1 /* $NetBSD: clock.c,v 1.42 2025/02/24 07:18:02 imil Exp $ */
2
3 /*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * William Jolitz and Don Ahn.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)clock.c 7.2 (Berkeley) 5/12/91
35 */
36 /*-
37 * Copyright (c) 1993, 1994 Charles M. Hannum.
38 *
39 * This code is derived from software contributed to Berkeley by
40 * William Jolitz and Don Ahn.
41 *
42 * Redistribution and use in source and binary forms, with or without
43 * modification, are permitted provided that the following conditions
44 * are met:
45 * 1. Redistributions of source code must retain the above copyright
46 * notice, this list of conditions and the following disclaimer.
47 * 2. Redistributions in binary form must reproduce the above copyright
48 * notice, this list of conditions and the following disclaimer in the
49 * documentation and/or other materials provided with the distribution.
50 * 3. All advertising materials mentioning features or use of this software
51 * must display the following acknowledgement:
52 * This product includes software developed by the University of
53 * California, Berkeley and its contributors.
54 * 4. Neither the name of the University nor the names of its contributors
55 * may be used to endorse or promote products derived from this software
56 * without specific prior written permission.
57 *
58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68 * SUCH DAMAGE.
69 *
70 * @(#)clock.c 7.2 (Berkeley) 5/12/91
71 */
72 /*
73 * Mach Operating System
74 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
75 * All Rights Reserved.
76 *
77 * Permission to use, copy, modify and distribute this software and its
78 * documentation is hereby granted, provided that both the copyright
79 * notice and this permission notice appear in all copies of the
80 * software, derivative works or modified versions, and any portions
81 * thereof, and that both notices appear in supporting documentation.
82 *
83 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
84 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
85 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
86 *
87 * Carnegie Mellon requests users of this software to return to
88 *
89 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
90 * School of Computer Science
91 * Carnegie Mellon University
92 * Pittsburgh PA 15213-3890
93 *
94 * any improvements or extensions that they make and grant Carnegie Mellon
95 * the rights to redistribute these changes.
96 */
97 /*
98 Copyright 1988, 1989 by Intel Corporation, Santa Clara, California.
99
100 All Rights Reserved
101
102 Permission to use, copy, modify, and distribute this software and
103 its documentation for any purpose and without fee is hereby
104 granted, provided that the above copyright notice appears in all
105 copies and that both the copyright notice and this permission notice
106 appear in supporting documentation, and that the name of Intel
107 not be used in advertising or publicity pertaining to distribution
108 of the software without specific, written prior permission.
109
110 INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
111 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
112 IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
113 CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
114 LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
115 NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
116 WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
117 */
118
119 /*
120 * Primitive clock interrupt routines.
121 */
122
123 #include <sys/cdefs.h>
124 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.42 2025/02/24 07:18:02 imil Exp $");
125
126 /* #define CLOCKDEBUG */
127 /* #define CLOCK_PARANOIA */
128
129 #include "opt_multiprocessor.h"
130 #include "opt_ntp.h"
131
132 #include <sys/param.h>
133 #include <sys/systm.h>
134 #include <sys/time.h>
135 #include <sys/timetc.h>
136 #include <sys/kernel.h>
137 #include <sys/device.h>
138 #include <sys/mutex.h>
139 #include <sys/cpu.h>
140 #include <sys/intr.h>
141
142 #include <machine/pio.h>
143 #include <machine/cpufunc.h>
144 #include <machine/lock.h>
145
146 #include <dev/isa/isareg.h>
147 #include <dev/isa/isavar.h>
148 #include <dev/ic/mc146818reg.h>
149 #include <dev/ic/i8253reg.h>
150 #include <i386/isa/nvram.h>
151 #include <x86/x86/tsc.h>
152 #include <x86/lock.h>
153 #include <machine/specialreg.h>
154 #include <x86/rtc.h>
155 #include <x86/intr_private.h>
156
157 #ifndef __x86_64__
158 #include "mca.h"
159 #endif
160 #if NMCA > 0
161 #include <machine/mca_machdep.h> /* for MCA_system */
162 #endif
163
164 #include "pcppi.h"
165 #if (NPCPPI > 0)
166 #include <dev/isa/pcppivar.h>
167
168 int sysbeepmatch(device_t, cfdata_t, void *);
169 void sysbeepattach(device_t, device_t, void *);
170 int sysbeepdetach(device_t, int);
171
172 CFATTACH_DECL3_NEW(sysbeep, 0,
173 sysbeepmatch, sysbeepattach, sysbeepdetach, NULL, NULL, NULL,
174 DVF_DETACH_SHUTDOWN);
175
176 static int ppi_attached;
177 static pcppi_tag_t ppicookie;
178 #endif /* PCPPI */
179
180 #ifdef CLOCKDEBUG
181 int clock_debug = 0;
182 #define DPRINTF(arg) if (clock_debug) printf arg
183 #else
184 #define DPRINTF(arg)
185 #endif
186
187 void (*x86_delay)(unsigned int) = i8254_delay;
188
189 void sysbeep(int, int);
190 static void tickle_tc(void);
191
192 int sysbeepdetach(device_t, int);
193
194 static unsigned int gettick_broken_latch(void);
195
196 static volatile uint32_t i8254_lastcount;
197 static volatile uint32_t i8254_offset;
198 static volatile int i8254_ticked;
199
200 /* to protect TC timer variables */
201 static __cpu_simple_lock_t tmr_lock = __SIMPLELOCK_UNLOCKED;
202
203 u_int i8254_get_timecount(struct timecounter *);
204
205 static struct timecounter i8254_timecounter = {
206 .tc_get_timecount = i8254_get_timecount,
207 .tc_counter_mask = ~0u,
208 .tc_frequency = TIMER_FREQ,
209 .tc_name = "i8254",
210 .tc_quality = 100,
211 };
212
213 u_long x86_rtclock_tval; /* i8254 reload value for countdown */
214 int rtclock_init = 0;
215
216 int clock_broken_latch = 0;
217
218 #ifdef CLOCK_PARANOIA
219 static int ticks[6];
220 #endif
221 /*
222 * i8254 latch check routine:
223 * National Geode (formerly Cyrix MediaGX) has a serious bug in
224 * its built-in i8254-compatible clock module.
225 * machdep sets the variable 'clock_broken_latch' to indicate it.
226 */
227
228 static unsigned int
gettick_broken_latch(void)229 gettick_broken_latch(void)
230 {
231 int v1, v2, v3;
232 int w1, w2, w3;
233 int s;
234
235 /* Don't want someone screwing with the counter while we're here. */
236 s = splhigh();
237 __cpu_simple_lock(&tmr_lock);
238 v1 = inb(IO_TIMER1+TIMER_CNTR0);
239 v1 |= inb(IO_TIMER1+TIMER_CNTR0) << 8;
240 v2 = inb(IO_TIMER1+TIMER_CNTR0);
241 v2 |= inb(IO_TIMER1+TIMER_CNTR0) << 8;
242 v3 = inb(IO_TIMER1+TIMER_CNTR0);
243 v3 |= inb(IO_TIMER1+TIMER_CNTR0) << 8;
244 __cpu_simple_unlock(&tmr_lock);
245 splx(s);
246
247 #ifdef CLOCK_PARANOIA
248 if (clock_debug) {
249 ticks[0] = ticks[3];
250 ticks[1] = ticks[4];
251 ticks[2] = ticks[5];
252 ticks[3] = v1;
253 ticks[4] = v2;
254 ticks[5] = v3;
255 }
256 #endif
257
258 if (v1 >= v2 && v2 >= v3 && v1 - v3 < 0x200)
259 return (v2);
260
261 #define _swap_val(a, b) do { \
262 int c = a; \
263 a = b; \
264 b = c; \
265 } while (0)
266
267 /*
268 * sort v1 v2 v3
269 */
270 if (v1 < v2)
271 _swap_val(v1, v2);
272 if (v2 < v3)
273 _swap_val(v2, v3);
274 if (v1 < v2)
275 _swap_val(v1, v2);
276
277 /*
278 * compute the middle value
279 */
280
281 if (v1 - v3 < 0x200)
282 return (v2);
283
284 w1 = v2 - v3;
285 w2 = v3 - v1 + x86_rtclock_tval;
286 w3 = v1 - v2;
287 if (w1 >= w2) {
288 if (w1 >= w3)
289 return (v1);
290 } else {
291 if (w2 >= w3)
292 return (v2);
293 }
294 return (v3);
295 }
296
297 /* minimal initialization, enough for delay() */
298 void
initrtclock(u_long freq)299 initrtclock(u_long freq)
300 {
301 u_long tval;
302
303 if (vm_guest == VM_GUEST_XENPVH)
304 return;
305
306 /*
307 * Compute timer_count, the count-down count the timer will be
308 * set to. Also, correctly round
309 * this by carrying an extra bit through the division.
310 */
311 tval = (freq * 2) / (u_long) hz;
312 tval = (tval / 2) + (tval & 0x1);
313
314 /* initialize 8254 clock */
315 outb(IO_TIMER1+TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT);
316
317 /* Correct rounding will buy us a better precision in timekeeping */
318 outb(IO_TIMER1+TIMER_CNTR0, tval % 256);
319 outb(IO_TIMER1+TIMER_CNTR0, tval / 256);
320
321 x86_rtclock_tval = tval ? tval : 0xFFFF;
322 rtclock_init = 1;
323 }
324
325 void
startrtclock(void)326 startrtclock(void)
327 {
328 int s;
329
330 /*
331 * Check that RTC is present, bits 0 to 6 of register D are
332 * read-only and must be 0. At least on QEMU/microvm, when
333 * rtc=off, all bits are set to 1
334 */
335 if ((mc146818_read(NULL, MC_REGD) & 0x7f) != 0)
336 return;
337
338 if (!rtclock_init)
339 initrtclock(TIMER_FREQ);
340
341 /* Check diagnostic status */
342 if ((s = mc146818_read(NULL, NVRAM_DIAG)) != 0) { /* XXX softc */
343 char bits[128];
344 snprintb(bits, sizeof(bits), NVRAM_DIAG_BITS, s);
345 printf("RTC BIOS diagnostic error %s\n", bits);
346 }
347
348 tc_init(&i8254_timecounter);
349 rtc_register();
350 }
351
352 /*
353 * Must be called at splsched().
354 */
355 static void
tickle_tc(void)356 tickle_tc(void)
357 {
358 #if defined(MULTIPROCESSOR)
359 struct cpu_info *ci = curcpu();
360 /*
361 * If we are not the primary CPU, we're not allowed to do
362 * any more work.
363 */
364 if (CPU_IS_PRIMARY(ci) == 0)
365 return;
366 #endif
367 if (x86_rtclock_tval &&
368 timecounter->tc_get_timecount == i8254_get_timecount) {
369 __cpu_simple_lock(&tmr_lock);
370 if (i8254_ticked)
371 i8254_ticked = 0;
372 else {
373 i8254_offset += x86_rtclock_tval;
374 i8254_lastcount = 0;
375 }
376 __cpu_simple_unlock(&tmr_lock);
377 }
378
379 }
380
381 int
i8254_clockintr(void * arg,struct intrframe * frame)382 i8254_clockintr(void *arg, struct intrframe *frame)
383 {
384 tickle_tc();
385
386 hardclock((struct clockframe *)frame);
387
388 #if NMCA > 0
389 if (MCA_system) {
390 /* Reset PS/2 clock interrupt by asserting bit 7 of port 0x61 */
391 outb(0x61, inb(0x61) | 0x80);
392 }
393 #endif
394 return -1;
395 }
396
397 u_int
i8254_get_timecount(struct timecounter * tc)398 i8254_get_timecount(struct timecounter *tc)
399 {
400 u_int count;
401 uint16_t rdval;
402 u_long psl;
403
404 /* Don't want someone screwing with the counter while we're here. */
405 psl = x86_read_psl();
406 x86_disable_intr();
407 __cpu_simple_lock(&tmr_lock);
408 /* Select timer0 and latch counter value. */
409 outb(IO_TIMER1 + TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
410 /* insb to make the read atomic */
411 rdval = inb(IO_TIMER1+TIMER_CNTR0);
412 rdval |= (inb(IO_TIMER1+TIMER_CNTR0) << 8);
413 count = x86_rtclock_tval - rdval;
414 if (x86_rtclock_tval && (count < i8254_lastcount &&
415 (!i8254_ticked || x86_rtclock_tval == 0xFFFF))) {
416 i8254_ticked = 1;
417 i8254_offset += x86_rtclock_tval;
418 }
419 i8254_lastcount = count;
420 count += i8254_offset;
421 __cpu_simple_unlock(&tmr_lock);
422 x86_write_psl(psl);
423
424 return (count);
425 }
426
427 unsigned int
gettick(void)428 gettick(void)
429 {
430 uint16_t rdval;
431 u_long psl;
432
433 if (clock_broken_latch)
434 return (gettick_broken_latch());
435
436 /* Don't want someone screwing with the counter while we're here. */
437 psl = x86_read_psl();
438 x86_disable_intr();
439 __cpu_simple_lock(&tmr_lock);
440 /* Select counter 0 and latch it. */
441 outb(IO_TIMER1+TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
442 rdval = inb(IO_TIMER1+TIMER_CNTR0);
443 rdval |= (inb(IO_TIMER1+TIMER_CNTR0) << 8);
444 __cpu_simple_unlock(&tmr_lock);
445 x86_write_psl(psl);
446
447 return rdval;
448 }
449
450 /*
451 * Wait approximately `n' microseconds.
452 * Relies on timer 1 counting down from (TIMER_FREQ / hz) at TIMER_FREQ Hz.
453 * Note: timer had better have been programmed before this is first used!
454 * (Note that we use `rate generator' mode, which counts at 1:1; `square
455 * wave' mode counts at 2:1).
456 * Don't rely on this being particularly accurate.
457 */
458 void
i8254_delay(unsigned int n)459 i8254_delay(unsigned int n)
460 {
461 unsigned int cur_tick, initial_tick;
462 int remaining;
463
464 /* allow DELAY() to be used before startrtclock() */
465 if (!rtclock_init)
466 initrtclock(TIMER_FREQ);
467
468 /*
469 * Read the counter first, so that the rest of the setup overhead is
470 * counted.
471 */
472 initial_tick = gettick();
473
474 if (n <= UINT_MAX / TIMER_FREQ) {
475 /*
476 * For unsigned arithmetic, division can be replaced with
477 * multiplication with the inverse and a shift.
478 */
479 remaining = n * TIMER_FREQ / 1000000;
480 } else {
481 /* This is a very long delay.
482 * Being slow here doesn't matter.
483 */
484 remaining = (unsigned long long) n * TIMER_FREQ / 1000000;
485 }
486
487 while (remaining > 1) {
488 #ifdef CLOCK_PARANOIA
489 int delta;
490 cur_tick = gettick();
491 if (cur_tick > initial_tick)
492 delta = x86_rtclock_tval - (cur_tick - initial_tick);
493 else
494 delta = initial_tick - cur_tick;
495 if (delta < 0 || delta >= x86_rtclock_tval / 2) {
496 DPRINTF(("delay: ignore ticks %.4x-%.4x",
497 initial_tick, cur_tick));
498 if (clock_broken_latch) {
499 DPRINTF((" (%.4x %.4x %.4x %.4x %.4x %.4x)\n",
500 ticks[0], ticks[1], ticks[2],
501 ticks[3], ticks[4], ticks[5]));
502 } else {
503 DPRINTF(("\n"));
504 }
505 } else
506 remaining -= delta;
507 #else
508 cur_tick = gettick();
509 if (cur_tick > initial_tick)
510 remaining -= x86_rtclock_tval - (cur_tick - initial_tick);
511 else
512 remaining -= initial_tick - cur_tick;
513 #endif
514 initial_tick = cur_tick;
515 }
516 }
517
518 #if (NPCPPI > 0)
519 int
sysbeepmatch(device_t parent,cfdata_t match,void * aux)520 sysbeepmatch(device_t parent, cfdata_t match, void *aux)
521 {
522 if (vm_guest == VM_GUEST_XENPVH)
523 return 0;
524 return (!ppi_attached);
525 }
526
527 void
sysbeepattach(device_t parent,device_t self,void * aux)528 sysbeepattach(device_t parent, device_t self, void *aux)
529 {
530 aprint_naive("\n");
531 aprint_normal("\n");
532
533 ppicookie = ((struct pcppi_attach_args *)aux)->pa_cookie;
534 ppi_attached = 1;
535
536 if (!pmf_device_register(self, NULL, NULL))
537 aprint_error_dev(self, "couldn't establish power handler\n");
538 }
539
540 int
sysbeepdetach(device_t self,int flags)541 sysbeepdetach(device_t self, int flags)
542 {
543 pmf_device_deregister(self);
544 ppi_attached = 0;
545 return 0;
546 }
547 #endif
548
549 void
sysbeep(int pitch,int period)550 sysbeep(int pitch, int period)
551 {
552 #if (NPCPPI > 0)
553 if (ppi_attached)
554 pcppi_bell(ppicookie, pitch, period, 0);
555 #endif
556 }
557
558 void
i8254_initclocks(void)559 i8254_initclocks(void)
560 {
561
562 /*
563 * XXX If you're doing strange things with multiple clocks, you might
564 * want to keep track of clock handlers.
565 *
566 * XXX This is an abuse of the interrupt handler signature with
567 * __FPTRCAST which requires a special case for IPL_CLOCK in
568 * intr_establish_xname. Please fix this nonsense! See also
569 * the comments about i8254_clockintr in x86/x86/intr.c.
570 */
571 (void)isa_intr_establish(NULL, 0, IST_PULSE, IPL_CLOCK,
572 __FPTRCAST(int (*)(void *), i8254_clockintr), 0);
573 }
574
575 void
setstatclockrate(int arg)576 setstatclockrate(int arg)
577 {
578 }
579