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 uint64_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 int tc_min_ticktock_freq = 1; 91 92 time_t time_second = 1; 93 time_t time_uptime = 1; 94 95 struct bintime boottimebin; 96 struct timeval boottime; 97 static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS); 98 SYSCTL_PROC(_kern, KERN_BOOTTIME, boottime, CTLTYPE_STRUCT|CTLFLAG_RD, 99 NULL, 0, sysctl_kern_boottime, "S,timeval", "System boottime"); 100 101 SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, ""); 102 static SYSCTL_NODE(_kern_timecounter, OID_AUTO, tc, CTLFLAG_RW, 0, ""); 103 104 static int timestepwarnings; 105 SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW, 106 ×tepwarnings, 0, "Log time steps"); 107 108 static void tc_windup(void); 109 static void cpu_tick_calibrate(int); 110 111 static int 112 sysctl_kern_boottime(SYSCTL_HANDLER_ARGS) 113 { 114 #ifdef SCTL_MASK32 115 int tv[2]; 116 117 if (req->flags & SCTL_MASK32) { 118 tv[0] = boottime.tv_sec; 119 tv[1] = boottime.tv_usec; 120 return SYSCTL_OUT(req, tv, sizeof(tv)); 121 } else 122 #endif 123 return SYSCTL_OUT(req, &boottime, sizeof(boottime)); 124 } 125 126 static int 127 sysctl_kern_timecounter_get(SYSCTL_HANDLER_ARGS) 128 { 129 u_int ncount; 130 struct timecounter *tc = arg1; 131 132 ncount = tc->tc_get_timecount(tc); 133 return sysctl_handle_int(oidp, &ncount, 0, req); 134 } 135 136 static int 137 sysctl_kern_timecounter_freq(SYSCTL_HANDLER_ARGS) 138 { 139 uint64_t freq; 140 struct timecounter *tc = arg1; 141 142 freq = tc->tc_frequency; 143 return sysctl_handle_64(oidp, &freq, 0, req); 144 } 145 146 /* 147 * Return the difference between the timehands' counter value now and what 148 * was when we copied it to the timehands' offset_count. 149 */ 150 static __inline u_int 151 tc_delta(struct timehands *th) 152 { 153 struct timecounter *tc; 154 155 tc = th->th_counter; 156 return ((tc->tc_get_timecount(tc) - th->th_offset_count) & 157 tc->tc_counter_mask); 158 } 159 160 /* 161 * Functions for reading the time. We have to loop until we are sure that 162 * the timehands that we operated on was not updated under our feet. See 163 * the comment in <sys/time.h> for a description of these 12 functions. 164 */ 165 166 void 167 binuptime(struct bintime *bt) 168 { 169 struct timehands *th; 170 u_int gen; 171 172 do { 173 th = timehands; 174 gen = th->th_generation; 175 *bt = th->th_offset; 176 bintime_addx(bt, th->th_scale * tc_delta(th)); 177 } while (gen == 0 || gen != th->th_generation); 178 } 179 180 void 181 nanouptime(struct timespec *tsp) 182 { 183 struct bintime bt; 184 185 binuptime(&bt); 186 bintime2timespec(&bt, tsp); 187 } 188 189 void 190 microuptime(struct timeval *tvp) 191 { 192 struct bintime bt; 193 194 binuptime(&bt); 195 bintime2timeval(&bt, tvp); 196 } 197 198 void 199 bintime(struct bintime *bt) 200 { 201 202 binuptime(bt); 203 bintime_add(bt, &boottimebin); 204 } 205 206 void 207 nanotime(struct timespec *tsp) 208 { 209 struct bintime bt; 210 211 bintime(&bt); 212 bintime2timespec(&bt, tsp); 213 } 214 215 void 216 microtime(struct timeval *tvp) 217 { 218 struct bintime bt; 219 220 bintime(&bt); 221 bintime2timeval(&bt, tvp); 222 } 223 224 void 225 getbinuptime(struct bintime *bt) 226 { 227 struct timehands *th; 228 u_int gen; 229 230 do { 231 th = timehands; 232 gen = th->th_generation; 233 *bt = th->th_offset; 234 } while (gen == 0 || gen != th->th_generation); 235 } 236 237 void 238 getnanouptime(struct timespec *tsp) 239 { 240 struct timehands *th; 241 u_int gen; 242 243 do { 244 th = timehands; 245 gen = th->th_generation; 246 bintime2timespec(&th->th_offset, tsp); 247 } while (gen == 0 || gen != th->th_generation); 248 } 249 250 void 251 getmicrouptime(struct timeval *tvp) 252 { 253 struct timehands *th; 254 u_int gen; 255 256 do { 257 th = timehands; 258 gen = th->th_generation; 259 bintime2timeval(&th->th_offset, tvp); 260 } while (gen == 0 || gen != th->th_generation); 261 } 262 263 void 264 getbintime(struct bintime *bt) 265 { 266 struct timehands *th; 267 u_int gen; 268 269 do { 270 th = timehands; 271 gen = th->th_generation; 272 *bt = th->th_offset; 273 } while (gen == 0 || gen != th->th_generation); 274 bintime_add(bt, &boottimebin); 275 } 276 277 void 278 getnanotime(struct timespec *tsp) 279 { 280 struct timehands *th; 281 u_int gen; 282 283 do { 284 th = timehands; 285 gen = th->th_generation; 286 *tsp = th->th_nanotime; 287 } while (gen == 0 || gen != th->th_generation); 288 } 289 290 void 291 getmicrotime(struct timeval *tvp) 292 { 293 struct timehands *th; 294 u_int gen; 295 296 do { 297 th = timehands; 298 gen = th->th_generation; 299 *tvp = th->th_microtime; 300 } while (gen == 0 || gen != th->th_generation); 301 } 302 303 /* 304 * Initialize a new timecounter and possibly use it. 305 */ 306 void 307 tc_init(struct timecounter *tc) 308 { 309 u_int u; 310 struct sysctl_oid *tc_root; 311 312 u = tc->tc_frequency / tc->tc_counter_mask; 313 /* XXX: We need some margin here, 10% is a guess */ 314 u *= 11; 315 u /= 10; 316 if (u > hz && tc->tc_quality >= 0) { 317 tc->tc_quality = -2000; 318 if (bootverbose) { 319 printf("Timecounter \"%s\" frequency %ju Hz", 320 tc->tc_name, (uintmax_t)tc->tc_frequency); 321 printf(" -- Insufficient hz, needs at least %u\n", u); 322 } 323 } else if (tc->tc_quality >= 0 || bootverbose) { 324 printf("Timecounter \"%s\" frequency %ju Hz quality %d\n", 325 tc->tc_name, (uintmax_t)tc->tc_frequency, 326 tc->tc_quality); 327 } 328 329 tc->tc_next = timecounters; 330 timecounters = tc; 331 /* 332 * Set up sysctl tree for this counter. 333 */ 334 tc_root = SYSCTL_ADD_NODE(NULL, 335 SYSCTL_STATIC_CHILDREN(_kern_timecounter_tc), OID_AUTO, tc->tc_name, 336 CTLFLAG_RW, 0, "timecounter description"); 337 SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 338 "mask", CTLFLAG_RD, &(tc->tc_counter_mask), 0, 339 "mask for implemented bits"); 340 SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 341 "counter", CTLTYPE_UINT | CTLFLAG_RD, tc, sizeof(*tc), 342 sysctl_kern_timecounter_get, "IU", "current timecounter value"); 343 SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 344 "frequency", CTLTYPE_U64 | CTLFLAG_RD, tc, sizeof(*tc), 345 sysctl_kern_timecounter_freq, "QU", "timecounter frequency"); 346 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, 347 "quality", CTLFLAG_RD, &(tc->tc_quality), 0, 348 "goodness of time counter"); 349 /* 350 * Never automatically use a timecounter with negative quality. 351 * Even though we run on the dummy counter, switching here may be 352 * worse since this timecounter may not be monotonous. 353 */ 354 if (tc->tc_quality < 0) 355 return; 356 if (tc->tc_quality < timecounter->tc_quality) 357 return; 358 if (tc->tc_quality == timecounter->tc_quality && 359 tc->tc_frequency < timecounter->tc_frequency) 360 return; 361 (void)tc->tc_get_timecount(tc); 362 (void)tc->tc_get_timecount(tc); 363 timecounter = tc; 364 } 365 366 /* Report the frequency of the current timecounter. */ 367 uint64_t 368 tc_getfrequency(void) 369 { 370 371 return (timehands->th_counter->tc_frequency); 372 } 373 374 /* 375 * Step our concept of UTC. This is done by modifying our estimate of 376 * when we booted. 377 * XXX: not locked. 378 */ 379 void 380 tc_setclock(struct timespec *ts) 381 { 382 struct timespec tbef, taft; 383 struct bintime bt, bt2; 384 385 cpu_tick_calibrate(1); 386 nanotime(&tbef); 387 timespec2bintime(ts, &bt); 388 binuptime(&bt2); 389 bintime_sub(&bt, &bt2); 390 bintime_add(&bt2, &boottimebin); 391 boottimebin = bt; 392 bintime2timeval(&bt, &boottime); 393 394 /* XXX fiddle all the little crinkly bits around the fiords... */ 395 tc_windup(); 396 nanotime(&taft); 397 if (timestepwarnings) { 398 log(LOG_INFO, 399 "Time stepped from %jd.%09ld to %jd.%09ld (%jd.%09ld)\n", 400 (intmax_t)tbef.tv_sec, tbef.tv_nsec, 401 (intmax_t)taft.tv_sec, taft.tv_nsec, 402 (intmax_t)ts->tv_sec, ts->tv_nsec); 403 } 404 cpu_tick_calibrate(1); 405 } 406 407 /* 408 * Initialize the next struct timehands in the ring and make 409 * it the active timehands. Along the way we might switch to a different 410 * timecounter and/or do seconds processing in NTP. Slightly magic. 411 */ 412 static void 413 tc_windup(void) 414 { 415 struct bintime bt; 416 struct timehands *th, *tho; 417 uint64_t scale; 418 u_int delta, ncount, ogen; 419 int i; 420 time_t t; 421 422 /* 423 * Make the next timehands a copy of the current one, but do not 424 * overwrite the generation or next pointer. While we update 425 * the contents, the generation must be zero. 426 */ 427 tho = timehands; 428 th = tho->th_next; 429 ogen = th->th_generation; 430 th->th_generation = 0; 431 bcopy(tho, th, offsetof(struct timehands, th_generation)); 432 433 /* 434 * Capture a timecounter delta on the current timecounter and if 435 * changing timecounters, a counter value from the new timecounter. 436 * Update the offset fields accordingly. 437 */ 438 delta = tc_delta(th); 439 if (th->th_counter != timecounter) 440 ncount = timecounter->tc_get_timecount(timecounter); 441 else 442 ncount = 0; 443 th->th_offset_count += delta; 444 th->th_offset_count &= th->th_counter->tc_counter_mask; 445 while (delta > th->th_counter->tc_frequency) { 446 /* Eat complete unadjusted seconds. */ 447 delta -= th->th_counter->tc_frequency; 448 th->th_offset.sec++; 449 } 450 if ((delta > th->th_counter->tc_frequency / 2) && 451 (th->th_scale * delta < ((uint64_t)1 << 63))) { 452 /* The product th_scale * delta just barely overflows. */ 453 th->th_offset.sec++; 454 } 455 bintime_addx(&th->th_offset, th->th_scale * delta); 456 457 /* 458 * Hardware latching timecounters may not generate interrupts on 459 * PPS events, so instead we poll them. There is a finite risk that 460 * the hardware might capture a count which is later than the one we 461 * got above, and therefore possibly in the next NTP second which might 462 * have a different rate than the current NTP second. It doesn't 463 * matter in practice. 464 */ 465 if (tho->th_counter->tc_poll_pps) 466 tho->th_counter->tc_poll_pps(tho->th_counter); 467 468 /* 469 * Deal with NTP second processing. The for loop normally 470 * iterates at most once, but in extreme situations it might 471 * keep NTP sane if timeouts are not run for several seconds. 472 * At boot, the time step can be large when the TOD hardware 473 * has been read, so on really large steps, we call 474 * ntp_update_second only twice. We need to call it twice in 475 * case we missed a leap second. 476 */ 477 bt = th->th_offset; 478 bintime_add(&bt, &boottimebin); 479 i = bt.sec - tho->th_microtime.tv_sec; 480 if (i > LARGE_STEP) 481 i = 2; 482 for (; i > 0; i--) { 483 t = bt.sec; 484 ntp_update_second(&th->th_adjustment, &bt.sec); 485 if (bt.sec != t) 486 boottimebin.sec += bt.sec - t; 487 } 488 /* Update the UTC timestamps used by the get*() functions. */ 489 /* XXX shouldn't do this here. Should force non-`get' versions. */ 490 bintime2timeval(&bt, &th->th_microtime); 491 bintime2timespec(&bt, &th->th_nanotime); 492 493 /* Now is a good time to change timecounters. */ 494 if (th->th_counter != timecounter) { 495 #ifndef __arm__ 496 if ((timecounter->tc_flags & TC_FLAGS_C3STOP) != 0) 497 cpu_disable_deep_sleep++; 498 if ((th->th_counter->tc_flags & TC_FLAGS_C3STOP) != 0) 499 cpu_disable_deep_sleep--; 500 #endif 501 th->th_counter = timecounter; 502 th->th_offset_count = ncount; 503 tc_min_ticktock_freq = max(1, timecounter->tc_frequency / 504 (((uint64_t)timecounter->tc_counter_mask + 1) / 3)); 505 } 506 507 /*- 508 * Recalculate the scaling factor. We want the number of 1/2^64 509 * fractions of a second per period of the hardware counter, taking 510 * into account the th_adjustment factor which the NTP PLL/adjtime(2) 511 * processing provides us with. 512 * 513 * The th_adjustment is nanoseconds per second with 32 bit binary 514 * fraction and we want 64 bit binary fraction of second: 515 * 516 * x = a * 2^32 / 10^9 = a * 4.294967296 517 * 518 * The range of th_adjustment is +/- 5000PPM so inside a 64bit int 519 * we can only multiply by about 850 without overflowing, that 520 * leaves no suitably precise fractions for multiply before divide. 521 * 522 * Divide before multiply with a fraction of 2199/512 results in a 523 * systematic undercompensation of 10PPM of th_adjustment. On a 524 * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. 525 * 526 * We happily sacrifice the lowest of the 64 bits of our result 527 * to the goddess of code clarity. 528 * 529 */ 530 scale = (uint64_t)1 << 63; 531 scale += (th->th_adjustment / 1024) * 2199; 532 scale /= th->th_counter->tc_frequency; 533 th->th_scale = scale * 2; 534 535 /* 536 * Now that the struct timehands is again consistent, set the new 537 * generation number, making sure to not make it zero. 538 */ 539 if (++ogen == 0) 540 ogen = 1; 541 th->th_generation = ogen; 542 543 /* Go live with the new struct timehands. */ 544 time_second = th->th_microtime.tv_sec; 545 time_uptime = th->th_offset.sec; 546 timehands = th; 547 } 548 549 /* Report or change the active timecounter hardware. */ 550 static int 551 sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) 552 { 553 char newname[32]; 554 struct timecounter *newtc, *tc; 555 int error; 556 557 tc = timecounter; 558 strlcpy(newname, tc->tc_name, sizeof(newname)); 559 560 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); 561 if (error != 0 || req->newptr == NULL || 562 strcmp(newname, tc->tc_name) == 0) 563 return (error); 564 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { 565 if (strcmp(newname, newtc->tc_name) != 0) 566 continue; 567 568 /* Warm up new timecounter. */ 569 (void)newtc->tc_get_timecount(newtc); 570 (void)newtc->tc_get_timecount(newtc); 571 572 timecounter = newtc; 573 return (0); 574 } 575 return (EINVAL); 576 } 577 578 SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, 579 0, 0, sysctl_kern_timecounter_hardware, "A", 580 "Timecounter hardware selected"); 581 582 583 /* Report or change the active timecounter hardware. */ 584 static int 585 sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS) 586 { 587 char buf[32], *spc; 588 struct timecounter *tc; 589 int error; 590 591 spc = ""; 592 error = 0; 593 for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { 594 sprintf(buf, "%s%s(%d)", 595 spc, tc->tc_name, tc->tc_quality); 596 error = SYSCTL_OUT(req, buf, strlen(buf)); 597 spc = " "; 598 } 599 return (error); 600 } 601 602 SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice, CTLTYPE_STRING | CTLFLAG_RD, 603 0, 0, sysctl_kern_timecounter_choice, "A", "Timecounter hardware detected"); 604 605 /* 606 * RFC 2783 PPS-API implementation. 607 */ 608 609 int 610 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps) 611 { 612 pps_params_t *app; 613 struct pps_fetch_args *fapi; 614 #ifdef PPS_SYNC 615 struct pps_kcbind_args *kapi; 616 #endif 617 618 KASSERT(pps != NULL, ("NULL pps pointer in pps_ioctl")); 619 switch (cmd) { 620 case PPS_IOC_CREATE: 621 return (0); 622 case PPS_IOC_DESTROY: 623 return (0); 624 case PPS_IOC_SETPARAMS: 625 app = (pps_params_t *)data; 626 if (app->mode & ~pps->ppscap) 627 return (EINVAL); 628 pps->ppsparam = *app; 629 return (0); 630 case PPS_IOC_GETPARAMS: 631 app = (pps_params_t *)data; 632 *app = pps->ppsparam; 633 app->api_version = PPS_API_VERS_1; 634 return (0); 635 case PPS_IOC_GETCAP: 636 *(int*)data = pps->ppscap; 637 return (0); 638 case PPS_IOC_FETCH: 639 fapi = (struct pps_fetch_args *)data; 640 if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC) 641 return (EINVAL); 642 if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec) 643 return (EOPNOTSUPP); 644 pps->ppsinfo.current_mode = pps->ppsparam.mode; 645 fapi->pps_info_buf = pps->ppsinfo; 646 return (0); 647 case PPS_IOC_KCBIND: 648 #ifdef PPS_SYNC 649 kapi = (struct pps_kcbind_args *)data; 650 /* XXX Only root should be able to do this */ 651 if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC) 652 return (EINVAL); 653 if (kapi->kernel_consumer != PPS_KC_HARDPPS) 654 return (EINVAL); 655 if (kapi->edge & ~pps->ppscap) 656 return (EINVAL); 657 pps->kcmode = kapi->edge; 658 return (0); 659 #else 660 return (EOPNOTSUPP); 661 #endif 662 default: 663 return (ENOIOCTL); 664 } 665 } 666 667 void 668 pps_init(struct pps_state *pps) 669 { 670 pps->ppscap |= PPS_TSFMT_TSPEC; 671 if (pps->ppscap & PPS_CAPTUREASSERT) 672 pps->ppscap |= PPS_OFFSETASSERT; 673 if (pps->ppscap & PPS_CAPTURECLEAR) 674 pps->ppscap |= PPS_OFFSETCLEAR; 675 } 676 677 void 678 pps_capture(struct pps_state *pps) 679 { 680 struct timehands *th; 681 682 KASSERT(pps != NULL, ("NULL pps pointer in pps_capture")); 683 th = timehands; 684 pps->capgen = th->th_generation; 685 pps->capth = th; 686 pps->capcount = th->th_counter->tc_get_timecount(th->th_counter); 687 if (pps->capgen != th->th_generation) 688 pps->capgen = 0; 689 } 690 691 void 692 pps_event(struct pps_state *pps, int event) 693 { 694 struct bintime bt; 695 struct timespec ts, *tsp, *osp; 696 u_int tcount, *pcount; 697 int foff, fhard; 698 pps_seq_t *pseq; 699 700 KASSERT(pps != NULL, ("NULL pps pointer in pps_event")); 701 /* If the timecounter was wound up underneath us, bail out. */ 702 if (pps->capgen == 0 || pps->capgen != pps->capth->th_generation) 703 return; 704 705 /* Things would be easier with arrays. */ 706 if (event == PPS_CAPTUREASSERT) { 707 tsp = &pps->ppsinfo.assert_timestamp; 708 osp = &pps->ppsparam.assert_offset; 709 foff = pps->ppsparam.mode & PPS_OFFSETASSERT; 710 fhard = pps->kcmode & PPS_CAPTUREASSERT; 711 pcount = &pps->ppscount[0]; 712 pseq = &pps->ppsinfo.assert_sequence; 713 } else { 714 tsp = &pps->ppsinfo.clear_timestamp; 715 osp = &pps->ppsparam.clear_offset; 716 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR; 717 fhard = pps->kcmode & PPS_CAPTURECLEAR; 718 pcount = &pps->ppscount[1]; 719 pseq = &pps->ppsinfo.clear_sequence; 720 } 721 722 /* 723 * If the timecounter changed, we cannot compare the count values, so 724 * we have to drop the rest of the PPS-stuff until the next event. 725 */ 726 if (pps->ppstc != pps->capth->th_counter) { 727 pps->ppstc = pps->capth->th_counter; 728 *pcount = pps->capcount; 729 pps->ppscount[2] = pps->capcount; 730 return; 731 } 732 733 /* Convert the count to a timespec. */ 734 tcount = pps->capcount - pps->capth->th_offset_count; 735 tcount &= pps->capth->th_counter->tc_counter_mask; 736 bt = pps->capth->th_offset; 737 bintime_addx(&bt, pps->capth->th_scale * tcount); 738 bintime_add(&bt, &boottimebin); 739 bintime2timespec(&bt, &ts); 740 741 /* If the timecounter was wound up underneath us, bail out. */ 742 if (pps->capgen != pps->capth->th_generation) 743 return; 744 745 *pcount = pps->capcount; 746 (*pseq)++; 747 *tsp = ts; 748 749 if (foff) { 750 timespecadd(tsp, osp); 751 if (tsp->tv_nsec < 0) { 752 tsp->tv_nsec += 1000000000; 753 tsp->tv_sec -= 1; 754 } 755 } 756 #ifdef PPS_SYNC 757 if (fhard) { 758 uint64_t scale; 759 760 /* 761 * Feed the NTP PLL/FLL. 762 * The FLL wants to know how many (hardware) nanoseconds 763 * elapsed since the previous event. 764 */ 765 tcount = pps->capcount - pps->ppscount[2]; 766 pps->ppscount[2] = pps->capcount; 767 tcount &= pps->capth->th_counter->tc_counter_mask; 768 scale = (uint64_t)1 << 63; 769 scale /= pps->capth->th_counter->tc_frequency; 770 scale *= 2; 771 bt.sec = 0; 772 bt.frac = 0; 773 bintime_addx(&bt, scale * tcount); 774 bintime2timespec(&bt, &ts); 775 hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); 776 } 777 #endif 778 } 779 780 /* 781 * Timecounters need to be updated every so often to prevent the hardware 782 * counter from overflowing. Updating also recalculates the cached values 783 * used by the get*() family of functions, so their precision depends on 784 * the update frequency. 785 */ 786 787 static int tc_tick; 788 SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0, 789 "Approximate number of hardclock ticks in a millisecond"); 790 791 void 792 tc_ticktock(int cnt) 793 { 794 static int count; 795 796 count += cnt; 797 if (count < tc_tick) 798 return; 799 count = 0; 800 tc_windup(); 801 } 802 803 static void 804 inittimecounter(void *dummy) 805 { 806 u_int p; 807 808 /* 809 * Set the initial timeout to 810 * max(1, <approx. number of hardclock ticks in a millisecond>). 811 * People should probably not use the sysctl to set the timeout 812 * to smaller than its inital value, since that value is the 813 * smallest reasonable one. If they want better timestamps they 814 * should use the non-"get"* functions. 815 */ 816 if (hz > 1000) 817 tc_tick = (hz + 500) / 1000; 818 else 819 tc_tick = 1; 820 p = (tc_tick * 1000000) / hz; 821 printf("Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000); 822 823 /* warm up new timecounter (again) and get rolling. */ 824 (void)timecounter->tc_get_timecount(timecounter); 825 (void)timecounter->tc_get_timecount(timecounter); 826 tc_windup(); 827 } 828 829 SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL); 830 831 /* Cpu tick handling -------------------------------------------------*/ 832 833 static int cpu_tick_variable; 834 static uint64_t cpu_tick_frequency; 835 836 static uint64_t 837 tc_cpu_ticks(void) 838 { 839 static uint64_t base; 840 static unsigned last; 841 unsigned u; 842 struct timecounter *tc; 843 844 tc = timehands->th_counter; 845 u = tc->tc_get_timecount(tc) & tc->tc_counter_mask; 846 if (u < last) 847 base += (uint64_t)tc->tc_counter_mask + 1; 848 last = u; 849 return (u + base); 850 } 851 852 void 853 cpu_tick_calibration(void) 854 { 855 static time_t last_calib; 856 857 if (time_uptime != last_calib && !(time_uptime & 0xf)) { 858 cpu_tick_calibrate(0); 859 last_calib = time_uptime; 860 } 861 } 862 863 /* 864 * This function gets called every 16 seconds on only one designated 865 * CPU in the system from hardclock() via cpu_tick_calibration()(). 866 * 867 * Whenever the real time clock is stepped we get called with reset=1 868 * to make sure we handle suspend/resume and similar events correctly. 869 */ 870 871 static void 872 cpu_tick_calibrate(int reset) 873 { 874 static uint64_t c_last; 875 uint64_t c_this, c_delta; 876 static struct bintime t_last; 877 struct bintime t_this, t_delta; 878 uint32_t divi; 879 880 if (reset) { 881 /* The clock was stepped, abort & reset */ 882 t_last.sec = 0; 883 return; 884 } 885 886 /* we don't calibrate fixed rate cputicks */ 887 if (!cpu_tick_variable) 888 return; 889 890 getbinuptime(&t_this); 891 c_this = cpu_ticks(); 892 if (t_last.sec != 0) { 893 c_delta = c_this - c_last; 894 t_delta = t_this; 895 bintime_sub(&t_delta, &t_last); 896 /* 897 * Headroom: 898 * 2^(64-20) / 16[s] = 899 * 2^(44) / 16[s] = 900 * 17.592.186.044.416 / 16 = 901 * 1.099.511.627.776 [Hz] 902 */ 903 divi = t_delta.sec << 20; 904 divi |= t_delta.frac >> (64 - 20); 905 c_delta <<= 20; 906 c_delta /= divi; 907 if (c_delta > cpu_tick_frequency) { 908 if (0 && bootverbose) 909 printf("cpu_tick increased to %ju Hz\n", 910 c_delta); 911 cpu_tick_frequency = c_delta; 912 } 913 } 914 c_last = c_this; 915 t_last = t_this; 916 } 917 918 void 919 set_cputicker(cpu_tick_f *func, uint64_t freq, unsigned var) 920 { 921 922 if (func == NULL) { 923 cpu_ticks = tc_cpu_ticks; 924 } else { 925 cpu_tick_frequency = freq; 926 cpu_tick_variable = var; 927 cpu_ticks = func; 928 } 929 } 930 931 uint64_t 932 cpu_tickrate(void) 933 { 934 935 if (cpu_ticks == tc_cpu_ticks) 936 return (tc_getfrequency()); 937 return (cpu_tick_frequency); 938 } 939 940 /* 941 * We need to be slightly careful converting cputicks to microseconds. 942 * There is plenty of margin in 64 bits of microseconds (half a million 943 * years) and in 64 bits at 4 GHz (146 years), but if we do a multiply 944 * before divide conversion (to retain precision) we find that the 945 * margin shrinks to 1.5 hours (one millionth of 146y). 946 * With a three prong approach we never lose significant bits, no 947 * matter what the cputick rate and length of timeinterval is. 948 */ 949 950 uint64_t 951 cputick2usec(uint64_t tick) 952 { 953 954 if (tick > 18446744073709551LL) /* floor(2^64 / 1000) */ 955 return (tick / (cpu_tickrate() / 1000000LL)); 956 else if (tick > 18446744073709LL) /* floor(2^64 / 1000000) */ 957 return ((tick * 1000LL) / (cpu_tickrate() / 1000LL)); 958 else 959 return ((tick * 1000000LL) / cpu_tickrate()); 960 } 961 962 cpu_tick_f *cpu_ticks = tc_cpu_ticks; 963