1 /*-
2 * Copyright (c) 1991 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * from: @(#)isa.c 7.2 (Berkeley) 5/13/91
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37
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
97 /* Try malloc() first. It works better if it works. */
98 buf = malloc(bouncebufsize, M_DEVBUF, flag);
99 if (buf != NULL) {
100 if (isa_dmarangecheck(buf, bouncebufsize, chan) != 0) {
101 free(buf, M_DEVBUF);
102 buf = NULL;
103 }
104 contig = 0;
105 }
106
107 if (buf == NULL) {
108 buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
109 1ul, chan & 4 ? 0x20000ul : 0x10000ul);
110 contig = 1;
111 }
112
113 if (buf == NULL)
114 return (ENOMEM);
115
116 mtx_lock(&isa_dma_lock);
117 /*
118 * If a DMA channel is shared, both drivers have to call isa_dma_init
119 * since they don't know that the other driver will do it.
120 * Just return if we're already set up good.
121 * XXX: this only works if they agree on the bouncebuf size. This
122 * XXX: is typically the case since they are multiple instances of
123 * XXX: the same driver.
124 */
125 if (dma_bouncebuf[chan] != NULL) {
126 if (contig)
127 contigfree(buf, bouncebufsize, M_DEVBUF);
128 else
129 free(buf, M_DEVBUF);
130 mtx_unlock(&isa_dma_lock);
131 return (0);
132 }
133
134 dma_bouncebufsize[chan] = bouncebufsize;
135 dma_bouncebuf[chan] = buf;
136
137 mtx_unlock(&isa_dma_lock);
138
139 return (0);
140 }
141
142 /*
143 * Register a DMA channel's usage. Usually called from a device driver
144 * in open() or during its initialization.
145 */
146 int
isa_dma_acquire(int chan)147 isa_dma_acquire(int chan)
148 {
149 #ifdef DIAGNOSTIC
150 if (chan & ~VALID_DMA_MASK)
151 panic("isa_dma_acquire: channel out of range");
152 #endif
153
154 mtx_lock(&isa_dma_lock);
155 if (dma_inuse & (1 << chan)) {
156 printf("isa_dma_acquire: channel %d already in use\n", chan);
157 mtx_unlock(&isa_dma_lock);
158 return (EBUSY);
159 }
160 dma_inuse |= (1 << chan);
161 dma_auto_mode &= ~(1 << chan);
162 mtx_unlock(&isa_dma_lock);
163
164 return (0);
165 }
166
167 /*
168 * Unregister a DMA channel's usage. Usually called from a device driver
169 * during close() or during its shutdown.
170 */
171 void
isa_dma_release(int chan)172 isa_dma_release(int chan)
173 {
174 #ifdef DIAGNOSTIC
175 if (chan & ~VALID_DMA_MASK)
176 panic("isa_dma_release: channel out of range");
177
178 mtx_lock(&isa_dma_lock);
179 if ((dma_inuse & (1 << chan)) == 0)
180 printf("isa_dma_release: channel %d not in use\n", chan);
181 #else
182 mtx_lock(&isa_dma_lock);
183 #endif
184
185 if (dma_busy & (1 << chan)) {
186 dma_busy &= ~(1 << chan);
187 /*
188 * XXX We should also do "dma_bounced &= (1 << chan);"
189 * because we are acting on behalf of isa_dmadone() which
190 * was not called to end the last DMA operation. This does
191 * not matter now, but it may in the future.
192 */
193 }
194
195 dma_inuse &= ~(1 << chan);
196 dma_auto_mode &= ~(1 << chan);
197
198 mtx_unlock(&isa_dma_lock);
199 }
200
201 /*
202 * isa_dmacascade(): program 8237 DMA controller channel to accept
203 * external dma control by a board.
204 */
205 void
isa_dmacascade(int chan)206 isa_dmacascade(int chan)
207 {
208 #ifdef DIAGNOSTIC
209 if (chan & ~VALID_DMA_MASK)
210 panic("isa_dmacascade: channel out of range");
211 #endif
212
213 mtx_lock(&isa_dma_lock);
214 /* set dma channel mode, and set dma channel mode */
215 if ((chan & 4) == 0) {
216 outb(DMA1_MODE, DMA37MD_CASCADE | chan);
217 outb(DMA1_SMSK, chan);
218 } else {
219 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
220 outb(DMA2_SMSK, chan & 3);
221 }
222 mtx_unlock(&isa_dma_lock);
223 }
224
225 /*
226 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
227 * problems by using a bounce buffer.
228 */
229 void
isa_dmastart(int flags,caddr_t addr,u_int nbytes,int chan)230 isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
231 {
232 vm_paddr_t phys;
233 int waport;
234 caddr_t newaddr;
235 int dma_range_checked;
236
237 dma_range_checked = isa_dmarangecheck(addr, nbytes, chan);
238
239 #ifdef DIAGNOSTIC
240 if (chan & ~VALID_DMA_MASK)
241 panic("isa_dmastart: channel out of range");
242
243 if ((chan < 4 && nbytes > (1<<16))
244 || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
245 panic("isa_dmastart: impossible request");
246
247 mtx_lock(&isa_dma_lock);
248 if ((dma_inuse & (1 << chan)) == 0)
249 printf("isa_dmastart: channel %d not acquired\n", chan);
250 #else
251 mtx_lock(&isa_dma_lock);
252 #endif
253
254 #if 0
255 /*
256 * XXX This should be checked, but drivers like ad1848 only call
257 * isa_dmastart() once because they use Auto DMA mode. If we
258 * leave this in, drivers that do this will print this continuously.
259 */
260 if (dma_busy & (1 << chan))
261 printf("isa_dmastart: channel %d busy\n", chan);
262 #endif
263
264 dma_busy |= (1 << chan);
265
266 if (dma_range_checked) {
267 if (dma_bouncebuf[chan] == NULL
268 || dma_bouncebufsize[chan] < nbytes)
269 panic("isa_dmastart: bad bounce buffer");
270 dma_bounced |= (1 << chan);
271 newaddr = dma_bouncebuf[chan];
272
273 /* copy bounce buffer on write */
274 if (!(flags & ISADMA_READ))
275 bcopy(addr, newaddr, nbytes);
276 addr = newaddr;
277 }
278
279 /* translate to physical */
280 phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
281
282 if (flags & ISADMA_RAW) {
283 dma_auto_mode |= (1 << chan);
284 } else {
285 dma_auto_mode &= ~(1 << chan);
286 }
287
288 if ((chan & 4) == 0) {
289 /*
290 * Program one of DMA channels 0..3. These are
291 * byte mode channels.
292 */
293 /* set dma channel mode, and reset address ff */
294
295 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
296 if (flags & ISADMA_RAW) {
297 if (flags & ISADMA_READ)
298 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
299 else
300 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
301 }
302 else
303 if (flags & ISADMA_READ)
304 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
305 else
306 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
307 outb(DMA1_FFC, 0);
308
309 /* send start address */
310 waport = DMA1_CHN(chan);
311 outb(waport, phys);
312 outb(waport, phys>>8);
313 outb(dmapageport[chan], phys>>16);
314
315 /* send count */
316 outb(waport + 1, --nbytes);
317 outb(waport + 1, nbytes>>8);
318
319 /* unmask channel */
320 outb(DMA1_SMSK, chan);
321 } else {
322 /*
323 * Program one of DMA channels 4..7. These are
324 * word mode channels.
325 */
326 /* set dma channel mode, and reset address ff */
327
328 /* If ISADMA_RAW flag is set, then use autoinitialise mode */
329 if (flags & ISADMA_RAW) {
330 if (flags & ISADMA_READ)
331 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
332 else
333 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
334 }
335 else
336 if (flags & ISADMA_READ)
337 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
338 else
339 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
340 outb(DMA2_FFC, 0);
341
342 /* send start address */
343 waport = DMA2_CHN(chan - 4);
344 outb(waport, phys>>1);
345 outb(waport, phys>>9);
346 outb(dmapageport[chan], phys>>16);
347
348 /* send count */
349 nbytes >>= 1;
350 outb(waport + 2, --nbytes);
351 outb(waport + 2, nbytes>>8);
352
353 /* unmask channel */
354 outb(DMA2_SMSK, chan & 3);
355 }
356 mtx_unlock(&isa_dma_lock);
357 }
358
359 void
isa_dmadone(int flags,caddr_t addr,int nbytes,int chan)360 isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
361 {
362 #ifdef DIAGNOSTIC
363 if (chan & ~VALID_DMA_MASK)
364 panic("isa_dmadone: channel out of range");
365
366 if ((dma_inuse & (1 << chan)) == 0)
367 printf("isa_dmadone: channel %d not acquired\n", chan);
368 #endif
369
370 mtx_lock(&isa_dma_lock);
371 if (((dma_busy & (1 << chan)) == 0) &&
372 (dma_auto_mode & (1 << chan)) == 0 )
373 printf("isa_dmadone: channel %d not busy\n", chan);
374
375 if ((dma_auto_mode & (1 << chan)) == 0)
376 outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
377
378 if (dma_bounced & (1 << chan)) {
379 /* copy bounce buffer on read */
380 if (flags & ISADMA_READ)
381 bcopy(dma_bouncebuf[chan], addr, nbytes);
382
383 dma_bounced &= ~(1 << chan);
384 }
385 dma_busy &= ~(1 << chan);
386 mtx_unlock(&isa_dma_lock);
387 }
388
389 /*
390 * Check for problems with the address range of a DMA transfer
391 * (non-contiguous physical pages, outside of bus address space,
392 * crossing DMA page boundaries).
393 * Return true if special handling needed.
394 */
395
396 static int
isa_dmarangecheck(caddr_t va,u_int length,int chan)397 isa_dmarangecheck(caddr_t va, u_int length, int chan)
398 {
399 vm_paddr_t phys, priorpage = 0;
400 vm_offset_t endva;
401 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);
402
403 endva = (vm_offset_t)round_page((vm_offset_t)va + length);
404 for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
405 phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
406 if (phys == 0)
407 panic("isa_dmacheck: no physical page present");
408 if (phys >= ISARAM_END)
409 return (1);
410 if (priorpage) {
411 if (priorpage + PAGE_SIZE != phys)
412 return (1);
413 /* check if crossing a DMA page boundary */
414 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
415 return (1);
416 }
417 priorpage = phys;
418 }
419 return (0);
420 }
421
422 /*
423 * Query the progress of a transfer on a DMA channel.
424 *
425 * To avoid having to interrupt a transfer in progress, we sample
426 * each of the high and low databytes twice, and apply the following
427 * logic to determine the correct count.
428 *
429 * Reads are performed with interrupts disabled, thus it is to be
430 * expected that the time between reads is very small. At most
431 * one rollover in the low count byte can be expected within the
432 * four reads that are performed.
433 *
434 * There are three gaps in which a rollover can occur :
435 *
436 * - read low1
437 * gap1
438 * - read high1
439 * gap2
440 * - read low2
441 * gap3
442 * - read high2
443 *
444 * If a rollover occurs in gap1 or gap2, the low2 value will be
445 * greater than the low1 value. In this case, low2 and high2 are a
446 * corresponding pair.
447 *
448 * In any other case, low1 and high1 can be considered to be correct.
449 *
450 * The function returns the number of bytes remaining in the transfer,
451 * or -1 if the channel requested is not active.
452 *
453 */
454 static int
isa_dmastatus_locked(int chan)455 isa_dmastatus_locked(int chan)
456 {
457 u_long cnt = 0;
458 int ffport, waport;
459 u_long low1, high1, low2, high2;
460
461 mtx_assert(&isa_dma_lock, MA_OWNED);
462
463 /* channel active? */
464 if ((dma_inuse & (1 << chan)) == 0) {
465 printf("isa_dmastatus: channel %d not active\n", chan);
466 return(-1);
467 }
468 /* channel busy? */
469
470 if (((dma_busy & (1 << chan)) == 0) &&
471 (dma_auto_mode & (1 << chan)) == 0 ) {
472 printf("chan %d not busy\n", chan);
473 return -2 ;
474 }
475 if (chan < 4) { /* low DMA controller */
476 ffport = DMA1_FFC;
477 waport = DMA1_CHN(chan) + 1;
478 } else { /* high DMA controller */
479 ffport = DMA2_FFC;
480 waport = DMA2_CHN(chan - 4) + 2;
481 }
482
483 disable_intr(); /* no interrupts Mr Jones! */
484 outb(ffport, 0); /* clear register LSB flipflop */
485 low1 = inb(waport);
486 high1 = inb(waport);
487 outb(ffport, 0); /* clear again */
488 low2 = inb(waport);
489 high2 = inb(waport);
490 enable_intr(); /* enable interrupts again */
491
492 /*
493 * Now decide if a wrap has tried to skew our results.
494 * Note that after TC, the count will read 0xffff, while we want
495 * to return zero, so we add and then mask to compensate.
496 */
497 if (low1 >= low2) {
498 cnt = (low1 + (high1 << 8) + 1) & 0xffff;
499 } else {
500 cnt = (low2 + (high2 << 8) + 1) & 0xffff;
501 }
502
503 if (chan >= 4) /* high channels move words */
504 cnt *= 2;
505 return(cnt);
506 }
507
508 int
isa_dmastatus(int chan)509 isa_dmastatus(int chan)
510 {
511 int status;
512
513 mtx_lock(&isa_dma_lock);
514 status = isa_dmastatus_locked(chan);
515 mtx_unlock(&isa_dma_lock);
516
517 return (status);
518 }
519
520 /*
521 * Reached terminal count yet ?
522 */
523 int
isa_dmatc(int chan)524 isa_dmatc(int chan)
525 {
526
527 if (chan < 4)
528 return(inb(DMA1_STATUS) & (1 << chan));
529 else
530 return(inb(DMA2_STATUS) & (1 << (chan & 3)));
531 }
532
533 /*
534 * Stop a DMA transfer currently in progress.
535 */
536 int
isa_dmastop(int chan)537 isa_dmastop(int chan)
538 {
539 int status;
540
541 mtx_lock(&isa_dma_lock);
542 if ((dma_inuse & (1 << chan)) == 0)
543 printf("isa_dmastop: channel %d not acquired\n", chan);
544
545 if (((dma_busy & (1 << chan)) == 0) &&
546 ((dma_auto_mode & (1 << chan)) == 0)) {
547 printf("chan %d not busy\n", chan);
548 mtx_unlock(&isa_dma_lock);
549 return -2 ;
550 }
551
552 if ((chan & 4) == 0) {
553 outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
554 } else {
555 outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
556 }
557
558 status = isa_dmastatus_locked(chan);
559
560 mtx_unlock(&isa_dma_lock);
561
562 return (status);
563 }
564
565 /*
566 * Attach to the ISA PnP descriptor for the AT DMA controller
567 */
568 static struct isa_pnp_id atdma_ids[] = {
569 { 0x0002d041 /* PNP0200 */, "AT DMA controller" },
570 { 0 }
571 };
572
573 static int
atdma_probe(device_t dev)574 atdma_probe(device_t dev)
575 {
576 int result;
577
578 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
579 device_quiet(dev);
580 return(result);
581 }
582
583 static int
atdma_attach(device_t dev)584 atdma_attach(device_t dev)
585 {
586 return(0);
587 }
588
589 static device_method_t atdma_methods[] = {
590 /* Device interface */
591 DEVMETHOD(device_probe, atdma_probe),
592 DEVMETHOD(device_attach, atdma_attach),
593 DEVMETHOD(device_detach, bus_generic_detach),
594 DEVMETHOD(device_shutdown, bus_generic_shutdown),
595 DEVMETHOD(device_suspend, bus_generic_suspend),
596 DEVMETHOD(device_resume, bus_generic_resume),
597 { 0, 0 }
598 };
599
600 static driver_t atdma_driver = {
601 "atdma",
602 atdma_methods,
603 1, /* no softc */
604 };
605
606 static devclass_t atdma_devclass;
607
608 DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
609 DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
610