1
2
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4
5
6
7
8#include <linux/capability.h>
9#include <linux/clocksource.h>
10#include <linux/workqueue.h>
11#include <linux/hrtimer.h>
12#include <linux/jiffies.h>
13#include <linux/math64.h>
14#include <linux/timex.h>
15#include <linux/time.h>
16#include <linux/mm.h>
17#include <linux/module.h>
18#include <linux/rtc.h>
19
20#include "tick-internal.h"
21#include "ntp_internal.h"
22
23
24
25
26
27
28
29
30
31unsigned long tick_usec = TICK_USEC;
32
33
34unsigned long tick_nsec;
35
36static u64 tick_length;
37static u64 tick_length_base;
38
39#define MAX_TICKADJ 500LL
40#define MAX_TICKADJ_SCALED \
41 (((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
42
43
44
45
46
47
48
49
50
51
52static int time_state = TIME_OK;
53
54
55static int time_status = STA_UNSYNC;
56
57
58static s64 time_offset;
59
60
61static long time_constant = 2;
62
63
64static long time_maxerror = NTP_PHASE_LIMIT;
65
66
67static long time_esterror = NTP_PHASE_LIMIT;
68
69
70static s64 time_freq;
71
72
73static long time_reftime;
74
75static long time_adjust;
76
77
78static s64 ntp_tick_adj;
79
80#ifdef CONFIG_NTP_PPS
81
82
83
84
85
86
87#define PPS_VALID 10
88#define PPS_POPCORN 4
89#define PPS_INTMIN 2
90#define PPS_INTMAX 8
91#define PPS_INTCOUNT 4
92
93
94#define PPS_MAXWANDER 100000
95
96static int pps_valid;
97static long pps_tf[3];
98static long pps_jitter;
99static struct timespec pps_fbase;
100static int pps_shift;
101static int pps_intcnt;
102static s64 pps_freq;
103static long pps_stabil;
104
105
106
107
108static long pps_calcnt;
109static long pps_jitcnt;
110static long pps_stbcnt;
111static long pps_errcnt;
112
113
114
115
116
117static inline s64 ntp_offset_chunk(s64 offset)
118{
119 if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL)
120 return offset;
121 else
122 return shift_right(offset, SHIFT_PLL + time_constant);
123}
124
125static inline void pps_reset_freq_interval(void)
126{
127
128
129 pps_shift = PPS_INTMIN;
130 pps_intcnt = 0;
131}
132
133
134
135
136static inline void pps_clear(void)
137{
138 pps_reset_freq_interval();
139 pps_tf[0] = 0;
140 pps_tf[1] = 0;
141 pps_tf[2] = 0;
142 pps_fbase.tv_sec = pps_fbase.tv_nsec = 0;
143 pps_freq = 0;
144}
145
146
147
148
149
150static inline void pps_dec_valid(void)
151{
152 if (pps_valid > 0)
153 pps_valid--;
154 else {
155 time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
156 STA_PPSWANDER | STA_PPSERROR);
157 pps_clear();
158 }
159}
160
161static inline void pps_set_freq(s64 freq)
162{
163 pps_freq = freq;
164}
165
166static inline int is_error_status(int status)
167{
168 return (time_status & (STA_UNSYNC|STA_CLOCKERR))
169
170
171
172 || ((time_status & (STA_PPSFREQ|STA_PPSTIME))
173 && !(time_status & STA_PPSSIGNAL))
174
175
176 || ((time_status & (STA_PPSTIME|STA_PPSJITTER))
177 == (STA_PPSTIME|STA_PPSJITTER))
178
179
180
181 || ((time_status & STA_PPSFREQ)
182 && (time_status & (STA_PPSWANDER|STA_PPSERROR)));
183}
184
185static inline void pps_fill_timex(struct timex *txc)
186{
187 txc->ppsfreq = shift_right((pps_freq >> PPM_SCALE_INV_SHIFT) *
188 PPM_SCALE_INV, NTP_SCALE_SHIFT);
189 txc->jitter = pps_jitter;
190 if (!(time_status & STA_NANO))
191 txc->jitter /= NSEC_PER_USEC;
192 txc->shift = pps_shift;
193 txc->stabil = pps_stabil;
194 txc->jitcnt = pps_jitcnt;
195 txc->calcnt = pps_calcnt;
196 txc->errcnt = pps_errcnt;
197 txc->stbcnt = pps_stbcnt;
198}
199
200#else
201
202static inline s64 ntp_offset_chunk(s64 offset)
203{
204 return shift_right(offset, SHIFT_PLL + time_constant);
205}
206
207static inline void pps_reset_freq_interval(void) {}
208static inline void pps_clear(void) {}
209static inline void pps_dec_valid(void) {}
210static inline void pps_set_freq(s64 freq) {}
211
212static inline int is_error_status(int status)
213{
214 return status & (STA_UNSYNC|STA_CLOCKERR);
215}
216
217static inline void pps_fill_timex(struct timex *txc)
218{
219
220 txc->ppsfreq = 0;
221 txc->jitter = 0;
222 txc->shift = 0;
223 txc->stabil = 0;
224 txc->jitcnt = 0;
225 txc->calcnt = 0;
226 txc->errcnt = 0;
227 txc->stbcnt = 0;
228}
229
230#endif
231
232
233
234
235
236
237static inline int ntp_synced(void)
238{
239 return !(time_status & STA_UNSYNC);
240}
241
242
243
244
245
246
247
248
249
250
251static void ntp_update_frequency(void)
252{
253 u64 second_length;
254 u64 new_base;
255
256 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
257 << NTP_SCALE_SHIFT;
258
259 second_length += ntp_tick_adj;
260 second_length += time_freq;
261
262 tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
263 new_base = div_u64(second_length, NTP_INTERVAL_FREQ);
264
265
266
267
268
269 tick_length += new_base - tick_length_base;
270 tick_length_base = new_base;
271}
272
273static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
274{
275 time_status &= ~STA_MODE;
276
277 if (secs < MINSEC)
278 return 0;
279
280 if (!(time_status & STA_FLL) && (secs <= MAXSEC))
281 return 0;
282
283 time_status |= STA_MODE;
284
285 return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
286}
287
288static void ntp_update_offset(long offset)
289{
290 s64 freq_adj;
291 s64 offset64;
292 long secs;
293
294 if (!(time_status & STA_PLL))
295 return;
296
297 if (!(time_status & STA_NANO))
298 offset *= NSEC_PER_USEC;
299
300
301
302
303
304 offset = min(offset, MAXPHASE);
305 offset = max(offset, -MAXPHASE);
306
307
308
309
310
311 secs = get_seconds() - time_reftime;
312 if (unlikely(time_status & STA_FREQHOLD))
313 secs = 0;
314
315 time_reftime = get_seconds();
316
317 offset64 = offset;
318 freq_adj = ntp_update_offset_fll(offset64, secs);
319
320
321
322
323
324
325 if (unlikely(secs > 1 << (SHIFT_PLL + 1 + time_constant)))
326 secs = 1 << (SHIFT_PLL + 1 + time_constant);
327
328 freq_adj += (offset64 * secs) <<
329 (NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
330
331 freq_adj = min(freq_adj + time_freq, MAXFREQ_SCALED);
332
333 time_freq = max(freq_adj, -MAXFREQ_SCALED);
334
335 time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
336}
337
338
339
340
341void ntp_clear(void)
342{
343 time_adjust = 0;
344 time_status |= STA_UNSYNC;
345 time_maxerror = NTP_PHASE_LIMIT;
346 time_esterror = NTP_PHASE_LIMIT;
347
348 ntp_update_frequency();
349
350 tick_length = tick_length_base;
351 time_offset = 0;
352
353
354 pps_clear();
355}
356
357
358u64 ntp_tick_length(void)
359{
360 return tick_length;
361}
362
363
364
365
366
367
368
369
370
371
372
373
374int second_overflow(unsigned long secs)
375{
376 s64 delta;
377 int leap = 0;
378
379
380
381
382
383
384 switch (time_state) {
385 case TIME_OK:
386 if (time_status & STA_INS)
387 time_state = TIME_INS;
388 else if (time_status & STA_DEL)
389 time_state = TIME_DEL;
390 break;
391 case TIME_INS:
392 if (!(time_status & STA_INS))
393 time_state = TIME_OK;
394 else if (secs % 86400 == 0) {
395 leap = -1;
396 time_state = TIME_OOP;
397 printk(KERN_NOTICE
398 "Clock: inserting leap second 23:59:60 UTC\n");
399 }
400 break;
401 case TIME_DEL:
402 if (!(time_status & STA_DEL))
403 time_state = TIME_OK;
404 else if ((secs + 1) % 86400 == 0) {
405 leap = 1;
406 time_state = TIME_WAIT;
407 printk(KERN_NOTICE
408 "Clock: deleting leap second 23:59:59 UTC\n");
409 }
410 break;
411 case TIME_OOP:
412 time_state = TIME_WAIT;
413 break;
414
415 case TIME_WAIT:
416 if (!(time_status & (STA_INS | STA_DEL)))
417 time_state = TIME_OK;
418 break;
419 }
420
421
422
423 time_maxerror += MAXFREQ / NSEC_PER_USEC;
424 if (time_maxerror > NTP_PHASE_LIMIT) {
425 time_maxerror = NTP_PHASE_LIMIT;
426 time_status |= STA_UNSYNC;
427 }
428
429
430 tick_length = tick_length_base;
431
432 delta = ntp_offset_chunk(time_offset);
433 time_offset -= delta;
434 tick_length += delta;
435
436
437 pps_dec_valid();
438
439 if (!time_adjust)
440 goto out;
441
442 if (time_adjust > MAX_TICKADJ) {
443 time_adjust -= MAX_TICKADJ;
444 tick_length += MAX_TICKADJ_SCALED;
445 goto out;
446 }
447
448 if (time_adjust < -MAX_TICKADJ) {
449 time_adjust += MAX_TICKADJ;
450 tick_length -= MAX_TICKADJ_SCALED;
451 goto out;
452 }
453
454 tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
455 << NTP_SCALE_SHIFT;
456 time_adjust = 0;
457
458out:
459 return leap;
460}
461
462#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC)
463static void sync_cmos_clock(struct work_struct *work);
464
465static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
466
467static void sync_cmos_clock(struct work_struct *work)
468{
469 struct timespec now, next;
470 int fail = 1;
471
472
473
474
475
476
477
478
479 if (!ntp_synced()) {
480
481
482
483
484 return;
485 }
486
487 getnstimeofday(&now);
488 if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) {
489 struct timespec adjust = now;
490
491 fail = -ENODEV;
492 if (persistent_clock_is_local)
493 adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
494#ifdef CONFIG_GENERIC_CMOS_UPDATE
495 fail = update_persistent_clock(adjust);
496#endif
497#ifdef CONFIG_RTC_SYSTOHC
498 if (fail == -ENODEV)
499 fail = rtc_set_ntp_time(adjust);
500#endif
501 }
502
503 next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
504 if (next.tv_nsec <= 0)
505 next.tv_nsec += NSEC_PER_SEC;
506
507 if (!fail || fail == -ENODEV)
508 next.tv_sec = 659;
509 else
510 next.tv_sec = 0;
511
512 if (next.tv_nsec >= NSEC_PER_SEC) {
513 next.tv_sec++;
514 next.tv_nsec -= NSEC_PER_SEC;
515 }
516 schedule_delayed_work(&sync_cmos_work, timespec_to_jiffies(&next));
517}
518
519static void notify_cmos_timer(void)
520{
521 schedule_delayed_work(&sync_cmos_work, 0);
522}
523
524#else
525static inline void notify_cmos_timer(void) { }
526#endif
527
528
529
530
531
532static inline void process_adj_status(struct timex *txc, struct timespec *ts)
533{
534 if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {
535 time_state = TIME_OK;
536 time_status = STA_UNSYNC;
537
538 pps_reset_freq_interval();
539 }
540
541
542
543
544
545 if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
546 time_reftime = get_seconds();
547
548
549 time_status &= STA_RONLY;
550 time_status |= txc->status & ~STA_RONLY;
551}
552
553
554static inline void process_adjtimex_modes(struct timex *txc,
555 struct timespec *ts,
556 s32 *time_tai)
557{
558 if (txc->modes & ADJ_STATUS)
559 process_adj_status(txc, ts);
560
561 if (txc->modes & ADJ_NANO)
562 time_status |= STA_NANO;
563
564 if (txc->modes & ADJ_MICRO)
565 time_status &= ~STA_NANO;
566
567 if (txc->modes & ADJ_FREQUENCY) {
568 time_freq = txc->freq * PPM_SCALE;
569 time_freq = min(time_freq, MAXFREQ_SCALED);
570 time_freq = max(time_freq, -MAXFREQ_SCALED);
571
572 pps_set_freq(time_freq);
573 }
574
575 if (txc->modes & ADJ_MAXERROR)
576 time_maxerror = txc->maxerror;
577
578 if (txc->modes & ADJ_ESTERROR)
579 time_esterror = txc->esterror;
580
581 if (txc->modes & ADJ_TIMECONST) {
582 time_constant = txc->constant;
583 if (!(time_status & STA_NANO))
584 time_constant += 4;
585 time_constant = min(time_constant, (long)MAXTC);
586 time_constant = max(time_constant, 0l);
587 }
588
589 if (txc->modes & ADJ_TAI && txc->constant > 0)
590 *time_tai = txc->constant;
591
592 if (txc->modes & ADJ_OFFSET)
593 ntp_update_offset(txc->offset);
594
595 if (txc->modes & ADJ_TICK)
596 tick_usec = txc->tick;
597
598 if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
599 ntp_update_frequency();
600}
601
602
603
604
605
606
607int ntp_validate_timex(struct timex *txc)
608{
609 if (txc->modes & ADJ_ADJTIME) {
610
611 if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
612 return -EINVAL;
613 if (!(txc->modes & ADJ_OFFSET_READONLY) &&
614 !capable(CAP_SYS_TIME))
615 return -EPERM;
616 } else {
617
618 if (txc->modes && !capable(CAP_SYS_TIME))
619 return -EPERM;
620
621
622
623
624 if (txc->modes & ADJ_TICK &&
625 (txc->tick < 900000/USER_HZ ||
626 txc->tick > 1100000/USER_HZ))
627 return -EINVAL;
628 }
629
630 if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
631 return -EPERM;
632
633 return 0;
634}
635
636
637
638
639
640
641int __do_adjtimex(struct timex *txc, struct timespec *ts, s32 *time_tai)
642{
643 int result;
644
645 if (txc->modes & ADJ_ADJTIME) {
646 long save_adjust = time_adjust;
647
648 if (!(txc->modes & ADJ_OFFSET_READONLY)) {
649
650 time_adjust = txc->offset;
651 ntp_update_frequency();
652 }
653 txc->offset = save_adjust;
654 } else {
655
656
657 if (txc->modes)
658 process_adjtimex_modes(txc, ts, time_tai);
659
660 txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
661 NTP_SCALE_SHIFT);
662 if (!(time_status & STA_NANO))
663 txc->offset /= NSEC_PER_USEC;
664 }
665
666 result = time_state;
667
668 if (is_error_status(time_status))
669 result = TIME_ERROR;
670
671 txc->freq = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
672 PPM_SCALE_INV, NTP_SCALE_SHIFT);
673 txc->maxerror = time_maxerror;
674 txc->esterror = time_esterror;
675 txc->status = time_status;
676 txc->constant = time_constant;
677 txc->precision = 1;
678 txc->tolerance = MAXFREQ_SCALED / PPM_SCALE;
679 txc->tick = tick_usec;
680 txc->tai = *time_tai;
681
682
683 pps_fill_timex(txc);
684
685 txc->time.tv_sec = ts->tv_sec;
686 txc->time.tv_usec = ts->tv_nsec;
687 if (!(time_status & STA_NANO))
688 txc->time.tv_usec /= NSEC_PER_USEC;
689
690 notify_cmos_timer();
691
692 return result;
693}
694
695#ifdef CONFIG_NTP_PPS
696
697
698
699
700
701struct pps_normtime {
702 __kernel_time_t sec;
703 long nsec;
704};
705
706
707
708static inline struct pps_normtime pps_normalize_ts(struct timespec ts)
709{
710 struct pps_normtime norm = {
711 .sec = ts.tv_sec,
712 .nsec = ts.tv_nsec
713 };
714
715 if (norm.nsec > (NSEC_PER_SEC >> 1)) {
716 norm.nsec -= NSEC_PER_SEC;
717 norm.sec++;
718 }
719
720 return norm;
721}
722
723
724static inline long pps_phase_filter_get(long *jitter)
725{
726 *jitter = pps_tf[0] - pps_tf[1];
727 if (*jitter < 0)
728 *jitter = -*jitter;
729
730
731 return pps_tf[0];
732}
733
734
735static inline void pps_phase_filter_add(long err)
736{
737 pps_tf[2] = pps_tf[1];
738 pps_tf[1] = pps_tf[0];
739 pps_tf[0] = err;
740}
741
742
743
744
745static inline void pps_dec_freq_interval(void)
746{
747 if (--pps_intcnt <= -PPS_INTCOUNT) {
748 pps_intcnt = -PPS_INTCOUNT;
749 if (pps_shift > PPS_INTMIN) {
750 pps_shift--;
751 pps_intcnt = 0;
752 }
753 }
754}
755
756
757
758
759static inline void pps_inc_freq_interval(void)
760{
761 if (++pps_intcnt >= PPS_INTCOUNT) {
762 pps_intcnt = PPS_INTCOUNT;
763 if (pps_shift < PPS_INTMAX) {
764 pps_shift++;
765 pps_intcnt = 0;
766 }
767 }
768}
769
770
771
772
773
774
775
776
777
778
779static long hardpps_update_freq(struct pps_normtime freq_norm)
780{
781 long delta, delta_mod;
782 s64 ftemp;
783
784
785 if (freq_norm.sec > (2 << pps_shift)) {
786 time_status |= STA_PPSERROR;
787 pps_errcnt++;
788 pps_dec_freq_interval();
789 pr_err("hardpps: PPSERROR: interval too long - %ld s\n",
790 freq_norm.sec);
791 return 0;
792 }
793
794
795
796
797
798 ftemp = div_s64(((s64)(-freq_norm.nsec)) << NTP_SCALE_SHIFT,
799 freq_norm.sec);
800 delta = shift_right(ftemp - pps_freq, NTP_SCALE_SHIFT);
801 pps_freq = ftemp;
802 if (delta > PPS_MAXWANDER || delta < -PPS_MAXWANDER) {
803 pr_warning("hardpps: PPSWANDER: change=%ld\n", delta);
804 time_status |= STA_PPSWANDER;
805 pps_stbcnt++;
806 pps_dec_freq_interval();
807 } else {
808 pps_inc_freq_interval();
809 }
810
811
812
813
814
815 delta_mod = delta;
816 if (delta_mod < 0)
817 delta_mod = -delta_mod;
818 pps_stabil += (div_s64(((s64)delta_mod) <<
819 (NTP_SCALE_SHIFT - SHIFT_USEC),
820 NSEC_PER_USEC) - pps_stabil) >> PPS_INTMIN;
821
822
823 if ((time_status & STA_PPSFREQ) != 0 &&
824 (time_status & STA_FREQHOLD) == 0) {
825 time_freq = pps_freq;
826 ntp_update_frequency();
827 }
828
829 return delta;
830}
831
832
833static void hardpps_update_phase(long error)
834{
835 long correction = -error;
836 long jitter;
837
838
839 pps_phase_filter_add(correction);
840 correction = pps_phase_filter_get(&jitter);
841
842
843
844
845
846 if (jitter > (pps_jitter << PPS_POPCORN)) {
847 pr_warning("hardpps: PPSJITTER: jitter=%ld, limit=%ld\n",
848 jitter, (pps_jitter << PPS_POPCORN));
849 time_status |= STA_PPSJITTER;
850 pps_jitcnt++;
851 } else if (time_status & STA_PPSTIME) {
852
853 time_offset = div_s64(((s64)correction) << NTP_SCALE_SHIFT,
854 NTP_INTERVAL_FREQ);
855
856 time_adjust = 0;
857 }
858
859 pps_jitter += (jitter - pps_jitter) >> PPS_INTMIN;
860}
861
862
863
864
865
866
867
868
869
870
871
872
873
874void __hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
875{
876 struct pps_normtime pts_norm, freq_norm;
877
878 pts_norm = pps_normalize_ts(*phase_ts);
879
880
881 time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
882
883
884 time_status |= STA_PPSSIGNAL;
885 pps_valid = PPS_VALID;
886
887
888
889 if (unlikely(pps_fbase.tv_sec == 0)) {
890 pps_fbase = *raw_ts;
891 return;
892 }
893
894
895 freq_norm = pps_normalize_ts(timespec_sub(*raw_ts, pps_fbase));
896
897
898
899 if ((freq_norm.sec == 0) ||
900 (freq_norm.nsec > MAXFREQ * freq_norm.sec) ||
901 (freq_norm.nsec < -MAXFREQ * freq_norm.sec)) {
902 time_status |= STA_PPSJITTER;
903
904 pps_fbase = *raw_ts;
905 pr_err("hardpps: PPSJITTER: bad pulse\n");
906 return;
907 }
908
909
910
911
912 if (freq_norm.sec >= (1 << pps_shift)) {
913 pps_calcnt++;
914
915 pps_fbase = *raw_ts;
916 hardpps_update_freq(freq_norm);
917 }
918
919 hardpps_update_phase(pts_norm.nsec);
920
921}
922#endif
923
924static int __init ntp_tick_adj_setup(char *str)
925{
926 ntp_tick_adj = simple_strtol(str, NULL, 0);
927 ntp_tick_adj <<= NTP_SCALE_SHIFT;
928
929 return 1;
930}
931
932__setup("ntp_tick_adj=", ntp_tick_adj_setup);
933
934void __init ntp_init(void)
935{
936 ntp_clear();
937}
938