xref: /netbsd-src/sys/arch/x86/isa/clock.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: clock.c,v 1.33 2009/06/16 21:05:34 bouyer 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 1.33 2009/06/16 21:05:34 bouyer 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 
156 #ifndef __x86_64__
157 #include "mca.h"
158 #endif
159 #if NMCA > 0
160 #include <machine/mca_machdep.h>	/* for MCA_system */
161 #endif
162 
163 #include "pcppi.h"
164 #if (NPCPPI > 0)
165 #include <dev/isa/pcppivar.h>
166 
167 int sysbeepmatch(device_t, cfdata_t, void *);
168 void sysbeepattach(device_t, device_t, void *);
169 int sysbeepdetach(device_t, int);
170 
171 CFATTACH_DECL3_NEW(sysbeep, 0,
172     sysbeepmatch, sysbeepattach, sysbeepdetach, NULL, NULL, NULL,
173     DVF_DETACH_SHUTDOWN);
174 
175 static int ppi_attached;
176 static pcppi_tag_t ppicookie;
177 #endif /* PCPPI */
178 
179 #ifdef CLOCKDEBUG
180 int clock_debug = 0;
181 #define DPRINTF(arg) if (clock_debug) printf arg
182 #else
183 #define DPRINTF(arg)
184 #endif
185 
186 /* Used by lapic.c */
187 unsigned int	gettick(void);
188 void		sysbeep(int, int);
189 static void     tickle_tc(void);
190 
191 static int	clockintr(void *, struct intrframe *);
192 
193 int 		sysbeepdetach(device_t, int);
194 
195 static unsigned int	gettick_broken_latch(void);
196 
197 static volatile uint32_t i8254_lastcount;
198 static volatile uint32_t i8254_offset;
199 static volatile int i8254_ticked;
200 
201 /* to protect TC timer variables */
202 static __cpu_simple_lock_t tmr_lock = __SIMPLELOCK_UNLOCKED;
203 
204 u_int i8254_get_timecount(struct timecounter *);
205 
206 static struct timecounter i8254_timecounter = {
207 	i8254_get_timecount,	/* get_timecount */
208 	0,			/* no poll_pps */
209 	~0u,			/* counter_mask */
210 	TIMER_FREQ,		/* frequency */
211 	"i8254",		/* name */
212 	100,			/* quality */
213 	NULL,			/* private data */
214 	NULL,			/* next */
215 };
216 
217 u_long rtclock_tval;		/* i8254 reload value for countdown */
218 int    rtclock_init = 0;
219 
220 int clock_broken_latch = 0;
221 
222 #ifdef CLOCK_PARANOIA
223 static int ticks[6];
224 #endif
225 /*
226  * i8254 latch check routine:
227  *     National Geode (formerly Cyrix MediaGX) has a serious bug in
228  *     its built-in i8254-compatible clock module.
229  *     machdep sets the variable 'clock_broken_latch' to indicate it.
230  */
231 
232 static unsigned int
233 gettick_broken_latch(void)
234 {
235 	int v1, v2, v3;
236 	int w1, w2, w3;
237 	int s;
238 
239 	/* Don't want someone screwing with the counter while we're here. */
240 	s = splhigh();
241 	__cpu_simple_lock(&tmr_lock);
242 	v1 = inb(IO_TIMER1+TIMER_CNTR0);
243 	v1 |= inb(IO_TIMER1+TIMER_CNTR0) << 8;
244 	v2 = inb(IO_TIMER1+TIMER_CNTR0);
245 	v2 |= inb(IO_TIMER1+TIMER_CNTR0) << 8;
246 	v3 = inb(IO_TIMER1+TIMER_CNTR0);
247 	v3 |= inb(IO_TIMER1+TIMER_CNTR0) << 8;
248 	__cpu_simple_unlock(&tmr_lock);
249 	splx(s);
250 
251 #ifdef CLOCK_PARANOIA
252 	if (clock_debug) {
253 		ticks[0] = ticks[3];
254 		ticks[1] = ticks[4];
255 		ticks[2] = ticks[5];
256 		ticks[3] = v1;
257 		ticks[4] = v2;
258 		ticks[5] = v3;
259 	}
260 #endif
261 
262 	if (v1 >= v2 && v2 >= v3 && v1 - v3 < 0x200)
263 		return (v2);
264 
265 #define _swap_val(a, b) do { \
266 	int c = a; \
267 	a = b; \
268 	b = c; \
269 } while (0)
270 
271 	/*
272 	 * sort v1 v2 v3
273 	 */
274 	if (v1 < v2)
275 		_swap_val(v1, v2);
276 	if (v2 < v3)
277 		_swap_val(v2, v3);
278 	if (v1 < v2)
279 		_swap_val(v1, v2);
280 
281 	/*
282 	 * compute the middle value
283 	 */
284 
285 	if (v1 - v3 < 0x200)
286 		return (v2);
287 
288 	w1 = v2 - v3;
289 	w2 = v3 - v1 + rtclock_tval;
290 	w3 = v1 - v2;
291 	if (w1 >= w2) {
292 		if (w1 >= w3)
293 		        return (v1);
294 	} else {
295 		if (w2 >= w3)
296 			return (v2);
297 	}
298 	return (v3);
299 }
300 
301 /* minimal initialization, enough for delay() */
302 void
303 initrtclock(u_long freq)
304 {
305 	u_long tval;
306 
307 	/*
308 	 * Compute timer_count, the count-down count the timer will be
309 	 * set to.  Also, correctly round
310 	 * this by carrying an extra bit through the division.
311 	 */
312 	tval = (freq * 2) / (u_long) hz;
313 	tval = (tval / 2) + (tval & 0x1);
314 
315 	/* initialize 8254 clock */
316 	outb(IO_TIMER1+TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT);
317 
318 	/* Correct rounding will buy us a better precision in timekeeping */
319 	outb(IO_TIMER1+TIMER_CNTR0, tval % 256);
320 	outb(IO_TIMER1+TIMER_CNTR0, tval / 256);
321 
322 	rtclock_tval = tval ? tval : 0xFFFF;
323 	rtclock_init = 1;
324 }
325 
326 void
327 startrtclock(void)
328 {
329 	int s;
330 
331 	if (!rtclock_init)
332 		initrtclock(TIMER_FREQ);
333 
334 	/* Check diagnostic status */
335 	if ((s = mc146818_read(NULL, NVRAM_DIAG)) != 0) { /* XXX softc */
336 		char bits[128];
337 		snprintb(bits, sizeof(bits), NVRAM_DIAG_BITS, s);
338 		printf("RTC BIOS diagnostic error %s\n", bits);
339 	}
340 
341 	tc_init(&i8254_timecounter);
342 	rtc_register();
343 }
344 
345 /*
346  * Must be called at splsched().
347  */
348 static void
349 tickle_tc(void)
350 {
351 #if defined(MULTIPROCESSOR)
352 	struct cpu_info *ci = curcpu();
353 	/*
354 	 * If we are not the primary CPU, we're not allowed to do
355 	 * any more work.
356 	 */
357 	if (CPU_IS_PRIMARY(ci) == 0)
358 		return;
359 #endif
360 	if (rtclock_tval && timecounter->tc_get_timecount == i8254_get_timecount) {
361 		__cpu_simple_lock(&tmr_lock);
362 		if (i8254_ticked)
363 			i8254_ticked    = 0;
364 		else {
365 			i8254_offset   += rtclock_tval;
366 			i8254_lastcount = 0;
367 		}
368 		__cpu_simple_unlock(&tmr_lock);
369 	}
370 
371 }
372 
373 static int
374 clockintr(void *arg, struct intrframe *frame)
375 {
376 	tickle_tc();
377 
378 	hardclock((struct clockframe *)frame);
379 
380 #if NMCA > 0
381 	if (MCA_system) {
382 		/* Reset PS/2 clock interrupt by asserting bit 7 of port 0x61 */
383 		outb(0x61, inb(0x61) | 0x80);
384 	}
385 #endif
386 	return -1;
387 }
388 
389 u_int
390 i8254_get_timecount(struct timecounter *tc)
391 {
392 	u_int count;
393 	uint16_t rdval;
394 	u_long psl;
395 
396 	/* Don't want someone screwing with the counter while we're here. */
397 	psl = x86_read_psl();
398 	x86_disable_intr();
399 	__cpu_simple_lock(&tmr_lock);
400 	/* Select timer0 and latch counter value. */
401 	outb(IO_TIMER1 + TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
402 	/* insb to make the read atomic */
403 	rdval = inb(IO_TIMER1+TIMER_CNTR0);
404 	rdval |= (inb(IO_TIMER1+TIMER_CNTR0) << 8);
405 	count = rtclock_tval - rdval;
406 	if (rtclock_tval && (count < i8254_lastcount &&
407 			     (!i8254_ticked || rtclock_tval == 0xFFFF))) {
408 		i8254_ticked = 1;
409 		i8254_offset += rtclock_tval;
410 	}
411 	i8254_lastcount = count;
412 	count += i8254_offset;
413 	__cpu_simple_unlock(&tmr_lock);
414 	x86_write_psl(psl);
415 
416 	return (count);
417 }
418 
419 unsigned int
420 gettick(void)
421 {
422 	uint16_t rdval;
423 	u_long psl;
424 
425 	if (clock_broken_latch)
426 		return (gettick_broken_latch());
427 
428 	/* Don't want someone screwing with the counter while we're here. */
429 	psl = x86_read_psl();
430 	x86_disable_intr();
431 	__cpu_simple_lock(&tmr_lock);
432 	/* Select counter 0 and latch it. */
433 	outb(IO_TIMER1+TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
434 	rdval = inb(IO_TIMER1+TIMER_CNTR0);
435 	rdval |= (inb(IO_TIMER1+TIMER_CNTR0) << 8);
436 	__cpu_simple_unlock(&tmr_lock);
437 	x86_write_psl(psl);
438 
439 	return rdval;
440 }
441 
442 /*
443  * Wait approximately `n' microseconds.
444  * Relies on timer 1 counting down from (TIMER_FREQ / hz) at TIMER_FREQ Hz.
445  * Note: timer had better have been programmed before this is first used!
446  * (Note that we use `rate generator' mode, which counts at 1:1; `square
447  * wave' mode counts at 2:1).
448  * Don't rely on this being particularly accurate.
449  */
450 void
451 i8254_delay(unsigned int n)
452 {
453 	unsigned int cur_tick, initial_tick;
454 	int remaining;
455 
456 	/* allow DELAY() to be used before startrtclock() */
457 	if (!rtclock_init)
458 		initrtclock(TIMER_FREQ);
459 
460 	/*
461 	 * Read the counter first, so that the rest of the setup overhead is
462 	 * counted.
463 	 */
464 	initial_tick = gettick();
465 
466 	if (n <= UINT_MAX / TIMER_FREQ) {
467 		/*
468 		 * For unsigned arithmetic, division can be replaced with
469 		 * multiplication with the inverse and a shift.
470 		 */
471 		remaining = n * TIMER_FREQ / 1000000;
472 	} else {
473 		/* This is a very long delay.
474 		 * Being slow here doesn't matter.
475 		 */
476 		remaining = (unsigned long long) n * TIMER_FREQ / 1000000;
477 	}
478 
479 	while (remaining > 1) {
480 #ifdef CLOCK_PARANOIA
481 		int delta;
482 		cur_tick = gettick();
483 		if (cur_tick > initial_tick)
484 			delta = rtclock_tval - (cur_tick - initial_tick);
485 		else
486 			delta = initial_tick - cur_tick;
487 		if (delta < 0 || delta >= rtclock_tval / 2) {
488 			DPRINTF(("delay: ignore ticks %.4x-%.4x",
489 				 initial_tick, cur_tick));
490 			if (clock_broken_latch) {
491 				DPRINTF(("  (%.4x %.4x %.4x %.4x %.4x %.4x)\n",
492 				         ticks[0], ticks[1], ticks[2],
493 				         ticks[3], ticks[4], ticks[5]));
494 			} else {
495 				DPRINTF(("\n"));
496 			}
497 		} else
498 			remaining -= delta;
499 #else
500 		cur_tick = gettick();
501 		if (cur_tick > initial_tick)
502 			remaining -= rtclock_tval - (cur_tick - initial_tick);
503 		else
504 			remaining -= initial_tick - cur_tick;
505 #endif
506 		initial_tick = cur_tick;
507 	}
508 }
509 
510 #if (NPCPPI > 0)
511 int
512 sysbeepmatch(device_t parent, cfdata_t match, void *aux)
513 {
514 	return (!ppi_attached);
515 }
516 
517 void
518 sysbeepattach(device_t parent, device_t self, void *aux)
519 {
520 	aprint_naive("\n");
521 	aprint_normal("\n");
522 
523 	ppicookie = ((struct pcppi_attach_args *)aux)->pa_cookie;
524 	ppi_attached = 1;
525 
526 	if (!pmf_device_register(self, NULL, NULL))
527 		aprint_error_dev(self, "couldn't establish power handler\n");
528 }
529 
530 int
531 sysbeepdetach(device_t self, int flags)
532 {
533 	pmf_device_deregister(self);
534 	ppi_attached = 0;
535 	return 0;
536 }
537 #endif
538 
539 void
540 sysbeep(int pitch, int period)
541 {
542 #if (NPCPPI > 0)
543 	if (ppi_attached)
544 		pcppi_bell(ppicookie, pitch, period, 0);
545 #endif
546 }
547 
548 void
549 i8254_initclocks(void)
550 {
551 
552 	/*
553 	 * XXX If you're doing strange things with multiple clocks, you might
554 	 * want to keep track of clock handlers.
555 	 */
556 	(void)isa_intr_establish(NULL, 0, IST_PULSE, IPL_CLOCK,
557 	    (int (*)(void *))clockintr, 0);
558 }
559 
560 void
561 setstatclockrate(int arg)
562 {
563 }
564