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: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp 38 * and 39 * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04 40 */ 41 42 #include <sys/cdefs.h> 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/bus.h> 47 #include <sys/clock.h> 48 #include <sys/limits.h> 49 #include <sys/sysctl.h> 50 #include <sys/timetc.h> 51 52 /* 53 * The adjkerntz and wall_cmos_clock sysctls are in the "machdep" sysctl 54 * namespace because they were misplaced there originally. 55 */ 56 static int adjkerntz; 57 static int 58 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS) 59 { 60 int error; 61 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 62 if (!error && req->newptr) 63 resettodr(); 64 return (error); 65 } 66 SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT | CTLFLAG_RW | 67 CTLFLAG_MPSAFE, &adjkerntz, 0, sysctl_machdep_adjkerntz, "I", 68 "Local offset from UTC in seconds"); 69 70 static int ct_debug; 71 SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RWTUN, 72 &ct_debug, 0, "Enable printing of clocktime debugging"); 73 74 static int wall_cmos_clock; 75 SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, CTLFLAG_RW, 76 &wall_cmos_clock, 0, "Enables application of machdep.adjkerntz"); 77 78 /*--------------------------------------------------------------------* 79 * Generic routines to convert between a POSIX date 80 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec 81 * Derived from NetBSD arch/hp300/hp300/clock.c 82 */ 83 84 #define FEBRUARY 2 85 #define days_in_year(y) (leapyear(y) ? 366 : 365) 86 #define days_in_month(y, m) \ 87 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0)) 88 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */ 89 #define day_of_week(days) (((days) + 4) % 7) 90 91 static const int month_days[12] = { 92 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 93 }; 94 95 /* 96 * Optimization: using a precomputed count of days between POSIX_BASE_YEAR and 97 * some recent year avoids lots of unnecessary loop iterations in conversion. 98 * recent_base_days is the number of days before the start of recent_base_year. 99 */ 100 static const int recent_base_year = 2017; 101 static const int recent_base_days = 17167; 102 103 /* 104 * Table to 'calculate' pow(10, 9 - nsdigits) via lookup of nsdigits. 105 * Before doing the lookup, the code asserts 0 <= nsdigits <= 9. 106 */ 107 static u_int nsdivisors[] = { 108 1000000000, 100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1 109 }; 110 111 /* 112 * This inline avoids some unnecessary modulo operations 113 * as compared with the usual macro: 114 * ( ((year % 4) == 0 && 115 * (year % 100) != 0) || 116 * ((year % 400) == 0) ) 117 * It is otherwise equivalent. 118 */ 119 static int 120 leapyear(int year) 121 { 122 int rv = 0; 123 124 if ((year & 3) == 0) { 125 rv = 1; 126 if ((year % 100) == 0) { 127 rv = 0; 128 if ((year % 400) == 0) 129 rv = 1; 130 } 131 } 132 return (rv); 133 } 134 135 int 136 clock_ct_to_ts(const struct clocktime *ct, struct timespec *ts) 137 { 138 int i, year, days; 139 140 if (ct_debug) { 141 printf("ct_to_ts(["); 142 clock_print_ct(ct, 9); 143 printf("])"); 144 } 145 146 /* 147 * Many realtime clocks store the year as 2-digit BCD; pivot on 70 to 148 * determine century. Some clocks have a "century bit" and drivers do 149 * year += 100, so interpret values between 70-199 as relative to 1900. 150 */ 151 year = ct->year; 152 if (year < 70) 153 year += 2000; 154 else if (year < 200) 155 year += 1900; 156 157 /* Sanity checks. */ 158 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 159 ct->day > days_in_month(year, ct->mon) || 160 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 || 161 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ 162 if (ct_debug) 163 printf(" = EINVAL\n"); 164 return (EINVAL); 165 } 166 167 /* 168 * Compute days since start of time 169 * First from years, then from months. 170 */ 171 if (year >= recent_base_year) { 172 i = recent_base_year; 173 days = recent_base_days; 174 } else { 175 i = POSIX_BASE_YEAR; 176 days = 0; 177 } 178 for (; i < year; i++) 179 days += days_in_year(i); 180 181 /* Months */ 182 for (i = 1; i < ct->mon; i++) 183 days += days_in_month(year, i); 184 days += (ct->day - 1); 185 186 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 + 187 ct->sec; 188 ts->tv_nsec = ct->nsec; 189 190 if (ct_debug) 191 printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec); 192 return (0); 193 } 194 195 int 196 clock_bcd_to_ts(const struct bcd_clocktime *bct, struct timespec *ts, bool ampm) 197 { 198 struct clocktime ct; 199 int bcent, byear; 200 201 /* 202 * Year may come in as 2-digit or 4-digit BCD. Split the value into 203 * separate BCD century and year values for validation and conversion. 204 */ 205 bcent = bct->year >> 8; 206 byear = bct->year & 0xff; 207 208 /* 209 * Ensure that all values are valid BCD numbers, to avoid assertions in 210 * the BCD-to-binary conversion routines. clock_ct_to_ts() will further 211 * validate the field ranges (such as 0 <= min <= 59) during conversion. 212 */ 213 if (!validbcd(bcent) || !validbcd(byear) || !validbcd(bct->mon) || 214 !validbcd(bct->day) || !validbcd(bct->hour) || 215 !validbcd(bct->min) || !validbcd(bct->sec)) { 216 if (ct_debug) 217 printf("clock_bcd_to_ts: bad BCD: " 218 "[%04x-%02x-%02x %02x:%02x:%02x]\n", 219 bct->year, bct->mon, bct->day, 220 bct->hour, bct->min, bct->sec); 221 return (EINVAL); 222 } 223 224 ct.year = FROMBCD(byear) + FROMBCD(bcent) * 100; 225 ct.mon = FROMBCD(bct->mon); 226 ct.day = FROMBCD(bct->day); 227 ct.hour = FROMBCD(bct->hour); 228 ct.min = FROMBCD(bct->min); 229 ct.sec = FROMBCD(bct->sec); 230 ct.dow = bct->dow; 231 ct.nsec = bct->nsec; 232 233 /* If asked to handle am/pm, convert from 12hr+pmflag to 24hr. */ 234 if (ampm) { 235 if (ct.hour == 12) 236 ct.hour = 0; 237 if (bct->ispm) 238 ct.hour += 12; 239 } 240 241 return (clock_ct_to_ts(&ct, ts)); 242 } 243 244 void 245 clock_ts_to_ct(const struct timespec *ts, struct clocktime *ct) 246 { 247 time_t i, year, days; 248 time_t rsec; /* remainder seconds */ 249 time_t secs; 250 251 secs = ts->tv_sec; 252 days = secs / SECDAY; 253 rsec = secs % SECDAY; 254 255 ct->dow = day_of_week(days); 256 257 /* Subtract out whole years. */ 258 if (days >= recent_base_days) { 259 year = recent_base_year; 260 days -= recent_base_days; 261 } else { 262 year = POSIX_BASE_YEAR; 263 } 264 for (; days >= days_in_year(year); year++) 265 days -= days_in_year(year); 266 ct->year = year; 267 268 /* Subtract out whole months, counting them in i. */ 269 for (i = 1; days >= days_in_month(year, i); i++) 270 days -= days_in_month(year, i); 271 ct->mon = i; 272 273 /* Days are what is left over (+1) from all that. */ 274 ct->day = days + 1; 275 276 /* Hours, minutes, seconds are easy */ 277 ct->hour = rsec / 3600; 278 rsec = rsec % 3600; 279 ct->min = rsec / 60; 280 rsec = rsec % 60; 281 ct->sec = rsec; 282 ct->nsec = ts->tv_nsec; 283 if (ct_debug) { 284 printf("ts_to_ct(%jd.%09ld) = [", 285 (intmax_t)ts->tv_sec, ts->tv_nsec); 286 clock_print_ct(ct, 9); 287 printf("]\n"); 288 } 289 290 KASSERT(ct->year >= 0 && ct->year < 10000, 291 ("year %d isn't a 4 digit year", ct->year)); 292 KASSERT(ct->mon >= 1 && ct->mon <= 12, 293 ("month %d not in 1-12", ct->mon)); 294 KASSERT(ct->day >= 1 && ct->day <= 31, 295 ("day %d not in 1-31", ct->day)); 296 KASSERT(ct->hour >= 0 && ct->hour <= 23, 297 ("hour %d not in 0-23", ct->hour)); 298 KASSERT(ct->min >= 0 && ct->min <= 59, 299 ("minute %d not in 0-59", ct->min)); 300 /* Not sure if this interface needs to handle leapseconds or not. */ 301 KASSERT(ct->sec >= 0 && ct->sec <= 60, 302 ("seconds %d not in 0-60", ct->sec)); 303 } 304 305 void 306 clock_ts_to_bcd(const struct timespec *ts, struct bcd_clocktime *bct, bool ampm) 307 { 308 struct clocktime ct; 309 310 clock_ts_to_ct(ts, &ct); 311 312 /* If asked to handle am/pm, convert from 24hr to 12hr+pmflag. */ 313 bct->ispm = false; 314 if (ampm) { 315 if (ct.hour >= 12) { 316 ct.hour -= 12; 317 bct->ispm = true; 318 } 319 if (ct.hour == 0) 320 ct.hour = 12; 321 } 322 323 bct->year = TOBCD(ct.year % 100) | (TOBCD(ct.year / 100) << 8); 324 bct->mon = TOBCD(ct.mon); 325 bct->day = TOBCD(ct.day); 326 bct->hour = TOBCD(ct.hour); 327 bct->min = TOBCD(ct.min); 328 bct->sec = TOBCD(ct.sec); 329 bct->dow = ct.dow; 330 bct->nsec = ct.nsec; 331 } 332 333 void 334 clock_print_bcd(const struct bcd_clocktime *bct, int nsdigits) 335 { 336 337 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 338 339 if (nsdigits > 0) { 340 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x.%*.*ld", 341 bct->year, bct->mon, bct->day, 342 bct->hour, bct->min, bct->sec, 343 nsdigits, nsdigits, bct->nsec / nsdivisors[nsdigits]); 344 } else { 345 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x", 346 bct->year, bct->mon, bct->day, 347 bct->hour, bct->min, bct->sec); 348 } 349 } 350 351 void 352 clock_print_ct(const struct clocktime *ct, int nsdigits) 353 { 354 355 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 356 357 if (nsdigits > 0) { 358 printf("%04d-%02d-%02d %02d:%02d:%02d.%*.*ld", 359 ct->year, ct->mon, ct->day, 360 ct->hour, ct->min, ct->sec, 361 nsdigits, nsdigits, ct->nsec / nsdivisors[nsdigits]); 362 } else { 363 printf("%04d-%02d-%02d %02d:%02d:%02d", 364 ct->year, ct->mon, ct->day, 365 ct->hour, ct->min, ct->sec); 366 } 367 } 368 369 void 370 clock_print_ts(const struct timespec *ts, int nsdigits) 371 { 372 struct clocktime ct; 373 374 clock_ts_to_ct(ts, &ct); 375 clock_print_ct(&ct, nsdigits); 376 } 377 378 int 379 utc_offset(void) 380 { 381 382 return (wall_cmos_clock ? adjkerntz : 0); 383 } 384