ide-dma.c revision 5ae5412d9a23b05ab08461b202bad21ad8f6b66d 
1/*
2 *  IDE DMA support (including IDE PCI BM-DMA).
3 *
4 *  Copyright (C) 1995-1998   Mark Lord
5 *  Copyright (C) 1999-2000   Andre Hedrick <andre@linux-ide.org>
6 *  Copyright (C) 2004, 2007  Bartlomiej Zolnierkiewicz
7 *
8 *  May be copied or modified under the terms of the GNU General Public License
9 *
10 *  DMA is supported for all IDE devices (disk drives, cdroms, tapes, floppies).
11 */
12
13/*
14 *  Special Thanks to Mark for his Six years of work.
15 */
16
17/*
18 * Thanks to "Christopher J. Reimer" <reimer@doe.carleton.ca> for
19 * fixing the problem with the BIOS on some Acer motherboards.
20 *
21 * Thanks to "Benoit Poulot-Cazajous" <poulot@chorus.fr> for testing
22 * "TX" chipset compatibility and for providing patches for the "TX" chipset.
23 *
24 * Thanks to Christian Brunner <chb@muc.de> for taking a good first crack
25 * at generic DMA -- his patches were referred to when preparing this code.
26 *
27 * Most importantly, thanks to Robert Bringman <rob@mars.trion.com>
28 * for supplying a Promise UDMA board & WD UDMA drive for this work!
29 */
30
31#include <linux/types.h>
32#include <linux/kernel.h>
33#include <linux/ide.h>
34#include <linux/scatterlist.h>
35#include <linux/dma-mapping.h>
36
37static const struct drive_list_entry drive_whitelist[] = {
38	{ "Micropolis 2112A"	,       NULL		},
39	{ "CONNER CTMA 4000"	,       NULL		},
40	{ "CONNER CTT8000-A"	,       NULL		},
41	{ "ST34342A"		,	NULL		},
42	{ NULL			,	NULL		}
43};
44
45static const struct drive_list_entry drive_blacklist[] = {
46	{ "WDC AC11000H"	,	NULL 		},
47	{ "WDC AC22100H"	,	NULL 		},
48	{ "WDC AC32500H"	,	NULL 		},
49	{ "WDC AC33100H"	,	NULL 		},
50	{ "WDC AC31600H"	,	NULL 		},
51	{ "WDC AC32100H"	,	"24.09P07"	},
52	{ "WDC AC23200L"	,	"21.10N21"	},
53	{ "Compaq CRD-8241B"	,	NULL 		},
54	{ "CRD-8400B"		,	NULL 		},
55	{ "CRD-8480B",			NULL 		},
56	{ "CRD-8482B",			NULL 		},
57	{ "CRD-84"		,	NULL 		},
58	{ "SanDisk SDP3B"	,	NULL 		},
59	{ "SanDisk SDP3B-64"	,	NULL 		},
60	{ "SANYO CD-ROM CRD"	,	NULL 		},
61	{ "HITACHI CDR-8"	,	NULL 		},
62	{ "HITACHI CDR-8335"	,	NULL 		},
63	{ "HITACHI CDR-8435"	,	NULL 		},
64	{ "Toshiba CD-ROM XM-6202B"	,	NULL 		},
65	{ "TOSHIBA CD-ROM XM-1702BC",	NULL 		},
66	{ "CD-532E-A"		,	NULL 		},
67	{ "E-IDE CD-ROM CR-840",	NULL 		},
68	{ "CD-ROM Drive/F5A",	NULL 		},
69	{ "WPI CDD-820",		NULL 		},
70	{ "SAMSUNG CD-ROM SC-148C",	NULL 		},
71	{ "SAMSUNG CD-ROM SC",	NULL 		},
72	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",	NULL 		},
73	{ "_NEC DV5800A",               NULL            },
74	{ "SAMSUNG CD-ROM SN-124",	"N001" },
75	{ "Seagate STT20000A",		NULL  },
76	{ "CD-ROM CDR_U200",		"1.09" },
77	{ NULL			,	NULL		}
78
79};
80
81/**
82 *	ide_dma_intr	-	IDE DMA interrupt handler
83 *	@drive: the drive the interrupt is for
84 *
85 *	Handle an interrupt completing a read/write DMA transfer on an
86 *	IDE device
87 */
88
89ide_startstop_t ide_dma_intr(ide_drive_t *drive)
90{
91	ide_hwif_t *hwif = drive->hwif;
92	u8 stat = 0, dma_stat = 0;
93
94	dma_stat = hwif->dma_ops->dma_end(drive);
95	ide_destroy_dmatable(drive);
96	stat = hwif->tp_ops->read_status(hwif);
97
98	if (OK_STAT(stat, DRIVE_READY, drive->bad_wstat | ATA_DRQ)) {
99		if (!dma_stat) {
100			struct ide_cmd *cmd = &hwif->cmd;
101
102			if ((cmd->tf_flags & IDE_TFLAG_FS) == 0)
103				ide_finish_cmd(drive, cmd, stat);
104			else
105				ide_complete_rq(drive, 0,
106						cmd->rq->nr_sectors << 9);
107			return ide_stopped;
108		}
109		printk(KERN_ERR "%s: %s: bad DMA status (0x%02x)\n",
110			drive->name, __func__, dma_stat);
111	}
112	return ide_error(drive, "dma_intr", stat);
113}
114
115int ide_dma_good_drive(ide_drive_t *drive)
116{
117	return ide_in_drive_list(drive->id, drive_whitelist);
118}
119
120/**
121 *	ide_build_sglist	-	map IDE scatter gather for DMA I/O
122 *	@drive: the drive to build the DMA table for
123 *	@cmd: command
124 *
125 *	Perform the DMA mapping magic necessary to access the source or
126 *	target buffers of a request via DMA.  The lower layers of the
127 *	kernel provide the necessary cache management so that we can
128 *	operate in a portable fashion.
129 */
130
131static int ide_build_sglist(ide_drive_t *drive, struct ide_cmd *cmd)
132{
133	ide_hwif_t *hwif = drive->hwif;
134	struct scatterlist *sg = hwif->sg_table;
135	int i;
136
137	ide_map_sg(drive, cmd);
138
139	if (cmd->tf_flags & IDE_TFLAG_WRITE)
140		cmd->sg_dma_direction = DMA_TO_DEVICE;
141	else
142		cmd->sg_dma_direction = DMA_FROM_DEVICE;
143
144	i = dma_map_sg(hwif->dev, sg, cmd->sg_nents, cmd->sg_dma_direction);
145	if (i == 0)
146		ide_map_sg(drive, cmd);
147	else {
148		cmd->orig_sg_nents = cmd->sg_nents;
149		cmd->sg_nents = i;
150	}
151
152	return i;
153}
154
155/**
156 *	ide_destroy_dmatable	-	clean up DMA mapping
157 *	@drive: The drive to unmap
158 *
159 *	Teardown mappings after DMA has completed. This must be called
160 *	after the completion of each use of ide_build_dmatable and before
161 *	the next use of ide_build_dmatable. Failure to do so will cause
162 *	an oops as only one mapping can be live for each target at a given
163 *	time.
164 */
165
166void ide_destroy_dmatable(ide_drive_t *drive)
167{
168	ide_hwif_t *hwif = drive->hwif;
169	struct ide_cmd *cmd = &hwif->cmd;
170
171	dma_unmap_sg(hwif->dev, hwif->sg_table, cmd->orig_sg_nents,
172		     cmd->sg_dma_direction);
173}
174EXPORT_SYMBOL_GPL(ide_destroy_dmatable);
175
176/**
177 *	ide_dma_off_quietly	-	Generic DMA kill
178 *	@drive: drive to control
179 *
180 *	Turn off the current DMA on this IDE controller.
181 */
182
183void ide_dma_off_quietly(ide_drive_t *drive)
184{
185	drive->dev_flags &= ~IDE_DFLAG_USING_DMA;
186	ide_toggle_bounce(drive, 0);
187
188	drive->hwif->dma_ops->dma_host_set(drive, 0);
189}
190EXPORT_SYMBOL(ide_dma_off_quietly);
191
192/**
193 *	ide_dma_off	-	disable DMA on a device
194 *	@drive: drive to disable DMA on
195 *
196 *	Disable IDE DMA for a device on this IDE controller.
197 *	Inform the user that DMA has been disabled.
198 */
199
200void ide_dma_off(ide_drive_t *drive)
201{
202	printk(KERN_INFO "%s: DMA disabled\n", drive->name);
203	ide_dma_off_quietly(drive);
204}
205EXPORT_SYMBOL(ide_dma_off);
206
207/**
208 *	ide_dma_on		-	Enable DMA on a device
209 *	@drive: drive to enable DMA on
210 *
211 *	Enable IDE DMA for a device on this IDE controller.
212 */
213
214void ide_dma_on(ide_drive_t *drive)
215{
216	drive->dev_flags |= IDE_DFLAG_USING_DMA;
217	ide_toggle_bounce(drive, 1);
218
219	drive->hwif->dma_ops->dma_host_set(drive, 1);
220}
221
222int __ide_dma_bad_drive(ide_drive_t *drive)
223{
224	u16 *id = drive->id;
225
226	int blacklist = ide_in_drive_list(id, drive_blacklist);
227	if (blacklist) {
228		printk(KERN_WARNING "%s: Disabling (U)DMA for %s (blacklisted)\n",
229				    drive->name, (char *)&id[ATA_ID_PROD]);
230		return blacklist;
231	}
232	return 0;
233}
234EXPORT_SYMBOL(__ide_dma_bad_drive);
235
236static const u8 xfer_mode_bases[] = {
237	XFER_UDMA_0,
238	XFER_MW_DMA_0,
239	XFER_SW_DMA_0,
240};
241
242static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base, u8 req_mode)
243{
244	u16 *id = drive->id;
245	ide_hwif_t *hwif = drive->hwif;
246	const struct ide_port_ops *port_ops = hwif->port_ops;
247	unsigned int mask = 0;
248
249	switch (base) {
250	case XFER_UDMA_0:
251		if ((id[ATA_ID_FIELD_VALID] & 4) == 0)
252			break;
253
254		if (port_ops && port_ops->udma_filter)
255			mask = port_ops->udma_filter(drive);
256		else
257			mask = hwif->ultra_mask;
258		mask &= id[ATA_ID_UDMA_MODES];
259
260		/*
261		 * avoid false cable warning from eighty_ninty_three()
262		 */
263		if (req_mode > XFER_UDMA_2) {
264			if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
265				mask &= 0x07;
266		}
267		break;
268	case XFER_MW_DMA_0:
269		if ((id[ATA_ID_FIELD_VALID] & 2) == 0)
270			break;
271		if (port_ops && port_ops->mdma_filter)
272			mask = port_ops->mdma_filter(drive);
273		else
274			mask = hwif->mwdma_mask;
275		mask &= id[ATA_ID_MWDMA_MODES];
276		break;
277	case XFER_SW_DMA_0:
278		if (id[ATA_ID_FIELD_VALID] & 2) {
279			mask = id[ATA_ID_SWDMA_MODES] & hwif->swdma_mask;
280		} else if (id[ATA_ID_OLD_DMA_MODES] >> 8) {
281			u8 mode = id[ATA_ID_OLD_DMA_MODES] >> 8;
282
283			/*
284			 * if the mode is valid convert it to the mask
285			 * (the maximum allowed mode is XFER_SW_DMA_2)
286			 */
287			if (mode <= 2)
288				mask = ((2 << mode) - 1) & hwif->swdma_mask;
289		}
290		break;
291	default:
292		BUG();
293		break;
294	}
295
296	return mask;
297}
298
299/**
300 *	ide_find_dma_mode	-	compute DMA speed
301 *	@drive: IDE device
302 *	@req_mode: requested mode
303 *
304 *	Checks the drive/host capabilities and finds the speed to use for
305 *	the DMA transfer.  The speed is then limited by the requested mode.
306 *
307 *	Returns 0 if the drive/host combination is incapable of DMA transfers
308 *	or if the requested mode is not a DMA mode.
309 */
310
311u8 ide_find_dma_mode(ide_drive_t *drive, u8 req_mode)
312{
313	ide_hwif_t *hwif = drive->hwif;
314	unsigned int mask;
315	int x, i;
316	u8 mode = 0;
317
318	if (drive->media != ide_disk) {
319		if (hwif->host_flags & IDE_HFLAG_NO_ATAPI_DMA)
320			return 0;
321	}
322
323	for (i = 0; i < ARRAY_SIZE(xfer_mode_bases); i++) {
324		if (req_mode < xfer_mode_bases[i])
325			continue;
326		mask = ide_get_mode_mask(drive, xfer_mode_bases[i], req_mode);
327		x = fls(mask) - 1;
328		if (x >= 0) {
329			mode = xfer_mode_bases[i] + x;
330			break;
331		}
332	}
333
334	if (hwif->chipset == ide_acorn && mode == 0) {
335		/*
336		 * is this correct?
337		 */
338		if (ide_dma_good_drive(drive) &&
339		    drive->id[ATA_ID_EIDE_DMA_TIME] < 150)
340			mode = XFER_MW_DMA_1;
341	}
342
343	mode = min(mode, req_mode);
344
345	printk(KERN_INFO "%s: %s mode selected\n", drive->name,
346			  mode ? ide_xfer_verbose(mode) : "no DMA");
347
348	return mode;
349}
350EXPORT_SYMBOL_GPL(ide_find_dma_mode);
351
352static int ide_tune_dma(ide_drive_t *drive)
353{
354	ide_hwif_t *hwif = drive->hwif;
355	u8 speed;
356
357	if (ata_id_has_dma(drive->id) == 0 ||
358	    (drive->dev_flags & IDE_DFLAG_NODMA))
359		return 0;
360
361	/* consult the list of known "bad" drives */
362	if (__ide_dma_bad_drive(drive))
363		return 0;
364
365	if (ide_id_dma_bug(drive))
366		return 0;
367
368	if (hwif->host_flags & IDE_HFLAG_TRUST_BIOS_FOR_DMA)
369		return config_drive_for_dma(drive);
370
371	speed = ide_max_dma_mode(drive);
372
373	if (!speed)
374		return 0;
375
376	if (ide_set_dma_mode(drive, speed))
377		return 0;
378
379	return 1;
380}
381
382static int ide_dma_check(ide_drive_t *drive)
383{
384	ide_hwif_t *hwif = drive->hwif;
385
386	if (ide_tune_dma(drive))
387		return 0;
388
389	/* TODO: always do PIO fallback */
390	if (hwif->host_flags & IDE_HFLAG_TRUST_BIOS_FOR_DMA)
391		return -1;
392
393	ide_set_max_pio(drive);
394
395	return -1;
396}
397
398int ide_id_dma_bug(ide_drive_t *drive)
399{
400	u16 *id = drive->id;
401
402	if (id[ATA_ID_FIELD_VALID] & 4) {
403		if ((id[ATA_ID_UDMA_MODES] >> 8) &&
404		    (id[ATA_ID_MWDMA_MODES] >> 8))
405			goto err_out;
406	} else if (id[ATA_ID_FIELD_VALID] & 2) {
407		if ((id[ATA_ID_MWDMA_MODES] >> 8) &&
408		    (id[ATA_ID_SWDMA_MODES] >> 8))
409			goto err_out;
410	}
411	return 0;
412err_out:
413	printk(KERN_ERR "%s: bad DMA info in identify block\n", drive->name);
414	return 1;
415}
416
417int ide_set_dma(ide_drive_t *drive)
418{
419	int rc;
420
421	/*
422	 * Force DMAing for the beginning of the check.
423	 * Some chipsets appear to do interesting
424	 * things, if not checked and cleared.
425	 *   PARANOIA!!!
426	 */
427	ide_dma_off_quietly(drive);
428
429	rc = ide_dma_check(drive);
430	if (rc)
431		return rc;
432
433	ide_dma_on(drive);
434
435	return 0;
436}
437
438void ide_check_dma_crc(ide_drive_t *drive)
439{
440	u8 mode;
441
442	ide_dma_off_quietly(drive);
443	drive->crc_count = 0;
444	mode = drive->current_speed;
445	/*
446	 * Don't try non Ultra-DMA modes without iCRC's.  Force the
447	 * device to PIO and make the user enable SWDMA/MWDMA modes.
448	 */
449	if (mode > XFER_UDMA_0 && mode <= XFER_UDMA_7)
450		mode--;
451	else
452		mode = XFER_PIO_4;
453	ide_set_xfer_rate(drive, mode);
454	if (drive->current_speed >= XFER_SW_DMA_0)
455		ide_dma_on(drive);
456}
457
458void ide_dma_lost_irq(ide_drive_t *drive)
459{
460	printk(KERN_ERR "%s: DMA interrupt recovery\n", drive->name);
461}
462EXPORT_SYMBOL_GPL(ide_dma_lost_irq);
463
464/*
465 * un-busy the port etc, and clear any pending DMA status. we want to
466 * retry the current request in pio mode instead of risking tossing it
467 * all away
468 */
469ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
470{
471	ide_hwif_t *hwif = drive->hwif;
472	const struct ide_dma_ops *dma_ops = hwif->dma_ops;
473	struct request *rq;
474	ide_startstop_t ret = ide_stopped;
475
476	/*
477	 * end current dma transaction
478	 */
479
480	if (error < 0) {
481		printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
482		(void)dma_ops->dma_end(drive);
483		ide_destroy_dmatable(drive);
484		ret = ide_error(drive, "dma timeout error",
485				hwif->tp_ops->read_status(hwif));
486	} else {
487		printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
488		if (dma_ops->dma_clear)
489			dma_ops->dma_clear(drive);
490		printk(KERN_ERR "%s: timeout waiting for DMA\n", drive->name);
491		if (dma_ops->dma_test_irq(drive) == 0) {
492			ide_dump_status(drive, "DMA timeout",
493					hwif->tp_ops->read_status(hwif));
494			(void)dma_ops->dma_end(drive);
495			ide_destroy_dmatable(drive);
496		}
497	}
498
499	/*
500	 * disable dma for now, but remember that we did so because of
501	 * a timeout -- we'll reenable after we finish this next request
502	 * (or rather the first chunk of it) in pio.
503	 */
504	drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY;
505	drive->retry_pio++;
506	ide_dma_off_quietly(drive);
507
508	/*
509	 * un-busy drive etc and make sure request is sane
510	 */
511
512	rq = hwif->rq;
513	if (!rq)
514		goto out;
515
516	hwif->rq = NULL;
517
518	rq->errors = 0;
519
520	if (!rq->bio)
521		goto out;
522
523	rq->sector = rq->bio->bi_sector;
524	rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
525	rq->hard_cur_sectors = rq->current_nr_sectors;
526	rq->buffer = bio_data(rq->bio);
527out:
528	return ret;
529}
530
531void ide_release_dma_engine(ide_hwif_t *hwif)
532{
533	if (hwif->dmatable_cpu) {
534		int prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
535
536		dma_free_coherent(hwif->dev, prd_size,
537				  hwif->dmatable_cpu, hwif->dmatable_dma);
538		hwif->dmatable_cpu = NULL;
539	}
540}
541EXPORT_SYMBOL_GPL(ide_release_dma_engine);
542
543int ide_allocate_dma_engine(ide_hwif_t *hwif)
544{
545	int prd_size;
546
547	if (hwif->prd_max_nents == 0)
548		hwif->prd_max_nents = PRD_ENTRIES;
549	if (hwif->prd_ent_size == 0)
550		hwif->prd_ent_size = PRD_BYTES;
551
552	prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
553
554	hwif->dmatable_cpu = dma_alloc_coherent(hwif->dev, prd_size,
555						&hwif->dmatable_dma,
556						GFP_ATOMIC);
557	if (hwif->dmatable_cpu == NULL) {
558		printk(KERN_ERR "%s: unable to allocate PRD table\n",
559			hwif->name);
560		return -ENOMEM;
561	}
562
563	return 0;
564}
565EXPORT_SYMBOL_GPL(ide_allocate_dma_engine);
566
567int ide_dma_prepare(ide_drive_t *drive, struct ide_cmd *cmd)
568{
569	if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
570	    ide_build_sglist(drive, cmd) == 0 ||
571	    drive->hwif->dma_ops->dma_setup(drive, cmd))
572		return 1;
573	return 0;
574}
575