From 3f31c649d16f2b5e9d77bc84c513949ec2a76868 Mon Sep 17 00:00:00 2001 From: Garrett Wollman Date: Sun, 18 Sep 1994 20:40:01 +0000 Subject: [PATCH] Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in ) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead. --- sys/amd64/amd64/tsc.c | 23 +- sys/amd64/include/clock.h | 49 ++++ sys/amd64/isa/clock.c | 23 +- sys/conf/files | 1 + sys/i386/i386/tsc.c | 23 +- sys/i386/include/clock.h | 49 ++++ sys/i386/isa/clock.c | 23 +- sys/isa/atrtc.c | 23 +- sys/kern/init_sysent.c | 4 +- sys/kern/kern_clock.c | 585 +++++++++++++++++++++++++++++++++++++- sys/kern/kern_ntptime.c | 269 ++++++++++++++++++ sys/kern/kern_sysctl.c | 9 +- sys/kern/kern_tc.c | 585 +++++++++++++++++++++++++++++++++++++- sys/kern/kern_timeout.c | 585 +++++++++++++++++++++++++++++++++++++- sys/kern/syscalls.c | 4 +- sys/kern/syscalls.master | 4 +- sys/sys/syscall-hide.h | 3 +- sys/sys/syscall.h | 3 +- sys/sys/sysctl.h | 6 +- sys/sys/timex.h | 12 + 20 files changed, 2129 insertions(+), 154 deletions(-) create mode 100644 sys/amd64/include/clock.h create mode 100644 sys/i386/include/clock.h create mode 100644 sys/kern/kern_ntptime.c diff --git a/sys/amd64/amd64/tsc.c b/sys/amd64/amd64/tsc.c index 88942db0f748..b7624423d42d 100644 --- a/sys/amd64/amd64/tsc.c +++ b/sys/amd64/amd64/tsc.c @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * from: @(#)clock.c 7.2 (Berkeley) 5/12/91 - * $Id: clock.c,v 1.16 1994/08/18 22:34:50 wollman Exp $ + * $Id: clock.c,v 1.17 1994/09/14 23:09:06 ache Exp $ */ /* @@ -79,27 +79,6 @@ void clkintr(frame) struct clockframe frame; { -#ifdef I586_CPU - /* - * This resets the CPU cycle counter to zero, to make our - * job easier in microtime(). Some fancy ifdefs could speed - * this up for Pentium-only kernels. - * We want this to be done as close as possible to the actual - * timer incrementing in hardclock(), because there is a window - * between the two where the value is no longer valid. Experimentation - * may reveal a good precompensation to apply in microtime(). - */ - if(pentium_mhz) { - __asm __volatile("movl $0x10,%%ecx\n" - "xorl %%eax,%%eax\n" - "movl %%eax,%%edx\n" - ".byte 0x0f, 0x30\n" - "#%0%1" - : "=m"(frame) /* no outputs */ - : "b"(&frame) /* fake input */ - : "ax", "cx", "dx"); - } -#endif hardclock(&frame); } diff --git a/sys/amd64/include/clock.h b/sys/amd64/include/clock.h new file mode 100644 index 000000000000..b7420e4adc66 --- /dev/null +++ b/sys/amd64/include/clock.h @@ -0,0 +1,49 @@ +/* + * Kernel interface to machine-dependent clock driver. + * Garrett Wollman, September 1994. + * This file is in the public domain. + */ + +#ifndef _MACHINE_CLOCK_H_ +#define _MACHINE_CLOCK_H_ 1 + +extern int pentium_mhz; + +#ifdef I586_CPU + /* + * This resets the CPU cycle counter to zero, to make our + * job easier in microtime(). Some fancy ifdefs could speed + * this up for Pentium-only kernels. + * We want this to be done as close as possible to the actual + * timer incrementing in hardclock(), because there is a window + * between the two where the value is no longer valid. Experimentation + * may reveal a good precompensation to apply in microtime(). + */ +#define CPU_CLOCKUPDATE(otime, ntime) \ + do { \ + if(pentium_mhz) { \ + __asm __volatile("cli\n" \ + "movl (%2),%%eax\n" \ + "movl %%eax,(%1)\n" \ + "movl 4(%2),%%eax\n" \ + "movl %%eax,4(%1)\n" \ + "movl $0x10,%%ecx\n" \ + "xorl %%eax,%%eax\n" \ + "movl %%eax,%%edx\n" \ + ".byte 0x0f, 0x30\n" \ + "sti\n" \ + "#%0%1%2" \ + : "=m"(*otime) /* no outputs */ \ + : "c"(otime), "b"(ntime) /* fake input */ \ + : "ax", "cx", "dx"); \ + } else { \ + *(otime) = *(ntime); \ + } \ + } while(0) + +#else +#define CPU_CLOCKUPDATE(otime, ntime) \ + (*(otime) = *(ntime)) +#endif + +#endif /* _MACHINE_CLOCK_H_ */ diff --git a/sys/amd64/isa/clock.c b/sys/amd64/isa/clock.c index 88942db0f748..b7624423d42d 100644 --- a/sys/amd64/isa/clock.c +++ b/sys/amd64/isa/clock.c @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * from: @(#)clock.c 7.2 (Berkeley) 5/12/91 - * $Id: clock.c,v 1.16 1994/08/18 22:34:50 wollman Exp $ + * $Id: clock.c,v 1.17 1994/09/14 23:09:06 ache Exp $ */ /* @@ -79,27 +79,6 @@ void clkintr(frame) struct clockframe frame; { -#ifdef I586_CPU - /* - * This resets the CPU cycle counter to zero, to make our - * job easier in microtime(). Some fancy ifdefs could speed - * this up for Pentium-only kernels. - * We want this to be done as close as possible to the actual - * timer incrementing in hardclock(), because there is a window - * between the two where the value is no longer valid. Experimentation - * may reveal a good precompensation to apply in microtime(). - */ - if(pentium_mhz) { - __asm __volatile("movl $0x10,%%ecx\n" - "xorl %%eax,%%eax\n" - "movl %%eax,%%edx\n" - ".byte 0x0f, 0x30\n" - "#%0%1" - : "=m"(frame) /* no outputs */ - : "b"(&frame) /* fake input */ - : "ax", "cx", "dx"); - } -#endif hardclock(&frame); } diff --git a/sys/conf/files b/sys/conf/files index e32c95be45bd..f314a1beda6f 100644 --- a/sys/conf/files +++ b/sys/conf/files @@ -49,6 +49,7 @@ kern/kern_ktrace.c standard kern/kern_lockf.c standard kern/kern_lkm.c optional lkm kern/kern_malloc.c standard +kern/kern_ntptime.c standard kern/kern_physio.c standard kern/kern_proc.c standard kern/kern_prot.c standard diff --git a/sys/i386/i386/tsc.c b/sys/i386/i386/tsc.c index 88942db0f748..b7624423d42d 100644 --- a/sys/i386/i386/tsc.c +++ b/sys/i386/i386/tsc.c @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * from: @(#)clock.c 7.2 (Berkeley) 5/12/91 - * $Id: clock.c,v 1.16 1994/08/18 22:34:50 wollman Exp $ + * $Id: clock.c,v 1.17 1994/09/14 23:09:06 ache Exp $ */ /* @@ -79,27 +79,6 @@ void clkintr(frame) struct clockframe frame; { -#ifdef I586_CPU - /* - * This resets the CPU cycle counter to zero, to make our - * job easier in microtime(). Some fancy ifdefs could speed - * this up for Pentium-only kernels. - * We want this to be done as close as possible to the actual - * timer incrementing in hardclock(), because there is a window - * between the two where the value is no longer valid. Experimentation - * may reveal a good precompensation to apply in microtime(). - */ - if(pentium_mhz) { - __asm __volatile("movl $0x10,%%ecx\n" - "xorl %%eax,%%eax\n" - "movl %%eax,%%edx\n" - ".byte 0x0f, 0x30\n" - "#%0%1" - : "=m"(frame) /* no outputs */ - : "b"(&frame) /* fake input */ - : "ax", "cx", "dx"); - } -#endif hardclock(&frame); } diff --git a/sys/i386/include/clock.h b/sys/i386/include/clock.h new file mode 100644 index 000000000000..b7420e4adc66 --- /dev/null +++ b/sys/i386/include/clock.h @@ -0,0 +1,49 @@ +/* + * Kernel interface to machine-dependent clock driver. + * Garrett Wollman, September 1994. + * This file is in the public domain. + */ + +#ifndef _MACHINE_CLOCK_H_ +#define _MACHINE_CLOCK_H_ 1 + +extern int pentium_mhz; + +#ifdef I586_CPU + /* + * This resets the CPU cycle counter to zero, to make our + * job easier in microtime(). Some fancy ifdefs could speed + * this up for Pentium-only kernels. + * We want this to be done as close as possible to the actual + * timer incrementing in hardclock(), because there is a window + * between the two where the value is no longer valid. Experimentation + * may reveal a good precompensation to apply in microtime(). + */ +#define CPU_CLOCKUPDATE(otime, ntime) \ + do { \ + if(pentium_mhz) { \ + __asm __volatile("cli\n" \ + "movl (%2),%%eax\n" \ + "movl %%eax,(%1)\n" \ + "movl 4(%2),%%eax\n" \ + "movl %%eax,4(%1)\n" \ + "movl $0x10,%%ecx\n" \ + "xorl %%eax,%%eax\n" \ + "movl %%eax,%%edx\n" \ + ".byte 0x0f, 0x30\n" \ + "sti\n" \ + "#%0%1%2" \ + : "=m"(*otime) /* no outputs */ \ + : "c"(otime), "b"(ntime) /* fake input */ \ + : "ax", "cx", "dx"); \ + } else { \ + *(otime) = *(ntime); \ + } \ + } while(0) + +#else +#define CPU_CLOCKUPDATE(otime, ntime) \ + (*(otime) = *(ntime)) +#endif + +#endif /* _MACHINE_CLOCK_H_ */ diff --git a/sys/i386/isa/clock.c b/sys/i386/isa/clock.c index 88942db0f748..b7624423d42d 100644 --- a/sys/i386/isa/clock.c +++ b/sys/i386/isa/clock.c @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * from: @(#)clock.c 7.2 (Berkeley) 5/12/91 - * $Id: clock.c,v 1.16 1994/08/18 22:34:50 wollman Exp $ + * $Id: clock.c,v 1.17 1994/09/14 23:09:06 ache Exp $ */ /* @@ -79,27 +79,6 @@ void clkintr(frame) struct clockframe frame; { -#ifdef I586_CPU - /* - * This resets the CPU cycle counter to zero, to make our - * job easier in microtime(). Some fancy ifdefs could speed - * this up for Pentium-only kernels. - * We want this to be done as close as possible to the actual - * timer incrementing in hardclock(), because there is a window - * between the two where the value is no longer valid. Experimentation - * may reveal a good precompensation to apply in microtime(). - */ - if(pentium_mhz) { - __asm __volatile("movl $0x10,%%ecx\n" - "xorl %%eax,%%eax\n" - "movl %%eax,%%edx\n" - ".byte 0x0f, 0x30\n" - "#%0%1" - : "=m"(frame) /* no outputs */ - : "b"(&frame) /* fake input */ - : "ax", "cx", "dx"); - } -#endif hardclock(&frame); } diff --git a/sys/isa/atrtc.c b/sys/isa/atrtc.c index 88942db0f748..b7624423d42d 100644 --- a/sys/isa/atrtc.c +++ b/sys/isa/atrtc.c @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * from: @(#)clock.c 7.2 (Berkeley) 5/12/91 - * $Id: clock.c,v 1.16 1994/08/18 22:34:50 wollman Exp $ + * $Id: clock.c,v 1.17 1994/09/14 23:09:06 ache Exp $ */ /* @@ -79,27 +79,6 @@ void clkintr(frame) struct clockframe frame; { -#ifdef I586_CPU - /* - * This resets the CPU cycle counter to zero, to make our - * job easier in microtime(). Some fancy ifdefs could speed - * this up for Pentium-only kernels. - * We want this to be done as close as possible to the actual - * timer incrementing in hardclock(), because there is a window - * between the two where the value is no longer valid. Experimentation - * may reveal a good precompensation to apply in microtime(). - */ - if(pentium_mhz) { - __asm __volatile("movl $0x10,%%ecx\n" - "xorl %%eax,%%eax\n" - "movl %%eax,%%edx\n" - ".byte 0x0f, 0x30\n" - "#%0%1" - : "=m"(frame) /* no outputs */ - : "b"(&frame) /* fake input */ - : "ax", "cx", "dx"); - } -#endif hardclock(&frame); } diff --git a/sys/kern/init_sysent.c b/sys/kern/init_sysent.c index a7f7988b5ac3..19219ab50b3d 100644 --- a/sys/kern/init_sysent.c +++ b/sys/kern/init_sysent.c @@ -2,7 +2,7 @@ * System call switch table. * * DO NOT EDIT-- this file is automatically generated. - * created from $Id: syscalls.master,v 1.7 1994/09/13 00:48:19 wollman Exp $ + * created from $Id: syscalls.master,v 1.8 1994/09/13 14:46:54 dfr Exp $ */ #include @@ -473,7 +473,7 @@ struct sysent sysent[] = { { 0, nosys }, /* 172 = nosys */ { 0, nosys }, /* 173 = nosys */ { 0, nosys }, /* 174 = nosys */ - { 1, nosys }, /* 175 = ntp_gettime */ + { 0, nosys }, /* 175 = nosys */ { 1, nosys }, /* 176 = ntp_adjtime */ { 0, nosys }, /* 177 = nosys */ { 0, nosys }, /* 178 = nosys */ diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c index 788e279bc68a..6b3f85f2707e 100644 --- a/sys/kern/kern_clock.c +++ b/sys/kern/kern_clock.c @@ -36,9 +36,26 @@ * SUCH DAMAGE. * * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 - * $Id: kern_clock.c,v 1.4 1994/08/18 22:34:58 wollman Exp $ + * $Id: kern_clock.c,v 1.5 1994/08/27 16:14:26 davidg Exp $ */ +/* Portions of this software are covered by the following: */ +/****************************************************************************** + * * + * Copyright (c) David L. Mills 1993, 1994 * + * * + * Permission to use, copy, modify, and distribute this software and its * + * documentation for any purpose and without fee is hereby granted, provided * + * that the above copyright notice appears in all copies and that both the * + * copyright notice and this permission notice appear in supporting * + * documentation, and that the name University of Delaware not be used in * + * advertising or publicity pertaining to distribution of the software * + * without specific, written prior permission. The University of Delaware * + * makes no representations about the suitability this software for any * + * purpose. It is provided "as is" without express or implied warranty. * + * * + *****************************************************************************/ + #include #include #include @@ -46,9 +63,11 @@ #include #include #include +#include #include #include +#include #ifdef GPROF #include @@ -127,6 +146,238 @@ int psratio; /* ratio: prof / stat */ volatile struct timeval time; volatile struct timeval mono_time; +/* + * Phase-lock loop (PLL) definitions + * + * The following variables are read and set by the ntp_adjtime() system + * call. + * + * time_state shows the state of the system clock, with values defined + * in the timex.h header file. + * + * time_status shows the status of the system clock, with bits defined + * in the timex.h header file. + * + * time_offset is used by the PLL to adjust the system time in small + * increments. + * + * time_constant determines the bandwidth or "stiffness" of the PLL. + * + * time_tolerance determines maximum frequency error or tolerance of the + * CPU clock oscillator and is a property of the architecture; however, + * in principle it could change as result of the presence of external + * discipline signals, for instance. + * + * time_precision is usually equal to the kernel tick variable; however, + * in cases where a precision clock counter or external clock is + * available, the resolution can be much less than this and depend on + * whether the external clock is working or not. + * + * time_maxerror is initialized by a ntp_adjtime() call and increased by + * the kernel once each second to reflect the maximum error + * bound growth. + * + * time_esterror is set and read by the ntp_adjtime() call, but + * otherwise not used by the kernel. + */ +int time_status = STA_UNSYNC; /* clock status bits */ +int time_state = TIME_OK; /* clock state */ +long time_offset = 0; /* time offset (us) */ +long time_constant = 0; /* pll time constant */ +long time_tolerance = MAXFREQ; /* frequency tolerance (scaled ppm) */ +long time_precision = 1; /* clock precision (us) */ +long time_maxerror = MAXPHASE; /* maximum error (us) */ +long time_esterror = MAXPHASE; /* estimated error (us) */ + +/* + * The following variables establish the state of the PLL and the + * residual time and frequency offset of the local clock. The scale + * factors are defined in the timex.h header file. + * + * time_phase and time_freq are the phase increment and the frequency + * increment, respectively, of the kernel time variable at each tick of + * the clock. + * + * time_freq is set via ntp_adjtime() from a value stored in a file when + * the synchronization daemon is first started. Its value is retrieved + * via ntp_adjtime() and written to the file about once per hour by the + * daemon. + * + * time_adj is the adjustment added to the value of tick at each timer + * interrupt and is recomputed at each timer interrupt. + * + * time_reftime is the second's portion of the system time on the last + * call to ntp_adjtime(). It is used to adjust the time_freq variable + * and to increase the time_maxerror as the time since last update + * increases. + */ +long time_phase = 0; /* phase offset (scaled us) */ +long time_freq = 0; /* frequency offset (scaled ppm) */ +long time_adj = 0; /* tick adjust (scaled 1 / hz) */ +long time_reftime = 0; /* time at last adjustment (s) */ + +#ifdef PPS_SYNC +/* + * The following variables are used only if the if the kernel PPS + * discipline code is configured (PPS_SYNC). The scale factors are + * defined in the timex.h header file. + * + * pps_time contains the time at each calibration interval, as read by + * microtime(). + * + * pps_offset is the time offset produced by the time median filter + * pps_tf[], while pps_jitter is the dispersion measured by this + * filter. + * + * pps_freq is the frequency offset produced by the frequency median + * filter pps_ff[], while pps_stabil is the dispersion measured by + * this filter. + * + * pps_usec is latched from a high resolution counter or external clock + * at pps_time. Here we want the hardware counter contents only, not the + * contents plus the time_tv.usec as usual. + * + * pps_valid counts the number of seconds since the last PPS update. It + * is used as a watchdog timer to disable the PPS discipline should the + * PPS signal be lost. + * + * pps_glitch counts the number of seconds since the beginning of an + * offset burst more than tick/2 from current nominal offset. It is used + * mainly to suppress error bursts due to priority conflicts between the + * PPS interrupt and timer interrupt. + * + * pps_count counts the seconds of the calibration interval, the + * duration of which is pps_shift in powers of two. + * + * pps_intcnt counts the calibration intervals for use in the interval- + * adaptation algorithm. It's just too complicated for words. + */ +struct timeval pps_time; /* kernel time at last interval */ +long pps_offset = 0; /* pps time offset (us) */ +long pps_jitter = MAXTIME; /* pps time dispersion (jitter) (us) */ +long pps_tf[] = {0, 0, 0}; /* pps time offset median filter (us) */ +long pps_freq = 0; /* frequency offset (scaled ppm) */ +long pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */ +long pps_ff[] = {0, 0, 0}; /* frequency offset median filter */ +long pps_usec = 0; /* microsec counter at last interval */ +long pps_valid = PPS_VALID; /* pps signal watchdog counter */ +int pps_glitch = 0; /* pps signal glitch counter */ +int pps_count = 0; /* calibration interval counter (s) */ +int pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */ +int pps_intcnt = 0; /* intervals at current duration */ + +/* + * PPS signal quality monitors + * + * pps_jitcnt counts the seconds that have been discarded because the + * jitter measured by the time median filter exceeds the limit MAXTIME + * (100 us). + * + * pps_calcnt counts the frequency calibration intervals, which are + * variable from 4 s to 256 s. + * + * pps_errcnt counts the calibration intervals which have been discarded + * because the wander exceeds the limit MAXFREQ (100 ppm) or where the + * calibration interval jitter exceeds two ticks. + * + * pps_stbcnt counts the calibration intervals that have been discarded + * because the frequency wander exceeds the limit MAXFREQ / 4 (25 us). + */ +long pps_jitcnt = 0; /* jitter limit exceeded */ +long pps_calcnt = 0; /* calibration intervals */ +long pps_errcnt = 0; /* calibration errors */ +long pps_stbcnt = 0; /* stability limit exceeded */ +#endif /* PPS_SYNC */ + +/* XXX none of this stuff works under FreeBSD */ +#ifdef EXT_CLOCK +/* + * External clock definitions + * + * The following definitions and declarations are used only if an + * external clock (HIGHBALL or TPRO) is configured on the system. + */ +#define CLOCK_INTERVAL 30 /* CPU clock update interval (s) */ + +/* + * The clock_count variable is set to CLOCK_INTERVAL at each PPS + * interrupt and decremented once each second. + */ +int clock_count = 0; /* CPU clock counter */ + +#ifdef HIGHBALL +/* + * The clock_offset and clock_cpu variables are used by the HIGHBALL + * interface. The clock_offset variable defines the offset between + * system time and the HIGBALL counters. The clock_cpu variable contains + * the offset between the system clock and the HIGHBALL clock for use in + * disciplining the kernel time variable. + */ +extern struct timeval clock_offset; /* Highball clock offset */ +long clock_cpu = 0; /* CPU clock adjust */ +#endif /* HIGHBALL */ +#endif /* EXT_CLOCK */ + +/* + * hardupdate() - local clock update + * + * This routine is called by ntp_adjtime() to update the local clock + * phase and frequency. This is used to implement an adaptive-parameter, + * first-order, type-II phase-lock loop. The code computes new time and + * frequency offsets each time it is called. The hardclock() routine + * amortizes these offsets at each tick interrupt. If the kernel PPS + * discipline code is configured (PPS_SYNC), the PPS signal itself + * determines the new time offset, instead of the calling argument. + * Presumably, calls to ntp_adjtime() occur only when the caller + * believes the local clock is valid within some bound (+-128 ms with + * NTP). If the caller's time is far different than the PPS time, an + * argument will ensue, and it's not clear who will lose. + * + * For default SHIFT_UPDATE = 12, the offset is limited to +-512 ms, the + * maximum interval between updates is 4096 s and the maximum frequency + * offset is +-31.25 ms/s. + * + * Note: splclock() is in effect. + */ +void +hardupdate(offset) + long offset; +{ + long ltemp, mtemp; + + if (!(time_status & STA_PLL) && !(time_status & STA_PPSTIME)) + return; + ltemp = offset; +#ifdef PPS_SYNC + if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL) + ltemp = pps_offset; +#endif /* PPS_SYNC */ + if (ltemp > MAXPHASE) + time_offset = MAXPHASE << SHIFT_UPDATE; + else if (ltemp < -MAXPHASE) + time_offset = -(MAXPHASE << SHIFT_UPDATE); + else + time_offset = ltemp << SHIFT_UPDATE; + mtemp = time.tv_sec - time_reftime; + time_reftime = time.tv_sec; + if (mtemp > MAXSEC) + mtemp = 0; + + /* ugly multiply should be replaced */ + if (ltemp < 0) + time_freq -= (-ltemp * mtemp) >> (time_constant + + time_constant + SHIFT_KF - SHIFT_USEC); + else + time_freq += (ltemp * mtemp) >> (time_constant + + time_constant + SHIFT_KF - SHIFT_USEC); + if (time_freq > time_tolerance) + time_freq = time_tolerance; + else if (time_freq < -time_tolerance) + time_freq = -time_tolerance; +} + + + /* * Initialize clock frequencies and start both clocks running. */ @@ -207,18 +458,164 @@ hardclock(frame) statclock(frame); /* - * Increment the time-of-day. The increment is just ``tick'' unless - * we are still adjusting the clock; see adjtime(). + * Increment the time-of-day. */ ticks++; - if (timedelta == 0) - delta = tick; - else { - delta = tick + tickdelta; - timedelta -= tickdelta; + { + int time_update; + struct timeval newtime = time; + long ltemp; + + if (timedelta == 0) { + time_update = tick; + } else { + if (timedelta < 0) { + time_update = tick - tickdelta; + timedelta += tickdelta; + } else { + time_update = tick + tickdelta; + timedelta -= tickdelta; + } + } + BUMPTIME(&mono_time, time_update); + + /* + * Compute the phase adjustment. If the low-order bits + * (time_phase) of the update overflow, bump the high-order bits + * (time_update). + */ + time_phase += time_adj; + if (time_phase <= -FINEUSEC) { + ltemp = -time_phase >> SHIFT_SCALE; + time_phase += ltemp << SHIFT_SCALE; + time_update -= ltemp; + } + else if (time_phase >= FINEUSEC) { + ltemp = time_phase >> SHIFT_SCALE; + time_phase -= ltemp << SHIFT_SCALE; + time_update += ltemp; + } + + newtime.tv_usec += time_update; + /* + * On rollover of the second the phase adjustment to be used for + * the next second is calculated. Also, the maximum error is + * increased by the tolerance. If the PPS frequency discipline + * code is present, the phase is increased to compensate for the + * CPU clock oscillator frequency error. + * + * With SHIFT_SCALE = 23, the maximum frequency adjustment is + * +-256 us per tick, or 25.6 ms/s at a clock frequency of 100 + * Hz. The time contribution is shifted right a minimum of two + * bits, while the frequency contribution is a right shift. + * Thus, overflow is prevented if the frequency contribution is + * limited to half the maximum or 15.625 ms/s. + */ + if (newtime.tv_usec >= 1000000) { + newtime.tv_usec -= 1000000; + newtime.tv_sec++; + time_maxerror += time_tolerance >> SHIFT_USEC; + if (time_offset < 0) { + ltemp = -time_offset >> + (SHIFT_KG + time_constant); + time_offset += ltemp; + time_adj = -ltemp << + (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } else { + ltemp = time_offset >> + (SHIFT_KG + time_constant); + time_offset -= ltemp; + time_adj = ltemp << + (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } +#ifdef PPS_SYNC + /* + * Gnaw on the watchdog counter and update the frequency + * computed by the pll and the PPS signal. + */ + pps_valid++; + if (pps_valid == PPS_VALID) { + pps_jitter = MAXTIME; + pps_stabil = MAXFREQ; + time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | + STA_PPSWANDER | STA_PPSERROR); + } + ltemp = time_freq + pps_freq; +#else + ltemp = time_freq; +#endif /* PPS_SYNC */ + if (ltemp < 0) + time_adj -= -ltemp >> + (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + else + time_adj += ltemp >> + (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + + /* + * When the CPU clock oscillator frequency is not a + * power of two in Hz, the SHIFT_HZ is only an + * approximate scale factor. In the SunOS kernel, this + * results in a PLL gain factor of 1/1.28 = 0.78 what it + * should be. In the following code the overall gain is + * increased by a factor of 1.25, which results in a + * residual error less than 3 percent. + */ + /* Same thing applies for FreeBSD --GAW */ + if (hz == 100) { + if (time_adj < 0) + time_adj -= -time_adj >> 2; + else + time_adj += time_adj >> 2; + } + + /* XXX - this is really bogus, but can't be fixed until + xntpd's idea of the system clock is fixed to know how + the user wants leap seconds handled; in the mean time, + we assume that users of NTP are running without proper + leap second support (this is now the default anyway) */ + /* + * Leap second processing. If in leap-insert state at + * the end of the day, the system clock is set back one + * second; if in leap-delete state, the system clock is + * set ahead one second. The microtime() routine or + * external clock driver will insure that reported time + * is always monotonic. The ugly divides should be + * replaced. + */ + switch (time_state) { + + case TIME_OK: + if (time_status & STA_INS) + time_state = TIME_INS; + else if (time_status & STA_DEL) + time_state = TIME_DEL; + break; + + case TIME_INS: + if (newtime.tv_sec % 86400 == 0) { + newtime.tv_sec--; + time_state = TIME_OOP; + } + break; + + case TIME_DEL: + if ((newtime.tv_sec + 1) % 86400 == 0) { + newtime.tv_sec++; + time_state = TIME_WAIT; + } + break; + + case TIME_OOP: + time_state = TIME_WAIT; + break; + + case TIME_WAIT: + if (!(time_status & (STA_INS | STA_DEL))) + time_state = TIME_OK; + } + } + CPU_CLOCKUPDATE(&time, &newtime); } - BUMPTIME(&time, delta); - BUMPTIME(&mono_time, delta); /* * Process callouts at a very low cpu priority, so we don't keep the @@ -563,3 +960,171 @@ sysctl_clockrate(where, sizep) clkinfo.stathz = stathz ? stathz : hz; return (sysctl_rdstruct(where, sizep, NULL, &clkinfo, sizeof(clkinfo))); } + +/*#ifdef PPS_SYNC*/ +#if 0 +/* This code is completely bogus; if anybody ever wants to use it, get + * the current version from Dave Mills. */ + +/* + * 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 integrates successive + * phase differences between the two oscillators and calculates the + * frequency offset. This is used in hardclock() to discipline the CPU + * clock oscillator so that intrinsic frequency error is cancelled out. + * The code requires the caller to capture the time and hardware + * counter value at the designated PPS signal transition. + */ +void +hardpps(tvp, usec) + struct timeval *tvp; /* time at PPS */ + long usec; /* hardware counter at PPS */ +{ + long u_usec, v_usec, bigtick; + long cal_sec, cal_usec; + + /* + * During the calibration interval adjust the starting time when + * the tick overflows. At the end of the interval compute the + * duration of the interval and the difference of the hardware + * counters at the beginning and end of the interval. This code + * is deliciously complicated by the fact valid differences may + * exceed the value of tick when using long calibration + * intervals and small ticks. Note that the counter can be + * greater than tick if caught at just the wrong instant, but + * the values returned and used here are correct. + */ + bigtick = (long)tick << SHIFT_USEC; + pps_usec -= ntp_pll.ybar; + if (pps_usec >= bigtick) + pps_usec -= bigtick; + if (pps_usec < 0) + pps_usec += bigtick; + pps_time.tv_sec++; + pps_count++; + if (pps_count < (1 << pps_shift)) + return; + pps_count = 0; + ntp_pll.calcnt++; + u_usec = usec << SHIFT_USEC; + v_usec = pps_usec - u_usec; + if (v_usec >= bigtick >> 1) + v_usec -= bigtick; + if (v_usec < -(bigtick >> 1)) + v_usec += bigtick; + if (v_usec < 0) + v_usec = -(-v_usec >> ntp_pll.shift); + else + v_usec = v_usec >> ntp_pll.shift; + pps_usec = u_usec; + cal_sec = tvp->tv_sec; + cal_usec = tvp->tv_usec; + cal_sec -= pps_time.tv_sec; + cal_usec -= pps_time.tv_usec; + if (cal_usec < 0) { + cal_usec += 1000000; + cal_sec--; + } + pps_time = *tvp; + + /* + * Check for lost interrupts, noise, excessive jitter and + * excessive frequency error. The number of timer ticks during + * the interval may vary +-1 tick. Add to this a margin of one + * tick for the PPS signal jitter and maximum frequency + * deviation. If the limits are exceeded, the calibration + * interval is reset to the minimum and we start over. + */ + u_usec = (long)tick << 1; + if (!((cal_sec == -1 && cal_usec > (1000000 - u_usec)) + || (cal_sec == 0 && cal_usec < u_usec)) + || v_usec > ntp_pll.tolerance || v_usec < -ntp_pll.tolerance) { + ntp_pll.jitcnt++; + ntp_pll.shift = NTP_PLL.SHIFT; + pps_dispinc = PPS_DISPINC; + ntp_pll.intcnt = 0; + return; + } + + /* + * A three-stage median filter is used to help deglitch the pps + * signal. The median sample becomes the offset estimate; the + * difference between the other two samples becomes the + * dispersion estimate. + */ + pps_mf[2] = pps_mf[1]; + pps_mf[1] = pps_mf[0]; + pps_mf[0] = v_usec; + if (pps_mf[0] > pps_mf[1]) { + if (pps_mf[1] > pps_mf[2]) { + u_usec = pps_mf[1]; /* 0 1 2 */ + v_usec = pps_mf[0] - pps_mf[2]; + } else if (pps_mf[2] > pps_mf[0]) { + u_usec = pps_mf[0]; /* 2 0 1 */ + v_usec = pps_mf[2] - pps_mf[1]; + } else { + u_usec = pps_mf[2]; /* 0 2 1 */ + v_usec = pps_mf[0] - pps_mf[1]; + } + } else { + if (pps_mf[1] < pps_mf[2]) { + u_usec = pps_mf[1]; /* 2 1 0 */ + v_usec = pps_mf[2] - pps_mf[0]; + } else if (pps_mf[2] < pps_mf[0]) { + u_usec = pps_mf[0]; /* 1 0 2 */ + v_usec = pps_mf[1] - pps_mf[2]; + } else { + u_usec = pps_mf[2]; /* 1 2 0 */ + v_usec = pps_mf[1] - pps_mf[0]; + } + } + + /* + * Here the dispersion average is updated. If it is less than + * the threshold pps_dispmax, the frequency average is updated + * as well, but clamped to the tolerance. + */ + v_usec = (v_usec >> 1) - ntp_pll.disp; + if (v_usec < 0) + ntp_pll.disp -= -v_usec >> PPS_AVG; + else + ntp_pll.disp += v_usec >> PPS_AVG; + if (ntp_pll.disp > pps_dispmax) { + ntp_pll.discnt++; + return; + } + if (u_usec < 0) { + ntp_pll.ybar -= -u_usec >> PPS_AVG; + if (ntp_pll.ybar < -ntp_pll.tolerance) + ntp_pll.ybar = -ntp_pll.tolerance; + u_usec = -u_usec; + } else { + ntp_pll.ybar += u_usec >> PPS_AVG; + if (ntp_pll.ybar > ntp_pll.tolerance) + ntp_pll.ybar = ntp_pll.tolerance; + } + + /* + * Here the calibration interval is adjusted. If the maximum + * time difference is greater than tick/4, reduce the interval + * by half. If this is not the case for four consecutive + * intervals, double the interval. + */ + if (u_usec << ntp_pll.shift > bigtick >> 2) { + ntp_pll.intcnt = 0; + if (ntp_pll.shift > NTP_PLL.SHIFT) { + ntp_pll.shift--; + pps_dispinc <<= 1; + } + } else if (ntp_pll.intcnt >= 4) { + ntp_pll.intcnt = 0; + if (ntp_pll.shift < NTP_PLL.SHIFTMAX) { + ntp_pll.shift++; + pps_dispinc >>= 1; + } + } else + ntp_pll.intcnt++; +} +#endif /* PPS_SYNC */ diff --git a/sys/kern/kern_ntptime.c b/sys/kern/kern_ntptime.c new file mode 100644 index 000000000000..9d4c1b932252 --- /dev/null +++ b/sys/kern/kern_ntptime.c @@ -0,0 +1,269 @@ +/****************************************************************************** + * * + * Copyright (c) David L. Mills 1993, 1994 * + * * + * Permission to use, copy, modify, and distribute this software and its * + * documentation for any purpose and without fee is hereby granted, provided * + * that the above copyright notice appears in all copies and that both the * + * copyright notice and this permission notice appear in supporting * + * documentation, and that the name University of Delaware not be used in * + * advertising or publicity pertaining to distribution of the software * + * without specific, written prior permission. The University of Delaware * + * makes no representations about the suitability this software for any * + * purpose. It is provided "as is" without express or implied warranty. * + * * + ******************************************************************************/ + +/* + * Modification history kern_ntptime.c + * + * 24 Mar 94 David L. Mills + * Revised syscall interface to include new variables for PPS + * time discipline. + * + * 14 Feb 94 David L. Mills + * Added code for external clock + * + * 28 Nov 93 David L. Mills + * Revised frequency scaling to conform with adjusted parameters + * + * 17 Sep 93 David L. Mills + * Created file + */ +/* + * ntp_gettime(), ntp_adjtime() - precision time interface for SunOS + * 4.1.1 and 4.1.3 + * + * These routines consitute the Network Time Protocol (NTP) interfaces + * for user and daemon application programs. The ntp_gettime() routine + * provides the time, maximum error (synch distance) and estimated error + * (dispersion) to client user application programs. The ntp_adjtime() + * routine is used by the NTP daemon to adjust the system clock to an + * externally derived time. The time offset and related variables set by + * this routine are used by hardclock() to adjust the phase and + * frequency of the phase-lock loop which controls the system clock. + */ +#include +#include +#include +#include +#include +#include + +/* + * The following variables are used by the hardclock() routine in the + * kern_clock.c module and are described in that module. + */ +extern struct timeval time; /* kernel time variable */ +extern int time_state; /* clock state */ +extern int time_status; /* clock status bits */ +extern long time_offset; /* time adjustment (us) */ +extern long time_freq; /* frequency offset (scaled ppm) */ +extern long time_maxerror; /* maximum error (us) */ +extern long time_esterror; /* estimated error (us) */ +extern long time_constant; /* pll time constant */ +extern long time_precision; /* clock precision (us) */ +extern long time_tolerance; /* frequency tolerance (scaled ppm) */ + +#ifdef PPS_SYNC +/* + * The following variables are used only if the PPS signal discipline + * is configured in the kernel. + */ +extern int pps_shift; /* interval duration (s) (shift) */ +extern long pps_freq; /* pps frequency offset (scaled ppm) */ +extern long pps_jitter; /* pps jitter (us) */ +extern long pps_stabil; /* pps stability (scaled ppm) */ +extern long pps_jitcnt; /* jitter limit exceeded */ +extern long pps_calcnt; /* calibration intervals */ +extern long pps_errcnt; /* calibration errors */ +extern long pps_stbcnt; /* stability limit exceeded */ +#endif /* PPS_SYNC */ + +int +ntp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, + void *newp, size_t newlen, struct proc *p) +{ + struct timeval atv; + struct ntptimeval ntv; + int s; + + /* All names at this level are terminal. */ + if (namelen != 1) { + return ENOTDIR; + } + + if (name[0] != NTP_PLL_GETTIME) { + return EOPNOTSUPP; + } + + s = splclock(); +#ifdef EXT_CLOCK + /* + * The microtime() external clock routine returns a + * status code. If less than zero, we declare an error + * in the clock status word and return the kernel + * (software) time variable. While there are other + * places that call microtime(), this is the only place + * that matters from an application point of view. + */ + if (microtime(&atv) < 0) { + time_status |= STA_CLOCKERR; + ntv.time = time; + } else { + time_status &= ~STA_CLOCKERR; + } +#else /* EXT_CLOCK */ + microtime(&atv); +#endif /* EXT_CLOCK */ + ntv.time = atv; + ntv.maxerror = time_maxerror; + ntv.esterror = time_esterror; + splx(s); + + ntv.time_state = time_state; + + /* + * Status word error decode. If any of these conditions + * occur, an error is returned, instead of the status + * word. Most applications will care only about the fact + * the system clock may not be trusted, not about the + * details. + * + * Hardware or software error + */ + if (time_status & (STA_UNSYNC | STA_CLOCKERR)) { + ntv.time_state = TIME_ERROR; + } + + /* + * PPS signal lost when either time or frequency + * synchronization requested + */ + if (time_status & (STA_PPSFREQ | STA_PPSTIME) && + !(time_status & STA_PPSSIGNAL)) { + ntv.time_state = TIME_ERROR; + } + + /* + * PPS jitter exceeded when time synchronization + * requested + */ + if (time_status & STA_PPSTIME && + time_status & STA_PPSJITTER) { + ntv.time_state = TIME_ERROR; + } + + /* + * PPS wander exceeded or calibration error when + * frequency synchronization requested + */ + if (time_status & STA_PPSFREQ && + time_status & (STA_PPSWANDER | STA_PPSERROR)) { + ntv.time_state = TIME_ERROR; + } + return(sysctl_rdstruct(oldp, oldlenp, newp, &ntv, sizeof ntv)); +} + +/* + * ntp_adjtime() - NTP daemon application interface + */ +struct ntp_adjtime_args { + struct timex *tp; +}; + +int +ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap, int *retval) +{ + struct timex ntv; + int modes; + int s; + int error; + + error = copyin((caddr_t)uap->tp, (caddr_t)&ntv, sizeof(ntv)); + if (error) + return error; + + /* + * 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. + */ + modes = ntv.modes; + if ((modes != 0) + && (error = suser(p->p_cred->pc_ucred, &p->p_acflag))) + return error; + + s = splclock(); + if (modes & MOD_FREQUENCY) +#ifdef PPS_SYNC + time_freq = ntv.freq - pps_freq; +#else /* PPS_SYNC */ + time_freq = ntv.freq; +#endif /* PPS_SYNC */ + if (modes & MOD_MAXERROR) + time_maxerror = ntv.maxerror; + if (modes & MOD_ESTERROR) + time_esterror = ntv.esterror; + if (modes & MOD_STATUS) { + time_status &= STA_RONLY; + time_status |= ntv.status & ~STA_RONLY; + } + if (modes & MOD_TIMECONST) + time_constant = ntv.constant; + if (modes & MOD_OFFSET) + hardupdate(ntv.offset); + + /* + * Retrieve all clock variables + */ + if (time_offset < 0) + ntv.offset = -(-time_offset >> SHIFT_UPDATE); + else + ntv.offset = time_offset >> SHIFT_UPDATE; +#ifdef PPS_SYNC + ntv.freq = time_freq + pps_freq; +#else /* PPS_SYNC */ + ntv.freq = time_freq; +#endif /* PPS_SYNC */ + ntv.maxerror = time_maxerror; + ntv.esterror = time_esterror; + ntv.status = time_status; + ntv.constant = time_constant; + ntv.precision = time_precision; + ntv.tolerance = time_tolerance; +#ifdef PPS_SYNC + ntv.shift = pps_shift; + ntv.ppsfreq = pps_freq; + ntv.jitter = pps_jitter >> PPS_AVG; + ntv.stabil = pps_stabil; + ntv.calcnt = pps_calcnt; + ntv.errcnt = pps_errcnt; + ntv.jitcnt = pps_jitcnt; + ntv.stbcnt = pps_stbcnt; +#endif /* PPS_SYNC */ + (void)splx(s); + + error = copyout((caddr_t)&ntv, (caddr_t)uap->tp, sizeof(ntv)); + if (!error) { + /* + * Status word error decode. See comments in + * ntp_gettime() routine. + */ + retval[0] = time_state; + if (time_status & (STA_UNSYNC | STA_CLOCKERR)) + retval[0] = TIME_ERROR; + if (time_status & (STA_PPSFREQ | STA_PPSTIME) && + !(time_status & STA_PPSSIGNAL)) + retval[0] = TIME_ERROR; + if (time_status & STA_PPSTIME && + time_status & STA_PPSJITTER) + retval[0] = TIME_ERROR; + if (time_status & STA_PPSFREQ && + time_status & (STA_PPSWANDER | STA_PPSERROR)) + retval[0] = TIME_ERROR; + } + return error; +} + + diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index 9911879d9787..457734df86b6 100644 --- a/sys/kern/kern_sysctl.c +++ b/sys/kern/kern_sysctl.c @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * @(#)kern_sysctl.c 8.4 (Berkeley) 4/14/94 - * $Id: kern_sysctl.c,v 1.10 1994/09/14 23:21:00 ache Exp $ + * $Id: kern_sysctl.c,v 1.11 1994/09/16 00:53:58 ache Exp $ */ /* @@ -64,6 +64,7 @@ extern sysctlfn vm_sysctl; extern sysctlfn fs_sysctl; extern sysctlfn net_sysctl; extern sysctlfn cpu_sysctl; +extern sysctlfn ntp_sysctl; /* * Locking and stats @@ -201,7 +202,8 @@ kern_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p) extern char ostype[], osrelease[]; /* all sysctl names at this level are terminal */ - if (namelen != 1 && !(name[0] == KERN_PROC || name[0] == KERN_PROF)) + if (namelen != 1 && !(name[0] == KERN_PROC || name[0] == KERN_PROF + || name[0] == KERN_NTP_PLL)) return (ENOTDIR); /* overloaded */ switch (name[0]) { @@ -289,6 +291,9 @@ kern_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p) #else return (sysctl_rdint(oldp, oldlenp, newp, 0)); #endif + case KERN_NTP_PLL: + return (ntp_sysctl(name + 1, namelen - 1, oldp, oldlenp, + newp, newlen, p)); default: return (EOPNOTSUPP); } diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c index 788e279bc68a..6b3f85f2707e 100644 --- a/sys/kern/kern_tc.c +++ b/sys/kern/kern_tc.c @@ -36,9 +36,26 @@ * SUCH DAMAGE. * * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 - * $Id: kern_clock.c,v 1.4 1994/08/18 22:34:58 wollman Exp $ + * $Id: kern_clock.c,v 1.5 1994/08/27 16:14:26 davidg Exp $ */ +/* Portions of this software are covered by the following: */ +/****************************************************************************** + * * + * Copyright (c) David L. Mills 1993, 1994 * + * * + * Permission to use, copy, modify, and distribute this software and its * + * documentation for any purpose and without fee is hereby granted, provided * + * that the above copyright notice appears in all copies and that both the * + * copyright notice and this permission notice appear in supporting * + * documentation, and that the name University of Delaware not be used in * + * advertising or publicity pertaining to distribution of the software * + * without specific, written prior permission. The University of Delaware * + * makes no representations about the suitability this software for any * + * purpose. It is provided "as is" without express or implied warranty. * + * * + *****************************************************************************/ + #include #include #include @@ -46,9 +63,11 @@ #include #include #include +#include #include #include +#include #ifdef GPROF #include @@ -127,6 +146,238 @@ int psratio; /* ratio: prof / stat */ volatile struct timeval time; volatile struct timeval mono_time; +/* + * Phase-lock loop (PLL) definitions + * + * The following variables are read and set by the ntp_adjtime() system + * call. + * + * time_state shows the state of the system clock, with values defined + * in the timex.h header file. + * + * time_status shows the status of the system clock, with bits defined + * in the timex.h header file. + * + * time_offset is used by the PLL to adjust the system time in small + * increments. + * + * time_constant determines the bandwidth or "stiffness" of the PLL. + * + * time_tolerance determines maximum frequency error or tolerance of the + * CPU clock oscillator and is a property of the architecture; however, + * in principle it could change as result of the presence of external + * discipline signals, for instance. + * + * time_precision is usually equal to the kernel tick variable; however, + * in cases where a precision clock counter or external clock is + * available, the resolution can be much less than this and depend on + * whether the external clock is working or not. + * + * time_maxerror is initialized by a ntp_adjtime() call and increased by + * the kernel once each second to reflect the maximum error + * bound growth. + * + * time_esterror is set and read by the ntp_adjtime() call, but + * otherwise not used by the kernel. + */ +int time_status = STA_UNSYNC; /* clock status bits */ +int time_state = TIME_OK; /* clock state */ +long time_offset = 0; /* time offset (us) */ +long time_constant = 0; /* pll time constant */ +long time_tolerance = MAXFREQ; /* frequency tolerance (scaled ppm) */ +long time_precision = 1; /* clock precision (us) */ +long time_maxerror = MAXPHASE; /* maximum error (us) */ +long time_esterror = MAXPHASE; /* estimated error (us) */ + +/* + * The following variables establish the state of the PLL and the + * residual time and frequency offset of the local clock. The scale + * factors are defined in the timex.h header file. + * + * time_phase and time_freq are the phase increment and the frequency + * increment, respectively, of the kernel time variable at each tick of + * the clock. + * + * time_freq is set via ntp_adjtime() from a value stored in a file when + * the synchronization daemon is first started. Its value is retrieved + * via ntp_adjtime() and written to the file about once per hour by the + * daemon. + * + * time_adj is the adjustment added to the value of tick at each timer + * interrupt and is recomputed at each timer interrupt. + * + * time_reftime is the second's portion of the system time on the last + * call to ntp_adjtime(). It is used to adjust the time_freq variable + * and to increase the time_maxerror as the time since last update + * increases. + */ +long time_phase = 0; /* phase offset (scaled us) */ +long time_freq = 0; /* frequency offset (scaled ppm) */ +long time_adj = 0; /* tick adjust (scaled 1 / hz) */ +long time_reftime = 0; /* time at last adjustment (s) */ + +#ifdef PPS_SYNC +/* + * The following variables are used only if the if the kernel PPS + * discipline code is configured (PPS_SYNC). The scale factors are + * defined in the timex.h header file. + * + * pps_time contains the time at each calibration interval, as read by + * microtime(). + * + * pps_offset is the time offset produced by the time median filter + * pps_tf[], while pps_jitter is the dispersion measured by this + * filter. + * + * pps_freq is the frequency offset produced by the frequency median + * filter pps_ff[], while pps_stabil is the dispersion measured by + * this filter. + * + * pps_usec is latched from a high resolution counter or external clock + * at pps_time. Here we want the hardware counter contents only, not the + * contents plus the time_tv.usec as usual. + * + * pps_valid counts the number of seconds since the last PPS update. It + * is used as a watchdog timer to disable the PPS discipline should the + * PPS signal be lost. + * + * pps_glitch counts the number of seconds since the beginning of an + * offset burst more than tick/2 from current nominal offset. It is used + * mainly to suppress error bursts due to priority conflicts between the + * PPS interrupt and timer interrupt. + * + * pps_count counts the seconds of the calibration interval, the + * duration of which is pps_shift in powers of two. + * + * pps_intcnt counts the calibration intervals for use in the interval- + * adaptation algorithm. It's just too complicated for words. + */ +struct timeval pps_time; /* kernel time at last interval */ +long pps_offset = 0; /* pps time offset (us) */ +long pps_jitter = MAXTIME; /* pps time dispersion (jitter) (us) */ +long pps_tf[] = {0, 0, 0}; /* pps time offset median filter (us) */ +long pps_freq = 0; /* frequency offset (scaled ppm) */ +long pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */ +long pps_ff[] = {0, 0, 0}; /* frequency offset median filter */ +long pps_usec = 0; /* microsec counter at last interval */ +long pps_valid = PPS_VALID; /* pps signal watchdog counter */ +int pps_glitch = 0; /* pps signal glitch counter */ +int pps_count = 0; /* calibration interval counter (s) */ +int pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */ +int pps_intcnt = 0; /* intervals at current duration */ + +/* + * PPS signal quality monitors + * + * pps_jitcnt counts the seconds that have been discarded because the + * jitter measured by the time median filter exceeds the limit MAXTIME + * (100 us). + * + * pps_calcnt counts the frequency calibration intervals, which are + * variable from 4 s to 256 s. + * + * pps_errcnt counts the calibration intervals which have been discarded + * because the wander exceeds the limit MAXFREQ (100 ppm) or where the + * calibration interval jitter exceeds two ticks. + * + * pps_stbcnt counts the calibration intervals that have been discarded + * because the frequency wander exceeds the limit MAXFREQ / 4 (25 us). + */ +long pps_jitcnt = 0; /* jitter limit exceeded */ +long pps_calcnt = 0; /* calibration intervals */ +long pps_errcnt = 0; /* calibration errors */ +long pps_stbcnt = 0; /* stability limit exceeded */ +#endif /* PPS_SYNC */ + +/* XXX none of this stuff works under FreeBSD */ +#ifdef EXT_CLOCK +/* + * External clock definitions + * + * The following definitions and declarations are used only if an + * external clock (HIGHBALL or TPRO) is configured on the system. + */ +#define CLOCK_INTERVAL 30 /* CPU clock update interval (s) */ + +/* + * The clock_count variable is set to CLOCK_INTERVAL at each PPS + * interrupt and decremented once each second. + */ +int clock_count = 0; /* CPU clock counter */ + +#ifdef HIGHBALL +/* + * The clock_offset and clock_cpu variables are used by the HIGHBALL + * interface. The clock_offset variable defines the offset between + * system time and the HIGBALL counters. The clock_cpu variable contains + * the offset between the system clock and the HIGHBALL clock for use in + * disciplining the kernel time variable. + */ +extern struct timeval clock_offset; /* Highball clock offset */ +long clock_cpu = 0; /* CPU clock adjust */ +#endif /* HIGHBALL */ +#endif /* EXT_CLOCK */ + +/* + * hardupdate() - local clock update + * + * This routine is called by ntp_adjtime() to update the local clock + * phase and frequency. This is used to implement an adaptive-parameter, + * first-order, type-II phase-lock loop. The code computes new time and + * frequency offsets each time it is called. The hardclock() routine + * amortizes these offsets at each tick interrupt. If the kernel PPS + * discipline code is configured (PPS_SYNC), the PPS signal itself + * determines the new time offset, instead of the calling argument. + * Presumably, calls to ntp_adjtime() occur only when the caller + * believes the local clock is valid within some bound (+-128 ms with + * NTP). If the caller's time is far different than the PPS time, an + * argument will ensue, and it's not clear who will lose. + * + * For default SHIFT_UPDATE = 12, the offset is limited to +-512 ms, the + * maximum interval between updates is 4096 s and the maximum frequency + * offset is +-31.25 ms/s. + * + * Note: splclock() is in effect. + */ +void +hardupdate(offset) + long offset; +{ + long ltemp, mtemp; + + if (!(time_status & STA_PLL) && !(time_status & STA_PPSTIME)) + return; + ltemp = offset; +#ifdef PPS_SYNC + if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL) + ltemp = pps_offset; +#endif /* PPS_SYNC */ + if (ltemp > MAXPHASE) + time_offset = MAXPHASE << SHIFT_UPDATE; + else if (ltemp < -MAXPHASE) + time_offset = -(MAXPHASE << SHIFT_UPDATE); + else + time_offset = ltemp << SHIFT_UPDATE; + mtemp = time.tv_sec - time_reftime; + time_reftime = time.tv_sec; + if (mtemp > MAXSEC) + mtemp = 0; + + /* ugly multiply should be replaced */ + if (ltemp < 0) + time_freq -= (-ltemp * mtemp) >> (time_constant + + time_constant + SHIFT_KF - SHIFT_USEC); + else + time_freq += (ltemp * mtemp) >> (time_constant + + time_constant + SHIFT_KF - SHIFT_USEC); + if (time_freq > time_tolerance) + time_freq = time_tolerance; + else if (time_freq < -time_tolerance) + time_freq = -time_tolerance; +} + + + /* * Initialize clock frequencies and start both clocks running. */ @@ -207,18 +458,164 @@ hardclock(frame) statclock(frame); /* - * Increment the time-of-day. The increment is just ``tick'' unless - * we are still adjusting the clock; see adjtime(). + * Increment the time-of-day. */ ticks++; - if (timedelta == 0) - delta = tick; - else { - delta = tick + tickdelta; - timedelta -= tickdelta; + { + int time_update; + struct timeval newtime = time; + long ltemp; + + if (timedelta == 0) { + time_update = tick; + } else { + if (timedelta < 0) { + time_update = tick - tickdelta; + timedelta += tickdelta; + } else { + time_update = tick + tickdelta; + timedelta -= tickdelta; + } + } + BUMPTIME(&mono_time, time_update); + + /* + * Compute the phase adjustment. If the low-order bits + * (time_phase) of the update overflow, bump the high-order bits + * (time_update). + */ + time_phase += time_adj; + if (time_phase <= -FINEUSEC) { + ltemp = -time_phase >> SHIFT_SCALE; + time_phase += ltemp << SHIFT_SCALE; + time_update -= ltemp; + } + else if (time_phase >= FINEUSEC) { + ltemp = time_phase >> SHIFT_SCALE; + time_phase -= ltemp << SHIFT_SCALE; + time_update += ltemp; + } + + newtime.tv_usec += time_update; + /* + * On rollover of the second the phase adjustment to be used for + * the next second is calculated. Also, the maximum error is + * increased by the tolerance. If the PPS frequency discipline + * code is present, the phase is increased to compensate for the + * CPU clock oscillator frequency error. + * + * With SHIFT_SCALE = 23, the maximum frequency adjustment is + * +-256 us per tick, or 25.6 ms/s at a clock frequency of 100 + * Hz. The time contribution is shifted right a minimum of two + * bits, while the frequency contribution is a right shift. + * Thus, overflow is prevented if the frequency contribution is + * limited to half the maximum or 15.625 ms/s. + */ + if (newtime.tv_usec >= 1000000) { + newtime.tv_usec -= 1000000; + newtime.tv_sec++; + time_maxerror += time_tolerance >> SHIFT_USEC; + if (time_offset < 0) { + ltemp = -time_offset >> + (SHIFT_KG + time_constant); + time_offset += ltemp; + time_adj = -ltemp << + (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } else { + ltemp = time_offset >> + (SHIFT_KG + time_constant); + time_offset -= ltemp; + time_adj = ltemp << + (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } +#ifdef PPS_SYNC + /* + * Gnaw on the watchdog counter and update the frequency + * computed by the pll and the PPS signal. + */ + pps_valid++; + if (pps_valid == PPS_VALID) { + pps_jitter = MAXTIME; + pps_stabil = MAXFREQ; + time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | + STA_PPSWANDER | STA_PPSERROR); + } + ltemp = time_freq + pps_freq; +#else + ltemp = time_freq; +#endif /* PPS_SYNC */ + if (ltemp < 0) + time_adj -= -ltemp >> + (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + else + time_adj += ltemp >> + (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + + /* + * When the CPU clock oscillator frequency is not a + * power of two in Hz, the SHIFT_HZ is only an + * approximate scale factor. In the SunOS kernel, this + * results in a PLL gain factor of 1/1.28 = 0.78 what it + * should be. In the following code the overall gain is + * increased by a factor of 1.25, which results in a + * residual error less than 3 percent. + */ + /* Same thing applies for FreeBSD --GAW */ + if (hz == 100) { + if (time_adj < 0) + time_adj -= -time_adj >> 2; + else + time_adj += time_adj >> 2; + } + + /* XXX - this is really bogus, but can't be fixed until + xntpd's idea of the system clock is fixed to know how + the user wants leap seconds handled; in the mean time, + we assume that users of NTP are running without proper + leap second support (this is now the default anyway) */ + /* + * Leap second processing. If in leap-insert state at + * the end of the day, the system clock is set back one + * second; if in leap-delete state, the system clock is + * set ahead one second. The microtime() routine or + * external clock driver will insure that reported time + * is always monotonic. The ugly divides should be + * replaced. + */ + switch (time_state) { + + case TIME_OK: + if (time_status & STA_INS) + time_state = TIME_INS; + else if (time_status & STA_DEL) + time_state = TIME_DEL; + break; + + case TIME_INS: + if (newtime.tv_sec % 86400 == 0) { + newtime.tv_sec--; + time_state = TIME_OOP; + } + break; + + case TIME_DEL: + if ((newtime.tv_sec + 1) % 86400 == 0) { + newtime.tv_sec++; + time_state = TIME_WAIT; + } + break; + + case TIME_OOP: + time_state = TIME_WAIT; + break; + + case TIME_WAIT: + if (!(time_status & (STA_INS | STA_DEL))) + time_state = TIME_OK; + } + } + CPU_CLOCKUPDATE(&time, &newtime); } - BUMPTIME(&time, delta); - BUMPTIME(&mono_time, delta); /* * Process callouts at a very low cpu priority, so we don't keep the @@ -563,3 +960,171 @@ sysctl_clockrate(where, sizep) clkinfo.stathz = stathz ? stathz : hz; return (sysctl_rdstruct(where, sizep, NULL, &clkinfo, sizeof(clkinfo))); } + +/*#ifdef PPS_SYNC*/ +#if 0 +/* This code is completely bogus; if anybody ever wants to use it, get + * the current version from Dave Mills. */ + +/* + * 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 integrates successive + * phase differences between the two oscillators and calculates the + * frequency offset. This is used in hardclock() to discipline the CPU + * clock oscillator so that intrinsic frequency error is cancelled out. + * The code requires the caller to capture the time and hardware + * counter value at the designated PPS signal transition. + */ +void +hardpps(tvp, usec) + struct timeval *tvp; /* time at PPS */ + long usec; /* hardware counter at PPS */ +{ + long u_usec, v_usec, bigtick; + long cal_sec, cal_usec; + + /* + * During the calibration interval adjust the starting time when + * the tick overflows. At the end of the interval compute the + * duration of the interval and the difference of the hardware + * counters at the beginning and end of the interval. This code + * is deliciously complicated by the fact valid differences may + * exceed the value of tick when using long calibration + * intervals and small ticks. Note that the counter can be + * greater than tick if caught at just the wrong instant, but + * the values returned and used here are correct. + */ + bigtick = (long)tick << SHIFT_USEC; + pps_usec -= ntp_pll.ybar; + if (pps_usec >= bigtick) + pps_usec -= bigtick; + if (pps_usec < 0) + pps_usec += bigtick; + pps_time.tv_sec++; + pps_count++; + if (pps_count < (1 << pps_shift)) + return; + pps_count = 0; + ntp_pll.calcnt++; + u_usec = usec << SHIFT_USEC; + v_usec = pps_usec - u_usec; + if (v_usec >= bigtick >> 1) + v_usec -= bigtick; + if (v_usec < -(bigtick >> 1)) + v_usec += bigtick; + if (v_usec < 0) + v_usec = -(-v_usec >> ntp_pll.shift); + else + v_usec = v_usec >> ntp_pll.shift; + pps_usec = u_usec; + cal_sec = tvp->tv_sec; + cal_usec = tvp->tv_usec; + cal_sec -= pps_time.tv_sec; + cal_usec -= pps_time.tv_usec; + if (cal_usec < 0) { + cal_usec += 1000000; + cal_sec--; + } + pps_time = *tvp; + + /* + * Check for lost interrupts, noise, excessive jitter and + * excessive frequency error. The number of timer ticks during + * the interval may vary +-1 tick. Add to this a margin of one + * tick for the PPS signal jitter and maximum frequency + * deviation. If the limits are exceeded, the calibration + * interval is reset to the minimum and we start over. + */ + u_usec = (long)tick << 1; + if (!((cal_sec == -1 && cal_usec > (1000000 - u_usec)) + || (cal_sec == 0 && cal_usec < u_usec)) + || v_usec > ntp_pll.tolerance || v_usec < -ntp_pll.tolerance) { + ntp_pll.jitcnt++; + ntp_pll.shift = NTP_PLL.SHIFT; + pps_dispinc = PPS_DISPINC; + ntp_pll.intcnt = 0; + return; + } + + /* + * A three-stage median filter is used to help deglitch the pps + * signal. The median sample becomes the offset estimate; the + * difference between the other two samples becomes the + * dispersion estimate. + */ + pps_mf[2] = pps_mf[1]; + pps_mf[1] = pps_mf[0]; + pps_mf[0] = v_usec; + if (pps_mf[0] > pps_mf[1]) { + if (pps_mf[1] > pps_mf[2]) { + u_usec = pps_mf[1]; /* 0 1 2 */ + v_usec = pps_mf[0] - pps_mf[2]; + } else if (pps_mf[2] > pps_mf[0]) { + u_usec = pps_mf[0]; /* 2 0 1 */ + v_usec = pps_mf[2] - pps_mf[1]; + } else { + u_usec = pps_mf[2]; /* 0 2 1 */ + v_usec = pps_mf[0] - pps_mf[1]; + } + } else { + if (pps_mf[1] < pps_mf[2]) { + u_usec = pps_mf[1]; /* 2 1 0 */ + v_usec = pps_mf[2] - pps_mf[0]; + } else if (pps_mf[2] < pps_mf[0]) { + u_usec = pps_mf[0]; /* 1 0 2 */ + v_usec = pps_mf[1] - pps_mf[2]; + } else { + u_usec = pps_mf[2]; /* 1 2 0 */ + v_usec = pps_mf[1] - pps_mf[0]; + } + } + + /* + * Here the dispersion average is updated. If it is less than + * the threshold pps_dispmax, the frequency average is updated + * as well, but clamped to the tolerance. + */ + v_usec = (v_usec >> 1) - ntp_pll.disp; + if (v_usec < 0) + ntp_pll.disp -= -v_usec >> PPS_AVG; + else + ntp_pll.disp += v_usec >> PPS_AVG; + if (ntp_pll.disp > pps_dispmax) { + ntp_pll.discnt++; + return; + } + if (u_usec < 0) { + ntp_pll.ybar -= -u_usec >> PPS_AVG; + if (ntp_pll.ybar < -ntp_pll.tolerance) + ntp_pll.ybar = -ntp_pll.tolerance; + u_usec = -u_usec; + } else { + ntp_pll.ybar += u_usec >> PPS_AVG; + if (ntp_pll.ybar > ntp_pll.tolerance) + ntp_pll.ybar = ntp_pll.tolerance; + } + + /* + * Here the calibration interval is adjusted. If the maximum + * time difference is greater than tick/4, reduce the interval + * by half. If this is not the case for four consecutive + * intervals, double the interval. + */ + if (u_usec << ntp_pll.shift > bigtick >> 2) { + ntp_pll.intcnt = 0; + if (ntp_pll.shift > NTP_PLL.SHIFT) { + ntp_pll.shift--; + pps_dispinc <<= 1; + } + } else if (ntp_pll.intcnt >= 4) { + ntp_pll.intcnt = 0; + if (ntp_pll.shift < NTP_PLL.SHIFTMAX) { + ntp_pll.shift++; + pps_dispinc >>= 1; + } + } else + ntp_pll.intcnt++; +} +#endif /* PPS_SYNC */ diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c index 788e279bc68a..6b3f85f2707e 100644 --- a/sys/kern/kern_timeout.c +++ b/sys/kern/kern_timeout.c @@ -36,9 +36,26 @@ * SUCH DAMAGE. * * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 - * $Id: kern_clock.c,v 1.4 1994/08/18 22:34:58 wollman Exp $ + * $Id: kern_clock.c,v 1.5 1994/08/27 16:14:26 davidg Exp $ */ +/* Portions of this software are covered by the following: */ +/****************************************************************************** + * * + * Copyright (c) David L. Mills 1993, 1994 * + * * + * Permission to use, copy, modify, and distribute this software and its * + * documentation for any purpose and without fee is hereby granted, provided * + * that the above copyright notice appears in all copies and that both the * + * copyright notice and this permission notice appear in supporting * + * documentation, and that the name University of Delaware not be used in * + * advertising or publicity pertaining to distribution of the software * + * without specific, written prior permission. The University of Delaware * + * makes no representations about the suitability this software for any * + * purpose. It is provided "as is" without express or implied warranty. * + * * + *****************************************************************************/ + #include #include #include @@ -46,9 +63,11 @@ #include #include #include +#include #include #include +#include #ifdef GPROF #include @@ -127,6 +146,238 @@ int psratio; /* ratio: prof / stat */ volatile struct timeval time; volatile struct timeval mono_time; +/* + * Phase-lock loop (PLL) definitions + * + * The following variables are read and set by the ntp_adjtime() system + * call. + * + * time_state shows the state of the system clock, with values defined + * in the timex.h header file. + * + * time_status shows the status of the system clock, with bits defined + * in the timex.h header file. + * + * time_offset is used by the PLL to adjust the system time in small + * increments. + * + * time_constant determines the bandwidth or "stiffness" of the PLL. + * + * time_tolerance determines maximum frequency error or tolerance of the + * CPU clock oscillator and is a property of the architecture; however, + * in principle it could change as result of the presence of external + * discipline signals, for instance. + * + * time_precision is usually equal to the kernel tick variable; however, + * in cases where a precision clock counter or external clock is + * available, the resolution can be much less than this and depend on + * whether the external clock is working or not. + * + * time_maxerror is initialized by a ntp_adjtime() call and increased by + * the kernel once each second to reflect the maximum error + * bound growth. + * + * time_esterror is set and read by the ntp_adjtime() call, but + * otherwise not used by the kernel. + */ +int time_status = STA_UNSYNC; /* clock status bits */ +int time_state = TIME_OK; /* clock state */ +long time_offset = 0; /* time offset (us) */ +long time_constant = 0; /* pll time constant */ +long time_tolerance = MAXFREQ; /* frequency tolerance (scaled ppm) */ +long time_precision = 1; /* clock precision (us) */ +long time_maxerror = MAXPHASE; /* maximum error (us) */ +long time_esterror = MAXPHASE; /* estimated error (us) */ + +/* + * The following variables establish the state of the PLL and the + * residual time and frequency offset of the local clock. The scale + * factors are defined in the timex.h header file. + * + * time_phase and time_freq are the phase increment and the frequency + * increment, respectively, of the kernel time variable at each tick of + * the clock. + * + * time_freq is set via ntp_adjtime() from a value stored in a file when + * the synchronization daemon is first started. Its value is retrieved + * via ntp_adjtime() and written to the file about once per hour by the + * daemon. + * + * time_adj is the adjustment added to the value of tick at each timer + * interrupt and is recomputed at each timer interrupt. + * + * time_reftime is the second's portion of the system time on the last + * call to ntp_adjtime(). It is used to adjust the time_freq variable + * and to increase the time_maxerror as the time since last update + * increases. + */ +long time_phase = 0; /* phase offset (scaled us) */ +long time_freq = 0; /* frequency offset (scaled ppm) */ +long time_adj = 0; /* tick adjust (scaled 1 / hz) */ +long time_reftime = 0; /* time at last adjustment (s) */ + +#ifdef PPS_SYNC +/* + * The following variables are used only if the if the kernel PPS + * discipline code is configured (PPS_SYNC). The scale factors are + * defined in the timex.h header file. + * + * pps_time contains the time at each calibration interval, as read by + * microtime(). + * + * pps_offset is the time offset produced by the time median filter + * pps_tf[], while pps_jitter is the dispersion measured by this + * filter. + * + * pps_freq is the frequency offset produced by the frequency median + * filter pps_ff[], while pps_stabil is the dispersion measured by + * this filter. + * + * pps_usec is latched from a high resolution counter or external clock + * at pps_time. Here we want the hardware counter contents only, not the + * contents plus the time_tv.usec as usual. + * + * pps_valid counts the number of seconds since the last PPS update. It + * is used as a watchdog timer to disable the PPS discipline should the + * PPS signal be lost. + * + * pps_glitch counts the number of seconds since the beginning of an + * offset burst more than tick/2 from current nominal offset. It is used + * mainly to suppress error bursts due to priority conflicts between the + * PPS interrupt and timer interrupt. + * + * pps_count counts the seconds of the calibration interval, the + * duration of which is pps_shift in powers of two. + * + * pps_intcnt counts the calibration intervals for use in the interval- + * adaptation algorithm. It's just too complicated for words. + */ +struct timeval pps_time; /* kernel time at last interval */ +long pps_offset = 0; /* pps time offset (us) */ +long pps_jitter = MAXTIME; /* pps time dispersion (jitter) (us) */ +long pps_tf[] = {0, 0, 0}; /* pps time offset median filter (us) */ +long pps_freq = 0; /* frequency offset (scaled ppm) */ +long pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */ +long pps_ff[] = {0, 0, 0}; /* frequency offset median filter */ +long pps_usec = 0; /* microsec counter at last interval */ +long pps_valid = PPS_VALID; /* pps signal watchdog counter */ +int pps_glitch = 0; /* pps signal glitch counter */ +int pps_count = 0; /* calibration interval counter (s) */ +int pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */ +int pps_intcnt = 0; /* intervals at current duration */ + +/* + * PPS signal quality monitors + * + * pps_jitcnt counts the seconds that have been discarded because the + * jitter measured by the time median filter exceeds the limit MAXTIME + * (100 us). + * + * pps_calcnt counts the frequency calibration intervals, which are + * variable from 4 s to 256 s. + * + * pps_errcnt counts the calibration intervals which have been discarded + * because the wander exceeds the limit MAXFREQ (100 ppm) or where the + * calibration interval jitter exceeds two ticks. + * + * pps_stbcnt counts the calibration intervals that have been discarded + * because the frequency wander exceeds the limit MAXFREQ / 4 (25 us). + */ +long pps_jitcnt = 0; /* jitter limit exceeded */ +long pps_calcnt = 0; /* calibration intervals */ +long pps_errcnt = 0; /* calibration errors */ +long pps_stbcnt = 0; /* stability limit exceeded */ +#endif /* PPS_SYNC */ + +/* XXX none of this stuff works under FreeBSD */ +#ifdef EXT_CLOCK +/* + * External clock definitions + * + * The following definitions and declarations are used only if an + * external clock (HIGHBALL or TPRO) is configured on the system. + */ +#define CLOCK_INTERVAL 30 /* CPU clock update interval (s) */ + +/* + * The clock_count variable is set to CLOCK_INTERVAL at each PPS + * interrupt and decremented once each second. + */ +int clock_count = 0; /* CPU clock counter */ + +#ifdef HIGHBALL +/* + * The clock_offset and clock_cpu variables are used by the HIGHBALL + * interface. The clock_offset variable defines the offset between + * system time and the HIGBALL counters. The clock_cpu variable contains + * the offset between the system clock and the HIGHBALL clock for use in + * disciplining the kernel time variable. + */ +extern struct timeval clock_offset; /* Highball clock offset */ +long clock_cpu = 0; /* CPU clock adjust */ +#endif /* HIGHBALL */ +#endif /* EXT_CLOCK */ + +/* + * hardupdate() - local clock update + * + * This routine is called by ntp_adjtime() to update the local clock + * phase and frequency. This is used to implement an adaptive-parameter, + * first-order, type-II phase-lock loop. The code computes new time and + * frequency offsets each time it is called. The hardclock() routine + * amortizes these offsets at each tick interrupt. If the kernel PPS + * discipline code is configured (PPS_SYNC), the PPS signal itself + * determines the new time offset, instead of the calling argument. + * Presumably, calls to ntp_adjtime() occur only when the caller + * believes the local clock is valid within some bound (+-128 ms with + * NTP). If the caller's time is far different than the PPS time, an + * argument will ensue, and it's not clear who will lose. + * + * For default SHIFT_UPDATE = 12, the offset is limited to +-512 ms, the + * maximum interval between updates is 4096 s and the maximum frequency + * offset is +-31.25 ms/s. + * + * Note: splclock() is in effect. + */ +void +hardupdate(offset) + long offset; +{ + long ltemp, mtemp; + + if (!(time_status & STA_PLL) && !(time_status & STA_PPSTIME)) + return; + ltemp = offset; +#ifdef PPS_SYNC + if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL) + ltemp = pps_offset; +#endif /* PPS_SYNC */ + if (ltemp > MAXPHASE) + time_offset = MAXPHASE << SHIFT_UPDATE; + else if (ltemp < -MAXPHASE) + time_offset = -(MAXPHASE << SHIFT_UPDATE); + else + time_offset = ltemp << SHIFT_UPDATE; + mtemp = time.tv_sec - time_reftime; + time_reftime = time.tv_sec; + if (mtemp > MAXSEC) + mtemp = 0; + + /* ugly multiply should be replaced */ + if (ltemp < 0) + time_freq -= (-ltemp * mtemp) >> (time_constant + + time_constant + SHIFT_KF - SHIFT_USEC); + else + time_freq += (ltemp * mtemp) >> (time_constant + + time_constant + SHIFT_KF - SHIFT_USEC); + if (time_freq > time_tolerance) + time_freq = time_tolerance; + else if (time_freq < -time_tolerance) + time_freq = -time_tolerance; +} + + + /* * Initialize clock frequencies and start both clocks running. */ @@ -207,18 +458,164 @@ hardclock(frame) statclock(frame); /* - * Increment the time-of-day. The increment is just ``tick'' unless - * we are still adjusting the clock; see adjtime(). + * Increment the time-of-day. */ ticks++; - if (timedelta == 0) - delta = tick; - else { - delta = tick + tickdelta; - timedelta -= tickdelta; + { + int time_update; + struct timeval newtime = time; + long ltemp; + + if (timedelta == 0) { + time_update = tick; + } else { + if (timedelta < 0) { + time_update = tick - tickdelta; + timedelta += tickdelta; + } else { + time_update = tick + tickdelta; + timedelta -= tickdelta; + } + } + BUMPTIME(&mono_time, time_update); + + /* + * Compute the phase adjustment. If the low-order bits + * (time_phase) of the update overflow, bump the high-order bits + * (time_update). + */ + time_phase += time_adj; + if (time_phase <= -FINEUSEC) { + ltemp = -time_phase >> SHIFT_SCALE; + time_phase += ltemp << SHIFT_SCALE; + time_update -= ltemp; + } + else if (time_phase >= FINEUSEC) { + ltemp = time_phase >> SHIFT_SCALE; + time_phase -= ltemp << SHIFT_SCALE; + time_update += ltemp; + } + + newtime.tv_usec += time_update; + /* + * On rollover of the second the phase adjustment to be used for + * the next second is calculated. Also, the maximum error is + * increased by the tolerance. If the PPS frequency discipline + * code is present, the phase is increased to compensate for the + * CPU clock oscillator frequency error. + * + * With SHIFT_SCALE = 23, the maximum frequency adjustment is + * +-256 us per tick, or 25.6 ms/s at a clock frequency of 100 + * Hz. The time contribution is shifted right a minimum of two + * bits, while the frequency contribution is a right shift. + * Thus, overflow is prevented if the frequency contribution is + * limited to half the maximum or 15.625 ms/s. + */ + if (newtime.tv_usec >= 1000000) { + newtime.tv_usec -= 1000000; + newtime.tv_sec++; + time_maxerror += time_tolerance >> SHIFT_USEC; + if (time_offset < 0) { + ltemp = -time_offset >> + (SHIFT_KG + time_constant); + time_offset += ltemp; + time_adj = -ltemp << + (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } else { + ltemp = time_offset >> + (SHIFT_KG + time_constant); + time_offset -= ltemp; + time_adj = ltemp << + (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE); + } +#ifdef PPS_SYNC + /* + * Gnaw on the watchdog counter and update the frequency + * computed by the pll and the PPS signal. + */ + pps_valid++; + if (pps_valid == PPS_VALID) { + pps_jitter = MAXTIME; + pps_stabil = MAXFREQ; + time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | + STA_PPSWANDER | STA_PPSERROR); + } + ltemp = time_freq + pps_freq; +#else + ltemp = time_freq; +#endif /* PPS_SYNC */ + if (ltemp < 0) + time_adj -= -ltemp >> + (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + else + time_adj += ltemp >> + (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE); + + /* + * When the CPU clock oscillator frequency is not a + * power of two in Hz, the SHIFT_HZ is only an + * approximate scale factor. In the SunOS kernel, this + * results in a PLL gain factor of 1/1.28 = 0.78 what it + * should be. In the following code the overall gain is + * increased by a factor of 1.25, which results in a + * residual error less than 3 percent. + */ + /* Same thing applies for FreeBSD --GAW */ + if (hz == 100) { + if (time_adj < 0) + time_adj -= -time_adj >> 2; + else + time_adj += time_adj >> 2; + } + + /* XXX - this is really bogus, but can't be fixed until + xntpd's idea of the system clock is fixed to know how + the user wants leap seconds handled; in the mean time, + we assume that users of NTP are running without proper + leap second support (this is now the default anyway) */ + /* + * Leap second processing. If in leap-insert state at + * the end of the day, the system clock is set back one + * second; if in leap-delete state, the system clock is + * set ahead one second. The microtime() routine or + * external clock driver will insure that reported time + * is always monotonic. The ugly divides should be + * replaced. + */ + switch (time_state) { + + case TIME_OK: + if (time_status & STA_INS) + time_state = TIME_INS; + else if (time_status & STA_DEL) + time_state = TIME_DEL; + break; + + case TIME_INS: + if (newtime.tv_sec % 86400 == 0) { + newtime.tv_sec--; + time_state = TIME_OOP; + } + break; + + case TIME_DEL: + if ((newtime.tv_sec + 1) % 86400 == 0) { + newtime.tv_sec++; + time_state = TIME_WAIT; + } + break; + + case TIME_OOP: + time_state = TIME_WAIT; + break; + + case TIME_WAIT: + if (!(time_status & (STA_INS | STA_DEL))) + time_state = TIME_OK; + } + } + CPU_CLOCKUPDATE(&time, &newtime); } - BUMPTIME(&time, delta); - BUMPTIME(&mono_time, delta); /* * Process callouts at a very low cpu priority, so we don't keep the @@ -563,3 +960,171 @@ sysctl_clockrate(where, sizep) clkinfo.stathz = stathz ? stathz : hz; return (sysctl_rdstruct(where, sizep, NULL, &clkinfo, sizeof(clkinfo))); } + +/*#ifdef PPS_SYNC*/ +#if 0 +/* This code is completely bogus; if anybody ever wants to use it, get + * the current version from Dave Mills. */ + +/* + * 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 integrates successive + * phase differences between the two oscillators and calculates the + * frequency offset. This is used in hardclock() to discipline the CPU + * clock oscillator so that intrinsic frequency error is cancelled out. + * The code requires the caller to capture the time and hardware + * counter value at the designated PPS signal transition. + */ +void +hardpps(tvp, usec) + struct timeval *tvp; /* time at PPS */ + long usec; /* hardware counter at PPS */ +{ + long u_usec, v_usec, bigtick; + long cal_sec, cal_usec; + + /* + * During the calibration interval adjust the starting time when + * the tick overflows. At the end of the interval compute the + * duration of the interval and the difference of the hardware + * counters at the beginning and end of the interval. This code + * is deliciously complicated by the fact valid differences may + * exceed the value of tick when using long calibration + * intervals and small ticks. Note that the counter can be + * greater than tick if caught at just the wrong instant, but + * the values returned and used here are correct. + */ + bigtick = (long)tick << SHIFT_USEC; + pps_usec -= ntp_pll.ybar; + if (pps_usec >= bigtick) + pps_usec -= bigtick; + if (pps_usec < 0) + pps_usec += bigtick; + pps_time.tv_sec++; + pps_count++; + if (pps_count < (1 << pps_shift)) + return; + pps_count = 0; + ntp_pll.calcnt++; + u_usec = usec << SHIFT_USEC; + v_usec = pps_usec - u_usec; + if (v_usec >= bigtick >> 1) + v_usec -= bigtick; + if (v_usec < -(bigtick >> 1)) + v_usec += bigtick; + if (v_usec < 0) + v_usec = -(-v_usec >> ntp_pll.shift); + else + v_usec = v_usec >> ntp_pll.shift; + pps_usec = u_usec; + cal_sec = tvp->tv_sec; + cal_usec = tvp->tv_usec; + cal_sec -= pps_time.tv_sec; + cal_usec -= pps_time.tv_usec; + if (cal_usec < 0) { + cal_usec += 1000000; + cal_sec--; + } + pps_time = *tvp; + + /* + * Check for lost interrupts, noise, excessive jitter and + * excessive frequency error. The number of timer ticks during + * the interval may vary +-1 tick. Add to this a margin of one + * tick for the PPS signal jitter and maximum frequency + * deviation. If the limits are exceeded, the calibration + * interval is reset to the minimum and we start over. + */ + u_usec = (long)tick << 1; + if (!((cal_sec == -1 && cal_usec > (1000000 - u_usec)) + || (cal_sec == 0 && cal_usec < u_usec)) + || v_usec > ntp_pll.tolerance || v_usec < -ntp_pll.tolerance) { + ntp_pll.jitcnt++; + ntp_pll.shift = NTP_PLL.SHIFT; + pps_dispinc = PPS_DISPINC; + ntp_pll.intcnt = 0; + return; + } + + /* + * A three-stage median filter is used to help deglitch the pps + * signal. The median sample becomes the offset estimate; the + * difference between the other two samples becomes the + * dispersion estimate. + */ + pps_mf[2] = pps_mf[1]; + pps_mf[1] = pps_mf[0]; + pps_mf[0] = v_usec; + if (pps_mf[0] > pps_mf[1]) { + if (pps_mf[1] > pps_mf[2]) { + u_usec = pps_mf[1]; /* 0 1 2 */ + v_usec = pps_mf[0] - pps_mf[2]; + } else if (pps_mf[2] > pps_mf[0]) { + u_usec = pps_mf[0]; /* 2 0 1 */ + v_usec = pps_mf[2] - pps_mf[1]; + } else { + u_usec = pps_mf[2]; /* 0 2 1 */ + v_usec = pps_mf[0] - pps_mf[1]; + } + } else { + if (pps_mf[1] < pps_mf[2]) { + u_usec = pps_mf[1]; /* 2 1 0 */ + v_usec = pps_mf[2] - pps_mf[0]; + } else if (pps_mf[2] < pps_mf[0]) { + u_usec = pps_mf[0]; /* 1 0 2 */ + v_usec = pps_mf[1] - pps_mf[2]; + } else { + u_usec = pps_mf[2]; /* 1 2 0 */ + v_usec = pps_mf[1] - pps_mf[0]; + } + } + + /* + * Here the dispersion average is updated. If it is less than + * the threshold pps_dispmax, the frequency average is updated + * as well, but clamped to the tolerance. + */ + v_usec = (v_usec >> 1) - ntp_pll.disp; + if (v_usec < 0) + ntp_pll.disp -= -v_usec >> PPS_AVG; + else + ntp_pll.disp += v_usec >> PPS_AVG; + if (ntp_pll.disp > pps_dispmax) { + ntp_pll.discnt++; + return; + } + if (u_usec < 0) { + ntp_pll.ybar -= -u_usec >> PPS_AVG; + if (ntp_pll.ybar < -ntp_pll.tolerance) + ntp_pll.ybar = -ntp_pll.tolerance; + u_usec = -u_usec; + } else { + ntp_pll.ybar += u_usec >> PPS_AVG; + if (ntp_pll.ybar > ntp_pll.tolerance) + ntp_pll.ybar = ntp_pll.tolerance; + } + + /* + * Here the calibration interval is adjusted. If the maximum + * time difference is greater than tick/4, reduce the interval + * by half. If this is not the case for four consecutive + * intervals, double the interval. + */ + if (u_usec << ntp_pll.shift > bigtick >> 2) { + ntp_pll.intcnt = 0; + if (ntp_pll.shift > NTP_PLL.SHIFT) { + ntp_pll.shift--; + pps_dispinc <<= 1; + } + } else if (ntp_pll.intcnt >= 4) { + ntp_pll.intcnt = 0; + if (ntp_pll.shift < NTP_PLL.SHIFTMAX) { + ntp_pll.shift++; + pps_dispinc >>= 1; + } + } else + ntp_pll.intcnt++; +} +#endif /* PPS_SYNC */ diff --git a/sys/kern/syscalls.c b/sys/kern/syscalls.c index 9050b018911f..edf4b58ea245 100644 --- a/sys/kern/syscalls.c +++ b/sys/kern/syscalls.c @@ -2,7 +2,7 @@ * System call names. * * DO NOT EDIT-- this file is automatically generated. - * created from $Id: syscalls.master,v 1.7 1994/09/13 00:48:19 wollman Exp $ + * created from $Id: syscalls.master,v 1.8 1994/09/13 14:46:54 dfr Exp $ */ char *syscallnames[] = { @@ -213,7 +213,7 @@ char *syscallnames[] = { "#172", /* 172 = nosys */ "#173", /* 173 = nosys */ "#174", /* 174 = nosys */ - "ntp_gettime", /* 175 = ntp_gettime */ + "#175", /* 175 = nosys */ "ntp_adjtime", /* 176 = ntp_adjtime */ "#177", /* 177 = nosys */ "#178", /* 178 = nosys */ diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master index c00bcd1f3bdc..d9fd50ee663f 100644 --- a/sys/kern/syscalls.master +++ b/sys/kern/syscalls.master @@ -1,4 +1,4 @@ - $Id: syscalls.master,v 1.7 1994/09/13 00:48:19 wollman Exp $ + $Id: syscalls.master,v 1.8 1994/09/13 14:46:54 dfr Exp $ ; from: @(#)syscalls.master 8.2 (Berkeley) 1/13/94 ; ; System call name/number master file. @@ -240,7 +240,7 @@ 172 UNIMPL 0 NOHIDE nosys 173 UNIMPL 0 NOHIDE nosys 174 UNIMPL 0 NOHIDE nosys -175 STD 1 BSD nosys ntp_gettime +175 UNIMPL 0 NOHIDE nosys 176 STD 1 BSD nosys ntp_adjtime 177 UNIMPL 0 NOHIDE nosys 178 UNIMPL 0 NOHIDE nosys diff --git a/sys/sys/syscall-hide.h b/sys/sys/syscall-hide.h index 92aea0160d2a..66912df651a0 100644 --- a/sys/sys/syscall-hide.h +++ b/sys/sys/syscall-hide.h @@ -2,7 +2,7 @@ * System call hiders. * * DO NOT EDIT-- this file is automatically generated. - * created from $Id: syscalls.master,v 1.7 1994/09/13 00:48:19 wollman Exp $ + * created from $Id: syscalls.master,v 1.8 1994/09/13 14:46:54 dfr Exp $ */ HIDE_POSIX(fork) @@ -189,7 +189,6 @@ HIDE_BSD(shmsys) HIDE_BSD(nosys) #endif HIDE_BSD(nosys) -HIDE_BSD(nosys) HIDE_POSIX(setgid) HIDE_BSD(setegid) HIDE_BSD(seteuid) diff --git a/sys/sys/syscall.h b/sys/sys/syscall.h index 7b43d43f52c8..fd409d2fbf8c 100644 --- a/sys/sys/syscall.h +++ b/sys/sys/syscall.h @@ -2,7 +2,7 @@ * System call numbers. * * DO NOT EDIT-- this file is automatically generated. - * created from $Id: syscalls.master,v 1.7 1994/09/13 00:48:19 wollman Exp $ + * created from $Id: syscalls.master,v 1.8 1994/09/13 14:46:54 dfr Exp $ */ #define SYS_syscall 0 @@ -168,7 +168,6 @@ #define SYS_semsys 169 #define SYS_msgsys 170 #define SYS_shmsys 171 -#define SYS_ntp_gettime 175 #define SYS_ntp_adjtime 176 #define SYS_setgid 181 #define SYS_setegid 182 diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h index a16e44ea3d2b..1fd75d6c5b0b 100644 --- a/sys/sys/sysctl.h +++ b/sys/sys/sysctl.h @@ -34,7 +34,7 @@ * SUCH DAMAGE. * * @(#)sysctl.h 8.1 (Berkeley) 6/2/93 - * $Id: sysctl.h,v 1.8 1994/09/16 00:50:02 ache Exp $ + * $Id: sysctl.h,v 1.9 1994/09/16 01:09:42 ache Exp $ */ #ifndef _SYS_SYSCTL_H_ @@ -131,7 +131,8 @@ struct ctlname { #define KERN_DOMAINNAME 22 /* string: YP domain name */ #define KERN_UPDATEINTERVAL 23 /* int: update process sleep time */ #define KERN_OSRELDATE 24 /* int: OS release date */ -#define KERN_MAXID 25 /* number of valid kern ids */ +#define KERN_NTP_PLL 25 /* node: NTP PLL control */ +#define KERN_MAXID 26 /* number of valid kern ids */ #define CTL_KERN_NAMES { \ { 0, 0 }, \ @@ -159,6 +160,7 @@ struct ctlname { { "domainname", CTLTYPE_STRING }, \ { "update", CTLTYPE_INT }, \ { "osreldate", CTLTYPE_INT }, \ + { "ntp_pll", CTLTYPE_NODE }, \ } /* diff --git a/sys/sys/timex.h b/sys/sys/timex.h index 8390ceddca6c..e3bdc66b25b4 100644 --- a/sys/sys/timex.h +++ b/sys/sys/timex.h @@ -242,6 +242,7 @@ struct ntptimeval { struct timeval time; /* current time (ro) */ long maxerror; /* maximum error (us) (ro) */ long esterror; /* estimated error (us) (ro) */ + int time_state; /* what ntp_gettime returns */ }; /* @@ -276,6 +277,17 @@ struct timex { }; #ifdef __FreeBSD__ +/* + * sysctl identifiers underneath kern.ntp_pll + */ +#define NTP_PLL_GETTIME 1 /* used by ntp_gettime() */ +#define NTP_PLL_MAXID 2 /* number of valid ids */ + +#define NTP_PLL_NAMES { \ + { 0, 0 }, \ + { "gettime", CTLTYPE_STRUCT }, \ + } + #ifndef KERNEL #include