ide-dma.c revision 9780e2dd8254351f6cbe11304849126b51dbd561 
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	struct ide_cmd *cmd = &hwif->cmd;
93	u8 stat = 0, dma_stat = 0;
94
95	drive->waiting_for_dma = 0;
96	dma_stat = hwif->dma_ops->dma_end(drive);
97	ide_dma_unmap_sg(drive, cmd);
98	stat = hwif->tp_ops->read_status(hwif);
99
100	if (OK_STAT(stat, DRIVE_READY, drive->bad_wstat | ATA_DRQ)) {
101		if (!dma_stat) {
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						blk_rq_sectors(cmd->rq) << 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_dma_map_sg	-	map IDE scatter gather for DMA I/O
122 *	@drive: the drive to map 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_dma_map_sg(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	if (cmd->tf_flags & IDE_TFLAG_WRITE)
138		cmd->sg_dma_direction = DMA_TO_DEVICE;
139	else
140		cmd->sg_dma_direction = DMA_FROM_DEVICE;
141
142	i = dma_map_sg(hwif->dev, sg, cmd->sg_nents, cmd->sg_dma_direction);
143	if (i) {
144		cmd->orig_sg_nents = cmd->sg_nents;
145		cmd->sg_nents = i;
146	}
147
148	return i;
149}
150
151/**
152 *	ide_dma_unmap_sg	-	clean up DMA mapping
153 *	@drive: The drive to unmap
154 *
155 *	Teardown mappings after DMA has completed. This must be called
156 *	after the completion of each use of ide_build_dmatable and before
157 *	the next use of ide_build_dmatable. Failure to do so will cause
158 *	an oops as only one mapping can be live for each target at a given
159 *	time.
160 */
161
162void ide_dma_unmap_sg(ide_drive_t *drive, struct ide_cmd *cmd)
163{
164	ide_hwif_t *hwif = drive->hwif;
165
166	dma_unmap_sg(hwif->dev, hwif->sg_table, cmd->orig_sg_nents,
167		     cmd->sg_dma_direction);
168}
169EXPORT_SYMBOL_GPL(ide_dma_unmap_sg);
170
171/**
172 *	ide_dma_off_quietly	-	Generic DMA kill
173 *	@drive: drive to control
174 *
175 *	Turn off the current DMA on this IDE controller.
176 */
177
178void ide_dma_off_quietly(ide_drive_t *drive)
179{
180	drive->dev_flags &= ~IDE_DFLAG_USING_DMA;
181	ide_toggle_bounce(drive, 0);
182
183	drive->hwif->dma_ops->dma_host_set(drive, 0);
184}
185EXPORT_SYMBOL(ide_dma_off_quietly);
186
187/**
188 *	ide_dma_off	-	disable DMA on a device
189 *	@drive: drive to disable DMA on
190 *
191 *	Disable IDE DMA for a device on this IDE controller.
192 *	Inform the user that DMA has been disabled.
193 */
194
195void ide_dma_off(ide_drive_t *drive)
196{
197	printk(KERN_INFO "%s: DMA disabled\n", drive->name);
198	ide_dma_off_quietly(drive);
199}
200EXPORT_SYMBOL(ide_dma_off);
201
202/**
203 *	ide_dma_on		-	Enable DMA on a device
204 *	@drive: drive to enable DMA on
205 *
206 *	Enable IDE DMA for a device on this IDE controller.
207 */
208
209void ide_dma_on(ide_drive_t *drive)
210{
211	drive->dev_flags |= IDE_DFLAG_USING_DMA;
212	ide_toggle_bounce(drive, 1);
213
214	drive->hwif->dma_ops->dma_host_set(drive, 1);
215}
216
217int __ide_dma_bad_drive(ide_drive_t *drive)
218{
219	u16 *id = drive->id;
220
221	int blacklist = ide_in_drive_list(id, drive_blacklist);
222	if (blacklist) {
223		printk(KERN_WARNING "%s: Disabling (U)DMA for %s (blacklisted)\n",
224				    drive->name, (char *)&id[ATA_ID_PROD]);
225		return blacklist;
226	}
227	return 0;
228}
229EXPORT_SYMBOL(__ide_dma_bad_drive);
230
231static const u8 xfer_mode_bases[] = {
232	XFER_UDMA_0,
233	XFER_MW_DMA_0,
234	XFER_SW_DMA_0,
235};
236
237static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base, u8 req_mode)
238{
239	u16 *id = drive->id;
240	ide_hwif_t *hwif = drive->hwif;
241	const struct ide_port_ops *port_ops = hwif->port_ops;
242	unsigned int mask = 0;
243
244	switch (base) {
245	case XFER_UDMA_0:
246		if ((id[ATA_ID_FIELD_VALID] & 4) == 0)
247			break;
248		mask = id[ATA_ID_UDMA_MODES];
249		if (port_ops && port_ops->udma_filter)
250			mask &= port_ops->udma_filter(drive);
251		else
252			mask &= hwif->ultra_mask;
253
254		/*
255		 * avoid false cable warning from eighty_ninty_three()
256		 */
257		if (req_mode > XFER_UDMA_2) {
258			if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
259				mask &= 0x07;
260		}
261		break;
262	case XFER_MW_DMA_0:
263		mask = id[ATA_ID_MWDMA_MODES];
264
265		/* Also look for the CF specific MWDMA modes... */
266		if (ata_id_is_cfa(id) && (id[ATA_ID_CFA_MODES] & 0x38)) {
267			u8 mode = ((id[ATA_ID_CFA_MODES] & 0x38) >> 3) - 1;
268
269			mask |= ((2 << mode) - 1) << 3;
270		}
271
272		if (port_ops && port_ops->mdma_filter)
273			mask &= port_ops->mdma_filter(drive);
274		else
275			mask &= hwif->mwdma_mask;
276		break;
277	case XFER_SW_DMA_0:
278		mask = id[ATA_ID_SWDMA_MODES];
279		if (!(mask & ATA_SWDMA2) && (id[ATA_ID_OLD_DMA_MODES] >> 8)) {
280			u8 mode = id[ATA_ID_OLD_DMA_MODES] >> 8;
281
282			/*
283			 * if the mode is valid convert it to the mask
284			 * (the maximum allowed mode is XFER_SW_DMA_2)
285			 */
286			if (mode <= 2)
287				mask = (2 << mode) - 1;
288		}
289		mask &= hwif->swdma_mask;
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_MWDMA_MODES] >> 8) &&
407		   (id[ATA_ID_SWDMA_MODES] >> 8))
408		goto err_out;
409
410	return 0;
411err_out:
412	printk(KERN_ERR "%s: bad DMA info in identify block\n", drive->name);
413	return 1;
414}
415
416int ide_set_dma(ide_drive_t *drive)
417{
418	int rc;
419
420	/*
421	 * Force DMAing for the beginning of the check.
422	 * Some chipsets appear to do interesting
423	 * things, if not checked and cleared.
424	 *   PARANOIA!!!
425	 */
426	ide_dma_off_quietly(drive);
427
428	rc = ide_dma_check(drive);
429	if (rc)
430		return rc;
431
432	ide_dma_on(drive);
433
434	return 0;
435}
436
437void ide_check_dma_crc(ide_drive_t *drive)
438{
439	u8 mode;
440
441	ide_dma_off_quietly(drive);
442	drive->crc_count = 0;
443	mode = drive->current_speed;
444	/*
445	 * Don't try non Ultra-DMA modes without iCRC's.  Force the
446	 * device to PIO and make the user enable SWDMA/MWDMA modes.
447	 */
448	if (mode > XFER_UDMA_0 && mode <= XFER_UDMA_7)
449		mode--;
450	else
451		mode = XFER_PIO_4;
452	ide_set_xfer_rate(drive, mode);
453	if (drive->current_speed >= XFER_SW_DMA_0)
454		ide_dma_on(drive);
455}
456
457void ide_dma_lost_irq(ide_drive_t *drive)
458{
459	printk(KERN_ERR "%s: DMA interrupt recovery\n", drive->name);
460}
461EXPORT_SYMBOL_GPL(ide_dma_lost_irq);
462
463/*
464 * un-busy the port etc, and clear any pending DMA status. we want to
465 * retry the current request in pio mode instead of risking tossing it
466 * all away
467 */
468ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
469{
470	ide_hwif_t *hwif = drive->hwif;
471	const struct ide_dma_ops *dma_ops = hwif->dma_ops;
472	struct ide_cmd *cmd = &hwif->cmd;
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		drive->waiting_for_dma = 0;
483		(void)dma_ops->dma_end(drive);
484		ide_dma_unmap_sg(drive, cmd);
485		ret = ide_error(drive, "dma timeout error",
486				hwif->tp_ops->read_status(hwif));
487	} else {
488		printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
489		if (dma_ops->dma_clear)
490			dma_ops->dma_clear(drive);
491		printk(KERN_ERR "%s: timeout waiting for DMA\n", drive->name);
492		if (dma_ops->dma_test_irq(drive) == 0) {
493			ide_dump_status(drive, "DMA timeout",
494					hwif->tp_ops->read_status(hwif));
495			drive->waiting_for_dma = 0;
496			(void)dma_ops->dma_end(drive);
497			ide_dma_unmap_sg(drive, cmd);
498		}
499	}
500
501	/*
502	 * disable dma for now, but remember that we did so because of
503	 * a timeout -- we'll reenable after we finish this next request
504	 * (or rather the first chunk of it) in pio.
505	 */
506	drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY;
507	drive->retry_pio++;
508	ide_dma_off_quietly(drive);
509
510	/*
511	 * un-busy drive etc and make sure request is sane
512	 */
513	rq = hwif->rq;
514	if (rq) {
515		hwif->rq = NULL;
516		rq->errors = 0;
517	}
518	return ret;
519}
520
521void ide_release_dma_engine(ide_hwif_t *hwif)
522{
523	if (hwif->dmatable_cpu) {
524		int prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
525
526		dma_free_coherent(hwif->dev, prd_size,
527				  hwif->dmatable_cpu, hwif->dmatable_dma);
528		hwif->dmatable_cpu = NULL;
529	}
530}
531EXPORT_SYMBOL_GPL(ide_release_dma_engine);
532
533int ide_allocate_dma_engine(ide_hwif_t *hwif)
534{
535	int prd_size;
536
537	if (hwif->prd_max_nents == 0)
538		hwif->prd_max_nents = PRD_ENTRIES;
539	if (hwif->prd_ent_size == 0)
540		hwif->prd_ent_size = PRD_BYTES;
541
542	prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
543
544	hwif->dmatable_cpu = dma_alloc_coherent(hwif->dev, prd_size,
545						&hwif->dmatable_dma,
546						GFP_ATOMIC);
547	if (hwif->dmatable_cpu == NULL) {
548		printk(KERN_ERR "%s: unable to allocate PRD table\n",
549			hwif->name);
550		return -ENOMEM;
551	}
552
553	return 0;
554}
555EXPORT_SYMBOL_GPL(ide_allocate_dma_engine);
556
557int ide_dma_prepare(ide_drive_t *drive, struct ide_cmd *cmd)
558{
559	const struct ide_dma_ops *dma_ops = drive->hwif->dma_ops;
560
561	if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
562	    (dma_ops->dma_check && dma_ops->dma_check(drive, cmd)))
563		goto out;
564	ide_map_sg(drive, cmd);
565	if (ide_dma_map_sg(drive, cmd) == 0)
566		goto out_map;
567	if (dma_ops->dma_setup(drive, cmd))
568		goto out_dma_unmap;
569	drive->waiting_for_dma = 1;
570	return 0;
571out_dma_unmap:
572	ide_dma_unmap_sg(drive, cmd);
573out_map:
574	ide_map_sg(drive, cmd);
575out:
576	return 1;
577}
578