From 97804a5c999e7d65a378b0a082482dd546aaeeef Mon Sep 17 00:00:00 2001 From: Poul-Henning Kamp Date: Mon, 4 Sep 2000 08:19:32 +0000 Subject: Update the NTP kernel PLL code to the 2000-08-29 version of Dave Mills nanokernel. The FreeBSD private mode hardpps Type 2 PLL has been removed. --- sys/kern/kern_ntptime.c | 169 +++++++++++++++++++++++------------------------- sys/sys/timex.h | 8 ++- 2 files changed, 88 insertions(+), 89 deletions(-) diff --git a/sys/kern/kern_ntptime.c b/sys/kern/kern_ntptime.c index fdf75eba12a1..e95cc4b3fa13 100644 --- a/sys/kern/kern_ntptime.c +++ b/sys/kern/kern_ntptime.c @@ -1,6 +1,6 @@ /*********************************************************************** * * - * Copyright (c) David L. Mills 1993-1999 * + * Copyright (c) David L. Mills 1993-2000 * * * * Permission to use, copy, modify, and distribute this software and * * its documentation for any purpose and without fee is hereby * @@ -92,7 +92,6 @@ typedef long long l_fp; * * Note that all routines must run at priority splclock or higher. */ - /* * Phase/frequency-lock loop (PLL/FLL) definitions * @@ -139,6 +138,8 @@ typedef long long l_fp; static int time_state = TIME_OK; /* clock state */ static int time_status = STA_UNSYNC; /* clock status bits */ +static long time_tai; /* TAI offset (s) */ +static long time_monitor; /* last time offset scaled (ns) */ static long time_constant; /* poll interval (shift) (s) */ static long time_precision = 1; /* clock precision (ns) */ static long time_maxerror = MAXPHASE / 1000; /* maximum error (us) */ @@ -147,7 +148,8 @@ static long time_reftime; /* time at last adjustment (s) */ static long time_tick; /* nanoseconds per tick (ns) */ static l_fp time_offset; /* time offset (ns) */ static l_fp time_freq; /* frequency offset (ns/s) */ -static l_fp time_adj; /* resulting adjustment */ +static l_fp time_adj; /* tick adjust (ns/s) */ +static l_fp time_phase; /* time phase (ns) */ #ifdef PPS_SYNC /* @@ -165,8 +167,8 @@ static l_fp time_adj; /* resulting adjustment */ #define PPS_POPCORN 2 /* popcorn spike threshold (shift) */ static struct timespec pps_tf[3]; /* phase median filter */ -static l_fp pps_offset; /* time offset (ns) */ static l_fp pps_freq; /* scaled frequency offset (ns/s) */ +static long pps_lastfreq; /* last scaled freq offset (ns/s) */ static long pps_fcount; /* frequency accumulator */ static long pps_jitter; /* nominal jitter (ns) */ static long pps_stabil; /* nominal stability (scaled ns/s) */ @@ -175,7 +177,6 @@ static int pps_valid; /* signal watchdog counter */ static int pps_shift = PPS_FAVG; /* interval duration (s) (shift) */ static int pps_shiftmax = PPS_FAVGDEF; /* max interval duration (s) (shift) */ static int pps_intcnt; /* wander counter */ -static int pps_letgo; /* PLL frequency hold-off */ /* * PPS signal quality monitors @@ -195,7 +196,9 @@ static void hardupdate(long offset); /* * ntp_gettime() - NTP user application interface * - * See the timex.h header file for synopsis and API description. + * See the timex.h header file for synopsis and API description. Note + * that the TAI offset is returned in the ntvtimeval.tai structure + * member. */ static int ntp_sysctl(SYSCTL_HANDLER_ARGS) @@ -208,7 +211,7 @@ ntp_sysctl(SYSCTL_HANDLER_ARGS) ntv.time.tv_nsec = atv.tv_nsec; ntv.maxerror = time_maxerror; ntv.esterror = time_esterror; - ntv.time_state = time_state; + ntv.tai = time_tai; /* * Status word error decode. If any of these conditions occur, @@ -253,12 +256,13 @@ SYSCTL_INT(_kern_ntp_pll, OID_AUTO, pps_shift, CTLFLAG_RW, &pps_shift, 0, ""); SYSCTL_OPAQUE(_kern_ntp_pll, OID_AUTO, pps_freq, CTLFLAG_RD, &pps_freq, sizeof(pps_freq), "I", ""); SYSCTL_OPAQUE(_kern_ntp_pll, OID_AUTO, time_freq, CTLFLAG_RD, &time_freq, sizeof(time_freq), "I", ""); -SYSCTL_OPAQUE(_kern_ntp_pll, OID_AUTO, pps_offset, CTLFLAG_RD, &pps_offset, sizeof(pps_offset), "I", ""); #endif /* * ntp_adjtime() - NTP daemon application interface * - * See the timex.h header file for synopsis and API description. + * See the timex.h header file for synopsis and API description. Note + * that the timex.constant structure member has a dual purpose to set + * the time constant and to set the TAI offset. */ #ifndef _SYS_SYSPROTO_H_ struct ntp_adjtime_args { @@ -283,6 +287,8 @@ ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap) * Update selected clock variables - only the superuser can * change anything. Note that there is no error checking here on * the assumption the superuser should know what it is doing. + * Note that either the time constant or TAI offset are loaded + * from the ntv.constant member, depending on the mode bits. */ modes = ntv.modes; if (modes) @@ -298,7 +304,6 @@ ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap) L_LINT(time_freq, -MAXFREQ); else L_LINT(time_freq, freq); - #ifdef PPS_SYNC pps_freq = time_freq; #endif /* PPS_SYNC */ @@ -319,6 +324,10 @@ ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap) else time_constant = ntv.constant; } + if (modes & MOD_TAI) { + if (ntv.constant > 0) /* XXX zero & negative numbers ? */ + time_tai = ntv.constant; + } #ifdef PPS_SYNC if (modes & MOD_PPSMAX) { if (ntv.shift < PPS_FAVG) @@ -345,12 +354,13 @@ ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap) } /* - * Retrieve all clock variables + * Retrieve all clock variables. Note that the TAI offset is + * returned only by ntp_gettime(); */ if (time_status & STA_NANO) - ntv.offset = L_GINT(time_offset); + ntv.offset = time_monitor; else - ntv.offset = L_GINT(time_offset) / 1000; + ntv.offset = time_monitor / 1000; /* XXX rounding ? */ ntv.freq = L_GINT((time_freq / 1000LL) << 16); ntv.maxerror = time_maxerror; ntv.esterror = time_esterror; @@ -409,6 +419,7 @@ void ntp_update_second(struct timecounter *tcp) { u_int32_t *newsec; + l_fp ftemp; /* 32/64-bit temporary */ newsec = &tcp->tc_offset_sec; /* @@ -461,6 +472,7 @@ ntp_update_second(struct timecounter *tcp) time_state = TIME_OK; else if (((*newsec) + 1) % 86400 == 0) { (*newsec)++; + time_tai--; time_state = TIME_WAIT; } break; @@ -469,7 +481,8 @@ ntp_update_second(struct timecounter *tcp) * Insert second in progress. */ case TIME_OOP: - time_state = TIME_WAIT; + time_tai++; + time_state = TIME_WAIT; break; /* @@ -487,22 +500,19 @@ ntp_update_second(struct timecounter *tcp) * value is in effect scaled by the clock frequency, * since the adjustment is added at each tick interrupt. */ + ftemp = time_offset; #ifdef PPS_SYNC - /* XXX even if signal dies we should finish adjustment ? */ - if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL) { - time_adj = pps_offset; - L_RSHIFT(time_adj, pps_shift); - L_SUB(pps_offset, time_adj); - } else { - time_adj = time_offset; - L_RSHIFT(time_adj, SHIFT_PLL + time_constant); - L_SUB(time_offset, time_adj); - } + /* XXX even if PPS signal dies we should finish adjustment ? */ + if (time_status & STA_PPSTIME && time_status & + STA_PPSSIGNAL) + L_RSHIFT(ftemp, pps_shift); + else + L_RSHIFT(ftemp, SHIFT_PLL + time_constant); #else - time_adj = time_offset; - L_RSHIFT(time_adj, SHIFT_PLL + time_constant); - L_SUB(time_offset, time_adj); + L_RSHIFT(ftemp, SHIFT_PLL + time_constant); #endif /* PPS_SYNC */ + time_adj = ftemp; + L_SUB(time_offset, ftemp); L_ADD(time_adj, time_freq); tcp->tc_adjustment = time_adj; #ifdef PPS_SYNC @@ -578,7 +588,7 @@ static void hardupdate(offset) long offset; /* clock offset (ns) */ { - long ltemp, mtemp; + long mtemp; l_fp ftemp; /* @@ -589,13 +599,16 @@ hardupdate(offset) */ if (!(time_status & STA_PLL)) return; - ltemp = offset; - if (ltemp > MAXPHASE) - ltemp = MAXPHASE; - else if (ltemp < -MAXPHASE) - ltemp = -MAXPHASE; - if (!(time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL)) - L_LINT(time_offset, ltemp); + if (!(time_status & STA_PPSTIME && time_status & + STA_PPSSIGNAL)) { + if (offset > MAXPHASE) + time_monitor = MAXPHASE; + else if (offset < -MAXPHASE) + time_monitor = -MAXPHASE; + else + time_monitor = offset; + L_LINT(time_offset, time_monitor); + } /* * Select how the frequency is to be controlled and in which @@ -610,13 +623,14 @@ hardupdate(offset) if (time_status & STA_FREQHOLD || time_reftime == 0) time_reftime = time_second; mtemp = time_second - time_reftime; - L_LINT(ftemp, ltemp); + L_LINT(ftemp, time_monitor); L_RSHIFT(ftemp, (SHIFT_PLL + 2 + time_constant) << 1); L_MPY(ftemp, mtemp); L_ADD(time_freq, ftemp); time_status &= ~STA_MODE; - if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) { - L_LINT(ftemp, (ltemp << 4) / mtemp); + if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > + MAXSEC)) { + L_LINT(ftemp, (time_monitor << 4) / mtemp); L_RSHIFT(ftemp, SHIFT_FLL + 4); L_ADD(time_freq, ftemp); time_status |= STA_MODE; @@ -633,14 +647,15 @@ hardupdate(offset) * hardpps() - discipline CPU clock oscillator to external PPS signal * * This routine is called at each PPS interrupt in order to discipline - * the CPU clock oscillator to the PPS signal. It measures the PPS phase - * and leaves it in a handy spot for the hardclock() routine. It - * integrates successive PPS phase differences and calculates the - * frequency offset. This is used in hardclock() to discipline the CPU - * clock oscillator so that the intrinsic frequency error is cancelled - * out. The code requires the caller to capture the time and - * architecture-dependent hardware counter values in nanoseconds at the - * on-time PPS signal transition. + * the CPU clock oscillator to the PPS signal. There are two independent + * first-order feedback loops, one for the phase, the other for the + * frequency. The phase loop measures and grooms the PPS phase offset + * and leaves it in a handy spot for the seconds overflow routine. The + * frequency loop averages successive PPS phase differences and + * calculates the PPS frequency offset, which is also processed by the + * seconds overflow routine. The code requires the caller to capture the + * time and architecture-dependent hardware counter values in + * nanoseconds at the on-time PPS signal transition. * * Note that, on some Unix systems this routine runs at an interrupt * priority level higher than the timer interrupt routine hardclock(). @@ -653,16 +668,18 @@ hardpps(tsp, nsec) struct timespec *tsp; /* time at PPS */ long nsec; /* hardware counter at PPS */ { - long u_sec, u_nsec, v_nsec, w_nsec; /* temps */ + long u_sec, u_nsec, v_nsec; /* temps */ l_fp ftemp; /* - * The signal is first processed by a frequency discriminator - * which rejects noise and input signals with frequencies - * outside the range 1 +-MAXFREQ PPS. If two hits occur in the - * same second, we ignore the later hit; if not and a hit occurs - * outside the range gate, keep the later hit but do not - * process it. + * The signal is first processed by a range gate and frequency + * discriminator. The range gate rejects noise spikes outside + * the range +-500 us. The frequency discriminator rejects input + * signals with apparent frequency outside the range 1 +-500 + * PPM. If two hits occur in the same second, we ignore the + * later hit; if not and a hit occurs outside the range gate, + * keep the later hit for later comparison, but do not process + * it. */ time_status |= STA_PPSSIGNAL | STA_PPSJITTER; time_status &= ~(STA_PPSWANDER | STA_PPSERROR); @@ -674,6 +691,7 @@ hardpps(tsp, nsec) u_sec++; } v_nsec = u_nsec - pps_tf[0].tv_nsec; + /* XXX: This test seems incomplete ? */ if (u_sec == pps_tf[0].tv_sec && v_nsec < -MAXFREQ) { return; } @@ -733,30 +751,17 @@ hardpps(tsp, nsec) /* * Nominal jitter is due to PPS signal noise and interrupt - * latency. If it exceeds the popcorn threshold, - * the sample is discarded. otherwise, if so enabled, the time - * offset is updated. We can tolerate a modest loss of data here - * without degrading time accuracy. + * latency. If it exceeds the popcorn threshold, the sample is + * discarded. otherwise, if so enabled, the time offset is + * updated. We can tolerate a modest loss of data here without + * much degrading time accuracy. */ if (u_nsec > (pps_jitter << PPS_POPCORN)) { time_status |= STA_PPSJITTER; pps_jitcnt++; } else if (time_status & STA_PPSTIME) { - L_LINT(time_offset, -v_nsec); - L_LINT(pps_offset, -v_nsec); - - if (pps_letgo >= 2) { - L_LINT(ftemp, -v_nsec); - L_RSHIFT(ftemp, (pps_shift * 2)); - L_ADD(ftemp, time_freq); - w_nsec = L_GINT(ftemp); - if (w_nsec > MAXFREQ) - L_LINT(ftemp, MAXFREQ); - else if (w_nsec < -MAXFREQ) - L_LINT(ftemp, -MAXFREQ); - time_freq = ftemp; - } - + time_monitor = -v_nsec; + L_LINT(time_offset, time_monitor); } pps_jitter += (u_nsec - pps_jitter) >> PPS_FAVG; u_sec = pps_tf[0].tv_sec - pps_lastsec; @@ -771,7 +776,7 @@ hardpps(tsp, nsec) * exceeds a sanity threshold, or if the actual calibration * interval is not equal to the expected length, the data are * discarded. We can tolerate a modest loss of data here without - * degrading frequency ccuracy. + * much degrading frequency accuracy. */ pps_calcnt++; v_nsec = -pps_fcount; @@ -813,20 +818,13 @@ hardpps(tsp, nsec) } else { pps_intcnt++; } - if (!(time_status & STA_PPSFREQ)) { - pps_intcnt = 0; - pps_shift = PPS_FAVG; - } else if (pps_shift > pps_shiftmax) { - /* If we lowered pps_shiftmax */ - pps_shift = pps_shiftmax; - pps_intcnt = 0; - } else if (pps_intcnt >= 4) { + if (pps_intcnt >= 4) { pps_intcnt = 4; if (pps_shift < pps_shiftmax) { pps_shift++; pps_intcnt = 0; } - } else if (pps_intcnt <= -4) { + } else if (pps_intcnt <= -4 || pps_shift > pps_shiftmax) { pps_intcnt = -4; if (pps_shift > PPS_FAVG) { pps_shift--; @@ -848,12 +846,7 @@ hardpps(tsp, nsec) L_LINT(pps_freq, MAXFREQ); else if (u_nsec < -MAXFREQ) L_LINT(pps_freq, -MAXFREQ); - if ((time_status & (STA_PPSFREQ | STA_PPSTIME)) == STA_PPSFREQ) { - pps_letgo = 0; + if (time_status & STA_PPSFREQ) time_freq = pps_freq; - } else if (time_status & STA_PPSTIME) { - if (pps_letgo < 2) - pps_letgo++; - } } #endif /* PPS_SYNC */ diff --git a/sys/sys/timex.h b/sys/sys/timex.h index 9de19957b7b2..7714b7b7d287 100644 --- a/sys/sys/timex.h +++ b/sys/sys/timex.h @@ -19,6 +19,10 @@ /* * Modification history timex.h * + * 16 Aug 00 David L. Mills + * API Version 4. Added MOD_TAI and tai member of ntptimeval + * structure. + * * 17 Nov 98 David L. Mills * Revised for nanosecond kernel and user interface. * @@ -90,7 +94,7 @@ */ #ifndef _SYS_TIMEX_H_ #define _SYS_TIMEX_H_ 1 -#define NTP_API 3 /* NTP API version */ +#define NTP_API 4 /* NTP API version */ #ifndef MSDOS /* Microsoft specific */ #include @@ -126,6 +130,7 @@ #define MOD_STATUS 0x0010 /* set clock status bits */ #define MOD_TIMECONST 0x0020 /* set PLL time constant */ #define MOD_PPSMAX 0x0040 /* set PPS maximum averaging time */ +#define MOD_TAI 0x0080 /* set TAI offset */ #define MOD_MICRO 0x1000 /* select microsecond resolution */ #define MOD_NANO 0x2000 /* select nanosecond resolution */ #define MOD_CLKB 0x4000 /* select clock B */ @@ -174,6 +179,7 @@ struct ntptimeval { struct timespec time; /* current time (ns) (ro) */ long maxerror; /* maximum error (us) (ro) */ long esterror; /* estimated error (us) (ro) */ + long tai; /* TAI offset */ int time_state; /* time status */ }; -- cgit v1.2.3