isa_dma.c revision 131647 
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 131647 2004-07-05 20:37:42Z 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
64/*
65**  Register definitions for DMA controller 1 (channels 0..3):
66*/
67#define	DMA1_CHN(c)	(IO_DMA1 + 1*(2*(c)))	/* addr reg for channel c */
68#define	DMA1_SMSK	(IO_DMA1 + 1*10)	/* single mask register */
69#define	DMA1_MODE	(IO_DMA1 + 1*11)	/* mode register */
70#define	DMA1_FFC	(IO_DMA1 + 1*12)	/* clear first/last FF */
71
72/*
73**  Register definitions for DMA controller 2 (channels 4..7):
74*/
75#define	DMA2_CHN(c)	(IO_DMA2 + 2*(2*(c)))	/* addr reg for channel c */
76#define	DMA2_SMSK	(IO_DMA2 + 2*10)	/* single mask register */
77#define	DMA2_MODE	(IO_DMA2 + 2*11)	/* mode register */
78#define	DMA2_FFC	(IO_DMA2 + 2*12)	/* clear first/last FF */
79
80static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
81
82static caddr_t	dma_bouncebuf[8];
83static u_int	dma_bouncebufsize[8];
84static u_int8_t	dma_bounced = 0;
85static u_int8_t	dma_busy = 0;		/* Used in isa_dmastart() */
86static u_int8_t	dma_inuse = 0;		/* User for acquire/release */
87static u_int8_t dma_auto_mode = 0;
88
89#define VALID_DMA_MASK (7)
90
91/* high byte of address is stored in this port for i-th dma channel */
92static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
93
94/*
95 * Setup a DMA channel's bounce buffer.
96 */
97void
98isa_dmainit(chan, bouncebufsize)
99	int chan;
100	u_int bouncebufsize;
101{
102	void *buf;
103
104	/*
105	 * If a DMA channel is shared, both drivers have to call isa_dmainit
106	 * since they don't know that the other driver will do it.
107	 * Just return if we're already set up good.
108	 * XXX: this only works if they agree on the bouncebuf size.  This
109	 * XXX: is typically the case since they are multiple instances of
110	 * XXX: the same driver.
111	 */
112	if (dma_bouncebuf[chan] != NULL)
113		return;
114
115#ifdef DIAGNOSTIC
116	if (chan & ~VALID_DMA_MASK)
117		panic("isa_dmainit: channel out of range");
118#endif
119
120	dma_bouncebufsize[chan] = bouncebufsize;
121
122	/* Try malloc() first.  It works better if it works. */
123	buf = malloc(bouncebufsize, M_DEVBUF, M_NOWAIT);
124	if (buf != NULL) {
125		if (isa_dmarangecheck(buf, bouncebufsize, chan) == 0) {
126			dma_bouncebuf[chan] = buf;
127			return;
128		}
129		free(buf, M_DEVBUF);
130	}
131	buf = contigmalloc(bouncebufsize, M_DEVBUF, M_NOWAIT, 0ul, 0xfffffful,
132			   1ul, chan & 4 ? 0x20000ul : 0x10000ul);
133	if (buf == NULL)
134		printf("isa_dmainit(%d, %d) failed\n", chan, bouncebufsize);
135	else
136		dma_bouncebuf[chan] = buf;
137}
138
139/*
140 * Register a DMA channel's usage.  Usually called from a device driver
141 * in open() or during its initialization.
142 */
143int
144isa_dma_acquire(chan)
145	int chan;
146{
147#ifdef DIAGNOSTIC
148	if (chan & ~VALID_DMA_MASK)
149		panic("isa_dma_acquire: channel out of range");
150#endif
151
152	if (dma_inuse & (1 << chan)) {
153		printf("isa_dma_acquire: channel %d already in use\n", chan);
154		return (EBUSY);
155	}
156	dma_inuse |= (1 << chan);
157	dma_auto_mode &= ~(1 << chan);
158
159	return (0);
160}
161
162/*
163 * Unregister a DMA channel's usage.  Usually called from a device driver
164 * during close() or during its shutdown.
165 */
166void
167isa_dma_release(chan)
168	int chan;
169{
170#ifdef DIAGNOSTIC
171	if (chan & ~VALID_DMA_MASK)
172		panic("isa_dma_release: channel out of range");
173
174	if ((dma_inuse & (1 << chan)) == 0)
175		printf("isa_dma_release: channel %d not in use\n", chan);
176#endif
177
178	if (dma_busy & (1 << chan)) {
179		dma_busy &= ~(1 << chan);
180		/*
181		 * XXX We should also do "dma_bounced &= (1 << chan);"
182		 * because we are acting on behalf of isa_dmadone() which
183		 * was not called to end the last DMA operation.  This does
184		 * not matter now, but it may in the future.
185		 */
186	}
187
188	dma_inuse &= ~(1 << chan);
189	dma_auto_mode &= ~(1 << chan);
190}
191
192/*
193 * isa_dmacascade(): program 8237 DMA controller channel to accept
194 * external dma control by a board.
195 */
196void
197isa_dmacascade(chan)
198	int chan;
199{
200#ifdef DIAGNOSTIC
201	if (chan & ~VALID_DMA_MASK)
202		panic("isa_dmacascade: channel out of range");
203#endif
204
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}
214
215/*
216 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
217 * problems by using a bounce buffer.
218 */
219void
220isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
221{
222	vm_paddr_t phys;
223	int waport;
224	caddr_t newaddr;
225
226	GIANT_REQUIRED;
227
228#ifdef DIAGNOSTIC
229	if (chan & ~VALID_DMA_MASK)
230		panic("isa_dmastart: channel out of range");
231
232	if ((chan < 4 && nbytes > (1<<16))
233	    || (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1)))
234		panic("isa_dmastart: impossible request");
235
236	if ((dma_inuse & (1 << chan)) == 0)
237		printf("isa_dmastart: channel %d not acquired\n", chan);
238#endif
239
240#if 0
241	/*
242	 * XXX This should be checked, but drivers like ad1848 only call
243	 * isa_dmastart() once because they use Auto DMA mode.  If we
244	 * leave this in, drivers that do this will print this continuously.
245	 */
246	if (dma_busy & (1 << chan))
247		printf("isa_dmastart: channel %d busy\n", chan);
248#endif
249
250	dma_busy |= (1 << chan);
251
252	if (isa_dmarangecheck(addr, nbytes, chan)) {
253		if (dma_bouncebuf[chan] == NULL
254		    || dma_bouncebufsize[chan] < nbytes)
255			panic("isa_dmastart: bad bounce buffer");
256		dma_bounced |= (1 << chan);
257		newaddr = dma_bouncebuf[chan];
258
259		/* copy bounce buffer on write */
260		if (!(flags & ISADMA_READ))
261			bcopy(addr, newaddr, nbytes);
262		addr = newaddr;
263	}
264
265	/* translate to physical */
266	phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
267
268	if (flags & ISADMA_RAW) {
269	    dma_auto_mode |= (1 << chan);
270	} else {
271	    dma_auto_mode &= ~(1 << chan);
272	}
273
274	if ((chan & 4) == 0) {
275		/*
276		 * Program one of DMA channels 0..3.  These are
277		 * byte mode channels.
278		 */
279		/* set dma channel mode, and reset address ff */
280
281		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
282		if (flags & ISADMA_RAW) {
283		  if (flags & ISADMA_READ)
284			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
285		  else
286			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
287		}
288		else
289		if (flags & ISADMA_READ)
290			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
291		else
292			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
293		outb(DMA1_FFC, 0);
294
295		/* send start address */
296		waport =  DMA1_CHN(chan);
297		outb(waport, phys);
298		outb(waport, phys>>8);
299		outb(dmapageport[chan], phys>>16);
300
301		/* send count */
302		outb(waport + 1, --nbytes);
303		outb(waport + 1, nbytes>>8);
304
305		/* unmask channel */
306		outb(DMA1_SMSK, chan);
307	} else {
308		/*
309		 * Program one of DMA channels 4..7.  These are
310		 * word mode channels.
311		 */
312		/* set dma channel mode, and reset address ff */
313
314		/* If ISADMA_RAW flag is set, then use autoinitialise mode */
315		if (flags & ISADMA_RAW) {
316		  if (flags & ISADMA_READ)
317			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3));
318		  else
319			outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3));
320		}
321		else
322		if (flags & ISADMA_READ)
323			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
324		else
325			outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
326		outb(DMA2_FFC, 0);
327
328		/* send start address */
329		waport = DMA2_CHN(chan - 4);
330		outb(waport, phys>>1);
331		outb(waport, phys>>9);
332		outb(dmapageport[chan], phys>>16);
333
334		/* send count */
335		nbytes >>= 1;
336		outb(waport + 2, --nbytes);
337		outb(waport + 2, nbytes>>8);
338
339		/* unmask channel */
340		outb(DMA2_SMSK, chan & 3);
341	}
342}
343
344void
345isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
346{
347#ifdef DIAGNOSTIC
348	if (chan & ~VALID_DMA_MASK)
349		panic("isa_dmadone: channel out of range");
350
351	if ((dma_inuse & (1 << chan)) == 0)
352		printf("isa_dmadone: channel %d not acquired\n", chan);
353#endif
354
355	if (((dma_busy & (1 << chan)) == 0) &&
356	    (dma_auto_mode & (1 << chan)) == 0 )
357		printf("isa_dmadone: channel %d not busy\n", chan);
358
359	if ((dma_auto_mode & (1 << chan)) == 0)
360		outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4);
361
362	if (dma_bounced & (1 << chan)) {
363		/* copy bounce buffer on read */
364		if (flags & ISADMA_READ)
365			bcopy(dma_bouncebuf[chan], addr, nbytes);
366
367		dma_bounced &= ~(1 << chan);
368	}
369	dma_busy &= ~(1 << chan);
370}
371
372/*
373 * Check for problems with the address range of a DMA transfer
374 * (non-contiguous physical pages, outside of bus address space,
375 * crossing DMA page boundaries).
376 * Return true if special handling needed.
377 */
378
379static int
380isa_dmarangecheck(caddr_t va, u_int length, int chan)
381{
382	vm_paddr_t phys, priorpage = 0;
383	vm_offset_t endva;
384	u_int dma_pgmsk = (chan & 4) ?  ~(128*1024-1) : ~(64*1024-1);
385
386	GIANT_REQUIRED;
387
388	endva = (vm_offset_t)round_page((vm_offset_t)va + length);
389	for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
390		phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
391#define ISARAM_END	RAM_END
392		if (phys == 0)
393			panic("isa_dmacheck: no physical page present");
394		if (phys >= ISARAM_END)
395			return (1);
396		if (priorpage) {
397			if (priorpage + PAGE_SIZE != phys)
398				return (1);
399			/* check if crossing a DMA page boundary */
400			if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
401				return (1);
402		}
403		priorpage = phys;
404	}
405	return (0);
406}
407
408/*
409 * Query the progress of a transfer on a DMA channel.
410 *
411 * To avoid having to interrupt a transfer in progress, we sample
412 * each of the high and low databytes twice, and apply the following
413 * logic to determine the correct count.
414 *
415 * Reads are performed with interrupts disabled, thus it is to be
416 * expected that the time between reads is very small.  At most
417 * one rollover in the low count byte can be expected within the
418 * four reads that are performed.
419 *
420 * There are three gaps in which a rollover can occur :
421 *
422 * - read low1
423 *              gap1
424 * - read high1
425 *              gap2
426 * - read low2
427 *              gap3
428 * - read high2
429 *
430 * If a rollover occurs in gap1 or gap2, the low2 value will be
431 * greater than the low1 value.  In this case, low2 and high2 are a
432 * corresponding pair.
433 *
434 * In any other case, low1 and high1 can be considered to be correct.
435 *
436 * The function returns the number of bytes remaining in the transfer,
437 * or -1 if the channel requested is not active.
438 *
439 */
440int
441isa_dmastatus(int chan)
442{
443	u_long	cnt = 0;
444	int	ffport, waport;
445	u_long	low1, high1, low2, high2;
446
447	/* channel active? */
448	if ((dma_inuse & (1 << chan)) == 0) {
449		printf("isa_dmastatus: channel %d not active\n", chan);
450		return(-1);
451	}
452	/* channel busy? */
453
454	if (((dma_busy & (1 << chan)) == 0) &&
455	    (dma_auto_mode & (1 << chan)) == 0 ) {
456	    printf("chan %d not busy\n", chan);
457	    return -2 ;
458	}
459	if (chan < 4) {			/* low DMA controller */
460		ffport = DMA1_FFC;
461		waport = DMA1_CHN(chan) + 1;
462	} else {			/* high DMA controller */
463		ffport = DMA2_FFC;
464		waport = DMA2_CHN(chan - 4) + 2;
465	}
466
467	disable_intr();			/* no interrupts Mr Jones! */
468	outb(ffport, 0);		/* clear register LSB flipflop */
469	low1 = inb(waport);
470	high1 = inb(waport);
471	outb(ffport, 0);		/* clear again */
472	low2 = inb(waport);
473	high2 = inb(waport);
474	enable_intr();			/* enable interrupts again */
475
476	/*
477	 * Now decide if a wrap has tried to skew our results.
478	 * Note that after TC, the count will read 0xffff, while we want
479	 * to return zero, so we add and then mask to compensate.
480	 */
481	if (low1 >= low2) {
482		cnt = (low1 + (high1 << 8) + 1) & 0xffff;
483	} else {
484		cnt = (low2 + (high2 << 8) + 1) & 0xffff;
485	}
486
487	if (chan >= 4)			/* high channels move words */
488		cnt *= 2;
489	return(cnt);
490}
491
492/*
493 * Stop a DMA transfer currently in progress.
494 */
495int
496isa_dmastop(int chan)
497{
498	if ((dma_inuse & (1 << chan)) == 0)
499		printf("isa_dmastop: channel %d not acquired\n", chan);
500
501	if (((dma_busy & (1 << chan)) == 0) &&
502	    ((dma_auto_mode & (1 << chan)) == 0)) {
503		printf("chan %d not busy\n", chan);
504		return -2 ;
505	}
506
507	if ((chan & 4) == 0) {
508		outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
509	} else {
510		outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */);
511	}
512	return(isa_dmastatus(chan));
513}
514
515/*
516 * Attach to the ISA PnP descriptor for the AT DMA controller
517 */
518static struct isa_pnp_id atdma_ids[] = {
519	{ 0x0002d041 /* PNP0200 */, "AT DMA controller" },
520	{ 0 }
521};
522
523static int
524atdma_probe(device_t dev)
525{
526	int result;
527
528	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
529		device_quiet(dev);
530	return(result);
531}
532
533static int
534atdma_attach(device_t dev)
535{
536	return(0);
537}
538
539static device_method_t atdma_methods[] = {
540	/* Device interface */
541	DEVMETHOD(device_probe,		atdma_probe),
542	DEVMETHOD(device_attach,	atdma_attach),
543	DEVMETHOD(device_detach,	bus_generic_detach),
544	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
545	DEVMETHOD(device_suspend,	bus_generic_suspend),
546	DEVMETHOD(device_resume,	bus_generic_resume),
547	{ 0, 0 }
548};
549
550static driver_t atdma_driver = {
551	"atdma",
552	atdma_methods,
553	1,		/* no softc */
554};
555
556static devclass_t atdma_devclass;
557
558DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
559DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0);
560