cbus_dma.c revision 145012 
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/pc98/cbus/cbus_dma.c 145012 2005-04-13 13:26:48Z nyan $");
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 "opt_pc98.h"
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 <machine/md_var.h>
60#include <vm/vm.h>
61#include <vm/vm_param.h>
62#include <vm/pmap.h>
63#include <pc98/pc98/pc98.h>
64#include <dev/ic/i8237.h>
65#include <isa/isavar.h>
66
67/*
68**  Register definitions for DMA controller 1 (channels 0..3):
69*/
70#define	DMA1_CHN(c)	(IO_DMA + (4*(c)))	/* addr reg for channel c */
71#define	DMA1_STATUS	(IO_DMA + 0x10)		/* status register */
72#define	DMA1_SMSK	(IO_DMA + 0x14)		/* single mask register */
73#define	DMA1_MODE	(IO_DMA + 0x16)		/* mode register */
74#define	DMA1_FFC	(IO_DMA + 0x18)		/* clear first/last FF */
75
76static int isa_dmarangecheck(caddr_t va, u_int length, int chan);
77
78static caddr_t	dma_bouncebuf[4];
79static u_int	dma_bouncebufsize[4];
80static u_int8_t	dma_bounced = 0;
81static u_int8_t	dma_busy = 0;		/* Used in isa_dmastart() */
82static u_int8_t	dma_inuse = 0;		/* User for acquire/release */
83static u_int8_t dma_auto_mode = 0;
84
85#define VALID_DMA_MASK (3)
86
87/* high byte of address is stored in this port for i-th dma channel */
88static int dmapageport[4] = { 0x27, 0x21, 0x23, 0x25 };
89
90/*
91 * Setup a DMA channel's bounce buffer.
92 */
93int
94isa_dma_init(int chan, u_int bouncebufsize, int flag)
95{
96	void *buf;
97
98#ifdef DIAGNOSTIC
99	if (chan & ~VALID_DMA_MASK)
100		panic("isa_dma_init: channel out of range");
101	if (dma_bouncebuf[chan] != NULL)
102		panic("isa_dma_init: impossible request");
103#endif
104
105	dma_bouncebufsize[chan] = bouncebufsize;
106
107	/* Try malloc() first.  It works better if it works. */
108	buf = malloc(bouncebufsize, M_DEVBUF, flag);
109	if (buf != NULL) {
110		if (isa_dmarangecheck(buf, bouncebufsize, chan) == 0) {
111			dma_bouncebuf[chan] = buf;
112			return (0);
113		}
114		free(buf, M_DEVBUF);
115	}
116	buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful,
117			   1ul, chan & 4 ? 0x20000ul : 0x10000ul);
118	if (buf == NULL)
119		return (ENOMEM);
120	dma_bouncebuf[chan] = buf;
121	return (0);
122}
123
124/*
125 * Register a DMA channel's usage.  Usually called from a device driver
126 * in open() or during its initialization.
127 */
128int
129isa_dma_acquire(chan)
130	int chan;
131{
132#ifdef DIAGNOSTIC
133	if (chan & ~VALID_DMA_MASK)
134		panic("isa_dma_acquire: channel out of range");
135#endif
136
137	if (dma_inuse & (1 << chan)) {
138		printf("isa_dma_acquire: channel %d already in use\n", chan);
139		return (EBUSY);
140	}
141	dma_inuse |= (1 << chan);
142	dma_auto_mode &= ~(1 << chan);
143
144	return (0);
145}
146
147/*
148 * Unregister a DMA channel's usage.  Usually called from a device driver
149 * during close() or during its shutdown.
150 */
151void
152isa_dma_release(chan)
153	int chan;
154{
155#ifdef DIAGNOSTIC
156	if (chan & ~VALID_DMA_MASK)
157		panic("isa_dma_release: channel out of range");
158
159	if ((dma_inuse & (1 << chan)) == 0)
160		printf("isa_dma_release: channel %d not in use\n", chan);
161#endif
162
163	if (dma_busy & (1 << chan)) {
164		dma_busy &= ~(1 << chan);
165		/*
166		 * XXX We should also do "dma_bounced &= (1 << chan);"
167		 * because we are acting on behalf of isa_dmadone() which
168		 * was not called to end the last DMA operation.  This does
169		 * not matter now, but it may in the future.
170		 */
171	}
172
173	dma_inuse &= ~(1 << chan);
174	dma_auto_mode &= ~(1 << chan);
175}
176
177/*
178 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
179 * problems by using a bounce buffer.
180 */
181void
182isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan)
183{
184	vm_paddr_t phys;
185	int waport;
186	caddr_t newaddr;
187
188	GIANT_REQUIRED;
189
190#ifdef DIAGNOSTIC
191	if (chan & ~VALID_DMA_MASK)
192		panic("isa_dmastart: channel out of range");
193
194	if ((chan < 4 && nbytes > (1<<16))
195	    || (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1)))
196		panic("isa_dmastart: impossible request");
197
198	if ((dma_inuse & (1 << chan)) == 0)
199		printf("isa_dmastart: channel %d not acquired\n", chan);
200#endif
201
202#if 0
203	/*
204	 * XXX This should be checked, but drivers like ad1848 only call
205	 * isa_dmastart() once because they use Auto DMA mode.  If we
206	 * leave this in, drivers that do this will print this continuously.
207	 */
208	if (dma_busy & (1 << chan))
209		printf("isa_dmastart: channel %d busy\n", chan);
210#endif
211
212	dma_busy |= (1 << chan);
213
214	if (isa_dmarangecheck(addr, nbytes, chan)) {
215		if (dma_bouncebuf[chan] == NULL
216		    || dma_bouncebufsize[chan] < nbytes)
217			panic("isa_dmastart: bad bounce buffer");
218		dma_bounced |= (1 << chan);
219		newaddr = dma_bouncebuf[chan];
220
221		/* copy bounce buffer on write */
222		if (!(flags & ISADMA_READ))
223			bcopy(addr, newaddr, nbytes);
224		addr = newaddr;
225	}
226
227	/* translate to physical */
228	phys = pmap_extract(kernel_pmap, (vm_offset_t)addr);
229
230	if (flags & ISADMA_RAW) {
231	    dma_auto_mode |= (1 << chan);
232	} else {
233	    dma_auto_mode &= ~(1 << chan);
234	}
235
236	if (need_pre_dma_flush)
237		wbinvd();		/* wbinvd (WB cache flush) */
238
239	/* set dma channel mode, and reset address ff */
240
241	/* If ISADMA_RAW flag is set, then use autoinitialise mode */
242	if (flags & ISADMA_RAW) {
243		if (flags & ISADMA_READ)
244			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan);
245		else
246			outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan);
247	} else {
248		if (flags & ISADMA_READ)
249			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
250		else
251			outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
252	}
253	outb(DMA1_FFC, 0);
254
255	/* send start address */
256	waport =  DMA1_CHN(chan);
257	outb(waport, phys);
258	outb(waport, phys>>8);
259	outb(dmapageport[chan], phys>>16);
260
261	/* send count */
262	outb(waport + 2, --nbytes);
263	outb(waport + 2, nbytes>>8);
264
265	/* unmask channel */
266	outb(DMA1_SMSK, chan);
267}
268
269void
270isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
271{
272
273	if (flags & ISADMA_READ) {
274		/* cache flush only after reading 92/12/9 by A.Kojima */
275		if (need_post_dma_flush)
276			invd();
277	}
278
279#ifdef DIAGNOSTIC
280	if (chan & ~VALID_DMA_MASK)
281		panic("isa_dmadone: channel out of range");
282
283	if ((dma_inuse & (1 << chan)) == 0)
284		printf("isa_dmadone: channel %d not acquired\n", chan);
285#endif
286
287	if (((dma_busy & (1 << chan)) == 0) &&
288	    (dma_auto_mode & (1 << chan)) == 0 )
289		printf("isa_dmadone: channel %d not busy\n", chan);
290
291	if ((dma_auto_mode & (1 << chan)) == 0)
292		outb(DMA1_SMSK, (chan & 3) | 4);
293
294	if (dma_bounced & (1 << chan)) {
295		/* copy bounce buffer on read */
296		if (flags & ISADMA_READ)
297			bcopy(dma_bouncebuf[chan], addr, nbytes);
298
299		dma_bounced &= ~(1 << chan);
300	}
301	dma_busy &= ~(1 << chan);
302}
303
304/*
305 * Check for problems with the address range of a DMA transfer
306 * (non-contiguous physical pages, outside of bus address space,
307 * crossing DMA page boundaries).
308 * Return true if special handling needed.
309 */
310
311static int
312isa_dmarangecheck(caddr_t va, u_int length, int chan)
313{
314	vm_paddr_t phys, priorpage = 0;
315	vm_offset_t endva;
316	u_int dma_pgmsk = (chan & 4) ?  ~(128*1024-1) : ~(64*1024-1);
317
318	GIANT_REQUIRED;
319
320	endva = (vm_offset_t)round_page((vm_offset_t)va + length);
321	for (; va < (caddr_t) endva ; va += PAGE_SIZE) {
322		phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va));
323#ifdef EPSON_BOUNCEDMA
324#define ISARAM_END	0xf00000
325#else
326#define ISARAM_END	RAM_END
327#endif
328		if (phys == 0)
329			panic("isa_dmacheck: no physical page present");
330		if (phys >= ISARAM_END)
331			return (1);
332		if (priorpage) {
333			if (priorpage + PAGE_SIZE != phys)
334				return (1);
335			/* check if crossing a DMA page boundary */
336			if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
337				return (1);
338		}
339		priorpage = phys;
340	}
341	return (0);
342}
343
344/*
345 * Query the progress of a transfer on a DMA channel.
346 *
347 * To avoid having to interrupt a transfer in progress, we sample
348 * each of the high and low databytes twice, and apply the following
349 * logic to determine the correct count.
350 *
351 * Reads are performed with interrupts disabled, thus it is to be
352 * expected that the time between reads is very small.  At most
353 * one rollover in the low count byte can be expected within the
354 * four reads that are performed.
355 *
356 * There are three gaps in which a rollover can occur :
357 *
358 * - read low1
359 *              gap1
360 * - read high1
361 *              gap2
362 * - read low2
363 *              gap3
364 * - read high2
365 *
366 * If a rollover occurs in gap1 or gap2, the low2 value will be
367 * greater than the low1 value.  In this case, low2 and high2 are a
368 * corresponding pair.
369 *
370 * In any other case, low1 and high1 can be considered to be correct.
371 *
372 * The function returns the number of bytes remaining in the transfer,
373 * or -1 if the channel requested is not active.
374 *
375 */
376int
377isa_dmastatus(int chan)
378{
379	u_long	cnt = 0;
380	int	ffport, waport;
381	u_long	low1, high1, low2, high2;
382
383	/* channel active? */
384	if ((dma_inuse & (1 << chan)) == 0) {
385		printf("isa_dmastatus: channel %d not active\n", chan);
386		return(-1);
387	}
388	/* channel busy? */
389
390	if (((dma_busy & (1 << chan)) == 0) &&
391	    (dma_auto_mode & (1 << chan)) == 0 ) {
392	    printf("chan %d not busy\n", chan);
393	    return -2 ;
394	}
395	ffport = DMA1_FFC;
396	waport = DMA1_CHN(chan) + 2;
397
398	disable_intr();			/* no interrupts Mr Jones! */
399	outb(ffport, 0);		/* clear register LSB flipflop */
400	low1 = inb(waport);
401	high1 = inb(waport);
402	outb(ffport, 0);		/* clear again */
403	low2 = inb(waport);
404	high2 = inb(waport);
405	enable_intr();			/* enable interrupts again */
406
407	/*
408	 * Now decide if a wrap has tried to skew our results.
409	 * Note that after TC, the count will read 0xffff, while we want
410	 * to return zero, so we add and then mask to compensate.
411	 */
412	if (low1 >= low2) {
413		cnt = (low1 + (high1 << 8) + 1) & 0xffff;
414	} else {
415		cnt = (low2 + (high2 << 8) + 1) & 0xffff;
416	}
417
418	if (chan >= 4)			/* high channels move words */
419		cnt *= 2;
420	return(cnt);
421}
422
423/*
424 * Reached terminal count yet ?
425 */
426int
427isa_dmatc(int chan)
428{
429
430	return(inb(DMA1_STATUS) & (1 << chan));
431}
432
433/*
434 * Stop a DMA transfer currently in progress.
435 */
436int
437isa_dmastop(int chan)
438{
439	if ((dma_inuse & (1 << chan)) == 0)
440		printf("isa_dmastop: channel %d not acquired\n", chan);
441
442	if (((dma_busy & (1 << chan)) == 0) &&
443	    ((dma_auto_mode & (1 << chan)) == 0)) {
444		printf("chan %d not busy\n", chan);
445		return -2 ;
446	}
447
448	if ((chan & 4) == 0)
449		outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */);
450
451	return(isa_dmastatus(chan));
452}
453
454/*
455 * Attach to the ISA PnP descriptor for the AT DMA controller
456 */
457static struct isa_pnp_id atdma_ids[] = {
458	{ 0x0002d041 /* PNP0200 */, "AT DMA controller" },
459	{ 0 }
460};
461
462static int
463atdma_probe(device_t dev)
464{
465	int result;
466
467	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0)
468		device_quiet(dev);
469	return(result);
470}
471
472static int
473atdma_attach(device_t dev)
474{
475	return(0);
476}
477
478static device_method_t atdma_methods[] = {
479	/* Device interface */
480	DEVMETHOD(device_probe,		atdma_probe),
481	DEVMETHOD(device_attach,	atdma_attach),
482	DEVMETHOD(device_detach,	bus_generic_detach),
483	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
484	DEVMETHOD(device_suspend,	bus_generic_suspend),
485	DEVMETHOD(device_resume,	bus_generic_resume),
486	{ 0, 0 }
487};
488
489static driver_t atdma_driver = {
490	"atdma",
491	atdma_methods,
492	1,		/* no softc */
493};
494
495static devclass_t atdma_devclass;
496
497DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0);
498