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kern_clock.c revision 1.114.6.1
      1  1.114.6.1    bouyer /*	$NetBSD: kern_clock.c,v 1.114.6.1 2008/01/02 21:55:46 bouyer Exp $	*/
      2       1.52   thorpej 
      3       1.52   thorpej /*-
      4      1.106        ad  * Copyright (c) 2000, 2004, 2006, 2007 The NetBSD Foundation, Inc.
      5       1.52   thorpej  * All rights reserved.
      6       1.52   thorpej  *
      7       1.52   thorpej  * This code is derived from software contributed to The NetBSD Foundation
      8       1.52   thorpej  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9       1.52   thorpej  * NASA Ames Research Center.
     10       1.94   mycroft  * This code is derived from software contributed to The NetBSD Foundation
     11       1.94   mycroft  * by Charles M. Hannum.
     12       1.52   thorpej  *
     13       1.52   thorpej  * Redistribution and use in source and binary forms, with or without
     14       1.52   thorpej  * modification, are permitted provided that the following conditions
     15       1.52   thorpej  * are met:
     16       1.52   thorpej  * 1. Redistributions of source code must retain the above copyright
     17       1.52   thorpej  *    notice, this list of conditions and the following disclaimer.
     18       1.52   thorpej  * 2. Redistributions in binary form must reproduce the above copyright
     19       1.52   thorpej  *    notice, this list of conditions and the following disclaimer in the
     20       1.52   thorpej  *    documentation and/or other materials provided with the distribution.
     21       1.52   thorpej  * 3. All advertising materials mentioning features or use of this software
     22       1.52   thorpej  *    must display the following acknowledgement:
     23       1.52   thorpej  *	This product includes software developed by the NetBSD
     24       1.52   thorpej  *	Foundation, Inc. and its contributors.
     25       1.52   thorpej  * 4. Neither the name of The NetBSD Foundation nor the names of its
     26       1.52   thorpej  *    contributors may be used to endorse or promote products derived
     27       1.52   thorpej  *    from this software without specific prior written permission.
     28       1.52   thorpej  *
     29       1.52   thorpej  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     30       1.52   thorpej  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     31       1.52   thorpej  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     32       1.52   thorpej  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     33       1.52   thorpej  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     34       1.52   thorpej  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     35       1.52   thorpej  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     36       1.52   thorpej  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     37       1.52   thorpej  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     38       1.52   thorpej  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     39       1.52   thorpej  * POSSIBILITY OF SUCH DAMAGE.
     40       1.52   thorpej  */
     41       1.19       cgd 
     42       1.19       cgd /*-
     43       1.19       cgd  * Copyright (c) 1982, 1986, 1991, 1993
     44       1.19       cgd  *	The Regents of the University of California.  All rights reserved.
     45       1.19       cgd  * (c) UNIX System Laboratories, Inc.
     46       1.19       cgd  * All or some portions of this file are derived from material licensed
     47       1.19       cgd  * to the University of California by American Telephone and Telegraph
     48       1.19       cgd  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     49       1.19       cgd  * the permission of UNIX System Laboratories, Inc.
     50       1.19       cgd  *
     51       1.19       cgd  * Redistribution and use in source and binary forms, with or without
     52       1.19       cgd  * modification, are permitted provided that the following conditions
     53       1.19       cgd  * are met:
     54       1.19       cgd  * 1. Redistributions of source code must retain the above copyright
     55       1.19       cgd  *    notice, this list of conditions and the following disclaimer.
     56       1.19       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     57       1.19       cgd  *    notice, this list of conditions and the following disclaimer in the
     58       1.19       cgd  *    documentation and/or other materials provided with the distribution.
     59       1.87       agc  * 3. Neither the name of the University nor the names of its contributors
     60       1.19       cgd  *    may be used to endorse or promote products derived from this software
     61       1.19       cgd  *    without specific prior written permission.
     62       1.19       cgd  *
     63       1.19       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     64       1.19       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     65       1.19       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     66       1.19       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     67       1.19       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     68       1.19       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     69       1.19       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     70       1.19       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     71       1.19       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     72       1.19       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     73       1.19       cgd  * SUCH DAMAGE.
     74       1.19       cgd  *
     75       1.19       cgd  *	@(#)kern_clock.c	8.5 (Berkeley) 1/21/94
     76       1.19       cgd  */
     77       1.78     lukem 
     78       1.78     lukem #include <sys/cdefs.h>
     79  1.114.6.1    bouyer __KERNEL_RCSID(0, "$NetBSD: kern_clock.c,v 1.114.6.1 2008/01/02 21:55:46 bouyer Exp $");
     80       1.44  jonathan 
     81       1.44  jonathan #include "opt_ntp.h"
     82       1.86    martin #include "opt_multiprocessor.h"
     83       1.80    briggs #include "opt_perfctrs.h"
     84       1.19       cgd 
     85       1.19       cgd #include <sys/param.h>
     86       1.19       cgd #include <sys/systm.h>
     87       1.19       cgd #include <sys/callout.h>
     88       1.19       cgd #include <sys/kernel.h>
     89       1.19       cgd #include <sys/proc.h>
     90       1.19       cgd #include <sys/resourcevar.h>
     91       1.25  christos #include <sys/signalvar.h>
     92       1.26  christos #include <sys/sysctl.h>
     93       1.27  jonathan #include <sys/timex.h>
     94       1.45      ross #include <sys/sched.h>
     95       1.82   thorpej #include <sys/time.h>
     96       1.99    kardel #include <sys/timetc.h>
     97      1.109        ad #include <sys/cpu.h>
     98       1.25  christos 
     99       1.19       cgd #ifdef GPROF
    100       1.19       cgd #include <sys/gmon.h>
    101       1.19       cgd #endif
    102       1.19       cgd 
    103       1.19       cgd /*
    104       1.19       cgd  * Clock handling routines.
    105       1.19       cgd  *
    106       1.19       cgd  * This code is written to operate with two timers that run independently of
    107       1.19       cgd  * each other.  The main clock, running hz times per second, is used to keep
    108       1.19       cgd  * track of real time.  The second timer handles kernel and user profiling,
    109       1.19       cgd  * and does resource use estimation.  If the second timer is programmable,
    110       1.19       cgd  * it is randomized to avoid aliasing between the two clocks.  For example,
    111       1.90       wiz  * the randomization prevents an adversary from always giving up the CPU
    112       1.19       cgd  * just before its quantum expires.  Otherwise, it would never accumulate
    113       1.90       wiz  * CPU ticks.  The mean frequency of the second timer is stathz.
    114       1.19       cgd  *
    115       1.19       cgd  * If no second timer exists, stathz will be zero; in this case we drive
    116       1.19       cgd  * profiling and statistics off the main clock.  This WILL NOT be accurate;
    117       1.19       cgd  * do not do it unless absolutely necessary.
    118       1.19       cgd  *
    119       1.19       cgd  * The statistics clock may (or may not) be run at a higher rate while
    120       1.19       cgd  * profiling.  This profile clock runs at profhz.  We require that profhz
    121       1.19       cgd  * be an integral multiple of stathz.
    122       1.19       cgd  *
    123       1.19       cgd  * If the statistics clock is running fast, it must be divided by the ratio
    124       1.19       cgd  * profhz/stathz for statistics.  (For profiling, every tick counts.)
    125       1.19       cgd  */
    126       1.19       cgd 
    127       1.99    kardel #ifndef __HAVE_TIMECOUNTER
    128       1.27  jonathan #ifdef NTP	/* NTP phase-locked loop in kernel */
    129       1.27  jonathan /*
    130       1.27  jonathan  * Phase/frequency-lock loop (PLL/FLL) definitions
    131       1.27  jonathan  *
    132       1.27  jonathan  * The following variables are read and set by the ntp_adjtime() system
    133       1.27  jonathan  * call.
    134       1.27  jonathan  *
    135       1.27  jonathan  * time_state shows the state of the system clock, with values defined
    136       1.27  jonathan  * in the timex.h header file.
    137       1.27  jonathan  *
    138       1.27  jonathan  * time_status shows the status of the system clock, with bits defined
    139       1.27  jonathan  * in the timex.h header file.
    140       1.27  jonathan  *
    141       1.27  jonathan  * time_offset is used by the PLL/FLL to adjust the system time in small
    142       1.27  jonathan  * increments.
    143       1.27  jonathan  *
    144       1.27  jonathan  * time_constant determines the bandwidth or "stiffness" of the PLL.
    145       1.27  jonathan  *
    146       1.27  jonathan  * time_tolerance determines maximum frequency error or tolerance of the
    147       1.27  jonathan  * CPU clock oscillator and is a property of the architecture; however,
    148       1.27  jonathan  * in principle it could change as result of the presence of external
    149       1.27  jonathan  * discipline signals, for instance.
    150       1.27  jonathan  *
    151       1.27  jonathan  * time_precision is usually equal to the kernel tick variable; however,
    152       1.27  jonathan  * in cases where a precision clock counter or external clock is
    153       1.27  jonathan  * available, the resolution can be much less than this and depend on
    154       1.27  jonathan  * whether the external clock is working or not.
    155       1.27  jonathan  *
    156       1.27  jonathan  * time_maxerror is initialized by a ntp_adjtime() call and increased by
    157       1.27  jonathan  * the kernel once each second to reflect the maximum error bound
    158       1.27  jonathan  * growth.
    159       1.27  jonathan  *
    160       1.27  jonathan  * time_esterror is set and read by the ntp_adjtime() call, but
    161       1.27  jonathan  * otherwise not used by the kernel.
    162       1.27  jonathan  */
    163       1.27  jonathan int time_state = TIME_OK;	/* clock state */
    164       1.27  jonathan int time_status = STA_UNSYNC;	/* clock status bits */
    165       1.27  jonathan long time_offset = 0;		/* time offset (us) */
    166       1.27  jonathan long time_constant = 0;		/* pll time constant */
    167       1.27  jonathan long time_tolerance = MAXFREQ;	/* frequency tolerance (scaled ppm) */
    168       1.27  jonathan long time_precision = 1;	/* clock precision (us) */
    169       1.27  jonathan long time_maxerror = MAXPHASE;	/* maximum error (us) */
    170       1.27  jonathan long time_esterror = MAXPHASE;	/* estimated error (us) */
    171       1.27  jonathan 
    172       1.27  jonathan /*
    173       1.27  jonathan  * The following variables establish the state of the PLL/FLL and the
    174       1.27  jonathan  * residual time and frequency offset of the local clock. The scale
    175       1.27  jonathan  * factors are defined in the timex.h header file.
    176       1.27  jonathan  *
    177       1.27  jonathan  * time_phase and time_freq are the phase increment and the frequency
    178       1.27  jonathan  * increment, respectively, of the kernel time variable.
    179       1.27  jonathan  *
    180       1.27  jonathan  * time_freq is set via ntp_adjtime() from a value stored in a file when
    181       1.27  jonathan  * the synchronization daemon is first started. Its value is retrieved
    182       1.27  jonathan  * via ntp_adjtime() and written to the file about once per hour by the
    183       1.27  jonathan  * daemon.
    184       1.27  jonathan  *
    185       1.27  jonathan  * time_adj is the adjustment added to the value of tick at each timer
    186       1.27  jonathan  * interrupt and is recomputed from time_phase and time_freq at each
    187       1.27  jonathan  * seconds rollover.
    188       1.27  jonathan  *
    189       1.27  jonathan  * time_reftime is the second's portion of the system time at the last
    190       1.27  jonathan  * call to ntp_adjtime(). It is used to adjust the time_freq variable
    191       1.27  jonathan  * and to increase the time_maxerror as the time since last update
    192       1.27  jonathan  * increases.
    193       1.27  jonathan  */
    194       1.27  jonathan long time_phase = 0;		/* phase offset (scaled us) */
    195       1.27  jonathan long time_freq = 0;		/* frequency offset (scaled ppm) */
    196       1.27  jonathan long time_adj = 0;		/* tick adjust (scaled 1 / hz) */
    197       1.27  jonathan long time_reftime = 0;		/* time at last adjustment (s) */
    198       1.27  jonathan 
    199       1.27  jonathan #ifdef PPS_SYNC
    200       1.27  jonathan /*
    201       1.27  jonathan  * The following variables are used only if the kernel PPS discipline
    202       1.27  jonathan  * code is configured (PPS_SYNC). The scale factors are defined in the
    203       1.27  jonathan  * timex.h header file.
    204       1.27  jonathan  *
    205       1.27  jonathan  * pps_time contains the time at each calibration interval, as read by
    206       1.27  jonathan  * microtime(). pps_count counts the seconds of the calibration
    207       1.27  jonathan  * interval, the duration of which is nominally pps_shift in powers of
    208       1.27  jonathan  * two.
    209       1.27  jonathan  *
    210       1.27  jonathan  * pps_offset is the time offset produced by the time median filter
    211       1.27  jonathan  * pps_tf[], while pps_jitter is the dispersion (jitter) measured by
    212       1.27  jonathan  * this filter.
    213       1.27  jonathan  *
    214       1.27  jonathan  * pps_freq is the frequency offset produced by the frequency median
    215       1.27  jonathan  * filter pps_ff[], while pps_stabil is the dispersion (wander) measured
    216       1.27  jonathan  * by this filter.
    217       1.27  jonathan  *
    218       1.27  jonathan  * pps_usec is latched from a high resolution counter or external clock
    219       1.27  jonathan  * at pps_time. Here we want the hardware counter contents only, not the
    220       1.27  jonathan  * contents plus the time_tv.usec as usual.
    221       1.27  jonathan  *
    222       1.27  jonathan  * pps_valid counts the number of seconds since the last PPS update. It
    223       1.27  jonathan  * is used as a watchdog timer to disable the PPS discipline should the
    224       1.27  jonathan  * PPS signal be lost.
    225       1.27  jonathan  *
    226       1.27  jonathan  * pps_glitch counts the number of seconds since the beginning of an
    227       1.27  jonathan  * offset burst more than tick/2 from current nominal offset. It is used
    228       1.27  jonathan  * mainly to suppress error bursts due to priority conflicts between the
    229       1.27  jonathan  * PPS interrupt and timer interrupt.
    230       1.27  jonathan  *
    231       1.27  jonathan  * pps_intcnt counts the calibration intervals for use in the interval-
    232       1.27  jonathan  * adaptation algorithm. It's just too complicated for words.
    233       1.89    simonb  *
    234       1.89    simonb  * pps_kc_hardpps_source contains an arbitrary value that uniquely
    235       1.89    simonb  * identifies the currently bound source of the PPS signal, or NULL
    236       1.89    simonb  * if no source is bound.
    237       1.89    simonb  *
    238       1.89    simonb  * pps_kc_hardpps_mode indicates which transitions, if any, of the PPS
    239       1.89    simonb  * signal should be reported.
    240       1.27  jonathan  */
    241       1.27  jonathan struct timeval pps_time;	/* kernel time at last interval */
    242       1.27  jonathan long pps_tf[] = {0, 0, 0};	/* pps time offset median filter (us) */
    243       1.27  jonathan long pps_offset = 0;		/* pps time offset (us) */
    244       1.27  jonathan long pps_jitter = MAXTIME;	/* time dispersion (jitter) (us) */
    245       1.27  jonathan long pps_ff[] = {0, 0, 0};	/* pps frequency offset median filter */
    246       1.27  jonathan long pps_freq = 0;		/* frequency offset (scaled ppm) */
    247       1.27  jonathan long pps_stabil = MAXFREQ;	/* frequency dispersion (scaled ppm) */
    248       1.27  jonathan long pps_usec = 0;		/* microsec counter at last interval */
    249       1.27  jonathan long pps_valid = PPS_VALID;	/* pps signal watchdog counter */
    250       1.27  jonathan int pps_glitch = 0;		/* pps signal glitch counter */
    251       1.27  jonathan int pps_count = 0;		/* calibration interval counter (s) */
    252       1.27  jonathan int pps_shift = PPS_SHIFT;	/* interval duration (s) (shift) */
    253       1.27  jonathan int pps_intcnt = 0;		/* intervals at current duration */
    254       1.89    simonb void *pps_kc_hardpps_source = NULL; /* current PPS supplier's identifier */
    255       1.89    simonb int pps_kc_hardpps_mode = 0;	/* interesting edges of PPS signal */
    256       1.27  jonathan 
    257       1.27  jonathan /*
    258       1.27  jonathan  * PPS signal quality monitors
    259       1.27  jonathan  *
    260       1.27  jonathan  * pps_jitcnt counts the seconds that have been discarded because the
    261       1.27  jonathan  * jitter measured by the time median filter exceeds the limit MAXTIME
    262       1.27  jonathan  * (100 us).
    263       1.27  jonathan  *
    264       1.27  jonathan  * pps_calcnt counts the frequency calibration intervals, which are
    265       1.27  jonathan  * variable from 4 s to 256 s.
    266       1.27  jonathan  *
    267       1.27  jonathan  * pps_errcnt counts the calibration intervals which have been discarded
    268       1.27  jonathan  * because the wander exceeds the limit MAXFREQ (100 ppm) or where the
    269       1.27  jonathan  * calibration interval jitter exceeds two ticks.
    270       1.27  jonathan  *
    271       1.27  jonathan  * pps_stbcnt counts the calibration intervals that have been discarded
    272       1.27  jonathan  * because the frequency wander exceeds the limit MAXFREQ / 4 (25 us).
    273       1.27  jonathan  */
    274       1.27  jonathan long pps_jitcnt = 0;		/* jitter limit exceeded */
    275       1.27  jonathan long pps_calcnt = 0;		/* calibration intervals */
    276       1.27  jonathan long pps_errcnt = 0;		/* calibration errors */
    277       1.27  jonathan long pps_stbcnt = 0;		/* stability limit exceeded */
    278       1.27  jonathan #endif /* PPS_SYNC */
    279       1.27  jonathan 
    280       1.27  jonathan #ifdef EXT_CLOCK
    281       1.27  jonathan /*
    282       1.27  jonathan  * External clock definitions
    283       1.27  jonathan  *
    284       1.27  jonathan  * The following definitions and declarations are used only if an
    285       1.27  jonathan  * external clock is configured on the system.
    286       1.27  jonathan  */
    287       1.27  jonathan #define CLOCK_INTERVAL 30	/* CPU clock update interval (s) */
    288       1.27  jonathan 
    289       1.27  jonathan /*
    290       1.27  jonathan  * The clock_count variable is set to CLOCK_INTERVAL at each PPS
    291       1.27  jonathan  * interrupt and decremented once each second.
    292       1.27  jonathan  */
    293       1.27  jonathan int clock_count = 0;		/* CPU clock counter */
    294       1.27  jonathan 
    295       1.27  jonathan #endif /* EXT_CLOCK */
    296       1.27  jonathan #endif /* NTP */
    297       1.27  jonathan 
    298       1.19       cgd /*
    299       1.19       cgd  * Bump a timeval by a small number of usec's.
    300       1.19       cgd  */
    301       1.19       cgd #define BUMPTIME(t, usec) { \
    302       1.55  augustss 	volatile struct timeval *tp = (t); \
    303       1.55  augustss 	long us; \
    304       1.19       cgd  \
    305       1.19       cgd 	tp->tv_usec = us = tp->tv_usec + (usec); \
    306       1.19       cgd 	if (us >= 1000000) { \
    307       1.19       cgd 		tp->tv_usec = us - 1000000; \
    308       1.19       cgd 		tp->tv_sec++; \
    309       1.19       cgd 	} \
    310       1.19       cgd }
    311       1.99    kardel #endif /* !__HAVE_TIMECOUNTER */
    312       1.19       cgd 
    313       1.19       cgd int	stathz;
    314       1.19       cgd int	profhz;
    315       1.80    briggs int	profsrc;
    316       1.75    simonb int	schedhz;
    317       1.19       cgd int	profprocs;
    318      1.100  drochner int	hardclock_ticks;
    319      1.114        ad static int hardscheddiv; /* hard => sched divider (used if schedhz == 0) */
    320       1.70  sommerfe static int psdiv;			/* prof => stat divider */
    321       1.22       cgd int	psratio;			/* ratio: prof / stat */
    322       1.99    kardel #ifndef __HAVE_TIMECOUNTER
    323       1.22       cgd int	tickfix, tickfixinterval;	/* used if tick not really integral */
    324       1.34    briggs #ifndef NTP
    325       1.39       cgd static int tickfixcnt;			/* accumulated fractional error */
    326       1.34    briggs #else
    327       1.27  jonathan int	fixtick;			/* used by NTP for same */
    328       1.31   mycroft int	shifthz;
    329       1.31   mycroft #endif
    330       1.19       cgd 
    331       1.48  christos /*
    332       1.48  christos  * We might want ldd to load the both words from time at once.
    333       1.48  christos  * To succeed we need to be quadword aligned.
    334       1.48  christos  * The sparc already does that, and that it has worked so far is a fluke.
    335       1.48  christos  */
    336       1.48  christos volatile struct	timeval time  __attribute__((__aligned__(__alignof__(quad_t))));
    337       1.19       cgd volatile struct	timeval mono_time;
    338       1.99    kardel #endif /* !__HAVE_TIMECOUNTER */
    339       1.19       cgd 
    340       1.99    kardel #ifdef __HAVE_TIMECOUNTER
    341       1.99    kardel static u_int get_intr_timecount(struct timecounter *);
    342       1.99    kardel 
    343       1.99    kardel static struct timecounter intr_timecounter = {
    344       1.99    kardel 	get_intr_timecount,	/* get_timecount */
    345       1.99    kardel 	0,			/* no poll_pps */
    346       1.99    kardel 	~0u,			/* counter_mask */
    347       1.99    kardel 	0,		        /* frequency */
    348       1.99    kardel 	"clockinterrupt",	/* name */
    349      1.102  christos 	0,			/* quality - minimum implementation level for a clock */
    350      1.102  christos 	NULL,			/* prev */
    351      1.102  christos 	NULL,			/* next */
    352       1.99    kardel };
    353       1.99    kardel 
    354       1.99    kardel static u_int
    355      1.104      yamt get_intr_timecount(struct timecounter *tc)
    356       1.99    kardel {
    357      1.104      yamt 
    358      1.100  drochner 	return (u_int)hardclock_ticks;
    359       1.99    kardel }
    360       1.99    kardel #endif
    361       1.73   thorpej 
    362       1.66   thorpej /*
    363       1.19       cgd  * Initialize clock frequencies and start both clocks running.
    364       1.19       cgd  */
    365       1.19       cgd void
    366       1.63   thorpej initclocks(void)
    367       1.19       cgd {
    368       1.55  augustss 	int i;
    369       1.19       cgd 
    370       1.19       cgd 	/*
    371       1.19       cgd 	 * Set divisors to 1 (normal case) and let the machine-specific
    372       1.19       cgd 	 * code do its bit.
    373       1.19       cgd 	 */
    374       1.70  sommerfe 	psdiv = 1;
    375       1.99    kardel #ifdef __HAVE_TIMECOUNTER
    376       1.99    kardel 	/*
    377       1.99    kardel 	 * provide minimum default time counter
    378       1.99    kardel 	 * will only run at interrupt resolution
    379       1.99    kardel 	 */
    380       1.99    kardel 	intr_timecounter.tc_frequency = hz;
    381       1.99    kardel 	tc_init(&intr_timecounter);
    382       1.99    kardel #endif
    383       1.19       cgd 	cpu_initclocks();
    384       1.19       cgd 
    385       1.19       cgd 	/*
    386      1.108      yamt 	 * Compute profhz and stathz, fix profhz if needed.
    387       1.19       cgd 	 */
    388       1.19       cgd 	i = stathz ? stathz : hz;
    389       1.19       cgd 	if (profhz == 0)
    390       1.19       cgd 		profhz = i;
    391       1.19       cgd 	psratio = profhz / i;
    392       1.91      yamt 	if (schedhz == 0) {
    393       1.91      yamt 		/* 16Hz is best */
    394      1.114        ad 		hardscheddiv = hz / 16;
    395      1.114        ad 		if (hardscheddiv <= 0)
    396      1.114        ad 			panic("hardscheddiv");
    397       1.91      yamt 	}
    398       1.31   mycroft 
    399       1.99    kardel #ifndef __HAVE_TIMECOUNTER
    400       1.31   mycroft #ifdef NTP
    401       1.31   mycroft 	switch (hz) {
    402       1.57   mycroft 	case 1:
    403       1.57   mycroft 		shifthz = SHIFT_SCALE - 0;
    404       1.57   mycroft 		break;
    405       1.57   mycroft 	case 2:
    406       1.57   mycroft 		shifthz = SHIFT_SCALE - 1;
    407       1.57   mycroft 		break;
    408       1.57   mycroft 	case 4:
    409       1.57   mycroft 		shifthz = SHIFT_SCALE - 2;
    410       1.57   mycroft 		break;
    411       1.57   mycroft 	case 8:
    412       1.57   mycroft 		shifthz = SHIFT_SCALE - 3;
    413       1.57   mycroft 		break;
    414       1.57   mycroft 	case 16:
    415       1.57   mycroft 		shifthz = SHIFT_SCALE - 4;
    416       1.57   mycroft 		break;
    417       1.57   mycroft 	case 32:
    418       1.57   mycroft 		shifthz = SHIFT_SCALE - 5;
    419       1.57   mycroft 		break;
    420       1.92       tls 	case 50:
    421       1.31   mycroft 	case 60:
    422       1.31   mycroft 	case 64:
    423       1.31   mycroft 		shifthz = SHIFT_SCALE - 6;
    424       1.31   mycroft 		break;
    425       1.31   mycroft 	case 96:
    426       1.31   mycroft 	case 100:
    427       1.31   mycroft 	case 128:
    428       1.31   mycroft 		shifthz = SHIFT_SCALE - 7;
    429       1.31   mycroft 		break;
    430       1.31   mycroft 	case 256:
    431       1.31   mycroft 		shifthz = SHIFT_SCALE - 8;
    432       1.41       tls 		break;
    433       1.41       tls 	case 512:
    434       1.41       tls 		shifthz = SHIFT_SCALE - 9;
    435       1.31   mycroft 		break;
    436       1.43      ross 	case 1000:
    437       1.31   mycroft 	case 1024:
    438       1.31   mycroft 		shifthz = SHIFT_SCALE - 10;
    439       1.31   mycroft 		break;
    440       1.57   mycroft 	case 1200:
    441       1.57   mycroft 	case 2048:
    442       1.57   mycroft 		shifthz = SHIFT_SCALE - 11;
    443       1.57   mycroft 		break;
    444       1.57   mycroft 	case 4096:
    445       1.57   mycroft 		shifthz = SHIFT_SCALE - 12;
    446       1.57   mycroft 		break;
    447       1.57   mycroft 	case 8192:
    448       1.57   mycroft 		shifthz = SHIFT_SCALE - 13;
    449       1.57   mycroft 		break;
    450       1.57   mycroft 	case 16384:
    451       1.57   mycroft 		shifthz = SHIFT_SCALE - 14;
    452       1.57   mycroft 		break;
    453       1.57   mycroft 	case 32768:
    454       1.57   mycroft 		shifthz = SHIFT_SCALE - 15;
    455       1.57   mycroft 		break;
    456       1.57   mycroft 	case 65536:
    457       1.57   mycroft 		shifthz = SHIFT_SCALE - 16;
    458       1.57   mycroft 		break;
    459       1.31   mycroft 	default:
    460       1.31   mycroft 		panic("weird hz");
    461       1.50  sommerfe 	}
    462       1.50  sommerfe 	if (fixtick == 0) {
    463       1.52   thorpej 		/*
    464       1.52   thorpej 		 * Give MD code a chance to set this to a better
    465       1.52   thorpej 		 * value; but, if it doesn't, we should.
    466       1.52   thorpej 		 */
    467       1.50  sommerfe 		fixtick = (1000000 - (hz*tick));
    468       1.31   mycroft 	}
    469       1.99    kardel #endif /* NTP */
    470       1.99    kardel #endif /* !__HAVE_TIMECOUNTER */
    471       1.19       cgd }
    472       1.19       cgd 
    473       1.19       cgd /*
    474       1.19       cgd  * The real-time timer, interrupting hz times per second.
    475       1.19       cgd  */
    476       1.19       cgd void
    477       1.63   thorpej hardclock(struct clockframe *frame)
    478       1.19       cgd {
    479       1.82   thorpej 	struct lwp *l;
    480       1.55  augustss 	struct proc *p;
    481       1.99    kardel 	struct cpu_info *ci = curcpu();
    482       1.99    kardel 	struct ptimer *pt;
    483       1.99    kardel #ifndef __HAVE_TIMECOUNTER
    484       1.55  augustss 	int delta;
    485       1.19       cgd 	extern int tickdelta;
    486       1.19       cgd 	extern long timedelta;
    487       1.30   mycroft #ifdef NTP
    488       1.55  augustss 	int time_update;
    489       1.55  augustss 	int ltemp;
    490       1.99    kardel #endif /* NTP */
    491       1.99    kardel #endif /* __HAVE_TIMECOUNTER */
    492       1.19       cgd 
    493      1.114        ad 	l = ci->ci_data.cpu_onproc;
    494      1.108      yamt 	if (!CURCPU_IDLE_P()) {
    495       1.82   thorpej 		p = l->l_proc;
    496       1.19       cgd 		/*
    497       1.19       cgd 		 * Run current process's virtual and profile time, as needed.
    498       1.19       cgd 		 */
    499       1.82   thorpej 		if (CLKF_USERMODE(frame) && p->p_timers &&
    500       1.82   thorpej 		    (pt = LIST_FIRST(&p->p_timers->pts_virtual)) != NULL)
    501       1.82   thorpej 			if (itimerdecr(pt, tick) == 0)
    502       1.82   thorpej 				itimerfire(pt);
    503       1.82   thorpej 		if (p->p_timers &&
    504       1.82   thorpej 		    (pt = LIST_FIRST(&p->p_timers->pts_prof)) != NULL)
    505       1.82   thorpej 			if (itimerdecr(pt, tick) == 0)
    506       1.82   thorpej 				itimerfire(pt);
    507       1.19       cgd 	}
    508       1.19       cgd 
    509       1.19       cgd 	/*
    510       1.19       cgd 	 * If no separate statistics clock is available, run it from here.
    511       1.19       cgd 	 */
    512       1.19       cgd 	if (stathz == 0)
    513       1.19       cgd 		statclock(frame);
    514      1.114        ad 	/*
    515      1.114        ad 	 * If no separate schedclock is provided, call it here
    516      1.114        ad 	 * at about 16 Hz.
    517      1.114        ad 	 */
    518      1.114        ad 	if (schedhz == 0) {
    519      1.114        ad 		if ((int)(--ci->ci_schedstate.spc_schedticks) <= 0) {
    520      1.114        ad 			schedclock(l);
    521      1.114        ad 			ci->ci_schedstate.spc_schedticks = hardscheddiv;
    522      1.114        ad 		}
    523      1.114        ad 	}
    524      1.108      yamt 	if ((--ci->ci_schedstate.spc_ticks) <= 0)
    525      1.108      yamt 		sched_tick(ci);
    526       1.93     perry 
    527       1.60   thorpej #if defined(MULTIPROCESSOR)
    528       1.60   thorpej 	/*
    529       1.60   thorpej 	 * If we are not the primary CPU, we're not allowed to do
    530       1.60   thorpej 	 * any more work.
    531       1.60   thorpej 	 */
    532       1.70  sommerfe 	if (CPU_IS_PRIMARY(ci) == 0)
    533       1.60   thorpej 		return;
    534       1.60   thorpej #endif
    535       1.60   thorpej 
    536       1.99    kardel 	hardclock_ticks++;
    537       1.99    kardel 
    538       1.99    kardel #ifdef __HAVE_TIMECOUNTER
    539       1.99    kardel 	tc_ticktock();
    540       1.99    kardel #else /* __HAVE_TIMECOUNTER */
    541       1.19       cgd 	/*
    542       1.22       cgd 	 * Increment the time-of-day.  The increment is normally just
    543       1.22       cgd 	 * ``tick''.  If the machine is one which has a clock frequency
    544       1.22       cgd 	 * such that ``hz'' would not divide the second evenly into
    545       1.22       cgd 	 * milliseconds, a periodic adjustment must be applied.  Finally,
    546       1.22       cgd 	 * if we are still adjusting the time (see adjtime()),
    547       1.22       cgd 	 * ``tickdelta'' may also be added in.
    548       1.19       cgd 	 */
    549       1.22       cgd 	delta = tick;
    550       1.27  jonathan 
    551       1.27  jonathan #ifndef NTP
    552       1.22       cgd 	if (tickfix) {
    553       1.39       cgd 		tickfixcnt += tickfix;
    554       1.24       cgd 		if (tickfixcnt >= tickfixinterval) {
    555       1.39       cgd 			delta++;
    556       1.39       cgd 			tickfixcnt -= tickfixinterval;
    557       1.22       cgd 		}
    558       1.22       cgd 	}
    559       1.27  jonathan #endif /* !NTP */
    560       1.27  jonathan 	/* Imprecise 4bsd adjtime() handling */
    561       1.22       cgd 	if (timedelta != 0) {
    562       1.38       cgd 		delta += tickdelta;
    563       1.19       cgd 		timedelta -= tickdelta;
    564       1.19       cgd 	}
    565       1.27  jonathan 
    566       1.27  jonathan #ifdef notyet
    567       1.27  jonathan 	microset();
    568       1.27  jonathan #endif
    569       1.27  jonathan 
    570       1.27  jonathan #ifndef NTP
    571       1.27  jonathan 	BUMPTIME(&time, delta);		/* XXX Now done using NTP code below */
    572       1.27  jonathan #endif
    573       1.19       cgd 	BUMPTIME(&mono_time, delta);
    574       1.27  jonathan 
    575       1.31   mycroft #ifdef NTP
    576       1.30   mycroft 	time_update = delta;
    577       1.27  jonathan 
    578       1.27  jonathan 	/*
    579       1.27  jonathan 	 * Compute the phase adjustment. If the low-order bits
    580       1.27  jonathan 	 * (time_phase) of the update overflow, bump the high-order bits
    581       1.27  jonathan 	 * (time_update).
    582       1.27  jonathan 	 */
    583       1.27  jonathan 	time_phase += time_adj;
    584       1.27  jonathan 	if (time_phase <= -FINEUSEC) {
    585       1.27  jonathan 		ltemp = -time_phase >> SHIFT_SCALE;
    586       1.27  jonathan 		time_phase += ltemp << SHIFT_SCALE;
    587       1.27  jonathan 		time_update -= ltemp;
    588       1.31   mycroft 	} else if (time_phase >= FINEUSEC) {
    589       1.27  jonathan 		ltemp = time_phase >> SHIFT_SCALE;
    590       1.27  jonathan 		time_phase -= ltemp << SHIFT_SCALE;
    591       1.27  jonathan 		time_update += ltemp;
    592       1.27  jonathan 	}
    593       1.27  jonathan 	time.tv_usec += time_update;
    594       1.27  jonathan 
    595       1.27  jonathan 	/*
    596       1.27  jonathan 	 * On rollover of the second the phase adjustment to be used for
    597       1.27  jonathan 	 * the next second is calculated. Also, the maximum error is
    598       1.27  jonathan 	 * increased by the tolerance. If the PPS frequency discipline
    599       1.27  jonathan 	 * code is present, the phase is increased to compensate for the
    600       1.27  jonathan 	 * CPU clock oscillator frequency error.
    601       1.27  jonathan 	 *
    602       1.27  jonathan  	 * On a 32-bit machine and given parameters in the timex.h
    603       1.27  jonathan 	 * header file, the maximum phase adjustment is +-512 ms and
    604       1.27  jonathan 	 * maximum frequency offset is a tad less than) +-512 ppm. On a
    605       1.27  jonathan 	 * 64-bit machine, you shouldn't need to ask.
    606       1.27  jonathan 	 */
    607       1.27  jonathan 	if (time.tv_usec >= 1000000) {
    608       1.27  jonathan 		time.tv_usec -= 1000000;
    609       1.27  jonathan 		time.tv_sec++;
    610       1.27  jonathan 		time_maxerror += time_tolerance >> SHIFT_USEC;
    611       1.27  jonathan 
    612       1.27  jonathan 		/*
    613       1.27  jonathan 		 * Leap second processing. If in leap-insert state at
    614       1.27  jonathan 		 * the end of the day, the system clock is set back one
    615       1.27  jonathan 		 * second; if in leap-delete state, the system clock is
    616       1.27  jonathan 		 * set ahead one second. The microtime() routine or
    617       1.27  jonathan 		 * external clock driver will insure that reported time
    618       1.27  jonathan 		 * is always monotonic. The ugly divides should be
    619       1.27  jonathan 		 * replaced.
    620       1.27  jonathan 		 */
    621       1.27  jonathan 		switch (time_state) {
    622       1.31   mycroft 		case TIME_OK:
    623       1.27  jonathan 			if (time_status & STA_INS)
    624       1.27  jonathan 				time_state = TIME_INS;
    625       1.27  jonathan 			else if (time_status & STA_DEL)
    626       1.27  jonathan 				time_state = TIME_DEL;
    627       1.27  jonathan 			break;
    628       1.27  jonathan 
    629       1.31   mycroft 		case TIME_INS:
    630       1.27  jonathan 			if (time.tv_sec % 86400 == 0) {
    631       1.27  jonathan 				time.tv_sec--;
    632       1.27  jonathan 				time_state = TIME_OOP;
    633       1.27  jonathan 			}
    634       1.27  jonathan 			break;
    635       1.27  jonathan 
    636       1.31   mycroft 		case TIME_DEL:
    637       1.27  jonathan 			if ((time.tv_sec + 1) % 86400 == 0) {
    638       1.27  jonathan 				time.tv_sec++;
    639       1.27  jonathan 				time_state = TIME_WAIT;
    640       1.27  jonathan 			}
    641       1.27  jonathan 			break;
    642       1.27  jonathan 
    643       1.31   mycroft 		case TIME_OOP:
    644       1.27  jonathan 			time_state = TIME_WAIT;
    645       1.27  jonathan 			break;
    646       1.27  jonathan 
    647       1.31   mycroft 		case TIME_WAIT:
    648       1.27  jonathan 			if (!(time_status & (STA_INS | STA_DEL)))
    649       1.27  jonathan 				time_state = TIME_OK;
    650       1.31   mycroft 			break;
    651       1.27  jonathan 		}
    652       1.27  jonathan 
    653       1.27  jonathan 		/*
    654       1.27  jonathan 		 * Compute the phase adjustment for the next second. In
    655       1.27  jonathan 		 * PLL mode, the offset is reduced by a fixed factor
    656       1.27  jonathan 		 * times the time constant. In FLL mode the offset is
    657       1.27  jonathan 		 * used directly. In either mode, the maximum phase
    658       1.27  jonathan 		 * adjustment for each second is clamped so as to spread
    659       1.27  jonathan 		 * the adjustment over not more than the number of
    660       1.27  jonathan 		 * seconds between updates.
    661       1.27  jonathan 		 */
    662       1.27  jonathan 		if (time_offset < 0) {
    663       1.27  jonathan 			ltemp = -time_offset;
    664       1.27  jonathan 			if (!(time_status & STA_FLL))
    665       1.27  jonathan 				ltemp >>= SHIFT_KG + time_constant;
    666       1.27  jonathan 			if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
    667       1.27  jonathan 				ltemp = (MAXPHASE / MINSEC) <<
    668       1.27  jonathan 				    SHIFT_UPDATE;
    669       1.27  jonathan 			time_offset += ltemp;
    670       1.31   mycroft 			time_adj = -ltemp << (shifthz - SHIFT_UPDATE);
    671       1.31   mycroft 		} else if (time_offset > 0) {
    672       1.27  jonathan 			ltemp = time_offset;
    673       1.27  jonathan 			if (!(time_status & STA_FLL))
    674       1.27  jonathan 				ltemp >>= SHIFT_KG + time_constant;
    675       1.27  jonathan 			if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
    676       1.27  jonathan 				ltemp = (MAXPHASE / MINSEC) <<
    677       1.27  jonathan 				    SHIFT_UPDATE;
    678       1.27  jonathan 			time_offset -= ltemp;
    679       1.31   mycroft 			time_adj = ltemp << (shifthz - SHIFT_UPDATE);
    680       1.31   mycroft 		} else
    681       1.31   mycroft 			time_adj = 0;
    682       1.27  jonathan 
    683       1.27  jonathan 		/*
    684       1.27  jonathan 		 * Compute the frequency estimate and additional phase
    685       1.27  jonathan 		 * adjustment due to frequency error for the next
    686       1.27  jonathan 		 * second. When the PPS signal is engaged, gnaw on the
    687       1.27  jonathan 		 * watchdog counter and update the frequency computed by
    688       1.27  jonathan 		 * the pll and the PPS signal.
    689       1.27  jonathan 		 */
    690       1.27  jonathan #ifdef PPS_SYNC
    691       1.27  jonathan 		pps_valid++;
    692       1.27  jonathan 		if (pps_valid == PPS_VALID) {
    693       1.27  jonathan 			pps_jitter = MAXTIME;
    694       1.27  jonathan 			pps_stabil = MAXFREQ;
    695       1.27  jonathan 			time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
    696       1.27  jonathan 			    STA_PPSWANDER | STA_PPSERROR);
    697       1.27  jonathan 		}
    698       1.27  jonathan 		ltemp = time_freq + pps_freq;
    699       1.27  jonathan #else
    700       1.27  jonathan 		ltemp = time_freq;
    701       1.27  jonathan #endif /* PPS_SYNC */
    702       1.27  jonathan 
    703       1.27  jonathan 		if (ltemp < 0)
    704       1.31   mycroft 			time_adj -= -ltemp >> (SHIFT_USEC - shifthz);
    705       1.27  jonathan 		else
    706       1.31   mycroft 			time_adj += ltemp >> (SHIFT_USEC - shifthz);
    707       1.31   mycroft 		time_adj += (long)fixtick << shifthz;
    708       1.27  jonathan 
    709       1.27  jonathan 		/*
    710       1.27  jonathan 		 * When the CPU clock oscillator frequency is not a
    711       1.31   mycroft 		 * power of 2 in Hz, shifthz is only an approximate
    712       1.31   mycroft 		 * scale factor.
    713       1.46   mycroft 		 *
    714       1.46   mycroft 		 * To determine the adjustment, you can do the following:
    715       1.46   mycroft 		 *   bc -q
    716       1.46   mycroft 		 *   scale=24
    717       1.46   mycroft 		 *   obase=2
    718       1.46   mycroft 		 *   idealhz/realhz
    719       1.46   mycroft 		 * where `idealhz' is the next higher power of 2, and `realhz'
    720       1.57   mycroft 		 * is the actual value.  You may need to factor this result
    721       1.57   mycroft 		 * into a sequence of 2 multipliers to get better precision.
    722       1.46   mycroft 		 *
    723       1.46   mycroft 		 * Likewise, the error can be calculated with (e.g. for 100Hz):
    724       1.46   mycroft 		 *   bc -q
    725       1.46   mycroft 		 *   scale=24
    726       1.57   mycroft 		 *   ((1+2^-2+2^-5)*(1-2^-10)*realhz-idealhz)/idealhz
    727       1.57   mycroft 		 * (and then multiply by 1000000 to get ppm).
    728       1.27  jonathan 		 */
    729       1.31   mycroft 		switch (hz) {
    730       1.58   mycroft 		case 60:
    731       1.58   mycroft 			/* A factor of 1.000100010001 gives about 15ppm
    732       1.58   mycroft 			   error. */
    733       1.58   mycroft 			if (time_adj < 0) {
    734       1.58   mycroft 				time_adj -= (-time_adj >> 4);
    735       1.58   mycroft 				time_adj -= (-time_adj >> 8);
    736       1.58   mycroft 			} else {
    737       1.58   mycroft 				time_adj += (time_adj >> 4);
    738       1.58   mycroft 				time_adj += (time_adj >> 8);
    739       1.58   mycroft 			}
    740       1.58   mycroft 			break;
    741       1.58   mycroft 
    742       1.31   mycroft 		case 96:
    743       1.56   mycroft 			/* A factor of 1.0101010101 gives about 244ppm error. */
    744       1.46   mycroft 			if (time_adj < 0) {
    745       1.46   mycroft 				time_adj -= (-time_adj >> 2);
    746       1.46   mycroft 				time_adj -= (-time_adj >> 4) + (-time_adj >> 8);
    747       1.46   mycroft 			} else {
    748       1.46   mycroft 				time_adj += (time_adj >> 2);
    749       1.46   mycroft 				time_adj += (time_adj >> 4) + (time_adj >> 8);
    750       1.46   mycroft 			}
    751       1.46   mycroft 			break;
    752       1.46   mycroft 
    753       1.92       tls 		case 50:
    754       1.31   mycroft 		case 100:
    755       1.56   mycroft 			/* A factor of 1.010001111010111 gives about 1ppm
    756       1.56   mycroft 			   error. */
    757       1.56   mycroft 			if (time_adj < 0) {
    758       1.46   mycroft 				time_adj -= (-time_adj >> 2) + (-time_adj >> 5);
    759       1.56   mycroft 				time_adj += (-time_adj >> 10);
    760       1.56   mycroft 			} else {
    761       1.46   mycroft 				time_adj += (time_adj >> 2) + (time_adj >> 5);
    762       1.56   mycroft 				time_adj -= (time_adj >> 10);
    763       1.56   mycroft 			}
    764       1.43      ross 			break;
    765       1.46   mycroft 
    766       1.43      ross 		case 1000:
    767       1.56   mycroft 			/* A factor of 1.000001100010100001 gives about 50ppm
    768       1.56   mycroft 			   error. */
    769       1.56   mycroft 			if (time_adj < 0) {
    770       1.56   mycroft 				time_adj -= (-time_adj >> 6) + (-time_adj >> 11);
    771       1.56   mycroft 				time_adj -= (-time_adj >> 7);
    772       1.56   mycroft 			} else {
    773       1.56   mycroft 				time_adj += (time_adj >> 6) + (time_adj >> 11);
    774       1.56   mycroft 				time_adj += (time_adj >> 7);
    775       1.56   mycroft 			}
    776       1.56   mycroft 			break;
    777       1.56   mycroft 
    778       1.56   mycroft 		case 1200:
    779       1.56   mycroft 			/* A factor of 1.1011010011100001 gives about 64ppm
    780       1.56   mycroft 			   error. */
    781       1.56   mycroft 			if (time_adj < 0) {
    782       1.56   mycroft 				time_adj -= (-time_adj >> 1) + (-time_adj >> 6);
    783       1.56   mycroft 				time_adj -= (-time_adj >> 3) + (-time_adj >> 10);
    784       1.56   mycroft 			} else {
    785       1.56   mycroft 				time_adj += (time_adj >> 1) + (time_adj >> 6);
    786       1.56   mycroft 				time_adj += (time_adj >> 3) + (time_adj >> 10);
    787       1.56   mycroft 			}
    788       1.31   mycroft 			break;
    789       1.27  jonathan 		}
    790       1.27  jonathan 
    791       1.27  jonathan #ifdef EXT_CLOCK
    792       1.27  jonathan 		/*
    793       1.27  jonathan 		 * If an external clock is present, it is necessary to
    794       1.27  jonathan 		 * discipline the kernel time variable anyway, since not
    795       1.27  jonathan 		 * all system components use the microtime() interface.
    796       1.27  jonathan 		 * Here, the time offset between the external clock and
    797       1.27  jonathan 		 * kernel time variable is computed every so often.
    798       1.27  jonathan 		 */
    799       1.27  jonathan 		clock_count++;
    800       1.27  jonathan 		if (clock_count > CLOCK_INTERVAL) {
    801       1.27  jonathan 			clock_count = 0;
    802       1.27  jonathan 			microtime(&clock_ext);
    803       1.27  jonathan 			delta.tv_sec = clock_ext.tv_sec - time.tv_sec;
    804       1.27  jonathan 			delta.tv_usec = clock_ext.tv_usec -
    805       1.27  jonathan 			    time.tv_usec;
    806       1.27  jonathan 			if (delta.tv_usec < 0)
    807       1.27  jonathan 				delta.tv_sec--;
    808       1.27  jonathan 			if (delta.tv_usec >= 500000) {
    809       1.27  jonathan 				delta.tv_usec -= 1000000;
    810       1.27  jonathan 				delta.tv_sec++;
    811       1.27  jonathan 			}
    812       1.27  jonathan 			if (delta.tv_usec < -500000) {
    813       1.27  jonathan 				delta.tv_usec += 1000000;
    814       1.27  jonathan 				delta.tv_sec--;
    815       1.27  jonathan 			}
    816       1.27  jonathan 			if (delta.tv_sec > 0 || (delta.tv_sec == 0 &&
    817       1.27  jonathan 			    delta.tv_usec > MAXPHASE) ||
    818       1.27  jonathan 			    delta.tv_sec < -1 || (delta.tv_sec == -1 &&
    819       1.27  jonathan 			    delta.tv_usec < -MAXPHASE)) {
    820       1.27  jonathan 				time = clock_ext;
    821       1.27  jonathan 				delta.tv_sec = 0;
    822       1.27  jonathan 				delta.tv_usec = 0;
    823       1.27  jonathan 			}
    824       1.27  jonathan 			hardupdate(delta.tv_usec);
    825       1.27  jonathan 		}
    826       1.27  jonathan #endif /* EXT_CLOCK */
    827       1.27  jonathan 	}
    828       1.27  jonathan 
    829       1.31   mycroft #endif /* NTP */
    830       1.99    kardel #endif /* !__HAVE_TIMECOUNTER */
    831       1.19       cgd 
    832       1.19       cgd 	/*
    833      1.106        ad 	 * Update real-time timeout queue.  Callouts are processed at a
    834      1.106        ad 	 * very low CPU priority, so we don't keep the relatively high
    835      1.106        ad 	 * clock interrupt priority any longer than necessary.
    836      1.106        ad 	 */
    837      1.109        ad 	callout_hardclock();
    838       1.19       cgd }
    839       1.19       cgd 
    840       1.19       cgd /*
    841       1.19       cgd  * Start profiling on a process.
    842       1.19       cgd  *
    843       1.19       cgd  * Kernel profiling passes proc0 which never exits and hence
    844       1.19       cgd  * keeps the profile clock running constantly.
    845       1.19       cgd  */
    846       1.19       cgd void
    847       1.63   thorpej startprofclock(struct proc *p)
    848       1.19       cgd {
    849       1.19       cgd 
    850      1.109        ad 	KASSERT(mutex_owned(&p->p_stmutex));
    851      1.105        ad 
    852      1.105        ad 	if ((p->p_stflag & PST_PROFIL) == 0) {
    853      1.105        ad 		p->p_stflag |= PST_PROFIL;
    854       1.80    briggs 		/*
    855       1.80    briggs 		 * This is only necessary if using the clock as the
    856       1.80    briggs 		 * profiling source.
    857       1.80    briggs 		 */
    858       1.70  sommerfe 		if (++profprocs == 1 && stathz != 0)
    859       1.70  sommerfe 			psdiv = psratio;
    860       1.19       cgd 	}
    861       1.19       cgd }
    862       1.19       cgd 
    863       1.19       cgd /*
    864       1.19       cgd  * Stop profiling on a process.
    865       1.19       cgd  */
    866       1.19       cgd void
    867       1.63   thorpej stopprofclock(struct proc *p)
    868       1.19       cgd {
    869       1.19       cgd 
    870      1.109        ad 	KASSERT(mutex_owned(&p->p_stmutex));
    871      1.105        ad 
    872      1.105        ad 	if (p->p_stflag & PST_PROFIL) {
    873      1.105        ad 		p->p_stflag &= ~PST_PROFIL;
    874       1.80    briggs 		/*
    875       1.80    briggs 		 * This is only necessary if using the clock as the
    876       1.80    briggs 		 * profiling source.
    877       1.80    briggs 		 */
    878       1.70  sommerfe 		if (--profprocs == 0 && stathz != 0)
    879       1.70  sommerfe 			psdiv = 1;
    880       1.19       cgd 	}
    881       1.19       cgd }
    882       1.19       cgd 
    883       1.80    briggs #if defined(PERFCTRS)
    884       1.80    briggs /*
    885       1.80    briggs  * Independent profiling "tick" in case we're using a separate
    886       1.80    briggs  * clock or profiling event source.  Currently, that's just
    887       1.80    briggs  * performance counters--hence the wrapper.
    888       1.80    briggs  */
    889       1.80    briggs void
    890       1.80    briggs proftick(struct clockframe *frame)
    891       1.80    briggs {
    892       1.80    briggs #ifdef GPROF
    893       1.93     perry         struct gmonparam *g;
    894       1.93     perry         intptr_t i;
    895       1.80    briggs #endif
    896      1.105        ad 	struct lwp *l;
    897       1.80    briggs 	struct proc *p;
    898       1.80    briggs 
    899      1.114        ad 	l = curcpu()->ci_data.cpu_onproc;
    900      1.105        ad 	p = (l ? l->l_proc : NULL);
    901       1.80    briggs 	if (CLKF_USERMODE(frame)) {
    902      1.105        ad 		mutex_spin_enter(&p->p_stmutex);
    903      1.105        ad 		if (p->p_stflag & PST_PROFIL)
    904      1.105        ad 			addupc_intr(l, CLKF_PC(frame));
    905      1.105        ad 		mutex_spin_exit(&p->p_stmutex);
    906       1.80    briggs 	} else {
    907       1.80    briggs #ifdef GPROF
    908       1.80    briggs 		g = &_gmonparam;
    909       1.80    briggs 		if (g->state == GMON_PROF_ON) {
    910       1.80    briggs 			i = CLKF_PC(frame) - g->lowpc;
    911       1.80    briggs 			if (i < g->textsize) {
    912       1.80    briggs 				i /= HISTFRACTION * sizeof(*g->kcount);
    913       1.80    briggs 				g->kcount[i]++;
    914       1.80    briggs 			}
    915       1.80    briggs 		}
    916       1.80    briggs #endif
    917      1.111        ad #ifdef LWP_PC
    918      1.111        ad 		if (p != NULL && (p->p_stflag & PST_PROFIL) != 0)
    919      1.112        ad 			addupc_intr(l, LWP_PC(l));
    920       1.93     perry #endif
    921       1.80    briggs 	}
    922       1.80    briggs }
    923       1.80    briggs #endif
    924       1.80    briggs 
    925      1.108      yamt void
    926      1.108      yamt schedclock(struct lwp *l)
    927      1.108      yamt {
    928      1.108      yamt 
    929      1.108      yamt 	if ((l->l_flag & LW_IDLE) != 0)
    930      1.108      yamt 		return;
    931      1.108      yamt 
    932      1.108      yamt 	sched_schedclock(l);
    933      1.108      yamt }
    934      1.108      yamt 
    935       1.19       cgd /*
    936       1.19       cgd  * Statistics clock.  Grab profile sample, and if divider reaches 0,
    937       1.19       cgd  * do process and kernel statistics.
    938       1.19       cgd  */
    939       1.19       cgd void
    940       1.63   thorpej statclock(struct clockframe *frame)
    941       1.19       cgd {
    942       1.19       cgd #ifdef GPROF
    943       1.55  augustss 	struct gmonparam *g;
    944       1.68       eeh 	intptr_t i;
    945       1.19       cgd #endif
    946       1.60   thorpej 	struct cpu_info *ci = curcpu();
    947       1.60   thorpej 	struct schedstate_percpu *spc = &ci->ci_schedstate;
    948       1.55  augustss 	struct proc *p;
    949       1.98  christos 	struct lwp *l;
    950       1.19       cgd 
    951       1.70  sommerfe 	/*
    952       1.70  sommerfe 	 * Notice changes in divisor frequency, and adjust clock
    953       1.70  sommerfe 	 * frequency accordingly.
    954       1.70  sommerfe 	 */
    955       1.70  sommerfe 	if (spc->spc_psdiv != psdiv) {
    956       1.70  sommerfe 		spc->spc_psdiv = psdiv;
    957       1.70  sommerfe 		spc->spc_pscnt = psdiv;
    958       1.70  sommerfe 		if (psdiv == 1) {
    959       1.70  sommerfe 			setstatclockrate(stathz);
    960       1.70  sommerfe 		} else {
    961       1.93     perry 			setstatclockrate(profhz);
    962       1.70  sommerfe 		}
    963       1.70  sommerfe 	}
    964      1.114        ad 	l = ci->ci_data.cpu_onproc;
    965      1.108      yamt 	if ((l->l_flag & LW_IDLE) != 0) {
    966      1.108      yamt 		/*
    967      1.108      yamt 		 * don't account idle lwps as swapper.
    968      1.108      yamt 		 */
    969      1.108      yamt 		p = NULL;
    970      1.108      yamt 	} else {
    971      1.108      yamt 		p = l->l_proc;
    972      1.105        ad 		mutex_spin_enter(&p->p_stmutex);
    973      1.108      yamt 	}
    974      1.108      yamt 
    975       1.19       cgd 	if (CLKF_USERMODE(frame)) {
    976      1.105        ad 		if ((p->p_stflag & PST_PROFIL) && profsrc == PROFSRC_CLOCK)
    977      1.105        ad 			addupc_intr(l, CLKF_PC(frame));
    978      1.105        ad 		if (--spc->spc_pscnt > 0) {
    979      1.105        ad 			mutex_spin_exit(&p->p_stmutex);
    980       1.19       cgd 			return;
    981      1.105        ad 		}
    982      1.105        ad 
    983       1.19       cgd 		/*
    984       1.19       cgd 		 * Came from user mode; CPU was in user state.
    985       1.19       cgd 		 * If this process is being profiled record the tick.
    986       1.19       cgd 		 */
    987       1.19       cgd 		p->p_uticks++;
    988       1.19       cgd 		if (p->p_nice > NZERO)
    989       1.60   thorpej 			spc->spc_cp_time[CP_NICE]++;
    990       1.19       cgd 		else
    991       1.60   thorpej 			spc->spc_cp_time[CP_USER]++;
    992       1.19       cgd 	} else {
    993       1.19       cgd #ifdef GPROF
    994       1.19       cgd 		/*
    995       1.19       cgd 		 * Kernel statistics are just like addupc_intr, only easier.
    996       1.19       cgd 		 */
    997       1.19       cgd 		g = &_gmonparam;
    998       1.80    briggs 		if (profsrc == PROFSRC_CLOCK && g->state == GMON_PROF_ON) {
    999       1.19       cgd 			i = CLKF_PC(frame) - g->lowpc;
   1000       1.19       cgd 			if (i < g->textsize) {
   1001       1.19       cgd 				i /= HISTFRACTION * sizeof(*g->kcount);
   1002       1.19       cgd 				g->kcount[i]++;
   1003       1.19       cgd 			}
   1004       1.19       cgd 		}
   1005       1.19       cgd #endif
   1006       1.82   thorpej #ifdef LWP_PC
   1007      1.108      yamt 		if (p != NULL && profsrc == PROFSRC_CLOCK &&
   1008      1.108      yamt 		    (p->p_stflag & PST_PROFIL)) {
   1009      1.105        ad 			addupc_intr(l, LWP_PC(l));
   1010      1.108      yamt 		}
   1011       1.72   mycroft #endif
   1012      1.105        ad 		if (--spc->spc_pscnt > 0) {
   1013      1.105        ad 			if (p != NULL)
   1014      1.105        ad 				mutex_spin_exit(&p->p_stmutex);
   1015       1.19       cgd 			return;
   1016      1.105        ad 		}
   1017       1.19       cgd 		/*
   1018       1.19       cgd 		 * Came from kernel mode, so we were:
   1019       1.19       cgd 		 * - handling an interrupt,
   1020       1.19       cgd 		 * - doing syscall or trap work on behalf of the current
   1021       1.19       cgd 		 *   user process, or
   1022       1.19       cgd 		 * - spinning in the idle loop.
   1023       1.19       cgd 		 * Whichever it is, charge the time as appropriate.
   1024       1.19       cgd 		 * Note that we charge interrupts to the current process,
   1025       1.19       cgd 		 * regardless of whether they are ``for'' that process,
   1026       1.19       cgd 		 * so that we know how much of its real time was spent
   1027       1.19       cgd 		 * in ``non-process'' (i.e., interrupt) work.
   1028       1.19       cgd 		 */
   1029      1.114        ad 		if (CLKF_INTR(frame) || (curlwp->l_pflag & LP_INTR) != 0) {
   1030      1.108      yamt 			if (p != NULL) {
   1031       1.19       cgd 				p->p_iticks++;
   1032      1.108      yamt 			}
   1033       1.60   thorpej 			spc->spc_cp_time[CP_INTR]++;
   1034       1.19       cgd 		} else if (p != NULL) {
   1035       1.19       cgd 			p->p_sticks++;
   1036       1.60   thorpej 			spc->spc_cp_time[CP_SYS]++;
   1037      1.108      yamt 		} else {
   1038       1.60   thorpej 			spc->spc_cp_time[CP_IDLE]++;
   1039      1.108      yamt 		}
   1040       1.19       cgd 	}
   1041       1.70  sommerfe 	spc->spc_pscnt = psdiv;
   1042       1.19       cgd 
   1043       1.97      elad 	if (p != NULL) {
   1044      1.108      yamt 		++l->l_cpticks;
   1045      1.105        ad 		mutex_spin_exit(&p->p_stmutex);
   1046      1.108      yamt 	}
   1047       1.19       cgd }
   1048       1.27  jonathan 
   1049       1.99    kardel #ifndef __HAVE_TIMECOUNTER
   1050       1.27  jonathan #ifdef NTP	/* NTP phase-locked loop in kernel */
   1051       1.27  jonathan /*
   1052       1.27  jonathan  * hardupdate() - local clock update
   1053       1.27  jonathan  *
   1054       1.27  jonathan  * This routine is called by ntp_adjtime() to update the local clock
   1055       1.27  jonathan  * phase and frequency. The implementation is of an adaptive-parameter,
   1056       1.27  jonathan  * hybrid phase/frequency-lock loop (PLL/FLL). The routine computes new
   1057       1.27  jonathan  * time and frequency offset estimates for each call. If the kernel PPS
   1058       1.27  jonathan  * discipline code is configured (PPS_SYNC), the PPS signal itself
   1059       1.27  jonathan  * determines the new time offset, instead of the calling argument.
   1060       1.27  jonathan  * Presumably, calls to ntp_adjtime() occur only when the caller
   1061       1.27  jonathan  * believes the local clock is valid within some bound (+-128 ms with
   1062       1.27  jonathan  * NTP). If the caller's time is far different than the PPS time, an
   1063       1.27  jonathan  * argument will ensue, and it's not clear who will lose.
   1064       1.27  jonathan  *
   1065       1.27  jonathan  * For uncompensated quartz crystal oscillatores and nominal update
   1066       1.27  jonathan  * intervals less than 1024 s, operation should be in phase-lock mode
   1067       1.27  jonathan  * (STA_FLL = 0), where the loop is disciplined to phase. For update
   1068       1.27  jonathan  * intervals greater than thiss, operation should be in frequency-lock
   1069       1.27  jonathan  * mode (STA_FLL = 1), where the loop is disciplined to frequency.
   1070       1.27  jonathan  *
   1071       1.27  jonathan  * Note: splclock() is in effect.
   1072       1.27  jonathan  */
   1073       1.27  jonathan void
   1074       1.63   thorpej hardupdate(long offset)
   1075       1.27  jonathan {
   1076       1.27  jonathan 	long ltemp, mtemp;
   1077       1.27  jonathan 
   1078       1.27  jonathan 	if (!(time_status & STA_PLL) && !(time_status & STA_PPSTIME))
   1079       1.27  jonathan 		return;
   1080       1.27  jonathan 	ltemp = offset;
   1081       1.27  jonathan #ifdef PPS_SYNC
   1082       1.27  jonathan 	if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL)
   1083       1.27  jonathan 		ltemp = pps_offset;
   1084       1.27  jonathan #endif /* PPS_SYNC */
   1085       1.27  jonathan 
   1086       1.27  jonathan 	/*
   1087       1.27  jonathan 	 * Scale the phase adjustment and clamp to the operating range.
   1088       1.27  jonathan 	 */
   1089       1.27  jonathan 	if (ltemp > MAXPHASE)
   1090       1.27  jonathan 		time_offset = MAXPHASE << SHIFT_UPDATE;
   1091       1.27  jonathan 	else if (ltemp < -MAXPHASE)
   1092       1.27  jonathan 		time_offset = -(MAXPHASE << SHIFT_UPDATE);
   1093       1.27  jonathan 	else
   1094       1.27  jonathan 		time_offset = ltemp << SHIFT_UPDATE;
   1095       1.27  jonathan 
   1096       1.27  jonathan 	/*
   1097       1.27  jonathan 	 * Select whether the frequency is to be controlled and in which
   1098       1.27  jonathan 	 * mode (PLL or FLL). Clamp to the operating range. Ugly
   1099       1.27  jonathan 	 * multiply/divide should be replaced someday.
   1100       1.27  jonathan 	 */
   1101       1.27  jonathan 	if (time_status & STA_FREQHOLD || time_reftime == 0)
   1102       1.27  jonathan 		time_reftime = time.tv_sec;
   1103       1.27  jonathan 	mtemp = time.tv_sec - time_reftime;
   1104       1.27  jonathan 	time_reftime = time.tv_sec;
   1105       1.27  jonathan 	if (time_status & STA_FLL) {
   1106       1.27  jonathan 		if (mtemp >= MINSEC) {
   1107       1.27  jonathan 			ltemp = ((time_offset / mtemp) << (SHIFT_USEC -
   1108       1.27  jonathan 			    SHIFT_UPDATE));
   1109       1.27  jonathan 			if (ltemp < 0)
   1110       1.27  jonathan 				time_freq -= -ltemp >> SHIFT_KH;
   1111       1.27  jonathan 			else
   1112       1.27  jonathan 				time_freq += ltemp >> SHIFT_KH;
   1113       1.27  jonathan 		}
   1114       1.27  jonathan 	} else {
   1115       1.27  jonathan 		if (mtemp < MAXSEC) {
   1116       1.27  jonathan 			ltemp *= mtemp;
   1117       1.27  jonathan 			if (ltemp < 0)
   1118       1.27  jonathan 				time_freq -= -ltemp >> (time_constant +
   1119       1.27  jonathan 				    time_constant + SHIFT_KF -
   1120       1.27  jonathan 				    SHIFT_USEC);
   1121       1.27  jonathan 			else
   1122       1.27  jonathan 				time_freq += ltemp >> (time_constant +
   1123       1.27  jonathan 				    time_constant + SHIFT_KF -
   1124       1.27  jonathan 				    SHIFT_USEC);
   1125       1.27  jonathan 		}
   1126       1.27  jonathan 	}
   1127       1.27  jonathan 	if (time_freq > time_tolerance)
   1128       1.27  jonathan 		time_freq = time_tolerance;
   1129       1.27  jonathan 	else if (time_freq < -time_tolerance)
   1130       1.27  jonathan 		time_freq = -time_tolerance;
   1131       1.27  jonathan }
   1132       1.27  jonathan 
   1133       1.27  jonathan #ifdef PPS_SYNC
   1134       1.27  jonathan /*
   1135       1.27  jonathan  * hardpps() - discipline CPU clock oscillator to external PPS signal
   1136       1.27  jonathan  *
   1137       1.27  jonathan  * This routine is called at each PPS interrupt in order to discipline
   1138       1.27  jonathan  * the CPU clock oscillator to the PPS signal. It measures the PPS phase
   1139       1.27  jonathan  * and leaves it in a handy spot for the hardclock() routine. It
   1140       1.27  jonathan  * integrates successive PPS phase differences and calculates the
   1141       1.27  jonathan  * frequency offset. This is used in hardclock() to discipline the CPU
   1142       1.27  jonathan  * clock oscillator so that intrinsic frequency error is cancelled out.
   1143       1.27  jonathan  * The code requires the caller to capture the time and hardware counter
   1144       1.27  jonathan  * value at the on-time PPS signal transition.
   1145       1.27  jonathan  *
   1146       1.27  jonathan  * Note that, on some Unix systems, this routine runs at an interrupt
   1147       1.27  jonathan  * priority level higher than the timer interrupt routine hardclock().
   1148       1.27  jonathan  * Therefore, the variables used are distinct from the hardclock()
   1149       1.27  jonathan  * variables, except for certain exceptions: The PPS frequency pps_freq
   1150       1.27  jonathan  * and phase pps_offset variables are determined by this routine and
   1151       1.27  jonathan  * updated atomically. The time_tolerance variable can be considered a
   1152       1.27  jonathan  * constant, since it is infrequently changed, and then only when the
   1153       1.27  jonathan  * PPS signal is disabled. The watchdog counter pps_valid is updated
   1154       1.27  jonathan  * once per second by hardclock() and is atomically cleared in this
   1155       1.27  jonathan  * routine.
   1156       1.27  jonathan  */
   1157       1.27  jonathan void
   1158       1.63   thorpej hardpps(struct timeval *tvp,		/* time at PPS */
   1159       1.63   thorpej 	long usec			/* hardware counter at PPS */)
   1160       1.27  jonathan {
   1161       1.27  jonathan 	long u_usec, v_usec, bigtick;
   1162       1.27  jonathan 	long cal_sec, cal_usec;
   1163       1.27  jonathan 
   1164       1.27  jonathan 	/*
   1165       1.27  jonathan 	 * An occasional glitch can be produced when the PPS interrupt
   1166       1.27  jonathan 	 * occurs in the hardclock() routine before the time variable is
   1167       1.27  jonathan 	 * updated. Here the offset is discarded when the difference
   1168       1.27  jonathan 	 * between it and the last one is greater than tick/2, but not
   1169       1.27  jonathan 	 * if the interval since the first discard exceeds 30 s.
   1170       1.27  jonathan 	 */
   1171       1.27  jonathan 	time_status |= STA_PPSSIGNAL;
   1172       1.27  jonathan 	time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
   1173       1.27  jonathan 	pps_valid = 0;
   1174       1.27  jonathan 	u_usec = -tvp->tv_usec;
   1175       1.27  jonathan 	if (u_usec < -500000)
   1176       1.27  jonathan 		u_usec += 1000000;
   1177       1.27  jonathan 	v_usec = pps_offset - u_usec;
   1178       1.27  jonathan 	if (v_usec < 0)
   1179       1.27  jonathan 		v_usec = -v_usec;
   1180       1.27  jonathan 	if (v_usec > (tick >> 1)) {
   1181       1.27  jonathan 		if (pps_glitch > MAXGLITCH) {
   1182       1.27  jonathan 			pps_glitch = 0;
   1183       1.27  jonathan 			pps_tf[2] = u_usec;
   1184       1.27  jonathan 			pps_tf[1] = u_usec;
   1185       1.27  jonathan 		} else {
   1186       1.27  jonathan 			pps_glitch++;
   1187       1.27  jonathan 			u_usec = pps_offset;
   1188       1.27  jonathan 		}
   1189       1.27  jonathan 	} else
   1190       1.27  jonathan 		pps_glitch = 0;
   1191       1.27  jonathan 
   1192       1.27  jonathan 	/*
   1193       1.27  jonathan 	 * A three-stage median filter is used to help deglitch the pps
   1194       1.27  jonathan 	 * time. The median sample becomes the time offset estimate; the
   1195       1.27  jonathan 	 * difference between the other two samples becomes the time
   1196       1.27  jonathan 	 * dispersion (jitter) estimate.
   1197       1.27  jonathan 	 */
   1198       1.27  jonathan 	pps_tf[2] = pps_tf[1];
   1199       1.27  jonathan 	pps_tf[1] = pps_tf[0];
   1200       1.27  jonathan 	pps_tf[0] = u_usec;
   1201       1.27  jonathan 	if (pps_tf[0] > pps_tf[1]) {
   1202       1.27  jonathan 		if (pps_tf[1] > pps_tf[2]) {
   1203       1.27  jonathan 			pps_offset = pps_tf[1];		/* 0 1 2 */
   1204       1.27  jonathan 			v_usec = pps_tf[0] - pps_tf[2];
   1205       1.27  jonathan 		} else if (pps_tf[2] > pps_tf[0]) {
   1206       1.27  jonathan 			pps_offset = pps_tf[0];		/* 2 0 1 */
   1207       1.27  jonathan 			v_usec = pps_tf[2] - pps_tf[1];
   1208       1.27  jonathan 		} else {
   1209       1.27  jonathan 			pps_offset = pps_tf[2];		/* 0 2 1 */
   1210       1.27  jonathan 			v_usec = pps_tf[0] - pps_tf[1];
   1211       1.27  jonathan 		}
   1212       1.27  jonathan 	} else {
   1213       1.27  jonathan 		if (pps_tf[1] < pps_tf[2]) {
   1214       1.27  jonathan 			pps_offset = pps_tf[1];		/* 2 1 0 */
   1215       1.27  jonathan 			v_usec = pps_tf[2] - pps_tf[0];
   1216       1.27  jonathan 		} else  if (pps_tf[2] < pps_tf[0]) {
   1217       1.27  jonathan 			pps_offset = pps_tf[0];		/* 1 0 2 */
   1218       1.27  jonathan 			v_usec = pps_tf[1] - pps_tf[2];
   1219       1.27  jonathan 		} else {
   1220       1.27  jonathan 			pps_offset = pps_tf[2];		/* 1 2 0 */
   1221       1.27  jonathan 			v_usec = pps_tf[1] - pps_tf[0];
   1222       1.27  jonathan 		}
   1223       1.27  jonathan 	}
   1224       1.27  jonathan 	if (v_usec > MAXTIME)
   1225       1.27  jonathan 		pps_jitcnt++;
   1226       1.27  jonathan 	v_usec = (v_usec << PPS_AVG) - pps_jitter;
   1227       1.27  jonathan 	if (v_usec < 0)
   1228       1.27  jonathan 		pps_jitter -= -v_usec >> PPS_AVG;
   1229       1.27  jonathan 	else
   1230       1.27  jonathan 		pps_jitter += v_usec >> PPS_AVG;
   1231       1.27  jonathan 	if (pps_jitter > (MAXTIME >> 1))
   1232       1.27  jonathan 		time_status |= STA_PPSJITTER;
   1233       1.27  jonathan 
   1234       1.27  jonathan 	/*
   1235       1.27  jonathan 	 * During the calibration interval adjust the starting time when
   1236       1.27  jonathan 	 * the tick overflows. At the end of the interval compute the
   1237       1.27  jonathan 	 * duration of the interval and the difference of the hardware
   1238       1.27  jonathan 	 * counters at the beginning and end of the interval. This code
   1239       1.27  jonathan 	 * is deliciously complicated by the fact valid differences may
   1240       1.27  jonathan 	 * exceed the value of tick when using long calibration
   1241       1.27  jonathan 	 * intervals and small ticks. Note that the counter can be
   1242       1.27  jonathan 	 * greater than tick if caught at just the wrong instant, but
   1243       1.27  jonathan 	 * the values returned and used here are correct.
   1244       1.27  jonathan 	 */
   1245       1.27  jonathan 	bigtick = (long)tick << SHIFT_USEC;
   1246       1.27  jonathan 	pps_usec -= pps_freq;
   1247       1.27  jonathan 	if (pps_usec >= bigtick)
   1248       1.27  jonathan 		pps_usec -= bigtick;
   1249       1.27  jonathan 	if (pps_usec < 0)
   1250       1.27  jonathan 		pps_usec += bigtick;
   1251       1.27  jonathan 	pps_time.tv_sec++;
   1252       1.27  jonathan 	pps_count++;
   1253       1.27  jonathan 	if (pps_count < (1 << pps_shift))
   1254       1.27  jonathan 		return;
   1255       1.27  jonathan 	pps_count = 0;
   1256       1.27  jonathan 	pps_calcnt++;
   1257       1.27  jonathan 	u_usec = usec << SHIFT_USEC;
   1258       1.27  jonathan 	v_usec = pps_usec - u_usec;
   1259       1.27  jonathan 	if (v_usec >= bigtick >> 1)
   1260       1.27  jonathan 		v_usec -= bigtick;
   1261       1.27  jonathan 	if (v_usec < -(bigtick >> 1))
   1262       1.27  jonathan 		v_usec += bigtick;
   1263       1.27  jonathan 	if (v_usec < 0)
   1264       1.27  jonathan 		v_usec = -(-v_usec >> pps_shift);
   1265       1.27  jonathan 	else
   1266       1.27  jonathan 		v_usec = v_usec >> pps_shift;
   1267       1.27  jonathan 	pps_usec = u_usec;
   1268       1.27  jonathan 	cal_sec = tvp->tv_sec;
   1269       1.27  jonathan 	cal_usec = tvp->tv_usec;
   1270       1.27  jonathan 	cal_sec -= pps_time.tv_sec;
   1271       1.27  jonathan 	cal_usec -= pps_time.tv_usec;
   1272       1.27  jonathan 	if (cal_usec < 0) {
   1273       1.27  jonathan 		cal_usec += 1000000;
   1274       1.27  jonathan 		cal_sec--;
   1275       1.27  jonathan 	}
   1276       1.27  jonathan 	pps_time = *tvp;
   1277       1.27  jonathan 
   1278       1.27  jonathan 	/*
   1279       1.27  jonathan 	 * Check for lost interrupts, noise, excessive jitter and
   1280       1.27  jonathan 	 * excessive frequency error. The number of timer ticks during
   1281       1.27  jonathan 	 * the interval may vary +-1 tick. Add to this a margin of one
   1282       1.27  jonathan 	 * tick for the PPS signal jitter and maximum frequency
   1283       1.27  jonathan 	 * deviation. If the limits are exceeded, the calibration
   1284       1.27  jonathan 	 * interval is reset to the minimum and we start over.
   1285       1.27  jonathan 	 */
   1286       1.27  jonathan 	u_usec = (long)tick << 1;
   1287       1.27  jonathan 	if (!((cal_sec == -1 && cal_usec > (1000000 - u_usec))
   1288       1.27  jonathan 	    || (cal_sec == 0 && cal_usec < u_usec))
   1289       1.27  jonathan 	    || v_usec > time_tolerance || v_usec < -time_tolerance) {
   1290       1.27  jonathan 		pps_errcnt++;
   1291       1.27  jonathan 		pps_shift = PPS_SHIFT;
   1292       1.27  jonathan 		pps_intcnt = 0;
   1293       1.27  jonathan 		time_status |= STA_PPSERROR;
   1294       1.27  jonathan 		return;
   1295       1.27  jonathan 	}
   1296       1.27  jonathan 
   1297       1.27  jonathan 	/*
   1298       1.27  jonathan 	 * A three-stage median filter is used to help deglitch the pps
   1299       1.27  jonathan 	 * frequency. The median sample becomes the frequency offset
   1300       1.27  jonathan 	 * estimate; the difference between the other two samples
   1301       1.27  jonathan 	 * becomes the frequency dispersion (stability) estimate.
   1302       1.27  jonathan 	 */
   1303       1.27  jonathan 	pps_ff[2] = pps_ff[1];
   1304       1.27  jonathan 	pps_ff[1] = pps_ff[0];
   1305       1.27  jonathan 	pps_ff[0] = v_usec;
   1306       1.27  jonathan 	if (pps_ff[0] > pps_ff[1]) {
   1307       1.27  jonathan 		if (pps_ff[1] > pps_ff[2]) {
   1308       1.27  jonathan 			u_usec = pps_ff[1];		/* 0 1 2 */
   1309       1.27  jonathan 			v_usec = pps_ff[0] - pps_ff[2];
   1310       1.27  jonathan 		} else if (pps_ff[2] > pps_ff[0]) {
   1311       1.27  jonathan 			u_usec = pps_ff[0];		/* 2 0 1 */
   1312       1.27  jonathan 			v_usec = pps_ff[2] - pps_ff[1];
   1313       1.27  jonathan 		} else {
   1314       1.27  jonathan 			u_usec = pps_ff[2];		/* 0 2 1 */
   1315       1.27  jonathan 			v_usec = pps_ff[0] - pps_ff[1];
   1316       1.27  jonathan 		}
   1317       1.27  jonathan 	} else {
   1318       1.27  jonathan 		if (pps_ff[1] < pps_ff[2]) {
   1319       1.27  jonathan 			u_usec = pps_ff[1];		/* 2 1 0 */
   1320       1.27  jonathan 			v_usec = pps_ff[2] - pps_ff[0];
   1321       1.27  jonathan 		} else  if (pps_ff[2] < pps_ff[0]) {
   1322       1.27  jonathan 			u_usec = pps_ff[0];		/* 1 0 2 */
   1323       1.27  jonathan 			v_usec = pps_ff[1] - pps_ff[2];
   1324       1.27  jonathan 		} else {
   1325       1.27  jonathan 			u_usec = pps_ff[2];		/* 1 2 0 */
   1326       1.27  jonathan 			v_usec = pps_ff[1] - pps_ff[0];
   1327       1.27  jonathan 		}
   1328       1.27  jonathan 	}
   1329       1.27  jonathan 
   1330       1.27  jonathan 	/*
   1331       1.27  jonathan 	 * Here the frequency dispersion (stability) is updated. If it
   1332       1.27  jonathan 	 * is less than one-fourth the maximum (MAXFREQ), the frequency
   1333       1.27  jonathan 	 * offset is updated as well, but clamped to the tolerance. It
   1334       1.27  jonathan 	 * will be processed later by the hardclock() routine.
   1335       1.27  jonathan 	 */
   1336       1.27  jonathan 	v_usec = (v_usec >> 1) - pps_stabil;
   1337       1.27  jonathan 	if (v_usec < 0)
   1338       1.27  jonathan 		pps_stabil -= -v_usec >> PPS_AVG;
   1339       1.27  jonathan 	else
   1340       1.27  jonathan 		pps_stabil += v_usec >> PPS_AVG;
   1341       1.27  jonathan 	if (pps_stabil > MAXFREQ >> 2) {
   1342       1.27  jonathan 		pps_stbcnt++;
   1343       1.27  jonathan 		time_status |= STA_PPSWANDER;
   1344       1.27  jonathan 		return;
   1345       1.27  jonathan 	}
   1346       1.27  jonathan 	if (time_status & STA_PPSFREQ) {
   1347       1.27  jonathan 		if (u_usec < 0) {
   1348       1.27  jonathan 			pps_freq -= -u_usec >> PPS_AVG;
   1349       1.27  jonathan 			if (pps_freq < -time_tolerance)
   1350       1.27  jonathan 				pps_freq = -time_tolerance;
   1351       1.27  jonathan 			u_usec = -u_usec;
   1352       1.27  jonathan 		} else {
   1353       1.27  jonathan 			pps_freq += u_usec >> PPS_AVG;
   1354       1.27  jonathan 			if (pps_freq > time_tolerance)
   1355       1.27  jonathan 				pps_freq = time_tolerance;
   1356       1.27  jonathan 		}
   1357       1.27  jonathan 	}
   1358       1.27  jonathan 
   1359       1.27  jonathan 	/*
   1360       1.27  jonathan 	 * Here the calibration interval is adjusted. If the maximum
   1361       1.27  jonathan 	 * time difference is greater than tick / 4, reduce the interval
   1362       1.27  jonathan 	 * by half. If this is not the case for four consecutive
   1363       1.27  jonathan 	 * intervals, double the interval.
   1364       1.27  jonathan 	 */
   1365       1.27  jonathan 	if (u_usec << pps_shift > bigtick >> 2) {
   1366       1.27  jonathan 		pps_intcnt = 0;
   1367       1.27  jonathan 		if (pps_shift > PPS_SHIFT)
   1368       1.27  jonathan 			pps_shift--;
   1369       1.27  jonathan 	} else if (pps_intcnt >= 4) {
   1370       1.27  jonathan 		pps_intcnt = 0;
   1371       1.27  jonathan 		if (pps_shift < PPS_SHIFTMAX)
   1372       1.27  jonathan 			pps_shift++;
   1373       1.27  jonathan 	} else
   1374       1.27  jonathan 		pps_intcnt++;
   1375       1.27  jonathan }
   1376       1.27  jonathan #endif /* PPS_SYNC */
   1377       1.27  jonathan #endif /* NTP  */
   1378       1.95  christos 
   1379       1.99    kardel /* timecounter compat functions */
   1380       1.99    kardel void
   1381  1.114.6.1    bouyer binuptime(struct bintime *bt)
   1382       1.95  christos {
   1383       1.95  christos 	struct timeval tv;
   1384       1.95  christos 
   1385  1.114.6.1    bouyer 	microuptime(&tv);
   1386  1.114.6.1    bouyer 	timeval2bintime(&tv, bt);
   1387       1.95  christos }
   1388       1.99    kardel 
   1389       1.99    kardel void
   1390  1.114.6.1    bouyer nanouptime(struct timespec *tsp)
   1391  1.114.6.1    bouyer {
   1392  1.114.6.1    bouyer 	struct timeval tv;
   1393  1.114.6.1    bouyer 
   1394  1.114.6.1    bouyer 	microuptime(&tv);
   1395  1.114.6.1    bouyer 	TIMEVAL_TO_TIMESPEC(&mono_time, tsp);
   1396  1.114.6.1    bouyer }
   1397  1.114.6.1    bouyer 
   1398  1.114.6.1    bouyer void
   1399  1.114.6.1    bouyer microuptime(struct timeval *tv)
   1400  1.114.6.1    bouyer {
   1401  1.114.6.1    bouyer 	struct timeval t;
   1402  1.114.6.1    bouyer 	int s;
   1403  1.114.6.1    bouyer 
   1404  1.114.6.1    bouyer 	/* microtime + time - mono_time */
   1405  1.114.6.1    bouyer 	microtime(&t);
   1406  1.114.6.1    bouyer 	s = splclock();
   1407  1.114.6.1    bouyer 	timeradd(&t, &time, &t);
   1408  1.114.6.1    bouyer 	timersub(&t, &mono_time, &t);
   1409  1.114.6.1    bouyer 	splx(s);
   1410  1.114.6.1    bouyer }
   1411  1.114.6.1    bouyer 
   1412  1.114.6.1    bouyer void
   1413  1.114.6.1    bouyer bintime(struct bintime *bt)
   1414       1.99    kardel {
   1415       1.99    kardel 	struct timeval tv;
   1416       1.99    kardel 
   1417       1.99    kardel 	microtime(&tv);
   1418       1.99    kardel 	timeval2bintime(&tv, bt);
   1419       1.99    kardel }
   1420       1.99    kardel 
   1421       1.99    kardel void
   1422  1.114.6.1    bouyer nanotime(struct timespec *ts)
   1423  1.114.6.1    bouyer {
   1424  1.114.6.1    bouyer 	struct timeval tv;
   1425  1.114.6.1    bouyer 
   1426  1.114.6.1    bouyer 	microtime(&tv);
   1427  1.114.6.1    bouyer 	TIMEVAL_TO_TIMESPEC(&tv, ts);
   1428  1.114.6.1    bouyer }
   1429  1.114.6.1    bouyer 
   1430  1.114.6.1    bouyer void
   1431  1.114.6.1    bouyer getbinuptime(struct bintime *bt)
   1432       1.99    kardel {
   1433       1.99    kardel 	int s;
   1434       1.99    kardel 
   1435       1.99    kardel 	s = splclock();
   1436  1.114.6.1    bouyer 	timeval2bintime(__UNVOLATILE(&mono_time), bt);
   1437       1.99    kardel 	splx(s);
   1438       1.99    kardel }
   1439       1.99    kardel 
   1440       1.99    kardel void
   1441       1.99    kardel getnanouptime(struct timespec *tsp)
   1442       1.99    kardel {
   1443       1.99    kardel 	int s;
   1444       1.99    kardel 
   1445       1.99    kardel 	s = splclock();
   1446       1.99    kardel 	TIMEVAL_TO_TIMESPEC(&mono_time, tsp);
   1447       1.99    kardel 	splx(s);
   1448       1.99    kardel }
   1449       1.99    kardel 
   1450       1.99    kardel void
   1451       1.99    kardel getmicrouptime(struct timeval *tvp)
   1452       1.99    kardel {
   1453       1.99    kardel 	int s;
   1454       1.99    kardel 
   1455       1.99    kardel 	s = splclock();
   1456       1.99    kardel 	*tvp = mono_time;
   1457       1.99    kardel 	splx(s);
   1458       1.99    kardel }
   1459       1.99    kardel 
   1460       1.99    kardel void
   1461  1.114.6.1    bouyer getbintime(struct bintime *bt)
   1462  1.114.6.1    bouyer {
   1463  1.114.6.1    bouyer 	int s;
   1464  1.114.6.1    bouyer 
   1465  1.114.6.1    bouyer 	s = splclock();
   1466  1.114.6.1    bouyer 	timeval2bintime(__UNVOLATILE(&time), bt);
   1467  1.114.6.1    bouyer 	splx(s);
   1468  1.114.6.1    bouyer }
   1469  1.114.6.1    bouyer 
   1470  1.114.6.1    bouyer void
   1471       1.99    kardel getnanotime(struct timespec *tsp)
   1472       1.99    kardel {
   1473       1.99    kardel 	int s;
   1474       1.99    kardel 
   1475       1.99    kardel 	s = splclock();
   1476       1.99    kardel 	TIMEVAL_TO_TIMESPEC(&time, tsp);
   1477       1.99    kardel 	splx(s);
   1478       1.99    kardel }
   1479       1.99    kardel 
   1480       1.99    kardel void
   1481       1.99    kardel getmicrotime(struct timeval *tvp)
   1482       1.99    kardel {
   1483       1.99    kardel 	int s;
   1484       1.99    kardel 
   1485       1.99    kardel 	s = splclock();
   1486       1.99    kardel 	*tvp = time;
   1487       1.99    kardel 	splx(s);
   1488       1.99    kardel }
   1489      1.107       dsl 
   1490      1.107       dsl u_int64_t
   1491      1.107       dsl tc_getfrequency(void)
   1492      1.107       dsl {
   1493      1.107       dsl 	return hz;
   1494      1.107       dsl }
   1495  1.114.6.1    bouyer 
   1496  1.114.6.1    bouyer void
   1497  1.114.6.1    bouyer tc_setclock(struct timespec *ts)
   1498  1.114.6.1    bouyer {
   1499  1.114.6.1    bouyer 	struct timeval tv;
   1500  1.114.6.1    bouyer 
   1501  1.114.6.1    bouyer 	TIMESPEC_TO_TIMEVAL(&tv, ts);
   1502  1.114.6.1    bouyer 	time = tv;
   1503  1.114.6.1    bouyer }
   1504       1.99    kardel #endif /* !__HAVE_TIMECOUNTER */
   1505