35
36#include "opt_ntp.h"
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/sysproto.h>
41#include <sys/eventhandler.h>
42#include <sys/kernel.h>
43#include <sys/priv.h>
44#include <sys/proc.h>
45#include <sys/lock.h>
46#include <sys/mutex.h>
47#include <sys/time.h>
48#include <sys/timex.h>
49#include <sys/timetc.h>
50#include <sys/timepps.h>
51#include <sys/syscallsubr.h>
52#include <sys/sysctl.h>
53
54/*
55 * Single-precision macros for 64-bit machines
56 */
57typedef int64_t l_fp;
58#define L_ADD(v, u) ((v) += (u))
59#define L_SUB(v, u) ((v) -= (u))
60#define L_ADDHI(v, a) ((v) += (int64_t)(a) << 32)
61#define L_NEG(v) ((v) = -(v))
62#define L_RSHIFT(v, n) \
63 do { \
64 if ((v) < 0) \
65 (v) = -(-(v) >> (n)); \
66 else \
67 (v) = (v) >> (n); \
68 } while (0)
69#define L_MPY(v, a) ((v) *= (a))
70#define L_CLR(v) ((v) = 0)
71#define L_ISNEG(v) ((v) < 0)
72#define L_LINT(v, a) ((v) = (int64_t)(a) << 32)
73#define L_GINT(v) ((v) < 0 ? -(-(v) >> 32) : (v) >> 32)
74
75/*
76 * Generic NTP kernel interface
77 *
78 * These routines constitute the Network Time Protocol (NTP) interfaces
79 * for user and daemon application programs. The ntp_gettime() routine
80 * provides the time, maximum error (synch distance) and estimated error
81 * (dispersion) to client user application programs. The ntp_adjtime()
82 * routine is used by the NTP daemon to adjust the system clock to an
83 * externally derived time. The time offset and related variables set by
84 * this routine are used by other routines in this module to adjust the
85 * phase and frequency of the clock discipline loop which controls the
86 * system clock.
87 *
88 * When the kernel time is reckoned directly in nanoseconds (NTP_NANO
89 * defined), the time at each tick interrupt is derived directly from
90 * the kernel time variable. When the kernel time is reckoned in
91 * microseconds, (NTP_NANO undefined), the time is derived from the
92 * kernel time variable together with a variable representing the
93 * leftover nanoseconds at the last tick interrupt. In either case, the
94 * current nanosecond time is reckoned from these values plus an
95 * interpolated value derived by the clock routines in another
96 * architecture-specific module. The interpolation can use either a
97 * dedicated counter or a processor cycle counter (PCC) implemented in
98 * some architectures.
99 *
100 * Note that all routines must run at priority splclock or higher.
101 */
102/*
103 * Phase/frequency-lock loop (PLL/FLL) definitions
104 *
105 * The nanosecond clock discipline uses two variable types, time
106 * variables and frequency variables. Both types are represented as 64-
107 * bit fixed-point quantities with the decimal point between two 32-bit
108 * halves. On a 32-bit machine, each half is represented as a single
109 * word and mathematical operations are done using multiple-precision
110 * arithmetic. On a 64-bit machine, ordinary computer arithmetic is
111 * used.
112 *
113 * A time variable is a signed 64-bit fixed-point number in ns and
114 * fraction. It represents the remaining time offset to be amortized
115 * over succeeding tick interrupts. The maximum time offset is about
116 * 0.5 s and the resolution is about 2.3e-10 ns.
117 *
118 * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
119 * 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
120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 * |s s s| ns |
122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123 * | fraction |
124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125 *
126 * A frequency variable is a signed 64-bit fixed-point number in ns/s
127 * and fraction. It represents the ns and fraction to be added to the
128 * kernel time variable at each second. The maximum frequency offset is
129 * about +-500000 ns/s and the resolution is about 2.3e-10 ns/s.
130 *
131 * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
132 * 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
133 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
134 * |s s s s s s s s s s s s s| ns/s |
135 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
136 * | fraction |
137 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
138 */
139/*
140 * The following variables establish the state of the PLL/FLL and the
141 * residual time and frequency offset of the local clock.
142 */
143#define SHIFT_PLL 4 /* PLL loop gain (shift) */
144#define SHIFT_FLL 2 /* FLL loop gain (shift) */
145
146static int time_state = TIME_OK; /* clock state */
147static int time_status = STA_UNSYNC; /* clock status bits */
148static long time_tai; /* TAI offset (s) */
149static long time_monitor; /* last time offset scaled (ns) */
150static long time_constant; /* poll interval (shift) (s) */
151static long time_precision = 1; /* clock precision (ns) */
152static long time_maxerror = MAXPHASE / 1000; /* maximum error (us) */
153static long time_esterror = MAXPHASE / 1000; /* estimated error (us) */
154static long time_reftime; /* time at last adjustment (s) */
155static l_fp time_offset; /* time offset (ns) */
156static l_fp time_freq; /* frequency offset (ns/s) */
157static l_fp time_adj; /* tick adjust (ns/s) */
158
159static int64_t time_adjtime; /* correction from adjtime(2) (usec) */
160
161#ifdef PPS_SYNC
162/*
163 * The following variables are used when a pulse-per-second (PPS) signal
164 * is available and connected via a modem control lead. They establish
165 * the engineering parameters of the clock discipline loop when
166 * controlled by the PPS signal.
167 */
168#define PPS_FAVG 2 /* min freq avg interval (s) (shift) */
169#define PPS_FAVGDEF 8 /* default freq avg int (s) (shift) */
170#define PPS_FAVGMAX 15 /* max freq avg interval (s) (shift) */
171#define PPS_PAVG 4 /* phase avg interval (s) (shift) */
172#define PPS_VALID 120 /* PPS signal watchdog max (s) */
173#define PPS_MAXWANDER 100000 /* max PPS wander (ns/s) */
174#define PPS_POPCORN 2 /* popcorn spike threshold (shift) */
175
176static struct timespec pps_tf[3]; /* phase median filter */
177static l_fp pps_freq; /* scaled frequency offset (ns/s) */
178static long pps_fcount; /* frequency accumulator */
179static long pps_jitter; /* nominal jitter (ns) */
180static long pps_stabil; /* nominal stability (scaled ns/s) */
181static long pps_lastsec; /* time at last calibration (s) */
182static int pps_valid; /* signal watchdog counter */
183static int pps_shift = PPS_FAVG; /* interval duration (s) (shift) */
184static int pps_shiftmax = PPS_FAVGDEF; /* max interval duration (s) (shift) */
185static int pps_intcnt; /* wander counter */
186
187/*
188 * PPS signal quality monitors
189 */
190static long pps_calcnt; /* calibration intervals */
191static long pps_jitcnt; /* jitter limit exceeded */
192static long pps_stbcnt; /* stability limit exceeded */
193static long pps_errcnt; /* calibration errors */
194#endif /* PPS_SYNC */
195/*
196 * End of phase/frequency-lock loop (PLL/FLL) definitions
197 */
198
199static void ntp_init(void);
200static void hardupdate(long offset);
201static void ntp_gettime1(struct ntptimeval *ntvp);
202static int ntp_is_time_error(void);
203
204static int
205ntp_is_time_error(void)
206{
207 /*
208 * Status word error decode. If any of these conditions occur,
209 * an error is returned, instead of the status word. Most
210 * applications will care only about the fact the system clock
211 * may not be trusted, not about the details.
212 *
213 * Hardware or software error
214 */
215 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) ||
216
217 /*
218 * PPS signal lost when either time or frequency synchronization
219 * requested
220 */
221 (time_status & (STA_PPSFREQ | STA_PPSTIME) &&
222 !(time_status & STA_PPSSIGNAL)) ||
223
224 /*
225 * PPS jitter exceeded when time synchronization requested
226 */
227 (time_status & STA_PPSTIME &&
228 time_status & STA_PPSJITTER) ||
229
230 /*
231 * PPS wander exceeded or calibration error when frequency
232 * synchronization requested
233 */
234 (time_status & STA_PPSFREQ &&
235 time_status & (STA_PPSWANDER | STA_PPSERROR)))
236 return (1);
237
238 return (0);
239}
240
241static void
242ntp_gettime1(struct ntptimeval *ntvp)
243{
244 struct timespec atv; /* nanosecond time */
245
246 GIANT_REQUIRED;
247
248 nanotime(&atv);
249 ntvp->time.tv_sec = atv.tv_sec;
250 ntvp->time.tv_nsec = atv.tv_nsec;
251 ntvp->maxerror = time_maxerror;
252 ntvp->esterror = time_esterror;
253 ntvp->tai = time_tai;
254 ntvp->time_state = time_state;
255
256 if (ntp_is_time_error())
257 ntvp->time_state = TIME_ERROR;
258}
259
260/*
261 * ntp_gettime() - NTP user application interface
262 *
263 * See the timex.h header file for synopsis and API description. Note that
264 * the TAI offset is returned in the ntvtimeval.tai structure member.
265 */
266#ifndef _SYS_SYSPROTO_H_
267struct ntp_gettime_args {
268 struct ntptimeval *ntvp;
269};
270#endif
271/* ARGSUSED */
272int
273ntp_gettime(struct thread *td, struct ntp_gettime_args *uap)
274{
275 struct ntptimeval ntv;
276
277 mtx_lock(&Giant);
278 ntp_gettime1(&ntv);
279 mtx_unlock(&Giant);
280
281 td->td_retval[0] = ntv.time_state;
282 return (copyout(&ntv, uap->ntvp, sizeof(ntv)));
283}
284
285static int
286ntp_sysctl(SYSCTL_HANDLER_ARGS)
287{
288 struct ntptimeval ntv; /* temporary structure */
289
290 ntp_gettime1(&ntv);
291
292 return (sysctl_handle_opaque(oidp, &ntv, sizeof(ntv), req));
293}
294
295SYSCTL_NODE(_kern, OID_AUTO, ntp_pll, CTLFLAG_RW, 0, "");
296SYSCTL_PROC(_kern_ntp_pll, OID_AUTO, gettime, CTLTYPE_OPAQUE|CTLFLAG_RD,
297 0, sizeof(struct ntptimeval) , ntp_sysctl, "S,ntptimeval", "");
298
299#ifdef PPS_SYNC
300SYSCTL_INT(_kern_ntp_pll, OID_AUTO, pps_shiftmax, CTLFLAG_RW, &pps_shiftmax, 0, "");
301SYSCTL_INT(_kern_ntp_pll, OID_AUTO, pps_shift, CTLFLAG_RW, &pps_shift, 0, "");
302SYSCTL_INT(_kern_ntp_pll, OID_AUTO, time_monitor, CTLFLAG_RD, &time_monitor, 0, "");
303
304SYSCTL_OPAQUE(_kern_ntp_pll, OID_AUTO, pps_freq, CTLFLAG_RD, &pps_freq, sizeof(pps_freq), "I", "");
305SYSCTL_OPAQUE(_kern_ntp_pll, OID_AUTO, time_freq, CTLFLAG_RD, &time_freq, sizeof(time_freq), "I", "");
306#endif
307
308/*
309 * ntp_adjtime() - NTP daemon application interface
310 *
311 * See the timex.h header file for synopsis and API description. Note that
312 * the timex.constant structure member has a dual purpose to set the time
313 * constant and to set the TAI offset.
314 */
315#ifndef _SYS_SYSPROTO_H_
316struct ntp_adjtime_args {
317 struct timex *tp;
318};
319#endif
320
321int
322ntp_adjtime(struct thread *td, struct ntp_adjtime_args *uap)
323{
324 struct timex ntv; /* temporary structure */
325 long freq; /* frequency ns/s) */
326 int modes; /* mode bits from structure */
327 int s; /* caller priority */
328 int error;
329
330 error = copyin((caddr_t)uap->tp, (caddr_t)&ntv, sizeof(ntv));
331 if (error)
332 return(error);
333
334 /*
335 * Update selected clock variables - only the superuser can
336 * change anything. Note that there is no error checking here on
337 * the assumption the superuser should know what it is doing.
338 * Note that either the time constant or TAI offset are loaded
339 * from the ntv.constant member, depending on the mode bits. If
340 * the STA_PLL bit in the status word is cleared, the state and
341 * status words are reset to the initial values at boot.
342 */
343 mtx_lock(&Giant);
344 modes = ntv.modes;
345 if (modes)
346 error = priv_check(td, PRIV_NTP_ADJTIME);
347 if (error)
348 goto done2;
349 s = splclock();
350 if (modes & MOD_MAXERROR)
351 time_maxerror = ntv.maxerror;
352 if (modes & MOD_ESTERROR)
353 time_esterror = ntv.esterror;
354 if (modes & MOD_STATUS) {
355 if (time_status & STA_PLL && !(ntv.status & STA_PLL)) {
356 time_state = TIME_OK;
357 time_status = STA_UNSYNC;
358#ifdef PPS_SYNC
359 pps_shift = PPS_FAVG;
360#endif /* PPS_SYNC */
361 }
362 time_status &= STA_RONLY;
363 time_status |= ntv.status & ~STA_RONLY;
364 }
365 if (modes & MOD_TIMECONST) {
366 if (ntv.constant < 0)
367 time_constant = 0;
368 else if (ntv.constant > MAXTC)
369 time_constant = MAXTC;
370 else
371 time_constant = ntv.constant;
372 }
373 if (modes & MOD_TAI) {
374 if (ntv.constant > 0) /* XXX zero & negative numbers ? */
375 time_tai = ntv.constant;
376 }
377#ifdef PPS_SYNC
378 if (modes & MOD_PPSMAX) {
379 if (ntv.shift < PPS_FAVG)
380 pps_shiftmax = PPS_FAVG;
381 else if (ntv.shift > PPS_FAVGMAX)
382 pps_shiftmax = PPS_FAVGMAX;
383 else
384 pps_shiftmax = ntv.shift;
385 }
386#endif /* PPS_SYNC */
387 if (modes & MOD_NANO)
388 time_status |= STA_NANO;
389 if (modes & MOD_MICRO)
390 time_status &= ~STA_NANO;
391 if (modes & MOD_CLKB)
392 time_status |= STA_CLK;
393 if (modes & MOD_CLKA)
394 time_status &= ~STA_CLK;
395 if (modes & MOD_FREQUENCY) {
396 freq = (ntv.freq * 1000LL) >> 16;
397 if (freq > MAXFREQ)
398 L_LINT(time_freq, MAXFREQ);
399 else if (freq < -MAXFREQ)
400 L_LINT(time_freq, -MAXFREQ);
401 else {
402 /*
403 * ntv.freq is [PPM * 2^16] = [us/s * 2^16]
404 * time_freq is [ns/s * 2^32]
405 */
406 time_freq = ntv.freq * 1000LL * 65536LL;
407 }
408#ifdef PPS_SYNC
409 pps_freq = time_freq;
410#endif /* PPS_SYNC */
411 }
412 if (modes & MOD_OFFSET) {
413 if (time_status & STA_NANO)
414 hardupdate(ntv.offset);
415 else
416 hardupdate(ntv.offset * 1000);
417 }
418
419 /*
420 * Retrieve all clock variables. Note that the TAI offset is
421 * returned only by ntp_gettime();
422 */
423 if (time_status & STA_NANO)
424 ntv.offset = L_GINT(time_offset);
425 else
426 ntv.offset = L_GINT(time_offset) / 1000; /* XXX rounding ? */
427 ntv.freq = L_GINT((time_freq / 1000LL) << 16);
428 ntv.maxerror = time_maxerror;
429 ntv.esterror = time_esterror;
430 ntv.status = time_status;
431 ntv.constant = time_constant;
432 if (time_status & STA_NANO)
433 ntv.precision = time_precision;
434 else
435 ntv.precision = time_precision / 1000;
436 ntv.tolerance = MAXFREQ * SCALE_PPM;
437#ifdef PPS_SYNC
438 ntv.shift = pps_shift;
439 ntv.ppsfreq = L_GINT((pps_freq / 1000LL) << 16);
440 if (time_status & STA_NANO)
441 ntv.jitter = pps_jitter;
442 else
443 ntv.jitter = pps_jitter / 1000;
444 ntv.stabil = pps_stabil;
445 ntv.calcnt = pps_calcnt;
446 ntv.errcnt = pps_errcnt;
447 ntv.jitcnt = pps_jitcnt;
448 ntv.stbcnt = pps_stbcnt;
449#endif /* PPS_SYNC */
450 splx(s);
451
452 error = copyout((caddr_t)&ntv, (caddr_t)uap->tp, sizeof(ntv));
453 if (error)
454 goto done2;
455
456 if (ntp_is_time_error())
457 td->td_retval[0] = TIME_ERROR;
458 else
459 td->td_retval[0] = time_state;
460
461done2:
462 mtx_unlock(&Giant);
463 return (error);
464}
465
466/*
467 * second_overflow() - called after ntp_tick_adjust()
468 *
469 * This routine is ordinarily called immediately following the above
470 * routine ntp_tick_adjust(). While these two routines are normally
471 * combined, they are separated here only for the purposes of
472 * simulation.
473 */
474void
475ntp_update_second(int64_t *adjustment, time_t *newsec)
476{
477 int tickrate;
478 l_fp ftemp; /* 32/64-bit temporary */
479
480 /*
481 * On rollover of the second both the nanosecond and microsecond
482 * clocks are updated and the state machine cranked as
483 * necessary. The phase adjustment to be used for the next
484 * second is calculated and the maximum error is increased by
485 * the tolerance.
486 */
487 time_maxerror += MAXFREQ / 1000;
488
489 /*
490 * Leap second processing. If in leap-insert state at
491 * the end of the day, the system clock is set back one
492 * second; if in leap-delete state, the system clock is
493 * set ahead one second. The nano_time() routine or
494 * external clock driver will insure that reported time
495 * is always monotonic.
496 */
497 switch (time_state) {
498
499 /*
500 * No warning.
501 */
502 case TIME_OK:
503 if (time_status & STA_INS)
504 time_state = TIME_INS;
505 else if (time_status & STA_DEL)
506 time_state = TIME_DEL;
507 break;
508
509 /*
510 * Insert second 23:59:60 following second
511 * 23:59:59.
512 */
513 case TIME_INS:
514 if (!(time_status & STA_INS))
515 time_state = TIME_OK;
516 else if ((*newsec) % 86400 == 0) {
517 (*newsec)--;
518 time_state = TIME_OOP;
519 time_tai++;
520 }
521 break;
522
523 /*
524 * Delete second 23:59:59.
525 */
526 case TIME_DEL:
527 if (!(time_status & STA_DEL))
528 time_state = TIME_OK;
529 else if (((*newsec) + 1) % 86400 == 0) {
530 (*newsec)++;
531 time_tai--;
532 time_state = TIME_WAIT;
533 }
534 break;
535
536 /*
537 * Insert second in progress.
538 */
539 case TIME_OOP:
540 time_state = TIME_WAIT;
541 break;
542
543 /*
544 * Wait for status bits to clear.
545 */
546 case TIME_WAIT:
547 if (!(time_status & (STA_INS | STA_DEL)))
548 time_state = TIME_OK;
549 }
550
551 /*
552 * Compute the total time adjustment for the next second
553 * in ns. The offset is reduced by a factor depending on
554 * whether the PPS signal is operating. Note that the
555 * value is in effect scaled by the clock frequency,
556 * since the adjustment is added at each tick interrupt.
557 */
558 ftemp = time_offset;
559#ifdef PPS_SYNC
560 /* XXX even if PPS signal dies we should finish adjustment ? */
561 if (time_status & STA_PPSTIME && time_status &
562 STA_PPSSIGNAL)
563 L_RSHIFT(ftemp, pps_shift);
564 else
565 L_RSHIFT(ftemp, SHIFT_PLL + time_constant);
566#else
567 L_RSHIFT(ftemp, SHIFT_PLL + time_constant);
568#endif /* PPS_SYNC */
569 time_adj = ftemp;
570 L_SUB(time_offset, ftemp);
571 L_ADD(time_adj, time_freq);
572
573 /*
574 * Apply any correction from adjtime(2). If more than one second
575 * off we slew at a rate of 5ms/s (5000 PPM) else 500us/s (500PPM)
576 * until the last second is slewed the final < 500 usecs.
577 */
578 if (time_adjtime != 0) {
579 if (time_adjtime > 1000000)
580 tickrate = 5000;
581 else if (time_adjtime < -1000000)
582 tickrate = -5000;
583 else if (time_adjtime > 500)
584 tickrate = 500;
585 else if (time_adjtime < -500)
586 tickrate = -500;
587 else
588 tickrate = time_adjtime;
589 time_adjtime -= tickrate;
590 L_LINT(ftemp, tickrate * 1000);
591 L_ADD(time_adj, ftemp);
592 }
593 *adjustment = time_adj;
594
595#ifdef PPS_SYNC
596 if (pps_valid > 0)
597 pps_valid--;
598 else
599 time_status &= ~STA_PPSSIGNAL;
600#endif /* PPS_SYNC */
601}
602
603/*
604 * ntp_init() - initialize variables and structures
605 *
606 * This routine must be called after the kernel variables hz and tick
607 * are set or changed and before the next tick interrupt. In this
608 * particular implementation, these values are assumed set elsewhere in
609 * the kernel. The design allows the clock frequency and tick interval
610 * to be changed while the system is running. So, this routine should
611 * probably be integrated with the code that does that.
612 */
613static void
614ntp_init()
615{
616
617 /*
618 * The following variables are initialized only at startup. Only
619 * those structures not cleared by the compiler need to be
620 * initialized, and these only in the simulator. In the actual
621 * kernel, any nonzero values here will quickly evaporate.
622 */
623 L_CLR(time_offset);
624 L_CLR(time_freq);
625#ifdef PPS_SYNC
626 pps_tf[0].tv_sec = pps_tf[0].tv_nsec = 0;
627 pps_tf[1].tv_sec = pps_tf[1].tv_nsec = 0;
628 pps_tf[2].tv_sec = pps_tf[2].tv_nsec = 0;
629 pps_fcount = 0;
630 L_CLR(pps_freq);
631#endif /* PPS_SYNC */
632}
633
634SYSINIT(ntpclocks, SI_SUB_CLOCKS, SI_ORDER_MIDDLE, ntp_init, NULL);
635
636/*
637 * hardupdate() - local clock update
638 *
639 * This routine is called by ntp_adjtime() to update the local clock
640 * phase and frequency. The implementation is of an adaptive-parameter,
641 * hybrid phase/frequency-lock loop (PLL/FLL). The routine computes new
642 * time and frequency offset estimates for each call. If the kernel PPS
643 * discipline code is configured (PPS_SYNC), the PPS signal itself
644 * determines the new time offset, instead of the calling argument.
645 * Presumably, calls to ntp_adjtime() occur only when the caller
646 * believes the local clock is valid within some bound (+-128 ms with
647 * NTP). If the caller's time is far different than the PPS time, an
648 * argument will ensue, and it's not clear who will lose.
649 *
650 * For uncompensated quartz crystal oscillators and nominal update
651 * intervals less than 256 s, operation should be in phase-lock mode,
652 * where the loop is disciplined to phase. For update intervals greater
653 * than 1024 s, operation should be in frequency-lock mode, where the
654 * loop is disciplined to frequency. Between 256 s and 1024 s, the mode
655 * is selected by the STA_MODE status bit.
656 */
657static void
658hardupdate(offset)
659 long offset; /* clock offset (ns) */
660{
661 long mtemp;
662 l_fp ftemp;
663
664 /*
665 * Select how the phase is to be controlled and from which
666 * source. If the PPS signal is present and enabled to
667 * discipline the time, the PPS offset is used; otherwise, the
668 * argument offset is used.
669 */
670 if (!(time_status & STA_PLL))
671 return;
672 if (!(time_status & STA_PPSTIME && time_status &
673 STA_PPSSIGNAL)) {
674 if (offset > MAXPHASE)
675 time_monitor = MAXPHASE;
676 else if (offset < -MAXPHASE)
677 time_monitor = -MAXPHASE;
678 else
679 time_monitor = offset;
680 L_LINT(time_offset, time_monitor);
681 }
682
683 /*
684 * Select how the frequency is to be controlled and in which
685 * mode (PLL or FLL). If the PPS signal is present and enabled
686 * to discipline the frequency, the PPS frequency is used;
687 * otherwise, the argument offset is used to compute it.
688 */
689 if (time_status & STA_PPSFREQ && time_status & STA_PPSSIGNAL) {
690 time_reftime = time_second;
691 return;
692 }
693 if (time_status & STA_FREQHOLD || time_reftime == 0)
694 time_reftime = time_second;
695 mtemp = time_second - time_reftime;
696 L_LINT(ftemp, time_monitor);
697 L_RSHIFT(ftemp, (SHIFT_PLL + 2 + time_constant) << 1);
698 L_MPY(ftemp, mtemp);
699 L_ADD(time_freq, ftemp);
700 time_status &= ~STA_MODE;
701 if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp >
702 MAXSEC)) {
703 L_LINT(ftemp, (time_monitor << 4) / mtemp);
704 L_RSHIFT(ftemp, SHIFT_FLL + 4);
705 L_ADD(time_freq, ftemp);
706 time_status |= STA_MODE;
707 }
708 time_reftime = time_second;
709 if (L_GINT(time_freq) > MAXFREQ)
710 L_LINT(time_freq, MAXFREQ);
711 else if (L_GINT(time_freq) < -MAXFREQ)
712 L_LINT(time_freq, -MAXFREQ);
713}
714
715#ifdef PPS_SYNC
716/*
717 * hardpps() - discipline CPU clock oscillator to external PPS signal
718 *
719 * This routine is called at each PPS interrupt in order to discipline
720 * the CPU clock oscillator to the PPS signal. There are two independent
721 * first-order feedback loops, one for the phase, the other for the
722 * frequency. The phase loop measures and grooms the PPS phase offset
723 * and leaves it in a handy spot for the seconds overflow routine. The
724 * frequency loop averages successive PPS phase differences and
725 * calculates the PPS frequency offset, which is also processed by the
726 * seconds overflow routine. The code requires the caller to capture the
727 * time and architecture-dependent hardware counter values in
728 * nanoseconds at the on-time PPS signal transition.
729 *
730 * Note that, on some Unix systems this routine runs at an interrupt
731 * priority level higher than the timer interrupt routine hardclock().
732 * Therefore, the variables used are distinct from the hardclock()
733 * variables, except for the actual time and frequency variables, which
734 * are determined by this routine and updated atomically.
735 */
736void
737hardpps(tsp, nsec)
738 struct timespec *tsp; /* time at PPS */
739 long nsec; /* hardware counter at PPS */
740{
741 long u_sec, u_nsec, v_nsec; /* temps */
742 l_fp ftemp;
743
744 /*
745 * The signal is first processed by a range gate and frequency
746 * discriminator. The range gate rejects noise spikes outside
747 * the range +-500 us. The frequency discriminator rejects input
748 * signals with apparent frequency outside the range 1 +-500
749 * PPM. If two hits occur in the same second, we ignore the
750 * later hit; if not and a hit occurs outside the range gate,
751 * keep the later hit for later comparison, but do not process
752 * it.
753 */
754 time_status |= STA_PPSSIGNAL | STA_PPSJITTER;
755 time_status &= ~(STA_PPSWANDER | STA_PPSERROR);
756 pps_valid = PPS_VALID;
757 u_sec = tsp->tv_sec;
758 u_nsec = tsp->tv_nsec;
759 if (u_nsec >= (NANOSECOND >> 1)) {
760 u_nsec -= NANOSECOND;
761 u_sec++;
762 }
763 v_nsec = u_nsec - pps_tf[0].tv_nsec;
764 if (u_sec == pps_tf[0].tv_sec && v_nsec < NANOSECOND -
765 MAXFREQ)
766 return;
767 pps_tf[2] = pps_tf[1];
768 pps_tf[1] = pps_tf[0];
769 pps_tf[0].tv_sec = u_sec;
770 pps_tf[0].tv_nsec = u_nsec;
771
772 /*
773 * Compute the difference between the current and previous
774 * counter values. If the difference exceeds 0.5 s, assume it
775 * has wrapped around, so correct 1.0 s. If the result exceeds
776 * the tick interval, the sample point has crossed a tick
777 * boundary during the last second, so correct the tick. Very
778 * intricate.
779 */
780 u_nsec = nsec;
781 if (u_nsec > (NANOSECOND >> 1))
782 u_nsec -= NANOSECOND;
783 else if (u_nsec < -(NANOSECOND >> 1))
784 u_nsec += NANOSECOND;
785 pps_fcount += u_nsec;
786 if (v_nsec > MAXFREQ || v_nsec < -MAXFREQ)
787 return;
788 time_status &= ~STA_PPSJITTER;
789
790 /*
791 * A three-stage median filter is used to help denoise the PPS
792 * time. The median sample becomes the time offset estimate; the
793 * difference between the other two samples becomes the time
794 * dispersion (jitter) estimate.
795 */
796 if (pps_tf[0].tv_nsec > pps_tf[1].tv_nsec) {
797 if (pps_tf[1].tv_nsec > pps_tf[2].tv_nsec) {
798 v_nsec = pps_tf[1].tv_nsec; /* 0 1 2 */
799 u_nsec = pps_tf[0].tv_nsec - pps_tf[2].tv_nsec;
800 } else if (pps_tf[2].tv_nsec > pps_tf[0].tv_nsec) {
801 v_nsec = pps_tf[0].tv_nsec; /* 2 0 1 */
802 u_nsec = pps_tf[2].tv_nsec - pps_tf[1].tv_nsec;
803 } else {
804 v_nsec = pps_tf[2].tv_nsec; /* 0 2 1 */
805 u_nsec = pps_tf[0].tv_nsec - pps_tf[1].tv_nsec;
806 }
807 } else {
808 if (pps_tf[1].tv_nsec < pps_tf[2].tv_nsec) {
809 v_nsec = pps_tf[1].tv_nsec; /* 2 1 0 */
810 u_nsec = pps_tf[2].tv_nsec - pps_tf[0].tv_nsec;
811 } else if (pps_tf[2].tv_nsec < pps_tf[0].tv_nsec) {
812 v_nsec = pps_tf[0].tv_nsec; /* 1 0 2 */
813 u_nsec = pps_tf[1].tv_nsec - pps_tf[2].tv_nsec;
814 } else {
815 v_nsec = pps_tf[2].tv_nsec; /* 1 2 0 */
816 u_nsec = pps_tf[1].tv_nsec - pps_tf[0].tv_nsec;
817 }
818 }
819
820 /*
821 * Nominal jitter is due to PPS signal noise and interrupt
822 * latency. If it exceeds the popcorn threshold, the sample is
823 * discarded. otherwise, if so enabled, the time offset is
824 * updated. We can tolerate a modest loss of data here without
825 * much degrading time accuracy.
826 */
827 if (u_nsec > (pps_jitter << PPS_POPCORN)) {
828 time_status |= STA_PPSJITTER;
829 pps_jitcnt++;
830 } else if (time_status & STA_PPSTIME) {
831 time_monitor = -v_nsec;
832 L_LINT(time_offset, time_monitor);
833 }
834 pps_jitter += (u_nsec - pps_jitter) >> PPS_FAVG;
835 u_sec = pps_tf[0].tv_sec - pps_lastsec;
836 if (u_sec < (1 << pps_shift))
837 return;
838
839 /*
840 * At the end of the calibration interval the difference between
841 * the first and last counter values becomes the scaled
842 * frequency. It will later be divided by the length of the
843 * interval to determine the frequency update. If the frequency
844 * exceeds a sanity threshold, or if the actual calibration
845 * interval is not equal to the expected length, the data are
846 * discarded. We can tolerate a modest loss of data here without
847 * much degrading frequency accuracy.
848 */
849 pps_calcnt++;
850 v_nsec = -pps_fcount;
851 pps_lastsec = pps_tf[0].tv_sec;
852 pps_fcount = 0;
853 u_nsec = MAXFREQ << pps_shift;
854 if (v_nsec > u_nsec || v_nsec < -u_nsec || u_sec != (1 <<
855 pps_shift)) {
856 time_status |= STA_PPSERROR;
857 pps_errcnt++;
858 return;
859 }
860
861 /*
862 * Here the raw frequency offset and wander (stability) is
863 * calculated. If the wander is less than the wander threshold
864 * for four consecutive averaging intervals, the interval is
865 * doubled; if it is greater than the threshold for four
866 * consecutive intervals, the interval is halved. The scaled
867 * frequency offset is converted to frequency offset. The
868 * stability metric is calculated as the average of recent
869 * frequency changes, but is used only for performance
870 * monitoring.
871 */
872 L_LINT(ftemp, v_nsec);
873 L_RSHIFT(ftemp, pps_shift);
874 L_SUB(ftemp, pps_freq);
875 u_nsec = L_GINT(ftemp);
876 if (u_nsec > PPS_MAXWANDER) {
877 L_LINT(ftemp, PPS_MAXWANDER);
878 pps_intcnt--;
879 time_status |= STA_PPSWANDER;
880 pps_stbcnt++;
881 } else if (u_nsec < -PPS_MAXWANDER) {
882 L_LINT(ftemp, -PPS_MAXWANDER);
883 pps_intcnt--;
884 time_status |= STA_PPSWANDER;
885 pps_stbcnt++;
886 } else {
887 pps_intcnt++;
888 }
889 if (pps_intcnt >= 4) {
890 pps_intcnt = 4;
891 if (pps_shift < pps_shiftmax) {
892 pps_shift++;
893 pps_intcnt = 0;
894 }
895 } else if (pps_intcnt <= -4 || pps_shift > pps_shiftmax) {
896 pps_intcnt = -4;
897 if (pps_shift > PPS_FAVG) {
898 pps_shift--;
899 pps_intcnt = 0;
900 }
901 }
902 if (u_nsec < 0)
903 u_nsec = -u_nsec;
904 pps_stabil += (u_nsec * SCALE_PPM - pps_stabil) >> PPS_FAVG;
905
906 /*
907 * The PPS frequency is recalculated and clamped to the maximum
908 * MAXFREQ. If enabled, the system clock frequency is updated as
909 * well.
910 */
911 L_ADD(pps_freq, ftemp);
912 u_nsec = L_GINT(pps_freq);
913 if (u_nsec > MAXFREQ)
914 L_LINT(pps_freq, MAXFREQ);
915 else if (u_nsec < -MAXFREQ)
916 L_LINT(pps_freq, -MAXFREQ);
917 if (time_status & STA_PPSFREQ)
918 time_freq = pps_freq;
919}
920#endif /* PPS_SYNC */
921
922#ifndef _SYS_SYSPROTO_H_
923struct adjtime_args {
924 struct timeval *delta;
925 struct timeval *olddelta;
926};
927#endif
928/* ARGSUSED */
929int
930adjtime(struct thread *td, struct adjtime_args *uap)
931{
932 struct timeval delta, olddelta, *deltap;
933 int error;
934
935 if (uap->delta) {
936 error = copyin(uap->delta, &delta, sizeof(delta));
937 if (error)
938 return (error);
939 deltap = δ
940 } else
941 deltap = NULL;
942 error = kern_adjtime(td, deltap, &olddelta);
943 if (uap->olddelta && error == 0)
944 error = copyout(&olddelta, uap->olddelta, sizeof(olddelta));
945 return (error);
946}
947
948int
949kern_adjtime(struct thread *td, struct timeval *delta, struct timeval *olddelta)
950{
951 struct timeval atv;
952 int error;
953
954 mtx_lock(&Giant);
955 if (olddelta) {
956 atv.tv_sec = time_adjtime / 1000000;
957 atv.tv_usec = time_adjtime % 1000000;
958 if (atv.tv_usec < 0) {
959 atv.tv_usec += 1000000;
960 atv.tv_sec--;
961 }
962 *olddelta = atv;
963 }
964 if (delta) {
965 if ((error = priv_check(td, PRIV_ADJTIME))) {
966 mtx_unlock(&Giant);
967 return (error);
968 }
969 time_adjtime = (int64_t)delta->tv_sec * 1000000 +
970 delta->tv_usec;
971 }
972 mtx_unlock(&Giant);
973 return (0);
974}
975
976static struct callout resettodr_callout;
977static int resettodr_period = 1800;
978
979static void
980periodic_resettodr(void *arg __unused)
981{
982
983 if (!ntp_is_time_error()) {
984 mtx_lock(&Giant);
985 resettodr();
986 mtx_unlock(&Giant);
987 }
988 if (resettodr_period > 0)
989 callout_schedule(&resettodr_callout, resettodr_period * hz);
990}
991
992static void
993shutdown_resettodr(void *arg __unused, int howto __unused)
994{
995
996 callout_drain(&resettodr_callout);
997 if (resettodr_period > 0 && !ntp_is_time_error()) {
998 mtx_lock(&Giant);
999 resettodr();
1000 mtx_unlock(&Giant);
1001 }
1002}
1003
1004static int
1005sysctl_resettodr_period(SYSCTL_HANDLER_ARGS)
1006{
1007 int error;
1008
1009 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1010 if (error || !req->newptr)
1011 return (error);
1012 if (resettodr_period == 0)
1013 callout_stop(&resettodr_callout);
1014 else
1015 callout_reset(&resettodr_callout, resettodr_period * hz,
1016 periodic_resettodr, NULL);
1017 return (0);
1018}
1019
1020SYSCTL_PROC(_machdep, OID_AUTO, rtc_save_period, CTLTYPE_INT|CTLFLAG_RW,
1021 &resettodr_period, 1800, sysctl_resettodr_period, "I",
1022 "Save system time to RTC with this period (in seconds)");
1023TUNABLE_INT("machdep.rtc_save_period", &resettodr_period);
1024
1025static void
1026start_periodic_resettodr(void *arg __unused)
1027{
1028
1029 EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_resettodr, NULL,
1030 SHUTDOWN_PRI_FIRST);
1031 callout_init(&resettodr_callout, 1);
1032 if (resettodr_period == 0)
1033 return;
1034 callout_reset(&resettodr_callout, resettodr_period * hz,
1035 periodic_resettodr, NULL);
1036}
1037
| 35
36#include "opt_ntp.h"
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/sysproto.h>
41#include <sys/eventhandler.h>
42#include <sys/kernel.h>
43#include <sys/priv.h>
44#include <sys/proc.h>
45#include <sys/lock.h>
46#include <sys/mutex.h>
47#include <sys/time.h>
48#include <sys/timex.h>
49#include <sys/timetc.h>
50#include <sys/timepps.h>
51#include <sys/syscallsubr.h>
52#include <sys/sysctl.h>
53
54/*
55 * Single-precision macros for 64-bit machines
56 */
57typedef int64_t l_fp;
58#define L_ADD(v, u) ((v) += (u))
59#define L_SUB(v, u) ((v) -= (u))
60#define L_ADDHI(v, a) ((v) += (int64_t)(a) << 32)
61#define L_NEG(v) ((v) = -(v))
62#define L_RSHIFT(v, n) \
63 do { \
64 if ((v) < 0) \
65 (v) = -(-(v) >> (n)); \
66 else \
67 (v) = (v) >> (n); \
68 } while (0)
69#define L_MPY(v, a) ((v) *= (a))
70#define L_CLR(v) ((v) = 0)
71#define L_ISNEG(v) ((v) < 0)
72#define L_LINT(v, a) ((v) = (int64_t)(a) << 32)
73#define L_GINT(v) ((v) < 0 ? -(-(v) >> 32) : (v) >> 32)
74
75/*
76 * Generic NTP kernel interface
77 *
78 * These routines constitute the Network Time Protocol (NTP) interfaces
79 * for user and daemon application programs. The ntp_gettime() routine
80 * provides the time, maximum error (synch distance) and estimated error
81 * (dispersion) to client user application programs. The ntp_adjtime()
82 * routine is used by the NTP daemon to adjust the system clock to an
83 * externally derived time. The time offset and related variables set by
84 * this routine are used by other routines in this module to adjust the
85 * phase and frequency of the clock discipline loop which controls the
86 * system clock.
87 *
88 * When the kernel time is reckoned directly in nanoseconds (NTP_NANO
89 * defined), the time at each tick interrupt is derived directly from
90 * the kernel time variable. When the kernel time is reckoned in
91 * microseconds, (NTP_NANO undefined), the time is derived from the
92 * kernel time variable together with a variable representing the
93 * leftover nanoseconds at the last tick interrupt. In either case, the
94 * current nanosecond time is reckoned from these values plus an
95 * interpolated value derived by the clock routines in another
96 * architecture-specific module. The interpolation can use either a
97 * dedicated counter or a processor cycle counter (PCC) implemented in
98 * some architectures.
99 *
100 * Note that all routines must run at priority splclock or higher.
101 */
102/*
103 * Phase/frequency-lock loop (PLL/FLL) definitions
104 *
105 * The nanosecond clock discipline uses two variable types, time
106 * variables and frequency variables. Both types are represented as 64-
107 * bit fixed-point quantities with the decimal point between two 32-bit
108 * halves. On a 32-bit machine, each half is represented as a single
109 * word and mathematical operations are done using multiple-precision
110 * arithmetic. On a 64-bit machine, ordinary computer arithmetic is
111 * used.
112 *
113 * A time variable is a signed 64-bit fixed-point number in ns and
114 * fraction. It represents the remaining time offset to be amortized
115 * over succeeding tick interrupts. The maximum time offset is about
116 * 0.5 s and the resolution is about 2.3e-10 ns.
117 *
118 * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
119 * 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
120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121 * |s s s| ns |
122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123 * | fraction |
124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
125 *
126 * A frequency variable is a signed 64-bit fixed-point number in ns/s
127 * and fraction. It represents the ns and fraction to be added to the
128 * kernel time variable at each second. The maximum frequency offset is
129 * about +-500000 ns/s and the resolution is about 2.3e-10 ns/s.
130 *
131 * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
132 * 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
133 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
134 * |s s s s s s s s s s s s s| ns/s |
135 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
136 * | fraction |
137 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
138 */
139/*
140 * The following variables establish the state of the PLL/FLL and the
141 * residual time and frequency offset of the local clock.
142 */
143#define SHIFT_PLL 4 /* PLL loop gain (shift) */
144#define SHIFT_FLL 2 /* FLL loop gain (shift) */
145
146static int time_state = TIME_OK; /* clock state */
147static int time_status = STA_UNSYNC; /* clock status bits */
148static long time_tai; /* TAI offset (s) */
149static long time_monitor; /* last time offset scaled (ns) */
150static long time_constant; /* poll interval (shift) (s) */
151static long time_precision = 1; /* clock precision (ns) */
152static long time_maxerror = MAXPHASE / 1000; /* maximum error (us) */
153static long time_esterror = MAXPHASE / 1000; /* estimated error (us) */
154static long time_reftime; /* time at last adjustment (s) */
155static l_fp time_offset; /* time offset (ns) */
156static l_fp time_freq; /* frequency offset (ns/s) */
157static l_fp time_adj; /* tick adjust (ns/s) */
158
159static int64_t time_adjtime; /* correction from adjtime(2) (usec) */
160
161#ifdef PPS_SYNC
162/*
163 * The following variables are used when a pulse-per-second (PPS) signal
164 * is available and connected via a modem control lead. They establish
165 * the engineering parameters of the clock discipline loop when
166 * controlled by the PPS signal.
167 */
168#define PPS_FAVG 2 /* min freq avg interval (s) (shift) */
169#define PPS_FAVGDEF 8 /* default freq avg int (s) (shift) */
170#define PPS_FAVGMAX 15 /* max freq avg interval (s) (shift) */
171#define PPS_PAVG 4 /* phase avg interval (s) (shift) */
172#define PPS_VALID 120 /* PPS signal watchdog max (s) */
173#define PPS_MAXWANDER 100000 /* max PPS wander (ns/s) */
174#define PPS_POPCORN 2 /* popcorn spike threshold (shift) */
175
176static struct timespec pps_tf[3]; /* phase median filter */
177static l_fp pps_freq; /* scaled frequency offset (ns/s) */
178static long pps_fcount; /* frequency accumulator */
179static long pps_jitter; /* nominal jitter (ns) */
180static long pps_stabil; /* nominal stability (scaled ns/s) */
181static long pps_lastsec; /* time at last calibration (s) */
182static int pps_valid; /* signal watchdog counter */
183static int pps_shift = PPS_FAVG; /* interval duration (s) (shift) */
184static int pps_shiftmax = PPS_FAVGDEF; /* max interval duration (s) (shift) */
185static int pps_intcnt; /* wander counter */
186
187/*
188 * PPS signal quality monitors
189 */
190static long pps_calcnt; /* calibration intervals */
191static long pps_jitcnt; /* jitter limit exceeded */
192static long pps_stbcnt; /* stability limit exceeded */
193static long pps_errcnt; /* calibration errors */
194#endif /* PPS_SYNC */
195/*
196 * End of phase/frequency-lock loop (PLL/FLL) definitions
197 */
198
199static void ntp_init(void);
200static void hardupdate(long offset);
201static void ntp_gettime1(struct ntptimeval *ntvp);
202static int ntp_is_time_error(void);
203
204static int
205ntp_is_time_error(void)
206{
207 /*
208 * Status word error decode. If any of these conditions occur,
209 * an error is returned, instead of the status word. Most
210 * applications will care only about the fact the system clock
211 * may not be trusted, not about the details.
212 *
213 * Hardware or software error
214 */
215 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) ||
216
217 /*
218 * PPS signal lost when either time or frequency synchronization
219 * requested
220 */
221 (time_status & (STA_PPSFREQ | STA_PPSTIME) &&
222 !(time_status & STA_PPSSIGNAL)) ||
223
224 /*
225 * PPS jitter exceeded when time synchronization requested
226 */
227 (time_status & STA_PPSTIME &&
228 time_status & STA_PPSJITTER) ||
229
230 /*
231 * PPS wander exceeded or calibration error when frequency
232 * synchronization requested
233 */
234 (time_status & STA_PPSFREQ &&
235 time_status & (STA_PPSWANDER | STA_PPSERROR)))
236 return (1);
237
238 return (0);
239}
240
241static void
242ntp_gettime1(struct ntptimeval *ntvp)
243{
244 struct timespec atv; /* nanosecond time */
245
246 GIANT_REQUIRED;
247
248 nanotime(&atv);
249 ntvp->time.tv_sec = atv.tv_sec;
250 ntvp->time.tv_nsec = atv.tv_nsec;
251 ntvp->maxerror = time_maxerror;
252 ntvp->esterror = time_esterror;
253 ntvp->tai = time_tai;
254 ntvp->time_state = time_state;
255
256 if (ntp_is_time_error())
257 ntvp->time_state = TIME_ERROR;
258}
259
260/*
261 * ntp_gettime() - NTP user application interface
262 *
263 * See the timex.h header file for synopsis and API description. Note that
264 * the TAI offset is returned in the ntvtimeval.tai structure member.
265 */
266#ifndef _SYS_SYSPROTO_H_
267struct ntp_gettime_args {
268 struct ntptimeval *ntvp;
269};
270#endif
271/* ARGSUSED */
272int
273ntp_gettime(struct thread *td, struct ntp_gettime_args *uap)
274{
275 struct ntptimeval ntv;
276
277 mtx_lock(&Giant);
278 ntp_gettime1(&ntv);
279 mtx_unlock(&Giant);
280
281 td->td_retval[0] = ntv.time_state;
282 return (copyout(&ntv, uap->ntvp, sizeof(ntv)));
283}
284
285static int
286ntp_sysctl(SYSCTL_HANDLER_ARGS)
287{
288 struct ntptimeval ntv; /* temporary structure */
289
290 ntp_gettime1(&ntv);
291
292 return (sysctl_handle_opaque(oidp, &ntv, sizeof(ntv), req));
293}
294
295SYSCTL_NODE(_kern, OID_AUTO, ntp_pll, CTLFLAG_RW, 0, "");
296SYSCTL_PROC(_kern_ntp_pll, OID_AUTO, gettime, CTLTYPE_OPAQUE|CTLFLAG_RD,
297 0, sizeof(struct ntptimeval) , ntp_sysctl, "S,ntptimeval", "");
298
299#ifdef PPS_SYNC
300SYSCTL_INT(_kern_ntp_pll, OID_AUTO, pps_shiftmax, CTLFLAG_RW, &pps_shiftmax, 0, "");
301SYSCTL_INT(_kern_ntp_pll, OID_AUTO, pps_shift, CTLFLAG_RW, &pps_shift, 0, "");
302SYSCTL_INT(_kern_ntp_pll, OID_AUTO, time_monitor, CTLFLAG_RD, &time_monitor, 0, "");
303
304SYSCTL_OPAQUE(_kern_ntp_pll, OID_AUTO, pps_freq, CTLFLAG_RD, &pps_freq, sizeof(pps_freq), "I", "");
305SYSCTL_OPAQUE(_kern_ntp_pll, OID_AUTO, time_freq, CTLFLAG_RD, &time_freq, sizeof(time_freq), "I", "");
306#endif
307
308/*
309 * ntp_adjtime() - NTP daemon application interface
310 *
311 * See the timex.h header file for synopsis and API description. Note that
312 * the timex.constant structure member has a dual purpose to set the time
313 * constant and to set the TAI offset.
314 */
315#ifndef _SYS_SYSPROTO_H_
316struct ntp_adjtime_args {
317 struct timex *tp;
318};
319#endif
320
321int
322ntp_adjtime(struct thread *td, struct ntp_adjtime_args *uap)
323{
324 struct timex ntv; /* temporary structure */
325 long freq; /* frequency ns/s) */
326 int modes; /* mode bits from structure */
327 int s; /* caller priority */
328 int error;
329
330 error = copyin((caddr_t)uap->tp, (caddr_t)&ntv, sizeof(ntv));
331 if (error)
332 return(error);
333
334 /*
335 * Update selected clock variables - only the superuser can
336 * change anything. Note that there is no error checking here on
337 * the assumption the superuser should know what it is doing.
338 * Note that either the time constant or TAI offset are loaded
339 * from the ntv.constant member, depending on the mode bits. If
340 * the STA_PLL bit in the status word is cleared, the state and
341 * status words are reset to the initial values at boot.
342 */
343 mtx_lock(&Giant);
344 modes = ntv.modes;
345 if (modes)
346 error = priv_check(td, PRIV_NTP_ADJTIME);
347 if (error)
348 goto done2;
349 s = splclock();
350 if (modes & MOD_MAXERROR)
351 time_maxerror = ntv.maxerror;
352 if (modes & MOD_ESTERROR)
353 time_esterror = ntv.esterror;
354 if (modes & MOD_STATUS) {
355 if (time_status & STA_PLL && !(ntv.status & STA_PLL)) {
356 time_state = TIME_OK;
357 time_status = STA_UNSYNC;
358#ifdef PPS_SYNC
359 pps_shift = PPS_FAVG;
360#endif /* PPS_SYNC */
361 }
362 time_status &= STA_RONLY;
363 time_status |= ntv.status & ~STA_RONLY;
364 }
365 if (modes & MOD_TIMECONST) {
366 if (ntv.constant < 0)
367 time_constant = 0;
368 else if (ntv.constant > MAXTC)
369 time_constant = MAXTC;
370 else
371 time_constant = ntv.constant;
372 }
373 if (modes & MOD_TAI) {
374 if (ntv.constant > 0) /* XXX zero & negative numbers ? */
375 time_tai = ntv.constant;
376 }
377#ifdef PPS_SYNC
378 if (modes & MOD_PPSMAX) {
379 if (ntv.shift < PPS_FAVG)
380 pps_shiftmax = PPS_FAVG;
381 else if (ntv.shift > PPS_FAVGMAX)
382 pps_shiftmax = PPS_FAVGMAX;
383 else
384 pps_shiftmax = ntv.shift;
385 }
386#endif /* PPS_SYNC */
387 if (modes & MOD_NANO)
388 time_status |= STA_NANO;
389 if (modes & MOD_MICRO)
390 time_status &= ~STA_NANO;
391 if (modes & MOD_CLKB)
392 time_status |= STA_CLK;
393 if (modes & MOD_CLKA)
394 time_status &= ~STA_CLK;
395 if (modes & MOD_FREQUENCY) {
396 freq = (ntv.freq * 1000LL) >> 16;
397 if (freq > MAXFREQ)
398 L_LINT(time_freq, MAXFREQ);
399 else if (freq < -MAXFREQ)
400 L_LINT(time_freq, -MAXFREQ);
401 else {
402 /*
403 * ntv.freq is [PPM * 2^16] = [us/s * 2^16]
404 * time_freq is [ns/s * 2^32]
405 */
406 time_freq = ntv.freq * 1000LL * 65536LL;
407 }
408#ifdef PPS_SYNC
409 pps_freq = time_freq;
410#endif /* PPS_SYNC */
411 }
412 if (modes & MOD_OFFSET) {
413 if (time_status & STA_NANO)
414 hardupdate(ntv.offset);
415 else
416 hardupdate(ntv.offset * 1000);
417 }
418
419 /*
420 * Retrieve all clock variables. Note that the TAI offset is
421 * returned only by ntp_gettime();
422 */
423 if (time_status & STA_NANO)
424 ntv.offset = L_GINT(time_offset);
425 else
426 ntv.offset = L_GINT(time_offset) / 1000; /* XXX rounding ? */
427 ntv.freq = L_GINT((time_freq / 1000LL) << 16);
428 ntv.maxerror = time_maxerror;
429 ntv.esterror = time_esterror;
430 ntv.status = time_status;
431 ntv.constant = time_constant;
432 if (time_status & STA_NANO)
433 ntv.precision = time_precision;
434 else
435 ntv.precision = time_precision / 1000;
436 ntv.tolerance = MAXFREQ * SCALE_PPM;
437#ifdef PPS_SYNC
438 ntv.shift = pps_shift;
439 ntv.ppsfreq = L_GINT((pps_freq / 1000LL) << 16);
440 if (time_status & STA_NANO)
441 ntv.jitter = pps_jitter;
442 else
443 ntv.jitter = pps_jitter / 1000;
444 ntv.stabil = pps_stabil;
445 ntv.calcnt = pps_calcnt;
446 ntv.errcnt = pps_errcnt;
447 ntv.jitcnt = pps_jitcnt;
448 ntv.stbcnt = pps_stbcnt;
449#endif /* PPS_SYNC */
450 splx(s);
451
452 error = copyout((caddr_t)&ntv, (caddr_t)uap->tp, sizeof(ntv));
453 if (error)
454 goto done2;
455
456 if (ntp_is_time_error())
457 td->td_retval[0] = TIME_ERROR;
458 else
459 td->td_retval[0] = time_state;
460
461done2:
462 mtx_unlock(&Giant);
463 return (error);
464}
465
466/*
467 * second_overflow() - called after ntp_tick_adjust()
468 *
469 * This routine is ordinarily called immediately following the above
470 * routine ntp_tick_adjust(). While these two routines are normally
471 * combined, they are separated here only for the purposes of
472 * simulation.
473 */
474void
475ntp_update_second(int64_t *adjustment, time_t *newsec)
476{
477 int tickrate;
478 l_fp ftemp; /* 32/64-bit temporary */
479
480 /*
481 * On rollover of the second both the nanosecond and microsecond
482 * clocks are updated and the state machine cranked as
483 * necessary. The phase adjustment to be used for the next
484 * second is calculated and the maximum error is increased by
485 * the tolerance.
486 */
487 time_maxerror += MAXFREQ / 1000;
488
489 /*
490 * Leap second processing. If in leap-insert state at
491 * the end of the day, the system clock is set back one
492 * second; if in leap-delete state, the system clock is
493 * set ahead one second. The nano_time() routine or
494 * external clock driver will insure that reported time
495 * is always monotonic.
496 */
497 switch (time_state) {
498
499 /*
500 * No warning.
501 */
502 case TIME_OK:
503 if (time_status & STA_INS)
504 time_state = TIME_INS;
505 else if (time_status & STA_DEL)
506 time_state = TIME_DEL;
507 break;
508
509 /*
510 * Insert second 23:59:60 following second
511 * 23:59:59.
512 */
513 case TIME_INS:
514 if (!(time_status & STA_INS))
515 time_state = TIME_OK;
516 else if ((*newsec) % 86400 == 0) {
517 (*newsec)--;
518 time_state = TIME_OOP;
519 time_tai++;
520 }
521 break;
522
523 /*
524 * Delete second 23:59:59.
525 */
526 case TIME_DEL:
527 if (!(time_status & STA_DEL))
528 time_state = TIME_OK;
529 else if (((*newsec) + 1) % 86400 == 0) {
530 (*newsec)++;
531 time_tai--;
532 time_state = TIME_WAIT;
533 }
534 break;
535
536 /*
537 * Insert second in progress.
538 */
539 case TIME_OOP:
540 time_state = TIME_WAIT;
541 break;
542
543 /*
544 * Wait for status bits to clear.
545 */
546 case TIME_WAIT:
547 if (!(time_status & (STA_INS | STA_DEL)))
548 time_state = TIME_OK;
549 }
550
551 /*
552 * Compute the total time adjustment for the next second
553 * in ns. The offset is reduced by a factor depending on
554 * whether the PPS signal is operating. Note that the
555 * value is in effect scaled by the clock frequency,
556 * since the adjustment is added at each tick interrupt.
557 */
558 ftemp = time_offset;
559#ifdef PPS_SYNC
560 /* XXX even if PPS signal dies we should finish adjustment ? */
561 if (time_status & STA_PPSTIME && time_status &
562 STA_PPSSIGNAL)
563 L_RSHIFT(ftemp, pps_shift);
564 else
565 L_RSHIFT(ftemp, SHIFT_PLL + time_constant);
566#else
567 L_RSHIFT(ftemp, SHIFT_PLL + time_constant);
568#endif /* PPS_SYNC */
569 time_adj = ftemp;
570 L_SUB(time_offset, ftemp);
571 L_ADD(time_adj, time_freq);
572
573 /*
574 * Apply any correction from adjtime(2). If more than one second
575 * off we slew at a rate of 5ms/s (5000 PPM) else 500us/s (500PPM)
576 * until the last second is slewed the final < 500 usecs.
577 */
578 if (time_adjtime != 0) {
579 if (time_adjtime > 1000000)
580 tickrate = 5000;
581 else if (time_adjtime < -1000000)
582 tickrate = -5000;
583 else if (time_adjtime > 500)
584 tickrate = 500;
585 else if (time_adjtime < -500)
586 tickrate = -500;
587 else
588 tickrate = time_adjtime;
589 time_adjtime -= tickrate;
590 L_LINT(ftemp, tickrate * 1000);
591 L_ADD(time_adj, ftemp);
592 }
593 *adjustment = time_adj;
594
595#ifdef PPS_SYNC
596 if (pps_valid > 0)
597 pps_valid--;
598 else
599 time_status &= ~STA_PPSSIGNAL;
600#endif /* PPS_SYNC */
601}
602
603/*
604 * ntp_init() - initialize variables and structures
605 *
606 * This routine must be called after the kernel variables hz and tick
607 * are set or changed and before the next tick interrupt. In this
608 * particular implementation, these values are assumed set elsewhere in
609 * the kernel. The design allows the clock frequency and tick interval
610 * to be changed while the system is running. So, this routine should
611 * probably be integrated with the code that does that.
612 */
613static void
614ntp_init()
615{
616
617 /*
618 * The following variables are initialized only at startup. Only
619 * those structures not cleared by the compiler need to be
620 * initialized, and these only in the simulator. In the actual
621 * kernel, any nonzero values here will quickly evaporate.
622 */
623 L_CLR(time_offset);
624 L_CLR(time_freq);
625#ifdef PPS_SYNC
626 pps_tf[0].tv_sec = pps_tf[0].tv_nsec = 0;
627 pps_tf[1].tv_sec = pps_tf[1].tv_nsec = 0;
628 pps_tf[2].tv_sec = pps_tf[2].tv_nsec = 0;
629 pps_fcount = 0;
630 L_CLR(pps_freq);
631#endif /* PPS_SYNC */
632}
633
634SYSINIT(ntpclocks, SI_SUB_CLOCKS, SI_ORDER_MIDDLE, ntp_init, NULL);
635
636/*
637 * hardupdate() - local clock update
638 *
639 * This routine is called by ntp_adjtime() to update the local clock
640 * phase and frequency. The implementation is of an adaptive-parameter,
641 * hybrid phase/frequency-lock loop (PLL/FLL). The routine computes new
642 * time and frequency offset estimates for each call. If the kernel PPS
643 * discipline code is configured (PPS_SYNC), the PPS signal itself
644 * determines the new time offset, instead of the calling argument.
645 * Presumably, calls to ntp_adjtime() occur only when the caller
646 * believes the local clock is valid within some bound (+-128 ms with
647 * NTP). If the caller's time is far different than the PPS time, an
648 * argument will ensue, and it's not clear who will lose.
649 *
650 * For uncompensated quartz crystal oscillators and nominal update
651 * intervals less than 256 s, operation should be in phase-lock mode,
652 * where the loop is disciplined to phase. For update intervals greater
653 * than 1024 s, operation should be in frequency-lock mode, where the
654 * loop is disciplined to frequency. Between 256 s and 1024 s, the mode
655 * is selected by the STA_MODE status bit.
656 */
657static void
658hardupdate(offset)
659 long offset; /* clock offset (ns) */
660{
661 long mtemp;
662 l_fp ftemp;
663
664 /*
665 * Select how the phase is to be controlled and from which
666 * source. If the PPS signal is present and enabled to
667 * discipline the time, the PPS offset is used; otherwise, the
668 * argument offset is used.
669 */
670 if (!(time_status & STA_PLL))
671 return;
672 if (!(time_status & STA_PPSTIME && time_status &
673 STA_PPSSIGNAL)) {
674 if (offset > MAXPHASE)
675 time_monitor = MAXPHASE;
676 else if (offset < -MAXPHASE)
677 time_monitor = -MAXPHASE;
678 else
679 time_monitor = offset;
680 L_LINT(time_offset, time_monitor);
681 }
682
683 /*
684 * Select how the frequency is to be controlled and in which
685 * mode (PLL or FLL). If the PPS signal is present and enabled
686 * to discipline the frequency, the PPS frequency is used;
687 * otherwise, the argument offset is used to compute it.
688 */
689 if (time_status & STA_PPSFREQ && time_status & STA_PPSSIGNAL) {
690 time_reftime = time_second;
691 return;
692 }
693 if (time_status & STA_FREQHOLD || time_reftime == 0)
694 time_reftime = time_second;
695 mtemp = time_second - time_reftime;
696 L_LINT(ftemp, time_monitor);
697 L_RSHIFT(ftemp, (SHIFT_PLL + 2 + time_constant) << 1);
698 L_MPY(ftemp, mtemp);
699 L_ADD(time_freq, ftemp);
700 time_status &= ~STA_MODE;
701 if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp >
702 MAXSEC)) {
703 L_LINT(ftemp, (time_monitor << 4) / mtemp);
704 L_RSHIFT(ftemp, SHIFT_FLL + 4);
705 L_ADD(time_freq, ftemp);
706 time_status |= STA_MODE;
707 }
708 time_reftime = time_second;
709 if (L_GINT(time_freq) > MAXFREQ)
710 L_LINT(time_freq, MAXFREQ);
711 else if (L_GINT(time_freq) < -MAXFREQ)
712 L_LINT(time_freq, -MAXFREQ);
713}
714
715#ifdef PPS_SYNC
716/*
717 * hardpps() - discipline CPU clock oscillator to external PPS signal
718 *
719 * This routine is called at each PPS interrupt in order to discipline
720 * the CPU clock oscillator to the PPS signal. There are two independent
721 * first-order feedback loops, one for the phase, the other for the
722 * frequency. The phase loop measures and grooms the PPS phase offset
723 * and leaves it in a handy spot for the seconds overflow routine. The
724 * frequency loop averages successive PPS phase differences and
725 * calculates the PPS frequency offset, which is also processed by the
726 * seconds overflow routine. The code requires the caller to capture the
727 * time and architecture-dependent hardware counter values in
728 * nanoseconds at the on-time PPS signal transition.
729 *
730 * Note that, on some Unix systems this routine runs at an interrupt
731 * priority level higher than the timer interrupt routine hardclock().
732 * Therefore, the variables used are distinct from the hardclock()
733 * variables, except for the actual time and frequency variables, which
734 * are determined by this routine and updated atomically.
735 */
736void
737hardpps(tsp, nsec)
738 struct timespec *tsp; /* time at PPS */
739 long nsec; /* hardware counter at PPS */
740{
741 long u_sec, u_nsec, v_nsec; /* temps */
742 l_fp ftemp;
743
744 /*
745 * The signal is first processed by a range gate and frequency
746 * discriminator. The range gate rejects noise spikes outside
747 * the range +-500 us. The frequency discriminator rejects input
748 * signals with apparent frequency outside the range 1 +-500
749 * PPM. If two hits occur in the same second, we ignore the
750 * later hit; if not and a hit occurs outside the range gate,
751 * keep the later hit for later comparison, but do not process
752 * it.
753 */
754 time_status |= STA_PPSSIGNAL | STA_PPSJITTER;
755 time_status &= ~(STA_PPSWANDER | STA_PPSERROR);
756 pps_valid = PPS_VALID;
757 u_sec = tsp->tv_sec;
758 u_nsec = tsp->tv_nsec;
759 if (u_nsec >= (NANOSECOND >> 1)) {
760 u_nsec -= NANOSECOND;
761 u_sec++;
762 }
763 v_nsec = u_nsec - pps_tf[0].tv_nsec;
764 if (u_sec == pps_tf[0].tv_sec && v_nsec < NANOSECOND -
765 MAXFREQ)
766 return;
767 pps_tf[2] = pps_tf[1];
768 pps_tf[1] = pps_tf[0];
769 pps_tf[0].tv_sec = u_sec;
770 pps_tf[0].tv_nsec = u_nsec;
771
772 /*
773 * Compute the difference between the current and previous
774 * counter values. If the difference exceeds 0.5 s, assume it
775 * has wrapped around, so correct 1.0 s. If the result exceeds
776 * the tick interval, the sample point has crossed a tick
777 * boundary during the last second, so correct the tick. Very
778 * intricate.
779 */
780 u_nsec = nsec;
781 if (u_nsec > (NANOSECOND >> 1))
782 u_nsec -= NANOSECOND;
783 else if (u_nsec < -(NANOSECOND >> 1))
784 u_nsec += NANOSECOND;
785 pps_fcount += u_nsec;
786 if (v_nsec > MAXFREQ || v_nsec < -MAXFREQ)
787 return;
788 time_status &= ~STA_PPSJITTER;
789
790 /*
791 * A three-stage median filter is used to help denoise the PPS
792 * time. The median sample becomes the time offset estimate; the
793 * difference between the other two samples becomes the time
794 * dispersion (jitter) estimate.
795 */
796 if (pps_tf[0].tv_nsec > pps_tf[1].tv_nsec) {
797 if (pps_tf[1].tv_nsec > pps_tf[2].tv_nsec) {
798 v_nsec = pps_tf[1].tv_nsec; /* 0 1 2 */
799 u_nsec = pps_tf[0].tv_nsec - pps_tf[2].tv_nsec;
800 } else if (pps_tf[2].tv_nsec > pps_tf[0].tv_nsec) {
801 v_nsec = pps_tf[0].tv_nsec; /* 2 0 1 */
802 u_nsec = pps_tf[2].tv_nsec - pps_tf[1].tv_nsec;
803 } else {
804 v_nsec = pps_tf[2].tv_nsec; /* 0 2 1 */
805 u_nsec = pps_tf[0].tv_nsec - pps_tf[1].tv_nsec;
806 }
807 } else {
808 if (pps_tf[1].tv_nsec < pps_tf[2].tv_nsec) {
809 v_nsec = pps_tf[1].tv_nsec; /* 2 1 0 */
810 u_nsec = pps_tf[2].tv_nsec - pps_tf[0].tv_nsec;
811 } else if (pps_tf[2].tv_nsec < pps_tf[0].tv_nsec) {
812 v_nsec = pps_tf[0].tv_nsec; /* 1 0 2 */
813 u_nsec = pps_tf[1].tv_nsec - pps_tf[2].tv_nsec;
814 } else {
815 v_nsec = pps_tf[2].tv_nsec; /* 1 2 0 */
816 u_nsec = pps_tf[1].tv_nsec - pps_tf[0].tv_nsec;
817 }
818 }
819
820 /*
821 * Nominal jitter is due to PPS signal noise and interrupt
822 * latency. If it exceeds the popcorn threshold, the sample is
823 * discarded. otherwise, if so enabled, the time offset is
824 * updated. We can tolerate a modest loss of data here without
825 * much degrading time accuracy.
826 */
827 if (u_nsec > (pps_jitter << PPS_POPCORN)) {
828 time_status |= STA_PPSJITTER;
829 pps_jitcnt++;
830 } else if (time_status & STA_PPSTIME) {
831 time_monitor = -v_nsec;
832 L_LINT(time_offset, time_monitor);
833 }
834 pps_jitter += (u_nsec - pps_jitter) >> PPS_FAVG;
835 u_sec = pps_tf[0].tv_sec - pps_lastsec;
836 if (u_sec < (1 << pps_shift))
837 return;
838
839 /*
840 * At the end of the calibration interval the difference between
841 * the first and last counter values becomes the scaled
842 * frequency. It will later be divided by the length of the
843 * interval to determine the frequency update. If the frequency
844 * exceeds a sanity threshold, or if the actual calibration
845 * interval is not equal to the expected length, the data are
846 * discarded. We can tolerate a modest loss of data here without
847 * much degrading frequency accuracy.
848 */
849 pps_calcnt++;
850 v_nsec = -pps_fcount;
851 pps_lastsec = pps_tf[0].tv_sec;
852 pps_fcount = 0;
853 u_nsec = MAXFREQ << pps_shift;
854 if (v_nsec > u_nsec || v_nsec < -u_nsec || u_sec != (1 <<
855 pps_shift)) {
856 time_status |= STA_PPSERROR;
857 pps_errcnt++;
858 return;
859 }
860
861 /*
862 * Here the raw frequency offset and wander (stability) is
863 * calculated. If the wander is less than the wander threshold
864 * for four consecutive averaging intervals, the interval is
865 * doubled; if it is greater than the threshold for four
866 * consecutive intervals, the interval is halved. The scaled
867 * frequency offset is converted to frequency offset. The
868 * stability metric is calculated as the average of recent
869 * frequency changes, but is used only for performance
870 * monitoring.
871 */
872 L_LINT(ftemp, v_nsec);
873 L_RSHIFT(ftemp, pps_shift);
874 L_SUB(ftemp, pps_freq);
875 u_nsec = L_GINT(ftemp);
876 if (u_nsec > PPS_MAXWANDER) {
877 L_LINT(ftemp, PPS_MAXWANDER);
878 pps_intcnt--;
879 time_status |= STA_PPSWANDER;
880 pps_stbcnt++;
881 } else if (u_nsec < -PPS_MAXWANDER) {
882 L_LINT(ftemp, -PPS_MAXWANDER);
883 pps_intcnt--;
884 time_status |= STA_PPSWANDER;
885 pps_stbcnt++;
886 } else {
887 pps_intcnt++;
888 }
889 if (pps_intcnt >= 4) {
890 pps_intcnt = 4;
891 if (pps_shift < pps_shiftmax) {
892 pps_shift++;
893 pps_intcnt = 0;
894 }
895 } else if (pps_intcnt <= -4 || pps_shift > pps_shiftmax) {
896 pps_intcnt = -4;
897 if (pps_shift > PPS_FAVG) {
898 pps_shift--;
899 pps_intcnt = 0;
900 }
901 }
902 if (u_nsec < 0)
903 u_nsec = -u_nsec;
904 pps_stabil += (u_nsec * SCALE_PPM - pps_stabil) >> PPS_FAVG;
905
906 /*
907 * The PPS frequency is recalculated and clamped to the maximum
908 * MAXFREQ. If enabled, the system clock frequency is updated as
909 * well.
910 */
911 L_ADD(pps_freq, ftemp);
912 u_nsec = L_GINT(pps_freq);
913 if (u_nsec > MAXFREQ)
914 L_LINT(pps_freq, MAXFREQ);
915 else if (u_nsec < -MAXFREQ)
916 L_LINT(pps_freq, -MAXFREQ);
917 if (time_status & STA_PPSFREQ)
918 time_freq = pps_freq;
919}
920#endif /* PPS_SYNC */
921
922#ifndef _SYS_SYSPROTO_H_
923struct adjtime_args {
924 struct timeval *delta;
925 struct timeval *olddelta;
926};
927#endif
928/* ARGSUSED */
929int
930adjtime(struct thread *td, struct adjtime_args *uap)
931{
932 struct timeval delta, olddelta, *deltap;
933 int error;
934
935 if (uap->delta) {
936 error = copyin(uap->delta, &delta, sizeof(delta));
937 if (error)
938 return (error);
939 deltap = δ
940 } else
941 deltap = NULL;
942 error = kern_adjtime(td, deltap, &olddelta);
943 if (uap->olddelta && error == 0)
944 error = copyout(&olddelta, uap->olddelta, sizeof(olddelta));
945 return (error);
946}
947
948int
949kern_adjtime(struct thread *td, struct timeval *delta, struct timeval *olddelta)
950{
951 struct timeval atv;
952 int error;
953
954 mtx_lock(&Giant);
955 if (olddelta) {
956 atv.tv_sec = time_adjtime / 1000000;
957 atv.tv_usec = time_adjtime % 1000000;
958 if (atv.tv_usec < 0) {
959 atv.tv_usec += 1000000;
960 atv.tv_sec--;
961 }
962 *olddelta = atv;
963 }
964 if (delta) {
965 if ((error = priv_check(td, PRIV_ADJTIME))) {
966 mtx_unlock(&Giant);
967 return (error);
968 }
969 time_adjtime = (int64_t)delta->tv_sec * 1000000 +
970 delta->tv_usec;
971 }
972 mtx_unlock(&Giant);
973 return (0);
974}
975
976static struct callout resettodr_callout;
977static int resettodr_period = 1800;
978
979static void
980periodic_resettodr(void *arg __unused)
981{
982
983 if (!ntp_is_time_error()) {
984 mtx_lock(&Giant);
985 resettodr();
986 mtx_unlock(&Giant);
987 }
988 if (resettodr_period > 0)
989 callout_schedule(&resettodr_callout, resettodr_period * hz);
990}
991
992static void
993shutdown_resettodr(void *arg __unused, int howto __unused)
994{
995
996 callout_drain(&resettodr_callout);
997 if (resettodr_period > 0 && !ntp_is_time_error()) {
998 mtx_lock(&Giant);
999 resettodr();
1000 mtx_unlock(&Giant);
1001 }
1002}
1003
1004static int
1005sysctl_resettodr_period(SYSCTL_HANDLER_ARGS)
1006{
1007 int error;
1008
1009 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1010 if (error || !req->newptr)
1011 return (error);
1012 if (resettodr_period == 0)
1013 callout_stop(&resettodr_callout);
1014 else
1015 callout_reset(&resettodr_callout, resettodr_period * hz,
1016 periodic_resettodr, NULL);
1017 return (0);
1018}
1019
1020SYSCTL_PROC(_machdep, OID_AUTO, rtc_save_period, CTLTYPE_INT|CTLFLAG_RW,
1021 &resettodr_period, 1800, sysctl_resettodr_period, "I",
1022 "Save system time to RTC with this period (in seconds)");
1023TUNABLE_INT("machdep.rtc_save_period", &resettodr_period);
1024
1025static void
1026start_periodic_resettodr(void *arg __unused)
1027{
1028
1029 EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_resettodr, NULL,
1030 SHUTDOWN_PRI_FIRST);
1031 callout_init(&resettodr_callout, 1);
1032 if (resettodr_period == 0)
1033 return;
1034 callout_reset(&resettodr_callout, resettodr_period * hz,
1035 periodic_resettodr, NULL);
1036}
1037
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