adjkerntz, 0, sysctl_machdep_adjkerntz, "I", "");

kobj_t	clockdev;
int	todr_initialized;

uint64_t ia64_clock_reload;

#ifndef SMP
static timecounter_get_t ia64_get_timecount;

static struct timecounter ia64_timecounter = {
	ia64_get_timecount,	/* get_timecount */
	0,			/* no poll_pps */
	~0u,			/* counter_mask */
	0,			/* frequency */
	"ITC"			/* name */
};

static unsigned
ia64_get_timecount(struct timecounter* tc)
{
	return ia64_get_itc();
}
#endif

static int
sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS)
{
	int error;

	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
	if (!error && req->newptr)
		resettodr();
	return (error);
}

void
clockattach(kobj_t dev)
{

	if (clockdev)
		panic("clockattach: multiple clocks");

	clockdev = dev;

#ifdef EVCNT_COUNTERS
	evcnt_attach(dev, "intr", &clock_intr_evcnt);
#endif

	/* Get the clock started. */
	CLOCK_INIT(clockdev);
}

void
pcpu_initclock(void)
{

	PCPU_SET(clockadj, 0);
	PCPU_SET(clock, ia64_get_itc());
	ia64_set_itm(PCPU_GET(clock) + ia64_clock_reload);
	ia64_set_itv(CLOCK_VECTOR);	/* highest priority class */
}

/*
 * Start the real-time and statistics clocks. We use cr.itc and cr.itm
 * to implement a 1000hz clock.
 */
void
cpu_initclocks()
{

	if (itc_frequency == 0)
		panic("Unknown clock frequency");

	stathz = hz;
	ia64_clock_reload = (itc_frequency + hz/2) / hz;

#ifndef SMP
	ia64_timecounter.tc_frequency = itc_frequency;
	tc_init(&ia64_timecounter);
#endif

	pcpu_initclock();
}

void
cpu_startprofclock(void)
{

	/* nothing to do */
}

void
cpu_stopprofclock(void)
{

	/* nothing to do */
}

/*
 * This code is defunct after 2099.
 * Will Unix still be here then??
 */
static short dayyr[12] = {
	0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
};

/*
 * Initialize the time of day register, based on the time base which is,
 * e.g. from a filesystem.  Base provides the time to within six months,
 * and the time of year clock (if any) provides the rest.
 */
void
inittodr(time_t base)
{
	struct clocktime ct;
	struct timespec ts;
	time_t deltat;
	int badbase, days, s, yr;

	if (base < 5*SECYR) {
		printf("WARNING: preposterous time in filesystem");
		/* read the system clock anyway */
		base = 6*SECYR + 186*SECDAY + SECDAY/2;
		badbase = 1;
	} else
		badbase = 0;

	CLOCK_GET(clockdev, base, &ct);
	todr_initialized = 1;

	/* simple sanity checks */
	if (ct.year < 70 || ct.mon < 1 || ct.mon > 12 || ct.day < 1 ||
	    ct.day > 31 || ct.hour > 23 || ct.min > 59 || ct.sec > 59) {
		/*
		 * Believe the time in the filesystem for lack of
		 * anything better, resetting the TODR.
		 */
		s = splclock();
		ts.tv_sec = base;
		ts.tv_nsec = 0;
		tc_setclock(&ts);
		splx(s);
		if (!badbase) {
			printf("WARNING: preposterous clock chip time\n");
			resettodr();
		}
		goto bad;
	}
	days = 0;
	for (yr = 70; yr < ct.year; yr++)
		days += LEAPYEAR(yr) ? 366 : 365;
	days += dayyr[ct.mon - 1] + ct.day - 1;
	if (LEAPYEAR(yr) && ct.mon > 2)
		days++;

	/* now have days since Jan 1, 1970; the rest is easy... */
	s = splclock();
	ts.tv_sec =
	    days * SECDAY + ct.hour * SECHOUR + ct.min * SECMIN + ct.sec;
	if (wall_cmos_clock)
		ts.tv_sec += adjkerntz;
	ts.tv_nsec = 0;
	tc_setclock(&ts);
	splx(s);

	if (!badbase) {
		/*
		 * See if we gained/lost two or more days;
		 * if so, assume something is amiss.
		 */
		deltat = ts.tv_sec - base;
		if (deltat < 0)
			deltat = -deltat;
		if (deltat < 2 * SECDAY)
			return;
		printf("WARNING: clock %s %ld days",
		    ts.tv_sec < base ? "lost" : "gained", deltat / SECDAY);
	}
bad:
	printf(" -- CHECK AND RESET THE DATE!\n");
}

/*
 * Reset the TODR based on the time value; used when the TODR has a
 * preposterous value and also when the time is reset by the stime
 * system call.  Also called when the TODR goes past
 * TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
 * to wrap the TODR around.
 */
void
resettodr()
{
	struct clocktime ct;
	unsigned long tm;
	int s, t, t2;

	if (!todr_initialized || disable_rtc_set)
		return;

	s = splclock();
	tm = time_second;
	splx(s);

	/* Calculate local time	to put in RTC */
	tm -= (wall_cmos_clock ? adjkerntz : 0);

	/* compute the day of week. */
	t2 = tm / SECDAY;
	ct.dow = (t2 + 4) % 7;	/* 1/1/1970 was thursday */

	/* compute the year */
	ct.year = 69;
	t = t2;			/* XXX ? */
	while (t2 >= 0) {	/* whittle off years */
		t = t2;
		ct.year++;
		t2 -= LEAPYEAR(ct.year) ? 366 : 365;
	}

	/* t = month + day; separate */
	t2 = LEAPYEAR(ct.year);
	for (ct.mon = 1; ct.mon < 12; ct.mon++)
		if (t < dayyr[ct.mon] + (t2 && ct.mon > 1))
			break;

	ct.day = t - dayyr[ct.mon - 1] + 1;
	if (t2 && ct.mon > 2)
		ct.day--;

	/* the rest is easy */
	t = tm % SECDAY;
	ct.hour = t / SECHOUR;
	t %= 3600;
	ct.min = t / SECMIN;
	ct.sec = t % SECMIN;

	CLOCK_SET(clockdev, &ct);
}