xref: /dragonfly/sys/kern/kern_clock.c (revision 73d83e2b)
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[CPUSTATES] = {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 		} else if (gd->gd_flags & GDF_VIRTUSER) {
833 			/*
834 			 * The vkernel doesn't do a good job providing trap
835 			 * frames that we can test.  If the GDF_VIRTUSER
836 			 * flag is set we probably interrupted user mode.
837 			 *
838 			 * We also use this flag on the host when entering
839 			 * VMM mode.
840 			 */
841 			td->td_uticks += bump;
842 
843 			/*
844 			 * Charge the time as appropriate
845 			 */
846 			if (p && p->p_nice > NZERO)
847 				cpu_time.cp_nice += bump;
848 			else
849 				cpu_time.cp_user += bump;
850 		} else {
851 			td->td_sticks += bump;
852 			if (td == &gd->gd_idlethread) {
853 				/*
854 				 * Token contention can cause us to mis-count
855 				 * a contended as idle, but it doesn't work
856 				 * properly for VKERNELs so just test on a
857 				 * real kernel.
858 				 */
859 #ifdef _KERNEL_VIRTUAL
860 				cpu_time.cp_idle += bump;
861 #else
862 				if (mycpu->gd_reqflags & RQF_IDLECHECK_WK_MASK)
863 					cpu_time.cp_sys += bump;
864 				else
865 					cpu_time.cp_idle += bump;
866 #endif
867 			} else {
868 				/*
869 				 * System thread was running.
870 				 */
871 #ifdef DEBUG_PCTRACK
872 				if (frame)
873 					do_pctrack(frame, PCTRACK_SYS);
874 #endif
875 				cpu_time.cp_sys += bump;
876 			}
877 		}
878 
879 #undef IS_INTR_RUNNING
880 	}
881 }
882 
883 #ifdef DEBUG_PCTRACK
884 /*
885  * Sample the PC when in the kernel or in an interrupt.  User code can
886  * retrieve the information and generate a histogram or other output.
887  */
888 
889 static void
890 do_pctrack(struct intrframe *frame, int which)
891 {
892 	struct kinfo_pctrack *pctrack;
893 
894 	pctrack = &cputime_pctrack[mycpu->gd_cpuid][which];
895 	pctrack->pc_array[pctrack->pc_index & PCTRACK_ARYMASK] =
896 		(void *)CLKF_PC(frame);
897 	++pctrack->pc_index;
898 }
899 
900 static int
901 sysctl_pctrack(SYSCTL_HANDLER_ARGS)
902 {
903 	struct kinfo_pcheader head;
904 	int error;
905 	int cpu;
906 	int ntrack;
907 
908 	head.pc_ntrack = PCTRACK_SIZE;
909 	head.pc_arysize = PCTRACK_ARYSIZE;
910 
911 	if ((error = SYSCTL_OUT(req, &head, sizeof(head))) != 0)
912 		return (error);
913 
914 	for (cpu = 0; cpu < ncpus; ++cpu) {
915 		for (ntrack = 0; ntrack < PCTRACK_SIZE; ++ntrack) {
916 			error = SYSCTL_OUT(req, &cputime_pctrack[cpu][ntrack],
917 					   sizeof(struct kinfo_pctrack));
918 			if (error)
919 				break;
920 		}
921 		if (error)
922 			break;
923 	}
924 	return (error);
925 }
926 SYSCTL_PROC(_kern, OID_AUTO, pctrack, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
927 	sysctl_pctrack, "S,kinfo_pcheader", "CPU PC tracking");
928 
929 #endif
930 
931 /*
932  * The scheduler clock typically runs at a 50Hz rate.  NOTE! systimer,
933  * the MP lock might not be held.  We can safely manipulate parts of curproc
934  * but that's about it.
935  *
936  * Each cpu has its own scheduler clock.
937  */
938 static void
939 schedclock(systimer_t info, int in_ipi __unused, struct intrframe *frame)
940 {
941 	struct lwp *lp;
942 	struct rusage *ru;
943 	struct vmspace *vm;
944 	long rss;
945 
946 	if ((lp = lwkt_preempted_proc()) != NULL) {
947 		/*
948 		 * Account for cpu time used and hit the scheduler.  Note
949 		 * that this call MUST BE MP SAFE, and the BGL IS NOT HELD
950 		 * HERE.
951 		 */
952 		++lp->lwp_cpticks;
953 		usched_schedulerclock(lp, info->periodic, info->time);
954 	} else {
955 		usched_schedulerclock(NULL, info->periodic, info->time);
956 	}
957 	if ((lp = curthread->td_lwp) != NULL) {
958 		/*
959 		 * Update resource usage integrals and maximums.
960 		 */
961 		if ((ru = &lp->lwp_proc->p_ru) &&
962 		    (vm = lp->lwp_proc->p_vmspace) != NULL) {
963 			ru->ru_ixrss += pgtok(vm->vm_tsize);
964 			ru->ru_idrss += pgtok(vm->vm_dsize);
965 			ru->ru_isrss += pgtok(vm->vm_ssize);
966 			if (lwkt_trytoken(&vm->vm_map.token)) {
967 				rss = pgtok(vmspace_resident_count(vm));
968 				if (ru->ru_maxrss < rss)
969 					ru->ru_maxrss = rss;
970 				lwkt_reltoken(&vm->vm_map.token);
971 			}
972 		}
973 	}
974 	/* Increment the global sched_ticks */
975 	if (mycpu->gd_cpuid == 0)
976 		++sched_ticks;
977 }
978 
979 /*
980  * Compute number of ticks for the specified amount of time.  The
981  * return value is intended to be used in a clock interrupt timed
982  * operation and guaranteed to meet or exceed the requested time.
983  * If the representation overflows, return INT_MAX.  The minimum return
984  * value is 1 ticks and the function will average the calculation up.
985  * If any value greater then 0 microseconds is supplied, a value
986  * of at least 2 will be returned to ensure that a near-term clock
987  * interrupt does not cause the timeout to occur (degenerately) early.
988  *
989  * Note that limit checks must take into account microseconds, which is
990  * done simply by using the smaller signed long maximum instead of
991  * the unsigned long maximum.
992  *
993  * If ints have 32 bits, then the maximum value for any timeout in
994  * 10ms ticks is 248 days.
995  */
996 int
997 tvtohz_high(struct timeval *tv)
998 {
999 	int ticks;
1000 	long sec, usec;
1001 
1002 	sec = tv->tv_sec;
1003 	usec = tv->tv_usec;
1004 	if (usec < 0) {
1005 		sec--;
1006 		usec += 1000000;
1007 	}
1008 	if (sec < 0) {
1009 #ifdef DIAGNOSTIC
1010 		if (usec > 0) {
1011 			sec++;
1012 			usec -= 1000000;
1013 		}
1014 		kprintf("tvtohz_high: negative time difference "
1015 			"%ld sec %ld usec\n",
1016 			sec, usec);
1017 #endif
1018 		ticks = 1;
1019 	} else if (sec <= INT_MAX / hz) {
1020 		ticks = (int)(sec * hz +
1021 			    ((u_long)usec + (ustick - 1)) / ustick) + 1;
1022 	} else {
1023 		ticks = INT_MAX;
1024 	}
1025 	return (ticks);
1026 }
1027 
1028 int
1029 tstohz_high(struct timespec *ts)
1030 {
1031 	int ticks;
1032 	long sec, nsec;
1033 
1034 	sec = ts->tv_sec;
1035 	nsec = ts->tv_nsec;
1036 	if (nsec < 0) {
1037 		sec--;
1038 		nsec += 1000000000;
1039 	}
1040 	if (sec < 0) {
1041 #ifdef DIAGNOSTIC
1042 		if (nsec > 0) {
1043 			sec++;
1044 			nsec -= 1000000000;
1045 		}
1046 		kprintf("tstohz_high: negative time difference "
1047 			"%ld sec %ld nsec\n",
1048 			sec, nsec);
1049 #endif
1050 		ticks = 1;
1051 	} else if (sec <= INT_MAX / hz) {
1052 		ticks = (int)(sec * hz +
1053 			    ((u_long)nsec + (nstick - 1)) / nstick) + 1;
1054 	} else {
1055 		ticks = INT_MAX;
1056 	}
1057 	return (ticks);
1058 }
1059 
1060 
1061 /*
1062  * Compute number of ticks for the specified amount of time, erroring on
1063  * the side of it being too low to ensure that sleeping the returned number
1064  * of ticks will not result in a late return.
1065  *
1066  * The supplied timeval may not be negative and should be normalized.  A
1067  * return value of 0 is possible if the timeval converts to less then
1068  * 1 tick.
1069  *
1070  * If ints have 32 bits, then the maximum value for any timeout in
1071  * 10ms ticks is 248 days.
1072  */
1073 int
1074 tvtohz_low(struct timeval *tv)
1075 {
1076 	int ticks;
1077 	long sec;
1078 
1079 	sec = tv->tv_sec;
1080 	if (sec <= INT_MAX / hz)
1081 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / ustick);
1082 	else
1083 		ticks = INT_MAX;
1084 	return (ticks);
1085 }
1086 
1087 int
1088 tstohz_low(struct timespec *ts)
1089 {
1090 	int ticks;
1091 	long sec;
1092 
1093 	sec = ts->tv_sec;
1094 	if (sec <= INT_MAX / hz)
1095 		ticks = (int)(sec * hz + (u_long)ts->tv_nsec / nstick);
1096 	else
1097 		ticks = INT_MAX;
1098 	return (ticks);
1099 }
1100 
1101 /*
1102  * Start profiling on a process.
1103  *
1104  * Caller must hold p->p_token();
1105  *
1106  * Kernel profiling passes proc0 which never exits and hence
1107  * keeps the profile clock running constantly.
1108  */
1109 void
1110 startprofclock(struct proc *p)
1111 {
1112 	if ((p->p_flags & P_PROFIL) == 0) {
1113 		p->p_flags |= P_PROFIL;
1114 #if 0	/* XXX */
1115 		if (++profprocs == 1 && stathz != 0) {
1116 			crit_enter();
1117 			psdiv = psratio;
1118 			setstatclockrate(profhz);
1119 			crit_exit();
1120 		}
1121 #endif
1122 	}
1123 }
1124 
1125 /*
1126  * Stop profiling on a process.
1127  *
1128  * caller must hold p->p_token
1129  */
1130 void
1131 stopprofclock(struct proc *p)
1132 {
1133 	if (p->p_flags & P_PROFIL) {
1134 		p->p_flags &= ~P_PROFIL;
1135 #if 0	/* XXX */
1136 		if (--profprocs == 0 && stathz != 0) {
1137 			crit_enter();
1138 			psdiv = 1;
1139 			setstatclockrate(stathz);
1140 			crit_exit();
1141 		}
1142 #endif
1143 	}
1144 }
1145 
1146 /*
1147  * Return information about system clocks.
1148  */
1149 static int
1150 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
1151 {
1152 	struct kinfo_clockinfo clkinfo;
1153 	/*
1154 	 * Construct clockinfo structure.
1155 	 */
1156 	clkinfo.ci_hz = hz;
1157 	clkinfo.ci_tick = ustick;
1158 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
1159 	clkinfo.ci_profhz = profhz;
1160 	clkinfo.ci_stathz = stathz ? stathz : hz;
1161 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
1162 }
1163 
1164 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
1165 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
1166 
1167 /*
1168  * We have eight functions for looking at the clock, four for
1169  * microseconds and four for nanoseconds.  For each there is fast
1170  * but less precise version "get{nano|micro}[up]time" which will
1171  * return a time which is up to 1/HZ previous to the call, whereas
1172  * the raw version "{nano|micro}[up]time" will return a timestamp
1173  * which is as precise as possible.  The "up" variants return the
1174  * time relative to system boot, these are well suited for time
1175  * interval measurements.
1176  *
1177  * Each cpu independently maintains the current time of day, so all
1178  * we need to do to protect ourselves from changes is to do a loop
1179  * check on the seconds field changing out from under us.
1180  *
1181  * The system timer maintains a 32 bit count and due to various issues
1182  * it is possible for the calculated delta to occasionally exceed
1183  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
1184  * multiplication can easily overflow, so we deal with the case.  For
1185  * uniformity we deal with the case in the usec case too.
1186  *
1187  * All the [get][micro,nano][time,uptime]() routines are MPSAFE.
1188  */
1189 void
1190 getmicrouptime(struct timeval *tvp)
1191 {
1192 	struct globaldata *gd = mycpu;
1193 	sysclock_t delta;
1194 
1195 	do {
1196 		tvp->tv_sec = gd->gd_time_seconds;
1197 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1198 	} while (tvp->tv_sec != gd->gd_time_seconds);
1199 
1200 	if (delta >= sys_cputimer->freq) {
1201 		tvp->tv_sec += delta / sys_cputimer->freq;
1202 		delta %= sys_cputimer->freq;
1203 	}
1204 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1205 	if (tvp->tv_usec >= 1000000) {
1206 		tvp->tv_usec -= 1000000;
1207 		++tvp->tv_sec;
1208 	}
1209 }
1210 
1211 void
1212 getnanouptime(struct timespec *tsp)
1213 {
1214 	struct globaldata *gd = mycpu;
1215 	sysclock_t delta;
1216 
1217 	do {
1218 		tsp->tv_sec = gd->gd_time_seconds;
1219 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1220 	} while (tsp->tv_sec != gd->gd_time_seconds);
1221 
1222 	if (delta >= sys_cputimer->freq) {
1223 		tsp->tv_sec += delta / sys_cputimer->freq;
1224 		delta %= sys_cputimer->freq;
1225 	}
1226 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1227 }
1228 
1229 void
1230 microuptime(struct timeval *tvp)
1231 {
1232 	struct globaldata *gd = mycpu;
1233 	sysclock_t delta;
1234 
1235 	do {
1236 		tvp->tv_sec = gd->gd_time_seconds;
1237 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1238 	} while (tvp->tv_sec != gd->gd_time_seconds);
1239 
1240 	if (delta >= sys_cputimer->freq) {
1241 		tvp->tv_sec += delta / sys_cputimer->freq;
1242 		delta %= sys_cputimer->freq;
1243 	}
1244 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1245 }
1246 
1247 void
1248 nanouptime(struct timespec *tsp)
1249 {
1250 	struct globaldata *gd = mycpu;
1251 	sysclock_t delta;
1252 
1253 	do {
1254 		tsp->tv_sec = gd->gd_time_seconds;
1255 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1256 	} while (tsp->tv_sec != gd->gd_time_seconds);
1257 
1258 	if (delta >= sys_cputimer->freq) {
1259 		tsp->tv_sec += delta / sys_cputimer->freq;
1260 		delta %= sys_cputimer->freq;
1261 	}
1262 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1263 }
1264 
1265 /*
1266  * realtime routines
1267  */
1268 void
1269 getmicrotime(struct timeval *tvp)
1270 {
1271 	struct globaldata *gd = mycpu;
1272 	struct timespec *bt;
1273 	sysclock_t delta;
1274 
1275 	do {
1276 		tvp->tv_sec = gd->gd_time_seconds;
1277 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1278 	} while (tvp->tv_sec != gd->gd_time_seconds);
1279 
1280 	if (delta >= sys_cputimer->freq) {
1281 		tvp->tv_sec += delta / sys_cputimer->freq;
1282 		delta %= sys_cputimer->freq;
1283 	}
1284 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1285 
1286 	bt = &basetime[basetime_index];
1287 	cpu_lfence();
1288 	tvp->tv_sec += bt->tv_sec;
1289 	tvp->tv_usec += bt->tv_nsec / 1000;
1290 	while (tvp->tv_usec >= 1000000) {
1291 		tvp->tv_usec -= 1000000;
1292 		++tvp->tv_sec;
1293 	}
1294 }
1295 
1296 void
1297 getnanotime(struct timespec *tsp)
1298 {
1299 	struct globaldata *gd = mycpu;
1300 	struct timespec *bt;
1301 	sysclock_t delta;
1302 
1303 	do {
1304 		tsp->tv_sec = gd->gd_time_seconds;
1305 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1306 	} while (tsp->tv_sec != gd->gd_time_seconds);
1307 
1308 	if (delta >= sys_cputimer->freq) {
1309 		tsp->tv_sec += delta / sys_cputimer->freq;
1310 		delta %= sys_cputimer->freq;
1311 	}
1312 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1313 
1314 	bt = &basetime[basetime_index];
1315 	cpu_lfence();
1316 	tsp->tv_sec += bt->tv_sec;
1317 	tsp->tv_nsec += bt->tv_nsec;
1318 	while (tsp->tv_nsec >= 1000000000) {
1319 		tsp->tv_nsec -= 1000000000;
1320 		++tsp->tv_sec;
1321 	}
1322 }
1323 
1324 static void
1325 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
1326 {
1327 	struct globaldata *gd = mycpu;
1328 	sysclock_t delta;
1329 
1330 	do {
1331 		tsp->tv_sec = gd->gd_time_seconds;
1332 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1333 	} while (tsp->tv_sec != gd->gd_time_seconds);
1334 
1335 	if (delta >= sys_cputimer->freq) {
1336 		tsp->tv_sec += delta / sys_cputimer->freq;
1337 		delta %= sys_cputimer->freq;
1338 	}
1339 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1340 
1341 	tsp->tv_sec += nbt->tv_sec;
1342 	tsp->tv_nsec += nbt->tv_nsec;
1343 	while (tsp->tv_nsec >= 1000000000) {
1344 		tsp->tv_nsec -= 1000000000;
1345 		++tsp->tv_sec;
1346 	}
1347 }
1348 
1349 
1350 void
1351 microtime(struct timeval *tvp)
1352 {
1353 	struct globaldata *gd = mycpu;
1354 	struct timespec *bt;
1355 	sysclock_t delta;
1356 
1357 	do {
1358 		tvp->tv_sec = gd->gd_time_seconds;
1359 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1360 	} while (tvp->tv_sec != gd->gd_time_seconds);
1361 
1362 	if (delta >= sys_cputimer->freq) {
1363 		tvp->tv_sec += delta / sys_cputimer->freq;
1364 		delta %= sys_cputimer->freq;
1365 	}
1366 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1367 
1368 	bt = &basetime[basetime_index];
1369 	cpu_lfence();
1370 	tvp->tv_sec += bt->tv_sec;
1371 	tvp->tv_usec += bt->tv_nsec / 1000;
1372 	while (tvp->tv_usec >= 1000000) {
1373 		tvp->tv_usec -= 1000000;
1374 		++tvp->tv_sec;
1375 	}
1376 }
1377 
1378 void
1379 nanotime(struct timespec *tsp)
1380 {
1381 	struct globaldata *gd = mycpu;
1382 	struct timespec *bt;
1383 	sysclock_t delta;
1384 
1385 	do {
1386 		tsp->tv_sec = gd->gd_time_seconds;
1387 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1388 	} while (tsp->tv_sec != gd->gd_time_seconds);
1389 
1390 	if (delta >= sys_cputimer->freq) {
1391 		tsp->tv_sec += delta / sys_cputimer->freq;
1392 		delta %= sys_cputimer->freq;
1393 	}
1394 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1395 
1396 	bt = &basetime[basetime_index];
1397 	cpu_lfence();
1398 	tsp->tv_sec += bt->tv_sec;
1399 	tsp->tv_nsec += bt->tv_nsec;
1400 	while (tsp->tv_nsec >= 1000000000) {
1401 		tsp->tv_nsec -= 1000000000;
1402 		++tsp->tv_sec;
1403 	}
1404 }
1405 
1406 /*
1407  * Get an approximate time_t.  It does not have to be accurate.  This
1408  * function is called only from KTR and can be called with the system in
1409  * any state so do not use a critical section or other complex operation
1410  * here.
1411  *
1412  * NOTE: This is not exactly synchronized with real time.  To do that we
1413  *	 would have to do what microtime does and check for a nanoseconds
1414  *	 overflow.
1415  */
1416 time_t
1417 get_approximate_time_t(void)
1418 {
1419 	struct globaldata *gd = mycpu;
1420 	struct timespec *bt;
1421 
1422 	bt = &basetime[basetime_index];
1423 	return(gd->gd_time_seconds + bt->tv_sec);
1424 }
1425 
1426 int
1427 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1428 {
1429 	pps_params_t *app;
1430 	struct pps_fetch_args *fapi;
1431 #ifdef PPS_SYNC
1432 	struct pps_kcbind_args *kapi;
1433 #endif
1434 
1435 	switch (cmd) {
1436 	case PPS_IOC_CREATE:
1437 		return (0);
1438 	case PPS_IOC_DESTROY:
1439 		return (0);
1440 	case PPS_IOC_SETPARAMS:
1441 		app = (pps_params_t *)data;
1442 		if (app->mode & ~pps->ppscap)
1443 			return (EINVAL);
1444 		pps->ppsparam = *app;
1445 		return (0);
1446 	case PPS_IOC_GETPARAMS:
1447 		app = (pps_params_t *)data;
1448 		*app = pps->ppsparam;
1449 		app->api_version = PPS_API_VERS_1;
1450 		return (0);
1451 	case PPS_IOC_GETCAP:
1452 		*(int*)data = pps->ppscap;
1453 		return (0);
1454 	case PPS_IOC_FETCH:
1455 		fapi = (struct pps_fetch_args *)data;
1456 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1457 			return (EINVAL);
1458 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1459 			return (EOPNOTSUPP);
1460 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1461 		fapi->pps_info_buf = pps->ppsinfo;
1462 		return (0);
1463 	case PPS_IOC_KCBIND:
1464 #ifdef PPS_SYNC
1465 		kapi = (struct pps_kcbind_args *)data;
1466 		/* XXX Only root should be able to do this */
1467 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1468 			return (EINVAL);
1469 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1470 			return (EINVAL);
1471 		if (kapi->edge & ~pps->ppscap)
1472 			return (EINVAL);
1473 		pps->kcmode = kapi->edge;
1474 		return (0);
1475 #else
1476 		return (EOPNOTSUPP);
1477 #endif
1478 	default:
1479 		return (ENOTTY);
1480 	}
1481 }
1482 
1483 void
1484 pps_init(struct pps_state *pps)
1485 {
1486 	pps->ppscap |= PPS_TSFMT_TSPEC;
1487 	if (pps->ppscap & PPS_CAPTUREASSERT)
1488 		pps->ppscap |= PPS_OFFSETASSERT;
1489 	if (pps->ppscap & PPS_CAPTURECLEAR)
1490 		pps->ppscap |= PPS_OFFSETCLEAR;
1491 }
1492 
1493 void
1494 pps_event(struct pps_state *pps, sysclock_t count, int event)
1495 {
1496 	struct globaldata *gd;
1497 	struct timespec *tsp;
1498 	struct timespec *osp;
1499 	struct timespec *bt;
1500 	struct timespec ts;
1501 	sysclock_t *pcount;
1502 #ifdef PPS_SYNC
1503 	sysclock_t tcount;
1504 #endif
1505 	sysclock_t delta;
1506 	pps_seq_t *pseq;
1507 	int foff;
1508 #ifdef PPS_SYNC
1509 	int fhard;
1510 #endif
1511 	int ni;
1512 
1513 	gd = mycpu;
1514 
1515 	/* Things would be easier with arrays... */
1516 	if (event == PPS_CAPTUREASSERT) {
1517 		tsp = &pps->ppsinfo.assert_timestamp;
1518 		osp = &pps->ppsparam.assert_offset;
1519 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1520 #ifdef PPS_SYNC
1521 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1522 #endif
1523 		pcount = &pps->ppscount[0];
1524 		pseq = &pps->ppsinfo.assert_sequence;
1525 	} else {
1526 		tsp = &pps->ppsinfo.clear_timestamp;
1527 		osp = &pps->ppsparam.clear_offset;
1528 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1529 #ifdef PPS_SYNC
1530 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1531 #endif
1532 		pcount = &pps->ppscount[1];
1533 		pseq = &pps->ppsinfo.clear_sequence;
1534 	}
1535 
1536 	/* Nothing really happened */
1537 	if (*pcount == count)
1538 		return;
1539 
1540 	*pcount = count;
1541 
1542 	do {
1543 		ts.tv_sec = gd->gd_time_seconds;
1544 		delta = count - gd->gd_cpuclock_base;
1545 	} while (ts.tv_sec != gd->gd_time_seconds);
1546 
1547 	if (delta >= sys_cputimer->freq) {
1548 		ts.tv_sec += delta / sys_cputimer->freq;
1549 		delta %= sys_cputimer->freq;
1550 	}
1551 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1552 	ni = basetime_index;
1553 	cpu_lfence();
1554 	bt = &basetime[ni];
1555 	ts.tv_sec += bt->tv_sec;
1556 	ts.tv_nsec += bt->tv_nsec;
1557 	while (ts.tv_nsec >= 1000000000) {
1558 		ts.tv_nsec -= 1000000000;
1559 		++ts.tv_sec;
1560 	}
1561 
1562 	(*pseq)++;
1563 	*tsp = ts;
1564 
1565 	if (foff) {
1566 		timespecadd(tsp, osp);
1567 		if (tsp->tv_nsec < 0) {
1568 			tsp->tv_nsec += 1000000000;
1569 			tsp->tv_sec -= 1;
1570 		}
1571 	}
1572 #ifdef PPS_SYNC
1573 	if (fhard) {
1574 		/* magic, at its best... */
1575 		tcount = count - pps->ppscount[2];
1576 		pps->ppscount[2] = count;
1577 		if (tcount >= sys_cputimer->freq) {
1578 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1579 				 sys_cputimer->freq64_nsec *
1580 				 (tcount % sys_cputimer->freq)) >> 32;
1581 		} else {
1582 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1583 		}
1584 		hardpps(tsp, delta);
1585 	}
1586 #endif
1587 }
1588 
1589 /*
1590  * Return the tsc target value for a delay of (ns).
1591  *
1592  * Returns -1 if the TSC is not supported.
1593  */
1594 int64_t
1595 tsc_get_target(int ns)
1596 {
1597 #if defined(_RDTSC_SUPPORTED_)
1598 	if (cpu_feature & CPUID_TSC) {
1599 		return (rdtsc() + tsc_frequency * ns / (int64_t)1000000000);
1600 	}
1601 #endif
1602 	return(-1);
1603 }
1604 
1605 /*
1606  * Compare the tsc against the passed target
1607  *
1608  * Returns +1 if the target has been reached
1609  * Returns  0 if the target has not yet been reached
1610  * Returns -1 if the TSC is not supported.
1611  *
1612  * Typical use:		while (tsc_test_target(target) == 0) { ...poll... }
1613  */
1614 int
1615 tsc_test_target(int64_t target)
1616 {
1617 #if defined(_RDTSC_SUPPORTED_)
1618 	if (cpu_feature & CPUID_TSC) {
1619 		if ((int64_t)(target - rdtsc()) <= 0)
1620 			return(1);
1621 		return(0);
1622 	}
1623 #endif
1624 	return(-1);
1625 }
1626 
1627 /*
1628  * Delay the specified number of nanoseconds using the tsc.  This function
1629  * returns immediately if the TSC is not supported.  At least one cpu_pause()
1630  * will be issued.
1631  */
1632 void
1633 tsc_delay(int ns)
1634 {
1635 	int64_t clk;
1636 
1637 	clk = tsc_get_target(ns);
1638 	cpu_pause();
1639 	while (tsc_test_target(clk) == 0)
1640 		cpu_pause();
1641 }
1642