Merge branch 'sched/urgent'
[linux-2.6/x86.git] / drivers / ide / ide-dma.c
blobd4136908f9166a6dbb7b6e991397e289e50c5623
1 /*
2 * IDE DMA support (including IDE PCI BM-DMA).
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
8 * May be copied or modified under the terms of the GNU General Public License
10 * DMA is supported for all IDE devices (disk drives, cdroms, tapes, floppies).
14 * Special Thanks to Mark for his Six years of work.
18 * Thanks to "Christopher J. Reimer" <reimer@doe.carleton.ca> for
19 * fixing the problem with the BIOS on some Acer motherboards.
21 * Thanks to "Benoit Poulot-Cazajous" <poulot@chorus.fr> for testing
22 * "TX" chipset compatibility and for providing patches for the "TX" chipset.
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.
27 * Most importantly, thanks to Robert Bringman <rob@mars.trion.com>
28 * for supplying a Promise UDMA board & WD UDMA drive for this work!
31 #include <linux/types.h>
32 #include <linux/gfp.h>
33 #include <linux/kernel.h>
34 #include <linux/ide.h>
35 #include <linux/scatterlist.h>
36 #include <linux/dma-mapping.h>
38 static const struct drive_list_entry drive_whitelist[] = {
39 { "Micropolis 2112A" , NULL },
40 { "CONNER CTMA 4000" , NULL },
41 { "CONNER CTT8000-A" , NULL },
42 { "ST34342A" , NULL },
43 { NULL , NULL }
46 static const struct drive_list_entry drive_blacklist[] = {
47 { "WDC AC11000H" , NULL },
48 { "WDC AC22100H" , NULL },
49 { "WDC AC32500H" , NULL },
50 { "WDC AC33100H" , NULL },
51 { "WDC AC31600H" , NULL },
52 { "WDC AC32100H" , "24.09P07" },
53 { "WDC AC23200L" , "21.10N21" },
54 { "Compaq CRD-8241B" , NULL },
55 { "CRD-8400B" , NULL },
56 { "CRD-8480B", NULL },
57 { "CRD-8482B", NULL },
58 { "CRD-84" , NULL },
59 { "SanDisk SDP3B" , NULL },
60 { "SanDisk SDP3B-64" , NULL },
61 { "SANYO CD-ROM CRD" , NULL },
62 { "HITACHI CDR-8" , NULL },
63 { "HITACHI CDR-8335" , NULL },
64 { "HITACHI CDR-8435" , NULL },
65 { "Toshiba CD-ROM XM-6202B" , NULL },
66 { "TOSHIBA CD-ROM XM-1702BC", NULL },
67 { "CD-532E-A" , NULL },
68 { "E-IDE CD-ROM CR-840", NULL },
69 { "CD-ROM Drive/F5A", NULL },
70 { "WPI CDD-820", NULL },
71 { "SAMSUNG CD-ROM SC-148C", NULL },
72 { "SAMSUNG CD-ROM SC", NULL },
73 { "ATAPI CD-ROM DRIVE 40X MAXIMUM", NULL },
74 { "_NEC DV5800A", NULL },
75 { "SAMSUNG CD-ROM SN-124", "N001" },
76 { "Seagate STT20000A", NULL },
77 { "CD-ROM CDR_U200", "1.09" },
78 { NULL , NULL }
82 /**
83 * ide_dma_intr - IDE DMA interrupt handler
84 * @drive: the drive the interrupt is for
86 * Handle an interrupt completing a read/write DMA transfer on an
87 * IDE device
90 ide_startstop_t ide_dma_intr(ide_drive_t *drive)
92 ide_hwif_t *hwif = drive->hwif;
93 struct ide_cmd *cmd = &hwif->cmd;
94 u8 stat = 0, dma_stat = 0;
96 drive->waiting_for_dma = 0;
97 dma_stat = hwif->dma_ops->dma_end(drive);
98 ide_dma_unmap_sg(drive, cmd);
99 stat = hwif->tp_ops->read_status(hwif);
101 if (OK_STAT(stat, DRIVE_READY, drive->bad_wstat | ATA_DRQ)) {
102 if (!dma_stat) {
103 if ((cmd->tf_flags & IDE_TFLAG_FS) == 0)
104 ide_finish_cmd(drive, cmd, stat);
105 else
106 ide_complete_rq(drive, 0,
107 blk_rq_sectors(cmd->rq) << 9);
108 return ide_stopped;
110 printk(KERN_ERR "%s: %s: bad DMA status (0x%02x)\n",
111 drive->name, __func__, dma_stat);
113 return ide_error(drive, "dma_intr", stat);
116 int ide_dma_good_drive(ide_drive_t *drive)
118 return ide_in_drive_list(drive->id, drive_whitelist);
122 * ide_dma_map_sg - map IDE scatter gather for DMA I/O
123 * @drive: the drive to map the DMA table for
124 * @cmd: command
126 * Perform the DMA mapping magic necessary to access the source or
127 * target buffers of a request via DMA. The lower layers of the
128 * kernel provide the necessary cache management so that we can
129 * operate in a portable fashion.
132 static int ide_dma_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
134 ide_hwif_t *hwif = drive->hwif;
135 struct scatterlist *sg = hwif->sg_table;
136 int i;
138 if (cmd->tf_flags & IDE_TFLAG_WRITE)
139 cmd->sg_dma_direction = DMA_TO_DEVICE;
140 else
141 cmd->sg_dma_direction = DMA_FROM_DEVICE;
143 i = dma_map_sg(hwif->dev, sg, cmd->sg_nents, cmd->sg_dma_direction);
144 if (i) {
145 cmd->orig_sg_nents = cmd->sg_nents;
146 cmd->sg_nents = i;
149 return i;
153 * ide_dma_unmap_sg - clean up DMA mapping
154 * @drive: The drive to unmap
156 * Teardown mappings after DMA has completed. This must be called
157 * after the completion of each use of ide_build_dmatable and before
158 * the next use of ide_build_dmatable. Failure to do so will cause
159 * an oops as only one mapping can be live for each target at a given
160 * time.
163 void ide_dma_unmap_sg(ide_drive_t *drive, struct ide_cmd *cmd)
165 ide_hwif_t *hwif = drive->hwif;
167 dma_unmap_sg(hwif->dev, hwif->sg_table, cmd->orig_sg_nents,
168 cmd->sg_dma_direction);
170 EXPORT_SYMBOL_GPL(ide_dma_unmap_sg);
173 * ide_dma_off_quietly - Generic DMA kill
174 * @drive: drive to control
176 * Turn off the current DMA on this IDE controller.
179 void ide_dma_off_quietly(ide_drive_t *drive)
181 drive->dev_flags &= ~IDE_DFLAG_USING_DMA;
182 ide_toggle_bounce(drive, 0);
184 drive->hwif->dma_ops->dma_host_set(drive, 0);
186 EXPORT_SYMBOL(ide_dma_off_quietly);
189 * ide_dma_off - disable DMA on a device
190 * @drive: drive to disable DMA on
192 * Disable IDE DMA for a device on this IDE controller.
193 * Inform the user that DMA has been disabled.
196 void ide_dma_off(ide_drive_t *drive)
198 printk(KERN_INFO "%s: DMA disabled\n", drive->name);
199 ide_dma_off_quietly(drive);
201 EXPORT_SYMBOL(ide_dma_off);
204 * ide_dma_on - Enable DMA on a device
205 * @drive: drive to enable DMA on
207 * Enable IDE DMA for a device on this IDE controller.
210 void ide_dma_on(ide_drive_t *drive)
212 drive->dev_flags |= IDE_DFLAG_USING_DMA;
213 ide_toggle_bounce(drive, 1);
215 drive->hwif->dma_ops->dma_host_set(drive, 1);
218 int __ide_dma_bad_drive(ide_drive_t *drive)
220 u16 *id = drive->id;
222 int blacklist = ide_in_drive_list(id, drive_blacklist);
223 if (blacklist) {
224 printk(KERN_WARNING "%s: Disabling (U)DMA for %s (blacklisted)\n",
225 drive->name, (char *)&id[ATA_ID_PROD]);
226 return blacklist;
228 return 0;
230 EXPORT_SYMBOL(__ide_dma_bad_drive);
232 static const u8 xfer_mode_bases[] = {
233 XFER_UDMA_0,
234 XFER_MW_DMA_0,
235 XFER_SW_DMA_0,
238 static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base, u8 req_mode)
240 u16 *id = drive->id;
241 ide_hwif_t *hwif = drive->hwif;
242 const struct ide_port_ops *port_ops = hwif->port_ops;
243 unsigned int mask = 0;
245 switch (base) {
246 case XFER_UDMA_0:
247 if ((id[ATA_ID_FIELD_VALID] & 4) == 0)
248 break;
249 mask = id[ATA_ID_UDMA_MODES];
250 if (port_ops && port_ops->udma_filter)
251 mask &= port_ops->udma_filter(drive);
252 else
253 mask &= hwif->ultra_mask;
256 * avoid false cable warning from eighty_ninty_three()
258 if (req_mode > XFER_UDMA_2) {
259 if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
260 mask &= 0x07;
262 break;
263 case XFER_MW_DMA_0:
264 mask = id[ATA_ID_MWDMA_MODES];
266 /* Also look for the CF specific MWDMA modes... */
267 if (ata_id_is_cfa(id) && (id[ATA_ID_CFA_MODES] & 0x38)) {
268 u8 mode = ((id[ATA_ID_CFA_MODES] & 0x38) >> 3) - 1;
270 mask |= ((2 << mode) - 1) << 3;
273 if (port_ops && port_ops->mdma_filter)
274 mask &= port_ops->mdma_filter(drive);
275 else
276 mask &= hwif->mwdma_mask;
277 break;
278 case XFER_SW_DMA_0:
279 mask = id[ATA_ID_SWDMA_MODES];
280 if (!(mask & ATA_SWDMA2) && (id[ATA_ID_OLD_DMA_MODES] >> 8)) {
281 u8 mode = id[ATA_ID_OLD_DMA_MODES] >> 8;
284 * if the mode is valid convert it to the mask
285 * (the maximum allowed mode is XFER_SW_DMA_2)
287 if (mode <= 2)
288 mask = (2 << mode) - 1;
290 mask &= hwif->swdma_mask;
291 break;
292 default:
293 BUG();
294 break;
297 return mask;
301 * ide_find_dma_mode - compute DMA speed
302 * @drive: IDE device
303 * @req_mode: requested mode
305 * Checks the drive/host capabilities and finds the speed to use for
306 * the DMA transfer. The speed is then limited by the requested mode.
308 * Returns 0 if the drive/host combination is incapable of DMA transfers
309 * or if the requested mode is not a DMA mode.
312 u8 ide_find_dma_mode(ide_drive_t *drive, u8 req_mode)
314 ide_hwif_t *hwif = drive->hwif;
315 unsigned int mask;
316 int x, i;
317 u8 mode = 0;
319 if (drive->media != ide_disk) {
320 if (hwif->host_flags & IDE_HFLAG_NO_ATAPI_DMA)
321 return 0;
324 for (i = 0; i < ARRAY_SIZE(xfer_mode_bases); i++) {
325 if (req_mode < xfer_mode_bases[i])
326 continue;
327 mask = ide_get_mode_mask(drive, xfer_mode_bases[i], req_mode);
328 x = fls(mask) - 1;
329 if (x >= 0) {
330 mode = xfer_mode_bases[i] + x;
331 break;
335 if (hwif->chipset == ide_acorn && mode == 0) {
337 * is this correct?
339 if (ide_dma_good_drive(drive) &&
340 drive->id[ATA_ID_EIDE_DMA_TIME] < 150)
341 mode = XFER_MW_DMA_1;
344 mode = min(mode, req_mode);
346 printk(KERN_INFO "%s: %s mode selected\n", drive->name,
347 mode ? ide_xfer_verbose(mode) : "no DMA");
349 return mode;
352 static int ide_tune_dma(ide_drive_t *drive)
354 ide_hwif_t *hwif = drive->hwif;
355 u8 speed;
357 if (ata_id_has_dma(drive->id) == 0 ||
358 (drive->dev_flags & IDE_DFLAG_NODMA))
359 return 0;
361 /* consult the list of known "bad" drives */
362 if (__ide_dma_bad_drive(drive))
363 return 0;
365 if (hwif->host_flags & IDE_HFLAG_TRUST_BIOS_FOR_DMA)
366 return config_drive_for_dma(drive);
368 speed = ide_max_dma_mode(drive);
370 if (!speed)
371 return 0;
373 if (ide_set_dma_mode(drive, speed))
374 return 0;
376 return 1;
379 static int ide_dma_check(ide_drive_t *drive)
381 ide_hwif_t *hwif = drive->hwif;
383 if (ide_tune_dma(drive))
384 return 0;
386 /* TODO: always do PIO fallback */
387 if (hwif->host_flags & IDE_HFLAG_TRUST_BIOS_FOR_DMA)
388 return -1;
390 ide_set_max_pio(drive);
392 return -1;
395 int ide_set_dma(ide_drive_t *drive)
397 int rc;
400 * Force DMAing for the beginning of the check.
401 * Some chipsets appear to do interesting
402 * things, if not checked and cleared.
403 * PARANOIA!!!
405 ide_dma_off_quietly(drive);
407 rc = ide_dma_check(drive);
408 if (rc)
409 return rc;
411 ide_dma_on(drive);
413 return 0;
416 void ide_check_dma_crc(ide_drive_t *drive)
418 u8 mode;
420 ide_dma_off_quietly(drive);
421 drive->crc_count = 0;
422 mode = drive->current_speed;
424 * Don't try non Ultra-DMA modes without iCRC's. Force the
425 * device to PIO and make the user enable SWDMA/MWDMA modes.
427 if (mode > XFER_UDMA_0 && mode <= XFER_UDMA_7)
428 mode--;
429 else
430 mode = XFER_PIO_4;
431 ide_set_xfer_rate(drive, mode);
432 if (drive->current_speed >= XFER_SW_DMA_0)
433 ide_dma_on(drive);
436 void ide_dma_lost_irq(ide_drive_t *drive)
438 printk(KERN_ERR "%s: DMA interrupt recovery\n", drive->name);
440 EXPORT_SYMBOL_GPL(ide_dma_lost_irq);
443 * un-busy the port etc, and clear any pending DMA status. we want to
444 * retry the current request in pio mode instead of risking tossing it
445 * all away
447 ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
449 ide_hwif_t *hwif = drive->hwif;
450 const struct ide_dma_ops *dma_ops = hwif->dma_ops;
451 struct ide_cmd *cmd = &hwif->cmd;
452 ide_startstop_t ret = ide_stopped;
455 * end current dma transaction
458 if (error < 0) {
459 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
460 drive->waiting_for_dma = 0;
461 (void)dma_ops->dma_end(drive);
462 ide_dma_unmap_sg(drive, cmd);
463 ret = ide_error(drive, "dma timeout error",
464 hwif->tp_ops->read_status(hwif));
465 } else {
466 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
467 if (dma_ops->dma_clear)
468 dma_ops->dma_clear(drive);
469 printk(KERN_ERR "%s: timeout waiting for DMA\n", drive->name);
470 if (dma_ops->dma_test_irq(drive) == 0) {
471 ide_dump_status(drive, "DMA timeout",
472 hwif->tp_ops->read_status(hwif));
473 drive->waiting_for_dma = 0;
474 (void)dma_ops->dma_end(drive);
475 ide_dma_unmap_sg(drive, cmd);
480 * disable dma for now, but remember that we did so because of
481 * a timeout -- we'll reenable after we finish this next request
482 * (or rather the first chunk of it) in pio.
484 drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY;
485 drive->retry_pio++;
486 ide_dma_off_quietly(drive);
489 * make sure request is sane
491 if (hwif->rq)
492 hwif->rq->errors = 0;
493 return ret;
496 void ide_release_dma_engine(ide_hwif_t *hwif)
498 if (hwif->dmatable_cpu) {
499 int prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
501 dma_free_coherent(hwif->dev, prd_size,
502 hwif->dmatable_cpu, hwif->dmatable_dma);
503 hwif->dmatable_cpu = NULL;
506 EXPORT_SYMBOL_GPL(ide_release_dma_engine);
508 int ide_allocate_dma_engine(ide_hwif_t *hwif)
510 int prd_size;
512 if (hwif->prd_max_nents == 0)
513 hwif->prd_max_nents = PRD_ENTRIES;
514 if (hwif->prd_ent_size == 0)
515 hwif->prd_ent_size = PRD_BYTES;
517 prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
519 hwif->dmatable_cpu = dma_alloc_coherent(hwif->dev, prd_size,
520 &hwif->dmatable_dma,
521 GFP_ATOMIC);
522 if (hwif->dmatable_cpu == NULL) {
523 printk(KERN_ERR "%s: unable to allocate PRD table\n",
524 hwif->name);
525 return -ENOMEM;
528 return 0;
530 EXPORT_SYMBOL_GPL(ide_allocate_dma_engine);
532 int ide_dma_prepare(ide_drive_t *drive, struct ide_cmd *cmd)
534 const struct ide_dma_ops *dma_ops = drive->hwif->dma_ops;
536 if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
537 (dma_ops->dma_check && dma_ops->dma_check(drive, cmd)))
538 goto out;
539 ide_map_sg(drive, cmd);
540 if (ide_dma_map_sg(drive, cmd) == 0)
541 goto out_map;
542 if (dma_ops->dma_setup(drive, cmd))
543 goto out_dma_unmap;
544 drive->waiting_for_dma = 1;
545 return 0;
546 out_dma_unmap:
547 ide_dma_unmap_sg(drive, cmd);
548 out_map:
549 ide_map_sg(drive, cmd);
550 out:
551 return 1;