1 /* $NetBSD: kern_tc.c,v 1.3 2006/06/09 22:47:56 kardel 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 1.3 2006/06/09 22:47:56 kardel 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 * maximum name length for TC names in sysctl interface 33 */ 34 #define MAX_TCNAMELEN 64 35 36 /* 37 * A large step happens on boot. This constant detects such steps. 38 * It is relatively small so that ntp_update_second gets called enough 39 * in the typical 'missed a couple of seconds' case, but doesn't loop 40 * forever when the time step is large. 41 */ 42 #define LARGE_STEP 200 43 44 /* 45 * Implement a dummy timecounter which we can use until we get a real one 46 * in the air. This allows the console and other early stuff to use 47 * time services. 48 */ 49 50 static u_int 51 dummy_get_timecount(struct timecounter *tc) 52 { 53 static u_int now; 54 55 return (++now); 56 } 57 58 static struct timecounter dummy_timecounter = { 59 dummy_get_timecount, 0, ~0u, 1000000, "dummy", -1000000 60 }; 61 62 struct timehands { 63 /* These fields must be initialized by the driver. */ 64 struct timecounter *th_counter; 65 int64_t th_adjustment; 66 u_int64_t th_scale; 67 u_int th_offset_count; 68 struct bintime th_offset; 69 struct timeval th_microtime; 70 struct timespec th_nanotime; 71 /* Fields not to be copied in tc_windup start with th_generation. */ 72 volatile u_int th_generation; 73 struct timehands *th_next; 74 }; 75 76 static struct timehands th0; 77 static struct timehands th9 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th0}; 78 static struct timehands th8 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th9}; 79 static struct timehands th7 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th8}; 80 static struct timehands th6 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th7}; 81 static struct timehands th5 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th6}; 82 static struct timehands th4 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th5}; 83 static struct timehands th3 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th4}; 84 static struct timehands th2 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th3}; 85 static struct timehands th1 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th2}; 86 static struct timehands th0 = { 87 &dummy_timecounter, 88 0, 89 (uint64_t)-1 / 1000000, 90 0, 91 {1, 0}, 92 {0, 0}, 93 {0, 0}, 94 1, 95 &th1 96 }; 97 98 static struct timehands *volatile timehands = &th0; 99 struct timecounter *timecounter = &dummy_timecounter; 100 static struct timecounter *timecounters = &dummy_timecounter; 101 102 time_t time_second = 1; 103 time_t time_uptime = 1; 104 105 static struct bintime boottimebin; 106 struct timeval boottime; 107 #ifdef __FreeBSD__ 108 static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS); 109 SYSCTL_PROC(_kern, KERN_BOOTTIME, boottime, CTLTYPE_STRUCT|CTLFLAG_RD, 110 NULL, 0, sysctl_kern_boottime, "S,timeval", "System boottime"); 111 112 SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, ""); 113 #endif /* __FreeBSD__ */ 114 115 static int timestepwarnings; 116 117 #ifdef __FreeBSD__ 118 SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW, 119 ×tepwarnings, 0, ""); 120 #endif /* __FreeBSD__ */ 121 122 /* 123 * sysctl helper routine for kern.timercounter.current 124 */ 125 static int 126 sysctl_kern_timecounter_hardware(SYSCTLFN_ARGS) 127 { 128 struct sysctlnode node; 129 int error; 130 char newname[MAX_TCNAMELEN]; 131 struct timecounter *newtc, *tc; 132 133 tc = timecounter; 134 135 strlcpy(newname, tc->tc_name, sizeof(newname)); 136 137 node = *rnode; 138 node.sysctl_data = newname; 139 node.sysctl_size = sizeof(newname); 140 141 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 142 143 if (error || 144 newp == NULL || 145 strncmp(newname, tc->tc_name, sizeof(newname)) == 0) 146 return error; 147 148 if (l && (error = kauth_authorize_generic(l->l_proc->p_cred, 149 KAUTH_GENERIC_ISSUSER, &l->l_proc->p_acflag)) != 0) 150 return (error); 151 152 /* XXX locking */ 153 154 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { 155 if (strcmp(newname, newtc->tc_name) != 0) 156 continue; 157 158 /* Warm up new timecounter. */ 159 (void)newtc->tc_get_timecount(newtc); 160 (void)newtc->tc_get_timecount(newtc); 161 162 timecounter = newtc; 163 164 /* XXX unlock */ 165 166 return (0); 167 } 168 169 /* XXX unlock */ 170 171 return (EINVAL); 172 } 173 174 static int 175 sysctl_kern_timecounter_choice(SYSCTLFN_ARGS) 176 { 177 char buf[48]; 178 char *where = oldp; 179 const char *spc; 180 struct timecounter *tc; 181 size_t needed, left, slen; 182 int error; 183 184 if (newp != NULL) 185 return (EPERM); 186 if (namelen != 0) 187 return (EINVAL); 188 189 spc = ""; 190 error = 0; 191 needed = 0; 192 left = *oldlenp; 193 194 /* XXX locking */ 195 196 for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { 197 if (where == NULL) { 198 needed += sizeof(buf); /* be conservative */ 199 } else { 200 slen = snprintf(buf, sizeof(buf), "%s%s(q=%d, f=%" PRId64 201 " Hz)", spc, tc->tc_name, tc->tc_quality, 202 tc->tc_frequency); 203 if (left < slen + 1) 204 break; 205 /* XXX use sysctl_copyout? (from sysctl_hw_disknames) */ 206 error = copyout(buf, where, slen + 1); 207 spc = " "; 208 where += slen; 209 needed += slen; 210 left -= slen; 211 } 212 } 213 214 /* XXX unlock */ 215 216 *oldlenp = needed; 217 return (error); 218 } 219 220 SYSCTL_SETUP(sysctl_timecounter_setup, "sysctl timecounter setup") 221 { 222 const struct sysctlnode *node; 223 224 sysctl_createv(clog, 0, NULL, &node, 225 CTLFLAG_PERMANENT, 226 CTLTYPE_NODE, "timecounter", 227 SYSCTL_DESCR("time counter information"), 228 NULL, 0, NULL, 0, 229 CTL_KERN, CTL_CREATE, CTL_EOL); 230 231 if (node != NULL) { 232 sysctl_createv(clog, 0, NULL, NULL, 233 CTLFLAG_PERMANENT, 234 CTLTYPE_STRING, "choice", 235 SYSCTL_DESCR("available counters"), 236 sysctl_kern_timecounter_choice, 0, NULL, 0, 237 CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); 238 239 sysctl_createv(clog, 0, NULL, NULL, 240 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 241 CTLTYPE_STRING, "hardware", 242 SYSCTL_DESCR("currently active time counter"), 243 sysctl_kern_timecounter_hardware, 0, NULL, MAX_TCNAMELEN, 244 CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); 245 246 sysctl_createv(clog, 0, NULL, NULL, 247 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 248 CTLTYPE_INT, "timestepwarnings", 249 SYSCTL_DESCR("log time steps"), 250 NULL, 0, ×tepwarnings, 0, 251 CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); 252 } 253 } 254 255 #define TC_STATS(name) \ 256 static struct evcnt n##name = \ 257 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "timecounter", #name); \ 258 EVCNT_ATTACH_STATIC(n##name) 259 260 TC_STATS(binuptime); TC_STATS(nanouptime); TC_STATS(microuptime); 261 TC_STATS(bintime); TC_STATS(nanotime); TC_STATS(microtime); 262 TC_STATS(getbinuptime); TC_STATS(getnanouptime); TC_STATS(getmicrouptime); 263 TC_STATS(getbintime); TC_STATS(getnanotime); TC_STATS(getmicrotime); 264 TC_STATS(setclock); 265 266 #undef TC_STATS 267 268 static void tc_windup(void); 269 270 #ifdef __FreeBSD__ 271 static int 272 sysctl_kern_boottime(SYSCTL_HANDLER_ARGS) 273 { 274 #ifdef SCTL_MASK32 275 int tv[2]; 276 277 if (req->flags & SCTL_MASK32) { 278 tv[0] = boottime.tv_sec; 279 tv[1] = boottime.tv_usec; 280 return SYSCTL_OUT(req, tv, sizeof(tv)); 281 } else 282 #endif 283 return SYSCTL_OUT(req, &boottime, sizeof(boottime)); 284 } 285 #endif /* __FreeBSD__ */ 286 287 /* 288 * Return the difference between the timehands' counter value now and what 289 * was when we copied it to the timehands' offset_count. 290 */ 291 static __inline u_int 292 tc_delta(struct timehands *th) 293 { 294 struct timecounter *tc; 295 296 tc = th->th_counter; 297 return ((tc->tc_get_timecount(tc) - 298 th->th_offset_count) & tc->tc_counter_mask); 299 } 300 301 /* 302 * Functions for reading the time. We have to loop until we are sure that 303 * the timehands that we operated on was not updated under our feet. See 304 * the comment in <sys/time.h> for a description of these 12 functions. 305 */ 306 307 void 308 binuptime(struct bintime *bt) 309 { 310 struct timehands *th; 311 u_int gen; 312 313 nbinuptime.ev_count++; 314 do { 315 th = timehands; 316 gen = th->th_generation; 317 *bt = th->th_offset; 318 bintime_addx(bt, th->th_scale * tc_delta(th)); 319 } while (gen == 0 || gen != th->th_generation); 320 } 321 322 void 323 nanouptime(struct timespec *tsp) 324 { 325 struct bintime bt; 326 327 nnanouptime.ev_count++; 328 binuptime(&bt); 329 bintime2timespec(&bt, tsp); 330 } 331 332 void 333 microuptime(struct timeval *tvp) 334 { 335 struct bintime bt; 336 337 nmicrouptime.ev_count++; 338 binuptime(&bt); 339 bintime2timeval(&bt, tvp); 340 } 341 342 void 343 bintime(struct bintime *bt) 344 { 345 346 nbintime.ev_count++; 347 binuptime(bt); 348 bintime_add(bt, &boottimebin); 349 } 350 351 void 352 nanotime(struct timespec *tsp) 353 { 354 struct bintime bt; 355 356 nnanotime.ev_count++; 357 bintime(&bt); 358 bintime2timespec(&bt, tsp); 359 } 360 361 void 362 microtime(struct timeval *tvp) 363 { 364 struct bintime bt; 365 366 nmicrotime.ev_count++; 367 bintime(&bt); 368 bintime2timeval(&bt, tvp); 369 } 370 371 void 372 getbinuptime(struct bintime *bt) 373 { 374 struct timehands *th; 375 u_int gen; 376 377 ngetbinuptime.ev_count++; 378 do { 379 th = timehands; 380 gen = th->th_generation; 381 *bt = th->th_offset; 382 } while (gen == 0 || gen != th->th_generation); 383 } 384 385 void 386 getnanouptime(struct timespec *tsp) 387 { 388 struct timehands *th; 389 u_int gen; 390 391 ngetnanouptime.ev_count++; 392 do { 393 th = timehands; 394 gen = th->th_generation; 395 bintime2timespec(&th->th_offset, tsp); 396 } while (gen == 0 || gen != th->th_generation); 397 } 398 399 void 400 getmicrouptime(struct timeval *tvp) 401 { 402 struct timehands *th; 403 u_int gen; 404 405 ngetmicrouptime.ev_count++; 406 do { 407 th = timehands; 408 gen = th->th_generation; 409 bintime2timeval(&th->th_offset, tvp); 410 } while (gen == 0 || gen != th->th_generation); 411 } 412 413 void 414 getbintime(struct bintime *bt) 415 { 416 struct timehands *th; 417 u_int gen; 418 419 ngetbintime.ev_count++; 420 do { 421 th = timehands; 422 gen = th->th_generation; 423 *bt = th->th_offset; 424 } while (gen == 0 || gen != th->th_generation); 425 bintime_add(bt, &boottimebin); 426 } 427 428 void 429 getnanotime(struct timespec *tsp) 430 { 431 struct timehands *th; 432 u_int gen; 433 434 ngetnanotime.ev_count++; 435 do { 436 th = timehands; 437 gen = th->th_generation; 438 *tsp = th->th_nanotime; 439 } while (gen == 0 || gen != th->th_generation); 440 } 441 442 void 443 getmicrotime(struct timeval *tvp) 444 { 445 struct timehands *th; 446 u_int gen; 447 448 ngetmicrotime.ev_count++; 449 do { 450 th = timehands; 451 gen = th->th_generation; 452 *tvp = th->th_microtime; 453 } while (gen == 0 || gen != th->th_generation); 454 } 455 456 /* 457 * Initialize a new timecounter and possibly use it. 458 */ 459 void 460 tc_init(struct timecounter *tc) 461 { 462 u_int u; 463 464 u = tc->tc_frequency / tc->tc_counter_mask; 465 /* XXX: We need some margin here, 10% is a guess */ 466 u *= 11; 467 u /= 10; 468 if (u > hz && tc->tc_quality >= 0) { 469 tc->tc_quality = -2000; 470 if (bootverbose) { 471 printf("timecounter: Timecounter \"%s\" frequency %ju Hz", 472 tc->tc_name, (uintmax_t)tc->tc_frequency); 473 printf(" -- Insufficient hz, needs at least %u\n", u); 474 } 475 } else if (tc->tc_quality >= 0 || bootverbose) { 476 printf("timecounter: Timecounter \"%s\" frequency %ju Hz quality %d\n", 477 tc->tc_name, (uintmax_t)tc->tc_frequency, 478 tc->tc_quality); 479 } 480 481 /* XXX locking */ 482 tc->tc_next = timecounters; 483 timecounters = tc; 484 /* 485 * Never automatically use a timecounter with negative quality. 486 * Even though we run on the dummy counter, switching here may be 487 * worse since this timecounter may not be monotonous. 488 */ 489 if (tc->tc_quality < 0) 490 return; 491 if (tc->tc_quality < timecounter->tc_quality) 492 return; 493 if (tc->tc_quality == timecounter->tc_quality && 494 tc->tc_frequency < timecounter->tc_frequency) 495 return; 496 (void)tc->tc_get_timecount(tc); 497 (void)tc->tc_get_timecount(tc); 498 timecounter = tc; 499 tc_windup(); 500 } 501 502 /* Report the frequency of the current timecounter. */ 503 u_int64_t 504 tc_getfrequency(void) 505 { 506 507 return (timehands->th_counter->tc_frequency); 508 } 509 510 /* 511 * Step our concept of UTC. This is done by modifying our estimate of 512 * when we booted. 513 * XXX: not locked. 514 */ 515 void 516 tc_setclock(struct timespec *ts) 517 { 518 struct timespec ts2; 519 struct bintime bt, bt2; 520 521 nsetclock.ev_count++; 522 binuptime(&bt2); 523 timespec2bintime(ts, &bt); 524 bintime_sub(&bt, &bt2); 525 bintime_add(&bt2, &boottimebin); 526 boottimebin = bt; 527 bintime2timeval(&bt, &boottime); 528 529 /* XXX fiddle all the little crinkly bits around the fiords... */ 530 tc_windup(); 531 if (timestepwarnings) { 532 bintime2timespec(&bt2, &ts2); 533 log(LOG_INFO, "Time stepped from %jd.%09ld to %jd.%09ld\n", 534 (intmax_t)ts2.tv_sec, ts2.tv_nsec, 535 (intmax_t)ts->tv_sec, ts->tv_nsec); 536 } 537 } 538 539 /* 540 * Initialize the next struct timehands in the ring and make 541 * it the active timehands. Along the way we might switch to a different 542 * timecounter and/or do seconds processing in NTP. Slightly magic. 543 */ 544 static void 545 tc_windup(void) 546 { 547 struct bintime bt; 548 struct timehands *th, *tho; 549 u_int64_t scale; 550 u_int delta, ncount, ogen; 551 int i; 552 time_t t; 553 554 /* 555 * Make the next timehands a copy of the current one, but do not 556 * overwrite the generation or next pointer. While we update 557 * the contents, the generation must be zero. 558 */ 559 tho = timehands; 560 th = tho->th_next; 561 ogen = th->th_generation; 562 th->th_generation = 0; 563 bcopy(tho, th, offsetof(struct timehands, th_generation)); 564 565 /* 566 * Capture a timecounter delta on the current timecounter and if 567 * changing timecounters, a counter value from the new timecounter. 568 * Update the offset fields accordingly. 569 */ 570 delta = tc_delta(th); 571 if (th->th_counter != timecounter) 572 ncount = timecounter->tc_get_timecount(timecounter); 573 else 574 ncount = 0; 575 th->th_offset_count += delta; 576 th->th_offset_count &= th->th_counter->tc_counter_mask; 577 bintime_addx(&th->th_offset, th->th_scale * delta); 578 579 /* 580 * Hardware latching timecounters may not generate interrupts on 581 * PPS events, so instead we poll them. There is a finite risk that 582 * the hardware might capture a count which is later than the one we 583 * got above, and therefore possibly in the next NTP second which might 584 * have a different rate than the current NTP second. It doesn't 585 * matter in practice. 586 */ 587 if (tho->th_counter->tc_poll_pps) 588 tho->th_counter->tc_poll_pps(tho->th_counter); 589 590 /* 591 * Deal with NTP second processing. The for loop normally 592 * iterates at most once, but in extreme situations it might 593 * keep NTP sane if timeouts are not run for several seconds. 594 * At boot, the time step can be large when the TOD hardware 595 * has been read, so on really large steps, we call 596 * ntp_update_second only twice. We need to call it twice in 597 * case we missed a leap second. 598 * If NTP is not compiled in ntp_update_second still calculates 599 * the adjustment resulting from adjtime() calls. 600 */ 601 bt = th->th_offset; 602 bintime_add(&bt, &boottimebin); 603 i = bt.sec - tho->th_microtime.tv_sec; 604 if (i > LARGE_STEP) 605 i = 2; 606 for (; i > 0; i--) { 607 t = bt.sec; 608 ntp_update_second(&th->th_adjustment, &bt.sec); 609 if (bt.sec != t) 610 boottimebin.sec += bt.sec - t; 611 } 612 613 /* Update the UTC timestamps used by the get*() functions. */ 614 /* XXX shouldn't do this here. Should force non-`get' versions. */ 615 bintime2timeval(&bt, &th->th_microtime); 616 bintime2timespec(&bt, &th->th_nanotime); 617 618 /* Now is a good time to change timecounters. */ 619 if (th->th_counter != timecounter) { 620 th->th_counter = timecounter; 621 th->th_offset_count = ncount; 622 623 printf("timecounter: selected timecounter \"%s\" frequency %ju Hz quality %d\n", 624 timecounter->tc_name, (uintmax_t)timecounter->tc_frequency, 625 timecounter->tc_quality); 626 } 627 628 /*- 629 * Recalculate the scaling factor. We want the number of 1/2^64 630 * fractions of a second per period of the hardware counter, taking 631 * into account the th_adjustment factor which the NTP PLL/adjtime(2) 632 * processing provides us with. 633 * 634 * The th_adjustment is nanoseconds per second with 32 bit binary 635 * fraction and we want 64 bit binary fraction of second: 636 * 637 * x = a * 2^32 / 10^9 = a * 4.294967296 638 * 639 * The range of th_adjustment is +/- 5000PPM so inside a 64bit int 640 * we can only multiply by about 850 without overflowing, but that 641 * leaves suitably precise fractions for multiply before divide. 642 * 643 * Divide before multiply with a fraction of 2199/512 results in a 644 * systematic undercompensation of 10PPM of th_adjustment. On a 645 * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. 646 * 647 * We happily sacrifice the lowest of the 64 bits of our result 648 * to the goddess of code clarity. 649 * 650 */ 651 scale = (u_int64_t)1 << 63; 652 scale += (th->th_adjustment / 1024) * 2199; 653 scale /= th->th_counter->tc_frequency; 654 th->th_scale = scale * 2; 655 656 /* 657 * Now that the struct timehands is again consistent, set the new 658 * generation number, making sure to not make it zero. 659 */ 660 if (++ogen == 0) 661 ogen = 1; 662 th->th_generation = ogen; 663 664 /* Go live with the new struct timehands. */ 665 time_second = th->th_microtime.tv_sec; 666 time_uptime = th->th_offset.sec; 667 timehands = th; 668 } 669 670 #ifdef __FreeBSD__ 671 /* Report or change the active timecounter hardware. */ 672 static int 673 sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) 674 { 675 char newname[32]; 676 struct timecounter *newtc, *tc; 677 int error; 678 679 tc = timecounter; 680 strlcpy(newname, tc->tc_name, sizeof(newname)); 681 682 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); 683 if (error != 0 || req->newptr == NULL || 684 strcmp(newname, tc->tc_name) == 0) 685 return (error); 686 687 for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { 688 if (strcmp(newname, newtc->tc_name) != 0) 689 continue; 690 691 /* Warm up new timecounter. */ 692 (void)newtc->tc_get_timecount(newtc); 693 (void)newtc->tc_get_timecount(newtc); 694 695 timecounter = newtc; 696 return (0); 697 } 698 return (EINVAL); 699 } 700 701 SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, 702 0, 0, sysctl_kern_timecounter_hardware, "A", ""); 703 704 705 /* Report or change the active timecounter hardware. */ 706 static int 707 sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS) 708 { 709 char buf[32], *spc; 710 struct timecounter *tc; 711 int error; 712 713 spc = ""; 714 error = 0; 715 for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { 716 sprintf(buf, "%s%s(%d)", 717 spc, tc->tc_name, tc->tc_quality); 718 error = SYSCTL_OUT(req, buf, strlen(buf)); 719 spc = " "; 720 } 721 return (error); 722 } 723 724 SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice, CTLTYPE_STRING | CTLFLAG_RD, 725 0, 0, sysctl_kern_timecounter_choice, "A", ""); 726 #endif /* __FreeBSD__ */ 727 728 /* 729 * RFC 2783 PPS-API implementation. 730 */ 731 732 int 733 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps) 734 { 735 pps_params_t *app; 736 pps_info_t *pipi; 737 #ifdef PPS_SYNC 738 int *epi; 739 #endif 740 741 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_ioctl") */ 742 switch (cmd) { 743 case PPS_IOC_CREATE: 744 return (0); 745 case PPS_IOC_DESTROY: 746 return (0); 747 case PPS_IOC_SETPARAMS: 748 app = (pps_params_t *)data; 749 if (app->mode & ~pps->ppscap) 750 return (EINVAL); 751 pps->ppsparam = *app; 752 return (0); 753 case PPS_IOC_GETPARAMS: 754 app = (pps_params_t *)data; 755 *app = pps->ppsparam; 756 app->api_version = PPS_API_VERS_1; 757 return (0); 758 case PPS_IOC_GETCAP: 759 *(int*)data = pps->ppscap; 760 return (0); 761 case PPS_IOC_FETCH: 762 pipi = (pps_info_t *)data; 763 pps->ppsinfo.current_mode = pps->ppsparam.mode; 764 *pipi = pps->ppsinfo; 765 return (0); 766 case PPS_IOC_KCBIND: 767 #ifdef PPS_SYNC 768 epi = (int *)data; 769 /* XXX Only root should be able to do this */ 770 if (*epi & ~pps->ppscap) 771 return (EINVAL); 772 pps->kcmode = *epi; 773 return (0); 774 #else 775 return (EOPNOTSUPP); 776 #endif 777 default: 778 return (EPASSTHROUGH); 779 } 780 } 781 782 void 783 pps_init(struct pps_state *pps) 784 { 785 pps->ppscap |= PPS_TSFMT_TSPEC; 786 if (pps->ppscap & PPS_CAPTUREASSERT) 787 pps->ppscap |= PPS_OFFSETASSERT; 788 if (pps->ppscap & PPS_CAPTURECLEAR) 789 pps->ppscap |= PPS_OFFSETCLEAR; 790 } 791 792 void 793 pps_capture(struct pps_state *pps) 794 { 795 struct timehands *th; 796 797 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_capture") */ 798 th = timehands; 799 pps->capgen = th->th_generation; 800 pps->capth = th; 801 pps->capcount = th->th_counter->tc_get_timecount(th->th_counter); 802 if (pps->capgen != th->th_generation) 803 pps->capgen = 0; 804 } 805 806 void 807 pps_event(struct pps_state *pps, int event) 808 { 809 struct bintime bt; 810 struct timespec ts, *tsp, *osp; 811 u_int tcount, *pcount; 812 int foff, fhard; 813 pps_seq_t *pseq; 814 815 KASSERT(pps != NULL); /* XXX ("NULL pps pointer in pps_event") */ 816 /* If the timecounter was wound up underneath us, bail out. */ 817 if (pps->capgen == 0 || pps->capgen != pps->capth->th_generation) 818 return; 819 820 /* Things would be easier with arrays. */ 821 if (event == PPS_CAPTUREASSERT) { 822 tsp = &pps->ppsinfo.assert_timestamp; 823 osp = &pps->ppsparam.assert_offset; 824 foff = pps->ppsparam.mode & PPS_OFFSETASSERT; 825 fhard = pps->kcmode & PPS_CAPTUREASSERT; 826 pcount = &pps->ppscount[0]; 827 pseq = &pps->ppsinfo.assert_sequence; 828 } else { 829 tsp = &pps->ppsinfo.clear_timestamp; 830 osp = &pps->ppsparam.clear_offset; 831 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR; 832 fhard = pps->kcmode & PPS_CAPTURECLEAR; 833 pcount = &pps->ppscount[1]; 834 pseq = &pps->ppsinfo.clear_sequence; 835 } 836 837 /* 838 * If the timecounter changed, we cannot compare the count values, so 839 * we have to drop the rest of the PPS-stuff until the next event. 840 */ 841 if (pps->ppstc != pps->capth->th_counter) { 842 pps->ppstc = pps->capth->th_counter; 843 *pcount = pps->capcount; 844 pps->ppscount[2] = pps->capcount; 845 return; 846 } 847 848 /* Convert the count to a timespec. */ 849 tcount = pps->capcount - pps->capth->th_offset_count; 850 tcount &= pps->capth->th_counter->tc_counter_mask; 851 bt = pps->capth->th_offset; 852 bintime_addx(&bt, pps->capth->th_scale * tcount); 853 bintime_add(&bt, &boottimebin); 854 bintime2timespec(&bt, &ts); 855 856 /* If the timecounter was wound up underneath us, bail out. */ 857 if (pps->capgen != pps->capth->th_generation) 858 return; 859 860 *pcount = pps->capcount; 861 (*pseq)++; 862 *tsp = ts; 863 864 if (foff) { 865 timespecadd(tsp, osp, tsp); 866 if (tsp->tv_nsec < 0) { 867 tsp->tv_nsec += 1000000000; 868 tsp->tv_sec -= 1; 869 } 870 } 871 #ifdef PPS_SYNC 872 if (fhard) { 873 u_int64_t scale; 874 875 /* 876 * Feed the NTP PLL/FLL. 877 * The FLL wants to know how many (hardware) nanoseconds 878 * elapsed since the previous event. 879 */ 880 tcount = pps->capcount - pps->ppscount[2]; 881 pps->ppscount[2] = pps->capcount; 882 tcount &= pps->capth->th_counter->tc_counter_mask; 883 scale = (u_int64_t)1 << 63; 884 scale /= pps->capth->th_counter->tc_frequency; 885 scale *= 2; 886 bt.sec = 0; 887 bt.frac = 0; 888 bintime_addx(&bt, scale * tcount); 889 bintime2timespec(&bt, &ts); 890 hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); 891 } 892 #endif 893 } 894 895 /* 896 * Timecounters need to be updated every so often to prevent the hardware 897 * counter from overflowing. Updating also recalculates the cached values 898 * used by the get*() family of functions, so their precision depends on 899 * the update frequency. 900 */ 901 902 static int tc_tick; 903 #ifdef __FreeBSD__ 904 SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0, ""); 905 #endif /* __FreeBSD__ */ 906 907 void 908 tc_ticktock(void) 909 { 910 static int count; 911 912 if (++count < tc_tick) 913 return; 914 count = 0; 915 tc_windup(); 916 } 917 918 void 919 inittimecounter(void) 920 { 921 u_int p; 922 923 /* 924 * Set the initial timeout to 925 * max(1, <approx. number of hardclock ticks in a millisecond>). 926 * People should probably not use the sysctl to set the timeout 927 * to smaller than its inital value, since that value is the 928 * smallest reasonable one. If they want better timestamps they 929 * should use the non-"get"* functions. 930 */ 931 if (hz > 1000) 932 tc_tick = (hz + 500) / 1000; 933 else 934 tc_tick = 1; 935 p = (tc_tick * 1000000) / hz; 936 printf("timecounter: Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000); 937 938 /* warm up new timecounter (again) and get rolling. */ 939 (void)timecounter->tc_get_timecount(timecounter); 940 (void)timecounter->tc_get_timecount(timecounter); 941 } 942 943 #ifdef __FreeBSD__ 944 SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL) 945 #endif /* __FreeBSD__ */ 946 #endif /* __HAVE_TIMECOUNTER */ 947