isa_dma.c revision 233675 
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: head/sys/x86/isa/isa_dma.c 233675 2012-03-29 18:58:02Z jhb $");
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	RAM_END
65
66static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
67
68static caddr_t	dma_bouncebuf[8];
69static u_int	dma_bouncebufsize[8];
70static u_int8_t	dma_bounced = 0;
71static u_int8_t	dma_busy = 0;		/* Used in isa_dmastart() */
72static u_int8_t	dma_inuse = 0;		/* User for acquire/release */
73static u_int8_t dma_auto_mode = 0;
74static struct mtx isa_dma_lock;
75MTX_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 */
80static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
81
82/*
83 * Setup a DMA channel's bounce buffer.
84 */
85int
86isa_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 */
146int
147isa_dma_acquire(chan)
148	int chan;
149{
150#ifdef DIAGNOSTIC
151	if (chan & ~VALID_DMA_MASK)
152		panic("isa_dma_acquire: channel out of range");
153#endif
154
155	mtx_lock(&isa_dma_lock);
156	if (dma_inuse & (1 << chan)) {
157		printf("isa_dma_acquire: channel %d already in use\n", chan);
158		mtx_unlock(&isa_dma_lock);
159		return (EBUSY);
160	}
161	dma_inuse |= (1 << chan);
162	dma_auto_mode &= ~(1 << chan);
163	mtx_unlock(&isa_dma_lock);
164
165	return (0);
166}
167
168/*
169 * Unregister a DMA channel's usage.  Usually called from a device driver
170 * during close() or during its shutdown.
171 */
172void
173isa_dma_release(chan)
174	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 */
207void
208isa_dmacascade(chan)
209	int chan;
210{
211#ifdef DIAGNOSTIC
212	if (chan & ~VALID_DMA_MASK)
213		panic("isa_dmacascade: channel out of range");
214#endif
215
216	mtx_lock(&isa_dma_lock);
217	/* set dma channel mode, and set dma channel mode */
218	if ((chan & 4) == 0) {
219		outb(DMA1_MODE, DMA37MD_CASCADE | chan);
220		outb(DMA1_SMSK, chan);
221	} else {
222		outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
223		outb(DMA2_SMSK, chan & 3);
224	}
225	mtx_unlock(&isa_dma_lock);
226}
227
228/*
229 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
230 * problems by using a bounce buffer.
231 */
232void
233isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
234{
235	vm_paddr_t phys;
236	int waport;
237	caddr_t newaddr;
238	int dma_range_checked;
239
240	dma_range_checked = isa_dmarangecheck(addr, nbytes, chan);
241
242#ifdef DIAGNOSTIC
243	if (chan & ~VALID_DMA_MASK)
244		panic("isa_dmastart: channel out of range");
245
246	if ((chan < 4 && nbytes > (1<<16))
247	    || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1)))
248		panic("isa_dmastart: impossible request");
249
250	mtx_lock(&isa_dma_lock);
251	if ((dma_inuse & (1 << chan)) == 0)
252		printf("isa_dmastart: channel %d not acquired\n", chan);
253#else
254	mtx_lock(&isa_dma_lock);
255#endif
256
257#if 0
258	/*
259	 * XXX This should be checked, but drivers like ad1848 only call
260	 * isa_dmastart() once because they use Auto DMA mode.  If we
261	 * leave this in, drivers that do this will print this continuously.
262	 */
263	if (dma_busy & (1 << chan))
264		printf("isa_dmastart: channel %d busy\n", chan);
265#endif
266
267	dma_busy |= (1 << chan);
268
269	if (dma_range_checked) {
270		if (dma_bouncebuf[chan] == NULL
271		    || dma_bouncebufsize[chan] < nbytes)
272			panic("isa_dmastart: bad bounce buffer");
273		dma_bounced |= (1 << chan);
274		newaddr = dma_bouncebuf[chan];
275
276		/* copy bounce buffer on write */
277		if (!(flags & ISADMA_READ))
278			bcopy(addr, newaddr, nbytes);
279		addr = newaddr;
280	}
281
282	/* translate to physical */
283	phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
284
285	if (flags & ISADMA_RAW) {
286	    dma_auto_mode |= (1 << chan);
287	} else {
288	    dma_auto_mode &= ~(1 << chan);
289	}
290
291	if ((chan & 4) == 0) {
292		/*
293		 * Program one of DMA channels 0..3.  These are
294		 * byte mode channels.
295		 */
296		/* set dma channel mode, and reset address ff */
297
298		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
299		if (flags & ISADMA_RAW) {
300		  if (flags & ISADMA_READ)
301			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
302		  else
303			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
304		}
305		else
306		if (flags & ISADMA_READ)
307			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
308		else
309			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
310		outb(DMA1_FFC, 0);
311
312		/* send start address */
313		waport =  DMA1_CHN(chan);
314		outb(waport, phys);
315		outb(waport, phys>>8);
316		outb(dmapageport[chan], phys>>16);
317
318		/* send count */
319		outb(waport + 1, --nbytes);
320		outb(waport + 1, nbytes>>8);
321
322		/* unmask channel */
323		outb(DMA1_SMSK, chan);
324	} else {
325		/*
326		 * Program one of DMA channels 4..7.  These are
327		 * word mode channels.
328		 */
329		/* set dma channel mode, and reset address ff */
330
331		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
332		if (flags & ISADMA_RAW) {
333		  if (flags & ISADMA_READ)
334			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
335		  else
336			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
337		}
338		else
339		if (flags & ISADMA_READ)
340			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
341		else
342			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
343		outb(DMA2_FFC, 0);
344
345		/* send start address */
346		waport = DMA2_CHN(chan - 4);
347		outb(waport, phys>>1);
348		outb(waport, phys>>9);
349		outb(dmapageport[chan], phys>>16);
350
351		/* send count */
352		nbytes >>= 1;
353		outb(waport + 2, --nbytes);
354		outb(waport + 2, nbytes>>8);
355
356		/* unmask channel */
357		outb(DMA2_SMSK, chan & 3);
358	}
359	mtx_unlock(&isa_dma_lock);
360}
361
362void
363isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
364{
365#ifdef DIAGNOSTIC
366	if (chan & ~VALID_DMA_MASK)
367		panic("isa_dmadone: channel out of range");
368
369	if ((dma_inuse & (1 << chan)) == 0)
370		printf("isa_dmadone: channel %d not acquired\n", chan);
371#endif
372
373	mtx_lock(&isa_dma_lock);
374	if (((dma_busy & (1 << chan)) == 0) &&
375	    (dma_auto_mode & (1 << chan)) == 0 )
376		printf("isa_dmadone: channel %d not busy\n", chan);
377
378	if ((dma_auto_mode & (1 << chan)) == 0)
379		outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
380
381	if (dma_bounced & (1 << chan)) {
382		/* copy bounce buffer on read */
383		if (flags & ISADMA_READ)
384			bcopy(dma_bouncebuf[chan], addr, nbytes);
385
386		dma_bounced &= ~(1 << chan);
387	}
388	dma_busy &= ~(1 << chan);
389	mtx_unlock(&isa_dma_lock);
390}
391
392/*
393 * Check for problems with the address range of a DMA transfer
394 * (non-contiguous physical pages, outside of bus address space,
395 * crossing DMA page boundaries).
396 * Return true if special handling needed.
397 */
398
399static int
400isa_dmarangecheck(caddr_t va, u_int length, int chan)
401{
402	vm_paddr_t phys, priorpage = 0;
403	vm_offset_t endva;
404	u_int dma_pgmsk = (chan & 4) ?  ~(128*1024-1) : ~(64*1024-1);
405
406	endva = (vm_offset_t)round_page((vm_offset_t)va + length);
407	for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
408		phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
409		if (phys == 0)
410			panic("isa_dmacheck: no physical page present");
411		if (phys >= ISARAM_END)
412			return (1);
413		if (priorpage) {
414			if (priorpage + PAGE_SIZE != phys)
415				return (1);
416			/* check if crossing a DMA page boundary */
417			if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
418				return (1);
419		}
420		priorpage = phys;
421	}
422	return (0);
423}
424
425/*
426 * Query the progress of a transfer on a DMA channel.
427 *
428 * To avoid having to interrupt a transfer in progress, we sample
429 * each of the high and low databytes twice, and apply the following
430 * logic to determine the correct count.
431 *
432 * Reads are performed with interrupts disabled, thus it is to be
433 * expected that the time between reads is very small.  At most
434 * one rollover in the low count byte can be expected within the
435 * four reads that are performed.
436 *
437 * There are three gaps in which a rollover can occur :
438 *
439 * - read low1
440 *              gap1
441 * - read high1
442 *              gap2
443 * - read low2
444 *              gap3
445 * - read high2
446 *
447 * If a rollover occurs in gap1 or gap2, the low2 value will be
448 * greater than the low1 value.  In this case, low2 and high2 are a
449 * corresponding pair.
450 *
451 * In any other case, low1 and high1 can be considered to be correct.
452 *
453 * The function returns the number of bytes remaining in the transfer,
454 * or -1 if the channel requested is not active.
455 *
456 */
457static int
458isa_dmastatus_locked(int chan)
459{
460	u_long	cnt = 0;
461	int	ffport, waport;
462	u_long	low1, high1, low2, high2;
463
464	mtx_assert(&isa_dma_lock, MA_OWNED);
465
466	/* channel active? */
467	if ((dma_inuse & (1 << chan)) == 0) {
468		printf("isa_dmastatus: channel %d not active\n", chan);
469		return(-1);
470	}
471	/* channel busy? */
472
473	if (((dma_busy & (1 << chan)) == 0) &&
474	    (dma_auto_mode & (1 << chan)) == 0 ) {
475	    printf("chan %d not busy\n", chan);
476	    return -2 ;
477	}
478	if (chan < 4) {			/* low DMA controller */
479		ffport = DMA1_FFC;
480		waport = DMA1_CHN(chan) + 1;
481	} else {			/* high DMA controller */
482		ffport = DMA2_FFC;
483		waport = DMA2_CHN(chan - 4) + 2;
484	}
485
486	disable_intr();			/* no interrupts Mr Jones! */
487	outb(ffport, 0);		/* clear register LSB flipflop */
488	low1 = inb(waport);
489	high1 = inb(waport);
490	outb(ffport, 0);		/* clear again */
491	low2 = inb(waport);
492	high2 = inb(waport);
493	enable_intr();			/* enable interrupts again */
494
495	/*
496	 * Now decide if a wrap has tried to skew our results.
497	 * Note that after TC, the count will read 0xffff, while we want
498	 * to return zero, so we add and then mask to compensate.
499	 */
500	if (low1 >= low2) {
501		cnt = (low1 + (high1 << 8) + 1) & 0xffff;
502	} else {
503		cnt = (low2 + (high2 << 8) + 1) & 0xffff;
504	}
505
506	if (chan >= 4)			/* high channels move words */
507		cnt *= 2;
508	return(cnt);
509}
510
511int
512isa_dmastatus(int chan)
513{
514	int status;
515
516	mtx_lock(&isa_dma_lock);
517	status = isa_dmastatus_locked(chan);
518	mtx_unlock(&isa_dma_lock);
519
520	return (status);
521}
522
523/*
524 * Reached terminal count yet ?
525 */
526int
527isa_dmatc(int chan)
528{
529
530	if (chan < 4)
531		return(inb(DMA1_STATUS) & (1 << chan));
532	else
533		return(inb(DMA2_STATUS) & (1 << (chan & 3)));
534}
535
536/*
537 * Stop a DMA transfer currently in progress.
538 */
539int
540isa_dmastop(int chan)
541{
542	int status;
543
544	mtx_lock(&isa_dma_lock);
545	if ((dma_inuse & (1 << chan)) == 0)
546		printf("isa_dmastop: channel %d not acquired\n", chan);
547
548	if (((dma_busy & (1 << chan)) == 0) &&
549	    ((dma_auto_mode & (1 << chan)) == 0)) {
550		printf("chan %d not busy\n", chan);
551		mtx_unlock(&isa_dma_lock);
552		return -2 ;
553	}
554
555	if ((chan & 4) == 0) {
556		outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
557	} else {
558		outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
559	}
560
561	status = isa_dmastatus_locked(chan);
562
563	mtx_unlock(&isa_dma_lock);
564
565	return (status);
566}
567
568/*
569 * Attach to the ISA PnP descriptor for the AT DMA controller
570 */
571static struct isa_pnp_id atdma_ids[] = {
572	{ 0x0002d041 /* PNP0200 */, "AT DMA controller" },
573	{ 0 }
574};
575
576static int
577atdma_probe(device_t dev)
578{
579	int result;
580
581	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
582		device_quiet(dev);
583	return(result);
584}
585
586static int
587atdma_attach(device_t dev)
588{
589	return(0);
590}
591
592static device_method_t atdma_methods[] = {
593	/* Device interface */
594	DEVMETHOD(device_probe,		atdma_probe),
595	DEVMETHOD(device_attach,	atdma_attach),
596	DEVMETHOD(device_detach,	bus_generic_detach),
597	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
598	DEVMETHOD(device_suspend,	bus_generic_suspend),
599	DEVMETHOD(device_resume,	bus_generic_resume),
600	{ 0, 0 }
601};
602
603static driver_t atdma_driver = {
604	"atdma",
605	atdma_methods,
606	1,		/* no softc */
607};
608
609static devclass_t atdma_devclass;
610
611DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
612DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
613