xref: /dflybsd-src/sys/kern/kern_clock.c (revision 475c7069e94570a897d1467613efd2b3f0212ff9)
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/mplock2.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 
275 /*
276  * Finish initializing clock frequencies and start all clocks running.
277  */
278 /* ARGSUSED*/
279 static void
280 initclocks(void *dummy)
281 {
282 	/*psratio = profhz / stathz;*/
283 	initclocks_pcpu();
284 	clocks_running = 1;
285 	if (kpmap) {
286 	    kpmap->tsc_freq = (uint64_t)tsc_frequency;
287 	    kpmap->tick_freq = hz;
288 	}
289 }
290 
291 /*
292  * Called on a per-cpu basis from the idle thread bootstrap on each cpu
293  * during SMP initialization.
294  *
295  * This routine is called concurrently during low-level SMP initialization
296  * and may not block in any way.  Meaning, among other things, we can't
297  * acquire any tokens.
298  */
299 void
300 initclocks_pcpu(void)
301 {
302 	struct globaldata *gd = mycpu;
303 
304 	crit_enter();
305 	if (gd->gd_cpuid == 0) {
306 	    gd->gd_time_seconds = 1;
307 	    gd->gd_cpuclock_base = sys_cputimer->count();
308 	    hardtime[0].time_second = gd->gd_time_seconds;
309 	    hardtime[0].cpuclock_base = gd->gd_cpuclock_base;
310 	} else {
311 	    gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
312 	    gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
313 	}
314 
315 	systimer_intr_enable();
316 
317 	crit_exit();
318 }
319 
320 /*
321  * This routine is called on just the BSP, just after SMP initialization
322  * completes to * finish initializing any clocks that might contend/block
323  * (e.g. like on a token).  We can't do this in initclocks_pcpu() because
324  * that function is called from the idle thread bootstrap for each cpu and
325  * not allowed to block at all.
326  */
327 static
328 void
329 initclocks_other(void *dummy)
330 {
331 	struct globaldata *ogd = mycpu;
332 	struct globaldata *gd;
333 	int n;
334 
335 	for (n = 0; n < ncpus; ++n) {
336 		lwkt_setcpu_self(globaldata_find(n));
337 		gd = mycpu;
338 
339 		/*
340 		 * Use a non-queued periodic systimer to prevent multiple
341 		 * ticks from building up if the sysclock jumps forward
342 		 * (8254 gets reset).  The sysclock will never jump backwards.
343 		 * Our time sync is based on the actual sysclock, not the
344 		 * ticks count.
345 		 */
346 		systimer_init_periodic_nq(&gd->gd_hardclock, hardclock,
347 					  NULL, hz);
348 		systimer_init_periodic_nq(&gd->gd_statclock, statclock,
349 					  NULL, stathz);
350 		/* XXX correct the frequency for scheduler / estcpu tests */
351 		systimer_init_periodic_nq(&gd->gd_schedclock, schedclock,
352 					  NULL, ESTCPUFREQ);
353 #ifdef IFPOLL_ENABLE
354 		ifpoll_init_pcpu(gd->gd_cpuid);
355 #endif
356 	}
357 	lwkt_setcpu_self(ogd);
358 }
359 SYSINIT(clocks2, SI_BOOT2_POST_SMP, SI_ORDER_ANY, initclocks_other, NULL);
360 
361 /*
362  * This sets the current real time of day.  Timespecs are in seconds and
363  * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
364  * instead we adjust basetime so basetime + gd_* results in the current
365  * time of day.  This way the gd_* fields are guaranteed to represent
366  * a monotonically increasing 'uptime' value.
367  *
368  * When set_timeofday() is called from userland, the system call forces it
369  * onto cpu #0 since only cpu #0 can update basetime_index.
370  */
371 void
372 set_timeofday(struct timespec *ts)
373 {
374 	struct timespec *nbt;
375 	int ni;
376 
377 	/*
378 	 * XXX SMP / non-atomic basetime updates
379 	 */
380 	crit_enter();
381 	ni = (basetime_index + 1) & BASETIME_ARYMASK;
382 	cpu_lfence();
383 	nbt = &basetime[ni];
384 	nanouptime(nbt);
385 	nbt->tv_sec = ts->tv_sec - nbt->tv_sec;
386 	nbt->tv_nsec = ts->tv_nsec - nbt->tv_nsec;
387 	if (nbt->tv_nsec < 0) {
388 	    nbt->tv_nsec += 1000000000;
389 	    --nbt->tv_sec;
390 	}
391 
392 	/*
393 	 * Note that basetime diverges from boottime as the clock drift is
394 	 * compensated for, so we cannot do away with boottime.  When setting
395 	 * the absolute time of day the drift is 0 (for an instant) and we
396 	 * can simply assign boottime to basetime.
397 	 *
398 	 * Note that nanouptime() is based on gd_time_seconds which is drift
399 	 * compensated up to a point (it is guaranteed to remain monotonically
400 	 * increasing).  gd_time_seconds is thus our best uptime guess and
401 	 * suitable for use in the boottime calculation.  It is already taken
402 	 * into account in the basetime calculation above.
403 	 */
404 	boottime.tv_sec = nbt->tv_sec;
405 	ntp_delta = 0;
406 
407 	/*
408 	 * We now have a new basetime, make sure all other cpus have it,
409 	 * then update the index.
410 	 */
411 	cpu_sfence();
412 	basetime_index = ni;
413 
414 	crit_exit();
415 }
416 
417 /*
418  * Each cpu has its own hardclock, but we only increments ticks and softticks
419  * on cpu #0.
420  *
421  * NOTE! systimer! the MP lock might not be held here.  We can only safely
422  * manipulate objects owned by the current cpu.
423  */
424 static void
425 hardclock(systimer_t info, int in_ipi, struct intrframe *frame)
426 {
427 	sysclock_t cputicks;
428 	struct proc *p;
429 	struct globaldata *gd = mycpu;
430 
431 	if ((gd->gd_reqflags & RQF_IPIQ) == 0 && lwkt_need_ipiq_process(gd)) {
432 		/* Defer to doreti on passive IPIQ processing */
433 		need_ipiq();
434 	}
435 
436 	/*
437 	 * We update the compensation base to calculate fine-grained time
438 	 * from the sys_cputimer on a per-cpu basis in order to avoid
439 	 * having to mess around with locks.  sys_cputimer is assumed to
440 	 * be consistent across all cpus.  CPU N copies the base state from
441 	 * CPU 0 using the same FIFO trick that we use for basetime (so we
442 	 * don't catch a CPU 0 update in the middle).
443 	 *
444 	 * Note that we never allow info->time (aka gd->gd_hardclock.time)
445 	 * to reverse index gd_cpuclock_base, but that it is possible for
446 	 * it to temporarily get behind in the seconds if something in the
447 	 * system locks interrupts for a long period of time.  Since periodic
448 	 * timers count events, though everything should resynch again
449 	 * immediately.
450 	 */
451 	if (gd->gd_cpuid == 0) {
452 		int ni;
453 
454 		cputicks = info->time - gd->gd_cpuclock_base;
455 		if (cputicks >= sys_cputimer->freq) {
456 			cputicks /= sys_cputimer->freq;
457 			if (cputicks != 0 && cputicks != 1)
458 				kprintf("Warning: hardclock missed > 1 sec\n");
459 			gd->gd_time_seconds += cputicks;
460 			gd->gd_cpuclock_base += sys_cputimer->freq * cputicks;
461 			/* uncorrected monotonic 1-sec gran */
462 			time_uptime += cputicks;
463 		}
464 		ni = (basetime_index + 1) & BASETIME_ARYMASK;
465 		hardtime[ni].time_second = gd->gd_time_seconds;
466 		hardtime[ni].cpuclock_base = gd->gd_cpuclock_base;
467 	} else {
468 		int ni;
469 
470 		ni = basetime_index;
471 		cpu_lfence();
472 		gd->gd_time_seconds = hardtime[ni].time_second;
473 		gd->gd_cpuclock_base = hardtime[ni].cpuclock_base;
474 	}
475 
476 	/*
477 	 * The system-wide ticks counter and NTP related timedelta/tickdelta
478 	 * adjustments only occur on cpu #0.  NTP adjustments are accomplished
479 	 * by updating basetime.
480 	 */
481 	if (gd->gd_cpuid == 0) {
482 	    struct timespec *nbt;
483 	    struct timespec nts;
484 	    int leap;
485 	    int ni;
486 
487 	    ++ticks;
488 
489 #if 0
490 	    if (tco->tc_poll_pps)
491 		tco->tc_poll_pps(tco);
492 #endif
493 
494 	    /*
495 	     * Calculate the new basetime index.  We are in a critical section
496 	     * on cpu #0 and can safely play with basetime_index.  Start
497 	     * with the current basetime and then make adjustments.
498 	     */
499 	    ni = (basetime_index + 1) & BASETIME_ARYMASK;
500 	    nbt = &basetime[ni];
501 	    *nbt = basetime[basetime_index];
502 
503 	    /*
504 	     * Apply adjtime corrections.  (adjtime() API)
505 	     *
506 	     * adjtime() only runs on cpu #0 so our critical section is
507 	     * sufficient to access these variables.
508 	     */
509 	    if (ntp_delta != 0) {
510 		nbt->tv_nsec += ntp_tick_delta;
511 		ntp_delta -= ntp_tick_delta;
512 		if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
513 		    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
514 			ntp_tick_delta = ntp_delta;
515  		}
516  	    }
517 
518 	    /*
519 	     * Apply permanent frequency corrections.  (sysctl API)
520 	     */
521 	    if (ntp_tick_permanent != 0) {
522 		ntp_tick_acc += ntp_tick_permanent;
523 		if (ntp_tick_acc >= (1LL << 32)) {
524 		    nbt->tv_nsec += ntp_tick_acc >> 32;
525 		    ntp_tick_acc -= (ntp_tick_acc >> 32) << 32;
526 		} else if (ntp_tick_acc <= -(1LL << 32)) {
527 		    /* Negate ntp_tick_acc to avoid shifting the sign bit. */
528 		    nbt->tv_nsec -= (-ntp_tick_acc) >> 32;
529 		    ntp_tick_acc += ((-ntp_tick_acc) >> 32) << 32;
530 		}
531  	    }
532 
533 	    if (nbt->tv_nsec >= 1000000000) {
534 		    nbt->tv_sec++;
535 		    nbt->tv_nsec -= 1000000000;
536 	    } else if (nbt->tv_nsec < 0) {
537 		    nbt->tv_sec--;
538 		    nbt->tv_nsec += 1000000000;
539 	    }
540 
541 	    /*
542 	     * Another per-tick compensation.  (for ntp_adjtime() API)
543 	     */
544 	    if (nsec_adj != 0) {
545 		nsec_acc += nsec_adj;
546 		if (nsec_acc >= 0x100000000LL) {
547 		    nbt->tv_nsec += nsec_acc >> 32;
548 		    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
549 		} else if (nsec_acc <= -0x100000000LL) {
550 		    nbt->tv_nsec -= -nsec_acc >> 32;
551 		    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
552 		}
553 		if (nbt->tv_nsec >= 1000000000) {
554 		    nbt->tv_nsec -= 1000000000;
555 		    ++nbt->tv_sec;
556 		} else if (nbt->tv_nsec < 0) {
557 		    nbt->tv_nsec += 1000000000;
558 		    --nbt->tv_sec;
559 		}
560 	    }
561 
562 	    /************************************************************
563 	     *			LEAP SECOND CORRECTION			*
564 	     ************************************************************
565 	     *
566 	     * Taking into account all the corrections made above, figure
567 	     * out the new real time.  If the seconds field has changed
568 	     * then apply any pending leap-second corrections.
569 	     */
570 	    getnanotime_nbt(nbt, &nts);
571 
572 	    if (time_second != nts.tv_sec) {
573 		/*
574 		 * Apply leap second (sysctl API).  Adjust nts for changes
575 		 * so we do not have to call getnanotime_nbt again.
576 		 */
577 		if (ntp_leap_second) {
578 		    if (ntp_leap_second == nts.tv_sec) {
579 			if (ntp_leap_insert) {
580 			    nbt->tv_sec++;
581 			    nts.tv_sec++;
582 			} else {
583 			    nbt->tv_sec--;
584 			    nts.tv_sec--;
585 			}
586 			ntp_leap_second--;
587 		    }
588 		}
589 
590 		/*
591 		 * Apply leap second (ntp_adjtime() API), calculate a new
592 		 * nsec_adj field.  ntp_update_second() returns nsec_adj
593 		 * as a per-second value but we need it as a per-tick value.
594 		 */
595 		leap = ntp_update_second(time_second, &nsec_adj);
596 		nsec_adj /= hz;
597 		nbt->tv_sec += leap;
598 		nts.tv_sec += leap;
599 
600 		/*
601 		 * Update the time_second 'approximate time' global.
602 		 */
603 		time_second = nts.tv_sec;
604 	    }
605 
606 	    /*
607 	     * Finally, our new basetime is ready to go live!
608 	     */
609 	    cpu_sfence();
610 	    basetime_index = ni;
611 
612 	    /*
613 	     * Update kpmap on each tick.  TS updates are integrated with
614 	     * fences and upticks allowing userland to read the data
615 	     * deterministically.
616 	     */
617 	    if (kpmap) {
618 		int w;
619 
620 		w = (kpmap->upticks + 1) & 1;
621 		getnanouptime(&kpmap->ts_uptime[w]);
622 		getnanotime(&kpmap->ts_realtime[w]);
623 		cpu_sfence();
624 		++kpmap->upticks;
625 		cpu_sfence();
626 	    }
627 	}
628 
629 	/*
630 	 * lwkt thread scheduler fair queueing
631 	 */
632 	lwkt_schedulerclock(curthread);
633 
634 	/*
635 	 * softticks are handled for all cpus
636 	 */
637 	hardclock_softtick(gd);
638 
639 	/*
640 	 * Rollup accumulated vmstats, copy-back for critical path checks.
641 	 */
642 	vmstats_rollup_cpu(gd);
643 	mycpu->gd_vmstats = vmstats;
644 
645 	/*
646 	 * ITimer handling is per-tick, per-cpu.
647 	 *
648 	 * We must acquire the per-process token in order for ksignal()
649 	 * to be non-blocking.  For the moment this requires an AST fault,
650 	 * the ksignal() cannot be safely issued from this hard interrupt.
651 	 *
652 	 * XXX Even the trytoken here isn't right, and itimer operation in
653 	 *     a multi threaded environment is going to be weird at the
654 	 *     very least.
655 	 */
656 	if ((p = curproc) != NULL && lwkt_trytoken(&p->p_token)) {
657 		crit_enter_hard();
658 		if (p->p_upmap)
659 			++p->p_upmap->runticks;
660 
661 		if (frame && CLKF_USERMODE(frame) &&
662 		    timevalisset(&p->p_timer[ITIMER_VIRTUAL].it_value) &&
663 		    itimerdecr(&p->p_timer[ITIMER_VIRTUAL], ustick) == 0) {
664 			p->p_flags |= P_SIGVTALRM;
665 			need_user_resched();
666 		}
667 		if (timevalisset(&p->p_timer[ITIMER_PROF].it_value) &&
668 		    itimerdecr(&p->p_timer[ITIMER_PROF], ustick) == 0) {
669 			p->p_flags |= P_SIGPROF;
670 			need_user_resched();
671 		}
672 		crit_exit_hard();
673 		lwkt_reltoken(&p->p_token);
674 	}
675 	setdelayed();
676 }
677 
678 /*
679  * The statistics clock typically runs at a 125Hz rate, and is intended
680  * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
681  *
682  * NOTE! systimer! the MP lock might not be held here.  We can only safely
683  * manipulate objects owned by the current cpu.
684  *
685  * The stats clock is responsible for grabbing a profiling sample.
686  * Most of the statistics are only used by user-level statistics programs.
687  * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
688  * p->p_estcpu.
689  *
690  * Like the other clocks, the stat clock is called from what is effectively
691  * a fast interrupt, so the context should be the thread/process that got
692  * interrupted.
693  */
694 static void
695 statclock(systimer_t info, int in_ipi, struct intrframe *frame)
696 {
697 #ifdef GPROF
698 	struct gmonparam *g;
699 	int i;
700 #endif
701 	thread_t td;
702 	struct proc *p;
703 	int bump;
704 	sysclock_t cv;
705 	sysclock_t scv;
706 
707 	/*
708 	 * How big was our timeslice relative to the last time?  Calculate
709 	 * in microseconds.
710 	 *
711 	 * NOTE: Use of microuptime() is typically MPSAFE, but usually not
712 	 *	 during early boot.  Just use the systimer count to be nice
713 	 *	 to e.g. qemu.  The systimer has a better chance of being
714 	 *	 MPSAFE at early boot.
715 	 */
716 	cv = sys_cputimer->count();
717 	scv = mycpu->statint.gd_statcv;
718 	if (scv == 0) {
719 		bump = 1;
720 	} else {
721 		bump = (sys_cputimer->freq64_usec * (cv - scv)) >> 32;
722 		if (bump < 0)
723 			bump = 0;
724 		if (bump > 1000000)
725 			bump = 1000000;
726 	}
727 	mycpu->statint.gd_statcv = cv;
728 
729 #if 0
730 	stv = &mycpu->gd_stattv;
731 	if (stv->tv_sec == 0) {
732 	    bump = 1;
733 	} else {
734 	    bump = tv.tv_usec - stv->tv_usec +
735 		(tv.tv_sec - stv->tv_sec) * 1000000;
736 	    if (bump < 0)
737 		bump = 0;
738 	    if (bump > 1000000)
739 		bump = 1000000;
740 	}
741 	*stv = tv;
742 #endif
743 
744 	td = curthread;
745 	p = td->td_proc;
746 
747 	if (frame && CLKF_USERMODE(frame)) {
748 		/*
749 		 * Came from userland, handle user time and deal with
750 		 * possible process.
751 		 */
752 		if (p && (p->p_flags & P_PROFIL))
753 			addupc_intr(p, CLKF_PC(frame), 1);
754 		td->td_uticks += bump;
755 
756 		/*
757 		 * Charge the time as appropriate
758 		 */
759 		if (p && p->p_nice > NZERO)
760 			cpu_time.cp_nice += bump;
761 		else
762 			cpu_time.cp_user += bump;
763 	} else {
764 		int intr_nest = mycpu->gd_intr_nesting_level;
765 
766 		if (in_ipi) {
767 			/*
768 			 * IPI processing code will bump gd_intr_nesting_level
769 			 * up by one, which breaks following CLKF_INTR testing,
770 			 * so we subtract it by one here.
771 			 */
772 			--intr_nest;
773 		}
774 #ifdef GPROF
775 		/*
776 		 * Kernel statistics are just like addupc_intr, only easier.
777 		 */
778 		g = &_gmonparam;
779 		if (g->state == GMON_PROF_ON && frame) {
780 			i = CLKF_PC(frame) - g->lowpc;
781 			if (i < g->textsize) {
782 				i /= HISTFRACTION * sizeof(*g->kcount);
783 				g->kcount[i]++;
784 			}
785 		}
786 #endif
787 
788 #define IS_INTR_RUNNING	((frame && CLKF_INTR(intr_nest)) || CLKF_INTR_TD(td))
789 
790 		/*
791 		 * Came from kernel mode, so we were:
792 		 * - handling an interrupt,
793 		 * - doing syscall or trap work on behalf of the current
794 		 *   user process, or
795 		 * - spinning in the idle loop.
796 		 * Whichever it is, charge the time as appropriate.
797 		 * Note that we charge interrupts to the current process,
798 		 * regardless of whether they are ``for'' that process,
799 		 * so that we know how much of its real time was spent
800 		 * in ``non-process'' (i.e., interrupt) work.
801 		 *
802 		 * XXX assume system if frame is NULL.  A NULL frame
803 		 * can occur if ipi processing is done from a crit_exit().
804 		 */
805 		if (IS_INTR_RUNNING)
806 			td->td_iticks += bump;
807 		else
808 			td->td_sticks += bump;
809 
810 		if (IS_INTR_RUNNING) {
811 			/*
812 			 * If we interrupted an interrupt thread, well,
813 			 * count it as interrupt time.
814 			 */
815 #ifdef DEBUG_PCTRACK
816 			if (frame)
817 				do_pctrack(frame, PCTRACK_INT);
818 #endif
819 			cpu_time.cp_intr += bump;
820 		} else {
821 			if (td == &mycpu->gd_idlethread) {
822 				/*
823 				 * Even if the current thread is the idle
824 				 * thread it could be due to token contention
825 				 * in the LWKT scheduler.  Count such as
826 				 * system time.
827 				 */
828 				if (mycpu->gd_reqflags & RQF_IDLECHECK_WK_MASK)
829 					cpu_time.cp_sys += bump;
830 				else
831 					cpu_time.cp_idle += bump;
832 			} else {
833 				/*
834 				 * System thread was running.
835 				 */
836 #ifdef DEBUG_PCTRACK
837 				if (frame)
838 					do_pctrack(frame, PCTRACK_SYS);
839 #endif
840 				cpu_time.cp_sys += bump;
841 			}
842 		}
843 
844 #undef IS_INTR_RUNNING
845 	}
846 }
847 
848 #ifdef DEBUG_PCTRACK
849 /*
850  * Sample the PC when in the kernel or in an interrupt.  User code can
851  * retrieve the information and generate a histogram or other output.
852  */
853 
854 static void
855 do_pctrack(struct intrframe *frame, int which)
856 {
857 	struct kinfo_pctrack *pctrack;
858 
859 	pctrack = &cputime_pctrack[mycpu->gd_cpuid][which];
860 	pctrack->pc_array[pctrack->pc_index & PCTRACK_ARYMASK] =
861 		(void *)CLKF_PC(frame);
862 	++pctrack->pc_index;
863 }
864 
865 static int
866 sysctl_pctrack(SYSCTL_HANDLER_ARGS)
867 {
868 	struct kinfo_pcheader head;
869 	int error;
870 	int cpu;
871 	int ntrack;
872 
873 	head.pc_ntrack = PCTRACK_SIZE;
874 	head.pc_arysize = PCTRACK_ARYSIZE;
875 
876 	if ((error = SYSCTL_OUT(req, &head, sizeof(head))) != 0)
877 		return (error);
878 
879 	for (cpu = 0; cpu < ncpus; ++cpu) {
880 		for (ntrack = 0; ntrack < PCTRACK_SIZE; ++ntrack) {
881 			error = SYSCTL_OUT(req, &cputime_pctrack[cpu][ntrack],
882 					   sizeof(struct kinfo_pctrack));
883 			if (error)
884 				break;
885 		}
886 		if (error)
887 			break;
888 	}
889 	return (error);
890 }
891 SYSCTL_PROC(_kern, OID_AUTO, pctrack, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
892 	sysctl_pctrack, "S,kinfo_pcheader", "CPU PC tracking");
893 
894 #endif
895 
896 /*
897  * The scheduler clock typically runs at a 50Hz rate.  NOTE! systimer,
898  * the MP lock might not be held.  We can safely manipulate parts of curproc
899  * but that's about it.
900  *
901  * Each cpu has its own scheduler clock.
902  */
903 static void
904 schedclock(systimer_t info, int in_ipi __unused, struct intrframe *frame)
905 {
906 	struct lwp *lp;
907 	struct rusage *ru;
908 	struct vmspace *vm;
909 	long rss;
910 
911 	if ((lp = lwkt_preempted_proc()) != NULL) {
912 		/*
913 		 * Account for cpu time used and hit the scheduler.  Note
914 		 * that this call MUST BE MP SAFE, and the BGL IS NOT HELD
915 		 * HERE.
916 		 */
917 		++lp->lwp_cpticks;
918 		usched_schedulerclock(lp, info->periodic, info->time);
919 	} else {
920 		usched_schedulerclock(NULL, info->periodic, info->time);
921 	}
922 	if ((lp = curthread->td_lwp) != NULL) {
923 		/*
924 		 * Update resource usage integrals and maximums.
925 		 */
926 		if ((ru = &lp->lwp_proc->p_ru) &&
927 		    (vm = lp->lwp_proc->p_vmspace) != NULL) {
928 			ru->ru_ixrss += pgtok(vm->vm_tsize);
929 			ru->ru_idrss += pgtok(vm->vm_dsize);
930 			ru->ru_isrss += pgtok(vm->vm_ssize);
931 			if (lwkt_trytoken(&vm->vm_map.token)) {
932 				rss = pgtok(vmspace_resident_count(vm));
933 				if (ru->ru_maxrss < rss)
934 					ru->ru_maxrss = rss;
935 				lwkt_reltoken(&vm->vm_map.token);
936 			}
937 		}
938 	}
939 	/* Increment the global sched_ticks */
940 	if (mycpu->gd_cpuid == 0)
941 		++sched_ticks;
942 }
943 
944 /*
945  * Compute number of ticks for the specified amount of time.  The
946  * return value is intended to be used in a clock interrupt timed
947  * operation and guaranteed to meet or exceed the requested time.
948  * If the representation overflows, return INT_MAX.  The minimum return
949  * value is 1 ticks and the function will average the calculation up.
950  * If any value greater then 0 microseconds is supplied, a value
951  * of at least 2 will be returned to ensure that a near-term clock
952  * interrupt does not cause the timeout to occur (degenerately) early.
953  *
954  * Note that limit checks must take into account microseconds, which is
955  * done simply by using the smaller signed long maximum instead of
956  * the unsigned long maximum.
957  *
958  * If ints have 32 bits, then the maximum value for any timeout in
959  * 10ms ticks is 248 days.
960  */
961 int
962 tvtohz_high(struct timeval *tv)
963 {
964 	int ticks;
965 	long sec, usec;
966 
967 	sec = tv->tv_sec;
968 	usec = tv->tv_usec;
969 	if (usec < 0) {
970 		sec--;
971 		usec += 1000000;
972 	}
973 	if (sec < 0) {
974 #ifdef DIAGNOSTIC
975 		if (usec > 0) {
976 			sec++;
977 			usec -= 1000000;
978 		}
979 		kprintf("tvtohz_high: negative time difference "
980 			"%ld sec %ld usec\n",
981 			sec, usec);
982 #endif
983 		ticks = 1;
984 	} else if (sec <= INT_MAX / hz) {
985 		ticks = (int)(sec * hz +
986 			    ((u_long)usec + (ustick - 1)) / ustick) + 1;
987 	} else {
988 		ticks = INT_MAX;
989 	}
990 	return (ticks);
991 }
992 
993 int
994 tstohz_high(struct timespec *ts)
995 {
996 	int ticks;
997 	long sec, nsec;
998 
999 	sec = ts->tv_sec;
1000 	nsec = ts->tv_nsec;
1001 	if (nsec < 0) {
1002 		sec--;
1003 		nsec += 1000000000;
1004 	}
1005 	if (sec < 0) {
1006 #ifdef DIAGNOSTIC
1007 		if (nsec > 0) {
1008 			sec++;
1009 			nsec -= 1000000000;
1010 		}
1011 		kprintf("tstohz_high: negative time difference "
1012 			"%ld sec %ld nsec\n",
1013 			sec, nsec);
1014 #endif
1015 		ticks = 1;
1016 	} else if (sec <= INT_MAX / hz) {
1017 		ticks = (int)(sec * hz +
1018 			    ((u_long)nsec + (nstick - 1)) / nstick) + 1;
1019 	} else {
1020 		ticks = INT_MAX;
1021 	}
1022 	return (ticks);
1023 }
1024 
1025 
1026 /*
1027  * Compute number of ticks for the specified amount of time, erroring on
1028  * the side of it being too low to ensure that sleeping the returned number
1029  * of ticks will not result in a late return.
1030  *
1031  * The supplied timeval may not be negative and should be normalized.  A
1032  * return value of 0 is possible if the timeval converts to less then
1033  * 1 tick.
1034  *
1035  * If ints have 32 bits, then the maximum value for any timeout in
1036  * 10ms ticks is 248 days.
1037  */
1038 int
1039 tvtohz_low(struct timeval *tv)
1040 {
1041 	int ticks;
1042 	long sec;
1043 
1044 	sec = tv->tv_sec;
1045 	if (sec <= INT_MAX / hz)
1046 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / ustick);
1047 	else
1048 		ticks = INT_MAX;
1049 	return (ticks);
1050 }
1051 
1052 int
1053 tstohz_low(struct timespec *ts)
1054 {
1055 	int ticks;
1056 	long sec;
1057 
1058 	sec = ts->tv_sec;
1059 	if (sec <= INT_MAX / hz)
1060 		ticks = (int)(sec * hz + (u_long)ts->tv_nsec / nstick);
1061 	else
1062 		ticks = INT_MAX;
1063 	return (ticks);
1064 }
1065 
1066 /*
1067  * Start profiling on a process.
1068  *
1069  * Kernel profiling passes proc0 which never exits and hence
1070  * keeps the profile clock running constantly.
1071  */
1072 void
1073 startprofclock(struct proc *p)
1074 {
1075 	if ((p->p_flags & P_PROFIL) == 0) {
1076 		p->p_flags |= P_PROFIL;
1077 #if 0	/* XXX */
1078 		if (++profprocs == 1 && stathz != 0) {
1079 			crit_enter();
1080 			psdiv = psratio;
1081 			setstatclockrate(profhz);
1082 			crit_exit();
1083 		}
1084 #endif
1085 	}
1086 }
1087 
1088 /*
1089  * Stop profiling on a process.
1090  *
1091  * caller must hold p->p_token
1092  */
1093 void
1094 stopprofclock(struct proc *p)
1095 {
1096 	if (p->p_flags & P_PROFIL) {
1097 		p->p_flags &= ~P_PROFIL;
1098 #if 0	/* XXX */
1099 		if (--profprocs == 0 && stathz != 0) {
1100 			crit_enter();
1101 			psdiv = 1;
1102 			setstatclockrate(stathz);
1103 			crit_exit();
1104 		}
1105 #endif
1106 	}
1107 }
1108 
1109 /*
1110  * Return information about system clocks.
1111  */
1112 static int
1113 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
1114 {
1115 	struct kinfo_clockinfo clkinfo;
1116 	/*
1117 	 * Construct clockinfo structure.
1118 	 */
1119 	clkinfo.ci_hz = hz;
1120 	clkinfo.ci_tick = ustick;
1121 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
1122 	clkinfo.ci_profhz = profhz;
1123 	clkinfo.ci_stathz = stathz ? stathz : hz;
1124 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
1125 }
1126 
1127 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
1128 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
1129 
1130 /*
1131  * We have eight functions for looking at the clock, four for
1132  * microseconds and four for nanoseconds.  For each there is fast
1133  * but less precise version "get{nano|micro}[up]time" which will
1134  * return a time which is up to 1/HZ previous to the call, whereas
1135  * the raw version "{nano|micro}[up]time" will return a timestamp
1136  * which is as precise as possible.  The "up" variants return the
1137  * time relative to system boot, these are well suited for time
1138  * interval measurements.
1139  *
1140  * Each cpu independently maintains the current time of day, so all
1141  * we need to do to protect ourselves from changes is to do a loop
1142  * check on the seconds field changing out from under us.
1143  *
1144  * The system timer maintains a 32 bit count and due to various issues
1145  * it is possible for the calculated delta to occasionally exceed
1146  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
1147  * multiplication can easily overflow, so we deal with the case.  For
1148  * uniformity we deal with the case in the usec case too.
1149  *
1150  * All the [get][micro,nano][time,uptime]() routines are MPSAFE.
1151  */
1152 void
1153 getmicrouptime(struct timeval *tvp)
1154 {
1155 	struct globaldata *gd = mycpu;
1156 	sysclock_t delta;
1157 
1158 	do {
1159 		tvp->tv_sec = gd->gd_time_seconds;
1160 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1161 	} while (tvp->tv_sec != gd->gd_time_seconds);
1162 
1163 	if (delta >= sys_cputimer->freq) {
1164 		tvp->tv_sec += delta / sys_cputimer->freq;
1165 		delta %= sys_cputimer->freq;
1166 	}
1167 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1168 	if (tvp->tv_usec >= 1000000) {
1169 		tvp->tv_usec -= 1000000;
1170 		++tvp->tv_sec;
1171 	}
1172 }
1173 
1174 void
1175 getnanouptime(struct timespec *tsp)
1176 {
1177 	struct globaldata *gd = mycpu;
1178 	sysclock_t delta;
1179 
1180 	do {
1181 		tsp->tv_sec = gd->gd_time_seconds;
1182 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1183 	} while (tsp->tv_sec != gd->gd_time_seconds);
1184 
1185 	if (delta >= sys_cputimer->freq) {
1186 		tsp->tv_sec += delta / sys_cputimer->freq;
1187 		delta %= sys_cputimer->freq;
1188 	}
1189 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1190 }
1191 
1192 void
1193 microuptime(struct timeval *tvp)
1194 {
1195 	struct globaldata *gd = mycpu;
1196 	sysclock_t delta;
1197 
1198 	do {
1199 		tvp->tv_sec = gd->gd_time_seconds;
1200 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1201 	} while (tvp->tv_sec != gd->gd_time_seconds);
1202 
1203 	if (delta >= sys_cputimer->freq) {
1204 		tvp->tv_sec += delta / sys_cputimer->freq;
1205 		delta %= sys_cputimer->freq;
1206 	}
1207 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1208 }
1209 
1210 void
1211 nanouptime(struct timespec *tsp)
1212 {
1213 	struct globaldata *gd = mycpu;
1214 	sysclock_t delta;
1215 
1216 	do {
1217 		tsp->tv_sec = gd->gd_time_seconds;
1218 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1219 	} while (tsp->tv_sec != gd->gd_time_seconds);
1220 
1221 	if (delta >= sys_cputimer->freq) {
1222 		tsp->tv_sec += delta / sys_cputimer->freq;
1223 		delta %= sys_cputimer->freq;
1224 	}
1225 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1226 }
1227 
1228 /*
1229  * realtime routines
1230  */
1231 void
1232 getmicrotime(struct timeval *tvp)
1233 {
1234 	struct globaldata *gd = mycpu;
1235 	struct timespec *bt;
1236 	sysclock_t delta;
1237 
1238 	do {
1239 		tvp->tv_sec = gd->gd_time_seconds;
1240 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1241 	} while (tvp->tv_sec != gd->gd_time_seconds);
1242 
1243 	if (delta >= sys_cputimer->freq) {
1244 		tvp->tv_sec += delta / sys_cputimer->freq;
1245 		delta %= sys_cputimer->freq;
1246 	}
1247 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1248 
1249 	bt = &basetime[basetime_index];
1250 	cpu_lfence();
1251 	tvp->tv_sec += bt->tv_sec;
1252 	tvp->tv_usec += bt->tv_nsec / 1000;
1253 	while (tvp->tv_usec >= 1000000) {
1254 		tvp->tv_usec -= 1000000;
1255 		++tvp->tv_sec;
1256 	}
1257 }
1258 
1259 void
1260 getnanotime(struct timespec *tsp)
1261 {
1262 	struct globaldata *gd = mycpu;
1263 	struct timespec *bt;
1264 	sysclock_t delta;
1265 
1266 	do {
1267 		tsp->tv_sec = gd->gd_time_seconds;
1268 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1269 	} while (tsp->tv_sec != gd->gd_time_seconds);
1270 
1271 	if (delta >= sys_cputimer->freq) {
1272 		tsp->tv_sec += delta / sys_cputimer->freq;
1273 		delta %= sys_cputimer->freq;
1274 	}
1275 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1276 
1277 	bt = &basetime[basetime_index];
1278 	cpu_lfence();
1279 	tsp->tv_sec += bt->tv_sec;
1280 	tsp->tv_nsec += bt->tv_nsec;
1281 	while (tsp->tv_nsec >= 1000000000) {
1282 		tsp->tv_nsec -= 1000000000;
1283 		++tsp->tv_sec;
1284 	}
1285 }
1286 
1287 static void
1288 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
1289 {
1290 	struct globaldata *gd = mycpu;
1291 	sysclock_t delta;
1292 
1293 	do {
1294 		tsp->tv_sec = gd->gd_time_seconds;
1295 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1296 	} while (tsp->tv_sec != gd->gd_time_seconds);
1297 
1298 	if (delta >= sys_cputimer->freq) {
1299 		tsp->tv_sec += delta / sys_cputimer->freq;
1300 		delta %= sys_cputimer->freq;
1301 	}
1302 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1303 
1304 	tsp->tv_sec += nbt->tv_sec;
1305 	tsp->tv_nsec += nbt->tv_nsec;
1306 	while (tsp->tv_nsec >= 1000000000) {
1307 		tsp->tv_nsec -= 1000000000;
1308 		++tsp->tv_sec;
1309 	}
1310 }
1311 
1312 
1313 void
1314 microtime(struct timeval *tvp)
1315 {
1316 	struct globaldata *gd = mycpu;
1317 	struct timespec *bt;
1318 	sysclock_t delta;
1319 
1320 	do {
1321 		tvp->tv_sec = gd->gd_time_seconds;
1322 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1323 	} while (tvp->tv_sec != gd->gd_time_seconds);
1324 
1325 	if (delta >= sys_cputimer->freq) {
1326 		tvp->tv_sec += delta / sys_cputimer->freq;
1327 		delta %= sys_cputimer->freq;
1328 	}
1329 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1330 
1331 	bt = &basetime[basetime_index];
1332 	cpu_lfence();
1333 	tvp->tv_sec += bt->tv_sec;
1334 	tvp->tv_usec += bt->tv_nsec / 1000;
1335 	while (tvp->tv_usec >= 1000000) {
1336 		tvp->tv_usec -= 1000000;
1337 		++tvp->tv_sec;
1338 	}
1339 }
1340 
1341 void
1342 nanotime(struct timespec *tsp)
1343 {
1344 	struct globaldata *gd = mycpu;
1345 	struct timespec *bt;
1346 	sysclock_t delta;
1347 
1348 	do {
1349 		tsp->tv_sec = gd->gd_time_seconds;
1350 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1351 	} while (tsp->tv_sec != gd->gd_time_seconds);
1352 
1353 	if (delta >= sys_cputimer->freq) {
1354 		tsp->tv_sec += delta / sys_cputimer->freq;
1355 		delta %= sys_cputimer->freq;
1356 	}
1357 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1358 
1359 	bt = &basetime[basetime_index];
1360 	cpu_lfence();
1361 	tsp->tv_sec += bt->tv_sec;
1362 	tsp->tv_nsec += bt->tv_nsec;
1363 	while (tsp->tv_nsec >= 1000000000) {
1364 		tsp->tv_nsec -= 1000000000;
1365 		++tsp->tv_sec;
1366 	}
1367 }
1368 
1369 /*
1370  * Get an approximate time_t.  It does not have to be accurate.  This
1371  * function is called only from KTR and can be called with the system in
1372  * any state so do not use a critical section or other complex operation
1373  * here.
1374  *
1375  * NOTE: This is not exactly synchronized with real time.  To do that we
1376  *	 would have to do what microtime does and check for a nanoseconds
1377  *	 overflow.
1378  */
1379 time_t
1380 get_approximate_time_t(void)
1381 {
1382 	struct globaldata *gd = mycpu;
1383 	struct timespec *bt;
1384 
1385 	bt = &basetime[basetime_index];
1386 	return(gd->gd_time_seconds + bt->tv_sec);
1387 }
1388 
1389 int
1390 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1391 {
1392 	pps_params_t *app;
1393 	struct pps_fetch_args *fapi;
1394 #ifdef PPS_SYNC
1395 	struct pps_kcbind_args *kapi;
1396 #endif
1397 
1398 	switch (cmd) {
1399 	case PPS_IOC_CREATE:
1400 		return (0);
1401 	case PPS_IOC_DESTROY:
1402 		return (0);
1403 	case PPS_IOC_SETPARAMS:
1404 		app = (pps_params_t *)data;
1405 		if (app->mode & ~pps->ppscap)
1406 			return (EINVAL);
1407 		pps->ppsparam = *app;
1408 		return (0);
1409 	case PPS_IOC_GETPARAMS:
1410 		app = (pps_params_t *)data;
1411 		*app = pps->ppsparam;
1412 		app->api_version = PPS_API_VERS_1;
1413 		return (0);
1414 	case PPS_IOC_GETCAP:
1415 		*(int*)data = pps->ppscap;
1416 		return (0);
1417 	case PPS_IOC_FETCH:
1418 		fapi = (struct pps_fetch_args *)data;
1419 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1420 			return (EINVAL);
1421 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1422 			return (EOPNOTSUPP);
1423 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1424 		fapi->pps_info_buf = pps->ppsinfo;
1425 		return (0);
1426 	case PPS_IOC_KCBIND:
1427 #ifdef PPS_SYNC
1428 		kapi = (struct pps_kcbind_args *)data;
1429 		/* XXX Only root should be able to do this */
1430 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1431 			return (EINVAL);
1432 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1433 			return (EINVAL);
1434 		if (kapi->edge & ~pps->ppscap)
1435 			return (EINVAL);
1436 		pps->kcmode = kapi->edge;
1437 		return (0);
1438 #else
1439 		return (EOPNOTSUPP);
1440 #endif
1441 	default:
1442 		return (ENOTTY);
1443 	}
1444 }
1445 
1446 void
1447 pps_init(struct pps_state *pps)
1448 {
1449 	pps->ppscap |= PPS_TSFMT_TSPEC;
1450 	if (pps->ppscap & PPS_CAPTUREASSERT)
1451 		pps->ppscap |= PPS_OFFSETASSERT;
1452 	if (pps->ppscap & PPS_CAPTURECLEAR)
1453 		pps->ppscap |= PPS_OFFSETCLEAR;
1454 }
1455 
1456 void
1457 pps_event(struct pps_state *pps, sysclock_t count, int event)
1458 {
1459 	struct globaldata *gd;
1460 	struct timespec *tsp;
1461 	struct timespec *osp;
1462 	struct timespec *bt;
1463 	struct timespec ts;
1464 	sysclock_t *pcount;
1465 #ifdef PPS_SYNC
1466 	sysclock_t tcount;
1467 #endif
1468 	sysclock_t delta;
1469 	pps_seq_t *pseq;
1470 	int foff;
1471 #ifdef PPS_SYNC
1472 	int fhard;
1473 #endif
1474 	int ni;
1475 
1476 	gd = mycpu;
1477 
1478 	/* Things would be easier with arrays... */
1479 	if (event == PPS_CAPTUREASSERT) {
1480 		tsp = &pps->ppsinfo.assert_timestamp;
1481 		osp = &pps->ppsparam.assert_offset;
1482 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1483 #ifdef PPS_SYNC
1484 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1485 #endif
1486 		pcount = &pps->ppscount[0];
1487 		pseq = &pps->ppsinfo.assert_sequence;
1488 	} else {
1489 		tsp = &pps->ppsinfo.clear_timestamp;
1490 		osp = &pps->ppsparam.clear_offset;
1491 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1492 #ifdef PPS_SYNC
1493 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1494 #endif
1495 		pcount = &pps->ppscount[1];
1496 		pseq = &pps->ppsinfo.clear_sequence;
1497 	}
1498 
1499 	/* Nothing really happened */
1500 	if (*pcount == count)
1501 		return;
1502 
1503 	*pcount = count;
1504 
1505 	do {
1506 		ts.tv_sec = gd->gd_time_seconds;
1507 		delta = count - gd->gd_cpuclock_base;
1508 	} while (ts.tv_sec != gd->gd_time_seconds);
1509 
1510 	if (delta >= sys_cputimer->freq) {
1511 		ts.tv_sec += delta / sys_cputimer->freq;
1512 		delta %= sys_cputimer->freq;
1513 	}
1514 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1515 	ni = basetime_index;
1516 	cpu_lfence();
1517 	bt = &basetime[ni];
1518 	ts.tv_sec += bt->tv_sec;
1519 	ts.tv_nsec += bt->tv_nsec;
1520 	while (ts.tv_nsec >= 1000000000) {
1521 		ts.tv_nsec -= 1000000000;
1522 		++ts.tv_sec;
1523 	}
1524 
1525 	(*pseq)++;
1526 	*tsp = ts;
1527 
1528 	if (foff) {
1529 		timespecadd(tsp, osp);
1530 		if (tsp->tv_nsec < 0) {
1531 			tsp->tv_nsec += 1000000000;
1532 			tsp->tv_sec -= 1;
1533 		}
1534 	}
1535 #ifdef PPS_SYNC
1536 	if (fhard) {
1537 		/* magic, at its best... */
1538 		tcount = count - pps->ppscount[2];
1539 		pps->ppscount[2] = count;
1540 		if (tcount >= sys_cputimer->freq) {
1541 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1542 				 sys_cputimer->freq64_nsec *
1543 				 (tcount % sys_cputimer->freq)) >> 32;
1544 		} else {
1545 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1546 		}
1547 		hardpps(tsp, delta);
1548 	}
1549 #endif
1550 }
1551 
1552 /*
1553  * Return the tsc target value for a delay of (ns).
1554  *
1555  * Returns -1 if the TSC is not supported.
1556  */
1557 int64_t
1558 tsc_get_target(int ns)
1559 {
1560 #if defined(_RDTSC_SUPPORTED_)
1561 	if (cpu_feature & CPUID_TSC) {
1562 		return (rdtsc() + tsc_frequency * ns / (int64_t)1000000000);
1563 	}
1564 #endif
1565 	return(-1);
1566 }
1567 
1568 /*
1569  * Compare the tsc against the passed target
1570  *
1571  * Returns +1 if the target has been reached
1572  * Returns  0 if the target has not yet been reached
1573  * Returns -1 if the TSC is not supported.
1574  *
1575  * Typical use:		while (tsc_test_target(target) == 0) { ...poll... }
1576  */
1577 int
1578 tsc_test_target(int64_t target)
1579 {
1580 #if defined(_RDTSC_SUPPORTED_)
1581 	if (cpu_feature & CPUID_TSC) {
1582 		if ((int64_t)(target - rdtsc()) <= 0)
1583 			return(1);
1584 		return(0);
1585 	}
1586 #endif
1587 	return(-1);
1588 }
1589 
1590 /*
1591  * Delay the specified number of nanoseconds using the tsc.  This function
1592  * returns immediately if the TSC is not supported.  At least one cpu_pause()
1593  * will be issued.
1594  */
1595 void
1596 tsc_delay(int ns)
1597 {
1598 	int64_t clk;
1599 
1600 	clk = tsc_get_target(ns);
1601 	cpu_pause();
1602 	while (tsc_test_target(clk) == 0)
1603 		cpu_pause();
1604 }
1605