1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991 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.
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 * from: @(#)isa.c 7.2 (Berkeley) 5/13/91
35 */
36
37 #include <sys/cdefs.h>
38 /*
39 * code to manage AT bus
40 *
41 * 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com):
42 * Fixed uninitialized variable problem and added code to deal
43 * with DMA page boundaries in isa_dmarangecheck(). Fixed word
44 * mode DMA count compution and reorganized DMA setup code in
45 * isa_dmastart()
46 */
47
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/bus.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/lock.h>
54 #include <sys/proc.h>
55 #include <sys/mutex.h>
56 #include <sys/module.h>
57 #include <vm/vm.h>
58 #include <vm/vm_param.h>
59 #include <vm/pmap.h>
60 #include <isa/isareg.h>
61 #include <isa/isavar.h>
62 #include <isa/isa_dmareg.h>
63
64 #define ISARAM_END 0x1000000
65
66 static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
67
68 static caddr_t dma_bouncebuf[8];
69 static u_int dma_bouncebufsize[8];
70 static u_int8_t dma_bounced = 0;
71 static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */
72 static u_int8_t dma_inuse = 0; /* User for acquire/release */
73 static u_int8_t dma_auto_mode = 0;
74 static struct mtx isa_dma_lock;
75 MTX_SYSINIT(isa_dma_lock, &isa_dma_lock, "isa DMA lock", MTX_DEF);
76
77 #define VALID_DMA_MASK (7)
78
79 /* high byte of address is stored in this port for i-th dma channel */
80 static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
81
82 /*
83 * Setup a DMA channel's bounce buffer.
84 */
85 int
isa_dma_init(int chan,u_int bouncebufsize,int flag)86 isa_dma_init(int chan, u_int bouncebufsize, int flag)
87 {
88 void *buf;
89 int contig;
90
91 #ifdef DIAGNOSTIC
92 if (chan & ~VALID_DMA_MASK)
93 panic("isa_dma_init: channel out of range");
94 #endif
95
96 /* Try malloc() first. It works better if it works. */
97 buf = malloc(bouncebufsize, M_DEVBUF, flag);
98 if (buf != NULL) {
99 if (isa_dmarangecheck(buf, bouncebufsize, chan) != 0) {
100 free(buf, M_DEVBUF);
101 buf = NULL;
102 }
103 contig = 0;
104 }
105
106 if (buf == NULL) {
107 buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
108 1ul, chan & 4 ? 0x20000ul : 0x10000ul);
109 contig = 1;
110 }
111
112 if (buf == NULL)
113 return (ENOMEM);
114
115 mtx_lock(&isa_dma_lock);
116 /*
117 * If a DMA channel is shared, both drivers have to call isa_dma_init
118 * since they don't know that the other driver will do it.
119 * Just return if we're already set up good.
120 * XXX: this only works if they agree on the bouncebuf size. This
121 * XXX: is typically the case since they are multiple instances of
122 * XXX: the same driver.
123 */
124 if (dma_bouncebuf[chan] != NULL) {
125 if (contig)
126 contigfree(buf, bouncebufsize, M_DEVBUF);
127 else
128 free(buf, M_DEVBUF);
129 mtx_unlock(&isa_dma_lock);
130 return (0);
131 }
132
133 dma_bouncebufsize[chan] = bouncebufsize;
134 dma_bouncebuf[chan] = buf;
135
136 mtx_unlock(&isa_dma_lock);
137
138 return (0);
139 }
140
141 /*
142 * Register a DMA channel's usage. Usually called from a device driver
143 * in open() or during its initialization.
144 */
145 int
isa_dma_acquire(int chan)146 isa_dma_acquire(int chan)
147 {
148 #ifdef DIAGNOSTIC
149 if (chan & ~VALID_DMA_MASK)
150 panic("isa_dma_acquire: channel out of range");
151 #endif
152
153 mtx_lock(&isa_dma_lock);
154 if (dma_inuse & (1 << chan)) {
155 printf("isa_dma_acquire: channel %d already in use\n", chan);
156 mtx_unlock(&isa_dma_lock);
157 return (EBUSY);
158 }
159 dma_inuse |= (1 << chan);
160 dma_auto_mode &= ~(1 << chan);
161 mtx_unlock(&isa_dma_lock);
162
163 return (0);
164 }
165
166 /*
167 * Unregister a DMA channel's usage. Usually called from a device driver
168 * during close() or during its shutdown.
169 */
170 void
isa_dma_release(int chan)171 isa_dma_release(int chan)
172 {
173 #ifdef DIAGNOSTIC
174 if (chan & ~VALID_DMA_MASK)
175 panic("isa_dma_release: channel out of range");
176
177 mtx_lock(&isa_dma_lock);
178 if ((dma_inuse & (1 << chan)) == 0)
179 printf("isa_dma_release: channel %d not in use\n", chan);
180 #else
181 mtx_lock(&isa_dma_lock);
182 #endif
183
184 if (dma_busy & (1 << chan)) {
185 dma_busy &= ~(1 << chan);
186 /*
187 * XXX We should also do "dma_bounced &= (1 << chan);"
188 * because we are acting on behalf of isa_dmadone() which
189 * was not called to end the last DMA operation. This does
190 * not matter now, but it may in the future.
191 */
192 }
193
194 dma_inuse &= ~(1 << chan);
195 dma_auto_mode &= ~(1 << chan);
196
197 mtx_unlock(&isa_dma_lock);
198 }
199
200 /*
201 * isa_dmacascade(): program 8237 DMA controller channel to accept
202 * external dma control by a board.
203 */
204 void
isa_dmacascade(int chan)205 isa_dmacascade(int chan)
206 {
207 #ifdef DIAGNOSTIC
208 if (chan & ~VALID_DMA_MASK)
209 panic("isa_dmacascade: channel out of range");
210 #endif
211
212 mtx_lock(&isa_dma_lock);
213 /* set dma channel mode, and set dma channel mode */
214 if ((chan & 4) == 0) {
215 outb(DMA1_MODE, DMA37MD_CASCADE | chan);
216 outb(DMA1_SMSK, chan);
217 } else {
218 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
219 outb(DMA2_SMSK, chan & 3);
220 }
221 mtx_unlock(&isa_dma_lock);
222 }
223
224 /*
225 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
226 * problems by using a bounce buffer.
227 */
228 void
isa_dmastart(int flags,caddr_t addr,u_int nbytes,int chan)229 isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
230 {
231 vm_paddr_t phys;
232 int waport;
233 caddr_t newaddr;
234 int dma_range_checked;
235
236 dma_range_checked = isa_dmarangecheck(addr, nbytes, chan);
237
238 #ifdef DIAGNOSTIC
239 if (chan & ~VALID_DMA_MASK)
240 panic("isa_dmastart: channel out of range");
241
242 if ((chan < 4 && nbytes > (1<<16))
243 || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
244 panic("isa_dmastart: impossible request");
245
246 mtx_lock(&isa_dma_lock);
247 if ((dma_inuse & (1 << chan)) == 0)
248 printf("isa_dmastart: channel %d not acquired\n", chan);
249 #else
250 mtx_lock(&isa_dma_lock);
251 #endif
252
253 #if 0
254 /*
255 * XXX This should be checked, but drivers like ad1848 only call
256 * isa_dmastart() once because they use Auto DMA mode. If we
257 * leave this in, drivers that do this will print this continuously.
258 */
259 if (dma_busy & (1 << chan))
260 printf("isa_dmastart: channel %d busy\n", chan);
261 #endif
262
263 dma_busy |= (1 << chan);
264
265 if (dma_range_checked) {
266 if (dma_bouncebuf[chan] == NULL
267 || dma_bouncebufsize[chan] < nbytes)
268 panic("isa_dmastart: bad bounce buffer");
269 dma_bounced |= (1 << chan);
270 newaddr = dma_bouncebuf[chan];
271
272 /* copy bounce buffer on write */
273 if (!(flags & ISADMA_READ))
274 bcopy(addr, newaddr, nbytes);
275 addr = newaddr;
276 }
277
278 /* translate to physical */
279 phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
280
281 if (flags & ISADMA_RAW) {
282 dma_auto_mode |= (1 << chan);
283 } else {
284 dma_auto_mode &= ~(1 << chan);
285 }
286
287 if ((chan & 4) == 0) {
288 /*
289 * Program one of DMA channels 0..3. These are
290 * byte mode channels.
291 */
292 /* set dma channel mode, and reset address ff */
293
294 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
295 if (flags & ISADMA_RAW) {
296 if (flags & ISADMA_READ)
297 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
298 else
299 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
300 }
301 else
302 if (flags & ISADMA_READ)
303 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
304 else
305 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
306 outb(DMA1_FFC, 0);
307
308 /* send start address */
309 waport = DMA1_CHN(chan);
310 outb(waport, phys);
311 outb(waport, phys>>8);
312 outb(dmapageport[chan], phys>>16);
313
314 /* send count */
315 outb(waport + 1, --nbytes);
316 outb(waport + 1, nbytes>>8);
317
318 /* unmask channel */
319 outb(DMA1_SMSK, chan);
320 } else {
321 /*
322 * Program one of DMA channels 4..7. These are
323 * word mode channels.
324 */
325 /* set dma channel mode, and reset address ff */
326
327 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
328 if (flags & ISADMA_RAW) {
329 if (flags & ISADMA_READ)
330 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
331 else
332 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
333 }
334 else
335 if (flags & ISADMA_READ)
336 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
337 else
338 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
339 outb(DMA2_FFC, 0);
340
341 /* send start address */
342 waport = DMA2_CHN(chan - 4);
343 outb(waport, phys>>1);
344 outb(waport, phys>>9);
345 outb(dmapageport[chan], phys>>16);
346
347 /* send count */
348 nbytes >>= 1;
349 outb(waport + 2, --nbytes);
350 outb(waport + 2, nbytes>>8);
351
352 /* unmask channel */
353 outb(DMA2_SMSK, chan & 3);
354 }
355 mtx_unlock(&isa_dma_lock);
356 }
357
358 void
isa_dmadone(int flags,caddr_t addr,int nbytes,int chan)359 isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
360 {
361 #ifdef DIAGNOSTIC
362 if (chan & ~VALID_DMA_MASK)
363 panic("isa_dmadone: channel out of range");
364
365 if ((dma_inuse & (1 << chan)) == 0)
366 printf("isa_dmadone: channel %d not acquired\n", chan);
367 #endif
368
369 mtx_lock(&isa_dma_lock);
370 if (((dma_busy & (1 << chan)) == 0) &&
371 (dma_auto_mode & (1 << chan)) == 0 )
372 printf("isa_dmadone: channel %d not busy\n", chan);
373
374 if ((dma_auto_mode & (1 << chan)) == 0)
375 outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
376
377 if (dma_bounced & (1 << chan)) {
378 /* copy bounce buffer on read */
379 if (flags & ISADMA_READ)
380 bcopy(dma_bouncebuf[chan], addr, nbytes);
381
382 dma_bounced &= ~(1 << chan);
383 }
384 dma_busy &= ~(1 << chan);
385 mtx_unlock(&isa_dma_lock);
386 }
387
388 /*
389 * Check for problems with the address range of a DMA transfer
390 * (non-contiguous physical pages, outside of bus address space,
391 * crossing DMA page boundaries).
392 * Return true if special handling needed.
393 */
394
395 static int
isa_dmarangecheck(caddr_t va,u_int length,int chan)396 isa_dmarangecheck(caddr_t va, u_int length, int chan)
397 {
398 vm_paddr_t phys, priorpage = 0;
399 vm_offset_t endva;
400 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);
401
402 endva = (vm_offset_t)round_page((vm_offset_t)va + length);
403 for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
404 phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
405 if (phys == 0)
406 panic("isa_dmacheck: no physical page present");
407 if (phys >= ISARAM_END)
408 return (1);
409 if (priorpage) {
410 if (priorpage + PAGE_SIZE != phys)
411 return (1);
412 /* check if crossing a DMA page boundary */
413 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
414 return (1);
415 }
416 priorpage = phys;
417 }
418 return (0);
419 }
420
421 /*
422 * Query the progress of a transfer on a DMA channel.
423 *
424 * To avoid having to interrupt a transfer in progress, we sample
425 * each of the high and low databytes twice, and apply the following
426 * logic to determine the correct count.
427 *
428 * Reads are performed with interrupts disabled, thus it is to be
429 * expected that the time between reads is very small. At most
430 * one rollover in the low count byte can be expected within the
431 * four reads that are performed.
432 *
433 * There are three gaps in which a rollover can occur :
434 *
435 * - read low1
436 * gap1
437 * - read high1
438 * gap2
439 * - read low2
440 * gap3
441 * - read high2
442 *
443 * If a rollover occurs in gap1 or gap2, the low2 value will be
444 * greater than the low1 value. In this case, low2 and high2 are a
445 * corresponding pair.
446 *
447 * In any other case, low1 and high1 can be considered to be correct.
448 *
449 * The function returns the number of bytes remaining in the transfer,
450 * or -1 if the channel requested is not active.
451 *
452 */
453 static int
isa_dmastatus_locked(int chan)454 isa_dmastatus_locked(int chan)
455 {
456 u_long cnt = 0;
457 int ffport, waport;
458 u_long low1, high1, low2, high2;
459
460 mtx_assert(&isa_dma_lock, MA_OWNED);
461
462 /* channel active? */
463 if ((dma_inuse & (1 << chan)) == 0) {
464 printf("isa_dmastatus: channel %d not active\n", chan);
465 return(-1);
466 }
467 /* channel busy? */
468
469 if (((dma_busy & (1 << chan)) == 0) &&
470 (dma_auto_mode & (1 << chan)) == 0 ) {
471 printf("chan %d not busy\n", chan);
472 return -2 ;
473 }
474 if (chan < 4) { /* low DMA controller */
475 ffport = DMA1_FFC;
476 waport = DMA1_CHN(chan) + 1;
477 } else { /* high DMA controller */
478 ffport = DMA2_FFC;
479 waport = DMA2_CHN(chan - 4) + 2;
480 }
481
482 disable_intr(); /* no interrupts Mr Jones! */
483 outb(ffport, 0); /* clear register LSB flipflop */
484 low1 = inb(waport);
485 high1 = inb(waport);
486 outb(ffport, 0); /* clear again */
487 low2 = inb(waport);
488 high2 = inb(waport);
489 enable_intr(); /* enable interrupts again */
490
491 /*
492 * Now decide if a wrap has tried to skew our results.
493 * Note that after TC, the count will read 0xffff, while we want
494 * to return zero, so we add and then mask to compensate.
495 */
496 if (low1 >= low2) {
497 cnt = (low1 + (high1 << 8) + 1) & 0xffff;
498 } else {
499 cnt = (low2 + (high2 << 8) + 1) & 0xffff;
500 }
501
502 if (chan >= 4) /* high channels move words */
503 cnt *= 2;
504 return(cnt);
505 }
506
507 int
isa_dmastatus(int chan)508 isa_dmastatus(int chan)
509 {
510 int status;
511
512 mtx_lock(&isa_dma_lock);
513 status = isa_dmastatus_locked(chan);
514 mtx_unlock(&isa_dma_lock);
515
516 return (status);
517 }
518
519 /*
520 * Reached terminal count yet ?
521 */
522 int
isa_dmatc(int chan)523 isa_dmatc(int chan)
524 {
525
526 if (chan < 4)
527 return(inb(DMA1_STATUS) & (1 << chan));
528 else
529 return(inb(DMA2_STATUS) & (1 << (chan & 3)));
530 }
531
532 /*
533 * Stop a DMA transfer currently in progress.
534 */
535 int
isa_dmastop(int chan)536 isa_dmastop(int chan)
537 {
538 int status;
539
540 mtx_lock(&isa_dma_lock);
541 if ((dma_inuse & (1 << chan)) == 0)
542 printf("isa_dmastop: channel %d not acquired\n", chan);
543
544 if (((dma_busy & (1 << chan)) == 0) &&
545 ((dma_auto_mode & (1 << chan)) == 0)) {
546 printf("chan %d not busy\n", chan);
547 mtx_unlock(&isa_dma_lock);
548 return -2 ;
549 }
550
551 if ((chan & 4) == 0) {
552 outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
553 } else {
554 outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
555 }
556
557 status = isa_dmastatus_locked(chan);
558
559 mtx_unlock(&isa_dma_lock);
560
561 return (status);
562 }
563
564 /*
565 * Attach to the ISA PnP descriptor for the AT DMA controller
566 */
567 static struct isa_pnp_id atdma_ids[] = {
568 { 0x0002d041 /* PNP0200 */, "AT DMA controller" },
569 { 0 }
570 };
571
572 static int
atdma_probe(device_t dev)573 atdma_probe(device_t dev)
574 {
575 int result;
576
577 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
578 device_quiet(dev);
579 return(result);
580 }
581
582 static int
atdma_attach(device_t dev)583 atdma_attach(device_t dev)
584 {
585 return(0);
586 }
587
588 static device_method_t atdma_methods[] = {
589 /* Device interface */
590 DEVMETHOD(device_probe, atdma_probe),
591 DEVMETHOD(device_attach, atdma_attach),
592 { 0, 0 }
593 };
594
595 static driver_t atdma_driver = {
596 "atdma",
597 atdma_methods,
598 1, /* no softc */
599 };
600
601 static devclass_t atdma_devclass;
602
603 DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
604 DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
605 ISA_PNP_INFO(atdma_ids);
606