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 88 #define FEBRUARY 2 89 #define days_in_year(y) (leapyear(y) ? 366 : 365) 90 #define days_in_month(y, m) \ 91 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0)) 92 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */ 93 #define day_of_week(days) (((days) + 4) % 7) 94 95 static const int month_days[12] = { 96 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 97 }; 98 99 /* 100 * Optimization: using a precomputed count of days between POSIX_BASE_YEAR and 101 * some recent year avoids lots of unnecessary loop iterations in conversion. 102 * recent_base_days is the number of days before the start of recent_base_year. 103 */ 104 static const int recent_base_year = 2017; 105 static const int recent_base_days = 17167; 106 107 /* 108 * Table to 'calculate' pow(10, 9 - nsdigits) via lookup of nsdigits. 109 * Before doing the lookup, the code asserts 0 <= nsdigits <= 9. 110 */ 111 static u_int nsdivisors[] = { 112 1000000000, 100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1 113 }; 114 115 /* 116 * This inline avoids some unnecessary modulo operations 117 * as compared with the usual macro: 118 * ( ((year % 4) == 0 && 119 * (year % 100) != 0) || 120 * ((year % 400) == 0) ) 121 * It is otherwise equivalent. 122 */ 123 static int 124 leapyear(int year) 125 { 126 int rv = 0; 127 128 if ((year & 3) == 0) { 129 rv = 1; 130 if ((year % 100) == 0) { 131 rv = 0; 132 if ((year % 400) == 0) 133 rv = 1; 134 } 135 } 136 return (rv); 137 } 138 139 int 140 clock_ct_to_ts(const struct clocktime *ct, struct timespec *ts) 141 { 142 int i, year, days; 143 144 if (ct_debug) { 145 printf("ct_to_ts(["); 146 clock_print_ct(ct, 9); 147 printf("])"); 148 } 149 150 /* 151 * Many realtime clocks store the year as 2-digit BCD; pivot on 70 to 152 * determine century. Some clocks have a "century bit" and drivers do 153 * year += 100, so interpret values between 70-199 as relative to 1900. 154 */ 155 year = ct->year; 156 if (year < 70) 157 year += 2000; 158 else if (year < 200) 159 year += 1900; 160 161 /* Sanity checks. */ 162 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 163 ct->day > days_in_month(year, ct->mon) || 164 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 || 165 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ 166 if (ct_debug) 167 printf(" = EINVAL\n"); 168 return (EINVAL); 169 } 170 171 /* 172 * Compute days since start of time 173 * First from years, then from months. 174 */ 175 if (year >= recent_base_year) { 176 i = recent_base_year; 177 days = recent_base_days; 178 } else { 179 i = POSIX_BASE_YEAR; 180 days = 0; 181 } 182 for (; i < year; i++) 183 days += days_in_year(i); 184 185 /* Months */ 186 for (i = 1; i < ct->mon; i++) 187 days += days_in_month(year, i); 188 days += (ct->day - 1); 189 190 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 + 191 ct->sec; 192 ts->tv_nsec = ct->nsec; 193 194 if (ct_debug) 195 printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec); 196 return (0); 197 } 198 199 int 200 clock_bcd_to_ts(const struct bcd_clocktime *bct, struct timespec *ts, bool ampm) 201 { 202 struct clocktime ct; 203 int bcent, byear; 204 205 /* 206 * Year may come in as 2-digit or 4-digit BCD. Split the value into 207 * separate BCD century and year values for validation and conversion. 208 */ 209 bcent = bct->year >> 8; 210 byear = bct->year & 0xff; 211 212 /* 213 * Ensure that all values are valid BCD numbers, to avoid assertions in 214 * the BCD-to-binary conversion routines. clock_ct_to_ts() will further 215 * validate the field ranges (such as 0 <= min <= 59) during conversion. 216 */ 217 if (!validbcd(bcent) || !validbcd(byear) || !validbcd(bct->mon) || 218 !validbcd(bct->day) || !validbcd(bct->hour) || 219 !validbcd(bct->min) || !validbcd(bct->sec)) { 220 if (ct_debug) 221 printf("clock_bcd_to_ts: bad BCD: " 222 "[%04x-%02x-%02x %02x:%02x:%02x]\n", 223 bct->year, bct->mon, bct->day, 224 bct->hour, bct->min, bct->sec); 225 return (EINVAL); 226 } 227 228 ct.year = FROMBCD(byear) + FROMBCD(bcent) * 100; 229 ct.mon = FROMBCD(bct->mon); 230 ct.day = FROMBCD(bct->day); 231 ct.hour = FROMBCD(bct->hour); 232 ct.min = FROMBCD(bct->min); 233 ct.sec = FROMBCD(bct->sec); 234 ct.dow = bct->dow; 235 ct.nsec = bct->nsec; 236 237 /* If asked to handle am/pm, convert from 12hr+pmflag to 24hr. */ 238 if (ampm) { 239 if (ct.hour == 12) 240 ct.hour = 0; 241 if (bct->ispm) 242 ct.hour += 12; 243 } 244 245 return (clock_ct_to_ts(&ct, ts)); 246 } 247 248 void 249 clock_ts_to_ct(const struct timespec *ts, struct clocktime *ct) 250 { 251 time_t i, year, days; 252 time_t rsec; /* remainder seconds */ 253 time_t secs; 254 255 secs = ts->tv_sec; 256 days = secs / SECDAY; 257 rsec = secs % SECDAY; 258 259 ct->dow = day_of_week(days); 260 261 /* Subtract out whole years. */ 262 if (days >= recent_base_days) { 263 year = recent_base_year; 264 days -= recent_base_days; 265 } else { 266 year = POSIX_BASE_YEAR; 267 } 268 for (; days >= days_in_year(year); year++) 269 days -= days_in_year(year); 270 ct->year = year; 271 272 /* Subtract out whole months, counting them in i. */ 273 for (i = 1; days >= days_in_month(year, i); i++) 274 days -= days_in_month(year, i); 275 ct->mon = i; 276 277 /* Days are what is left over (+1) from all that. */ 278 ct->day = days + 1; 279 280 /* Hours, minutes, seconds are easy */ 281 ct->hour = rsec / 3600; 282 rsec = rsec % 3600; 283 ct->min = rsec / 60; 284 rsec = rsec % 60; 285 ct->sec = rsec; 286 ct->nsec = ts->tv_nsec; 287 if (ct_debug) { 288 printf("ts_to_ct(%jd.%09ld) = [", 289 (intmax_t)ts->tv_sec, ts->tv_nsec); 290 clock_print_ct(ct, 9); 291 printf("]\n"); 292 } 293 294 KASSERT(ct->year >= 0 && ct->year < 10000, 295 ("year %d isn't a 4 digit year", ct->year)); 296 KASSERT(ct->mon >= 1 && ct->mon <= 12, 297 ("month %d not in 1-12", ct->mon)); 298 KASSERT(ct->day >= 1 && ct->day <= 31, 299 ("day %d not in 1-31", ct->day)); 300 KASSERT(ct->hour >= 0 && ct->hour <= 23, 301 ("hour %d not in 0-23", ct->hour)); 302 KASSERT(ct->min >= 0 && ct->min <= 59, 303 ("minute %d not in 0-59", ct->min)); 304 /* Not sure if this interface needs to handle leapseconds or not. */ 305 KASSERT(ct->sec >= 0 && ct->sec <= 60, 306 ("seconds %d not in 0-60", ct->sec)); 307 } 308 309 void 310 clock_ts_to_bcd(const struct timespec *ts, struct bcd_clocktime *bct, bool ampm) 311 { 312 struct clocktime ct; 313 314 clock_ts_to_ct(ts, &ct); 315 316 /* If asked to handle am/pm, convert from 24hr to 12hr+pmflag. */ 317 bct->ispm = false; 318 if (ampm) { 319 if (ct.hour >= 12) { 320 ct.hour -= 12; 321 bct->ispm = true; 322 } 323 if (ct.hour == 0) 324 ct.hour = 12; 325 } 326 327 bct->year = TOBCD(ct.year % 100) | (TOBCD(ct.year / 100) << 8); 328 bct->mon = TOBCD(ct.mon); 329 bct->day = TOBCD(ct.day); 330 bct->hour = TOBCD(ct.hour); 331 bct->min = TOBCD(ct.min); 332 bct->sec = TOBCD(ct.sec); 333 bct->dow = ct.dow; 334 bct->nsec = ct.nsec; 335 } 336 337 void 338 clock_print_bcd(const struct bcd_clocktime *bct, int nsdigits) 339 { 340 341 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 342 343 if (nsdigits > 0) { 344 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x.%*.*ld", 345 bct->year, bct->mon, bct->day, 346 bct->hour, bct->min, bct->sec, 347 nsdigits, nsdigits, bct->nsec / nsdivisors[nsdigits]); 348 } else { 349 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x", 350 bct->year, bct->mon, bct->day, 351 bct->hour, bct->min, bct->sec); 352 } 353 } 354 355 void 356 clock_print_ct(const struct clocktime *ct, int nsdigits) 357 { 358 359 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 360 361 if (nsdigits > 0) { 362 printf("%04d-%02d-%02d %02d:%02d:%02d.%*.*ld", 363 ct->year, ct->mon, ct->day, 364 ct->hour, ct->min, ct->sec, 365 nsdigits, nsdigits, ct->nsec / nsdivisors[nsdigits]); 366 } else { 367 printf("%04d-%02d-%02d %02d:%02d:%02d", 368 ct->year, ct->mon, ct->day, 369 ct->hour, ct->min, ct->sec); 370 } 371 } 372 373 void 374 clock_print_ts(const struct timespec *ts, int nsdigits) 375 { 376 struct clocktime ct; 377 378 clock_ts_to_ct(ts, &ct); 379 clock_print_ct(&ct, nsdigits); 380 } 381 382 int 383 utc_offset(void) 384 { 385 386 return (wall_cmos_clock ? adjkerntz : 0); 387 } 388