1 /*- 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 */ 9 10 #include <sys/cdefs.h> 11 __FBSDID("$FreeBSD$"); 12 13 #include "opt_ntp.h" 14 15 #include <sys/param.h> 16 #include <sys/kernel.h> 17 #include <sys/sysctl.h> 18 #include <sys/syslog.h> 19 #include <sys/systm.h> 20 #include <sys/timepps.h> 21 #include <sys/timetc.h> 22 #include <sys/timex.h> 23 24 /* 25 * A large step happens on boot. This constant detects such steps. 26 * It is relatively small so that ntp_update_second gets called enough 27 * in the typical 'missed a couple of seconds' case, but doesn't loop 28 * forever when the time step is large. 29 */ 30 #define LARGE_STEP 200 31 32 /* 33 * Implement a dummy timecounter which we can use until we get a real one 34 * in the air. This allows the console and other early stuff to use 35 * time services. 36 */ 37 38 static u_int 39 dummy_get_timecount(struct timecounter *tc) 40 { 41 static u_int now; 42 43 return (++now); 44 } 45 46 static struct timecounter dummy_timecounter = { 47 dummy_get_timecount, 0, ~0u, 1000000, "dummy", -1000000 48 }; 49 50 struct timehands { 51 /* These fields must be initialized by the driver. */ 52 struct timecounter *th_counter; 53 int64_t th_adjustment; 54 u_int64_t th_scale; 55 u_int th_offset_count; 56 struct bintime th_offset; 57 struct timeval th_microtime; 58 struct timespec th_nanotime; 59 /* Fields not to be copied in tc_windup start with th_generation. */ 60 volatile u_int th_generation; 61 struct timehands *th_next; 62 }; 63 64 static struct timehands th0; 65 static struct timehands th9 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th0}; 66 static struct timehands th8 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th9}; 67 static struct timehands th7 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th8}; 68 static struct timehands th6 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th7}; 69 static struct timehands th5 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th6}; 70 static struct timehands th4 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th5}; 71 static struct timehands th3 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th4}; 72 static struct timehands th2 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th3}; 73 static struct timehands th1 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th2}; 74 static struct timehands th0 = { 75 &dummy_timecounter, 76 0, 77 (uint64_t)-1 / 1000000, 78 0, 79 {1, 0}, 80 {0, 0}, 81 {0, 0}, 82 1, 83 &th1 84 }; 85 86 static struct timehands *volatile timehands = &th0; 87 struct timecounter *timecounter = &dummy_timecounter; 88 static struct timecounter *timecounters = &dummy_timecounter; 89 90 time_t time_second = 1; 91 time_t time_uptime = 1; 92 93 static struct bintime boottimebin; 94 struct timeval boottime; 95 static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS); 96 SYSCTL_PROC(_kern, KERN_BOOTTIME, boottime, CTLTYPE_STRUCT|CTLFLAG_RD, 97 NULL, 0, sysctl_kern_boottime, "S,timeval", "System boottime"); 98 99 SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, ""); 100 SYSCTL_NODE(_kern_timecounter, OID_AUTO, tc, CTLFLAG_RW, 0, ""); 101 102 static int timestepwarnings; 103 SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW, 104 ×tepwarnings, 0, ""); 105 106 #ifdef TC_COUNTERS 107 #define TC_STATS(foo) \ 108 static u_int foo; \ 109 SYSCTL_UINT(_kern_timecounter, OID_AUTO, foo, CTLFLAG_RD, &foo, 0, "");\ 110 struct __hack 111 112 TC_STATS(nbinuptime); TC_STATS(nnanouptime); TC_STATS(nmicrouptime); 113 TC_STATS(nbintime); TC_STATS(nnanotime); TC_STATS(nmicrotime); 114 TC_STATS(ngetbinuptime); TC_STATS(ngetnanouptime); TC_STATS(ngetmicrouptime); 115 TC_STATS(ngetbintime); TC_STATS(ngetnanotime); TC_STATS(ngetmicrotime); 116 TC_STATS(nsetclock); 117 118 #define TC_COUNT(var) var++ 119 #undef TC_STATS 120 #else 121 #define TC_COUNT(var) /* nothing */ 122 #endif /* TC_COUNTERS */ 123 124 static void tc_windup(void); 125 static void cpu_tick_calibrate(int); 126 127 static int 128 sysctl_kern_boottime(SYSCTL_HANDLER_ARGS) 129 { 130 #ifdef SCTL_MASK32 131 int tv[2]; 132 133 if (req->flags & SCTL_MASK32) { 134 tv[0] = boottime.tv_sec; 135 tv[1] = boottime.tv_usec; 136 return SYSCTL_OUT(req, tv, sizeof(tv)); 137 } else 138 #endif 139 return SYSCTL_OUT(req, &boottime, sizeof(boottime)); 140 } 141 142 static int 143 sysctl_kern_timecounter_get(SYSCTL_HANDLER_ARGS) 144 { 145 u_int ncount; 146 struct timecounter *tc = arg1; 147 148 ncount = tc->tc_get_timecount(tc); 149 return sysctl_handle_int(oidp, &ncount, 0, req); 150 } 151 152 static int 153 sysctl_kern_timecounter_freq(SYSCTL_HANDLER_ARGS) 154 { 155 u_int64_t freq; 156 struct timecounter *tc = arg1; 157 158 freq = tc->tc_frequency; 159 return sysctl_handle_quad(oidp, &freq, 0, req); 160 } 161 162 /* 163 * Return the difference between the timehands' counter value now and what 164 * was when we copied it to the timehands' offset_count. 165 */ 166 static __inline u_int 167 tc_delta(struct timehands *th) 168 { 169 struct timecounter *tc; 170 171 tc = th->th_counter; 172 return ((tc->tc_get_timecount(tc) - th->th_offset_count) & 173 tc->tc_counter_mask); 174 } 175 176 /* 177 * Functions for reading the time. We have to loop until we are sure that 178 * the timehands that we operated on was not updated under our feet. See 179 * the comment in <sys/time.h> for a description of these 12 functions. 180 */ 181 182 void 183 binuptime(struct bintime *bt) 184 { 185 struct timehands *th; 186 u_int gen; 187 188 TC_COUNT(nbinuptime); 189 do { 190 th = timehands; 191 gen = th->th_generation; 192 *bt = th->th_offset; 193 bintime_addx(bt, th->th_scale * tc_delta(th)); 194 } while (gen == 0 || gen != th->th_generation); 195 } 196 197 void 198 nanouptime(struct timespec *tsp) 199 { 200 struct bintime bt; 201 202 TC_COUNT(nnanouptime); 203 binuptime(&bt); 204 bintime2timespec(&bt, tsp); 205 } 206 207 void 208 microuptime(struct timeval *tvp) 209 { 210 struct bintime bt; 211 212 TC_COUNT(nmicrouptime); 213 binuptime(&bt); 214 bintime2timeval(&bt, tvp); 215 } 216 217 void 218 bintime(struct bintime *bt) 219 { 220 221 TC_COUNT(nbintime); 222 binuptime(bt); 223 bintime_add(bt, &boottimebin); 224 } 225 226 void 227 nanotime(struct timespec *tsp) 228 { 229 struct bintime bt; 230 231 TC_COUNT(nnanotime); 232 bintime(&bt); 233 bintime2timespec(&bt, tsp); 234 } 235 236 void 237 microtime(struct timeval *tvp) 238 { 239 struct bintime bt; 240 241 TC_COUNT(nmicrotime); 242 bintime(&bt); 243 bintime2timeval(&bt, tvp); 244 } 245 246 void 247 getbinuptime(struct bintime *bt) 248 { 249 struct timehands *th; 250 u_int gen; 251 252 TC_COUNT(ngetbinuptime); 253 do { 254 th = timehands; 255 gen = th->th_generation; 256 *bt = th->th_offset; 257 } while (gen == 0 || gen != th->th_generation); 258 } 259 260 void 261 getnanouptime(struct timespec *tsp) 262 { 263 struct timehands *th; 264 u_int gen; 265 266 TC_COUNT(ngetnanouptime); 267 do { 268 th = timehands; 269 gen = th->th_generation; 270 bintime2timespec(&th->th_offset, tsp); 271 } while (gen == 0 || gen != th->th_generation); 272 } 273 274 void 275 getmicrouptime(struct timeval *tvp) 276 { 277 struct timehands *th; 278 u_int gen; 279 280 TC_COUNT(ngetmicrouptime); 281 do { 282 th = timehands; 283 gen = th->th_generation; 284 bintime2timeval(&th->th_offset, tvp); 285 } while (gen == 0 || gen != th->th_generation); 286 } 287 288 void 289 getbintime(struct bintime *bt) 290 { 291 struct timehands *th; 292 u_int gen; 293 294 TC_COUNT(ngetbintime); 295 do { 296 th = timehands; 297 gen = th->th_generation; 298 *bt = th->th_offset; 299 } while (gen == 0 || gen != th->th_generation); 300 bintime_add(bt, &boottimebin); 301 } 302 303 void 304 getnanotime(struct timespec *tsp) 305 { 306 struct timehands *th; 307 u_int gen; 308 309 TC_COUNT(ngetnanotime); 310 do { 311 th = timehands; 312 gen = th->th_generation; 313 *tsp = th->th_nanotime; 314 } while (gen == 0 || gen != th->th_generation); 315 } 316 317 void 318 getmicrotime(struct timeval *tvp) 319 { 320 struct timehands *th; 321 u_int gen; 322 323 TC_COUNT(ngetmicrotime); 324 do { 325 th = timehands; 326 gen = th->th_generation; 327 *tvp = th->th_microtime; 328 } while (gen == 0 || gen != th->th_generation); 329 } 330 331 /* 332 * Initialize a new timecounter and possibly use it. 333 */ 334 void 335 tc_init(struct timecounter *tc) 336 { 337 u_int u; 338 struct sysctl_oid *tc_root; 339 340 u = tc->tc_frequency / tc->tc_counter_mask; 341 /* XXX: We need some margin here, 10% is a guess */ 342 u *= 11; 343 u /= 10; 344 if (u > hz && tc->tc_quality >= 0) { 345 tc->tc_quality = -2000; 346 if (bootverbose) { 347 printf("Timecounter \"%s\" frequency %ju Hz", 348 tc->tc_name, (uintmax_t)tc->tc_frequency); 349 printf(" -- Insufficient hz, needs at least %u\n", u); 350 } 351 } else if (tc->tc_quality >= 0 || bootverbose) { 352 printf("Timecounter \"%s\" frequency %ju Hz quality %d\n", 353 tc->tc_name, (uintmax_t)tc->tc_frequency, 354 tc->tc_quality); 355 } 356 357 tc->tc_next = timecounters; 358 timecounters = tc; 359 /* 360 * Set up sysctl tree for this counter. 361 */ 362 tc_root = SYSCTL_ADD_NODE(NULL, 363 SYSCTL_STATIC_CHILDREN(_kern_timecounter_tc), OID_AUTO, tc->tc_name, 364 CTLFLAG_RW, 0, "timecounter description"); 365 SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 366 "mask", CTLFLAG_RD, &(tc->tc_counter_mask), 0, 367 "mask for implemented bits"); 368 SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 369 "counter", CTLTYPE_UINT | CTLFLAG_RD, tc, sizeof(*tc), 370 sysctl_kern_timecounter_get, "IU", "current timecounter value"); 371 SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 372 "frequency", CTLTYPE_QUAD | CTLFLAG_RD, tc, sizeof(*tc), 373 sysctl_kern_timecounter_freq, "QU", "timecounter frequency"); 374 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 375 "quality", CTLFLAG_RD, &(tc->tc_quality), 0, 376 "goodness of time counter"); 377 /* 378 * Never automatically use a timecounter with negative quality. 379 * Even though we run on the dummy counter, switching here may be 380 * worse since this timecounter may not be monotonous. 381 */ 382 if (tc->tc_quality < 0) 383 return; 384 if (tc->tc_quality < timecounter->tc_quality) 385 return; 386 if (tc->tc_quality == timecounter->tc_quality && 387 tc->tc_frequency < timecounter->tc_frequency) 388 return; 389 (void)tc->tc_get_timecount(tc); 390 (void)tc->tc_get_timecount(tc); 391 timecounter = tc; 392 } 393 394 /* Report the frequency of the current timecounter. */ 395 u_int64_t 396 tc_getfrequency(void) 397 { 398 399 return (timehands->th_counter->tc_frequency); 400 } 401 402 /* 403 * Step our concept of UTC. This is done by modifying our estimate of 404 * when we booted. 405 * XXX: not locked. 406 */ 407 void 408 tc_setclock(struct timespec *ts) 409 { 410 struct timespec tbef, taft; 411 struct bintime bt, bt2; 412 413 cpu_tick_calibrate(1); 414 TC_COUNT(nsetclock); 415 nanotime(&tbef); 416 timespec2bintime(ts, &bt); 417 binuptime(&bt2); 418 bintime_sub(&bt, &bt2); 419 bintime_add(&bt2, &boottimebin); 420 boottimebin = bt; 421 bintime2timeval(&bt, &boottime); 422 423 /* XXX fiddle all the little crinkly bits around the fiords... */ 424 tc_windup(); 425 nanotime(&taft); 426 if (timestepwarnings) { 427 log(LOG_INFO, 428 "Time stepped from %jd.%09ld to %jd.%09ld (%jd.%09ld)\n", 429 (intmax_t)tbef.tv_sec, tbef.tv_nsec, 430 (intmax_t)taft.tv_sec, taft.tv_nsec, 431 (intmax_t)ts->tv_sec, ts->tv_nsec); 432 } 433 cpu_tick_calibrate(1); 434 } 435 436 /* 437 * Initialize the next struct timehands in the ring and make 438 * it the active timehands. Along the way we might switch to a different 439 * timecounter and/or do seconds processing in NTP. Slightly magic. 440 */ 441 static void 442 tc_windup(void) 443 { 444 struct bintime bt; 445 struct timehands *th, *tho; 446 u_int64_t scale; 447 u_int delta, ncount, ogen; 448 int i; 449 time_t t; 450 451 /* 452 * Make the next timehands a copy of the current one, but do not 453 * overwrite the generation or next pointer. While we update 454 * the contents, the generation must be zero. 455 */ 456 tho = timehands; 457 th = tho->th_next; 458 ogen = th->th_generation; 459 th->th_generation = 0; 460 bcopy(tho, th, offsetof(struct timehands, th_generation)); 461 462 /* 463 * Capture a timecounter delta on the current timecounter and if 464 * changing timecounters, a counter value from the new timecounter. 465 * Update the offset fields accordingly. 466 */ 467 delta = tc_delta(th); 468 if (th->th_counter != timecounter) 469 ncount = timecounter->tc_get_timecount(timecounter); 470 else 471 ncount = 0; 472 th->th_offset_count += delta; 473 th->th_offset_count &= th->th_counter->tc_counter_mask; 474 bintime_addx(&th->th_offset, th->th_scale * delta); 475 476 /* 477 * Hardware latching timecounters may not generate interrupts on 478 * PPS events, so instead we poll them. There is a finite risk that 479 * the hardware might capture a count which is later than the one we 480 * got above, and therefore possibly in the next NTP second which might 481 * have a different rate than the current NTP second. It doesn't 482 * matter in practice. 483 */ 484 if (tho->th_counter->tc_poll_pps) 485 tho->th_counter->tc_poll_pps(tho->th_counter); 486 487 /* 488 * Deal with NTP second processing. The for loop normally 489 * iterates at most once, but in extreme situations it might 490 * keep NTP sane if timeouts are not run for several seconds. 491 * At boot, the time step can be large when the TOD hardware 492 * has been read, so on really large steps, we call 493 * ntp_update_second only twice. We need to call it twice in 494 * case we missed a leap second. 495 */ 496 bt = th->th_offset; 497 bintime_add(&bt, &boottimebin); 498 i = bt.sec - tho->th_microtime.tv_sec; 499 if (i > LARGE_STEP) 500 i = 2; 501 for (; i > 0; i--) { 502 t = bt.sec; 503 ntp_update_second(&th->th_adjustment, &bt.sec); 504 if (bt.sec != t) 505 boottimebin.sec += bt.sec - t; 506 } 507 /* Update the UTC timestamps used by the get*() functions. */ 508 /* XXX shouldn't do this here. Should force non-`get' versions. */ 509 bintime2timeval(&bt, &th->th_microtime); 510 bintime2timespec(&bt, &th->th_nanotime); 511 512 /* Now is a good time to change timecounters. */ 513 if (th->th_counter != timecounter) { 514 th->th_counter = timecounter; 515 th->th_offset_count = ncount; 516 } 517 518 /*- 519 * Recalculate the scaling factor. We want the number of 1/2^64 520 * fractions of a second per period of the hardware counter, taking 521 * into account the th_adjustment factor which the NTP PLL/adjtime(2) 522 * processing provides us with. 523 * 524 * The th_adjustment is nanoseconds per second with 32 bit binary 525 * fraction and we want 64 bit binary fraction of second: 526 * 527 * x = a * 2^32 / 10^9 = a * 4.294967296 528 * 529 * The range of th_adjustment is +/- 5000PPM so inside a 64bit int 530 * we can only multiply by about 850 without overflowing, that 531 * leaves no suitably precise fractions for multiply before divide. 532 * 533 * Divide before multiply with a fraction of 2199/512 results in a 534 * systematic undercompensation of 10PPM of th_adjustment. On a 535 * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. 536 * 537 * We happily sacrifice the lowest of the 64 bits of our result 538 * to the goddess of code clarity. 539 * 540 */ 541 scale = (u_int64_t)1 << 63; 542 scale += (th->th_adjustment / 1024) * 2199; 543 scale /= th->th_counter->tc_frequency; 544 th->th_scale = scale * 2; 545 546 /* 547 * Now that the struct timehands is again consistent, set the new 548 * generation number, making sure to not make it zero. 549 */ 550 if (++ogen == 0) 551 ogen = 1; 552 th->th_generation = ogen; 553 554 /* Go live with the new struct timehands. */ 555 time_second = th->th_microtime.tv_sec; 556 time_uptime = th->th_offset.sec; 557 timehands = th; 558 } 559 560 /* Report or change the active timecounter hardware. */ 561 static int 562 sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) 563 { 564 char newname[32]; 565 struct timecounter *newtc, *tc; 566 int error; 567 568 tc = timecounter; 569 strlcpy(newname, tc->tc_name, sizeof(newname)); 570 571 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); 572 if (error != 0 || req->newptr == NULL || 573 strcmp(newname, tc->tc_name) == 0) 574 return (error); 575 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { 576 if (strcmp(newname, newtc->tc_name) != 0) 577 continue; 578 579 /* Warm up new timecounter. */ 580 (void)newtc->tc_get_timecount(newtc); 581 (void)newtc->tc_get_timecount(newtc); 582 583 timecounter = newtc; 584 return (0); 585 } 586 return (EINVAL); 587 } 588 589 SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, 590 0, 0, sysctl_kern_timecounter_hardware, "A", ""); 591 592 593 /* Report or change the active timecounter hardware. */ 594 static int 595 sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS) 596 { 597 char buf[32], *spc; 598 struct timecounter *tc; 599 int error; 600 601 spc = ""; 602 error = 0; 603 for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { 604 sprintf(buf, "%s%s(%d)", 605 spc, tc->tc_name, tc->tc_quality); 606 error = SYSCTL_OUT(req, buf, strlen(buf)); 607 spc = " "; 608 } 609 return (error); 610 } 611 612 SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice, CTLTYPE_STRING | CTLFLAG_RD, 613 0, 0, sysctl_kern_timecounter_choice, "A", ""); 614 615 /* 616 * RFC 2783 PPS-API implementation. 617 */ 618 619 int 620 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps) 621 { 622 pps_params_t *app; 623 struct pps_fetch_args *fapi; 624 #ifdef PPS_SYNC 625 struct pps_kcbind_args *kapi; 626 #endif 627 628 KASSERT(pps != NULL, ("NULL pps pointer in pps_ioctl")); 629 switch (cmd) { 630 case PPS_IOC_CREATE: 631 return (0); 632 case PPS_IOC_DESTROY: 633 return (0); 634 case PPS_IOC_SETPARAMS: 635 app = (pps_params_t *)data; 636 if (app->mode & ~pps->ppscap) 637 return (EINVAL); 638 pps->ppsparam = *app; 639 return (0); 640 case PPS_IOC_GETPARAMS: 641 app = (pps_params_t *)data; 642 *app = pps->ppsparam; 643 app->api_version = PPS_API_VERS_1; 644 return (0); 645 case PPS_IOC_GETCAP: 646 *(int*)data = pps->ppscap; 647 return (0); 648 case PPS_IOC_FETCH: 649 fapi = (struct pps_fetch_args *)data; 650 if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC) 651 return (EINVAL); 652 if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec) 653 return (EOPNOTSUPP); 654 pps->ppsinfo.current_mode = pps->ppsparam.mode; 655 fapi->pps_info_buf = pps->ppsinfo; 656 return (0); 657 case PPS_IOC_KCBIND: 658 #ifdef PPS_SYNC 659 kapi = (struct pps_kcbind_args *)data; 660 /* XXX Only root should be able to do this */ 661 if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC) 662 return (EINVAL); 663 if (kapi->kernel_consumer != PPS_KC_HARDPPS) 664 return (EINVAL); 665 if (kapi->edge & ~pps->ppscap) 666 return (EINVAL); 667 pps->kcmode = kapi->edge; 668 return (0); 669 #else 670 return (EOPNOTSUPP); 671 #endif 672 default: 673 return (ENOIOCTL); 674 } 675 } 676 677 void 678 pps_init(struct pps_state *pps) 679 { 680 pps->ppscap |= PPS_TSFMT_TSPEC; 681 if (pps->ppscap & PPS_CAPTUREASSERT) 682 pps->ppscap |= PPS_OFFSETASSERT; 683 if (pps->ppscap & PPS_CAPTURECLEAR) 684 pps->ppscap |= PPS_OFFSETCLEAR; 685 } 686 687 void 688 pps_capture(struct pps_state *pps) 689 { 690 struct timehands *th; 691 692 KASSERT(pps != NULL, ("NULL pps pointer in pps_capture")); 693 th = timehands; 694 pps->capgen = th->th_generation; 695 pps->capth = th; 696 pps->capcount = th->th_counter->tc_get_timecount(th->th_counter); 697 if (pps->capgen != th->th_generation) 698 pps->capgen = 0; 699 } 700 701 void 702 pps_event(struct pps_state *pps, int event) 703 { 704 struct bintime bt; 705 struct timespec ts, *tsp, *osp; 706 u_int tcount, *pcount; 707 int foff, fhard; 708 pps_seq_t *pseq; 709 710 KASSERT(pps != NULL, ("NULL pps pointer in pps_event")); 711 /* If the timecounter was wound up underneath us, bail out. */ 712 if (pps->capgen == 0 || pps->capgen != pps->capth->th_generation) 713 return; 714 715 /* Things would be easier with arrays. */ 716 if (event == PPS_CAPTUREASSERT) { 717 tsp = &pps->ppsinfo.assert_timestamp; 718 osp = &pps->ppsparam.assert_offset; 719 foff = pps->ppsparam.mode & PPS_OFFSETASSERT; 720 fhard = pps->kcmode & PPS_CAPTUREASSERT; 721 pcount = &pps->ppscount[0]; 722 pseq = &pps->ppsinfo.assert_sequence; 723 } else { 724 tsp = &pps->ppsinfo.clear_timestamp; 725 osp = &pps->ppsparam.clear_offset; 726 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR; 727 fhard = pps->kcmode & PPS_CAPTURECLEAR; 728 pcount = &pps->ppscount[1]; 729 pseq = &pps->ppsinfo.clear_sequence; 730 } 731 732 /* 733 * If the timecounter changed, we cannot compare the count values, so 734 * we have to drop the rest of the PPS-stuff until the next event. 735 */ 736 if (pps->ppstc != pps->capth->th_counter) { 737 pps->ppstc = pps->capth->th_counter; 738 *pcount = pps->capcount; 739 pps->ppscount[2] = pps->capcount; 740 return; 741 } 742 743 /* Convert the count to a timespec. */ 744 tcount = pps->capcount - pps->capth->th_offset_count; 745 tcount &= pps->capth->th_counter->tc_counter_mask; 746 bt = pps->capth->th_offset; 747 bintime_addx(&bt, pps->capth->th_scale * tcount); 748 bintime_add(&bt, &boottimebin); 749 bintime2timespec(&bt, &ts); 750 751 /* If the timecounter was wound up underneath us, bail out. */ 752 if (pps->capgen != pps->capth->th_generation) 753 return; 754 755 *pcount = pps->capcount; 756 (*pseq)++; 757 *tsp = ts; 758 759 if (foff) { 760 timespecadd(tsp, osp); 761 if (tsp->tv_nsec < 0) { 762 tsp->tv_nsec += 1000000000; 763 tsp->tv_sec -= 1; 764 } 765 } 766 #ifdef PPS_SYNC 767 if (fhard) { 768 u_int64_t scale; 769 770 /* 771 * Feed the NTP PLL/FLL. 772 * The FLL wants to know how many (hardware) nanoseconds 773 * elapsed since the previous event. 774 */ 775 tcount = pps->capcount - pps->ppscount[2]; 776 pps->ppscount[2] = pps->capcount; 777 tcount &= pps->capth->th_counter->tc_counter_mask; 778 scale = (u_int64_t)1 << 63; 779 scale /= pps->capth->th_counter->tc_frequency; 780 scale *= 2; 781 bt.sec = 0; 782 bt.frac = 0; 783 bintime_addx(&bt, scale * tcount); 784 bintime2timespec(&bt, &ts); 785 hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); 786 } 787 #endif 788 } 789 790 /* 791 * Timecounters need to be updated every so often to prevent the hardware 792 * counter from overflowing. Updating also recalculates the cached values 793 * used by the get*() family of functions, so their precision depends on 794 * the update frequency. 795 */ 796 797 static int tc_tick; 798 SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0, ""); 799 800 void 801 tc_ticktock(void) 802 { 803 static int count; 804 static time_t last_calib; 805 806 if (++count < tc_tick) 807 return; 808 count = 0; 809 tc_windup(); 810 if (time_uptime != last_calib && !(time_uptime & 0xf)) { 811 cpu_tick_calibrate(0); 812 last_calib = time_uptime; 813 } 814 } 815 816 static void 817 inittimecounter(void *dummy) 818 { 819 u_int p; 820 821 /* 822 * Set the initial timeout to 823 * max(1, <approx. number of hardclock ticks in a millisecond>). 824 * People should probably not use the sysctl to set the timeout 825 * to smaller than its inital value, since that value is the 826 * smallest reasonable one. If they want better timestamps they 827 * should use the non-"get"* functions. 828 */ 829 if (hz > 1000) 830 tc_tick = (hz + 500) / 1000; 831 else 832 tc_tick = 1; 833 p = (tc_tick * 1000000) / hz; 834 printf("Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000); 835 836 /* warm up new timecounter (again) and get rolling. */ 837 (void)timecounter->tc_get_timecount(timecounter); 838 (void)timecounter->tc_get_timecount(timecounter); 839 } 840 841 SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL); 842 843 /* Cpu tick handling -------------------------------------------------*/ 844 845 static int cpu_tick_variable; 846 static uint64_t cpu_tick_frequency; 847 848 static uint64_t 849 tc_cpu_ticks(void) 850 { 851 static uint64_t base; 852 static unsigned last; 853 unsigned u; 854 struct timecounter *tc; 855 856 tc = timehands->th_counter; 857 u = tc->tc_get_timecount(tc) & tc->tc_counter_mask; 858 if (u < last) 859 base += (uint64_t)tc->tc_counter_mask + 1; 860 last = u; 861 return (u + base); 862 } 863 864 /* 865 * This function gets called every 16 seconds on only one designated 866 * CPU in the system from hardclock() via tc_ticktock(). 867 * 868 * Whenever the real time clock is stepped we get called with reset=1 869 * to make sure we handle suspend/resume and similar events correctly. 870 */ 871 872 static void 873 cpu_tick_calibrate(int reset) 874 { 875 static uint64_t c_last; 876 uint64_t c_this, c_delta; 877 static struct bintime t_last; 878 struct bintime t_this, t_delta; 879 uint32_t divi; 880 881 if (reset) { 882 /* The clock was stepped, abort & reset */ 883 t_last.sec = 0; 884 return; 885 } 886 887 /* we don't calibrate fixed rate cputicks */ 888 if (!cpu_tick_variable) 889 return; 890 891 getbinuptime(&t_this); 892 c_this = cpu_ticks(); 893 if (t_last.sec != 0) { 894 c_delta = c_this - c_last; 895 t_delta = t_this; 896 bintime_sub(&t_delta, &t_last); 897 /* 898 * Validate that 16 +/- 1/256 seconds passed. 899 * After division by 16 this gives us a precision of 900 * roughly 250PPM which is sufficient 901 */ 902 if (t_delta.sec > 16 || ( 903 t_delta.sec == 16 && t_delta.frac >= (0x01LL << 56))) { 904 /* too long */ 905 if (bootverbose) 906 printf("t_delta %ju.%016jx too long\n", 907 (uintmax_t)t_delta.sec, 908 (uintmax_t)t_delta.frac); 909 } else if (t_delta.sec < 15 || 910 (t_delta.sec == 15 && t_delta.frac <= (0xffLL << 56))) { 911 /* too short */ 912 if (bootverbose) 913 printf("t_delta %ju.%016jx too short\n", 914 (uintmax_t)t_delta.sec, 915 (uintmax_t)t_delta.frac); 916 } else { 917 /* just right */ 918 /* 919 * Headroom: 920 * 2^(64-20) / 16[s] = 921 * 2^(44) / 16[s] = 922 * 17.592.186.044.416 / 16 = 923 * 1.099.511.627.776 [Hz] 924 */ 925 divi = t_delta.sec << 20; 926 divi |= t_delta.frac >> (64 - 20); 927 c_delta <<= 20; 928 c_delta /= divi; 929 if (c_delta > cpu_tick_frequency) { 930 if (0 && bootverbose) 931 printf("cpu_tick increased to %ju Hz\n", 932 c_delta); 933 cpu_tick_frequency = c_delta; 934 } 935 } 936 } 937 c_last = c_this; 938 t_last = t_this; 939 } 940 941 void 942 set_cputicker(cpu_tick_f *func, uint64_t freq, unsigned var) 943 { 944 945 if (func == NULL) { 946 cpu_ticks = tc_cpu_ticks; 947 } else { 948 cpu_tick_frequency = freq; 949 cpu_tick_variable = var; 950 cpu_ticks = func; 951 } 952 } 953 954 uint64_t 955 cpu_tickrate(void) 956 { 957 958 if (cpu_ticks == tc_cpu_ticks) 959 return (tc_getfrequency()); 960 return (cpu_tick_frequency); 961 } 962 963 /* 964 * We need to be slightly careful converting cputicks to microseconds. 965 * There is plenty of margin in 64 bits of microseconds (half a million 966 * years) and in 64 bits at 4 GHz (146 years), but if we do a multiply 967 * before divide conversion (to retain precision) we find that the 968 * margin shrinks to 1.5 hours (one millionth of 146y). 969 * With a three prong approach we never lose significant bits, no 970 * matter what the cputick rate and length of timeinterval is. 971 */ 972 973 uint64_t 974 cputick2usec(uint64_t tick) 975 { 976 977 if (tick > 18446744073709551LL) /* floor(2^64 / 1000) */ 978 return (tick / (cpu_tickrate() / 1000000LL)); 979 else if (tick > 18446744073709LL) /* floor(2^64 / 1000000) */ 980 return ((tick * 1000LL) / (cpu_tickrate() / 1000LL)); 981 else 982 return ((tick * 1000000LL) / cpu_tickrate()); 983 } 984 985 cpu_tick_f *cpu_ticks = tc_cpu_ticks; 986