/* * ---------------------------------------------------------------------------- * "THE BEER-WARE LICENSE" (Revision 42): * 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: head/sys/kern/kern_tc.c 91065 2002-02-22 12:59:20Z phk $ */ #include "opt_ntp.h" #include #include #include #include #include #include #include #include /* * Number of timecounters used to implement stable storage */ #ifndef NTIMECOUNTER #define NTIMECOUNTER hz #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 bintime boottimebin; 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 *volatile 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 binuptime(struct bintime *bt) { struct timecounter *tc; tc = timecounter; *bt = tc->tc_offset; bintime_addx(bt, tc->tc_scale * tco_delta(tc)); } void bintime(struct bintime *bt) { binuptime(bt); bintime_add(bt, &boottimebin); } 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 bintime bt; nmicrotime++; bintime(&bt); bintime2timeval(&bt, tv); } void nanotime(struct timespec *ts) { struct bintime bt; nnanotime++; bintime(&bt); bintime2timespec(&bt, ts); } void getmicrouptime(struct timeval *tvp) { struct timecounter *tc; ngetmicrouptime++; tc = timecounter; bintime2timeval(&tc->tc_offset, tvp); } void getnanouptime(struct timespec *tsp) { struct timecounter *tc; ngetnanouptime++; tc = timecounter; bintime2timespec(&tc->tc_offset, tsp); } void microuptime(struct timeval *tv) { struct bintime bt; nmicrouptime++; binuptime(&bt); bintime2timeval(&bt, tv); } void nanouptime(struct timespec *ts) { struct bintime bt; nnanouptime++; binuptime(&bt); bintime2timespec(&bt, ts); } static void tco_setscales(struct timecounter *tc) { u_int64_t scale; /* Sacrifice the lower bit to the deity for code clarity */ scale = 1ULL << 63; /* * We get nanoseconds with 32 bit binary fraction and want * 64 bit binary fraction: x = a * 2^32 / 10^9 = a * 4.294967296 * The range is +/- 500PPM so we can multiply by about 8500 * without overflowing. 4398/1024 = is very close to ideal. */ scale += (tc->tc_adjustment * 4398) >> 10; scale /= tc->tc_tweak->tc_frequency; tc->tc_scale = scale * 2; } void tc_update(struct timecounter *tc) { tco_setscales(tc); } void tc_init(struct timecounter *tc) { 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; t3 = NULL; 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); binuptime(&tc->tc_offset); 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--; } timeval2bintime(&boottime, &boottimebin); /* fiddle all the little crinkly bits around the fiords... */ tc_windup(); } static void switch_timecounter(struct timecounter *newtc) { int s; struct timecounter *tc; s = splclock(); tc = timecounter; if (newtc->tc_tweak == tc->tc_tweak) { splx(s); return; } newtc = newtc->tc_tweak->tc_other; binuptime(&newtc->tc_offset); 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; bintime_addx(&tc->tc_offset, tc->tc_scale * delta); return (tc); } void tc_windup(void) { struct timecounter *tc, *tco; struct bintime bt; struct timeval tvt; int i; 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; timeval2bintime(&boottime, &boottimebin); timedelta -= tickdelta; } for (i = tc->tc_offset.sec - tco->tc_offset.sec; i > 0; i--) { ntp_update_second(tc); /* XXX only needed if xntpd runs */ tco_setscales(tc); } bt = tc->tc_offset; bintime_add(&bt, &boottimebin); bintime2timeval(&bt, &tc->tc_microtime); bintime2timespec(&bt, &tc->tc_nanotime); time_second = tc->tc_microtime.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; unsigned tcount, *pcount; struct bintime bt; 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 */ tcount = count - tc->tc_offset_count; tcount &= tc->tc_counter_mask; bt = tc->tc_offset; bintime_addx(&bt, tc->tc_scale * tcount); bintime2timespec(&bt, &ts); (*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) { u_int64_t delta; /* magic, at its best... */ tcount = count - pps->ppscount[2]; pps->ppscount[2] = count; tcount &= tc->tc_counter_mask; bt.sec = 0; bt.frac = 0; bintime_addx(&bt, tc->tc_scale * tcount); bintime2timespec(&bt, &ts); hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); } #endif }