isa_dma.c revision 141391 
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/i386/isa/isa_dma.c 141391 2005-02-06 13:46:39Z phk $");
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 <i386/isa/isa.h>
61#include <dev/ic/i8237.h>
62#include <isa/isavar.h>
63
64static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
65
66static caddr_t	dma_bouncebuf[8];
67static u_int	dma_bouncebufsize[8];
68static u_int8_t	dma_bounced = 0;
69static u_int8_t	dma_busy = 0;		/* Used in isa_dmastart() */
70static u_int8_t	dma_inuse = 0;		/* User for acquire/release */
71static u_int8_t dma_auto_mode = 0;
72
73#define VALID_DMA_MASK (7)
74
75/* high byte of address is stored in this port for i-th dma channel */
76static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
77
78/*
79 * Setup a DMA channel's bounce buffer.
80 */
81int
82isa_dma_init(int chan, u_int bouncebufsize, int flag)
83{
84	void *buf;
85
86	/*
87	 * If a DMA channel is shared, both drivers have to call isa_dma_init
88	 * since they don't know that the other driver will do it.
89	 * Just return if we're already set up good.
90	 * XXX: this only works if they agree on the bouncebuf size.  This
91	 * XXX: is typically the case since they are multiple instances of
92	 * XXX: the same driver.
93	 */
94	if (dma_bouncebuf[chan] != NULL)
95		return (0);
96
97#ifdef DIAGNOSTIC
98	if (chan & ~VALID_DMA_MASK)
99		panic("isa_dma_init: channel out of range");
100#endif
101
102	dma_bouncebufsize[chan] = bouncebufsize;
103
104	/* Try malloc() first.  It works better if it works. */
105	buf = malloc(bouncebufsize, M_DEVBUF, flag);
106	if (buf != NULL) {
107		if (isa_dmarangecheck(buf, bouncebufsize, chan) == 0) {
108			dma_bouncebuf[chan] = buf;
109			return (0);
110		}
111		free(buf, M_DEVBUF);
112	}
113	buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
114			   1ul, chan & 4 ? 0x20000ul : 0x10000ul);
115	if (buf == NULL)
116		return (ENOMEM);
117	dma_bouncebuf[chan] = buf;
118	return (0);
119}
120
121/*
122 * Register a DMA channel's usage.  Usually called from a device driver
123 * in open() or during its initialization.
124 */
125int
126isa_dma_acquire(chan)
127	int chan;
128{
129#ifdef DIAGNOSTIC
130	if (chan & ~VALID_DMA_MASK)
131		panic("isa_dma_acquire: channel out of range");
132#endif
133
134	if (dma_inuse & (1 << chan)) {
135		printf("isa_dma_acquire: channel %d already in use\n", chan);
136		return (EBUSY);
137	}
138	dma_inuse |= (1 << chan);
139	dma_auto_mode &= ~(1 << chan);
140
141	return (0);
142}
143
144/*
145 * Unregister a DMA channel's usage.  Usually called from a device driver
146 * during close() or during its shutdown.
147 */
148void
149isa_dma_release(chan)
150	int chan;
151{
152#ifdef DIAGNOSTIC
153	if (chan & ~VALID_DMA_MASK)
154		panic("isa_dma_release: channel out of range");
155
156	if ((dma_inuse & (1 << chan)) == 0)
157		printf("isa_dma_release: channel %d not in use\n", chan);
158#endif
159
160	if (dma_busy & (1 << chan)) {
161		dma_busy &= ~(1 << chan);
162		/*
163		 * XXX We should also do "dma_bounced &= (1 << chan);"
164		 * because we are acting on behalf of isa_dmadone() which
165		 * was not called to end the last DMA operation.  This does
166		 * not matter now, but it may in the future.
167		 */
168	}
169
170	dma_inuse &= ~(1 << chan);
171	dma_auto_mode &= ~(1 << chan);
172}
173
174/*
175 * isa_dmacascade(): program 8237 DMA controller channel to accept
176 * external dma control by a board.
177 */
178void
179isa_dmacascade(chan)
180	int chan;
181{
182#ifdef DIAGNOSTIC
183	if (chan & ~VALID_DMA_MASK)
184		panic("isa_dmacascade: channel out of range");
185#endif
186
187	/* set dma channel mode, and set dma channel mode */
188	if ((chan & 4) == 0) {
189		outb(DMA1_MODE, DMA37MD_CASCADE | chan);
190		outb(DMA1_SMSK, chan);
191	} else {
192		outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
193		outb(DMA2_SMSK, chan & 3);
194	}
195}
196
197/*
198 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
199 * problems by using a bounce buffer.
200 */
201void
202isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
203{
204	vm_paddr_t phys;
205	int waport;
206	caddr_t newaddr;
207
208	GIANT_REQUIRED;
209
210#ifdef DIAGNOSTIC
211	if (chan & ~VALID_DMA_MASK)
212		panic("isa_dmastart: channel out of range");
213
214	if ((chan < 4 && nbytes > (1<<16))
215	    || (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1)))
216		panic("isa_dmastart: impossible request");
217
218	if ((dma_inuse & (1 << chan)) == 0)
219		printf("isa_dmastart: channel %d not acquired\n", chan);
220#endif
221
222#if 0
223	/*
224	 * XXX This should be checked, but drivers like ad1848 only call
225	 * isa_dmastart() once because they use Auto DMA mode.  If we
226	 * leave this in, drivers that do this will print this continuously.
227	 */
228	if (dma_busy & (1 << chan))
229		printf("isa_dmastart: channel %d busy\n", chan);
230#endif
231
232	dma_busy |= (1 << chan);
233
234	if (isa_dmarangecheck(addr, nbytes, chan)) {
235		if (dma_bouncebuf[chan] == NULL
236		    || dma_bouncebufsize[chan] < nbytes)
237			panic("isa_dmastart: bad bounce buffer");
238		dma_bounced |= (1 << chan);
239		newaddr = dma_bouncebuf[chan];
240
241		/* copy bounce buffer on write */
242		if (!(flags & ISADMA_READ))
243			bcopy(addr, newaddr, nbytes);
244		addr = newaddr;
245	}
246
247	/* translate to physical */
248	phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
249
250	if (flags & ISADMA_RAW) {
251	    dma_auto_mode |= (1 << chan);
252	} else {
253	    dma_auto_mode &= ~(1 << chan);
254	}
255
256	if ((chan & 4) == 0) {
257		/*
258		 * Program one of DMA channels 0..3.  These are
259		 * byte mode channels.
260		 */
261		/* set dma channel mode, and reset address ff */
262
263		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
264		if (flags & ISADMA_RAW) {
265		  if (flags & ISADMA_READ)
266			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
267		  else
268			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
269		}
270		else
271		if (flags & ISADMA_READ)
272			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
273		else
274			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
275		outb(DMA1_FFC, 0);
276
277		/* send start address */
278		waport =  DMA1_CHN(chan);
279		outb(waport, phys);
280		outb(waport, phys>>8);
281		outb(dmapageport[chan], phys>>16);
282
283		/* send count */
284		outb(waport + 1, --nbytes);
285		outb(waport + 1, nbytes>>8);
286
287		/* unmask channel */
288		outb(DMA1_SMSK, chan);
289	} else {
290		/*
291		 * Program one of DMA channels 4..7.  These are
292		 * word mode channels.
293		 */
294		/* set dma channel mode, and reset address ff */
295
296		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
297		if (flags & ISADMA_RAW) {
298		  if (flags & ISADMA_READ)
299			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
300		  else
301			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
302		}
303		else
304		if (flags & ISADMA_READ)
305			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
306		else
307			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
308		outb(DMA2_FFC, 0);
309
310		/* send start address */
311		waport = DMA2_CHN(chan - 4);
312		outb(waport, phys>>1);
313		outb(waport, phys>>9);
314		outb(dmapageport[chan], phys>>16);
315
316		/* send count */
317		nbytes >>= 1;
318		outb(waport + 2, --nbytes);
319		outb(waport + 2, nbytes>>8);
320
321		/* unmask channel */
322		outb(DMA2_SMSK, chan & 3);
323	}
324}
325
326void
327isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
328{
329#ifdef DIAGNOSTIC
330	if (chan & ~VALID_DMA_MASK)
331		panic("isa_dmadone: channel out of range");
332
333	if ((dma_inuse & (1 << chan)) == 0)
334		printf("isa_dmadone: channel %d not acquired\n", chan);
335#endif
336
337	if (((dma_busy & (1 << chan)) == 0) &&
338	    (dma_auto_mode & (1 << chan)) == 0 )
339		printf("isa_dmadone: channel %d not busy\n", chan);
340
341	if ((dma_auto_mode & (1 << chan)) == 0)
342		outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
343
344	if (dma_bounced & (1 << chan)) {
345		/* copy bounce buffer on read */
346		if (flags & ISADMA_READ)
347			bcopy(dma_bouncebuf[chan], addr, nbytes);
348
349		dma_bounced &= ~(1 << chan);
350	}
351	dma_busy &= ~(1 << chan);
352}
353
354/*
355 * Check for problems with the address range of a DMA transfer
356 * (non-contiguous physical pages, outside of bus address space,
357 * crossing DMA page boundaries).
358 * Return true if special handling needed.
359 */
360
361static int
362isa_dmarangecheck(caddr_t va, u_int length, int chan)
363{
364	vm_paddr_t phys, priorpage = 0;
365	vm_offset_t endva;
366	u_int dma_pgmsk = (chan & 4) ?  ~(128*1024-1) : ~(64*1024-1);
367
368	GIANT_REQUIRED;
369
370	endva = (vm_offset_t)round_page((vm_offset_t)va + length);
371	for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
372		phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
373#define ISARAM_END	RAM_END
374		if (phys == 0)
375			panic("isa_dmacheck: no physical page present");
376		if (phys >= ISARAM_END)
377			return (1);
378		if (priorpage) {
379			if (priorpage + PAGE_SIZE != phys)
380				return (1);
381			/* check if crossing a DMA page boundary */
382			if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
383				return (1);
384		}
385		priorpage = phys;
386	}
387	return (0);
388}
389
390/*
391 * Query the progress of a transfer on a DMA channel.
392 *
393 * To avoid having to interrupt a transfer in progress, we sample
394 * each of the high and low databytes twice, and apply the following
395 * logic to determine the correct count.
396 *
397 * Reads are performed with interrupts disabled, thus it is to be
398 * expected that the time between reads is very small.  At most
399 * one rollover in the low count byte can be expected within the
400 * four reads that are performed.
401 *
402 * There are three gaps in which a rollover can occur :
403 *
404 * - read low1
405 *              gap1
406 * - read high1
407 *              gap2
408 * - read low2
409 *              gap3
410 * - read high2
411 *
412 * If a rollover occurs in gap1 or gap2, the low2 value will be
413 * greater than the low1 value.  In this case, low2 and high2 are a
414 * corresponding pair.
415 *
416 * In any other case, low1 and high1 can be considered to be correct.
417 *
418 * The function returns the number of bytes remaining in the transfer,
419 * or -1 if the channel requested is not active.
420 *
421 */
422int
423isa_dmastatus(int chan)
424{
425	u_long	cnt = 0;
426	int	ffport, waport;
427	u_long	low1, high1, low2, high2;
428
429	/* channel active? */
430	if ((dma_inuse & (1 << chan)) == 0) {
431		printf("isa_dmastatus: channel %d not active\n", chan);
432		return(-1);
433	}
434	/* channel busy? */
435
436	if (((dma_busy & (1 << chan)) == 0) &&
437	    (dma_auto_mode & (1 << chan)) == 0 ) {
438	    printf("chan %d not busy\n", chan);
439	    return -2 ;
440	}
441	if (chan < 4) {			/* low DMA controller */
442		ffport = DMA1_FFC;
443		waport = DMA1_CHN(chan) + 1;
444	} else {			/* high DMA controller */
445		ffport = DMA2_FFC;
446		waport = DMA2_CHN(chan - 4) + 2;
447	}
448
449	disable_intr();			/* no interrupts Mr Jones! */
450	outb(ffport, 0);		/* clear register LSB flipflop */
451	low1 = inb(waport);
452	high1 = inb(waport);
453	outb(ffport, 0);		/* clear again */
454	low2 = inb(waport);
455	high2 = inb(waport);
456	enable_intr();			/* enable interrupts again */
457
458	/*
459	 * Now decide if a wrap has tried to skew our results.
460	 * Note that after TC, the count will read 0xffff, while we want
461	 * to return zero, so we add and then mask to compensate.
462	 */
463	if (low1 >= low2) {
464		cnt = (low1 + (high1 << 8) + 1) & 0xffff;
465	} else {
466		cnt = (low2 + (high2 << 8) + 1) & 0xffff;
467	}
468
469	if (chan >= 4)			/* high channels move words */
470		cnt *= 2;
471	return(cnt);
472}
473
474/*
475 * Reached terminal count yet ?
476 */
477int
478isa_dmatc(int chan)
479{
480
481	if (chan < 4)
482		return(inb(DMA1_STATUS) & (1 << chan));
483	else
484		return(inb(DMA2_STATUS) & (1 << (chan & 3)));
485}
486
487/*
488 * Stop a DMA transfer currently in progress.
489 */
490int
491isa_dmastop(int chan)
492{
493	if ((dma_inuse & (1 << chan)) == 0)
494		printf("isa_dmastop: channel %d not acquired\n", chan);
495
496	if (((dma_busy & (1 << chan)) == 0) &&
497	    ((dma_auto_mode & (1 << chan)) == 0)) {
498		printf("chan %d not busy\n", chan);
499		return -2 ;
500	}
501
502	if ((chan & 4) == 0) {
503		outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
504	} else {
505		outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
506	}
507	return(isa_dmastatus(chan));
508}
509
510/*
511 * Attach to the ISA PnP descriptor for the AT DMA controller
512 */
513static struct isa_pnp_id atdma_ids[] = {
514	{ 0x0002d041 /* PNP0200 */, "AT DMA controller" },
515	{ 0 }
516};
517
518static int
519atdma_probe(device_t dev)
520{
521	int result;
522
523	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
524		device_quiet(dev);
525	return(result);
526}
527
528static int
529atdma_attach(device_t dev)
530{
531	return(0);
532}
533
534static device_method_t atdma_methods[] = {
535	/* Device interface */
536	DEVMETHOD(device_probe,		atdma_probe),
537	DEVMETHOD(device_attach,	atdma_attach),
538	DEVMETHOD(device_detach,	bus_generic_detach),
539	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
540	DEVMETHOD(device_suspend,	bus_generic_suspend),
541	DEVMETHOD(device_resume,	bus_generic_resume),
542	{ 0, 0 }
543};
544
545static driver_t atdma_driver = {
546	"atdma",
547	atdma_methods,
548	1,		/* no softc */
549};
550
551static devclass_t atdma_devclass;
552
553DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
554DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
555