65#include <sys/sysctl.h> 66#include <sys/cons.h> 67 68#include <machine/clock.h> 69#ifdef CLK_CALIBRATION_LOOP 70#endif 71#include <machine/cputypes.h> 72#include <machine/frame.h> 73#include <machine/limits.h> 74#include <machine/md_var.h> 75#include <machine/psl.h> 76#ifdef APIC_IO 77#include <machine/segments.h> 78#endif 79#if defined(SMP) || defined(APIC_IO) 80#include <machine/smp.h> 81#endif /* SMP || APIC_IO */ 82#include <machine/specialreg.h> 83 84#include <i386/isa/icu.h> 85#include <i386/isa/isa.h> 86#include <isa/rtc.h> 87#include <isa/isavar.h> 88#include <i386/isa/timerreg.h> 89 90#include <i386/isa/intr_machdep.h> 91 92#ifdef DEV_MCA 93#include <i386/isa/mca_machdep.h> 94#endif 95 96#ifdef APIC_IO 97#include <i386/isa/intr_machdep.h> 98/* The interrupt triggered by the 8254 (timer) chip */ 99int apic_8254_intr; 100static u_long read_intr_count __P((int vec)); 101static void setup_8254_mixed_mode __P((void)); 102#endif 103 104/* 105 * 32-bit time_t's can't reach leap years before 1904 or after 2036, so we 106 * can use a simple formula for leap years. 107 */ 108#define LEAPYEAR(y) ((u_int)(y) % 4 == 0) 109#define DAYSPERYEAR (31+28+31+30+31+30+31+31+30+31+30+31) 110 111#define TIMER_DIV(x) ((timer_freq + (x) / 2) / (x)) 112 113/* 114 * Time in timer cycles that it takes for microtime() to disable interrupts 115 * and latch the count. microtime() currently uses "cli; outb ..." so it 116 * normally takes less than 2 timer cycles. Add a few for cache misses. 117 * Add a few more to allow for latency in bogus calls to microtime() with 118 * interrupts already disabled. 119 */ 120#define TIMER0_LATCH_COUNT 20 121 122/* 123 * Maximum frequency that we are willing to allow for timer0. Must be 124 * low enough to guarantee that the timer interrupt handler returns 125 * before the next timer interrupt. 126 */ 127#define TIMER0_MAX_FREQ 20000 128 129int adjkerntz; /* local offset from GMT in seconds */ 130int clkintr_pending; 131int disable_rtc_set; /* disable resettodr() if != 0 */ 132int statclock_disable; 133#ifndef TIMER_FREQ 134#define TIMER_FREQ 1193182 135#endif 136u_int timer_freq = TIMER_FREQ; 137int timer0_max_count; 138u_int tsc_freq; 139int tsc_is_broken; 140u_int tsc_present; 141int wall_cmos_clock; /* wall CMOS clock assumed if != 0 */ 142struct mtx clock_lock; 143 144static int beeping = 0; 145static const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31}; 146static u_int hardclock_max_count; 147static u_int32_t i8254_lastcount; 148static u_int32_t i8254_offset; 149static int i8254_ticked; 150/* 151 * XXX new_function and timer_func should not handle clockframes, but 152 * timer_func currently needs to hold hardclock to handle the 153 * timer0_state == 0 case. We should use inthand_add()/inthand_remove() 154 * to switch between clkintr() and a slightly different timerintr(). 155 */ 156static void (*new_function) __P((struct clockframe *frame)); 157static u_int new_rate; 158static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF; 159static u_char rtc_statusb = RTCSB_24HR | RTCSB_PINTR; 160static u_int timer0_prescaler_count; 161 162/* Values for timerX_state: */ 163#define RELEASED 0 164#define RELEASE_PENDING 1 165#define ACQUIRED 2 166#define ACQUIRE_PENDING 3 167 168static u_char timer0_state; 169static u_char timer2_state; 170static void (*timer_func) __P((struct clockframe *frame)) = hardclock; 171 172static unsigned i8254_get_timecount __P((struct timecounter *tc)); 173static unsigned tsc_get_timecount __P((struct timecounter *tc)); 174static void set_timer_freq(u_int freq, int intr_freq); 175 176static struct timecounter tsc_timecounter = { 177 tsc_get_timecount, /* get_timecount */ 178 0, /* no poll_pps */ 179 ~0u, /* counter_mask */ 180 0, /* frequency */ 181 "TSC" /* name */ 182}; 183 184SYSCTL_OPAQUE(_debug, OID_AUTO, tsc_timecounter, CTLFLAG_RD, 185 &tsc_timecounter, sizeof(tsc_timecounter), "S,timecounter", ""); 186 187static struct timecounter i8254_timecounter = { 188 i8254_get_timecount, /* get_timecount */ 189 0, /* no poll_pps */ 190 ~0u, /* counter_mask */ 191 0, /* frequency */ 192 "i8254" /* name */ 193}; 194 195SYSCTL_OPAQUE(_debug, OID_AUTO, i8254_timecounter, CTLFLAG_RD, 196 &i8254_timecounter, sizeof(i8254_timecounter), "S,timecounter", ""); 197 198static void 199clkintr(struct clockframe frame) 200{ 201 202 if (timecounter->tc_get_timecount == i8254_get_timecount) { 203 mtx_lock_spin(&clock_lock); 204 if (i8254_ticked) 205 i8254_ticked = 0; 206 else { 207 i8254_offset += timer0_max_count; 208 i8254_lastcount = 0; 209 } 210 clkintr_pending = 0; 211 mtx_unlock_spin(&clock_lock); 212 } 213 timer_func(&frame); 214 switch (timer0_state) { 215 216 case RELEASED: 217 break; 218 219 case ACQUIRED: 220 if ((timer0_prescaler_count += timer0_max_count) 221 >= hardclock_max_count) { 222 timer0_prescaler_count -= hardclock_max_count; 223 hardclock(&frame); 224 } 225 break; 226 227 case ACQUIRE_PENDING: 228 mtx_lock_spin(&clock_lock); 229 i8254_offset = i8254_get_timecount(NULL); 230 i8254_lastcount = 0; 231 timer0_max_count = TIMER_DIV(new_rate); 232 outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT); 233 outb(TIMER_CNTR0, timer0_max_count & 0xff); 234 outb(TIMER_CNTR0, timer0_max_count >> 8); 235 mtx_unlock_spin(&clock_lock); 236 timer_func = new_function; 237 timer0_state = ACQUIRED; 238 break; 239 240 case RELEASE_PENDING: 241 if ((timer0_prescaler_count += timer0_max_count) 242 >= hardclock_max_count) { 243 mtx_lock_spin(&clock_lock); 244 i8254_offset = i8254_get_timecount(NULL); 245 i8254_lastcount = 0; 246 timer0_max_count = hardclock_max_count; 247 outb(TIMER_MODE, 248 TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT); 249 outb(TIMER_CNTR0, timer0_max_count & 0xff); 250 outb(TIMER_CNTR0, timer0_max_count >> 8); 251 mtx_unlock_spin(&clock_lock); 252 timer0_prescaler_count = 0; 253 timer_func = hardclock; 254 timer0_state = RELEASED; 255 hardclock(&frame); 256 } 257 break; 258 } 259#ifdef DEV_MCA 260 /* Reset clock interrupt by asserting bit 7 of port 0x61 */ 261 if (MCA_system) 262 outb(0x61, inb(0x61) | 0x80); 263#endif 264} 265 266/* 267 * The acquire and release functions must be called at ipl >= splclock(). 268 */ 269int 270acquire_timer0(int rate, void (*function) __P((struct clockframe *frame))) 271{ 272 static int old_rate; 273 274 if (rate <= 0 || rate > TIMER0_MAX_FREQ) 275 return (-1); 276 switch (timer0_state) { 277 278 case RELEASED: 279 timer0_state = ACQUIRE_PENDING; 280 break; 281 282 case RELEASE_PENDING: 283 if (rate != old_rate) 284 return (-1); 285 /* 286 * The timer has been released recently, but is being 287 * re-acquired before the release completed. In this 288 * case, we simply reclaim it as if it had not been 289 * released at all. 290 */ 291 timer0_state = ACQUIRED; 292 break; 293 294 default: 295 return (-1); /* busy */ 296 } 297 new_function = function; 298 old_rate = new_rate = rate; 299 return (0); 300} 301 302int 303acquire_timer2(int mode) 304{ 305 306 if (timer2_state != RELEASED) 307 return (-1); 308 timer2_state = ACQUIRED; 309 310 /* 311 * This access to the timer registers is as atomic as possible 312 * because it is a single instruction. We could do better if we 313 * knew the rate. Use of splclock() limits glitches to 10-100us, 314 * and this is probably good enough for timer2, so we aren't as 315 * careful with it as with timer0. 316 */ 317 outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f)); 318 319 return (0); 320} 321 322int 323release_timer0() 324{ 325 switch (timer0_state) { 326 327 case ACQUIRED: 328 timer0_state = RELEASE_PENDING; 329 break; 330 331 case ACQUIRE_PENDING: 332 /* Nothing happened yet, release quickly. */ 333 timer0_state = RELEASED; 334 break; 335 336 default: 337 return (-1); 338 } 339 return (0); 340} 341 342int 343release_timer2() 344{ 345 346 if (timer2_state != ACQUIRED) 347 return (-1); 348 timer2_state = RELEASED; 349 outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT); 350 return (0); 351} 352 353/* 354 * This routine receives statistical clock interrupts from the RTC. 355 * As explained above, these occur at 128 interrupts per second. 356 * When profiling, we receive interrupts at a rate of 1024 Hz. 357 * 358 * This does not actually add as much overhead as it sounds, because 359 * when the statistical clock is active, the hardclock driver no longer 360 * needs to keep (inaccurate) statistics on its own. This decouples 361 * statistics gathering from scheduling interrupts. 362 * 363 * The RTC chip requires that we read status register C (RTC_INTR) 364 * to acknowledge an interrupt, before it will generate the next one. 365 * Under high interrupt load, rtcintr() can be indefinitely delayed and 366 * the clock can tick immediately after the read from RTC_INTR. In this 367 * case, the mc146818A interrupt signal will not drop for long enough 368 * to register with the 8259 PIC. If an interrupt is missed, the stat 369 * clock will halt, considerably degrading system performance. This is 370 * why we use 'while' rather than a more straightforward 'if' below. 371 * Stat clock ticks can still be lost, causing minor loss of accuracy 372 * in the statistics, but the stat clock will no longer stop. 373 */ 374static void 375rtcintr(struct clockframe frame) 376{ 377 while (rtcin(RTC_INTR) & RTCIR_PERIOD) 378 statclock(&frame); 379} 380 381#include "opt_ddb.h" 382#ifdef DDB 383#include <ddb/ddb.h> 384 385DB_SHOW_COMMAND(rtc, rtc) 386{ 387 printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n", 388 rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY), 389 rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC), 390 rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR)); 391} 392#endif /* DDB */ 393 394static int 395getit(void) 396{ 397 int high, low; 398 399 mtx_lock_spin(&clock_lock); 400 401 /* Select timer0 and latch counter value. */ 402 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); 403 404 low = inb(TIMER_CNTR0); 405 high = inb(TIMER_CNTR0); 406 407 mtx_unlock_spin(&clock_lock); 408 return ((high << 8) | low); 409} 410 411/* 412 * Wait "n" microseconds. 413 * Relies on timer 1 counting down from (timer_freq / hz) 414 * Note: timer had better have been programmed before this is first used! 415 */ 416void 417DELAY(int n) 418{ 419 int delta, prev_tick, tick, ticks_left; 420 421#ifdef DELAYDEBUG 422 int getit_calls = 1; 423 int n1; 424 static int state = 0; 425 426 if (state == 0) { 427 state = 1; 428 for (n1 = 1; n1 <= 10000000; n1 *= 10) 429 DELAY(n1); 430 state = 2; 431 } 432 if (state == 1) 433 printf("DELAY(%d)...", n); 434#endif 435 /* 436 * Guard against the timer being uninitialized if we are called 437 * early for console i/o. 438 */ 439 if (timer0_max_count == 0) 440 set_timer_freq(timer_freq, hz); 441 442 /* 443 * Read the counter first, so that the rest of the setup overhead is 444 * counted. Guess the initial overhead is 20 usec (on most systems it 445 * takes about 1.5 usec for each of the i/o's in getit(). The loop 446 * takes about 6 usec on a 486/33 and 13 usec on a 386/20. The 447 * multiplications and divisions to scale the count take a while). 448 */ 449 prev_tick = getit(); 450 n -= 0; /* XXX actually guess no initial overhead */ 451 /* 452 * Calculate (n * (timer_freq / 1e6)) without using floating point 453 * and without any avoidable overflows. 454 */ 455 if (n <= 0) 456 ticks_left = 0; 457 else if (n < 256) 458 /* 459 * Use fixed point to avoid a slow division by 1000000. 460 * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest. 461 * 2^15 is the first power of 2 that gives exact results 462 * for n between 0 and 256. 463 */ 464 ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15; 465 else 466 /* 467 * Don't bother using fixed point, although gcc-2.7.2 468 * generates particularly poor code for the long long 469 * division, since even the slow way will complete long 470 * before the delay is up (unless we're interrupted). 471 */ 472 ticks_left = ((u_int)n * (long long)timer_freq + 999999) 473 / 1000000; 474 475 while (ticks_left > 0) { 476 tick = getit(); 477#ifdef DELAYDEBUG 478 ++getit_calls; 479#endif 480 delta = prev_tick - tick; 481 prev_tick = tick; 482 if (delta < 0) { 483 delta += timer0_max_count; 484 /* 485 * Guard against timer0_max_count being wrong. 486 * This shouldn't happen in normal operation, 487 * but it may happen if set_timer_freq() is 488 * traced. 489 */ 490 if (delta < 0) 491 delta = 0; 492 } 493 ticks_left -= delta; 494 } 495#ifdef DELAYDEBUG 496 if (state == 1) 497 printf(" %d calls to getit() at %d usec each\n", 498 getit_calls, (n + 5) / getit_calls); 499#endif 500} 501 502static void 503sysbeepstop(void *chan) 504{ 505 outb(IO_PPI, inb(IO_PPI)&0xFC); /* disable counter2 output to speaker */ 506 release_timer2(); 507 beeping = 0; 508} 509 510int 511sysbeep(int pitch, int period) 512{ 513 int x = splclock(); 514 515 if (acquire_timer2(TIMER_SQWAVE|TIMER_16BIT)) 516 if (!beeping) { 517 /* Something else owns it. */ 518 splx(x); 519 return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */ 520 } 521 mtx_lock_spin(&clock_lock); 522 outb(TIMER_CNTR2, pitch); 523 outb(TIMER_CNTR2, (pitch>>8)); 524 mtx_unlock_spin(&clock_lock); 525 if (!beeping) { 526 /* enable counter2 output to speaker */ 527 outb(IO_PPI, inb(IO_PPI) | 3); 528 beeping = period; 529 timeout(sysbeepstop, (void *)NULL, period); 530 } 531 splx(x); 532 return (0); 533} 534 535/* 536 * RTC support routines 537 */ 538 539int 540rtcin(reg) 541 int reg; 542{ 543 int s; 544 u_char val; 545 546 s = splhigh(); 547 outb(IO_RTC, reg); 548 inb(0x84); 549 val = inb(IO_RTC + 1); 550 inb(0x84); 551 splx(s); 552 return (val); 553} 554 555static __inline void 556writertc(u_char reg, u_char val) 557{ 558 int s; 559 560 s = splhigh(); 561 inb(0x84); 562 outb(IO_RTC, reg); 563 inb(0x84); 564 outb(IO_RTC + 1, val); 565 inb(0x84); /* XXX work around wrong order in rtcin() */ 566 splx(s); 567} 568 569static __inline int 570readrtc(int port) 571{ 572 return(bcd2bin(rtcin(port))); 573} 574 575static u_int 576calibrate_clocks(void) 577{ 578 u_int64_t old_tsc; 579 u_int count, prev_count, tot_count; 580 int sec, start_sec, timeout; 581 582 if (bootverbose) 583 printf("Calibrating clock(s) ... "); 584 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) 585 goto fail; 586 timeout = 100000000; 587 588 /* Read the mc146818A seconds counter. */ 589 for (;;) { 590 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) { 591 sec = rtcin(RTC_SEC); 592 break; 593 } 594 if (--timeout == 0) 595 goto fail; 596 } 597 598 /* Wait for the mC146818A seconds counter to change. */ 599 start_sec = sec; 600 for (;;) { 601 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) { 602 sec = rtcin(RTC_SEC); 603 if (sec != start_sec) 604 break; 605 } 606 if (--timeout == 0) 607 goto fail; 608 } 609 610 /* Start keeping track of the i8254 counter. */ 611 prev_count = getit(); 612 if (prev_count == 0 || prev_count > timer0_max_count) 613 goto fail; 614 tot_count = 0; 615 616 if (tsc_present) 617 old_tsc = rdtsc(); 618 else 619 old_tsc = 0; /* shut up gcc */ 620 621 /* 622 * Wait for the mc146818A seconds counter to change. Read the i8254 623 * counter for each iteration since this is convenient and only 624 * costs a few usec of inaccuracy. The timing of the final reads 625 * of the counters almost matches the timing of the initial reads, 626 * so the main cause of inaccuracy is the varying latency from 627 * inside getit() or rtcin(RTC_STATUSA) to the beginning of the 628 * rtcin(RTC_SEC) that returns a changed seconds count. The 629 * maximum inaccuracy from this cause is < 10 usec on 486's. 630 */ 631 start_sec = sec; 632 for (;;) { 633 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) 634 sec = rtcin(RTC_SEC); 635 count = getit(); 636 if (count == 0 || count > timer0_max_count) 637 goto fail; 638 if (count > prev_count) 639 tot_count += prev_count - (count - timer0_max_count); 640 else 641 tot_count += prev_count - count; 642 prev_count = count; 643 if (sec != start_sec) 644 break; 645 if (--timeout == 0) 646 goto fail; 647 } 648 649 /* 650 * Read the cpu cycle counter. The timing considerations are 651 * similar to those for the i8254 clock. 652 */ 653 if (tsc_present) 654 tsc_freq = rdtsc() - old_tsc; 655 656 if (bootverbose) { 657 if (tsc_present) 658 printf("TSC clock: %u Hz, ", tsc_freq); 659 printf("i8254 clock: %u Hz\n", tot_count); 660 } 661 return (tot_count); 662 663fail: 664 if (bootverbose) 665 printf("failed, using default i8254 clock of %u Hz\n", 666 timer_freq); 667 return (timer_freq); 668} 669 670static void 671set_timer_freq(u_int freq, int intr_freq) 672{ 673 int new_timer0_max_count; 674 675 mtx_lock_spin(&clock_lock); 676 timer_freq = freq; 677 new_timer0_max_count = hardclock_max_count = TIMER_DIV(intr_freq); 678 if (new_timer0_max_count != timer0_max_count) { 679 timer0_max_count = new_timer0_max_count; 680 outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT); 681 outb(TIMER_CNTR0, timer0_max_count & 0xff); 682 outb(TIMER_CNTR0, timer0_max_count >> 8); 683 } 684 mtx_unlock_spin(&clock_lock); 685} 686 687/* 688 * i8254_restore is called from apm_default_resume() to reload 689 * the countdown register. 690 * this should not be necessary but there are broken laptops that 691 * do not restore the countdown register on resume. 692 * when it happnes, it messes up the hardclock interval and system clock, 693 * which leads to the infamous "calcru: negative time" problem. 694 */ 695void 696i8254_restore(void) 697{ 698 699 mtx_lock_spin(&clock_lock); 700 outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT); 701 outb(TIMER_CNTR0, timer0_max_count & 0xff); 702 outb(TIMER_CNTR0, timer0_max_count >> 8); 703 mtx_unlock_spin(&clock_lock); 704} 705 706/* 707 * Initialize 8254 timer 0 early so that it can be used in DELAY(). 708 * XXX initialization of other timers is unintentionally left blank. 709 */ 710void 711startrtclock() 712{ 713 u_int delta, freq; 714 715 if (cpu_feature & CPUID_TSC) 716 tsc_present = 1; 717 else 718 tsc_present = 0; 719 720 writertc(RTC_STATUSA, rtc_statusa); 721 writertc(RTC_STATUSB, RTCSB_24HR); 722 723 set_timer_freq(timer_freq, hz); 724 freq = calibrate_clocks(); 725#ifdef CLK_CALIBRATION_LOOP 726 if (bootverbose) { 727 printf( 728 "Press a key on the console to abort clock calibration\n"); 729 while (cncheckc() == -1) 730 calibrate_clocks(); 731 } 732#endif 733 734 /* 735 * Use the calibrated i8254 frequency if it seems reasonable. 736 * Otherwise use the default, and don't use the calibrated i586 737 * frequency. 738 */ 739 delta = freq > timer_freq ? freq - timer_freq : timer_freq - freq; 740 if (delta < timer_freq / 100) { 741#ifndef CLK_USE_I8254_CALIBRATION 742 if (bootverbose) 743 printf( 744"CLK_USE_I8254_CALIBRATION not specified - using default frequency\n"); 745 freq = timer_freq; 746#endif 747 timer_freq = freq; 748 } else { 749 if (bootverbose) 750 printf( 751 "%d Hz differs from default of %d Hz by more than 1%%\n", 752 freq, timer_freq); 753 tsc_freq = 0; 754 } 755 756 set_timer_freq(timer_freq, hz); 757 i8254_timecounter.tc_frequency = timer_freq; 758 tc_init(&i8254_timecounter); 759 760#ifndef CLK_USE_TSC_CALIBRATION 761 if (tsc_freq != 0) { 762 if (bootverbose) 763 printf( 764"CLK_USE_TSC_CALIBRATION not specified - using old calibration method\n"); 765 tsc_freq = 0; 766 } 767#endif 768 if (tsc_present && tsc_freq == 0) { 769 /* 770 * Calibration of the i586 clock relative to the mc146818A 771 * clock failed. Do a less accurate calibration relative 772 * to the i8254 clock. 773 */ 774 u_int64_t old_tsc = rdtsc(); 775 776 DELAY(1000000); 777 tsc_freq = rdtsc() - old_tsc; 778#ifdef CLK_USE_TSC_CALIBRATION 779 if (bootverbose) 780 printf("TSC clock: %u Hz (Method B)\n", tsc_freq); 781#endif 782 } 783 784#if !defined(SMP) 785 /* 786 * We can not use the TSC in SMP mode, until we figure out a 787 * cheap (impossible), reliable and precise (yeah right!) way 788 * to synchronize the TSCs of all the CPUs. 789 * Curse Intel for leaving the counter out of the I/O APIC. 790 */ 791 792#ifdef DEV_APM 793 /* 794 * We can not use the TSC if we support APM. Precise timekeeping 795 * on an APM'ed machine is at best a fools pursuit, since 796 * any and all of the time spent in various SMM code can't 797 * be reliably accounted for. Reading the RTC is your only 798 * source of reliable time info. The i8254 looses too of course 799 * but we need to have some kind of time... 800 * We don't know at this point whether APM is going to be used 801 * or not, nor when it might be activated. Play it safe. 802 */ 803 { 804 int disabled = 0; 805 resource_int_value("apm", 0, "disabled", &disabled); 806 if (disabled == 0) 807 return; 808 } 809#endif /* DEV_APM */ 810 811 if (tsc_present && tsc_freq != 0 && !tsc_is_broken) { 812 tsc_timecounter.tc_frequency = tsc_freq; 813 tc_init(&tsc_timecounter); 814 } 815 816#endif /* !defined(SMP) */ 817} 818 819/* 820 * Initialize the time of day register, based on the time base which is, e.g. 821 * from a filesystem. 822 */ 823void 824inittodr(time_t base) 825{ 826 unsigned long sec, days; 827 int yd; 828 int year, month; 829 int y, m, s; 830 struct timespec ts; 831 832 if (base) { 833 s = splclock(); 834 ts.tv_sec = base; 835 ts.tv_nsec = 0; 836 tc_setclock(&ts); 837 splx(s); 838 } 839 840 /* Look if we have a RTC present and the time is valid */ 841 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) 842 goto wrong_time; 843 844 /* wait for time update to complete */ 845 /* If RTCSA_TUP is zero, we have at least 244us before next update */ 846 s = splhigh(); 847 while (rtcin(RTC_STATUSA) & RTCSA_TUP) { 848 splx(s); 849 s = splhigh(); 850 } 851 852 days = 0; 853#ifdef USE_RTC_CENTURY 854 year = readrtc(RTC_YEAR) + readrtc(RTC_CENTURY) * 100; 855#else 856 year = readrtc(RTC_YEAR) + 1900; 857 if (year < 1970) 858 year += 100; 859#endif 860 if (year < 1970) { 861 splx(s); 862 goto wrong_time; 863 } 864 month = readrtc(RTC_MONTH); 865 for (m = 1; m < month; m++) 866 days += daysinmonth[m-1]; 867 if ((month > 2) && LEAPYEAR(year)) 868 days ++; 869 days += readrtc(RTC_DAY) - 1; 870 yd = days; 871 for (y = 1970; y < year; y++) 872 days += DAYSPERYEAR + LEAPYEAR(y); 873 sec = ((( days * 24 + 874 readrtc(RTC_HRS)) * 60 + 875 readrtc(RTC_MIN)) * 60 + 876 readrtc(RTC_SEC)); 877 /* sec now contains the number of seconds, since Jan 1 1970, 878 in the local time zone */ 879 880 sec += tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0); 881 882 y = time_second - sec; 883 if (y <= -2 || y >= 2) { 884 /* badly off, adjust it */ 885 ts.tv_sec = sec; 886 ts.tv_nsec = 0; 887 tc_setclock(&ts); 888 } 889 splx(s); 890 return; 891 892wrong_time: 893 printf("Invalid time in real time clock.\n"); 894 printf("Check and reset the date immediately!\n"); 895} 896 897/* 898 * Write system time back to RTC 899 */ 900void 901resettodr() 902{ 903 unsigned long tm; 904 int y, m, s; 905 906 if (disable_rtc_set) 907 return; 908 909 s = splclock(); 910 tm = time_second; 911 splx(s); 912 913 /* Disable RTC updates and interrupts. */ 914 writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR); 915 916 /* Calculate local time to put in RTC */ 917 918 tm -= tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0); 919 920 writertc(RTC_SEC, bin2bcd(tm%60)); tm /= 60; /* Write back Seconds */ 921 writertc(RTC_MIN, bin2bcd(tm%60)); tm /= 60; /* Write back Minutes */ 922 writertc(RTC_HRS, bin2bcd(tm%24)); tm /= 24; /* Write back Hours */ 923 924 /* We have now the days since 01-01-1970 in tm */ 925 writertc(RTC_WDAY, (tm+4)%7); /* Write back Weekday */ 926 for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y); 927 tm >= m; 928 y++, m = DAYSPERYEAR + LEAPYEAR(y)) 929 tm -= m; 930 931 /* Now we have the years in y and the day-of-the-year in tm */ 932 writertc(RTC_YEAR, bin2bcd(y%100)); /* Write back Year */ 933#ifdef USE_RTC_CENTURY 934 writertc(RTC_CENTURY, bin2bcd(y/100)); /* ... and Century */ 935#endif 936 for (m = 0; ; m++) { 937 int ml; 938 939 ml = daysinmonth[m]; 940 if (m == 1 && LEAPYEAR(y)) 941 ml++; 942 if (tm < ml) 943 break; 944 tm -= ml; 945 } 946 947 writertc(RTC_MONTH, bin2bcd(m + 1)); /* Write back Month */ 948 writertc(RTC_DAY, bin2bcd(tm + 1)); /* Write back Month Day */ 949 950 /* Reenable RTC updates and interrupts. */ 951 writertc(RTC_STATUSB, rtc_statusb); 952} 953 954 955/* 956 * Start both clocks running. 957 */ 958void 959cpu_initclocks() 960{ 961 int diag; 962#ifdef APIC_IO 963 int apic_8254_trial; 964 void *clkdesc; 965#endif /* APIC_IO */ 966 967 if (statclock_disable) { 968 /* 969 * The stat interrupt mask is different without the 970 * statistics clock. Also, don't set the interrupt 971 * flag which would normally cause the RTC to generate 972 * interrupts. 973 */ 974 rtc_statusb = RTCSB_24HR; 975 } else { 976 /* Setting stathz to nonzero early helps avoid races. */ 977 stathz = RTC_NOPROFRATE; 978 profhz = RTC_PROFRATE; 979 } 980 981 /* Finish initializing 8253 timer 0. */ 982#ifdef APIC_IO 983 984 apic_8254_intr = isa_apic_irq(0); 985 apic_8254_trial = 0; 986 if (apic_8254_intr >= 0 ) { 987 if (apic_int_type(0, 0) == 3) 988 apic_8254_trial = 1; 989 } else { 990 /* look for ExtInt on pin 0 */ 991 if (apic_int_type(0, 0) == 3) { 992 apic_8254_intr = apic_irq(0, 0); 993 setup_8254_mixed_mode(); 994 } else 995 panic("APIC_IO: Cannot route 8254 interrupt to CPU"); 996 } 997 998 inthand_add("clk", apic_8254_intr, (driver_intr_t *)clkintr, NULL, 999 INTR_TYPE_CLK | INTR_FAST, &clkdesc); 1000 INTREN(1 << apic_8254_intr); 1001 1002#else /* APIC_IO */ 1003 1004 /* 1005 * XXX Check the priority of this interrupt handler. I 1006 * couldn't find anything suitable in the BSD/OS code (grog, 1007 * 19 July 2000). 1008 */ 1009 inthand_add("clk", 0, (driver_intr_t *)clkintr, NULL, 1010 INTR_TYPE_CLK | INTR_FAST, NULL); 1011 INTREN(IRQ0); 1012 1013#endif /* APIC_IO */ 1014 1015 /* Initialize RTC. */ 1016 writertc(RTC_STATUSA, rtc_statusa); 1017 writertc(RTC_STATUSB, RTCSB_24HR); 1018 1019 /* Don't bother enabling the statistics clock. */ 1020 if (statclock_disable) 1021 return; 1022 diag = rtcin(RTC_DIAG); 1023 if (diag != 0) 1024 printf("RTC BIOS diagnostic error %b\n", diag, RTCDG_BITS); 1025 1026#ifdef APIC_IO 1027 if (isa_apic_irq(8) != 8) 1028 panic("APIC RTC != 8"); 1029#endif /* APIC_IO */ 1030 1031 inthand_add("rtc", 8, (driver_intr_t *)rtcintr, NULL, 1032 INTR_TYPE_CLK | INTR_FAST, NULL); 1033 1034#ifdef APIC_IO 1035 INTREN(APIC_IRQ8); 1036#else 1037 INTREN(IRQ8); 1038#endif /* APIC_IO */ 1039 1040 writertc(RTC_STATUSB, rtc_statusb); 1041 1042#ifdef APIC_IO 1043 if (apic_8254_trial) { 1044 1045 printf("APIC_IO: Testing 8254 interrupt delivery\n"); 1046 while (read_intr_count(8) < 6) 1047 ; /* nothing */ 1048 if (read_intr_count(apic_8254_intr) < 3) { 1049 /* 1050 * The MP table is broken. 1051 * The 8254 was not connected to the specified pin 1052 * on the IO APIC. 1053 * Workaround: Limited variant of mixed mode. 1054 */ 1055 INTRDIS(1 << apic_8254_intr); 1056 inthand_remove(clkdesc); 1057 printf("APIC_IO: Broken MP table detected: " 1058 "8254 is not connected to " 1059 "IOAPIC #%d intpin %d\n", 1060 int_to_apicintpin[apic_8254_intr].ioapic, 1061 int_to_apicintpin[apic_8254_intr].int_pin); 1062 /* 1063 * Revoke current ISA IRQ 0 assignment and 1064 * configure a fallback interrupt routing from 1065 * the 8254 Timer via the 8259 PIC to the 1066 * an ExtInt interrupt line on IOAPIC #0 intpin 0. 1067 * We reuse the low level interrupt handler number. 1068 */ 1069 if (apic_irq(0, 0) < 0) { 1070 revoke_apic_irq(apic_8254_intr); 1071 assign_apic_irq(0, 0, apic_8254_intr); 1072 } 1073 apic_8254_intr = apic_irq(0, 0); 1074 setup_8254_mixed_mode(); 1075 inthand_add("clk", apic_8254_intr, 1076 (driver_intr_t *)clkintr, NULL, 1077 INTR_TYPE_CLK | INTR_FAST, NULL); 1078 INTREN(1 << apic_8254_intr); 1079 } 1080 1081 } 1082 if (apic_int_type(0, 0) != 3 || 1083 int_to_apicintpin[apic_8254_intr].ioapic != 0 || 1084 int_to_apicintpin[apic_8254_intr].int_pin != 0) 1085 printf("APIC_IO: routing 8254 via IOAPIC #%d intpin %d\n", 1086 int_to_apicintpin[apic_8254_intr].ioapic, 1087 int_to_apicintpin[apic_8254_intr].int_pin); 1088 else 1089 printf("APIC_IO: " 1090 "routing 8254 via 8259 and IOAPIC #0 intpin 0\n"); 1091#endif 1092 1093} 1094 1095#ifdef APIC_IO 1096static u_long 1097read_intr_count(int vec) 1098{ 1099 u_long *up; 1100 up = intr_countp[vec]; 1101 if (up) 1102 return *up; 1103 return 0UL; 1104} 1105 1106static void 1107setup_8254_mixed_mode() 1108{ 1109 /* 1110 * Allow 8254 timer to INTerrupt 8259: 1111 * re-initialize master 8259: 1112 * reset; prog 4 bytes, single ICU, edge triggered 1113 */ 1114 outb(IO_ICU1, 0x13); 1115 outb(IO_ICU1 + 1, NRSVIDT); /* start vector (unused) */ 1116 outb(IO_ICU1 + 1, 0x00); /* ignore slave */ 1117 outb(IO_ICU1 + 1, 0x03); /* auto EOI, 8086 */ 1118 outb(IO_ICU1 + 1, 0xfe); /* unmask INT0 */ 1119 1120 /* program IO APIC for type 3 INT on INT0 */ 1121 if (ext_int_setup(0, 0) < 0) 1122 panic("8254 redirect via APIC pin0 impossible!"); 1123} 1124#endif 1125 1126void 1127setstatclockrate(int newhz) 1128{ 1129 if (newhz == RTC_PROFRATE) 1130 rtc_statusa = RTCSA_DIVIDER | RTCSA_PROF; 1131 else 1132 rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF; 1133 writertc(RTC_STATUSA, rtc_statusa); 1134} 1135 1136static int 1137sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS) 1138{ 1139 int error; 1140 u_int freq; 1141 1142 /* 1143 * Use `i8254' instead of `timer' in external names because `timer' 1144 * is is too generic. Should use it everywhere. 1145 */ 1146 freq = timer_freq; 1147 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 1148 if (error == 0 && req->newptr != NULL) { 1149 if (timer0_state != RELEASED) 1150 return (EBUSY); /* too much trouble to handle */ 1151 set_timer_freq(freq, hz); 1152 i8254_timecounter.tc_frequency = freq; 1153 tc_update(&i8254_timecounter); 1154 } 1155 return (error); 1156} 1157 1158SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW, 1159 0, sizeof(u_int), sysctl_machdep_i8254_freq, "I", ""); 1160 1161static int 1162sysctl_machdep_tsc_freq(SYSCTL_HANDLER_ARGS) 1163{ 1164 int error; 1165 u_int freq; 1166 1167 if (tsc_timecounter.tc_frequency == 0) 1168 return (EOPNOTSUPP); 1169 freq = tsc_freq; 1170 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); 1171 if (error == 0 && req->newptr != NULL) { 1172 tsc_freq = freq; 1173 tsc_timecounter.tc_frequency = tsc_freq; 1174 tc_update(&tsc_timecounter); 1175 } 1176 return (error); 1177} 1178 1179SYSCTL_PROC(_machdep, OID_AUTO, tsc_freq, CTLTYPE_INT | CTLFLAG_RW, 1180 0, sizeof(u_int), sysctl_machdep_tsc_freq, "I", ""); 1181 1182static unsigned 1183i8254_get_timecount(struct timecounter *tc) 1184{ 1185 u_int count; 1186 u_int high, low; 1187 u_int eflags; 1188 1189 eflags = read_eflags(); 1190 mtx_lock_spin(&clock_lock); 1191 1192 /* Select timer0 and latch counter value. */ 1193 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); 1194 1195 low = inb(TIMER_CNTR0); 1196 high = inb(TIMER_CNTR0); 1197 count = timer0_max_count - ((high << 8) | low); 1198 if (count < i8254_lastcount || 1199 (!i8254_ticked && (clkintr_pending || 1200 ((count < 20 || (!(eflags & PSL_I) && count < timer0_max_count / 2u)) && 1201#ifdef APIC_IO 1202#define lapic_irr1 ((volatile u_int *)&lapic)[0x210 / 4] /* XXX XXX */ 1203 /* XXX this assumes that apic_8254_intr is < 24. */ 1204 (lapic_irr1 & (1 << apic_8254_intr)))) 1205#else 1206 (inb(IO_ICU1) & 1))) 1207#endif 1208 )) { 1209 i8254_ticked = 1; 1210 i8254_offset += timer0_max_count; 1211 } 1212 i8254_lastcount = count; 1213 count += i8254_offset; 1214 mtx_unlock_spin(&clock_lock); 1215 return (count); 1216} 1217 1218static unsigned 1219tsc_get_timecount(struct timecounter *tc) 1220{ 1221 return (rdtsc()); 1222} 1223 1224/* 1225 * Attach to the ISA PnP descriptors for the timer and realtime clock. 1226 */ 1227static struct isa_pnp_id attimer_ids[] = { 1228 { 0x0001d041 /* PNP0100 */, "AT timer" }, 1229 { 0x000bd041 /* PNP0B00 */, "AT realtime clock" }, 1230 { 0 } 1231}; 1232 1233static int 1234attimer_probe(device_t dev) 1235{ 1236 int result; 1237 1238 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids)) <= 0) 1239 device_quiet(dev); 1240 return(result); 1241} 1242 1243static int 1244attimer_attach(device_t dev) 1245{ 1246 return(0); 1247} 1248 1249static device_method_t attimer_methods[] = { 1250 /* Device interface */ 1251 DEVMETHOD(device_probe, attimer_probe), 1252 DEVMETHOD(device_attach, attimer_attach), 1253 DEVMETHOD(device_detach, bus_generic_detach), 1254 DEVMETHOD(device_shutdown, bus_generic_shutdown), 1255 DEVMETHOD(device_suspend, bus_generic_suspend), /* XXX stop statclock? */ 1256 DEVMETHOD(device_resume, bus_generic_resume), /* XXX restart statclock? */ 1257 { 0, 0 } 1258}; 1259 1260static driver_t attimer_driver = { 1261 "attimer", 1262 attimer_methods, 1263 1, /* no softc */ 1264}; 1265 1266static devclass_t attimer_devclass; 1267 1268DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0);
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