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