1 /* $NetBSD: kern_tc.c,v 1.16 2006/11/01 10:17:58 yamt Exp $ */ 2 3 /*- 4 * ---------------------------------------------------------------------------- 5 * "THE BEER-WARE LICENSE" (Revision 42): 6 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 7 * can do whatever you want with this stuff. If we meet some day, and you think 8 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 9 * --------------------------------------------------------------------------- 10 */ 11 12 #include <sys/cdefs.h> 13 /* __FBSDID("$FreeBSD: src/sys/kern/kern_tc.c,v 1.166 2005/09/19 22:16:31 andre Exp $"); */ 14 __KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.16 2006/11/01 10:17:58 yamt Exp $"); 15 16 #include "opt_ntp.h" 17 18 #include <sys/param.h> 19 #ifdef __HAVE_TIMECOUNTER /* XXX */ 20 #include <sys/kernel.h> 21 #include <sys/reboot.h> /* XXX just to get AB_VERBOSE */ 22 #include <sys/sysctl.h> 23 #include <sys/syslog.h> 24 #include <sys/systm.h> 25 #include <sys/timepps.h> 26 #include <sys/timetc.h> 27 #include <sys/timex.h> 28 #include <sys/evcnt.h> 29 #include <sys/kauth.h> 30 31 /* 32 * A large step happens on boot. This constant detects such steps. 33 * It is relatively small so that ntp_update_second gets called enough 34 * in the typical 'missed a couple of seconds' case, but doesn't loop 35 * forever when the time step is large. 36 */ 37 #define LARGE_STEP 200 38 39 /* 40 * Implement a dummy timecounter which we can use until we get a real one 41 * in the air. This allows the console and other early stuff to use 42 * time services. 43 */ 44 45 static u_int 46 dummy_get_timecount(struct timecounter *tc) 47 { 48 static u_int now; 49 50 return (++now); 51 } 52 53 static struct timecounter dummy_timecounter = { 54 dummy_get_timecount, 0, ~0u, 1000000, "dummy", -1000000, NULL, NULL, 55 }; 56 57 struct timehands { 58 /* These fields must be initialized by the driver. */ 59 struct timecounter *th_counter; 60 int64_t th_adjustment; 61 u_int64_t th_scale; 62 u_int th_offset_count; 63 struct bintime th_offset; 64 struct timeval th_microtime; 65 struct timespec th_nanotime; 66 /* Fields not to be copied in tc_windup start with th_generation. */ 67 volatile u_int th_generation; 68 struct timehands *th_next; 69 }; 70 71 static struct timehands th0; 72 static struct timehands th9 = { .th_next = &th0, }; 73 static struct timehands th8 = { .th_next = &th9, }; 74 static struct timehands th7 = { .th_next = &th8, }; 75 static struct timehands th6 = { .th_next = &th7, }; 76 static struct timehands th5 = { .th_next = &th6, }; 77 static struct timehands th4 = { .th_next = &th5, }; 78 static struct timehands th3 = { .th_next = &th4, }; 79 static struct timehands th2 = { .th_next = &th3, }; 80 static struct timehands th1 = { .th_next = &th2, }; 81 static struct timehands th0 = { 82 .th_counter = &dummy_timecounter, 83 .th_scale = (uint64_t)-1 / 1000000, 84 .th_offset = { .sec = 1, .frac = 0 }, 85 .th_generation = 1, 86 .th_next = &th1, 87 }; 88 89 static struct timehands *volatile timehands = &th0; 90 struct timecounter *timecounter = &dummy_timecounter; 91 static struct timecounter *timecounters = &dummy_timecounter; 92 93 time_t time_second = 1; 94 time_t time_uptime = 1; 95 96 static struct bintime timebasebin; 97 98 static int timestepwarnings; 99 100 #ifdef __FreeBSD__ 101 SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW, 102 ×tepwarnings, 0, ""); 103 #endif /* __FreeBSD__ */ 104 105 /* 106 * sysctl helper routine for kern.timercounter.current 107 */ 108 static int 109 sysctl_kern_timecounter_hardware(SYSCTLFN_ARGS) 110 { 111 struct sysctlnode node; 112 int error; 113 char newname[MAX_TCNAMELEN]; 114 struct timecounter *newtc, *tc; 115 116 tc = timecounter; 117 118 strlcpy(newname, tc->tc_name, sizeof(newname)); 119 120 node = *rnode; 121 node.sysctl_data = newname; 122 node.sysctl_size = sizeof(newname); 123 124 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 125 126 if (error || 127 newp == NULL || 128 strncmp(newname, tc->tc_name, sizeof(newname)) == 0) 129 return error; 130 131 if (l != NULL && (error = kauth_authorize_generic(l->l_cred, 132 KAUTH_GENERIC_ISSUSER, &l->l_acflag)) != 0) 133 return (error); 134 135 /* XXX locking */ 136 137 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { 138 if (strcmp(newname, newtc->tc_name) != 0) 139 continue; 140 141 /* Warm up new timecounter. */ 142 (void)newtc->tc_get_timecount(newtc); 143 (void)newtc->tc_get_timecount(newtc); 144 145 timecounter = newtc; 146 147 /* XXX unlock */ 148 149 return (0); 150 } 151 152 /* XXX unlock */ 153 154 return (EINVAL); 155 } 156 157 static int 158 sysctl_kern_timecounter_choice(SYSCTLFN_ARGS) 159 { 160 char buf[MAX_TCNAMELEN+48]; 161 char *where = oldp; 162 const char *spc; 163 struct timecounter *tc; 164 size_t needed, left, slen; 165 int error; 166 167 if (newp != NULL) 168 return (EPERM); 169 if (namelen != 0) 170 return (EINVAL); 171 172 spc = ""; 173 error = 0; 174 needed = 0; 175 left = *oldlenp; 176 177 /* XXX locking */ 178 179 for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { 180 if (where == NULL) { 181 needed += sizeof(buf); /* be conservative */ 182 } else { 183 slen = snprintf(buf, sizeof(buf), "%s%s(q=%d, f=%" PRId64 184 " Hz)", spc, tc->tc_name, tc->tc_quality, 185 tc->tc_frequency); 186 if (left < slen + 1) 187 break; 188 /* XXX use sysctl_copyout? (from sysctl_hw_disknames) */ 189 error = copyout(buf, where, slen + 1); 190 spc = " "; 191 where += slen; 192 needed += slen; 193 left -= slen; 194 } 195 } 196 197 /* XXX unlock */ 198 199 *oldlenp = needed; 200 return (error); 201 } 202 203 SYSCTL_SETUP(sysctl_timecounter_setup, "sysctl timecounter setup") 204 { 205 const struct sysctlnode *node; 206 207 sysctl_createv(clog, 0, NULL, &node, 208 CTLFLAG_PERMANENT, 209 CTLTYPE_NODE, "timecounter", 210 SYSCTL_DESCR("time counter information"), 211 NULL, 0, NULL, 0, 212 CTL_KERN, CTL_CREATE, CTL_EOL); 213 214 if (node != NULL) { 215 sysctl_createv(clog, 0, NULL, NULL, 216 CTLFLAG_PERMANENT, 217 CTLTYPE_STRING, "choice", 218 SYSCTL_DESCR("available counters"), 219 sysctl_kern_timecounter_choice, 0, NULL, 0, 220 CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); 221 222 sysctl_createv(clog, 0, NULL, NULL, 223 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 224 CTLTYPE_STRING, "hardware", 225 SYSCTL_DESCR("currently active time counter"), 226 sysctl_kern_timecounter_hardware, 0, NULL, MAX_TCNAMELEN, 227 CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); 228 229 sysctl_createv(clog, 0, NULL, NULL, 230 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 231 CTLTYPE_INT, "timestepwarnings", 232 SYSCTL_DESCR("log time steps"), 233 NULL, 0, ×tepwarnings, 0, 234 CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); 235 } 236 } 237 238 #define TC_STATS(name) \ 239 static struct evcnt n##name = \ 240 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "timecounter", #name); \ 241 EVCNT_ATTACH_STATIC(n##name) 242 243 TC_STATS(binuptime); TC_STATS(nanouptime); TC_STATS(microuptime); 244 TC_STATS(bintime); TC_STATS(nanotime); TC_STATS(microtime); 245 TC_STATS(getbinuptime); TC_STATS(getnanouptime); TC_STATS(getmicrouptime); 246 TC_STATS(getbintime); TC_STATS(getnanotime); TC_STATS(getmicrotime); 247 TC_STATS(setclock); 248 249 #undef TC_STATS 250 251 static void tc_windup(void); 252 253 /* 254 * Return the difference between the timehands' counter value now and what 255 * was when we copied it to the timehands' offset_count. 256 */ 257 static __inline u_int 258 tc_delta(struct timehands *th) 259 { 260 struct timecounter *tc; 261 262 tc = th->th_counter; 263 return ((tc->tc_get_timecount(tc) - 264 th->th_offset_count) & tc->tc_counter_mask); 265 } 266 267 /* 268 * Functions for reading the time. We have to loop until we are sure that 269 * the timehands that we operated on was not updated under our feet. See 270 * the comment in <sys/time.h> for a description of these 12 functions. 271 */ 272 273 void 274 binuptime(struct bintime *bt) 275 { 276 struct timehands *th; 277 u_int gen; 278 279 nbinuptime.ev_count++; 280 do { 281 th = timehands; 282 gen = th->th_generation; 283 *bt = th->th_offset; 284 bintime_addx(bt, th->th_scale * tc_delta(th)); 285 } while (gen == 0 || gen != th->th_generation); 286 } 287 288 void 289 nanouptime(struct timespec *tsp) 290 { 291 struct bintime bt; 292 293 nnanouptime.ev_count++; 294 binuptime(&bt); 295 bintime2timespec(&bt, tsp); 296 } 297 298 void 299 microuptime(struct timeval *tvp) 300 { 301 struct bintime bt; 302 303 nmicrouptime.ev_count++; 304 binuptime(&bt); 305 bintime2timeval(&bt, tvp); 306 } 307 308 void 309 bintime(struct bintime *bt) 310 { 311 312 nbintime.ev_count++; 313 binuptime(bt); 314 bintime_add(bt, &timebasebin); 315 } 316 317 void 318 nanotime(struct timespec *tsp) 319 { 320 struct bintime bt; 321 322 nnanotime.ev_count++; 323 bintime(&bt); 324 bintime2timespec(&bt, tsp); 325 } 326 327 void 328 microtime(struct timeval *tvp) 329 { 330 struct bintime bt; 331 332 nmicrotime.ev_count++; 333 bintime(&bt); 334 bintime2timeval(&bt, tvp); 335 } 336 337 void 338 getbinuptime(struct bintime *bt) 339 { 340 struct timehands *th; 341 u_int gen; 342 343 ngetbinuptime.ev_count++; 344 do { 345 th = timehands; 346 gen = th->th_generation; 347 *bt = th->th_offset; 348 } while (gen == 0 || gen != th->th_generation); 349 } 350 351 void 352 getnanouptime(struct timespec *tsp) 353 { 354 struct timehands *th; 355 u_int gen; 356 357 ngetnanouptime.ev_count++; 358 do { 359 th = timehands; 360 gen = th->th_generation; 361 bintime2timespec(&th->th_offset, tsp); 362 } while (gen == 0 || gen != th->th_generation); 363 } 364 365 void 366 getmicrouptime(struct timeval *tvp) 367 { 368 struct timehands *th; 369 u_int gen; 370 371 ngetmicrouptime.ev_count++; 372 do { 373 th = timehands; 374 gen = th->th_generation; 375 bintime2timeval(&th->th_offset, tvp); 376 } while (gen == 0 || gen != th->th_generation); 377 } 378 379 void 380 getbintime(struct bintime *bt) 381 { 382 struct timehands *th; 383 u_int gen; 384 385 ngetbintime.ev_count++; 386 do { 387 th = timehands; 388 gen = th->th_generation; 389 *bt = th->th_offset; 390 } while (gen == 0 || gen != th->th_generation); 391 bintime_add(bt, &timebasebin); 392 } 393 394 void 395 getnanotime(struct timespec *tsp) 396 { 397 struct timehands *th; 398 u_int gen; 399 400 ngetnanotime.ev_count++; 401 do { 402 th = timehands; 403 gen = th->th_generation; 404 *tsp = th->th_nanotime; 405 } while (gen == 0 || gen != th->th_generation); 406 } 407 408 void 409 getmicrotime(struct timeval *tvp) 410 { 411 struct timehands *th; 412 u_int gen; 413 414 ngetmicrotime.ev_count++; 415 do { 416 th = timehands; 417 gen = th->th_generation; 418 *tvp = th->th_microtime; 419 } while (gen == 0 || gen != th->th_generation); 420 } 421 422 /* 423 * Initialize a new timecounter and possibly use it. 424 */ 425 void 426 tc_init(struct timecounter *tc) 427 { 428 u_int u; 429 int s; 430 431 u = tc->tc_frequency / tc->tc_counter_mask; 432 /* XXX: We need some margin here, 10% is a guess */ 433 u *= 11; 434 u /= 10; 435 if (u > hz && tc->tc_quality >= 0) { 436 tc->tc_quality = -2000; 437 if (bootverbose) { 438 printf("timecounter: Timecounter \"%s\" frequency %ju Hz", 439 tc->tc_name, (uintmax_t)tc->tc_frequency); 440 printf(" -- Insufficient hz, needs at least %u\n", u); 441 } 442 } else if (tc->tc_quality >= 0 || bootverbose) { 443 printf("timecounter: Timecounter \"%s\" frequency %ju Hz quality %d\n", 444 tc->tc_name, (uintmax_t)tc->tc_frequency, 445 tc->tc_quality); 446 } 447 448 s = splclock(); 449 450 tc->tc_next = timecounters; 451 timecounters = tc; 452 /* 453 * Never automatically use a timecounter with negative quality. 454 * Even though we run on the dummy counter, switching here may be 455 * worse since this timecounter may not be monotonous. 456 */ 457 if (tc->tc_quality < 0) 458 goto out; 459 if (tc->tc_quality < timecounter->tc_quality) 460 goto out; 461 if (tc->tc_quality == timecounter->tc_quality && 462 tc->tc_frequency < timecounter->tc_frequency) 463 goto out; 464 (void)tc->tc_get_timecount(tc); 465 (void)tc->tc_get_timecount(tc); 466 timecounter = tc; 467 tc_windup(); 468 469 out: 470 splx(s); 471 } 472 473 /* Report the frequency of the current timecounter. */ 474 u_int64_t 475 tc_getfrequency(void) 476 { 477 478 return (timehands->th_counter->tc_frequency); 479 } 480 481 /* 482 * Step our concept of UTC. This is done by modifying our estimate of 483 * when we booted. 484 * XXX: not locked. 485 */ 486 void 487 tc_setclock(struct timespec *ts) 488 { 489 struct timespec ts2; 490 struct bintime bt, bt2; 491 492 nsetclock.ev_count++; 493 binuptime(&bt2); 494 timespec2bintime(ts, &bt); 495 bintime_sub(&bt, &bt2); 496 bintime_add(&bt2, &timebasebin); 497 timebasebin = bt; 498 499 /* XXX fiddle all the little crinkly bits around the fiords... */ 500 tc_windup(); 501 if (timestepwarnings) { 502 bintime2timespec(&bt2, &ts2); 503 log(LOG_INFO, "Time stepped from %jd.%09ld to %jd.%09ld\n", 504 (intmax_t)ts2.tv_sec, ts2.tv_nsec, 505 (intmax_t)ts->tv_sec, ts->tv_nsec); 506 } 507 } 508 509 /* 510 * Initialize the next struct timehands in the ring and make 511 * it the active timehands. Along the way we might switch to a different 512 * timecounter and/or do seconds processing in NTP. Slightly magic. 513 */ 514 static void 515 tc_windup(void) 516 { 517 struct bintime bt; 518 struct timehands *th, *tho; 519 u_int64_t scale; 520 u_int delta, ncount, ogen; 521 int i, s_update; 522 time_t t; 523 524 s_update = 0; 525 /* 526 * Make the next timehands a copy of the current one, but do not 527 * overwrite the generation or next pointer. While we update 528 * the contents, the generation must be zero. 529 */ 530 tho = timehands; 531 th = tho->th_next; 532 ogen = th->th_generation; 533 th->th_generation = 0; 534 bcopy(tho, th, offsetof(struct timehands, th_generation)); 535 536 /* 537 * Capture a timecounter delta on the current timecounter and if 538 * changing timecounters, a counter value from the new timecounter. 539 * Update the offset fields accordingly. 540 */ 541 delta = tc_delta(th); 542 if (th->th_counter != timecounter) 543 ncount = timecounter->tc_get_timecount(timecounter); 544 else 545 ncount = 0; 546 th->th_offset_count += delta; 547 th->th_offset_count &= th->th_counter->tc_counter_mask; 548 bintime_addx(&th->th_offset, th->th_scale * delta); 549 550 /* 551 * Hardware latching timecounters may not generate interrupts on 552 * PPS events, so instead we poll them. There is a finite risk that 553 * the hardware might capture a count which is later than the one we 554 * got above, and therefore possibly in the next NTP second which might 555 * have a different rate than the current NTP second. It doesn't 556 * matter in practice. 557 */ 558 if (tho->th_counter->tc_poll_pps) 559 tho->th_counter->tc_poll_pps(tho->th_counter); 560 561 /* 562 * Deal with NTP second processing. The for loop normally 563 * iterates at most once, but in extreme situations it might 564 * keep NTP sane if timeouts are not run for several seconds. 565 * At boot, the time step can be large when the TOD hardware 566 * has been read, so on really large steps, we call 567 * ntp_update_second only twice. We need to call it twice in 568 * case we missed a leap second. 569 * If NTP is not compiled in ntp_update_second still calculates 570 * the adjustment resulting from adjtime() calls. 571 */ 572 bt = th->th_offset; 573 bintime_add(&bt, &timebasebin); 574 i = bt.sec - tho->th_microtime.tv_sec; 575 if (i > LARGE_STEP) 576 i = 2; 577 for (; i > 0; i--) { 578 t = bt.sec; 579 ntp_update_second(&th->th_adjustment, &bt.sec); 580 s_update = 1; 581 if (bt.sec != t) 582 timebasebin.sec += bt.sec - t; 583 } 584 585 /* Update the UTC timestamps used by the get*() functions. */ 586 /* XXX shouldn't do this here. Should force non-`get' versions. */ 587 bintime2timeval(&bt, &th->th_microtime); 588 bintime2timespec(&bt, &th->th_nanotime); 589 590 /* Now is a good time to change timecounters. */ 591 if (th->th_counter != timecounter) { 592 th->th_counter = timecounter; 593 th->th_offset_count = ncount; 594 s_update = 1; 595 } 596 597 /*- 598 * Recalculate the scaling factor. We want the number of 1/2^64 599 * fractions of a second per period of the hardware counter, taking 600 * into account the th_adjustment factor which the NTP PLL/adjtime(2) 601 * processing provides us with. 602 * 603 * The th_adjustment is nanoseconds per second with 32 bit binary 604 * fraction and we want 64 bit binary fraction of second: 605 * 606 * x = a * 2^32 / 10^9 = a * 4.294967296 607 * 608 * The range of th_adjustment is +/- 5000PPM so inside a 64bit int 609 * we can only multiply by about 850 without overflowing, but that 610 * leaves suitably precise fractions for multiply before divide. 611 * 612 * Divide before multiply with a fraction of 2199/512 results in a 613 * systematic undercompensation of 10PPM of th_adjustment. On a 614 * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. 615 * 616 * We happily sacrifice the lowest of the 64 bits of our result 617 * to the goddess of code clarity. 618 * 619 */ 620 if (s_update) { 621 scale = (u_int64_t)1 << 63; 622 scale += (th->th_adjustment / 1024) * 2199; 623 scale /= th->th_counter->tc_frequency; 624 th->th_scale = scale * 2; 625 } 626 /* 627 * Now that the struct timehands is again consistent, set the new 628 * generation number, making sure to not make it zero. 629 */ 630 if (++ogen == 0) 631 ogen = 1; 632 th->th_generation = ogen; 633 634 /* Go live with the new struct timehands. */ 635 time_second = th->th_microtime.tv_sec; 636 time_uptime = th->th_offset.sec; 637 timehands = th; 638 } 639 640 #ifdef __FreeBSD__ 641 /* Report or change the active timecounter hardware. */ 642 static int 643 sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) 644 { 645 char newname[32]; 646 struct timecounter *newtc, *tc; 647 int error; 648 649 tc = timecounter; 650 strlcpy(newname, tc->tc_name, sizeof(newname)); 651 652 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); 653 if (error != 0 || req->newptr == NULL || 654 strcmp(newname, tc->tc_name) == 0) 655 return (error); 656 657 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { 658 if (strcmp(newname, newtc->tc_name) != 0) 659 continue; 660 661 /* Warm up new timecounter. */ 662 (void)newtc->tc_get_timecount(newtc); 663 (void)newtc->tc_get_timecount(newtc); 664 665 timecounter = newtc; 666 return (0); 667 } 668 return (EINVAL); 669 } 670 671 SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, 672 0, 0, sysctl_kern_timecounter_hardware, "A", ""); 673 674 675 /* Report or change the active timecounter hardware. */ 676 static int 677 sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS) 678 { 679 char buf[32], *spc; 680 struct timecounter *tc; 681 int error; 682 683 spc = ""; 684 error = 0; 685 for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { 686 sprintf(buf, "%s%s(%d)", 687 spc, tc->tc_name, tc->tc_quality); 688 error = SYSCTL_OUT(req, buf, strlen(buf)); 689 spc = " "; 690 } 691 return (error); 692 } 693 694 SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice, CTLTYPE_STRING | CTLFLAG_RD, 695 0, 0, sysctl_kern_timecounter_choice, "A", ""); 696 #endif /* __FreeBSD__ */ 697 698 /* 699 * RFC 2783 PPS-API implementation. 700 */ 701 702 int 703 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps) 704 { 705 pps_params_t *app; 706 pps_info_t *pipi; 707 #ifdef PPS_SYNC 708 int *epi; 709 #endif 710 711 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_ioctl") */ 712 switch (cmd) { 713 case PPS_IOC_CREATE: 714 return (0); 715 case PPS_IOC_DESTROY: 716 return (0); 717 case PPS_IOC_SETPARAMS: 718 app = (pps_params_t *)data; 719 if (app->mode & ~pps->ppscap) 720 return (EINVAL); 721 pps->ppsparam = *app; 722 return (0); 723 case PPS_IOC_GETPARAMS: 724 app = (pps_params_t *)data; 725 *app = pps->ppsparam; 726 app->api_version = PPS_API_VERS_1; 727 return (0); 728 case PPS_IOC_GETCAP: 729 *(int*)data = pps->ppscap; 730 return (0); 731 case PPS_IOC_FETCH: 732 pipi = (pps_info_t *)data; 733 pps->ppsinfo.current_mode = pps->ppsparam.mode; 734 *pipi = pps->ppsinfo; 735 return (0); 736 case PPS_IOC_KCBIND: 737 #ifdef PPS_SYNC 738 epi = (int *)data; 739 /* XXX Only root should be able to do this */ 740 if (*epi & ~pps->ppscap) 741 return (EINVAL); 742 pps->kcmode = *epi; 743 return (0); 744 #else 745 return (EOPNOTSUPP); 746 #endif 747 default: 748 return (EPASSTHROUGH); 749 } 750 } 751 752 void 753 pps_init(struct pps_state *pps) 754 { 755 pps->ppscap |= PPS_TSFMT_TSPEC; 756 if (pps->ppscap & PPS_CAPTUREASSERT) 757 pps->ppscap |= PPS_OFFSETASSERT; 758 if (pps->ppscap & PPS_CAPTURECLEAR) 759 pps->ppscap |= PPS_OFFSETCLEAR; 760 } 761 762 void 763 pps_capture(struct pps_state *pps) 764 { 765 struct timehands *th; 766 767 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_capture") */ 768 th = timehands; 769 pps->capgen = th->th_generation; 770 pps->capth = th; 771 pps->capcount = th->th_counter->tc_get_timecount(th->th_counter); 772 if (pps->capgen != th->th_generation) 773 pps->capgen = 0; 774 } 775 776 void 777 pps_event(struct pps_state *pps, int event) 778 { 779 struct bintime bt; 780 struct timespec ts, *tsp, *osp; 781 u_int tcount, *pcount; 782 int foff, fhard; 783 pps_seq_t *pseq; 784 785 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_event") */ 786 /* If the timecounter was wound up underneath us, bail out. */ 787 if (pps->capgen == 0 || pps->capgen != pps->capth->th_generation) 788 return; 789 790 /* Things would be easier with arrays. */ 791 if (event == PPS_CAPTUREASSERT) { 792 tsp = &pps->ppsinfo.assert_timestamp; 793 osp = &pps->ppsparam.assert_offset; 794 foff = pps->ppsparam.mode & PPS_OFFSETASSERT; 795 fhard = pps->kcmode & PPS_CAPTUREASSERT; 796 pcount = &pps->ppscount[0]; 797 pseq = &pps->ppsinfo.assert_sequence; 798 } else { 799 tsp = &pps->ppsinfo.clear_timestamp; 800 osp = &pps->ppsparam.clear_offset; 801 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR; 802 fhard = pps->kcmode & PPS_CAPTURECLEAR; 803 pcount = &pps->ppscount[1]; 804 pseq = &pps->ppsinfo.clear_sequence; 805 } 806 807 /* 808 * If the timecounter changed, we cannot compare the count values, so 809 * we have to drop the rest of the PPS-stuff until the next event. 810 */ 811 if (pps->ppstc != pps->capth->th_counter) { 812 pps->ppstc = pps->capth->th_counter; 813 *pcount = pps->capcount; 814 pps->ppscount[2] = pps->capcount; 815 return; 816 } 817 818 /* Convert the count to a timespec. */ 819 tcount = pps->capcount - pps->capth->th_offset_count; 820 tcount &= pps->capth->th_counter->tc_counter_mask; 821 bt = pps->capth->th_offset; 822 bintime_addx(&bt, pps->capth->th_scale * tcount); 823 bintime_add(&bt, &timebasebin); 824 bintime2timespec(&bt, &ts); 825 826 /* If the timecounter was wound up underneath us, bail out. */ 827 if (pps->capgen != pps->capth->th_generation) 828 return; 829 830 *pcount = pps->capcount; 831 (*pseq)++; 832 *tsp = ts; 833 834 if (foff) { 835 timespecadd(tsp, osp, tsp); 836 if (tsp->tv_nsec < 0) { 837 tsp->tv_nsec += 1000000000; 838 tsp->tv_sec -= 1; 839 } 840 } 841 #ifdef PPS_SYNC 842 if (fhard) { 843 u_int64_t scale; 844 845 /* 846 * Feed the NTP PLL/FLL. 847 * The FLL wants to know how many (hardware) nanoseconds 848 * elapsed since the previous event. 849 */ 850 tcount = pps->capcount - pps->ppscount[2]; 851 pps->ppscount[2] = pps->capcount; 852 tcount &= pps->capth->th_counter->tc_counter_mask; 853 scale = (u_int64_t)1 << 63; 854 scale /= pps->capth->th_counter->tc_frequency; 855 scale *= 2; 856 bt.sec = 0; 857 bt.frac = 0; 858 bintime_addx(&bt, scale * tcount); 859 bintime2timespec(&bt, &ts); 860 hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); 861 } 862 #endif 863 } 864 865 /* 866 * Timecounters need to be updated every so often to prevent the hardware 867 * counter from overflowing. Updating also recalculates the cached values 868 * used by the get*() family of functions, so their precision depends on 869 * the update frequency. 870 */ 871 872 static int tc_tick; 873 #ifdef __FreeBSD__ 874 SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0, ""); 875 #endif /* __FreeBSD__ */ 876 877 void 878 tc_ticktock(void) 879 { 880 static int count; 881 882 if (++count < tc_tick) 883 return; 884 count = 0; 885 tc_windup(); 886 } 887 888 void 889 inittimecounter(void) 890 { 891 u_int p; 892 893 /* 894 * Set the initial timeout to 895 * max(1, <approx. number of hardclock ticks in a millisecond>). 896 * People should probably not use the sysctl to set the timeout 897 * to smaller than its inital value, since that value is the 898 * smallest reasonable one. If they want better timestamps they 899 * should use the non-"get"* functions. 900 */ 901 if (hz > 1000) 902 tc_tick = (hz + 500) / 1000; 903 else 904 tc_tick = 1; 905 p = (tc_tick * 1000000) / hz; 906 printf("timecounter: Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000); 907 908 /* warm up new timecounter (again) and get rolling. */ 909 (void)timecounter->tc_get_timecount(timecounter); 910 (void)timecounter->tc_get_timecount(timecounter); 911 } 912 913 #ifdef __FreeBSD__ 914 SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL) 915 #endif /* __FreeBSD__ */ 916 #endif /* __HAVE_TIMECOUNTER */ 917