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 __FBSDID("$FreeBSD$"); 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/bus.h> 50 #include <sys/clock.h> 51 #include <sys/limits.h> 52 #include <sys/sysctl.h> 53 #include <sys/timetc.h> 54 55 /* 56 * The adjkerntz and wall_cmos_clock sysctls are in the "machdep" sysctl 57 * namespace because they were misplaced there originally. 58 */ 59 static int adjkerntz; 60 static int 61 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS) 62 { 63 int error; 64 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 65 if (!error && req->newptr) 66 resettodr(); 67 return (error); 68 } 69 SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT | CTLFLAG_RW | 70 CTLFLAG_MPSAFE, &adjkerntz, 0, sysctl_machdep_adjkerntz, "I", 71 "Local offset from UTC in seconds"); 72 73 static int ct_debug; 74 SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RWTUN, 75 &ct_debug, 0, "Enable printing of clocktime debugging"); 76 77 static int wall_cmos_clock; 78 SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, CTLFLAG_RW, 79 &wall_cmos_clock, 0, "Enables application of machdep.adjkerntz"); 80 81 /*--------------------------------------------------------------------* 82 * Generic routines to convert between a POSIX date 83 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec 84 * Derived from NetBSD arch/hp300/hp300/clock.c 85 */ 86 87 #define FEBRUARY 2 88 #define days_in_year(y) (leapyear(y) ? 366 : 365) 89 #define days_in_month(y, m) \ 90 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0)) 91 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */ 92 #define day_of_week(days) (((days) + 4) % 7) 93 94 static const int month_days[12] = { 95 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 96 }; 97 98 /* 99 * Optimization: using a precomputed count of days between POSIX_BASE_YEAR and 100 * some recent year avoids lots of unnecessary loop iterations in conversion. 101 * recent_base_days is the number of days before the start of recent_base_year. 102 */ 103 static const int recent_base_year = 2017; 104 static const int recent_base_days = 17167; 105 106 /* 107 * Table to 'calculate' pow(10, 9 - nsdigits) via lookup of nsdigits. 108 * Before doing the lookup, the code asserts 0 <= nsdigits <= 9. 109 */ 110 static u_int nsdivisors[] = { 111 1000000000, 100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1 112 }; 113 114 /* 115 * This inline avoids some unnecessary modulo operations 116 * as compared with the usual macro: 117 * ( ((year % 4) == 0 && 118 * (year % 100) != 0) || 119 * ((year % 400) == 0) ) 120 * It is otherwise equivalent. 121 */ 122 static int 123 leapyear(int year) 124 { 125 int rv = 0; 126 127 if ((year & 3) == 0) { 128 rv = 1; 129 if ((year % 100) == 0) { 130 rv = 0; 131 if ((year % 400) == 0) 132 rv = 1; 133 } 134 } 135 return (rv); 136 } 137 138 int 139 clock_ct_to_ts(const struct clocktime *ct, struct timespec *ts) 140 { 141 int i, year, days; 142 143 if (ct_debug) { 144 printf("ct_to_ts(["); 145 clock_print_ct(ct, 9); 146 printf("])"); 147 } 148 149 /* 150 * Many realtime clocks store the year as 2-digit BCD; pivot on 70 to 151 * determine century. Some clocks have a "century bit" and drivers do 152 * year += 100, so interpret values between 70-199 as relative to 1900. 153 */ 154 year = ct->year; 155 if (year < 70) 156 year += 2000; 157 else if (year < 200) 158 year += 1900; 159 160 /* Sanity checks. */ 161 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 162 ct->day > days_in_month(year, ct->mon) || 163 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 || 164 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ 165 if (ct_debug) 166 printf(" = EINVAL\n"); 167 return (EINVAL); 168 } 169 170 /* 171 * Compute days since start of time 172 * First from years, then from months. 173 */ 174 if (year >= recent_base_year) { 175 i = recent_base_year; 176 days = recent_base_days; 177 } else { 178 i = POSIX_BASE_YEAR; 179 days = 0; 180 } 181 for (; i < year; i++) 182 days += days_in_year(i); 183 184 /* Months */ 185 for (i = 1; i < ct->mon; i++) 186 days += days_in_month(year, i); 187 days += (ct->day - 1); 188 189 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 + 190 ct->sec; 191 ts->tv_nsec = ct->nsec; 192 193 if (ct_debug) 194 printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec); 195 return (0); 196 } 197 198 int 199 clock_bcd_to_ts(const struct bcd_clocktime *bct, struct timespec *ts, bool ampm) 200 { 201 struct clocktime ct; 202 int bcent, byear; 203 204 /* 205 * Year may come in as 2-digit or 4-digit BCD. Split the value into 206 * separate BCD century and year values for validation and conversion. 207 */ 208 bcent = bct->year >> 8; 209 byear = bct->year & 0xff; 210 211 /* 212 * Ensure that all values are valid BCD numbers, to avoid assertions in 213 * the BCD-to-binary conversion routines. clock_ct_to_ts() will further 214 * validate the field ranges (such as 0 <= min <= 59) during conversion. 215 */ 216 if (!validbcd(bcent) || !validbcd(byear) || !validbcd(bct->mon) || 217 !validbcd(bct->day) || !validbcd(bct->hour) || 218 !validbcd(bct->min) || !validbcd(bct->sec)) { 219 if (ct_debug) 220 printf("clock_bcd_to_ts: bad BCD: " 221 "[%04x-%02x-%02x %02x:%02x:%02x]\n", 222 bct->year, bct->mon, bct->day, 223 bct->hour, bct->min, bct->sec); 224 return (EINVAL); 225 } 226 227 ct.year = FROMBCD(byear) + FROMBCD(bcent) * 100; 228 ct.mon = FROMBCD(bct->mon); 229 ct.day = FROMBCD(bct->day); 230 ct.hour = FROMBCD(bct->hour); 231 ct.min = FROMBCD(bct->min); 232 ct.sec = FROMBCD(bct->sec); 233 ct.dow = bct->dow; 234 ct.nsec = bct->nsec; 235 236 /* If asked to handle am/pm, convert from 12hr+pmflag to 24hr. */ 237 if (ampm) { 238 if (ct.hour == 12) 239 ct.hour = 0; 240 if (bct->ispm) 241 ct.hour += 12; 242 } 243 244 return (clock_ct_to_ts(&ct, ts)); 245 } 246 247 void 248 clock_ts_to_ct(const struct timespec *ts, struct clocktime *ct) 249 { 250 time_t i, year, days; 251 time_t rsec; /* remainder seconds */ 252 time_t secs; 253 254 secs = ts->tv_sec; 255 days = secs / SECDAY; 256 rsec = secs % SECDAY; 257 258 ct->dow = day_of_week(days); 259 260 /* Subtract out whole years. */ 261 if (days >= recent_base_days) { 262 year = recent_base_year; 263 days -= recent_base_days; 264 } else { 265 year = POSIX_BASE_YEAR; 266 } 267 for (; days >= days_in_year(year); year++) 268 days -= days_in_year(year); 269 ct->year = year; 270 271 /* Subtract out whole months, counting them in i. */ 272 for (i = 1; days >= days_in_month(year, i); i++) 273 days -= days_in_month(year, i); 274 ct->mon = i; 275 276 /* Days are what is left over (+1) from all that. */ 277 ct->day = days + 1; 278 279 /* Hours, minutes, seconds are easy */ 280 ct->hour = rsec / 3600; 281 rsec = rsec % 3600; 282 ct->min = rsec / 60; 283 rsec = rsec % 60; 284 ct->sec = rsec; 285 ct->nsec = ts->tv_nsec; 286 if (ct_debug) { 287 printf("ts_to_ct(%jd.%09ld) = [", 288 (intmax_t)ts->tv_sec, ts->tv_nsec); 289 clock_print_ct(ct, 9); 290 printf("]\n"); 291 } 292 293 KASSERT(ct->year >= 0 && ct->year < 10000, 294 ("year %d isn't a 4 digit year", ct->year)); 295 KASSERT(ct->mon >= 1 && ct->mon <= 12, 296 ("month %d not in 1-12", ct->mon)); 297 KASSERT(ct->day >= 1 && ct->day <= 31, 298 ("day %d not in 1-31", ct->day)); 299 KASSERT(ct->hour >= 0 && ct->hour <= 23, 300 ("hour %d not in 0-23", ct->hour)); 301 KASSERT(ct->min >= 0 && ct->min <= 59, 302 ("minute %d not in 0-59", ct->min)); 303 /* Not sure if this interface needs to handle leapseconds or not. */ 304 KASSERT(ct->sec >= 0 && ct->sec <= 60, 305 ("seconds %d not in 0-60", ct->sec)); 306 } 307 308 void 309 clock_ts_to_bcd(const struct timespec *ts, struct bcd_clocktime *bct, bool ampm) 310 { 311 struct clocktime ct; 312 313 clock_ts_to_ct(ts, &ct); 314 315 /* If asked to handle am/pm, convert from 24hr to 12hr+pmflag. */ 316 bct->ispm = false; 317 if (ampm) { 318 if (ct.hour >= 12) { 319 ct.hour -= 12; 320 bct->ispm = true; 321 } 322 if (ct.hour == 0) 323 ct.hour = 12; 324 } 325 326 bct->year = TOBCD(ct.year % 100) | (TOBCD(ct.year / 100) << 8); 327 bct->mon = TOBCD(ct.mon); 328 bct->day = TOBCD(ct.day); 329 bct->hour = TOBCD(ct.hour); 330 bct->min = TOBCD(ct.min); 331 bct->sec = TOBCD(ct.sec); 332 bct->dow = ct.dow; 333 bct->nsec = ct.nsec; 334 } 335 336 void 337 clock_print_bcd(const struct bcd_clocktime *bct, int nsdigits) 338 { 339 340 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 341 342 if (nsdigits > 0) { 343 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x.%*.*ld", 344 bct->year, bct->mon, bct->day, 345 bct->hour, bct->min, bct->sec, 346 nsdigits, nsdigits, bct->nsec / nsdivisors[nsdigits]); 347 } else { 348 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x", 349 bct->year, bct->mon, bct->day, 350 bct->hour, bct->min, bct->sec); 351 } 352 } 353 354 void 355 clock_print_ct(const struct clocktime *ct, int nsdigits) 356 { 357 358 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 359 360 if (nsdigits > 0) { 361 printf("%04d-%02d-%02d %02d:%02d:%02d.%*.*ld", 362 ct->year, ct->mon, ct->day, 363 ct->hour, ct->min, ct->sec, 364 nsdigits, nsdigits, ct->nsec / nsdivisors[nsdigits]); 365 } else { 366 printf("%04d-%02d-%02d %02d:%02d:%02d", 367 ct->year, ct->mon, ct->day, 368 ct->hour, ct->min, ct->sec); 369 } 370 } 371 372 void 373 clock_print_ts(const struct timespec *ts, int nsdigits) 374 { 375 struct clocktime ct; 376 377 clock_ts_to_ct(ts, &ct); 378 clock_print_ct(&ct, nsdigits); 379 } 380 381 int 382 utc_offset(void) 383 { 384 385 return (wall_cmos_clock ? adjkerntz : 0); 386 } 387