/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1990, 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.
*
* 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 $Hdr: clock.c 1.18 91/01/21$
* from: @(#)clock.c 8.2 (Berkeley) 1/12/94
* from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp
* and
* from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/clock.h>
#include <sys/limits.h>
#include <sys/sysctl.h>
#include <sys/timetc.h>
/*
* The adjkerntz and wall_cmos_clock sysctls are in the "machdep" sysctl
* namespace because they were misplaced there originally.
*/
static int adjkerntz;
static int
sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS)
{
int error;
error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
if (!error && req->newptr)
resettodr();
return (error);
}
SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT | CTLFLAG_RW |
CTLFLAG_MPSAFE, &adjkerntz, 0, sysctl_machdep_adjkerntz, "I",
"Local offset from UTC in seconds");
static int ct_debug;
SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RWTUN,
&ct_debug, 0, "Enable printing of clocktime debugging");
static int wall_cmos_clock;
SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, CTLFLAG_RW,
&wall_cmos_clock, 0, "Enables application of machdep.adjkerntz");
/*--------------------------------------------------------------------*
* Generic routines to convert between a POSIX date
* (seconds since 1/1/1970) and yr/mo/day/hr/min/sec
* Derived from NetBSD arch/hp300/hp300/clock.c
*/
#define FEBRUARY 2
#define days_in_year(y) (leapyear(y) ? 366 : 365)
#define days_in_month(y, m) \
(month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0))
/* Day of week. Days are counted from 1/1/1970, which was a Thursday */
#define day_of_week(days) (((days) + 4) % 7)
static const int month_days[12] = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
/*
* Optimization: using a precomputed count of days between POSIX_BASE_YEAR and
* some recent year avoids lots of unnecessary loop iterations in conversion.
* recent_base_days is the number of days before the start of recent_base_year.
*/
static const int recent_base_year = 2017;
static const int recent_base_days = 17167;
/*
* Table to 'calculate' pow(10, 9 - nsdigits) via lookup of nsdigits.
* Before doing the lookup, the code asserts 0 <= nsdigits <= 9.
*/
static u_int nsdivisors[] = {
1000000000, 100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1
};
/*
* This inline avoids some unnecessary modulo operations
* as compared with the usual macro:
* ( ((year % 4) == 0 &&
* (year % 100) != 0) ||
* ((year % 400) == 0) )
* It is otherwise equivalent.
*/
static int
leapyear(int year)
{
int rv = 0;
if ((year & 3) == 0) {
rv = 1;
if ((year % 100) == 0) {
rv = 0;
if ((year % 400) == 0)
rv = 1;
}
}
return (rv);
}
int
clock_ct_to_ts(const struct clocktime *ct, struct timespec *ts)
{
int i, year, days;
if (ct_debug) {
printf("ct_to_ts([");
clock_print_ct(ct, 9);
printf("])");
}
/*
* Many realtime clocks store the year as 2-digit BCD; pivot on 70 to
* determine century. Some clocks have a "century bit" and drivers do
* year += 100, so interpret values between 70-199 as relative to 1900.
*/
year = ct->year;
if (year < 70)
year += 2000;
else if (year < 200)
year += 1900;
/* Sanity checks. */
if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 ||
ct->day > days_in_month(year, ct->mon) ||
ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 ||
(sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */
if (ct_debug)
printf(" = EINVAL\n");
return (EINVAL);
}
/*
* Compute days since start of time
* First from years, then from months.
*/
if (year >= recent_base_year) {
i = recent_base_year;
days = recent_base_days;
} else {
i = POSIX_BASE_YEAR;
days = 0;
}
for (; i < year; i++)
days += days_in_year(i);
/* Months */
for (i = 1; i < ct->mon; i++)
days += days_in_month(year, i);
days += (ct->day - 1);
ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 +
ct->sec;
ts->tv_nsec = ct->nsec;
if (ct_debug)
printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec);
return (0);
}
int
clock_bcd_to_ts(const struct bcd_clocktime *bct, struct timespec *ts, bool ampm)
{
struct clocktime ct;
int bcent, byear;
/*
* Year may come in as 2-digit or 4-digit BCD. Split the value into
* separate BCD century and year values for validation and conversion.
*/
bcent = bct->year >> 8;
byear = bct->year & 0xff;
/*
* Ensure that all values are valid BCD numbers, to avoid assertions in
* the BCD-to-binary conversion routines. clock_ct_to_ts() will further
* validate the field ranges (such as 0 <= min <= 59) during conversion.
*/
if (!validbcd(bcent) || !validbcd(byear) || !validbcd(bct->mon) ||
!validbcd(bct->day) || !validbcd(bct->hour) ||
!validbcd(bct->min) || !validbcd(bct->sec)) {
if (ct_debug)
printf("clock_bcd_to_ts: bad BCD: "
"[%04x-%02x-%02x %02x:%02x:%02x]\n",
bct->year, bct->mon, bct->day,
bct->hour, bct->min, bct->sec);
return (EINVAL);
}
ct.year = FROMBCD(byear) + FROMBCD(bcent) * 100;
ct.mon = FROMBCD(bct->mon);
ct.day = FROMBCD(bct->day);
ct.hour = FROMBCD(bct->hour);
ct.min = FROMBCD(bct->min);
ct.sec = FROMBCD(bct->sec);
ct.dow = bct->dow;
ct.nsec = bct->nsec;
/* If asked to handle am/pm, convert from 12hr+pmflag to 24hr. */
if (ampm) {
if (ct.hour == 12)
ct.hour = 0;
if (bct->ispm)
ct.hour += 12;
}
return (clock_ct_to_ts(&ct, ts));
}
void
clock_ts_to_ct(const struct timespec *ts, struct clocktime *ct)
{
time_t i, year, days;
time_t rsec; /* remainder seconds */
time_t secs;
secs = ts->tv_sec;
days = secs / SECDAY;
rsec = secs % SECDAY;
ct->dow = day_of_week(days);
/* Subtract out whole years. */
if (days >= recent_base_days) {
year = recent_base_year;
days -= recent_base_days;
} else {
year = POSIX_BASE_YEAR;
}
for (; days >= days_in_year(year); year++)
days -= days_in_year(year);
ct->year = year;
/* Subtract out whole months, counting them in i. */
for (i = 1; days >= days_in_month(year, i); i++)
days -= days_in_month(year, i);
ct->mon = i;
/* Days are what is left over (+1) from all that. */
ct->day = days + 1;
/* Hours, minutes, seconds are easy */
ct->hour = rsec / 3600;
rsec = rsec % 3600;
ct->min = rsec / 60;
rsec = rsec % 60;
ct->sec = rsec;
ct->nsec = ts->tv_nsec;
if (ct_debug) {
printf("ts_to_ct(%jd.%09ld) = [",
(intmax_t)ts->tv_sec, ts->tv_nsec);
clock_print_ct(ct, 9);
printf("]\n");
}
KASSERT(ct->year >= 0 && ct->year < 10000,
("year %d isn't a 4 digit year", ct->year));
KASSERT(ct->mon >= 1 && ct->mon <= 12,
("month %d not in 1-12", ct->mon));
KASSERT(ct->day >= 1 && ct->day <= 31,
("day %d not in 1-31", ct->day));
KASSERT(ct->hour >= 0 && ct->hour <= 23,
("hour %d not in 0-23", ct->hour));
KASSERT(ct->min >= 0 && ct->min <= 59,
("minute %d not in 0-59", ct->min));
/* Not sure if this interface needs to handle leapseconds or not. */
KASSERT(ct->sec >= 0 && ct->sec <= 60,
("seconds %d not in 0-60", ct->sec));
}
void
clock_ts_to_bcd(const struct timespec *ts, struct bcd_clocktime *bct, bool ampm)
{
struct clocktime ct;
clock_ts_to_ct(ts, &ct);
/* If asked to handle am/pm, convert from 24hr to 12hr+pmflag. */
bct->ispm = false;
if (ampm) {
if (ct.hour >= 12) {
ct.hour -= 12;
bct->ispm = true;
}
if (ct.hour == 0)
ct.hour = 12;
}
bct->year = TOBCD(ct.year % 100) | (TOBCD(ct.year / 100) << 8);
bct->mon = TOBCD(ct.mon);
bct->day = TOBCD(ct.day);
bct->hour = TOBCD(ct.hour);
bct->min = TOBCD(ct.min);
bct->sec = TOBCD(ct.sec);
bct->dow = ct.dow;
bct->nsec = ct.nsec;
}
void
clock_print_bcd(const struct bcd_clocktime *bct, int nsdigits)
{
KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits));
if (nsdigits > 0) {
printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x.%*.*ld",
bct->year, bct->mon, bct->day,
bct->hour, bct->min, bct->sec,
nsdigits, nsdigits, bct->nsec / nsdivisors[nsdigits]);
} else {
printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x",
bct->year, bct->mon, bct->day,
bct->hour, bct->min, bct->sec);
}
}
void
clock_print_ct(const struct clocktime *ct, int nsdigits)
{
KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits));
if (nsdigits > 0) {
printf("%04d-%02d-%02d %02d:%02d:%02d.%*.*ld",
ct->year, ct->mon, ct->day,
ct->hour, ct->min, ct->sec,
nsdigits, nsdigits, ct->nsec / nsdivisors[nsdigits]);
} else {
printf("%04d-%02d-%02d %02d:%02d:%02d",
ct->year, ct->mon, ct->day,
ct->hour, ct->min, ct->sec);
}
}
void
clock_print_ts(const struct timespec *ts, int nsdigits)
{
struct clocktime ct;
clock_ts_to_ct(ts, &ct);
clock_print_ct(&ct, nsdigits);
}
int
utc_offset(void)
{
return (wall_cmos_clock ? adjkerntz : 0);
}
