xref: /netbsd-src/sys/dev/isa/isadma.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: isadma.c,v 1.65 2010/07/26 22:33:24 jym 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 1.65 2010/07/26 22:33:24 jym 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 (!bus_space_is_equal(ids->ids_bst, bst) ||
159 		    ids->ids_dmat != dmat)
160 			panic("_isa_dmainit: inconsistent ISA tags");
161 	} else {
162 		ids->ids_bst = bst;
163 		ids->ids_dmat = dmat;
164 
165 		/*
166 		 * Map the registers used by the ISA DMA controller.
167 		 */
168 		if (bus_space_map(ids->ids_bst, IO_DMA1, DMA1_IOSIZE, 0,
169 		    &ids->ids_dma1h))
170 			panic("_isa_dmainit: unable to map DMA controller #1");
171 		if (bus_space_map(ids->ids_bst, IO_DMA2, DMA2_IOSIZE, 0,
172 		    &ids->ids_dma2h))
173 			panic("_isa_dmainit: unable to map DMA controller #2");
174 		if (bus_space_map(ids->ids_bst, IO_DMAPG, 0xf, 0,
175 		    &ids->ids_dmapgh))
176 			panic("_isa_dmainit: unable to map DMA page registers");
177 
178 		/*
179 		 * All 8 DMA channels start out "masked".
180 		 */
181 		ids->ids_masked = 0xff;
182 
183 		/*
184 		 * Initialize the max transfer size for each channel, if
185 		 * it is not initialized already (i.e. by a bus-dependent
186 		 * front-end).
187 		 */
188 		for (chan = 0; chan < 8; chan++) {
189 			if (ids->ids_maxsize[chan] == 0)
190 				ids->ids_maxsize[chan] =
191 				    ISA_DMA_MAXSIZE_DEFAULT(chan);
192 		}
193 
194 		ids->ids_initialized = 1;
195 
196 		/*
197 		 * DRQ 4 is used to chain the two 8237s together; make
198 		 * sure it's always cascaded, and that it will be unmasked
199 		 * when DMA is thawed.
200 		 */
201 		_isa_dmacascade(ids, 4);
202 	}
203 }
204 
205 void
206 _isa_dmadestroy(struct isa_dma_state *ids)
207 {
208 	if (!ids->ids_initialized)
209 		return;
210 
211 	_isa_dmacascade_stop(ids, 4);
212 
213 	/*
214 	 * Unmap the registers used by the ISA DMA controller.
215 	 */
216 	bus_space_unmap(ids->ids_bst, ids->ids_dmapgh, 0xf);
217 	bus_space_unmap(ids->ids_bst, ids->ids_dma2h, DMA2_IOSIZE);
218 	bus_space_unmap(ids->ids_bst, ids->ids_dma1h, DMA1_IOSIZE);
219 
220 	ids->ids_initialized = 0;
221 }
222 
223 /*
224  * _isa_dmacascade(): program 8237 DMA controller channel to accept
225  * external dma control by a board.
226  */
227 int
228 _isa_dmacascade(struct isa_dma_state *ids, int chan)
229 {
230 	int ochan = chan & 3;
231 
232 	if (chan < 0 || chan > 7) {
233 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
234 		return (EINVAL);
235 	}
236 
237 	if (!ISA_DMA_DRQ_ISFREE(ids, chan)) {
238 		printf("%s: DRQ %d is not free\n", device_xname(ids->ids_dev),
239 		    chan);
240 		return (EAGAIN);
241 	}
242 
243 	ISA_DMA_DRQ_ALLOC(ids, chan);
244 
245 	/* set dma channel mode, and set dma channel mode */
246 	if ((chan & 4) == 0)
247 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
248 		    DMA1_MODE, ochan | DMA37MD_CASCADE);
249 	else
250 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
251 		    DMA2_MODE, ochan | DMA37MD_CASCADE);
252 
253 	_isa_dmaunmask(ids, chan);
254 	return (0);
255 }
256 
257 /*
258  * _isa_dmacascade_stop(): turn off cascading on the 8237 DMA controller channel
259  * external dma control by a board.
260  */
261 int
262 _isa_dmacascade_stop(struct isa_dma_state *ids, int chan)
263 {
264 	if (chan < 0 || chan > 7) {
265 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
266 		return EINVAL;
267 	}
268 
269 	if (ISA_DMA_DRQ_ISFREE(ids, chan))
270 		return 0;
271 
272 	_isa_dmamask(ids, chan);
273 
274 	ISA_DMA_DRQ_FREE(ids, chan);
275 
276 	return 0;
277 }
278 
279 int
280 _isa_drq_alloc(struct isa_dma_state *ids, int chan)
281 {
282 	if (!ISA_DMA_DRQ_ISFREE(ids, chan))
283 		return EBUSY;
284 	ISA_DMA_DRQ_ALLOC(ids, chan);
285 	return 0;
286 }
287 
288 int
289 _isa_drq_free(struct isa_dma_state *ids, int chan)
290 {
291 	if (ISA_DMA_DRQ_ISFREE(ids, chan))
292 		return EINVAL;
293 	ISA_DMA_DRQ_FREE(ids, chan);
294 	return 0;
295 }
296 
297 bus_size_t
298 _isa_dmamaxsize(struct isa_dma_state *ids, int chan)
299 {
300 
301 	if (chan < 0 || chan > 7) {
302 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
303 		return (0);
304 	}
305 
306 	return (ids->ids_maxsize[chan]);
307 }
308 
309 int
310 _isa_dmamap_create(struct isa_dma_state *ids, int chan, bus_size_t size, int flags)
311 {
312 	int error;
313 
314 	if (chan < 0 || chan > 7) {
315 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
316 		return (EINVAL);
317 	}
318 
319 	if (size > ids->ids_maxsize[chan])
320 		return (EINVAL);
321 
322 	error = bus_dmamap_create(ids->ids_dmat, size, 1, size,
323 	    ids->ids_maxsize[chan], flags, &ids->ids_dmamaps[chan]);
324 
325 	return (error);
326 }
327 
328 void
329 _isa_dmamap_destroy(struct isa_dma_state *ids, int chan)
330 {
331 
332 	if (chan < 0 || chan > 7) {
333 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
334 		goto lose;
335 	}
336 
337 	bus_dmamap_destroy(ids->ids_dmat, ids->ids_dmamaps[chan]);
338 	return;
339 
340  lose:
341 	panic("_isa_dmamap_destroy");
342 }
343 
344 /*
345  * _isa_dmastart(): program 8237 DMA controller channel and set it
346  * in motion.
347  */
348 int
349 _isa_dmastart(struct isa_dma_state *ids, int chan, void *addr, bus_size_t nbytes, struct proc *p, int flags, int busdmaflags)
350 {
351 	bus_dmamap_t dmam;
352 	bus_addr_t dmaaddr;
353 	int waport;
354 	int ochan = chan & 3;
355 	int error;
356 
357 	if (chan < 0 || chan > 7) {
358 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
359 		goto lose;
360 	}
361 
362 #ifdef ISADMA_DEBUG
363 	printf("_isa_dmastart: drq %d, addr %p, nbytes 0x%lx, p %p, "
364 	    "flags 0x%x, dmaflags 0x%x\n",
365 	    chan, addr, (u_long)nbytes, p, flags, busdmaflags);
366 #endif
367 
368 	if (ISA_DMA_DRQ_ISFREE(ids, chan)) {
369 		printf("%s: dma start on free channel %d\n",
370 		    device_xname(ids->ids_dev), chan);
371 		goto lose;
372 	}
373 
374 	if (chan & 4) {
375 		if (nbytes > (1 << 17) || nbytes & 1 || (u_long)addr & 1) {
376 			printf("%s: drq %d, nbytes 0x%lx, addr %p\n",
377 			    device_xname(ids->ids_dev), chan,
378 			    (unsigned long) nbytes, addr);
379 			goto lose;
380 		}
381 	} else {
382 		if (nbytes > (1 << 16)) {
383 			printf("%s: drq %d, nbytes 0x%lx\n",
384 			    device_xname(ids->ids_dev), chan,
385 			    (unsigned long) nbytes);
386 			goto lose;
387 		}
388 	}
389 
390 	dmam = ids->ids_dmamaps[chan];
391 	if (dmam == NULL)
392 		panic("_isa_dmastart: no DMA map for chan %d", chan);
393 
394 	error = bus_dmamap_load(ids->ids_dmat, dmam, addr, nbytes,
395 	    p, busdmaflags |
396 	    ((flags & DMAMODE_READ) ? BUS_DMA_READ : BUS_DMA_WRITE));
397 	if (error)
398 		return (error);
399 
400 #ifdef ISADMA_DEBUG
401 	__asm(".globl isa_dmastart_afterload ; isa_dmastart_afterload:");
402 #endif
403 
404 	if (flags & DMAMODE_READ) {
405 		bus_dmamap_sync(ids->ids_dmat, dmam, 0, dmam->dm_mapsize,
406 		    BUS_DMASYNC_PREREAD);
407 		ids->ids_dmareads |= (1 << chan);
408 	} else {
409 		bus_dmamap_sync(ids->ids_dmat, dmam, 0, dmam->dm_mapsize,
410 		    BUS_DMASYNC_PREWRITE);
411 		ids->ids_dmareads &= ~(1 << chan);
412 	}
413 
414 	dmaaddr = dmam->dm_segs[0].ds_addr;
415 
416 #ifdef ISADMA_DEBUG
417 	printf("     dmaaddr %#" PRIxPADDR "\n", dmaaddr);
418 
419 	__asm(".globl isa_dmastart_aftersync ; isa_dmastart_aftersync:");
420 #endif
421 
422 	ids->ids_dmalength[chan] = nbytes;
423 
424 	_isa_dmamask(ids, chan);
425 	ids->ids_dmafinished &= ~(1 << chan);
426 
427 	if ((chan & 4) == 0) {
428 		/* set dma channel mode */
429 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, DMA1_MODE,
430 		    ochan | dmamode[flags]);
431 
432 		/* send start address */
433 		waport = DMA1_CHN(ochan);
434 		bus_space_write_1(ids->ids_bst, ids->ids_dmapgh,
435 		    dmapageport[0][ochan], (dmaaddr >> 16) & 0xff);
436 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport,
437 		    dmaaddr & 0xff);
438 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport,
439 		    (dmaaddr >> 8) & 0xff);
440 
441 		/* send count */
442 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport + 1,
443 		    (--nbytes) & 0xff);
444 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h, waport + 1,
445 		    (nbytes >> 8) & 0xff);
446 	} else {
447 		/* set dma channel mode */
448 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, DMA2_MODE,
449 		    ochan | dmamode[flags]);
450 
451 		/* send start address */
452 		waport = DMA2_CHN(ochan);
453 		bus_space_write_1(ids->ids_bst, ids->ids_dmapgh,
454 		    dmapageport[1][ochan], (dmaaddr >> 16) & 0xff);
455 		dmaaddr >>= 1;
456 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport,
457 		    dmaaddr & 0xff);
458 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport,
459 		    (dmaaddr >> 8) & 0xff);
460 
461 		/* send count */
462 		nbytes >>= 1;
463 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport + 2,
464 		    (--nbytes) & 0xff);
465 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h, waport + 2,
466 		    (nbytes >> 8) & 0xff);
467 	}
468 
469 	_isa_dmaunmask(ids, chan);
470 	return (0);
471 
472  lose:
473 	panic("_isa_dmastart");
474 }
475 
476 void
477 _isa_dmaabort(struct isa_dma_state *ids, int chan)
478 {
479 
480 	if (chan < 0 || chan > 7) {
481 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
482 		panic("_isa_dmaabort");
483 	}
484 
485 	_isa_dmamask(ids, chan);
486 	bus_dmamap_unload(ids->ids_dmat, ids->ids_dmamaps[chan]);
487 	ids->ids_dmareads &= ~(1 << chan);
488 }
489 
490 bus_size_t
491 _isa_dmacount(struct isa_dma_state *ids, int chan)
492 {
493 	int waport;
494 	bus_size_t nbytes;
495 	int ochan = chan & 3;
496 
497 	if (chan < 0 || chan > 7) {
498 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
499 		panic("isa_dmacount");
500 	}
501 
502 	_isa_dmamask(ids, chan);
503 
504 	/*
505 	 * We have to shift the byte count by 1.  If we're in auto-initialize
506 	 * mode, the count may have wrapped around to the initial value.  We
507 	 * can't use the TC bit to check for this case, so instead we compare
508 	 * against the original byte count.
509 	 * If we're not in auto-initialize mode, then the count will wrap to
510 	 * -1, so we also handle that case.
511 	 */
512 	if ((chan & 4) == 0) {
513 		waport = DMA1_CHN(ochan);
514 		nbytes = bus_space_read_1(ids->ids_bst, ids->ids_dma1h,
515 		    waport + 1) + 1;
516 		nbytes += bus_space_read_1(ids->ids_bst, ids->ids_dma1h,
517 		    waport + 1) << 8;
518 		nbytes &= 0xffff;
519 	} else {
520 		waport = DMA2_CHN(ochan);
521 		nbytes = bus_space_read_1(ids->ids_bst, ids->ids_dma2h,
522 		    waport + 2) + 1;
523 		nbytes += bus_space_read_1(ids->ids_bst, ids->ids_dma2h,
524 		    waport + 2) << 8;
525 		nbytes <<= 1;
526 		nbytes &= 0x1ffff;
527 	}
528 
529 	if (nbytes == ids->ids_dmalength[chan])
530 		nbytes = 0;
531 
532 	_isa_dmaunmask(ids, chan);
533 	return (nbytes);
534 }
535 
536 int
537 _isa_dmafinished(struct isa_dma_state *ids, int chan)
538 {
539 
540 	if (chan < 0 || chan > 7) {
541 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
542 		panic("_isa_dmafinished");
543 	}
544 
545 	/* check that the terminal count was reached */
546 	if ((chan & 4) == 0)
547 		ids->ids_dmafinished |= bus_space_read_1(ids->ids_bst,
548 		    ids->ids_dma1h, DMA1_SR) & 0x0f;
549 	else
550 		ids->ids_dmafinished |= (bus_space_read_1(ids->ids_bst,
551 		    ids->ids_dma2h, DMA2_SR) & 0x0f) << 4;
552 
553 	return ((ids->ids_dmafinished & (1 << chan)) != 0);
554 }
555 
556 void
557 _isa_dmadone(struct isa_dma_state *ids, int chan)
558 {
559 	bus_dmamap_t dmam;
560 
561 	if (chan < 0 || chan > 7) {
562 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
563 		panic("_isa_dmadone");
564 	}
565 
566 	dmam = ids->ids_dmamaps[chan];
567 
568 	_isa_dmamask(ids, chan);
569 
570 	if (_isa_dmafinished(ids, chan) == 0)
571 		printf("%s: _isa_dmadone: channel %d not finished\n",
572 		    device_xname(ids->ids_dev), chan);
573 
574 	bus_dmamap_sync(ids->ids_dmat, dmam, 0, dmam->dm_mapsize,
575 	    (ids->ids_dmareads & (1 << chan)) ? BUS_DMASYNC_POSTREAD :
576 	    BUS_DMASYNC_POSTWRITE);
577 
578 	bus_dmamap_unload(ids->ids_dmat, dmam);
579 	ids->ids_dmareads &= ~(1 << chan);
580 }
581 
582 void
583 _isa_dmafreeze(struct isa_dma_state *ids)
584 {
585 	int s;
586 
587 	s = splhigh();
588 
589 	if (ids->ids_frozen == 0) {
590 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
591 		    DMA1_MASK, 0x0f);
592 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
593 		    DMA2_MASK, 0x0f);
594 	}
595 
596 	ids->ids_frozen++;
597 	if (ids->ids_frozen < 1)
598 		panic("_isa_dmafreeze: overflow");
599 
600 	splx(s);
601 }
602 
603 void
604 _isa_dmathaw(struct isa_dma_state *ids)
605 {
606 	int s;
607 
608 	s = splhigh();
609 
610 	ids->ids_frozen--;
611 	if (ids->ids_frozen < 0)
612 		panic("_isa_dmathaw: underflow");
613 
614 	if (ids->ids_frozen == 0) {
615 		bus_space_write_1(ids->ids_bst, ids->ids_dma1h,
616 		    DMA1_MASK, ids->ids_masked & 0x0f);
617 		bus_space_write_1(ids->ids_bst, ids->ids_dma2h,
618 		    DMA2_MASK, (ids->ids_masked >> 4) & 0x0f);
619 	}
620 
621 	splx(s);
622 }
623 
624 int
625 _isa_dmamem_alloc(struct isa_dma_state *ids, int chan, bus_size_t size, bus_addr_t *addrp, int flags)
626 {
627 	bus_dma_segment_t seg;
628 	int error, boundary, rsegs;
629 
630 	if (chan < 0 || chan > 7) {
631 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
632 		panic("_isa_dmamem_alloc");
633 	}
634 
635 	boundary = (chan & 4) ? (1 << 17) : (1 << 16);
636 
637 	size = round_page(size);
638 
639 	error = bus_dmamem_alloc(ids->ids_dmat, size, PAGE_SIZE, boundary,
640 	    &seg, 1, &rsegs, flags);
641 	if (error)
642 		return (error);
643 
644 	*addrp = seg.ds_addr;
645 	return (0);
646 }
647 
648 void
649 _isa_dmamem_free(struct isa_dma_state *ids, int chan, bus_addr_t addr, bus_size_t size)
650 {
651 	bus_dma_segment_t seg;
652 
653 	if (chan < 0 || chan > 7) {
654 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
655 		panic("_isa_dmamem_free");
656 	}
657 
658 	seg.ds_addr = addr;
659 	seg.ds_len = size;
660 
661 	bus_dmamem_free(ids->ids_dmat, &seg, 1);
662 }
663 
664 int
665 _isa_dmamem_map(struct isa_dma_state *ids, int chan, bus_addr_t addr, bus_size_t size, void **kvap, int flags)
666 {
667 	bus_dma_segment_t seg;
668 
669 	if (chan < 0 || chan > 7) {
670 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
671 		panic("_isa_dmamem_map");
672 	}
673 
674 	seg.ds_addr = addr;
675 	seg.ds_len = size;
676 
677 	return (bus_dmamem_map(ids->ids_dmat, &seg, 1, size, kvap, flags));
678 }
679 
680 void
681 _isa_dmamem_unmap(struct isa_dma_state *ids, int chan, void *kva, size_t size)
682 {
683 
684 	if (chan < 0 || chan > 7) {
685 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
686 		panic("_isa_dmamem_unmap");
687 	}
688 
689 	bus_dmamem_unmap(ids->ids_dmat, kva, size);
690 }
691 
692 paddr_t
693 _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)
694 {
695 	bus_dma_segment_t seg;
696 
697 	if (chan < 0 || chan > 7) {
698 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
699 		panic("_isa_dmamem_mmap");
700 	}
701 
702 	if (off < 0)
703 		return (-1);
704 
705 	seg.ds_addr = addr;
706 	seg.ds_len = size;
707 
708 	return (bus_dmamem_mmap(ids->ids_dmat, &seg, 1, off, prot, flags));
709 }
710 
711 int
712 _isa_drq_isfree(struct isa_dma_state *ids, int chan)
713 {
714 
715 	if (chan < 0 || chan > 7) {
716 		printf("%s: bogus drq %d\n", device_xname(ids->ids_dev), chan);
717 		panic("_isa_drq_isfree");
718 	}
719 
720 	return ISA_DMA_DRQ_ISFREE(ids, chan);
721 }
722 
723 void *
724 _isa_malloc(struct isa_dma_state *ids, int chan, size_t size, struct malloc_type *pool, int flags)
725 {
726 	bus_addr_t addr;
727 	void *kva;
728 	int bflags;
729 	struct isa_mem *m;
730 
731 	bflags = flags & M_WAITOK ? BUS_DMA_WAITOK : BUS_DMA_NOWAIT;
732 
733 	if (_isa_dmamem_alloc(ids, chan, size, &addr, bflags))
734 		return 0;
735 	if (_isa_dmamem_map(ids, chan, addr, size, &kva, bflags)) {
736 		_isa_dmamem_free(ids, chan, addr, size);
737 		return 0;
738 	}
739 	m = malloc(sizeof(*m), pool, flags);
740 	if (m == 0) {
741 		_isa_dmamem_unmap(ids, chan, kva, size);
742 		_isa_dmamem_free(ids, chan, addr, size);
743 		return 0;
744 	}
745 	m->ids = ids;
746 	m->chan = chan;
747 	m->size = size;
748 	m->addr = addr;
749 	m->kva = kva;
750 	m->next = isa_mem_head;
751 	isa_mem_head = m;
752 	return (void *)kva;
753 }
754 
755 void
756 _isa_free(void *addr, struct malloc_type *pool)
757 {
758 	struct isa_mem **mp, *m;
759 	void *kva = (void *)addr;
760 
761 	for(mp = &isa_mem_head; *mp && (*mp)->kva != kva;
762 	    mp = &(*mp)->next)
763 		;
764 	m = *mp;
765 	if (!m) {
766 		printf("_isa_free: freeing unallocted memory\n");
767 		return;
768 	}
769 	*mp = m->next;
770 	_isa_dmamem_unmap(m->ids, m->chan, kva, m->size);
771 	_isa_dmamem_free(m->ids, m->chan, m->addr, m->size);
772 	free(m, pool);
773 }
774 
775 paddr_t
776 _isa_mappage(void *mem, off_t off, int prot)
777 {
778 	struct isa_mem *m;
779 
780 	for(m = isa_mem_head; m && m->kva != (void *)mem; m = m->next)
781 		;
782 	if (!m) {
783 		printf("_isa_mappage: mapping unallocted memory\n");
784 		return -1;
785 	}
786 	return _isa_dmamem_mmap(m->ids, m->chan, m->addr,
787 	    m->size, off, prot, BUS_DMA_WAITOK);
788 }
789