xref: /dflybsd-src/sys/kern/kern_clock.c (revision a6d5e0d89a9c7db991a06391d6a4a6ddadf6af51)
1 /*
2  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * Copyright (c) 1997, 1998 Poul-Henning Kamp <phk@FreeBSD.org>
35  * Copyright (c) 1982, 1986, 1991, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  * (c) UNIX System Laboratories, Inc.
38  * All or some portions of this file are derived from material licensed
39  * to the University of California by American Telephone and Telegraph
40  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
41  * the permission of UNIX System Laboratories, Inc.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. All advertising materials mentioning features or use of this software
52  *    must display the following acknowledgement:
53  *	This product includes software developed by the University of
54  *	California, Berkeley and its contributors.
55  * 4. Neither the name of the University nor the names of its contributors
56  *    may be used to endorse or promote products derived from this software
57  *    without specific prior written permission.
58  *
59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69  * SUCH DAMAGE.
70  *
71  *	@(#)kern_clock.c	8.5 (Berkeley) 1/21/94
72  * $FreeBSD: src/sys/kern/kern_clock.c,v 1.105.2.10 2002/10/17 13:19:40 maxim Exp $
73  * $DragonFly: src/sys/kern/kern_clock.c,v 1.43 2005/06/06 15:02:27 dillon Exp $
74  */
75 
76 #include "opt_ntp.h"
77 
78 #include <sys/param.h>
79 #include <sys/systm.h>
80 #include <sys/callout.h>
81 #include <sys/kernel.h>
82 #include <sys/kinfo.h>
83 #include <sys/proc.h>
84 #include <sys/malloc.h>
85 #include <sys/resourcevar.h>
86 #include <sys/signalvar.h>
87 #include <sys/timex.h>
88 #include <sys/timepps.h>
89 #include <vm/vm.h>
90 #include <sys/lock.h>
91 #include <vm/pmap.h>
92 #include <vm/vm_map.h>
93 #include <sys/sysctl.h>
94 #include <sys/thread2.h>
95 
96 #include <machine/cpu.h>
97 #include <machine/limits.h>
98 #include <machine/smp.h>
99 
100 #ifdef GPROF
101 #include <sys/gmon.h>
102 #endif
103 
104 #ifdef DEVICE_POLLING
105 extern void init_device_poll(void);
106 extern void hardclock_device_poll(void);
107 #endif /* DEVICE_POLLING */
108 
109 static void initclocks (void *dummy);
110 SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
111 
112 /*
113  * Some of these don't belong here, but it's easiest to concentrate them.
114  * Note that cpu_time counts in microseconds, but most userland programs
115  * just compare relative times against the total by delta.
116  */
117 struct kinfo_cputime cputime_percpu[MAXCPU];
118 #ifdef SMP
119 static int
120 sysctl_cputime(SYSCTL_HANDLER_ARGS)
121 {
122 	int cpu, error = 0;
123 	size_t size = sizeof(struct kinfo_cputime);
124 
125 	for (cpu = 0; cpu < ncpus; ++cpu) {
126 		if ((error = SYSCTL_OUT(req, &cputime_percpu[cpu], size)))
127 			break;
128 	}
129 
130 	return (error);
131 }
132 SYSCTL_PROC(_kern, OID_AUTO, cputime, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
133 	sysctl_cputime, "S,kinfo_cputime", "CPU time statistics");
134 #else
135 SYSCTL_STRUCT(_kern, OID_AUTO, cputime, CTLFLAG_RD, &cpu_time, kinfo_cputime,
136     "CPU time statistics");
137 #endif
138 
139 /*
140  * boottime is used to calculate the 'real' uptime.  Do not confuse this with
141  * microuptime().  microtime() is not drift compensated.  The real uptime
142  * with compensation is nanotime() - bootime.  boottime is recalculated
143  * whenever the real time is set based on the compensated elapsed time
144  * in seconds (gd->gd_time_seconds).
145  *
146  * The gd_time_seconds and gd_cpuclock_base fields remain fairly monotonic.
147  * Slight adjustments to gd_cpuclock_base are made to phase-lock it to
148  * the real time.
149  */
150 struct timespec boottime;	/* boot time (realtime) for reference only */
151 time_t time_second;		/* read-only 'passive' uptime in seconds */
152 
153 /*
154  * basetime is used to calculate the compensated real time of day.  The
155  * basetime can be modified on a per-tick basis by the adjtime(),
156  * ntp_adjtime(), and sysctl-based time correction APIs.
157  *
158  * Note that frequency corrections can also be made by adjusting
159  * gd_cpuclock_base.
160  *
161  * basetime is a tail-chasing FIFO, updated only by cpu #0.  The FIFO is
162  * used on both SMP and UP systems to avoid MP races between cpu's and
163  * interrupt races on UP systems.
164  */
165 #define BASETIME_ARYSIZE	16
166 #define BASETIME_ARYMASK	(BASETIME_ARYSIZE - 1)
167 static struct timespec basetime[BASETIME_ARYSIZE];
168 static volatile int basetime_index;
169 
170 static int
171 sysctl_get_basetime(SYSCTL_HANDLER_ARGS)
172 {
173 	struct timespec *bt;
174 	int error;
175 	int index;
176 
177 	/*
178 	 * Because basetime data and index may be updated by another cpu,
179 	 * a load fence is required to ensure that the data we read has
180 	 * not been speculatively read relative to a possibly updated index.
181 	 */
182 	index = basetime_index;
183 	cpu_lfence();
184 	bt = &basetime[index];
185 	error = SYSCTL_OUT(req, bt, sizeof(*bt));
186 	return (error);
187 }
188 
189 SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
190     &boottime, timespec, "System boottime");
191 SYSCTL_PROC(_kern, OID_AUTO, basetime, CTLTYPE_STRUCT|CTLFLAG_RD, 0, 0,
192     sysctl_get_basetime, "S,timespec", "System basetime");
193 
194 static void hardclock(systimer_t info, struct intrframe *frame);
195 static void statclock(systimer_t info, struct intrframe *frame);
196 static void schedclock(systimer_t info, struct intrframe *frame);
197 static void getnanotime_nbt(struct timespec *nbt, struct timespec *tsp);
198 
199 int	ticks;			/* system master ticks at hz */
200 int	clocks_running;		/* tsleep/timeout clocks operational */
201 int64_t	nsec_adj;		/* ntpd per-tick adjustment in nsec << 32 */
202 int64_t	nsec_acc;		/* accumulator */
203 
204 /* NTPD time correction fields */
205 int64_t	ntp_tick_permanent;	/* per-tick adjustment in nsec << 32 */
206 int64_t	ntp_tick_acc;		/* accumulator for per-tick adjustment */
207 int64_t	ntp_delta;		/* one-time correction in nsec */
208 int64_t ntp_big_delta = 1000000000;
209 int32_t	ntp_tick_delta;		/* current adjustment rate */
210 int32_t	ntp_default_tick_delta;	/* adjustment rate for ntp_delta */
211 time_t	ntp_leap_second;	/* time of next leap second */
212 int	ntp_leap_insert;	/* whether to insert or remove a second */
213 
214 /*
215  * Finish initializing clock frequencies and start all clocks running.
216  */
217 /* ARGSUSED*/
218 static void
219 initclocks(void *dummy)
220 {
221 	cpu_initclocks();
222 #ifdef DEVICE_POLLING
223 	init_device_poll();
224 #endif
225 	/*psratio = profhz / stathz;*/
226 	initclocks_pcpu();
227 	clocks_running = 1;
228 }
229 
230 /*
231  * Called on a per-cpu basis
232  */
233 void
234 initclocks_pcpu(void)
235 {
236 	struct globaldata *gd = mycpu;
237 
238 	crit_enter();
239 	if (gd->gd_cpuid == 0) {
240 	    gd->gd_time_seconds = 1;
241 	    gd->gd_cpuclock_base = sys_cputimer->count();
242 	} else {
243 	    /* XXX */
244 	    gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
245 	    gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
246 	}
247 
248 	/*
249 	 * Use a non-queued periodic systimer to prevent multiple ticks from
250 	 * building up if the sysclock jumps forward (8254 gets reset).  The
251 	 * sysclock will never jump backwards.  Our time sync is based on
252 	 * the actual sysclock, not the ticks count.
253 	 */
254 	systimer_init_periodic_nq(&gd->gd_hardclock, hardclock, NULL, hz);
255 	systimer_init_periodic_nq(&gd->gd_statclock, statclock, NULL, stathz);
256 	/* XXX correct the frequency for scheduler / estcpu tests */
257 	systimer_init_periodic_nq(&gd->gd_schedclock, schedclock,
258 				NULL, ESTCPUFREQ);
259 	crit_exit();
260 }
261 
262 /*
263  * This sets the current real time of day.  Timespecs are in seconds and
264  * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
265  * instead we adjust basetime so basetime + gd_* results in the current
266  * time of day.  This way the gd_* fields are guarenteed to represent
267  * a monotonically increasing 'uptime' value.
268  *
269  * When set_timeofday() is called from userland, the system call forces it
270  * onto cpu #0 since only cpu #0 can update basetime_index.
271  */
272 void
273 set_timeofday(struct timespec *ts)
274 {
275 	struct timespec *nbt;
276 	int ni;
277 
278 	/*
279 	 * XXX SMP / non-atomic basetime updates
280 	 */
281 	crit_enter();
282 	ni = (basetime_index + 1) & BASETIME_ARYMASK;
283 	nbt = &basetime[ni];
284 	nanouptime(nbt);
285 	nbt->tv_sec = ts->tv_sec - nbt->tv_sec;
286 	nbt->tv_nsec = ts->tv_nsec - nbt->tv_nsec;
287 	if (nbt->tv_nsec < 0) {
288 	    nbt->tv_nsec += 1000000000;
289 	    --nbt->tv_sec;
290 	}
291 
292 	/*
293 	 * Note that basetime diverges from boottime as the clock drift is
294 	 * compensated for, so we cannot do away with boottime.  When setting
295 	 * the absolute time of day the drift is 0 (for an instant) and we
296 	 * can simply assign boottime to basetime.
297 	 *
298 	 * Note that nanouptime() is based on gd_time_seconds which is drift
299 	 * compensated up to a point (it is guarenteed to remain monotonically
300 	 * increasing).  gd_time_seconds is thus our best uptime guess and
301 	 * suitable for use in the boottime calculation.  It is already taken
302 	 * into account in the basetime calculation above.
303 	 */
304 	boottime.tv_sec = nbt->tv_sec;
305 	ntp_delta = 0;
306 
307 	/*
308 	 * We now have a new basetime, make sure all other cpus have it,
309 	 * then update the index.
310 	 */
311 	cpu_sfence();
312 	basetime_index = ni;
313 
314 	crit_exit();
315 }
316 
317 /*
318  * Each cpu has its own hardclock, but we only increments ticks and softticks
319  * on cpu #0.
320  *
321  * NOTE! systimer! the MP lock might not be held here.  We can only safely
322  * manipulate objects owned by the current cpu.
323  */
324 static void
325 hardclock(systimer_t info, struct intrframe *frame)
326 {
327 	sysclock_t cputicks;
328 	struct proc *p;
329 	struct pstats *pstats;
330 	struct globaldata *gd = mycpu;
331 
332 	/*
333 	 * Realtime updates are per-cpu.  Note that timer corrections as
334 	 * returned by microtime() and friends make an additional adjustment
335 	 * using a system-wise 'basetime', but the running time is always
336 	 * taken from the per-cpu globaldata area.  Since the same clock
337 	 * is distributing (XXX SMP) to all cpus, the per-cpu timebases
338 	 * stay in synch.
339 	 *
340 	 * Note that we never allow info->time (aka gd->gd_hardclock.time)
341 	 * to reverse index gd_cpuclock_base, but that it is possible for
342 	 * it to temporarily get behind in the seconds if something in the
343 	 * system locks interrupts for a long period of time.  Since periodic
344 	 * timers count events, though everything should resynch again
345 	 * immediately.
346 	 */
347 	cputicks = info->time - gd->gd_cpuclock_base;
348 	if (cputicks >= sys_cputimer->freq) {
349 		++gd->gd_time_seconds;
350 		gd->gd_cpuclock_base += sys_cputimer->freq;
351 	}
352 
353 	/*
354 	 * The system-wide ticks counter and NTP related timedelta/tickdelta
355 	 * adjustments only occur on cpu #0.  NTP adjustments are accomplished
356 	 * by updating basetime.
357 	 */
358 	if (gd->gd_cpuid == 0) {
359 	    struct timespec *nbt;
360 	    struct timespec nts;
361 	    int leap;
362 	    int ni;
363 
364 	    ++ticks;
365 
366 #ifdef DEVICE_POLLING
367 	    hardclock_device_poll();	/* mpsafe, short and quick */
368 #endif /* DEVICE_POLLING */
369 
370 #if 0
371 	    if (tco->tc_poll_pps)
372 		tco->tc_poll_pps(tco);
373 #endif
374 
375 	    /*
376 	     * Calculate the new basetime index.  We are in a critical section
377 	     * on cpu #0 and can safely play with basetime_index.  Start
378 	     * with the current basetime and then make adjustments.
379 	     */
380 	    ni = (basetime_index + 1) & BASETIME_ARYMASK;
381 	    nbt = &basetime[ni];
382 	    *nbt = basetime[basetime_index];
383 
384 	    /*
385 	     * Apply adjtime corrections.  (adjtime() API)
386 	     *
387 	     * adjtime() only runs on cpu #0 so our critical section is
388 	     * sufficient to access these variables.
389 	     */
390 	    if (ntp_delta != 0) {
391 		nbt->tv_nsec += ntp_tick_delta;
392 		ntp_delta -= ntp_tick_delta;
393 		if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
394 		    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
395 			ntp_tick_delta = ntp_delta;
396  		}
397  	    }
398 
399 	    /*
400 	     * Apply permanent frequency corrections.  (sysctl API)
401 	     */
402 	    if (ntp_tick_permanent != 0) {
403 		ntp_tick_acc += ntp_tick_permanent;
404 		if (ntp_tick_acc >= (1LL << 32)) {
405 		    nbt->tv_nsec += ntp_tick_acc >> 32;
406 		    ntp_tick_acc -= (ntp_tick_acc >> 32) << 32;
407 		} else if (ntp_tick_acc <= -(1LL << 32)) {
408 		    /* Negate ntp_tick_acc to avoid shifting the sign bit. */
409 		    nbt->tv_nsec -= (-ntp_tick_acc) >> 32;
410 		    ntp_tick_acc += ((-ntp_tick_acc) >> 32) << 32;
411 		}
412  	    }
413 
414 	    if (nbt->tv_nsec >= 1000000000) {
415 		    nbt->tv_sec++;
416 		    nbt->tv_nsec -= 1000000000;
417 	    } else if (nbt->tv_nsec < 0) {
418 		    nbt->tv_sec--;
419 		    nbt->tv_nsec += 1000000000;
420 	    }
421 
422 	    /*
423 	     * Another per-tick compensation.  (for ntp_adjtime() API)
424 	     */
425 	    if (nsec_adj != 0) {
426 		nsec_acc += nsec_adj;
427 		if (nsec_acc >= 0x100000000LL) {
428 		    nbt->tv_nsec += nsec_acc >> 32;
429 		    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
430 		} else if (nsec_acc <= -0x100000000LL) {
431 		    nbt->tv_nsec -= -nsec_acc >> 32;
432 		    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
433 		}
434 		if (nbt->tv_nsec >= 1000000000) {
435 		    nbt->tv_nsec -= 1000000000;
436 		    ++nbt->tv_sec;
437 		} else if (nbt->tv_nsec < 0) {
438 		    nbt->tv_nsec += 1000000000;
439 		    --nbt->tv_sec;
440 		}
441 	    }
442 
443 	    /************************************************************
444 	     *			LEAP SECOND CORRECTION			*
445 	     ************************************************************
446 	     *
447 	     * Taking into account all the corrections made above, figure
448 	     * out the new real time.  If the seconds field has changed
449 	     * then apply any pending leap-second corrections.
450 	     */
451 	    getnanotime_nbt(nbt, &nts);
452 
453 	    if (time_second != nts.tv_sec) {
454 		/*
455 		 * Apply leap second (sysctl API).  Adjust nts for changes
456 		 * so we do not have to call getnanotime_nbt again.
457 		 */
458 		if (ntp_leap_second) {
459 		    if (ntp_leap_second == nts.tv_sec) {
460 			if (ntp_leap_insert) {
461 			    nbt->tv_sec++;
462 			    nts.tv_sec++;
463 			} else {
464 			    nbt->tv_sec--;
465 			    nts.tv_sec--;
466 			}
467 			ntp_leap_second--;
468 		    }
469 		}
470 
471 		/*
472 		 * Apply leap second (ntp_adjtime() API), calculate a new
473 		 * nsec_adj field.  ntp_update_second() returns nsec_adj
474 		 * as a per-second value but we need it as a per-tick value.
475 		 */
476 		leap = ntp_update_second(time_second, &nsec_adj);
477 		nsec_adj /= hz;
478 		nbt->tv_sec += leap;
479 		nts.tv_sec += leap;
480 
481 		/*
482 		 * Update the time_second 'approximate time' global.
483 		 */
484 		time_second = nts.tv_sec;
485 	    }
486 
487 	    /*
488 	     * Finally, our new basetime is ready to go live!
489 	     */
490 	    cpu_sfence();
491 	    basetime_index = ni;
492 	}
493 
494 	/*
495 	 * softticks are handled for all cpus
496 	 */
497 	hardclock_softtick(gd);
498 
499 	/*
500 	 * ITimer handling is per-tick, per-cpu.  I don't think psignal()
501 	 * is mpsafe on curproc, so XXX get the mplock.
502 	 */
503 	if ((p = curproc) != NULL && try_mplock()) {
504 		pstats = p->p_stats;
505 		if (frame && CLKF_USERMODE(frame) &&
506 		    timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) &&
507 		    itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0)
508 			psignal(p, SIGVTALRM);
509 		if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value) &&
510 		    itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0)
511 			psignal(p, SIGPROF);
512 		rel_mplock();
513 	}
514 	setdelayed();
515 }
516 
517 /*
518  * The statistics clock typically runs at a 125Hz rate, and is intended
519  * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
520  *
521  * NOTE! systimer! the MP lock might not be held here.  We can only safely
522  * manipulate objects owned by the current cpu.
523  *
524  * The stats clock is responsible for grabbing a profiling sample.
525  * Most of the statistics are only used by user-level statistics programs.
526  * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
527  * p->p_estcpu.
528  *
529  * Like the other clocks, the stat clock is called from what is effectively
530  * a fast interrupt, so the context should be the thread/process that got
531  * interrupted.
532  */
533 static void
534 statclock(systimer_t info, struct intrframe *frame)
535 {
536 #ifdef GPROF
537 	struct gmonparam *g;
538 	int i;
539 #endif
540 	thread_t td;
541 	struct proc *p;
542 	int bump;
543 	struct timeval tv;
544 	struct timeval *stv;
545 
546 	/*
547 	 * How big was our timeslice relative to the last time?
548 	 */
549 	microuptime(&tv);	/* mpsafe */
550 	stv = &mycpu->gd_stattv;
551 	if (stv->tv_sec == 0) {
552 	    bump = 1;
553 	} else {
554 	    bump = tv.tv_usec - stv->tv_usec +
555 		(tv.tv_sec - stv->tv_sec) * 1000000;
556 	    if (bump < 0)
557 		bump = 0;
558 	    if (bump > 1000000)
559 		bump = 1000000;
560 	}
561 	*stv = tv;
562 
563 	td = curthread;
564 	p = td->td_proc;
565 
566 	if (frame && CLKF_USERMODE(frame)) {
567 		/*
568 		 * Came from userland, handle user time and deal with
569 		 * possible process.
570 		 */
571 		if (p && (p->p_flag & P_PROFIL))
572 			addupc_intr(p, CLKF_PC(frame), 1);
573 		td->td_uticks += bump;
574 
575 		/*
576 		 * Charge the time as appropriate
577 		 */
578 		if (p && p->p_nice > NZERO)
579 			cpu_time.cp_nice += bump;
580 		else
581 			cpu_time.cp_user += bump;
582 	} else {
583 #ifdef GPROF
584 		/*
585 		 * Kernel statistics are just like addupc_intr, only easier.
586 		 */
587 		g = &_gmonparam;
588 		if (g->state == GMON_PROF_ON && frame) {
589 			i = CLKF_PC(frame) - g->lowpc;
590 			if (i < g->textsize) {
591 				i /= HISTFRACTION * sizeof(*g->kcount);
592 				g->kcount[i]++;
593 			}
594 		}
595 #endif
596 		/*
597 		 * Came from kernel mode, so we were:
598 		 * - handling an interrupt,
599 		 * - doing syscall or trap work on behalf of the current
600 		 *   user process, or
601 		 * - spinning in the idle loop.
602 		 * Whichever it is, charge the time as appropriate.
603 		 * Note that we charge interrupts to the current process,
604 		 * regardless of whether they are ``for'' that process,
605 		 * so that we know how much of its real time was spent
606 		 * in ``non-process'' (i.e., interrupt) work.
607 		 *
608 		 * XXX assume system if frame is NULL.  A NULL frame
609 		 * can occur if ipi processing is done from a crit_exit().
610 		 */
611 		if (frame && CLKF_INTR(frame))
612 			td->td_iticks += bump;
613 		else
614 			td->td_sticks += bump;
615 
616 		if (frame && CLKF_INTR(frame)) {
617 			cpu_time.cp_intr += bump;
618 		} else {
619 			if (td == &mycpu->gd_idlethread)
620 				cpu_time.cp_idle += bump;
621 			else
622 				cpu_time.cp_sys += bump;
623 		}
624 	}
625 }
626 
627 /*
628  * The scheduler clock typically runs at a 20Hz rate.  NOTE! systimer,
629  * the MP lock might not be held.  We can safely manipulate parts of curproc
630  * but that's about it.
631  */
632 static void
633 schedclock(systimer_t info, struct intrframe *frame)
634 {
635 	struct proc *p;
636 	struct pstats *pstats;
637 	struct rusage *ru;
638 	struct vmspace *vm;
639 	long rss;
640 
641 	schedulerclock(NULL);	/* mpsafe */
642 	if ((p = curproc) != NULL) {
643 		/* Update resource usage integrals and maximums. */
644 		if ((pstats = p->p_stats) != NULL &&
645 		    (ru = &pstats->p_ru) != NULL &&
646 		    (vm = p->p_vmspace) != NULL) {
647 			ru->ru_ixrss += pgtok(vm->vm_tsize);
648 			ru->ru_idrss += pgtok(vm->vm_dsize);
649 			ru->ru_isrss += pgtok(vm->vm_ssize);
650 			rss = pgtok(vmspace_resident_count(vm));
651 			if (ru->ru_maxrss < rss)
652 				ru->ru_maxrss = rss;
653 		}
654 	}
655 }
656 
657 /*
658  * Compute number of ticks for the specified amount of time.  The
659  * return value is intended to be used in a clock interrupt timed
660  * operation and guarenteed to meet or exceed the requested time.
661  * If the representation overflows, return INT_MAX.  The minimum return
662  * value is 1 ticks and the function will average the calculation up.
663  * If any value greater then 0 microseconds is supplied, a value
664  * of at least 2 will be returned to ensure that a near-term clock
665  * interrupt does not cause the timeout to occur (degenerately) early.
666  *
667  * Note that limit checks must take into account microseconds, which is
668  * done simply by using the smaller signed long maximum instead of
669  * the unsigned long maximum.
670  *
671  * If ints have 32 bits, then the maximum value for any timeout in
672  * 10ms ticks is 248 days.
673  */
674 int
675 tvtohz_high(struct timeval *tv)
676 {
677 	int ticks;
678 	long sec, usec;
679 
680 	sec = tv->tv_sec;
681 	usec = tv->tv_usec;
682 	if (usec < 0) {
683 		sec--;
684 		usec += 1000000;
685 	}
686 	if (sec < 0) {
687 #ifdef DIAGNOSTIC
688 		if (usec > 0) {
689 			sec++;
690 			usec -= 1000000;
691 		}
692 		printf("tvotohz: negative time difference %ld sec %ld usec\n",
693 		       sec, usec);
694 #endif
695 		ticks = 1;
696 	} else if (sec <= INT_MAX / hz) {
697 		ticks = (int)(sec * hz +
698 			    ((u_long)usec + (tick - 1)) / tick) + 1;
699 	} else {
700 		ticks = INT_MAX;
701 	}
702 	return (ticks);
703 }
704 
705 /*
706  * Compute number of ticks for the specified amount of time, erroring on
707  * the side of it being too low to ensure that sleeping the returned number
708  * of ticks will not result in a late return.
709  *
710  * The supplied timeval may not be negative and should be normalized.  A
711  * return value of 0 is possible if the timeval converts to less then
712  * 1 tick.
713  *
714  * If ints have 32 bits, then the maximum value for any timeout in
715  * 10ms ticks is 248 days.
716  */
717 int
718 tvtohz_low(struct timeval *tv)
719 {
720 	int ticks;
721 	long sec;
722 
723 	sec = tv->tv_sec;
724 	if (sec <= INT_MAX / hz)
725 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / tick);
726 	else
727 		ticks = INT_MAX;
728 	return (ticks);
729 }
730 
731 
732 /*
733  * Start profiling on a process.
734  *
735  * Kernel profiling passes proc0 which never exits and hence
736  * keeps the profile clock running constantly.
737  */
738 void
739 startprofclock(struct proc *p)
740 {
741 	if ((p->p_flag & P_PROFIL) == 0) {
742 		p->p_flag |= P_PROFIL;
743 #if 0	/* XXX */
744 		if (++profprocs == 1 && stathz != 0) {
745 			crit_enter();
746 			psdiv = psratio;
747 			setstatclockrate(profhz);
748 			crit_exit();
749 		}
750 #endif
751 	}
752 }
753 
754 /*
755  * Stop profiling on a process.
756  */
757 void
758 stopprofclock(struct proc *p)
759 {
760 	if (p->p_flag & P_PROFIL) {
761 		p->p_flag &= ~P_PROFIL;
762 #if 0	/* XXX */
763 		if (--profprocs == 0 && stathz != 0) {
764 			crit_enter();
765 			psdiv = 1;
766 			setstatclockrate(stathz);
767 			crit_exit();
768 		}
769 #endif
770 	}
771 }
772 
773 /*
774  * Return information about system clocks.
775  */
776 static int
777 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
778 {
779 	struct kinfo_clockinfo clkinfo;
780 	/*
781 	 * Construct clockinfo structure.
782 	 */
783 	clkinfo.ci_hz = hz;
784 	clkinfo.ci_tick = tick;
785 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
786 	clkinfo.ci_profhz = profhz;
787 	clkinfo.ci_stathz = stathz ? stathz : hz;
788 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
789 }
790 
791 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
792 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
793 
794 /*
795  * We have eight functions for looking at the clock, four for
796  * microseconds and four for nanoseconds.  For each there is fast
797  * but less precise version "get{nano|micro}[up]time" which will
798  * return a time which is up to 1/HZ previous to the call, whereas
799  * the raw version "{nano|micro}[up]time" will return a timestamp
800  * which is as precise as possible.  The "up" variants return the
801  * time relative to system boot, these are well suited for time
802  * interval measurements.
803  *
804  * Each cpu independantly maintains the current time of day, so all
805  * we need to do to protect ourselves from changes is to do a loop
806  * check on the seconds field changing out from under us.
807  *
808  * The system timer maintains a 32 bit count and due to various issues
809  * it is possible for the calculated delta to occassionally exceed
810  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
811  * multiplication can easily overflow, so we deal with the case.  For
812  * uniformity we deal with the case in the usec case too.
813  */
814 void
815 getmicrouptime(struct timeval *tvp)
816 {
817 	struct globaldata *gd = mycpu;
818 	sysclock_t delta;
819 
820 	do {
821 		tvp->tv_sec = gd->gd_time_seconds;
822 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
823 	} while (tvp->tv_sec != gd->gd_time_seconds);
824 
825 	if (delta >= sys_cputimer->freq) {
826 		tvp->tv_sec += delta / sys_cputimer->freq;
827 		delta %= sys_cputimer->freq;
828 	}
829 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
830 	if (tvp->tv_usec >= 1000000) {
831 		tvp->tv_usec -= 1000000;
832 		++tvp->tv_sec;
833 	}
834 }
835 
836 void
837 getnanouptime(struct timespec *tsp)
838 {
839 	struct globaldata *gd = mycpu;
840 	sysclock_t delta;
841 
842 	do {
843 		tsp->tv_sec = gd->gd_time_seconds;
844 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
845 	} while (tsp->tv_sec != gd->gd_time_seconds);
846 
847 	if (delta >= sys_cputimer->freq) {
848 		tsp->tv_sec += delta / sys_cputimer->freq;
849 		delta %= sys_cputimer->freq;
850 	}
851 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
852 }
853 
854 void
855 microuptime(struct timeval *tvp)
856 {
857 	struct globaldata *gd = mycpu;
858 	sysclock_t delta;
859 
860 	do {
861 		tvp->tv_sec = gd->gd_time_seconds;
862 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
863 	} while (tvp->tv_sec != gd->gd_time_seconds);
864 
865 	if (delta >= sys_cputimer->freq) {
866 		tvp->tv_sec += delta / sys_cputimer->freq;
867 		delta %= sys_cputimer->freq;
868 	}
869 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
870 }
871 
872 void
873 nanouptime(struct timespec *tsp)
874 {
875 	struct globaldata *gd = mycpu;
876 	sysclock_t delta;
877 
878 	do {
879 		tsp->tv_sec = gd->gd_time_seconds;
880 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
881 	} while (tsp->tv_sec != gd->gd_time_seconds);
882 
883 	if (delta >= sys_cputimer->freq) {
884 		tsp->tv_sec += delta / sys_cputimer->freq;
885 		delta %= sys_cputimer->freq;
886 	}
887 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
888 }
889 
890 /*
891  * realtime routines
892  */
893 
894 void
895 getmicrotime(struct timeval *tvp)
896 {
897 	struct globaldata *gd = mycpu;
898 	struct timespec *bt;
899 	sysclock_t delta;
900 
901 	do {
902 		tvp->tv_sec = gd->gd_time_seconds;
903 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
904 	} while (tvp->tv_sec != gd->gd_time_seconds);
905 
906 	if (delta >= sys_cputimer->freq) {
907 		tvp->tv_sec += delta / sys_cputimer->freq;
908 		delta %= sys_cputimer->freq;
909 	}
910 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
911 
912 	bt = &basetime[basetime_index];
913 	tvp->tv_sec += bt->tv_sec;
914 	tvp->tv_usec += bt->tv_nsec / 1000;
915 	while (tvp->tv_usec >= 1000000) {
916 		tvp->tv_usec -= 1000000;
917 		++tvp->tv_sec;
918 	}
919 }
920 
921 void
922 getnanotime(struct timespec *tsp)
923 {
924 	struct globaldata *gd = mycpu;
925 	struct timespec *bt;
926 	sysclock_t delta;
927 
928 	do {
929 		tsp->tv_sec = gd->gd_time_seconds;
930 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
931 	} while (tsp->tv_sec != gd->gd_time_seconds);
932 
933 	if (delta >= sys_cputimer->freq) {
934 		tsp->tv_sec += delta / sys_cputimer->freq;
935 		delta %= sys_cputimer->freq;
936 	}
937 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
938 
939 	bt = &basetime[basetime_index];
940 	tsp->tv_sec += bt->tv_sec;
941 	tsp->tv_nsec += bt->tv_nsec;
942 	while (tsp->tv_nsec >= 1000000000) {
943 		tsp->tv_nsec -= 1000000000;
944 		++tsp->tv_sec;
945 	}
946 }
947 
948 static void
949 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
950 {
951 	struct globaldata *gd = mycpu;
952 	sysclock_t delta;
953 
954 	do {
955 		tsp->tv_sec = gd->gd_time_seconds;
956 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
957 	} while (tsp->tv_sec != gd->gd_time_seconds);
958 
959 	if (delta >= sys_cputimer->freq) {
960 		tsp->tv_sec += delta / sys_cputimer->freq;
961 		delta %= sys_cputimer->freq;
962 	}
963 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
964 
965 	tsp->tv_sec += nbt->tv_sec;
966 	tsp->tv_nsec += nbt->tv_nsec;
967 	while (tsp->tv_nsec >= 1000000000) {
968 		tsp->tv_nsec -= 1000000000;
969 		++tsp->tv_sec;
970 	}
971 }
972 
973 
974 void
975 microtime(struct timeval *tvp)
976 {
977 	struct globaldata *gd = mycpu;
978 	struct timespec *bt;
979 	sysclock_t delta;
980 
981 	do {
982 		tvp->tv_sec = gd->gd_time_seconds;
983 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
984 	} while (tvp->tv_sec != gd->gd_time_seconds);
985 
986 	if (delta >= sys_cputimer->freq) {
987 		tvp->tv_sec += delta / sys_cputimer->freq;
988 		delta %= sys_cputimer->freq;
989 	}
990 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
991 
992 	bt = &basetime[basetime_index];
993 	tvp->tv_sec += bt->tv_sec;
994 	tvp->tv_usec += bt->tv_nsec / 1000;
995 	while (tvp->tv_usec >= 1000000) {
996 		tvp->tv_usec -= 1000000;
997 		++tvp->tv_sec;
998 	}
999 }
1000 
1001 void
1002 nanotime(struct timespec *tsp)
1003 {
1004 	struct globaldata *gd = mycpu;
1005 	struct timespec *bt;
1006 	sysclock_t delta;
1007 
1008 	do {
1009 		tsp->tv_sec = gd->gd_time_seconds;
1010 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1011 	} while (tsp->tv_sec != gd->gd_time_seconds);
1012 
1013 	if (delta >= sys_cputimer->freq) {
1014 		tsp->tv_sec += delta / sys_cputimer->freq;
1015 		delta %= sys_cputimer->freq;
1016 	}
1017 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1018 
1019 	bt = &basetime[basetime_index];
1020 	tsp->tv_sec += bt->tv_sec;
1021 	tsp->tv_nsec += bt->tv_nsec;
1022 	while (tsp->tv_nsec >= 1000000000) {
1023 		tsp->tv_nsec -= 1000000000;
1024 		++tsp->tv_sec;
1025 	}
1026 }
1027 
1028 /*
1029  * note: this is not exactly synchronized with real time.  To do that we
1030  * would have to do what microtime does and check for a nanoseconds overflow.
1031  */
1032 time_t
1033 get_approximate_time_t(void)
1034 {
1035 	struct globaldata *gd = mycpu;
1036 	struct timespec *bt;
1037 
1038 	bt = &basetime[basetime_index];
1039 	return(gd->gd_time_seconds + bt->tv_sec);
1040 }
1041 
1042 int
1043 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1044 {
1045 	pps_params_t *app;
1046 	struct pps_fetch_args *fapi;
1047 #ifdef PPS_SYNC
1048 	struct pps_kcbind_args *kapi;
1049 #endif
1050 
1051 	switch (cmd) {
1052 	case PPS_IOC_CREATE:
1053 		return (0);
1054 	case PPS_IOC_DESTROY:
1055 		return (0);
1056 	case PPS_IOC_SETPARAMS:
1057 		app = (pps_params_t *)data;
1058 		if (app->mode & ~pps->ppscap)
1059 			return (EINVAL);
1060 		pps->ppsparam = *app;
1061 		return (0);
1062 	case PPS_IOC_GETPARAMS:
1063 		app = (pps_params_t *)data;
1064 		*app = pps->ppsparam;
1065 		app->api_version = PPS_API_VERS_1;
1066 		return (0);
1067 	case PPS_IOC_GETCAP:
1068 		*(int*)data = pps->ppscap;
1069 		return (0);
1070 	case PPS_IOC_FETCH:
1071 		fapi = (struct pps_fetch_args *)data;
1072 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1073 			return (EINVAL);
1074 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1075 			return (EOPNOTSUPP);
1076 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1077 		fapi->pps_info_buf = pps->ppsinfo;
1078 		return (0);
1079 	case PPS_IOC_KCBIND:
1080 #ifdef PPS_SYNC
1081 		kapi = (struct pps_kcbind_args *)data;
1082 		/* XXX Only root should be able to do this */
1083 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1084 			return (EINVAL);
1085 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1086 			return (EINVAL);
1087 		if (kapi->edge & ~pps->ppscap)
1088 			return (EINVAL);
1089 		pps->kcmode = kapi->edge;
1090 		return (0);
1091 #else
1092 		return (EOPNOTSUPP);
1093 #endif
1094 	default:
1095 		return (ENOTTY);
1096 	}
1097 }
1098 
1099 void
1100 pps_init(struct pps_state *pps)
1101 {
1102 	pps->ppscap |= PPS_TSFMT_TSPEC;
1103 	if (pps->ppscap & PPS_CAPTUREASSERT)
1104 		pps->ppscap |= PPS_OFFSETASSERT;
1105 	if (pps->ppscap & PPS_CAPTURECLEAR)
1106 		pps->ppscap |= PPS_OFFSETCLEAR;
1107 }
1108 
1109 void
1110 pps_event(struct pps_state *pps, sysclock_t count, int event)
1111 {
1112 	struct globaldata *gd;
1113 	struct timespec *tsp;
1114 	struct timespec *osp;
1115 	struct timespec *bt;
1116 	struct timespec ts;
1117 	sysclock_t *pcount;
1118 #ifdef PPS_SYNC
1119 	sysclock_t tcount;
1120 #endif
1121 	sysclock_t delta;
1122 	pps_seq_t *pseq;
1123 	int foff;
1124 	int fhard;
1125 
1126 	gd = mycpu;
1127 
1128 	/* Things would be easier with arrays... */
1129 	if (event == PPS_CAPTUREASSERT) {
1130 		tsp = &pps->ppsinfo.assert_timestamp;
1131 		osp = &pps->ppsparam.assert_offset;
1132 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1133 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1134 		pcount = &pps->ppscount[0];
1135 		pseq = &pps->ppsinfo.assert_sequence;
1136 	} else {
1137 		tsp = &pps->ppsinfo.clear_timestamp;
1138 		osp = &pps->ppsparam.clear_offset;
1139 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1140 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1141 		pcount = &pps->ppscount[1];
1142 		pseq = &pps->ppsinfo.clear_sequence;
1143 	}
1144 
1145 	/* Nothing really happened */
1146 	if (*pcount == count)
1147 		return;
1148 
1149 	*pcount = count;
1150 
1151 	do {
1152 		ts.tv_sec = gd->gd_time_seconds;
1153 		delta = count - gd->gd_cpuclock_base;
1154 	} while (ts.tv_sec != gd->gd_time_seconds);
1155 
1156 	if (delta >= sys_cputimer->freq) {
1157 		ts.tv_sec += delta / sys_cputimer->freq;
1158 		delta %= sys_cputimer->freq;
1159 	}
1160 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1161 	bt = &basetime[basetime_index];
1162 	ts.tv_sec += bt->tv_sec;
1163 	ts.tv_nsec += bt->tv_nsec;
1164 	while (ts.tv_nsec >= 1000000000) {
1165 		ts.tv_nsec -= 1000000000;
1166 		++ts.tv_sec;
1167 	}
1168 
1169 	(*pseq)++;
1170 	*tsp = ts;
1171 
1172 	if (foff) {
1173 		timespecadd(tsp, osp);
1174 		if (tsp->tv_nsec < 0) {
1175 			tsp->tv_nsec += 1000000000;
1176 			tsp->tv_sec -= 1;
1177 		}
1178 	}
1179 #ifdef PPS_SYNC
1180 	if (fhard) {
1181 		/* magic, at its best... */
1182 		tcount = count - pps->ppscount[2];
1183 		pps->ppscount[2] = count;
1184 		if (tcount >= sys_cputimer->freq) {
1185 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1186 				 sys_cputimer->freq64_nsec *
1187 				 (tcount % sys_cputimer->freq)) >> 32;
1188 		} else {
1189 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1190 		}
1191 		hardpps(tsp, delta);
1192 	}
1193 #endif
1194 }
1195 
1196