Compensate for the frequency error that occurs at higher 'hz' settings.
[dragonfly.git] / sys / kern / kern_clock.c
CommitLineData
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1/*-
2 * Copyright (c) 1997, 1998 Poul-Henning Kamp <phk@FreeBSD.org>
3 * Copyright (c) 1982, 1986, 1991, 1993
4 * The Regents of the University of California. All rights reserved.
5 * (c) UNIX System Laboratories, Inc.
6 * All or some portions of this file are derived from material licensed
7 * to the University of California by American Telephone and Telegraph
8 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
9 * the permission of UNIX System Laboratories, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
40 * $FreeBSD: src/sys/kern/kern_clock.c,v 1.105.2.10 2002/10/17 13:19:40 maxim Exp $
435ff993 41 * $DragonFly: src/sys/kern/kern_clock.c,v 1.12 2003/10/17 07:30:42 dillon Exp $
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42 */
43
44#include "opt_ntp.h"
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/dkstat.h>
49#include <sys/callout.h>
50#include <sys/kernel.h>
51#include <sys/proc.h>
52#include <sys/malloc.h>
53#include <sys/resourcevar.h>
54#include <sys/signalvar.h>
55#include <sys/timex.h>
56#include <sys/timepps.h>
57#include <vm/vm.h>
58#include <sys/lock.h>
59#include <vm/pmap.h>
60#include <vm/vm_map.h>
61#include <sys/sysctl.h>
62
63#include <machine/cpu.h>
64#include <machine/limits.h>
65#include <machine/smp.h>
66
67#ifdef GPROF
68#include <sys/gmon.h>
69#endif
70
71#ifdef DEVICE_POLLING
72extern void init_device_poll(void);
73extern void hardclock_device_poll(void);
74#endif /* DEVICE_POLLING */
75
76/*
77 * Number of timecounters used to implement stable storage
78 */
79#ifndef NTIMECOUNTER
80#define NTIMECOUNTER 5
81#endif
82
83static MALLOC_DEFINE(M_TIMECOUNTER, "timecounter",
84 "Timecounter stable storage");
85
402ed7e1 86static void initclocks (void *dummy);
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87SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
88
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89static void tco_forward (int force);
90static void tco_setscales (struct timecounter *tc);
91static __inline unsigned tco_delta (struct timecounter *tc);
984263bc 92
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93/*
94 * Some of these don't belong here, but it's easiest to concentrate them.
95 * Note that cp_time[] counts in microseconds, but most userland programs
96 * just compare relative times against the total by delta.
97 */
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98long cp_time[CPUSTATES];
99
100SYSCTL_OPAQUE(_kern, OID_AUTO, cp_time, CTLFLAG_RD, &cp_time, sizeof(cp_time),
101 "LU", "CPU time statistics");
102
103long tk_cancc;
104long tk_nin;
105long tk_nout;
106long tk_rawcc;
107
108time_t time_second;
109
110struct timeval boottime;
111SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
112 &boottime, timeval, "System boottime");
113
114/*
115 * Which update policy to use.
116 * 0 - every tick, bad hardware may fail with "calcru negative..."
117 * 1 - more resistent to the above hardware, but less efficient.
118 */
119static int tco_method;
120
121/*
122 * Implement a dummy timecounter which we can use until we get a real one
123 * in the air. This allows the console and other early stuff to use
124 * timeservices.
125 */
126
127static unsigned
128dummy_get_timecount(struct timecounter *tc)
129{
130 static unsigned now;
131 return (++now);
132}
133
134static struct timecounter dummy_timecounter = {
135 dummy_get_timecount,
136 0,
137 ~0u,
138 1000000,
139 "dummy"
140};
141
142struct timecounter *timecounter = &dummy_timecounter;
143
144/*
145 * Clock handling routines.
146 *
147 * This code is written to operate with two timers that run independently of
148 * each other.
149 *
150 * The main timer, running hz times per second, is used to trigger interval
151 * timers, timeouts and rescheduling as needed.
152 *
153 * The second timer handles kernel and user profiling,
154 * and does resource use estimation. If the second timer is programmable,
155 * it is randomized to avoid aliasing between the two clocks. For example,
156 * the randomization prevents an adversary from always giving up the cpu
157 * just before its quantum expires. Otherwise, it would never accumulate
158 * cpu ticks. The mean frequency of the second timer is stathz.
159 *
160 * If no second timer exists, stathz will be zero; in this case we drive
161 * profiling and statistics off the main clock. This WILL NOT be accurate;
162 * do not do it unless absolutely necessary.
163 *
164 * The statistics clock may (or may not) be run at a higher rate while
165 * profiling. This profile clock runs at profhz. We require that profhz
166 * be an integral multiple of stathz.
167 *
168 * If the statistics clock is running fast, it must be divided by the ratio
169 * profhz/stathz for statistics. (For profiling, every tick counts.)
170 *
171 * Time-of-day is maintained using a "timecounter", which may or may
172 * not be related to the hardware generating the above mentioned
173 * interrupts.
174 */
175
176int stathz;
177int profhz;
178static int profprocs;
179int ticks;
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180static int psticks; /* profiler ticks */
181static int psdiv; /* prof / stat divider */
182int psratio; /* ratio: prof * 100 / stat */
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183
184/*
185 * Initialize clock frequencies and start both clocks running.
186 */
187/* ARGSUSED*/
188static void
189initclocks(dummy)
190 void *dummy;
191{
1fd87d54 192 int i;
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193
194 /*
195 * Set divisors to 1 (normal case) and let the machine-specific
196 * code do its bit.
197 */
6ad39cae 198 psdiv = 1;
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199 cpu_initclocks();
200
201#ifdef DEVICE_POLLING
202 init_device_poll();
203#endif
204
205 /*
206 * Compute profhz/stathz, and fix profhz if needed.
207 */
208 i = stathz ? stathz : hz;
209 if (profhz == 0)
210 profhz = i;
211 psratio = profhz / i;
212}
213
214/*
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215 * The real-time timer, interrupting hz times per second. This is implemented
216 * as a FAST interrupt so it is in the context of the thread it interrupted,
217 * and not in an interrupt thread. YYY needs help.
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218 */
219void
220hardclock(frame)
1fd87d54 221 struct clockframe *frame;
984263bc 222{
1fd87d54 223 struct proc *p;
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224
225 p = curproc;
226 if (p) {
1fd87d54 227 struct pstats *pstats;
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228
229 /*
230 * Run current process's virtual and profile time, as needed.
231 */
232 pstats = p->p_stats;
233 if (CLKF_USERMODE(frame) &&
234 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) &&
235 itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0)
236 psignal(p, SIGVTALRM);
237 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value) &&
238 itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0)
239 psignal(p, SIGPROF);
240 }
241
6ad39cae 242#if 0 /* SMP and BETTER_CLOCK */
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243 forward_hardclock(pscnt);
244#endif
245
246 /*
247 * If no separate statistics clock is available, run it from here.
248 */
249 if (stathz == 0)
250 statclock(frame);
251
252 tco_forward(0);
253 ticks++;
254
255#ifdef DEVICE_POLLING
256 hardclock_device_poll(); /* this is very short and quick */
257#endif /* DEVICE_POLLING */
258
259 /*
260 * Process callouts at a very low cpu priority, so we don't keep the
261 * relatively high clock interrupt priority any longer than necessary.
262 */
263 if (TAILQ_FIRST(&callwheel[ticks & callwheelmask]) != NULL) {
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264 setsoftclock();
265 } else if (softticks + 1 == ticks) {
984263bc 266 ++softticks;
b68b7282 267 }
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268}
269
270/*
271 * Compute number of ticks in the specified amount of time.
272 */
273int
274tvtohz(tv)
275 struct timeval *tv;
276{
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277 unsigned long ticks;
278 long sec, usec;
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279
280 /*
281 * If the number of usecs in the whole seconds part of the time
282 * difference fits in a long, then the total number of usecs will
283 * fit in an unsigned long. Compute the total and convert it to
284 * ticks, rounding up and adding 1 to allow for the current tick
285 * to expire. Rounding also depends on unsigned long arithmetic
286 * to avoid overflow.
287 *
288 * Otherwise, if the number of ticks in the whole seconds part of
289 * the time difference fits in a long, then convert the parts to
290 * ticks separately and add, using similar rounding methods and
291 * overflow avoidance. This method would work in the previous
292 * case but it is slightly slower and assumes that hz is integral.
293 *
294 * Otherwise, round the time difference down to the maximum
295 * representable value.
296 *
297 * If ints have 32 bits, then the maximum value for any timeout in
298 * 10ms ticks is 248 days.
299 */
300 sec = tv->tv_sec;
301 usec = tv->tv_usec;
302 if (usec < 0) {
303 sec--;
304 usec += 1000000;
305 }
306 if (sec < 0) {
307#ifdef DIAGNOSTIC
308 if (usec > 0) {
309 sec++;
310 usec -= 1000000;
311 }
312 printf("tvotohz: negative time difference %ld sec %ld usec\n",
313 sec, usec);
314#endif
315 ticks = 1;
316 } else if (sec <= LONG_MAX / 1000000)
317 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
318 / tick + 1;
319 else if (sec <= LONG_MAX / hz)
320 ticks = sec * hz
321 + ((unsigned long)usec + (tick - 1)) / tick + 1;
322 else
323 ticks = LONG_MAX;
324 if (ticks > INT_MAX)
325 ticks = INT_MAX;
326 return ((int)ticks);
327}
328
329/*
330 * Start profiling on a process.
331 *
332 * Kernel profiling passes proc0 which never exits and hence
333 * keeps the profile clock running constantly.
334 */
335void
336startprofclock(p)
1fd87d54 337 struct proc *p;
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338{
339 int s;
340
341 if ((p->p_flag & P_PROFIL) == 0) {
342 p->p_flag |= P_PROFIL;
343 if (++profprocs == 1 && stathz != 0) {
344 s = splstatclock();
6ad39cae 345 psdiv = psratio;
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346 setstatclockrate(profhz);
347 splx(s);
348 }
349 }
350}
351
352/*
353 * Stop profiling on a process.
354 */
355void
356stopprofclock(p)
1fd87d54 357 struct proc *p;
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358{
359 int s;
360
361 if (p->p_flag & P_PROFIL) {
362 p->p_flag &= ~P_PROFIL;
363 if (--profprocs == 0 && stathz != 0) {
364 s = splstatclock();
6ad39cae 365 psdiv = 1;
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366 setstatclockrate(stathz);
367 splx(s);
368 }
369 }
370}
371
372/*
373 * Statistics clock. Grab profile sample, and if divider reaches 0,
374 * do process and kernel statistics. Most of the statistics are only
375 * used by user-level statistics programs. The main exceptions are
376 * p->p_uticks, p->p_sticks, p->p_iticks, and p->p_estcpu.
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377 *
378 * The statclock should be called from an exclusive, fast interrupt,
379 * so the context should be the thread/process that got interrupted and
380 * not an interrupt thread.
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381 */
382void
383statclock(frame)
1fd87d54 384 struct clockframe *frame;
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385{
386#ifdef GPROF
1fd87d54 387 struct gmonparam *g;
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388 int i;
389#endif
d16a8831 390 thread_t td;
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391 struct pstats *pstats;
392 long rss;
393 struct rusage *ru;
394 struct vmspace *vm;
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395 struct proc *p;
396 int bump;
397 struct timeval tv;
398 struct timeval *stv;
984263bc 399
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400 /*
401 * How big was our timeslice relative to the last time
402 */
403 microuptime(&tv);
404 stv = &mycpu->gd_stattv;
405 if (stv->tv_sec == 0) {
406 bump = 1;
407 } else {
408 bump = tv.tv_usec - stv->tv_usec +
409 (tv.tv_sec - stv->tv_sec) * 1000000;
410 if (bump < 0)
411 bump = 0;
412 if (bump > 1000000)
413 bump = 1000000;
414 }
415 *stv = tv;
416
417 td = curthread;
418 p = td->td_proc;
419
420 if (CLKF_USERMODE(frame)) {
984263bc 421 /*
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422 * Came from userland, handle user time and deal with
423 * possible process.
984263bc 424 */
d16a8831 425 if (p && (p->p_flag & P_PROFIL))
984263bc 426 addupc_intr(p, CLKF_PC(frame), 1);
6ad39cae 427#if 0 /* SMP and BETTER_CLOCK */
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428 if (stathz != 0)
429 forward_statclock(pscnt);
430#endif
d16a8831 431 td->td_uticks += bump;
d16a8831 432
984263bc 433 /*
d16a8831 434 * Charge the time as appropriate
984263bc 435 */
d16a8831 436 if (p && p->p_nice > NZERO)
6ad39cae 437 cp_time[CP_NICE] += bump;
984263bc 438 else
6ad39cae 439 cp_time[CP_USER] += bump;
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440 } else {
441#ifdef GPROF
442 /*
443 * Kernel statistics are just like addupc_intr, only easier.
444 */
445 g = &_gmonparam;
446 if (g->state == GMON_PROF_ON) {
447 i = CLKF_PC(frame) - g->lowpc;
448 if (i < g->textsize) {
449 i /= HISTFRACTION * sizeof(*g->kcount);
450 g->kcount[i]++;
451 }
452 }
453#endif
6ad39cae 454#if 0 /* SMP and BETTER_CLOCK */
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455 if (stathz != 0)
456 forward_statclock(pscnt);
457#endif
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458 /*
459 * Came from kernel mode, so we were:
460 * - handling an interrupt,
461 * - doing syscall or trap work on behalf of the current
462 * user process, or
463 * - spinning in the idle loop.
464 * Whichever it is, charge the time as appropriate.
465 * Note that we charge interrupts to the current process,
466 * regardless of whether they are ``for'' that process,
467 * so that we know how much of its real time was spent
468 * in ``non-process'' (i.e., interrupt) work.
469 */
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470 if (CLKF_INTR(frame))
471 td->td_iticks += bump;
472 else
473 td->td_sticks += bump;
474
984263bc 475 if (CLKF_INTR(frame)) {
6ad39cae 476 cp_time[CP_INTR] += bump;
d16a8831 477 } else {
a2a5ad0d 478 if (td == &mycpu->gd_idlethread)
6ad39cae 479 cp_time[CP_IDLE] += bump;
d16a8831 480 else
6ad39cae 481 cp_time[CP_SYS] += bump;
d16a8831 482 }
984263bc 483 }
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484
485 /*
486 * bump psticks and check against gd_psticks. When we hit the
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487 * 1*hz mark (psdiv ticks) we do the more expensive stuff. If
488 * psdiv changes we reset everything to avoid confusion.
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489 */
490 ++psticks;
18ec3a74 491 if (psticks < mycpu->gd_psticks && psdiv == mycpu->gd_psdiv)
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492 return;
493
494 mycpu->gd_psdiv = psdiv;
495 mycpu->gd_psticks = psticks + psdiv;
984263bc 496
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497 /*
498 * XXX YYY DragonFly... need to rewrite all of this,
499 * only schedclock is distributed at the moment
500 */
501 schedclock(NULL);
502#ifdef SMP
503 if (smp_started && invltlb_ok && !cold && !panicstr) /* YYY */
504 lwkt_send_ipiq_mask(mycpu->gd_other_cpus, schedclock, NULL);
505#endif
984263bc 506
435ff993 507 if (p != NULL) {
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508 /* Update resource usage integrals and maximums. */
509 if ((pstats = p->p_stats) != NULL &&
510 (ru = &pstats->p_ru) != NULL &&
511 (vm = p->p_vmspace) != NULL) {
512 ru->ru_ixrss += pgtok(vm->vm_tsize);
513 ru->ru_idrss += pgtok(vm->vm_dsize);
514 ru->ru_isrss += pgtok(vm->vm_ssize);
515 rss = pgtok(vmspace_resident_count(vm));
516 if (ru->ru_maxrss < rss)
517 ru->ru_maxrss = rss;
518 }
519 }
520}
521
522/*
523 * Return information about system clocks.
524 */
525static int
526sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
527{
528 struct clockinfo clkinfo;
529 /*
530 * Construct clockinfo structure.
531 */
532 clkinfo.hz = hz;
533 clkinfo.tick = tick;
534 clkinfo.tickadj = tickadj;
535 clkinfo.profhz = profhz;
536 clkinfo.stathz = stathz ? stathz : hz;
537 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
538}
539
540SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
541 0, 0, sysctl_kern_clockrate, "S,clockinfo","");
542
543static __inline unsigned
544tco_delta(struct timecounter *tc)
545{
546
547 return ((tc->tc_get_timecount(tc) - tc->tc_offset_count) &
548 tc->tc_counter_mask);
549}
550
551/*
552 * We have eight functions for looking at the clock, four for
553 * microseconds and four for nanoseconds. For each there is fast
554 * but less precise version "get{nano|micro}[up]time" which will
555 * return a time which is up to 1/HZ previous to the call, whereas
556 * the raw version "{nano|micro}[up]time" will return a timestamp
557 * which is as precise as possible. The "up" variants return the
558 * time relative to system boot, these are well suited for time
559 * interval measurements.
560 */
561
562void
563getmicrotime(struct timeval *tvp)
564{
565 struct timecounter *tc;
566
567 if (!tco_method) {
568 tc = timecounter;
569 *tvp = tc->tc_microtime;
570 } else {
571 microtime(tvp);
572 }
573}
574
575void
576getnanotime(struct timespec *tsp)
577{
578 struct timecounter *tc;
579
580 if (!tco_method) {
581 tc = timecounter;
582 *tsp = tc->tc_nanotime;
583 } else {
584 nanotime(tsp);
585 }
586}
587
588void
589microtime(struct timeval *tv)
590{
591 struct timecounter *tc;
592
593 tc = timecounter;
594 tv->tv_sec = tc->tc_offset_sec;
595 tv->tv_usec = tc->tc_offset_micro;
596 tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32;
597 tv->tv_usec += boottime.tv_usec;
598 tv->tv_sec += boottime.tv_sec;
599 while (tv->tv_usec < 0) {
600 tv->tv_usec += 1000000;
601 if (tv->tv_sec > 0)
602 tv->tv_sec--;
603 }
604 while (tv->tv_usec >= 1000000) {
605 tv->tv_usec -= 1000000;
606 tv->tv_sec++;
607 }
608}
609
610void
611nanotime(struct timespec *ts)
612{
613 unsigned count;
614 u_int64_t delta;
615 struct timecounter *tc;
616
617 tc = timecounter;
618 ts->tv_sec = tc->tc_offset_sec;
619 count = tco_delta(tc);
620 delta = tc->tc_offset_nano;
621 delta += ((u_int64_t)count * tc->tc_scale_nano_f);
622 delta >>= 32;
623 delta += ((u_int64_t)count * tc->tc_scale_nano_i);
624 delta += boottime.tv_usec * 1000;
625 ts->tv_sec += boottime.tv_sec;
626 while (delta < 0) {
627 delta += 1000000000;
628 if (ts->tv_sec > 0)
629 ts->tv_sec--;
630 }
631 while (delta >= 1000000000) {
632 delta -= 1000000000;
633 ts->tv_sec++;
634 }
635 ts->tv_nsec = delta;
636}
637
638void
639getmicrouptime(struct timeval *tvp)
640{
641 struct timecounter *tc;
642
643 if (!tco_method) {
644 tc = timecounter;
645 tvp->tv_sec = tc->tc_offset_sec;
646 tvp->tv_usec = tc->tc_offset_micro;
647 } else {
648 microuptime(tvp);
649 }
650}
651
652void
653getnanouptime(struct timespec *tsp)
654{
655 struct timecounter *tc;
656
657 if (!tco_method) {
658 tc = timecounter;
659 tsp->tv_sec = tc->tc_offset_sec;
660 tsp->tv_nsec = tc->tc_offset_nano >> 32;
661 } else {
662 nanouptime(tsp);
663 }
664}
665
666void
667microuptime(struct timeval *tv)
668{
669 struct timecounter *tc;
670
671 tc = timecounter;
672 tv->tv_sec = tc->tc_offset_sec;
673 tv->tv_usec = tc->tc_offset_micro;
674 tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32;
675 while (tv->tv_usec < 0) {
676 tv->tv_usec += 1000000;
677 if (tv->tv_sec > 0)
678 tv->tv_sec--;
679 }
680 while (tv->tv_usec >= 1000000) {
681 tv->tv_usec -= 1000000;
682 tv->tv_sec++;
683 }
684}
685
686void
687nanouptime(struct timespec *ts)
688{
689 unsigned count;
690 u_int64_t delta;
691 struct timecounter *tc;
692
693 tc = timecounter;
694 ts->tv_sec = tc->tc_offset_sec;
695 count = tco_delta(tc);
696 delta = tc->tc_offset_nano;
697 delta += ((u_int64_t)count * tc->tc_scale_nano_f);
698 delta >>= 32;
699 delta += ((u_int64_t)count * tc->tc_scale_nano_i);
700 while (delta < 0) {
701 delta += 1000000000;
702 if (ts->tv_sec > 0)
703 ts->tv_sec--;
704 }
705 while (delta >= 1000000000) {
706 delta -= 1000000000;
707 ts->tv_sec++;
708 }
709 ts->tv_nsec = delta;
710}
711
712static void
713tco_setscales(struct timecounter *tc)
714{
715 u_int64_t scale;
716
717 scale = 1000000000LL << 32;
718 scale += tc->tc_adjustment;
719 scale /= tc->tc_tweak->tc_frequency;
720 tc->tc_scale_micro = scale / 1000;
721 tc->tc_scale_nano_f = scale & 0xffffffff;
722 tc->tc_scale_nano_i = scale >> 32;
723}
724
725void
726update_timecounter(struct timecounter *tc)
727{
728 tco_setscales(tc);
729}
730
731void
732init_timecounter(struct timecounter *tc)
733{
734 struct timespec ts1;
735 struct timecounter *t1, *t2, *t3;
736 unsigned u;
737 int i;
738
739 u = tc->tc_frequency / tc->tc_counter_mask;
740 if (u > hz) {
741 printf("Timecounter \"%s\" frequency %lu Hz"
742 " -- Insufficient hz, needs at least %u\n",
743 tc->tc_name, (u_long) tc->tc_frequency, u);
744 return;
745 }
746
747 tc->tc_adjustment = 0;
748 tc->tc_tweak = tc;
749 tco_setscales(tc);
750 tc->tc_offset_count = tc->tc_get_timecount(tc);
751 if (timecounter == &dummy_timecounter)
752 tc->tc_avail = tc;
753 else {
754 tc->tc_avail = timecounter->tc_tweak->tc_avail;
755 timecounter->tc_tweak->tc_avail = tc;
756 }
757 MALLOC(t1, struct timecounter *, sizeof *t1, M_TIMECOUNTER, M_WAITOK);
758 tc->tc_other = t1;
759 *t1 = *tc;
760 t2 = t1;
761 for (i = 1; i < NTIMECOUNTER; i++) {
762 MALLOC(t3, struct timecounter *, sizeof *t3,
763 M_TIMECOUNTER, M_WAITOK);
764 *t3 = *tc;
765 t3->tc_other = t2;
766 t2 = t3;
767 }
768 t1->tc_other = t3;
769 tc = t1;
770
771 printf("Timecounter \"%s\" frequency %lu Hz\n",
772 tc->tc_name, (u_long)tc->tc_frequency);
773
774 /* XXX: For now always start using the counter. */
775 tc->tc_offset_count = tc->tc_get_timecount(tc);
776 nanouptime(&ts1);
777 tc->tc_offset_nano = (u_int64_t)ts1.tv_nsec << 32;
778 tc->tc_offset_micro = ts1.tv_nsec / 1000;
779 tc->tc_offset_sec = ts1.tv_sec;
780 timecounter = tc;
781}
782
783void
784set_timecounter(struct timespec *ts)
785{
786 struct timespec ts2;
787
788 nanouptime(&ts2);
789 boottime.tv_sec = ts->tv_sec - ts2.tv_sec;
790 boottime.tv_usec = (ts->tv_nsec - ts2.tv_nsec) / 1000;
791 if (boottime.tv_usec < 0) {
792 boottime.tv_usec += 1000000;
793 boottime.tv_sec--;
794 }
795 /* fiddle all the little crinkly bits around the fiords... */
796 tco_forward(1);
797}
798
799static void
800switch_timecounter(struct timecounter *newtc)
801{
802 int s;
803 struct timecounter *tc;
804 struct timespec ts;
805
806 s = splclock();
807 tc = timecounter;
808 if (newtc->tc_tweak == tc->tc_tweak) {
809 splx(s);
810 return;
811 }
812 newtc = newtc->tc_tweak->tc_other;
813 nanouptime(&ts);
814 newtc->tc_offset_sec = ts.tv_sec;
815 newtc->tc_offset_nano = (u_int64_t)ts.tv_nsec << 32;
816 newtc->tc_offset_micro = ts.tv_nsec / 1000;
817 newtc->tc_offset_count = newtc->tc_get_timecount(newtc);
818 tco_setscales(newtc);
819 timecounter = newtc;
820 splx(s);
821}
822
823static struct timecounter *
824sync_other_counter(void)
825{
826 struct timecounter *tc, *tcn, *tco;
827 unsigned delta;
828
829 tco = timecounter;
830 tc = tco->tc_other;
831 tcn = tc->tc_other;
832 *tc = *tco;
833 tc->tc_other = tcn;
834 delta = tco_delta(tc);
835 tc->tc_offset_count += delta;
836 tc->tc_offset_count &= tc->tc_counter_mask;
837 tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_f;
838 tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_i << 32;
839 return (tc);
840}
841
842static void
843tco_forward(int force)
844{
845 struct timecounter *tc, *tco;
846 struct timeval tvt;
847
848 tco = timecounter;
849 tc = sync_other_counter();
850 /*
851 * We may be inducing a tiny error here, the tc_poll_pps() may
852 * process a latched count which happens after the tco_delta()
853 * in sync_other_counter(), which would extend the previous
854 * counters parameters into the domain of this new one.
855 * Since the timewindow is very small for this, the error is
856 * going to be only a few weenieseconds (as Dave Mills would
857 * say), so lets just not talk more about it, OK ?
858 */
859 if (tco->tc_poll_pps)
860 tco->tc_poll_pps(tco);
861 if (timedelta != 0) {
862 tvt = boottime;
863 tvt.tv_usec += tickdelta;
864 if (tvt.tv_usec >= 1000000) {
865 tvt.tv_sec++;
866 tvt.tv_usec -= 1000000;
867 } else if (tvt.tv_usec < 0) {
868 tvt.tv_sec--;
869 tvt.tv_usec += 1000000;
870 }
871 boottime = tvt;
872 timedelta -= tickdelta;
873 }
874
875 while (tc->tc_offset_nano >= 1000000000ULL << 32) {
876 tc->tc_offset_nano -= 1000000000ULL << 32;
877 tc->tc_offset_sec++;
878 ntp_update_second(tc); /* XXX only needed if xntpd runs */
879 tco_setscales(tc);
880 force++;
881 }
882
883 if (tco_method && !force)
884 return;
885
886 tc->tc_offset_micro = (tc->tc_offset_nano / 1000) >> 32;
887
888 /* Figure out the wall-clock time */
889 tc->tc_nanotime.tv_sec = tc->tc_offset_sec + boottime.tv_sec;
890 tc->tc_nanotime.tv_nsec =
891 (tc->tc_offset_nano >> 32) + boottime.tv_usec * 1000;
892 tc->tc_microtime.tv_usec = tc->tc_offset_micro + boottime.tv_usec;
893 while (tc->tc_nanotime.tv_nsec >= 1000000000) {
894 tc->tc_nanotime.tv_nsec -= 1000000000;
895 tc->tc_microtime.tv_usec -= 1000000;
896 tc->tc_nanotime.tv_sec++;
897 }
898 time_second = tc->tc_microtime.tv_sec = tc->tc_nanotime.tv_sec;
899
900 timecounter = tc;
901}
902
903SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, "");
904
905SYSCTL_INT(_kern_timecounter, OID_AUTO, method, CTLFLAG_RW, &tco_method, 0,
906 "This variable determines the method used for updating timecounters. "
907 "If the default algorithm (0) fails with \"calcru negative...\" messages "
908 "try the alternate algorithm (1) which handles bad hardware better."
909
910);
911
912static int
913sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS)
914{
915 char newname[32];
916 struct timecounter *newtc, *tc;
917 int error;
918
919 tc = timecounter->tc_tweak;
920 strncpy(newname, tc->tc_name, sizeof(newname));
921 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req);
922 if (error == 0 && req->newptr != NULL &&
923 strcmp(newname, tc->tc_name) != 0) {
924 for (newtc = tc->tc_avail; newtc != tc;
925 newtc = newtc->tc_avail) {
926 if (strcmp(newname, newtc->tc_name) == 0) {
927 /* Warm up new timecounter. */
928 (void)newtc->tc_get_timecount(newtc);
929
930 switch_timecounter(newtc);
931 return (0);
932 }
933 }
934 return (EINVAL);
935 }
936 return (error);
937}
938
939SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW,
940 0, 0, sysctl_kern_timecounter_hardware, "A", "");
941
942
943int
944pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
945{
946 pps_params_t *app;
947 struct pps_fetch_args *fapi;
948#ifdef PPS_SYNC
949 struct pps_kcbind_args *kapi;
950#endif
951
952 switch (cmd) {
953 case PPS_IOC_CREATE:
954 return (0);
955 case PPS_IOC_DESTROY:
956 return (0);
957 case PPS_IOC_SETPARAMS:
958 app = (pps_params_t *)data;
959 if (app->mode & ~pps->ppscap)
960 return (EINVAL);
961 pps->ppsparam = *app;
962 return (0);
963 case PPS_IOC_GETPARAMS:
964 app = (pps_params_t *)data;
965 *app = pps->ppsparam;
966 app->api_version = PPS_API_VERS_1;
967 return (0);
968 case PPS_IOC_GETCAP:
969 *(int*)data = pps->ppscap;
970 return (0);
971 case PPS_IOC_FETCH:
972 fapi = (struct pps_fetch_args *)data;
973 if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
974 return (EINVAL);
975 if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
976 return (EOPNOTSUPP);
977 pps->ppsinfo.current_mode = pps->ppsparam.mode;
978 fapi->pps_info_buf = pps->ppsinfo;
979 return (0);
980 case PPS_IOC_KCBIND:
981#ifdef PPS_SYNC
982 kapi = (struct pps_kcbind_args *)data;
983 /* XXX Only root should be able to do this */
984 if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
985 return (EINVAL);
986 if (kapi->kernel_consumer != PPS_KC_HARDPPS)
987 return (EINVAL);
988 if (kapi->edge & ~pps->ppscap)
989 return (EINVAL);
990 pps->kcmode = kapi->edge;
991 return (0);
992#else
993 return (EOPNOTSUPP);
994#endif
995 default:
996 return (ENOTTY);
997 }
998}
999
1000void
1001pps_init(struct pps_state *pps)
1002{
1003 pps->ppscap |= PPS_TSFMT_TSPEC;
1004 if (pps->ppscap & PPS_CAPTUREASSERT)
1005 pps->ppscap |= PPS_OFFSETASSERT;
1006 if (pps->ppscap & PPS_CAPTURECLEAR)
1007 pps->ppscap |= PPS_OFFSETCLEAR;
1008}
1009
1010void
1011pps_event(struct pps_state *pps, struct timecounter *tc, unsigned count, int event)
1012{
1013 struct timespec ts, *tsp, *osp;
1014 u_int64_t delta;
1015 unsigned tcount, *pcount;
1016 int foff, fhard;
1017 pps_seq_t *pseq;
1018
1019 /* Things would be easier with arrays... */
1020 if (event == PPS_CAPTUREASSERT) {
1021 tsp = &pps->ppsinfo.assert_timestamp;
1022 osp = &pps->ppsparam.assert_offset;
1023 foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1024 fhard = pps->kcmode & PPS_CAPTUREASSERT;
1025 pcount = &pps->ppscount[0];
1026 pseq = &pps->ppsinfo.assert_sequence;
1027 } else {
1028 tsp = &pps->ppsinfo.clear_timestamp;
1029 osp = &pps->ppsparam.clear_offset;
1030 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1031 fhard = pps->kcmode & PPS_CAPTURECLEAR;
1032 pcount = &pps->ppscount[1];
1033 pseq = &pps->ppsinfo.clear_sequence;
1034 }
1035
1036 /* The timecounter changed: bail */
1037 if (!pps->ppstc ||
1038 pps->ppstc->tc_name != tc->tc_name ||
1039 tc->tc_name != timecounter->tc_name) {
1040 pps->ppstc = tc;
1041 *pcount = count;
1042 return;
1043 }
1044
1045 /* Nothing really happened */
1046 if (*pcount == count)
1047 return;
1048
1049 *pcount = count;
1050
1051 /* Convert the count to timespec */
1052 ts.tv_sec = tc->tc_offset_sec;
1053 tcount = count - tc->tc_offset_count;
1054 tcount &= tc->tc_counter_mask;
1055 delta = tc->tc_offset_nano;
1056 delta += ((u_int64_t)tcount * tc->tc_scale_nano_f);
1057 delta >>= 32;
1058 delta += ((u_int64_t)tcount * tc->tc_scale_nano_i);
1059 delta += boottime.tv_usec * 1000;
1060 ts.tv_sec += boottime.tv_sec;
1061 while (delta >= 1000000000) {
1062 delta -= 1000000000;
1063 ts.tv_sec++;
1064 }
1065 ts.tv_nsec = delta;
1066
1067 (*pseq)++;
1068 *tsp = ts;
1069
1070 if (foff) {
1071 timespecadd(tsp, osp);
1072 if (tsp->tv_nsec < 0) {
1073 tsp->tv_nsec += 1000000000;
1074 tsp->tv_sec -= 1;
1075 }
1076 }
1077#ifdef PPS_SYNC
1078 if (fhard) {
1079 /* magic, at its best... */
1080 tcount = count - pps->ppscount[2];
1081 pps->ppscount[2] = count;
1082 tcount &= tc->tc_counter_mask;
1083 delta = ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_f);
1084 delta >>= 32;
1085 delta += ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_i);
1086 hardpps(tsp, delta);
1087 }
1088#endif
1089}