xref: /netbsd-src/sys/dev/isa/isadma.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: isadma.c,v 1.32 1997/09/05 01:48:33 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center.
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. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the NetBSD
22  *	Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Device driver for the ISA on-board DMA controller.
42  */
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/proc.h>
47 #include <sys/device.h>
48 
49 #include <vm/vm.h>
50 
51 #include <machine/bus.h>
52 
53 #include <dev/isa/isareg.h>
54 #include <dev/isa/isavar.h>
55 #include <dev/isa/isadmavar.h>
56 #include <dev/isa/isadmareg.h>
57 
58 /* Used by isa_malloc() */
59 #include <sys/malloc.h>
60 struct isa_mem {
61 	struct device *isadev;
62 	int chan;
63 	bus_size_t size;
64 	bus_addr_t addr;
65 	caddr_t kva;
66 	struct isa_mem *next;
67 } *isa_mem_head = 0;
68 
69 /*
70  * High byte of DMA address is stored in this DMAPG register for
71  * the Nth DMA channel.
72  */
73 static int dmapageport[2][4] = {
74 	{0x7, 0x3, 0x1, 0x2},
75 	{0xf, 0xb, 0x9, 0xa}
76 };
77 
78 static u_int8_t dmamode[4] = {
79 	DMA37MD_READ | DMA37MD_SINGLE,
80 	DMA37MD_WRITE | DMA37MD_SINGLE,
81 	DMA37MD_READ | DMA37MD_SINGLE | DMA37MD_LOOP,
82 	DMA37MD_WRITE | DMA37MD_SINGLE | DMA37MD_LOOP
83 };
84 
85 static inline void isa_dmaunmask __P((struct isa_softc *, int));
86 static inline void isa_dmamask __P((struct isa_softc *, int));
87 
88 static inline void
89 isa_dmaunmask(sc, chan)
90 	struct isa_softc *sc;
91 	int chan;
92 {
93 	int ochan = chan & 3;
94 
95 	/* set dma channel mode, and set dma channel mode */
96 	if ((chan & 4) == 0)
97 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h,
98 		    DMA1_SMSK, ochan | DMA37SM_CLEAR);
99 	else
100 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h,
101 		    DMA2_SMSK, ochan | DMA37SM_CLEAR);
102 }
103 
104 static inline void
105 isa_dmamask(sc, chan)
106 	struct isa_softc *sc;
107 	int chan;
108 {
109 	int ochan = chan & 3;
110 
111 	/* set dma channel mode, and set dma channel mode */
112 	if ((chan & 4) == 0) {
113 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h,
114 		    DMA1_SMSK, ochan | DMA37SM_SET);
115 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h,
116 		    DMA1_FFC, 0);
117 	} else {
118 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h,
119 		    DMA2_SMSK, ochan | DMA37SM_SET);
120 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h,
121 		    DMA2_FFC, 0);
122 	}
123 }
124 
125 /*
126  * isa_dmacascade(): program 8237 DMA controller channel to accept
127  * external dma control by a board.
128  */
129 void
130 isa_dmacascade(isadev, chan)
131 	struct device *isadev;
132 	int chan;
133 {
134 	struct isa_softc *sc = (struct isa_softc *)isadev;
135 	int ochan = chan & 3;
136 
137 	if (chan < 0 || chan > 7) {
138 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
139 		goto lose;
140 	}
141 
142 	if (ISA_DRQ_ISFREE(sc, chan) == 0) {
143 		printf("%s: DRQ %d is not free\n", sc->sc_dev.dv_xname, chan);
144 		goto lose;
145 	}
146 
147 	ISA_DRQ_ALLOC(sc, chan);
148 
149 	/* set dma channel mode, and set dma channel mode */
150 	if ((chan & 4) == 0)
151 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h,
152 		    DMA1_MODE, ochan | DMA37MD_CASCADE);
153 	else
154 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h,
155 		    DMA2_MODE, ochan | DMA37MD_CASCADE);
156 
157 	isa_dmaunmask(sc, chan);
158 	return;
159 
160  lose:
161 	panic("isa_dmacascade");
162 }
163 
164 int
165 isa_dmamap_create(isadev, chan, size, flags)
166 	struct device *isadev;
167 	int chan;
168 	bus_size_t size;
169 	int flags;
170 {
171 	struct isa_softc *sc = (struct isa_softc *)isadev;
172 	bus_size_t maxsize;
173 
174 	if (chan < 0 || chan > 7) {
175 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
176 		goto lose;
177 	}
178 
179 	if (chan & 4)
180 		maxsize = (1 << 17);
181 	else
182 		maxsize = (1 << 16);
183 
184 	if (size > maxsize)
185 		return (EINVAL);
186 
187 	if (ISA_DRQ_ISFREE(sc, chan) == 0) {
188 		printf("%s: drq %d is not free\n", sc->sc_dev.dv_xname, chan);
189 		goto lose;
190 	}
191 
192 	ISA_DRQ_ALLOC(sc, chan);
193 
194 	return (bus_dmamap_create(sc->sc_dmat, size, 1, size, maxsize,
195 	    flags, &sc->sc_dmamaps[chan]));
196 
197  lose:
198 	panic("isa_dmamap_create");
199 }
200 
201 void
202 isa_dmamap_destroy(isadev, chan)
203 	struct device *isadev;
204 	int chan;
205 {
206 	struct isa_softc *sc = (struct isa_softc *)isadev;
207 
208 	if (chan < 0 || chan > 7) {
209 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
210 		goto lose;
211 	}
212 
213 	if (ISA_DRQ_ISFREE(sc, chan)) {
214 		printf("%s: drq %d is already free\n",
215 		    sc->sc_dev.dv_xname, chan);
216 		goto lose;
217 	}
218 
219 	ISA_DRQ_FREE(sc, chan);
220 
221 	bus_dmamap_destroy(sc->sc_dmat, sc->sc_dmamaps[chan]);
222 	return;
223 
224  lose:
225 	panic("isa_dmamap_destroy");
226 }
227 
228 /*
229  * isa_dmastart(): program 8237 DMA controller channel and set it
230  * in motion.
231  */
232 int
233 isa_dmastart(isadev, chan, addr, nbytes, p, flags, busdmaflags)
234 	struct device *isadev;
235 	int chan;
236 	void *addr;
237 	bus_size_t nbytes;
238 	struct proc *p;
239 	int flags;
240 	int busdmaflags;
241 {
242 	struct isa_softc *sc = (struct isa_softc *)isadev;
243 	bus_dmamap_t dmam;
244 	bus_addr_t dmaaddr;
245 	int waport;
246 	int ochan = chan & 3;
247 	int error;
248 
249 	if (chan < 0 || chan > 7) {
250 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
251 		goto lose;
252 	}
253 
254 #ifdef ISADMA_DEBUG
255 	printf("isa_dmastart: drq %d, addr %p, nbytes 0x%lx, p %p, "
256 	    "flags 0x%x, dmaflags 0x%x\n",
257 	    chan, addr, nbytes, p, flags, busdmaflags);
258 #endif
259 
260 	if (chan & 4) {
261 		if (nbytes > (1 << 17) || nbytes & 1 || (u_long)addr & 1) {
262 			printf("%s: drq %d, nbytes 0x%lx, addr %p\n",
263 			    sc->sc_dev.dv_xname, chan, nbytes, addr);
264 			goto lose;
265 		}
266 	} else {
267 		if (nbytes > (1 << 16)) {
268 			printf("%s: drq %d, nbytes 0x%lx\n",
269 			    sc->sc_dev.dv_xname, chan, nbytes);
270 			goto lose;
271 		}
272 	}
273 
274 	dmam = sc->sc_dmamaps[chan];
275 	if (dmam == NULL)
276 		panic("isa_dmastart: no DMA map for chan %d\n", chan);
277 
278 	error = bus_dmamap_load(sc->sc_dmat, dmam, addr, nbytes,
279 	    p, busdmaflags);
280 	if (error)
281 		return (error);
282 
283 #ifdef ISADMA_DEBUG
284 	__asm(".globl isa_dmastart_afterload ; isa_dmastart_afterload:");
285 #endif
286 
287 	if (flags & DMAMODE_READ) {
288 		bus_dmamap_sync(sc->sc_dmat, dmam, BUS_DMASYNC_PREREAD);
289 		sc->sc_dmareads |= (1 << chan);
290 	} else {
291 		bus_dmamap_sync(sc->sc_dmat, dmam, BUS_DMASYNC_PREWRITE);
292 		sc->sc_dmareads &= ~(1 << chan);
293 	}
294 
295 	dmaaddr = dmam->dm_segs[0].ds_addr;
296 
297 #ifdef ISADMA_DEBUG
298 	printf("     dmaaddr 0x%lx\n", dmaaddr);
299 
300 	__asm(".globl isa_dmastart_aftersync ; isa_dmastart_aftersync:");
301 #endif
302 
303 	sc->sc_dmalength[chan] = nbytes;
304 
305 	isa_dmamask(sc, chan);
306 	sc->sc_dmafinished &= ~(1 << chan);
307 
308 	if ((chan & 4) == 0) {
309 		/* set dma channel mode */
310 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h, DMA1_MODE,
311 		    ochan | dmamode[flags]);
312 
313 		/* send start address */
314 		waport = DMA1_CHN(ochan);
315 		bus_space_write_1(sc->sc_iot, sc->sc_dmapgh,
316 		    dmapageport[0][ochan], (dmaaddr >> 16) & 0xff);
317 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h, waport,
318 		    dmaaddr & 0xff);
319 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h, waport,
320 		    (dmaaddr >> 8) & 0xff);
321 
322 		/* send count */
323 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h, waport + 1,
324 		    (--nbytes) & 0xff);
325 		bus_space_write_1(sc->sc_iot, sc->sc_dma1h, waport + 1,
326 		    (nbytes >> 8) & 0xff);
327 	} else {
328 		/* set dma channel mode */
329 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h, DMA2_MODE,
330 		    ochan | dmamode[flags]);
331 
332 		/* send start address */
333 		waport = DMA2_CHN(ochan);
334 		bus_space_write_1(sc->sc_iot, sc->sc_dmapgh,
335 		    dmapageport[1][ochan], (dmaaddr >> 16) & 0xff);
336 		dmaaddr >>= 1;
337 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h, waport,
338 		    dmaaddr & 0xff);
339 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h, waport,
340 		    (dmaaddr >> 8) & 0xff);
341 
342 		/* send count */
343 		nbytes >>= 1;
344 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h, waport + 2,
345 		    (--nbytes) & 0xff);
346 		bus_space_write_1(sc->sc_iot, sc->sc_dma2h, waport + 2,
347 		    (nbytes >> 8) & 0xff);
348 	}
349 
350 	isa_dmaunmask(sc, chan);
351 	return (0);
352 
353  lose:
354 	panic("isa_dmastart");
355 }
356 
357 void
358 isa_dmaabort(isadev, chan)
359 	struct device *isadev;
360 	int chan;
361 {
362 	struct isa_softc *sc = (struct isa_softc *)isadev;
363 
364 	if (chan < 0 || chan > 7) {
365 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
366 		panic("isa_dmaabort");
367 	}
368 
369 	isa_dmamask(sc, chan);
370 	bus_dmamap_unload(sc->sc_dmat, sc->sc_dmamaps[chan]);
371 	sc->sc_dmareads &= ~(1 << chan);
372 }
373 
374 bus_size_t
375 isa_dmacount(isadev, chan)
376 	struct device *isadev;
377 	int chan;
378 {
379 	struct isa_softc *sc = (struct isa_softc *)isadev;
380 	int waport;
381 	bus_size_t nbytes;
382 	int ochan = chan & 3;
383 
384 	if (chan < 0 || chan > 7) {
385 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
386 		panic("isa_dmacount");
387 	}
388 
389 	isa_dmamask(sc, chan);
390 
391 	/*
392 	 * We have to shift the byte count by 1.  If we're in auto-initialize
393 	 * mode, the count may have wrapped around to the initial value.  We
394 	 * can't use the TC bit to check for this case, so instead we compare
395 	 * against the original byte count.
396 	 * If we're not in auto-initialize mode, then the count will wrap to
397 	 * -1, so we also handle that case.
398 	 */
399 	if ((chan & 4) == 0) {
400 		waport = DMA1_CHN(ochan);
401 		nbytes = bus_space_read_1(sc->sc_iot, sc->sc_dma1h,
402 		    waport + 1) + 1;
403 		nbytes += bus_space_read_1(sc->sc_iot, sc->sc_dma1h,
404 		    waport + 1) << 8;
405 		nbytes &= 0xffff;
406 	} else {
407 		waport = DMA2_CHN(ochan);
408 		nbytes = bus_space_read_1(sc->sc_iot, sc->sc_dma2h,
409 		    waport + 2) + 1;
410 		nbytes += bus_space_read_1(sc->sc_iot, sc->sc_dma2h,
411 		    waport + 2) << 8;
412 		nbytes <<= 1;
413 		nbytes &= 0x1ffff;
414 	}
415 
416 	if (nbytes == sc->sc_dmalength[chan])
417 		nbytes = 0;
418 
419 	isa_dmaunmask(sc, chan);
420 	return (nbytes);
421 }
422 
423 int
424 isa_dmafinished(isadev, chan)
425 	struct device *isadev;
426 	int chan;
427 {
428 	struct isa_softc *sc = (struct isa_softc *)isadev;
429 
430 	if (chan < 0 || chan > 7) {
431 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
432 		panic("isa_dmafinished");
433 	}
434 
435 	/* check that the terminal count was reached */
436 	if ((chan & 4) == 0)
437 		sc->sc_dmafinished |= bus_space_read_1(sc->sc_iot,
438 		    sc->sc_dma1h, DMA1_SR) & 0x0f;
439 	else
440 		sc->sc_dmafinished |= (bus_space_read_1(sc->sc_iot,
441 		    sc->sc_dma2h, DMA2_SR) & 0x0f) << 4;
442 
443 	return ((sc->sc_dmafinished & (1 << chan)) != 0);
444 }
445 
446 void
447 isa_dmadone(isadev, chan)
448 	struct device *isadev;
449 	int chan;
450 {
451 	struct isa_softc *sc = (struct isa_softc *)isadev;
452 	bus_dmamap_t dmam;
453 
454 	if (chan < 0 || chan > 7) {
455 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
456 		panic("isa_dmadone");
457 	}
458 
459 	dmam = sc->sc_dmamaps[chan];
460 
461 	isa_dmamask(sc, chan);
462 
463 	if (isa_dmafinished(isadev, chan) == 0)
464 		printf("%s: isa_dmadone: channel %d not finished\n",
465 		    sc->sc_dev.dv_xname, chan);
466 
467 	bus_dmamap_sync(sc->sc_dmat, dmam,
468 	    (sc->sc_dmareads & (1 << chan)) ? BUS_DMASYNC_POSTREAD :
469 	    BUS_DMASYNC_POSTWRITE);
470 
471 	bus_dmamap_unload(sc->sc_dmat, dmam);
472 	sc->sc_dmareads &= ~(1 << chan);
473 }
474 
475 int
476 isa_dmamem_alloc(isadev, chan, size, addrp, flags)
477 	struct device *isadev;
478 	int chan;
479 	bus_size_t size;
480 	bus_addr_t *addrp;
481 	int flags;
482 {
483 	struct isa_softc *sc = (struct isa_softc *)isadev;
484 	bus_dma_segment_t seg;
485 	int error, boundary, rsegs;
486 
487 	if (chan < 0 || chan > 7) {
488 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
489 		panic("isa_dmamem_alloc");
490 	}
491 
492 	boundary = (chan & 4) ? (1 << 17) : (1 << 16);
493 
494 	size = round_page(size);
495 
496 	error = bus_dmamem_alloc(sc->sc_dmat, size, NBPG, boundary,
497 	    &seg, 1, &rsegs, flags);
498 	if (error)
499 		return (error);
500 
501 	*addrp = seg.ds_addr;
502 	return (0);
503 }
504 
505 void
506 isa_dmamem_free(isadev, chan, addr, size)
507 	struct device *isadev;
508 	int chan;
509 	bus_addr_t addr;
510 	bus_size_t size;
511 {
512 	struct isa_softc *sc = (struct isa_softc *)isadev;
513 	bus_dma_segment_t seg;
514 
515 	if (chan < 0 || chan > 7) {
516 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
517 		panic("isa_dmamem_free");
518 	}
519 
520 	seg.ds_addr = addr;
521 	seg.ds_len = size;
522 
523 	bus_dmamem_free(sc->sc_dmat, &seg, 1);
524 }
525 
526 int
527 isa_dmamem_map(isadev, chan, addr, size, kvap, flags)
528 	struct device *isadev;
529 	int chan;
530 	bus_addr_t addr;
531 	bus_size_t size;
532 	caddr_t *kvap;
533 	int flags;
534 {
535 	struct isa_softc *sc = (struct isa_softc *)isadev;
536 	bus_dma_segment_t seg;
537 
538 	if (chan < 0 || chan > 7) {
539 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
540 		panic("isa_dmamem_map");
541 	}
542 
543 	seg.ds_addr = addr;
544 	seg.ds_len = size;
545 
546 	return (bus_dmamem_map(sc->sc_dmat, &seg, 1, size, kvap, flags));
547 }
548 
549 void
550 isa_dmamem_unmap(isadev, chan, kva, size)
551 	struct device *isadev;
552 	int chan;
553 	caddr_t kva;
554 	size_t size;
555 {
556 	struct isa_softc *sc = (struct isa_softc *)isadev;
557 
558 	if (chan < 0 || chan > 7) {
559 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
560 		panic("isa_dmamem_unmap");
561 	}
562 
563 	bus_dmamem_unmap(sc->sc_dmat, kva, size);
564 }
565 
566 int
567 isa_dmamem_mmap(isadev, chan, addr, size, off, prot, flags)
568 	struct device *isadev;
569 	int chan;
570 	bus_addr_t addr;
571 	bus_size_t size;
572 	int off, prot, flags;
573 {
574 	struct isa_softc *sc = (struct isa_softc *)isadev;
575 	bus_dma_segment_t seg;
576 
577 	if (chan < 0 || chan > 7) {
578 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
579 		panic("isa_dmamem_mmap");
580 	}
581 
582 	seg.ds_addr = addr;
583 	seg.ds_len = size;
584 
585 	return (bus_dmamem_mmap(sc->sc_dmat, &seg, 1, off, prot, flags));
586 }
587 
588 int
589 isa_drq_isfree(isadev, chan)
590 	struct device *isadev;
591 	int chan;
592 {
593 	struct isa_softc *sc = (struct isa_softc *)isadev;
594 	if (chan < 0 || chan > 7) {
595 		printf("%s: bogus drq %d\n", sc->sc_dev.dv_xname, chan);
596 		panic("isa_drq_isfree");
597 	}
598 	return ISA_DRQ_ISFREE(sc, chan);
599 }
600 
601 void *
602 isa_malloc(isadev, chan, size, pool, flags)
603 	struct device *isadev;
604 	int chan;
605 	size_t size;
606 	int pool;
607 	int flags;
608 {
609 	bus_addr_t addr;
610 	caddr_t kva;
611 	int bflags;
612 	struct isa_mem *m;
613 
614 	bflags = flags & M_WAITOK ? BUS_DMA_WAITOK : BUS_DMA_NOWAIT;
615 
616 	if (isa_dmamem_alloc(isadev, chan, size, &addr, bflags))
617 		return 0;
618 	if (isa_dmamem_map(isadev, chan, addr, size, &kva, bflags)) {
619 		isa_dmamem_free(isadev, chan, addr, size);
620 		return 0;
621 	}
622 	m = malloc(sizeof(*m), pool, flags);
623 	if (m == 0) {
624 		isa_dmamem_unmap(isadev, chan, kva, size);
625 		isa_dmamem_free(isadev, chan, addr, size);
626 		return 0;
627 	}
628 	m->isadev = isadev;
629 	m->chan = chan;
630 	m->size = size;
631 	m->addr = addr;
632 	m->kva = kva;
633 	m->next = isa_mem_head;
634 	isa_mem_head = m;
635 	return (void *)kva;
636 }
637 
638 void
639 isa_free(addr, pool)
640 	void *addr;
641 	int pool;
642 {
643 	struct isa_mem **mp, *m;
644 	caddr_t kva = (caddr_t)addr;
645 
646 	for(mp = &isa_mem_head; *mp && (*mp)->kva != kva; mp = &(*mp)->next)
647 		;
648 	m = *mp;
649 	if (!m) {
650 		printf("isa_free: freeing unallocted memory\n");
651 		return;
652 	}
653 	*mp = m->next;
654 	isa_dmamem_unmap(m->isadev, m->chan, kva, m->size);
655 	isa_dmamem_free(m->isadev, m->chan, m->addr, m->size);
656 	free(m, pool);
657 }
658 
659 int
660 isa_mappage(mem, off, prot)
661 	void *mem;
662 	int off;
663 	int prot;
664 {
665 	struct isa_mem *m;
666 
667 	for(m = isa_mem_head; m && m->kva != (caddr_t)mem; m = m->next)
668 		;
669 	if (!m) {
670 		printf("isa_mappage: mapping unallocted memory\n");
671 		return -1;
672 	}
673 	return isa_dmamem_mmap(m->isadev, m->chan, m->addr,
674 			       m->size, off, prot, BUS_DMA_WAITOK);
675 }
676