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-rw-r--r--sys/kern/kern_clock.c1015
1 files changed, 1015 insertions, 0 deletions
diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c
new file mode 100644
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--- /dev/null
+++ b/sys/kern/kern_clock.c
@@ -0,0 +1,1015 @@
+/*-
+ * 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
+ * $FreeBSD$
+ */
+
+#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/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 <machine/cpu.h>
+#include <machine/limits.h>
+
+#ifdef GPROF
+#include <sys/gmon.h>
+#endif
+
+#if defined(SMP) && defined(BETTER_CLOCK)
+#include <machine/smp.h>
+#endif
+
+/*
+ * Number of timecounters used to implement stable storage
+ */
+#ifndef NTIMECOUNTER
+#define NTIMECOUNTER 5
+#endif
+
+static MALLOC_DEFINE(M_TIMECOUNTER, "timecounter",
+ "Timecounter stable storage");
+
+static void initclocks __P((void *dummy));
+SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
+
+static void tco_forward __P((int force));
+static void tco_setscales __P((struct timecounter *tc));
+static __inline unsigned tco_delta __P((struct timecounter *tc));
+
+/* Some of these don't belong here, but it's easiest to concentrate them. */
+#if defined(SMP) && defined(BETTER_CLOCK)
+long cp_time[CPUSTATES];
+#else
+static long cp_time[CPUSTATES];
+#endif
+
+long tk_cancc;
+long tk_nin;
+long tk_nout;
+long tk_rawcc;
+
+time_t time_second;
+
+struct timeval boottime;
+SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
+ &boottime, timeval, "System boottime");
+
+/*
+ * Which update policy to use.
+ * 0 - every tick, bad hardware may fail with "calcru negative..."
+ * 1 - more resistent to the above hardware, but less efficient.
+ */
+static int tco_method;
+
+/*
+ * Implement a dummy timecounter which we can use until we get a real one
+ * in the air. This allows the console and other early stuff to use
+ * timeservices.
+ */
+
+static unsigned
+dummy_get_timecount(struct timecounter *tc)
+{
+ static unsigned now;
+ return (++now);
+}
+
+static struct timecounter dummy_timecounter = {
+ dummy_get_timecount,
+ 0,
+ ~0u,
+ 1000000,
+ "dummy"
+};
+
+struct timecounter *timecounter = &dummy_timecounter;
+
+/*
+ * Clock handling routines.
+ *
+ * This code is written to operate with two timers that run independently of
+ * each other.
+ *
+ * The main timer, running hz times per second, is used to trigger interval
+ * timers, timeouts and rescheduling as needed.
+ *
+ * The second timer handles kernel and user profiling,
+ * and does resource use estimation. If the second timer is programmable,
+ * it is randomized to avoid aliasing between the two clocks. For example,
+ * the randomization prevents an adversary from always giving up the cpu
+ * just before its quantum expires. Otherwise, it would never accumulate
+ * cpu ticks. The mean frequency of the second timer is stathz.
+ *
+ * If no second timer exists, stathz will be zero; in this case we drive
+ * profiling and statistics off the main clock. This WILL NOT be accurate;
+ * do not do it unless absolutely necessary.
+ *
+ * The statistics clock may (or may not) be run at a higher rate while
+ * profiling. This profile clock runs at profhz. We require that profhz
+ * be an integral multiple of stathz.
+ *
+ * If the statistics clock is running fast, it must be divided by the ratio
+ * profhz/stathz for statistics. (For profiling, every tick counts.)
+ *
+ * Time-of-day is maintained using a "timecounter", which may or may
+ * not be related to the hardware generating the above mentioned
+ * interrupts.
+ */
+
+int stathz;
+int profhz;
+static int profprocs;
+int ticks;
+static int psdiv, pscnt; /* prof => stat divider */
+int psratio; /* ratio: prof / stat */
+
+/*
+ * Initialize clock frequencies and start both clocks running.
+ */
+/* ARGSUSED*/
+static void
+initclocks(dummy)
+ void *dummy;
+{
+ register int i;
+
+ /*
+ * Set divisors to 1 (normal case) and let the machine-specific
+ * code do its bit.
+ */
+ psdiv = pscnt = 1;
+ cpu_initclocks();
+
+ /*
+ * Compute profhz/stathz, and fix profhz if needed.
+ */
+ i = stathz ? stathz : hz;
+ if (profhz == 0)
+ profhz = i;
+ psratio = profhz / i;
+}
+
+/*
+ * The real-time timer, interrupting hz times per second.
+ */
+void
+hardclock(frame)
+ register struct clockframe *frame;
+{
+ register struct proc *p;
+
+ p = curproc;
+ if (p) {
+ register struct pstats *pstats;
+
+ /*
+ * Run current process's virtual and profile time, as needed.
+ */
+ pstats = p->p_stats;
+ if (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);
+ }
+
+#if defined(SMP) && defined(BETTER_CLOCK)
+ forward_hardclock(pscnt);
+#endif
+
+ /*
+ * If no separate statistics clock is available, run it from here.
+ */
+ if (stathz == 0)
+ statclock(frame);
+
+ tco_forward(0);
+ ticks++;
+
+ /*
+ * Process callouts at a very low cpu priority, so we don't keep the
+ * relatively high clock interrupt priority any longer than necessary.
+ */
+ if (TAILQ_FIRST(&callwheel[ticks & callwheelmask]) != NULL) {
+ if (CLKF_BASEPRI(frame)) {
+ /*
+ * Save the overhead of a software interrupt;
+ * it will happen as soon as we return, so do it now.
+ */
+ (void)splsoftclock();
+ softclock();
+ } else
+ setsoftclock();
+ } else if (softticks + 1 == ticks)
+ ++softticks;
+}
+
+/*
+ * Compute number of ticks in the specified amount of time.
+ */
+int
+tvtohz(tv)
+ struct timeval *tv;
+{
+ register unsigned long ticks;
+ register long sec, usec;
+
+ /*
+ * If the number of usecs in the whole seconds part of the time
+ * difference fits in a long, then the total number of usecs will
+ * fit in an unsigned long. Compute the total and convert it to
+ * ticks, rounding up and adding 1 to allow for the current tick
+ * to expire. Rounding also depends on unsigned long arithmetic
+ * to avoid overflow.
+ *
+ * Otherwise, if the number of ticks in the whole seconds part of
+ * the time difference fits in a long, then convert the parts to
+ * ticks separately and add, using similar rounding methods and
+ * overflow avoidance. This method would work in the previous
+ * case but it is slightly slower and assumes that hz is integral.
+ *
+ * Otherwise, round the time difference down to the maximum
+ * representable value.
+ *
+ * If ints have 32 bits, then the maximum value for any timeout in
+ * 10ms ticks is 248 days.
+ */
+ 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 <= LONG_MAX / 1000000)
+ ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
+ / tick + 1;
+ else if (sec <= LONG_MAX / hz)
+ ticks = sec * hz
+ + ((unsigned long)usec + (tick - 1)) / tick + 1;
+ else
+ ticks = LONG_MAX;
+ if (ticks > INT_MAX)
+ ticks = INT_MAX;
+ return ((int)ticks);
+}
+
+/*
+ * Start profiling on a process.
+ *
+ * Kernel profiling passes proc0 which never exits and hence
+ * keeps the profile clock running constantly.
+ */
+void
+startprofclock(p)
+ register struct proc *p;
+{
+ int s;
+
+ if ((p->p_flag & P_PROFIL) == 0) {
+ p->p_flag |= P_PROFIL;
+ if (++profprocs == 1 && stathz != 0) {
+ s = splstatclock();
+ psdiv = pscnt = psratio;
+ setstatclockrate(profhz);
+ splx(s);
+ }
+ }
+}
+
+/*
+ * Stop profiling on a process.
+ */
+void
+stopprofclock(p)
+ register struct proc *p;
+{
+ int s;
+
+ if (p->p_flag & P_PROFIL) {
+ p->p_flag &= ~P_PROFIL;
+ if (--profprocs == 0 && stathz != 0) {
+ s = splstatclock();
+ psdiv = pscnt = 1;
+ setstatclockrate(stathz);
+ splx(s);
+ }
+ }
+}
+
+/*
+ * Statistics clock. Grab profile sample, and if divider reaches 0,
+ * do process and kernel statistics.
+ */
+void
+statclock(frame)
+ register struct clockframe *frame;
+{
+#ifdef GPROF
+ register struct gmonparam *g;
+ int i;
+#endif
+ register struct proc *p;
+ struct pstats *pstats;
+ long rss;
+ struct rusage *ru;
+ struct vmspace *vm;
+
+ if (curproc != NULL && CLKF_USERMODE(frame)) {
+ p = curproc;
+ if (p->p_flag & P_PROFIL)
+ addupc_intr(p, CLKF_PC(frame), 1);
+#if defined(SMP) && defined(BETTER_CLOCK)
+ if (stathz != 0)
+ forward_statclock(pscnt);
+#endif
+ if (--pscnt > 0)
+ return;
+ /*
+ * Came from user mode; CPU was in user state.
+ * If this process is being profiled record the tick.
+ */
+ p->p_uticks++;
+ if (p->p_nice > NZERO)
+ cp_time[CP_NICE]++;
+ else
+ cp_time[CP_USER]++;
+ } else {
+#ifdef GPROF
+ /*
+ * Kernel statistics are just like addupc_intr, only easier.
+ */
+ g = &_gmonparam;
+ if (g->state == GMON_PROF_ON) {
+ i = CLKF_PC(frame) - g->lowpc;
+ if (i < g->textsize) {
+ i /= HISTFRACTION * sizeof(*g->kcount);
+ g->kcount[i]++;
+ }
+ }
+#endif
+#if defined(SMP) && defined(BETTER_CLOCK)
+ if (stathz != 0)
+ forward_statclock(pscnt);
+#endif
+ if (--pscnt > 0)
+ return;
+ /*
+ * 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.
+ */
+ p = curproc;
+ if (CLKF_INTR(frame)) {
+ if (p != NULL)
+ p->p_iticks++;
+ cp_time[CP_INTR]++;
+ } else if (p != NULL) {
+ p->p_sticks++;
+ cp_time[CP_SYS]++;
+ } else
+ cp_time[CP_IDLE]++;
+ }
+ pscnt = psdiv;
+
+ /*
+ * We maintain statistics shown by user-level statistics
+ * programs: the amount of time in each cpu state.
+ */
+
+ /*
+ * We adjust the priority of the current process. The priority of
+ * a process gets worse as it accumulates CPU time. The cpu usage
+ * estimator (p_estcpu) is increased here. The formula for computing
+ * priorities (in kern_synch.c) will compute a different value each
+ * time p_estcpu increases by 4. The cpu usage estimator ramps up
+ * quite quickly when the process is running (linearly), and decays
+ * away exponentially, at a rate which is proportionally slower when
+ * the system is busy. The basic principal is that the system will
+ * 90% forget that the process used a lot of CPU time in 5 * loadav
+ * seconds. This causes the system to favor processes which haven't
+ * run much recently, and to round-robin among other processes.
+ */
+ if (p != NULL) {
+ p->p_cpticks++;
+ if (++p->p_estcpu == 0)
+ p->p_estcpu--;
+ if ((p->p_estcpu & 3) == 0) {
+ resetpriority(p);
+ if (p->p_priority >= PUSER)
+ p->p_priority = p->p_usrpri;
+ }
+
+ /* 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;
+ }
+ }
+}
+
+/*
+ * Return information about system clocks.
+ */
+static int
+sysctl_kern_clockrate SYSCTL_HANDLER_ARGS
+{
+ struct clockinfo clkinfo;
+ /*
+ * Construct clockinfo structure.
+ */
+ clkinfo.hz = hz;
+ clkinfo.tick = tick;
+ clkinfo.tickadj = tickadj;
+ clkinfo.profhz = profhz;
+ clkinfo.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","");
+
+static __inline unsigned
+tco_delta(struct timecounter *tc)
+{
+
+ return ((tc->tc_get_timecount(tc) - tc->tc_offset_count) &
+ tc->tc_counter_mask);
+}
+
+/*
+ * 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.
+ */
+
+void
+getmicrotime(struct timeval *tvp)
+{
+ struct timecounter *tc;
+
+ if (!tco_method) {
+ tc = timecounter;
+ *tvp = tc->tc_microtime;
+ } else {
+ microtime(tvp);
+ }
+}
+
+void
+getnanotime(struct timespec *tsp)
+{
+ struct timecounter *tc;
+
+ if (!tco_method) {
+ tc = timecounter;
+ *tsp = tc->tc_nanotime;
+ } else {
+ nanotime(tsp);
+ }
+}
+
+void
+microtime(struct timeval *tv)
+{
+ struct timecounter *tc;
+
+ tc = timecounter;
+ tv->tv_sec = tc->tc_offset_sec;
+ tv->tv_usec = tc->tc_offset_micro;
+ tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32;
+ tv->tv_usec += boottime.tv_usec;
+ tv->tv_sec += boottime.tv_sec;
+ while (tv->tv_usec >= 1000000) {
+ tv->tv_usec -= 1000000;
+ tv->tv_sec++;
+ }
+}
+
+void
+nanotime(struct timespec *ts)
+{
+ unsigned count;
+ u_int64_t delta;
+ struct timecounter *tc;
+
+ tc = timecounter;
+ ts->tv_sec = tc->tc_offset_sec;
+ count = tco_delta(tc);
+ delta = tc->tc_offset_nano;
+ delta += ((u_int64_t)count * tc->tc_scale_nano_f);
+ delta >>= 32;
+ delta += ((u_int64_t)count * tc->tc_scale_nano_i);
+ delta += boottime.tv_usec * 1000;
+ ts->tv_sec += boottime.tv_sec;
+ while (delta >= 1000000000) {
+ delta -= 1000000000;
+ ts->tv_sec++;
+ }
+ ts->tv_nsec = delta;
+}
+
+void
+getmicrouptime(struct timeval *tvp)
+{
+ struct timecounter *tc;
+
+ if (!tco_method) {
+ tc = timecounter;
+ tvp->tv_sec = tc->tc_offset_sec;
+ tvp->tv_usec = tc->tc_offset_micro;
+ } else {
+ microuptime(tvp);
+ }
+}
+
+void
+getnanouptime(struct timespec *tsp)
+{
+ struct timecounter *tc;
+
+ if (!tco_method) {
+ tc = timecounter;
+ tsp->tv_sec = tc->tc_offset_sec;
+ tsp->tv_nsec = tc->tc_offset_nano >> 32;
+ } else {
+ nanouptime(tsp);
+ }
+}
+
+void
+microuptime(struct timeval *tv)
+{
+ struct timecounter *tc;
+
+ tc = timecounter;
+ tv->tv_sec = tc->tc_offset_sec;
+ tv->tv_usec = tc->tc_offset_micro;
+ tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32;
+ if (tv->tv_usec >= 1000000) {
+ tv->tv_usec -= 1000000;
+ tv->tv_sec++;
+ }
+}
+
+void
+nanouptime(struct timespec *ts)
+{
+ unsigned count;
+ u_int64_t delta;
+ struct timecounter *tc;
+
+ tc = timecounter;
+ ts->tv_sec = tc->tc_offset_sec;
+ count = tco_delta(tc);
+ delta = tc->tc_offset_nano;
+ delta += ((u_int64_t)count * tc->tc_scale_nano_f);
+ delta >>= 32;
+ delta += ((u_int64_t)count * tc->tc_scale_nano_i);
+ if (delta >= 1000000000) {
+ delta -= 1000000000;
+ ts->tv_sec++;
+ }
+ ts->tv_nsec = delta;
+}
+
+static void
+tco_setscales(struct timecounter *tc)
+{
+ u_int64_t scale;
+
+ scale = 1000000000LL << 32;
+ scale += tc->tc_adjustment;
+ scale /= tc->tc_tweak->tc_frequency;
+ tc->tc_scale_micro = scale / 1000;
+ tc->tc_scale_nano_f = scale & 0xffffffff;
+ tc->tc_scale_nano_i = scale >> 32;
+}
+
+void
+update_timecounter(struct timecounter *tc)
+{
+ tco_setscales(tc);
+}
+
+void
+init_timecounter(struct timecounter *tc)
+{
+ struct timespec ts1;
+ struct timecounter *t1, *t2, *t3;
+ int i;
+
+ tc->tc_adjustment = 0;
+ tc->tc_tweak = tc;
+ tco_setscales(tc);
+ tc->tc_offset_count = tc->tc_get_timecount(tc);
+ if (timecounter == &dummy_timecounter)
+ tc->tc_avail = tc;
+ else {
+ tc->tc_avail = timecounter->tc_tweak->tc_avail;
+ timecounter->tc_tweak->tc_avail = tc;
+ }
+ MALLOC(t1, struct timecounter *, sizeof *t1, M_TIMECOUNTER, M_WAITOK);
+ tc->tc_other = t1;
+ *t1 = *tc;
+ t2 = t1;
+ for (i = 1; i < NTIMECOUNTER; i++) {
+ MALLOC(t3, struct timecounter *, sizeof *t3,
+ M_TIMECOUNTER, M_WAITOK);
+ *t3 = *tc;
+ t3->tc_other = t2;
+ t2 = t3;
+ }
+ t1->tc_other = t3;
+ tc = t1;
+
+ printf("Timecounter \"%s\" frequency %lu Hz\n",
+ tc->tc_name, (u_long)tc->tc_frequency);
+
+ /* XXX: For now always start using the counter. */
+ tc->tc_offset_count = tc->tc_get_timecount(tc);
+ nanouptime(&ts1);
+ tc->tc_offset_nano = (u_int64_t)ts1.tv_nsec << 32;
+ tc->tc_offset_micro = ts1.tv_nsec / 1000;
+ tc->tc_offset_sec = ts1.tv_sec;
+ timecounter = tc;
+}
+
+void
+set_timecounter(struct timespec *ts)
+{
+ struct timespec ts2;
+
+ nanouptime(&ts2);
+ boottime.tv_sec = ts->tv_sec - ts2.tv_sec;
+ boottime.tv_usec = (ts->tv_nsec - ts2.tv_nsec) / 1000;
+ if (boottime.tv_usec < 0) {
+ boottime.tv_usec += 1000000;
+ boottime.tv_sec--;
+ }
+ /* fiddle all the little crinkly bits around the fiords... */
+ tco_forward(1);
+}
+
+static void
+switch_timecounter(struct timecounter *newtc)
+{
+ int s;
+ struct timecounter *tc;
+ struct timespec ts;
+
+ s = splclock();
+ tc = timecounter;
+ if (newtc->tc_tweak == tc->tc_tweak) {
+ splx(s);
+ return;
+ }
+ newtc = newtc->tc_tweak->tc_other;
+ nanouptime(&ts);
+ newtc->tc_offset_sec = ts.tv_sec;
+ newtc->tc_offset_nano = (u_int64_t)ts.tv_nsec << 32;
+ newtc->tc_offset_micro = ts.tv_nsec / 1000;
+ newtc->tc_offset_count = newtc->tc_get_timecount(newtc);
+ tco_setscales(newtc);
+ timecounter = newtc;
+ splx(s);
+}
+
+static struct timecounter *
+sync_other_counter(void)
+{
+ struct timecounter *tc, *tcn, *tco;
+ unsigned delta;
+
+ tco = timecounter;
+ tc = tco->tc_other;
+ tcn = tc->tc_other;
+ *tc = *tco;
+ tc->tc_other = tcn;
+ delta = tco_delta(tc);
+ tc->tc_offset_count += delta;
+ tc->tc_offset_count &= tc->tc_counter_mask;
+ tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_f;
+ tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_i << 32;
+ return (tc);
+}
+
+static void
+tco_forward(int force)
+{
+ struct timecounter *tc, *tco;
+
+ tco = timecounter;
+ tc = sync_other_counter();
+ /*
+ * We may be inducing a tiny error here, the tc_poll_pps() may
+ * process a latched count which happens after the tco_delta()
+ * in sync_other_counter(), which would extend the previous
+ * counters parameters into the domain of this new one.
+ * Since the timewindow is very small for this, the error is
+ * going to be only a few weenieseconds (as Dave Mills would
+ * say), so lets just not talk more about it, OK ?
+ */
+ if (tco->tc_poll_pps)
+ tco->tc_poll_pps(tco);
+ if (timedelta != 0) {
+ tc->tc_offset_nano += (u_int64_t)(tickdelta * 1000) << 32;
+ timedelta -= tickdelta;
+ force++;
+ }
+
+ while (tc->tc_offset_nano >= 1000000000ULL << 32) {
+ tc->tc_offset_nano -= 1000000000ULL << 32;
+ tc->tc_offset_sec++;
+ ntp_update_second(tc); /* XXX only needed if xntpd runs */
+ tco_setscales(tc);
+ force++;
+ }
+
+ if (tco_method && !force)
+ return;
+
+ tc->tc_offset_micro = (tc->tc_offset_nano / 1000) >> 32;
+
+ /* Figure out the wall-clock time */
+ tc->tc_nanotime.tv_sec = tc->tc_offset_sec + boottime.tv_sec;
+ tc->tc_nanotime.tv_nsec =
+ (tc->tc_offset_nano >> 32) + boottime.tv_usec * 1000;
+ tc->tc_microtime.tv_usec = tc->tc_offset_micro + boottime.tv_usec;
+ if (tc->tc_nanotime.tv_nsec >= 1000000000) {
+ tc->tc_nanotime.tv_nsec -= 1000000000;
+ tc->tc_microtime.tv_usec -= 1000000;
+ tc->tc_nanotime.tv_sec++;
+ }
+ time_second = tc->tc_microtime.tv_sec = tc->tc_nanotime.tv_sec;
+
+ timecounter = tc;
+}
+
+SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, "");
+
+SYSCTL_INT(_kern_timecounter, OID_AUTO, method, CTLFLAG_RW, &tco_method, 0,
+ "This variable determines the method used for updating timecounters. "
+ "If the default algorithm (0) fails with \"calcru negative...\" messages "
+ "try the alternate algorithm (1) which handles bad hardware better."
+
+);
+
+static int
+sysctl_kern_timecounter_hardware SYSCTL_HANDLER_ARGS
+{
+ char newname[32];
+ struct timecounter *newtc, *tc;
+ int error;
+
+ tc = timecounter->tc_tweak;
+ strncpy(newname, tc->tc_name, sizeof(newname));
+ error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req);
+ if (error == 0 && req->newptr != NULL &&
+ strcmp(newname, tc->tc_name) != 0) {
+ for (newtc = tc->tc_avail; newtc != tc;
+ newtc = newtc->tc_avail) {
+ if (strcmp(newname, newtc->tc_name) == 0) {
+ /* Warm up new timecounter. */
+ (void)newtc->tc_get_timecount(newtc);
+
+ switch_timecounter(newtc);
+ return (0);
+ }
+ }
+ return (EINVAL);
+ }
+ return (error);
+}
+
+SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW,
+ 0, 0, sysctl_kern_timecounter_hardware, "A", "");
+
+
+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, struct timecounter *tc, unsigned count, int event)
+{
+ struct timespec ts, *tsp, *osp;
+ u_int64_t delta;
+ unsigned tcount, *pcount;
+ int foff, fhard;
+ pps_seq_t *pseq;
+
+ /* 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;
+ }
+
+ /* The timecounter changed: bail */
+ if (!pps->ppstc ||
+ pps->ppstc->tc_name != tc->tc_name ||
+ tc->tc_name != timecounter->tc_name) {
+ pps->ppstc = tc;
+ *pcount = count;
+ return;
+ }
+
+ /* Nothing really happened */
+ if (*pcount == count)
+ return;
+
+ *pcount = count;
+
+ /* Convert the count to timespec */
+ ts.tv_sec = tc->tc_offset_sec;
+ tcount = count - tc->tc_offset_count;
+ tcount &= tc->tc_counter_mask;
+ delta = tc->tc_offset_nano;
+ delta += ((u_int64_t)tcount * tc->tc_scale_nano_f);
+ delta >>= 32;
+ delta += ((u_int64_t)tcount * tc->tc_scale_nano_i);
+ delta += boottime.tv_usec * 1000;
+ ts.tv_sec += boottime.tv_sec;
+ while (delta >= 1000000000) {
+ delta -= 1000000000;
+ ts.tv_sec++;
+ }
+ ts.tv_nsec = delta;
+
+ (*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;
+ tcount &= tc->tc_counter_mask;
+ delta = ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_f);
+ delta >>= 32;
+ delta += ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_i);
+ hardpps(tsp, delta);
+ }
+#endif
+}
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