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[dragonfly.git] / sys / kern / kern_time.c
CommitLineData
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1/*
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)kern_time.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: src/sys/kern/kern_time.c,v 1.68.2.1 2002/10/01 08:00:41 bde Exp $
157202af 35 * $DragonFly: src/sys/kern/kern_time.c,v 1.24 2005/04/22 17:41:15 joerg Exp $
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36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/buf.h>
41#include <sys/sysproto.h>
42#include <sys/resourcevar.h>
43#include <sys/signalvar.h>
44#include <sys/kernel.h>
45#include <sys/systm.h>
46#include <sys/sysent.h>
df2244e3 47#include <sys/sysunion.h>
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48#include <sys/proc.h>
49#include <sys/time.h>
50#include <sys/vnode.h>
a94976ad 51#include <sys/sysctl.h>
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52#include <vm/vm.h>
53#include <vm/vm_extern.h>
245e4f17 54#include <sys/msgport2.h>
88c4d2f6 55#include <sys/thread2.h>
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56
57struct timezone tz;
58
59/*
60 * Time of day and interval timer support.
61 *
62 * These routines provide the kernel entry points to get and set
63 * the time-of-day and per-process interval timers. Subroutines
64 * here provide support for adding and subtracting timeval structures
65 * and decrementing interval timers, optionally reloading the interval
66 * timers when they expire.
67 */
68
402ed7e1
RG
69static int nanosleep1 (struct timespec *rqt,
70 struct timespec *rmt);
71static int settime (struct timeval *);
72static void timevalfix (struct timeval *);
73static void no_lease_updatetime (int);
984263bc 74
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75static int sleep_hard_us = 100;
76SYSCTL_INT(_kern, OID_AUTO, sleep_hard_us, CTLFLAG_RW, &sleep_hard_us, 0, "")
a94976ad 77
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78static void
79no_lease_updatetime(deltat)
80 int deltat;
81{
82}
83
402ed7e1 84void (*lease_updatetime) (int) = no_lease_updatetime;
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85
86static int
87settime(tv)
88 struct timeval *tv;
89{
90 struct timeval delta, tv1, tv2;
91 static struct timeval maxtime, laststep;
92 struct timespec ts;
33924148
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93 int origcpu;
94
157202af 95 if ((origcpu = mycpu->gd_cpuid) != 0)
33924148 96 lwkt_setcpu_self(globaldata_find(0));
984263bc 97
88c4d2f6 98 crit_enter();
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99 microtime(&tv1);
100 delta = *tv;
101 timevalsub(&delta, &tv1);
102
103 /*
104 * If the system is secure, we do not allow the time to be
105 * set to a value earlier than 1 second less than the highest
106 * time we have yet seen. The worst a miscreant can do in
107 * this circumstance is "freeze" time. He couldn't go
108 * back to the past.
109 *
110 * We similarly do not allow the clock to be stepped more
111 * than one second, nor more than once per second. This allows
112 * a miscreant to make the clock march double-time, but no worse.
113 */
114 if (securelevel > 1) {
115 if (delta.tv_sec < 0 || delta.tv_usec < 0) {
116 /*
117 * Update maxtime to latest time we've seen.
118 */
119 if (tv1.tv_sec > maxtime.tv_sec)
120 maxtime = tv1;
121 tv2 = *tv;
122 timevalsub(&tv2, &maxtime);
123 if (tv2.tv_sec < -1) {
124 tv->tv_sec = maxtime.tv_sec - 1;
125 printf("Time adjustment clamped to -1 second\n");
126 }
127 } else {
128 if (tv1.tv_sec == laststep.tv_sec) {
88c4d2f6 129 crit_exit();
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130 return (EPERM);
131 }
132 if (delta.tv_sec > 1) {
133 tv->tv_sec = tv1.tv_sec + 1;
134 printf("Time adjustment clamped to +1 second\n");
135 }
136 laststep = *tv;
137 }
138 }
139
140 ts.tv_sec = tv->tv_sec;
141 ts.tv_nsec = tv->tv_usec * 1000;
88c4d2f6 142 set_timeofday(&ts);
984263bc 143 lease_updatetime(delta.tv_sec);
88c4d2f6 144 crit_exit();
33924148 145
157202af 146 if (origcpu != 0)
33924148 147 lwkt_setcpu_self(globaldata_find(origcpu));
33924148 148
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149 resettodr();
150 return (0);
151}
152
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153/* ARGSUSED */
154int
41c20dac 155clock_gettime(struct clock_gettime_args *uap)
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156{
157 struct timespec ats;
158
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159 switch(uap->clock_id) {
160 case CLOCK_REALTIME:
161 nanotime(&ats);
162 return (copyout(&ats, uap->tp, sizeof(ats)));
163 case CLOCK_MONOTONIC:
164 nanouptime(&ats);
165 return (copyout(&ats, uap->tp, sizeof(ats)));
166 default:
984263bc 167 return (EINVAL);
26be1876 168 }
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169}
170
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171/* ARGSUSED */
172int
41c20dac 173clock_settime(struct clock_settime_args *uap)
984263bc 174{
dadab5e9 175 struct thread *td = curthread;
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176 struct timeval atv;
177 struct timespec ats;
178 int error;
179
dadab5e9 180 if ((error = suser(td)) != 0)
984263bc 181 return (error);
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182 switch(uap->clock_id) {
183 case CLOCK_REALTIME:
184 if ((error = copyin(uap->tp, &ats, sizeof(ats))) != 0)
185 return (error);
186 if (ats.tv_nsec < 0 || ats.tv_nsec >= 1000000000)
187 return (EINVAL);
188 /* XXX Don't convert nsec->usec and back */
189 TIMESPEC_TO_TIMEVAL(&atv, &ats);
190 error = settime(&atv);
984263bc 191 return (error);
26be1876 192 default:
984263bc 193 return (EINVAL);
26be1876 194 }
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195}
196
984263bc 197int
41c20dac 198clock_getres(struct clock_getres_args *uap)
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199{
200 struct timespec ts;
984263bc 201
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202 switch(uap->clock_id) {
203 case CLOCK_REALTIME:
204 case CLOCK_MONOTONIC:
984263bc 205 /*
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206 * Round up the result of the division cheaply
207 * by adding 1. Rounding up is especially important
208 * if rounding down would give 0. Perfect rounding
209 * is unimportant.
984263bc 210 */
26be1876 211 ts.tv_sec = 0;
88c4d2f6 212 ts.tv_nsec = 1000000000 / cputimer_freq + 1;
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213 return(copyout(&ts, uap->tp, sizeof(ts)));
214 default:
215 return(EINVAL);
984263bc 216 }
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217}
218
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219/*
220 * nanosleep1()
221 *
222 * This is a general helper function for nanosleep() (aka sleep() aka
223 * usleep()).
224 *
225 * If there is less then one tick's worth of time left and
226 * we haven't done a yield, or the remaining microseconds is
227 * ridiculously low, do a yield. This avoids having
228 * to deal with systimer overheads when the system is under
229 * heavy loads. If we have done a yield already then use
230 * a systimer and an uninterruptable thread wait.
231 *
232 * If there is more then a tick's worth of time left,
233 * calculate the baseline ticks and use an interruptable
234 * tsleep, then handle the fine-grained delay on the next
235 * loop. This usually results in two sleeps occuring, a long one
236 * and a short one.
237 */
238static void
239ns1_systimer(systimer_t info)
240{
241 lwkt_schedule(info->data);
242}
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243
244static int
41c20dac 245nanosleep1(struct timespec *rqt, struct timespec *rmt)
984263bc 246{
88c4d2f6 247 static int nanowait;
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248 struct timespec ts, ts2, ts3;
249 struct timeval tv;
250 int error;
88c4d2f6 251 int tried_yield;
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252
253 if (rqt->tv_nsec < 0 || rqt->tv_nsec >= 1000000000)
254 return (EINVAL);
255 if (rqt->tv_sec < 0 || (rqt->tv_sec == 0 && rqt->tv_nsec == 0))
256 return (0);
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257 nanouptime(&ts);
258 timespecadd(&ts, rqt); /* ts = target timestamp compare */
259 TIMESPEC_TO_TIMEVAL(&tv, rqt); /* tv = sleep interval */
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260 tried_yield = 0;
261
984263bc 262 for (;;) {
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263 int ticks;
264 struct systimer info;
265
266 ticks = tv.tv_usec / tick; /* approximate */
a94976ad 267
88c4d2f6 268 if (tv.tv_sec == 0 && ticks == 0) {
37af14fe 269 thread_t td = curthread;
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270 if (tried_yield || tv.tv_usec < sleep_hard_us) {
271 tried_yield = 0;
a94976ad 272 uio_yield();
a94976ad 273 } else {
37af14fe 274 crit_enter_quick(td);
88c4d2f6 275 systimer_init_oneshot(&info, ns1_systimer,
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276 td, tv.tv_usec);
277 lwkt_deschedule_self(td);
278 crit_exit_quick(td);
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279 lwkt_switch();
280 systimer_del(&info); /* make sure it's gone */
a94976ad 281 }
37af14fe 282 error = iscaught(td->td_proc);
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283 } else if (tv.tv_sec == 0) {
284 error = tsleep(&nanowait, PCATCH, "nanslp", ticks);
a94976ad 285 } else {
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286 ticks = tvtohz_low(&tv); /* also handles overflow */
287 error = tsleep(&nanowait, PCATCH, "nanslp", ticks);
a94976ad
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288 }
289 nanouptime(&ts2);
88c4d2f6 290 if (error && error != EWOULDBLOCK) {
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291 if (error == ERESTART)
292 error = EINTR;
293 if (rmt != NULL) {
294 timespecsub(&ts, &ts2);
295 if (ts.tv_sec < 0)
296 timespecclear(&ts);
297 *rmt = ts;
298 }
299 return (error);
300 }
301 if (timespeccmp(&ts2, &ts, >=))
302 return (0);
303 ts3 = ts;
304 timespecsub(&ts3, &ts2);
305 TIMESPEC_TO_TIMEVAL(&tv, &ts3);
306 }
307}
308
245e4f17 309static void nanosleep_done(void *arg);
df2244e3 310static void nanosleep_copyout(union sysunion *sysun);
245e4f17 311
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312/* ARGSUSED */
313int
41c20dac 314nanosleep(struct nanosleep_args *uap)
984263bc 315{
245e4f17 316 int error;
df2244e3 317 struct sysmsg_sleep *smsleep = &uap->sysmsg.sm.sleep;
984263bc 318
df2244e3 319 error = copyin(uap->rqtp, &smsleep->rqt, sizeof(smsleep->rqt));
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320 if (error)
321 return (error);
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322 /*
323 * YYY clean this up to always use the callout, note that an abort
324 * implementation should record the residual in the async case.
325 */
df2244e3 326 if (uap->sysmsg.lmsg.ms_flags & MSGF_ASYNC) {
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327 quad_t ticks;
328
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329 ticks = (quad_t)smsleep->rqt.tv_nsec * hz / 1000000000LL;
330 if (smsleep->rqt.tv_sec)
331 ticks += (quad_t)smsleep->rqt.tv_sec * hz;
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MD
332 if (ticks <= 0) {
333 if (ticks == 0)
334 error = 0;
335 else
336 error = EINVAL;
337 } else {
df2244e3 338 uap->sysmsg.copyout = nanosleep_copyout;
1fa2b4b4 339 uap->sysmsg.lmsg.ms_flags &= ~MSGF_DONE;
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340 callout_init(&smsleep->timer);
341 callout_reset(&smsleep->timer, ticks, nanosleep_done, uap);
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342 error = EASYNC;
343 }
344 } else {
345 /*
346 * Old synchronous sleep code, copyout the residual if
347 * nanosleep was interrupted.
348 */
df2244e3 349 error = nanosleep1(&smsleep->rqt, &smsleep->rmt);
ab2eb4eb
DR
350 if (error && uap->rmtp)
351 error = copyout(&smsleep->rmt, uap->rmtp, sizeof(smsleep->rmt));
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352 }
353 return (error);
354}
355
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356/*
357 * Asynch completion for the nanosleep() syscall. This function may be
358 * called from any context and cannot legally access the originating
359 * thread, proc, or its user space.
360 *
361 * YYY change the callout interface API so we can simply assign the replymsg
362 * function to it directly.
363 */
364static void
365nanosleep_done(void *arg)
366{
367 struct nanosleep_args *uap = arg;
1fa2b4b4 368 lwkt_msg_t msg = &uap->sysmsg.lmsg;
245e4f17 369
1fa2b4b4 370 lwkt_replymsg(msg, 0);
245e4f17
MD
371}
372
373/*
374 * Asynch return for the nanosleep() syscall, called in the context of the
375 * originating thread when it pulls the message off the reply port. This
376 * function is responsible for any copyouts to userland. Kernel threads
377 * which do their own internal system calls will not usually call the return
378 * function.
379 */
380static void
df2244e3 381nanosleep_copyout(union sysunion *sysun)
245e4f17 382{
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383 struct nanosleep_args *uap = &sysun->nanosleep;
384 struct sysmsg_sleep *smsleep = &uap->sysmsg.sm.sleep;
245e4f17 385
df2244e3
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386 if (sysun->lmsg.ms_error && uap->rmtp) {
387 sysun->lmsg.ms_error =
388 copyout(&smsleep->rmt, uap->rmtp, sizeof(smsleep->rmt));
245e4f17
MD
389 }
390}
391
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392/* ARGSUSED */
393int
41c20dac 394gettimeofday(struct gettimeofday_args *uap)
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MD
395{
396 struct timeval atv;
397 int error = 0;
398
399 if (uap->tp) {
400 microtime(&atv);
401 if ((error = copyout((caddr_t)&atv, (caddr_t)uap->tp,
402 sizeof (atv))))
403 return (error);
404 }
405 if (uap->tzp)
406 error = copyout((caddr_t)&tz, (caddr_t)uap->tzp,
407 sizeof (tz));
408 return (error);
409}
410
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411/* ARGSUSED */
412int
41c20dac 413settimeofday(struct settimeofday_args *uap)
984263bc 414{
dadab5e9 415 struct thread *td = curthread;
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416 struct timeval atv;
417 struct timezone atz;
418 int error;
419
dadab5e9 420 if ((error = suser(td)))
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421 return (error);
422 /* Verify all parameters before changing time. */
423 if (uap->tv) {
424 if ((error = copyin((caddr_t)uap->tv, (caddr_t)&atv,
425 sizeof(atv))))
426 return (error);
427 if (atv.tv_usec < 0 || atv.tv_usec >= 1000000)
428 return (EINVAL);
429 }
430 if (uap->tzp &&
431 (error = copyin((caddr_t)uap->tzp, (caddr_t)&atz, sizeof(atz))))
432 return (error);
433 if (uap->tv && (error = settime(&atv)))
434 return (error);
435 if (uap->tzp)
436 tz = atz;
437 return (0);
438}
439
4026c000
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440static void
441kern_adjtime_common(void)
442{
443 if ((ntp_delta >= 0 && ntp_delta < ntp_default_tick_delta) ||
444 (ntp_delta < 0 && ntp_delta > ntp_default_tick_delta))
445 ntp_tick_delta = ntp_delta;
446 else if (ntp_delta > ntp_big_delta)
447 ntp_tick_delta = 10 * ntp_default_tick_delta;
448 else if (ntp_delta < -ntp_big_delta)
449 ntp_tick_delta = -10 * ntp_default_tick_delta;
450 else if (ntp_delta > 0)
451 ntp_tick_delta = ntp_default_tick_delta;
452 else
453 ntp_tick_delta = -ntp_default_tick_delta;
454}
455
456void
457kern_adjtime(int64_t delta, int64_t *odelta)
458{
459 int origcpu;
460
157202af 461 if ((origcpu = mycpu->gd_cpuid) != 0)
4026c000 462 lwkt_setcpu_self(globaldata_find(0));
4026c000
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463
464 crit_enter();
465 *odelta = ntp_delta;
466 ntp_delta += delta;
467 kern_adjtime_common();
468 crit_exit();
469
157202af 470 if (origcpu != 0)
4026c000 471 lwkt_setcpu_self(globaldata_find(origcpu));
4026c000
JS
472}
473
474void
475kern_reladjtime(int64_t delta)
476{
477 int origcpu;
478
157202af 479 if ((origcpu = mycpu->gd_cpuid) != 0)
4026c000 480 lwkt_setcpu_self(globaldata_find(0));
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481
482 crit_enter();
483 ntp_delta += delta;
484 kern_adjtime_common();
485 crit_exit();
486
157202af 487 if (origcpu != 0)
4026c000 488 lwkt_setcpu_self(globaldata_find(origcpu));
4026c000 489}
984263bc 490
0143455b
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491static void
492kern_adjfreq(int64_t rate)
493{
494 int origcpu;
495
157202af 496 if ((origcpu = mycpu->gd_cpuid) != 0)
0143455b 497 lwkt_setcpu_self(globaldata_find(0));
0143455b
JS
498
499 crit_enter();
500 ntp_tick_permanent = rate;
501 crit_exit();
502
157202af 503 if (origcpu != 0)
0143455b 504 lwkt_setcpu_self(globaldata_find(origcpu));
0143455b
JS
505}
506
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507/* ARGSUSED */
508int
41c20dac 509adjtime(struct adjtime_args *uap)
984263bc 510{
dadab5e9 511 struct thread *td = curthread;
984263bc 512 struct timeval atv;
4026c000 513 int64_t ndelta, odelta;
88c4d2f6 514 int error;
984263bc 515
dadab5e9 516 if ((error = suser(td)))
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517 return (error);
518 if ((error =
519 copyin((caddr_t)uap->delta, (caddr_t)&atv, sizeof(struct timeval))))
520 return (error);
521
522 /*
523 * Compute the total correction and the rate at which to apply it.
524 * Round the adjustment down to a whole multiple of the per-tick
525 * delta, so that after some number of incremental changes in
526 * hardclock(), tickdelta will become zero, lest the correction
527 * overshoot and start taking us away from the desired final time.
528 */
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529 ndelta = atv.tv_sec * 1000000000 + atv.tv_usec * 1000;
530 kern_adjtime(ndelta, &odelta);
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531
532 if (uap->olddelta) {
4026c000
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533 atv.tv_sec = odelta / 1000000000;
534 atv.tv_usec = odelta % 1000000 / 1000;
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535 (void) copyout((caddr_t)&atv, (caddr_t)uap->olddelta,
536 sizeof(struct timeval));
537 }
538 return (0);
539}
540
4026c000
JS
541static int
542sysctl_adjtime(SYSCTL_HANDLER_ARGS)
543{
544 int64_t delta;
545 int error;
546
547 if (req->oldptr != NULL) {
548 delta = 0;
549 error = SYSCTL_OUT(req, &delta, sizeof(delta));
550 if (error)
551 return (error);
552 }
553 if (req->newptr != NULL) {
554 if (suser(curthread))
555 return (EPERM);
556 error = SYSCTL_IN(req, &delta, sizeof(delta));
557 if (error)
558 return (error);
559 kern_reladjtime(delta);
560 }
561 return (0);
562}
563
0143455b
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564static int
565sysctl_adjfreq(SYSCTL_HANDLER_ARGS)
566{
567 int64_t freqdelta;
568 int error;
569
570 if (req->oldptr != NULL) {
571 freqdelta = ntp_tick_permanent * hz;
572 error = SYSCTL_OUT(req, &freqdelta, sizeof(freqdelta));
573 if (error)
574 return (error);
575 }
576 if (req->newptr != NULL) {
577 if (suser(curthread))
578 return (EPERM);
579 error = SYSCTL_IN(req, &freqdelta, sizeof(freqdelta));
580 if (error)
581 return (error);
582
583 freqdelta /= hz;
584 kern_adjfreq(freqdelta);
585 }
586 return (0);
587}
588
4026c000 589SYSCTL_NODE(_kern, OID_AUTO, ntp, CTLFLAG_RW, 0, "NTP related controls");
0143455b
JS
590SYSCTL_PROC(_kern_ntp, OID_AUTO, permanent,
591 CTLTYPE_OPAQUE|CTLFLAG_RW, 0, 0,
592 sysctl_adjfreq, "LU", "permanent correction per second");
4026c000
JS
593SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, delta, CTLFLAG_RD,
594 &ntp_delta, sizeof(ntp_delta), "LU",
595 "one-time delta");
596SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, big_delta, CTLFLAG_RD,
597 &ntp_big_delta, sizeof(ntp_big_delta), "LU",
598 "threshold for fast adjustment");
599SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, tick_delta, CTLFLAG_RD,
600 &ntp_tick_delta, sizeof(ntp_tick_delta), "LU",
601 "per-tick adjustment");
602SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, default_tick_delta, CTLFLAG_RD,
603 &ntp_default_tick_delta, sizeof(ntp_default_tick_delta), "LU",
604 "default per-tick adjustment");
48590578
JS
605SYSCTL_OPAQUE(_kern_ntp, OID_AUTO, next_leap_second, CTLFLAG_RW,
606 &ntp_leap_second, sizeof(ntp_leap_second), "LU",
607 "next leap second");
608SYSCTL_INT(_kern_ntp, OID_AUTO, insert_leap_second, CTLFLAG_RW,
609 &ntp_leap_insert, 0, "insert or remove leap second");
4026c000
JS
610SYSCTL_PROC(_kern_ntp, OID_AUTO, adjust,
611 CTLTYPE_OPAQUE|CTLFLAG_RW, 0, 0,
612 sysctl_adjtime, "", "relative adjust for delta");
613
984263bc
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614/*
615 * Get value of an interval timer. The process virtual and
616 * profiling virtual time timers are kept in the p_stats area, since
617 * they can be swapped out. These are kept internally in the
618 * way they are specified externally: in time until they expire.
619 *
620 * The real time interval timer is kept in the process table slot
621 * for the process, and its value (it_value) is kept as an
622 * absolute time rather than as a delta, so that it is easy to keep
623 * periodic real-time signals from drifting.
624 *
625 * Virtual time timers are processed in the hardclock() routine of
626 * kern_clock.c. The real time timer is processed by a timeout
627 * routine, called from the softclock() routine. Since a callout
628 * may be delayed in real time due to interrupt processing in the system,
629 * it is possible for the real time timeout routine (realitexpire, given below),
630 * to be delayed in real time past when it is supposed to occur. It
631 * does not suffice, therefore, to reload the real timer .it_value from the
632 * real time timers .it_interval. Rather, we compute the next time in
633 * absolute time the timer should go off.
634 */
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635/* ARGSUSED */
636int
41c20dac 637getitimer(struct getitimer_args *uap)
984263bc 638{
41c20dac 639 struct proc *p = curproc;
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640 struct timeval ctv;
641 struct itimerval aitv;
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642
643 if (uap->which > ITIMER_PROF)
644 return (EINVAL);
88c4d2f6 645 crit_enter();
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646 if (uap->which == ITIMER_REAL) {
647 /*
648 * Convert from absolute to relative time in .it_value
649 * part of real time timer. If time for real time timer
650 * has passed return 0, else return difference between
651 * current time and time for the timer to go off.
652 */
653 aitv = p->p_realtimer;
654 if (timevalisset(&aitv.it_value)) {
655 getmicrouptime(&ctv);
656 if (timevalcmp(&aitv.it_value, &ctv, <))
657 timevalclear(&aitv.it_value);
658 else
659 timevalsub(&aitv.it_value, &ctv);
660 }
88c4d2f6 661 } else {
984263bc 662 aitv = p->p_stats->p_timer[uap->which];
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663 }
664 crit_exit();
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665 return (copyout((caddr_t)&aitv, (caddr_t)uap->itv,
666 sizeof (struct itimerval)));
667}
668
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669/* ARGSUSED */
670int
41c20dac 671setitimer(struct setitimer_args *uap)
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672{
673 struct itimerval aitv;
674 struct timeval ctv;
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675 struct itimerval *itvp;
676 struct proc *p = curproc;
88c4d2f6 677 int error;
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678
679 if (uap->which > ITIMER_PROF)
680 return (EINVAL);
681 itvp = uap->itv;
682 if (itvp && (error = copyin((caddr_t)itvp, (caddr_t)&aitv,
683 sizeof(struct itimerval))))
684 return (error);
685 if ((uap->itv = uap->oitv) &&
41c20dac 686 (error = getitimer((struct getitimer_args *)uap)))
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687 return (error);
688 if (itvp == 0)
689 return (0);
690 if (itimerfix(&aitv.it_value))
691 return (EINVAL);
692 if (!timevalisset(&aitv.it_value))
693 timevalclear(&aitv.it_interval);
694 else if (itimerfix(&aitv.it_interval))
695 return (EINVAL);
88c4d2f6 696 crit_enter();
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697 if (uap->which == ITIMER_REAL) {
698 if (timevalisset(&p->p_realtimer.it_value))
8fbf9130 699 callout_stop(&p->p_ithandle);
984263bc 700 if (timevalisset(&aitv.it_value))
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701 callout_reset(&p->p_ithandle,
702 tvtohz_high(&aitv.it_value), realitexpire, p);
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703 getmicrouptime(&ctv);
704 timevaladd(&aitv.it_value, &ctv);
705 p->p_realtimer = aitv;
88c4d2f6 706 } else {
984263bc 707 p->p_stats->p_timer[uap->which] = aitv;
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708 }
709 crit_exit();
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710 return (0);
711}
712
713/*
714 * Real interval timer expired:
715 * send process whose timer expired an alarm signal.
716 * If time is not set up to reload, then just return.
717 * Else compute next time timer should go off which is > current time.
718 * This is where delay in processing this timeout causes multiple
719 * SIGALRM calls to be compressed into one.
a94976ad 720 * tvtohz_high() always adds 1 to allow for the time until the next clock
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721 * interrupt being strictly less than 1 clock tick, but we don't want
722 * that here since we want to appear to be in sync with the clock
723 * interrupt even when we're delayed.
724 */
725void
726realitexpire(arg)
727 void *arg;
728{
1fd87d54 729 struct proc *p;
984263bc 730 struct timeval ctv, ntv;
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731
732 p = (struct proc *)arg;
733 psignal(p, SIGALRM);
734 if (!timevalisset(&p->p_realtimer.it_interval)) {
735 timevalclear(&p->p_realtimer.it_value);
736 return;
737 }
738 for (;;) {
88c4d2f6 739 crit_enter();
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740 timevaladd(&p->p_realtimer.it_value,
741 &p->p_realtimer.it_interval);
742 getmicrouptime(&ctv);
743 if (timevalcmp(&p->p_realtimer.it_value, &ctv, >)) {
744 ntv = p->p_realtimer.it_value;
745 timevalsub(&ntv, &ctv);
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746 callout_reset(&p->p_ithandle, tvtohz_low(&ntv),
747 realitexpire, p);
88c4d2f6 748 crit_exit();
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749 return;
750 }
88c4d2f6 751 crit_exit();
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752 }
753}
754
755/*
756 * Check that a proposed value to load into the .it_value or
757 * .it_interval part of an interval timer is acceptable, and
758 * fix it to have at least minimal value (i.e. if it is less
759 * than the resolution of the clock, round it up.)
760 */
761int
762itimerfix(tv)
763 struct timeval *tv;
764{
765
766 if (tv->tv_sec < 0 || tv->tv_sec > 100000000 ||
767 tv->tv_usec < 0 || tv->tv_usec >= 1000000)
768 return (EINVAL);
769 if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick)
770 tv->tv_usec = tick;
771 return (0);
772}
773
774/*
775 * Decrement an interval timer by a specified number
776 * of microseconds, which must be less than a second,
777 * i.e. < 1000000. If the timer expires, then reload
778 * it. In this case, carry over (usec - old value) to
779 * reduce the value reloaded into the timer so that
780 * the timer does not drift. This routine assumes
781 * that it is called in a context where the timers
782 * on which it is operating cannot change in value.
783 */
784int
785itimerdecr(itp, usec)
1fd87d54 786 struct itimerval *itp;
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787 int usec;
788{
789
790 if (itp->it_value.tv_usec < usec) {
791 if (itp->it_value.tv_sec == 0) {
792 /* expired, and already in next interval */
793 usec -= itp->it_value.tv_usec;
794 goto expire;
795 }
796 itp->it_value.tv_usec += 1000000;
797 itp->it_value.tv_sec--;
798 }
799 itp->it_value.tv_usec -= usec;
800 usec = 0;
801 if (timevalisset(&itp->it_value))
802 return (1);
803 /* expired, exactly at end of interval */
804expire:
805 if (timevalisset(&itp->it_interval)) {
806 itp->it_value = itp->it_interval;
807 itp->it_value.tv_usec -= usec;
808 if (itp->it_value.tv_usec < 0) {
809 itp->it_value.tv_usec += 1000000;
810 itp->it_value.tv_sec--;
811 }
812 } else
813 itp->it_value.tv_usec = 0; /* sec is already 0 */
814 return (0);
815}
816
817/*
818 * Add and subtract routines for timevals.
819 * N.B.: subtract routine doesn't deal with
820 * results which are before the beginning,
821 * it just gets very confused in this case.
822 * Caveat emptor.
823 */
824void
825timevaladd(t1, t2)
826 struct timeval *t1, *t2;
827{
828
829 t1->tv_sec += t2->tv_sec;
830 t1->tv_usec += t2->tv_usec;
831 timevalfix(t1);
832}
833
834void
835timevalsub(t1, t2)
836 struct timeval *t1, *t2;
837{
838
839 t1->tv_sec -= t2->tv_sec;
840 t1->tv_usec -= t2->tv_usec;
841 timevalfix(t1);
842}
843
844static void
845timevalfix(t1)
846 struct timeval *t1;
847{
848
849 if (t1->tv_usec < 0) {
850 t1->tv_sec--;
851 t1->tv_usec += 1000000;
852 }
853 if (t1->tv_usec >= 1000000) {
854 t1->tv_sec++;
855 t1->tv_usec -= 1000000;
856 }
857}
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858
859/*
860 * ratecheck(): simple time-based rate-limit checking.
861 */
862int
863ratecheck(struct timeval *lasttime, const struct timeval *mininterval)
864{
865 struct timeval tv, delta;
866 int rv = 0;
867
868 getmicrouptime(&tv); /* NB: 10ms precision */
869 delta = tv;
870 timevalsub(&delta, lasttime);
871
872 /*
873 * check for 0,0 is so that the message will be seen at least once,
874 * even if interval is huge.
875 */
876 if (timevalcmp(&delta, mininterval, >=) ||
877 (lasttime->tv_sec == 0 && lasttime->tv_usec == 0)) {
878 *lasttime = tv;
879 rv = 1;
880 }
881
882 return (rv);
883}
884
885/*
886 * ppsratecheck(): packets (or events) per second limitation.
887 *
888 * Return 0 if the limit is to be enforced (e.g. the caller
889 * should drop a packet because of the rate limitation).
890 *
891 * maxpps of 0 always causes zero to be returned. maxpps of -1
892 * always causes 1 to be returned; this effectively defeats rate
893 * limiting.
894 *
895 * Note that we maintain the struct timeval for compatibility
896 * with other bsd systems. We reuse the storage and just monitor
897 * clock ticks for minimal overhead.
898 */
899int
900ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps)
901{
902 int now;
903
904 /*
905 * Reset the last time and counter if this is the first call
906 * or more than a second has passed since the last update of
907 * lasttime.
908 */
909 now = ticks;
910 if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) {
911 lasttime->tv_sec = now;
912 *curpps = 1;
913 return (maxpps != 0);
914 } else {
915 (*curpps)++; /* NB: ignore potential overflow */
916 return (maxpps < 0 || *curpps < maxpps);
917 }
918}
919