1/*-
2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
8 *
9 * Copyright (c) 2011, 2015, 2016 The FreeBSD Foundation
10 * All rights reserved.
11 *
12 * Portions of this software were developed by Julien Ridoux at the University
13 * of Melbourne under sponsorship from the FreeBSD Foundation.
14 *
15 * Portions of this software were developed by Konstantin Belousov
16 * under sponsorship from the FreeBSD Foundation.
17 */
18
19#include <sys/cdefs.h>
20__FBSDID("$FreeBSD: stable/11/sys/kern/kern_tc.c 305866 2016-09-16 10:04:28Z kib $");
21
22#include "opt_compat.h"
23#include "opt_ntp.h"
24#include "opt_ffclock.h"
25
26#include <sys/param.h>
27#include <sys/kernel.h>
28#include <sys/limits.h>
29#include <sys/lock.h>
30#include <sys/mutex.h>
31#include <sys/sbuf.h>
32#include <sys/sysctl.h>
33#include <sys/syslog.h>
34#include <sys/systm.h>
35#include <sys/timeffc.h>
36#include <sys/timepps.h>
37#include <sys/timetc.h>
38#include <sys/timex.h>
39#include <sys/vdso.h>
40
41/*
42 * A large step happens on boot. This constant detects such steps.
43 * It is relatively small so that ntp_update_second gets called enough
44 * in the typical 'missed a couple of seconds' case, but doesn't loop
45 * forever when the time step is large.
46 */
47#define LARGE_STEP 200
48
49/*
50 * Implement a dummy timecounter which we can use until we get a real one
51 * in the air. This allows the console and other early stuff to use
52 * time services.
53 */
54
55static u_int
56dummy_get_timecount(struct timecounter *tc)
57{
58 static u_int now;
59
60 return (++now);
61}
62
63static struct timecounter dummy_timecounter = {
64 dummy_get_timecount, 0, ~0u, 1000000, "dummy", -1000000
65};
66
67struct timehands {
68 /* These fields must be initialized by the driver. */
69 struct timecounter *th_counter;
70 int64_t th_adjustment;
71 uint64_t th_scale;
72 u_int th_offset_count;
73 struct bintime th_offset;
74 struct bintime th_bintime;
75 struct timeval th_microtime;
76 struct timespec th_nanotime;
77 struct bintime th_boottime;
78 /* Fields not to be copied in tc_windup start with th_generation. */
79 u_int th_generation;
80 struct timehands *th_next;
81};
82
83static struct timehands th0;
84static struct timehands th1 = {
85 .th_next = &th0
86};
87static struct timehands th0 = {
88 .th_counter = &dummy_timecounter,
89 .th_scale = (uint64_t)-1 / 1000000,
90 .th_offset = { .sec = 1 },
91 .th_generation = 1,
92 .th_next = &th1
93};
94
95static struct timehands *volatile timehands = &th0;
96struct timecounter *timecounter = &dummy_timecounter;
97static struct timecounter *timecounters = &dummy_timecounter;
98
99int tc_min_ticktock_freq = 1;
100
101volatile time_t time_second = 1;
102volatile time_t time_uptime = 1;
103
104struct bintime boottimebin;
105struct timeval boottime;
106static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS);
107SYSCTL_PROC(_kern, KERN_BOOTTIME, boottime, CTLTYPE_STRUCT|CTLFLAG_RD,
108 NULL, 0, sysctl_kern_boottime, "S,timeval", "System boottime");
109
110SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, "");
111static SYSCTL_NODE(_kern_timecounter, OID_AUTO, tc, CTLFLAG_RW, 0, "");
112
113static int timestepwarnings;
114SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW,
115 &timestepwarnings, 0, "Log time steps");
116
117struct bintime bt_timethreshold;
118struct bintime bt_tickthreshold;
119sbintime_t sbt_timethreshold;
120sbintime_t sbt_tickthreshold;
121struct bintime tc_tick_bt;
122sbintime_t tc_tick_sbt;
123int tc_precexp;
124int tc_timepercentage = TC_DEFAULTPERC;
125static int sysctl_kern_timecounter_adjprecision(SYSCTL_HANDLER_ARGS);
126SYSCTL_PROC(_kern_timecounter, OID_AUTO, alloweddeviation,
127 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, 0,
128 sysctl_kern_timecounter_adjprecision, "I",
129 "Allowed time interval deviation in percents");
130
131static int tc_chosen; /* Non-zero if a specific tc was chosen via sysctl. */
132
133static void tc_windup(struct bintime *new_boottimebin);
134static void cpu_tick_calibrate(int);
135
136void dtrace_getnanotime(struct timespec *tsp);
137
138static int
139sysctl_kern_boottime(SYSCTL_HANDLER_ARGS)
140{
141 struct timeval boottime_x;
142
143 getboottime(&boottime_x);
144
145#ifndef __mips__
146#ifdef SCTL_MASK32
147 int tv[2];
148
149 if (req->flags & SCTL_MASK32) {
150 tv[0] = boottime_x.tv_sec;
151 tv[1] = boottime_x.tv_usec;
152 return (SYSCTL_OUT(req, tv, sizeof(tv)));
153 }
154#endif
155#endif
156 return (SYSCTL_OUT(req, &boottime_x, sizeof(boottime_x)));
157}
158
159static int
160sysctl_kern_timecounter_get(SYSCTL_HANDLER_ARGS)
161{
162 u_int ncount;
163 struct timecounter *tc = arg1;
164
165 ncount = tc->tc_get_timecount(tc);
166 return (sysctl_handle_int(oidp, &ncount, 0, req));
167}
168
169static int
170sysctl_kern_timecounter_freq(SYSCTL_HANDLER_ARGS)
171{
172 uint64_t freq;
173 struct timecounter *tc = arg1;
174
175 freq = tc->tc_frequency;
176 return (sysctl_handle_64(oidp, &freq, 0, req));
177}
178
179/*
180 * Return the difference between the timehands' counter value now and what
181 * was when we copied it to the timehands' offset_count.
182 */
183static __inline u_int
184tc_delta(struct timehands *th)
185{
186 struct timecounter *tc;
187
188 tc = th->th_counter;
189 return ((tc->tc_get_timecount(tc) - th->th_offset_count) &
190 tc->tc_counter_mask);
191}
192
193/*
194 * Functions for reading the time. We have to loop until we are sure that
195 * the timehands that we operated on was not updated under our feet. See
196 * the comment in <sys/time.h> for a description of these 12 functions.
197 */
198
199#ifdef FFCLOCK
200void
201fbclock_binuptime(struct bintime *bt)
202{
203 struct timehands *th;
204 unsigned int gen;
205
206 do {
207 th = timehands;
208 gen = atomic_load_acq_int(&th->th_generation);
209 *bt = th->th_offset;
210 bintime_addx(bt, th->th_scale * tc_delta(th));
211 atomic_thread_fence_acq();
212 } while (gen == 0 || gen != th->th_generation);
213}
214
215void
216fbclock_nanouptime(struct timespec *tsp)
217{
218 struct bintime bt;
219
220 fbclock_binuptime(&bt);
221 bintime2timespec(&bt, tsp);
222}
223
224void
225fbclock_microuptime(struct timeval *tvp)
226{
227 struct bintime bt;
228
229 fbclock_binuptime(&bt);
230 bintime2timeval(&bt, tvp);
231}
232
233void
234fbclock_bintime(struct bintime *bt)
235{
236 struct timehands *th;
237 unsigned int gen;
238
239 do {
240 th = timehands;
241 gen = atomic_load_acq_int(&th->th_generation);
242 *bt = th->th_bintime;
243 bintime_addx(bt, th->th_scale * tc_delta(th));
244 atomic_thread_fence_acq();
245 } while (gen == 0 || gen != th->th_generation);
246}
247
248void
249fbclock_nanotime(struct timespec *tsp)
250{
251 struct bintime bt;
252
253 fbclock_bintime(&bt);
254 bintime2timespec(&bt, tsp);
255}
256
257void
258fbclock_microtime(struct timeval *tvp)
259{
260 struct bintime bt;
261
262 fbclock_bintime(&bt);
263 bintime2timeval(&bt, tvp);
264}
265
266void
267fbclock_getbinuptime(struct bintime *bt)
268{
269 struct timehands *th;
270 unsigned int gen;
271
272 do {
273 th = timehands;
274 gen = atomic_load_acq_int(&th->th_generation);
275 *bt = th->th_offset;
276 atomic_thread_fence_acq();
277 } while (gen == 0 || gen != th->th_generation);
278}
279
280void
281fbclock_getnanouptime(struct timespec *tsp)
282{
283 struct timehands *th;
284 unsigned int gen;
285
286 do {
287 th = timehands;
288 gen = atomic_load_acq_int(&th->th_generation);
289 bintime2timespec(&th->th_offset, tsp);
290 atomic_thread_fence_acq();
291 } while (gen == 0 || gen != th->th_generation);
292}
293
294void
295fbclock_getmicrouptime(struct timeval *tvp)
296{
297 struct timehands *th;
298 unsigned int gen;
299
300 do {
301 th = timehands;
302 gen = atomic_load_acq_int(&th->th_generation);
303 bintime2timeval(&th->th_offset, tvp);
304 atomic_thread_fence_acq();
305 } while (gen == 0 || gen != th->th_generation);
306}
307
308void
309fbclock_getbintime(struct bintime *bt)
310{
311 struct timehands *th;
312 unsigned int gen;
313
314 do {
315 th = timehands;
316 gen = atomic_load_acq_int(&th->th_generation);
317 *bt = th->th_bintime;
318 atomic_thread_fence_acq();
319 } while (gen == 0 || gen != th->th_generation);
320}
321
322void
323fbclock_getnanotime(struct timespec *tsp)
324{
325 struct timehands *th;
326 unsigned int gen;
327
328 do {
329 th = timehands;
330 gen = atomic_load_acq_int(&th->th_generation);
331 *tsp = th->th_nanotime;
332 atomic_thread_fence_acq();
333 } while (gen == 0 || gen != th->th_generation);
334}
335
336void
337fbclock_getmicrotime(struct timeval *tvp)
338{
339 struct timehands *th;
340 unsigned int gen;
341
342 do {
343 th = timehands;
344 gen = atomic_load_acq_int(&th->th_generation);
345 *tvp = th->th_microtime;
346 atomic_thread_fence_acq();
347 } while (gen == 0 || gen != th->th_generation);
348}
349#else /* !FFCLOCK */
350void
351binuptime(struct bintime *bt)
352{
353 struct timehands *th;
354 u_int gen;
355
356 do {
357 th = timehands;
358 gen = atomic_load_acq_int(&th->th_generation);
359 *bt = th->th_offset;
360 bintime_addx(bt, th->th_scale * tc_delta(th));
361 atomic_thread_fence_acq();
362 } while (gen == 0 || gen != th->th_generation);
363}
364
365void
366nanouptime(struct timespec *tsp)
367{
368 struct bintime bt;
369
370 binuptime(&bt);
371 bintime2timespec(&bt, tsp);
372}
373
374void
375microuptime(struct timeval *tvp)
376{
377 struct bintime bt;
378
379 binuptime(&bt);
380 bintime2timeval(&bt, tvp);
381}
382
383void
384bintime(struct bintime *bt)
385{
386 struct timehands *th;
387 u_int gen;
388
389 do {
390 th = timehands;
391 gen = atomic_load_acq_int(&th->th_generation);
392 *bt = th->th_bintime;
393 bintime_addx(bt, th->th_scale * tc_delta(th));
394 atomic_thread_fence_acq();
395 } while (gen == 0 || gen != th->th_generation);
396}
397
398void
399nanotime(struct timespec *tsp)
400{
401 struct bintime bt;
402
403 bintime(&bt);
404 bintime2timespec(&bt, tsp);
405}
406
407void
408microtime(struct timeval *tvp)
409{
410 struct bintime bt;
411
412 bintime(&bt);
413 bintime2timeval(&bt, tvp);
414}
415
416void
417getbinuptime(struct bintime *bt)
418{
419 struct timehands *th;
420 u_int gen;
421
422 do {
423 th = timehands;
424 gen = atomic_load_acq_int(&th->th_generation);
425 *bt = th->th_offset;
426 atomic_thread_fence_acq();
427 } while (gen == 0 || gen != th->th_generation);
428}
429
430void
431getnanouptime(struct timespec *tsp)
432{
433 struct timehands *th;
434 u_int gen;
435
436 do {
437 th = timehands;
438 gen = atomic_load_acq_int(&th->th_generation);
439 bintime2timespec(&th->th_offset, tsp);
440 atomic_thread_fence_acq();
441 } while (gen == 0 || gen != th->th_generation);
442}
443
444void
445getmicrouptime(struct timeval *tvp)
446{
447 struct timehands *th;
448 u_int gen;
449
450 do {
451 th = timehands;
452 gen = atomic_load_acq_int(&th->th_generation);
453 bintime2timeval(&th->th_offset, tvp);
454 atomic_thread_fence_acq();
455 } while (gen == 0 || gen != th->th_generation);
456}
457
458void
459getbintime(struct bintime *bt)
460{
461 struct timehands *th;
462 u_int gen;
463
464 do {
465 th = timehands;
466 gen = atomic_load_acq_int(&th->th_generation);
467 *bt = th->th_bintime;
468 atomic_thread_fence_acq();
469 } while (gen == 0 || gen != th->th_generation);
470}
471
472void
473getnanotime(struct timespec *tsp)
474{
475 struct timehands *th;
476 u_int gen;
477
478 do {
479 th = timehands;
480 gen = atomic_load_acq_int(&th->th_generation);
481 *tsp = th->th_nanotime;
482 atomic_thread_fence_acq();
483 } while (gen == 0 || gen != th->th_generation);
484}
485
486void
487getmicrotime(struct timeval *tvp)
488{
489 struct timehands *th;
490 u_int gen;
491
492 do {
493 th = timehands;
494 gen = atomic_load_acq_int(&th->th_generation);
495 *tvp = th->th_microtime;
496 atomic_thread_fence_acq();
497 } while (gen == 0 || gen != th->th_generation);
498}
499#endif /* FFCLOCK */
500
501void
502getboottime(struct timeval *boottime_x)
503{
504 struct bintime boottimebin_x;
505
506 getboottimebin(&boottimebin_x);
507 bintime2timeval(&boottimebin_x, boottime_x);
508}
509
510void
511getboottimebin(struct bintime *boottimebin_x)
512{
513 struct timehands *th;
514 u_int gen;
515
516 do {
517 th = timehands;
518 gen = atomic_load_acq_int(&th->th_generation);
519 *boottimebin_x = th->th_boottime;
520 atomic_thread_fence_acq();
521 } while (gen == 0 || gen != th->th_generation);
522}
523
524#ifdef FFCLOCK
525/*
526 * Support for feed-forward synchronization algorithms. This is heavily inspired
527 * by the timehands mechanism but kept independent from it. *_windup() functions
528 * have some connection to avoid accessing the timecounter hardware more than
529 * necessary.
530 */
531
532/* Feed-forward clock estimates kept updated by the synchronization daemon. */
533struct ffclock_estimate ffclock_estimate;
534struct bintime ffclock_boottime; /* Feed-forward boot time estimate. */
535uint32_t ffclock_status; /* Feed-forward clock status. */
536int8_t ffclock_updated; /* New estimates are available. */
537struct mtx ffclock_mtx; /* Mutex on ffclock_estimate. */
538
539struct fftimehands {
540 struct ffclock_estimate cest;
541 struct bintime tick_time;
542 struct bintime tick_time_lerp;
543 ffcounter tick_ffcount;
544 uint64_t period_lerp;
545 volatile uint8_t gen;
546 struct fftimehands *next;
547};
548
549#define NUM_ELEMENTS(x) (sizeof(x) / sizeof(*x))
550
551static struct fftimehands ffth[10];
552static struct fftimehands *volatile fftimehands = ffth;
553
554static void
555ffclock_init(void)
556{
557 struct fftimehands *cur;
558 struct fftimehands *last;
559
560 memset(ffth, 0, sizeof(ffth));
561
562 last = ffth + NUM_ELEMENTS(ffth) - 1;
563 for (cur = ffth; cur < last; cur++)
564 cur->next = cur + 1;
565 last->next = ffth;
566
567 ffclock_updated = 0;
568 ffclock_status = FFCLOCK_STA_UNSYNC;
569 mtx_init(&ffclock_mtx, "ffclock lock", NULL, MTX_DEF);
570}
571
572/*
573 * Reset the feed-forward clock estimates. Called from inittodr() to get things
574 * kick started and uses the timecounter nominal frequency as a first period
575 * estimate. Note: this function may be called several time just after boot.
576 * Note: this is the only function that sets the value of boot time for the
577 * monotonic (i.e. uptime) version of the feed-forward clock.
578 */
579void
580ffclock_reset_clock(struct timespec *ts)
581{
582 struct timecounter *tc;
583 struct ffclock_estimate cest;
584
585 tc = timehands->th_counter;
586 memset(&cest, 0, sizeof(struct ffclock_estimate));
587
588 timespec2bintime(ts, &ffclock_boottime);
589 timespec2bintime(ts, &(cest.update_time));
590 ffclock_read_counter(&cest.update_ffcount);
591 cest.leapsec_next = 0;
592 cest.period = ((1ULL << 63) / tc->tc_frequency) << 1;
593 cest.errb_abs = 0;
594 cest.errb_rate = 0;
595 cest.status = FFCLOCK_STA_UNSYNC;
596 cest.leapsec_total = 0;
597 cest.leapsec = 0;
598
599 mtx_lock(&ffclock_mtx);
600 bcopy(&cest, &ffclock_estimate, sizeof(struct ffclock_estimate));
601 ffclock_updated = INT8_MAX;
602 mtx_unlock(&ffclock_mtx);
603
604 printf("ffclock reset: %s (%llu Hz), time = %ld.%09lu\n", tc->tc_name,
605 (unsigned long long)tc->tc_frequency, (long)ts->tv_sec,
606 (unsigned long)ts->tv_nsec);
607}
608
609/*
610 * Sub-routine to convert a time interval measured in RAW counter units to time
611 * in seconds stored in bintime format.
612 * NOTE: bintime_mul requires u_int, but the value of the ffcounter may be
613 * larger than the max value of u_int (on 32 bit architecture). Loop to consume
614 * extra cycles.
615 */
616static void
617ffclock_convert_delta(ffcounter ffdelta, uint64_t period, struct bintime *bt)
618{
619 struct bintime bt2;
620 ffcounter delta, delta_max;
621
622 delta_max = (1ULL << (8 * sizeof(unsigned int))) - 1;
623 bintime_clear(bt);
624 do {
625 if (ffdelta > delta_max)
626 delta = delta_max;
627 else
628 delta = ffdelta;
629 bt2.sec = 0;
630 bt2.frac = period;
631 bintime_mul(&bt2, (unsigned int)delta);
632 bintime_add(bt, &bt2);
633 ffdelta -= delta;
634 } while (ffdelta > 0);
635}
636
637/*
638 * Update the fftimehands.
639 * Push the tick ffcount and time(s) forward based on current clock estimate.
640 * The conversion from ffcounter to bintime relies on the difference clock
641 * principle, whose accuracy relies on computing small time intervals. If a new
642 * clock estimate has been passed by the synchronisation daemon, make it
643 * current, and compute the linear interpolation for monotonic time if needed.
644 */
645static void
646ffclock_windup(unsigned int delta)
647{
648 struct ffclock_estimate *cest;
649 struct fftimehands *ffth;
650 struct bintime bt, gap_lerp;
651 ffcounter ffdelta;
652 uint64_t frac;
653 unsigned int polling;
654 uint8_t forward_jump, ogen;
655
656 /*
657 * Pick the next timehand, copy current ffclock estimates and move tick
658 * times and counter forward.
659 */
660 forward_jump = 0;
661 ffth = fftimehands->next;
662 ogen = ffth->gen;
663 ffth->gen = 0;
664 cest = &ffth->cest;
665 bcopy(&fftimehands->cest, cest, sizeof(struct ffclock_estimate));
666 ffdelta = (ffcounter)delta;
667 ffth->period_lerp = fftimehands->period_lerp;
668
669 ffth->tick_time = fftimehands->tick_time;
670 ffclock_convert_delta(ffdelta, cest->period, &bt);
671 bintime_add(&ffth->tick_time, &bt);
672
673 ffth->tick_time_lerp = fftimehands->tick_time_lerp;
674 ffclock_convert_delta(ffdelta, ffth->period_lerp, &bt);
675 bintime_add(&ffth->tick_time_lerp, &bt);
676
677 ffth->tick_ffcount = fftimehands->tick_ffcount + ffdelta;
678
679 /*
680 * Assess the status of the clock, if the last update is too old, it is
681 * likely the synchronisation daemon is dead and the clock is free
682 * running.
683 */
684 if (ffclock_updated == 0) {
685 ffdelta = ffth->tick_ffcount - cest->update_ffcount;
686 ffclock_convert_delta(ffdelta, cest->period, &bt);
687 if (bt.sec > 2 * FFCLOCK_SKM_SCALE)
688 ffclock_status |= FFCLOCK_STA_UNSYNC;
689 }
690
691 /*
692 * If available, grab updated clock estimates and make them current.
693 * Recompute time at this tick using the updated estimates. The clock
694 * estimates passed the feed-forward synchronisation daemon may result
695 * in time conversion that is not monotonically increasing (just after
696 * the update). time_lerp is a particular linear interpolation over the
697 * synchronisation algo polling period that ensures monotonicity for the
698 * clock ids requesting it.
699 */
700 if (ffclock_updated > 0) {
701 bcopy(&ffclock_estimate, cest, sizeof(struct ffclock_estimate));
702 ffdelta = ffth->tick_ffcount - cest->update_ffcount;
703 ffth->tick_time = cest->update_time;
704 ffclock_convert_delta(ffdelta, cest->period, &bt);
705 bintime_add(&ffth->tick_time, &bt);
706
707 /* ffclock_reset sets ffclock_updated to INT8_MAX */
708 if (ffclock_updated == INT8_MAX)
709 ffth->tick_time_lerp = ffth->tick_time;
710
711 if (bintime_cmp(&ffth->tick_time, &ffth->tick_time_lerp, >))
712 forward_jump = 1;
713 else
714 forward_jump = 0;
715
716 bintime_clear(&gap_lerp);
717 if (forward_jump) {
718 gap_lerp = ffth->tick_time;
719 bintime_sub(&gap_lerp, &ffth->tick_time_lerp);
720 } else {
721 gap_lerp = ffth->tick_time_lerp;
722 bintime_sub(&gap_lerp, &ffth->tick_time);
723 }
724
725 /*
726 * The reset from the RTC clock may be far from accurate, and
727 * reducing the gap between real time and interpolated time
728 * could take a very long time if the interpolated clock insists
729 * on strict monotonicity. The clock is reset under very strict
730 * conditions (kernel time is known to be wrong and
731 * synchronization daemon has been restarted recently.
732 * ffclock_boottime absorbs the jump to ensure boot time is
733 * correct and uptime functions stay consistent.
734 */
735 if (((ffclock_status & FFCLOCK_STA_UNSYNC) == FFCLOCK_STA_UNSYNC) &&
736 ((cest->status & FFCLOCK_STA_UNSYNC) == 0) &&
737 ((cest->status & FFCLOCK_STA_WARMUP) == FFCLOCK_STA_WARMUP)) {
738 if (forward_jump)
739 bintime_add(&ffclock_boottime, &gap_lerp);
740 else
741 bintime_sub(&ffclock_boottime, &gap_lerp);
742 ffth->tick_time_lerp = ffth->tick_time;
743 bintime_clear(&gap_lerp);
744 }
745
746 ffclock_status = cest->status;
747 ffth->period_lerp = cest->period;
748
749 /*
750 * Compute corrected period used for the linear interpolation of
751 * time. The rate of linear interpolation is capped to 5000PPM
752 * (5ms/s).
753 */
754 if (bintime_isset(&gap_lerp)) {
755 ffdelta = cest->update_ffcount;
756 ffdelta -= fftimehands->cest.update_ffcount;
757 ffclock_convert_delta(ffdelta, cest->period, &bt);
758 polling = bt.sec;
759 bt.sec = 0;
760 bt.frac = 5000000 * (uint64_t)18446744073LL;
761 bintime_mul(&bt, polling);
762 if (bintime_cmp(&gap_lerp, &bt, >))
763 gap_lerp = bt;
764
765 /* Approximate 1 sec by 1-(1/2^64) to ease arithmetic */
766 frac = 0;
767 if (gap_lerp.sec > 0) {
768 frac -= 1;
769 frac /= ffdelta / gap_lerp.sec;
770 }
771 frac += gap_lerp.frac / ffdelta;
772
773 if (forward_jump)
774 ffth->period_lerp += frac;
775 else
776 ffth->period_lerp -= frac;
777 }
778
779 ffclock_updated = 0;
780 }
781 if (++ogen == 0)
782 ogen = 1;
783 ffth->gen = ogen;
784 fftimehands = ffth;
785}
786
787/*
788 * Adjust the fftimehands when the timecounter is changed. Stating the obvious,
789 * the old and new hardware counter cannot be read simultaneously. tc_windup()
790 * does read the two counters 'back to back', but a few cycles are effectively
791 * lost, and not accumulated in tick_ffcount. This is a fairly radical
792 * operation for a feed-forward synchronization daemon, and it is its job to not
793 * pushing irrelevant data to the kernel. Because there is no locking here,
794 * simply force to ignore pending or next update to give daemon a chance to
795 * realize the counter has changed.
796 */
797static void
798ffclock_change_tc(struct timehands *th)
799{
800 struct fftimehands *ffth;
801 struct ffclock_estimate *cest;
802 struct timecounter *tc;
803 uint8_t ogen;
804
805 tc = th->th_counter;
806 ffth = fftimehands->next;
807 ogen = ffth->gen;
808 ffth->gen = 0;
809
810 cest = &ffth->cest;
811 bcopy(&(fftimehands->cest), cest, sizeof(struct ffclock_estimate));
812 cest->period = ((1ULL << 63) / tc->tc_frequency ) << 1;
813 cest->errb_abs = 0;
814 cest->errb_rate = 0;
815 cest->status |= FFCLOCK_STA_UNSYNC;
816
817 ffth->tick_ffcount = fftimehands->tick_ffcount;
818 ffth->tick_time_lerp = fftimehands->tick_time_lerp;
819 ffth->tick_time = fftimehands->tick_time;
820 ffth->period_lerp = cest->period;
821
822 /* Do not lock but ignore next update from synchronization daemon. */
823 ffclock_updated--;
824
825 if (++ogen == 0)
826 ogen = 1;
827 ffth->gen = ogen;
828 fftimehands = ffth;
829}
830
831/*
832 * Retrieve feed-forward counter and time of last kernel tick.
833 */
834void
835ffclock_last_tick(ffcounter *ffcount, struct bintime *bt, uint32_t flags)
836{
837 struct fftimehands *ffth;
838 uint8_t gen;
839
840 /*
841 * No locking but check generation has not changed. Also need to make
842 * sure ffdelta is positive, i.e. ffcount > tick_ffcount.
843 */
844 do {
845 ffth = fftimehands;
846 gen = ffth->gen;
847 if ((flags & FFCLOCK_LERP) == FFCLOCK_LERP)
848 *bt = ffth->tick_time_lerp;
849 else
850 *bt = ffth->tick_time;
851 *ffcount = ffth->tick_ffcount;
852 } while (gen == 0 || gen != ffth->gen);
853}
854
855/*
856 * Absolute clock conversion. Low level function to convert ffcounter to
857 * bintime. The ffcounter is converted using the current ffclock period estimate
858 * or the "interpolated period" to ensure monotonicity.
859 * NOTE: this conversion may have been deferred, and the clock updated since the
860 * hardware counter has been read.
861 */
862void
863ffclock_convert_abs(ffcounter ffcount, struct bintime *bt, uint32_t flags)
864{
865 struct fftimehands *ffth;
866 struct bintime bt2;
867 ffcounter ffdelta;
868 uint8_t gen;
869
870 /*
871 * No locking but check generation has not changed. Also need to make
872 * sure ffdelta is positive, i.e. ffcount > tick_ffcount.
873 */
874 do {
875 ffth = fftimehands;
876 gen = ffth->gen;
877 if (ffcount > ffth->tick_ffcount)
878 ffdelta = ffcount - ffth->tick_ffcount;
879 else
880 ffdelta = ffth->tick_ffcount - ffcount;
881
882 if ((flags & FFCLOCK_LERP) == FFCLOCK_LERP) {
883 *bt = ffth->tick_time_lerp;
884 ffclock_convert_delta(ffdelta, ffth->period_lerp, &bt2);
885 } else {
886 *bt = ffth->tick_time;
887 ffclock_convert_delta(ffdelta, ffth->cest.period, &bt2);
888 }
889
890 if (ffcount > ffth->tick_ffcount)
891 bintime_add(bt, &bt2);
892 else
893 bintime_sub(bt, &bt2);
894 } while (gen == 0 || gen != ffth->gen);
895}
896
897/*
898 * Difference clock conversion.
899 * Low level function to Convert a time interval measured in RAW counter units
900 * into bintime. The difference clock allows measuring small intervals much more
901 * reliably than the absolute clock.
902 */
903void
904ffclock_convert_diff(ffcounter ffdelta, struct bintime *bt)
905{
906 struct fftimehands *ffth;
907 uint8_t gen;
908
909 /* No locking but check generation has not changed. */
910 do {
911 ffth = fftimehands;
912 gen = ffth->gen;
913 ffclock_convert_delta(ffdelta, ffth->cest.period, bt);
914 } while (gen == 0 || gen != ffth->gen);
915}
916
917/*
918 * Access to current ffcounter value.
919 */
920void
921ffclock_read_counter(ffcounter *ffcount)
922{
923 struct timehands *th;
924 struct fftimehands *ffth;
925 unsigned int gen, delta;
926
927 /*
928 * ffclock_windup() called from tc_windup(), safe to rely on
929 * th->th_generation only, for correct delta and ffcounter.
930 */
931 do {
932 th = timehands;
933 gen = atomic_load_acq_int(&th->th_generation);
934 ffth = fftimehands;
935 delta = tc_delta(th);
936 *ffcount = ffth->tick_ffcount;
937 atomic_thread_fence_acq();
938 } while (gen == 0 || gen != th->th_generation);
939
940 *ffcount += delta;
941}
942
943void
944binuptime(struct bintime *bt)
945{
946
947 binuptime_fromclock(bt, sysclock_active);
948}
949
950void
951nanouptime(struct timespec *tsp)
952{
953
954 nanouptime_fromclock(tsp, sysclock_active);
955}
956
957void
958microuptime(struct timeval *tvp)
959{
960
961 microuptime_fromclock(tvp, sysclock_active);
962}
963
964void
965bintime(struct bintime *bt)
966{
967
968 bintime_fromclock(bt, sysclock_active);
969}
970
971void
972nanotime(struct timespec *tsp)
973{
974
975 nanotime_fromclock(tsp, sysclock_active);
976}
977
978void
979microtime(struct timeval *tvp)
980{
981
982 microtime_fromclock(tvp, sysclock_active);
983}
984
985void
986getbinuptime(struct bintime *bt)
987{
988
989 getbinuptime_fromclock(bt, sysclock_active);
990}
991
992void
993getnanouptime(struct timespec *tsp)
994{
995
996 getnanouptime_fromclock(tsp, sysclock_active);
997}
998
999void
1000getmicrouptime(struct timeval *tvp)
1001{
1002
1003 getmicrouptime_fromclock(tvp, sysclock_active);
1004}
1005
1006void
1007getbintime(struct bintime *bt)
1008{
1009
1010 getbintime_fromclock(bt, sysclock_active);
1011}
1012
1013void
1014getnanotime(struct timespec *tsp)
1015{
1016
1017 getnanotime_fromclock(tsp, sysclock_active);
1018}
1019
1020void
1021getmicrotime(struct timeval *tvp)
1022{
1023
1024 getmicrouptime_fromclock(tvp, sysclock_active);
1025}
1026
1027#endif /* FFCLOCK */
1028
1029/*
1030 * This is a clone of getnanotime and used for walltimestamps.
1031 * The dtrace_ prefix prevents fbt from creating probes for
1032 * it so walltimestamp can be safely used in all fbt probes.
1033 */
1034void
1035dtrace_getnanotime(struct timespec *tsp)
1036{
1037 struct timehands *th;
1038 u_int gen;
1039
1040 do {
1041 th = timehands;
1042 gen = atomic_load_acq_int(&th->th_generation);
1043 *tsp = th->th_nanotime;
1044 atomic_thread_fence_acq();
1045 } while (gen == 0 || gen != th->th_generation);
1046}
1047
1048/*
1049 * System clock currently providing time to the system. Modifiable via sysctl
1050 * when the FFCLOCK option is defined.
1051 */
1052int sysclock_active = SYSCLOCK_FBCK;
1053
1054/* Internal NTP status and error estimates. */
1055extern int time_status;
1056extern long time_esterror;
1057
1058/*
1059 * Take a snapshot of sysclock data which can be used to compare system clocks
1060 * and generate timestamps after the fact.
1061 */
1062void
1063sysclock_getsnapshot(struct sysclock_snap *clock_snap, int fast)
1064{
1065 struct fbclock_info *fbi;
1066 struct timehands *th;
1067 struct bintime bt;
1068 unsigned int delta, gen;
1069#ifdef FFCLOCK
1070 ffcounter ffcount;
1071 struct fftimehands *ffth;
1072 struct ffclock_info *ffi;
1073 struct ffclock_estimate cest;
1074
1075 ffi = &clock_snap->ff_info;
1076#endif
1077
1078 fbi = &clock_snap->fb_info;
1079 delta = 0;
1080
1081 do {
1082 th = timehands;
1083 gen = atomic_load_acq_int(&th->th_generation);
1084 fbi->th_scale = th->th_scale;
1085 fbi->tick_time = th->th_offset;
1086#ifdef FFCLOCK
1087 ffth = fftimehands;
1088 ffi->tick_time = ffth->tick_time_lerp;
1089 ffi->tick_time_lerp = ffth->tick_time_lerp;
1090 ffi->period = ffth->cest.period;
1091 ffi->period_lerp = ffth->period_lerp;
1092 clock_snap->ffcount = ffth->tick_ffcount;
1093 cest = ffth->cest;
1094#endif
1095 if (!fast)
1096 delta = tc_delta(th);
1097 atomic_thread_fence_acq();
1098 } while (gen == 0 || gen != th->th_generation);
1099
1100 clock_snap->delta = delta;
1101 clock_snap->sysclock_active = sysclock_active;
1102
1103 /* Record feedback clock status and error. */
1104 clock_snap->fb_info.status = time_status;
1105 /* XXX: Very crude estimate of feedback clock error. */
1106 bt.sec = time_esterror / 1000000;
1107 bt.frac = ((time_esterror - bt.sec) * 1000000) *
1108 (uint64_t)18446744073709ULL;
1109 clock_snap->fb_info.error = bt;
1110
1111#ifdef FFCLOCK
1112 if (!fast)
1113 clock_snap->ffcount += delta;
1114
1115 /* Record feed-forward clock leap second adjustment. */
1116 ffi->leapsec_adjustment = cest.leapsec_total;
1117 if (clock_snap->ffcount > cest.leapsec_next)
1118 ffi->leapsec_adjustment -= cest.leapsec;
1119
1120 /* Record feed-forward clock status and error. */
1121 clock_snap->ff_info.status = cest.status;
1122 ffcount = clock_snap->ffcount - cest.update_ffcount;
1123 ffclock_convert_delta(ffcount, cest.period, &bt);
1124 /* 18446744073709 = int(2^64/1e12), err_bound_rate in [ps/s]. */
1125 bintime_mul(&bt, cest.errb_rate * (uint64_t)18446744073709ULL);
1126 /* 18446744073 = int(2^64 / 1e9), since err_abs in [ns]. */
1127 bintime_addx(&bt, cest.errb_abs * (uint64_t)18446744073ULL);
1128 clock_snap->ff_info.error = bt;
1129#endif
1130}
1131
1132/*
1133 * Convert a sysclock snapshot into a struct bintime based on the specified
1134 * clock source and flags.
1135 */
1136int
1137sysclock_snap2bintime(struct sysclock_snap *cs, struct bintime *bt,
1138 int whichclock, uint32_t flags)
1139{
1140 struct bintime boottimebin_x;
1141#ifdef FFCLOCK
1142 struct bintime bt2;
1143 uint64_t period;
1144#endif
1145
1146 switch (whichclock) {
1147 case SYSCLOCK_FBCK:
1148 *bt = cs->fb_info.tick_time;
1149
1150 /* If snapshot was created with !fast, delta will be >0. */
1151 if (cs->delta > 0)
1152 bintime_addx(bt, cs->fb_info.th_scale * cs->delta);
1153
1154 if ((flags & FBCLOCK_UPTIME) == 0) {
1155 getboottimebin(&boottimebin_x);
1156 bintime_add(bt, &boottimebin_x);
1157 }
1158 break;
1159#ifdef FFCLOCK
1160 case SYSCLOCK_FFWD:
1161 if (flags & FFCLOCK_LERP) {
1162 *bt = cs->ff_info.tick_time_lerp;
1163 period = cs->ff_info.period_lerp;
1164 } else {
1165 *bt = cs->ff_info.tick_time;
1166 period = cs->ff_info.period;
1167 }
1168
1169 /* If snapshot was created with !fast, delta will be >0. */
1170 if (cs->delta > 0) {
1171 ffclock_convert_delta(cs->delta, period, &bt2);
1172 bintime_add(bt, &bt2);
1173 }
1174
1175 /* Leap second adjustment. */
1176 if (flags & FFCLOCK_LEAPSEC)
1177 bt->sec -= cs->ff_info.leapsec_adjustment;
1178
1179 /* Boot time adjustment, for uptime/monotonic clocks. */
1180 if (flags & FFCLOCK_UPTIME)
1181 bintime_sub(bt, &ffclock_boottime);
1182 break;
1183#endif
1184 default:
1185 return (EINVAL);
1186 break;
1187 }
1188
1189 return (0);
1190}
1191
1192/*
1193 * Initialize a new timecounter and possibly use it.
1194 */
1195void
1196tc_init(struct timecounter *tc)
1197{
1198 u_int u;
1199 struct sysctl_oid *tc_root;
1200
1201 u = tc->tc_frequency / tc->tc_counter_mask;
1202 /* XXX: We need some margin here, 10% is a guess */
1203 u *= 11;
1204 u /= 10;
1205 if (u > hz && tc->tc_quality >= 0) {
1206 tc->tc_quality = -2000;
1207 if (bootverbose) {
1208 printf("Timecounter \"%s\" frequency %ju Hz",
1209 tc->tc_name, (uintmax_t)tc->tc_frequency);
1210 printf(" -- Insufficient hz, needs at least %u\n", u);
1211 }
1212 } else if (tc->tc_quality >= 0 || bootverbose) {
1213 printf("Timecounter \"%s\" frequency %ju Hz quality %d\n",
1214 tc->tc_name, (uintmax_t)tc->tc_frequency,
1215 tc->tc_quality);
1216 }
1217
1218 tc->tc_next = timecounters;
1219 timecounters = tc;
1220 /*
1221 * Set up sysctl tree for this counter.
1222 */
1223 tc_root = SYSCTL_ADD_NODE(NULL,
1224 SYSCTL_STATIC_CHILDREN(_kern_timecounter_tc), OID_AUTO, tc->tc_name,
1225 CTLFLAG_RW, 0, "timecounter description");
1226 SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
1227 "mask", CTLFLAG_RD, &(tc->tc_counter_mask), 0,
1228 "mask for implemented bits");
1229 SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
1230 "counter", CTLTYPE_UINT | CTLFLAG_RD, tc, sizeof(*tc),
1231 sysctl_kern_timecounter_get, "IU", "current timecounter value");
1232 SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
1233 "frequency", CTLTYPE_U64 | CTLFLAG_RD, tc, sizeof(*tc),
1234 sysctl_kern_timecounter_freq, "QU", "timecounter frequency");
1235 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO,
1236 "quality", CTLFLAG_RD, &(tc->tc_quality), 0,
1237 "goodness of time counter");
1238 /*
1239 * Do not automatically switch if the current tc was specifically
1240 * chosen. Never automatically use a timecounter with negative quality.
1241 * Even though we run on the dummy counter, switching here may be
1242 * worse since this timecounter may not be monotonic.
1243 */
1244 if (tc_chosen)
1245 return;
1246 if (tc->tc_quality < 0)
1247 return;
1248 if (tc->tc_quality < timecounter->tc_quality)
1249 return;
1250 if (tc->tc_quality == timecounter->tc_quality &&
1251 tc->tc_frequency < timecounter->tc_frequency)
1252 return;
1253 (void)tc->tc_get_timecount(tc);
1254 (void)tc->tc_get_timecount(tc);
1255 timecounter = tc;
1256}
1257
1258/* Report the frequency of the current timecounter. */
1259uint64_t
1260tc_getfrequency(void)
1261{
1262
1263 return (timehands->th_counter->tc_frequency);
1264}
1265
1266static struct mtx tc_setclock_mtx;
1267MTX_SYSINIT(tc_setclock_init, &tc_setclock_mtx, "tcsetc", MTX_SPIN);
1268
1269/*
1270 * Step our concept of UTC. This is done by modifying our estimate of
1271 * when we booted.
1272 */
1273void
1274tc_setclock(struct timespec *ts)
1275{
1276 struct timespec tbef, taft;
1277 struct bintime bt, bt2;
1278
1279 timespec2bintime(ts, &bt);
1280 nanotime(&tbef);
1281 mtx_lock_spin(&tc_setclock_mtx);
1282 cpu_tick_calibrate(1);
1283 binuptime(&bt2);
1284 bintime_sub(&bt, &bt2);
1285
1286 /* XXX fiddle all the little crinkly bits around the fiords... */
1287 tc_windup(&bt);
1288 mtx_unlock_spin(&tc_setclock_mtx);
1289 getboottimebin(&boottimebin);
1290 bintime2timeval(&boottimebin, &boottime);
1291 if (timestepwarnings) {
1292 nanotime(&taft);
1293 log(LOG_INFO,
1294 "Time stepped from %jd.%09ld to %jd.%09ld (%jd.%09ld)\n",
1295 (intmax_t)tbef.tv_sec, tbef.tv_nsec,
1296 (intmax_t)taft.tv_sec, taft.tv_nsec,
1297 (intmax_t)ts->tv_sec, ts->tv_nsec);
1298 }
1299}
1300
1301/*
1302 * Initialize the next struct timehands in the ring and make
1303 * it the active timehands. Along the way we might switch to a different
1304 * timecounter and/or do seconds processing in NTP. Slightly magic.
1305 */
1306static void
1307tc_windup(struct bintime *new_boottimebin)
1308{
1309 struct bintime bt;
1310 struct timehands *th, *tho;
1311 uint64_t scale;
1312 u_int delta, ncount, ogen;
1313 int i;
1314 time_t t;
1315
1316 /*
1317 * Make the next timehands a copy of the current one, but do
1318 * not overwrite the generation or next pointer. While we
1319 * update the contents, the generation must be zero. We need
1320 * to ensure that the zero generation is visible before the
1321 * data updates become visible, which requires release fence.
1322 * For similar reasons, re-reading of the generation after the
1323 * data is read should use acquire fence.
1324 */
1325 tho = timehands;
1326 th = tho->th_next;
1327 ogen = th->th_generation;
1328 th->th_generation = 0;
1329 atomic_thread_fence_rel();
1330 bcopy(tho, th, offsetof(struct timehands, th_generation));
1331 if (new_boottimebin != NULL)
1332 th->th_boottime = *new_boottimebin;
1333
1334 /*
1335 * Capture a timecounter delta on the current timecounter and if
1336 * changing timecounters, a counter value from the new timecounter.
1337 * Update the offset fields accordingly.
1338 */
1339 delta = tc_delta(th);
1340 if (th->th_counter != timecounter)
1341 ncount = timecounter->tc_get_timecount(timecounter);
1342 else
1343 ncount = 0;
1344#ifdef FFCLOCK
1345 ffclock_windup(delta);
1346#endif
1347 th->th_offset_count += delta;
1348 th->th_offset_count &= th->th_counter->tc_counter_mask;
1349 while (delta > th->th_counter->tc_frequency) {
1350 /* Eat complete unadjusted seconds. */
1351 delta -= th->th_counter->tc_frequency;
1352 th->th_offset.sec++;
1353 }
1354 if ((delta > th->th_counter->tc_frequency / 2) &&
1355 (th->th_scale * delta < ((uint64_t)1 << 63))) {
1356 /* The product th_scale * delta just barely overflows. */
1357 th->th_offset.sec++;
1358 }
1359 bintime_addx(&th->th_offset, th->th_scale * delta);
1360
1361 /*
1362 * Hardware latching timecounters may not generate interrupts on
1363 * PPS events, so instead we poll them. There is a finite risk that
1364 * the hardware might capture a count which is later than the one we
1365 * got above, and therefore possibly in the next NTP second which might
1366 * have a different rate than the current NTP second. It doesn't
1367 * matter in practice.
1368 */
1369 if (tho->th_counter->tc_poll_pps)
1370 tho->th_counter->tc_poll_pps(tho->th_counter);
1371
1372 /*
1373 * Deal with NTP second processing. The for loop normally
1374 * iterates at most once, but in extreme situations it might
1375 * keep NTP sane if timeouts are not run for several seconds.
1376 * At boot, the time step can be large when the TOD hardware
1377 * has been read, so on really large steps, we call
1378 * ntp_update_second only twice. We need to call it twice in
1379 * case we missed a leap second.
1380 */
1381 bt = th->th_offset;
1382 bintime_add(&bt, &th->th_boottime);
1383 i = bt.sec - tho->th_microtime.tv_sec;
1384 if (i > LARGE_STEP)
1385 i = 2;
1386 for (; i > 0; i--) {
1387 t = bt.sec;
1388 ntp_update_second(&th->th_adjustment, &bt.sec);
1389 if (bt.sec != t)
1390 th->th_boottime.sec += bt.sec - t;
1391 }
1392 th->th_bintime = th->th_offset;
1393 bintime_add(&th->th_bintime, &th->th_boottime);
1394 /* Update the UTC timestamps used by the get*() functions. */
1395 /* XXX shouldn't do this here. Should force non-`get' versions. */
1396 bintime2timeval(&bt, &th->th_microtime);
1397 bintime2timespec(&bt, &th->th_nanotime);
1398
1399 /* Now is a good time to change timecounters. */
1400 if (th->th_counter != timecounter) {
1401#ifndef __arm__
1402 if ((timecounter->tc_flags & TC_FLAGS_C2STOP) != 0)
1403 cpu_disable_c2_sleep++;
1404 if ((th->th_counter->tc_flags & TC_FLAGS_C2STOP) != 0)
1405 cpu_disable_c2_sleep--;
1406#endif
1407 th->th_counter = timecounter;
1408 th->th_offset_count = ncount;
1409 tc_min_ticktock_freq = max(1, timecounter->tc_frequency /
1410 (((uint64_t)timecounter->tc_counter_mask + 1) / 3));
1411#ifdef FFCLOCK
1412 ffclock_change_tc(th);
1413#endif
1414 }
1415
1416 /*-
1417 * Recalculate the scaling factor. We want the number of 1/2^64
1418 * fractions of a second per period of the hardware counter, taking
1419 * into account the th_adjustment factor which the NTP PLL/adjtime(2)
1420 * processing provides us with.
1421 *
1422 * The th_adjustment is nanoseconds per second with 32 bit binary
1423 * fraction and we want 64 bit binary fraction of second:
1424 *
1425 * x = a * 2^32 / 10^9 = a * 4.294967296
1426 *
1427 * The range of th_adjustment is +/- 5000PPM so inside a 64bit int
1428 * we can only multiply by about 850 without overflowing, that
1429 * leaves no suitably precise fractions for multiply before divide.
1430 *
1431 * Divide before multiply with a fraction of 2199/512 results in a
1432 * systematic undercompensation of 10PPM of th_adjustment. On a
1433 * 5000PPM adjustment this is a 0.05PPM error. This is acceptable.
1434 *
1435 * We happily sacrifice the lowest of the 64 bits of our result
1436 * to the goddess of code clarity.
1437 *
1438 */
1439 scale = (uint64_t)1 << 63;
1440 scale += (th->th_adjustment / 1024) * 2199;
1441 scale /= th->th_counter->tc_frequency;
1442 th->th_scale = scale * 2;
1443
1444 /*
1445 * Now that the struct timehands is again consistent, set the new
1446 * generation number, making sure to not make it zero.
1447 */
1448 if (++ogen == 0)
1449 ogen = 1;
1450 atomic_store_rel_int(&th->th_generation, ogen);
1451
1452 /* Go live with the new struct timehands. */
1453#ifdef FFCLOCK
1454 switch (sysclock_active) {
1455 case SYSCLOCK_FBCK:
1456#endif
1457 time_second = th->th_microtime.tv_sec;
1458 time_uptime = th->th_offset.sec;
1459#ifdef FFCLOCK
1460 break;
1461 case SYSCLOCK_FFWD:
1462 time_second = fftimehands->tick_time_lerp.sec;
1463 time_uptime = fftimehands->tick_time_lerp.sec - ffclock_boottime.sec;
1464 break;
1465 }
1466#endif
1467
1468 timehands = th;
1469 timekeep_push_vdso();
1470}
1471
1472/* Report or change the active timecounter hardware. */
1473static int
1474sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS)
1475{
1476 char newname[32];
1477 struct timecounter *newtc, *tc;
1478 int error;
1479
1480 tc = timecounter;
1481 strlcpy(newname, tc->tc_name, sizeof(newname));
1482
1483 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req);
1484 if (error != 0 || req->newptr == NULL)
1485 return (error);
1486 /* Record that the tc in use now was specifically chosen. */
1487 tc_chosen = 1;
1488 if (strcmp(newname, tc->tc_name) == 0)
1489 return (0);
1490 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) {
1491 if (strcmp(newname, newtc->tc_name) != 0)
1492 continue;
1493
1494 /* Warm up new timecounter. */
1495 (void)newtc->tc_get_timecount(newtc);
1496 (void)newtc->tc_get_timecount(newtc);
1497
1498 timecounter = newtc;
1499
1500 /*
1501 * The vdso timehands update is deferred until the next
1502 * 'tc_windup()'.
1503 *
1504 * This is prudent given that 'timekeep_push_vdso()' does not
1505 * use any locking and that it can be called in hard interrupt
1506 * context via 'tc_windup()'.
1507 */
1508 return (0);
1509 }
1510 return (EINVAL);
1511}
1512
1513SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW,
1514 0, 0, sysctl_kern_timecounter_hardware, "A",
1515 "Timecounter hardware selected");
1516
1517
1518/* Report the available timecounter hardware. */
1519static int
1520sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS)
1521{
1522 struct sbuf sb;
1523 struct timecounter *tc;
1524 int error;
1525
1526 sbuf_new_for_sysctl(&sb, NULL, 0, req);
1527 for (tc = timecounters; tc != NULL; tc = tc->tc_next) {
1528 if (tc != timecounters)
1529 sbuf_putc(&sb, ' ');
1530 sbuf_printf(&sb, "%s(%d)", tc->tc_name, tc->tc_quality);
1531 }
1532 error = sbuf_finish(&sb);
1533 sbuf_delete(&sb);
1534 return (error);
1535}
1536
1537SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice, CTLTYPE_STRING | CTLFLAG_RD,
1538 0, 0, sysctl_kern_timecounter_choice, "A", "Timecounter hardware detected");
1539
1540/*
1541 * RFC 2783 PPS-API implementation.
1542 */
1543
1544/*
1545 * Return true if the driver is aware of the abi version extensions in the
1546 * pps_state structure, and it supports at least the given abi version number.
1547 */
1548static inline int
1549abi_aware(struct pps_state *pps, int vers)
1550{
1551
1552 return ((pps->kcmode & KCMODE_ABIFLAG) && pps->driver_abi >= vers);
1553}
1554
1555static int
1556pps_fetch(struct pps_fetch_args *fapi, struct pps_state *pps)
1557{
1558 int err, timo;
1559 pps_seq_t aseq, cseq;
1560 struct timeval tv;
1561
1562 if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1563 return (EINVAL);
1564
1565 /*
1566 * If no timeout is requested, immediately return whatever values were
1567 * most recently captured. If timeout seconds is -1, that's a request
1568 * to block without a timeout. WITNESS won't let us sleep forever
1569 * without a lock (we really don't need a lock), so just repeatedly
1570 * sleep a long time.
1571 */
1572 if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec) {
1573 if (fapi->timeout.tv_sec == -1)
1574 timo = 0x7fffffff;
1575 else {
1576 tv.tv_sec = fapi->timeout.tv_sec;
1577 tv.tv_usec = fapi->timeout.tv_nsec / 1000;
1578 timo = tvtohz(&tv);
1579 }
1580 aseq = pps->ppsinfo.assert_sequence;
1581 cseq = pps->ppsinfo.clear_sequence;
1582 while (aseq == pps->ppsinfo.assert_sequence &&
1583 cseq == pps->ppsinfo.clear_sequence) {
1584 if (abi_aware(pps, 1) && pps->driver_mtx != NULL) {
1585 if (pps->flags & PPSFLAG_MTX_SPIN) {
1586 err = msleep_spin(pps, pps->driver_mtx,
1587 "ppsfch", timo);
1588 } else {
1589 err = msleep(pps, pps->driver_mtx, PCATCH,
1590 "ppsfch", timo);
1591 }
1592 } else {
1593 err = tsleep(pps, PCATCH, "ppsfch", timo);
1594 }
1595 if (err == EWOULDBLOCK) {
1596 if (fapi->timeout.tv_sec == -1) {
1597 continue;
1598 } else {
1599 return (ETIMEDOUT);
1600 }
1601 } else if (err != 0) {
1602 return (err);
1603 }
1604 }
1605 }
1606
1607 pps->ppsinfo.current_mode = pps->ppsparam.mode;
1608 fapi->pps_info_buf = pps->ppsinfo;
1609
1610 return (0);
1611}
1612
1613int
1614pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1615{
1616 pps_params_t *app;
1617 struct pps_fetch_args *fapi;
1618#ifdef FFCLOCK
1619 struct pps_fetch_ffc_args *fapi_ffc;
1620#endif
1621#ifdef PPS_SYNC
1622 struct pps_kcbind_args *kapi;
1623#endif
1624
1625 KASSERT(pps != NULL, ("NULL pps pointer in pps_ioctl"));
1626 switch (cmd) {
1627 case PPS_IOC_CREATE:
1628 return (0);
1629 case PPS_IOC_DESTROY:
1630 return (0);
1631 case PPS_IOC_SETPARAMS:
1632 app = (pps_params_t *)data;
1633 if (app->mode & ~pps->ppscap)
1634 return (EINVAL);
1635#ifdef FFCLOCK
1636 /* Ensure only a single clock is selected for ffc timestamp. */
1637 if ((app->mode & PPS_TSCLK_MASK) == PPS_TSCLK_MASK)
1638 return (EINVAL);
1639#endif
1640 pps->ppsparam = *app;
1641 return (0);
1642 case PPS_IOC_GETPARAMS:
1643 app = (pps_params_t *)data;
1644 *app = pps->ppsparam;
1645 app->api_version = PPS_API_VERS_1;
1646 return (0);
1647 case PPS_IOC_GETCAP:
1648 *(int*)data = pps->ppscap;
1649 return (0);
1650 case PPS_IOC_FETCH:
1651 fapi = (struct pps_fetch_args *)data;
1652 return (pps_fetch(fapi, pps));
1653#ifdef FFCLOCK
1654 case PPS_IOC_FETCH_FFCOUNTER:
1655 fapi_ffc = (struct pps_fetch_ffc_args *)data;
1656 if (fapi_ffc->tsformat && fapi_ffc->tsformat !=
1657 PPS_TSFMT_TSPEC)
1658 return (EINVAL);
1659 if (fapi_ffc->timeout.tv_sec || fapi_ffc->timeout.tv_nsec)
1660 return (EOPNOTSUPP);
1661 pps->ppsinfo_ffc.current_mode = pps->ppsparam.mode;
1662 fapi_ffc->pps_info_buf_ffc = pps->ppsinfo_ffc;
1663 /* Overwrite timestamps if feedback clock selected. */
1664 switch (pps->ppsparam.mode & PPS_TSCLK_MASK) {
1665 case PPS_TSCLK_FBCK:
1666 fapi_ffc->pps_info_buf_ffc.assert_timestamp =
1667 pps->ppsinfo.assert_timestamp;
1668 fapi_ffc->pps_info_buf_ffc.clear_timestamp =
1669 pps->ppsinfo.clear_timestamp;
1670 break;
1671 case PPS_TSCLK_FFWD:
1672 break;
1673 default:
1674 break;
1675 }
1676 return (0);
1677#endif /* FFCLOCK */
1678 case PPS_IOC_KCBIND:
1679#ifdef PPS_SYNC
1680 kapi = (struct pps_kcbind_args *)data;
1681 /* XXX Only root should be able to do this */
1682 if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1683 return (EINVAL);
1684 if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1685 return (EINVAL);
1686 if (kapi->edge & ~pps->ppscap)
1687 return (EINVAL);
1688 pps->kcmode = (kapi->edge & KCMODE_EDGEMASK) |
1689 (pps->kcmode & KCMODE_ABIFLAG);
1690 return (0);
1691#else
1692 return (EOPNOTSUPP);
1693#endif
1694 default:
1695 return (ENOIOCTL);
1696 }
1697}
1698
1699void
1700pps_init(struct pps_state *pps)
1701{
1702 pps->ppscap |= PPS_TSFMT_TSPEC | PPS_CANWAIT;
1703 if (pps->ppscap & PPS_CAPTUREASSERT)
1704 pps->ppscap |= PPS_OFFSETASSERT;
1705 if (pps->ppscap & PPS_CAPTURECLEAR)
1706 pps->ppscap |= PPS_OFFSETCLEAR;
1707#ifdef FFCLOCK
1708 pps->ppscap |= PPS_TSCLK_MASK;
1709#endif
1710 pps->kcmode &= ~KCMODE_ABIFLAG;
1711}
1712
1713void
1714pps_init_abi(struct pps_state *pps)
1715{
1716
1717 pps_init(pps);
1718 if (pps->driver_abi > 0) {
1719 pps->kcmode |= KCMODE_ABIFLAG;
1720 pps->kernel_abi = PPS_ABI_VERSION;
1721 }
1722}
1723
1724void
1725pps_capture(struct pps_state *pps)
1726{
1727 struct timehands *th;
1728
1729 KASSERT(pps != NULL, ("NULL pps pointer in pps_capture"));
1730 th = timehands;
1731 pps->capgen = atomic_load_acq_int(&th->th_generation);
1732 pps->capth = th;
1733#ifdef FFCLOCK
1734 pps->capffth = fftimehands;
1735#endif
1736 pps->capcount = th->th_counter->tc_get_timecount(th->th_counter);
1737 atomic_thread_fence_acq();
1738 if (pps->capgen != th->th_generation)
1739 pps->capgen = 0;
1740}
1741
1742void
1743pps_event(struct pps_state *pps, int event)
1744{
1745 struct bintime bt;
1746 struct timespec ts, *tsp, *osp;
1747 u_int tcount, *pcount;
1748 int foff;
1749 pps_seq_t *pseq;
1750#ifdef FFCLOCK
1751 struct timespec *tsp_ffc;
1752 pps_seq_t *pseq_ffc;
1753 ffcounter *ffcount;
1754#endif
1755#ifdef PPS_SYNC
1756 int fhard;
1757#endif
1758
1759 KASSERT(pps != NULL, ("NULL pps pointer in pps_event"));
1760 /* Nothing to do if not currently set to capture this event type. */
1761 if ((event & pps->ppsparam.mode) == 0)
1762 return;
1763 /* If the timecounter was wound up underneath us, bail out. */
1764 if (pps->capgen == 0 || pps->capgen !=
1765 atomic_load_acq_int(&pps->capth->th_generation))
1766 return;
1767
1768 /* Things would be easier with arrays. */
1769 if (event == PPS_CAPTUREASSERT) {
1770 tsp = &pps->ppsinfo.assert_timestamp;
1771 osp = &pps->ppsparam.assert_offset;
1772 foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1773#ifdef PPS_SYNC
1774 fhard = pps->kcmode & PPS_CAPTUREASSERT;
1775#endif
1776 pcount = &pps->ppscount[0];
1777 pseq = &pps->ppsinfo.assert_sequence;
1778#ifdef FFCLOCK
1779 ffcount = &pps->ppsinfo_ffc.assert_ffcount;
1780 tsp_ffc = &pps->ppsinfo_ffc.assert_timestamp;
1781 pseq_ffc = &pps->ppsinfo_ffc.assert_sequence;
1782#endif
1783 } else {
1784 tsp = &pps->ppsinfo.clear_timestamp;
1785 osp = &pps->ppsparam.clear_offset;
1786 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1787#ifdef PPS_SYNC
1788 fhard = pps->kcmode & PPS_CAPTURECLEAR;
1789#endif
1790 pcount = &pps->ppscount[1];
1791 pseq = &pps->ppsinfo.clear_sequence;
1792#ifdef FFCLOCK
1793 ffcount = &pps->ppsinfo_ffc.clear_ffcount;
1794 tsp_ffc = &pps->ppsinfo_ffc.clear_timestamp;
1795 pseq_ffc = &pps->ppsinfo_ffc.clear_sequence;
1796#endif
1797 }
1798
1799 /*
1800 * If the timecounter changed, we cannot compare the count values, so
1801 * we have to drop the rest of the PPS-stuff until the next event.
1802 */
1803 if (pps->ppstc != pps->capth->th_counter) {
1804 pps->ppstc = pps->capth->th_counter;
1805 *pcount = pps->capcount;
1806 pps->ppscount[2] = pps->capcount;
1807 return;
1808 }
1809
1810 /* Convert the count to a timespec. */
1811 tcount = pps->capcount - pps->capth->th_offset_count;
1812 tcount &= pps->capth->th_counter->tc_counter_mask;
1813 bt = pps->capth->th_bintime;
1814 bintime_addx(&bt, pps->capth->th_scale * tcount);
1815 bintime2timespec(&bt, &ts);
1816
1817 /* If the timecounter was wound up underneath us, bail out. */
1818 atomic_thread_fence_acq();
1819 if (pps->capgen != pps->capth->th_generation)
1820 return;
1821
1822 *pcount = pps->capcount;
1823 (*pseq)++;
1824 *tsp = ts;
1825
1826 if (foff) {
1827 timespecadd(tsp, osp);
1828 if (tsp->tv_nsec < 0) {
1829 tsp->tv_nsec += 1000000000;
1830 tsp->tv_sec -= 1;
1831 }
1832 }
1833
1834#ifdef FFCLOCK
1835 *ffcount = pps->capffth->tick_ffcount + tcount;
1836 bt = pps->capffth->tick_time;
1837 ffclock_convert_delta(tcount, pps->capffth->cest.period, &bt);
1838 bintime_add(&bt, &pps->capffth->tick_time);
1839 bintime2timespec(&bt, &ts);
1840 (*pseq_ffc)++;
1841 *tsp_ffc = ts;
1842#endif
1843
1844#ifdef PPS_SYNC
1845 if (fhard) {
1846 uint64_t scale;
1847
1848 /*
1849 * Feed the NTP PLL/FLL.
1850 * The FLL wants to know how many (hardware) nanoseconds
1851 * elapsed since the previous event.
1852 */
1853 tcount = pps->capcount - pps->ppscount[2];
1854 pps->ppscount[2] = pps->capcount;
1855 tcount &= pps->capth->th_counter->tc_counter_mask;
1856 scale = (uint64_t)1 << 63;
1857 scale /= pps->capth->th_counter->tc_frequency;
1858 scale *= 2;
1859 bt.sec = 0;
1860 bt.frac = 0;
1861 bintime_addx(&bt, scale * tcount);
1862 bintime2timespec(&bt, &ts);
1863 hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec);
1864 }
1865#endif
1866
1867 /* Wakeup anyone sleeping in pps_fetch(). */
1868 wakeup(pps);
1869}
1870
1871/*
1872 * Timecounters need to be updated every so often to prevent the hardware
1873 * counter from overflowing. Updating also recalculates the cached values
1874 * used by the get*() family of functions, so their precision depends on
1875 * the update frequency.
1876 */
1877
1878static int tc_tick;
1879SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0,
1880 "Approximate number of hardclock ticks in a millisecond");
1881
1882void
1883tc_ticktock(int cnt)
1884{
1885 static int count;
1886
1887 if (mtx_trylock_spin(&tc_setclock_mtx)) {
1888 count += cnt;
1889 if (count >= tc_tick) {
1890 count = 0;
1891 tc_windup(NULL);
1892 }
1893 mtx_unlock_spin(&tc_setclock_mtx);
1894 }
1895}
1896
1897static void __inline
1898tc_adjprecision(void)
1899{
1900 int t;
1901
1902 if (tc_timepercentage > 0) {
1903 t = (99 + tc_timepercentage) / tc_timepercentage;
1904 tc_precexp = fls(t + (t >> 1)) - 1;
1905 FREQ2BT(hz / tc_tick, &bt_timethreshold);
1906 FREQ2BT(hz, &bt_tickthreshold);
1907 bintime_shift(&bt_timethreshold, tc_precexp);
1908 bintime_shift(&bt_tickthreshold, tc_precexp);
1909 } else {
1910 tc_precexp = 31;
1911 bt_timethreshold.sec = INT_MAX;
1912 bt_timethreshold.frac = ~(uint64_t)0;
1913 bt_tickthreshold = bt_timethreshold;
1914 }
1915 sbt_timethreshold = bttosbt(bt_timethreshold);
1916 sbt_tickthreshold = bttosbt(bt_tickthreshold);
1917}
1918
1919static int
1920sysctl_kern_timecounter_adjprecision(SYSCTL_HANDLER_ARGS)
1921{
1922 int error, val;
1923
1924 val = tc_timepercentage;
1925 error = sysctl_handle_int(oidp, &val, 0, req);
1926 if (error != 0 || req->newptr == NULL)
1927 return (error);
1928 tc_timepercentage = val;
1929 if (cold)
1930 goto done;
1931 tc_adjprecision();
1932done:
1933 return (0);
1934}
1935
1936static void
1937inittimecounter(void *dummy)
1938{
1939 u_int p;
1940 int tick_rate;
1941
1942 /*
1943 * Set the initial timeout to
1944 * max(1, <approx. number of hardclock ticks in a millisecond>).
1945 * People should probably not use the sysctl to set the timeout
1946 * to smaller than its initial value, since that value is the
1947 * smallest reasonable one. If they want better timestamps they
1948 * should use the non-"get"* functions.
1949 */
1950 if (hz > 1000)
1951 tc_tick = (hz + 500) / 1000;
1952 else
1953 tc_tick = 1;
1954 tc_adjprecision();
1955 FREQ2BT(hz, &tick_bt);
1956 tick_sbt = bttosbt(tick_bt);
1957 tick_rate = hz / tc_tick;
1958 FREQ2BT(tick_rate, &tc_tick_bt);
1959 tc_tick_sbt = bttosbt(tc_tick_bt);
1960 p = (tc_tick * 1000000) / hz;
1961 printf("Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000);
1962
1963#ifdef FFCLOCK
1964 ffclock_init();
1965#endif
1966 /* warm up new timecounter (again) and get rolling. */
1967 (void)timecounter->tc_get_timecount(timecounter);
1968 (void)timecounter->tc_get_timecount(timecounter);
1969 mtx_lock_spin(&tc_setclock_mtx);
1970 tc_windup(NULL);
1971 mtx_unlock_spin(&tc_setclock_mtx);
1972}
1973
1974SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL);
1975
1976/* Cpu tick handling -------------------------------------------------*/
1977
1978static int cpu_tick_variable;
1979static uint64_t cpu_tick_frequency;
1980
1981static DPCPU_DEFINE(uint64_t, tc_cpu_ticks_base);
1982static DPCPU_DEFINE(unsigned, tc_cpu_ticks_last);
1983
1984static uint64_t
1985tc_cpu_ticks(void)
1986{
1987 struct timecounter *tc;
1988 uint64_t res, *base;
1989 unsigned u, *last;
1990
1991 critical_enter();
1992 base = DPCPU_PTR(tc_cpu_ticks_base);
1993 last = DPCPU_PTR(tc_cpu_ticks_last);
1994 tc = timehands->th_counter;
1995 u = tc->tc_get_timecount(tc) & tc->tc_counter_mask;
1996 if (u < *last)
1997 *base += (uint64_t)tc->tc_counter_mask + 1;
1998 *last = u;
1999 res = u + *base;
2000 critical_exit();
2001 return (res);
2002}
2003
2004void
2005cpu_tick_calibration(void)
2006{
2007 static time_t last_calib;
2008
2009 if (time_uptime != last_calib && !(time_uptime & 0xf)) {
2010 cpu_tick_calibrate(0);
2011 last_calib = time_uptime;
2012 }
2013}
2014
2015/*
2016 * This function gets called every 16 seconds on only one designated
2017 * CPU in the system from hardclock() via cpu_tick_calibration()().
2018 *
2019 * Whenever the real time clock is stepped we get called with reset=1
2020 * to make sure we handle suspend/resume and similar events correctly.
2021 */
2022
2023static void
2024cpu_tick_calibrate(int reset)
2025{
2026 static uint64_t c_last;
2027 uint64_t c_this, c_delta;
2028 static struct bintime t_last;
2029 struct bintime t_this, t_delta;
2030 uint32_t divi;
2031
2032 if (reset) {
2033 /* The clock was stepped, abort & reset */
2034 t_last.sec = 0;
2035 return;
2036 }
2037
2038 /* we don't calibrate fixed rate cputicks */
2039 if (!cpu_tick_variable)
2040 return;
2041
2042 getbinuptime(&t_this);
2043 c_this = cpu_ticks();
2044 if (t_last.sec != 0) {
2045 c_delta = c_this - c_last;
2046 t_delta = t_this;
2047 bintime_sub(&t_delta, &t_last);
2048 /*
2049 * Headroom:
2050 * 2^(64-20) / 16[s] =
2051 * 2^(44) / 16[s] =
2052 * 17.592.186.044.416 / 16 =
2053 * 1.099.511.627.776 [Hz]
2054 */
2055 divi = t_delta.sec << 20;
2056 divi |= t_delta.frac >> (64 - 20);
2057 c_delta <<= 20;
2058 c_delta /= divi;
2059 if (c_delta > cpu_tick_frequency) {
2060 if (0 && bootverbose)
2061 printf("cpu_tick increased to %ju Hz\n",
2062 c_delta);
2063 cpu_tick_frequency = c_delta;
2064 }
2065 }
2066 c_last = c_this;
2067 t_last = t_this;
2068}
2069
2070void
2071set_cputicker(cpu_tick_f *func, uint64_t freq, unsigned var)
2072{
2073
2074 if (func == NULL) {
2075 cpu_ticks = tc_cpu_ticks;
2076 } else {
2077 cpu_tick_frequency = freq;
2078 cpu_tick_variable = var;
2079 cpu_ticks = func;
2080 }
2081}
2082
2083uint64_t
2084cpu_tickrate(void)
2085{
2086
2087 if (cpu_ticks == tc_cpu_ticks)
2088 return (tc_getfrequency());
2089 return (cpu_tick_frequency);
2090}
2091
2092/*
2093 * We need to be slightly careful converting cputicks to microseconds.
2094 * There is plenty of margin in 64 bits of microseconds (half a million
2095 * years) and in 64 bits at 4 GHz (146 years), but if we do a multiply
2096 * before divide conversion (to retain precision) we find that the
2097 * margin shrinks to 1.5 hours (one millionth of 146y).
2098 * With a three prong approach we never lose significant bits, no
2099 * matter what the cputick rate and length of timeinterval is.
2100 */
2101
2102uint64_t
2103cputick2usec(uint64_t tick)
2104{
2105
2106 if (tick > 18446744073709551LL) /* floor(2^64 / 1000) */
2107 return (tick / (cpu_tickrate() / 1000000LL));
2108 else if (tick > 18446744073709LL) /* floor(2^64 / 1000000) */
2109 return ((tick * 1000LL) / (cpu_tickrate() / 1000LL));
2110 else
2111 return ((tick * 1000000LL) / cpu_tickrate());
2112}
2113
2114cpu_tick_f *cpu_ticks = tc_cpu_ticks;
2115
2116static int vdso_th_enable = 1;
2117static int
2118sysctl_fast_gettime(SYSCTL_HANDLER_ARGS)
2119{
2120 int old_vdso_th_enable, error;
2121
2122 old_vdso_th_enable = vdso_th_enable;
2123 error = sysctl_handle_int(oidp, &old_vdso_th_enable, 0, req);
2124 if (error != 0)
2125 return (error);
2126 vdso_th_enable = old_vdso_th_enable;
2127 return (0);
2128}
2129SYSCTL_PROC(_kern_timecounter, OID_AUTO, fast_gettime,
2130 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
2131 NULL, 0, sysctl_fast_gettime, "I", "Enable fast time of day");
2132
2133uint32_t
2134tc_fill_vdso_timehands(struct vdso_timehands *vdso_th)
2135{
2136 struct timehands *th;
2137 uint32_t enabled;
2138
2139 th = timehands;
2140 vdso_th->th_scale = th->th_scale;
2141 vdso_th->th_offset_count = th->th_offset_count;
2142 vdso_th->th_counter_mask = th->th_counter->tc_counter_mask;
2143 vdso_th->th_offset = th->th_offset;
2144 vdso_th->th_boottime = th->th_boottime;
2145 if (th->th_counter->tc_fill_vdso_timehands != NULL) {
2146 enabled = th->th_counter->tc_fill_vdso_timehands(vdso_th,
2147 th->th_counter);
2148 } else
2149 enabled = 0;
2150 if (!vdso_th_enable)
2151 enabled = 0;
2152 return (enabled);
2153}
2154
2155#ifdef COMPAT_FREEBSD32
2156uint32_t
2157tc_fill_vdso_timehands32(struct vdso_timehands32 *vdso_th32)
2158{
2159 struct timehands *th;
2160 uint32_t enabled;
2161
2162 th = timehands;
2163 *(uint64_t *)&vdso_th32->th_scale[0] = th->th_scale;
2164 vdso_th32->th_offset_count = th->th_offset_count;
2165 vdso_th32->th_counter_mask = th->th_counter->tc_counter_mask;
2166 vdso_th32->th_offset.sec = th->th_offset.sec;
2167 *(uint64_t *)&vdso_th32->th_offset.frac[0] = th->th_offset.frac;
2168 vdso_th32->th_boottime.sec = th->th_boottime.sec;
2169 *(uint64_t *)&vdso_th32->th_boottime.frac[0] = th->th_boottime.frac;
2170 if (th->th_counter->tc_fill_vdso_timehands32 != NULL) {
2171 enabled = th->th_counter->tc_fill_vdso_timehands32(vdso_th32,
2172 th->th_counter);
2173 } else
2174 enabled = 0;
2175 if (!vdso_th_enable)
2176 enabled = 0;
2177 return (enabled);
2178}
2179#endif