xref: /dragonfly/sys/kern/kern_clock.c (revision 409b4c59)
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 1.62 2008/09/09 04:06:13 dillon Exp $
74  */
75 
76 #include "opt_ntp.h"
77 #include "opt_polling.h"
78 #include "opt_ifpoll.h"
79 #include "opt_pctrack.h"
80 
81 #include <sys/param.h>
82 #include <sys/systm.h>
83 #include <sys/callout.h>
84 #include <sys/kernel.h>
85 #include <sys/kinfo.h>
86 #include <sys/proc.h>
87 #include <sys/malloc.h>
88 #include <sys/resourcevar.h>
89 #include <sys/signalvar.h>
90 #include <sys/timex.h>
91 #include <sys/timepps.h>
92 #include <vm/vm.h>
93 #include <sys/lock.h>
94 #include <vm/pmap.h>
95 #include <vm/vm_map.h>
96 #include <vm/vm_extern.h>
97 #include <sys/sysctl.h>
98 #include <sys/thread2.h>
99 
100 #include <machine/cpu.h>
101 #include <machine/limits.h>
102 #include <machine/smp.h>
103 
104 #ifdef GPROF
105 #include <sys/gmon.h>
106 #endif
107 
108 #ifdef DEVICE_POLLING
109 extern void init_device_poll_pcpu(int);
110 #endif
111 
112 #ifdef IFPOLL_ENABLE
113 extern void ifpoll_init_pcpu(int);
114 #endif
115 
116 #ifdef DEBUG_PCTRACK
117 static void do_pctrack(struct intrframe *frame, int which);
118 #endif
119 
120 static void initclocks (void *dummy);
121 SYSINIT(clocks, SI_BOOT2_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
122 
123 /*
124  * Some of these don't belong here, but it's easiest to concentrate them.
125  * Note that cpu_time counts in microseconds, but most userland programs
126  * just compare relative times against the total by delta.
127  */
128 struct kinfo_cputime cputime_percpu[MAXCPU];
129 #ifdef DEBUG_PCTRACK
130 struct kinfo_pcheader cputime_pcheader = { PCTRACK_SIZE, PCTRACK_ARYSIZE };
131 struct kinfo_pctrack cputime_pctrack[MAXCPU][PCTRACK_SIZE];
132 #endif
133 
134 #ifdef SMP
135 static int
136 sysctl_cputime(SYSCTL_HANDLER_ARGS)
137 {
138 	int cpu, error = 0;
139 	size_t size = sizeof(struct kinfo_cputime);
140 
141 	for (cpu = 0; cpu < ncpus; ++cpu) {
142 		if ((error = SYSCTL_OUT(req, &cputime_percpu[cpu], size)))
143 			break;
144 	}
145 
146 	return (error);
147 }
148 SYSCTL_PROC(_kern, OID_AUTO, cputime, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
149 	sysctl_cputime, "S,kinfo_cputime", "CPU time statistics");
150 #else
151 SYSCTL_STRUCT(_kern, OID_AUTO, cputime, CTLFLAG_RD, &cpu_time, kinfo_cputime,
152     "CPU time statistics");
153 #endif
154 
155 /*
156  * boottime is used to calculate the 'real' uptime.  Do not confuse this with
157  * microuptime().  microtime() is not drift compensated.  The real uptime
158  * with compensation is nanotime() - bootime.  boottime is recalculated
159  * whenever the real time is set based on the compensated elapsed time
160  * in seconds (gd->gd_time_seconds).
161  *
162  * The gd_time_seconds and gd_cpuclock_base fields remain fairly monotonic.
163  * Slight adjustments to gd_cpuclock_base are made to phase-lock it to
164  * the real time.
165  */
166 struct timespec boottime;	/* boot time (realtime) for reference only */
167 time_t time_second;		/* read-only 'passive' uptime in seconds */
168 
169 /*
170  * basetime is used to calculate the compensated real time of day.  The
171  * basetime can be modified on a per-tick basis by the adjtime(),
172  * ntp_adjtime(), and sysctl-based time correction APIs.
173  *
174  * Note that frequency corrections can also be made by adjusting
175  * gd_cpuclock_base.
176  *
177  * basetime is a tail-chasing FIFO, updated only by cpu #0.  The FIFO is
178  * used on both SMP and UP systems to avoid MP races between cpu's and
179  * interrupt races on UP systems.
180  */
181 #define BASETIME_ARYSIZE	16
182 #define BASETIME_ARYMASK	(BASETIME_ARYSIZE - 1)
183 static struct timespec basetime[BASETIME_ARYSIZE];
184 static volatile int basetime_index;
185 
186 static int
187 sysctl_get_basetime(SYSCTL_HANDLER_ARGS)
188 {
189 	struct timespec *bt;
190 	int error;
191 	int index;
192 
193 	/*
194 	 * Because basetime data and index may be updated by another cpu,
195 	 * a load fence is required to ensure that the data we read has
196 	 * not been speculatively read relative to a possibly updated index.
197 	 */
198 	index = basetime_index;
199 	cpu_lfence();
200 	bt = &basetime[index];
201 	error = SYSCTL_OUT(req, bt, sizeof(*bt));
202 	return (error);
203 }
204 
205 SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
206     &boottime, timespec, "System boottime");
207 SYSCTL_PROC(_kern, OID_AUTO, basetime, CTLTYPE_STRUCT|CTLFLAG_RD, 0, 0,
208     sysctl_get_basetime, "S,timespec", "System basetime");
209 
210 static void hardclock(systimer_t info, struct intrframe *frame);
211 static void statclock(systimer_t info, struct intrframe *frame);
212 static void schedclock(systimer_t info, struct intrframe *frame);
213 static void getnanotime_nbt(struct timespec *nbt, struct timespec *tsp);
214 
215 int	ticks;			/* system master ticks at hz */
216 int	clocks_running;		/* tsleep/timeout clocks operational */
217 int64_t	nsec_adj;		/* ntpd per-tick adjustment in nsec << 32 */
218 int64_t	nsec_acc;		/* accumulator */
219 
220 /* NTPD time correction fields */
221 int64_t	ntp_tick_permanent;	/* per-tick adjustment in nsec << 32 */
222 int64_t	ntp_tick_acc;		/* accumulator for per-tick adjustment */
223 int64_t	ntp_delta;		/* one-time correction in nsec */
224 int64_t ntp_big_delta = 1000000000;
225 int32_t	ntp_tick_delta;		/* current adjustment rate */
226 int32_t	ntp_default_tick_delta;	/* adjustment rate for ntp_delta */
227 time_t	ntp_leap_second;	/* time of next leap second */
228 int	ntp_leap_insert;	/* whether to insert or remove a second */
229 
230 /*
231  * Finish initializing clock frequencies and start all clocks running.
232  */
233 /* ARGSUSED*/
234 static void
235 initclocks(void *dummy)
236 {
237 	/*psratio = profhz / stathz;*/
238 	initclocks_pcpu();
239 	clocks_running = 1;
240 }
241 
242 /*
243  * Called on a per-cpu basis
244  */
245 void
246 initclocks_pcpu(void)
247 {
248 	struct globaldata *gd = mycpu;
249 
250 	crit_enter();
251 	if (gd->gd_cpuid == 0) {
252 	    gd->gd_time_seconds = 1;
253 	    gd->gd_cpuclock_base = sys_cputimer->count();
254 	} else {
255 	    /* XXX */
256 	    gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
257 	    gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
258 	}
259 
260 #ifdef DEVICE_POLLING
261 	init_device_poll_pcpu(gd->gd_cpuid);
262 #endif
263 
264 #ifdef IFPOLL_ENABLE
265 	ifpoll_init_pcpu(gd->gd_cpuid);
266 #endif
267 
268 	/*
269 	 * Use a non-queued periodic systimer to prevent multiple ticks from
270 	 * building up if the sysclock jumps forward (8254 gets reset).  The
271 	 * sysclock will never jump backwards.  Our time sync is based on
272 	 * the actual sysclock, not the ticks count.
273 	 */
274 	systimer_init_periodic_nq(&gd->gd_hardclock, hardclock, NULL, hz);
275 	systimer_init_periodic_nq(&gd->gd_statclock, statclock, NULL, stathz);
276 	/* XXX correct the frequency for scheduler / estcpu tests */
277 	systimer_init_periodic_nq(&gd->gd_schedclock, schedclock,
278 				NULL, ESTCPUFREQ);
279 	crit_exit();
280 }
281 
282 /*
283  * This sets the current real time of day.  Timespecs are in seconds and
284  * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
285  * instead we adjust basetime so basetime + gd_* results in the current
286  * time of day.  This way the gd_* fields are guarenteed to represent
287  * a monotonically increasing 'uptime' value.
288  *
289  * When set_timeofday() is called from userland, the system call forces it
290  * onto cpu #0 since only cpu #0 can update basetime_index.
291  */
292 void
293 set_timeofday(struct timespec *ts)
294 {
295 	struct timespec *nbt;
296 	int ni;
297 
298 	/*
299 	 * XXX SMP / non-atomic basetime updates
300 	 */
301 	crit_enter();
302 	ni = (basetime_index + 1) & BASETIME_ARYMASK;
303 	nbt = &basetime[ni];
304 	nanouptime(nbt);
305 	nbt->tv_sec = ts->tv_sec - nbt->tv_sec;
306 	nbt->tv_nsec = ts->tv_nsec - nbt->tv_nsec;
307 	if (nbt->tv_nsec < 0) {
308 	    nbt->tv_nsec += 1000000000;
309 	    --nbt->tv_sec;
310 	}
311 
312 	/*
313 	 * Note that basetime diverges from boottime as the clock drift is
314 	 * compensated for, so we cannot do away with boottime.  When setting
315 	 * the absolute time of day the drift is 0 (for an instant) and we
316 	 * can simply assign boottime to basetime.
317 	 *
318 	 * Note that nanouptime() is based on gd_time_seconds which is drift
319 	 * compensated up to a point (it is guarenteed to remain monotonically
320 	 * increasing).  gd_time_seconds is thus our best uptime guess and
321 	 * suitable for use in the boottime calculation.  It is already taken
322 	 * into account in the basetime calculation above.
323 	 */
324 	boottime.tv_sec = nbt->tv_sec;
325 	ntp_delta = 0;
326 
327 	/*
328 	 * We now have a new basetime, make sure all other cpus have it,
329 	 * then update the index.
330 	 */
331 	cpu_sfence();
332 	basetime_index = ni;
333 
334 	crit_exit();
335 }
336 
337 /*
338  * Each cpu has its own hardclock, but we only increments ticks and softticks
339  * on cpu #0.
340  *
341  * NOTE! systimer! the MP lock might not be held here.  We can only safely
342  * manipulate objects owned by the current cpu.
343  */
344 static void
345 hardclock(systimer_t info, struct intrframe *frame)
346 {
347 	sysclock_t cputicks;
348 	struct proc *p;
349 	struct globaldata *gd = mycpu;
350 
351 	/*
352 	 * Realtime updates are per-cpu.  Note that timer corrections as
353 	 * returned by microtime() and friends make an additional adjustment
354 	 * using a system-wise 'basetime', but the running time is always
355 	 * taken from the per-cpu globaldata area.  Since the same clock
356 	 * is distributing (XXX SMP) to all cpus, the per-cpu timebases
357 	 * stay in synch.
358 	 *
359 	 * Note that we never allow info->time (aka gd->gd_hardclock.time)
360 	 * to reverse index gd_cpuclock_base, but that it is possible for
361 	 * it to temporarily get behind in the seconds if something in the
362 	 * system locks interrupts for a long period of time.  Since periodic
363 	 * timers count events, though everything should resynch again
364 	 * immediately.
365 	 */
366 	cputicks = info->time - gd->gd_cpuclock_base;
367 	if (cputicks >= sys_cputimer->freq) {
368 		++gd->gd_time_seconds;
369 		gd->gd_cpuclock_base += sys_cputimer->freq;
370 	}
371 
372 	/*
373 	 * The system-wide ticks counter and NTP related timedelta/tickdelta
374 	 * adjustments only occur on cpu #0.  NTP adjustments are accomplished
375 	 * by updating basetime.
376 	 */
377 	if (gd->gd_cpuid == 0) {
378 	    struct timespec *nbt;
379 	    struct timespec nts;
380 	    int leap;
381 	    int ni;
382 
383 	    ++ticks;
384 
385 #if 0
386 	    if (tco->tc_poll_pps)
387 		tco->tc_poll_pps(tco);
388 #endif
389 
390 	    /*
391 	     * Calculate the new basetime index.  We are in a critical section
392 	     * on cpu #0 and can safely play with basetime_index.  Start
393 	     * with the current basetime and then make adjustments.
394 	     */
395 	    ni = (basetime_index + 1) & BASETIME_ARYMASK;
396 	    nbt = &basetime[ni];
397 	    *nbt = basetime[basetime_index];
398 
399 	    /*
400 	     * Apply adjtime corrections.  (adjtime() API)
401 	     *
402 	     * adjtime() only runs on cpu #0 so our critical section is
403 	     * sufficient to access these variables.
404 	     */
405 	    if (ntp_delta != 0) {
406 		nbt->tv_nsec += ntp_tick_delta;
407 		ntp_delta -= ntp_tick_delta;
408 		if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
409 		    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
410 			ntp_tick_delta = ntp_delta;
411  		}
412  	    }
413 
414 	    /*
415 	     * Apply permanent frequency corrections.  (sysctl API)
416 	     */
417 	    if (ntp_tick_permanent != 0) {
418 		ntp_tick_acc += ntp_tick_permanent;
419 		if (ntp_tick_acc >= (1LL << 32)) {
420 		    nbt->tv_nsec += ntp_tick_acc >> 32;
421 		    ntp_tick_acc -= (ntp_tick_acc >> 32) << 32;
422 		} else if (ntp_tick_acc <= -(1LL << 32)) {
423 		    /* Negate ntp_tick_acc to avoid shifting the sign bit. */
424 		    nbt->tv_nsec -= (-ntp_tick_acc) >> 32;
425 		    ntp_tick_acc += ((-ntp_tick_acc) >> 32) << 32;
426 		}
427  	    }
428 
429 	    if (nbt->tv_nsec >= 1000000000) {
430 		    nbt->tv_sec++;
431 		    nbt->tv_nsec -= 1000000000;
432 	    } else if (nbt->tv_nsec < 0) {
433 		    nbt->tv_sec--;
434 		    nbt->tv_nsec += 1000000000;
435 	    }
436 
437 	    /*
438 	     * Another per-tick compensation.  (for ntp_adjtime() API)
439 	     */
440 	    if (nsec_adj != 0) {
441 		nsec_acc += nsec_adj;
442 		if (nsec_acc >= 0x100000000LL) {
443 		    nbt->tv_nsec += nsec_acc >> 32;
444 		    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
445 		} else if (nsec_acc <= -0x100000000LL) {
446 		    nbt->tv_nsec -= -nsec_acc >> 32;
447 		    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
448 		}
449 		if (nbt->tv_nsec >= 1000000000) {
450 		    nbt->tv_nsec -= 1000000000;
451 		    ++nbt->tv_sec;
452 		} else if (nbt->tv_nsec < 0) {
453 		    nbt->tv_nsec += 1000000000;
454 		    --nbt->tv_sec;
455 		}
456 	    }
457 
458 	    /************************************************************
459 	     *			LEAP SECOND CORRECTION			*
460 	     ************************************************************
461 	     *
462 	     * Taking into account all the corrections made above, figure
463 	     * out the new real time.  If the seconds field has changed
464 	     * then apply any pending leap-second corrections.
465 	     */
466 	    getnanotime_nbt(nbt, &nts);
467 
468 	    if (time_second != nts.tv_sec) {
469 		/*
470 		 * Apply leap second (sysctl API).  Adjust nts for changes
471 		 * so we do not have to call getnanotime_nbt again.
472 		 */
473 		if (ntp_leap_second) {
474 		    if (ntp_leap_second == nts.tv_sec) {
475 			if (ntp_leap_insert) {
476 			    nbt->tv_sec++;
477 			    nts.tv_sec++;
478 			} else {
479 			    nbt->tv_sec--;
480 			    nts.tv_sec--;
481 			}
482 			ntp_leap_second--;
483 		    }
484 		}
485 
486 		/*
487 		 * Apply leap second (ntp_adjtime() API), calculate a new
488 		 * nsec_adj field.  ntp_update_second() returns nsec_adj
489 		 * as a per-second value but we need it as a per-tick value.
490 		 */
491 		leap = ntp_update_second(time_second, &nsec_adj);
492 		nsec_adj /= hz;
493 		nbt->tv_sec += leap;
494 		nts.tv_sec += leap;
495 
496 		/*
497 		 * Update the time_second 'approximate time' global.
498 		 */
499 		time_second = nts.tv_sec;
500 	    }
501 
502 	    /*
503 	     * Finally, our new basetime is ready to go live!
504 	     */
505 	    cpu_sfence();
506 	    basetime_index = ni;
507 
508 	    /*
509 	     * Figure out how badly the system is starved for memory
510 	     */
511 	    vm_fault_ratecheck();
512 	}
513 
514 	/*
515 	 * softticks are handled for all cpus
516 	 */
517 	hardclock_softtick(gd);
518 
519 	/*
520 	 * The LWKT scheduler will generally allow the current process to
521 	 * return to user mode even if there are other runnable LWKT threads
522 	 * running in kernel mode on behalf of a user process.  This will
523 	 * ensure that those other threads have an opportunity to run in
524 	 * fairly short order (but not instantly).
525 	 */
526 	need_lwkt_resched();
527 
528 	/*
529 	 * ITimer handling is per-tick, per-cpu.  I don't think ksignal()
530 	 * is mpsafe on curproc, so XXX get the mplock.
531 	 */
532 	if ((p = curproc) != NULL && try_mplock()) {
533 		if (frame && CLKF_USERMODE(frame) &&
534 		    timevalisset(&p->p_timer[ITIMER_VIRTUAL].it_value) &&
535 		    itimerdecr(&p->p_timer[ITIMER_VIRTUAL], tick) == 0)
536 			ksignal(p, SIGVTALRM);
537 		if (timevalisset(&p->p_timer[ITIMER_PROF].it_value) &&
538 		    itimerdecr(&p->p_timer[ITIMER_PROF], tick) == 0)
539 			ksignal(p, SIGPROF);
540 		rel_mplock();
541 	}
542 	setdelayed();
543 }
544 
545 /*
546  * The statistics clock typically runs at a 125Hz rate, and is intended
547  * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
548  *
549  * NOTE! systimer! the MP lock might not be held here.  We can only safely
550  * manipulate objects owned by the current cpu.
551  *
552  * The stats clock is responsible for grabbing a profiling sample.
553  * Most of the statistics are only used by user-level statistics programs.
554  * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
555  * p->p_estcpu.
556  *
557  * Like the other clocks, the stat clock is called from what is effectively
558  * a fast interrupt, so the context should be the thread/process that got
559  * interrupted.
560  */
561 static void
562 statclock(systimer_t info, struct intrframe *frame)
563 {
564 #ifdef GPROF
565 	struct gmonparam *g;
566 	int i;
567 #endif
568 	thread_t td;
569 	struct proc *p;
570 	int bump;
571 	struct timeval tv;
572 	struct timeval *stv;
573 
574 	/*
575 	 * How big was our timeslice relative to the last time?
576 	 */
577 	microuptime(&tv);	/* mpsafe */
578 	stv = &mycpu->gd_stattv;
579 	if (stv->tv_sec == 0) {
580 	    bump = 1;
581 	} else {
582 	    bump = tv.tv_usec - stv->tv_usec +
583 		(tv.tv_sec - stv->tv_sec) * 1000000;
584 	    if (bump < 0)
585 		bump = 0;
586 	    if (bump > 1000000)
587 		bump = 1000000;
588 	}
589 	*stv = tv;
590 
591 	td = curthread;
592 	p = td->td_proc;
593 
594 	if (frame && CLKF_USERMODE(frame)) {
595 		/*
596 		 * Came from userland, handle user time and deal with
597 		 * possible process.
598 		 */
599 		if (p && (p->p_flag & P_PROFIL))
600 			addupc_intr(p, CLKF_PC(frame), 1);
601 		td->td_uticks += bump;
602 
603 		/*
604 		 * Charge the time as appropriate
605 		 */
606 		if (p && p->p_nice > NZERO)
607 			cpu_time.cp_nice += bump;
608 		else
609 			cpu_time.cp_user += bump;
610 	} else {
611 #ifdef GPROF
612 		/*
613 		 * Kernel statistics are just like addupc_intr, only easier.
614 		 */
615 		g = &_gmonparam;
616 		if (g->state == GMON_PROF_ON && frame) {
617 			i = CLKF_PC(frame) - g->lowpc;
618 			if (i < g->textsize) {
619 				i /= HISTFRACTION * sizeof(*g->kcount);
620 				g->kcount[i]++;
621 			}
622 		}
623 #endif
624 		/*
625 		 * Came from kernel mode, so we were:
626 		 * - handling an interrupt,
627 		 * - doing syscall or trap work on behalf of the current
628 		 *   user process, or
629 		 * - spinning in the idle loop.
630 		 * Whichever it is, charge the time as appropriate.
631 		 * Note that we charge interrupts to the current process,
632 		 * regardless of whether they are ``for'' that process,
633 		 * so that we know how much of its real time was spent
634 		 * in ``non-process'' (i.e., interrupt) work.
635 		 *
636 		 * XXX assume system if frame is NULL.  A NULL frame
637 		 * can occur if ipi processing is done from a crit_exit().
638 		 */
639 		if (frame && CLKF_INTR(frame))
640 			td->td_iticks += bump;
641 		else
642 			td->td_sticks += bump;
643 
644 		if (frame && CLKF_INTR(frame)) {
645 #ifdef DEBUG_PCTRACK
646 			do_pctrack(frame, PCTRACK_INT);
647 #endif
648 			cpu_time.cp_intr += bump;
649 		} else {
650 			if (td == &mycpu->gd_idlethread) {
651 				cpu_time.cp_idle += bump;
652 			} else {
653 #ifdef DEBUG_PCTRACK
654 				if (frame)
655 					do_pctrack(frame, PCTRACK_SYS);
656 #endif
657 				cpu_time.cp_sys += bump;
658 			}
659 		}
660 	}
661 }
662 
663 #ifdef DEBUG_PCTRACK
664 /*
665  * Sample the PC when in the kernel or in an interrupt.  User code can
666  * retrieve the information and generate a histogram or other output.
667  */
668 
669 static void
670 do_pctrack(struct intrframe *frame, int which)
671 {
672 	struct kinfo_pctrack *pctrack;
673 
674 	pctrack = &cputime_pctrack[mycpu->gd_cpuid][which];
675 	pctrack->pc_array[pctrack->pc_index & PCTRACK_ARYMASK] =
676 		(void *)CLKF_PC(frame);
677 	++pctrack->pc_index;
678 }
679 
680 static int
681 sysctl_pctrack(SYSCTL_HANDLER_ARGS)
682 {
683 	struct kinfo_pcheader head;
684 	int error;
685 	int cpu;
686 	int ntrack;
687 
688 	head.pc_ntrack = PCTRACK_SIZE;
689 	head.pc_arysize = PCTRACK_ARYSIZE;
690 
691 	if ((error = SYSCTL_OUT(req, &head, sizeof(head))) != 0)
692 		return (error);
693 
694 	for (cpu = 0; cpu < ncpus; ++cpu) {
695 		for (ntrack = 0; ntrack < PCTRACK_SIZE; ++ntrack) {
696 			error = SYSCTL_OUT(req, &cputime_pctrack[cpu][ntrack],
697 					   sizeof(struct kinfo_pctrack));
698 			if (error)
699 				break;
700 		}
701 		if (error)
702 			break;
703 	}
704 	return (error);
705 }
706 SYSCTL_PROC(_kern, OID_AUTO, pctrack, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
707 	sysctl_pctrack, "S,kinfo_pcheader", "CPU PC tracking");
708 
709 #endif
710 
711 /*
712  * The scheduler clock typically runs at a 50Hz rate.  NOTE! systimer,
713  * the MP lock might not be held.  We can safely manipulate parts of curproc
714  * but that's about it.
715  *
716  * Each cpu has its own scheduler clock.
717  */
718 static void
719 schedclock(systimer_t info, struct intrframe *frame)
720 {
721 	struct lwp *lp;
722 	struct rusage *ru;
723 	struct vmspace *vm;
724 	long rss;
725 
726 	if ((lp = lwkt_preempted_proc()) != NULL) {
727 		/*
728 		 * Account for cpu time used and hit the scheduler.  Note
729 		 * that this call MUST BE MP SAFE, and the BGL IS NOT HELD
730 		 * HERE.
731 		 */
732 		++lp->lwp_cpticks;
733 		lp->lwp_proc->p_usched->schedulerclock(lp, info->periodic,
734 						       info->time);
735 	}
736 	if ((lp = curthread->td_lwp) != NULL) {
737 		/*
738 		 * Update resource usage integrals and maximums.
739 		 */
740 		if ((ru = &lp->lwp_proc->p_ru) &&
741 		    (vm = lp->lwp_proc->p_vmspace) != NULL) {
742 			ru->ru_ixrss += pgtok(vm->vm_tsize);
743 			ru->ru_idrss += pgtok(vm->vm_dsize);
744 			ru->ru_isrss += pgtok(vm->vm_ssize);
745 			rss = pgtok(vmspace_resident_count(vm));
746 			if (ru->ru_maxrss < rss)
747 				ru->ru_maxrss = rss;
748 		}
749 	}
750 }
751 
752 /*
753  * Compute number of ticks for the specified amount of time.  The
754  * return value is intended to be used in a clock interrupt timed
755  * operation and guarenteed to meet or exceed the requested time.
756  * If the representation overflows, return INT_MAX.  The minimum return
757  * value is 1 ticks and the function will average the calculation up.
758  * If any value greater then 0 microseconds is supplied, a value
759  * of at least 2 will be returned to ensure that a near-term clock
760  * interrupt does not cause the timeout to occur (degenerately) early.
761  *
762  * Note that limit checks must take into account microseconds, which is
763  * done simply by using the smaller signed long maximum instead of
764  * the unsigned long maximum.
765  *
766  * If ints have 32 bits, then the maximum value for any timeout in
767  * 10ms ticks is 248 days.
768  */
769 int
770 tvtohz_high(struct timeval *tv)
771 {
772 	int ticks;
773 	long sec, usec;
774 
775 	sec = tv->tv_sec;
776 	usec = tv->tv_usec;
777 	if (usec < 0) {
778 		sec--;
779 		usec += 1000000;
780 	}
781 	if (sec < 0) {
782 #ifdef DIAGNOSTIC
783 		if (usec > 0) {
784 			sec++;
785 			usec -= 1000000;
786 		}
787 		kprintf("tvtohz_high: negative time difference %ld sec %ld usec\n",
788 		       sec, usec);
789 #endif
790 		ticks = 1;
791 	} else if (sec <= INT_MAX / hz) {
792 		ticks = (int)(sec * hz +
793 			    ((u_long)usec + (tick - 1)) / tick) + 1;
794 	} else {
795 		ticks = INT_MAX;
796 	}
797 	return (ticks);
798 }
799 
800 /*
801  * Compute number of ticks for the specified amount of time, erroring on
802  * the side of it being too low to ensure that sleeping the returned number
803  * of ticks will not result in a late return.
804  *
805  * The supplied timeval may not be negative and should be normalized.  A
806  * return value of 0 is possible if the timeval converts to less then
807  * 1 tick.
808  *
809  * If ints have 32 bits, then the maximum value for any timeout in
810  * 10ms ticks is 248 days.
811  */
812 int
813 tvtohz_low(struct timeval *tv)
814 {
815 	int ticks;
816 	long sec;
817 
818 	sec = tv->tv_sec;
819 	if (sec <= INT_MAX / hz)
820 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / tick);
821 	else
822 		ticks = INT_MAX;
823 	return (ticks);
824 }
825 
826 
827 /*
828  * Start profiling on a process.
829  *
830  * Kernel profiling passes proc0 which never exits and hence
831  * keeps the profile clock running constantly.
832  */
833 void
834 startprofclock(struct proc *p)
835 {
836 	if ((p->p_flag & P_PROFIL) == 0) {
837 		p->p_flag |= P_PROFIL;
838 #if 0	/* XXX */
839 		if (++profprocs == 1 && stathz != 0) {
840 			crit_enter();
841 			psdiv = psratio;
842 			setstatclockrate(profhz);
843 			crit_exit();
844 		}
845 #endif
846 	}
847 }
848 
849 /*
850  * Stop profiling on a process.
851  */
852 void
853 stopprofclock(struct proc *p)
854 {
855 	if (p->p_flag & P_PROFIL) {
856 		p->p_flag &= ~P_PROFIL;
857 #if 0	/* XXX */
858 		if (--profprocs == 0 && stathz != 0) {
859 			crit_enter();
860 			psdiv = 1;
861 			setstatclockrate(stathz);
862 			crit_exit();
863 		}
864 #endif
865 	}
866 }
867 
868 /*
869  * Return information about system clocks.
870  */
871 static int
872 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
873 {
874 	struct kinfo_clockinfo clkinfo;
875 	/*
876 	 * Construct clockinfo structure.
877 	 */
878 	clkinfo.ci_hz = hz;
879 	clkinfo.ci_tick = tick;
880 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
881 	clkinfo.ci_profhz = profhz;
882 	clkinfo.ci_stathz = stathz ? stathz : hz;
883 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
884 }
885 
886 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
887 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
888 
889 /*
890  * We have eight functions for looking at the clock, four for
891  * microseconds and four for nanoseconds.  For each there is fast
892  * but less precise version "get{nano|micro}[up]time" which will
893  * return a time which is up to 1/HZ previous to the call, whereas
894  * the raw version "{nano|micro}[up]time" will return a timestamp
895  * which is as precise as possible.  The "up" variants return the
896  * time relative to system boot, these are well suited for time
897  * interval measurements.
898  *
899  * Each cpu independantly maintains the current time of day, so all
900  * we need to do to protect ourselves from changes is to do a loop
901  * check on the seconds field changing out from under us.
902  *
903  * The system timer maintains a 32 bit count and due to various issues
904  * it is possible for the calculated delta to occassionally exceed
905  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
906  * multiplication can easily overflow, so we deal with the case.  For
907  * uniformity we deal with the case in the usec case too.
908  */
909 void
910 getmicrouptime(struct timeval *tvp)
911 {
912 	struct globaldata *gd = mycpu;
913 	sysclock_t delta;
914 
915 	do {
916 		tvp->tv_sec = gd->gd_time_seconds;
917 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
918 	} while (tvp->tv_sec != gd->gd_time_seconds);
919 
920 	if (delta >= sys_cputimer->freq) {
921 		tvp->tv_sec += delta / sys_cputimer->freq;
922 		delta %= sys_cputimer->freq;
923 	}
924 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
925 	if (tvp->tv_usec >= 1000000) {
926 		tvp->tv_usec -= 1000000;
927 		++tvp->tv_sec;
928 	}
929 }
930 
931 void
932 getnanouptime(struct timespec *tsp)
933 {
934 	struct globaldata *gd = mycpu;
935 	sysclock_t delta;
936 
937 	do {
938 		tsp->tv_sec = gd->gd_time_seconds;
939 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
940 	} while (tsp->tv_sec != gd->gd_time_seconds);
941 
942 	if (delta >= sys_cputimer->freq) {
943 		tsp->tv_sec += delta / sys_cputimer->freq;
944 		delta %= sys_cputimer->freq;
945 	}
946 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
947 }
948 
949 void
950 microuptime(struct timeval *tvp)
951 {
952 	struct globaldata *gd = mycpu;
953 	sysclock_t delta;
954 
955 	do {
956 		tvp->tv_sec = gd->gd_time_seconds;
957 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
958 	} while (tvp->tv_sec != gd->gd_time_seconds);
959 
960 	if (delta >= sys_cputimer->freq) {
961 		tvp->tv_sec += delta / sys_cputimer->freq;
962 		delta %= sys_cputimer->freq;
963 	}
964 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
965 }
966 
967 void
968 nanouptime(struct timespec *tsp)
969 {
970 	struct globaldata *gd = mycpu;
971 	sysclock_t delta;
972 
973 	do {
974 		tsp->tv_sec = gd->gd_time_seconds;
975 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
976 	} while (tsp->tv_sec != gd->gd_time_seconds);
977 
978 	if (delta >= sys_cputimer->freq) {
979 		tsp->tv_sec += delta / sys_cputimer->freq;
980 		delta %= sys_cputimer->freq;
981 	}
982 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
983 }
984 
985 /*
986  * realtime routines
987  */
988 
989 void
990 getmicrotime(struct timeval *tvp)
991 {
992 	struct globaldata *gd = mycpu;
993 	struct timespec *bt;
994 	sysclock_t delta;
995 
996 	do {
997 		tvp->tv_sec = gd->gd_time_seconds;
998 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
999 	} while (tvp->tv_sec != gd->gd_time_seconds);
1000 
1001 	if (delta >= sys_cputimer->freq) {
1002 		tvp->tv_sec += delta / sys_cputimer->freq;
1003 		delta %= sys_cputimer->freq;
1004 	}
1005 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1006 
1007 	bt = &basetime[basetime_index];
1008 	tvp->tv_sec += bt->tv_sec;
1009 	tvp->tv_usec += bt->tv_nsec / 1000;
1010 	while (tvp->tv_usec >= 1000000) {
1011 		tvp->tv_usec -= 1000000;
1012 		++tvp->tv_sec;
1013 	}
1014 }
1015 
1016 void
1017 getnanotime(struct timespec *tsp)
1018 {
1019 	struct globaldata *gd = mycpu;
1020 	struct timespec *bt;
1021 	sysclock_t delta;
1022 
1023 	do {
1024 		tsp->tv_sec = gd->gd_time_seconds;
1025 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1026 	} while (tsp->tv_sec != gd->gd_time_seconds);
1027 
1028 	if (delta >= sys_cputimer->freq) {
1029 		tsp->tv_sec += delta / sys_cputimer->freq;
1030 		delta %= sys_cputimer->freq;
1031 	}
1032 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1033 
1034 	bt = &basetime[basetime_index];
1035 	tsp->tv_sec += bt->tv_sec;
1036 	tsp->tv_nsec += bt->tv_nsec;
1037 	while (tsp->tv_nsec >= 1000000000) {
1038 		tsp->tv_nsec -= 1000000000;
1039 		++tsp->tv_sec;
1040 	}
1041 }
1042 
1043 static void
1044 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
1045 {
1046 	struct globaldata *gd = mycpu;
1047 	sysclock_t delta;
1048 
1049 	do {
1050 		tsp->tv_sec = gd->gd_time_seconds;
1051 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1052 	} while (tsp->tv_sec != gd->gd_time_seconds);
1053 
1054 	if (delta >= sys_cputimer->freq) {
1055 		tsp->tv_sec += delta / sys_cputimer->freq;
1056 		delta %= sys_cputimer->freq;
1057 	}
1058 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1059 
1060 	tsp->tv_sec += nbt->tv_sec;
1061 	tsp->tv_nsec += nbt->tv_nsec;
1062 	while (tsp->tv_nsec >= 1000000000) {
1063 		tsp->tv_nsec -= 1000000000;
1064 		++tsp->tv_sec;
1065 	}
1066 }
1067 
1068 
1069 void
1070 microtime(struct timeval *tvp)
1071 {
1072 	struct globaldata *gd = mycpu;
1073 	struct timespec *bt;
1074 	sysclock_t delta;
1075 
1076 	do {
1077 		tvp->tv_sec = gd->gd_time_seconds;
1078 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1079 	} while (tvp->tv_sec != gd->gd_time_seconds);
1080 
1081 	if (delta >= sys_cputimer->freq) {
1082 		tvp->tv_sec += delta / sys_cputimer->freq;
1083 		delta %= sys_cputimer->freq;
1084 	}
1085 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1086 
1087 	bt = &basetime[basetime_index];
1088 	tvp->tv_sec += bt->tv_sec;
1089 	tvp->tv_usec += bt->tv_nsec / 1000;
1090 	while (tvp->tv_usec >= 1000000) {
1091 		tvp->tv_usec -= 1000000;
1092 		++tvp->tv_sec;
1093 	}
1094 }
1095 
1096 void
1097 nanotime(struct timespec *tsp)
1098 {
1099 	struct globaldata *gd = mycpu;
1100 	struct timespec *bt;
1101 	sysclock_t delta;
1102 
1103 	do {
1104 		tsp->tv_sec = gd->gd_time_seconds;
1105 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1106 	} while (tsp->tv_sec != gd->gd_time_seconds);
1107 
1108 	if (delta >= sys_cputimer->freq) {
1109 		tsp->tv_sec += delta / sys_cputimer->freq;
1110 		delta %= sys_cputimer->freq;
1111 	}
1112 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1113 
1114 	bt = &basetime[basetime_index];
1115 	tsp->tv_sec += bt->tv_sec;
1116 	tsp->tv_nsec += bt->tv_nsec;
1117 	while (tsp->tv_nsec >= 1000000000) {
1118 		tsp->tv_nsec -= 1000000000;
1119 		++tsp->tv_sec;
1120 	}
1121 }
1122 
1123 /*
1124  * note: this is not exactly synchronized with real time.  To do that we
1125  * would have to do what microtime does and check for a nanoseconds overflow.
1126  */
1127 time_t
1128 get_approximate_time_t(void)
1129 {
1130 	struct globaldata *gd = mycpu;
1131 	struct timespec *bt;
1132 
1133 	bt = &basetime[basetime_index];
1134 	return(gd->gd_time_seconds + bt->tv_sec);
1135 }
1136 
1137 int
1138 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1139 {
1140 	pps_params_t *app;
1141 	struct pps_fetch_args *fapi;
1142 #ifdef PPS_SYNC
1143 	struct pps_kcbind_args *kapi;
1144 #endif
1145 
1146 	switch (cmd) {
1147 	case PPS_IOC_CREATE:
1148 		return (0);
1149 	case PPS_IOC_DESTROY:
1150 		return (0);
1151 	case PPS_IOC_SETPARAMS:
1152 		app = (pps_params_t *)data;
1153 		if (app->mode & ~pps->ppscap)
1154 			return (EINVAL);
1155 		pps->ppsparam = *app;
1156 		return (0);
1157 	case PPS_IOC_GETPARAMS:
1158 		app = (pps_params_t *)data;
1159 		*app = pps->ppsparam;
1160 		app->api_version = PPS_API_VERS_1;
1161 		return (0);
1162 	case PPS_IOC_GETCAP:
1163 		*(int*)data = pps->ppscap;
1164 		return (0);
1165 	case PPS_IOC_FETCH:
1166 		fapi = (struct pps_fetch_args *)data;
1167 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1168 			return (EINVAL);
1169 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1170 			return (EOPNOTSUPP);
1171 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1172 		fapi->pps_info_buf = pps->ppsinfo;
1173 		return (0);
1174 	case PPS_IOC_KCBIND:
1175 #ifdef PPS_SYNC
1176 		kapi = (struct pps_kcbind_args *)data;
1177 		/* XXX Only root should be able to do this */
1178 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1179 			return (EINVAL);
1180 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1181 			return (EINVAL);
1182 		if (kapi->edge & ~pps->ppscap)
1183 			return (EINVAL);
1184 		pps->kcmode = kapi->edge;
1185 		return (0);
1186 #else
1187 		return (EOPNOTSUPP);
1188 #endif
1189 	default:
1190 		return (ENOTTY);
1191 	}
1192 }
1193 
1194 void
1195 pps_init(struct pps_state *pps)
1196 {
1197 	pps->ppscap |= PPS_TSFMT_TSPEC;
1198 	if (pps->ppscap & PPS_CAPTUREASSERT)
1199 		pps->ppscap |= PPS_OFFSETASSERT;
1200 	if (pps->ppscap & PPS_CAPTURECLEAR)
1201 		pps->ppscap |= PPS_OFFSETCLEAR;
1202 }
1203 
1204 void
1205 pps_event(struct pps_state *pps, sysclock_t count, int event)
1206 {
1207 	struct globaldata *gd;
1208 	struct timespec *tsp;
1209 	struct timespec *osp;
1210 	struct timespec *bt;
1211 	struct timespec ts;
1212 	sysclock_t *pcount;
1213 #ifdef PPS_SYNC
1214 	sysclock_t tcount;
1215 #endif
1216 	sysclock_t delta;
1217 	pps_seq_t *pseq;
1218 	int foff;
1219 	int fhard;
1220 
1221 	gd = mycpu;
1222 
1223 	/* Things would be easier with arrays... */
1224 	if (event == PPS_CAPTUREASSERT) {
1225 		tsp = &pps->ppsinfo.assert_timestamp;
1226 		osp = &pps->ppsparam.assert_offset;
1227 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1228 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1229 		pcount = &pps->ppscount[0];
1230 		pseq = &pps->ppsinfo.assert_sequence;
1231 	} else {
1232 		tsp = &pps->ppsinfo.clear_timestamp;
1233 		osp = &pps->ppsparam.clear_offset;
1234 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1235 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1236 		pcount = &pps->ppscount[1];
1237 		pseq = &pps->ppsinfo.clear_sequence;
1238 	}
1239 
1240 	/* Nothing really happened */
1241 	if (*pcount == count)
1242 		return;
1243 
1244 	*pcount = count;
1245 
1246 	do {
1247 		ts.tv_sec = gd->gd_time_seconds;
1248 		delta = count - gd->gd_cpuclock_base;
1249 	} while (ts.tv_sec != gd->gd_time_seconds);
1250 
1251 	if (delta >= sys_cputimer->freq) {
1252 		ts.tv_sec += delta / sys_cputimer->freq;
1253 		delta %= sys_cputimer->freq;
1254 	}
1255 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1256 	bt = &basetime[basetime_index];
1257 	ts.tv_sec += bt->tv_sec;
1258 	ts.tv_nsec += bt->tv_nsec;
1259 	while (ts.tv_nsec >= 1000000000) {
1260 		ts.tv_nsec -= 1000000000;
1261 		++ts.tv_sec;
1262 	}
1263 
1264 	(*pseq)++;
1265 	*tsp = ts;
1266 
1267 	if (foff) {
1268 		timespecadd(tsp, osp);
1269 		if (tsp->tv_nsec < 0) {
1270 			tsp->tv_nsec += 1000000000;
1271 			tsp->tv_sec -= 1;
1272 		}
1273 	}
1274 #ifdef PPS_SYNC
1275 	if (fhard) {
1276 		/* magic, at its best... */
1277 		tcount = count - pps->ppscount[2];
1278 		pps->ppscount[2] = count;
1279 		if (tcount >= sys_cputimer->freq) {
1280 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1281 				 sys_cputimer->freq64_nsec *
1282 				 (tcount % sys_cputimer->freq)) >> 32;
1283 		} else {
1284 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1285 		}
1286 		hardpps(tsp, delta);
1287 	}
1288 #endif
1289 }
1290 
1291