kern_clock.c

基于组件方式开发操作系统的OSKIT源代码

	 */
	clkinfo.hz = hz;
	clkinfo.tick = tick;
	clkinfo.tickadj = tickadj;
	clkinfo.profhz = profhz;
	clkinfo.stathz = stathz ? stathz : hz;
	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
}

SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
#endif /* !OSKIT */

static __inline unsigned
tco_delta(struct timecounter *tc)
{

	return ((tc->tc_get_timecount(tc) - tc->tc_offset_count) & 
	    tc->tc_counter_mask);
}

/*
 * We have four functions for looking at the clock, two for microseconds
 * and two for nanoseconds.  For each there is fast but less precise
 * version "get{nano|micro}time" which will return a time which is up
 * to 1/HZ previous to the call, whereas the raw version "{nano|micro}time"
 * will return a timestamp which is as precise as possible.
 */

void
getmicrotime(struct timeval *tvp)
{
	struct timecounter *tc;

	if (!tco_method) {
		tc = timecounter;
		*tvp = tc->tc_microtime;
	} else {
		microtime(tvp);
	}
}

void
getnanotime(struct timespec *tsp)
{
	struct timecounter *tc;

	if (!tco_method) {
		tc = timecounter;
		*tsp = tc->tc_nanotime;
	} else {
		nanotime(tsp);
	}
}

void
microtime(struct timeval *tv)
{
	struct timecounter *tc;

	tc = (struct timecounter *)timecounter;
	tv->tv_sec = tc->tc_offset_sec;
	tv->tv_usec = tc->tc_offset_micro;
	tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32;
	tv->tv_usec += boottime.tv_usec;
	tv->tv_sec += boottime.tv_sec;
	while (tv->tv_usec >= 1000000) {
		tv->tv_usec -= 1000000;
		tv->tv_sec++;
	}
}

void
nanotime(struct timespec *ts)
{
	unsigned count;
	u_int64_t delta;
	struct timecounter *tc;

	tc = (struct timecounter *)timecounter;
	ts->tv_sec = tc->tc_offset_sec;
	count = tco_delta(tc);
	delta = tc->tc_offset_nano;
	delta += ((u_int64_t)count * tc->tc_scale_nano_f);
	delta >>= 32;
	delta += ((u_int64_t)count * tc->tc_scale_nano_i);
	delta += boottime.tv_usec * 1000;
	ts->tv_sec += boottime.tv_sec;
	while (delta >= 1000000000) {
		delta -= 1000000000;
		ts->tv_sec++;
	}
	ts->tv_nsec = delta;
}

void
timecounter_timespec(unsigned count, struct timespec *ts)
{
	u_int64_t delta;
	struct timecounter *tc;

	tc = (struct timecounter *)timecounter;
	ts->tv_sec = tc->tc_offset_sec;
	count -= tc->tc_offset_count;
	count &= tc->tc_counter_mask;
	delta = tc->tc_offset_nano;
	delta += ((u_int64_t)count * tc->tc_scale_nano_f);
	delta >>= 32;
	delta += ((u_int64_t)count * tc->tc_scale_nano_i);
	delta += boottime.tv_usec * 1000;
	ts->tv_sec += boottime.tv_sec;
	while (delta >= 1000000000) {
		delta -= 1000000000;
		ts->tv_sec++;
	}
	ts->tv_nsec = delta;
}

void
getmicrouptime(struct timeval *tvp)
{
	struct timecounter *tc;

	if (!tco_method) {
		tc = timecounter;
		tvp->tv_sec = tc->tc_offset_sec;
		tvp->tv_usec = tc->tc_offset_micro;
	} else {
		microuptime(tvp);
	}
}

void
getnanouptime(struct timespec *tsp)
{
	struct timecounter *tc;

	if (!tco_method) {
		tc = timecounter;
		tsp->tv_sec = tc->tc_offset_sec;
		tsp->tv_nsec = tc->tc_offset_nano >> 32;
	} else {
		nanouptime(tsp);
	}
}

void
microuptime(struct timeval *tv)
{
	struct timecounter *tc;

	tc = (struct timecounter *)timecounter;
	tv->tv_sec = tc->tc_offset_sec;
	tv->tv_usec = tc->tc_offset_micro;
	tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32;
	if (tv->tv_usec >= 1000000) {
		tv->tv_usec -= 1000000;
		tv->tv_sec++;
	}
}

void
nanouptime(struct timespec *ts)
{
	unsigned count;
	u_int64_t delta;
	struct timecounter *tc;

	tc = (struct timecounter *)timecounter;
	ts->tv_sec = tc->tc_offset_sec;
	count = tco_delta(tc);
	delta = tc->tc_offset_nano;
	delta += ((u_int64_t)count * tc->tc_scale_nano_f);
	delta >>= 32;
	delta += ((u_int64_t)count * tc->tc_scale_nano_i);
	if (delta >= 1000000000) {
		delta -= 1000000000;
		ts->tv_sec++;
	}
	ts->tv_nsec = delta;
}

static void
tco_setscales(struct timecounter *tc)
{
	u_int64_t scale;

	scale = 1000000000LL << 32;
	if (tc->tc_adjustment > 0)
		scale += (tc->tc_adjustment * 1000LL) << 10;
	else
		scale -= (-tc->tc_adjustment * 1000LL) << 10;
	scale /= tc->tc_frequency;
	tc->tc_scale_micro = scale / 1000;
	tc->tc_scale_nano_f = scale & 0xffffffff;
	tc->tc_scale_nano_i = scale >> 32;
}

void
init_timecounter(struct timecounter *tc)
{
	struct timespec ts1;
	struct timecounter *t1, *t2, *t3;
	int i;

	tc->tc_adjustment = 0;
	tco_setscales(tc);
	tc->tc_offset_count = tc->tc_get_timecount(tc);
	tc->tc_tweak = tc;
	MALLOC(t1, struct timecounter *, sizeof *t1, M_TIMECOUNTER, M_WAITOK);
	*t1 = *tc;
	t2 = t1;
	for (i = 1; i < NTIMECOUNTER; i++) {
		MALLOC(t3, struct timecounter *, sizeof *t3,
		    M_TIMECOUNTER, M_WAITOK);
		*t3 = *tc;
		t3->tc_other = t2;
		t2 = t3;
	}
	t1->tc_other = t3;
	tc = t1;

#ifndef OSKIT
	printf("Timecounter \"%s\"  frequency %lu Hz\n", 
	    tc->tc_name, (u_long)tc->tc_frequency);
#endif

	/* XXX: For now always start using the counter. */
	tc->tc_offset_count = tc->tc_get_timecount(tc);
	nanouptime(&ts1);
	tc->tc_offset_nano = (u_int64_t)ts1.tv_nsec << 32;
	tc->tc_offset_micro = ts1.tv_nsec / 1000;
	tc->tc_offset_sec = ts1.tv_sec;
	timecounter = tc;
}

void
set_timecounter(struct timespec *ts)
{
	struct timespec ts2;

	nanouptime(&ts2);
	boottime.tv_sec = ts->tv_sec - ts2.tv_sec;
	boottime.tv_usec = (ts->tv_nsec - ts2.tv_nsec) / 1000;
	if (boottime.tv_usec < 0) {
		boottime.tv_usec += 1000000;
		boottime.tv_sec--;
	}
	/* fiddle all the little crinkly bits around the fiords... */
	tco_forward(1);
}


#if 0 /* Currently unused */
void
switch_timecounter(struct timecounter *newtc)
{
	int s;
	struct timecounter *tc;
	struct timespec ts;

	s = splclock();
	tc = timecounter;
	if (newtc == tc || newtc == tc->tc_other) {
		splx(s);
		return;
	}
	nanouptime(&ts);
	newtc->tc_offset_sec = ts.tv_sec;
	newtc->tc_offset_nano = (u_int64_t)ts.tv_nsec << 32;
	newtc->tc_offset_micro = ts.tv_nsec / 1000;
	newtc->tc_offset_count = newtc->tc_get_timecount(newtc);
	timecounter = newtc;
	splx(s);
}
#endif

static struct timecounter *
sync_other_counter(void)
{
	struct timecounter *tc, *tcn, *tco;
	unsigned delta;

	tco = timecounter;
	tc = tco->tc_other;
	tcn = tc->tc_other;
	*tc = *tco;
	tc->tc_other = tcn;
	delta = tco_delta(tc);
	tc->tc_offset_count += delta;
	tc->tc_offset_count &= tc->tc_counter_mask;
	tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_f;
	tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_i << 32;
	return (tc);
}

static void
tco_forward(int force)
{
	struct timecounter *tc, *tco;

	tco = timecounter;
	tc = sync_other_counter();
	/*
	 * We may be inducing a tiny error here, the tc_poll_pps() may
	 * process a latched count which happens after the tco_delta()
	 * in sync_other_counter(), which would extend the previous
	 * counters parameters into the domain of this new one.
	 * Since the timewindow is very small for this, the error is
	 * going to be only a few weenieseconds (as Dave Mills would
	 * say), so lets just not talk more about it, OK ?
	 */
	if (tco->tc_poll_pps) 
		tco->tc_poll_pps(tco);
#ifndef OSKIT
	if (timedelta != 0) {
		tc->tc_offset_nano += (u_int64_t)(tickdelta * 1000) << 32;
		timedelta -= tickdelta;
		force++;
	}
#endif

	while (tc->tc_offset_nano >= 1000000000ULL << 32) {
		tc->tc_offset_nano -= 1000000000ULL << 32;
		tc->tc_offset_sec++;
		tc->tc_frequency = tc->tc_tweak->tc_frequency;
		tc->tc_adjustment = tc->tc_tweak->tc_adjustment;
#ifndef OSKIT
		ntp_update_second(tc);	/* XXX only needed if xntpd runs */
#endif
		tco_setscales(tc);
		force++;
	}

	if (tco_method && !force)
		return;

	tc->tc_offset_micro = (tc->tc_offset_nano / 1000) >> 32;

	/* Figure out the wall-clock time */
	tc->tc_nanotime.tv_sec = tc->tc_offset_sec + boottime.tv_sec;
	tc->tc_nanotime.tv_nsec = 
	    (tc->tc_offset_nano >> 32) + boottime.tv_usec * 1000;
	tc->tc_microtime.tv_usec = tc->tc_offset_micro + boottime.tv_usec;
	if (tc->tc_nanotime.tv_nsec >= 1000000000) {
		tc->tc_nanotime.tv_nsec -= 1000000000;
		tc->tc_microtime.tv_usec -= 1000000;
		tc->tc_nanotime.tv_sec++;
	}
	time_second = tc->tc_microtime.tv_sec = tc->tc_nanotime.tv_sec;

	timecounter = tc;
}

static int
sysctl_kern_timecounter_frequency SYSCTL_HANDLER_ARGS
{

	return (sysctl_handle_opaque(oidp, 
	    &timecounter->tc_tweak->tc_frequency,
	    sizeof(timecounter->tc_tweak->tc_frequency), req));
}

static int
sysctl_kern_timecounter_adjustment SYSCTL_HANDLER_ARGS
{

	return (sysctl_handle_opaque(oidp, 
	    &timecounter->tc_tweak->tc_adjustment,
	    sizeof(timecounter->tc_tweak->tc_adjustment), req));
}

SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, "");

SYSCTL_INT(_kern_timecounter, KERN_ARGMAX, method, CTLFLAG_RW, &tco_method, 0,
    "This variable determines the method used for updating timecounters. "
    "If the default algorithm (0) fails with \"calcru negative...\" messages "
    "try the alternate algorithm (1) which handles bad hardware better."

);

SYSCTL_PROC(_kern_timecounter, OID_AUTO, frequency, CTLTYPE_INT | CTLFLAG_RW,
    0, sizeof(u_int), sysctl_kern_timecounter_frequency, "I", "");

SYSCTL_PROC(_kern_timecounter, OID_AUTO, adjustment, CTLTYPE_INT | CTLFLAG_RW,
    0, sizeof(int), sysctl_kern_timecounter_adjustment, "I", "");



int
pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
{
        pps_params_t *app;
        pps_info_t *api;

        switch (cmd) {
        case PPS_IOC_CREATE:
                return (0);
        case PPS_IOC_DESTROY:
                return (0);
        case PPS_IOC_SETPARAMS:
                app = (pps_params_t *)data;
                if (app->mode & ~pps->ppscap)
                        return (EINVAL);
                pps->ppsparam = *app;         
                return (0);
        case PPS_IOC_GETPARAMS:
                app = (pps_params_t *)data;
                *app = pps->ppsparam;
                return (0);
        case PPS_IOC_GETCAP:
                *(int*)data = pps->ppscap;
                return (0);
        case PPS_IOC_FETCH:
                api = (pps_info_t *)data;
                pps->ppsinfo.current_mode = pps->ppsparam.mode;         
                *api = pps->ppsinfo;
                return (0);
        case PPS_IOC_WAIT:
                return (EOPNOTSUPP);
        default:
                return (ENOTTY);
        }
}

void
pps_init(struct pps_state *pps)
{
	pps->ppscap |= PPS_TSFMT_TSPEC;
	if (pps->ppscap & PPS_CAPTUREASSERT)
		pps->ppscap |= PPS_OFFSETASSERT;
	if (pps->ppscap & PPS_CAPTURECLEAR)
		pps->ppscap |= PPS_OFFSETCLEAR;
#ifdef PPS_SYNC
	if (pps->ppscap & PPS_CAPTUREASSERT)
		pps->ppscap |= PPS_HARDPPSONASSERT;
	if (pps->ppscap & PPS_CAPTURECLEAR)
		pps->ppscap |= PPS_HARDPPSONCLEAR;
#endif
}

void
pps_event(struct pps_state *pps, struct timecounter *tc, unsigned count, int event)
{
	struct timespec ts, *tsp, *osp;
	u_int64_t delta;
	unsigned tcount, *pcount;
	int foff, fhard;
	pps_seq_t	*pseq;

	/* Things would be easier with arrays... */
	if (event == PPS_CAPTUREASSERT) {
		tsp = &pps->ppsinfo.assert_timestamp;
		osp = &pps->ppsparam.assert_offset;
		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
		fhard = pps->ppsparam.mode & PPS_HARDPPSONASSERT;
		pcount = &pps->ppscount[0];
		pseq = &pps->ppsinfo.assert_sequence;
	} else {
		tsp = &pps->ppsinfo.clear_timestamp;
		osp = &pps->ppsparam.clear_offset;
		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
		fhard = pps->ppsparam.mode & PPS_HARDPPSONCLEAR;
		pcount = &pps->ppscount[1];
		pseq = &pps->ppsinfo.clear_sequence;
	}

	/* The timecounter changed: bail */
	if (!pps->ppstc || 
	    pps->ppstc->tc_name != tc->tc_name || 
	    tc->tc_name != timecounter->tc_name) {
		pps->ppstc = tc;
		*pcount = count;
		return;
	}

	/* Nothing really happened */
	if (*pcount == count)
		return;

	*pcount = count;

	/* Convert the count to timespec */
	ts.tv_sec = tc->tc_offset_sec;
	tcount = count - tc->tc_offset_count;
	tcount &= tc->tc_counter_mask;
	delta = tc->tc_offset_nano;
	delta += ((u_int64_t)tcount * tc->tc_scale_nano_f);
	delta >>= 32;
	delta += ((u_int64_t)tcount * tc->tc_scale_nano_i);
	delta += boottime.tv_usec * 1000;
	ts.tv_sec += boottime.tv_sec;
	while (delta >= 1000000000) {
		delta -= 1000000000;
		ts.tv_sec++;
	}
	ts.tv_nsec = delta;

	(*pseq)++;
	*tsp = ts;
	
	if (foff) {
		timespecadd(tsp, osp);
		if (tsp->tv_nsec < 0) {
			tsp->tv_nsec += 1000000000;
			tsp->tv_sec -= 1;
		}
	}
#ifdef PPS_SYNC
	if (fhard) {
		/* magic, at its best... */
		tcount = count - pps->ppscount[2];
		pps->ppscount[2] = count;
		tcount &= tc->tc_counter_mask;
		delta = ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_f);
		delta >>= 32;
		delta += ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_i);
		hardpps(tsp, delta);
	}
#endif
}