xref: /netbsd-src/sys/dev/isa/isa.c (revision cda4f8f6ee55684e8d311b86c99ea59191e6b74f)
1 /*-
2  * Copyright (c) 1991 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.
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: @(#)isa.c	7.2 (Berkeley) 5/13/91
37  *	$Id: isa.c,v 1.26 1993/07/11 14:03:54 mycroft Exp $
38  */
39 
40 /*
41  * code to manage AT bus
42  *
43  * 92/08/18  Frank P. MacLachlan (fpm@crash.cts.com):
44  * Fixed uninitialized variable problem and added code to deal
45  * with DMA page boundaries in isa_dmarangecheck().  Fixed word
46  * mode DMA count compution and reorganized DMA setup code in
47  * isa_dmastart()
48  */
49 
50 #include "param.h"
51 #include "systm.h"
52 #include "conf.h"
53 #include "file.h"
54 #include "buf.h"
55 #include "uio.h"
56 #include "syslog.h"
57 #include "malloc.h"
58 #include "machine/segments.h"
59 #include "machine/cpufunc.h"
60 #include "vm/vm.h"
61 #include "i386/isa/isa_device.h"
62 #include "i386/isa/isa.h"
63 #include "i386/isa/icu.h"
64 #include "i386/isa/ic/i8237.h"
65 #include "i386/isa/ic/i8042.h"
66 #include "i386/isa/timerreg.h"
67 
68 /* sorry, has to be here, no place else really suitable */
69 #include "machine/pc/display.h"
70 u_short *Crtat = (u_short *)MONO_BUF;
71 
72 /*
73 **  Register definitions for DMA controller 1 (channels 0..3):
74 */
75 #define	DMA1_CHN(c)	(IO_DMA1 + 1*(2*(c)))	/* addr reg for channel c */
76 #define	DMA1_SMSK	(IO_DMA1 + 1*10)	/* single mask register */
77 #define	DMA1_MODE	(IO_DMA1 + 1*11)	/* mode register */
78 #define	DMA1_FFC	(IO_DMA1 + 1*12)	/* clear first/last FF */
79 
80 /*
81 **  Register definitions for DMA controller 2 (channels 4..7):
82 */
83 #define	DMA2_CHN(c)	(IO_DMA1 + 2*(2*(c)))	/* addr reg for channel c */
84 #define	DMA2_SMSK	(IO_DMA2 + 2*10)	/* single mask register */
85 #define	DMA2_MODE	(IO_DMA2 + 2*11)	/* mode register */
86 #define	DMA2_FFC	(IO_DMA2 + 2*12)	/* clear first/last FF */
87 
88 int config_isadev(struct isa_device *, u_int *);
89 void config_attach(struct isa_driver *, struct isa_device *);
90 static void sysbeepstop(int);
91 
92 /*
93  * Configure all ISA devices
94  */
95 void
96 isa_configure() {
97 	struct isa_device *dvp;
98 	struct isa_driver *dp;
99 
100 	enable_intr();
101 	splhigh();
102 	INTREN(IRQ_SLAVE);
103 	for (dvp = isa_devtab_tty; config_isadev(dvp,&ttymask); dvp++)
104 		;
105 	for (dvp = isa_devtab_bio; config_isadev(dvp,&biomask); dvp++)
106 		;
107 	for (dvp = isa_devtab_net; config_isadev(dvp,&netmask); dvp++)
108 		;
109 	for (dvp = isa_devtab_null; config_isadev(dvp, (u_int *) NULL); dvp++)
110 		;
111 
112 	impmask = ttymask | netmask;
113 
114 	/* and the problem is... if netmask == 0, then the loopback
115 	 * code can do some really ugly things.
116 	 * workaround for this: if netmask == 0, set it to 0x8000, which
117 	 * is the value used by splsoftclock.  this is nasty, but it
118 	 * should work until this interrupt system goes away. -- cgd
119 	 */
120 	if (netmask == 0)
121 		netmask = 0x8000;	/* same as for softclock.  XXX */
122 
123 	/* biomask |= ttymask ;  can some tty devices use buffers? */
124 	printf("biomask %x ttymask %x netmask %x impmask %x\n",
125 	       biomask, ttymask, netmask, impmask);
126 	splnone();
127 }
128 
129 /*
130  * Configure an ISA device.
131  */
132 int
133 config_isadev(isdp, mp)
134 	struct isa_device *isdp;
135 	u_int *mp;
136 {
137 	struct isa_driver *dp;
138 
139 	if (dp = isdp->id_driver) {
140 		if (isdp->id_maddr) {
141 			extern u_int atdevbase;
142 
143 			isdp->id_maddr -= 0xa0000; /* XXX should be a define */
144 			isdp->id_maddr += atdevbase;
145 		}
146 		isdp->id_alive = (*dp->probe)(isdp);
147 		if (isdp->id_irq == (u_short)-1)
148 			isdp->id_alive = 0;
149 		/*
150 		 * Only print the I/O address range if id_alive != -1
151 		 * Right now this is a temporary fix just for the new
152 		 * NPX code so that if it finds a 486 that can use trap
153 		 * 16 it will not report I/O addresses.
154 		 * Rod Grimes 04/26/94
155 		 *
156 		 * XXX -- cgd
157 		 */
158 		if (isdp->id_alive) {
159 			printf("%s%d", dp->name, isdp->id_unit);
160 			printf(" at 0x%x", isdp->id_iobase);
161 			if ((isdp->id_iobase + isdp->id_alive - 1) !=
162 			     isdp->id_iobase)
163 				printf("-0x%x",
164 				       isdp->id_iobase + isdp->id_alive - 1);
165 			if (isdp->id_irq != 0)
166 				printf(" irq %d", ffs(isdp->id_irq)-1);
167 			if (isdp->id_drq != -1)
168 				printf(" drq %d", isdp->id_drq);
169 			if (isdp->id_maddr != 0)
170 				printf(" maddr 0x%x", kvtop(isdp->id_maddr));
171 			if (isdp->id_msize != 0)
172 				printf("-0x%x", kvtop(isdp->id_maddr) +
173 					isdp->id_msize - 1);
174 			if (isdp->id_flags != 0)
175 				printf(" flags 0x%x", isdp->id_flags);
176 			printf(" on isa\n");
177 
178 			config_attach(dp, isdp);
179 
180 			if (isdp->id_irq) {
181 				int intrno;
182 
183 				intrno = ffs(isdp->id_irq)-1;
184 				setidt(ICU_OFFSET+intrno, isdp->id_intr,
185 					 SDT_SYS386IGT, SEL_KPL);
186 				if(mp)
187 					INTRMASK(*mp,isdp->id_irq);
188 				INTREN(isdp->id_irq);
189 			}
190 		}
191 		return (1);
192 	} else	return(0);
193 }
194 
195 void
196 config_attach(struct isa_driver *dp, struct isa_device *isdp)
197 {
198 	extern struct isa_device isa_subdev[];
199 	struct isa_device *dvp;
200 
201 	if(isdp->id_masunit==-1) {
202 		(void)(*dp->attach)(isdp);
203 		return;
204 	}
205 
206 	if(isdp->id_masunit==0) {
207 		for(dvp = isa_subdev; dvp->id_driver; dvp++) {
208 			if (dvp->id_driver != dp)
209 				continue;
210 			if (dvp->id_masunit != isdp->id_unit)
211 				continue;
212 			if (dvp->id_physid == -1)
213 				continue;
214 			dvp->id_alive = (*dp->attach)(dvp);
215 		}
216 		for(dvp = isa_subdev; dvp->id_driver; dvp++) {
217 			if (dvp->id_driver != dp)
218 				continue;
219 			if (dvp->id_masunit != isdp->id_unit)
220 				continue;
221 			if (dvp->id_physid != -1)
222 				continue;
223 			dvp->id_alive = (*dp->attach)(dvp);
224 		}
225 		return;
226 	}
227 	printf("id_masunit has weird value\n");
228 }
229 
230 
231 #define	IDTVEC(name)	__CONCAT(X,name)
232 /* default interrupt vector table entries */
233 extern	IDTVEC(intr0), IDTVEC(intr1), IDTVEC(intr2), IDTVEC(intr3),
234 	IDTVEC(intr4), IDTVEC(intr5), IDTVEC(intr6), IDTVEC(intr7),
235 	IDTVEC(intr8), IDTVEC(intr9), IDTVEC(intr10), IDTVEC(intr11),
236 	IDTVEC(intr12), IDTVEC(intr13), IDTVEC(intr14), IDTVEC(intr15);
237 
238 static *defvec[16] = {
239 	&IDTVEC(intr0), &IDTVEC(intr1), &IDTVEC(intr2), &IDTVEC(intr3),
240 	&IDTVEC(intr4), &IDTVEC(intr5), &IDTVEC(intr6), &IDTVEC(intr7),
241 	&IDTVEC(intr8), &IDTVEC(intr9), &IDTVEC(intr10), &IDTVEC(intr11),
242 	&IDTVEC(intr12), &IDTVEC(intr13), &IDTVEC(intr14), &IDTVEC(intr15) };
243 
244 /* out of range default interrupt vector gate entry */
245 extern	IDTVEC(intrdefault);
246 
247 /*
248  * Fill in default interrupt table (in case of spuruious interrupt
249  * during configuration of kernel, setup interrupt control unit
250  */
251 void
252 isa_defaultirq() {
253 	int i;
254 
255 	/* icu vectors */
256 	for (i = NRSVIDT ; i < NRSVIDT+ICU_LEN ; i++)
257 		setidt(i, defvec[i],  SDT_SYS386IGT, SEL_KPL);
258 
259 	/* out of range vectors */
260 	for (i = NRSVIDT; i < NIDT; i++)
261 		setidt(i, &IDTVEC(intrdefault), SDT_SYS386IGT, SEL_KPL);
262 
263 	/* initialize 8259's */
264 	outb(IO_ICU1, 0x11);		/* reset; program device, four bytes */
265 	outb(IO_ICU1+1, NRSVIDT);	/* starting at this vector index */
266 	outb(IO_ICU1+1, 1<<2);		/* slave on line 2 */
267 #ifdef AUTO_EOI_1
268 	outb(IO_ICU1+1, 2 | 1);		/* auto EOI, 8086 mode */
269 #else
270 	outb(IO_ICU1+1, 1);		/* 8086 mode */
271 #endif
272 	outb(IO_ICU1+1, 0xff);		/* leave interrupts masked */
273 	outb(IO_ICU1, 0x0a);		/* default to IRR on read */
274 #ifdef REORDER_IRQ
275 	outb(IO_ICU1, 0xc0 | (3 - 1));	/* pri order 3-7, 0-2 (com2 first) */
276 #endif
277 
278 	outb(IO_ICU2, 0x11);		/* reset; program device, four bytes */
279 	outb(IO_ICU2+1, NRSVIDT+8);	/* staring at this vector index */
280 	outb(IO_ICU2+1,2);		/* my slave id is 2 */
281 #ifdef AUTO_EOI_2
282 	outb(IO_ICU2+1, 2 | 1);		/* auto EOI, 8086 mode */
283 #else
284 	outb(IO_ICU2+1,1);		/* 8086 mode */
285 #endif
286 	outb(IO_ICU2+1, 0xff);		/* leave interrupts masked */
287 	outb(IO_ICU2, 0x0a);		/* default to IRR on read */
288 }
289 
290 /* region of physical memory known to be contiguous */
291 vm_offset_t isaphysmem;
292 static caddr_t dma_bounce[8];		/* XXX */
293 static char bounced[8];		/* XXX */
294 #define MAXDMASZ 512		/* XXX */
295 
296 /* high byte of address is stored in this port for i-th dma channel */
297 static short dmapageport[8] =
298 	{ 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
299 
300 /*
301  * isa_dmacascade(): program 8237 DMA controller channel to accept
302  * external dma control by a board.
303  */
304 void
305 isa_dmacascade(unsigned chan)
306 {
307 	if (chan > 7)
308 		panic("isa_dmacascade: impossible request");
309 
310 	/* set dma channel mode, and set dma channel mode */
311 	if ((chan & 4) == 0) {
312 		outb(DMA1_MODE, DMA37MD_CASCADE | chan);
313 		outb(DMA1_SMSK, chan);
314 	} else {
315 		outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
316 		outb(DMA2_SMSK, chan & 3);
317 	}
318 }
319 
320 /*
321  * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
322  * problems by using a bounce buffer.
323  */
324 void
325 isa_dmastart(int flags, caddr_t addr, unsigned nbytes, unsigned chan)
326 {	vm_offset_t phys;
327 	int waport;
328 	caddr_t newaddr;
329 
330 	if (    chan > 7
331 	    || (chan < 4 && nbytes > (1<<16))
332 	    || (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1)))
333 		panic("isa_dmastart: impossible request");
334 
335 	if (isa_dmarangecheck(addr, nbytes, chan)) {
336 		if (dma_bounce[chan] == 0)
337 			dma_bounce[chan] =
338 				/*(caddr_t)malloc(MAXDMASZ, M_TEMP, M_WAITOK);*/
339 				(caddr_t) isaphysmem + NBPG*chan;
340 		bounced[chan] = 1;
341 		newaddr = dma_bounce[chan];
342 		*(int *) newaddr = 0;	/* XXX */
343 
344 		/* copy bounce buffer on write */
345 		if (!(flags & B_READ))
346 			bcopy(addr, newaddr, nbytes);
347 		addr = newaddr;
348 	}
349 
350 	/* translate to physical */
351 	phys = pmap_extract(pmap_kernel(), (vm_offset_t)addr);
352 
353 	if ((chan & 4) == 0) {
354 		/*
355 		 * Program one of DMA channels 0..3.  These are
356 		 * byte mode channels.
357 		 */
358 		/* set dma channel mode, and reset address ff */
359 		if (flags & B_READ)
360 			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
361 		else
362 			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
363 		outb(DMA1_FFC, 0);
364 
365 		/* send start address */
366 		waport =  DMA1_CHN(chan);
367 		outb(waport, phys);
368 		outb(waport, phys>>8);
369 		outb(dmapageport[chan], phys>>16);
370 
371 		/* send count */
372 		outb(waport + 1, --nbytes);
373 		outb(waport + 1, nbytes>>8);
374 
375 		/* unmask channel */
376 		outb(DMA1_SMSK, chan);
377 	} else {
378 		/*
379 		 * Program one of DMA channels 4..7.  These are
380 		 * word mode channels.
381 		 */
382 		/* set dma channel mode, and reset address ff */
383 		if (flags & B_READ)
384 			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
385 		else
386 			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
387 		outb(DMA2_FFC, 0);
388 
389 		/* send start address */
390 		waport = DMA2_CHN(chan - 4);
391 		outb(waport, phys>>1);
392 		outb(waport, phys>>9);
393 		outb(dmapageport[chan], phys>>16);
394 
395 		/* send count */
396 		nbytes >>= 1;
397 		outb(waport + 2, --nbytes);
398 		outb(waport + 2, nbytes>>8);
399 
400 		/* unmask channel */
401 		outb(DMA2_SMSK, chan & 3);
402 	}
403 }
404 
405 void
406 isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
407 {
408 
409 	/* copy bounce buffer on read */
410 	/*if ((flags & (B_PHYS|B_READ)) == (B_PHYS|B_READ))*/
411 	if (bounced[chan]) {
412 		bcopy(dma_bounce[chan], addr, nbytes);
413 		bounced[chan] = 0;
414 	}
415 }
416 
417 /*
418  * Check for problems with the address range of a DMA transfer
419  * (non-contiguous physical pages, outside of bus address space,
420  * crossing DMA page boundaries).
421  * Return true if special handling needed.
422  */
423 
424 int
425 isa_dmarangecheck(caddr_t va, unsigned length, unsigned chan) {
426 	vm_offset_t phys, priorpage = 0, endva;
427 	u_int dma_pgmsk = (chan & 4) ?  ~(128*1024-1) : ~(64*1024-1);
428 
429 	endva = (vm_offset_t)round_page(va + length);
430 	for (; va < (caddr_t) endva ; va += NBPG) {
431 		phys = trunc_page(pmap_extract(pmap_kernel(), (vm_offset_t)va));
432 #define ISARAM_END	RAM_END
433 		if (phys == 0)
434 			panic("isa_dmacheck: no physical page present");
435 		if (phys > ISARAM_END)
436 			return (1);
437 		if (priorpage) {
438 			if (priorpage + NBPG != phys)
439 				return (1);
440 			/* check if crossing a DMA page boundary */
441 			if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
442 				return (1);
443 		}
444 		priorpage = phys;
445 	}
446 	return (0);
447 }
448 
449 /* head of queue waiting for physmem to become available */
450 struct buf isa_physmemq;
451 
452 /* blocked waiting for resource to become free for exclusive use */
453 static isaphysmemflag;
454 /* if waited for and call requested when free (B_CALL) */
455 static void (*isaphysmemunblock)(); /* needs to be a list */
456 
457 /*
458  * Allocate contiguous physical memory for transfer, returning
459  * a *virtual* address to region. May block waiting for resource.
460  * (assumed to be called at splbio())
461  */
462 caddr_t
463 isa_allocphysmem(caddr_t va, unsigned length, void (*func)()) {
464 
465 	isaphysmemunblock = func;
466 	while (isaphysmemflag & B_BUSY) {
467 		isaphysmemflag |= B_WANTED;
468 		sleep((caddr_t)&isaphysmemflag, PRIBIO);
469 	}
470 	isaphysmemflag |= B_BUSY;
471 
472 	return((caddr_t)isaphysmem);
473 }
474 
475 /*
476  * Free contiguous physical memory used for transfer.
477  * (assumed to be called at splbio())
478  */
479 void
480 isa_freephysmem(caddr_t va, unsigned length) {
481 
482 	isaphysmemflag &= ~B_BUSY;
483 	if (isaphysmemflag & B_WANTED) {
484 		isaphysmemflag &= B_WANTED;
485 		wakeup((caddr_t)&isaphysmemflag);
486 		if (isaphysmemunblock)
487 			(*isaphysmemunblock)();
488 	}
489 }
490 
491 /*
492  * Handle a NMI, possibly a machine check.
493  * return true to panic system, false to ignore.
494  */
495 int
496 isa_nmi(cd) {
497 
498 	log(LOG_CRIT, "\nNMI port 61 %x, port 70 %x\n", inb(0x61), inb(0x70));
499 	return(0);
500 }
501 
502 /*
503  * Caught a stray interrupt, notify
504  */
505 void
506 isa_strayintr(d) {
507 
508 	/* DON'T BOTHER FOR NOW! */
509 	/* for some reason, we get bursts of intr #7, even if not enabled! */
510 	/*
511 	 * Well the reason you got bursts of intr #7 is because someone
512 	 * raised an interrupt line and dropped it before the 8259 could
513 	 * prioritize it.  This is documented in the intel data book.  This
514 	 * means you have BAD hardware!  I have changed this so that only
515 	 * the first 5 get logged, then it quits logging them, and puts
516 	 * out a special message. rgrimes 3/25/1993
517 	 */
518 	extern u_long intrcnt_stray;
519 
520 	intrcnt_stray++;
521 	if (intrcnt_stray <= 5)
522 		log(LOG_ERR,"ISA strayintr %x\n", d);
523 	if (intrcnt_stray == 5)
524 		log(LOG_CRIT,"Too many ISA strayintr not logging any more\n");
525 }
526 
527 /*
528  * Wait "n" microseconds.
529  * Relies on timer 1 counting down from (TIMER_FREQ / hz) at
530  * (1 * TIMER_FREQ) Hz.
531  * Note: timer had better have been programmed before this is first used!
532  * (Note that we use `rate generator' mode, which counts at 1:1; `square
533  * wave' mode counts at 2:1).
534  */
535 #define       CF              (1 * TIMER_FREQ)
536 
537 extern int hz;                        /* XXX - should be elsewhere */
538 
539 void
540 DELAY(n)
541 	int n;
542 {
543 	int counter_limit;
544 	int prev_tick;
545 	int tick;
546 	int ticks_left;
547 	int sec;
548 	int usec;
549 
550 #ifdef DELAYDEBUG
551 	int gettick_calls = 1;
552 	int n1;
553 	static int state = 0;
554 
555 	if (state == 0) {
556 		state = 1;
557 		for (n1 = 1; n1 <= 10000000; n1 *= 10)
558 			DELAY(n1);
559 		state = 2;
560 	}
561 	if (state == 1)
562 		printf("DELAY(%d)...", n);
563 #endif
564 
565 	/*
566 	 * Read the counter first, so that the rest of the setup overhead is
567 	 * counted.  Guess the initial overhead is 20 usec (on most systems it
568 	 * takes about 1.5 usec for each of the i/o's in gettick().  The loop
569 	 * takes about 6 usec on a 486/33 and 13 usec on a 386/20.  The
570 	 * multiplications and divisions to scale the count take a while).
571 	 */
572 	prev_tick = gettick();
573 	n -= 20;
574 
575 	/*
576 	 * Calculate (n * (CF / 1e6)) without using floating point and without
577 	 * any avoidable overflows.
578 	 */
579 	sec = n / 1000000;
580 	usec = n - sec * 1000000;
581 	ticks_left = sec * CF
582 		+ usec * (CF / 1000000)
583 		+ usec * ((CF % 1000000) / 1000) / 1000
584 		+ usec * (CF % 1000) / 1000000;
585 
586 	counter_limit = TIMER_FREQ / hz;
587 	while (ticks_left > 0) {
588 		tick = gettick();
589 #ifdef DELAYDEBUG
590 		++gettick_calls;
591 #endif
592 		if (tick > prev_tick)
593 			ticks_left -= prev_tick - (tick - counter_limit);
594 		else
595 			ticks_left -= prev_tick - tick;
596 		prev_tick = tick;
597 	}
598 #ifdef DELAYDEBUG
599 	if (state == 1)
600 		printf(" %d calls to gettick() at %d usec each\n",
601 			gettick_calls, (n + 5) / gettick_calls);
602 #endif
603 }
604 
605 int
606 gettick() {
607 	int high;
608 	int low;
609 
610 	/*
611 	 * Protect ourself against interrupts.
612 	 */
613 	disable_intr();
614 	/*
615 	 * Latch the count for 'timer' (cc00xxxx, c = counter, x = any).
616 	 */
617 	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
618 	low = inb(TIMER_CNTR0);
619 	high = inb(TIMER_CNTR0);
620 	enable_intr();
621 	return ((high << 8) | low);
622 }
623 
624 static beeping;
625 static void
626 sysbeepstop(int f)
627 {
628 	int s = splhigh();
629 
630 	/* disable counter 2 */
631 	disable_intr();
632 	outb(0x61, inb(0x61) & 0xFC);
633 	enable_intr();
634 	if (f)
635 		timeout((timeout_t)sysbeepstop, (caddr_t)0, f);
636 	else
637 		beeping = 0;
638 
639 	splx(s);
640 }
641 
642 void
643 sysbeep(int pitch, int period)
644 {
645 	int s = splhigh();
646 	static int last_pitch, last_period;
647 
648 	if (beeping) {
649 		untimeout((timeout_t)sysbeepstop, (caddr_t)(last_period/2));
650 		untimeout((timeout_t)sysbeepstop, (caddr_t)0);
651 	}
652 	if (!beeping || last_pitch != pitch) {
653 		/*
654 	 	* XXX - move timer stuff to clock.c.
655 	 	*/
656 		disable_intr();
657 		outb(TIMER_MODE, TIMER_SEL2|TIMER_16BIT|TIMER_SQWAVE);
658 		outb(TIMER_CNTR2, TIMER_DIV(pitch)%256);
659 		outb(TIMER_CNTR2, TIMER_DIV(pitch)/256);
660 		outb(0x61, inb(0x61) | 3);	/* enable counter 2 */
661 		enable_intr();
662 	}
663 	last_pitch = pitch;
664 	beeping = last_period = period;
665 	timeout((timeout_t)sysbeepstop, (caddr_t)(period/2), period);
666 
667 	splx(s);
668 }
669 
670 /*
671  * Pass command to keyboard controller (8042)
672  */
673 unsigned
674 kbc_8042cmd(int val)
675 {
676 	while (inb(KBSTATP)&KBS_IBF);
677 	if (val) outb(KBCMDP, val);
678 	while (inb(KBSTATP)&KBS_IBF);
679 	return (inb(KBDATAP));
680 }
681 
682 /*
683  * Return nonzero if a (masked) irq is pending for a given device.
684  */
685 int
686 isa_irq_pending(dvp)
687 	struct isa_device *dvp;
688 {
689 	unsigned id_irq;
690 
691 	id_irq = (unsigned short) dvp->id_irq;	/* XXX silly type in struct */
692 	if (id_irq & 0xff)
693 		return (inb(IO_ICU1) & id_irq);
694 	return (inb(IO_ICU2) & (id_irq >> 8));
695 }
696