xref: /netbsd-src/sys/dev/isa/isadma.c (revision a7e090f70e491979434963c9a27df4020fe0a18b)
1 /*	$NetBSD: isadma.c,v 1.63 2010/03/22 22:30:58 dyoung Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 2000 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  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Device driver for the ISA on-board DMA controller.
35  */
36 
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: isadma.c,v 1.63 2010/03/22 22:30:58 dyoung Exp $");
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/proc.h>
43 #include <sys/device.h>
44 #include <sys/malloc.h>
45 
46 #include <sys/bus.h>
47 
48 #include <uvm/uvm_extern.h>
49 
50 #include <dev/isa/isareg.h>
51 #include <dev/isa/isavar.h>
52 #include <dev/isa/isadmavar.h>
53 #include <dev/isa/isadmareg.h>
54 
55 struct isa_mem *isa_mem_head;
56 
57 /*
58  * High byte of DMA address is stored in this DMAPG register for
59  * the Nth DMA channel.
60  */
61 static int dmapageport[2][4] = {
62 	{0x7, 0x3, 0x1, 0x2},
63 	{0xf, 0xb, 0x9, 0xa}
64 };
65 
66 static u_int8_t dmamode[] = {
67 	/* write to device/read from device */
68 	DMA37MD_READ | DMA37MD_SINGLE,
69 	DMA37MD_WRITE | DMA37MD_SINGLE,
70 
71 	/* write to device/read from device */
72 	DMA37MD_READ | DMA37MD_DEMAND,
73 	DMA37MD_WRITE | DMA37MD_DEMAND,
74 
75 	/* write to device/read from device - DMAMODE_LOOP */
76 	DMA37MD_READ | DMA37MD_SINGLE | DMA37MD_LOOP,
77 	DMA37MD_WRITE | DMA37MD_SINGLE | DMA37MD_LOOP,
78 
79 	/* write to device/read from device - DMAMODE_LOOPDEMAND */
80 	DMA37MD_READ | DMA37MD_DEMAND | DMA37MD_LOOP,
81 	DMA37MD_WRITE | DMA37MD_DEMAND | DMA37MD_LOOP,
82 };
83 
84 static inline void _isa_dmaunmask(struct isa_dma_state *, int);
85 static inline void _isa_dmamask(struct isa_dma_state *, int);
86 
87 static inline void
88 _isa_dmaunmask(struct isa_dma_state *ids, int chan)
89 {
90 	int ochan = chan & 3;
91 
92 	ISA_DMA_MASK_CLR(ids, chan);
93 
94 	/*
95 	 * If DMA is frozen, don't unmask it now.  It will be
96 	 * unmasked when DMA is thawed again.
97 	 */
98 	if (ids->ids_frozen)
99 		return;
100 
101 	/* set dma channel mode, and set dma channel mode */
102 	if ((chan & 4) == 0)
103 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
104 		    DMA1_SMSK, ochan | DMA37SM_CLEAR);
105 	else
106 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
107 		    DMA2_SMSK, ochan | DMA37SM_CLEAR);
108 }
109 
110 static inline void
111 _isa_dmamask(struct isa_dma_state *ids, int chan)
112 {
113 	int ochan = chan & 3;
114 
115 	ISA_DMA_MASK_SET(ids, chan);
116 
117 	/*
118 	 * XXX Should we avoid masking the channel if DMA is
119 	 * XXX frozen?  It seems like what we're doing should
120 	 * XXX be safe, and we do need to reset FFC...
121 	 */
122 
123 	/* set dma channel mode, and set dma channel mode */
124 	if ((chan & 4) == 0) {
125 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
126 		    DMA1_SMSK, ochan | DMA37SM_SET);
127 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
128 		    DMA1_FFC, 0);
129 	} else {
130 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
131 		    DMA2_SMSK, ochan | DMA37SM_SET);
132 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
133 		    DMA2_FFC, 0);
134 	}
135 }
136 
137 /*
138  * _isa_dmainit(): Initialize the isa_dma_state for this chipset.
139  */
140 void
141 _isa_dmainit(struct isa_dma_state *ids, bus_space_tag_t bst, bus_dma_tag_t dmat, device_t dev)
142 {
143 	int chan;
144 
145 	ids->ids_dev = dev;
146 
147 	if (ids->ids_initialized) {
148 		/*
149 		 * Some systems may have e.g. `ofisa' (OpenFirmware
150 		 * configuration of ISA bus) and a regular `isa'.
151 		 * We allow both to call the initialization function,
152 		 * and take the device name from the last caller
153 		 * (assuming it will be the indirect ISA bus).  Since
154 		 * `ofisa' and `isa' are the same bus with different
155 		 * configuration mechanisms, the space and dma tags
156 		 * must be the same!
157 		 */
158 #if 0	/* XXX Comparing bus_space_tag_t is a no-no! */
159 		if (ids->ids_bst != bst || ids->ids_dmat != dmat)
160 			panic("_isa_dmainit: inconsistent ISA tags");
161 #endif
162 	} else {
163 		ids->ids_bst = bst;
164 		ids->ids_dmat = dmat;
165 
166 		/*
167 		 * Map the registers used by the ISA DMA controller.
168 		 */
169 		if (bus_space_map(ids->ids_bst, IO_DMA1, DMA1_IOSIZE, 0,
170 		    &ids->ids_dma1h))
171 			panic("_isa_dmainit: unable to map DMA controller #1");
172 		if (bus_space_map(ids->ids_bst, IO_DMA2, DMA2_IOSIZE, 0,
173 		    &ids->ids_dma2h))
174 			panic("_isa_dmainit: unable to map DMA controller #2");
175 		if (bus_space_map(ids->ids_bst, IO_DMAPG, 0xf, 0,
176 		    &ids->ids_dmapgh))
177 			panic("_isa_dmainit: unable to map DMA page registers");
178 
179 		/*
180 		 * All 8 DMA channels start out "masked".
181 		 */
182 		ids->ids_masked = 0xff;
183 
184 		/*
185 		 * Initialize the max transfer size for each channel, if
186 		 * it is not initialized already (i.e. by a bus-dependent
187 		 * front-end).
188 		 */
189 		for (chan = 0; chan < 8; chan++) {
190 			if (ids->ids_maxsize[chan] == 0)
191 				ids->ids_maxsize[chan] =
192 				    ISA_DMA_MAXSIZE_DEFAULT(chan);
193 		}
194 
195 		ids->ids_initialized = 1;
196 
197 		/*
198 		 * DRQ 4 is used to chain the two 8237s together; make
199 		 * sure it's always cascaded, and that it will be unmasked
200 		 * when DMA is thawed.
201 		 */
202 		_isa_dmacascade(ids, 4);
203 	}
204 }
205 
206 void
207 _isa_dmadestroy(struct isa_dma_state *ids)
208 {
209 	if (!ids->ids_initialized)
210 		return;
211 
212 	_isa_dmacascade_stop(ids, 4);
213 
214 	/*
215 	 * Unmap the registers used by the ISA DMA controller.
216 	 */
217 	bus_space_unmap(ids->ids_bst, ids->ids_dmapgh, 0xf);
218 	bus_space_unmap(ids->ids_bst, ids->ids_dma2h, DMA2_IOSIZE);
219 	bus_space_unmap(ids->ids_bst, ids->ids_dma1h, DMA1_IOSIZE);
220 
221 	ids->ids_initialized = 0;
222 }
223 
224 /*
225  * _isa_dmacascade(): program 8237 DMA controller channel to accept
226  * external dma control by a board.
227  */
228 int
229 _isa_dmacascade(struct isa_dma_state *ids, int chan)
230 {
231 	int ochan = chan & 3;
232 
233 	if (chan < 0 || chan > 7) {
234 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
235 		return (EINVAL);
236 	}
237 
238 	if (!ISA_DMA_DRQ_ISFREE(ids, chan)) {
239 		printf("%s: DRQ %d is not free\n", device_xname(ids->ids_dev),
240 		    chan);
241 		return (EAGAIN);
242 	}
243 
244 	ISA_DMA_DRQ_ALLOC(ids, chan);
245 
246 	/* set dma channel mode, and set dma channel mode */
247 	if ((chan & 4) == 0)
248 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
249 		    DMA1_MODE, ochan | DMA37MD_CASCADE);
250 	else
251 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
252 		    DMA2_MODE, ochan | DMA37MD_CASCADE);
253 
254 	_isa_dmaunmask(ids, chan);
255 	return (0);
256 }
257 
258 /*
259  * _isa_dmacascade_stop(): turn off cascading on the 8237 DMA controller channel
260  * external dma control by a board.
261  */
262 int
263 _isa_dmacascade_stop(struct isa_dma_state *ids, int chan)
264 {
265 	if (chan < 0 || chan > 7) {
266 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
267 		return EINVAL;
268 	}
269 
270 	if (ISA_DMA_DRQ_ISFREE(ids, chan))
271 		return 0;
272 
273 	_isa_dmamask(ids, chan);
274 
275 	ISA_DMA_DRQ_FREE(ids, chan);
276 
277 	return 0;
278 }
279 
280 int
281 _isa_drq_alloc(struct isa_dma_state *ids, int chan)
282 {
283 	if (!ISA_DMA_DRQ_ISFREE(ids, chan))
284 		return EBUSY;
285 	ISA_DMA_DRQ_ALLOC(ids, chan);
286 	return 0;
287 }
288 
289 int
290 _isa_drq_free(struct isa_dma_state *ids, int chan)
291 {
292 	if (ISA_DMA_DRQ_ISFREE(ids, chan))
293 		return EINVAL;
294 	ISA_DMA_DRQ_FREE(ids, chan);
295 	return 0;
296 }
297 
298 bus_size_t
299 _isa_dmamaxsize(struct isa_dma_state *ids, int chan)
300 {
301 
302 	if (chan < 0 || chan > 7) {
303 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
304 		return (0);
305 	}
306 
307 	return (ids->ids_maxsize[chan]);
308 }
309 
310 int
311 _isa_dmamap_create(struct isa_dma_state *ids, int chan, bus_size_t size, int flags)
312 {
313 	int error;
314 
315 	if (chan < 0 || chan > 7) {
316 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
317 		return (EINVAL);
318 	}
319 
320 	if (size > ids->ids_maxsize[chan])
321 		return (EINVAL);
322 
323 	error = bus_dmamap_create(ids->ids_dmat, size, 1, size,
324 	    ids->ids_maxsize[chan], flags, &ids->ids_dmamaps[chan]);
325 
326 	return (error);
327 }
328 
329 void
330 _isa_dmamap_destroy(struct isa_dma_state *ids, int chan)
331 {
332 
333 	if (chan < 0 || chan > 7) {
334 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
335 		goto lose;
336 	}
337 
338 	bus_dmamap_destroy(ids->ids_dmat, ids->ids_dmamaps[chan]);
339 	return;
340 
341  lose:
342 	panic("_isa_dmamap_destroy");
343 }
344 
345 /*
346  * _isa_dmastart(): program 8237 DMA controller channel and set it
347  * in motion.
348  */
349 int
350 _isa_dmastart(struct isa_dma_state *ids, int chan, void *addr, bus_size_t nbytes, struct proc *p, int flags, int busdmaflags)
351 {
352 	bus_dmamap_t dmam;
353 	bus_addr_t dmaaddr;
354 	int waport;
355 	int ochan = chan & 3;
356 	int error;
357 
358 	if (chan < 0 || chan > 7) {
359 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
360 		goto lose;
361 	}
362 
363 #ifdef ISADMA_DEBUG
364 	printf("_isa_dmastart: drq %d, addr %p, nbytes 0x%lx, p %p, "
365 	    "flags 0x%x, dmaflags 0x%x\n",
366 	    chan, addr, (u_long)nbytes, p, flags, busdmaflags);
367 #endif
368 
369 	if (ISA_DMA_DRQ_ISFREE(ids, chan)) {
370 		printf("%s: dma start on free channel %d\n",
371 		    device_xname(ids->ids_dev), chan);
372 		goto lose;
373 	}
374 
375 	if (chan & 4) {
376 		if (nbytes > (1 << 17) || nbytes & 1 || (u_long)addr & 1) {
377 			printf("%s: drq %d, nbytes 0x%lx, addr %p\n",
378 			    device_xname(ids->ids_dev), chan,
379 			    (unsigned long) nbytes, addr);
380 			goto lose;
381 		}
382 	} else {
383 		if (nbytes > (1 << 16)) {
384 			printf("%s: drq %d, nbytes 0x%lx\n",
385 			    device_xname(ids->ids_dev), chan,
386 			    (unsigned long) nbytes);
387 			goto lose;
388 		}
389 	}
390 
391 	dmam = ids->ids_dmamaps[chan];
392 	if (dmam == NULL)
393 		panic("_isa_dmastart: no DMA map for chan %d", chan);
394 
395 	error = bus_dmamap_load(ids->ids_dmat, dmam, addr, nbytes,
396 	    p, busdmaflags |
397 	    ((flags & DMAMODE_READ) ? BUS_DMA_READ : BUS_DMA_WRITE));
398 	if (error)
399 		return (error);
400 
401 #ifdef ISADMA_DEBUG
402 	__asm(".globl isa_dmastart_afterload ; isa_dmastart_afterload:");
403 #endif
404 
405 	if (flags & DMAMODE_READ) {
406 		bus_dmamap_sync(ids->ids_dmat, dmam, 0, dmam->dm_mapsize,
407 		    BUS_DMASYNC_PREREAD);
408 		ids->ids_dmareads |= (1 << chan);
409 	} else {
410 		bus_dmamap_sync(ids->ids_dmat, dmam, 0, dmam->dm_mapsize,
411 		    BUS_DMASYNC_PREWRITE);
412 		ids->ids_dmareads &= ~(1 << chan);
413 	}
414 
415 	dmaaddr = dmam->dm_segs[0].ds_addr;
416 
417 #ifdef ISADMA_DEBUG
418 	printf("     dmaaddr 0x%lx\n", dmaaddr);
419 
420 	__asm(".globl isa_dmastart_aftersync ; isa_dmastart_aftersync:");
421 #endif
422 
423 	ids->ids_dmalength[chan] = nbytes;
424 
425 	_isa_dmamask(ids, chan);
426 	ids->ids_dmafinished &= ~(1 << chan);
427 
428 	if ((chan & 4) == 0) {
429 		/* set dma channel mode */
430 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, DMA1_MODE,
431 		    ochan | dmamode[flags]);
432 
433 		/* send start address */
434 		waport = DMA1_CHN(ochan);
435 		bus_space_write_1(ids->ids_bst, ids->ids_dmapgh,
436 		    dmapageport[0][ochan], (dmaaddr >> 16) & 0xff);
437 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport,
438 		    dmaaddr & 0xff);
439 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport,
440 		    (dmaaddr >> 8) & 0xff);
441 
442 		/* send count */
443 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport + 1,
444 		    (--nbytes) & 0xff);
445 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport + 1,
446 		    (nbytes >> 8) & 0xff);
447 	} else {
448 		/* set dma channel mode */
449 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, DMA2_MODE,
450 		    ochan | dmamode[flags]);
451 
452 		/* send start address */
453 		waport = DMA2_CHN(ochan);
454 		bus_space_write_1(ids->ids_bst, ids->ids_dmapgh,
455 		    dmapageport[1][ochan], (dmaaddr >> 16) & 0xff);
456 		dmaaddr >>= 1;
457 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport,
458 		    dmaaddr & 0xff);
459 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport,
460 		    (dmaaddr >> 8) & 0xff);
461 
462 		/* send count */
463 		nbytes >>= 1;
464 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport + 2,
465 		    (--nbytes) & 0xff);
466 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport + 2,
467 		    (nbytes >> 8) & 0xff);
468 	}
469 
470 	_isa_dmaunmask(ids, chan);
471 	return (0);
472 
473  lose:
474 	panic("_isa_dmastart");
475 }
476 
477 void
478 _isa_dmaabort(struct isa_dma_state *ids, int chan)
479 {
480 
481 	if (chan < 0 || chan > 7) {
482 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
483 		panic("_isa_dmaabort");
484 	}
485 
486 	_isa_dmamask(ids, chan);
487 	bus_dmamap_unload(ids->ids_dmat, ids->ids_dmamaps[chan]);
488 	ids->ids_dmareads &= ~(1 << chan);
489 }
490 
491 bus_size_t
492 _isa_dmacount(struct isa_dma_state *ids, int chan)
493 {
494 	int waport;
495 	bus_size_t nbytes;
496 	int ochan = chan & 3;
497 
498 	if (chan < 0 || chan > 7) {
499 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
500 		panic("isa_dmacount");
501 	}
502 
503 	_isa_dmamask(ids, chan);
504 
505 	/*
506 	 * We have to shift the byte count by 1.  If we're in auto-initialize
507 	 * mode, the count may have wrapped around to the initial value.  We
508 	 * can't use the TC bit to check for this case, so instead we compare
509 	 * against the original byte count.
510 	 * If we're not in auto-initialize mode, then the count will wrap to
511 	 * -1, so we also handle that case.
512 	 */
513 	if ((chan & 4) == 0) {
514 		waport = DMA1_CHN(ochan);
515 		nbytes = bus_space_read_1(ids->ids_bst, ids->ids_dma1h,
516 		    waport + 1) + 1;
517 		nbytes += bus_space_read_1(ids->ids_bst, ids->ids_dma1h,
518 		    waport + 1) << 8;
519 		nbytes &= 0xffff;
520 	} else {
521 		waport = DMA2_CHN(ochan);
522 		nbytes = bus_space_read_1(ids->ids_bst, ids->ids_dma2h,
523 		    waport + 2) + 1;
524 		nbytes += bus_space_read_1(ids->ids_bst, ids->ids_dma2h,
525 		    waport + 2) << 8;
526 		nbytes <<= 1;
527 		nbytes &= 0x1ffff;
528 	}
529 
530 	if (nbytes == ids->ids_dmalength[chan])
531 		nbytes = 0;
532 
533 	_isa_dmaunmask(ids, chan);
534 	return (nbytes);
535 }
536 
537 int
538 _isa_dmafinished(struct isa_dma_state *ids, int chan)
539 {
540 
541 	if (chan < 0 || chan > 7) {
542 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
543 		panic("_isa_dmafinished");
544 	}
545 
546 	/* check that the terminal count was reached */
547 	if ((chan & 4) == 0)
548 		ids->ids_dmafinished |= bus_space_read_1(ids->ids_bst,
549 		    ids->ids_dma1h, DMA1_SR) & 0x0f;
550 	else
551 		ids->ids_dmafinished |= (bus_space_read_1(ids->ids_bst,
552 		    ids->ids_dma2h, DMA2_SR) & 0x0f) << 4;
553 
554 	return ((ids->ids_dmafinished & (1 << chan)) != 0);
555 }
556 
557 void
558 _isa_dmadone(struct isa_dma_state *ids, int chan)
559 {
560 	bus_dmamap_t dmam;
561 
562 	if (chan < 0 || chan > 7) {
563 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
564 		panic("_isa_dmadone");
565 	}
566 
567 	dmam = ids->ids_dmamaps[chan];
568 
569 	_isa_dmamask(ids, chan);
570 
571 	if (_isa_dmafinished(ids, chan) == 0)
572 		printf("%s: _isa_dmadone: channel %d not finished\n",
573 		    device_xname(ids->ids_dev), chan);
574 
575 	bus_dmamap_sync(ids->ids_dmat, dmam, 0, dmam->dm_mapsize,
576 	    (ids->ids_dmareads & (1 << chan)) ? BUS_DMASYNC_POSTREAD :
577 	    BUS_DMASYNC_POSTWRITE);
578 
579 	bus_dmamap_unload(ids->ids_dmat, dmam);
580 	ids->ids_dmareads &= ~(1 << chan);
581 }
582 
583 void
584 _isa_dmafreeze(struct isa_dma_state *ids)
585 {
586 	int s;
587 
588 	s = splhigh();
589 
590 	if (ids->ids_frozen == 0) {
591 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
592 		    DMA1_MASK, 0x0f);
593 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
594 		    DMA2_MASK, 0x0f);
595 	}
596 
597 	ids->ids_frozen++;
598 	if (ids->ids_frozen < 1)
599 		panic("_isa_dmafreeze: overflow");
600 
601 	splx(s);
602 }
603 
604 void
605 _isa_dmathaw(struct isa_dma_state *ids)
606 {
607 	int s;
608 
609 	s = splhigh();
610 
611 	ids->ids_frozen--;
612 	if (ids->ids_frozen < 0)
613 		panic("_isa_dmathaw: underflow");
614 
615 	if (ids->ids_frozen == 0) {
616 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
617 		    DMA1_MASK, ids->ids_masked & 0x0f);
618 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
619 		    DMA2_MASK, (ids->ids_masked >> 4) & 0x0f);
620 	}
621 
622 	splx(s);
623 }
624 
625 int
626 _isa_dmamem_alloc(struct isa_dma_state *ids, int chan, bus_size_t size, bus_addr_t *addrp, int flags)
627 {
628 	bus_dma_segment_t seg;
629 	int error, boundary, rsegs;
630 
631 	if (chan < 0 || chan > 7) {
632 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
633 		panic("_isa_dmamem_alloc");
634 	}
635 
636 	boundary = (chan & 4) ? (1 << 17) : (1 << 16);
637 
638 	size = round_page(size);
639 
640 	error = bus_dmamem_alloc(ids->ids_dmat, size, PAGE_SIZE, boundary,
641 	    &seg, 1, &rsegs, flags);
642 	if (error)
643 		return (error);
644 
645 	*addrp = seg.ds_addr;
646 	return (0);
647 }
648 
649 void
650 _isa_dmamem_free(struct isa_dma_state *ids, int chan, bus_addr_t addr, bus_size_t size)
651 {
652 	bus_dma_segment_t seg;
653 
654 	if (chan < 0 || chan > 7) {
655 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
656 		panic("_isa_dmamem_free");
657 	}
658 
659 	seg.ds_addr = addr;
660 	seg.ds_len = size;
661 
662 	bus_dmamem_free(ids->ids_dmat, &seg, 1);
663 }
664 
665 int
666 _isa_dmamem_map(struct isa_dma_state *ids, int chan, bus_addr_t addr, bus_size_t size, void **kvap, int flags)
667 {
668 	bus_dma_segment_t seg;
669 
670 	if (chan < 0 || chan > 7) {
671 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
672 		panic("_isa_dmamem_map");
673 	}
674 
675 	seg.ds_addr = addr;
676 	seg.ds_len = size;
677 
678 	return (bus_dmamem_map(ids->ids_dmat, &seg, 1, size, kvap, flags));
679 }
680 
681 void
682 _isa_dmamem_unmap(struct isa_dma_state *ids, int chan, void *kva, size_t size)
683 {
684 
685 	if (chan < 0 || chan > 7) {
686 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
687 		panic("_isa_dmamem_unmap");
688 	}
689 
690 	bus_dmamem_unmap(ids->ids_dmat, kva, size);
691 }
692 
693 paddr_t
694 _isa_dmamem_mmap(struct isa_dma_state *ids, int chan, bus_addr_t addr, bus_size_t size, off_t off, int prot, int flags)
695 {
696 	bus_dma_segment_t seg;
697 
698 	if (chan < 0 || chan > 7) {
699 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
700 		panic("_isa_dmamem_mmap");
701 	}
702 
703 	if (off < 0)
704 		return (-1);
705 
706 	seg.ds_addr = addr;
707 	seg.ds_len = size;
708 
709 	return (bus_dmamem_mmap(ids->ids_dmat, &seg, 1, off, prot, flags));
710 }
711 
712 int
713 _isa_drq_isfree(struct isa_dma_state *ids, int chan)
714 {
715 
716 	if (chan < 0 || chan > 7) {
717 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
718 		panic("_isa_drq_isfree");
719 	}
720 
721 	return ISA_DMA_DRQ_ISFREE(ids, chan);
722 }
723 
724 void *
725 _isa_malloc(struct isa_dma_state *ids, int chan, size_t size, struct malloc_type *pool, int flags)
726 {
727 	bus_addr_t addr;
728 	void *kva;
729 	int bflags;
730 	struct isa_mem *m;
731 
732 	bflags = flags & M_WAITOK ? BUS_DMA_WAITOK : BUS_DMA_NOWAIT;
733 
734 	if (_isa_dmamem_alloc(ids, chan, size, &addr, bflags))
735 		return 0;
736 	if (_isa_dmamem_map(ids, chan, addr, size, &kva, bflags)) {
737 		_isa_dmamem_free(ids, chan, addr, size);
738 		return 0;
739 	}
740 	m = malloc(sizeof(*m), pool, flags);
741 	if (m == 0) {
742 		_isa_dmamem_unmap(ids, chan, kva, size);
743 		_isa_dmamem_free(ids, chan, addr, size);
744 		return 0;
745 	}
746 	m->ids = ids;
747 	m->chan = chan;
748 	m->size = size;
749 	m->addr = addr;
750 	m->kva = kva;
751 	m->next = isa_mem_head;
752 	isa_mem_head = m;
753 	return (void *)kva;
754 }
755 
756 void
757 _isa_free(void *addr, struct malloc_type *pool)
758 {
759 	struct isa_mem **mp, *m;
760 	void *kva = (void *)addr;
761 
762 	for(mp = &isa_mem_head; *mp && (*mp)->kva != kva;
763 	    mp = &(*mp)->next)
764 		;
765 	m = *mp;
766 	if (!m) {
767 		printf("_isa_free: freeing unallocted memory\n");
768 		return;
769 	}
770 	*mp = m->next;
771 	_isa_dmamem_unmap(m->ids, m->chan, kva, m->size);
772 	_isa_dmamem_free(m->ids, m->chan, m->addr, m->size);
773 	free(m, pool);
774 }
775 
776 paddr_t
777 _isa_mappage(void *mem, off_t off, int prot)
778 {
779 	struct isa_mem *m;
780 
781 	for(m = isa_mem_head; m && m->kva != (void *)mem; m = m->next)
782 		;
783 	if (!m) {
784 		printf("_isa_mappage: mapping unallocted memory\n");
785 		return -1;
786 	}
787 	return _isa_dmamem_mmap(m->ids, m->chan, m->addr,
788 	    m->size, off, prot, BUS_DMA_WAITOK);
789 }
790