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freebsd/sys/kern/kern_tc.c
2000-07-04 11:25:35 +00:00

582 lines
14 KiB
C

/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $FreeBSD$
*/
#include "opt_ntp.h"
#include <sys/param.h>
#include <sys/timetc.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/timex.h>
#include <sys/timepps.h>
/*
* Number of timecounters used to implement stable storage
*/
#ifndef NTIMECOUNTER
#define NTIMECOUNTER 5
#endif
static MALLOC_DEFINE(M_TIMECOUNTER, "timecounter",
"Timecounter stable storage");
static void tco_setscales __P((struct timecounter *tc));
static __inline unsigned tco_delta __P((struct timecounter *tc));
time_t time_second;
struct timeval boottime;
SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
&boottime, timeval, "System boottime");
SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, "");
static unsigned nmicrotime;
static unsigned nnanotime;
static unsigned ngetmicrotime;
static unsigned ngetnanotime;
static unsigned nmicrouptime;
static unsigned nnanouptime;
static unsigned ngetmicrouptime;
static unsigned ngetnanouptime;
SYSCTL_INT(_kern_timecounter, OID_AUTO, nmicrotime, CTLFLAG_RD, &nmicrotime, 0, "");
SYSCTL_INT(_kern_timecounter, OID_AUTO, nnanotime, CTLFLAG_RD, &nnanotime, 0, "");
SYSCTL_INT(_kern_timecounter, OID_AUTO, nmicrouptime, CTLFLAG_RD, &nmicrouptime, 0, "");
SYSCTL_INT(_kern_timecounter, OID_AUTO, nnanouptime, CTLFLAG_RD, &nnanouptime, 0, "");
SYSCTL_INT(_kern_timecounter, OID_AUTO, ngetmicrotime, CTLFLAG_RD, &ngetmicrotime, 0, "");
SYSCTL_INT(_kern_timecounter, OID_AUTO, ngetnanotime, CTLFLAG_RD, &ngetnanotime, 0, "");
SYSCTL_INT(_kern_timecounter, OID_AUTO, ngetmicrouptime, CTLFLAG_RD, &ngetmicrouptime, 0, "");
SYSCTL_INT(_kern_timecounter, OID_AUTO, ngetnanouptime, CTLFLAG_RD, &ngetnanouptime, 0, "");
/*
* Implement a dummy timecounter which we can use until we get a real one
* in the air. This allows the console and other early stuff to use
* timeservices.
*/
static unsigned
dummy_get_timecount(struct timecounter *tc)
{
static unsigned now;
return (++now);
}
static struct timecounter dummy_timecounter = {
dummy_get_timecount,
0,
~0u,
1000000,
"dummy"
};
struct timecounter *timecounter = &dummy_timecounter;
static __inline unsigned
tco_delta(struct timecounter *tc)
{
return ((tc->tc_get_timecount(tc) - tc->tc_offset_count) &
tc->tc_counter_mask);
}
/*
* We have eight functions for looking at the clock, four for
* microseconds and four for nanoseconds. For each there is fast
* but less precise version "get{nano|micro}[up]time" which will
* return a time which is up to 1/HZ previous to the call, whereas
* the raw version "{nano|micro}[up]time" will return a timestamp
* which is as precise as possible. The "up" variants return the
* time relative to system boot, these are well suited for time
* interval measurements.
*/
void
getmicrotime(struct timeval *tvp)
{
struct timecounter *tc;
ngetmicrotime++;
tc = timecounter;
*tvp = tc->tc_microtime;
}
void
getnanotime(struct timespec *tsp)
{
struct timecounter *tc;
ngetnanotime++;
tc = timecounter;
*tsp = tc->tc_nanotime;
}
void
microtime(struct timeval *tv)
{
struct timecounter *tc;
nmicrotime++;
tc = 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;
nnanotime++;
tc = 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
getmicrouptime(struct timeval *tvp)
{
struct timecounter *tc;
ngetmicrouptime++;
tc = timecounter;
tvp->tv_sec = tc->tc_offset_sec;
tvp->tv_usec = tc->tc_offset_micro;
}
void
getnanouptime(struct timespec *tsp)
{
struct timecounter *tc;
ngetnanouptime++;
tc = timecounter;
tsp->tv_sec = tc->tc_offset_sec;
tsp->tv_nsec = tc->tc_offset_nano >> 32;
}
void
microuptime(struct timeval *tv)
{
struct timecounter *tc;
nmicrouptime++;
tc = 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;
nnanouptime++;
tc = 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;
scale += tc->tc_adjustment;
scale /= tc->tc_tweak->tc_frequency;
tc->tc_scale_micro = scale / 1000;
tc->tc_scale_nano_f = scale & 0xffffffff;
tc->tc_scale_nano_i = scale >> 32;
}
void
tc_update(struct timecounter *tc)
{
tco_setscales(tc);
}
void
tc_init(struct timecounter *tc)
{
struct timespec ts1;
struct timecounter *t1, *t2, *t3;
int i;
tc->tc_adjustment = 0;
tc->tc_tweak = tc;
tco_setscales(tc);
tc->tc_offset_count = tc->tc_get_timecount(tc);
if (timecounter == &dummy_timecounter)
tc->tc_avail = tc;
else {
tc->tc_avail = timecounter->tc_tweak->tc_avail;
timecounter->tc_tweak->tc_avail = tc;
}
MALLOC(t1, struct timecounter *, sizeof *t1, M_TIMECOUNTER, M_WAITOK);
tc->tc_other = t1;
*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;
printf("Timecounter \"%s\" frequency %lu Hz\n",
tc->tc_name, (u_long)tc->tc_frequency);
/* 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
tc_setclock(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... */
tc_windup();
}
static void
switch_timecounter(struct timecounter *newtc)
{
int s;
struct timecounter *tc;
struct timespec ts;
s = splclock();
tc = timecounter;
if (newtc->tc_tweak == tc->tc_tweak) {
splx(s);
return;
}
newtc = newtc->tc_tweak->tc_other;
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);
tco_setscales(newtc);
timecounter = newtc;
splx(s);
}
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);
}
void
tc_windup(void)
{
struct timecounter *tc, *tco;
struct timeval tvt;
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);
if (timedelta != 0) {
tvt = boottime;
tvt.tv_usec += tickdelta;
if (tvt.tv_usec >= 1000000) {
tvt.tv_sec++;
tvt.tv_usec -= 1000000;
} else if (tvt.tv_usec < 0) {
tvt.tv_sec--;
tvt.tv_usec += 1000000;
}
boottime = tvt;
timedelta -= tickdelta;
}
while (tc->tc_offset_nano >= 1000000000ULL << 32) {
tc->tc_offset_nano -= 1000000000ULL << 32;
tc->tc_offset_sec++;
ntp_update_second(tc); /* XXX only needed if xntpd runs */
tco_setscales(tc);
}
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_hardware(SYSCTL_HANDLER_ARGS)
{
char newname[32];
struct timecounter *newtc, *tc;
int error;
tc = timecounter->tc_tweak;
strncpy(newname, tc->tc_name, sizeof(newname));
error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req);
if (error == 0 && req->newptr != NULL &&
strcmp(newname, tc->tc_name) != 0) {
for (newtc = tc->tc_avail; newtc != tc;
newtc = newtc->tc_avail) {
if (strcmp(newname, newtc->tc_name) == 0) {
/* Warm up new timecounter. */
(void)newtc->tc_get_timecount(newtc);
switch_timecounter(newtc);
return (0);
}
}
return (EINVAL);
}
return (error);
}
SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW,
0, 0, sysctl_kern_timecounter_hardware, "A", "");
int
pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
{
pps_params_t *app;
struct pps_fetch_args *fapi;
#ifdef PPS_SYNC
struct pps_kcbind_args *kapi;
#endif
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;
app->api_version = PPS_API_VERS_1;
return (0);
case PPS_IOC_GETCAP:
*(int*)data = pps->ppscap;
return (0);
case PPS_IOC_FETCH:
fapi = (struct pps_fetch_args *)data;
if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
return (EINVAL);
if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
return (EOPNOTSUPP);
pps->ppsinfo.current_mode = pps->ppsparam.mode;
fapi->pps_info_buf = pps->ppsinfo;
return (0);
case PPS_IOC_KCBIND:
#ifdef PPS_SYNC
kapi = (struct pps_kcbind_args *)data;
/* XXX Only root should be able to do this */
if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
return (EINVAL);
if (kapi->kernel_consumer != PPS_KC_HARDPPS)
return (EINVAL);
if (kapi->edge & ~pps->ppscap)
return (EINVAL);
pps->kcmode = kapi->edge;
return (0);
#else
return (EOPNOTSUPP);
#endif
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;
}
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->kcmode & PPS_CAPTUREASSERT;
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->kcmode & PPS_CAPTURECLEAR;
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
}