1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990 The Regents of the University of California.
5 * Copyright (c) 2010 Alexander Motin <[email protected]>
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * William Jolitz and Don Ahn.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * from: @(#)clock.c 7.2 (Berkeley) 5/12/91
36 */
37
38 #include <sys/cdefs.h>
39 /*
40 * Routines to handle clock hardware.
41 */
42
43 #ifdef __amd64__
44 #define DEV_APIC
45 #else
46 #include "opt_apic.h"
47 #endif
48 #include "opt_clock.h"
49 #include "opt_isa.h"
50
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/bus.h>
54 #include <sys/lock.h>
55 #include <sys/kdb.h>
56 #include <sys/mutex.h>
57 #include <sys/proc.h>
58 #include <sys/kernel.h>
59 #include <sys/module.h>
60 #include <sys/rman.h>
61 #include <sys/sched.h>
62 #include <sys/smp.h>
63 #include <sys/sysctl.h>
64 #include <sys/timeet.h>
65 #include <sys/timetc.h>
66
67 #include <machine/clock.h>
68 #include <machine/cpu.h>
69 #include <machine/intr_machdep.h>
70 #include <x86/apicvar.h>
71 #include <x86/init.h>
72 #include <x86/ppireg.h>
73 #include <x86/timerreg.h>
74
75 #include <isa/rtc.h>
76 #ifdef DEV_ISA
77 #include <isa/isareg.h>
78 #include <isa/isavar.h>
79 #endif
80
81 int clkintr_pending;
82 #ifndef TIMER_FREQ
83 #define TIMER_FREQ 1193182
84 #endif
85 u_int i8254_freq = TIMER_FREQ;
86 TUNABLE_INT("hw.i8254.freq", &i8254_freq);
87 int i8254_max_count;
88 static int i8254_timecounter = 1;
89
90 static struct mtx clock_lock;
91 static struct intsrc *i8254_intsrc;
92 static uint16_t i8254_lastcount;
93 static uint16_t i8254_offset;
94 static int (*i8254_pending)(struct intsrc *);
95 static int i8254_ticked;
96
97 struct attimer_softc {
98 int intr_en;
99 int port_rid, intr_rid;
100 struct resource *port_res;
101 struct resource *intr_res;
102 void *intr_handler;
103 struct timecounter tc;
104 struct eventtimer et;
105 int mode;
106 #define MODE_STOP 0
107 #define MODE_PERIODIC 1
108 #define MODE_ONESHOT 2
109 uint32_t period;
110 };
111 static struct attimer_softc *attimer_sc = NULL;
112
113 static int timer0_period = -2;
114 static int timer0_mode = 0xffff;
115 static int timer0_last = 0xffff;
116
117 /* Values for timerX_state: */
118 #define RELEASED 0
119 #define RELEASE_PENDING 1
120 #define ACQUIRED 2
121 #define ACQUIRE_PENDING 3
122
123 static u_char timer2_state;
124
125 static unsigned i8254_get_timecount(struct timecounter *tc);
126 static void set_i8254_freq(int mode, uint32_t period);
127
128 void
clock_init(void)129 clock_init(void)
130 {
131 /* Init the clock lock */
132 mtx_init(&clock_lock, "clk", NULL, MTX_SPIN | MTX_NOPROFILE);
133 /* Init the clock in order to use DELAY */
134 init_ops.early_clock_source_init();
135 tsc_init();
136 }
137
138 static int
clkintr(void * arg)139 clkintr(void *arg)
140 {
141 struct attimer_softc *sc = (struct attimer_softc *)arg;
142
143 if (i8254_timecounter && sc->period != 0) {
144 mtx_lock_spin(&clock_lock);
145 if (i8254_ticked)
146 i8254_ticked = 0;
147 else {
148 i8254_offset += i8254_max_count;
149 i8254_lastcount = 0;
150 }
151 clkintr_pending = 0;
152 mtx_unlock_spin(&clock_lock);
153 }
154
155 if (sc->et.et_active && sc->mode != MODE_STOP)
156 sc->et.et_event_cb(&sc->et, sc->et.et_arg);
157
158 return (FILTER_HANDLED);
159 }
160
161 int
timer_spkr_acquire(void)162 timer_spkr_acquire(void)
163 {
164 int mode;
165
166 mode = TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT;
167
168 if (timer2_state != RELEASED)
169 return (-1);
170 timer2_state = ACQUIRED;
171
172 /*
173 * This access to the timer registers is as atomic as possible
174 * because it is a single instruction. We could do better if we
175 * knew the rate. Use of splclock() limits glitches to 10-100us,
176 * and this is probably good enough for timer2, so we aren't as
177 * careful with it as with timer0.
178 */
179 outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f));
180
181 ppi_spkr_on(); /* enable counter2 output to speaker */
182 return (0);
183 }
184
185 int
timer_spkr_release(void)186 timer_spkr_release(void)
187 {
188
189 if (timer2_state != ACQUIRED)
190 return (-1);
191 timer2_state = RELEASED;
192 outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT);
193
194 ppi_spkr_off(); /* disable counter2 output to speaker */
195 return (0);
196 }
197
198 void
timer_spkr_setfreq(int freq)199 timer_spkr_setfreq(int freq)
200 {
201
202 freq = i8254_freq / freq;
203 mtx_lock_spin(&clock_lock);
204 outb(TIMER_CNTR2, freq & 0xff);
205 outb(TIMER_CNTR2, freq >> 8);
206 mtx_unlock_spin(&clock_lock);
207 }
208
209 static int
getit(void)210 getit(void)
211 {
212 int high, low;
213
214 mtx_lock_spin(&clock_lock);
215
216 /* Select timer0 and latch counter value. */
217 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
218
219 low = inb(TIMER_CNTR0);
220 high = inb(TIMER_CNTR0);
221
222 mtx_unlock_spin(&clock_lock);
223 return ((high << 8) | low);
224 }
225
226 /*
227 * Wait "n" microseconds.
228 * Relies on timer 1 counting down from (i8254_freq / hz)
229 * Note: timer had better have been programmed before this is first used!
230 */
231 void
i8254_delay(int n)232 i8254_delay(int n)
233 {
234 int delta, prev_tick, tick, ticks_left;
235 #ifdef DELAYDEBUG
236 int getit_calls = 1;
237 int n1;
238 static int state = 0;
239
240 if (state == 0) {
241 state = 1;
242 for (n1 = 1; n1 <= 10000000; n1 *= 10)
243 DELAY(n1);
244 state = 2;
245 }
246 if (state == 1)
247 printf("DELAY(%d)...", n);
248 #endif
249 /*
250 * Read the counter first, so that the rest of the setup overhead is
251 * counted. Guess the initial overhead is 20 usec (on most systems it
252 * takes about 1.5 usec for each of the i/o's in getit(). The loop
253 * takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
254 * multiplications and divisions to scale the count take a while).
255 *
256 * However, if ddb is active then use a fake counter since reading
257 * the i8254 counter involves acquiring a lock. ddb must not do
258 * locking for many reasons, but it calls here for at least atkbd
259 * input.
260 */
261 #ifdef KDB
262 if (kdb_active)
263 prev_tick = 1;
264 else
265 #endif
266 prev_tick = getit();
267 n -= 0; /* XXX actually guess no initial overhead */
268 /*
269 * Calculate (n * (i8254_freq / 1e6)) without using floating point
270 * and without any avoidable overflows.
271 */
272 if (n <= 0)
273 ticks_left = 0;
274 else if (n < 256)
275 /*
276 * Use fixed point to avoid a slow division by 1000000.
277 * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest.
278 * 2^15 is the first power of 2 that gives exact results
279 * for n between 0 and 256.
280 */
281 ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15;
282 else
283 /*
284 * Don't bother using fixed point, although gcc-2.7.2
285 * generates particularly poor code for the long long
286 * division, since even the slow way will complete long
287 * before the delay is up (unless we're interrupted).
288 */
289 ticks_left = ((u_int)n * (long long)i8254_freq + 999999)
290 / 1000000;
291
292 while (ticks_left > 0) {
293 #ifdef KDB
294 if (kdb_active) {
295 inb(0x84);
296 tick = prev_tick - 1;
297 if (tick <= 0)
298 tick = i8254_max_count;
299 } else
300 #endif
301 tick = getit();
302 #ifdef DELAYDEBUG
303 ++getit_calls;
304 #endif
305 delta = prev_tick - tick;
306 prev_tick = tick;
307 if (delta < 0) {
308 delta += i8254_max_count;
309 /*
310 * Guard against i8254_max_count being wrong.
311 * This shouldn't happen in normal operation,
312 * but it may happen if set_i8254_freq() is
313 * traced.
314 */
315 if (delta < 0)
316 delta = 0;
317 }
318 ticks_left -= delta;
319 }
320 #ifdef DELAYDEBUG
321 if (state == 1)
322 printf(" %d calls to getit() at %d usec each\n",
323 getit_calls, (n + 5) / getit_calls);
324 #endif
325 }
326
327 static void
set_i8254_freq(int mode,uint32_t period)328 set_i8254_freq(int mode, uint32_t period)
329 {
330 int new_count, new_mode;
331
332 mtx_lock_spin(&clock_lock);
333 if (mode == MODE_STOP) {
334 if (i8254_timecounter) {
335 mode = MODE_PERIODIC;
336 new_count = 0x10000;
337 } else
338 new_count = -1;
339 } else {
340 new_count = min(((uint64_t)i8254_freq * period +
341 0x80000000LLU) >> 32, 0x10000);
342 }
343 if (new_count == timer0_period)
344 goto out;
345 i8254_max_count = ((new_count & ~0xffff) != 0) ? 0xffff : new_count;
346 timer0_period = (mode == MODE_PERIODIC) ? new_count : -1;
347 switch (mode) {
348 case MODE_STOP:
349 new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT;
350 outb(TIMER_MODE, new_mode);
351 outb(TIMER_CNTR0, 0);
352 outb(TIMER_CNTR0, 0);
353 break;
354 case MODE_PERIODIC:
355 new_mode = TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT;
356 outb(TIMER_MODE, new_mode);
357 outb(TIMER_CNTR0, new_count & 0xff);
358 outb(TIMER_CNTR0, new_count >> 8);
359 break;
360 case MODE_ONESHOT:
361 if (new_count < 256 && timer0_last < 256) {
362 new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_LSB;
363 if (new_mode != timer0_mode)
364 outb(TIMER_MODE, new_mode);
365 outb(TIMER_CNTR0, new_count & 0xff);
366 break;
367 }
368 new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT;
369 if (new_mode != timer0_mode)
370 outb(TIMER_MODE, new_mode);
371 outb(TIMER_CNTR0, new_count & 0xff);
372 outb(TIMER_CNTR0, new_count >> 8);
373 break;
374 default:
375 panic("set_i8254_freq: unknown operational mode");
376 }
377 timer0_mode = new_mode;
378 timer0_last = new_count;
379 out:
380 mtx_unlock_spin(&clock_lock);
381 }
382
383 static void
i8254_restore(void)384 i8254_restore(void)
385 {
386
387 timer0_period = -2;
388 timer0_mode = 0xffff;
389 timer0_last = 0xffff;
390 if (attimer_sc != NULL)
391 set_i8254_freq(attimer_sc->mode, attimer_sc->period);
392 else
393 set_i8254_freq(MODE_STOP, 0);
394 }
395
396 /* This is separate from startrtclock() so that it can be called early. */
397 void
i8254_init(void)398 i8254_init(void)
399 {
400
401 set_i8254_freq(MODE_STOP, 0);
402 }
403
404 void
startrtclock(void)405 startrtclock(void)
406 {
407
408 start_TSC();
409 }
410
411 void
cpu_initclocks(void)412 cpu_initclocks(void)
413 {
414 struct thread *td;
415 int i;
416
417 td = curthread;
418
419 tsc_calibrate();
420 #ifdef DEV_APIC
421 lapic_calibrate_timer();
422 #endif
423 cpu_initclocks_bsp();
424 CPU_FOREACH(i) {
425 if (i == 0)
426 continue;
427 thread_lock(td);
428 sched_bind(td, i);
429 thread_unlock(td);
430 cpu_initclocks_ap();
431 }
432 thread_lock(td);
433 if (sched_is_bound(td))
434 sched_unbind(td);
435 thread_unlock(td);
436 }
437
438 static int
sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS)439 sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS)
440 {
441 int error;
442 u_int freq;
443
444 /*
445 * Use `i8254' instead of `timer' in external names because `timer'
446 * is too generic. Should use it everywhere.
447 */
448 freq = i8254_freq;
449 error = sysctl_handle_int(oidp, &freq, 0, req);
450 if (error == 0 && req->newptr != NULL) {
451 i8254_freq = freq;
452 if (attimer_sc != NULL) {
453 set_i8254_freq(attimer_sc->mode, attimer_sc->period);
454 attimer_sc->tc.tc_frequency = freq;
455 } else {
456 set_i8254_freq(MODE_STOP, 0);
457 }
458 }
459 return (error);
460 }
461
462 SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq,
463 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
464 0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU",
465 "i8254 timer frequency");
466
467 static unsigned
i8254_get_timecount(struct timecounter * tc)468 i8254_get_timecount(struct timecounter *tc)
469 {
470 device_t dev = (device_t)tc->tc_priv;
471 struct attimer_softc *sc = device_get_softc(dev);
472 register_t flags;
473 uint16_t count;
474 u_int high, low;
475
476 if (sc->period == 0)
477 return (i8254_max_count - getit());
478
479 #ifdef __amd64__
480 flags = read_rflags();
481 #else
482 flags = read_eflags();
483 #endif
484 mtx_lock_spin(&clock_lock);
485
486 /* Select timer0 and latch counter value. */
487 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
488
489 low = inb(TIMER_CNTR0);
490 high = inb(TIMER_CNTR0);
491 count = i8254_max_count - ((high << 8) | low);
492 if (count < i8254_lastcount ||
493 (!i8254_ticked && (clkintr_pending ||
494 ((count < 20 || (!(flags & PSL_I) &&
495 count < i8254_max_count / 2u)) &&
496 i8254_pending != NULL && i8254_pending(i8254_intsrc))))) {
497 i8254_ticked = 1;
498 i8254_offset += i8254_max_count;
499 }
500 i8254_lastcount = count;
501 count += i8254_offset;
502 mtx_unlock_spin(&clock_lock);
503 return (count);
504 }
505
506 static int
attimer_start(struct eventtimer * et,sbintime_t first,sbintime_t period)507 attimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
508 {
509 device_t dev = (device_t)et->et_priv;
510 struct attimer_softc *sc = device_get_softc(dev);
511
512 if (period != 0) {
513 sc->mode = MODE_PERIODIC;
514 sc->period = period;
515 } else {
516 sc->mode = MODE_ONESHOT;
517 sc->period = first;
518 }
519 if (!sc->intr_en) {
520 i8254_intsrc->is_pic->pic_enable_source(i8254_intsrc);
521 sc->intr_en = 1;
522 }
523 set_i8254_freq(sc->mode, sc->period);
524 return (0);
525 }
526
527 static int
attimer_stop(struct eventtimer * et)528 attimer_stop(struct eventtimer *et)
529 {
530 device_t dev = (device_t)et->et_priv;
531 struct attimer_softc *sc = device_get_softc(dev);
532
533 sc->mode = MODE_STOP;
534 sc->period = 0;
535 set_i8254_freq(sc->mode, sc->period);
536 return (0);
537 }
538
539 #ifdef DEV_ISA
540 /*
541 * Attach to the ISA PnP descriptors for the timer
542 */
543 static struct isa_pnp_id attimer_ids[] = {
544 { 0x0001d041 /* PNP0100 */, "AT timer" },
545 { 0 }
546 };
547
548 static int
attimer_probe(device_t dev)549 attimer_probe(device_t dev)
550 {
551 int result;
552
553 result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids);
554 /* ENOENT means no PnP-ID, device is hinted. */
555 if (result == ENOENT) {
556 device_set_desc(dev, "AT timer");
557 return (BUS_PROBE_LOW_PRIORITY);
558 }
559 return (result);
560 }
561
562 static int
attimer_attach(device_t dev)563 attimer_attach(device_t dev)
564 {
565 struct attimer_softc *sc;
566 rman_res_t s;
567 int i;
568
569 attimer_sc = sc = device_get_softc(dev);
570 bzero(sc, sizeof(struct attimer_softc));
571 if (!(sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT,
572 &sc->port_rid, IO_TIMER1, IO_TIMER1 + 3, 4, RF_ACTIVE)))
573 device_printf(dev,"Warning: Couldn't map I/O.\n");
574 i8254_intsrc = intr_lookup_source(0);
575 if (i8254_intsrc != NULL)
576 i8254_pending = i8254_intsrc->is_pic->pic_source_pending;
577 resource_int_value(device_get_name(dev), device_get_unit(dev),
578 "timecounter", &i8254_timecounter);
579 set_i8254_freq(MODE_STOP, 0);
580 if (i8254_timecounter) {
581 sc->tc.tc_get_timecount = i8254_get_timecount;
582 sc->tc.tc_counter_mask = 0xffff;
583 sc->tc.tc_frequency = i8254_freq;
584 sc->tc.tc_name = "i8254";
585 sc->tc.tc_quality = 0;
586 sc->tc.tc_priv = dev;
587 tc_init(&sc->tc);
588 }
589 if (resource_int_value(device_get_name(dev), device_get_unit(dev),
590 "clock", &i) != 0 || i != 0) {
591 sc->intr_rid = 0;
592 while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid,
593 &s, NULL) == 0 && s != 0)
594 sc->intr_rid++;
595 if (!(sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ,
596 &sc->intr_rid, 0, 0, 1, RF_ACTIVE))) {
597 device_printf(dev,"Can't map interrupt.\n");
598 return (0);
599 }
600 /* Dirty hack, to make bus_setup_intr to not enable source. */
601 i8254_intsrc->is_handlers++;
602 if ((bus_setup_intr(dev, sc->intr_res,
603 INTR_MPSAFE | INTR_TYPE_CLK,
604 (driver_filter_t *)clkintr, NULL,
605 sc, &sc->intr_handler))) {
606 device_printf(dev, "Can't setup interrupt.\n");
607 i8254_intsrc->is_handlers--;
608 return (0);
609 }
610 i8254_intsrc->is_handlers--;
611 i8254_intsrc->is_pic->pic_enable_intr(i8254_intsrc);
612 sc->et.et_name = "i8254";
613 sc->et.et_flags = ET_FLAGS_PERIODIC;
614 if (!i8254_timecounter)
615 sc->et.et_flags |= ET_FLAGS_ONESHOT;
616 sc->et.et_quality = 100;
617 sc->et.et_frequency = i8254_freq;
618 sc->et.et_min_period = (0x0002LLU << 32) / i8254_freq;
619 sc->et.et_max_period = (0xfffeLLU << 32) / i8254_freq;
620 sc->et.et_start = attimer_start;
621 sc->et.et_stop = attimer_stop;
622 sc->et.et_priv = dev;
623 et_register(&sc->et);
624 }
625 return(0);
626 }
627
628 static int
attimer_resume(device_t dev)629 attimer_resume(device_t dev)
630 {
631
632 i8254_restore();
633 return (0);
634 }
635
636 static device_method_t attimer_methods[] = {
637 /* Device interface */
638 DEVMETHOD(device_probe, attimer_probe),
639 DEVMETHOD(device_attach, attimer_attach),
640 DEVMETHOD(device_detach, bus_generic_detach),
641 DEVMETHOD(device_shutdown, bus_generic_shutdown),
642 DEVMETHOD(device_suspend, bus_generic_suspend),
643 DEVMETHOD(device_resume, attimer_resume),
644 { 0, 0 }
645 };
646
647 static driver_t attimer_driver = {
648 "attimer",
649 attimer_methods,
650 sizeof(struct attimer_softc),
651 };
652
653 DRIVER_MODULE(attimer, isa, attimer_driver, 0, 0);
654 DRIVER_MODULE(attimer, acpi, attimer_driver, 0, 0);
655 ISA_PNP_INFO(attimer_ids);
656
657 #endif /* DEV_ISA */
658