1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1982, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 37 * from: @(#)clock.c 8.2 (Berkeley) 1/12/94 38 * from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp 39 * and 40 * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04 41 */ 42 43 #include <sys/cdefs.h> 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 /* 54 * The adjkerntz and wall_cmos_clock sysctls are in the "machdep" sysctl 55 * namespace because they were misplaced there originally. 56 */ 57 static int adjkerntz; 58 static int 59 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS) 60 { 61 int error; 62 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 63 if (!error && req->newptr) 64 resettodr(); 65 return (error); 66 } 67 SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT | CTLFLAG_RW | 68 CTLFLAG_MPSAFE, &adjkerntz, 0, sysctl_machdep_adjkerntz, "I", 69 "Local offset from UTC in seconds"); 70 71 static int ct_debug; 72 SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RWTUN, 73 &ct_debug, 0, "Enable printing of clocktime debugging"); 74 75 static int wall_cmos_clock; 76 SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, CTLFLAG_RW, 77 &wall_cmos_clock, 0, "Enables application of machdep.adjkerntz"); 78 79 /*--------------------------------------------------------------------* 80 * Generic routines to convert between a POSIX date 81 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec 82 * Derived from NetBSD arch/hp300/hp300/clock.c 83 */ 84 85 #define FEBRUARY 2 86 #define days_in_year(y) (leapyear(y) ? 366 : 365) 87 #define days_in_month(y, m) \ 88 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0)) 89 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */ 90 #define day_of_week(days) (((days) + 4) % 7) 91 92 static const int month_days[12] = { 93 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 94 }; 95 96 /* 97 * Optimization: using a precomputed count of days between POSIX_BASE_YEAR and 98 * some recent year avoids lots of unnecessary loop iterations in conversion. 99 * recent_base_days is the number of days before the start of recent_base_year. 100 */ 101 static const int recent_base_year = 2017; 102 static const int recent_base_days = 17167; 103 104 /* 105 * Table to 'calculate' pow(10, 9 - nsdigits) via lookup of nsdigits. 106 * Before doing the lookup, the code asserts 0 <= nsdigits <= 9. 107 */ 108 static u_int nsdivisors[] = { 109 1000000000, 100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1 110 }; 111 112 /* 113 * This inline avoids some unnecessary modulo operations 114 * as compared with the usual macro: 115 * ( ((year % 4) == 0 && 116 * (year % 100) != 0) || 117 * ((year % 400) == 0) ) 118 * It is otherwise equivalent. 119 */ 120 static int 121 leapyear(int year) 122 { 123 int rv = 0; 124 125 if ((year & 3) == 0) { 126 rv = 1; 127 if ((year % 100) == 0) { 128 rv = 0; 129 if ((year % 400) == 0) 130 rv = 1; 131 } 132 } 133 return (rv); 134 } 135 136 int 137 clock_ct_to_ts(const struct clocktime *ct, struct timespec *ts) 138 { 139 int i, year, days; 140 141 if (ct_debug) { 142 printf("ct_to_ts(["); 143 clock_print_ct(ct, 9); 144 printf("])"); 145 } 146 147 /* 148 * Many realtime clocks store the year as 2-digit BCD; pivot on 70 to 149 * determine century. Some clocks have a "century bit" and drivers do 150 * year += 100, so interpret values between 70-199 as relative to 1900. 151 */ 152 year = ct->year; 153 if (year < 70) 154 year += 2000; 155 else if (year < 200) 156 year += 1900; 157 158 /* Sanity checks. */ 159 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 160 ct->day > days_in_month(year, ct->mon) || 161 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 || 162 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ 163 if (ct_debug) 164 printf(" = EINVAL\n"); 165 return (EINVAL); 166 } 167 168 /* 169 * Compute days since start of time 170 * First from years, then from months. 171 */ 172 if (year >= recent_base_year) { 173 i = recent_base_year; 174 days = recent_base_days; 175 } else { 176 i = POSIX_BASE_YEAR; 177 days = 0; 178 } 179 for (; i < year; i++) 180 days += days_in_year(i); 181 182 /* Months */ 183 for (i = 1; i < ct->mon; i++) 184 days += days_in_month(year, i); 185 days += (ct->day - 1); 186 187 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 + 188 ct->sec; 189 ts->tv_nsec = ct->nsec; 190 191 if (ct_debug) 192 printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec); 193 return (0); 194 } 195 196 int 197 clock_bcd_to_ts(const struct bcd_clocktime *bct, struct timespec *ts, bool ampm) 198 { 199 struct clocktime ct; 200 int bcent, byear; 201 202 /* 203 * Year may come in as 2-digit or 4-digit BCD. Split the value into 204 * separate BCD century and year values for validation and conversion. 205 */ 206 bcent = bct->year >> 8; 207 byear = bct->year & 0xff; 208 209 /* 210 * Ensure that all values are valid BCD numbers, to avoid assertions in 211 * the BCD-to-binary conversion routines. clock_ct_to_ts() will further 212 * validate the field ranges (such as 0 <= min <= 59) during conversion. 213 */ 214 if (!validbcd(bcent) || !validbcd(byear) || !validbcd(bct->mon) || 215 !validbcd(bct->day) || !validbcd(bct->hour) || 216 !validbcd(bct->min) || !validbcd(bct->sec)) { 217 if (ct_debug) 218 printf("clock_bcd_to_ts: bad BCD: " 219 "[%04x-%02x-%02x %02x:%02x:%02x]\n", 220 bct->year, bct->mon, bct->day, 221 bct->hour, bct->min, bct->sec); 222 return (EINVAL); 223 } 224 225 ct.year = FROMBCD(byear) + FROMBCD(bcent) * 100; 226 ct.mon = FROMBCD(bct->mon); 227 ct.day = FROMBCD(bct->day); 228 ct.hour = FROMBCD(bct->hour); 229 ct.min = FROMBCD(bct->min); 230 ct.sec = FROMBCD(bct->sec); 231 ct.dow = bct->dow; 232 ct.nsec = bct->nsec; 233 234 /* If asked to handle am/pm, convert from 12hr+pmflag to 24hr. */ 235 if (ampm) { 236 if (ct.hour == 12) 237 ct.hour = 0; 238 if (bct->ispm) 239 ct.hour += 12; 240 } 241 242 return (clock_ct_to_ts(&ct, ts)); 243 } 244 245 void 246 clock_ts_to_ct(const struct timespec *ts, struct clocktime *ct) 247 { 248 time_t i, year, days; 249 time_t rsec; /* remainder seconds */ 250 time_t secs; 251 252 secs = ts->tv_sec; 253 days = secs / SECDAY; 254 rsec = secs % SECDAY; 255 256 ct->dow = day_of_week(days); 257 258 /* Subtract out whole years. */ 259 if (days >= recent_base_days) { 260 year = recent_base_year; 261 days -= recent_base_days; 262 } else { 263 year = POSIX_BASE_YEAR; 264 } 265 for (; days >= days_in_year(year); year++) 266 days -= days_in_year(year); 267 ct->year = year; 268 269 /* Subtract out whole months, counting them in i. */ 270 for (i = 1; days >= days_in_month(year, i); i++) 271 days -= days_in_month(year, i); 272 ct->mon = i; 273 274 /* Days are what is left over (+1) from all that. */ 275 ct->day = days + 1; 276 277 /* Hours, minutes, seconds are easy */ 278 ct->hour = rsec / 3600; 279 rsec = rsec % 3600; 280 ct->min = rsec / 60; 281 rsec = rsec % 60; 282 ct->sec = rsec; 283 ct->nsec = ts->tv_nsec; 284 if (ct_debug) { 285 printf("ts_to_ct(%jd.%09ld) = [", 286 (intmax_t)ts->tv_sec, ts->tv_nsec); 287 clock_print_ct(ct, 9); 288 printf("]\n"); 289 } 290 291 KASSERT(ct->year >= 0 && ct->year < 10000, 292 ("year %d isn't a 4 digit year", ct->year)); 293 KASSERT(ct->mon >= 1 && ct->mon <= 12, 294 ("month %d not in 1-12", ct->mon)); 295 KASSERT(ct->day >= 1 && ct->day <= 31, 296 ("day %d not in 1-31", ct->day)); 297 KASSERT(ct->hour >= 0 && ct->hour <= 23, 298 ("hour %d not in 0-23", ct->hour)); 299 KASSERT(ct->min >= 0 && ct->min <= 59, 300 ("minute %d not in 0-59", ct->min)); 301 /* Not sure if this interface needs to handle leapseconds or not. */ 302 KASSERT(ct->sec >= 0 && ct->sec <= 60, 303 ("seconds %d not in 0-60", ct->sec)); 304 } 305 306 void 307 clock_ts_to_bcd(const struct timespec *ts, struct bcd_clocktime *bct, bool ampm) 308 { 309 struct clocktime ct; 310 311 clock_ts_to_ct(ts, &ct); 312 313 /* If asked to handle am/pm, convert from 24hr to 12hr+pmflag. */ 314 bct->ispm = false; 315 if (ampm) { 316 if (ct.hour >= 12) { 317 ct.hour -= 12; 318 bct->ispm = true; 319 } 320 if (ct.hour == 0) 321 ct.hour = 12; 322 } 323 324 bct->year = TOBCD(ct.year % 100) | (TOBCD(ct.year / 100) << 8); 325 bct->mon = TOBCD(ct.mon); 326 bct->day = TOBCD(ct.day); 327 bct->hour = TOBCD(ct.hour); 328 bct->min = TOBCD(ct.min); 329 bct->sec = TOBCD(ct.sec); 330 bct->dow = ct.dow; 331 bct->nsec = ct.nsec; 332 } 333 334 void 335 clock_print_bcd(const struct bcd_clocktime *bct, int nsdigits) 336 { 337 338 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 339 340 if (nsdigits > 0) { 341 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x.%*.*ld", 342 bct->year, bct->mon, bct->day, 343 bct->hour, bct->min, bct->sec, 344 nsdigits, nsdigits, bct->nsec / nsdivisors[nsdigits]); 345 } else { 346 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x", 347 bct->year, bct->mon, bct->day, 348 bct->hour, bct->min, bct->sec); 349 } 350 } 351 352 void 353 clock_print_ct(const struct clocktime *ct, int nsdigits) 354 { 355 356 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 357 358 if (nsdigits > 0) { 359 printf("%04d-%02d-%02d %02d:%02d:%02d.%*.*ld", 360 ct->year, ct->mon, ct->day, 361 ct->hour, ct->min, ct->sec, 362 nsdigits, nsdigits, ct->nsec / nsdivisors[nsdigits]); 363 } else { 364 printf("%04d-%02d-%02d %02d:%02d:%02d", 365 ct->year, ct->mon, ct->day, 366 ct->hour, ct->min, ct->sec); 367 } 368 } 369 370 void 371 clock_print_ts(const struct timespec *ts, int nsdigits) 372 { 373 struct clocktime ct; 374 375 clock_ts_to_ct(ts, &ct); 376 clock_print_ct(&ct, nsdigits); 377 } 378 379 int 380 utc_offset(void) 381 { 382 383 return (wall_cmos_clock ? adjkerntz : 0); 384 } 385