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NetBSD/sys/kern/kern_todr.c

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/* $NetBSD: kern_todr.c,v 1.35 2013/08/29 01:05:29 tls Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department and Ralph Campbell.
*
* 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 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.
*
* from: Utah Hdr: clock.c 1.18 91/01/21
*
* @(#)clock.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_todr.c,v 1.35 2013/08/29 01:05:29 tls Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/timetc.h>
#include <sys/intr.h>
#include <sys/rnd.h>
#include <dev/clock_subr.h> /* hmm.. this should probably move to sys */
static todr_chip_handle_t todr_handle = NULL;
/*
* Attach the clock device to todr_handle.
*/
void
todr_attach(todr_chip_handle_t todr)
{
if (todr_handle) {
printf("todr_attach: TOD already configured\n");
return;
}
todr_handle = todr;
}
static bool timeset = false;
/*
* Set up the system's time, given a `reasonable' time value.
*/
void
inittodr(time_t base)
{
bool badbase = false;
bool waszero = (base == 0);
bool goodtime = false;
bool badrtc = false;
int s;
struct timespec ts;
struct timeval tv;
rnd_add_data(NULL, &base, sizeof(base), 0);
if (base < 5 * SECYR) {
struct clock_ymdhms basedate;
/*
* If base is 0, assume filesystem time is just unknown
* instead of preposterous. Don't bark.
*/
if (base != 0)
printf("WARNING: preposterous time in file system\n");
/* not going to use it anyway, if the chip is readable */
basedate.dt_year = 2010;
basedate.dt_mon = 1;
basedate.dt_day = 1;
basedate.dt_hour = 12;
basedate.dt_min = 0;
basedate.dt_sec = 0;
base = clock_ymdhms_to_secs(&basedate);
badbase = true;
}
/*
* Some ports need to be supplied base in order to fabricate a time_t.
*/
if (todr_handle)
todr_handle->base_time = base;
if ((todr_handle == NULL) ||
(todr_gettime(todr_handle, &tv) != 0) ||
(tv.tv_sec < (25 * SECYR))) {
if (todr_handle != NULL)
printf("WARNING: preposterous TOD clock time\n");
else
printf("WARNING: no TOD clock present\n");
badrtc = true;
} else {
time_t deltat = tv.tv_sec - base;
if (deltat < 0)
deltat = -deltat;
if (!badbase && deltat >= 2 * SECDAY) {
if (tv.tv_sec < base) {
/*
* The clock should never go backwards
* relative to filesystem time. If it
* does by more than the threshold,
* believe the filesystem.
*/
printf("WARNING: clock lost %" PRId64 " days\n",
deltat / SECDAY);
badrtc = true;
} else {
aprint_verbose("WARNING: clock gained %" PRId64
" days\n", deltat / SECDAY);
goodtime = true;
}
} else {
goodtime = true;
}
rnd_add_data(NULL, &tv, sizeof(tv), 0);
}
/* if the rtc time is bad, use the filesystem time */
if (badrtc) {
if (badbase) {
printf("WARNING: using default initial time\n");
} else {
printf("WARNING: using filesystem time\n");
}
tv.tv_sec = base;
tv.tv_usec = 0;
}
timeset = true;
ts.tv_sec = tv.tv_sec;
ts.tv_nsec = tv.tv_usec * 1000;
s = splclock();
tc_setclock(&ts);
splx(s);
if (waszero || goodtime)
return;
printf("WARNING: CHECK AND RESET THE DATE!\n");
}
/*
* Reset the TODR based on the time value; used when the TODR
* has a preposterous value and also when the time is reset
* by the stime system call. Also called when the TODR goes past
* TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
* to wrap the TODR around.
*/
void
resettodr(void)
{
struct timeval tv;
/*
* We might have been called by boot() due to a crash early
* on. Don't reset the clock chip if we don't know what time
* it is.
*/
if (!timeset)
return;
getmicrotime(&tv);
if (tv.tv_sec == 0)
return;
if (todr_handle)
if (todr_settime(todr_handle, &tv) != 0)
printf("Cannot set TOD clock time\n");
}
#ifdef TODR_DEBUG
static void
todr_debug(const char *prefix, int rv, struct clock_ymdhms *dt,
struct timeval *tvp)
{
struct timeval tv_val;
struct clock_ymdhms dt_val;
if (dt == NULL) {
clock_secs_to_ymdhms(tvp->tv_sec, &dt_val);
dt = &dt_val;
}
if (tvp == NULL) {
tvp = &tv_val;
tvp->tv_sec = clock_ymdhms_to_secs(dt);
tvp->tv_usec = 0;
}
printf("%s: rv = %d\n", prefix, rv);
printf("%s: rtc_offset = %d\n", prefix, rtc_offset);
printf("%s: %4u/%02u/%02u %02u:%02u:%02u, (wday %d) (epoch %u.%06u)\n",
prefix,
dt->dt_year, dt->dt_mon, dt->dt_day,
dt->dt_hour, dt->dt_min, dt->dt_sec,
dt->dt_wday, (unsigned)tvp->tv_sec, (unsigned)tvp->tv_usec);
}
#else /* !TODR_DEBUG */
#define todr_debug(prefix, rv, dt, tvp)
#endif /* TODR_DEBUG */
int
todr_gettime(todr_chip_handle_t tch, struct timeval *tvp)
{
struct clock_ymdhms dt;
int rv;
if (tch->todr_gettime) {
rv = tch->todr_gettime(tch, tvp);
/*
* Some unconverted ports have their own references to
* rtc_offset. A converted port must not do that.
*/
if (rv == 0)
tvp->tv_sec += rtc_offset * 60;
todr_debug("TODR-GET-SECS", rv, NULL, tvp);
return rv;
} else if (tch->todr_gettime_ymdhms) {
rv = tch->todr_gettime_ymdhms(tch, &dt);
todr_debug("TODR-GET-YMDHMS", rv, &dt, NULL);
if (rv)
return rv;
/*
* Simple sanity checks. Note that this includes a
* value for clocks that can return a leap second.
* Note that we don't support double leap seconds,
* since this was apparently an error/misunderstanding
* on the part of the ISO C committee, and can never
* actually occur. If your clock issues us a double
* leap second, it must be broken. Ultimately, you'd
* have to be trying to read time at precisely that
* instant to even notice, so even broken clocks will
* work the vast majority of the time. In such a case
* it is recommended correction be applied in the
* clock driver.
*/
if (dt.dt_mon < 1 || dt.dt_mon > 12 ||
dt.dt_day < 1 || dt.dt_day > 31 ||
dt.dt_hour > 23 || dt.dt_min > 59 || dt.dt_sec > 60) {
return EINVAL;
}
tvp->tv_sec = clock_ymdhms_to_secs(&dt) + rtc_offset * 60;
tvp->tv_usec = 0;
return tvp->tv_sec < 0 ? EINVAL : 0;
}
return ENXIO;
}
int
todr_settime(todr_chip_handle_t tch, struct timeval *tvp)
{
struct clock_ymdhms dt;
int rv;
if (tch->todr_settime) {
/* See comments above in gettime why this is ifdef'd */
struct timeval copy = *tvp;
copy.tv_sec -= rtc_offset * 60;
rv = tch->todr_settime(tch, &copy);
todr_debug("TODR-SET-SECS", rv, NULL, tvp);
return rv;
} else if (tch->todr_settime_ymdhms) {
time_t sec = tvp->tv_sec - rtc_offset * 60;
if (tvp->tv_usec >= 500000)
sec++;
clock_secs_to_ymdhms(sec, &dt);
rv = tch->todr_settime_ymdhms(tch, &dt);
todr_debug("TODR-SET-YMDHMS", rv, &dt, NULL);
return rv;
} else {
return ENXIO;
}
}
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