xref: /dflybsd-src/sys/kern/kern_clock.c (revision 64ed7155dec9fea48b542f16c80a6f0dd25dca37)
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_polling.h"
77 #include "opt_ifpoll.h"
78 #include "opt_pctrack.h"
79 
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/callout.h>
83 #include <sys/kernel.h>
84 #include <sys/kinfo.h>
85 #include <sys/proc.h>
86 #include <sys/malloc.h>
87 #include <sys/resource.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 
99 #include <sys/thread2.h>
100 
101 #include <machine/cpu.h>
102 #include <machine/limits.h>
103 #include <machine/smp.h>
104 #include <machine/cpufunc.h>
105 #include <machine/specialreg.h>
106 #include <machine/clock.h>
107 
108 #ifdef GPROF
109 #include <sys/gmon.h>
110 #endif
111 
112 #ifdef DEVICE_POLLING
113 extern void init_device_poll_pcpu(int);
114 #endif
115 
116 #ifdef IFPOLL_ENABLE
117 extern void ifpoll_init_pcpu(int);
118 #endif
119 
120 #ifdef DEBUG_PCTRACK
121 static void do_pctrack(struct intrframe *frame, int which);
122 #endif
123 
124 static void initclocks (void *dummy);
125 SYSINIT(clocks, SI_BOOT2_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
126 
127 /*
128  * Some of these don't belong here, but it's easiest to concentrate them.
129  * Note that cpu_time counts in microseconds, but most userland programs
130  * just compare relative times against the total by delta.
131  */
132 struct kinfo_cputime cputime_percpu[MAXCPU];
133 #ifdef DEBUG_PCTRACK
134 struct kinfo_pcheader cputime_pcheader = { PCTRACK_SIZE, PCTRACK_ARYSIZE };
135 struct kinfo_pctrack cputime_pctrack[MAXCPU][PCTRACK_SIZE];
136 #endif
137 
138 static int
139 sysctl_cputime(SYSCTL_HANDLER_ARGS)
140 {
141 	int cpu, error = 0;
142 	size_t size = sizeof(struct kinfo_cputime);
143 
144 	for (cpu = 0; cpu < ncpus; ++cpu) {
145 		if ((error = SYSCTL_OUT(req, &cputime_percpu[cpu], size)))
146 			break;
147 	}
148 
149 	return (error);
150 }
151 SYSCTL_PROC(_kern, OID_AUTO, cputime, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
152 	sysctl_cputime, "S,kinfo_cputime", "CPU time statistics");
153 
154 static int
155 sysctl_cp_time(SYSCTL_HANDLER_ARGS)
156 {
157 	long cpu_states[5] = {0};
158 	int cpu, error = 0;
159 	size_t size = sizeof(cpu_states);
160 
161 	for (cpu = 0; cpu < ncpus; ++cpu) {
162 		cpu_states[CP_USER] += cputime_percpu[cpu].cp_user;
163 		cpu_states[CP_NICE] += cputime_percpu[cpu].cp_nice;
164 		cpu_states[CP_SYS] += cputime_percpu[cpu].cp_sys;
165 		cpu_states[CP_INTR] += cputime_percpu[cpu].cp_intr;
166 		cpu_states[CP_IDLE] += cputime_percpu[cpu].cp_idle;
167 	}
168 
169 	error = SYSCTL_OUT(req, cpu_states, size);
170 
171 	return (error);
172 }
173 
174 SYSCTL_PROC(_kern, OID_AUTO, cp_time, (CTLTYPE_LONG|CTLFLAG_RD), 0, 0,
175 	sysctl_cp_time, "LU", "CPU time statistics");
176 
177 /*
178  * boottime is used to calculate the 'real' uptime.  Do not confuse this with
179  * microuptime().  microtime() is not drift compensated.  The real uptime
180  * with compensation is nanotime() - bootime.  boottime is recalculated
181  * whenever the real time is set based on the compensated elapsed time
182  * in seconds (gd->gd_time_seconds).
183  *
184  * The gd_time_seconds and gd_cpuclock_base fields remain fairly monotonic.
185  * Slight adjustments to gd_cpuclock_base are made to phase-lock it to
186  * the real time.
187  */
188 struct timespec boottime;	/* boot time (realtime) for reference only */
189 time_t time_second;		/* read-only 'passive' uptime in seconds */
190 
191 /*
192  * basetime is used to calculate the compensated real time of day.  The
193  * basetime can be modified on a per-tick basis by the adjtime(),
194  * ntp_adjtime(), and sysctl-based time correction APIs.
195  *
196  * Note that frequency corrections can also be made by adjusting
197  * gd_cpuclock_base.
198  *
199  * basetime is a tail-chasing FIFO, updated only by cpu #0.  The FIFO is
200  * used on both SMP and UP systems to avoid MP races between cpu's and
201  * interrupt races on UP systems.
202  */
203 #define BASETIME_ARYSIZE	16
204 #define BASETIME_ARYMASK	(BASETIME_ARYSIZE - 1)
205 static struct timespec basetime[BASETIME_ARYSIZE];
206 static volatile int basetime_index;
207 
208 static int
209 sysctl_get_basetime(SYSCTL_HANDLER_ARGS)
210 {
211 	struct timespec *bt;
212 	int error;
213 	int index;
214 
215 	/*
216 	 * Because basetime data and index may be updated by another cpu,
217 	 * a load fence is required to ensure that the data we read has
218 	 * not been speculatively read relative to a possibly updated index.
219 	 */
220 	index = basetime_index;
221 	cpu_lfence();
222 	bt = &basetime[index];
223 	error = SYSCTL_OUT(req, bt, sizeof(*bt));
224 	return (error);
225 }
226 
227 SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
228     &boottime, timespec, "System boottime");
229 SYSCTL_PROC(_kern, OID_AUTO, basetime, CTLTYPE_STRUCT|CTLFLAG_RD, 0, 0,
230     sysctl_get_basetime, "S,timespec", "System basetime");
231 
232 static void hardclock(systimer_t info, int, struct intrframe *frame);
233 static void statclock(systimer_t info, int, struct intrframe *frame);
234 static void schedclock(systimer_t info, int, struct intrframe *frame);
235 static void getnanotime_nbt(struct timespec *nbt, struct timespec *tsp);
236 
237 int	ticks;			/* system master ticks at hz */
238 int	clocks_running;		/* tsleep/timeout clocks operational */
239 int64_t	nsec_adj;		/* ntpd per-tick adjustment in nsec << 32 */
240 int64_t	nsec_acc;		/* accumulator */
241 int	sched_ticks;		/* global schedule clock ticks */
242 
243 /* NTPD time correction fields */
244 int64_t	ntp_tick_permanent;	/* per-tick adjustment in nsec << 32 */
245 int64_t	ntp_tick_acc;		/* accumulator for per-tick adjustment */
246 int64_t	ntp_delta;		/* one-time correction in nsec */
247 int64_t ntp_big_delta = 1000000000;
248 int32_t	ntp_tick_delta;		/* current adjustment rate */
249 int32_t	ntp_default_tick_delta;	/* adjustment rate for ntp_delta */
250 time_t	ntp_leap_second;	/* time of next leap second */
251 int	ntp_leap_insert;	/* whether to insert or remove a second */
252 
253 /*
254  * Finish initializing clock frequencies and start all clocks running.
255  */
256 /* ARGSUSED*/
257 static void
258 initclocks(void *dummy)
259 {
260 	/*psratio = profhz / stathz;*/
261 	initclocks_pcpu();
262 	clocks_running = 1;
263 }
264 
265 /*
266  * Called on a per-cpu basis
267  */
268 void
269 initclocks_pcpu(void)
270 {
271 	struct globaldata *gd = mycpu;
272 
273 	crit_enter();
274 	if (gd->gd_cpuid == 0) {
275 	    gd->gd_time_seconds = 1;
276 	    gd->gd_cpuclock_base = sys_cputimer->count();
277 	} else {
278 	    /* XXX */
279 	    gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
280 	    gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
281 	}
282 
283 	systimer_intr_enable();
284 
285 #ifdef DEVICE_POLLING
286 	init_device_poll_pcpu(gd->gd_cpuid);
287 #endif
288 
289 #ifdef IFPOLL_ENABLE
290 	ifpoll_init_pcpu(gd->gd_cpuid);
291 #endif
292 
293 	/*
294 	 * Use a non-queued periodic systimer to prevent multiple ticks from
295 	 * building up if the sysclock jumps forward (8254 gets reset).  The
296 	 * sysclock will never jump backwards.  Our time sync is based on
297 	 * the actual sysclock, not the ticks count.
298 	 */
299 	systimer_init_periodic_nq(&gd->gd_hardclock, hardclock, NULL, hz);
300 	systimer_init_periodic_nq(&gd->gd_statclock, statclock, NULL, stathz);
301 	/* XXX correct the frequency for scheduler / estcpu tests */
302 	systimer_init_periodic_nq(&gd->gd_schedclock, schedclock,
303 				NULL, ESTCPUFREQ);
304 	crit_exit();
305 }
306 
307 /*
308  * This sets the current real time of day.  Timespecs are in seconds and
309  * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
310  * instead we adjust basetime so basetime + gd_* results in the current
311  * time of day.  This way the gd_* fields are guarenteed to represent
312  * a monotonically increasing 'uptime' value.
313  *
314  * When set_timeofday() is called from userland, the system call forces it
315  * onto cpu #0 since only cpu #0 can update basetime_index.
316  */
317 void
318 set_timeofday(struct timespec *ts)
319 {
320 	struct timespec *nbt;
321 	int ni;
322 
323 	/*
324 	 * XXX SMP / non-atomic basetime updates
325 	 */
326 	crit_enter();
327 	ni = (basetime_index + 1) & BASETIME_ARYMASK;
328 	nbt = &basetime[ni];
329 	nanouptime(nbt);
330 	nbt->tv_sec = ts->tv_sec - nbt->tv_sec;
331 	nbt->tv_nsec = ts->tv_nsec - nbt->tv_nsec;
332 	if (nbt->tv_nsec < 0) {
333 	    nbt->tv_nsec += 1000000000;
334 	    --nbt->tv_sec;
335 	}
336 
337 	/*
338 	 * Note that basetime diverges from boottime as the clock drift is
339 	 * compensated for, so we cannot do away with boottime.  When setting
340 	 * the absolute time of day the drift is 0 (for an instant) and we
341 	 * can simply assign boottime to basetime.
342 	 *
343 	 * Note that nanouptime() is based on gd_time_seconds which is drift
344 	 * compensated up to a point (it is guarenteed to remain monotonically
345 	 * increasing).  gd_time_seconds is thus our best uptime guess and
346 	 * suitable for use in the boottime calculation.  It is already taken
347 	 * into account in the basetime calculation above.
348 	 */
349 	boottime.tv_sec = nbt->tv_sec;
350 	ntp_delta = 0;
351 
352 	/*
353 	 * We now have a new basetime, make sure all other cpus have it,
354 	 * then update the index.
355 	 */
356 	cpu_sfence();
357 	basetime_index = ni;
358 
359 	crit_exit();
360 }
361 
362 /*
363  * Each cpu has its own hardclock, but we only increments ticks and softticks
364  * on cpu #0.
365  *
366  * NOTE! systimer! the MP lock might not be held here.  We can only safely
367  * manipulate objects owned by the current cpu.
368  */
369 static void
370 hardclock(systimer_t info, int in_ipi __unused, struct intrframe *frame)
371 {
372 	sysclock_t cputicks;
373 	struct proc *p;
374 	struct globaldata *gd = mycpu;
375 
376 	/*
377 	 * Realtime updates are per-cpu.  Note that timer corrections as
378 	 * returned by microtime() and friends make an additional adjustment
379 	 * using a system-wise 'basetime', but the running time is always
380 	 * taken from the per-cpu globaldata area.  Since the same clock
381 	 * is distributing (XXX SMP) to all cpus, the per-cpu timebases
382 	 * stay in synch.
383 	 *
384 	 * Note that we never allow info->time (aka gd->gd_hardclock.time)
385 	 * to reverse index gd_cpuclock_base, but that it is possible for
386 	 * it to temporarily get behind in the seconds if something in the
387 	 * system locks interrupts for a long period of time.  Since periodic
388 	 * timers count events, though everything should resynch again
389 	 * immediately.
390 	 */
391 	cputicks = info->time - gd->gd_cpuclock_base;
392 	if (cputicks >= sys_cputimer->freq) {
393 		++gd->gd_time_seconds;
394 		gd->gd_cpuclock_base += sys_cputimer->freq;
395 	}
396 
397 	/*
398 	 * The system-wide ticks counter and NTP related timedelta/tickdelta
399 	 * adjustments only occur on cpu #0.  NTP adjustments are accomplished
400 	 * by updating basetime.
401 	 */
402 	if (gd->gd_cpuid == 0) {
403 	    struct timespec *nbt;
404 	    struct timespec nts;
405 	    int leap;
406 	    int ni;
407 
408 	    ++ticks;
409 
410 #if 0
411 	    if (tco->tc_poll_pps)
412 		tco->tc_poll_pps(tco);
413 #endif
414 
415 	    /*
416 	     * Calculate the new basetime index.  We are in a critical section
417 	     * on cpu #0 and can safely play with basetime_index.  Start
418 	     * with the current basetime and then make adjustments.
419 	     */
420 	    ni = (basetime_index + 1) & BASETIME_ARYMASK;
421 	    nbt = &basetime[ni];
422 	    *nbt = basetime[basetime_index];
423 
424 	    /*
425 	     * Apply adjtime corrections.  (adjtime() API)
426 	     *
427 	     * adjtime() only runs on cpu #0 so our critical section is
428 	     * sufficient to access these variables.
429 	     */
430 	    if (ntp_delta != 0) {
431 		nbt->tv_nsec += ntp_tick_delta;
432 		ntp_delta -= ntp_tick_delta;
433 		if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
434 		    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
435 			ntp_tick_delta = ntp_delta;
436  		}
437  	    }
438 
439 	    /*
440 	     * Apply permanent frequency corrections.  (sysctl API)
441 	     */
442 	    if (ntp_tick_permanent != 0) {
443 		ntp_tick_acc += ntp_tick_permanent;
444 		if (ntp_tick_acc >= (1LL << 32)) {
445 		    nbt->tv_nsec += ntp_tick_acc >> 32;
446 		    ntp_tick_acc -= (ntp_tick_acc >> 32) << 32;
447 		} else if (ntp_tick_acc <= -(1LL << 32)) {
448 		    /* Negate ntp_tick_acc to avoid shifting the sign bit. */
449 		    nbt->tv_nsec -= (-ntp_tick_acc) >> 32;
450 		    ntp_tick_acc += ((-ntp_tick_acc) >> 32) << 32;
451 		}
452  	    }
453 
454 	    if (nbt->tv_nsec >= 1000000000) {
455 		    nbt->tv_sec++;
456 		    nbt->tv_nsec -= 1000000000;
457 	    } else if (nbt->tv_nsec < 0) {
458 		    nbt->tv_sec--;
459 		    nbt->tv_nsec += 1000000000;
460 	    }
461 
462 	    /*
463 	     * Another per-tick compensation.  (for ntp_adjtime() API)
464 	     */
465 	    if (nsec_adj != 0) {
466 		nsec_acc += nsec_adj;
467 		if (nsec_acc >= 0x100000000LL) {
468 		    nbt->tv_nsec += nsec_acc >> 32;
469 		    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
470 		} else if (nsec_acc <= -0x100000000LL) {
471 		    nbt->tv_nsec -= -nsec_acc >> 32;
472 		    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
473 		}
474 		if (nbt->tv_nsec >= 1000000000) {
475 		    nbt->tv_nsec -= 1000000000;
476 		    ++nbt->tv_sec;
477 		} else if (nbt->tv_nsec < 0) {
478 		    nbt->tv_nsec += 1000000000;
479 		    --nbt->tv_sec;
480 		}
481 	    }
482 
483 	    /************************************************************
484 	     *			LEAP SECOND CORRECTION			*
485 	     ************************************************************
486 	     *
487 	     * Taking into account all the corrections made above, figure
488 	     * out the new real time.  If the seconds field has changed
489 	     * then apply any pending leap-second corrections.
490 	     */
491 	    getnanotime_nbt(nbt, &nts);
492 
493 	    if (time_second != nts.tv_sec) {
494 		/*
495 		 * Apply leap second (sysctl API).  Adjust nts for changes
496 		 * so we do not have to call getnanotime_nbt again.
497 		 */
498 		if (ntp_leap_second) {
499 		    if (ntp_leap_second == nts.tv_sec) {
500 			if (ntp_leap_insert) {
501 			    nbt->tv_sec++;
502 			    nts.tv_sec++;
503 			} else {
504 			    nbt->tv_sec--;
505 			    nts.tv_sec--;
506 			}
507 			ntp_leap_second--;
508 		    }
509 		}
510 
511 		/*
512 		 * Apply leap second (ntp_adjtime() API), calculate a new
513 		 * nsec_adj field.  ntp_update_second() returns nsec_adj
514 		 * as a per-second value but we need it as a per-tick value.
515 		 */
516 		leap = ntp_update_second(time_second, &nsec_adj);
517 		nsec_adj /= hz;
518 		nbt->tv_sec += leap;
519 		nts.tv_sec += leap;
520 
521 		/*
522 		 * Update the time_second 'approximate time' global.
523 		 */
524 		time_second = nts.tv_sec;
525 	    }
526 
527 	    /*
528 	     * Finally, our new basetime is ready to go live!
529 	     */
530 	    cpu_sfence();
531 	    basetime_index = ni;
532 	}
533 
534 	/*
535 	 * lwkt thread scheduler fair queueing
536 	 */
537 	lwkt_schedulerclock(curthread);
538 
539 	/*
540 	 * softticks are handled for all cpus
541 	 */
542 	hardclock_softtick(gd);
543 
544 	/*
545 	 * ITimer handling is per-tick, per-cpu.
546 	 *
547 	 * We must acquire the per-process token in order for ksignal()
548 	 * to be non-blocking.  For the moment this requires an AST fault,
549 	 * the ksignal() cannot be safely issued from this hard interrupt.
550 	 *
551 	 * XXX Even the trytoken here isn't right, and itimer operation in
552 	 *     a multi threaded environment is going to be weird at the
553 	 *     very least.
554 	 */
555 	if ((p = curproc) != NULL && lwkt_trytoken(&p->p_token)) {
556 		crit_enter_hard();
557 		if (frame && CLKF_USERMODE(frame) &&
558 		    timevalisset(&p->p_timer[ITIMER_VIRTUAL].it_value) &&
559 		    itimerdecr(&p->p_timer[ITIMER_VIRTUAL], ustick) == 0) {
560 			p->p_flags |= P_SIGVTALRM;
561 			need_user_resched();
562 		}
563 		if (timevalisset(&p->p_timer[ITIMER_PROF].it_value) &&
564 		    itimerdecr(&p->p_timer[ITIMER_PROF], ustick) == 0) {
565 			p->p_flags |= P_SIGPROF;
566 			need_user_resched();
567 		}
568 		crit_exit_hard();
569 		lwkt_reltoken(&p->p_token);
570 	}
571 	setdelayed();
572 }
573 
574 /*
575  * The statistics clock typically runs at a 125Hz rate, and is intended
576  * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
577  *
578  * NOTE! systimer! the MP lock might not be held here.  We can only safely
579  * manipulate objects owned by the current cpu.
580  *
581  * The stats clock is responsible for grabbing a profiling sample.
582  * Most of the statistics are only used by user-level statistics programs.
583  * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
584  * p->p_estcpu.
585  *
586  * Like the other clocks, the stat clock is called from what is effectively
587  * a fast interrupt, so the context should be the thread/process that got
588  * interrupted.
589  */
590 static void
591 statclock(systimer_t info, int in_ipi, struct intrframe *frame)
592 {
593 #ifdef GPROF
594 	struct gmonparam *g;
595 	int i;
596 #endif
597 	thread_t td;
598 	struct proc *p;
599 	int bump;
600 	struct timeval tv;
601 	struct timeval *stv;
602 
603 	/*
604 	 * How big was our timeslice relative to the last time?
605 	 */
606 	microuptime(&tv);	/* mpsafe */
607 	stv = &mycpu->gd_stattv;
608 	if (stv->tv_sec == 0) {
609 	    bump = 1;
610 	} else {
611 	    bump = tv.tv_usec - stv->tv_usec +
612 		(tv.tv_sec - stv->tv_sec) * 1000000;
613 	    if (bump < 0)
614 		bump = 0;
615 	    if (bump > 1000000)
616 		bump = 1000000;
617 	}
618 	*stv = tv;
619 
620 	td = curthread;
621 	p = td->td_proc;
622 
623 	if (frame && CLKF_USERMODE(frame)) {
624 		/*
625 		 * Came from userland, handle user time and deal with
626 		 * possible process.
627 		 */
628 		if (p && (p->p_flags & P_PROFIL))
629 			addupc_intr(p, CLKF_PC(frame), 1);
630 		td->td_uticks += bump;
631 
632 		/*
633 		 * Charge the time as appropriate
634 		 */
635 		if (p && p->p_nice > NZERO)
636 			cpu_time.cp_nice += bump;
637 		else
638 			cpu_time.cp_user += bump;
639 	} else {
640 		int intr_nest = mycpu->gd_intr_nesting_level;
641 
642 		if (in_ipi) {
643 			/*
644 			 * IPI processing code will bump gd_intr_nesting_level
645 			 * up by one, which breaks following CLKF_INTR testing,
646 			 * so we substract it by one here.
647 			 */
648 			--intr_nest;
649 		}
650 #ifdef GPROF
651 		/*
652 		 * Kernel statistics are just like addupc_intr, only easier.
653 		 */
654 		g = &_gmonparam;
655 		if (g->state == GMON_PROF_ON && frame) {
656 			i = CLKF_PC(frame) - g->lowpc;
657 			if (i < g->textsize) {
658 				i /= HISTFRACTION * sizeof(*g->kcount);
659 				g->kcount[i]++;
660 			}
661 		}
662 #endif
663 
664 #define IS_INTR_RUNNING	((frame && CLKF_INTR(intr_nest)) || CLKF_INTR_TD(td))
665 
666 		/*
667 		 * Came from kernel mode, so we were:
668 		 * - handling an interrupt,
669 		 * - doing syscall or trap work on behalf of the current
670 		 *   user process, or
671 		 * - spinning in the idle loop.
672 		 * Whichever it is, charge the time as appropriate.
673 		 * Note that we charge interrupts to the current process,
674 		 * regardless of whether they are ``for'' that process,
675 		 * so that we know how much of its real time was spent
676 		 * in ``non-process'' (i.e., interrupt) work.
677 		 *
678 		 * XXX assume system if frame is NULL.  A NULL frame
679 		 * can occur if ipi processing is done from a crit_exit().
680 		 */
681 		if (IS_INTR_RUNNING)
682 			td->td_iticks += bump;
683 		else
684 			td->td_sticks += bump;
685 
686 		if (IS_INTR_RUNNING) {
687 #ifdef DEBUG_PCTRACK
688 			if (frame)
689 				do_pctrack(frame, PCTRACK_INT);
690 #endif
691 			cpu_time.cp_intr += bump;
692 		} else {
693 			if (td == &mycpu->gd_idlethread) {
694 				cpu_time.cp_idle += bump;
695 			} else {
696 #ifdef DEBUG_PCTRACK
697 				if (frame)
698 					do_pctrack(frame, PCTRACK_SYS);
699 #endif
700 				cpu_time.cp_sys += bump;
701 			}
702 		}
703 
704 #undef IS_INTR_RUNNING
705 	}
706 }
707 
708 #ifdef DEBUG_PCTRACK
709 /*
710  * Sample the PC when in the kernel or in an interrupt.  User code can
711  * retrieve the information and generate a histogram or other output.
712  */
713 
714 static void
715 do_pctrack(struct intrframe *frame, int which)
716 {
717 	struct kinfo_pctrack *pctrack;
718 
719 	pctrack = &cputime_pctrack[mycpu->gd_cpuid][which];
720 	pctrack->pc_array[pctrack->pc_index & PCTRACK_ARYMASK] =
721 		(void *)CLKF_PC(frame);
722 	++pctrack->pc_index;
723 }
724 
725 static int
726 sysctl_pctrack(SYSCTL_HANDLER_ARGS)
727 {
728 	struct kinfo_pcheader head;
729 	int error;
730 	int cpu;
731 	int ntrack;
732 
733 	head.pc_ntrack = PCTRACK_SIZE;
734 	head.pc_arysize = PCTRACK_ARYSIZE;
735 
736 	if ((error = SYSCTL_OUT(req, &head, sizeof(head))) != 0)
737 		return (error);
738 
739 	for (cpu = 0; cpu < ncpus; ++cpu) {
740 		for (ntrack = 0; ntrack < PCTRACK_SIZE; ++ntrack) {
741 			error = SYSCTL_OUT(req, &cputime_pctrack[cpu][ntrack],
742 					   sizeof(struct kinfo_pctrack));
743 			if (error)
744 				break;
745 		}
746 		if (error)
747 			break;
748 	}
749 	return (error);
750 }
751 SYSCTL_PROC(_kern, OID_AUTO, pctrack, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
752 	sysctl_pctrack, "S,kinfo_pcheader", "CPU PC tracking");
753 
754 #endif
755 
756 /*
757  * The scheduler clock typically runs at a 50Hz rate.  NOTE! systimer,
758  * the MP lock might not be held.  We can safely manipulate parts of curproc
759  * but that's about it.
760  *
761  * Each cpu has its own scheduler clock.
762  */
763 static void
764 schedclock(systimer_t info, int in_ipi __unused, struct intrframe *frame)
765 {
766 	struct lwp *lp;
767 	struct rusage *ru;
768 	struct vmspace *vm;
769 	long rss;
770 
771 	if ((lp = lwkt_preempted_proc()) != NULL) {
772 		/*
773 		 * Account for cpu time used and hit the scheduler.  Note
774 		 * that this call MUST BE MP SAFE, and the BGL IS NOT HELD
775 		 * HERE.
776 		 */
777 		++lp->lwp_cpticks;
778 		usched_schedulerclock(lp, info->periodic, info->time);
779 	} else {
780 		usched_schedulerclock(NULL, info->periodic, info->time);
781 	}
782 	if ((lp = curthread->td_lwp) != NULL) {
783 		/*
784 		 * Update resource usage integrals and maximums.
785 		 */
786 		if ((ru = &lp->lwp_proc->p_ru) &&
787 		    (vm = lp->lwp_proc->p_vmspace) != NULL) {
788 			ru->ru_ixrss += pgtok(vm->vm_tsize);
789 			ru->ru_idrss += pgtok(vm->vm_dsize);
790 			ru->ru_isrss += pgtok(vm->vm_ssize);
791 			if (lwkt_trytoken(&vm->vm_map.token)) {
792 				rss = pgtok(vmspace_resident_count(vm));
793 				if (ru->ru_maxrss < rss)
794 					ru->ru_maxrss = rss;
795 				lwkt_reltoken(&vm->vm_map.token);
796 			}
797 		}
798 	}
799 	/* Increment the global sched_ticks */
800 	if (mycpu->gd_cpuid == 0)
801 		++sched_ticks;
802 }
803 
804 /*
805  * Compute number of ticks for the specified amount of time.  The
806  * return value is intended to be used in a clock interrupt timed
807  * operation and guarenteed to meet or exceed the requested time.
808  * If the representation overflows, return INT_MAX.  The minimum return
809  * value is 1 ticks and the function will average the calculation up.
810  * If any value greater then 0 microseconds is supplied, a value
811  * of at least 2 will be returned to ensure that a near-term clock
812  * interrupt does not cause the timeout to occur (degenerately) early.
813  *
814  * Note that limit checks must take into account microseconds, which is
815  * done simply by using the smaller signed long maximum instead of
816  * the unsigned long maximum.
817  *
818  * If ints have 32 bits, then the maximum value for any timeout in
819  * 10ms ticks is 248 days.
820  */
821 int
822 tvtohz_high(struct timeval *tv)
823 {
824 	int ticks;
825 	long sec, usec;
826 
827 	sec = tv->tv_sec;
828 	usec = tv->tv_usec;
829 	if (usec < 0) {
830 		sec--;
831 		usec += 1000000;
832 	}
833 	if (sec < 0) {
834 #ifdef DIAGNOSTIC
835 		if (usec > 0) {
836 			sec++;
837 			usec -= 1000000;
838 		}
839 		kprintf("tvtohz_high: negative time difference "
840 			"%ld sec %ld usec\n",
841 			sec, usec);
842 #endif
843 		ticks = 1;
844 	} else if (sec <= INT_MAX / hz) {
845 		ticks = (int)(sec * hz +
846 			    ((u_long)usec + (ustick - 1)) / ustick) + 1;
847 	} else {
848 		ticks = INT_MAX;
849 	}
850 	return (ticks);
851 }
852 
853 int
854 tstohz_high(struct timespec *ts)
855 {
856 	int ticks;
857 	long sec, nsec;
858 
859 	sec = ts->tv_sec;
860 	nsec = ts->tv_nsec;
861 	if (nsec < 0) {
862 		sec--;
863 		nsec += 1000000000;
864 	}
865 	if (sec < 0) {
866 #ifdef DIAGNOSTIC
867 		if (nsec > 0) {
868 			sec++;
869 			nsec -= 1000000000;
870 		}
871 		kprintf("tstohz_high: negative time difference "
872 			"%ld sec %ld nsec\n",
873 			sec, nsec);
874 #endif
875 		ticks = 1;
876 	} else if (sec <= INT_MAX / hz) {
877 		ticks = (int)(sec * hz +
878 			    ((u_long)nsec + (nstick - 1)) / nstick) + 1;
879 	} else {
880 		ticks = INT_MAX;
881 	}
882 	return (ticks);
883 }
884 
885 
886 /*
887  * Compute number of ticks for the specified amount of time, erroring on
888  * the side of it being too low to ensure that sleeping the returned number
889  * of ticks will not result in a late return.
890  *
891  * The supplied timeval may not be negative and should be normalized.  A
892  * return value of 0 is possible if the timeval converts to less then
893  * 1 tick.
894  *
895  * If ints have 32 bits, then the maximum value for any timeout in
896  * 10ms ticks is 248 days.
897  */
898 int
899 tvtohz_low(struct timeval *tv)
900 {
901 	int ticks;
902 	long sec;
903 
904 	sec = tv->tv_sec;
905 	if (sec <= INT_MAX / hz)
906 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / ustick);
907 	else
908 		ticks = INT_MAX;
909 	return (ticks);
910 }
911 
912 int
913 tstohz_low(struct timespec *ts)
914 {
915 	int ticks;
916 	long sec;
917 
918 	sec = ts->tv_sec;
919 	if (sec <= INT_MAX / hz)
920 		ticks = (int)(sec * hz + (u_long)ts->tv_nsec / nstick);
921 	else
922 		ticks = INT_MAX;
923 	return (ticks);
924 }
925 
926 /*
927  * Start profiling on a process.
928  *
929  * Kernel profiling passes proc0 which never exits and hence
930  * keeps the profile clock running constantly.
931  */
932 void
933 startprofclock(struct proc *p)
934 {
935 	if ((p->p_flags & P_PROFIL) == 0) {
936 		p->p_flags |= P_PROFIL;
937 #if 0	/* XXX */
938 		if (++profprocs == 1 && stathz != 0) {
939 			crit_enter();
940 			psdiv = psratio;
941 			setstatclockrate(profhz);
942 			crit_exit();
943 		}
944 #endif
945 	}
946 }
947 
948 /*
949  * Stop profiling on a process.
950  *
951  * caller must hold p->p_token
952  */
953 void
954 stopprofclock(struct proc *p)
955 {
956 	if (p->p_flags & P_PROFIL) {
957 		p->p_flags &= ~P_PROFIL;
958 #if 0	/* XXX */
959 		if (--profprocs == 0 && stathz != 0) {
960 			crit_enter();
961 			psdiv = 1;
962 			setstatclockrate(stathz);
963 			crit_exit();
964 		}
965 #endif
966 	}
967 }
968 
969 /*
970  * Return information about system clocks.
971  */
972 static int
973 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
974 {
975 	struct kinfo_clockinfo clkinfo;
976 	/*
977 	 * Construct clockinfo structure.
978 	 */
979 	clkinfo.ci_hz = hz;
980 	clkinfo.ci_tick = ustick;
981 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
982 	clkinfo.ci_profhz = profhz;
983 	clkinfo.ci_stathz = stathz ? stathz : hz;
984 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
985 }
986 
987 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
988 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
989 
990 /*
991  * We have eight functions for looking at the clock, four for
992  * microseconds and four for nanoseconds.  For each there is fast
993  * but less precise version "get{nano|micro}[up]time" which will
994  * return a time which is up to 1/HZ previous to the call, whereas
995  * the raw version "{nano|micro}[up]time" will return a timestamp
996  * which is as precise as possible.  The "up" variants return the
997  * time relative to system boot, these are well suited for time
998  * interval measurements.
999  *
1000  * Each cpu independantly maintains the current time of day, so all
1001  * we need to do to protect ourselves from changes is to do a loop
1002  * check on the seconds field changing out from under us.
1003  *
1004  * The system timer maintains a 32 bit count and due to various issues
1005  * it is possible for the calculated delta to occassionally exceed
1006  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
1007  * multiplication can easily overflow, so we deal with the case.  For
1008  * uniformity we deal with the case in the usec case too.
1009  *
1010  * All the [get][micro,nano][time,uptime]() routines are MPSAFE.
1011  */
1012 void
1013 getmicrouptime(struct timeval *tvp)
1014 {
1015 	struct globaldata *gd = mycpu;
1016 	sysclock_t delta;
1017 
1018 	do {
1019 		tvp->tv_sec = gd->gd_time_seconds;
1020 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1021 	} while (tvp->tv_sec != gd->gd_time_seconds);
1022 
1023 	if (delta >= sys_cputimer->freq) {
1024 		tvp->tv_sec += delta / sys_cputimer->freq;
1025 		delta %= sys_cputimer->freq;
1026 	}
1027 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1028 	if (tvp->tv_usec >= 1000000) {
1029 		tvp->tv_usec -= 1000000;
1030 		++tvp->tv_sec;
1031 	}
1032 }
1033 
1034 void
1035 getnanouptime(struct timespec *tsp)
1036 {
1037 	struct globaldata *gd = mycpu;
1038 	sysclock_t delta;
1039 
1040 	do {
1041 		tsp->tv_sec = gd->gd_time_seconds;
1042 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1043 	} while (tsp->tv_sec != gd->gd_time_seconds);
1044 
1045 	if (delta >= sys_cputimer->freq) {
1046 		tsp->tv_sec += delta / sys_cputimer->freq;
1047 		delta %= sys_cputimer->freq;
1048 	}
1049 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1050 }
1051 
1052 void
1053 microuptime(struct timeval *tvp)
1054 {
1055 	struct globaldata *gd = mycpu;
1056 	sysclock_t delta;
1057 
1058 	do {
1059 		tvp->tv_sec = gd->gd_time_seconds;
1060 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1061 	} while (tvp->tv_sec != gd->gd_time_seconds);
1062 
1063 	if (delta >= sys_cputimer->freq) {
1064 		tvp->tv_sec += delta / sys_cputimer->freq;
1065 		delta %= sys_cputimer->freq;
1066 	}
1067 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1068 }
1069 
1070 void
1071 nanouptime(struct timespec *tsp)
1072 {
1073 	struct globaldata *gd = mycpu;
1074 	sysclock_t delta;
1075 
1076 	do {
1077 		tsp->tv_sec = gd->gd_time_seconds;
1078 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1079 	} while (tsp->tv_sec != gd->gd_time_seconds);
1080 
1081 	if (delta >= sys_cputimer->freq) {
1082 		tsp->tv_sec += delta / sys_cputimer->freq;
1083 		delta %= sys_cputimer->freq;
1084 	}
1085 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1086 }
1087 
1088 /*
1089  * realtime routines
1090  */
1091 void
1092 getmicrotime(struct timeval *tvp)
1093 {
1094 	struct globaldata *gd = mycpu;
1095 	struct timespec *bt;
1096 	sysclock_t delta;
1097 
1098 	do {
1099 		tvp->tv_sec = gd->gd_time_seconds;
1100 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1101 	} while (tvp->tv_sec != gd->gd_time_seconds);
1102 
1103 	if (delta >= sys_cputimer->freq) {
1104 		tvp->tv_sec += delta / sys_cputimer->freq;
1105 		delta %= sys_cputimer->freq;
1106 	}
1107 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1108 
1109 	bt = &basetime[basetime_index];
1110 	tvp->tv_sec += bt->tv_sec;
1111 	tvp->tv_usec += bt->tv_nsec / 1000;
1112 	while (tvp->tv_usec >= 1000000) {
1113 		tvp->tv_usec -= 1000000;
1114 		++tvp->tv_sec;
1115 	}
1116 }
1117 
1118 void
1119 getnanotime(struct timespec *tsp)
1120 {
1121 	struct globaldata *gd = mycpu;
1122 	struct timespec *bt;
1123 	sysclock_t delta;
1124 
1125 	do {
1126 		tsp->tv_sec = gd->gd_time_seconds;
1127 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1128 	} while (tsp->tv_sec != gd->gd_time_seconds);
1129 
1130 	if (delta >= sys_cputimer->freq) {
1131 		tsp->tv_sec += delta / sys_cputimer->freq;
1132 		delta %= sys_cputimer->freq;
1133 	}
1134 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1135 
1136 	bt = &basetime[basetime_index];
1137 	tsp->tv_sec += bt->tv_sec;
1138 	tsp->tv_nsec += bt->tv_nsec;
1139 	while (tsp->tv_nsec >= 1000000000) {
1140 		tsp->tv_nsec -= 1000000000;
1141 		++tsp->tv_sec;
1142 	}
1143 }
1144 
1145 static void
1146 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
1147 {
1148 	struct globaldata *gd = mycpu;
1149 	sysclock_t delta;
1150 
1151 	do {
1152 		tsp->tv_sec = gd->gd_time_seconds;
1153 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1154 	} while (tsp->tv_sec != gd->gd_time_seconds);
1155 
1156 	if (delta >= sys_cputimer->freq) {
1157 		tsp->tv_sec += delta / sys_cputimer->freq;
1158 		delta %= sys_cputimer->freq;
1159 	}
1160 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1161 
1162 	tsp->tv_sec += nbt->tv_sec;
1163 	tsp->tv_nsec += nbt->tv_nsec;
1164 	while (tsp->tv_nsec >= 1000000000) {
1165 		tsp->tv_nsec -= 1000000000;
1166 		++tsp->tv_sec;
1167 	}
1168 }
1169 
1170 
1171 void
1172 microtime(struct timeval *tvp)
1173 {
1174 	struct globaldata *gd = mycpu;
1175 	struct timespec *bt;
1176 	sysclock_t delta;
1177 
1178 	do {
1179 		tvp->tv_sec = gd->gd_time_seconds;
1180 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1181 	} while (tvp->tv_sec != gd->gd_time_seconds);
1182 
1183 	if (delta >= sys_cputimer->freq) {
1184 		tvp->tv_sec += delta / sys_cputimer->freq;
1185 		delta %= sys_cputimer->freq;
1186 	}
1187 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1188 
1189 	bt = &basetime[basetime_index];
1190 	tvp->tv_sec += bt->tv_sec;
1191 	tvp->tv_usec += bt->tv_nsec / 1000;
1192 	while (tvp->tv_usec >= 1000000) {
1193 		tvp->tv_usec -= 1000000;
1194 		++tvp->tv_sec;
1195 	}
1196 }
1197 
1198 void
1199 nanotime(struct timespec *tsp)
1200 {
1201 	struct globaldata *gd = mycpu;
1202 	struct timespec *bt;
1203 	sysclock_t delta;
1204 
1205 	do {
1206 		tsp->tv_sec = gd->gd_time_seconds;
1207 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1208 	} while (tsp->tv_sec != gd->gd_time_seconds);
1209 
1210 	if (delta >= sys_cputimer->freq) {
1211 		tsp->tv_sec += delta / sys_cputimer->freq;
1212 		delta %= sys_cputimer->freq;
1213 	}
1214 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1215 
1216 	bt = &basetime[basetime_index];
1217 	tsp->tv_sec += bt->tv_sec;
1218 	tsp->tv_nsec += bt->tv_nsec;
1219 	while (tsp->tv_nsec >= 1000000000) {
1220 		tsp->tv_nsec -= 1000000000;
1221 		++tsp->tv_sec;
1222 	}
1223 }
1224 
1225 /*
1226  * note: this is not exactly synchronized with real time.  To do that we
1227  * would have to do what microtime does and check for a nanoseconds overflow.
1228  */
1229 time_t
1230 get_approximate_time_t(void)
1231 {
1232 	struct globaldata *gd = mycpu;
1233 	struct timespec *bt;
1234 
1235 	bt = &basetime[basetime_index];
1236 	return(gd->gd_time_seconds + bt->tv_sec);
1237 }
1238 
1239 int
1240 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1241 {
1242 	pps_params_t *app;
1243 	struct pps_fetch_args *fapi;
1244 #ifdef PPS_SYNC
1245 	struct pps_kcbind_args *kapi;
1246 #endif
1247 
1248 	switch (cmd) {
1249 	case PPS_IOC_CREATE:
1250 		return (0);
1251 	case PPS_IOC_DESTROY:
1252 		return (0);
1253 	case PPS_IOC_SETPARAMS:
1254 		app = (pps_params_t *)data;
1255 		if (app->mode & ~pps->ppscap)
1256 			return (EINVAL);
1257 		pps->ppsparam = *app;
1258 		return (0);
1259 	case PPS_IOC_GETPARAMS:
1260 		app = (pps_params_t *)data;
1261 		*app = pps->ppsparam;
1262 		app->api_version = PPS_API_VERS_1;
1263 		return (0);
1264 	case PPS_IOC_GETCAP:
1265 		*(int*)data = pps->ppscap;
1266 		return (0);
1267 	case PPS_IOC_FETCH:
1268 		fapi = (struct pps_fetch_args *)data;
1269 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1270 			return (EINVAL);
1271 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1272 			return (EOPNOTSUPP);
1273 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1274 		fapi->pps_info_buf = pps->ppsinfo;
1275 		return (0);
1276 	case PPS_IOC_KCBIND:
1277 #ifdef PPS_SYNC
1278 		kapi = (struct pps_kcbind_args *)data;
1279 		/* XXX Only root should be able to do this */
1280 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1281 			return (EINVAL);
1282 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1283 			return (EINVAL);
1284 		if (kapi->edge & ~pps->ppscap)
1285 			return (EINVAL);
1286 		pps->kcmode = kapi->edge;
1287 		return (0);
1288 #else
1289 		return (EOPNOTSUPP);
1290 #endif
1291 	default:
1292 		return (ENOTTY);
1293 	}
1294 }
1295 
1296 void
1297 pps_init(struct pps_state *pps)
1298 {
1299 	pps->ppscap |= PPS_TSFMT_TSPEC;
1300 	if (pps->ppscap & PPS_CAPTUREASSERT)
1301 		pps->ppscap |= PPS_OFFSETASSERT;
1302 	if (pps->ppscap & PPS_CAPTURECLEAR)
1303 		pps->ppscap |= PPS_OFFSETCLEAR;
1304 }
1305 
1306 void
1307 pps_event(struct pps_state *pps, sysclock_t count, int event)
1308 {
1309 	struct globaldata *gd;
1310 	struct timespec *tsp;
1311 	struct timespec *osp;
1312 	struct timespec *bt;
1313 	struct timespec ts;
1314 	sysclock_t *pcount;
1315 #ifdef PPS_SYNC
1316 	sysclock_t tcount;
1317 #endif
1318 	sysclock_t delta;
1319 	pps_seq_t *pseq;
1320 	int foff;
1321 	int fhard;
1322 
1323 	gd = mycpu;
1324 
1325 	/* Things would be easier with arrays... */
1326 	if (event == PPS_CAPTUREASSERT) {
1327 		tsp = &pps->ppsinfo.assert_timestamp;
1328 		osp = &pps->ppsparam.assert_offset;
1329 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1330 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1331 		pcount = &pps->ppscount[0];
1332 		pseq = &pps->ppsinfo.assert_sequence;
1333 	} else {
1334 		tsp = &pps->ppsinfo.clear_timestamp;
1335 		osp = &pps->ppsparam.clear_offset;
1336 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1337 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1338 		pcount = &pps->ppscount[1];
1339 		pseq = &pps->ppsinfo.clear_sequence;
1340 	}
1341 
1342 	/* Nothing really happened */
1343 	if (*pcount == count)
1344 		return;
1345 
1346 	*pcount = count;
1347 
1348 	do {
1349 		ts.tv_sec = gd->gd_time_seconds;
1350 		delta = count - gd->gd_cpuclock_base;
1351 	} while (ts.tv_sec != gd->gd_time_seconds);
1352 
1353 	if (delta >= sys_cputimer->freq) {
1354 		ts.tv_sec += delta / sys_cputimer->freq;
1355 		delta %= sys_cputimer->freq;
1356 	}
1357 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1358 	bt = &basetime[basetime_index];
1359 	ts.tv_sec += bt->tv_sec;
1360 	ts.tv_nsec += bt->tv_nsec;
1361 	while (ts.tv_nsec >= 1000000000) {
1362 		ts.tv_nsec -= 1000000000;
1363 		++ts.tv_sec;
1364 	}
1365 
1366 	(*pseq)++;
1367 	*tsp = ts;
1368 
1369 	if (foff) {
1370 		timespecadd(tsp, osp);
1371 		if (tsp->tv_nsec < 0) {
1372 			tsp->tv_nsec += 1000000000;
1373 			tsp->tv_sec -= 1;
1374 		}
1375 	}
1376 #ifdef PPS_SYNC
1377 	if (fhard) {
1378 		/* magic, at its best... */
1379 		tcount = count - pps->ppscount[2];
1380 		pps->ppscount[2] = count;
1381 		if (tcount >= sys_cputimer->freq) {
1382 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1383 				 sys_cputimer->freq64_nsec *
1384 				 (tcount % sys_cputimer->freq)) >> 32;
1385 		} else {
1386 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1387 		}
1388 		hardpps(tsp, delta);
1389 	}
1390 #endif
1391 }
1392 
1393 /*
1394  * Return the tsc target value for a delay of (ns).
1395  *
1396  * Returns -1 if the TSC is not supported.
1397  */
1398 int64_t
1399 tsc_get_target(int ns)
1400 {
1401 #if defined(_RDTSC_SUPPORTED_)
1402 	if (cpu_feature & CPUID_TSC) {
1403 		return (rdtsc() + tsc_frequency * ns / (int64_t)1000000000);
1404 	}
1405 #endif
1406 	return(-1);
1407 }
1408 
1409 /*
1410  * Compare the tsc against the passed target
1411  *
1412  * Returns +1 if the target has been reached
1413  * Returns  0 if the target has not yet been reached
1414  * Returns -1 if the TSC is not supported.
1415  *
1416  * Typical use:		while (tsc_test_target(target) == 0) { ...poll... }
1417  */
1418 int
1419 tsc_test_target(int64_t target)
1420 {
1421 #if defined(_RDTSC_SUPPORTED_)
1422 	if (cpu_feature & CPUID_TSC) {
1423 		if ((int64_t)(target - rdtsc()) <= 0)
1424 			return(1);
1425 		return(0);
1426 	}
1427 #endif
1428 	return(-1);
1429 }
1430 
1431 /*
1432  * Delay the specified number of nanoseconds using the tsc.  This function
1433  * returns immediately if the TSC is not supported.  At least one cpu_pause()
1434  * will be issued.
1435  */
1436 void
1437 tsc_delay(int ns)
1438 {
1439 	int64_t clk;
1440 
1441 	clk = tsc_get_target(ns);
1442 	cpu_pause();
1443 	while (tsc_test_target(clk) == 0)
1444 		cpu_pause();
1445 }
1446