1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz and Don Ahn.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: @(#)clock.c 7.2 (Berkeley) 5/12/91
37 * $Id: clock.c,v 1.116 1998/03/14 03:11:50 tegge Exp $
38 */
39
40/*
41 * Routines to handle clock hardware.
42 */
43
44/*
45 * inittodr, settodr and support routines written
46 * by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>
47 *
48 * reintroduced and updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
49 */
50
51#include "opt_clock.h"
52#include "apm.h"
53
54#include <sys/param.h>
55#include <sys/systm.h>
56#include <sys/time.h>
57#include <sys/kernel.h>
58#ifndef SMP
59#include <sys/lock.h>
60#endif
61#include <sys/sysctl.h>
62
63#include <machine/clock.h>
64#ifdef CLK_CALIBRATION_LOOP
65#include <machine/cons.h>
66#endif
67#include <machine/cputypes.h>
68#include <machine/frame.h>
69#include <machine/ipl.h>
70#include <machine/limits.h>
71#include <machine/md_var.h>
72#if NAPM > 0
73#include <machine/apm_bios.h>
74#include <i386/apm/apm_setup.h>
75#endif
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 <i386/isa/rtc.h>
87#include <i386/isa/timerreg.h>
88
89#include <sys/interrupt.h>
90
91#ifdef SMP
92#define disable_intr() CLOCK_DISABLE_INTR()
93#define enable_intr() CLOCK_ENABLE_INTR()
94
95#ifdef APIC_IO
96#include <i386/isa/intr_machdep.h>
97/* The interrupt triggered by the 8254 (timer) chip */
98int apic_8254_intr;
99static u_long read_intr_count __P((int vec));
100static void setup_8254_mixed_mode __P((void));
101#endif
102#endif /* SMP */
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 disable_rtc_set; /* disable resettodr() if != 0 */
131u_int idelayed;
132int statclock_disable;
133u_int stat_imask = SWI_CLOCK_MASK;
134#ifndef TIMER_FREQ
135#define TIMER_FREQ 1193182
136#endif
137u_int timer_freq = TIMER_FREQ;
138int timer0_max_count;
139u_int tsc_freq;
140int wall_cmos_clock; /* wall CMOS clock assumed if != 0 */
141
142static int beeping = 0;
143static u_int clk_imask = HWI_MASK | SWI_MASK;
144static const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31};
145static u_int hardclock_max_count;
146static u_int32_t i8254_lastcount;
147static u_int32_t i8254_offset;
148static int i8254_ticked;
149/*
150 * XXX new_function and timer_func should not handle clockframes, but
151 * timer_func currently needs to hold hardclock to handle the
152 * timer0_state == 0 case. We should use register_intr()/unregister_intr()
153 * to switch between clkintr() and a slightly different timerintr().
154 */
155static void (*new_function) __P((struct clockframe *frame));
156static u_int new_rate;
157static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
158static u_char rtc_statusb = RTCSB_24HR | RTCSB_PINTR;
159static u_int timer0_prescaler_count;
160
161/* Values for timerX_state: */
162#define RELEASED 0
163#define RELEASE_PENDING 1
164#define ACQUIRED 2
165#define ACQUIRE_PENDING 3
166
167static u_char timer0_state;
168static u_char timer2_state;
169static void (*timer_func) __P((struct clockframe *frame)) = hardclock;
170static u_int tsc_present;
171
172static u_int64_t i8254_get_timecount __P((void));
173static void set_timer_freq(u_int freq, int intr_freq);
174static u_int64_t tsc_get_timecount __P((void));
175static u_int32_t tsc_get_timedelta __P((struct timecounter *tc));
176
177static struct timecounter tsc_timecounter[3] = {
178 tsc_get_timedelta, /* get_timedelta */
179 tsc_get_timecount, /* get_timecount */
180 ~0, /* counter_mask */
181 0, /* frequency */
182 "TSC" /* name */
183};
184
185SYSCTL_OPAQUE(_debug, OID_AUTO, tsc_timecounter, CTLFLAG_RD,
186 tsc_timecounter, sizeof(tsc_timecounter), "S,timecounter", "");
187
188static struct timecounter i8254_timecounter[3] = {
189 0, /* get_timedelta */
190 i8254_get_timecount, /* get_timecount */
191 (1ULL << 32) - 1, /* counter_mask */
192 0, /* frequency */
193 "i8254" /* name */
194};
195
196SYSCTL_OPAQUE(_debug, OID_AUTO, i8254_timecounter, CTLFLAG_RD,
197 i8254_timecounter, sizeof(i8254_timecounter), "S,timecounter", "");
198
199static void
200clkintr(struct clockframe frame)
201{
202 if (!i8254_ticked)
203 i8254_offset += timer0_max_count;
204 else
205 i8254_ticked = 0;
206 i8254_lastcount = 0;
207 timer_func(&frame);
208 switch (timer0_state) {
209
210 case RELEASED:
211 setdelayed();
212 break;
213
214 case ACQUIRED:
215 if ((timer0_prescaler_count += timer0_max_count)
216 >= hardclock_max_count) {
217 timer0_prescaler_count -= hardclock_max_count;
218 hardclock(&frame);
219 setdelayed();
220 }
221 break;
222
223 case ACQUIRE_PENDING:
224 setdelayed();
225 timer0_max_count = TIMER_DIV(new_rate);
226 disable_intr();
227 outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
228 outb(TIMER_CNTR0, timer0_max_count & 0xff);
229 outb(TIMER_CNTR0, timer0_max_count >> 8);
230 enable_intr();
231 timer0_prescaler_count = 0;
232 timer_func = new_function;
233 timer0_state = ACQUIRED;
234 break;
235
236 case RELEASE_PENDING:
237 if ((timer0_prescaler_count += timer0_max_count)
238 >= hardclock_max_count) {
239 timer0_prescaler_count -= hardclock_max_count;
240 /*
241 * See microtime.s for this magic.
242 */
243 time.tv_usec += (27465 * timer0_prescaler_count) >> 15;
244 if (time.tv_usec >= 1000000)
245 time.tv_usec -= 1000000;
246 hardclock(&frame);
247 setdelayed();
248 timer0_max_count = hardclock_max_count;
249 disable_intr();
250 outb(TIMER_MODE,
251 TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
252 outb(TIMER_CNTR0, timer0_max_count & 0xff);
253 outb(TIMER_CNTR0, timer0_max_count >> 8);
254 enable_intr();
255 timer0_prescaler_count = 0;
256 timer_func = hardclock;
257 timer0_state = RELEASED;
258 }
259 break;
260 }
261}
262
263/*
264 * The acquire and release functions must be called at ipl >= splclock().
265 */
266int
267acquire_timer0(int rate, void (*function) __P((struct clockframe *frame)))
268{
269 static int old_rate;
270
271 if (rate <= 0 || rate > TIMER0_MAX_FREQ)
272 return (-1);
273 if (strcmp(timecounter->name, "i8254") == 0)
274 return (-1);
275 switch (timer0_state) {
276
277 case RELEASED:
278 timer0_state = ACQUIRE_PENDING;
279 break;
280
281 case RELEASE_PENDING:
282 if (rate != old_rate)
283 return (-1);
284 /*
285 * The timer has been released recently, but is being
286 * re-acquired before the release completed. In this
287 * case, we simply reclaim it as if it had not been
288 * released at all.
289 */
290 timer0_state = ACQUIRED;
291 break;
292
293 default:
294 return (-1); /* busy */
295 }
296 new_function = function;
297 old_rate = new_rate = rate;
298 return (0);
299}
300
301int
302acquire_timer2(int mode)
303{
304
305 if (timer2_state != RELEASED)
306 return (-1);
307 timer2_state = ACQUIRED;
308
309 /*
310 * This access to the timer registers is as atomic as possible
311 * because it is a single instruction. We could do better if we
312 * knew the rate. Use of splclock() limits glitches to 10-100us,
313 * and this is probably good enough for timer2, so we aren't as
314 * careful with it as with timer0.
315 */
316 outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
317
318 return (0);
319}
320
321int
322release_timer0()
323{
324 switch (timer0_state) {
325
326 case ACQUIRED:
327 timer0_state = RELEASE_PENDING;
328 break;
329
330 case ACQUIRE_PENDING:
331 /* Nothing happened yet, release quickly. */
332 timer0_state = RELEASED;
333 break;
334
335 default:
336 return (-1);
337 }
338 return (0);
339}
340
341int
342release_timer2()
343{
344
345 if (timer2_state != ACQUIRED)
346 return (-1);
347 timer2_state = RELEASED;
348 outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
349 return (0);
350}
351
352/*
353 * This routine receives statistical clock interrupts from the RTC.
354 * As explained above, these occur at 128 interrupts per second.
355 * When profiling, we receive interrupts at a rate of 1024 Hz.
356 *
357 * This does not actually add as much overhead as it sounds, because
358 * when the statistical clock is active, the hardclock driver no longer
359 * needs to keep (inaccurate) statistics on its own. This decouples
360 * statistics gathering from scheduling interrupts.
361 *
362 * The RTC chip requires that we read status register C (RTC_INTR)
363 * to acknowledge an interrupt, before it will generate the next one.
364 * Under high interrupt load, rtcintr() can be indefinitely delayed and
365 * the clock can tick immediately after the read from RTC_INTR. In this
366 * case, the mc146818A interrupt signal will not drop for long enough
367 * to register with the 8259 PIC. If an interrupt is missed, the stat
368 * clock will halt, considerably degrading system performance. This is
369 * why we use 'while' rather than a more straightforward 'if' below.
370 * Stat clock ticks can still be lost, causing minor loss of accuracy
371 * in the statistics, but the stat clock will no longer stop.
372 */
373static void
374rtcintr(struct clockframe frame)
375{
376 while (rtcin(RTC_INTR) & RTCIR_PERIOD)
377 statclock(&frame);
378}
379
380#include "opt_ddb.h"
381#ifdef DDB
382#include <ddb/ddb.h>
383
384DB_SHOW_COMMAND(rtc, rtc)
385{
386 printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n",
387 rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY),
388 rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC),
389 rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR));
390}
391#endif /* DDB */
392
393static int
394getit(void)
395{
396 u_long ef;
397 int high, low;
398
399 ef = read_eflags();
400 disable_intr();
401
402 /* Select timer0 and latch counter value. */
403 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
404
405 low = inb(TIMER_CNTR0);
406 high = inb(TIMER_CNTR0);
407
408 CLOCK_UNLOCK();
409 write_eflags(ef);
410 return ((high << 8) | low);
411}
412
413/*
414 * Wait "n" microseconds.
415 * Relies on timer 1 counting down from (timer_freq / hz)
416 * Note: timer had better have been programmed before this is first used!
417 */
418void
419DELAY(int n)
420{
421 int delta, prev_tick, tick, ticks_left;
422
423#ifdef DELAYDEBUG
424 int getit_calls = 1;
425 int n1;
426 static int state = 0;
427
428 if (state == 0) {
429 state = 1;
430 for (n1 = 1; n1 <= 10000000; n1 *= 10)
431 DELAY(n1);
432 state = 2;
433 }
434 if (state == 1)
435 printf("DELAY(%d)...", n);
436#endif
437 /*
438 * Guard against the timer being uninitialized if we are called
439 * early for console i/o.
440 */
441 if (timer0_max_count == 0)
442 set_timer_freq(timer_freq, hz);
443
444 /*
445 * Read the counter first, so that the rest of the setup overhead is
446 * counted. Guess the initial overhead is 20 usec (on most systems it
447 * takes about 1.5 usec for each of the i/o's in getit(). The loop
448 * takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
449 * multiplications and divisions to scale the count take a while).
450 */
451 prev_tick = getit();
452 n -= 0; /* XXX actually guess no initial overhead */
453 /*
454 * Calculate (n * (timer_freq / 1e6)) without using floating point
455 * and without any avoidable overflows.
456 */
457 if (n <= 0)
458 ticks_left = 0;
459 else if (n < 256)
460 /*
461 * Use fixed point to avoid a slow division by 1000000.
462 * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
463 * 2^15 is the first power of 2 that gives exact results
464 * for n between 0 and 256.
465 */
466 ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
467 else
468 /*
469 * Don't bother using fixed point, although gcc-2.7.2
470 * generates particularly poor code for the long long
471 * division, since even the slow way will complete long
472 * before the delay is up (unless we're interrupted).
473 */
474 ticks_left = ((u_int)n * (long long)timer_freq + 999999)
475 / 1000000;
476
477 while (ticks_left > 0) {
478 tick = getit();
479#ifdef DELAYDEBUG
480 ++getit_calls;
481#endif
482 delta = prev_tick - tick;
483 prev_tick = tick;
484 if (delta < 0) {
485 delta += timer0_max_count;
486 /*
487 * Guard against timer0_max_count being wrong.
488 * This shouldn't happen in normal operation,
489 * but it may happen if set_timer_freq() is
490 * traced.
491 */
492 if (delta < 0)
493 delta = 0;
494 }
495 ticks_left -= delta;
496 }
497#ifdef DELAYDEBUG
498 if (state == 1)
499 printf(" %d calls to getit() at %d usec each\n",
500 getit_calls, (n + 5) / getit_calls);
501#endif
502}
503
504static void
505sysbeepstop(void *chan)
506{
507 outb(IO_PPI, inb(IO_PPI)&0xFC); /* disable counter2 output to speaker */
508 release_timer2();
509 beeping = 0;
510}
511
512int
513sysbeep(int pitch, int period)
514{
515 int x = splclock();
516
517 if (acquire_timer2(TIMER_SQWAVE|TIMER_16BIT))
518 if (!beeping) {
519 /* Something else owns it. */
520 splx(x);
521 return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
522 }
523 disable_intr();
524 outb(TIMER_CNTR2, pitch);
525 outb(TIMER_CNTR2, (pitch>>8));
526 enable_intr();
527 if (!beeping) {
528 /* enable counter2 output to speaker */
529 outb(IO_PPI, inb(IO_PPI) | 3);
530 beeping = period;
531 timeout(sysbeepstop, (void *)NULL, period);
532 }
533 splx(x);
534 return (0);
535}
536
537/*
538 * RTC support routines
539 */
540
541int
542rtcin(reg)
543 int reg;
544{
545 u_char val;
546
547 outb(IO_RTC, reg);
548 inb(0x84);
549 val = inb(IO_RTC + 1);
550 inb(0x84);
551 return (val);
552}
553
554static __inline void
555writertc(u_char reg, u_char val)
556{
557 inb(0x84);
558 outb(IO_RTC, reg);
559 inb(0x84);
560 outb(IO_RTC + 1, val);
561 inb(0x84); /* XXX work around wrong order in rtcin() */
562}
563
564static __inline int
565readrtc(int port)
566{
567 return(bcd2bin(rtcin(port)));
568}
569
570static u_int
571calibrate_clocks(void)
572{
573 u_int count, prev_count, tot_count;
574 int sec, start_sec, timeout;
575
576 if (bootverbose)
577 printf("Calibrating clock(s) ... ");
578 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
579 goto fail;
580 timeout = 100000000;
581
582 /* Read the mc146818A seconds counter. */
583 for (;;) {
584 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
585 sec = rtcin(RTC_SEC);
586 break;
587 }
588 if (--timeout == 0)
589 goto fail;
590 }
591
592 /* Wait for the mC146818A seconds counter to change. */
593 start_sec = sec;
594 for (;;) {
595 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
596 sec = rtcin(RTC_SEC);
597 if (sec != start_sec)
598 break;
599 }
600 if (--timeout == 0)
601 goto fail;
602 }
603
604 /* Start keeping track of the i8254 counter. */
605 prev_count = getit();
606 if (prev_count == 0 || prev_count > timer0_max_count)
607 goto fail;
608 tot_count = 0;
609
610 if (tsc_present)
611 wrmsr(0x10, 0LL); /* XXX 0x10 is the MSR for the TSC */
612
613 /*
614 * Wait for the mc146818A seconds counter to change. Read the i8254
615 * counter for each iteration since this is convenient and only
616 * costs a few usec of inaccuracy. The timing of the final reads
617 * of the counters almost matches the timing of the initial reads,
618 * so the main cause of inaccuracy is the varying latency from
619 * inside getit() or rtcin(RTC_STATUSA) to the beginning of the
620 * rtcin(RTC_SEC) that returns a changed seconds count. The
621 * maximum inaccuracy from this cause is < 10 usec on 486's.
622 */
623 start_sec = sec;
624 for (;;) {
625 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP))
626 sec = rtcin(RTC_SEC);
627 count = getit();
628 if (count == 0 || count > timer0_max_count)
629 goto fail;
630 if (count > prev_count)
631 tot_count += prev_count - (count - timer0_max_count);
632 else
633 tot_count += prev_count - count;
634 prev_count = count;
635 if (sec != start_sec)
636 break;
637 if (--timeout == 0)
638 goto fail;
639 }
640
641 /*
642 * Read the cpu cycle counter. The timing considerations are
643 * similar to those for the i8254 clock.
644 */
645 if (tsc_present)
646 tsc_freq = rdtsc();
647
648 if (bootverbose) {
649 if (tsc_present)
650 printf("TSC clock: %u Hz, ", tsc_freq);
651 printf("i8254 clock: %u Hz\n", tot_count);
652 }
653 return (tot_count);
654
655fail:
656 if (bootverbose)
657 printf("failed, using default i8254 clock of %u Hz\n",
658 timer_freq);
659 return (timer_freq);
660}
661
662static void
663set_timer_freq(u_int freq, int intr_freq)
664{
665 u_long ef;
666 int new_timer0_max_count;
667
668 ef = read_eflags();
669 disable_intr();
670 timer_freq = freq;
671 new_timer0_max_count = hardclock_max_count = TIMER_DIV(intr_freq);
672 if (new_timer0_max_count != timer0_max_count) {
673 timer0_max_count = new_timer0_max_count;
674 outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
675 outb(TIMER_CNTR0, timer0_max_count & 0xff);
676 outb(TIMER_CNTR0, timer0_max_count >> 8);
677 }
678 CLOCK_UNLOCK();
679 write_eflags(ef);
680}
681
682/*
683 * Initialize 8254 timer 0 early so that it can be used in DELAY().
684 * XXX initialization of other timers is unintentionally left blank.
685 */
686void
687startrtclock()
688{
689 u_int delta, freq;
690
691 if (cpu_feature & CPUID_TSC)
692 tsc_present = 1;
693 else
694 tsc_present = 0;
695
696 writertc(RTC_STATUSA, rtc_statusa);
697 writertc(RTC_STATUSB, RTCSB_24HR);
698
699 set_timer_freq(timer_freq, hz);
700 freq = calibrate_clocks();
701#ifdef CLK_CALIBRATION_LOOP
702 if (bootverbose) {
703 printf(
704 "Press a key on the console to abort clock calibration\n");
705 while (cncheckc() == -1)
706 calibrate_clocks();
707 }
708#endif
709
710 /*
711 * Use the calibrated i8254 frequency if it seems reasonable.
712 * Otherwise use the default, and don't use the calibrated i586
713 * frequency.
714 */
715 delta = freq > timer_freq ? freq - timer_freq : timer_freq - freq;
716 if (delta < timer_freq / 100) {
717#ifndef CLK_USE_I8254_CALIBRATION
718 if (bootverbose)
719 printf(
720"CLK_USE_I8254_CALIBRATION not specified - using default frequency\n");
721 freq = timer_freq;
722#endif
723 timer_freq = freq;
724 } else {
725 if (bootverbose)
726 printf(
727 "%d Hz differs from default of %d Hz by more than 1%%\n",
728 freq, timer_freq);
729 tsc_freq = 0;
730 }
731
732 set_timer_freq(timer_freq, hz);
733 i8254_timecounter[0].frequency = timer_freq;
734 init_timecounter(i8254_timecounter);
735
736#ifndef CLK_USE_TSC_CALIBRATION
737 if (tsc_freq != 0) {
738 if (bootverbose)
739 printf(
740"CLK_USE_TSC_CALIBRATION not specified - using old calibration method\n");
741 tsc_freq = 0;
742 }
743#endif
744 if (tsc_present && tsc_freq == 0) {
745 /*
746 * Calibration of the i586 clock relative to the mc146818A
747 * clock failed. Do a less accurate calibration relative
748 * to the i8254 clock.
749 */
750 wrmsr(0x10, 0LL); /* XXX */
751 DELAY(1000000);
752 tsc_freq = rdtsc();
753#ifdef CLK_USE_TSC_CALIBRATION
754 if (bootverbose)
755 printf("TSC clock: %u Hz (Method B)\n", tsc_freq);
756#endif
757 }
758
759#if !defined(SMP)
760 /*
761 * We can not use the TSC in SMP mode, until we figure out a
762 * cheap (impossible), reliable and precise (yeah right!) way
763 * to synchronize the TSCs of all the CPUs.
764 * Curse Intel for leaving the counter out of the I/O APIC.
765 */
766
767#if NAPM > 0
768 /*
769 * We can not use the TSC if we found an APM bios. Too many
770 * of them lie about their ability&intention to fiddle the CPU
771 * clock for us to rely on this. Precise timekeeping on an
772 * APM'ed machine is at best a fools pursuit anyway, since
773 * any and all of the time spent in various SMM code can't
774 * be reliably accounted for. Reading the RTC is your only
775 * source of reliable time info. The i8254 looses too of course
776 * but we need to have some kind of time...
777 */
778 if (apm_version != APMINI_CANTFIND)
779 return;
780#endif /* NAPM > 0 */
781
782 if (tsc_present && tsc_freq != 0) {
783 tsc_timecounter[0].frequency = tsc_freq;
784 init_timecounter(tsc_timecounter);
785 }
786
787#endif /* !defined(SMP) */
788}
789
790/*
791 * Initialize the time of day register, based on the time base which is, e.g.
792 * from a filesystem.
793 */
794void
795inittodr(time_t base)
796{
797 unsigned long sec, days;
798 int yd;
799 int year, month;
800 int y, m, s;
801 struct timespec ts;
802
803 if (base) {
804 s = splclock();
805 ts.tv_sec = base;
806 ts.tv_nsec = 0;
807 set_timecounter(&ts);
808 splx(s);
809 }
810
811 /* Look if we have a RTC present and the time is valid */
812 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
813 goto wrong_time;
814
815 /* wait for time update to complete */
816 /* If RTCSA_TUP is zero, we have at least 244us before next update */
817 while (rtcin(RTC_STATUSA) & RTCSA_TUP);
818
819 days = 0;
820#ifdef USE_RTC_CENTURY
821 year = readrtc(RTC_YEAR) + readrtc(RTC_CENTURY) * 100;
822#else
823 year = readrtc(RTC_YEAR) + 1900;
824 if (year < 1970)
825 year += 100;
826#endif
827 if (year < 1970)
828 goto wrong_time;
829 month = readrtc(RTC_MONTH);
830 for (m = 1; m < month; m++)
831 days += daysinmonth[m-1];
832 if ((month > 2) && LEAPYEAR(year))
833 days ++;
834 days += readrtc(RTC_DAY) - 1;
835 yd = days;
836 for (y = 1970; y < year; y++)
837 days += DAYSPERYEAR + LEAPYEAR(y);
838 sec = ((( days * 24 +
839 readrtc(RTC_HRS)) * 60 +
840 readrtc(RTC_MIN)) * 60 +
841 readrtc(RTC_SEC));
842 /* sec now contains the number of seconds, since Jan 1 1970,
843 in the local time zone */
844
845 sec += tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
846
847 y = time.tv_sec - sec;
848 if (y <= -2 || y >= 2) {
849 /* badly off, adjust it */
850 s = splclock();
851 ts.tv_sec = sec;
852 ts.tv_nsec = 0;
853 set_timecounter(&ts);
854 splx(s);
855 }
856 return;
857
858wrong_time:
859 printf("Invalid time in real time clock.\n");
860 printf("Check and reset the date immediately!\n");
861}
862
863/*
864 * Write system time back to RTC
865 */
866void
867resettodr()
868{
869 unsigned long tm;
870 int y, m, s;
871
872 if (disable_rtc_set)
873 return;
874
875 s = splclock();
876 tm = time.tv_sec;
877 splx(s);
878
879 /* Disable RTC updates and interrupts. */
880 writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR);
881
882 /* Calculate local time to put in RTC */
883
884 tm -= tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
885
886 writertc(RTC_SEC, bin2bcd(tm%60)); tm /= 60; /* Write back Seconds */
887 writertc(RTC_MIN, bin2bcd(tm%60)); tm /= 60; /* Write back Minutes */
888 writertc(RTC_HRS, bin2bcd(tm%24)); tm /= 24; /* Write back Hours */
889
890 /* We have now the days since 01-01-1970 in tm */
891 writertc(RTC_WDAY, (tm+4)%7); /* Write back Weekday */
892 for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
893 tm >= m;
894 y++, m = DAYSPERYEAR + LEAPYEAR(y))
895 tm -= m;
896
897 /* Now we have the years in y and the day-of-the-year in tm */
898 writertc(RTC_YEAR, bin2bcd(y%100)); /* Write back Year */
899#ifdef USE_RTC_CENTURY
900 writertc(RTC_CENTURY, bin2bcd(y/100)); /* ... and Century */
901#endif
902 for (m = 0; ; m++) {
903 int ml;
904
905 ml = daysinmonth[m];
906 if (m == 1 && LEAPYEAR(y))
907 ml++;
908 if (tm < ml)
909 break;
910 tm -= ml;
911 }
912
913 writertc(RTC_MONTH, bin2bcd(m + 1)); /* Write back Month */
914 writertc(RTC_DAY, bin2bcd(tm + 1)); /* Write back Month Day */
915
916 /* Reenable RTC updates and interrupts. */
917 writertc(RTC_STATUSB, rtc_statusb);
918}
919
920
921/*
922 * Start both clocks running.
923 */
924void
925cpu_initclocks()
926{
927 int diag;
928#ifdef APIC_IO
929 int apic_8254_trial;
930#endif /* APIC_IO */
931
932 if (statclock_disable) {
933 /*
934 * The stat interrupt mask is different without the
935 * statistics clock. Also, don't set the interrupt
936 * flag which would normally cause the RTC to generate
937 * interrupts.
938 */
939 stat_imask = HWI_MASK | SWI_MASK;
940 rtc_statusb = RTCSB_24HR;
941 } else {
942 /* Setting stathz to nonzero early helps avoid races. */
943 stathz = RTC_NOPROFRATE;
944 profhz = RTC_PROFRATE;
945 }
946
947 /* Finish initializing 8253 timer 0. */
948#ifdef APIC_IO
949
950 apic_8254_intr = isa_apic_pin(0);
951 apic_8254_trial = 0;
952 if (apic_8254_intr >= 0 ) {
953 if (apic_int_type(0, 0) == 3)
954 apic_8254_trial = 1;
955 } else {
956 /* look for ExtInt on pin 0 */
957 if (apic_int_type(0, 0) == 3) {
958 apic_8254_intr = 0;
959 setup_8254_mixed_mode();
960 } else
961 panic("APIC_IO: Cannot route 8254 interrupt to CPU");
962 }
963
964 register_intr(/* irq */ apic_8254_intr, /* XXX id */ 0, /* flags */ 0,
965 /* XXX */ (inthand2_t *)clkintr, &clk_imask,
966 /* unit */ 0);
967 INTREN(1 << apic_8254_intr);
968
969#else /* APIC_IO */
970
971 register_intr(/* irq */ 0, /* XXX id */ 0, /* flags */ 0,
972 /* XXX */ (inthand2_t *)clkintr, &clk_imask,
973 /* unit */ 0);
974 INTREN(IRQ0);
975
976#endif /* APIC_IO */
977
978 /* Initialize RTC. */
979 writertc(RTC_STATUSA, rtc_statusa);
980 writertc(RTC_STATUSB, RTCSB_24HR);
981
982 /* Don't bother enabling the statistics clock. */
983 if (statclock_disable)
984 return;
985 diag = rtcin(RTC_DIAG);
986 if (diag != 0)
987 printf("RTC BIOS diagnostic error %b\n", diag, RTCDG_BITS);
988
989#ifdef APIC_IO
990 if (isa_apic_pin(8) != 8)
991 panic("APIC RTC != 8");
992#endif /* APIC_IO */
993
994 register_intr(/* irq */ 8, /* XXX id */ 1, /* flags */ 0,
995 /* XXX */ (inthand2_t *)rtcintr, &stat_imask,
996 /* unit */ 0);
997
998#ifdef APIC_IO
999 INTREN(APIC_IRQ8);
1000#else
1001 INTREN(IRQ8);
1002#endif /* APIC_IO */
1003
1004 writertc(RTC_STATUSB, rtc_statusb);
1005
1006#ifdef APIC_IO
1007 if (apic_8254_trial) {
1008
1009 printf("APIC_IO: Testing 8254 interrupt delivery\n");
1010 __asm __volatile("sti" : : : "memory");
1011 while (read_intr_count(8) < 6)
1012 __asm __volatile("sti" : : : "memory");
1013 if (read_intr_count(apic_8254_intr) < 3) {
1014 /*
1015 * The MP table is broken.
1016 * The 8254 was not connected to the specified pin
1017 * on the IO APIC.
1018 * Workaround: Limited variant of mixed mode.
1019 */
1020 INTRDIS(1 << apic_8254_intr);
1021 unregister_intr(apic_8254_intr,
1022 /* XXX */ (inthand2_t *) clkintr);
1023 printf("APIC_IO: Broken MP table detected: "
1024 "8254 is not connected to IO APIC int pin %d\n",
1025 apic_8254_intr);
1026
1027 apic_8254_intr = 0;
1028 setup_8254_mixed_mode();
1029 register_intr(/* irq */ apic_8254_intr, /* XXX id */ 0, /* flags */ 0,
1030 /* XXX */ (inthand2_t *)clkintr, &clk_imask,
1031 /* unit */ 0);
1032 INTREN(1 << apic_8254_intr);
1033 }
1034
1035 }
1036 if (apic_8254_intr)
1037 printf("APIC_IO: routing 8254 via pin %d\n",apic_8254_intr);
1038 else
1039 printf("APIC_IO: routing 8254 via 8259 on pin 0\n");
1040#endif
1041
1042}
1043
1044#ifdef APIC_IO
1045static u_long
1046read_intr_count(int vec)
1047{
1048 u_long *up;
1049 up = intr_countp[vec];
1050 if (up)
1051 return *up;
1052 return 0UL;
1053}
1054
1055static void
1056setup_8254_mixed_mode()
1057{
1058 /*
1059 * Allow 8254 timer to INTerrupt 8259:
1060 * re-initialize master 8259:
1061 * reset; prog 4 bytes, single ICU, edge triggered
1062 */
1063 outb(IO_ICU1, 0x13);
1064 outb(IO_ICU1 + 1, NRSVIDT); /* start vector (unused) */
1065 outb(IO_ICU1 + 1, 0x00); /* ignore slave */
1066 outb(IO_ICU1 + 1, 0x03); /* auto EOI, 8086 */
1067 outb(IO_ICU1 + 1, 0xfe); /* unmask INT0 */
1068
1069 /* program IO APIC for type 3 INT on INT0 */
1070 if (ext_int_setup(0, 0) < 0)
1071 panic("8254 redirect via APIC pin0 impossible!");
1072}
1073#endif
1074
1075void
1076setstatclockrate(int newhz)
1077{
1078 if (newhz == RTC_PROFRATE)
1079 rtc_statusa = RTCSA_DIVIDER | RTCSA_PROF;
1080 else
1081 rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
1082 writertc(RTC_STATUSA, rtc_statusa);
1083}
1084
1085static int
1086sysctl_machdep_i8254_freq SYSCTL_HANDLER_ARGS
1087{
1088 int error;
1089 u_int freq;
1090
1091 /*
1092 * Use `i8254' instead of `timer' in external names because `timer'
1093 * is is too generic. Should use it everywhere.
1094 */
1095 freq = timer_freq;
1096 error = sysctl_handle_opaque(oidp, &freq, sizeof freq, req);
1097 if (error == 0 && req->newptr != NULL) {
1098 if (timer0_state != RELEASED)
1099 return (EBUSY); /* too much trouble to handle */
1100 set_timer_freq(freq, hz);
1101 i8254_timecounter[0].frequency = freq;
1102 }
1103 return (error);
1104}
1105
1106SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
1107 0, sizeof(u_int), sysctl_machdep_i8254_freq, "I", "");
1108
1109static int
1110sysctl_machdep_tsc_freq SYSCTL_HANDLER_ARGS
1111{
1112 int error;
1113 u_int freq;
1114
1115 if (!tsc_present)
1116 return (EOPNOTSUPP);
1117 freq = tsc_freq;
1118 error = sysctl_handle_opaque(oidp, &freq, sizeof freq, req);
1119 if (error == 0 && req->newptr != NULL) {
1120 tsc_freq = freq;
1121 tsc_timecounter[0].frequency = tsc_freq;
1122 }
1123 return (error);
1124}
1125
1126SYSCTL_PROC(_machdep, OID_AUTO, tsc_freq, CTLTYPE_INT | CTLFLAG_RW,
1127 0, sizeof(u_int), sysctl_machdep_tsc_freq, "I", "");
1128
1129static u_int64_t
1130i8254_get_timecount(void)
1131{
1132 u_int32_t count;
1133 u_long ef;
1134 u_int high, low;
1135
1136 ef = read_eflags();
1137 disable_intr();
1138
1139 /* Select timer0 and latch counter value. */
1140 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
1141
1142 low = inb(TIMER_CNTR0);
1143 high = inb(TIMER_CNTR0);
1144
1145 count = hardclock_max_count - ((high << 8) | low);
1146 if (count < i8254_lastcount) {
1147 i8254_ticked = 1;
1148 i8254_offset += hardclock_max_count;
1149 }
1150
1151 i8254_lastcount = count;
1152 count += i8254_offset;
1153 CLOCK_UNLOCK();
1154 write_eflags(ef);
1155 return (count);
1156}
1157
1158static u_int64_t
1159tsc_get_timecount(void)
1160{
1161 return ((u_int64_t)rdtsc());
1162}
1163
1164static u_int32_t
1165tsc_get_timedelta(struct timecounter *tc)
1166{
1167 return ((u_int64_t)rdtsc() - tc->offset_count);
1168}
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz and Don Ahn.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: @(#)clock.c 7.2 (Berkeley) 5/12/91
37 * $Id: clock.c,v 1.116 1998/03/14 03:11:50 tegge Exp $
38 */
39
40/*
41 * Routines to handle clock hardware.
42 */
43
44/*
45 * inittodr, settodr and support routines written
46 * by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>
47 *
48 * reintroduced and updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
49 */
50
51#include "opt_clock.h"
52#include "apm.h"
53
54#include <sys/param.h>
55#include <sys/systm.h>
56#include <sys/time.h>
57#include <sys/kernel.h>
58#ifndef SMP
59#include <sys/lock.h>
60#endif
61#include <sys/sysctl.h>
62
63#include <machine/clock.h>
64#ifdef CLK_CALIBRATION_LOOP
65#include <machine/cons.h>
66#endif
67#include <machine/cputypes.h>
68#include <machine/frame.h>
69#include <machine/ipl.h>
70#include <machine/limits.h>
71#include <machine/md_var.h>
72#if NAPM > 0
73#include <machine/apm_bios.h>
74#include <i386/apm/apm_setup.h>
75#endif
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 <i386/isa/rtc.h>
87#include <i386/isa/timerreg.h>
88
89#include <sys/interrupt.h>
90
91#ifdef SMP
92#define disable_intr() CLOCK_DISABLE_INTR()
93#define enable_intr() CLOCK_ENABLE_INTR()
94
95#ifdef APIC_IO
96#include <i386/isa/intr_machdep.h>
97/* The interrupt triggered by the 8254 (timer) chip */
98int apic_8254_intr;
99static u_long read_intr_count __P((int vec));
100static void setup_8254_mixed_mode __P((void));
101#endif
102#endif /* SMP */
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 disable_rtc_set; /* disable resettodr() if != 0 */
131u_int idelayed;
132int statclock_disable;
133u_int stat_imask = SWI_CLOCK_MASK;
134#ifndef TIMER_FREQ
135#define TIMER_FREQ 1193182
136#endif
137u_int timer_freq = TIMER_FREQ;
138int timer0_max_count;
139u_int tsc_freq;
140int wall_cmos_clock; /* wall CMOS clock assumed if != 0 */
141
142static int beeping = 0;
143static u_int clk_imask = HWI_MASK | SWI_MASK;
144static const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31};
145static u_int hardclock_max_count;
146static u_int32_t i8254_lastcount;
147static u_int32_t i8254_offset;
148static int i8254_ticked;
149/*
150 * XXX new_function and timer_func should not handle clockframes, but
151 * timer_func currently needs to hold hardclock to handle the
152 * timer0_state == 0 case. We should use register_intr()/unregister_intr()
153 * to switch between clkintr() and a slightly different timerintr().
154 */
155static void (*new_function) __P((struct clockframe *frame));
156static u_int new_rate;
157static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
158static u_char rtc_statusb = RTCSB_24HR | RTCSB_PINTR;
159static u_int timer0_prescaler_count;
160
161/* Values for timerX_state: */
162#define RELEASED 0
163#define RELEASE_PENDING 1
164#define ACQUIRED 2
165#define ACQUIRE_PENDING 3
166
167static u_char timer0_state;
168static u_char timer2_state;
169static void (*timer_func) __P((struct clockframe *frame)) = hardclock;
170static u_int tsc_present;
171
172static u_int64_t i8254_get_timecount __P((void));
173static void set_timer_freq(u_int freq, int intr_freq);
174static u_int64_t tsc_get_timecount __P((void));
175static u_int32_t tsc_get_timedelta __P((struct timecounter *tc));
176
177static struct timecounter tsc_timecounter[3] = {
178 tsc_get_timedelta, /* get_timedelta */
179 tsc_get_timecount, /* get_timecount */
180 ~0, /* counter_mask */
181 0, /* frequency */
182 "TSC" /* name */
183};
184
185SYSCTL_OPAQUE(_debug, OID_AUTO, tsc_timecounter, CTLFLAG_RD,
186 tsc_timecounter, sizeof(tsc_timecounter), "S,timecounter", "");
187
188static struct timecounter i8254_timecounter[3] = {
189 0, /* get_timedelta */
190 i8254_get_timecount, /* get_timecount */
191 (1ULL << 32) - 1, /* counter_mask */
192 0, /* frequency */
193 "i8254" /* name */
194};
195
196SYSCTL_OPAQUE(_debug, OID_AUTO, i8254_timecounter, CTLFLAG_RD,
197 i8254_timecounter, sizeof(i8254_timecounter), "S,timecounter", "");
198
199static void
200clkintr(struct clockframe frame)
201{
202 if (!i8254_ticked)
203 i8254_offset += timer0_max_count;
204 else
205 i8254_ticked = 0;
206 i8254_lastcount = 0;
207 timer_func(&frame);
208 switch (timer0_state) {
209
210 case RELEASED:
211 setdelayed();
212 break;
213
214 case ACQUIRED:
215 if ((timer0_prescaler_count += timer0_max_count)
216 >= hardclock_max_count) {
217 timer0_prescaler_count -= hardclock_max_count;
218 hardclock(&frame);
219 setdelayed();
220 }
221 break;
222
223 case ACQUIRE_PENDING:
224 setdelayed();
225 timer0_max_count = TIMER_DIV(new_rate);
226 disable_intr();
227 outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
228 outb(TIMER_CNTR0, timer0_max_count & 0xff);
229 outb(TIMER_CNTR0, timer0_max_count >> 8);
230 enable_intr();
231 timer0_prescaler_count = 0;
232 timer_func = new_function;
233 timer0_state = ACQUIRED;
234 break;
235
236 case RELEASE_PENDING:
237 if ((timer0_prescaler_count += timer0_max_count)
238 >= hardclock_max_count) {
239 timer0_prescaler_count -= hardclock_max_count;
240 /*
241 * See microtime.s for this magic.
242 */
243 time.tv_usec += (27465 * timer0_prescaler_count) >> 15;
244 if (time.tv_usec >= 1000000)
245 time.tv_usec -= 1000000;
246 hardclock(&frame);
247 setdelayed();
248 timer0_max_count = hardclock_max_count;
249 disable_intr();
250 outb(TIMER_MODE,
251 TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
252 outb(TIMER_CNTR0, timer0_max_count & 0xff);
253 outb(TIMER_CNTR0, timer0_max_count >> 8);
254 enable_intr();
255 timer0_prescaler_count = 0;
256 timer_func = hardclock;
257 timer0_state = RELEASED;
258 }
259 break;
260 }
261}
262
263/*
264 * The acquire and release functions must be called at ipl >= splclock().
265 */
266int
267acquire_timer0(int rate, void (*function) __P((struct clockframe *frame)))
268{
269 static int old_rate;
270
271 if (rate <= 0 || rate > TIMER0_MAX_FREQ)
272 return (-1);
273 if (strcmp(timecounter->name, "i8254") == 0)
274 return (-1);
275 switch (timer0_state) {
276
277 case RELEASED:
278 timer0_state = ACQUIRE_PENDING;
279 break;
280
281 case RELEASE_PENDING:
282 if (rate != old_rate)
283 return (-1);
284 /*
285 * The timer has been released recently, but is being
286 * re-acquired before the release completed. In this
287 * case, we simply reclaim it as if it had not been
288 * released at all.
289 */
290 timer0_state = ACQUIRED;
291 break;
292
293 default:
294 return (-1); /* busy */
295 }
296 new_function = function;
297 old_rate = new_rate = rate;
298 return (0);
299}
300
301int
302acquire_timer2(int mode)
303{
304
305 if (timer2_state != RELEASED)
306 return (-1);
307 timer2_state = ACQUIRED;
308
309 /*
310 * This access to the timer registers is as atomic as possible
311 * because it is a single instruction. We could do better if we
312 * knew the rate. Use of splclock() limits glitches to 10-100us,
313 * and this is probably good enough for timer2, so we aren't as
314 * careful with it as with timer0.
315 */
316 outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
317
318 return (0);
319}
320
321int
322release_timer0()
323{
324 switch (timer0_state) {
325
326 case ACQUIRED:
327 timer0_state = RELEASE_PENDING;
328 break;
329
330 case ACQUIRE_PENDING:
331 /* Nothing happened yet, release quickly. */
332 timer0_state = RELEASED;
333 break;
334
335 default:
336 return (-1);
337 }
338 return (0);
339}
340
341int
342release_timer2()
343{
344
345 if (timer2_state != ACQUIRED)
346 return (-1);
347 timer2_state = RELEASED;
348 outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
349 return (0);
350}
351
352/*
353 * This routine receives statistical clock interrupts from the RTC.
354 * As explained above, these occur at 128 interrupts per second.
355 * When profiling, we receive interrupts at a rate of 1024 Hz.
356 *
357 * This does not actually add as much overhead as it sounds, because
358 * when the statistical clock is active, the hardclock driver no longer
359 * needs to keep (inaccurate) statistics on its own. This decouples
360 * statistics gathering from scheduling interrupts.
361 *
362 * The RTC chip requires that we read status register C (RTC_INTR)
363 * to acknowledge an interrupt, before it will generate the next one.
364 * Under high interrupt load, rtcintr() can be indefinitely delayed and
365 * the clock can tick immediately after the read from RTC_INTR. In this
366 * case, the mc146818A interrupt signal will not drop for long enough
367 * to register with the 8259 PIC. If an interrupt is missed, the stat
368 * clock will halt, considerably degrading system performance. This is
369 * why we use 'while' rather than a more straightforward 'if' below.
370 * Stat clock ticks can still be lost, causing minor loss of accuracy
371 * in the statistics, but the stat clock will no longer stop.
372 */
373static void
374rtcintr(struct clockframe frame)
375{
376 while (rtcin(RTC_INTR) & RTCIR_PERIOD)
377 statclock(&frame);
378}
379
380#include "opt_ddb.h"
381#ifdef DDB
382#include <ddb/ddb.h>
383
384DB_SHOW_COMMAND(rtc, rtc)
385{
386 printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n",
387 rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY),
388 rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC),
389 rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR));
390}
391#endif /* DDB */
392
393static int
394getit(void)
395{
396 u_long ef;
397 int high, low;
398
399 ef = read_eflags();
400 disable_intr();
401
402 /* Select timer0 and latch counter value. */
403 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
404
405 low = inb(TIMER_CNTR0);
406 high = inb(TIMER_CNTR0);
407
408 CLOCK_UNLOCK();
409 write_eflags(ef);
410 return ((high << 8) | low);
411}
412
413/*
414 * Wait "n" microseconds.
415 * Relies on timer 1 counting down from (timer_freq / hz)
416 * Note: timer had better have been programmed before this is first used!
417 */
418void
419DELAY(int n)
420{
421 int delta, prev_tick, tick, ticks_left;
422
423#ifdef DELAYDEBUG
424 int getit_calls = 1;
425 int n1;
426 static int state = 0;
427
428 if (state == 0) {
429 state = 1;
430 for (n1 = 1; n1 <= 10000000; n1 *= 10)
431 DELAY(n1);
432 state = 2;
433 }
434 if (state == 1)
435 printf("DELAY(%d)...", n);
436#endif
437 /*
438 * Guard against the timer being uninitialized if we are called
439 * early for console i/o.
440 */
441 if (timer0_max_count == 0)
442 set_timer_freq(timer_freq, hz);
443
444 /*
445 * Read the counter first, so that the rest of the setup overhead is
446 * counted. Guess the initial overhead is 20 usec (on most systems it
447 * takes about 1.5 usec for each of the i/o's in getit(). The loop
448 * takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
449 * multiplications and divisions to scale the count take a while).
450 */
451 prev_tick = getit();
452 n -= 0; /* XXX actually guess no initial overhead */
453 /*
454 * Calculate (n * (timer_freq / 1e6)) without using floating point
455 * and without any avoidable overflows.
456 */
457 if (n <= 0)
458 ticks_left = 0;
459 else if (n < 256)
460 /*
461 * Use fixed point to avoid a slow division by 1000000.
462 * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
463 * 2^15 is the first power of 2 that gives exact results
464 * for n between 0 and 256.
465 */
466 ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
467 else
468 /*
469 * Don't bother using fixed point, although gcc-2.7.2
470 * generates particularly poor code for the long long
471 * division, since even the slow way will complete long
472 * before the delay is up (unless we're interrupted).
473 */
474 ticks_left = ((u_int)n * (long long)timer_freq + 999999)
475 / 1000000;
476
477 while (ticks_left > 0) {
478 tick = getit();
479#ifdef DELAYDEBUG
480 ++getit_calls;
481#endif
482 delta = prev_tick - tick;
483 prev_tick = tick;
484 if (delta < 0) {
485 delta += timer0_max_count;
486 /*
487 * Guard against timer0_max_count being wrong.
488 * This shouldn't happen in normal operation,
489 * but it may happen if set_timer_freq() is
490 * traced.
491 */
492 if (delta < 0)
493 delta = 0;
494 }
495 ticks_left -= delta;
496 }
497#ifdef DELAYDEBUG
498 if (state == 1)
499 printf(" %d calls to getit() at %d usec each\n",
500 getit_calls, (n + 5) / getit_calls);
501#endif
502}
503
504static void
505sysbeepstop(void *chan)
506{
507 outb(IO_PPI, inb(IO_PPI)&0xFC); /* disable counter2 output to speaker */
508 release_timer2();
509 beeping = 0;
510}
511
512int
513sysbeep(int pitch, int period)
514{
515 int x = splclock();
516
517 if (acquire_timer2(TIMER_SQWAVE|TIMER_16BIT))
518 if (!beeping) {
519 /* Something else owns it. */
520 splx(x);
521 return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
522 }
523 disable_intr();
524 outb(TIMER_CNTR2, pitch);
525 outb(TIMER_CNTR2, (pitch>>8));
526 enable_intr();
527 if (!beeping) {
528 /* enable counter2 output to speaker */
529 outb(IO_PPI, inb(IO_PPI) | 3);
530 beeping = period;
531 timeout(sysbeepstop, (void *)NULL, period);
532 }
533 splx(x);
534 return (0);
535}
536
537/*
538 * RTC support routines
539 */
540
541int
542rtcin(reg)
543 int reg;
544{
545 u_char val;
546
547 outb(IO_RTC, reg);
548 inb(0x84);
549 val = inb(IO_RTC + 1);
550 inb(0x84);
551 return (val);
552}
553
554static __inline void
555writertc(u_char reg, u_char val)
556{
557 inb(0x84);
558 outb(IO_RTC, reg);
559 inb(0x84);
560 outb(IO_RTC + 1, val);
561 inb(0x84); /* XXX work around wrong order in rtcin() */
562}
563
564static __inline int
565readrtc(int port)
566{
567 return(bcd2bin(rtcin(port)));
568}
569
570static u_int
571calibrate_clocks(void)
572{
573 u_int count, prev_count, tot_count;
574 int sec, start_sec, timeout;
575
576 if (bootverbose)
577 printf("Calibrating clock(s) ... ");
578 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
579 goto fail;
580 timeout = 100000000;
581
582 /* Read the mc146818A seconds counter. */
583 for (;;) {
584 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
585 sec = rtcin(RTC_SEC);
586 break;
587 }
588 if (--timeout == 0)
589 goto fail;
590 }
591
592 /* Wait for the mC146818A seconds counter to change. */
593 start_sec = sec;
594 for (;;) {
595 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP)) {
596 sec = rtcin(RTC_SEC);
597 if (sec != start_sec)
598 break;
599 }
600 if (--timeout == 0)
601 goto fail;
602 }
603
604 /* Start keeping track of the i8254 counter. */
605 prev_count = getit();
606 if (prev_count == 0 || prev_count > timer0_max_count)
607 goto fail;
608 tot_count = 0;
609
610 if (tsc_present)
611 wrmsr(0x10, 0LL); /* XXX 0x10 is the MSR for the TSC */
612
613 /*
614 * Wait for the mc146818A seconds counter to change. Read the i8254
615 * counter for each iteration since this is convenient and only
616 * costs a few usec of inaccuracy. The timing of the final reads
617 * of the counters almost matches the timing of the initial reads,
618 * so the main cause of inaccuracy is the varying latency from
619 * inside getit() or rtcin(RTC_STATUSA) to the beginning of the
620 * rtcin(RTC_SEC) that returns a changed seconds count. The
621 * maximum inaccuracy from this cause is < 10 usec on 486's.
622 */
623 start_sec = sec;
624 for (;;) {
625 if (!(rtcin(RTC_STATUSA) & RTCSA_TUP))
626 sec = rtcin(RTC_SEC);
627 count = getit();
628 if (count == 0 || count > timer0_max_count)
629 goto fail;
630 if (count > prev_count)
631 tot_count += prev_count - (count - timer0_max_count);
632 else
633 tot_count += prev_count - count;
634 prev_count = count;
635 if (sec != start_sec)
636 break;
637 if (--timeout == 0)
638 goto fail;
639 }
640
641 /*
642 * Read the cpu cycle counter. The timing considerations are
643 * similar to those for the i8254 clock.
644 */
645 if (tsc_present)
646 tsc_freq = rdtsc();
647
648 if (bootverbose) {
649 if (tsc_present)
650 printf("TSC clock: %u Hz, ", tsc_freq);
651 printf("i8254 clock: %u Hz\n", tot_count);
652 }
653 return (tot_count);
654
655fail:
656 if (bootverbose)
657 printf("failed, using default i8254 clock of %u Hz\n",
658 timer_freq);
659 return (timer_freq);
660}
661
662static void
663set_timer_freq(u_int freq, int intr_freq)
664{
665 u_long ef;
666 int new_timer0_max_count;
667
668 ef = read_eflags();
669 disable_intr();
670 timer_freq = freq;
671 new_timer0_max_count = hardclock_max_count = TIMER_DIV(intr_freq);
672 if (new_timer0_max_count != timer0_max_count) {
673 timer0_max_count = new_timer0_max_count;
674 outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
675 outb(TIMER_CNTR0, timer0_max_count & 0xff);
676 outb(TIMER_CNTR0, timer0_max_count >> 8);
677 }
678 CLOCK_UNLOCK();
679 write_eflags(ef);
680}
681
682/*
683 * Initialize 8254 timer 0 early so that it can be used in DELAY().
684 * XXX initialization of other timers is unintentionally left blank.
685 */
686void
687startrtclock()
688{
689 u_int delta, freq;
690
691 if (cpu_feature & CPUID_TSC)
692 tsc_present = 1;
693 else
694 tsc_present = 0;
695
696 writertc(RTC_STATUSA, rtc_statusa);
697 writertc(RTC_STATUSB, RTCSB_24HR);
698
699 set_timer_freq(timer_freq, hz);
700 freq = calibrate_clocks();
701#ifdef CLK_CALIBRATION_LOOP
702 if (bootverbose) {
703 printf(
704 "Press a key on the console to abort clock calibration\n");
705 while (cncheckc() == -1)
706 calibrate_clocks();
707 }
708#endif
709
710 /*
711 * Use the calibrated i8254 frequency if it seems reasonable.
712 * Otherwise use the default, and don't use the calibrated i586
713 * frequency.
714 */
715 delta = freq > timer_freq ? freq - timer_freq : timer_freq - freq;
716 if (delta < timer_freq / 100) {
717#ifndef CLK_USE_I8254_CALIBRATION
718 if (bootverbose)
719 printf(
720"CLK_USE_I8254_CALIBRATION not specified - using default frequency\n");
721 freq = timer_freq;
722#endif
723 timer_freq = freq;
724 } else {
725 if (bootverbose)
726 printf(
727 "%d Hz differs from default of %d Hz by more than 1%%\n",
728 freq, timer_freq);
729 tsc_freq = 0;
730 }
731
732 set_timer_freq(timer_freq, hz);
733 i8254_timecounter[0].frequency = timer_freq;
734 init_timecounter(i8254_timecounter);
735
736#ifndef CLK_USE_TSC_CALIBRATION
737 if (tsc_freq != 0) {
738 if (bootverbose)
739 printf(
740"CLK_USE_TSC_CALIBRATION not specified - using old calibration method\n");
741 tsc_freq = 0;
742 }
743#endif
744 if (tsc_present && tsc_freq == 0) {
745 /*
746 * Calibration of the i586 clock relative to the mc146818A
747 * clock failed. Do a less accurate calibration relative
748 * to the i8254 clock.
749 */
750 wrmsr(0x10, 0LL); /* XXX */
751 DELAY(1000000);
752 tsc_freq = rdtsc();
753#ifdef CLK_USE_TSC_CALIBRATION
754 if (bootverbose)
755 printf("TSC clock: %u Hz (Method B)\n", tsc_freq);
756#endif
757 }
758
759#if !defined(SMP)
760 /*
761 * We can not use the TSC in SMP mode, until we figure out a
762 * cheap (impossible), reliable and precise (yeah right!) way
763 * to synchronize the TSCs of all the CPUs.
764 * Curse Intel for leaving the counter out of the I/O APIC.
765 */
766
767#if NAPM > 0
768 /*
769 * We can not use the TSC if we found an APM bios. Too many
770 * of them lie about their ability&intention to fiddle the CPU
771 * clock for us to rely on this. Precise timekeeping on an
772 * APM'ed machine is at best a fools pursuit anyway, since
773 * any and all of the time spent in various SMM code can't
774 * be reliably accounted for. Reading the RTC is your only
775 * source of reliable time info. The i8254 looses too of course
776 * but we need to have some kind of time...
777 */
778 if (apm_version != APMINI_CANTFIND)
779 return;
780#endif /* NAPM > 0 */
781
782 if (tsc_present && tsc_freq != 0) {
783 tsc_timecounter[0].frequency = tsc_freq;
784 init_timecounter(tsc_timecounter);
785 }
786
787#endif /* !defined(SMP) */
788}
789
790/*
791 * Initialize the time of day register, based on the time base which is, e.g.
792 * from a filesystem.
793 */
794void
795inittodr(time_t base)
796{
797 unsigned long sec, days;
798 int yd;
799 int year, month;
800 int y, m, s;
801 struct timespec ts;
802
803 if (base) {
804 s = splclock();
805 ts.tv_sec = base;
806 ts.tv_nsec = 0;
807 set_timecounter(&ts);
808 splx(s);
809 }
810
811 /* Look if we have a RTC present and the time is valid */
812 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR))
813 goto wrong_time;
814
815 /* wait for time update to complete */
816 /* If RTCSA_TUP is zero, we have at least 244us before next update */
817 while (rtcin(RTC_STATUSA) & RTCSA_TUP);
818
819 days = 0;
820#ifdef USE_RTC_CENTURY
821 year = readrtc(RTC_YEAR) + readrtc(RTC_CENTURY) * 100;
822#else
823 year = readrtc(RTC_YEAR) + 1900;
824 if (year < 1970)
825 year += 100;
826#endif
827 if (year < 1970)
828 goto wrong_time;
829 month = readrtc(RTC_MONTH);
830 for (m = 1; m < month; m++)
831 days += daysinmonth[m-1];
832 if ((month > 2) && LEAPYEAR(year))
833 days ++;
834 days += readrtc(RTC_DAY) - 1;
835 yd = days;
836 for (y = 1970; y < year; y++)
837 days += DAYSPERYEAR + LEAPYEAR(y);
838 sec = ((( days * 24 +
839 readrtc(RTC_HRS)) * 60 +
840 readrtc(RTC_MIN)) * 60 +
841 readrtc(RTC_SEC));
842 /* sec now contains the number of seconds, since Jan 1 1970,
843 in the local time zone */
844
845 sec += tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
846
847 y = time.tv_sec - sec;
848 if (y <= -2 || y >= 2) {
849 /* badly off, adjust it */
850 s = splclock();
851 ts.tv_sec = sec;
852 ts.tv_nsec = 0;
853 set_timecounter(&ts);
854 splx(s);
855 }
856 return;
857
858wrong_time:
859 printf("Invalid time in real time clock.\n");
860 printf("Check and reset the date immediately!\n");
861}
862
863/*
864 * Write system time back to RTC
865 */
866void
867resettodr()
868{
869 unsigned long tm;
870 int y, m, s;
871
872 if (disable_rtc_set)
873 return;
874
875 s = splclock();
876 tm = time.tv_sec;
877 splx(s);
878
879 /* Disable RTC updates and interrupts. */
880 writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR);
881
882 /* Calculate local time to put in RTC */
883
884 tm -= tz.tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
885
886 writertc(RTC_SEC, bin2bcd(tm%60)); tm /= 60; /* Write back Seconds */
887 writertc(RTC_MIN, bin2bcd(tm%60)); tm /= 60; /* Write back Minutes */
888 writertc(RTC_HRS, bin2bcd(tm%24)); tm /= 24; /* Write back Hours */
889
890 /* We have now the days since 01-01-1970 in tm */
891 writertc(RTC_WDAY, (tm+4)%7); /* Write back Weekday */
892 for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y);
893 tm >= m;
894 y++, m = DAYSPERYEAR + LEAPYEAR(y))
895 tm -= m;
896
897 /* Now we have the years in y and the day-of-the-year in tm */
898 writertc(RTC_YEAR, bin2bcd(y%100)); /* Write back Year */
899#ifdef USE_RTC_CENTURY
900 writertc(RTC_CENTURY, bin2bcd(y/100)); /* ... and Century */
901#endif
902 for (m = 0; ; m++) {
903 int ml;
904
905 ml = daysinmonth[m];
906 if (m == 1 && LEAPYEAR(y))
907 ml++;
908 if (tm < ml)
909 break;
910 tm -= ml;
911 }
912
913 writertc(RTC_MONTH, bin2bcd(m + 1)); /* Write back Month */
914 writertc(RTC_DAY, bin2bcd(tm + 1)); /* Write back Month Day */
915
916 /* Reenable RTC updates and interrupts. */
917 writertc(RTC_STATUSB, rtc_statusb);
918}
919
920
921/*
922 * Start both clocks running.
923 */
924void
925cpu_initclocks()
926{
927 int diag;
928#ifdef APIC_IO
929 int apic_8254_trial;
930#endif /* APIC_IO */
931
932 if (statclock_disable) {
933 /*
934 * The stat interrupt mask is different without the
935 * statistics clock. Also, don't set the interrupt
936 * flag which would normally cause the RTC to generate
937 * interrupts.
938 */
939 stat_imask = HWI_MASK | SWI_MASK;
940 rtc_statusb = RTCSB_24HR;
941 } else {
942 /* Setting stathz to nonzero early helps avoid races. */
943 stathz = RTC_NOPROFRATE;
944 profhz = RTC_PROFRATE;
945 }
946
947 /* Finish initializing 8253 timer 0. */
948#ifdef APIC_IO
949
950 apic_8254_intr = isa_apic_pin(0);
951 apic_8254_trial = 0;
952 if (apic_8254_intr >= 0 ) {
953 if (apic_int_type(0, 0) == 3)
954 apic_8254_trial = 1;
955 } else {
956 /* look for ExtInt on pin 0 */
957 if (apic_int_type(0, 0) == 3) {
958 apic_8254_intr = 0;
959 setup_8254_mixed_mode();
960 } else
961 panic("APIC_IO: Cannot route 8254 interrupt to CPU");
962 }
963
964 register_intr(/* irq */ apic_8254_intr, /* XXX id */ 0, /* flags */ 0,
965 /* XXX */ (inthand2_t *)clkintr, &clk_imask,
966 /* unit */ 0);
967 INTREN(1 << apic_8254_intr);
968
969#else /* APIC_IO */
970
971 register_intr(/* irq */ 0, /* XXX id */ 0, /* flags */ 0,
972 /* XXX */ (inthand2_t *)clkintr, &clk_imask,
973 /* unit */ 0);
974 INTREN(IRQ0);
975
976#endif /* APIC_IO */
977
978 /* Initialize RTC. */
979 writertc(RTC_STATUSA, rtc_statusa);
980 writertc(RTC_STATUSB, RTCSB_24HR);
981
982 /* Don't bother enabling the statistics clock. */
983 if (statclock_disable)
984 return;
985 diag = rtcin(RTC_DIAG);
986 if (diag != 0)
987 printf("RTC BIOS diagnostic error %b\n", diag, RTCDG_BITS);
988
989#ifdef APIC_IO
990 if (isa_apic_pin(8) != 8)
991 panic("APIC RTC != 8");
992#endif /* APIC_IO */
993
994 register_intr(/* irq */ 8, /* XXX id */ 1, /* flags */ 0,
995 /* XXX */ (inthand2_t *)rtcintr, &stat_imask,
996 /* unit */ 0);
997
998#ifdef APIC_IO
999 INTREN(APIC_IRQ8);
1000#else
1001 INTREN(IRQ8);
1002#endif /* APIC_IO */
1003
1004 writertc(RTC_STATUSB, rtc_statusb);
1005
1006#ifdef APIC_IO
1007 if (apic_8254_trial) {
1008
1009 printf("APIC_IO: Testing 8254 interrupt delivery\n");
1010 __asm __volatile("sti" : : : "memory");
1011 while (read_intr_count(8) < 6)
1012 __asm __volatile("sti" : : : "memory");
1013 if (read_intr_count(apic_8254_intr) < 3) {
1014 /*
1015 * The MP table is broken.
1016 * The 8254 was not connected to the specified pin
1017 * on the IO APIC.
1018 * Workaround: Limited variant of mixed mode.
1019 */
1020 INTRDIS(1 << apic_8254_intr);
1021 unregister_intr(apic_8254_intr,
1022 /* XXX */ (inthand2_t *) clkintr);
1023 printf("APIC_IO: Broken MP table detected: "
1024 "8254 is not connected to IO APIC int pin %d\n",
1025 apic_8254_intr);
1026
1027 apic_8254_intr = 0;
1028 setup_8254_mixed_mode();
1029 register_intr(/* irq */ apic_8254_intr, /* XXX id */ 0, /* flags */ 0,
1030 /* XXX */ (inthand2_t *)clkintr, &clk_imask,
1031 /* unit */ 0);
1032 INTREN(1 << apic_8254_intr);
1033 }
1034
1035 }
1036 if (apic_8254_intr)
1037 printf("APIC_IO: routing 8254 via pin %d\n",apic_8254_intr);
1038 else
1039 printf("APIC_IO: routing 8254 via 8259 on pin 0\n");
1040#endif
1041
1042}
1043
1044#ifdef APIC_IO
1045static u_long
1046read_intr_count(int vec)
1047{
1048 u_long *up;
1049 up = intr_countp[vec];
1050 if (up)
1051 return *up;
1052 return 0UL;
1053}
1054
1055static void
1056setup_8254_mixed_mode()
1057{
1058 /*
1059 * Allow 8254 timer to INTerrupt 8259:
1060 * re-initialize master 8259:
1061 * reset; prog 4 bytes, single ICU, edge triggered
1062 */
1063 outb(IO_ICU1, 0x13);
1064 outb(IO_ICU1 + 1, NRSVIDT); /* start vector (unused) */
1065 outb(IO_ICU1 + 1, 0x00); /* ignore slave */
1066 outb(IO_ICU1 + 1, 0x03); /* auto EOI, 8086 */
1067 outb(IO_ICU1 + 1, 0xfe); /* unmask INT0 */
1068
1069 /* program IO APIC for type 3 INT on INT0 */
1070 if (ext_int_setup(0, 0) < 0)
1071 panic("8254 redirect via APIC pin0 impossible!");
1072}
1073#endif
1074
1075void
1076setstatclockrate(int newhz)
1077{
1078 if (newhz == RTC_PROFRATE)
1079 rtc_statusa = RTCSA_DIVIDER | RTCSA_PROF;
1080 else
1081 rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
1082 writertc(RTC_STATUSA, rtc_statusa);
1083}
1084
1085static int
1086sysctl_machdep_i8254_freq SYSCTL_HANDLER_ARGS
1087{
1088 int error;
1089 u_int freq;
1090
1091 /*
1092 * Use `i8254' instead of `timer' in external names because `timer'
1093 * is is too generic. Should use it everywhere.
1094 */
1095 freq = timer_freq;
1096 error = sysctl_handle_opaque(oidp, &freq, sizeof freq, req);
1097 if (error == 0 && req->newptr != NULL) {
1098 if (timer0_state != RELEASED)
1099 return (EBUSY); /* too much trouble to handle */
1100 set_timer_freq(freq, hz);
1101 i8254_timecounter[0].frequency = freq;
1102 }
1103 return (error);
1104}
1105
1106SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW,
1107 0, sizeof(u_int), sysctl_machdep_i8254_freq, "I", "");
1108
1109static int
1110sysctl_machdep_tsc_freq SYSCTL_HANDLER_ARGS
1111{
1112 int error;
1113 u_int freq;
1114
1115 if (!tsc_present)
1116 return (EOPNOTSUPP);
1117 freq = tsc_freq;
1118 error = sysctl_handle_opaque(oidp, &freq, sizeof freq, req);
1119 if (error == 0 && req->newptr != NULL) {
1120 tsc_freq = freq;
1121 tsc_timecounter[0].frequency = tsc_freq;
1122 }
1123 return (error);
1124}
1125
1126SYSCTL_PROC(_machdep, OID_AUTO, tsc_freq, CTLTYPE_INT | CTLFLAG_RW,
1127 0, sizeof(u_int), sysctl_machdep_tsc_freq, "I", "");
1128
1129static u_int64_t
1130i8254_get_timecount(void)
1131{
1132 u_int32_t count;
1133 u_long ef;
1134 u_int high, low;
1135
1136 ef = read_eflags();
1137 disable_intr();
1138
1139 /* Select timer0 and latch counter value. */
1140 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
1141
1142 low = inb(TIMER_CNTR0);
1143 high = inb(TIMER_CNTR0);
1144
1145 count = hardclock_max_count - ((high << 8) | low);
1146 if (count < i8254_lastcount) {
1147 i8254_ticked = 1;
1148 i8254_offset += hardclock_max_count;
1149 }
1150
1151 i8254_lastcount = count;
1152 count += i8254_offset;
1153 CLOCK_UNLOCK();
1154 write_eflags(ef);
1155 return (count);
1156}
1157
1158static u_int64_t
1159tsc_get_timecount(void)
1160{
1161 return ((u_int64_t)rdtsc());
1162}
1163
1164static u_int32_t
1165tsc_get_timedelta(struct timecounter *tc)
1166{
1167 return ((u_int64_t)rdtsc() - tc->offset_count);
1168}