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freebsd-dev/sys/kern/kern_clock.c

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/*-
* 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
* $Id: kern_clock.c,v 1.96 1999/07/18 15:07:18 bde 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/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;
/*
* 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;
pps_info_t *api;
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;
return (0);
case PPS_IOC_GETCAP:
*(int*)data = pps->ppscap;
return (0);
case PPS_IOC_FETCH:
api = (pps_info_t *)data;
pps->ppsinfo.current_mode = pps->ppsparam.mode;
*api = pps->ppsinfo;
return (0);
case PPS_IOC_WAIT:
return (EOPNOTSUPP);
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;
#ifdef PPS_SYNC
if (pps->ppscap & PPS_CAPTUREASSERT)
pps->ppscap |= PPS_HARDPPSONASSERT;
if (pps->ppscap & PPS_CAPTURECLEAR)
pps->ppscap |= PPS_HARDPPSONCLEAR;
#endif
}
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->ppsparam.mode & PPS_HARDPPSONASSERT;
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->ppsparam.mode & PPS_HARDPPSONCLEAR;
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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