FreeBSD/Linux Kernel Cross Reference
sys/x86/isa/isa_dma.c
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 __FBSDID("$FreeBSD$");
39
40 /*
41 * code to manage AT bus
42 *
43 * 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com):
44 * Fixed uninitialized variable problem and added code to deal
45 * with DMA page boundaries in isa_dmarangecheck(). Fixed word
46 * mode DMA count compution and reorganized DMA setup code in
47 * isa_dmastart()
48 */
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/bus.h>
53 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/lock.h>
56 #include <sys/proc.h>
57 #include <sys/mutex.h>
58 #include <sys/module.h>
59 #include <vm/vm.h>
60 #include <vm/vm_param.h>
61 #include <vm/pmap.h>
62 #include <isa/isareg.h>
63 #include <isa/isavar.h>
64 #include <isa/isa_dmareg.h>
65
66 #define ISARAM_END 0x1000000
67
68 static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
69
70 static caddr_t dma_bouncebuf[8];
71 static u_int dma_bouncebufsize[8];
72 static u_int8_t dma_bounced = 0;
73 static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */
74 static u_int8_t dma_inuse = 0; /* User for acquire/release */
75 static u_int8_t dma_auto_mode = 0;
76 static struct mtx isa_dma_lock;
77 MTX_SYSINIT(isa_dma_lock, &isa_dma_lock, "isa DMA lock", MTX_DEF);
78
79 #define VALID_DMA_MASK (7)
80
81 /* high byte of address is stored in this port for i-th dma channel */
82 static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
83
84 /*
85 * Setup a DMA channel's bounce buffer.
86 */
87 int
88 isa_dma_init(int chan, u_int bouncebufsize, int flag)
89 {
90 void *buf;
91 int contig;
92
93 #ifdef DIAGNOSTIC
94 if (chan & ~VALID_DMA_MASK)
95 panic("isa_dma_init: channel out of range");
96 #endif
97
98
99 /* Try malloc() first. It works better if it works. */
100 buf = malloc(bouncebufsize, M_DEVBUF, flag);
101 if (buf != NULL) {
102 if (isa_dmarangecheck(buf, bouncebufsize, chan) != 0) {
103 free(buf, M_DEVBUF);
104 buf = NULL;
105 }
106 contig = 0;
107 }
108
109 if (buf == NULL) {
110 buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
111 1ul, chan & 4 ? 0x20000ul : 0x10000ul);
112 contig = 1;
113 }
114
115 if (buf == NULL)
116 return (ENOMEM);
117
118 mtx_lock(&isa_dma_lock);
119 /*
120 * If a DMA channel is shared, both drivers have to call isa_dma_init
121 * since they don't know that the other driver will do it.
122 * Just return if we're already set up good.
123 * XXX: this only works if they agree on the bouncebuf size. This
124 * XXX: is typically the case since they are multiple instances of
125 * XXX: the same driver.
126 */
127 if (dma_bouncebuf[chan] != NULL) {
128 if (contig)
129 contigfree(buf, bouncebufsize, M_DEVBUF);
130 else
131 free(buf, M_DEVBUF);
132 mtx_unlock(&isa_dma_lock);
133 return (0);
134 }
135
136 dma_bouncebufsize[chan] = bouncebufsize;
137 dma_bouncebuf[chan] = buf;
138
139 mtx_unlock(&isa_dma_lock);
140
141 return (0);
142 }
143
144 /*
145 * Register a DMA channel's usage. Usually called from a device driver
146 * in open() or during its initialization.
147 */
148 int
149 isa_dma_acquire(int chan)
150 {
151 #ifdef DIAGNOSTIC
152 if (chan & ~VALID_DMA_MASK)
153 panic("isa_dma_acquire: channel out of range");
154 #endif
155
156 mtx_lock(&isa_dma_lock);
157 if (dma_inuse & (1 << chan)) {
158 printf("isa_dma_acquire: channel %d already in use\n", chan);
159 mtx_unlock(&isa_dma_lock);
160 return (EBUSY);
161 }
162 dma_inuse |= (1 << chan);
163 dma_auto_mode &= ~(1 << chan);
164 mtx_unlock(&isa_dma_lock);
165
166 return (0);
167 }
168
169 /*
170 * Unregister a DMA channel's usage. Usually called from a device driver
171 * during close() or during its shutdown.
172 */
173 void
174 isa_dma_release(int chan)
175 {
176 #ifdef DIAGNOSTIC
177 if (chan & ~VALID_DMA_MASK)
178 panic("isa_dma_release: channel out of range");
179
180 mtx_lock(&isa_dma_lock);
181 if ((dma_inuse & (1 << chan)) == 0)
182 printf("isa_dma_release: channel %d not in use\n", chan);
183 #else
184 mtx_lock(&isa_dma_lock);
185 #endif
186
187 if (dma_busy & (1 << chan)) {
188 dma_busy &= ~(1 << chan);
189 /*
190 * XXX We should also do "dma_bounced &= (1 << chan);"
191 * because we are acting on behalf of isa_dmadone() which
192 * was not called to end the last DMA operation. This does
193 * not matter now, but it may in the future.
194 */
195 }
196
197 dma_inuse &= ~(1 << chan);
198 dma_auto_mode &= ~(1 << chan);
199
200 mtx_unlock(&isa_dma_lock);
201 }
202
203 /*
204 * isa_dmacascade(): program 8237 DMA controller channel to accept
205 * external dma control by a board.
206 */
207 void
208 isa_dmacascade(int chan)
209 {
210 #ifdef DIAGNOSTIC
211 if (chan & ~VALID_DMA_MASK)
212 panic("isa_dmacascade: channel out of range");
213 #endif
214
215 mtx_lock(&isa_dma_lock);
216 /* set dma channel mode, and set dma channel mode */
217 if ((chan & 4) == 0) {
218 outb(DMA1_MODE, DMA37MD_CASCADE | chan);
219 outb(DMA1_SMSK, chan);
220 } else {
221 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
222 outb(DMA2_SMSK, chan & 3);
223 }
224 mtx_unlock(&isa_dma_lock);
225 }
226
227 /*
228 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
229 * problems by using a bounce buffer.
230 */
231 void
232 isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
233 {
234 vm_paddr_t phys;
235 int waport;
236 caddr_t newaddr;
237 int dma_range_checked;
238
239 dma_range_checked = isa_dmarangecheck(addr, nbytes, chan);
240
241 #ifdef DIAGNOSTIC
242 if (chan & ~VALID_DMA_MASK)
243 panic("isa_dmastart: channel out of range");
244
245 if ((chan < 4 && nbytes > (1<<16))
246 || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
247 panic("isa_dmastart: impossible request");
248
249 mtx_lock(&isa_dma_lock);
250 if ((dma_inuse & (1 << chan)) == 0)
251 printf("isa_dmastart: channel %d not acquired\n", chan);
252 #else
253 mtx_lock(&isa_dma_lock);
254 #endif
255
256 #if 0
257 /*
258 * XXX This should be checked, but drivers like ad1848 only call
259 * isa_dmastart() once because they use Auto DMA mode. If we
260 * leave this in, drivers that do this will print this continuously.
261 */
262 if (dma_busy & (1 << chan))
263 printf("isa_dmastart: channel %d busy\n", chan);
264 #endif
265
266 dma_busy |= (1 << chan);
267
268 if (dma_range_checked) {
269 if (dma_bouncebuf[chan] == NULL
270 || dma_bouncebufsize[chan] < nbytes)
271 panic("isa_dmastart: bad bounce buffer");
272 dma_bounced |= (1 << chan);
273 newaddr = dma_bouncebuf[chan];
274
275 /* copy bounce buffer on write */
276 if (!(flags & ISADMA_READ))
277 bcopy(addr, newaddr, nbytes);
278 addr = newaddr;
279 }
280
281 /* translate to physical */
282 phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
283
284 if (flags & ISADMA_RAW) {
285 dma_auto_mode |= (1 << chan);
286 } else {
287 dma_auto_mode &= ~(1 << chan);
288 }
289
290 if ((chan & 4) == 0) {
291 /*
292 * Program one of DMA channels 0..3. These are
293 * byte mode channels.
294 */
295 /* set dma channel mode, and reset address ff */
296
297 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
298 if (flags & ISADMA_RAW) {
299 if (flags & ISADMA_READ)
300 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
301 else
302 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
303 }
304 else
305 if (flags & ISADMA_READ)
306 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
307 else
308 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
309 outb(DMA1_FFC, 0);
310
311 /* send start address */
312 waport = DMA1_CHN(chan);
313 outb(waport, phys);
314 outb(waport, phys>>8);
315 outb(dmapageport[chan], phys>>16);
316
317 /* send count */
318 outb(waport + 1, --nbytes);
319 outb(waport + 1, nbytes>>8);
320
321 /* unmask channel */
322 outb(DMA1_SMSK, chan);
323 } else {
324 /*
325 * Program one of DMA channels 4..7. These are
326 * word mode channels.
327 */
328 /* set dma channel mode, and reset address ff */
329
330 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
331 if (flags & ISADMA_RAW) {
332 if (flags & ISADMA_READ)
333 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
334 else
335 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
336 }
337 else
338 if (flags & ISADMA_READ)
339 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
340 else
341 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
342 outb(DMA2_FFC, 0);
343
344 /* send start address */
345 waport = DMA2_CHN(chan - 4);
346 outb(waport, phys>>1);
347 outb(waport, phys>>9);
348 outb(dmapageport[chan], phys>>16);
349
350 /* send count */
351 nbytes >>= 1;
352 outb(waport + 2, --nbytes);
353 outb(waport + 2, nbytes>>8);
354
355 /* unmask channel */
356 outb(DMA2_SMSK, chan & 3);
357 }
358 mtx_unlock(&isa_dma_lock);
359 }
360
361 void
362 isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
363 {
364 #ifdef DIAGNOSTIC
365 if (chan & ~VALID_DMA_MASK)
366 panic("isa_dmadone: channel out of range");
367
368 if ((dma_inuse & (1 << chan)) == 0)
369 printf("isa_dmadone: channel %d not acquired\n", chan);
370 #endif
371
372 mtx_lock(&isa_dma_lock);
373 if (((dma_busy & (1 << chan)) == 0) &&
374 (dma_auto_mode & (1 << chan)) == 0 )
375 printf("isa_dmadone: channel %d not busy\n", chan);
376
377 if ((dma_auto_mode & (1 << chan)) == 0)
378 outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
379
380 if (dma_bounced & (1 << chan)) {
381 /* copy bounce buffer on read */
382 if (flags & ISADMA_READ)
383 bcopy(dma_bouncebuf[chan], addr, nbytes);
384
385 dma_bounced &= ~(1 << chan);
386 }
387 dma_busy &= ~(1 << chan);
388 mtx_unlock(&isa_dma_lock);
389 }
390
391 /*
392 * Check for problems with the address range of a DMA transfer
393 * (non-contiguous physical pages, outside of bus address space,
394 * crossing DMA page boundaries).
395 * Return true if special handling needed.
396 */
397
398 static int
399 isa_dmarangecheck(caddr_t va, u_int length, int chan)
400 {
401 vm_paddr_t phys, priorpage = 0;
402 vm_offset_t endva;
403 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);
404
405 endva = (vm_offset_t)round_page((vm_offset_t)va + length);
406 for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
407 phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
408 if (phys == 0)
409 panic("isa_dmacheck: no physical page present");
410 if (phys >= ISARAM_END)
411 return (1);
412 if (priorpage) {
413 if (priorpage + PAGE_SIZE != phys)
414 return (1);
415 /* check if crossing a DMA page boundary */
416 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
417 return (1);
418 }
419 priorpage = phys;
420 }
421 return (0);
422 }
423
424 /*
425 * Query the progress of a transfer on a DMA channel.
426 *
427 * To avoid having to interrupt a transfer in progress, we sample
428 * each of the high and low databytes twice, and apply the following
429 * logic to determine the correct count.
430 *
431 * Reads are performed with interrupts disabled, thus it is to be
432 * expected that the time between reads is very small. At most
433 * one rollover in the low count byte can be expected within the
434 * four reads that are performed.
435 *
436 * There are three gaps in which a rollover can occur :
437 *
438 * - read low1
439 * gap1
440 * - read high1
441 * gap2
442 * - read low2
443 * gap3
444 * - read high2
445 *
446 * If a rollover occurs in gap1 or gap2, the low2 value will be
447 * greater than the low1 value. In this case, low2 and high2 are a
448 * corresponding pair.
449 *
450 * In any other case, low1 and high1 can be considered to be correct.
451 *
452 * The function returns the number of bytes remaining in the transfer,
453 * or -1 if the channel requested is not active.
454 *
455 */
456 static int
457 isa_dmastatus_locked(int chan)
458 {
459 u_long cnt = 0;
460 int ffport, waport;
461 u_long low1, high1, low2, high2;
462
463 mtx_assert(&isa_dma_lock, MA_OWNED);
464
465 /* channel active? */
466 if ((dma_inuse & (1 << chan)) == 0) {
467 printf("isa_dmastatus: channel %d not active\n", chan);
468 return(-1);
469 }
470 /* channel busy? */
471
472 if (((dma_busy & (1 << chan)) == 0) &&
473 (dma_auto_mode & (1 << chan)) == 0 ) {
474 printf("chan %d not busy\n", chan);
475 return -2 ;
476 }
477 if (chan < 4) { /* low DMA controller */
478 ffport = DMA1_FFC;
479 waport = DMA1_CHN(chan) + 1;
480 } else { /* high DMA controller */
481 ffport = DMA2_FFC;
482 waport = DMA2_CHN(chan - 4) + 2;
483 }
484
485 disable_intr(); /* no interrupts Mr Jones! */
486 outb(ffport, 0); /* clear register LSB flipflop */
487 low1 = inb(waport);
488 high1 = inb(waport);
489 outb(ffport, 0); /* clear again */
490 low2 = inb(waport);
491 high2 = inb(waport);
492 enable_intr(); /* enable interrupts again */
493
494 /*
495 * Now decide if a wrap has tried to skew our results.
496 * Note that after TC, the count will read 0xffff, while we want
497 * to return zero, so we add and then mask to compensate.
498 */
499 if (low1 >= low2) {
500 cnt = (low1 + (high1 << 8) + 1) & 0xffff;
501 } else {
502 cnt = (low2 + (high2 << 8) + 1) & 0xffff;
503 }
504
505 if (chan >= 4) /* high channels move words */
506 cnt *= 2;
507 return(cnt);
508 }
509
510 int
511 isa_dmastatus(int chan)
512 {
513 int status;
514
515 mtx_lock(&isa_dma_lock);
516 status = isa_dmastatus_locked(chan);
517 mtx_unlock(&isa_dma_lock);
518
519 return (status);
520 }
521
522 /*
523 * Reached terminal count yet ?
524 */
525 int
526 isa_dmatc(int chan)
527 {
528
529 if (chan < 4)
530 return(inb(DMA1_STATUS) & (1 << chan));
531 else
532 return(inb(DMA2_STATUS) & (1 << (chan & 3)));
533 }
534
535 /*
536 * Stop a DMA transfer currently in progress.
537 */
538 int
539 isa_dmastop(int chan)
540 {
541 int status;
542
543 mtx_lock(&isa_dma_lock);
544 if ((dma_inuse & (1 << chan)) == 0)
545 printf("isa_dmastop: channel %d not acquired\n", chan);
546
547 if (((dma_busy & (1 << chan)) == 0) &&
548 ((dma_auto_mode & (1 << chan)) == 0)) {
549 printf("chan %d not busy\n", chan);
550 mtx_unlock(&isa_dma_lock);
551 return -2 ;
552 }
553
554 if ((chan & 4) == 0) {
555 outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
556 } else {
557 outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
558 }
559
560 status = isa_dmastatus_locked(chan);
561
562 mtx_unlock(&isa_dma_lock);
563
564 return (status);
565 }
566
567 /*
568 * Attach to the ISA PnP descriptor for the AT DMA controller
569 */
570 static struct isa_pnp_id atdma_ids[] = {
571 { 0x0002d041 /* PNP0200 */, "AT DMA controller" },
572 { 0 }
573 };
574
575 static int
576 atdma_probe(device_t dev)
577 {
578 int result;
579
580 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
581 device_quiet(dev);
582 return(result);
583 }
584
585 static int
586 atdma_attach(device_t dev)
587 {
588 return(0);
589 }
590
591 static device_method_t atdma_methods[] = {
592 /* Device interface */
593 DEVMETHOD(device_probe, atdma_probe),
594 DEVMETHOD(device_attach, atdma_attach),
595 DEVMETHOD(device_detach, bus_generic_detach),
596 DEVMETHOD(device_shutdown, bus_generic_shutdown),
597 DEVMETHOD(device_suspend, bus_generic_suspend),
598 DEVMETHOD(device_resume, bus_generic_resume),
599 { 0, 0 }
600 };
601
602 static driver_t atdma_driver = {
603 "atdma",
604 atdma_methods,
605 1, /* no softc */
606 };
607
608 static devclass_t atdma_devclass;
609
610 DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
611 DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
612 ISA_PNP_INFO(atdma_ids);
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