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