kern_todr.c revision 1.39.18.1
1 /* $NetBSD: kern_todr.c,v 1.39.18.1 2020/04/08 14:08:51 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 2020 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 1988 University of Utah. 34 * Copyright (c) 1992, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * This code is derived from software contributed to Berkeley by 38 * the Systems Programming Group of the University of Utah Computer 39 * Science Department and Ralph Campbell. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * from: Utah Hdr: clock.c 1.18 91/01/21 66 * 67 * @(#)clock.c 8.1 (Berkeley) 6/10/93 68 */ 69 70 #include "opt_todr.h" 71 72 #include <sys/cdefs.h> 73 __KERNEL_RCSID(0, "$NetBSD: kern_todr.c,v 1.39.18.1 2020/04/08 14:08:51 martin Exp $"); 74 75 #include <sys/param.h> 76 #include <sys/kernel.h> 77 #include <sys/systm.h> 78 #include <sys/device.h> 79 #include <sys/timetc.h> 80 #include <sys/intr.h> 81 #include <sys/rndsource.h> 82 #include <sys/mutex.h> 83 84 #include <dev/clock_subr.h> /* hmm.. this should probably move to sys */ 85 86 static int todr_gettime(todr_chip_handle_t, struct timeval *); 87 static int todr_settime(todr_chip_handle_t, struct timeval *); 88 89 static kmutex_t todr_mutex; 90 static todr_chip_handle_t todr_handle; 91 static bool todr_initialized; 92 93 /* 94 * todr_init: 95 * Initialize TOD clock data. 96 */ 97 void 98 todr_init(void) 99 { 100 101 mutex_init(&todr_mutex, MUTEX_DEFAULT, IPL_NONE); 102 todr_initialized = true; 103 } 104 105 /* 106 * todr_lock: 107 * Acquire the TODR lock. 108 */ 109 void 110 todr_lock(void) 111 { 112 113 mutex_enter(&todr_mutex); 114 } 115 116 /* 117 * todr_unlock: 118 * Release the TODR lock. 119 */ 120 void 121 todr_unlock(void) 122 { 123 124 mutex_exit(&todr_mutex); 125 } 126 127 /* 128 * todr_lock_owned: 129 * Return true if the current thread owns the TODR lock. 130 * This is to be used by diagnostic assertions only. 131 */ 132 bool 133 todr_lock_owned(void) 134 { 135 136 return mutex_owned(&todr_mutex) ? true : false; 137 } 138 139 /* 140 * todr_attach: 141 * Attach the clock device to todr_handle. 142 */ 143 void 144 todr_attach(todr_chip_handle_t todr) 145 { 146 147 /* 148 * todr_init() is called very early in main(), but this is 149 * here to catch a case where todr_attach() is called before 150 * main(). 151 */ 152 KASSERT(todr_initialized); 153 154 todr_lock(); 155 if (todr_handle) { 156 todr_unlock(); 157 printf("todr_attach: TOD already configured\n"); 158 return; 159 } 160 todr_handle = todr; 161 todr_unlock(); 162 } 163 164 static bool timeset = false; 165 166 /* 167 * todr_set_systime: 168 * Set up the system's time. The "base" argument is a best-guess 169 * close-enough value to use if the TOD clock is unavailable or 170 * contains garbage. Must be called with the TODR lock held. 171 */ 172 void 173 todr_set_systime(time_t base) 174 { 175 bool badbase = false; 176 bool waszero = (base == 0); 177 bool goodtime = false; 178 bool badrtc = false; 179 struct timespec ts; 180 struct timeval tv; 181 182 KASSERT(todr_lock_owned()); 183 184 rnd_add_data(NULL, &base, sizeof(base), 0); 185 186 if (base < 5 * SECS_PER_COMMON_YEAR) { 187 struct clock_ymdhms basedate; 188 189 /* 190 * If base is 0, assume filesystem time is just unknown 191 * instead of preposterous. Don't bark. 192 */ 193 if (base != 0) 194 printf("WARNING: preposterous time in file system\n"); 195 /* not going to use it anyway, if the chip is readable */ 196 basedate.dt_year = 2010; 197 basedate.dt_mon = 1; 198 basedate.dt_day = 1; 199 basedate.dt_hour = 12; 200 basedate.dt_min = 0; 201 basedate.dt_sec = 0; 202 base = clock_ymdhms_to_secs(&basedate); 203 badbase = true; 204 } 205 206 /* 207 * Some ports need to be supplied base in order to fabricate a time_t. 208 */ 209 if (todr_handle) 210 todr_handle->base_time = base; 211 212 if ((todr_handle == NULL) || 213 (todr_gettime(todr_handle, &tv) != 0) || 214 (tv.tv_sec < (25 * SECS_PER_COMMON_YEAR))) { 215 216 if (todr_handle != NULL) 217 printf("WARNING: preposterous TOD clock time\n"); 218 else 219 printf("WARNING: no TOD clock present\n"); 220 badrtc = true; 221 } else { 222 time_t deltat = tv.tv_sec - base; 223 224 if (deltat < 0) 225 deltat = -deltat; 226 227 if (!badbase && deltat >= 2 * SECS_PER_DAY) { 228 229 if (tv.tv_sec < base) { 230 /* 231 * The clock should never go backwards 232 * relative to filesystem time. If it 233 * does by more than the threshold, 234 * believe the filesystem. 235 */ 236 printf("WARNING: clock lost %" PRId64 " days\n", 237 deltat / SECS_PER_DAY); 238 badrtc = true; 239 } else { 240 aprint_verbose("WARNING: clock gained %" PRId64 241 " days\n", deltat / SECS_PER_DAY); 242 goodtime = true; 243 } 244 } else { 245 goodtime = true; 246 } 247 248 rnd_add_data(NULL, &tv, sizeof(tv), 0); 249 } 250 251 /* if the rtc time is bad, use the filesystem time */ 252 if (badrtc) { 253 if (badbase) { 254 printf("WARNING: using default initial time\n"); 255 } else { 256 printf("WARNING: using filesystem time\n"); 257 } 258 tv.tv_sec = base; 259 tv.tv_usec = 0; 260 } 261 262 timeset = true; 263 264 ts.tv_sec = tv.tv_sec; 265 ts.tv_nsec = tv.tv_usec * 1000; 266 tc_setclock(&ts); 267 268 if (waszero || goodtime) 269 return; 270 271 printf("WARNING: CHECK AND RESET THE DATE!\n"); 272 } 273 274 /* 275 * todr_save_systime: 276 * Save the current system time back to the TOD clock. 277 * Must be called with the TODR lock held. 278 */ 279 void 280 todr_save_systime(void) 281 { 282 struct timeval tv; 283 284 KASSERT(todr_lock_owned()); 285 286 /* 287 * We might have been called by boot() due to a crash early 288 * on. Don't reset the clock chip if we don't know what time 289 * it is. 290 */ 291 if (!timeset) 292 return; 293 294 getmicrotime(&tv); 295 296 if (tv.tv_sec == 0) 297 return; 298 299 if (todr_handle) 300 if (todr_settime(todr_handle, &tv) != 0) 301 printf("Cannot set TOD clock time\n"); 302 } 303 304 /* 305 * inittodr: 306 * Legacy wrapper around todr_set_systime(). 307 */ 308 void 309 inittodr(time_t base) 310 { 311 312 todr_lock(); 313 todr_set_systime(base); 314 todr_unlock(); 315 } 316 317 /* 318 * resettodr: 319 * Legacy wrapper around todr_save_systime(). 320 */ 321 void 322 resettodr(void) 323 { 324 325 /* 326 * If we're shutting down, we don't want to get stuck in case 327 * someone was already fiddling with the TOD clock. 328 */ 329 if (shutting_down) { 330 if (mutex_tryenter(&todr_mutex) == 0) { 331 printf("WARNING: Cannot set TOD clock time (busy)\n"); 332 return; 333 } 334 } else { 335 todr_lock(); 336 } 337 todr_save_systime(); 338 todr_unlock(); 339 } 340 341 #ifdef TODR_DEBUG 342 static void 343 todr_debug(const char *prefix, int rv, struct clock_ymdhms *dt, 344 struct timeval *tvp) 345 { 346 struct timeval tv_val; 347 struct clock_ymdhms dt_val; 348 349 if (dt == NULL) { 350 clock_secs_to_ymdhms(tvp->tv_sec, &dt_val); 351 dt = &dt_val; 352 } 353 if (tvp == NULL) { 354 tvp = &tv_val; 355 tvp->tv_sec = clock_ymdhms_to_secs(dt); 356 tvp->tv_usec = 0; 357 } 358 printf("%s: rv = %d\n", prefix, rv); 359 printf("%s: rtc_offset = %d\n", prefix, rtc_offset); 360 printf("%s: %4u/%02u/%02u %02u:%02u:%02u, (wday %d) (epoch %u.%06u)\n", 361 prefix, 362 (unsigned)dt->dt_year, dt->dt_mon, dt->dt_day, 363 dt->dt_hour, dt->dt_min, dt->dt_sec, 364 dt->dt_wday, (unsigned)tvp->tv_sec, (unsigned)tvp->tv_usec); 365 } 366 #else /* !TODR_DEBUG */ 367 #define todr_debug(prefix, rv, dt, tvp) 368 #endif /* TODR_DEBUG */ 369 370 static int 371 todr_wenable(todr_chip_handle_t todr, int onoff) 372 { 373 374 if (todr->todr_setwen != NULL) 375 return todr->todr_setwen(todr, onoff); 376 377 return 0; 378 } 379 380 #define ENABLE_TODR_WRITES() \ 381 do { \ 382 if ((rv = todr_wenable(tch, 1)) != 0) { \ 383 printf("%s: cannot enable TODR writes\n", __func__); \ 384 return rv; \ 385 } \ 386 } while (/*CONSTCOND*/0) 387 388 #define DISABLE_TODR_WRITES() \ 389 do { \ 390 if (todr_wenable(tch, 0) != 0) \ 391 printf("%s: WARNING: cannot disable TODR writes\n", \ 392 __func__); \ 393 } while (/*CONSTCOND*/0) 394 395 static int 396 todr_gettime(todr_chip_handle_t tch, struct timeval *tvp) 397 { 398 int rv; 399 400 /* 401 * Write-enable is used even when reading the TODR because 402 * writing to registers may be required in order to do so. 403 */ 404 405 if (tch->todr_gettime) { 406 ENABLE_TODR_WRITES(); 407 rv = tch->todr_gettime(tch, tvp); 408 DISABLE_TODR_WRITES(); 409 /* 410 * Some unconverted ports have their own references to 411 * rtc_offset. A converted port must not do that. 412 */ 413 if (rv == 0) 414 tvp->tv_sec += rtc_offset * 60; 415 todr_debug("TODR-GET-SECS", rv, NULL, tvp); 416 return rv; 417 } else if (tch->todr_gettime_ymdhms) { 418 struct clock_ymdhms dt = { 0 }; 419 ENABLE_TODR_WRITES(); 420 rv = tch->todr_gettime_ymdhms(tch, &dt); 421 DISABLE_TODR_WRITES(); 422 todr_debug("TODR-GET-YMDHMS", rv, &dt, NULL); 423 if (rv) 424 return rv; 425 426 /* 427 * Simple sanity checks. Note that this includes a 428 * value for clocks that can return a leap second. 429 * Note that we don't support double leap seconds, 430 * since this was apparently an error/misunderstanding 431 * on the part of the ISO C committee, and can never 432 * actually occur. If your clock issues us a double 433 * leap second, it must be broken. Ultimately, you'd 434 * have to be trying to read time at precisely that 435 * instant to even notice, so even broken clocks will 436 * work the vast majority of the time. In such a case 437 * it is recommended correction be applied in the 438 * clock driver. 439 */ 440 if (dt.dt_mon < 1 || dt.dt_mon > 12 || 441 dt.dt_day < 1 || dt.dt_day > 31 || 442 dt.dt_hour > 23 || dt.dt_min > 59 || dt.dt_sec > 60) { 443 return EINVAL; 444 } 445 tvp->tv_sec = clock_ymdhms_to_secs(&dt) + rtc_offset * 60; 446 tvp->tv_usec = 0; 447 return tvp->tv_sec < 0 ? EINVAL : 0; 448 } 449 450 return ENXIO; 451 } 452 453 static int 454 todr_settime(todr_chip_handle_t tch, struct timeval *tvp) 455 { 456 int rv; 457 458 if (tch->todr_settime) { 459 struct timeval copy = *tvp; 460 copy.tv_sec -= rtc_offset * 60; 461 ENABLE_TODR_WRITES(); 462 rv = tch->todr_settime(tch, ©); 463 DISABLE_TODR_WRITES(); 464 todr_debug("TODR-SET-SECS", rv, NULL, tvp); 465 return rv; 466 } else if (tch->todr_settime_ymdhms) { 467 struct clock_ymdhms dt; 468 time_t sec = tvp->tv_sec - rtc_offset * 60; 469 if (tvp->tv_usec >= 500000) 470 sec++; 471 clock_secs_to_ymdhms(sec, &dt); 472 ENABLE_TODR_WRITES(); 473 rv = tch->todr_settime_ymdhms(tch, &dt); 474 DISABLE_TODR_WRITES(); 475 todr_debug("TODR-SET-YMDHMS", rv, &dt, NULL); 476 return rv; 477 } 478 479 return ENXIO; 480 } 481
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