staticize lwkt_reqtoken_remote().

[dragonfly/netmp.git] / sys / kern / kern_clock.c

/*
 * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
 * 
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * Copyright (c) 1997, 1998 Poul-Henning Kamp <phk@FreeBSD.org>
 * Copyright (c) 1982, 1986, 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)kern_clock.c        8.5 (Berkeley) 1/21/94
 * $FreeBSD: src/sys/kern/kern_clock.c,v 1.105.2.10 2002/10/17 13:19:40 maxim Exp $
 * $DragonFly: src/sys/kern/kern_clock.c,v 1.34 2005/04/14 11:15:52 joerg Exp $
 */

#include "opt_ntp.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/dkstat.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/kinfo.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/timex.h>
#include <sys/timepps.h>
#include <vm/vm.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <sys/sysctl.h>
#include <sys/thread2.h>

#include <machine/cpu.h>
#include <machine/limits.h>
#include <machine/smp.h>

#ifdef GPROF
#include <sys/gmon.h>
#endif

#ifdef DEVICE_POLLING
extern void init_device_poll(void);
extern void hardclock_device_poll(void);
#endif /* DEVICE_POLLING */

static void initclocks (void *dummy);
SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)

/*
 * Some of these don't belong here, but it's easiest to concentrate them.
 * Note that cp_time counts in microseconds, but most userland programs
 * just compare relative times against the total by delta.
 */
struct cp_time cp_time;

SYSCTL_OPAQUE(_kern, OID_AUTO, cp_time, CTLFLAG_RD, &cp_time, sizeof(cp_time),
    "LU", "CPU time statistics");

/*
 * boottime is used to calculate the 'real' uptime.  Do not confuse this with
 * microuptime().  microtime() is not drift compensated.  The real uptime
 * with compensation is nanotime() - bootime.  boottime is recalculated
 * whenever the real time is set based on the compensated elapsed time
 * in seconds (gd->gd_time_seconds).
 *
 * basetime is used to calculate the compensated real time of day.  Chunky
 * changes to the time, aka settimeofday(), are made by modifying basetime.
 *
 * The gd_time_seconds and gd_cpuclock_base fields remain fairly monotonic.
 * Slight adjustments to gd_cpuclock_base are made to phase-lock it to
 * the real time.
 */
struct timespec boottime;       /* boot time (realtime) for reference only */
struct timespec basetime;       /* base time adjusts uptime -> realtime */
time_t time_second;             /* read-only 'passive' uptime in seconds */

SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
    &boottime, timeval, "System boottime");
SYSCTL_STRUCT(_kern, OID_AUTO, basetime, CTLFLAG_RD,
    &basetime, timeval, "System basetime");

static void hardclock(systimer_t info, struct intrframe *frame);
static void statclock(systimer_t info, struct intrframe *frame);
static void schedclock(systimer_t info, struct intrframe *frame);

int     ticks;                  /* system master ticks at hz */
int     clocks_running;         /* tsleep/timeout clocks operational */
int64_t nsec_adj;               /* ntpd per-tick adjustment in nsec << 32 */
int64_t nsec_acc;               /* accumulator */

/* NTPD time correction fields */
int64_t ntp_tick_permanent;     /* per-tick adjustment in nsec << 32 */
int64_t ntp_tick_acc;           /* accumulator for per-tick adjustment */
int64_t ntp_delta;              /* one-time correction in nsec */
int64_t ntp_big_delta = 1000000000;
int32_t ntp_tick_delta;         /* current adjustment rate */
int32_t ntp_default_tick_delta; /* adjustment rate for ntp_delta */
time_t  ntp_leap_second;        /* time of next leap second */
int     ntp_leap_insert;        /* whether to insert or remove a second */

/*
 * Finish initializing clock frequencies and start all clocks running.
 */
/* ARGSUSED*/
static void
initclocks(void *dummy)
{
        cpu_initclocks();
#ifdef DEVICE_POLLING
        init_device_poll();
#endif
        /*psratio = profhz / stathz;*/
        initclocks_pcpu();
        clocks_running = 1;
}

/*
 * Called on a per-cpu basis
 */
void
initclocks_pcpu(void)
{
        struct globaldata *gd = mycpu;

        crit_enter();
        if (gd->gd_cpuid == 0) {
            gd->gd_time_seconds = 1;
            gd->gd_cpuclock_base = cputimer_count();
        } else {
            /* XXX */
            gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
            gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
        }

        /*
         * Use a non-queued periodic systimer to prevent multiple ticks from
         * building up if the sysclock jumps forward (8254 gets reset).  The
         * sysclock will never jump backwards.  Our time sync is based on
         * the actual sysclock, not the ticks count.
         */
        systimer_init_periodic_nq(&gd->gd_hardclock, hardclock, NULL, hz);
        systimer_init_periodic_nq(&gd->gd_statclock, statclock, NULL, stathz);
        /* XXX correct the frequency for scheduler / estcpu tests */
        systimer_init_periodic_nq(&gd->gd_schedclock, schedclock, 
                                NULL, ESTCPUFREQ); 
        crit_exit();
}

/*
 * This sets the current real time of day.  Timespecs are in seconds and
 * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
 * instead we adjust basetime so basetime + gd_* results in the current
 * time of day.  This way the gd_* fields are guarenteed to represent
 * a monotonically increasing 'uptime' value.
 */
void
set_timeofday(struct timespec *ts)
{
        struct timespec ts2;

        /*
         * XXX SMP / non-atomic basetime updates
         */
        crit_enter();
        nanouptime(&ts2);
        basetime.tv_sec = ts->tv_sec - ts2.tv_sec;
        basetime.tv_nsec = ts->tv_nsec - ts2.tv_nsec;
        if (basetime.tv_nsec < 0) {
            basetime.tv_nsec += 1000000000;
            --basetime.tv_sec;
        }

        /*
         * Note that basetime diverges from boottime as the clock drift is
         * compensated for, so we cannot do away with boottime.  When setting
         * the absolute time of day the drift is 0 (for an instant) and we
         * can simply assign boottime to basetime.  
         *
         * Note that nanouptime() is based on gd_time_seconds which is drift
         * compensated up to a point (it is guarenteed to remain monotonically
         * increasing).  gd_time_seconds is thus our best uptime guess and
         * suitable for use in the boottime calculation.  It is already taken
         * into account in the basetime calculation above.
         */
        boottime.tv_sec = basetime.tv_sec;
        ntp_delta = 0;
        crit_exit();
}
        
/*
 * Each cpu has its own hardclock, but we only increments ticks and softticks
 * on cpu #0.
 *
 * NOTE! systimer! the MP lock might not be held here.  We can only safely
 * manipulate objects owned by the current cpu.
 */
static void
hardclock(systimer_t info, struct intrframe *frame)
{
        sysclock_t cputicks;
        struct proc *p;
        struct pstats *pstats;
        struct globaldata *gd = mycpu;

        /*
         * Realtime updates are per-cpu.  Note that timer corrections as
         * returned by microtime() and friends make an additional adjustment
         * using a system-wise 'basetime', but the running time is always
         * taken from the per-cpu globaldata area.  Since the same clock
         * is distributing (XXX SMP) to all cpus, the per-cpu timebases
         * stay in synch.
         *
         * Note that we never allow info->time (aka gd->gd_hardclock.time)
         * to reverse index gd_cpuclock_base, but that it is possible for
         * it to temporarily get behind in the seconds if something in the
         * system locks interrupts for a long period of time.  Since periodic
         * timers count events, though everything should resynch again
         * immediately.
         */
        cputicks = info->time - gd->gd_cpuclock_base;
        if (cputicks >= cputimer_freq) {
                ++gd->gd_time_seconds;
                gd->gd_cpuclock_base += cputimer_freq;
        }

        /*
         * The system-wide ticks counter and NTP related timedelta/tickdelta
         * adjustments only occur on cpu #0.  NTP adjustments are accomplished
         * by updating basetime.
         */
        if (gd->gd_cpuid == 0) {
            struct timespec nts;
            int leap;

            ++ticks;

#ifdef DEVICE_POLLING
            hardclock_device_poll();    /* mpsafe, short and quick */
#endif /* DEVICE_POLLING */

#if 0
            if (tco->tc_poll_pps) 
                tco->tc_poll_pps(tco);
#endif
            /*
             * Apply adjtime corrections.  At the moment only do this if 
             * we can get the MP lock to interlock with adjtime's modification
             * of these variables.  Note that basetime adjustments are not
             * MP safe either XXX.
             */
            if (ntp_delta != 0) {
                basetime.tv_nsec += ntp_tick_delta;
                ntp_delta -= ntp_tick_delta;
                if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
                    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
                                ntp_tick_delta = ntp_delta;
                }
            }

            if (ntp_tick_permanent != 0) {
                ntp_tick_acc += ntp_tick_permanent;
                if (ntp_tick_acc >= (1LL << 32)) {
                    basetime.tv_nsec += (-ntp_tick_acc) >> 32;
                    ntp_tick_acc &= (1LL << 32) - 1;
                } else if (ntp_tick_acc <= -(1LL << 32)) {
                    basetime.tv_nsec -= (-ntp_tick_acc) >> 32;
                    ntp_tick_acc = -((-ntp_tick_acc) & ((1LL << 32) - 1));
                }
            }

            if (basetime.tv_nsec >= 1000000000) {
                    basetime.tv_sec++;
                    basetime.tv_nsec -= 1000000000;
            } else if (basetime.tv_nsec < 0) {
                    basetime.tv_sec--;
                    basetime.tv_nsec += 1000000000;
            }

            if (ntp_leap_second) {
                struct timespec tsp;
                nanotime(&tsp);

                if (ntp_leap_second == tsp.tv_sec) {
                        if (ntp_leap_insert)
                                basetime.tv_sec++;
                        else
                                basetime.tv_sec--;
                        ntp_leap_second--;
                }
            }

            /*
             * Apply per-tick compensation.  ticks_adj adjusts for both
             * offset and frequency, and could be negative.
             */
            if (nsec_adj != 0 && try_mplock()) {
                nsec_acc += nsec_adj;
                if (nsec_acc >= 0x100000000LL) {
                    basetime.tv_nsec += nsec_acc >> 32;
                    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
                } else if (nsec_acc <= -0x100000000LL) {
                    basetime.tv_nsec -= -nsec_acc >> 32;
                    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
                }
                if (basetime.tv_nsec >= 1000000000) {
                    basetime.tv_nsec -= 1000000000;
                    ++basetime.tv_sec;
                } else if (basetime.tv_nsec < 0) {
                    basetime.tv_nsec += 1000000000;
                    --basetime.tv_sec;
                }
                rel_mplock();
            }

            /*
             * If the realtime-adjusted seconds hand rolls over then tell
             * ntp_update_second() what we did in the last second so it can
             * calculate what to do in the next second.  It may also add
             * or subtract a leap second.
             */
            getnanotime(&nts);
            if (time_second != nts.tv_sec) {
                leap = ntp_update_second(time_second, &nsec_adj);
                basetime.tv_sec += leap;
                time_second = nts.tv_sec + leap;
                nsec_adj /= hz;
            }
        }

        /*
         * softticks are handled for all cpus
         */
        hardclock_softtick(gd);

        /*
         * ITimer handling is per-tick, per-cpu.  I don't think psignal()
         * is mpsafe on curproc, so XXX get the mplock.
         */
        if ((p = curproc) != NULL && try_mplock()) {
                pstats = p->p_stats;
                if (frame && CLKF_USERMODE(frame) &&
                    timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) &&
                    itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0)
                        psignal(p, SIGVTALRM);
                if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value) &&
                    itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0)
                        psignal(p, SIGPROF);
                rel_mplock();
        }
        setdelayed();
}

/*
 * The statistics clock typically runs at a 125Hz rate, and is intended
 * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
 *
 * NOTE! systimer! the MP lock might not be held here.  We can only safely
 * manipulate objects owned by the current cpu.
 *
 * The stats clock is responsible for grabbing a profiling sample.
 * Most of the statistics are only used by user-level statistics programs.
 * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
 * p->p_estcpu.
 *
 * Like the other clocks, the stat clock is called from what is effectively
 * a fast interrupt, so the context should be the thread/process that got
 * interrupted.
 */
static void
statclock(systimer_t info, struct intrframe *frame)
{
#ifdef GPROF
        struct gmonparam *g;
        int i;
#endif
        thread_t td;
        struct proc *p;
        int bump;
        struct timeval tv;
        struct timeval *stv;

        /*
         * How big was our timeslice relative to the last time?
         */
        microuptime(&tv);       /* mpsafe */
        stv = &mycpu->gd_stattv;
        if (stv->tv_sec == 0) {
            bump = 1;
        } else {
            bump = tv.tv_usec - stv->tv_usec +
                (tv.tv_sec - stv->tv_sec) * 1000000;
            if (bump < 0)
                bump = 0;
            if (bump > 1000000)
                bump = 1000000;
        }
        *stv = tv;

        td = curthread;
        p = td->td_proc;

        if (frame && CLKF_USERMODE(frame)) {
                /*
                 * Came from userland, handle user time and deal with
                 * possible process.
                 */
                if (p && (p->p_flag & P_PROFIL))
                        addupc_intr(p, CLKF_PC(frame), 1);
                td->td_uticks += bump;

                /*
                 * Charge the time as appropriate
                 */
                if (p && p->p_nice > NZERO)
                        cp_time.cp_nice += bump;
                else
                        cp_time.cp_user += bump;
        } else {
#ifdef GPROF
                /*
                 * Kernel statistics are just like addupc_intr, only easier.
                 */
                g = &_gmonparam;
                if (g->state == GMON_PROF_ON && frame) {
                        i = CLKF_PC(frame) - g->lowpc;
                        if (i < g->textsize) {
                                i /= HISTFRACTION * sizeof(*g->kcount);
                                g->kcount[i]++;
                        }
                }
#endif
                /*
                 * Came from kernel mode, so we were:
                 * - handling an interrupt,
                 * - doing syscall or trap work on behalf of the current
                 *   user process, or
                 * - spinning in the idle loop.
                 * Whichever it is, charge the time as appropriate.
                 * Note that we charge interrupts to the current process,
                 * regardless of whether they are ``for'' that process,
                 * so that we know how much of its real time was spent
                 * in ``non-process'' (i.e., interrupt) work.
                 *
                 * XXX assume system if frame is NULL.  A NULL frame 
                 * can occur if ipi processing is done from an splx().
                 */
                if (frame && CLKF_INTR(frame))
                        td->td_iticks += bump;
                else
                        td->td_sticks += bump;

                if (frame && CLKF_INTR(frame)) {
                        cp_time.cp_intr += bump;
                } else {
                        if (td == &mycpu->gd_idlethread)
                                cp_time.cp_idle += bump;
                        else
                                cp_time.cp_sys += bump;
                }
        }
}

/*
 * The scheduler clock typically runs at a 20Hz rate.  NOTE! systimer,
 * the MP lock might not be held.  We can safely manipulate parts of curproc
 * but that's about it.
 */
static void
schedclock(systimer_t info, struct intrframe *frame)
{
        struct proc *p;
        struct pstats *pstats;
        struct rusage *ru;
        struct vmspace *vm;
        long rss;

        schedulerclock(NULL);   /* mpsafe */
        if ((p = curproc) != NULL) {
                /* Update resource usage integrals and maximums. */
                if ((pstats = p->p_stats) != NULL &&
                    (ru = &pstats->p_ru) != NULL &&
                    (vm = p->p_vmspace) != NULL) {
                        ru->ru_ixrss += pgtok(vm->vm_tsize);
                        ru->ru_idrss += pgtok(vm->vm_dsize);
                        ru->ru_isrss += pgtok(vm->vm_ssize);
                        rss = pgtok(vmspace_resident_count(vm));
                        if (ru->ru_maxrss < rss)
                                ru->ru_maxrss = rss;
                }
        }
}

/*
 * Compute number of ticks for the specified amount of time.  The 
 * return value is intended to be used in a clock interrupt timed
 * operation and guarenteed to meet or exceed the requested time.
 * If the representation overflows, return INT_MAX.  The minimum return
 * value is 1 ticks and the function will average the calculation up.
 * If any value greater then 0 microseconds is supplied, a value
 * of at least 2 will be returned to ensure that a near-term clock
 * interrupt does not cause the timeout to occur (degenerately) early.
 *
 * Note that limit checks must take into account microseconds, which is
 * done simply by using the smaller signed long maximum instead of
 * the unsigned long maximum.
 *
 * If ints have 32 bits, then the maximum value for any timeout in
 * 10ms ticks is 248 days.
 */
int
tvtohz_high(struct timeval *tv)
{
        int ticks;
        long sec, usec;

        sec = tv->tv_sec;
        usec = tv->tv_usec;
        if (usec < 0) {
                sec--;
                usec += 1000000;
        }
        if (sec < 0) {
#ifdef DIAGNOSTIC
                if (usec > 0) {
                        sec++;
                        usec -= 1000000;
                }
                printf("tvotohz: negative time difference %ld sec %ld usec\n",
                       sec, usec);
#endif
                ticks = 1;
        } else if (sec <= INT_MAX / hz) {
                ticks = (int)(sec * hz + 
                            ((u_long)usec + (tick - 1)) / tick) + 1;
        } else {
                ticks = INT_MAX;
        }
        return (ticks);
}

/*
 * Compute number of ticks for the specified amount of time, erroring on
 * the side of it being too low to ensure that sleeping the returned number
 * of ticks will not result in a late return.
 *
 * The supplied timeval may not be negative and should be normalized.  A
 * return value of 0 is possible if the timeval converts to less then
 * 1 tick.
 *
 * If ints have 32 bits, then the maximum value for any timeout in
 * 10ms ticks is 248 days.
 */
int
tvtohz_low(struct timeval *tv)
{
        int ticks;
        long sec;

        sec = tv->tv_sec;
        if (sec <= INT_MAX / hz)
                ticks = (int)(sec * hz + (u_long)tv->tv_usec / tick);
        else
                ticks = INT_MAX;
        return (ticks);
}


/*
 * Start profiling on a process.
 *
 * Kernel profiling passes proc0 which never exits and hence
 * keeps the profile clock running constantly.
 */
void
startprofclock(struct proc *p)
{
        if ((p->p_flag & P_PROFIL) == 0) {
                p->p_flag |= P_PROFIL;
#if 0   /* XXX */
                if (++profprocs == 1 && stathz != 0) {
                        s = splstatclock();
                        psdiv = psratio;
                        setstatclockrate(profhz);
                        splx(s);
                }
#endif
        }
}

/*
 * Stop profiling on a process.
 */
void
stopprofclock(struct proc *p)
{
        if (p->p_flag & P_PROFIL) {
                p->p_flag &= ~P_PROFIL;
#if 0   /* XXX */
                if (--profprocs == 0 && stathz != 0) {
                        s = splstatclock();
                        psdiv = 1;
                        setstatclockrate(stathz);
                        splx(s);
                }
#endif
        }
}

/*
 * Return information about system clocks.
 */
static int
sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
{
        struct kinfo_clockinfo clkinfo;
        /*
         * Construct clockinfo structure.
         */
        clkinfo.ci_hz = hz;
        clkinfo.ci_tick = tick;
        clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
        clkinfo.ci_profhz = profhz;
        clkinfo.ci_stathz = stathz ? stathz : hz;
        return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
}

SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
        0, 0, sysctl_kern_clockrate, "S,clockinfo","");

/*
 * We have eight functions for looking at the clock, four for
 * microseconds and four for nanoseconds.  For each there is fast
 * but less precise version "get{nano|micro}[up]time" which will
 * return a time which is up to 1/HZ previous to the call, whereas
 * the raw version "{nano|micro}[up]time" will return a timestamp
 * which is as precise as possible.  The "up" variants return the
 * time relative to system boot, these are well suited for time
 * interval measurements.
 *
 * Each cpu independantly maintains the current time of day, so all
 * we need to do to protect ourselves from changes is to do a loop
 * check on the seconds field changing out from under us.
 *
 * The system timer maintains a 32 bit count and due to various issues
 * it is possible for the calculated delta to occassionally exceed
 * cputimer_freq.  If this occurs the cputimer_freq64_nsec multiplication
 * can easily overflow, so we deal with the case.  For uniformity we deal
 * with the case in the usec case too.
 */
void
getmicrouptime(struct timeval *tvp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tvp->tv_sec = gd->gd_time_seconds;
                delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
        } while (tvp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tvp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tvp->tv_usec = (cputimer_freq64_usec * delta) >> 32;
        if (tvp->tv_usec >= 1000000) {
                tvp->tv_usec -= 1000000;
                ++tvp->tv_sec;
        }
}

void
getnanouptime(struct timespec *tsp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tsp->tv_sec = gd->gd_time_seconds;
                delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
        } while (tsp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tsp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tsp->tv_nsec = (cputimer_freq64_nsec * delta) >> 32;
}

void
microuptime(struct timeval *tvp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tvp->tv_sec = gd->gd_time_seconds;
                delta = cputimer_count() - gd->gd_cpuclock_base;
        } while (tvp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tvp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tvp->tv_usec = (cputimer_freq64_usec * delta) >> 32;
}

void
nanouptime(struct timespec *tsp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tsp->tv_sec = gd->gd_time_seconds;
                delta = cputimer_count() - gd->gd_cpuclock_base;
        } while (tsp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tsp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tsp->tv_nsec = (cputimer_freq64_nsec * delta) >> 32;
}

/*
 * realtime routines
 */

void
getmicrotime(struct timeval *tvp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tvp->tv_sec = gd->gd_time_seconds;
                delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
        } while (tvp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tvp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tvp->tv_usec = (cputimer_freq64_usec * delta) >> 32;

        tvp->tv_sec += basetime.tv_sec;
        tvp->tv_usec += basetime.tv_nsec / 1000;
        while (tvp->tv_usec >= 1000000) {
                tvp->tv_usec -= 1000000;
                ++tvp->tv_sec;
        }
}

void
getnanotime(struct timespec *tsp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tsp->tv_sec = gd->gd_time_seconds;
                delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
        } while (tsp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tsp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tsp->tv_nsec = (cputimer_freq64_nsec * delta) >> 32;

        tsp->tv_sec += basetime.tv_sec;
        tsp->tv_nsec += basetime.tv_nsec;
        while (tsp->tv_nsec >= 1000000000) {
                tsp->tv_nsec -= 1000000000;
                ++tsp->tv_sec;
        }
}

void
microtime(struct timeval *tvp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tvp->tv_sec = gd->gd_time_seconds;
                delta = cputimer_count() - gd->gd_cpuclock_base;
        } while (tvp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tvp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tvp->tv_usec = (cputimer_freq64_usec * delta) >> 32;

        tvp->tv_sec += basetime.tv_sec;
        tvp->tv_usec += basetime.tv_nsec / 1000;
        while (tvp->tv_usec >= 1000000) {
                tvp->tv_usec -= 1000000;
                ++tvp->tv_sec;
        }
}

void
nanotime(struct timespec *tsp)
{
        struct globaldata *gd = mycpu;
        sysclock_t delta;

        do {
                tsp->tv_sec = gd->gd_time_seconds;
                delta = cputimer_count() - gd->gd_cpuclock_base;
        } while (tsp->tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                tsp->tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        tsp->tv_nsec = (cputimer_freq64_nsec * delta) >> 32;

        tsp->tv_sec += basetime.tv_sec;
        tsp->tv_nsec += basetime.tv_nsec;
        while (tsp->tv_nsec >= 1000000000) {
                tsp->tv_nsec -= 1000000000;
                ++tsp->tv_sec;
        }
}

/*
 * note: this is not exactly synchronized with real time.  To do that we
 * would have to do what microtime does and check for a nanoseconds overflow.
 */
time_t
get_approximate_time_t(void)
{
        struct globaldata *gd = mycpu;
        return(gd->gd_time_seconds + basetime.tv_sec);
}

int
pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
{
        pps_params_t *app;
        struct pps_fetch_args *fapi;
#ifdef PPS_SYNC
        struct pps_kcbind_args *kapi;
#endif

        switch (cmd) {
        case PPS_IOC_CREATE:
                return (0);
        case PPS_IOC_DESTROY:
                return (0);
        case PPS_IOC_SETPARAMS:
                app = (pps_params_t *)data;
                if (app->mode & ~pps->ppscap)
                        return (EINVAL);
                pps->ppsparam = *app;         
                return (0);
        case PPS_IOC_GETPARAMS:
                app = (pps_params_t *)data;
                *app = pps->ppsparam;
                app->api_version = PPS_API_VERS_1;
                return (0);
        case PPS_IOC_GETCAP:
                *(int*)data = pps->ppscap;
                return (0);
        case PPS_IOC_FETCH:
                fapi = (struct pps_fetch_args *)data;
                if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
                        return (EINVAL);
                if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
                        return (EOPNOTSUPP);
                pps->ppsinfo.current_mode = pps->ppsparam.mode;         
                fapi->pps_info_buf = pps->ppsinfo;
                return (0);
        case PPS_IOC_KCBIND:
#ifdef PPS_SYNC
                kapi = (struct pps_kcbind_args *)data;
                /* XXX Only root should be able to do this */
                if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
                        return (EINVAL);
                if (kapi->kernel_consumer != PPS_KC_HARDPPS)
                        return (EINVAL);
                if (kapi->edge & ~pps->ppscap)
                        return (EINVAL);
                pps->kcmode = kapi->edge;
                return (0);
#else
                return (EOPNOTSUPP);
#endif
        default:
                return (ENOTTY);
        }
}

void
pps_init(struct pps_state *pps)
{
        pps->ppscap |= PPS_TSFMT_TSPEC;
        if (pps->ppscap & PPS_CAPTUREASSERT)
                pps->ppscap |= PPS_OFFSETASSERT;
        if (pps->ppscap & PPS_CAPTURECLEAR)
                pps->ppscap |= PPS_OFFSETCLEAR;
}

void
pps_event(struct pps_state *pps, sysclock_t count, int event)
{
        struct globaldata *gd;
        struct timespec *tsp;
        struct timespec *osp;
        struct timespec ts;
        sysclock_t *pcount;
#ifdef PPS_SYNC
        sysclock_t tcount;
#endif
        sysclock_t delta;
        pps_seq_t *pseq;
        int foff;
        int fhard;

        gd = mycpu;

        /* Things would be easier with arrays... */
        if (event == PPS_CAPTUREASSERT) {
                tsp = &pps->ppsinfo.assert_timestamp;
                osp = &pps->ppsparam.assert_offset;
                foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
                fhard = pps->kcmode & PPS_CAPTUREASSERT;
                pcount = &pps->ppscount[0];
                pseq = &pps->ppsinfo.assert_sequence;
        } else {
                tsp = &pps->ppsinfo.clear_timestamp;
                osp = &pps->ppsparam.clear_offset;
                foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
                fhard = pps->kcmode & PPS_CAPTURECLEAR;
                pcount = &pps->ppscount[1];
                pseq = &pps->ppsinfo.clear_sequence;
        }

        /* Nothing really happened */
        if (*pcount == count)
                return;

        *pcount = count;

        do {
                ts.tv_sec = gd->gd_time_seconds;
                delta = count - gd->gd_cpuclock_base;
        } while (ts.tv_sec != gd->gd_time_seconds);

        if (delta >= cputimer_freq) {
                ts.tv_sec += delta / cputimer_freq;
                delta %= cputimer_freq;
        }
        ts.tv_nsec = (cputimer_freq64_nsec * delta) >> 32;
        ts.tv_sec += basetime.tv_sec;
        ts.tv_nsec += basetime.tv_nsec;
        while (ts.tv_nsec >= 1000000000) {
                ts.tv_nsec -= 1000000000;
                ++ts.tv_sec;
        }

        (*pseq)++;
        *tsp = ts;

        if (foff) {
                timespecadd(tsp, osp);
                if (tsp->tv_nsec < 0) {
                        tsp->tv_nsec += 1000000000;
                        tsp->tv_sec -= 1;
                }
        }
#ifdef PPS_SYNC
        if (fhard) {
                /* magic, at its best... */
                tcount = count - pps->ppscount[2];
                pps->ppscount[2] = count;
                if (tcount >= cputimer_freq) {
                        delta = (1000000000 * (tcount / cputimer_freq) +
                                 cputimer_freq64_nsec * 
                                 (tcount % cputimer_freq)) >> 32;
                } else {
                        delta = (cputimer_freq64_nsec * tcount) >> 32;
                }
                hardpps(tsp, delta);
        }
#endif
}