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