xref: /dflybsd-src/sys/kern/kern_clock.c (revision 0087561d6d4d84b8ac1a312cc720339cbf66781d)
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. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  *	@(#)kern_clock.c	8.5 (Berkeley) 1/21/94
68  * $FreeBSD: src/sys/kern/kern_clock.c,v 1.105.2.10 2002/10/17 13:19:40 maxim Exp $
69  */
70 
71 #include "opt_ntp.h"
72 #include "opt_ifpoll.h"
73 #include "opt_pctrack.h"
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/callout.h>
78 #include <sys/kernel.h>
79 #include <sys/kinfo.h>
80 #include <sys/proc.h>
81 #include <sys/malloc.h>
82 #include <sys/resource.h>
83 #include <sys/resourcevar.h>
84 #include <sys/signalvar.h>
85 #include <sys/priv.h>
86 #include <sys/timex.h>
87 #include <sys/timepps.h>
88 #include <sys/upmap.h>
89 #include <vm/vm.h>
90 #include <sys/lock.h>
91 #include <vm/pmap.h>
92 #include <vm/vm_map.h>
93 #include <vm/vm_extern.h>
94 #include <sys/sysctl.h>
95 
96 #include <sys/thread2.h>
97 #include <sys/spinlock2.h>
98 
99 #include <machine/cpu.h>
100 #include <machine/limits.h>
101 #include <machine/smp.h>
102 #include <machine/cpufunc.h>
103 #include <machine/specialreg.h>
104 #include <machine/clock.h>
105 
106 #ifdef GPROF
107 #include <sys/gmon.h>
108 #endif
109 
110 #ifdef IFPOLL_ENABLE
111 extern void ifpoll_init_pcpu(int);
112 #endif
113 
114 #ifdef DEBUG_PCTRACK
115 static void do_pctrack(struct intrframe *frame, int which);
116 #endif
117 
118 static void initclocks (void *dummy);
119 SYSINIT(clocks, SI_BOOT2_CLOCKS, SI_ORDER_FIRST, initclocks, NULL);
120 
121 /*
122  * Some of these don't belong here, but it's easiest to concentrate them.
123  * Note that cpu_time counts in microseconds, but most userland programs
124  * just compare relative times against the total by delta.
125  */
126 struct kinfo_cputime cputime_percpu[MAXCPU];
127 #ifdef DEBUG_PCTRACK
128 struct kinfo_pcheader cputime_pcheader = { PCTRACK_SIZE, PCTRACK_ARYSIZE };
129 struct kinfo_pctrack cputime_pctrack[MAXCPU][PCTRACK_SIZE];
130 #endif
131 
132 static int
133 sysctl_cputime(SYSCTL_HANDLER_ARGS)
134 {
135 	int cpu, error = 0;
136 	int root_error;
137 	size_t size = sizeof(struct kinfo_cputime);
138 	struct kinfo_cputime tmp;
139 
140 	/*
141 	 * NOTE: For security reasons, only root can sniff %rip
142 	 */
143 	root_error = priv_check_cred(curthread->td_ucred, PRIV_ROOT, 0);
144 
145 	for (cpu = 0; cpu < ncpus; ++cpu) {
146 		tmp = cputime_percpu[cpu];
147 		if (root_error == 0) {
148 			tmp.cp_sample_pc =
149 				(int64_t)globaldata_find(cpu)->gd_sample_pc;
150 			tmp.cp_sample_sp =
151 				(int64_t)globaldata_find(cpu)->gd_sample_sp;
152 		}
153 		if ((error = SYSCTL_OUT(req, &tmp, size)) != 0)
154 			break;
155 	}
156 
157 	if (root_error == 0)
158 		smp_sniff();
159 
160 	return (error);
161 }
162 SYSCTL_PROC(_kern, OID_AUTO, cputime, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
163 	sysctl_cputime, "S,kinfo_cputime", "CPU time statistics");
164 
165 static int
166 sysctl_cp_time(SYSCTL_HANDLER_ARGS)
167 {
168 	long cpu_states[5] = {0};
169 	int cpu, error = 0;
170 	size_t size = sizeof(cpu_states);
171 
172 	for (cpu = 0; cpu < ncpus; ++cpu) {
173 		cpu_states[CP_USER] += cputime_percpu[cpu].cp_user;
174 		cpu_states[CP_NICE] += cputime_percpu[cpu].cp_nice;
175 		cpu_states[CP_SYS] += cputime_percpu[cpu].cp_sys;
176 		cpu_states[CP_INTR] += cputime_percpu[cpu].cp_intr;
177 		cpu_states[CP_IDLE] += cputime_percpu[cpu].cp_idle;
178 	}
179 
180 	error = SYSCTL_OUT(req, cpu_states, size);
181 
182 	return (error);
183 }
184 
185 SYSCTL_PROC(_kern, OID_AUTO, cp_time, (CTLTYPE_LONG|CTLFLAG_RD), 0, 0,
186 	sysctl_cp_time, "LU", "CPU time statistics");
187 
188 /*
189  * boottime is used to calculate the 'real' uptime.  Do not confuse this with
190  * microuptime().  microtime() is not drift compensated.  The real uptime
191  * with compensation is nanotime() - bootime.  boottime is recalculated
192  * whenever the real time is set based on the compensated elapsed time
193  * in seconds (gd->gd_time_seconds).
194  *
195  * The gd_time_seconds and gd_cpuclock_base fields remain fairly monotonic.
196  * Slight adjustments to gd_cpuclock_base are made to phase-lock it to
197  * the real time.
198  *
199  * WARNING! time_second can backstep on time corrections. Also, unlike
200  *          time_second, time_uptime is not a "real" time_t (seconds
201  *          since the Epoch) but seconds since booting.
202  */
203 struct timespec boottime;	/* boot time (realtime) for reference only */
204 time_t time_second;		/* read-only 'passive' realtime in seconds */
205 time_t time_uptime;		/* read-only 'passive' uptime in seconds */
206 
207 /*
208  * basetime is used to calculate the compensated real time of day.  The
209  * basetime can be modified on a per-tick basis by the adjtime(),
210  * ntp_adjtime(), and sysctl-based time correction APIs.
211  *
212  * Note that frequency corrections can also be made by adjusting
213  * gd_cpuclock_base.
214  *
215  * basetime is a tail-chasing FIFO, updated only by cpu #0.  The FIFO is
216  * used on both SMP and UP systems to avoid MP races between cpu's and
217  * interrupt races on UP systems.
218  */
219 struct hardtime {
220 	__uint32_t time_second;
221 	sysclock_t cpuclock_base;
222 };
223 
224 #define BASETIME_ARYSIZE	16
225 #define BASETIME_ARYMASK	(BASETIME_ARYSIZE - 1)
226 static struct timespec basetime[BASETIME_ARYSIZE];
227 static struct hardtime hardtime[BASETIME_ARYSIZE];
228 static volatile int basetime_index;
229 
230 static int
231 sysctl_get_basetime(SYSCTL_HANDLER_ARGS)
232 {
233 	struct timespec *bt;
234 	int error;
235 	int index;
236 
237 	/*
238 	 * Because basetime data and index may be updated by another cpu,
239 	 * a load fence is required to ensure that the data we read has
240 	 * not been speculatively read relative to a possibly updated index.
241 	 */
242 	index = basetime_index;
243 	cpu_lfence();
244 	bt = &basetime[index];
245 	error = SYSCTL_OUT(req, bt, sizeof(*bt));
246 	return (error);
247 }
248 
249 SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
250     &boottime, timespec, "System boottime");
251 SYSCTL_PROC(_kern, OID_AUTO, basetime, CTLTYPE_STRUCT|CTLFLAG_RD, 0, 0,
252     sysctl_get_basetime, "S,timespec", "System basetime");
253 
254 static void hardclock(systimer_t info, int, struct intrframe *frame);
255 static void statclock(systimer_t info, int, struct intrframe *frame);
256 static void schedclock(systimer_t info, int, struct intrframe *frame);
257 static void getnanotime_nbt(struct timespec *nbt, struct timespec *tsp);
258 
259 int	ticks;			/* system master ticks at hz */
260 int	clocks_running;		/* tsleep/timeout clocks operational */
261 int64_t	nsec_adj;		/* ntpd per-tick adjustment in nsec << 32 */
262 int64_t	nsec_acc;		/* accumulator */
263 int	sched_ticks;		/* global schedule clock ticks */
264 
265 /* NTPD time correction fields */
266 int64_t	ntp_tick_permanent;	/* per-tick adjustment in nsec << 32 */
267 int64_t	ntp_tick_acc;		/* accumulator for per-tick adjustment */
268 int64_t	ntp_delta;		/* one-time correction in nsec */
269 int64_t ntp_big_delta = 1000000000;
270 int32_t	ntp_tick_delta;		/* current adjustment rate */
271 int32_t	ntp_default_tick_delta;	/* adjustment rate for ntp_delta */
272 time_t	ntp_leap_second;	/* time of next leap second */
273 int	ntp_leap_insert;	/* whether to insert or remove a second */
274 struct spinlock ntp_spin;
275 
276 /*
277  * Finish initializing clock frequencies and start all clocks running.
278  */
279 /* ARGSUSED*/
280 static void
281 initclocks(void *dummy)
282 {
283 	/*psratio = profhz / stathz;*/
284 	spin_init(&ntp_spin, "ntp");
285 	initclocks_pcpu();
286 	clocks_running = 1;
287 	if (kpmap) {
288 	    kpmap->tsc_freq = (uint64_t)tsc_frequency;
289 	    kpmap->tick_freq = hz;
290 	}
291 }
292 
293 /*
294  * Called on a per-cpu basis from the idle thread bootstrap on each cpu
295  * during SMP initialization.
296  *
297  * This routine is called concurrently during low-level SMP initialization
298  * and may not block in any way.  Meaning, among other things, we can't
299  * acquire any tokens.
300  */
301 void
302 initclocks_pcpu(void)
303 {
304 	struct globaldata *gd = mycpu;
305 
306 	crit_enter();
307 	if (gd->gd_cpuid == 0) {
308 	    gd->gd_time_seconds = 1;
309 	    gd->gd_cpuclock_base = sys_cputimer->count();
310 	    hardtime[0].time_second = gd->gd_time_seconds;
311 	    hardtime[0].cpuclock_base = gd->gd_cpuclock_base;
312 	} else {
313 	    gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
314 	    gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
315 	}
316 
317 	systimer_intr_enable();
318 
319 	crit_exit();
320 }
321 
322 /*
323  * This routine is called on just the BSP, just after SMP initialization
324  * completes to * finish initializing any clocks that might contend/block
325  * (e.g. like on a token).  We can't do this in initclocks_pcpu() because
326  * that function is called from the idle thread bootstrap for each cpu and
327  * not allowed to block at all.
328  */
329 static
330 void
331 initclocks_other(void *dummy)
332 {
333 	struct globaldata *ogd = mycpu;
334 	struct globaldata *gd;
335 	int n;
336 
337 	for (n = 0; n < ncpus; ++n) {
338 		lwkt_setcpu_self(globaldata_find(n));
339 		gd = mycpu;
340 
341 		/*
342 		 * Use a non-queued periodic systimer to prevent multiple
343 		 * ticks from building up if the sysclock jumps forward
344 		 * (8254 gets reset).  The sysclock will never jump backwards.
345 		 * Our time sync is based on the actual sysclock, not the
346 		 * ticks count.
347 		 *
348 		 * Install statclock before hardclock to prevent statclock
349 		 * from misinterpreting gd_flags for tick assignment when
350 		 * they overlap.
351 		 */
352 		systimer_init_periodic_nq(&gd->gd_statclock, statclock,
353 					  NULL, stathz);
354 		systimer_init_periodic_nq(&gd->gd_hardclock, hardclock,
355 					  NULL, hz);
356 		/* XXX correct the frequency for scheduler / estcpu tests */
357 		systimer_init_periodic_nq(&gd->gd_schedclock, schedclock,
358 					  NULL, ESTCPUFREQ);
359 #ifdef IFPOLL_ENABLE
360 		ifpoll_init_pcpu(gd->gd_cpuid);
361 #endif
362 	}
363 	lwkt_setcpu_self(ogd);
364 }
365 SYSINIT(clocks2, SI_BOOT2_POST_SMP, SI_ORDER_ANY, initclocks_other, NULL);
366 
367 /*
368  * This sets the current real time of day.  Timespecs are in seconds and
369  * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
370  * instead we adjust basetime so basetime + gd_* results in the current
371  * time of day.  This way the gd_* fields are guaranteed to represent
372  * a monotonically increasing 'uptime' value.
373  *
374  * When set_timeofday() is called from userland, the system call forces it
375  * onto cpu #0 since only cpu #0 can update basetime_index.
376  */
377 void
378 set_timeofday(struct timespec *ts)
379 {
380 	struct timespec *nbt;
381 	int ni;
382 
383 	/*
384 	 * XXX SMP / non-atomic basetime updates
385 	 */
386 	crit_enter();
387 	ni = (basetime_index + 1) & BASETIME_ARYMASK;
388 	cpu_lfence();
389 	nbt = &basetime[ni];
390 	nanouptime(nbt);
391 	nbt->tv_sec = ts->tv_sec - nbt->tv_sec;
392 	nbt->tv_nsec = ts->tv_nsec - nbt->tv_nsec;
393 	if (nbt->tv_nsec < 0) {
394 	    nbt->tv_nsec += 1000000000;
395 	    --nbt->tv_sec;
396 	}
397 
398 	/*
399 	 * Note that basetime diverges from boottime as the clock drift is
400 	 * compensated for, so we cannot do away with boottime.  When setting
401 	 * the absolute time of day the drift is 0 (for an instant) and we
402 	 * can simply assign boottime to basetime.
403 	 *
404 	 * Note that nanouptime() is based on gd_time_seconds which is drift
405 	 * compensated up to a point (it is guaranteed to remain monotonically
406 	 * increasing).  gd_time_seconds is thus our best uptime guess and
407 	 * suitable for use in the boottime calculation.  It is already taken
408 	 * into account in the basetime calculation above.
409 	 */
410 	spin_lock(&ntp_spin);
411 	boottime.tv_sec = nbt->tv_sec;
412 	ntp_delta = 0;
413 
414 	/*
415 	 * We now have a new basetime, make sure all other cpus have it,
416 	 * then update the index.
417 	 */
418 	cpu_sfence();
419 	basetime_index = ni;
420 	spin_unlock(&ntp_spin);
421 
422 	crit_exit();
423 }
424 
425 /*
426  * Each cpu has its own hardclock, but we only increments ticks and softticks
427  * on cpu #0.
428  *
429  * NOTE! systimer! the MP lock might not be held here.  We can only safely
430  * manipulate objects owned by the current cpu.
431  */
432 static void
433 hardclock(systimer_t info, int in_ipi, struct intrframe *frame)
434 {
435 	sysclock_t cputicks;
436 	struct proc *p;
437 	struct globaldata *gd = mycpu;
438 
439 	if ((gd->gd_reqflags & RQF_IPIQ) == 0 && lwkt_need_ipiq_process(gd)) {
440 		/* Defer to doreti on passive IPIQ processing */
441 		need_ipiq();
442 	}
443 
444 	/*
445 	 * We update the compensation base to calculate fine-grained time
446 	 * from the sys_cputimer on a per-cpu basis in order to avoid
447 	 * having to mess around with locks.  sys_cputimer is assumed to
448 	 * be consistent across all cpus.  CPU N copies the base state from
449 	 * CPU 0 using the same FIFO trick that we use for basetime (so we
450 	 * don't catch a CPU 0 update in the middle).
451 	 *
452 	 * Note that we never allow info->time (aka gd->gd_hardclock.time)
453 	 * to reverse index gd_cpuclock_base, but that it is possible for
454 	 * it to temporarily get behind in the seconds if something in the
455 	 * system locks interrupts for a long period of time.  Since periodic
456 	 * timers count events, though everything should resynch again
457 	 * immediately.
458 	 */
459 	if (gd->gd_cpuid == 0) {
460 		int ni;
461 
462 		cputicks = info->time - gd->gd_cpuclock_base;
463 		if (cputicks >= sys_cputimer->freq) {
464 			cputicks /= sys_cputimer->freq;
465 			if (cputicks != 0 && cputicks != 1)
466 				kprintf("Warning: hardclock missed > 1 sec\n");
467 			gd->gd_time_seconds += cputicks;
468 			gd->gd_cpuclock_base += sys_cputimer->freq * cputicks;
469 			/* uncorrected monotonic 1-sec gran */
470 			time_uptime += cputicks;
471 		}
472 		ni = (basetime_index + 1) & BASETIME_ARYMASK;
473 		hardtime[ni].time_second = gd->gd_time_seconds;
474 		hardtime[ni].cpuclock_base = gd->gd_cpuclock_base;
475 	} else {
476 		int ni;
477 
478 		ni = basetime_index;
479 		cpu_lfence();
480 		gd->gd_time_seconds = hardtime[ni].time_second;
481 		gd->gd_cpuclock_base = hardtime[ni].cpuclock_base;
482 	}
483 
484 	/*
485 	 * The system-wide ticks counter and NTP related timedelta/tickdelta
486 	 * adjustments only occur on cpu #0.  NTP adjustments are accomplished
487 	 * by updating basetime.
488 	 */
489 	if (gd->gd_cpuid == 0) {
490 	    struct timespec *nbt;
491 	    struct timespec nts;
492 	    int leap;
493 	    int ni;
494 
495 	    ++ticks;
496 
497 #if 0
498 	    if (tco->tc_poll_pps)
499 		tco->tc_poll_pps(tco);
500 #endif
501 
502 	    /*
503 	     * Calculate the new basetime index.  We are in a critical section
504 	     * on cpu #0 and can safely play with basetime_index.  Start
505 	     * with the current basetime and then make adjustments.
506 	     */
507 	    ni = (basetime_index + 1) & BASETIME_ARYMASK;
508 	    nbt = &basetime[ni];
509 	    *nbt = basetime[basetime_index];
510 
511 	    /*
512 	     * ntp adjustments only occur on cpu 0 and are protected by
513 	     * ntp_spin.  This spinlock virtually never conflicts.
514 	     */
515 	    spin_lock(&ntp_spin);
516 
517 	    /*
518 	     * Apply adjtime corrections.  (adjtime() API)
519 	     *
520 	     * adjtime() only runs on cpu #0 so our critical section is
521 	     * sufficient to access these variables.
522 	     */
523 	    if (ntp_delta != 0) {
524 		nbt->tv_nsec += ntp_tick_delta;
525 		ntp_delta -= ntp_tick_delta;
526 		if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
527 		    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
528 			ntp_tick_delta = ntp_delta;
529  		}
530  	    }
531 
532 	    /*
533 	     * Apply permanent frequency corrections.  (sysctl API)
534 	     */
535 	    if (ntp_tick_permanent != 0) {
536 		ntp_tick_acc += ntp_tick_permanent;
537 		if (ntp_tick_acc >= (1LL << 32)) {
538 		    nbt->tv_nsec += ntp_tick_acc >> 32;
539 		    ntp_tick_acc -= (ntp_tick_acc >> 32) << 32;
540 		} else if (ntp_tick_acc <= -(1LL << 32)) {
541 		    /* Negate ntp_tick_acc to avoid shifting the sign bit. */
542 		    nbt->tv_nsec -= (-ntp_tick_acc) >> 32;
543 		    ntp_tick_acc += ((-ntp_tick_acc) >> 32) << 32;
544 		}
545  	    }
546 
547 	    if (nbt->tv_nsec >= 1000000000) {
548 		    nbt->tv_sec++;
549 		    nbt->tv_nsec -= 1000000000;
550 	    } else if (nbt->tv_nsec < 0) {
551 		    nbt->tv_sec--;
552 		    nbt->tv_nsec += 1000000000;
553 	    }
554 
555 	    /*
556 	     * Another per-tick compensation.  (for ntp_adjtime() API)
557 	     */
558 	    if (nsec_adj != 0) {
559 		nsec_acc += nsec_adj;
560 		if (nsec_acc >= 0x100000000LL) {
561 		    nbt->tv_nsec += nsec_acc >> 32;
562 		    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
563 		} else if (nsec_acc <= -0x100000000LL) {
564 		    nbt->tv_nsec -= -nsec_acc >> 32;
565 		    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
566 		}
567 		if (nbt->tv_nsec >= 1000000000) {
568 		    nbt->tv_nsec -= 1000000000;
569 		    ++nbt->tv_sec;
570 		} else if (nbt->tv_nsec < 0) {
571 		    nbt->tv_nsec += 1000000000;
572 		    --nbt->tv_sec;
573 		}
574 	    }
575 	    spin_unlock(&ntp_spin);
576 
577 	    /************************************************************
578 	     *			LEAP SECOND CORRECTION			*
579 	     ************************************************************
580 	     *
581 	     * Taking into account all the corrections made above, figure
582 	     * out the new real time.  If the seconds field has changed
583 	     * then apply any pending leap-second corrections.
584 	     */
585 	    getnanotime_nbt(nbt, &nts);
586 
587 	    if (time_second != nts.tv_sec) {
588 		/*
589 		 * Apply leap second (sysctl API).  Adjust nts for changes
590 		 * so we do not have to call getnanotime_nbt again.
591 		 */
592 		if (ntp_leap_second) {
593 		    if (ntp_leap_second == nts.tv_sec) {
594 			if (ntp_leap_insert) {
595 			    nbt->tv_sec++;
596 			    nts.tv_sec++;
597 			} else {
598 			    nbt->tv_sec--;
599 			    nts.tv_sec--;
600 			}
601 			ntp_leap_second--;
602 		    }
603 		}
604 
605 		/*
606 		 * Apply leap second (ntp_adjtime() API), calculate a new
607 		 * nsec_adj field.  ntp_update_second() returns nsec_adj
608 		 * as a per-second value but we need it as a per-tick value.
609 		 */
610 		leap = ntp_update_second(time_second, &nsec_adj);
611 		nsec_adj /= hz;
612 		nbt->tv_sec += leap;
613 		nts.tv_sec += leap;
614 
615 		/*
616 		 * Update the time_second 'approximate time' global.
617 		 */
618 		time_second = nts.tv_sec;
619 	    }
620 
621 	    /*
622 	     * Finally, our new basetime is ready to go live!
623 	     */
624 	    cpu_sfence();
625 	    basetime_index = ni;
626 
627 	    /*
628 	     * Update kpmap on each tick.  TS updates are integrated with
629 	     * fences and upticks allowing userland to read the data
630 	     * deterministically.
631 	     */
632 	    if (kpmap) {
633 		int w;
634 
635 		w = (kpmap->upticks + 1) & 1;
636 		getnanouptime(&kpmap->ts_uptime[w]);
637 		getnanotime(&kpmap->ts_realtime[w]);
638 		cpu_sfence();
639 		++kpmap->upticks;
640 		cpu_sfence();
641 	    }
642 	}
643 
644 	/*
645 	 * lwkt thread scheduler fair queueing
646 	 */
647 	lwkt_schedulerclock(curthread);
648 
649 	/*
650 	 * softticks are handled for all cpus
651 	 */
652 	hardclock_softtick(gd);
653 
654 	/*
655 	 * Rollup accumulated vmstats, copy-back for critical path checks.
656 	 */
657 	vmstats_rollup_cpu(gd);
658 	mycpu->gd_vmstats = vmstats;
659 
660 	/*
661 	 * ITimer handling is per-tick, per-cpu.
662 	 *
663 	 * We must acquire the per-process token in order for ksignal()
664 	 * to be non-blocking.  For the moment this requires an AST fault,
665 	 * the ksignal() cannot be safely issued from this hard interrupt.
666 	 *
667 	 * XXX Even the trytoken here isn't right, and itimer operation in
668 	 *     a multi threaded environment is going to be weird at the
669 	 *     very least.
670 	 */
671 	if ((p = curproc) != NULL && lwkt_trytoken(&p->p_token)) {
672 		crit_enter_hard();
673 		if (p->p_upmap)
674 			++p->p_upmap->runticks;
675 
676 		if (frame && CLKF_USERMODE(frame) &&
677 		    timevalisset(&p->p_timer[ITIMER_VIRTUAL].it_value) &&
678 		    itimerdecr(&p->p_timer[ITIMER_VIRTUAL], ustick) == 0) {
679 			p->p_flags |= P_SIGVTALRM;
680 			need_user_resched();
681 		}
682 		if (timevalisset(&p->p_timer[ITIMER_PROF].it_value) &&
683 		    itimerdecr(&p->p_timer[ITIMER_PROF], ustick) == 0) {
684 			p->p_flags |= P_SIGPROF;
685 			need_user_resched();
686 		}
687 		crit_exit_hard();
688 		lwkt_reltoken(&p->p_token);
689 	}
690 	setdelayed();
691 }
692 
693 /*
694  * The statistics clock typically runs at a 125Hz rate, and is intended
695  * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
696  *
697  * NOTE! systimer! the MP lock might not be held here.  We can only safely
698  * manipulate objects owned by the current cpu.
699  *
700  * The stats clock is responsible for grabbing a profiling sample.
701  * Most of the statistics are only used by user-level statistics programs.
702  * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
703  * p->p_estcpu.
704  *
705  * Like the other clocks, the stat clock is called from what is effectively
706  * a fast interrupt, so the context should be the thread/process that got
707  * interrupted.
708  */
709 static void
710 statclock(systimer_t info, int in_ipi, struct intrframe *frame)
711 {
712 #ifdef GPROF
713 	struct gmonparam *g;
714 	int i;
715 #endif
716 	globaldata_t gd = mycpu;
717 	thread_t td;
718 	struct proc *p;
719 	int bump;
720 	sysclock_t cv;
721 	sysclock_t scv;
722 
723 	/*
724 	 * How big was our timeslice relative to the last time?  Calculate
725 	 * in microseconds.
726 	 *
727 	 * NOTE: Use of microuptime() is typically MPSAFE, but usually not
728 	 *	 during early boot.  Just use the systimer count to be nice
729 	 *	 to e.g. qemu.  The systimer has a better chance of being
730 	 *	 MPSAFE at early boot.
731 	 */
732 	cv = sys_cputimer->count();
733 	scv = gd->statint.gd_statcv;
734 	if (scv == 0) {
735 		bump = 1;
736 	} else {
737 		bump = (sys_cputimer->freq64_usec * (cv - scv)) >> 32;
738 		if (bump < 0)
739 			bump = 0;
740 		if (bump > 1000000)
741 			bump = 1000000;
742 	}
743 	gd->statint.gd_statcv = cv;
744 
745 #if 0
746 	stv = &gd->gd_stattv;
747 	if (stv->tv_sec == 0) {
748 	    bump = 1;
749 	} else {
750 	    bump = tv.tv_usec - stv->tv_usec +
751 		(tv.tv_sec - stv->tv_sec) * 1000000;
752 	    if (bump < 0)
753 		bump = 0;
754 	    if (bump > 1000000)
755 		bump = 1000000;
756 	}
757 	*stv = tv;
758 #endif
759 
760 	td = curthread;
761 	p = td->td_proc;
762 
763 	if (frame && CLKF_USERMODE(frame)) {
764 		/*
765 		 * Came from userland, handle user time and deal with
766 		 * possible process.
767 		 */
768 		if (p && (p->p_flags & P_PROFIL))
769 			addupc_intr(p, CLKF_PC(frame), 1);
770 		td->td_uticks += bump;
771 
772 		/*
773 		 * Charge the time as appropriate
774 		 */
775 		if (p && p->p_nice > NZERO)
776 			cpu_time.cp_nice += bump;
777 		else
778 			cpu_time.cp_user += bump;
779 	} else {
780 		int intr_nest = gd->gd_intr_nesting_level;
781 
782 		if (in_ipi) {
783 			/*
784 			 * IPI processing code will bump gd_intr_nesting_level
785 			 * up by one, which breaks following CLKF_INTR testing,
786 			 * so we subtract it by one here.
787 			 */
788 			--intr_nest;
789 		}
790 #ifdef GPROF
791 		/*
792 		 * Kernel statistics are just like addupc_intr, only easier.
793 		 */
794 		g = &_gmonparam;
795 		if (g->state == GMON_PROF_ON && frame) {
796 			i = CLKF_PC(frame) - g->lowpc;
797 			if (i < g->textsize) {
798 				i /= HISTFRACTION * sizeof(*g->kcount);
799 				g->kcount[i]++;
800 			}
801 		}
802 #endif
803 
804 #define IS_INTR_RUNNING	((frame && CLKF_INTR(intr_nest)) || CLKF_INTR_TD(td))
805 
806 		/*
807 		 * Came from kernel mode, so we were:
808 		 * - handling an interrupt,
809 		 * - doing syscall or trap work on behalf of the current
810 		 *   user process, or
811 		 * - spinning in the idle loop.
812 		 * Whichever it is, charge the time as appropriate.
813 		 * Note that we charge interrupts to the current process,
814 		 * regardless of whether they are ``for'' that process,
815 		 * so that we know how much of its real time was spent
816 		 * in ``non-process'' (i.e., interrupt) work.
817 		 *
818 		 * XXX assume system if frame is NULL.  A NULL frame
819 		 * can occur if ipi processing is done from a crit_exit().
820 		 */
821 		if (IS_INTR_RUNNING) {
822 			/*
823 			 * If we interrupted an interrupt thread, well,
824 			 * count it as interrupt time.
825 			 */
826 			td->td_iticks += bump;
827 #ifdef DEBUG_PCTRACK
828 			if (frame)
829 				do_pctrack(frame, PCTRACK_INT);
830 #endif
831 			cpu_time.cp_intr += bump;
832 #ifdef _KERNEL_VIRTUAL
833 		} else if (gd->gd_flags & GDF_VIRTUSER) {
834 			/*
835 			 * The vkernel doesn't do a good job providing trap
836 			 * frames that we can test.  If the GDF_VIRTUSER
837 			 * flag is set we probably interrupted user mode.
838 			 */
839 			td->td_uticks += bump;
840 
841 			/*
842 			 * Charge the time as appropriate
843 			 */
844 			if (p && p->p_nice > NZERO)
845 				cpu_time.cp_nice += bump;
846 			else
847 				cpu_time.cp_user += bump;
848 #endif
849 		} else {
850 #if 0
851 			kprintf("THREAD %s %p %p %08x\n", td->td_comm, td, &gd->gd_idlethread, gd->gd_reqflags);
852 #endif
853 			td->td_sticks += bump;
854 			if (td == &gd->gd_idlethread) {
855 				/*
856 				 * Token contention can cause us to mis-count
857 				 * a contended as idle, but the previous use
858 				 * of gd_reqflags was not a good way to figure
859 				 * it out so for now just eat it.
860 				 */
861 				cpu_time.cp_idle += bump;
862 			} else {
863 				/*
864 				 * System thread was running.
865 				 */
866 #ifdef DEBUG_PCTRACK
867 				if (frame)
868 					do_pctrack(frame, PCTRACK_SYS);
869 #endif
870 				cpu_time.cp_sys += bump;
871 			}
872 		}
873 
874 #undef IS_INTR_RUNNING
875 	}
876 }
877 
878 #ifdef DEBUG_PCTRACK
879 /*
880  * Sample the PC when in the kernel or in an interrupt.  User code can
881  * retrieve the information and generate a histogram or other output.
882  */
883 
884 static void
885 do_pctrack(struct intrframe *frame, int which)
886 {
887 	struct kinfo_pctrack *pctrack;
888 
889 	pctrack = &cputime_pctrack[mycpu->gd_cpuid][which];
890 	pctrack->pc_array[pctrack->pc_index & PCTRACK_ARYMASK] =
891 		(void *)CLKF_PC(frame);
892 	++pctrack->pc_index;
893 }
894 
895 static int
896 sysctl_pctrack(SYSCTL_HANDLER_ARGS)
897 {
898 	struct kinfo_pcheader head;
899 	int error;
900 	int cpu;
901 	int ntrack;
902 
903 	head.pc_ntrack = PCTRACK_SIZE;
904 	head.pc_arysize = PCTRACK_ARYSIZE;
905 
906 	if ((error = SYSCTL_OUT(req, &head, sizeof(head))) != 0)
907 		return (error);
908 
909 	for (cpu = 0; cpu < ncpus; ++cpu) {
910 		for (ntrack = 0; ntrack < PCTRACK_SIZE; ++ntrack) {
911 			error = SYSCTL_OUT(req, &cputime_pctrack[cpu][ntrack],
912 					   sizeof(struct kinfo_pctrack));
913 			if (error)
914 				break;
915 		}
916 		if (error)
917 			break;
918 	}
919 	return (error);
920 }
921 SYSCTL_PROC(_kern, OID_AUTO, pctrack, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
922 	sysctl_pctrack, "S,kinfo_pcheader", "CPU PC tracking");
923 
924 #endif
925 
926 /*
927  * The scheduler clock typically runs at a 50Hz rate.  NOTE! systimer,
928  * the MP lock might not be held.  We can safely manipulate parts of curproc
929  * but that's about it.
930  *
931  * Each cpu has its own scheduler clock.
932  */
933 static void
934 schedclock(systimer_t info, int in_ipi __unused, struct intrframe *frame)
935 {
936 	struct lwp *lp;
937 	struct rusage *ru;
938 	struct vmspace *vm;
939 	long rss;
940 
941 	if ((lp = lwkt_preempted_proc()) != NULL) {
942 		/*
943 		 * Account for cpu time used and hit the scheduler.  Note
944 		 * that this call MUST BE MP SAFE, and the BGL IS NOT HELD
945 		 * HERE.
946 		 */
947 		++lp->lwp_cpticks;
948 		usched_schedulerclock(lp, info->periodic, info->time);
949 	} else {
950 		usched_schedulerclock(NULL, info->periodic, info->time);
951 	}
952 	if ((lp = curthread->td_lwp) != NULL) {
953 		/*
954 		 * Update resource usage integrals and maximums.
955 		 */
956 		if ((ru = &lp->lwp_proc->p_ru) &&
957 		    (vm = lp->lwp_proc->p_vmspace) != NULL) {
958 			ru->ru_ixrss += pgtok(vm->vm_tsize);
959 			ru->ru_idrss += pgtok(vm->vm_dsize);
960 			ru->ru_isrss += pgtok(vm->vm_ssize);
961 			if (lwkt_trytoken(&vm->vm_map.token)) {
962 				rss = pgtok(vmspace_resident_count(vm));
963 				if (ru->ru_maxrss < rss)
964 					ru->ru_maxrss = rss;
965 				lwkt_reltoken(&vm->vm_map.token);
966 			}
967 		}
968 	}
969 	/* Increment the global sched_ticks */
970 	if (mycpu->gd_cpuid == 0)
971 		++sched_ticks;
972 }
973 
974 /*
975  * Compute number of ticks for the specified amount of time.  The
976  * return value is intended to be used in a clock interrupt timed
977  * operation and guaranteed to meet or exceed the requested time.
978  * If the representation overflows, return INT_MAX.  The minimum return
979  * value is 1 ticks and the function will average the calculation up.
980  * If any value greater then 0 microseconds is supplied, a value
981  * of at least 2 will be returned to ensure that a near-term clock
982  * interrupt does not cause the timeout to occur (degenerately) early.
983  *
984  * Note that limit checks must take into account microseconds, which is
985  * done simply by using the smaller signed long maximum instead of
986  * the unsigned long maximum.
987  *
988  * If ints have 32 bits, then the maximum value for any timeout in
989  * 10ms ticks is 248 days.
990  */
991 int
992 tvtohz_high(struct timeval *tv)
993 {
994 	int ticks;
995 	long sec, usec;
996 
997 	sec = tv->tv_sec;
998 	usec = tv->tv_usec;
999 	if (usec < 0) {
1000 		sec--;
1001 		usec += 1000000;
1002 	}
1003 	if (sec < 0) {
1004 #ifdef DIAGNOSTIC
1005 		if (usec > 0) {
1006 			sec++;
1007 			usec -= 1000000;
1008 		}
1009 		kprintf("tvtohz_high: negative time difference "
1010 			"%ld sec %ld usec\n",
1011 			sec, usec);
1012 #endif
1013 		ticks = 1;
1014 	} else if (sec <= INT_MAX / hz) {
1015 		ticks = (int)(sec * hz +
1016 			    ((u_long)usec + (ustick - 1)) / ustick) + 1;
1017 	} else {
1018 		ticks = INT_MAX;
1019 	}
1020 	return (ticks);
1021 }
1022 
1023 int
1024 tstohz_high(struct timespec *ts)
1025 {
1026 	int ticks;
1027 	long sec, nsec;
1028 
1029 	sec = ts->tv_sec;
1030 	nsec = ts->tv_nsec;
1031 	if (nsec < 0) {
1032 		sec--;
1033 		nsec += 1000000000;
1034 	}
1035 	if (sec < 0) {
1036 #ifdef DIAGNOSTIC
1037 		if (nsec > 0) {
1038 			sec++;
1039 			nsec -= 1000000000;
1040 		}
1041 		kprintf("tstohz_high: negative time difference "
1042 			"%ld sec %ld nsec\n",
1043 			sec, nsec);
1044 #endif
1045 		ticks = 1;
1046 	} else if (sec <= INT_MAX / hz) {
1047 		ticks = (int)(sec * hz +
1048 			    ((u_long)nsec + (nstick - 1)) / nstick) + 1;
1049 	} else {
1050 		ticks = INT_MAX;
1051 	}
1052 	return (ticks);
1053 }
1054 
1055 
1056 /*
1057  * Compute number of ticks for the specified amount of time, erroring on
1058  * the side of it being too low to ensure that sleeping the returned number
1059  * of ticks will not result in a late return.
1060  *
1061  * The supplied timeval may not be negative and should be normalized.  A
1062  * return value of 0 is possible if the timeval converts to less then
1063  * 1 tick.
1064  *
1065  * If ints have 32 bits, then the maximum value for any timeout in
1066  * 10ms ticks is 248 days.
1067  */
1068 int
1069 tvtohz_low(struct timeval *tv)
1070 {
1071 	int ticks;
1072 	long sec;
1073 
1074 	sec = tv->tv_sec;
1075 	if (sec <= INT_MAX / hz)
1076 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / ustick);
1077 	else
1078 		ticks = INT_MAX;
1079 	return (ticks);
1080 }
1081 
1082 int
1083 tstohz_low(struct timespec *ts)
1084 {
1085 	int ticks;
1086 	long sec;
1087 
1088 	sec = ts->tv_sec;
1089 	if (sec <= INT_MAX / hz)
1090 		ticks = (int)(sec * hz + (u_long)ts->tv_nsec / nstick);
1091 	else
1092 		ticks = INT_MAX;
1093 	return (ticks);
1094 }
1095 
1096 /*
1097  * Start profiling on a process.
1098  *
1099  * Caller must hold p->p_token();
1100  *
1101  * Kernel profiling passes proc0 which never exits and hence
1102  * keeps the profile clock running constantly.
1103  */
1104 void
1105 startprofclock(struct proc *p)
1106 {
1107 	if ((p->p_flags & P_PROFIL) == 0) {
1108 		p->p_flags |= P_PROFIL;
1109 #if 0	/* XXX */
1110 		if (++profprocs == 1 && stathz != 0) {
1111 			crit_enter();
1112 			psdiv = psratio;
1113 			setstatclockrate(profhz);
1114 			crit_exit();
1115 		}
1116 #endif
1117 	}
1118 }
1119 
1120 /*
1121  * Stop profiling on a process.
1122  *
1123  * caller must hold p->p_token
1124  */
1125 void
1126 stopprofclock(struct proc *p)
1127 {
1128 	if (p->p_flags & P_PROFIL) {
1129 		p->p_flags &= ~P_PROFIL;
1130 #if 0	/* XXX */
1131 		if (--profprocs == 0 && stathz != 0) {
1132 			crit_enter();
1133 			psdiv = 1;
1134 			setstatclockrate(stathz);
1135 			crit_exit();
1136 		}
1137 #endif
1138 	}
1139 }
1140 
1141 /*
1142  * Return information about system clocks.
1143  */
1144 static int
1145 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
1146 {
1147 	struct kinfo_clockinfo clkinfo;
1148 	/*
1149 	 * Construct clockinfo structure.
1150 	 */
1151 	clkinfo.ci_hz = hz;
1152 	clkinfo.ci_tick = ustick;
1153 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
1154 	clkinfo.ci_profhz = profhz;
1155 	clkinfo.ci_stathz = stathz ? stathz : hz;
1156 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
1157 }
1158 
1159 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
1160 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
1161 
1162 /*
1163  * We have eight functions for looking at the clock, four for
1164  * microseconds and four for nanoseconds.  For each there is fast
1165  * but less precise version "get{nano|micro}[up]time" which will
1166  * return a time which is up to 1/HZ previous to the call, whereas
1167  * the raw version "{nano|micro}[up]time" will return a timestamp
1168  * which is as precise as possible.  The "up" variants return the
1169  * time relative to system boot, these are well suited for time
1170  * interval measurements.
1171  *
1172  * Each cpu independently maintains the current time of day, so all
1173  * we need to do to protect ourselves from changes is to do a loop
1174  * check on the seconds field changing out from under us.
1175  *
1176  * The system timer maintains a 32 bit count and due to various issues
1177  * it is possible for the calculated delta to occasionally exceed
1178  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
1179  * multiplication can easily overflow, so we deal with the case.  For
1180  * uniformity we deal with the case in the usec case too.
1181  *
1182  * All the [get][micro,nano][time,uptime]() routines are MPSAFE.
1183  */
1184 void
1185 getmicrouptime(struct timeval *tvp)
1186 {
1187 	struct globaldata *gd = mycpu;
1188 	sysclock_t delta;
1189 
1190 	do {
1191 		tvp->tv_sec = gd->gd_time_seconds;
1192 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1193 	} while (tvp->tv_sec != gd->gd_time_seconds);
1194 
1195 	if (delta >= sys_cputimer->freq) {
1196 		tvp->tv_sec += delta / sys_cputimer->freq;
1197 		delta %= sys_cputimer->freq;
1198 	}
1199 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1200 	if (tvp->tv_usec >= 1000000) {
1201 		tvp->tv_usec -= 1000000;
1202 		++tvp->tv_sec;
1203 	}
1204 }
1205 
1206 void
1207 getnanouptime(struct timespec *tsp)
1208 {
1209 	struct globaldata *gd = mycpu;
1210 	sysclock_t delta;
1211 
1212 	do {
1213 		tsp->tv_sec = gd->gd_time_seconds;
1214 		delta = gd->gd_hardclock.time - 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 
1224 void
1225 microuptime(struct timeval *tvp)
1226 {
1227 	struct globaldata *gd = mycpu;
1228 	sysclock_t delta;
1229 
1230 	do {
1231 		tvp->tv_sec = gd->gd_time_seconds;
1232 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1233 	} while (tvp->tv_sec != gd->gd_time_seconds);
1234 
1235 	if (delta >= sys_cputimer->freq) {
1236 		tvp->tv_sec += delta / sys_cputimer->freq;
1237 		delta %= sys_cputimer->freq;
1238 	}
1239 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1240 }
1241 
1242 void
1243 nanouptime(struct timespec *tsp)
1244 {
1245 	struct globaldata *gd = mycpu;
1246 	sysclock_t delta;
1247 
1248 	do {
1249 		tsp->tv_sec = gd->gd_time_seconds;
1250 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1251 	} while (tsp->tv_sec != gd->gd_time_seconds);
1252 
1253 	if (delta >= sys_cputimer->freq) {
1254 		tsp->tv_sec += delta / sys_cputimer->freq;
1255 		delta %= sys_cputimer->freq;
1256 	}
1257 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1258 }
1259 
1260 /*
1261  * realtime routines
1262  */
1263 void
1264 getmicrotime(struct timeval *tvp)
1265 {
1266 	struct globaldata *gd = mycpu;
1267 	struct timespec *bt;
1268 	sysclock_t delta;
1269 
1270 	do {
1271 		tvp->tv_sec = gd->gd_time_seconds;
1272 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1273 	} while (tvp->tv_sec != gd->gd_time_seconds);
1274 
1275 	if (delta >= sys_cputimer->freq) {
1276 		tvp->tv_sec += delta / sys_cputimer->freq;
1277 		delta %= sys_cputimer->freq;
1278 	}
1279 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1280 
1281 	bt = &basetime[basetime_index];
1282 	cpu_lfence();
1283 	tvp->tv_sec += bt->tv_sec;
1284 	tvp->tv_usec += bt->tv_nsec / 1000;
1285 	while (tvp->tv_usec >= 1000000) {
1286 		tvp->tv_usec -= 1000000;
1287 		++tvp->tv_sec;
1288 	}
1289 }
1290 
1291 void
1292 getnanotime(struct timespec *tsp)
1293 {
1294 	struct globaldata *gd = mycpu;
1295 	struct timespec *bt;
1296 	sysclock_t delta;
1297 
1298 	do {
1299 		tsp->tv_sec = gd->gd_time_seconds;
1300 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1301 	} while (tsp->tv_sec != gd->gd_time_seconds);
1302 
1303 	if (delta >= sys_cputimer->freq) {
1304 		tsp->tv_sec += delta / sys_cputimer->freq;
1305 		delta %= sys_cputimer->freq;
1306 	}
1307 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1308 
1309 	bt = &basetime[basetime_index];
1310 	cpu_lfence();
1311 	tsp->tv_sec += bt->tv_sec;
1312 	tsp->tv_nsec += bt->tv_nsec;
1313 	while (tsp->tv_nsec >= 1000000000) {
1314 		tsp->tv_nsec -= 1000000000;
1315 		++tsp->tv_sec;
1316 	}
1317 }
1318 
1319 static void
1320 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
1321 {
1322 	struct globaldata *gd = mycpu;
1323 	sysclock_t delta;
1324 
1325 	do {
1326 		tsp->tv_sec = gd->gd_time_seconds;
1327 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1328 	} while (tsp->tv_sec != gd->gd_time_seconds);
1329 
1330 	if (delta >= sys_cputimer->freq) {
1331 		tsp->tv_sec += delta / sys_cputimer->freq;
1332 		delta %= sys_cputimer->freq;
1333 	}
1334 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1335 
1336 	tsp->tv_sec += nbt->tv_sec;
1337 	tsp->tv_nsec += nbt->tv_nsec;
1338 	while (tsp->tv_nsec >= 1000000000) {
1339 		tsp->tv_nsec -= 1000000000;
1340 		++tsp->tv_sec;
1341 	}
1342 }
1343 
1344 
1345 void
1346 microtime(struct timeval *tvp)
1347 {
1348 	struct globaldata *gd = mycpu;
1349 	struct timespec *bt;
1350 	sysclock_t delta;
1351 
1352 	do {
1353 		tvp->tv_sec = gd->gd_time_seconds;
1354 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1355 	} while (tvp->tv_sec != gd->gd_time_seconds);
1356 
1357 	if (delta >= sys_cputimer->freq) {
1358 		tvp->tv_sec += delta / sys_cputimer->freq;
1359 		delta %= sys_cputimer->freq;
1360 	}
1361 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1362 
1363 	bt = &basetime[basetime_index];
1364 	cpu_lfence();
1365 	tvp->tv_sec += bt->tv_sec;
1366 	tvp->tv_usec += bt->tv_nsec / 1000;
1367 	while (tvp->tv_usec >= 1000000) {
1368 		tvp->tv_usec -= 1000000;
1369 		++tvp->tv_sec;
1370 	}
1371 }
1372 
1373 void
1374 nanotime(struct timespec *tsp)
1375 {
1376 	struct globaldata *gd = mycpu;
1377 	struct timespec *bt;
1378 	sysclock_t delta;
1379 
1380 	do {
1381 		tsp->tv_sec = gd->gd_time_seconds;
1382 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1383 	} while (tsp->tv_sec != gd->gd_time_seconds);
1384 
1385 	if (delta >= sys_cputimer->freq) {
1386 		tsp->tv_sec += delta / sys_cputimer->freq;
1387 		delta %= sys_cputimer->freq;
1388 	}
1389 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1390 
1391 	bt = &basetime[basetime_index];
1392 	cpu_lfence();
1393 	tsp->tv_sec += bt->tv_sec;
1394 	tsp->tv_nsec += bt->tv_nsec;
1395 	while (tsp->tv_nsec >= 1000000000) {
1396 		tsp->tv_nsec -= 1000000000;
1397 		++tsp->tv_sec;
1398 	}
1399 }
1400 
1401 /*
1402  * Get an approximate time_t.  It does not have to be accurate.  This
1403  * function is called only from KTR and can be called with the system in
1404  * any state so do not use a critical section or other complex operation
1405  * here.
1406  *
1407  * NOTE: This is not exactly synchronized with real time.  To do that we
1408  *	 would have to do what microtime does and check for a nanoseconds
1409  *	 overflow.
1410  */
1411 time_t
1412 get_approximate_time_t(void)
1413 {
1414 	struct globaldata *gd = mycpu;
1415 	struct timespec *bt;
1416 
1417 	bt = &basetime[basetime_index];
1418 	return(gd->gd_time_seconds + bt->tv_sec);
1419 }
1420 
1421 int
1422 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1423 {
1424 	pps_params_t *app;
1425 	struct pps_fetch_args *fapi;
1426 #ifdef PPS_SYNC
1427 	struct pps_kcbind_args *kapi;
1428 #endif
1429 
1430 	switch (cmd) {
1431 	case PPS_IOC_CREATE:
1432 		return (0);
1433 	case PPS_IOC_DESTROY:
1434 		return (0);
1435 	case PPS_IOC_SETPARAMS:
1436 		app = (pps_params_t *)data;
1437 		if (app->mode & ~pps->ppscap)
1438 			return (EINVAL);
1439 		pps->ppsparam = *app;
1440 		return (0);
1441 	case PPS_IOC_GETPARAMS:
1442 		app = (pps_params_t *)data;
1443 		*app = pps->ppsparam;
1444 		app->api_version = PPS_API_VERS_1;
1445 		return (0);
1446 	case PPS_IOC_GETCAP:
1447 		*(int*)data = pps->ppscap;
1448 		return (0);
1449 	case PPS_IOC_FETCH:
1450 		fapi = (struct pps_fetch_args *)data;
1451 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1452 			return (EINVAL);
1453 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1454 			return (EOPNOTSUPP);
1455 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1456 		fapi->pps_info_buf = pps->ppsinfo;
1457 		return (0);
1458 	case PPS_IOC_KCBIND:
1459 #ifdef PPS_SYNC
1460 		kapi = (struct pps_kcbind_args *)data;
1461 		/* XXX Only root should be able to do this */
1462 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1463 			return (EINVAL);
1464 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1465 			return (EINVAL);
1466 		if (kapi->edge & ~pps->ppscap)
1467 			return (EINVAL);
1468 		pps->kcmode = kapi->edge;
1469 		return (0);
1470 #else
1471 		return (EOPNOTSUPP);
1472 #endif
1473 	default:
1474 		return (ENOTTY);
1475 	}
1476 }
1477 
1478 void
1479 pps_init(struct pps_state *pps)
1480 {
1481 	pps->ppscap |= PPS_TSFMT_TSPEC;
1482 	if (pps->ppscap & PPS_CAPTUREASSERT)
1483 		pps->ppscap |= PPS_OFFSETASSERT;
1484 	if (pps->ppscap & PPS_CAPTURECLEAR)
1485 		pps->ppscap |= PPS_OFFSETCLEAR;
1486 }
1487 
1488 void
1489 pps_event(struct pps_state *pps, sysclock_t count, int event)
1490 {
1491 	struct globaldata *gd;
1492 	struct timespec *tsp;
1493 	struct timespec *osp;
1494 	struct timespec *bt;
1495 	struct timespec ts;
1496 	sysclock_t *pcount;
1497 #ifdef PPS_SYNC
1498 	sysclock_t tcount;
1499 #endif
1500 	sysclock_t delta;
1501 	pps_seq_t *pseq;
1502 	int foff;
1503 #ifdef PPS_SYNC
1504 	int fhard;
1505 #endif
1506 	int ni;
1507 
1508 	gd = mycpu;
1509 
1510 	/* Things would be easier with arrays... */
1511 	if (event == PPS_CAPTUREASSERT) {
1512 		tsp = &pps->ppsinfo.assert_timestamp;
1513 		osp = &pps->ppsparam.assert_offset;
1514 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1515 #ifdef PPS_SYNC
1516 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1517 #endif
1518 		pcount = &pps->ppscount[0];
1519 		pseq = &pps->ppsinfo.assert_sequence;
1520 	} else {
1521 		tsp = &pps->ppsinfo.clear_timestamp;
1522 		osp = &pps->ppsparam.clear_offset;
1523 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1524 #ifdef PPS_SYNC
1525 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1526 #endif
1527 		pcount = &pps->ppscount[1];
1528 		pseq = &pps->ppsinfo.clear_sequence;
1529 	}
1530 
1531 	/* Nothing really happened */
1532 	if (*pcount == count)
1533 		return;
1534 
1535 	*pcount = count;
1536 
1537 	do {
1538 		ts.tv_sec = gd->gd_time_seconds;
1539 		delta = count - gd->gd_cpuclock_base;
1540 	} while (ts.tv_sec != gd->gd_time_seconds);
1541 
1542 	if (delta >= sys_cputimer->freq) {
1543 		ts.tv_sec += delta / sys_cputimer->freq;
1544 		delta %= sys_cputimer->freq;
1545 	}
1546 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1547 	ni = basetime_index;
1548 	cpu_lfence();
1549 	bt = &basetime[ni];
1550 	ts.tv_sec += bt->tv_sec;
1551 	ts.tv_nsec += bt->tv_nsec;
1552 	while (ts.tv_nsec >= 1000000000) {
1553 		ts.tv_nsec -= 1000000000;
1554 		++ts.tv_sec;
1555 	}
1556 
1557 	(*pseq)++;
1558 	*tsp = ts;
1559 
1560 	if (foff) {
1561 		timespecadd(tsp, osp);
1562 		if (tsp->tv_nsec < 0) {
1563 			tsp->tv_nsec += 1000000000;
1564 			tsp->tv_sec -= 1;
1565 		}
1566 	}
1567 #ifdef PPS_SYNC
1568 	if (fhard) {
1569 		/* magic, at its best... */
1570 		tcount = count - pps->ppscount[2];
1571 		pps->ppscount[2] = count;
1572 		if (tcount >= sys_cputimer->freq) {
1573 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1574 				 sys_cputimer->freq64_nsec *
1575 				 (tcount % sys_cputimer->freq)) >> 32;
1576 		} else {
1577 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1578 		}
1579 		hardpps(tsp, delta);
1580 	}
1581 #endif
1582 }
1583 
1584 /*
1585  * Return the tsc target value for a delay of (ns).
1586  *
1587  * Returns -1 if the TSC is not supported.
1588  */
1589 int64_t
1590 tsc_get_target(int ns)
1591 {
1592 #if defined(_RDTSC_SUPPORTED_)
1593 	if (cpu_feature & CPUID_TSC) {
1594 		return (rdtsc() + tsc_frequency * ns / (int64_t)1000000000);
1595 	}
1596 #endif
1597 	return(-1);
1598 }
1599 
1600 /*
1601  * Compare the tsc against the passed target
1602  *
1603  * Returns +1 if the target has been reached
1604  * Returns  0 if the target has not yet been reached
1605  * Returns -1 if the TSC is not supported.
1606  *
1607  * Typical use:		while (tsc_test_target(target) == 0) { ...poll... }
1608  */
1609 int
1610 tsc_test_target(int64_t target)
1611 {
1612 #if defined(_RDTSC_SUPPORTED_)
1613 	if (cpu_feature & CPUID_TSC) {
1614 		if ((int64_t)(target - rdtsc()) <= 0)
1615 			return(1);
1616 		return(0);
1617 	}
1618 #endif
1619 	return(-1);
1620 }
1621 
1622 /*
1623  * Delay the specified number of nanoseconds using the tsc.  This function
1624  * returns immediately if the TSC is not supported.  At least one cpu_pause()
1625  * will be issued.
1626  */
1627 void
1628 tsc_delay(int ns)
1629 {
1630 	int64_t clk;
1631 
1632 	clk = tsc_get_target(ns);
1633 	cpu_pause();
1634 	while (tsc_test_target(clk) == 0)
1635 		cpu_pause();
1636 }
1637