kern_clock.c revision 48887
1/*- 2 * Copyright (c) 1997, 1998 Poul-Henning Kamp <phk@FreeBSD.org> 3 * Copyright (c) 1982, 1986, 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * (c) UNIX System Laboratories, Inc. 6 * All or some portions of this file are derived from material licensed 7 * to the University of California by American Telephone and Telegraph 8 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 9 * the permission of UNIX System Laboratories, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 40 * $Id: kern_clock.c,v 1.95 1999/07/18 01:35:26 jdp Exp $ 41 */ 42 43#include "opt_ntp.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/dkstat.h> 48#include <sys/callout.h> 49#include <sys/kernel.h> 50#include <sys/proc.h> 51#include <sys/malloc.h> 52#include <sys/resourcevar.h> 53#include <sys/signalvar.h> 54#include <sys/timex.h> 55#include <sys/timepps.h> 56#include <vm/vm.h> 57#include <sys/lock.h> 58#include <vm/pmap.h> 59#include <vm/vm_map.h> 60#include <sys/sysctl.h> 61 62#include <machine/cpu.h> 63#include <machine/limits.h> 64 65#ifdef GPROF 66#include <sys/gmon.h> 67#endif 68 69#if defined(SMP) && defined(BETTER_CLOCK) 70#include <machine/smp.h> 71#endif 72 73/* 74 * Number of timecounters used to implement stable storage 75 */ 76#ifndef NTIMECOUNTER 77#define NTIMECOUNTER 5 78#endif 79 80static MALLOC_DEFINE(M_TIMECOUNTER, "timecounter", 81 "Timecounter stable storage"); 82 83static void initclocks __P((void *dummy)); 84SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL) 85 86static void tco_forward __P((int force)); 87static void tco_setscales __P((struct timecounter *tc)); 88static __inline unsigned tco_delta __P((struct timecounter *tc)); 89 90/* Some of these don't belong here, but it's easiest to concentrate them. */ 91#if defined(SMP) && defined(BETTER_CLOCK) 92long cp_time[CPUSTATES]; 93#else 94static long cp_time[CPUSTATES]; 95#endif 96 97long tk_cancc; 98long tk_nin; 99long tk_nout; 100long tk_rawcc; 101 102time_t time_second; 103 104/* 105 * Which update policy to use. 106 * 0 - every tick, bad hardware may fail with "calcru negative..." 107 * 1 - more resistent to the above hardware, but less efficient. 108 */ 109static int tco_method; 110 111/* 112 * Implement a dummy timecounter which we can use until we get a real one 113 * in the air. This allows the console and other early stuff to use 114 * timeservices. 115 */ 116 117static unsigned 118dummy_get_timecount(struct timecounter *tc) 119{ 120 static unsigned now; 121 return (++now); 122} 123 124static struct timecounter dummy_timecounter = { 125 dummy_get_timecount, 126 0, 127 ~0u, 128 1000000, 129 "dummy" 130}; 131 132struct timecounter *timecounter = &dummy_timecounter; 133 134/* 135 * Clock handling routines. 136 * 137 * This code is written to operate with two timers that run independently of 138 * each other. 139 * 140 * The main timer, running hz times per second, is used to trigger interval 141 * timers, timeouts and rescheduling as needed. 142 * 143 * The second timer handles kernel and user profiling, 144 * and does resource use estimation. If the second timer is programmable, 145 * it is randomized to avoid aliasing between the two clocks. For example, 146 * the randomization prevents an adversary from always giving up the cpu 147 * just before its quantum expires. Otherwise, it would never accumulate 148 * cpu ticks. The mean frequency of the second timer is stathz. 149 * 150 * If no second timer exists, stathz will be zero; in this case we drive 151 * profiling and statistics off the main clock. This WILL NOT be accurate; 152 * do not do it unless absolutely necessary. 153 * 154 * The statistics clock may (or may not) be run at a higher rate while 155 * profiling. This profile clock runs at profhz. We require that profhz 156 * be an integral multiple of stathz. 157 * 158 * If the statistics clock is running fast, it must be divided by the ratio 159 * profhz/stathz for statistics. (For profiling, every tick counts.) 160 * 161 * Time-of-day is maintained using a "timecounter", which may or may 162 * not be related to the hardware generating the above mentioned 163 * interrupts. 164 */ 165 166int stathz; 167int profhz; 168static int profprocs; 169int ticks; 170static int psdiv, pscnt; /* prof => stat divider */ 171int psratio; /* ratio: prof / stat */ 172 173/* 174 * Initialize clock frequencies and start both clocks running. 175 */ 176/* ARGSUSED*/ 177static void 178initclocks(dummy) 179 void *dummy; 180{ 181 register int i; 182 183 /* 184 * Set divisors to 1 (normal case) and let the machine-specific 185 * code do its bit. 186 */ 187 psdiv = pscnt = 1; 188 cpu_initclocks(); 189 190 /* 191 * Compute profhz/stathz, and fix profhz if needed. 192 */ 193 i = stathz ? stathz : hz; 194 if (profhz == 0) 195 profhz = i; 196 psratio = profhz / i; 197} 198 199/* 200 * The real-time timer, interrupting hz times per second. 201 */ 202void 203hardclock(frame) 204 register struct clockframe *frame; 205{ 206 register struct proc *p; 207 208 p = curproc; 209 if (p) { 210 register struct pstats *pstats; 211 212 /* 213 * Run current process's virtual and profile time, as needed. 214 */ 215 pstats = p->p_stats; 216 if (CLKF_USERMODE(frame) && 217 timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) && 218 itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0) 219 psignal(p, SIGVTALRM); 220 if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value) && 221 itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0) 222 psignal(p, SIGPROF); 223 } 224 225#if defined(SMP) && defined(BETTER_CLOCK) 226 forward_hardclock(pscnt); 227#endif 228 229 /* 230 * If no separate statistics clock is available, run it from here. 231 */ 232 if (stathz == 0) 233 statclock(frame); 234 235 tco_forward(0); 236 ticks++; 237 238 /* 239 * Process callouts at a very low cpu priority, so we don't keep the 240 * relatively high clock interrupt priority any longer than necessary. 241 */ 242 if (TAILQ_FIRST(&callwheel[ticks & callwheelmask]) != NULL) { 243 if (CLKF_BASEPRI(frame)) { 244 /* 245 * Save the overhead of a software interrupt; 246 * it will happen as soon as we return, so do it now. 247 */ 248 (void)splsoftclock(); 249 softclock(); 250 } else 251 setsoftclock(); 252 } else if (softticks + 1 == ticks) 253 ++softticks; 254} 255 256/* 257 * Compute number of ticks in the specified amount of time. 258 */ 259int 260tvtohz(tv) 261 struct timeval *tv; 262{ 263 register unsigned long ticks; 264 register long sec, usec; 265 266 /* 267 * If the number of usecs in the whole seconds part of the time 268 * difference fits in a long, then the total number of usecs will 269 * fit in an unsigned long. Compute the total and convert it to 270 * ticks, rounding up and adding 1 to allow for the current tick 271 * to expire. Rounding also depends on unsigned long arithmetic 272 * to avoid overflow. 273 * 274 * Otherwise, if the number of ticks in the whole seconds part of 275 * the time difference fits in a long, then convert the parts to 276 * ticks separately and add, using similar rounding methods and 277 * overflow avoidance. This method would work in the previous 278 * case but it is slightly slower and assumes that hz is integral. 279 * 280 * Otherwise, round the time difference down to the maximum 281 * representable value. 282 * 283 * If ints have 32 bits, then the maximum value for any timeout in 284 * 10ms ticks is 248 days. 285 */ 286 sec = tv->tv_sec; 287 usec = tv->tv_usec; 288 if (usec < 0) { 289 sec--; 290 usec += 1000000; 291 } 292 if (sec < 0) { 293#ifdef DIAGNOSTIC 294 if (usec > 0) { 295 sec++; 296 usec -= 1000000; 297 } 298 printf("tvotohz: negative time difference %ld sec %ld usec\n", 299 sec, usec); 300#endif 301 ticks = 1; 302 } else if (sec <= LONG_MAX / 1000000) 303 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1)) 304 / tick + 1; 305 else if (sec <= LONG_MAX / hz) 306 ticks = sec * hz 307 + ((unsigned long)usec + (tick - 1)) / tick + 1; 308 else 309 ticks = LONG_MAX; 310 if (ticks > INT_MAX) 311 ticks = INT_MAX; 312 return ((int)ticks); 313} 314 315/* 316 * Start profiling on a process. 317 * 318 * Kernel profiling passes proc0 which never exits and hence 319 * keeps the profile clock running constantly. 320 */ 321void 322startprofclock(p) 323 register struct proc *p; 324{ 325 int s; 326 327 if ((p->p_flag & P_PROFIL) == 0) { 328 p->p_flag |= P_PROFIL; 329 if (++profprocs == 1 && stathz != 0) { 330 s = splstatclock(); 331 psdiv = pscnt = psratio; 332 setstatclockrate(profhz); 333 splx(s); 334 } 335 } 336} 337 338/* 339 * Stop profiling on a process. 340 */ 341void 342stopprofclock(p) 343 register struct proc *p; 344{ 345 int s; 346 347 if (p->p_flag & P_PROFIL) { 348 p->p_flag &= ~P_PROFIL; 349 if (--profprocs == 0 && stathz != 0) { 350 s = splstatclock(); 351 psdiv = pscnt = 1; 352 setstatclockrate(stathz); 353 splx(s); 354 } 355 } 356} 357 358/* 359 * Statistics clock. Grab profile sample, and if divider reaches 0, 360 * do process and kernel statistics. 361 */ 362void 363statclock(frame) 364 register struct clockframe *frame; 365{ 366#ifdef GPROF 367 register struct gmonparam *g; 368 int i; 369#endif 370 register struct proc *p; 371 struct pstats *pstats; 372 long rss; 373 struct rusage *ru; 374 struct vmspace *vm; 375 376 if (curproc != NULL && CLKF_USERMODE(frame)) { 377 p = curproc; 378 if (p->p_flag & P_PROFIL) 379 addupc_intr(p, CLKF_PC(frame), 1); 380#if defined(SMP) && defined(BETTER_CLOCK) 381 if (stathz != 0) 382 forward_statclock(pscnt); 383#endif 384 if (--pscnt > 0) 385 return; 386 /* 387 * Came from user mode; CPU was in user state. 388 * If this process is being profiled record the tick. 389 */ 390 p->p_uticks++; 391 if (p->p_nice > NZERO) 392 cp_time[CP_NICE]++; 393 else 394 cp_time[CP_USER]++; 395 } else { 396#ifdef GPROF 397 /* 398 * Kernel statistics are just like addupc_intr, only easier. 399 */ 400 g = &_gmonparam; 401 if (g->state == GMON_PROF_ON) { 402 i = CLKF_PC(frame) - g->lowpc; 403 if (i < g->textsize) { 404 i /= HISTFRACTION * sizeof(*g->kcount); 405 g->kcount[i]++; 406 } 407 } 408#endif 409#if defined(SMP) && defined(BETTER_CLOCK) 410 if (stathz != 0) 411 forward_statclock(pscnt); 412#endif 413 if (--pscnt > 0) 414 return; 415 /* 416 * Came from kernel mode, so we were: 417 * - handling an interrupt, 418 * - doing syscall or trap work on behalf of the current 419 * user process, or 420 * - spinning in the idle loop. 421 * Whichever it is, charge the time as appropriate. 422 * Note that we charge interrupts to the current process, 423 * regardless of whether they are ``for'' that process, 424 * so that we know how much of its real time was spent 425 * in ``non-process'' (i.e., interrupt) work. 426 */ 427 p = curproc; 428 if (CLKF_INTR(frame)) { 429 if (p != NULL) 430 p->p_iticks++; 431 cp_time[CP_INTR]++; 432 } else if (p != NULL) { 433 p->p_sticks++; 434 cp_time[CP_SYS]++; 435 } else 436 cp_time[CP_IDLE]++; 437 } 438 pscnt = psdiv; 439 440 /* 441 * We maintain statistics shown by user-level statistics 442 * programs: the amount of time in each cpu state. 443 */ 444 445 /* 446 * We adjust the priority of the current process. The priority of 447 * a process gets worse as it accumulates CPU time. The cpu usage 448 * estimator (p_estcpu) is increased here. The formula for computing 449 * priorities (in kern_synch.c) will compute a different value each 450 * time p_estcpu increases by 4. The cpu usage estimator ramps up 451 * quite quickly when the process is running (linearly), and decays 452 * away exponentially, at a rate which is proportionally slower when 453 * the system is busy. The basic principal is that the system will 454 * 90% forget that the process used a lot of CPU time in 5 * loadav 455 * seconds. This causes the system to favor processes which haven't 456 * run much recently, and to round-robin among other processes. 457 */ 458 if (p != NULL) { 459 p->p_cpticks++; 460 if (++p->p_estcpu == 0) 461 p->p_estcpu--; 462 if ((p->p_estcpu & 3) == 0) { 463 resetpriority(p); 464 if (p->p_priority >= PUSER) 465 p->p_priority = p->p_usrpri; 466 } 467 468 /* Update resource usage integrals and maximums. */ 469 if ((pstats = p->p_stats) != NULL && 470 (ru = &pstats->p_ru) != NULL && 471 (vm = p->p_vmspace) != NULL) { 472 ru->ru_ixrss += pgtok(vm->vm_tsize); 473 ru->ru_idrss += pgtok(vm->vm_dsize); 474 ru->ru_isrss += pgtok(vm->vm_ssize); 475 rss = pgtok(vmspace_resident_count(vm)); 476 if (ru->ru_maxrss < rss) 477 ru->ru_maxrss = rss; 478 } 479 } 480} 481 482/* 483 * Return information about system clocks. 484 */ 485static int 486sysctl_kern_clockrate SYSCTL_HANDLER_ARGS 487{ 488 struct clockinfo clkinfo; 489 /* 490 * Construct clockinfo structure. 491 */ 492 clkinfo.hz = hz; 493 clkinfo.tick = tick; 494 clkinfo.tickadj = tickadj; 495 clkinfo.profhz = profhz; 496 clkinfo.stathz = stathz ? stathz : hz; 497 return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req)); 498} 499 500SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD, 501 0, 0, sysctl_kern_clockrate, "S,clockinfo",""); 502 503static __inline unsigned 504tco_delta(struct timecounter *tc) 505{ 506 507 return ((tc->tc_get_timecount(tc) - tc->tc_offset_count) & 508 tc->tc_counter_mask); 509} 510 511/* 512 * We have eight functions for looking at the clock, four for 513 * microseconds and four for nanoseconds. For each there is fast 514 * but less precise version "get{nano|micro}[up]time" which will 515 * return a time which is up to 1/HZ previous to the call, whereas 516 * the raw version "{nano|micro}[up]time" will return a timestamp 517 * which is as precise as possible. The "up" variants return the 518 * time relative to system boot, these are well suited for time 519 * interval measurements. 520 */ 521 522void 523getmicrotime(struct timeval *tvp) 524{ 525 struct timecounter *tc; 526 527 if (!tco_method) { 528 tc = timecounter; 529 *tvp = tc->tc_microtime; 530 } else { 531 microtime(tvp); 532 } 533} 534 535void 536getnanotime(struct timespec *tsp) 537{ 538 struct timecounter *tc; 539 540 if (!tco_method) { 541 tc = timecounter; 542 *tsp = tc->tc_nanotime; 543 } else { 544 nanotime(tsp); 545 } 546} 547 548void 549microtime(struct timeval *tv) 550{ 551 struct timecounter *tc; 552 553 tc = timecounter; 554 tv->tv_sec = tc->tc_offset_sec; 555 tv->tv_usec = tc->tc_offset_micro; 556 tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32; 557 tv->tv_usec += boottime.tv_usec; 558 tv->tv_sec += boottime.tv_sec; 559 while (tv->tv_usec >= 1000000) { 560 tv->tv_usec -= 1000000; 561 tv->tv_sec++; 562 } 563} 564 565void 566nanotime(struct timespec *ts) 567{ 568 unsigned count; 569 u_int64_t delta; 570 struct timecounter *tc; 571 572 tc = timecounter; 573 ts->tv_sec = tc->tc_offset_sec; 574 count = tco_delta(tc); 575 delta = tc->tc_offset_nano; 576 delta += ((u_int64_t)count * tc->tc_scale_nano_f); 577 delta >>= 32; 578 delta += ((u_int64_t)count * tc->tc_scale_nano_i); 579 delta += boottime.tv_usec * 1000; 580 ts->tv_sec += boottime.tv_sec; 581 while (delta >= 1000000000) { 582 delta -= 1000000000; 583 ts->tv_sec++; 584 } 585 ts->tv_nsec = delta; 586} 587 588void 589getmicrouptime(struct timeval *tvp) 590{ 591 struct timecounter *tc; 592 593 if (!tco_method) { 594 tc = timecounter; 595 tvp->tv_sec = tc->tc_offset_sec; 596 tvp->tv_usec = tc->tc_offset_micro; 597 } else { 598 microuptime(tvp); 599 } 600} 601 602void 603getnanouptime(struct timespec *tsp) 604{ 605 struct timecounter *tc; 606 607 if (!tco_method) { 608 tc = timecounter; 609 tsp->tv_sec = tc->tc_offset_sec; 610 tsp->tv_nsec = tc->tc_offset_nano >> 32; 611 } else { 612 nanouptime(tsp); 613 } 614} 615 616void 617microuptime(struct timeval *tv) 618{ 619 struct timecounter *tc; 620 621 tc = timecounter; 622 tv->tv_sec = tc->tc_offset_sec; 623 tv->tv_usec = tc->tc_offset_micro; 624 tv->tv_usec += ((u_int64_t)tco_delta(tc) * tc->tc_scale_micro) >> 32; 625 if (tv->tv_usec >= 1000000) { 626 tv->tv_usec -= 1000000; 627 tv->tv_sec++; 628 } 629} 630 631void 632nanouptime(struct timespec *ts) 633{ 634 unsigned count; 635 u_int64_t delta; 636 struct timecounter *tc; 637 638 tc = timecounter; 639 ts->tv_sec = tc->tc_offset_sec; 640 count = tco_delta(tc); 641 delta = tc->tc_offset_nano; 642 delta += ((u_int64_t)count * tc->tc_scale_nano_f); 643 delta >>= 32; 644 delta += ((u_int64_t)count * tc->tc_scale_nano_i); 645 if (delta >= 1000000000) { 646 delta -= 1000000000; 647 ts->tv_sec++; 648 } 649 ts->tv_nsec = delta; 650} 651 652static void 653tco_setscales(struct timecounter *tc) 654{ 655 u_int64_t scale; 656 657 scale = 1000000000LL << 32; 658 scale += tc->tc_adjustment; 659 scale /= tc->tc_tweak->tc_frequency; 660 tc->tc_scale_micro = scale / 1000; 661 tc->tc_scale_nano_f = scale & 0xffffffff; 662 tc->tc_scale_nano_i = scale >> 32; 663} 664 665void 666update_timecounter(struct timecounter *tc) 667{ 668 tco_setscales(tc); 669} 670 671void 672init_timecounter(struct timecounter *tc) 673{ 674 struct timespec ts1; 675 struct timecounter *t1, *t2, *t3; 676 int i; 677 678 tc->tc_adjustment = 0; 679 tc->tc_tweak = tc; 680 tco_setscales(tc); 681 tc->tc_offset_count = tc->tc_get_timecount(tc); 682 if (timecounter == &dummy_timecounter) 683 tc->tc_avail = tc; 684 else { 685 tc->tc_avail = timecounter->tc_tweak->tc_avail; 686 timecounter->tc_tweak->tc_avail = tc; 687 } 688 MALLOC(t1, struct timecounter *, sizeof *t1, M_TIMECOUNTER, M_WAITOK); 689 tc->tc_other = t1; 690 *t1 = *tc; 691 t2 = t1; 692 for (i = 1; i < NTIMECOUNTER; i++) { 693 MALLOC(t3, struct timecounter *, sizeof *t3, 694 M_TIMECOUNTER, M_WAITOK); 695 *t3 = *tc; 696 t3->tc_other = t2; 697 t2 = t3; 698 } 699 t1->tc_other = t3; 700 tc = t1; 701 702 printf("Timecounter \"%s\" frequency %lu Hz\n", 703 tc->tc_name, (u_long)tc->tc_frequency); 704 705 /* XXX: For now always start using the counter. */ 706 tc->tc_offset_count = tc->tc_get_timecount(tc); 707 nanouptime(&ts1); 708 tc->tc_offset_nano = (u_int64_t)ts1.tv_nsec << 32; 709 tc->tc_offset_micro = ts1.tv_nsec / 1000; 710 tc->tc_offset_sec = ts1.tv_sec; 711 timecounter = tc; 712} 713 714void 715set_timecounter(struct timespec *ts) 716{ 717 struct timespec ts2; 718 719 nanouptime(&ts2); 720 boottime.tv_sec = ts->tv_sec - ts2.tv_sec; 721 boottime.tv_usec = (ts->tv_nsec - ts2.tv_nsec) / 1000; 722 if (boottime.tv_usec < 0) { 723 boottime.tv_usec += 1000000; 724 boottime.tv_sec--; 725 } 726 /* fiddle all the little crinkly bits around the fiords... */ 727 tco_forward(1); 728} 729 730static void 731switch_timecounter(struct timecounter *newtc) 732{ 733 int s; 734 struct timecounter *tc; 735 struct timespec ts; 736 737 s = splclock(); 738 tc = timecounter; 739 if (newtc->tc_tweak == tc->tc_tweak) { 740 splx(s); 741 return; 742 } 743 newtc = newtc->tc_tweak->tc_other; 744 nanouptime(&ts); 745 newtc->tc_offset_sec = ts.tv_sec; 746 newtc->tc_offset_nano = (u_int64_t)ts.tv_nsec << 32; 747 newtc->tc_offset_micro = ts.tv_nsec / 1000; 748 newtc->tc_offset_count = newtc->tc_get_timecount(newtc); 749 tco_setscales(newtc); 750 timecounter = newtc; 751 splx(s); 752} 753 754static struct timecounter * 755sync_other_counter(void) 756{ 757 struct timecounter *tc, *tcn, *tco; 758 unsigned delta; 759 760 tco = timecounter; 761 tc = tco->tc_other; 762 tcn = tc->tc_other; 763 *tc = *tco; 764 tc->tc_other = tcn; 765 delta = tco_delta(tc); 766 tc->tc_offset_count += delta; 767 tc->tc_offset_count &= tc->tc_counter_mask; 768 tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_f; 769 tc->tc_offset_nano += (u_int64_t)delta * tc->tc_scale_nano_i << 32; 770 return (tc); 771} 772 773static void 774tco_forward(int force) 775{ 776 struct timecounter *tc, *tco; 777 778 tco = timecounter; 779 tc = sync_other_counter(); 780 /* 781 * We may be inducing a tiny error here, the tc_poll_pps() may 782 * process a latched count which happens after the tco_delta() 783 * in sync_other_counter(), which would extend the previous 784 * counters parameters into the domain of this new one. 785 * Since the timewindow is very small for this, the error is 786 * going to be only a few weenieseconds (as Dave Mills would 787 * say), so lets just not talk more about it, OK ? 788 */ 789 if (tco->tc_poll_pps) 790 tco->tc_poll_pps(tco); 791 if (timedelta != 0) { 792 tc->tc_offset_nano += (u_int64_t)(tickdelta * 1000) << 32; 793 timedelta -= tickdelta; 794 force++; 795 } 796 797 while (tc->tc_offset_nano >= 1000000000ULL << 32) { 798 tc->tc_offset_nano -= 1000000000ULL << 32; 799 tc->tc_offset_sec++; 800 ntp_update_second(tc); /* XXX only needed if xntpd runs */ 801 tco_setscales(tc); 802 force++; 803 } 804 805 if (tco_method && !force) 806 return; 807 808 tc->tc_offset_micro = (tc->tc_offset_nano / 1000) >> 32; 809 810 /* Figure out the wall-clock time */ 811 tc->tc_nanotime.tv_sec = tc->tc_offset_sec + boottime.tv_sec; 812 tc->tc_nanotime.tv_nsec = 813 (tc->tc_offset_nano >> 32) + boottime.tv_usec * 1000; 814 tc->tc_microtime.tv_usec = tc->tc_offset_micro + boottime.tv_usec; 815 if (tc->tc_nanotime.tv_nsec >= 1000000000) { 816 tc->tc_nanotime.tv_nsec -= 1000000000; 817 tc->tc_microtime.tv_usec -= 1000000; 818 tc->tc_nanotime.tv_sec++; 819 } 820 time_second = tc->tc_microtime.tv_sec = tc->tc_nanotime.tv_sec; 821 822 timecounter = tc; 823} 824 825SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, ""); 826 827SYSCTL_INT(_kern_timecounter, OID_AUTO, method, CTLFLAG_RW, &tco_method, 0, 828 "This variable determines the method used for updating timecounters. " 829 "If the default algorithm (0) fails with \"calcru negative...\" messages " 830 "try the alternate algorithm (1) which handles bad hardware better." 831 832); 833 834static int 835sysctl_kern_timecounter_hardware SYSCTL_HANDLER_ARGS 836{ 837 char newname[32]; 838 struct timecounter *newtc, *tc; 839 int error; 840 841 tc = timecounter->tc_tweak; 842 strncpy(newname, tc->tc_name, sizeof(newname)); 843 error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); 844 if (error == 0 && req->newptr != NULL && 845 strcmp(newname, tc->tc_name) != 0) { 846 for (newtc = tc->tc_avail; newtc != tc; newtc = tc->tc_avail) { 847 if (strcmp(newname, newtc->tc_name) == 0) { 848 /* Warm up new timecounter. */ 849 (void)newtc->tc_get_timecount(newtc); 850 851 switch_timecounter(newtc); 852 return (0); 853 } 854 } 855 return (EINVAL); 856 } 857 return (error); 858} 859 860SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, 861 0, 0, sysctl_kern_timecounter_hardware, "A", ""); 862 863 864int 865pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps) 866{ 867 pps_params_t *app; 868 pps_info_t *api; 869 870 switch (cmd) { 871 case PPS_IOC_CREATE: 872 return (0); 873 case PPS_IOC_DESTROY: 874 return (0); 875 case PPS_IOC_SETPARAMS: 876 app = (pps_params_t *)data; 877 if (app->mode & ~pps->ppscap) 878 return (EINVAL); 879 pps->ppsparam = *app; 880 return (0); 881 case PPS_IOC_GETPARAMS: 882 app = (pps_params_t *)data; 883 *app = pps->ppsparam; 884 return (0); 885 case PPS_IOC_GETCAP: 886 *(int*)data = pps->ppscap; 887 return (0); 888 case PPS_IOC_FETCH: 889 api = (pps_info_t *)data; 890 pps->ppsinfo.current_mode = pps->ppsparam.mode; 891 *api = pps->ppsinfo; 892 return (0); 893 case PPS_IOC_WAIT: 894 return (EOPNOTSUPP); 895 default: 896 return (ENOTTY); 897 } 898} 899 900void 901pps_init(struct pps_state *pps) 902{ 903 pps->ppscap |= PPS_TSFMT_TSPEC; 904 if (pps->ppscap & PPS_CAPTUREASSERT) 905 pps->ppscap |= PPS_OFFSETASSERT; 906 if (pps->ppscap & PPS_CAPTURECLEAR) 907 pps->ppscap |= PPS_OFFSETCLEAR; 908#ifdef PPS_SYNC 909 if (pps->ppscap & PPS_CAPTUREASSERT) 910 pps->ppscap |= PPS_HARDPPSONASSERT; 911 if (pps->ppscap & PPS_CAPTURECLEAR) 912 pps->ppscap |= PPS_HARDPPSONCLEAR; 913#endif 914} 915 916void 917pps_event(struct pps_state *pps, struct timecounter *tc, unsigned count, int event) 918{ 919 struct timespec ts, *tsp, *osp; 920 u_int64_t delta; 921 unsigned tcount, *pcount; 922 int foff, fhard; 923 pps_seq_t *pseq; 924 925 /* Things would be easier with arrays... */ 926 if (event == PPS_CAPTUREASSERT) { 927 tsp = &pps->ppsinfo.assert_timestamp; 928 osp = &pps->ppsparam.assert_offset; 929 foff = pps->ppsparam.mode & PPS_OFFSETASSERT; 930 fhard = pps->ppsparam.mode & PPS_HARDPPSONASSERT; 931 pcount = &pps->ppscount[0]; 932 pseq = &pps->ppsinfo.assert_sequence; 933 } else { 934 tsp = &pps->ppsinfo.clear_timestamp; 935 osp = &pps->ppsparam.clear_offset; 936 foff = pps->ppsparam.mode & PPS_OFFSETCLEAR; 937 fhard = pps->ppsparam.mode & PPS_HARDPPSONCLEAR; 938 pcount = &pps->ppscount[1]; 939 pseq = &pps->ppsinfo.clear_sequence; 940 } 941 942 /* The timecounter changed: bail */ 943 if (!pps->ppstc || 944 pps->ppstc->tc_name != tc->tc_name || 945 tc->tc_name != timecounter->tc_name) { 946 pps->ppstc = tc; 947 *pcount = count; 948 return; 949 } 950 951 /* Nothing really happened */ 952 if (*pcount == count) 953 return; 954 955 *pcount = count; 956 957 /* Convert the count to timespec */ 958 ts.tv_sec = tc->tc_offset_sec; 959 tcount = count - tc->tc_offset_count; 960 tcount &= tc->tc_counter_mask; 961 delta = tc->tc_offset_nano; 962 delta += ((u_int64_t)tcount * tc->tc_scale_nano_f); 963 delta >>= 32; 964 delta += ((u_int64_t)tcount * tc->tc_scale_nano_i); 965 delta += boottime.tv_usec * 1000; 966 ts.tv_sec += boottime.tv_sec; 967 while (delta >= 1000000000) { 968 delta -= 1000000000; 969 ts.tv_sec++; 970 } 971 ts.tv_nsec = delta; 972 973 (*pseq)++; 974 *tsp = ts; 975 976 if (foff) { 977 timespecadd(tsp, osp); 978 if (tsp->tv_nsec < 0) { 979 tsp->tv_nsec += 1000000000; 980 tsp->tv_sec -= 1; 981 } 982 } 983#ifdef PPS_SYNC 984 if (fhard) { 985 /* magic, at its best... */ 986 tcount = count - pps->ppscount[2]; 987 pps->ppscount[2] = count; 988 tcount &= tc->tc_counter_mask; 989 delta = ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_f); 990 delta >>= 32; 991 delta += ((u_int64_t)tcount * tc->tc_tweak->tc_scale_nano_i); 992 hardpps(tsp, delta); 993 } 994#endif 995} 996 997