1 /*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 35 * from: @(#)clock.c 8.2 (Berkeley) 1/12/94 36 * from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp 37 * and 38 * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/bus.h> 48 #include <sys/clock.h> 49 #include <sys/limits.h> 50 #include <sys/sysctl.h> 51 #include <sys/timetc.h> 52 53 int tz_minuteswest; 54 int tz_dsttime; 55 56 /* 57 * The adjkerntz and wall_cmos_clock sysctls are in the "machdep" sysctl 58 * namespace because they were misplaced there originally. 59 */ 60 static int adjkerntz; 61 static int 62 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS) 63 { 64 int error; 65 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 66 if (!error && req->newptr) 67 resettodr(); 68 return (error); 69 } 70 SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT | CTLFLAG_RW | 71 CTLFLAG_MPSAFE, &adjkerntz, 0, sysctl_machdep_adjkerntz, "I", 72 "Local offset from UTC in seconds"); 73 74 static int ct_debug; 75 SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RWTUN, 76 &ct_debug, 0, "Enable printing of clocktime debugging"); 77 78 static int wall_cmos_clock; 79 SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, CTLFLAG_RW, 80 &wall_cmos_clock, 0, "Enables application of machdep.adjkerntz"); 81 82 /*--------------------------------------------------------------------* 83 * Generic routines to convert between a POSIX date 84 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec 85 * Derived from NetBSD arch/hp300/hp300/clock.c 86 */ 87 88 89 #define FEBRUARY 2 90 #define days_in_year(y) (leapyear(y) ? 366 : 365) 91 #define days_in_month(y, m) \ 92 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0)) 93 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */ 94 #define day_of_week(days) (((days) + 4) % 7) 95 96 static const int month_days[12] = { 97 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 98 }; 99 100 /* 101 * Optimization: using a precomputed count of days between POSIX_BASE_YEAR and 102 * some recent year avoids lots of unnecessary loop iterations in conversion. 103 * recent_base_days is the number of days before the start of recent_base_year. 104 */ 105 static const int recent_base_year = 2017; 106 static const int recent_base_days = 17167; 107 108 /* 109 * This inline avoids some unnecessary modulo operations 110 * as compared with the usual macro: 111 * ( ((year % 4) == 0 && 112 * (year % 100) != 0) || 113 * ((year % 400) == 0) ) 114 * It is otherwise equivalent. 115 */ 116 static int 117 leapyear(int year) 118 { 119 int rv = 0; 120 121 if ((year & 3) == 0) { 122 rv = 1; 123 if ((year % 100) == 0) { 124 rv = 0; 125 if ((year % 400) == 0) 126 rv = 1; 127 } 128 } 129 return (rv); 130 } 131 132 static void 133 print_ct(struct clocktime *ct) 134 { 135 printf("[%04d-%02d-%02d %02d:%02d:%02d]", 136 ct->year, ct->mon, ct->day, 137 ct->hour, ct->min, ct->sec); 138 } 139 140 int 141 clock_ct_to_ts(struct clocktime *ct, struct timespec *ts) 142 { 143 int i, year, days; 144 145 year = ct->year; 146 147 if (ct_debug) { 148 printf("ct_to_ts("); 149 print_ct(ct); 150 printf(")"); 151 } 152 153 /* Sanity checks. */ 154 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 155 ct->day > days_in_month(year, ct->mon) || 156 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || 157 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ 158 if (ct_debug) 159 printf(" = EINVAL\n"); 160 return (EINVAL); 161 } 162 163 /* 164 * Compute days since start of time 165 * First from years, then from months. 166 */ 167 if (year >= recent_base_year) { 168 i = recent_base_year; 169 days = recent_base_days; 170 } else { 171 i = POSIX_BASE_YEAR; 172 days = 0; 173 } 174 for (; i < year; i++) 175 days += days_in_year(i); 176 177 /* Months */ 178 for (i = 1; i < ct->mon; i++) 179 days += days_in_month(year, i); 180 days += (ct->day - 1); 181 182 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 + 183 ct->sec; 184 ts->tv_nsec = ct->nsec; 185 186 if (ct_debug) 187 printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec); 188 return (0); 189 } 190 191 void 192 clock_ts_to_ct(struct timespec *ts, struct clocktime *ct) 193 { 194 time_t i, year, days; 195 time_t rsec; /* remainder seconds */ 196 time_t secs; 197 198 secs = ts->tv_sec; 199 days = secs / SECDAY; 200 rsec = secs % SECDAY; 201 202 ct->dow = day_of_week(days); 203 204 /* Subtract out whole years. */ 205 if (days >= recent_base_days) { 206 year = recent_base_year; 207 days -= recent_base_days; 208 } else { 209 year = POSIX_BASE_YEAR; 210 } 211 for (; days >= days_in_year(year); year++) 212 days -= days_in_year(year); 213 ct->year = year; 214 215 /* Subtract out whole months, counting them in i. */ 216 for (i = 1; days >= days_in_month(year, i); i++) 217 days -= days_in_month(year, i); 218 ct->mon = i; 219 220 /* Days are what is left over (+1) from all that. */ 221 ct->day = days + 1; 222 223 /* Hours, minutes, seconds are easy */ 224 ct->hour = rsec / 3600; 225 rsec = rsec % 3600; 226 ct->min = rsec / 60; 227 rsec = rsec % 60; 228 ct->sec = rsec; 229 ct->nsec = ts->tv_nsec; 230 if (ct_debug) { 231 printf("ts_to_ct(%jd.%09ld) = ", 232 (intmax_t)ts->tv_sec, ts->tv_nsec); 233 print_ct(ct); 234 printf("\n"); 235 } 236 237 KASSERT(ct->year >= 0 && ct->year < 10000, 238 ("year %d isn't a 4 digit year", ct->year)); 239 KASSERT(ct->mon >= 1 && ct->mon <= 12, 240 ("month %d not in 1-12", ct->mon)); 241 KASSERT(ct->day >= 1 && ct->day <= 31, 242 ("day %d not in 1-31", ct->day)); 243 KASSERT(ct->hour >= 0 && ct->hour <= 23, 244 ("hour %d not in 0-23", ct->hour)); 245 KASSERT(ct->min >= 0 && ct->min <= 59, 246 ("minute %d not in 0-59", ct->min)); 247 /* Not sure if this interface needs to handle leapseconds or not. */ 248 KASSERT(ct->sec >= 0 && ct->sec <= 60, 249 ("seconds %d not in 0-60", ct->sec)); 250 } 251 252 int 253 utc_offset(void) 254 { 255 256 return (tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0)); 257 } 258