xref: /dragonfly/sys/kern/kern_clock.c (revision e7d467f4)
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  */
74 
75 #include "opt_ntp.h"
76 #include "opt_ifpoll.h"
77 #include "opt_pctrack.h"
78 
79 #include <sys/param.h>
80 #include <sys/systm.h>
81 #include <sys/callout.h>
82 #include <sys/kernel.h>
83 #include <sys/kinfo.h>
84 #include <sys/proc.h>
85 #include <sys/malloc.h>
86 #include <sys/resource.h>
87 #include <sys/resourcevar.h>
88 #include <sys/signalvar.h>
89 #include <sys/timex.h>
90 #include <sys/timepps.h>
91 #include <vm/vm.h>
92 #include <sys/lock.h>
93 #include <vm/pmap.h>
94 #include <vm/vm_map.h>
95 #include <vm/vm_extern.h>
96 #include <sys/sysctl.h>
97 
98 #include <sys/thread2.h>
99 
100 #include <machine/cpu.h>
101 #include <machine/limits.h>
102 #include <machine/smp.h>
103 #include <machine/cpufunc.h>
104 #include <machine/specialreg.h>
105 #include <machine/clock.h>
106 
107 #ifdef GPROF
108 #include <sys/gmon.h>
109 #endif
110 
111 #ifdef IFPOLL_ENABLE
112 extern void ifpoll_init_pcpu(int);
113 #endif
114 
115 #ifdef DEBUG_PCTRACK
116 static void do_pctrack(struct intrframe *frame, int which);
117 #endif
118 
119 static void initclocks (void *dummy);
120 SYSINIT(clocks, SI_BOOT2_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
121 
122 /*
123  * Some of these don't belong here, but it's easiest to concentrate them.
124  * Note that cpu_time counts in microseconds, but most userland programs
125  * just compare relative times against the total by delta.
126  */
127 struct kinfo_cputime cputime_percpu[MAXCPU];
128 #ifdef DEBUG_PCTRACK
129 struct kinfo_pcheader cputime_pcheader = { PCTRACK_SIZE, PCTRACK_ARYSIZE };
130 struct kinfo_pctrack cputime_pctrack[MAXCPU][PCTRACK_SIZE];
131 #endif
132 
133 static int
134 sysctl_cputime(SYSCTL_HANDLER_ARGS)
135 {
136 	int cpu, error = 0;
137 	size_t size = sizeof(struct kinfo_cputime);
138 
139 	for (cpu = 0; cpu < ncpus; ++cpu) {
140 		if ((error = SYSCTL_OUT(req, &cputime_percpu[cpu], size)))
141 			break;
142 	}
143 
144 	return (error);
145 }
146 SYSCTL_PROC(_kern, OID_AUTO, cputime, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
147 	sysctl_cputime, "S,kinfo_cputime", "CPU time statistics");
148 
149 static int
150 sysctl_cp_time(SYSCTL_HANDLER_ARGS)
151 {
152 	long cpu_states[5] = {0};
153 	int cpu, error = 0;
154 	size_t size = sizeof(cpu_states);
155 
156 	for (cpu = 0; cpu < ncpus; ++cpu) {
157 		cpu_states[CP_USER] += cputime_percpu[cpu].cp_user;
158 		cpu_states[CP_NICE] += cputime_percpu[cpu].cp_nice;
159 		cpu_states[CP_SYS] += cputime_percpu[cpu].cp_sys;
160 		cpu_states[CP_INTR] += cputime_percpu[cpu].cp_intr;
161 		cpu_states[CP_IDLE] += cputime_percpu[cpu].cp_idle;
162 	}
163 
164 	error = SYSCTL_OUT(req, cpu_states, size);
165 
166 	return (error);
167 }
168 
169 SYSCTL_PROC(_kern, OID_AUTO, cp_time, (CTLTYPE_LONG|CTLFLAG_RD), 0, 0,
170 	sysctl_cp_time, "LU", "CPU time statistics");
171 
172 /*
173  * boottime is used to calculate the 'real' uptime.  Do not confuse this with
174  * microuptime().  microtime() is not drift compensated.  The real uptime
175  * with compensation is nanotime() - bootime.  boottime is recalculated
176  * whenever the real time is set based on the compensated elapsed time
177  * in seconds (gd->gd_time_seconds).
178  *
179  * The gd_time_seconds and gd_cpuclock_base fields remain fairly monotonic.
180  * Slight adjustments to gd_cpuclock_base are made to phase-lock it to
181  * the real time.
182  */
183 struct timespec boottime;	/* boot time (realtime) for reference only */
184 time_t time_second;		/* read-only 'passive' uptime in seconds */
185 
186 /*
187  * basetime is used to calculate the compensated real time of day.  The
188  * basetime can be modified on a per-tick basis by the adjtime(),
189  * ntp_adjtime(), and sysctl-based time correction APIs.
190  *
191  * Note that frequency corrections can also be made by adjusting
192  * gd_cpuclock_base.
193  *
194  * basetime is a tail-chasing FIFO, updated only by cpu #0.  The FIFO is
195  * used on both SMP and UP systems to avoid MP races between cpu's and
196  * interrupt races on UP systems.
197  */
198 #define BASETIME_ARYSIZE	16
199 #define BASETIME_ARYMASK	(BASETIME_ARYSIZE - 1)
200 static struct timespec basetime[BASETIME_ARYSIZE];
201 static volatile int basetime_index;
202 
203 static int
204 sysctl_get_basetime(SYSCTL_HANDLER_ARGS)
205 {
206 	struct timespec *bt;
207 	int error;
208 	int index;
209 
210 	/*
211 	 * Because basetime data and index may be updated by another cpu,
212 	 * a load fence is required to ensure that the data we read has
213 	 * not been speculatively read relative to a possibly updated index.
214 	 */
215 	index = basetime_index;
216 	cpu_lfence();
217 	bt = &basetime[index];
218 	error = SYSCTL_OUT(req, bt, sizeof(*bt));
219 	return (error);
220 }
221 
222 SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
223     &boottime, timespec, "System boottime");
224 SYSCTL_PROC(_kern, OID_AUTO, basetime, CTLTYPE_STRUCT|CTLFLAG_RD, 0, 0,
225     sysctl_get_basetime, "S,timespec", "System basetime");
226 
227 static void hardclock(systimer_t info, int, struct intrframe *frame);
228 static void statclock(systimer_t info, int, struct intrframe *frame);
229 static void schedclock(systimer_t info, int, struct intrframe *frame);
230 static void getnanotime_nbt(struct timespec *nbt, struct timespec *tsp);
231 
232 int	ticks;			/* system master ticks at hz */
233 int	clocks_running;		/* tsleep/timeout clocks operational */
234 int64_t	nsec_adj;		/* ntpd per-tick adjustment in nsec << 32 */
235 int64_t	nsec_acc;		/* accumulator */
236 int	sched_ticks;		/* global schedule clock ticks */
237 
238 /* NTPD time correction fields */
239 int64_t	ntp_tick_permanent;	/* per-tick adjustment in nsec << 32 */
240 int64_t	ntp_tick_acc;		/* accumulator for per-tick adjustment */
241 int64_t	ntp_delta;		/* one-time correction in nsec */
242 int64_t ntp_big_delta = 1000000000;
243 int32_t	ntp_tick_delta;		/* current adjustment rate */
244 int32_t	ntp_default_tick_delta;	/* adjustment rate for ntp_delta */
245 time_t	ntp_leap_second;	/* time of next leap second */
246 int	ntp_leap_insert;	/* whether to insert or remove a second */
247 
248 /*
249  * Finish initializing clock frequencies and start all clocks running.
250  */
251 /* ARGSUSED*/
252 static void
253 initclocks(void *dummy)
254 {
255 	/*psratio = profhz / stathz;*/
256 	initclocks_pcpu();
257 	clocks_running = 1;
258 }
259 
260 /*
261  * Called on a per-cpu basis
262  */
263 void
264 initclocks_pcpu(void)
265 {
266 	struct globaldata *gd = mycpu;
267 
268 	crit_enter();
269 	if (gd->gd_cpuid == 0) {
270 	    gd->gd_time_seconds = 1;
271 	    gd->gd_cpuclock_base = sys_cputimer->count();
272 	} else {
273 	    /* XXX */
274 	    gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
275 	    gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
276 	}
277 
278 	systimer_intr_enable();
279 
280 #ifdef IFPOLL_ENABLE
281 	ifpoll_init_pcpu(gd->gd_cpuid);
282 #endif
283 
284 	/*
285 	 * Use a non-queued periodic systimer to prevent multiple ticks from
286 	 * building up if the sysclock jumps forward (8254 gets reset).  The
287 	 * sysclock will never jump backwards.  Our time sync is based on
288 	 * the actual sysclock, not the ticks count.
289 	 */
290 	systimer_init_periodic_nq(&gd->gd_hardclock, hardclock, NULL, hz);
291 	systimer_init_periodic_nq(&gd->gd_statclock, statclock, NULL, stathz);
292 	/* XXX correct the frequency for scheduler / estcpu tests */
293 	systimer_init_periodic_nq(&gd->gd_schedclock, schedclock,
294 				NULL, ESTCPUFREQ);
295 	crit_exit();
296 }
297 
298 /*
299  * This sets the current real time of day.  Timespecs are in seconds and
300  * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
301  * instead we adjust basetime so basetime + gd_* results in the current
302  * time of day.  This way the gd_* fields are guarenteed to represent
303  * a monotonically increasing 'uptime' value.
304  *
305  * When set_timeofday() is called from userland, the system call forces it
306  * onto cpu #0 since only cpu #0 can update basetime_index.
307  */
308 void
309 set_timeofday(struct timespec *ts)
310 {
311 	struct timespec *nbt;
312 	int ni;
313 
314 	/*
315 	 * XXX SMP / non-atomic basetime updates
316 	 */
317 	crit_enter();
318 	ni = (basetime_index + 1) & BASETIME_ARYMASK;
319 	nbt = &basetime[ni];
320 	nanouptime(nbt);
321 	nbt->tv_sec = ts->tv_sec - nbt->tv_sec;
322 	nbt->tv_nsec = ts->tv_nsec - nbt->tv_nsec;
323 	if (nbt->tv_nsec < 0) {
324 	    nbt->tv_nsec += 1000000000;
325 	    --nbt->tv_sec;
326 	}
327 
328 	/*
329 	 * Note that basetime diverges from boottime as the clock drift is
330 	 * compensated for, so we cannot do away with boottime.  When setting
331 	 * the absolute time of day the drift is 0 (for an instant) and we
332 	 * can simply assign boottime to basetime.
333 	 *
334 	 * Note that nanouptime() is based on gd_time_seconds which is drift
335 	 * compensated up to a point (it is guarenteed to remain monotonically
336 	 * increasing).  gd_time_seconds is thus our best uptime guess and
337 	 * suitable for use in the boottime calculation.  It is already taken
338 	 * into account in the basetime calculation above.
339 	 */
340 	boottime.tv_sec = nbt->tv_sec;
341 	ntp_delta = 0;
342 
343 	/*
344 	 * We now have a new basetime, make sure all other cpus have it,
345 	 * then update the index.
346 	 */
347 	cpu_sfence();
348 	basetime_index = ni;
349 
350 	crit_exit();
351 }
352 
353 /*
354  * Each cpu has its own hardclock, but we only increments ticks and softticks
355  * on cpu #0.
356  *
357  * NOTE! systimer! the MP lock might not be held here.  We can only safely
358  * manipulate objects owned by the current cpu.
359  */
360 static void
361 hardclock(systimer_t info, int in_ipi __unused, struct intrframe *frame)
362 {
363 	sysclock_t cputicks;
364 	struct proc *p;
365 	struct globaldata *gd = mycpu;
366 
367 	/*
368 	 * Realtime updates are per-cpu.  Note that timer corrections as
369 	 * returned by microtime() and friends make an additional adjustment
370 	 * using a system-wise 'basetime', but the running time is always
371 	 * taken from the per-cpu globaldata area.  Since the same clock
372 	 * is distributing (XXX SMP) to all cpus, the per-cpu timebases
373 	 * stay in synch.
374 	 *
375 	 * Note that we never allow info->time (aka gd->gd_hardclock.time)
376 	 * to reverse index gd_cpuclock_base, but that it is possible for
377 	 * it to temporarily get behind in the seconds if something in the
378 	 * system locks interrupts for a long period of time.  Since periodic
379 	 * timers count events, though everything should resynch again
380 	 * immediately.
381 	 */
382 	cputicks = info->time - gd->gd_cpuclock_base;
383 	if (cputicks >= sys_cputimer->freq) {
384 		++gd->gd_time_seconds;
385 		gd->gd_cpuclock_base += sys_cputimer->freq;
386 	}
387 
388 	/*
389 	 * The system-wide ticks counter and NTP related timedelta/tickdelta
390 	 * adjustments only occur on cpu #0.  NTP adjustments are accomplished
391 	 * by updating basetime.
392 	 */
393 	if (gd->gd_cpuid == 0) {
394 	    struct timespec *nbt;
395 	    struct timespec nts;
396 	    int leap;
397 	    int ni;
398 
399 	    ++ticks;
400 
401 #if 0
402 	    if (tco->tc_poll_pps)
403 		tco->tc_poll_pps(tco);
404 #endif
405 
406 	    /*
407 	     * Calculate the new basetime index.  We are in a critical section
408 	     * on cpu #0 and can safely play with basetime_index.  Start
409 	     * with the current basetime and then make adjustments.
410 	     */
411 	    ni = (basetime_index + 1) & BASETIME_ARYMASK;
412 	    nbt = &basetime[ni];
413 	    *nbt = basetime[basetime_index];
414 
415 	    /*
416 	     * Apply adjtime corrections.  (adjtime() API)
417 	     *
418 	     * adjtime() only runs on cpu #0 so our critical section is
419 	     * sufficient to access these variables.
420 	     */
421 	    if (ntp_delta != 0) {
422 		nbt->tv_nsec += ntp_tick_delta;
423 		ntp_delta -= ntp_tick_delta;
424 		if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
425 		    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
426 			ntp_tick_delta = ntp_delta;
427  		}
428  	    }
429 
430 	    /*
431 	     * Apply permanent frequency corrections.  (sysctl API)
432 	     */
433 	    if (ntp_tick_permanent != 0) {
434 		ntp_tick_acc += ntp_tick_permanent;
435 		if (ntp_tick_acc >= (1LL << 32)) {
436 		    nbt->tv_nsec += ntp_tick_acc >> 32;
437 		    ntp_tick_acc -= (ntp_tick_acc >> 32) << 32;
438 		} else if (ntp_tick_acc <= -(1LL << 32)) {
439 		    /* Negate ntp_tick_acc to avoid shifting the sign bit. */
440 		    nbt->tv_nsec -= (-ntp_tick_acc) >> 32;
441 		    ntp_tick_acc += ((-ntp_tick_acc) >> 32) << 32;
442 		}
443  	    }
444 
445 	    if (nbt->tv_nsec >= 1000000000) {
446 		    nbt->tv_sec++;
447 		    nbt->tv_nsec -= 1000000000;
448 	    } else if (nbt->tv_nsec < 0) {
449 		    nbt->tv_sec--;
450 		    nbt->tv_nsec += 1000000000;
451 	    }
452 
453 	    /*
454 	     * Another per-tick compensation.  (for ntp_adjtime() API)
455 	     */
456 	    if (nsec_adj != 0) {
457 		nsec_acc += nsec_adj;
458 		if (nsec_acc >= 0x100000000LL) {
459 		    nbt->tv_nsec += nsec_acc >> 32;
460 		    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
461 		} else if (nsec_acc <= -0x100000000LL) {
462 		    nbt->tv_nsec -= -nsec_acc >> 32;
463 		    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
464 		}
465 		if (nbt->tv_nsec >= 1000000000) {
466 		    nbt->tv_nsec -= 1000000000;
467 		    ++nbt->tv_sec;
468 		} else if (nbt->tv_nsec < 0) {
469 		    nbt->tv_nsec += 1000000000;
470 		    --nbt->tv_sec;
471 		}
472 	    }
473 
474 	    /************************************************************
475 	     *			LEAP SECOND CORRECTION			*
476 	     ************************************************************
477 	     *
478 	     * Taking into account all the corrections made above, figure
479 	     * out the new real time.  If the seconds field has changed
480 	     * then apply any pending leap-second corrections.
481 	     */
482 	    getnanotime_nbt(nbt, &nts);
483 
484 	    if (time_second != nts.tv_sec) {
485 		/*
486 		 * Apply leap second (sysctl API).  Adjust nts for changes
487 		 * so we do not have to call getnanotime_nbt again.
488 		 */
489 		if (ntp_leap_second) {
490 		    if (ntp_leap_second == nts.tv_sec) {
491 			if (ntp_leap_insert) {
492 			    nbt->tv_sec++;
493 			    nts.tv_sec++;
494 			} else {
495 			    nbt->tv_sec--;
496 			    nts.tv_sec--;
497 			}
498 			ntp_leap_second--;
499 		    }
500 		}
501 
502 		/*
503 		 * Apply leap second (ntp_adjtime() API), calculate a new
504 		 * nsec_adj field.  ntp_update_second() returns nsec_adj
505 		 * as a per-second value but we need it as a per-tick value.
506 		 */
507 		leap = ntp_update_second(time_second, &nsec_adj);
508 		nsec_adj /= hz;
509 		nbt->tv_sec += leap;
510 		nts.tv_sec += leap;
511 
512 		/*
513 		 * Update the time_second 'approximate time' global.
514 		 */
515 		time_second = nts.tv_sec;
516 	    }
517 
518 	    /*
519 	     * Finally, our new basetime is ready to go live!
520 	     */
521 	    cpu_sfence();
522 	    basetime_index = ni;
523 	}
524 
525 	/*
526 	 * lwkt thread scheduler fair queueing
527 	 */
528 	lwkt_schedulerclock(curthread);
529 
530 	/*
531 	 * softticks are handled for all cpus
532 	 */
533 	hardclock_softtick(gd);
534 
535 	/*
536 	 * ITimer handling is per-tick, per-cpu.
537 	 *
538 	 * We must acquire the per-process token in order for ksignal()
539 	 * to be non-blocking.  For the moment this requires an AST fault,
540 	 * the ksignal() cannot be safely issued from this hard interrupt.
541 	 *
542 	 * XXX Even the trytoken here isn't right, and itimer operation in
543 	 *     a multi threaded environment is going to be weird at the
544 	 *     very least.
545 	 */
546 	if ((p = curproc) != NULL && lwkt_trytoken(&p->p_token)) {
547 		crit_enter_hard();
548 		if (frame && CLKF_USERMODE(frame) &&
549 		    timevalisset(&p->p_timer[ITIMER_VIRTUAL].it_value) &&
550 		    itimerdecr(&p->p_timer[ITIMER_VIRTUAL], ustick) == 0) {
551 			p->p_flags |= P_SIGVTALRM;
552 			need_user_resched();
553 		}
554 		if (timevalisset(&p->p_timer[ITIMER_PROF].it_value) &&
555 		    itimerdecr(&p->p_timer[ITIMER_PROF], ustick) == 0) {
556 			p->p_flags |= P_SIGPROF;
557 			need_user_resched();
558 		}
559 		crit_exit_hard();
560 		lwkt_reltoken(&p->p_token);
561 	}
562 	setdelayed();
563 }
564 
565 /*
566  * The statistics clock typically runs at a 125Hz rate, and is intended
567  * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
568  *
569  * NOTE! systimer! the MP lock might not be held here.  We can only safely
570  * manipulate objects owned by the current cpu.
571  *
572  * The stats clock is responsible for grabbing a profiling sample.
573  * Most of the statistics are only used by user-level statistics programs.
574  * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
575  * p->p_estcpu.
576  *
577  * Like the other clocks, the stat clock is called from what is effectively
578  * a fast interrupt, so the context should be the thread/process that got
579  * interrupted.
580  */
581 static void
582 statclock(systimer_t info, int in_ipi, struct intrframe *frame)
583 {
584 #ifdef GPROF
585 	struct gmonparam *g;
586 	int i;
587 #endif
588 	thread_t td;
589 	struct proc *p;
590 	int bump;
591 	struct timeval tv;
592 	struct timeval *stv;
593 
594 	/*
595 	 * How big was our timeslice relative to the last time?
596 	 */
597 	microuptime(&tv);	/* mpsafe */
598 	stv = &mycpu->gd_stattv;
599 	if (stv->tv_sec == 0) {
600 	    bump = 1;
601 	} else {
602 	    bump = tv.tv_usec - stv->tv_usec +
603 		(tv.tv_sec - stv->tv_sec) * 1000000;
604 	    if (bump < 0)
605 		bump = 0;
606 	    if (bump > 1000000)
607 		bump = 1000000;
608 	}
609 	*stv = tv;
610 
611 	td = curthread;
612 	p = td->td_proc;
613 
614 	if (frame && CLKF_USERMODE(frame)) {
615 		/*
616 		 * Came from userland, handle user time and deal with
617 		 * possible process.
618 		 */
619 		if (p && (p->p_flags & P_PROFIL))
620 			addupc_intr(p, CLKF_PC(frame), 1);
621 		td->td_uticks += bump;
622 
623 		/*
624 		 * Charge the time as appropriate
625 		 */
626 		if (p && p->p_nice > NZERO)
627 			cpu_time.cp_nice += bump;
628 		else
629 			cpu_time.cp_user += bump;
630 	} else {
631 		int intr_nest = mycpu->gd_intr_nesting_level;
632 
633 		if (in_ipi) {
634 			/*
635 			 * IPI processing code will bump gd_intr_nesting_level
636 			 * up by one, which breaks following CLKF_INTR testing,
637 			 * so we substract it by one here.
638 			 */
639 			--intr_nest;
640 		}
641 #ifdef GPROF
642 		/*
643 		 * Kernel statistics are just like addupc_intr, only easier.
644 		 */
645 		g = &_gmonparam;
646 		if (g->state == GMON_PROF_ON && frame) {
647 			i = CLKF_PC(frame) - g->lowpc;
648 			if (i < g->textsize) {
649 				i /= HISTFRACTION * sizeof(*g->kcount);
650 				g->kcount[i]++;
651 			}
652 		}
653 #endif
654 
655 #define IS_INTR_RUNNING	((frame && CLKF_INTR(intr_nest)) || CLKF_INTR_TD(td))
656 
657 		/*
658 		 * Came from kernel mode, so we were:
659 		 * - handling an interrupt,
660 		 * - doing syscall or trap work on behalf of the current
661 		 *   user process, or
662 		 * - spinning in the idle loop.
663 		 * Whichever it is, charge the time as appropriate.
664 		 * Note that we charge interrupts to the current process,
665 		 * regardless of whether they are ``for'' that process,
666 		 * so that we know how much of its real time was spent
667 		 * in ``non-process'' (i.e., interrupt) work.
668 		 *
669 		 * XXX assume system if frame is NULL.  A NULL frame
670 		 * can occur if ipi processing is done from a crit_exit().
671 		 */
672 		if (IS_INTR_RUNNING)
673 			td->td_iticks += bump;
674 		else
675 			td->td_sticks += bump;
676 
677 		if (IS_INTR_RUNNING) {
678 			/*
679 			 * If we interrupted an interrupt thread, well,
680 			 * count it as interrupt time.
681 			 */
682 #ifdef DEBUG_PCTRACK
683 			if (frame)
684 				do_pctrack(frame, PCTRACK_INT);
685 #endif
686 			cpu_time.cp_intr += bump;
687 		} else {
688 			if (td == &mycpu->gd_idlethread) {
689 				/*
690 				 * Even if the current thread is the idle
691 				 * thread it could be due to token contention
692 				 * in the LWKT scheduler.  Count such as
693 				 * system time.
694 				 */
695 				if (mycpu->gd_reqflags & RQF_AST_LWKT_RESCHED)
696 					cpu_time.cp_sys += bump;
697 				else
698 					cpu_time.cp_idle += bump;
699 			} else {
700 				/*
701 				 * System thread was running.
702 				 */
703 #ifdef DEBUG_PCTRACK
704 				if (frame)
705 					do_pctrack(frame, PCTRACK_SYS);
706 #endif
707 				cpu_time.cp_sys += bump;
708 			}
709 		}
710 
711 #undef IS_INTR_RUNNING
712 	}
713 }
714 
715 #ifdef DEBUG_PCTRACK
716 /*
717  * Sample the PC when in the kernel or in an interrupt.  User code can
718  * retrieve the information and generate a histogram or other output.
719  */
720 
721 static void
722 do_pctrack(struct intrframe *frame, int which)
723 {
724 	struct kinfo_pctrack *pctrack;
725 
726 	pctrack = &cputime_pctrack[mycpu->gd_cpuid][which];
727 	pctrack->pc_array[pctrack->pc_index & PCTRACK_ARYMASK] =
728 		(void *)CLKF_PC(frame);
729 	++pctrack->pc_index;
730 }
731 
732 static int
733 sysctl_pctrack(SYSCTL_HANDLER_ARGS)
734 {
735 	struct kinfo_pcheader head;
736 	int error;
737 	int cpu;
738 	int ntrack;
739 
740 	head.pc_ntrack = PCTRACK_SIZE;
741 	head.pc_arysize = PCTRACK_ARYSIZE;
742 
743 	if ((error = SYSCTL_OUT(req, &head, sizeof(head))) != 0)
744 		return (error);
745 
746 	for (cpu = 0; cpu < ncpus; ++cpu) {
747 		for (ntrack = 0; ntrack < PCTRACK_SIZE; ++ntrack) {
748 			error = SYSCTL_OUT(req, &cputime_pctrack[cpu][ntrack],
749 					   sizeof(struct kinfo_pctrack));
750 			if (error)
751 				break;
752 		}
753 		if (error)
754 			break;
755 	}
756 	return (error);
757 }
758 SYSCTL_PROC(_kern, OID_AUTO, pctrack, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
759 	sysctl_pctrack, "S,kinfo_pcheader", "CPU PC tracking");
760 
761 #endif
762 
763 /*
764  * The scheduler clock typically runs at a 50Hz rate.  NOTE! systimer,
765  * the MP lock might not be held.  We can safely manipulate parts of curproc
766  * but that's about it.
767  *
768  * Each cpu has its own scheduler clock.
769  */
770 static void
771 schedclock(systimer_t info, int in_ipi __unused, struct intrframe *frame)
772 {
773 	struct lwp *lp;
774 	struct rusage *ru;
775 	struct vmspace *vm;
776 	long rss;
777 
778 	if ((lp = lwkt_preempted_proc()) != NULL) {
779 		/*
780 		 * Account for cpu time used and hit the scheduler.  Note
781 		 * that this call MUST BE MP SAFE, and the BGL IS NOT HELD
782 		 * HERE.
783 		 */
784 		++lp->lwp_cpticks;
785 		usched_schedulerclock(lp, info->periodic, info->time);
786 	} else {
787 		usched_schedulerclock(NULL, info->periodic, info->time);
788 	}
789 	if ((lp = curthread->td_lwp) != NULL) {
790 		/*
791 		 * Update resource usage integrals and maximums.
792 		 */
793 		if ((ru = &lp->lwp_proc->p_ru) &&
794 		    (vm = lp->lwp_proc->p_vmspace) != NULL) {
795 			ru->ru_ixrss += pgtok(vm->vm_tsize);
796 			ru->ru_idrss += pgtok(vm->vm_dsize);
797 			ru->ru_isrss += pgtok(vm->vm_ssize);
798 			if (lwkt_trytoken(&vm->vm_map.token)) {
799 				rss = pgtok(vmspace_resident_count(vm));
800 				if (ru->ru_maxrss < rss)
801 					ru->ru_maxrss = rss;
802 				lwkt_reltoken(&vm->vm_map.token);
803 			}
804 		}
805 	}
806 	/* Increment the global sched_ticks */
807 	if (mycpu->gd_cpuid == 0)
808 		++sched_ticks;
809 }
810 
811 /*
812  * Compute number of ticks for the specified amount of time.  The
813  * return value is intended to be used in a clock interrupt timed
814  * operation and guarenteed to meet or exceed the requested time.
815  * If the representation overflows, return INT_MAX.  The minimum return
816  * value is 1 ticks and the function will average the calculation up.
817  * If any value greater then 0 microseconds is supplied, a value
818  * of at least 2 will be returned to ensure that a near-term clock
819  * interrupt does not cause the timeout to occur (degenerately) early.
820  *
821  * Note that limit checks must take into account microseconds, which is
822  * done simply by using the smaller signed long maximum instead of
823  * the unsigned long maximum.
824  *
825  * If ints have 32 bits, then the maximum value for any timeout in
826  * 10ms ticks is 248 days.
827  */
828 int
829 tvtohz_high(struct timeval *tv)
830 {
831 	int ticks;
832 	long sec, usec;
833 
834 	sec = tv->tv_sec;
835 	usec = tv->tv_usec;
836 	if (usec < 0) {
837 		sec--;
838 		usec += 1000000;
839 	}
840 	if (sec < 0) {
841 #ifdef DIAGNOSTIC
842 		if (usec > 0) {
843 			sec++;
844 			usec -= 1000000;
845 		}
846 		kprintf("tvtohz_high: negative time difference "
847 			"%ld sec %ld usec\n",
848 			sec, usec);
849 #endif
850 		ticks = 1;
851 	} else if (sec <= INT_MAX / hz) {
852 		ticks = (int)(sec * hz +
853 			    ((u_long)usec + (ustick - 1)) / ustick) + 1;
854 	} else {
855 		ticks = INT_MAX;
856 	}
857 	return (ticks);
858 }
859 
860 int
861 tstohz_high(struct timespec *ts)
862 {
863 	int ticks;
864 	long sec, nsec;
865 
866 	sec = ts->tv_sec;
867 	nsec = ts->tv_nsec;
868 	if (nsec < 0) {
869 		sec--;
870 		nsec += 1000000000;
871 	}
872 	if (sec < 0) {
873 #ifdef DIAGNOSTIC
874 		if (nsec > 0) {
875 			sec++;
876 			nsec -= 1000000000;
877 		}
878 		kprintf("tstohz_high: negative time difference "
879 			"%ld sec %ld nsec\n",
880 			sec, nsec);
881 #endif
882 		ticks = 1;
883 	} else if (sec <= INT_MAX / hz) {
884 		ticks = (int)(sec * hz +
885 			    ((u_long)nsec + (nstick - 1)) / nstick) + 1;
886 	} else {
887 		ticks = INT_MAX;
888 	}
889 	return (ticks);
890 }
891 
892 
893 /*
894  * Compute number of ticks for the specified amount of time, erroring on
895  * the side of it being too low to ensure that sleeping the returned number
896  * of ticks will not result in a late return.
897  *
898  * The supplied timeval may not be negative and should be normalized.  A
899  * return value of 0 is possible if the timeval converts to less then
900  * 1 tick.
901  *
902  * If ints have 32 bits, then the maximum value for any timeout in
903  * 10ms ticks is 248 days.
904  */
905 int
906 tvtohz_low(struct timeval *tv)
907 {
908 	int ticks;
909 	long sec;
910 
911 	sec = tv->tv_sec;
912 	if (sec <= INT_MAX / hz)
913 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / ustick);
914 	else
915 		ticks = INT_MAX;
916 	return (ticks);
917 }
918 
919 int
920 tstohz_low(struct timespec *ts)
921 {
922 	int ticks;
923 	long sec;
924 
925 	sec = ts->tv_sec;
926 	if (sec <= INT_MAX / hz)
927 		ticks = (int)(sec * hz + (u_long)ts->tv_nsec / nstick);
928 	else
929 		ticks = INT_MAX;
930 	return (ticks);
931 }
932 
933 /*
934  * Start profiling on a process.
935  *
936  * Kernel profiling passes proc0 which never exits and hence
937  * keeps the profile clock running constantly.
938  */
939 void
940 startprofclock(struct proc *p)
941 {
942 	if ((p->p_flags & P_PROFIL) == 0) {
943 		p->p_flags |= P_PROFIL;
944 #if 0	/* XXX */
945 		if (++profprocs == 1 && stathz != 0) {
946 			crit_enter();
947 			psdiv = psratio;
948 			setstatclockrate(profhz);
949 			crit_exit();
950 		}
951 #endif
952 	}
953 }
954 
955 /*
956  * Stop profiling on a process.
957  *
958  * caller must hold p->p_token
959  */
960 void
961 stopprofclock(struct proc *p)
962 {
963 	if (p->p_flags & P_PROFIL) {
964 		p->p_flags &= ~P_PROFIL;
965 #if 0	/* XXX */
966 		if (--profprocs == 0 && stathz != 0) {
967 			crit_enter();
968 			psdiv = 1;
969 			setstatclockrate(stathz);
970 			crit_exit();
971 		}
972 #endif
973 	}
974 }
975 
976 /*
977  * Return information about system clocks.
978  */
979 static int
980 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
981 {
982 	struct kinfo_clockinfo clkinfo;
983 	/*
984 	 * Construct clockinfo structure.
985 	 */
986 	clkinfo.ci_hz = hz;
987 	clkinfo.ci_tick = ustick;
988 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
989 	clkinfo.ci_profhz = profhz;
990 	clkinfo.ci_stathz = stathz ? stathz : hz;
991 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
992 }
993 
994 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
995 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
996 
997 /*
998  * We have eight functions for looking at the clock, four for
999  * microseconds and four for nanoseconds.  For each there is fast
1000  * but less precise version "get{nano|micro}[up]time" which will
1001  * return a time which is up to 1/HZ previous to the call, whereas
1002  * the raw version "{nano|micro}[up]time" will return a timestamp
1003  * which is as precise as possible.  The "up" variants return the
1004  * time relative to system boot, these are well suited for time
1005  * interval measurements.
1006  *
1007  * Each cpu independantly maintains the current time of day, so all
1008  * we need to do to protect ourselves from changes is to do a loop
1009  * check on the seconds field changing out from under us.
1010  *
1011  * The system timer maintains a 32 bit count and due to various issues
1012  * it is possible for the calculated delta to occassionally exceed
1013  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
1014  * multiplication can easily overflow, so we deal with the case.  For
1015  * uniformity we deal with the case in the usec case too.
1016  *
1017  * All the [get][micro,nano][time,uptime]() routines are MPSAFE.
1018  */
1019 void
1020 getmicrouptime(struct timeval *tvp)
1021 {
1022 	struct globaldata *gd = mycpu;
1023 	sysclock_t delta;
1024 
1025 	do {
1026 		tvp->tv_sec = gd->gd_time_seconds;
1027 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1028 	} while (tvp->tv_sec != gd->gd_time_seconds);
1029 
1030 	if (delta >= sys_cputimer->freq) {
1031 		tvp->tv_sec += delta / sys_cputimer->freq;
1032 		delta %= sys_cputimer->freq;
1033 	}
1034 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1035 	if (tvp->tv_usec >= 1000000) {
1036 		tvp->tv_usec -= 1000000;
1037 		++tvp->tv_sec;
1038 	}
1039 }
1040 
1041 void
1042 getnanouptime(struct timespec *tsp)
1043 {
1044 	struct globaldata *gd = mycpu;
1045 	sysclock_t delta;
1046 
1047 	do {
1048 		tsp->tv_sec = gd->gd_time_seconds;
1049 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1050 	} while (tsp->tv_sec != gd->gd_time_seconds);
1051 
1052 	if (delta >= sys_cputimer->freq) {
1053 		tsp->tv_sec += delta / sys_cputimer->freq;
1054 		delta %= sys_cputimer->freq;
1055 	}
1056 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1057 }
1058 
1059 void
1060 microuptime(struct timeval *tvp)
1061 {
1062 	struct globaldata *gd = mycpu;
1063 	sysclock_t delta;
1064 
1065 	do {
1066 		tvp->tv_sec = gd->gd_time_seconds;
1067 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1068 	} while (tvp->tv_sec != gd->gd_time_seconds);
1069 
1070 	if (delta >= sys_cputimer->freq) {
1071 		tvp->tv_sec += delta / sys_cputimer->freq;
1072 		delta %= sys_cputimer->freq;
1073 	}
1074 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1075 }
1076 
1077 void
1078 nanouptime(struct timespec *tsp)
1079 {
1080 	struct globaldata *gd = mycpu;
1081 	sysclock_t delta;
1082 
1083 	do {
1084 		tsp->tv_sec = gd->gd_time_seconds;
1085 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1086 	} while (tsp->tv_sec != gd->gd_time_seconds);
1087 
1088 	if (delta >= sys_cputimer->freq) {
1089 		tsp->tv_sec += delta / sys_cputimer->freq;
1090 		delta %= sys_cputimer->freq;
1091 	}
1092 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1093 }
1094 
1095 /*
1096  * realtime routines
1097  */
1098 void
1099 getmicrotime(struct timeval *tvp)
1100 {
1101 	struct globaldata *gd = mycpu;
1102 	struct timespec *bt;
1103 	sysclock_t delta;
1104 
1105 	do {
1106 		tvp->tv_sec = gd->gd_time_seconds;
1107 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1108 	} while (tvp->tv_sec != gd->gd_time_seconds);
1109 
1110 	if (delta >= sys_cputimer->freq) {
1111 		tvp->tv_sec += delta / sys_cputimer->freq;
1112 		delta %= sys_cputimer->freq;
1113 	}
1114 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1115 
1116 	bt = &basetime[basetime_index];
1117 	tvp->tv_sec += bt->tv_sec;
1118 	tvp->tv_usec += bt->tv_nsec / 1000;
1119 	while (tvp->tv_usec >= 1000000) {
1120 		tvp->tv_usec -= 1000000;
1121 		++tvp->tv_sec;
1122 	}
1123 }
1124 
1125 void
1126 getnanotime(struct timespec *tsp)
1127 {
1128 	struct globaldata *gd = mycpu;
1129 	struct timespec *bt;
1130 	sysclock_t delta;
1131 
1132 	do {
1133 		tsp->tv_sec = gd->gd_time_seconds;
1134 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1135 	} while (tsp->tv_sec != gd->gd_time_seconds);
1136 
1137 	if (delta >= sys_cputimer->freq) {
1138 		tsp->tv_sec += delta / sys_cputimer->freq;
1139 		delta %= sys_cputimer->freq;
1140 	}
1141 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1142 
1143 	bt = &basetime[basetime_index];
1144 	tsp->tv_sec += bt->tv_sec;
1145 	tsp->tv_nsec += bt->tv_nsec;
1146 	while (tsp->tv_nsec >= 1000000000) {
1147 		tsp->tv_nsec -= 1000000000;
1148 		++tsp->tv_sec;
1149 	}
1150 }
1151 
1152 static void
1153 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
1154 {
1155 	struct globaldata *gd = mycpu;
1156 	sysclock_t delta;
1157 
1158 	do {
1159 		tsp->tv_sec = gd->gd_time_seconds;
1160 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1161 	} while (tsp->tv_sec != gd->gd_time_seconds);
1162 
1163 	if (delta >= sys_cputimer->freq) {
1164 		tsp->tv_sec += delta / sys_cputimer->freq;
1165 		delta %= sys_cputimer->freq;
1166 	}
1167 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1168 
1169 	tsp->tv_sec += nbt->tv_sec;
1170 	tsp->tv_nsec += nbt->tv_nsec;
1171 	while (tsp->tv_nsec >= 1000000000) {
1172 		tsp->tv_nsec -= 1000000000;
1173 		++tsp->tv_sec;
1174 	}
1175 }
1176 
1177 
1178 void
1179 microtime(struct timeval *tvp)
1180 {
1181 	struct globaldata *gd = mycpu;
1182 	struct timespec *bt;
1183 	sysclock_t delta;
1184 
1185 	do {
1186 		tvp->tv_sec = gd->gd_time_seconds;
1187 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1188 	} while (tvp->tv_sec != gd->gd_time_seconds);
1189 
1190 	if (delta >= sys_cputimer->freq) {
1191 		tvp->tv_sec += delta / sys_cputimer->freq;
1192 		delta %= sys_cputimer->freq;
1193 	}
1194 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1195 
1196 	bt = &basetime[basetime_index];
1197 	tvp->tv_sec += bt->tv_sec;
1198 	tvp->tv_usec += bt->tv_nsec / 1000;
1199 	while (tvp->tv_usec >= 1000000) {
1200 		tvp->tv_usec -= 1000000;
1201 		++tvp->tv_sec;
1202 	}
1203 }
1204 
1205 void
1206 nanotime(struct timespec *tsp)
1207 {
1208 	struct globaldata *gd = mycpu;
1209 	struct timespec *bt;
1210 	sysclock_t delta;
1211 
1212 	do {
1213 		tsp->tv_sec = gd->gd_time_seconds;
1214 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1215 	} while (tsp->tv_sec != gd->gd_time_seconds);
1216 
1217 	if (delta >= sys_cputimer->freq) {
1218 		tsp->tv_sec += delta / sys_cputimer->freq;
1219 		delta %= sys_cputimer->freq;
1220 	}
1221 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1222 
1223 	bt = &basetime[basetime_index];
1224 	tsp->tv_sec += bt->tv_sec;
1225 	tsp->tv_nsec += bt->tv_nsec;
1226 	while (tsp->tv_nsec >= 1000000000) {
1227 		tsp->tv_nsec -= 1000000000;
1228 		++tsp->tv_sec;
1229 	}
1230 }
1231 
1232 /*
1233  * note: this is not exactly synchronized with real time.  To do that we
1234  * would have to do what microtime does and check for a nanoseconds overflow.
1235  */
1236 time_t
1237 get_approximate_time_t(void)
1238 {
1239 	struct globaldata *gd = mycpu;
1240 	struct timespec *bt;
1241 
1242 	bt = &basetime[basetime_index];
1243 	return(gd->gd_time_seconds + bt->tv_sec);
1244 }
1245 
1246 int
1247 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1248 {
1249 	pps_params_t *app;
1250 	struct pps_fetch_args *fapi;
1251 #ifdef PPS_SYNC
1252 	struct pps_kcbind_args *kapi;
1253 #endif
1254 
1255 	switch (cmd) {
1256 	case PPS_IOC_CREATE:
1257 		return (0);
1258 	case PPS_IOC_DESTROY:
1259 		return (0);
1260 	case PPS_IOC_SETPARAMS:
1261 		app = (pps_params_t *)data;
1262 		if (app->mode & ~pps->ppscap)
1263 			return (EINVAL);
1264 		pps->ppsparam = *app;
1265 		return (0);
1266 	case PPS_IOC_GETPARAMS:
1267 		app = (pps_params_t *)data;
1268 		*app = pps->ppsparam;
1269 		app->api_version = PPS_API_VERS_1;
1270 		return (0);
1271 	case PPS_IOC_GETCAP:
1272 		*(int*)data = pps->ppscap;
1273 		return (0);
1274 	case PPS_IOC_FETCH:
1275 		fapi = (struct pps_fetch_args *)data;
1276 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1277 			return (EINVAL);
1278 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1279 			return (EOPNOTSUPP);
1280 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1281 		fapi->pps_info_buf = pps->ppsinfo;
1282 		return (0);
1283 	case PPS_IOC_KCBIND:
1284 #ifdef PPS_SYNC
1285 		kapi = (struct pps_kcbind_args *)data;
1286 		/* XXX Only root should be able to do this */
1287 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1288 			return (EINVAL);
1289 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1290 			return (EINVAL);
1291 		if (kapi->edge & ~pps->ppscap)
1292 			return (EINVAL);
1293 		pps->kcmode = kapi->edge;
1294 		return (0);
1295 #else
1296 		return (EOPNOTSUPP);
1297 #endif
1298 	default:
1299 		return (ENOTTY);
1300 	}
1301 }
1302 
1303 void
1304 pps_init(struct pps_state *pps)
1305 {
1306 	pps->ppscap |= PPS_TSFMT_TSPEC;
1307 	if (pps->ppscap & PPS_CAPTUREASSERT)
1308 		pps->ppscap |= PPS_OFFSETASSERT;
1309 	if (pps->ppscap & PPS_CAPTURECLEAR)
1310 		pps->ppscap |= PPS_OFFSETCLEAR;
1311 }
1312 
1313 void
1314 pps_event(struct pps_state *pps, sysclock_t count, int event)
1315 {
1316 	struct globaldata *gd;
1317 	struct timespec *tsp;
1318 	struct timespec *osp;
1319 	struct timespec *bt;
1320 	struct timespec ts;
1321 	sysclock_t *pcount;
1322 #ifdef PPS_SYNC
1323 	sysclock_t tcount;
1324 #endif
1325 	sysclock_t delta;
1326 	pps_seq_t *pseq;
1327 	int foff;
1328 	int fhard;
1329 
1330 	gd = mycpu;
1331 
1332 	/* Things would be easier with arrays... */
1333 	if (event == PPS_CAPTUREASSERT) {
1334 		tsp = &pps->ppsinfo.assert_timestamp;
1335 		osp = &pps->ppsparam.assert_offset;
1336 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1337 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1338 		pcount = &pps->ppscount[0];
1339 		pseq = &pps->ppsinfo.assert_sequence;
1340 	} else {
1341 		tsp = &pps->ppsinfo.clear_timestamp;
1342 		osp = &pps->ppsparam.clear_offset;
1343 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1344 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1345 		pcount = &pps->ppscount[1];
1346 		pseq = &pps->ppsinfo.clear_sequence;
1347 	}
1348 
1349 	/* Nothing really happened */
1350 	if (*pcount == count)
1351 		return;
1352 
1353 	*pcount = count;
1354 
1355 	do {
1356 		ts.tv_sec = gd->gd_time_seconds;
1357 		delta = count - gd->gd_cpuclock_base;
1358 	} while (ts.tv_sec != gd->gd_time_seconds);
1359 
1360 	if (delta >= sys_cputimer->freq) {
1361 		ts.tv_sec += delta / sys_cputimer->freq;
1362 		delta %= sys_cputimer->freq;
1363 	}
1364 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1365 	bt = &basetime[basetime_index];
1366 	ts.tv_sec += bt->tv_sec;
1367 	ts.tv_nsec += bt->tv_nsec;
1368 	while (ts.tv_nsec >= 1000000000) {
1369 		ts.tv_nsec -= 1000000000;
1370 		++ts.tv_sec;
1371 	}
1372 
1373 	(*pseq)++;
1374 	*tsp = ts;
1375 
1376 	if (foff) {
1377 		timespecadd(tsp, osp);
1378 		if (tsp->tv_nsec < 0) {
1379 			tsp->tv_nsec += 1000000000;
1380 			tsp->tv_sec -= 1;
1381 		}
1382 	}
1383 #ifdef PPS_SYNC
1384 	if (fhard) {
1385 		/* magic, at its best... */
1386 		tcount = count - pps->ppscount[2];
1387 		pps->ppscount[2] = count;
1388 		if (tcount >= sys_cputimer->freq) {
1389 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1390 				 sys_cputimer->freq64_nsec *
1391 				 (tcount % sys_cputimer->freq)) >> 32;
1392 		} else {
1393 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1394 		}
1395 		hardpps(tsp, delta);
1396 	}
1397 #endif
1398 }
1399 
1400 /*
1401  * Return the tsc target value for a delay of (ns).
1402  *
1403  * Returns -1 if the TSC is not supported.
1404  */
1405 int64_t
1406 tsc_get_target(int ns)
1407 {
1408 #if defined(_RDTSC_SUPPORTED_)
1409 	if (cpu_feature & CPUID_TSC) {
1410 		return (rdtsc() + tsc_frequency * ns / (int64_t)1000000000);
1411 	}
1412 #endif
1413 	return(-1);
1414 }
1415 
1416 /*
1417  * Compare the tsc against the passed target
1418  *
1419  * Returns +1 if the target has been reached
1420  * Returns  0 if the target has not yet been reached
1421  * Returns -1 if the TSC is not supported.
1422  *
1423  * Typical use:		while (tsc_test_target(target) == 0) { ...poll... }
1424  */
1425 int
1426 tsc_test_target(int64_t target)
1427 {
1428 #if defined(_RDTSC_SUPPORTED_)
1429 	if (cpu_feature & CPUID_TSC) {
1430 		if ((int64_t)(target - rdtsc()) <= 0)
1431 			return(1);
1432 		return(0);
1433 	}
1434 #endif
1435 	return(-1);
1436 }
1437 
1438 /*
1439  * Delay the specified number of nanoseconds using the tsc.  This function
1440  * returns immediately if the TSC is not supported.  At least one cpu_pause()
1441  * will be issued.
1442  */
1443 void
1444 tsc_delay(int ns)
1445 {
1446 	int64_t clk;
1447 
1448 	clk = tsc_get_target(ns);
1449 	cpu_pause();
1450 	while (tsc_test_target(clk) == 0)
1451 		cpu_pause();
1452 }
1453