1c68996e2SPoul-Henning Kamp /*********************************************************************** 23f31c649SGarrett Wollman * * 3f425c1f6SPoul-Henning Kamp * Copyright (c) David L. Mills 1993-1999 * 43f31c649SGarrett Wollman * * 5c68996e2SPoul-Henning Kamp * Permission to use, copy, modify, and distribute this software and * 6c68996e2SPoul-Henning Kamp * its documentation for any purpose and without fee is hereby * 7c68996e2SPoul-Henning Kamp * granted, provided that the above copyright notice appears in all * 8c68996e2SPoul-Henning Kamp * copies and that both the copyright notice and this permission * 9c68996e2SPoul-Henning Kamp * notice appear in supporting documentation, and that the name * 10c68996e2SPoul-Henning Kamp * University of Delaware not be used in advertising or publicity * 11c68996e2SPoul-Henning Kamp * pertaining to distribution of the software without specific, * 12c68996e2SPoul-Henning Kamp * written prior permission. The University of Delaware makes no * 13c68996e2SPoul-Henning Kamp * representations about the suitability this software for any * 14c68996e2SPoul-Henning Kamp * purpose. It is provided "as is" without express or implied * 15c68996e2SPoul-Henning Kamp * warranty. * 163f31c649SGarrett Wollman * * 17c68996e2SPoul-Henning Kamp **********************************************************************/ 183f31c649SGarrett Wollman 193f31c649SGarrett Wollman /* 20c68996e2SPoul-Henning Kamp * Adapted from the original sources for FreeBSD and timecounters by: 2132c20357SPoul-Henning Kamp * Poul-Henning Kamp <phk@FreeBSD.org>. 223f31c649SGarrett Wollman * 23c68996e2SPoul-Henning Kamp * The 32bit version of the "LP" macros seems a bit past its "sell by" 24c68996e2SPoul-Henning Kamp * date so I have retained only the 64bit version and included it directly 25c68996e2SPoul-Henning Kamp * in this file. 26885bd8e4SJohn Hay * 27c68996e2SPoul-Henning Kamp * Only minor changes done to interface with the timecounters over in 28c68996e2SPoul-Henning Kamp * sys/kern/kern_clock.c. Some of the comments below may be (even more) 29c68996e2SPoul-Henning Kamp * confusing and/or plain wrong in that context. 303f31c649SGarrett Wollman */ 31e0d781f3SEivind Eklund 3232c20357SPoul-Henning Kamp #include "opt_ntp.h" 3332c20357SPoul-Henning Kamp 343f31c649SGarrett Wollman #include <sys/param.h> 353f31c649SGarrett Wollman #include <sys/systm.h> 36d2d3e875SBruce Evans #include <sys/sysproto.h> 373f31c649SGarrett Wollman #include <sys/kernel.h> 383f31c649SGarrett Wollman #include <sys/proc.h> 39c68996e2SPoul-Henning Kamp #include <sys/time.h> 403f31c649SGarrett Wollman #include <sys/timex.h> 41938ee3ceSPoul-Henning Kamp #include <sys/timepps.h> 423f31c649SGarrett Wollman #include <sys/sysctl.h> 433f31c649SGarrett Wollman 443f31c649SGarrett Wollman /* 45c68996e2SPoul-Henning Kamp * Single-precision macros for 64-bit machines 463f31c649SGarrett Wollman */ 47c68996e2SPoul-Henning Kamp typedef long long l_fp; 48c68996e2SPoul-Henning Kamp #define L_ADD(v, u) ((v) += (u)) 49c68996e2SPoul-Henning Kamp #define L_SUB(v, u) ((v) -= (u)) 50c68996e2SPoul-Henning Kamp #define L_ADDHI(v, a) ((v) += (long long)(a) << 32) 51c68996e2SPoul-Henning Kamp #define L_NEG(v) ((v) = -(v)) 52c68996e2SPoul-Henning Kamp #define L_RSHIFT(v, n) \ 53c68996e2SPoul-Henning Kamp do { \ 54c68996e2SPoul-Henning Kamp if ((v) < 0) \ 55c68996e2SPoul-Henning Kamp (v) = -(-(v) >> (n)); \ 56c68996e2SPoul-Henning Kamp else \ 57c68996e2SPoul-Henning Kamp (v) = (v) >> (n); \ 58c68996e2SPoul-Henning Kamp } while (0) 59c68996e2SPoul-Henning Kamp #define L_MPY(v, a) ((v) *= (a)) 60c68996e2SPoul-Henning Kamp #define L_CLR(v) ((v) = 0) 61c68996e2SPoul-Henning Kamp #define L_ISNEG(v) ((v) < 0) 62c68996e2SPoul-Henning Kamp #define L_LINT(v, a) ((v) = (long long)(a) << 32) 63c68996e2SPoul-Henning Kamp #define L_GINT(v) ((v) < 0 ? -(-(v) >> 32) : (v) >> 32) 646f70df15SPoul-Henning Kamp 656f70df15SPoul-Henning Kamp /* 66c68996e2SPoul-Henning Kamp * Generic NTP kernel interface 676f70df15SPoul-Henning Kamp * 68c68996e2SPoul-Henning Kamp * These routines constitute the Network Time Protocol (NTP) interfaces 69c68996e2SPoul-Henning Kamp * for user and daemon application programs. The ntp_gettime() routine 70c68996e2SPoul-Henning Kamp * provides the time, maximum error (synch distance) and estimated error 71c68996e2SPoul-Henning Kamp * (dispersion) to client user application programs. The ntp_adjtime() 72c68996e2SPoul-Henning Kamp * routine is used by the NTP daemon to adjust the system clock to an 73c68996e2SPoul-Henning Kamp * externally derived time. The time offset and related variables set by 74c68996e2SPoul-Henning Kamp * this routine are used by other routines in this module to adjust the 75c68996e2SPoul-Henning Kamp * phase and frequency of the clock discipline loop which controls the 76c68996e2SPoul-Henning Kamp * system clock. 776f70df15SPoul-Henning Kamp * 78f425c1f6SPoul-Henning Kamp * When the kernel time is reckoned directly in nanoseconds (NTP_NANO 79c68996e2SPoul-Henning Kamp * defined), the time at each tick interrupt is derived directly from 80c68996e2SPoul-Henning Kamp * the kernel time variable. When the kernel time is reckoned in 81f425c1f6SPoul-Henning Kamp * microseconds, (NTP_NANO undefined), the time is derived from the 82f425c1f6SPoul-Henning Kamp * kernel time variable together with a variable representing the 83f425c1f6SPoul-Henning Kamp * leftover nanoseconds at the last tick interrupt. In either case, the 84f425c1f6SPoul-Henning Kamp * current nanosecond time is reckoned from these values plus an 85f425c1f6SPoul-Henning Kamp * interpolated value derived by the clock routines in another 86f425c1f6SPoul-Henning Kamp * architecture-specific module. The interpolation can use either a 87f425c1f6SPoul-Henning Kamp * dedicated counter or a processor cycle counter (PCC) implemented in 88f425c1f6SPoul-Henning Kamp * some architectures. 896f70df15SPoul-Henning Kamp * 90c68996e2SPoul-Henning Kamp * Note that all routines must run at priority splclock or higher. 916f70df15SPoul-Henning Kamp */ 92c68996e2SPoul-Henning Kamp 93c68996e2SPoul-Henning Kamp /* 94c68996e2SPoul-Henning Kamp * Phase/frequency-lock loop (PLL/FLL) definitions 95c68996e2SPoul-Henning Kamp * 96c68996e2SPoul-Henning Kamp * The nanosecond clock discipline uses two variable types, time 97c68996e2SPoul-Henning Kamp * variables and frequency variables. Both types are represented as 64- 98c68996e2SPoul-Henning Kamp * bit fixed-point quantities with the decimal point between two 32-bit 99c68996e2SPoul-Henning Kamp * halves. On a 32-bit machine, each half is represented as a single 100c68996e2SPoul-Henning Kamp * word and mathematical operations are done using multiple-precision 101c68996e2SPoul-Henning Kamp * arithmetic. On a 64-bit machine, ordinary computer arithmetic is 102c68996e2SPoul-Henning Kamp * used. 103c68996e2SPoul-Henning Kamp * 104c68996e2SPoul-Henning Kamp * A time variable is a signed 64-bit fixed-point number in ns and 105c68996e2SPoul-Henning Kamp * fraction. It represents the remaining time offset to be amortized 106c68996e2SPoul-Henning Kamp * over succeeding tick interrupts. The maximum time offset is about 107f425c1f6SPoul-Henning Kamp * 0.5 s and the resolution is about 2.3e-10 ns. 108c68996e2SPoul-Henning Kamp * 109c68996e2SPoul-Henning Kamp * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 110c68996e2SPoul-Henning Kamp * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 111c68996e2SPoul-Henning Kamp * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 112c68996e2SPoul-Henning Kamp * |s s s| ns | 113c68996e2SPoul-Henning Kamp * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 114c68996e2SPoul-Henning Kamp * | fraction | 115c68996e2SPoul-Henning Kamp * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 116c68996e2SPoul-Henning Kamp * 117c68996e2SPoul-Henning Kamp * A frequency variable is a signed 64-bit fixed-point number in ns/s 118c68996e2SPoul-Henning Kamp * and fraction. It represents the ns and fraction to be added to the 119c68996e2SPoul-Henning Kamp * kernel time variable at each second. The maximum frequency offset is 120f425c1f6SPoul-Henning Kamp * about +-500000 ns/s and the resolution is about 2.3e-10 ns/s. 121c68996e2SPoul-Henning Kamp * 122c68996e2SPoul-Henning Kamp * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 123c68996e2SPoul-Henning Kamp * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 124c68996e2SPoul-Henning Kamp * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 125c68996e2SPoul-Henning Kamp * |s s s s s s s s s s s s s| ns/s | 126c68996e2SPoul-Henning Kamp * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 127c68996e2SPoul-Henning Kamp * | fraction | 128c68996e2SPoul-Henning Kamp * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 129c68996e2SPoul-Henning Kamp */ 130c68996e2SPoul-Henning Kamp /* 131c68996e2SPoul-Henning Kamp * The following variables establish the state of the PLL/FLL and the 132c68996e2SPoul-Henning Kamp * residual time and frequency offset of the local clock. 133c68996e2SPoul-Henning Kamp */ 134c68996e2SPoul-Henning Kamp #define SHIFT_PLL 4 /* PLL loop gain (shift) */ 135c68996e2SPoul-Henning Kamp #define SHIFT_FLL 2 /* FLL loop gain (shift) */ 136c68996e2SPoul-Henning Kamp 137c68996e2SPoul-Henning Kamp static int time_state = TIME_OK; /* clock state */ 138c68996e2SPoul-Henning Kamp static int time_status = STA_UNSYNC; /* clock status bits */ 139c68996e2SPoul-Henning Kamp static long time_constant; /* poll interval (shift) (s) */ 140c68996e2SPoul-Henning Kamp static long time_precision = 1; /* clock precision (ns) */ 141c68996e2SPoul-Henning Kamp static long time_maxerror = MAXPHASE / 1000; /* maximum error (us) */ 142c68996e2SPoul-Henning Kamp static long time_esterror = MAXPHASE / 1000; /* estimated error (us) */ 143c68996e2SPoul-Henning Kamp static long time_reftime; /* time at last adjustment (s) */ 144c68996e2SPoul-Henning Kamp static long time_tick; /* nanoseconds per tick (ns) */ 145c68996e2SPoul-Henning Kamp static l_fp time_offset; /* time offset (ns) */ 146c68996e2SPoul-Henning Kamp static l_fp time_freq; /* frequency offset (ns/s) */ 1473f31c649SGarrett Wollman 148f425c1f6SPoul-Henning Kamp int ntp_mult; 149f425c1f6SPoul-Henning Kamp int ntp_div; 1503f31c649SGarrett Wollman #ifdef PPS_SYNC 1513f31c649SGarrett Wollman /* 152c68996e2SPoul-Henning Kamp * The following variables are used when a pulse-per-second (PPS) signal 153c68996e2SPoul-Henning Kamp * is available and connected via a modem control lead. They establish 154c68996e2SPoul-Henning Kamp * the engineering parameters of the clock discipline loop when 155c68996e2SPoul-Henning Kamp * controlled by the PPS signal. 1563f31c649SGarrett Wollman */ 157c68996e2SPoul-Henning Kamp #define PPS_FAVG 2 /* min freq avg interval (s) (shift) */ 158f425c1f6SPoul-Henning Kamp #define PPS_FAVGMAX 8 /* max freq avg interval (s) (shift) */ 159c68996e2SPoul-Henning Kamp #define PPS_PAVG 4 /* phase avg interval (s) (shift) */ 160c68996e2SPoul-Henning Kamp #define PPS_VALID 120 /* PPS signal watchdog max (s) */ 161c68996e2SPoul-Henning Kamp #define MAXTIME 500000 /* max PPS error (jitter) (ns) */ 162c68996e2SPoul-Henning Kamp #define MAXWANDER 500000 /* max PPS wander (ns/s/s) */ 163c68996e2SPoul-Henning Kamp 164c68996e2SPoul-Henning Kamp struct ppstime { 165c68996e2SPoul-Henning Kamp long sec; /* PPS seconds */ 166c68996e2SPoul-Henning Kamp long nsec; /* PPS nanoseconds */ 167c68996e2SPoul-Henning Kamp }; 168c68996e2SPoul-Henning Kamp static struct ppstime pps_tf[3]; /* phase median filter */ 169c68996e2SPoul-Henning Kamp static struct ppstime pps_filt; /* phase offset */ 170c68996e2SPoul-Henning Kamp static l_fp pps_freq; /* scaled frequency offset (ns/s) */ 171c68996e2SPoul-Henning Kamp static long pps_offacc; /* offset accumulator */ 172f425c1f6SPoul-Henning Kamp static long pps_fcount; /* frequency accumulator */ 173c68996e2SPoul-Henning Kamp static long pps_jitter; /* scaled time dispersion (ns) */ 174c68996e2SPoul-Henning Kamp static long pps_stabil; /* scaled frequency dispersion (ns/s) */ 175c68996e2SPoul-Henning Kamp static long pps_lastsec; /* time at last calibration (s) */ 176c68996e2SPoul-Henning Kamp static int pps_valid; /* signal watchdog counter */ 177c68996e2SPoul-Henning Kamp static int pps_shift = PPS_FAVG; /* interval duration (s) (shift) */ 178c68996e2SPoul-Henning Kamp static int pps_intcnt; /* wander counter */ 179c68996e2SPoul-Henning Kamp static int pps_offcnt; /* offset accumulator counter */ 1806f70df15SPoul-Henning Kamp 1816f70df15SPoul-Henning Kamp /* 1826f70df15SPoul-Henning Kamp * PPS signal quality monitors 1836f70df15SPoul-Henning Kamp */ 184c68996e2SPoul-Henning Kamp static long pps_calcnt; /* calibration intervals */ 185c68996e2SPoul-Henning Kamp static long pps_jitcnt; /* jitter limit exceeded */ 186c68996e2SPoul-Henning Kamp static long pps_stbcnt; /* stability limit exceeded */ 187c68996e2SPoul-Henning Kamp static long pps_errcnt; /* calibration errors */ 1883f31c649SGarrett Wollman #endif /* PPS_SYNC */ 189c68996e2SPoul-Henning Kamp /* 190c68996e2SPoul-Henning Kamp * End of phase/frequency-lock loop (PLL/FLL) definitions 191c68996e2SPoul-Henning Kamp */ 1923f31c649SGarrett Wollman 193c68996e2SPoul-Henning Kamp static void ntp_init(void); 194c68996e2SPoul-Henning Kamp static void hardupdate(long offset); 195c68996e2SPoul-Henning Kamp 196c68996e2SPoul-Henning Kamp /* 197c68996e2SPoul-Henning Kamp * ntp_gettime() - NTP user application interface 198c68996e2SPoul-Henning Kamp * 199c68996e2SPoul-Henning Kamp * See the timex.h header file for synopsis and API description. 200c68996e2SPoul-Henning Kamp */ 201c68996e2SPoul-Henning Kamp static int 202c68996e2SPoul-Henning Kamp ntp_sysctl SYSCTL_HANDLER_ARGS 203c68996e2SPoul-Henning Kamp { 204c68996e2SPoul-Henning Kamp struct ntptimeval ntv; /* temporary structure */ 205c68996e2SPoul-Henning Kamp struct timespec atv; /* nanosecond time */ 206c68996e2SPoul-Henning Kamp 207c68996e2SPoul-Henning Kamp nanotime(&atv); 208c68996e2SPoul-Henning Kamp ntv.time.tv_sec = atv.tv_sec; 209c68996e2SPoul-Henning Kamp ntv.time.tv_nsec = atv.tv_nsec; 210c68996e2SPoul-Henning Kamp ntv.maxerror = time_maxerror; 211c68996e2SPoul-Henning Kamp ntv.esterror = time_esterror; 212c68996e2SPoul-Henning Kamp ntv.time_state = time_state; 213c68996e2SPoul-Henning Kamp 214c68996e2SPoul-Henning Kamp /* 215c68996e2SPoul-Henning Kamp * Status word error decode. If any of these conditions occur, 216c68996e2SPoul-Henning Kamp * an error is returned, instead of the status word. Most 217c68996e2SPoul-Henning Kamp * applications will care only about the fact the system clock 218c68996e2SPoul-Henning Kamp * may not be trusted, not about the details. 219c68996e2SPoul-Henning Kamp * 220c68996e2SPoul-Henning Kamp * Hardware or software error 221c68996e2SPoul-Henning Kamp */ 222c68996e2SPoul-Henning Kamp if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 223c68996e2SPoul-Henning Kamp 224c68996e2SPoul-Henning Kamp /* 225c68996e2SPoul-Henning Kamp * PPS signal lost when either time or frequency synchronization 226c68996e2SPoul-Henning Kamp * requested 227c68996e2SPoul-Henning Kamp */ 228c68996e2SPoul-Henning Kamp (time_status & (STA_PPSFREQ | STA_PPSTIME) && 229c68996e2SPoul-Henning Kamp !(time_status & STA_PPSSIGNAL)) || 230c68996e2SPoul-Henning Kamp 231c68996e2SPoul-Henning Kamp /* 232c68996e2SPoul-Henning Kamp * PPS jitter exceeded when time synchronization requested 233c68996e2SPoul-Henning Kamp */ 234c68996e2SPoul-Henning Kamp (time_status & STA_PPSTIME && 235c68996e2SPoul-Henning Kamp time_status & STA_PPSJITTER) || 236c68996e2SPoul-Henning Kamp 237c68996e2SPoul-Henning Kamp /* 238c68996e2SPoul-Henning Kamp * PPS wander exceeded or calibration error when frequency 239c68996e2SPoul-Henning Kamp * synchronization requested 240c68996e2SPoul-Henning Kamp */ 241c68996e2SPoul-Henning Kamp (time_status & STA_PPSFREQ && 242c68996e2SPoul-Henning Kamp time_status & (STA_PPSWANDER | STA_PPSERROR))) 243c68996e2SPoul-Henning Kamp ntv.time_state = TIME_ERROR; 244c68996e2SPoul-Henning Kamp return (sysctl_handle_opaque(oidp, &ntv, sizeof ntv, req)); 245c68996e2SPoul-Henning Kamp } 246c68996e2SPoul-Henning Kamp 247c68996e2SPoul-Henning Kamp SYSCTL_NODE(_kern, OID_AUTO, ntp_pll, CTLFLAG_RW, 0, ""); 248c68996e2SPoul-Henning Kamp SYSCTL_PROC(_kern_ntp_pll, OID_AUTO, gettime, CTLTYPE_OPAQUE|CTLFLAG_RD, 249c68996e2SPoul-Henning Kamp 0, sizeof(struct ntptimeval) , ntp_sysctl, "S,ntptimeval", ""); 250c68996e2SPoul-Henning Kamp 251f425c1f6SPoul-Henning Kamp SYSCTL_INT(_kern_ntp_pll, OID_AUTO, mult, CTLFLAG_RW, &ntp_mult, 0, ""); 252f425c1f6SPoul-Henning Kamp SYSCTL_INT(_kern_ntp_pll, OID_AUTO, div, CTLFLAG_RW, &ntp_div, 0, ""); 253c68996e2SPoul-Henning Kamp 254c68996e2SPoul-Henning Kamp /* 255c68996e2SPoul-Henning Kamp * ntp_adjtime() - NTP daemon application interface 256c68996e2SPoul-Henning Kamp * 257c68996e2SPoul-Henning Kamp * See the timex.h header file for synopsis and API description. 258c68996e2SPoul-Henning Kamp */ 259c68996e2SPoul-Henning Kamp #ifndef _SYS_SYSPROTO_H_ 260c68996e2SPoul-Henning Kamp struct ntp_adjtime_args { 261c68996e2SPoul-Henning Kamp struct timex *tp; 262c68996e2SPoul-Henning Kamp }; 263c68996e2SPoul-Henning Kamp #endif 264c68996e2SPoul-Henning Kamp 265c68996e2SPoul-Henning Kamp int 266c68996e2SPoul-Henning Kamp ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap) 267c68996e2SPoul-Henning Kamp { 268c68996e2SPoul-Henning Kamp struct timex ntv; /* temporary structure */ 269f425c1f6SPoul-Henning Kamp long freq; /* frequency ns/s) */ 270c68996e2SPoul-Henning Kamp int modes; /* mode bits from structure */ 271c68996e2SPoul-Henning Kamp int s; /* caller priority */ 272c68996e2SPoul-Henning Kamp int error; 273c68996e2SPoul-Henning Kamp 274c68996e2SPoul-Henning Kamp error = copyin((caddr_t)uap->tp, (caddr_t)&ntv, sizeof(ntv)); 275c68996e2SPoul-Henning Kamp if (error) 276c68996e2SPoul-Henning Kamp return(error); 277c68996e2SPoul-Henning Kamp 278c68996e2SPoul-Henning Kamp /* 279c68996e2SPoul-Henning Kamp * Update selected clock variables - only the superuser can 280c68996e2SPoul-Henning Kamp * change anything. Note that there is no error checking here on 281c68996e2SPoul-Henning Kamp * the assumption the superuser should know what it is doing. 282c68996e2SPoul-Henning Kamp */ 283c68996e2SPoul-Henning Kamp modes = ntv.modes; 284fafbe352SPoul-Henning Kamp if (modes) 285c68996e2SPoul-Henning Kamp error = suser(p->p_cred->pc_ucred, &p->p_acflag); 286c68996e2SPoul-Henning Kamp if (error) 287c68996e2SPoul-Henning Kamp return (error); 288c68996e2SPoul-Henning Kamp s = splclock(); 289c68996e2SPoul-Henning Kamp if (modes & MOD_FREQUENCY) { 290f425c1f6SPoul-Henning Kamp freq = (ntv.freq * 1000) << 16; 291f425c1f6SPoul-Henning Kamp if (freq > MAXFREQ) 292f425c1f6SPoul-Henning Kamp L_LINT(time_freq, MAXFREQ); 293f425c1f6SPoul-Henning Kamp else if (freq < -MAXFREQ) 294f425c1f6SPoul-Henning Kamp L_LINT(time_freq, -MAXFREQ); 295f425c1f6SPoul-Henning Kamp else 296f425c1f6SPoul-Henning Kamp L_LINT(time_freq, freq); 297f425c1f6SPoul-Henning Kamp 298c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC 299c68996e2SPoul-Henning Kamp pps_freq = time_freq; 300c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */ 301c68996e2SPoul-Henning Kamp } 302c68996e2SPoul-Henning Kamp if (modes & MOD_MAXERROR) 303c68996e2SPoul-Henning Kamp time_maxerror = ntv.maxerror; 304c68996e2SPoul-Henning Kamp if (modes & MOD_ESTERROR) 305c68996e2SPoul-Henning Kamp time_esterror = ntv.esterror; 306c68996e2SPoul-Henning Kamp if (modes & MOD_STATUS) { 307c68996e2SPoul-Henning Kamp time_status &= STA_RONLY; 308c68996e2SPoul-Henning Kamp time_status |= ntv.status & ~STA_RONLY; 309c68996e2SPoul-Henning Kamp } 310f425c1f6SPoul-Henning Kamp if (modes & MOD_TIMECONST) { 311f425c1f6SPoul-Henning Kamp if (ntv.constant < 0) 312f425c1f6SPoul-Henning Kamp time_constant = 0; 313f425c1f6SPoul-Henning Kamp else if (ntv.constant > MAXTC) 314f425c1f6SPoul-Henning Kamp time_constant = MAXTC; 315f425c1f6SPoul-Henning Kamp else 316c68996e2SPoul-Henning Kamp time_constant = ntv.constant; 317f425c1f6SPoul-Henning Kamp } 318c68996e2SPoul-Henning Kamp if (modes & MOD_NANO) 319c68996e2SPoul-Henning Kamp time_status |= STA_NANO; 320c68996e2SPoul-Henning Kamp if (modes & MOD_MICRO) 321c68996e2SPoul-Henning Kamp time_status &= ~STA_NANO; 322c68996e2SPoul-Henning Kamp if (modes & MOD_CLKB) 323c68996e2SPoul-Henning Kamp time_status |= STA_CLK; 324c68996e2SPoul-Henning Kamp if (modes & MOD_CLKA) 325c68996e2SPoul-Henning Kamp time_status &= ~STA_CLK; 326c68996e2SPoul-Henning Kamp if (modes & MOD_OFFSET) { 327c68996e2SPoul-Henning Kamp if (time_status & STA_NANO) 328c68996e2SPoul-Henning Kamp hardupdate(ntv.offset); 329c68996e2SPoul-Henning Kamp else 330c68996e2SPoul-Henning Kamp hardupdate(ntv.offset * 1000); 331c68996e2SPoul-Henning Kamp } 332c68996e2SPoul-Henning Kamp 333c68996e2SPoul-Henning Kamp /* 334c68996e2SPoul-Henning Kamp * Retrieve all clock variables 335c68996e2SPoul-Henning Kamp */ 336c68996e2SPoul-Henning Kamp if (time_status & STA_NANO) 337c68996e2SPoul-Henning Kamp ntv.offset = L_GINT(time_offset); 338c68996e2SPoul-Henning Kamp else 339c68996e2SPoul-Henning Kamp ntv.offset = L_GINT(time_offset) / 1000; 340f425c1f6SPoul-Henning Kamp ntv.freq = L_GINT((time_freq / 1000) << 16); 341c68996e2SPoul-Henning Kamp ntv.maxerror = time_maxerror; 342c68996e2SPoul-Henning Kamp ntv.esterror = time_esterror; 343c68996e2SPoul-Henning Kamp ntv.status = time_status; 344f425c1f6SPoul-Henning Kamp ntv.constant = time_constant; 345c68996e2SPoul-Henning Kamp if (time_status & STA_NANO) 346c68996e2SPoul-Henning Kamp ntv.precision = time_precision; 347c68996e2SPoul-Henning Kamp else 348c68996e2SPoul-Henning Kamp ntv.precision = time_precision / 1000; 349c68996e2SPoul-Henning Kamp ntv.tolerance = MAXFREQ * SCALE_PPM; 350c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC 351c68996e2SPoul-Henning Kamp ntv.shift = pps_shift; 352f425c1f6SPoul-Henning Kamp ntv.ppsfreq = L_GINT((pps_freq / 1000) << 16); 353c68996e2SPoul-Henning Kamp ntv.jitter = pps_jitter; 354c68996e2SPoul-Henning Kamp if (time_status & STA_NANO) 355c68996e2SPoul-Henning Kamp ntv.jitter = pps_jitter; 356c68996e2SPoul-Henning Kamp else 357c68996e2SPoul-Henning Kamp ntv.jitter = pps_jitter / 1000; 358c68996e2SPoul-Henning Kamp ntv.stabil = pps_stabil; 359c68996e2SPoul-Henning Kamp ntv.calcnt = pps_calcnt; 360c68996e2SPoul-Henning Kamp ntv.errcnt = pps_errcnt; 361c68996e2SPoul-Henning Kamp ntv.jitcnt = pps_jitcnt; 362c68996e2SPoul-Henning Kamp ntv.stbcnt = pps_stbcnt; 363c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */ 364c68996e2SPoul-Henning Kamp splx(s); 365c68996e2SPoul-Henning Kamp 366c68996e2SPoul-Henning Kamp error = copyout((caddr_t)&ntv, (caddr_t)uap->tp, sizeof(ntv)); 367c68996e2SPoul-Henning Kamp if (error) 368c68996e2SPoul-Henning Kamp return (error); 369c68996e2SPoul-Henning Kamp 370c68996e2SPoul-Henning Kamp /* 371c68996e2SPoul-Henning Kamp * Status word error decode. See comments in 372c68996e2SPoul-Henning Kamp * ntp_gettime() routine. 373c68996e2SPoul-Henning Kamp */ 374c68996e2SPoul-Henning Kamp if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 375c68996e2SPoul-Henning Kamp (time_status & (STA_PPSFREQ | STA_PPSTIME) && 376c68996e2SPoul-Henning Kamp !(time_status & STA_PPSSIGNAL)) || 377c68996e2SPoul-Henning Kamp (time_status & STA_PPSTIME && 378c68996e2SPoul-Henning Kamp time_status & STA_PPSJITTER) || 379c68996e2SPoul-Henning Kamp (time_status & STA_PPSFREQ && 380c68996e2SPoul-Henning Kamp time_status & (STA_PPSWANDER | STA_PPSERROR))) 381c68996e2SPoul-Henning Kamp return (TIME_ERROR); 382c68996e2SPoul-Henning Kamp return (time_state); 383c68996e2SPoul-Henning Kamp } 384c68996e2SPoul-Henning Kamp 385c68996e2SPoul-Henning Kamp /* 386c68996e2SPoul-Henning Kamp * second_overflow() - called after ntp_tick_adjust() 387c68996e2SPoul-Henning Kamp * 388c68996e2SPoul-Henning Kamp * This routine is ordinarily called immediately following the above 389c68996e2SPoul-Henning Kamp * routine ntp_tick_adjust(). While these two routines are normally 390c68996e2SPoul-Henning Kamp * combined, they are separated here only for the purposes of 391c68996e2SPoul-Henning Kamp * simulation. 392c68996e2SPoul-Henning Kamp */ 393c68996e2SPoul-Henning Kamp void 394c68996e2SPoul-Henning Kamp ntp_update_second(struct timecounter *tcp) 395c68996e2SPoul-Henning Kamp { 396c68996e2SPoul-Henning Kamp u_int32_t *newsec; 39732c20357SPoul-Henning Kamp l_fp ftemp, time_adj; /* 32/64-bit temporaries */ 398c68996e2SPoul-Henning Kamp 399c68996e2SPoul-Henning Kamp newsec = &tcp->tc_offset_sec; 400c68996e2SPoul-Henning Kamp time_maxerror += MAXFREQ / 1000; 401c68996e2SPoul-Henning Kamp 402c68996e2SPoul-Henning Kamp /* 403c68996e2SPoul-Henning Kamp * Leap second processing. If in leap-insert state at 404c68996e2SPoul-Henning Kamp * the end of the day, the system clock is set back one 405c68996e2SPoul-Henning Kamp * second; if in leap-delete state, the system clock is 406c68996e2SPoul-Henning Kamp * set ahead one second. The nano_time() routine or 407c68996e2SPoul-Henning Kamp * external clock driver will insure that reported time 408c68996e2SPoul-Henning Kamp * is always monotonic. 409c68996e2SPoul-Henning Kamp */ 410c68996e2SPoul-Henning Kamp switch (time_state) { 411c68996e2SPoul-Henning Kamp 412c68996e2SPoul-Henning Kamp /* 413c68996e2SPoul-Henning Kamp * No warning. 414c68996e2SPoul-Henning Kamp */ 415c68996e2SPoul-Henning Kamp case TIME_OK: 416c68996e2SPoul-Henning Kamp if (time_status & STA_INS) 417c68996e2SPoul-Henning Kamp time_state = TIME_INS; 418c68996e2SPoul-Henning Kamp else if (time_status & STA_DEL) 419c68996e2SPoul-Henning Kamp time_state = TIME_DEL; 420c68996e2SPoul-Henning Kamp break; 421c68996e2SPoul-Henning Kamp 422c68996e2SPoul-Henning Kamp /* 423c68996e2SPoul-Henning Kamp * Insert second 23:59:60 following second 424c68996e2SPoul-Henning Kamp * 23:59:59. 425c68996e2SPoul-Henning Kamp */ 426c68996e2SPoul-Henning Kamp case TIME_INS: 427c68996e2SPoul-Henning Kamp if (!(time_status & STA_INS)) 428c68996e2SPoul-Henning Kamp time_state = TIME_OK; 429c68996e2SPoul-Henning Kamp else if ((*newsec) % 86400 == 0) { 430c68996e2SPoul-Henning Kamp (*newsec)--; 431c68996e2SPoul-Henning Kamp time_state = TIME_OOP; 432c68996e2SPoul-Henning Kamp } 433c68996e2SPoul-Henning Kamp break; 434c68996e2SPoul-Henning Kamp 435c68996e2SPoul-Henning Kamp /* 436c68996e2SPoul-Henning Kamp * Delete second 23:59:59. 437c68996e2SPoul-Henning Kamp */ 438c68996e2SPoul-Henning Kamp case TIME_DEL: 439c68996e2SPoul-Henning Kamp if (!(time_status & STA_DEL)) 440c68996e2SPoul-Henning Kamp time_state = TIME_OK; 441c68996e2SPoul-Henning Kamp else if (((*newsec) + 1) % 86400 == 0) { 442c68996e2SPoul-Henning Kamp (*newsec)++; 443c68996e2SPoul-Henning Kamp time_state = TIME_WAIT; 444c68996e2SPoul-Henning Kamp } 445c68996e2SPoul-Henning Kamp break; 446c68996e2SPoul-Henning Kamp 447c68996e2SPoul-Henning Kamp /* 448c68996e2SPoul-Henning Kamp * Insert second in progress. 449c68996e2SPoul-Henning Kamp */ 450c68996e2SPoul-Henning Kamp case TIME_OOP: 451c68996e2SPoul-Henning Kamp time_state = TIME_WAIT; 452c68996e2SPoul-Henning Kamp break; 453c68996e2SPoul-Henning Kamp 454c68996e2SPoul-Henning Kamp /* 455c68996e2SPoul-Henning Kamp * Wait for status bits to clear. 456c68996e2SPoul-Henning Kamp */ 457c68996e2SPoul-Henning Kamp case TIME_WAIT: 458c68996e2SPoul-Henning Kamp if (!(time_status & (STA_INS | STA_DEL))) 459c68996e2SPoul-Henning Kamp time_state = TIME_OK; 460c68996e2SPoul-Henning Kamp } 461c68996e2SPoul-Henning Kamp 462c68996e2SPoul-Henning Kamp /* 463c68996e2SPoul-Henning Kamp * Compute the total time adjustment for the next 464c68996e2SPoul-Henning Kamp * second in ns. The offset is reduced by a factor 465c68996e2SPoul-Henning Kamp * depending on FLL or PLL mode and whether the PPS 466c68996e2SPoul-Henning Kamp * signal is operating. Note that the value is in effect 467c68996e2SPoul-Henning Kamp * scaled by the clock frequency, since the adjustment 468c68996e2SPoul-Henning Kamp * is added at each tick interrupt. 469c68996e2SPoul-Henning Kamp */ 470c68996e2SPoul-Henning Kamp ftemp = time_offset; 471c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC 472c68996e2SPoul-Henning Kamp if (time_status & STA_PPSTIME && time_status & 473c68996e2SPoul-Henning Kamp STA_PPSSIGNAL) 474c68996e2SPoul-Henning Kamp L_RSHIFT(ftemp, PPS_FAVG); 475c68996e2SPoul-Henning Kamp else if (time_status & STA_MODE) 476c68996e2SPoul-Henning Kamp #else 477c68996e2SPoul-Henning Kamp if (time_status & STA_MODE) 478c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */ 479c68996e2SPoul-Henning Kamp L_RSHIFT(ftemp, SHIFT_FLL); 480c68996e2SPoul-Henning Kamp else 481c68996e2SPoul-Henning Kamp L_RSHIFT(ftemp, SHIFT_PLL + time_constant); 482c68996e2SPoul-Henning Kamp time_adj = ftemp; 483c68996e2SPoul-Henning Kamp L_SUB(time_offset, ftemp); 484c68996e2SPoul-Henning Kamp L_ADD(time_adj, time_freq); 485c68996e2SPoul-Henning Kamp tcp->tc_adjustment = time_adj; 486c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC 487c68996e2SPoul-Henning Kamp if (pps_valid > 0) 488c68996e2SPoul-Henning Kamp pps_valid--; 489c68996e2SPoul-Henning Kamp else 490c68996e2SPoul-Henning Kamp time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER | 491c68996e2SPoul-Henning Kamp STA_PPSWANDER | STA_PPSERROR); 492c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */ 493c68996e2SPoul-Henning Kamp } 494c68996e2SPoul-Henning Kamp 495c68996e2SPoul-Henning Kamp /* 496c68996e2SPoul-Henning Kamp * ntp_init() - initialize variables and structures 497c68996e2SPoul-Henning Kamp * 498c68996e2SPoul-Henning Kamp * This routine must be called after the kernel variables hz and tick 499c68996e2SPoul-Henning Kamp * are set or changed and before the next tick interrupt. In this 500c68996e2SPoul-Henning Kamp * particular implementation, these values are assumed set elsewhere in 501c68996e2SPoul-Henning Kamp * the kernel. The design allows the clock frequency and tick interval 502c68996e2SPoul-Henning Kamp * to be changed while the system is running. So, this routine should 503c68996e2SPoul-Henning Kamp * probably be integrated with the code that does that. 504c68996e2SPoul-Henning Kamp */ 505c68996e2SPoul-Henning Kamp static void 506c68996e2SPoul-Henning Kamp ntp_init() 507c68996e2SPoul-Henning Kamp { 508c68996e2SPoul-Henning Kamp 509c68996e2SPoul-Henning Kamp /* 510c68996e2SPoul-Henning Kamp * The following variable must be initialized any time the 511c68996e2SPoul-Henning Kamp * kernel variable hz is changed. 512c68996e2SPoul-Henning Kamp */ 513c68996e2SPoul-Henning Kamp time_tick = NANOSECOND / hz; 514c68996e2SPoul-Henning Kamp 515c68996e2SPoul-Henning Kamp /* 516c68996e2SPoul-Henning Kamp * The following variables are initialized only at startup. Only 517c68996e2SPoul-Henning Kamp * those structures not cleared by the compiler need to be 518c68996e2SPoul-Henning Kamp * initialized, and these only in the simulator. In the actual 519c68996e2SPoul-Henning Kamp * kernel, any nonzero values here will quickly evaporate. 520c68996e2SPoul-Henning Kamp */ 521c68996e2SPoul-Henning Kamp L_CLR(time_offset); 522c68996e2SPoul-Henning Kamp L_CLR(time_freq); 523c68996e2SPoul-Henning Kamp #ifdef PPS_SYNC 524884ab557SPoul-Henning Kamp pps_filt.sec = pps_filt.nsec = 0; 525c68996e2SPoul-Henning Kamp pps_tf[0] = pps_tf[1] = pps_tf[2] = pps_filt; 526f425c1f6SPoul-Henning Kamp pps_fcount = 0; 527c68996e2SPoul-Henning Kamp L_CLR(pps_freq); 528c68996e2SPoul-Henning Kamp #endif /* PPS_SYNC */ 529c68996e2SPoul-Henning Kamp } 530c68996e2SPoul-Henning Kamp 531c68996e2SPoul-Henning Kamp SYSINIT(ntpclocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, ntp_init, NULL) 5326f70df15SPoul-Henning Kamp 5336f70df15SPoul-Henning Kamp /* 5346f70df15SPoul-Henning Kamp * hardupdate() - local clock update 5356f70df15SPoul-Henning Kamp * 5366f70df15SPoul-Henning Kamp * This routine is called by ntp_adjtime() to update the local clock 5376f70df15SPoul-Henning Kamp * phase and frequency. The implementation is of an adaptive-parameter, 5386f70df15SPoul-Henning Kamp * hybrid phase/frequency-lock loop (PLL/FLL). The routine computes new 5396f70df15SPoul-Henning Kamp * time and frequency offset estimates for each call. If the kernel PPS 5406f70df15SPoul-Henning Kamp * discipline code is configured (PPS_SYNC), the PPS signal itself 5416f70df15SPoul-Henning Kamp * determines the new time offset, instead of the calling argument. 5426f70df15SPoul-Henning Kamp * Presumably, calls to ntp_adjtime() occur only when the caller 5436f70df15SPoul-Henning Kamp * believes the local clock is valid within some bound (+-128 ms with 5446f70df15SPoul-Henning Kamp * NTP). If the caller's time is far different than the PPS time, an 5456f70df15SPoul-Henning Kamp * argument will ensue, and it's not clear who will lose. 5466f70df15SPoul-Henning Kamp * 547c68996e2SPoul-Henning Kamp * For uncompensated quartz crystal oscillators and nominal update 548c68996e2SPoul-Henning Kamp * intervals less than 256 s, operation should be in phase-lock mode, 549c68996e2SPoul-Henning Kamp * where the loop is disciplined to phase. For update intervals greater 550c68996e2SPoul-Henning Kamp * than 1024 s, operation should be in frequency-lock mode, where the 551c68996e2SPoul-Henning Kamp * loop is disciplined to frequency. Between 256 s and 1024 s, the mode 552c68996e2SPoul-Henning Kamp * is selected by the STA_MODE status bit. 5536f70df15SPoul-Henning Kamp */ 5546f70df15SPoul-Henning Kamp static void 555c68996e2SPoul-Henning Kamp hardupdate(offset) 556c68996e2SPoul-Henning Kamp long offset; /* clock offset (ns) */ 5576f70df15SPoul-Henning Kamp { 558c68996e2SPoul-Henning Kamp long ltemp, mtemp; 559c68996e2SPoul-Henning Kamp l_fp ftemp; 5606f70df15SPoul-Henning Kamp 561c68996e2SPoul-Henning Kamp /* 562c68996e2SPoul-Henning Kamp * Select how the phase is to be controlled and from which 563c68996e2SPoul-Henning Kamp * source. If the PPS signal is present and enabled to 564c68996e2SPoul-Henning Kamp * discipline the time, the PPS offset is used; otherwise, the 565c68996e2SPoul-Henning Kamp * argument offset is used. 566c68996e2SPoul-Henning Kamp */ 5676f70df15SPoul-Henning Kamp ltemp = offset; 568c68996e2SPoul-Henning Kamp if (ltemp > MAXPHASE) 569c68996e2SPoul-Henning Kamp ltemp = MAXPHASE; 570c68996e2SPoul-Henning Kamp else if (ltemp < -MAXPHASE) 571c68996e2SPoul-Henning Kamp ltemp = -MAXPHASE; 572c68996e2SPoul-Henning Kamp if (!(time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL)) 573c68996e2SPoul-Henning Kamp L_LINT(time_offset, ltemp); 5746f70df15SPoul-Henning Kamp 5756f70df15SPoul-Henning Kamp /* 576c68996e2SPoul-Henning Kamp * Select how the frequency is to be controlled and in which 577c68996e2SPoul-Henning Kamp * mode (PLL or FLL). If the PPS signal is present and enabled 578c68996e2SPoul-Henning Kamp * to discipline the frequency, the PPS frequency is used; 579c68996e2SPoul-Henning Kamp * otherwise, the argument offset is used to compute it. 5806f70df15SPoul-Henning Kamp */ 581c68996e2SPoul-Henning Kamp if (time_status & STA_PPSFREQ && time_status & STA_PPSSIGNAL) { 582c68996e2SPoul-Henning Kamp time_reftime = time_second; 583c68996e2SPoul-Henning Kamp return; 584c68996e2SPoul-Henning Kamp } 5856f70df15SPoul-Henning Kamp if (time_status & STA_FREQHOLD || time_reftime == 0) 586227ee8a1SPoul-Henning Kamp time_reftime = time_second; 587227ee8a1SPoul-Henning Kamp mtemp = time_second - time_reftime; 588c68996e2SPoul-Henning Kamp if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC) 589c68996e2SPoul-Henning Kamp ) { 590c68996e2SPoul-Henning Kamp L_LINT(ftemp, (ltemp << 4) / mtemp); 591c68996e2SPoul-Henning Kamp L_RSHIFT(ftemp, SHIFT_FLL + 4); 592c68996e2SPoul-Henning Kamp L_ADD(time_freq, ftemp); 593c68996e2SPoul-Henning Kamp time_status |= STA_MODE; 594c68996e2SPoul-Henning Kamp } else { 595c68996e2SPoul-Henning Kamp L_LINT(ftemp, ltemp); 596c68996e2SPoul-Henning Kamp L_RSHIFT(ftemp, (SHIFT_PLL + 2 + time_constant) << 1); 597c68996e2SPoul-Henning Kamp L_MPY(ftemp, mtemp); 598c68996e2SPoul-Henning Kamp L_ADD(time_freq, ftemp); 599c68996e2SPoul-Henning Kamp time_status &= ~STA_MODE; 600c68996e2SPoul-Henning Kamp } 601227ee8a1SPoul-Henning Kamp time_reftime = time_second; 602c68996e2SPoul-Henning Kamp if (L_GINT(time_freq) > MAXFREQ) 603c68996e2SPoul-Henning Kamp L_LINT(time_freq, MAXFREQ); 604c68996e2SPoul-Henning Kamp else if (L_GINT(time_freq) < -MAXFREQ) 605c68996e2SPoul-Henning Kamp L_LINT(time_freq, -MAXFREQ); 6063f31c649SGarrett Wollman } 6073f31c649SGarrett Wollman 6086f70df15SPoul-Henning Kamp #ifdef PPS_SYNC 6096f70df15SPoul-Henning Kamp /* 6106f70df15SPoul-Henning Kamp * hardpps() - discipline CPU clock oscillator to external PPS signal 6116f70df15SPoul-Henning Kamp * 6126f70df15SPoul-Henning Kamp * This routine is called at each PPS interrupt in order to discipline 6136f70df15SPoul-Henning Kamp * the CPU clock oscillator to the PPS signal. It measures the PPS phase 6146f70df15SPoul-Henning Kamp * and leaves it in a handy spot for the hardclock() routine. It 6156f70df15SPoul-Henning Kamp * integrates successive PPS phase differences and calculates the 6166f70df15SPoul-Henning Kamp * frequency offset. This is used in hardclock() to discipline the CPU 617c68996e2SPoul-Henning Kamp * clock oscillator so that the intrinsic frequency error is cancelled 618c68996e2SPoul-Henning Kamp * out. The code requires the caller to capture the time and 619c68996e2SPoul-Henning Kamp * architecture-dependent hardware counter values in nanoseconds at the 620c68996e2SPoul-Henning Kamp * on-time PPS signal transition. 6216f70df15SPoul-Henning Kamp * 622c68996e2SPoul-Henning Kamp * Note that, on some Unix systems this routine runs at an interrupt 6236f70df15SPoul-Henning Kamp * priority level higher than the timer interrupt routine hardclock(). 6246f70df15SPoul-Henning Kamp * Therefore, the variables used are distinct from the hardclock() 625c68996e2SPoul-Henning Kamp * variables, except for the actual time and frequency variables, which 626c68996e2SPoul-Henning Kamp * are determined by this routine and updated atomically. 6276f70df15SPoul-Henning Kamp */ 6286f70df15SPoul-Henning Kamp void 629c68996e2SPoul-Henning Kamp hardpps(tsp, nsec) 630c68996e2SPoul-Henning Kamp struct timespec *tsp; /* time at PPS */ 631c68996e2SPoul-Henning Kamp long nsec; /* hardware counter at PPS */ 6326f70df15SPoul-Henning Kamp { 633c68996e2SPoul-Henning Kamp long u_sec, u_nsec, v_nsec; /* temps */ 634c68996e2SPoul-Henning Kamp l_fp ftemp; 6356f70df15SPoul-Henning Kamp 6366f70df15SPoul-Henning Kamp /* 637c68996e2SPoul-Henning Kamp * The signal is first processed by a frequency discriminator 638c68996e2SPoul-Henning Kamp * which rejects noise and input signals with frequencies 639c68996e2SPoul-Henning Kamp * outside the range 1 +-MAXFREQ PPS. If two hits occur in the 640c68996e2SPoul-Henning Kamp * same second, we ignore the later hit; if not and a hit occurs 641c68996e2SPoul-Henning Kamp * outside the range gate, keep the later hit but do not 642c68996e2SPoul-Henning Kamp * process it. 6436f70df15SPoul-Henning Kamp */ 644c68996e2SPoul-Henning Kamp time_status |= STA_PPSSIGNAL | STA_PPSJITTER; 645c68996e2SPoul-Henning Kamp time_status &= ~(STA_PPSWANDER | STA_PPSERROR); 646c68996e2SPoul-Henning Kamp pps_valid = PPS_VALID; 647c68996e2SPoul-Henning Kamp u_sec = tsp->tv_sec; 648c68996e2SPoul-Henning Kamp u_nsec = tsp->tv_nsec; 649c68996e2SPoul-Henning Kamp if (u_nsec >= (NANOSECOND >> 1)) { 650c68996e2SPoul-Henning Kamp u_nsec -= NANOSECOND; 651c68996e2SPoul-Henning Kamp u_sec++; 6526f70df15SPoul-Henning Kamp } 653c68996e2SPoul-Henning Kamp v_nsec = u_nsec - pps_tf[0].nsec; 654c68996e2SPoul-Henning Kamp if (u_sec == pps_tf[0].sec && v_nsec < -MAXFREQ) { 655c68996e2SPoul-Henning Kamp return; 656c68996e2SPoul-Henning Kamp } 657c68996e2SPoul-Henning Kamp pps_tf[2] = pps_tf[1]; 658c68996e2SPoul-Henning Kamp pps_tf[1] = pps_tf[0]; 659c68996e2SPoul-Henning Kamp pps_tf[0].sec = u_sec; 660c68996e2SPoul-Henning Kamp pps_tf[0].nsec = u_nsec; 6616f70df15SPoul-Henning Kamp 6626f70df15SPoul-Henning Kamp /* 663c68996e2SPoul-Henning Kamp * Compute the difference between the current and previous 664c68996e2SPoul-Henning Kamp * counter values. If the difference exceeds 0.5 s, assume it 665c68996e2SPoul-Henning Kamp * has wrapped around, so correct 1.0 s. If the result exceeds 666c68996e2SPoul-Henning Kamp * the tick interval, the sample point has crossed a tick 667c68996e2SPoul-Henning Kamp * boundary during the last second, so correct the tick. Very 668c68996e2SPoul-Henning Kamp * intricate. 669c68996e2SPoul-Henning Kamp */ 67032c20357SPoul-Henning Kamp u_nsec = nsec; 671c68996e2SPoul-Henning Kamp if (u_nsec > (NANOSECOND >> 1)) 672c68996e2SPoul-Henning Kamp u_nsec -= NANOSECOND; 673c68996e2SPoul-Henning Kamp else if (u_nsec < -(NANOSECOND >> 1)) 674c68996e2SPoul-Henning Kamp u_nsec += NANOSECOND; 675884ab557SPoul-Henning Kamp pps_fcount += u_nsec; 676c68996e2SPoul-Henning Kamp if (v_nsec > MAXFREQ) { 677c68996e2SPoul-Henning Kamp return; 678c68996e2SPoul-Henning Kamp } 679c68996e2SPoul-Henning Kamp time_status &= ~STA_PPSJITTER; 680c68996e2SPoul-Henning Kamp 681c68996e2SPoul-Henning Kamp /* 682c68996e2SPoul-Henning Kamp * A three-stage median filter is used to help denoise the PPS 6836f70df15SPoul-Henning Kamp * time. The median sample becomes the time offset estimate; the 6846f70df15SPoul-Henning Kamp * difference between the other two samples becomes the time 6856f70df15SPoul-Henning Kamp * dispersion (jitter) estimate. 6866f70df15SPoul-Henning Kamp */ 687c68996e2SPoul-Henning Kamp if (pps_tf[0].nsec > pps_tf[1].nsec) { 688c68996e2SPoul-Henning Kamp if (pps_tf[1].nsec > pps_tf[2].nsec) { 689c68996e2SPoul-Henning Kamp pps_filt = pps_tf[1]; /* 0 1 2 */ 690c68996e2SPoul-Henning Kamp u_nsec = pps_tf[0].nsec - pps_tf[2].nsec; 691c68996e2SPoul-Henning Kamp } else if (pps_tf[2].nsec > pps_tf[0].nsec) { 692c68996e2SPoul-Henning Kamp pps_filt = pps_tf[0]; /* 2 0 1 */ 693c68996e2SPoul-Henning Kamp u_nsec = pps_tf[2].nsec - pps_tf[1].nsec; 6946f70df15SPoul-Henning Kamp } else { 695c68996e2SPoul-Henning Kamp pps_filt = pps_tf[2]; /* 0 2 1 */ 696c68996e2SPoul-Henning Kamp u_nsec = pps_tf[0].nsec - pps_tf[1].nsec; 697c68996e2SPoul-Henning Kamp } 698c68996e2SPoul-Henning Kamp } else { 699c68996e2SPoul-Henning Kamp if (pps_tf[1].nsec < pps_tf[2].nsec) { 700c68996e2SPoul-Henning Kamp pps_filt = pps_tf[1]; /* 2 1 0 */ 701c68996e2SPoul-Henning Kamp u_nsec = pps_tf[2].nsec - pps_tf[0].nsec; 702c68996e2SPoul-Henning Kamp } else if (pps_tf[2].nsec < pps_tf[0].nsec) { 703c68996e2SPoul-Henning Kamp pps_filt = pps_tf[0]; /* 1 0 2 */ 704c68996e2SPoul-Henning Kamp u_nsec = pps_tf[1].nsec - pps_tf[2].nsec; 705c68996e2SPoul-Henning Kamp } else { 706c68996e2SPoul-Henning Kamp pps_filt = pps_tf[2]; /* 1 2 0 */ 707c68996e2SPoul-Henning Kamp u_nsec = pps_tf[1].nsec - pps_tf[0].nsec; 7086f70df15SPoul-Henning Kamp } 7096f70df15SPoul-Henning Kamp } 7106f70df15SPoul-Henning Kamp 7116f70df15SPoul-Henning Kamp /* 712c68996e2SPoul-Henning Kamp * Nominal jitter is due to PPS signal noise and interrupt 713c68996e2SPoul-Henning Kamp * latency. If it exceeds the jitter limit, the sample is 714c68996e2SPoul-Henning Kamp * discarded. otherwise, if so enabled, the time offset is 715c68996e2SPoul-Henning Kamp * updated. The offsets are accumulated over the phase averaging 716c68996e2SPoul-Henning Kamp * interval to improve accuracy. The jitter is averaged only for 717c68996e2SPoul-Henning Kamp * performance monitoring. We can tolerate a modest loss of data 718c68996e2SPoul-Henning Kamp * here without degrading time accuracy. 7196f70df15SPoul-Henning Kamp */ 720c68996e2SPoul-Henning Kamp if (u_nsec > MAXTIME) { 721c68996e2SPoul-Henning Kamp time_status |= STA_PPSJITTER; 722c68996e2SPoul-Henning Kamp pps_jitcnt++; 723c68996e2SPoul-Henning Kamp } else if (time_status & STA_PPSTIME) { 724c68996e2SPoul-Henning Kamp pps_offacc -= pps_filt.nsec; 725c68996e2SPoul-Henning Kamp pps_offcnt++; 726c68996e2SPoul-Henning Kamp } 727c68996e2SPoul-Henning Kamp if (pps_offcnt >= (1 << PPS_PAVG)) { 728c68996e2SPoul-Henning Kamp if (time_status & STA_PPSTIME) { 729c68996e2SPoul-Henning Kamp L_LINT(time_offset, pps_offacc); 730c68996e2SPoul-Henning Kamp L_RSHIFT(time_offset, PPS_PAVG); 731c68996e2SPoul-Henning Kamp } 732c68996e2SPoul-Henning Kamp pps_offacc = 0; 733c68996e2SPoul-Henning Kamp pps_offcnt = 0; 734c68996e2SPoul-Henning Kamp } 735c68996e2SPoul-Henning Kamp pps_jitter += (u_nsec - pps_jitter) >> PPS_FAVG; 736c68996e2SPoul-Henning Kamp u_sec = pps_tf[0].sec - pps_lastsec; 737f425c1f6SPoul-Henning Kamp if (ntp_div && ntp_mult) { 738f425c1f6SPoul-Henning Kamp L_LINT(ftemp, (pps_filt.nsec)); 739f425c1f6SPoul-Henning Kamp L_RSHIFT(ftemp, ntp_div); 740f425c1f6SPoul-Henning Kamp L_MPY(ftemp, ntp_mult); 741f425c1f6SPoul-Henning Kamp L_ADD(pps_freq, ftemp); 742f425c1f6SPoul-Henning Kamp if (time_status & STA_PPSFREQ) 743f425c1f6SPoul-Henning Kamp time_freq = pps_freq; 744f425c1f6SPoul-Henning Kamp return; 745f425c1f6SPoul-Henning Kamp } 746c68996e2SPoul-Henning Kamp if (u_sec < (1 << pps_shift)) 747c68996e2SPoul-Henning Kamp return; 748c68996e2SPoul-Henning Kamp 749c68996e2SPoul-Henning Kamp /* 750c68996e2SPoul-Henning Kamp * At the end of the calibration interval the difference between 751c68996e2SPoul-Henning Kamp * the first and last counter values becomes the scaled 752c68996e2SPoul-Henning Kamp * frequency. It will later be divided by the length of the 753c68996e2SPoul-Henning Kamp * interval to determine the frequency update. If the frequency 754c68996e2SPoul-Henning Kamp * exceeds a sanity threshold, or if the actual calibration 755c68996e2SPoul-Henning Kamp * interval is not equal to the expected length, the data are 756c68996e2SPoul-Henning Kamp * discarded. We can tolerate a modest loss of data here without 757c68996e2SPoul-Henning Kamp * degrading frequency ccuracy. 758c68996e2SPoul-Henning Kamp */ 759c68996e2SPoul-Henning Kamp pps_calcnt++; 760884ab557SPoul-Henning Kamp v_nsec = -pps_fcount; 761c68996e2SPoul-Henning Kamp pps_lastsec = pps_tf[0].sec; 762884ab557SPoul-Henning Kamp pps_fcount = 0; 763c68996e2SPoul-Henning Kamp u_nsec = MAXFREQ << pps_shift; 764c68996e2SPoul-Henning Kamp if (v_nsec > u_nsec || v_nsec < -u_nsec || u_sec != (1 << 765c68996e2SPoul-Henning Kamp pps_shift)) { 766c68996e2SPoul-Henning Kamp time_status |= STA_PPSERROR; 767c68996e2SPoul-Henning Kamp pps_errcnt++; 768c68996e2SPoul-Henning Kamp return; 769c68996e2SPoul-Henning Kamp } 770c68996e2SPoul-Henning Kamp 771c68996e2SPoul-Henning Kamp /* 772c68996e2SPoul-Henning Kamp * If the actual calibration interval is not equal to the 773c68996e2SPoul-Henning Kamp * expected length, the data are discarded. If the wander is 774c68996e2SPoul-Henning Kamp * less than the wander threshold for four consecutive 775c68996e2SPoul-Henning Kamp * intervals, the interval is doubled; if it is greater than the 776c68996e2SPoul-Henning Kamp * threshold for four consecutive intervals, the interval is 777c68996e2SPoul-Henning Kamp * halved. The scaled frequency offset is converted to frequency 778c68996e2SPoul-Henning Kamp * offset. The stability metric is calculated as the average of 779c68996e2SPoul-Henning Kamp * recent frequency changes, but is used only for performance 780c68996e2SPoul-Henning Kamp * monitoring. 781c68996e2SPoul-Henning Kamp */ 782c68996e2SPoul-Henning Kamp L_LINT(ftemp, v_nsec); 783c68996e2SPoul-Henning Kamp L_RSHIFT(ftemp, pps_shift); 784c68996e2SPoul-Henning Kamp L_SUB(ftemp, pps_freq); 785c68996e2SPoul-Henning Kamp u_nsec = L_GINT(ftemp); 786c68996e2SPoul-Henning Kamp if (u_nsec > MAXWANDER) { 787c68996e2SPoul-Henning Kamp L_LINT(ftemp, MAXWANDER); 788c68996e2SPoul-Henning Kamp pps_intcnt--; 789c68996e2SPoul-Henning Kamp time_status |= STA_PPSWANDER; 790c68996e2SPoul-Henning Kamp pps_stbcnt++; 791c68996e2SPoul-Henning Kamp } else if (u_nsec < -MAXWANDER) { 792c68996e2SPoul-Henning Kamp L_LINT(ftemp, -MAXWANDER); 793c68996e2SPoul-Henning Kamp pps_intcnt--; 794c68996e2SPoul-Henning Kamp time_status |= STA_PPSWANDER; 795c68996e2SPoul-Henning Kamp pps_stbcnt++; 796c68996e2SPoul-Henning Kamp } else { 7976f70df15SPoul-Henning Kamp pps_intcnt++; 7986f70df15SPoul-Henning Kamp } 799c68996e2SPoul-Henning Kamp if (pps_intcnt >= 4) { 800c68996e2SPoul-Henning Kamp pps_intcnt = 4; 801c68996e2SPoul-Henning Kamp if (pps_shift < PPS_FAVGMAX) { 802c68996e2SPoul-Henning Kamp pps_shift++; 803c68996e2SPoul-Henning Kamp pps_intcnt = 0; 804c68996e2SPoul-Henning Kamp } 805c68996e2SPoul-Henning Kamp } else if (pps_intcnt <= -4) { 806c68996e2SPoul-Henning Kamp pps_intcnt = -4; 807c68996e2SPoul-Henning Kamp if (pps_shift > PPS_FAVG) { 808c68996e2SPoul-Henning Kamp pps_shift--; 809c68996e2SPoul-Henning Kamp pps_intcnt = 0; 810c68996e2SPoul-Henning Kamp } 811c68996e2SPoul-Henning Kamp } 812c68996e2SPoul-Henning Kamp if (u_nsec < 0) 813c68996e2SPoul-Henning Kamp u_nsec = -u_nsec; 814c68996e2SPoul-Henning Kamp pps_stabil += (u_nsec * SCALE_PPM - pps_stabil) >> PPS_FAVG; 8159ada5a50SPoul-Henning Kamp 816c68996e2SPoul-Henning Kamp /* 817c68996e2SPoul-Henning Kamp * The frequency offset is averaged into the PPS frequency. If 818c68996e2SPoul-Henning Kamp * enabled, the system clock frequency is updated as well. 819c68996e2SPoul-Henning Kamp */ 820f425c1f6SPoul-Henning Kamp L_RSHIFT(ftemp, PPS_FAVG); 821c68996e2SPoul-Henning Kamp L_ADD(pps_freq, ftemp); 822c68996e2SPoul-Henning Kamp u_nsec = L_GINT(pps_freq); 823c68996e2SPoul-Henning Kamp if (u_nsec > MAXFREQ) 824c68996e2SPoul-Henning Kamp L_LINT(pps_freq, MAXFREQ); 825c68996e2SPoul-Henning Kamp else if (u_nsec < -MAXFREQ) 826c68996e2SPoul-Henning Kamp L_LINT(pps_freq, -MAXFREQ); 827c68996e2SPoul-Henning Kamp if (time_status & STA_PPSFREQ) 828c68996e2SPoul-Henning Kamp time_freq = pps_freq; 829c68996e2SPoul-Henning Kamp } 8306f70df15SPoul-Henning Kamp #endif /* PPS_SYNC */ 831