/* * ---------------------------------------------------------------------------- * "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 95551 2002-04-27 07:28:54Z phk $ */ #include "opt_ntp.h" #include #include #include #include #include #include #include /* * 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 timehands { /* These fields must be initialized by the driver. */ struct timecounter *tc_counter; int64_t tc_adjustment; u_int64_t tc_scale; unsigned tc_offset_count; struct bintime tc_offset; struct timeval tc_microtime; struct timespec tc_nanotime; /* Fields not to be copied in tc_windup start with tc_generation */ volatile unsigned tc_generation; struct timehands *tc_next; }; extern struct timehands th0; static struct timehands th9 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th0}; static struct timehands th8 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th9}; static struct timehands th7 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th8}; static struct timehands th6 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th7}; static struct timehands th5 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th6}; static struct timehands th4 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th5}; static struct timehands th3 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th4}; static struct timehands th2 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th3}; static struct timehands th1 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 1, &th2}; static struct timehands th0 = { &dummy_timecounter, 0, 18446744073709ULL, /* 2^64/1000000 */ 0, {769769981, 0}, /* Tue May 24 08:59:41 GMT 1994 */ {0, 0}, {0, 0}, 1, &th1 }; static struct timehands *volatile timehands = &th0; struct timecounter *timecounter = &dummy_timecounter; static struct timecounter *timecounters = &dummy_timecounter; 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, ""); #define TC_STATS(foo) \ static unsigned foo; \ SYSCTL_INT(_kern_timecounter, OID_AUTO, foo, CTLFLAG_RD, & foo, 0, "") TC_STATS(nbinuptime); TC_STATS(nnanouptime); TC_STATS(nmicrouptime); TC_STATS(nbintime); TC_STATS(nnanotime); TC_STATS(nmicrotime); TC_STATS(ngetbinuptime); TC_STATS(ngetnanouptime); TC_STATS(ngetmicrouptime); TC_STATS(ngetbintime); TC_STATS(ngetnanotime); TC_STATS(ngetmicrotime); #undef TC_STATS static void tc_windup(void); static __inline unsigned tc_delta(struct timehands *tc) { return ((tc->tc_counter->tc_get_timecount(tc->tc_counter) - tc->tc_offset_count) & tc->tc_counter->tc_counter_mask); } void binuptime(struct bintime *bt) { struct timehands *tc; unsigned gen; nbinuptime++; do { tc = timehands; gen = tc->tc_generation; *bt = tc->tc_offset; bintime_addx(bt, tc->tc_scale * tc_delta(tc)); } while (gen == 0 || gen != tc->tc_generation); } void nanouptime(struct timespec *ts) { struct bintime bt; nnanouptime++; binuptime(&bt); bintime2timespec(&bt, ts); } void microuptime(struct timeval *tv) { struct bintime bt; nmicrouptime++; binuptime(&bt); bintime2timeval(&bt, tv); } void bintime(struct bintime *bt) { nbintime++; binuptime(bt); bintime_add(bt, &boottimebin); } void nanotime(struct timespec *ts) { struct bintime bt; nnanotime++; bintime(&bt); bintime2timespec(&bt, ts); } void microtime(struct timeval *tv) { struct bintime bt; nmicrotime++; bintime(&bt); bintime2timeval(&bt, tv); } void getbinuptime(struct bintime *bt) { struct timehands *tc; unsigned gen; ngetbinuptime++; do { tc = timehands; gen = tc->tc_generation; *bt = tc->tc_offset; } while (gen == 0 || gen != tc->tc_generation); } void getnanouptime(struct timespec *tsp) { struct timehands *tc; unsigned gen; ngetnanouptime++; do { tc = timehands; gen = tc->tc_generation; bintime2timespec(&tc->tc_offset, tsp); } while (gen == 0 || gen != tc->tc_generation); } void getmicrouptime(struct timeval *tvp) { struct timehands *tc; unsigned gen; ngetmicrouptime++; do { tc = timehands; gen = tc->tc_generation; bintime2timeval(&tc->tc_offset, tvp); } while (gen == 0 || gen != tc->tc_generation); } void getbintime(struct bintime *bt) { struct timehands *tc; unsigned gen; ngetbintime++; do { tc = timehands; gen = tc->tc_generation; *bt = tc->tc_offset; } while (gen == 0 || gen != tc->tc_generation); bintime_add(bt, &boottimebin); } void getnanotime(struct timespec *tsp) { struct timehands *tc; unsigned gen; ngetnanotime++; do { tc = timehands; gen = tc->tc_generation; *tsp = tc->tc_nanotime; } while (gen == 0 || gen != tc->tc_generation); } void getmicrotime(struct timeval *tvp) { struct timehands *tc; unsigned gen; ngetmicrotime++; do { tc = timehands; gen = tc->tc_generation; *tvp = tc->tc_microtime; } while (gen == 0 || gen != tc->tc_generation); } static void tc_setscales(struct timehands *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 +/- 5000PPM so we can only multiply by about 850 * without overflowing. The best suitable fraction is 2199/512. * Divide by 2 times 512 to match the temporary lower precision. */ scale += (tc->tc_adjustment / 1024) * 2199; scale /= tc->tc_counter->tc_frequency; tc->tc_scale = scale * 2; } void tc_init(struct timecounter *tc) { tc->tc_next = timecounters; timecounters = tc; printf("Timecounter \"%s\" frequency %lu Hz\n", tc->tc_name, (u_long)tc->tc_frequency); timecounter = tc; } u_int32_t tc_getfrequency(void) { return (timehands->tc_counter->tc_frequency); } 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 tc_windup(void) { struct timehands *tc, *tco; struct bintime bt; unsigned ogen, delta, ncount; int i; ncount = 0; /* GCC is lame */ tco = timehands; tc = tco->tc_next; ogen = tc->tc_generation; tc->tc_generation = 0; bcopy(tco, tc, __offsetof(struct timehands, tc_generation)); delta = tc_delta(tc); if (tc->tc_counter != timecounter) ncount = timecounter->tc_get_timecount(timecounter); tc->tc_offset_count += delta; tc->tc_offset_count &= tc->tc_counter->tc_counter_mask; bintime_addx(&tc->tc_offset, tc->tc_scale * delta); /* * We may be inducing a tiny error here, the tc_poll_pps() may * process a latched count which happens after the tc_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_counter->tc_poll_pps) tco->tc_counter->tc_poll_pps(tco->tc_counter); for (i = tc->tc_offset.sec - tco->tc_offset.sec; i > 0; i--) ntp_update_second(&tc->tc_adjustment, &tc->tc_offset.sec); if (tc->tc_counter != timecounter) { tc->tc_counter = timecounter; tc->tc_offset_count = ncount; } tc_setscales(tc); bt = tc->tc_offset; bintime_add(&bt, &boottimebin); bintime2timeval(&bt, &tc->tc_microtime); bintime2timespec(&bt, &tc->tc_nanotime); ogen++; if (ogen == 0) ogen++; tc->tc_generation = ogen; time_second = tc->tc_microtime.tv_sec; timehands = tc; } static int sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) { char newname[32]; struct timecounter *newtc, *tc; int error; tc = timecounter; 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)) return(error); for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { if (strcmp(newname, newtc->tc_name)) continue; /* Warm up new timecounter. */ (void)newtc->tc_get_timecount(newtc); (void)newtc->tc_get_timecount(newtc); timecounter = newtc; return (0); } return (EINVAL); } 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_capture(struct pps_state *pps) { struct timehands *tc; tc = timehands; pps->captc = tc; pps->capgen = tc->tc_generation; pps->capcount = tc->tc_counter->tc_get_timecount(tc->tc_counter); } void pps_event(struct pps_state *pps, int event) { struct timespec ts, *tsp, *osp; unsigned tcount, *pcount; struct bintime bt; int foff, fhard; pps_seq_t *pseq; /* If the timecounter were wound up, bail. */ if (pps->capgen != pps->capgen) return; /* 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 != pps->captc->tc_counter || pps->captc->tc_counter != timehands->tc_counter) { pps->ppstc = pps->captc->tc_counter; *pcount = pps->capcount; #ifdef PPS_SYNC pps->ppscount[2] = pps->capcount; #endif return; } /* Nothing really happened */ if (*pcount == pps->capcount) return; /* Convert the count to timespec */ tcount = pps->capcount - pps->captc->tc_offset_count; tcount &= pps->captc->tc_counter->tc_counter_mask; bt = pps->captc->tc_offset; bintime_addx(&bt, pps->captc->tc_scale * tcount); bintime2timespec(&bt, &ts); /* If the timecounter were wound up, bail. */ if (pps->capgen != pps->capgen) return; *pcount = pps->capcount; (*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 = pps->capcount - pps->ppscount[2]; pps->ppscount[2] = pps->capcount; tcount &= pps->captc->tc_counter->tc_counter_mask; bt.sec = 0; bt.frac = 0; bintime_addx(&bt, pps->captc->tc_scale * tcount); bintime2timespec(&bt, &ts); hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); } #endif } /*- * Timecounters need to be updated every so often to prevent the hardware * counter from overflowing. Updating also recalculates the cached values * used by the get*() family of functions, so their precision depends on * the update frequency. * Don't update faster than approx once per millisecond, if people want * better timestamps they should use the non-"get" functions. */ static int tc_tick; SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tick, 0, ""); static void tc_ticktock(void *dummy) { tc_windup(); timeout(tc_ticktock, NULL, tc_tick); } static void inittimecounter(void *dummy) { u_int p; if (hz > 1000) tc_tick = (hz + 500) / 1000; else tc_tick = 1; p = (tc_tick * 1000000) / hz; printf("Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000); tc_ticktock(NULL); } SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_FIRST, inittimecounter, NULL)