1 /* $NetBSD: kern_tc.c,v 1.20 2007/08/17 21:20:24 ad 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 1.20 2007/08/17 21:20:24 ad 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, NULL)) != 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 mb_read(); 284 *bt = th->th_offset; 285 bintime_addx(bt, th->th_scale * tc_delta(th)); 286 mb_read(); 287 } while (gen == 0 || gen != th->th_generation); 288 } 289 290 void 291 nanouptime(struct timespec *tsp) 292 { 293 struct bintime bt; 294 295 nnanouptime.ev_count++; 296 binuptime(&bt); 297 bintime2timespec(&bt, tsp); 298 } 299 300 void 301 microuptime(struct timeval *tvp) 302 { 303 struct bintime bt; 304 305 nmicrouptime.ev_count++; 306 binuptime(&bt); 307 bintime2timeval(&bt, tvp); 308 } 309 310 void 311 bintime(struct bintime *bt) 312 { 313 314 nbintime.ev_count++; 315 binuptime(bt); 316 bintime_add(bt, &timebasebin); 317 } 318 319 void 320 nanotime(struct timespec *tsp) 321 { 322 struct bintime bt; 323 324 nnanotime.ev_count++; 325 bintime(&bt); 326 bintime2timespec(&bt, tsp); 327 } 328 329 void 330 microtime(struct timeval *tvp) 331 { 332 struct bintime bt; 333 334 nmicrotime.ev_count++; 335 bintime(&bt); 336 bintime2timeval(&bt, tvp); 337 } 338 339 void 340 getbinuptime(struct bintime *bt) 341 { 342 struct timehands *th; 343 u_int gen; 344 345 ngetbinuptime.ev_count++; 346 do { 347 th = timehands; 348 gen = th->th_generation; 349 mb_read(); 350 *bt = th->th_offset; 351 mb_read(); 352 } while (gen == 0 || gen != th->th_generation); 353 } 354 355 void 356 getnanouptime(struct timespec *tsp) 357 { 358 struct timehands *th; 359 u_int gen; 360 361 ngetnanouptime.ev_count++; 362 do { 363 th = timehands; 364 gen = th->th_generation; 365 mb_read(); 366 bintime2timespec(&th->th_offset, tsp); 367 mb_read(); 368 } while (gen == 0 || gen != th->th_generation); 369 } 370 371 void 372 getmicrouptime(struct timeval *tvp) 373 { 374 struct timehands *th; 375 u_int gen; 376 377 ngetmicrouptime.ev_count++; 378 do { 379 th = timehands; 380 gen = th->th_generation; 381 mb_read(); 382 bintime2timeval(&th->th_offset, tvp); 383 mb_read(); 384 } while (gen == 0 || gen != th->th_generation); 385 } 386 387 void 388 getbintime(struct bintime *bt) 389 { 390 struct timehands *th; 391 u_int gen; 392 393 ngetbintime.ev_count++; 394 do { 395 th = timehands; 396 gen = th->th_generation; 397 mb_read(); 398 *bt = th->th_offset; 399 mb_read(); 400 } while (gen == 0 || gen != th->th_generation); 401 bintime_add(bt, &timebasebin); 402 } 403 404 void 405 getnanotime(struct timespec *tsp) 406 { 407 struct timehands *th; 408 u_int gen; 409 410 ngetnanotime.ev_count++; 411 do { 412 th = timehands; 413 gen = th->th_generation; 414 mb_read(); 415 *tsp = th->th_nanotime; 416 mb_read(); 417 } while (gen == 0 || gen != th->th_generation); 418 } 419 420 void 421 getmicrotime(struct timeval *tvp) 422 { 423 struct timehands *th; 424 u_int gen; 425 426 ngetmicrotime.ev_count++; 427 do { 428 th = timehands; 429 gen = th->th_generation; 430 mb_read(); 431 *tvp = th->th_microtime; 432 mb_read(); 433 } while (gen == 0 || gen != th->th_generation); 434 } 435 436 /* 437 * Initialize a new timecounter and possibly use it. 438 */ 439 void 440 tc_init(struct timecounter *tc) 441 { 442 u_int u; 443 int s; 444 445 u = tc->tc_frequency / tc->tc_counter_mask; 446 /* XXX: We need some margin here, 10% is a guess */ 447 u *= 11; 448 u /= 10; 449 if (u > hz && tc->tc_quality >= 0) { 450 tc->tc_quality = -2000; 451 aprint_verbose( 452 "timecounter: Timecounter \"%s\" frequency %ju Hz", 453 tc->tc_name, (uintmax_t)tc->tc_frequency); 454 aprint_verbose(" -- Insufficient hz, needs at least %u\n", u); 455 } else if (tc->tc_quality >= 0 || bootverbose) { 456 aprint_verbose( 457 "timecounter: Timecounter \"%s\" frequency %ju Hz " 458 "quality %d\n", tc->tc_name, (uintmax_t)tc->tc_frequency, 459 tc->tc_quality); 460 } 461 462 s = splclock(); 463 464 tc->tc_next = timecounters; 465 timecounters = tc; 466 /* 467 * Never automatically use a timecounter with negative quality. 468 * Even though we run on the dummy counter, switching here may be 469 * worse since this timecounter may not be monotonous. 470 */ 471 if (tc->tc_quality < 0) 472 goto out; 473 if (tc->tc_quality < timecounter->tc_quality) 474 goto out; 475 if (tc->tc_quality == timecounter->tc_quality && 476 tc->tc_frequency < timecounter->tc_frequency) 477 goto out; 478 (void)tc->tc_get_timecount(tc); 479 (void)tc->tc_get_timecount(tc); 480 timecounter = tc; 481 tc_windup(); 482 483 out: 484 splx(s); 485 } 486 487 /* Report the frequency of the current timecounter. */ 488 u_int64_t 489 tc_getfrequency(void) 490 { 491 492 return (timehands->th_counter->tc_frequency); 493 } 494 495 /* 496 * Step our concept of UTC. This is done by modifying our estimate of 497 * when we booted. 498 * XXX: not locked. 499 */ 500 void 501 tc_setclock(struct timespec *ts) 502 { 503 struct timespec ts2; 504 struct bintime bt, bt2; 505 506 nsetclock.ev_count++; 507 binuptime(&bt2); 508 timespec2bintime(ts, &bt); 509 bintime_sub(&bt, &bt2); 510 bintime_add(&bt2, &timebasebin); 511 timebasebin = bt; 512 513 /* XXX fiddle all the little crinkly bits around the fiords... */ 514 tc_windup(); 515 if (timestepwarnings) { 516 bintime2timespec(&bt2, &ts2); 517 log(LOG_INFO, "Time stepped from %jd.%09ld to %jd.%09ld\n", 518 (intmax_t)ts2.tv_sec, ts2.tv_nsec, 519 (intmax_t)ts->tv_sec, ts->tv_nsec); 520 } 521 } 522 523 /* 524 * Initialize the next struct timehands in the ring and make 525 * it the active timehands. Along the way we might switch to a different 526 * timecounter and/or do seconds processing in NTP. Slightly magic. 527 */ 528 static void 529 tc_windup(void) 530 { 531 struct bintime bt; 532 struct timehands *th, *tho; 533 u_int64_t scale; 534 u_int delta, ncount, ogen; 535 int i, s_update; 536 time_t t; 537 538 s_update = 0; 539 540 /* 541 * Make the next timehands a copy of the current one, but do not 542 * overwrite the generation or next pointer. While we update 543 * the contents, the generation must be zero. Ensure global 544 * visibility of the generation before proceeding. 545 */ 546 tho = timehands; 547 th = tho->th_next; 548 ogen = th->th_generation; 549 th->th_generation = 0; 550 mb_write(); 551 bcopy(tho, th, offsetof(struct timehands, th_generation)); 552 553 /* 554 * Capture a timecounter delta on the current timecounter and if 555 * changing timecounters, a counter value from the new timecounter. 556 * Update the offset fields accordingly. 557 */ 558 delta = tc_delta(th); 559 if (th->th_counter != timecounter) 560 ncount = timecounter->tc_get_timecount(timecounter); 561 else 562 ncount = 0; 563 th->th_offset_count += delta; 564 th->th_offset_count &= th->th_counter->tc_counter_mask; 565 bintime_addx(&th->th_offset, th->th_scale * delta); 566 567 /* 568 * Hardware latching timecounters may not generate interrupts on 569 * PPS events, so instead we poll them. There is a finite risk that 570 * the hardware might capture a count which is later than the one we 571 * got above, and therefore possibly in the next NTP second which might 572 * have a different rate than the current NTP second. It doesn't 573 * matter in practice. 574 */ 575 if (tho->th_counter->tc_poll_pps) 576 tho->th_counter->tc_poll_pps(tho->th_counter); 577 578 /* 579 * Deal with NTP second processing. The for loop normally 580 * iterates at most once, but in extreme situations it might 581 * keep NTP sane if timeouts are not run for several seconds. 582 * At boot, the time step can be large when the TOD hardware 583 * has been read, so on really large steps, we call 584 * ntp_update_second only twice. We need to call it twice in 585 * case we missed a leap second. 586 * If NTP is not compiled in ntp_update_second still calculates 587 * the adjustment resulting from adjtime() calls. 588 */ 589 bt = th->th_offset; 590 bintime_add(&bt, &timebasebin); 591 i = bt.sec - tho->th_microtime.tv_sec; 592 if (i > LARGE_STEP) 593 i = 2; 594 for (; i > 0; i--) { 595 t = bt.sec; 596 ntp_update_second(&th->th_adjustment, &bt.sec); 597 s_update = 1; 598 if (bt.sec != t) 599 timebasebin.sec += bt.sec - t; 600 } 601 602 /* Update the UTC timestamps used by the get*() functions. */ 603 /* XXX shouldn't do this here. Should force non-`get' versions. */ 604 bintime2timeval(&bt, &th->th_microtime); 605 bintime2timespec(&bt, &th->th_nanotime); 606 607 /* Now is a good time to change timecounters. */ 608 if (th->th_counter != timecounter) { 609 th->th_counter = timecounter; 610 th->th_offset_count = ncount; 611 s_update = 1; 612 } 613 614 /*- 615 * Recalculate the scaling factor. We want the number of 1/2^64 616 * fractions of a second per period of the hardware counter, taking 617 * into account the th_adjustment factor which the NTP PLL/adjtime(2) 618 * processing provides us with. 619 * 620 * The th_adjustment is nanoseconds per second with 32 bit binary 621 * fraction and we want 64 bit binary fraction of second: 622 * 623 * x = a * 2^32 / 10^9 = a * 4.294967296 624 * 625 * The range of th_adjustment is +/- 5000PPM so inside a 64bit int 626 * we can only multiply by about 850 without overflowing, but that 627 * leaves suitably precise fractions for multiply before divide. 628 * 629 * Divide before multiply with a fraction of 2199/512 results in a 630 * systematic undercompensation of 10PPM of th_adjustment. On a 631 * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. 632 * 633 * We happily sacrifice the lowest of the 64 bits of our result 634 * to the goddess of code clarity. 635 * 636 */ 637 if (s_update) { 638 scale = (u_int64_t)1 << 63; 639 scale += (th->th_adjustment / 1024) * 2199; 640 scale /= th->th_counter->tc_frequency; 641 th->th_scale = scale * 2; 642 } 643 /* 644 * Now that the struct timehands is again consistent, set the new 645 * generation number, making sure to not make it zero. Ensure 646 * changes are globally visible before changing. 647 */ 648 if (++ogen == 0) 649 ogen = 1; 650 mb_write(); 651 th->th_generation = ogen; 652 653 /* 654 * Go live with the new struct timehands. Ensure changes are 655 * globally visible before changing. 656 */ 657 time_second = th->th_microtime.tv_sec; 658 time_uptime = th->th_offset.sec; 659 mb_write(); 660 timehands = th; 661 } 662 663 #ifdef __FreeBSD__ 664 /* Report or change the active timecounter hardware. */ 665 static int 666 sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) 667 { 668 char newname[32]; 669 struct timecounter *newtc, *tc; 670 int error; 671 672 tc = timecounter; 673 strlcpy(newname, tc->tc_name, sizeof(newname)); 674 675 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); 676 if (error != 0 || req->newptr == NULL || 677 strcmp(newname, tc->tc_name) == 0) 678 return (error); 679 680 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { 681 if (strcmp(newname, newtc->tc_name) != 0) 682 continue; 683 684 /* Warm up new timecounter. */ 685 (void)newtc->tc_get_timecount(newtc); 686 (void)newtc->tc_get_timecount(newtc); 687 688 timecounter = newtc; 689 return (0); 690 } 691 return (EINVAL); 692 } 693 694 SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, 695 0, 0, sysctl_kern_timecounter_hardware, "A", ""); 696 697 698 /* Report or change the active timecounter hardware. */ 699 static int 700 sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS) 701 { 702 char buf[32], *spc; 703 struct timecounter *tc; 704 int error; 705 706 spc = ""; 707 error = 0; 708 for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { 709 sprintf(buf, "%s%s(%d)", 710 spc, tc->tc_name, tc->tc_quality); 711 error = SYSCTL_OUT(req, buf, strlen(buf)); 712 spc = " "; 713 } 714 return (error); 715 } 716 717 SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice, CTLTYPE_STRING | CTLFLAG_RD, 718 0, 0, sysctl_kern_timecounter_choice, "A", ""); 719 #endif /* __FreeBSD__ */ 720 721 /* 722 * RFC 2783 PPS-API implementation. 723 */ 724 725 int 726 pps_ioctl(u_long cmd, void *data, struct pps_state *pps) 727 { 728 pps_params_t *app; 729 pps_info_t *pipi; 730 #ifdef PPS_SYNC 731 int *epi; 732 #endif 733 734 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_ioctl") */ 735 switch (cmd) { 736 case PPS_IOC_CREATE: 737 return (0); 738 case PPS_IOC_DESTROY: 739 return (0); 740 case PPS_IOC_SETPARAMS: 741 app = (pps_params_t *)data; 742 if (app->mode & ~pps->ppscap) 743 return (EINVAL); 744 pps->ppsparam = *app; 745 return (0); 746 case PPS_IOC_GETPARAMS: 747 app = (pps_params_t *)data; 748 *app = pps->ppsparam; 749 app->api_version = PPS_API_VERS_1; 750 return (0); 751 case PPS_IOC_GETCAP: 752 *(int*)data = pps->ppscap; 753 return (0); 754 case PPS_IOC_FETCH: 755 pipi = (pps_info_t *)data; 756 pps->ppsinfo.current_mode = pps->ppsparam.mode; 757 *pipi = pps->ppsinfo; 758 return (0); 759 case PPS_IOC_KCBIND: 760 #ifdef PPS_SYNC 761 epi = (int *)data; 762 /* XXX Only root should be able to do this */ 763 if (*epi & ~pps->ppscap) 764 return (EINVAL); 765 pps->kcmode = *epi; 766 return (0); 767 #else 768 return (EOPNOTSUPP); 769 #endif 770 default: 771 return (EPASSTHROUGH); 772 } 773 } 774 775 void 776 pps_init(struct pps_state *pps) 777 { 778 pps->ppscap |= PPS_TSFMT_TSPEC; 779 if (pps->ppscap & PPS_CAPTUREASSERT) 780 pps->ppscap |= PPS_OFFSETASSERT; 781 if (pps->ppscap & PPS_CAPTURECLEAR) 782 pps->ppscap |= PPS_OFFSETCLEAR; 783 } 784 785 void 786 pps_capture(struct pps_state *pps) 787 { 788 struct timehands *th; 789 790 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_capture") */ 791 th = timehands; 792 pps->capgen = th->th_generation; 793 pps->capth = th; 794 pps->capcount = th->th_counter->tc_get_timecount(th->th_counter); 795 if (pps->capgen != th->th_generation) 796 pps->capgen = 0; 797 } 798 799 void 800 pps_event(struct pps_state *pps, int event) 801 { 802 struct bintime bt; 803 struct timespec ts, *tsp, *osp; 804 u_int tcount, *pcount; 805 int foff, fhard; 806 pps_seq_t *pseq; 807 808 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_event") */ 809 /* If the timecounter was wound up underneath us, bail out. */ 810 if (pps->capgen == 0 || pps->capgen != pps->capth->th_generation) 811 return; 812 813 /* Things would be easier with arrays. */ 814 if (event == PPS_CAPTUREASSERT) { 815 tsp = &pps->ppsinfo.assert_timestamp; 816 osp = &pps->ppsparam.assert_offset; 817 foff = pps->ppsparam.mode & PPS_OFFSETASSERT; 818 fhard = pps->kcmode & PPS_CAPTUREASSERT; 819 pcount = &pps->ppscount[0]; 820 pseq = &pps->ppsinfo.assert_sequence; 821 } else { 822 tsp = &pps->ppsinfo.clear_timestamp; 823 osp = &pps->ppsparam.clear_offset; 824 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR; 825 fhard = pps->kcmode & PPS_CAPTURECLEAR; 826 pcount = &pps->ppscount[1]; 827 pseq = &pps->ppsinfo.clear_sequence; 828 } 829 830 /* 831 * If the timecounter changed, we cannot compare the count values, so 832 * we have to drop the rest of the PPS-stuff until the next event. 833 */ 834 if (pps->ppstc != pps->capth->th_counter) { 835 pps->ppstc = pps->capth->th_counter; 836 *pcount = pps->capcount; 837 pps->ppscount[2] = pps->capcount; 838 return; 839 } 840 841 /* Convert the count to a timespec. */ 842 tcount = pps->capcount - pps->capth->th_offset_count; 843 tcount &= pps->capth->th_counter->tc_counter_mask; 844 bt = pps->capth->th_offset; 845 bintime_addx(&bt, pps->capth->th_scale * tcount); 846 bintime_add(&bt, &timebasebin); 847 bintime2timespec(&bt, &ts); 848 849 /* If the timecounter was wound up underneath us, bail out. */ 850 if (pps->capgen != pps->capth->th_generation) 851 return; 852 853 *pcount = pps->capcount; 854 (*pseq)++; 855 *tsp = ts; 856 857 if (foff) { 858 timespecadd(tsp, osp, tsp); 859 if (tsp->tv_nsec < 0) { 860 tsp->tv_nsec += 1000000000; 861 tsp->tv_sec -= 1; 862 } 863 } 864 #ifdef PPS_SYNC 865 if (fhard) { 866 u_int64_t scale; 867 868 /* 869 * Feed the NTP PLL/FLL. 870 * The FLL wants to know how many (hardware) nanoseconds 871 * elapsed since the previous event. 872 */ 873 tcount = pps->capcount - pps->ppscount[2]; 874 pps->ppscount[2] = pps->capcount; 875 tcount &= pps->capth->th_counter->tc_counter_mask; 876 scale = (u_int64_t)1 << 63; 877 scale /= pps->capth->th_counter->tc_frequency; 878 scale *= 2; 879 bt.sec = 0; 880 bt.frac = 0; 881 bintime_addx(&bt, scale * tcount); 882 bintime2timespec(&bt, &ts); 883 hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); 884 } 885 #endif 886 } 887 888 /* 889 * Timecounters need to be updated every so often to prevent the hardware 890 * counter from overflowing. Updating also recalculates the cached values 891 * used by the get*() family of functions, so their precision depends on 892 * the update frequency. 893 */ 894 895 static int tc_tick; 896 #ifdef __FreeBSD__ 897 SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0, ""); 898 #endif /* __FreeBSD__ */ 899 900 void 901 tc_ticktock(void) 902 { 903 static int count; 904 905 if (++count < tc_tick) 906 return; 907 count = 0; 908 tc_windup(); 909 } 910 911 void 912 inittimecounter(void) 913 { 914 u_int p; 915 916 /* 917 * Set the initial timeout to 918 * max(1, <approx. number of hardclock ticks in a millisecond>). 919 * People should probably not use the sysctl to set the timeout 920 * to smaller than its inital value, since that value is the 921 * smallest reasonable one. If they want better timestamps they 922 * should use the non-"get"* functions. 923 */ 924 if (hz > 1000) 925 tc_tick = (hz + 500) / 1000; 926 else 927 tc_tick = 1; 928 p = (tc_tick * 1000000) / hz; 929 aprint_verbose("timecounter: Timecounters tick every %d.%03u msec\n", 930 p / 1000, p % 1000); 931 932 /* warm up new timecounter (again) and get rolling. */ 933 (void)timecounter->tc_get_timecount(timecounter); 934 (void)timecounter->tc_get_timecount(timecounter); 935 } 936 937 #ifdef __FreeBSD__ 938 SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL) 939 #endif /* __FreeBSD__ */ 940 #endif /* __HAVE_TIMECOUNTER */ 941