root/drivers/ide/ide-dma.c

DEFINITIONS

1. ide_dma_intr
2. ide_dma_good_drive
3. ide_dma_map_sg
4. ide_dma_unmap_sg
5. ide_dma_off_quietly
6. ide_dma_off
7. ide_dma_on
8. __ide_dma_bad_drive
9. ide_get_mode_mask
10. ide_find_dma_mode
11. ide_tune_dma
12. ide_dma_check
13. ide_set_dma
14. ide_check_dma_crc
15. ide_dma_lost_irq
16. ide_dma_timeout_retry
17. ide_release_dma_engine
18. ide_allocate_dma_engine
19. ide_dma_prepare

   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/gfp.h>
  33 #include <linux/kernel.h>
  34 #include <linux/export.h>
  35 #include <linux/ide.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/dma-mapping.h>
  38 
  39 static const struct drive_list_entry drive_whitelist[] = {
  40         { "Micropolis 2112A"    ,       NULL            },
  41         { "CONNER CTMA 4000"    ,       NULL            },
  42         { "CONNER CTT8000-A"    ,       NULL            },
  43         { "ST34342A"            ,       NULL            },
  44         { NULL                  ,       NULL            }
  45 };
  46 
  47 static const struct drive_list_entry drive_blacklist[] = {
  48         { "WDC AC11000H"        ,       NULL            },
  49         { "WDC AC22100H"        ,       NULL            },
  50         { "WDC AC32500H"        ,       NULL            },
  51         { "WDC AC33100H"        ,       NULL            },
  52         { "WDC AC31600H"        ,       NULL            },
  53         { "WDC AC32100H"        ,       "24.09P07"      },
  54         { "WDC AC23200L"        ,       "21.10N21"      },
  55         { "Compaq CRD-8241B"    ,       NULL            },
  56         { "CRD-8400B"           ,       NULL            },
  57         { "CRD-8480B",                  NULL            },
  58         { "CRD-8482B",                  NULL            },
  59         { "CRD-84"              ,       NULL            },
  60         { "SanDisk SDP3B"       ,       NULL            },
  61         { "SanDisk SDP3B-64"    ,       NULL            },
  62         { "SANYO CD-ROM CRD"    ,       NULL            },
  63         { "HITACHI CDR-8"       ,       NULL            },
  64         { "HITACHI CDR-8335"    ,       NULL            },
  65         { "HITACHI CDR-8435"    ,       NULL            },
  66         { "Toshiba CD-ROM XM-6202B"     ,       NULL            },
  67         { "TOSHIBA CD-ROM XM-1702BC",   NULL            },
  68         { "CD-532E-A"           ,       NULL            },
  69         { "E-IDE CD-ROM CR-840",        NULL            },
  70         { "CD-ROM Drive/F5A",   NULL            },
  71         { "WPI CDD-820",                NULL            },
  72         { "SAMSUNG CD-ROM SC-148C",     NULL            },
  73         { "SAMSUNG CD-ROM SC",  NULL            },
  74         { "ATAPI CD-ROM DRIVE 40X MAXIMUM",     NULL            },
  75         { "_NEC DV5800A",               NULL            },
  76         { "SAMSUNG CD-ROM SN-124",      "N001" },
  77         { "Seagate STT20000A",          NULL  },
  78         { "CD-ROM CDR_U200",            "1.09" },
  79         { NULL                  ,       NULL            }
  80 
  81 };
  82 
  83 /**
  84  *      ide_dma_intr    -       IDE DMA interrupt handler
  85  *      @drive: the drive the interrupt is for
  86  *
  87  *      Handle an interrupt completing a read/write DMA transfer on an
  88  *      IDE device
  89  */
  90 
  91 ide_startstop_t ide_dma_intr(ide_drive_t *drive)
  92 {
  93         ide_hwif_t *hwif = drive->hwif;
  94         struct ide_cmd *cmd = &hwif->cmd;
  95         u8 stat = 0, dma_stat = 0;
  96 
  97         drive->waiting_for_dma = 0;
  98         dma_stat = hwif->dma_ops->dma_end(drive);
  99         ide_dma_unmap_sg(drive, cmd);
 100         stat = hwif->tp_ops->read_status(hwif);
 101 
 102         if (OK_STAT(stat, DRIVE_READY, drive->bad_wstat | ATA_DRQ)) {
 103                 if (!dma_stat) {
 104                         if ((cmd->tf_flags & IDE_TFLAG_FS) == 0)
 105                                 ide_finish_cmd(drive, cmd, stat);
 106                         else
 107                                 ide_complete_rq(drive, BLK_STS_OK,
 108                                                 blk_rq_sectors(cmd->rq) << 9);
 109                         return ide_stopped;
 110                 }
 111                 printk(KERN_ERR "%s: %s: bad DMA status (0x%02x)\n",
 112                         drive->name, __func__, dma_stat);
 113         }
 114         return ide_error(drive, "dma_intr", stat);
 115 }
 116 
 117 int ide_dma_good_drive(ide_drive_t *drive)
 118 {
 119         return ide_in_drive_list(drive->id, drive_whitelist);
 120 }
 121 
 122 /**
 123  *      ide_dma_map_sg  -       map IDE scatter gather for DMA I/O
 124  *      @drive: the drive to map the DMA table for
 125  *      @cmd: command
 126  *
 127  *      Perform the DMA mapping magic necessary to access the source or
 128  *      target buffers of a request via DMA.  The lower layers of the
 129  *      kernel provide the necessary cache management so that we can
 130  *      operate in a portable fashion.
 131  */
 132 
 133 static int ide_dma_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
 134 {
 135         ide_hwif_t *hwif = drive->hwif;
 136         struct scatterlist *sg = hwif->sg_table;
 137         int i;
 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) {
 146                 cmd->orig_sg_nents = cmd->sg_nents;
 147                 cmd->sg_nents = i;
 148         }
 149 
 150         return i;
 151 }
 152 
 153 /**
 154  *      ide_dma_unmap_sg        -       clean up DMA mapping
 155  *      @drive: The drive to unmap
 156  *
 157  *      Teardown mappings after DMA has completed. This must be called
 158  *      after the completion of each use of ide_build_dmatable and before
 159  *      the next use of ide_build_dmatable. Failure to do so will cause
 160  *      an oops as only one mapping can be live for each target at a given
 161  *      time.
 162  */
 163 
 164 void ide_dma_unmap_sg(ide_drive_t *drive, struct ide_cmd *cmd)
 165 {
 166         ide_hwif_t *hwif = drive->hwif;
 167 
 168         dma_unmap_sg(hwif->dev, hwif->sg_table, cmd->orig_sg_nents,
 169                      cmd->sg_dma_direction);
 170 }
 171 EXPORT_SYMBOL_GPL(ide_dma_unmap_sg);
 172 
 173 /**
 174  *      ide_dma_off_quietly     -       Generic DMA kill
 175  *      @drive: drive to control
 176  *
 177  *      Turn off the current DMA on this IDE controller.
 178  */
 179 
 180 void ide_dma_off_quietly(ide_drive_t *drive)
 181 {
 182         drive->dev_flags &= ~IDE_DFLAG_USING_DMA;
 183 
 184         drive->hwif->dma_ops->dma_host_set(drive, 0);
 185 }
 186 EXPORT_SYMBOL(ide_dma_off_quietly);
 187 
 188 /**
 189  *      ide_dma_off     -       disable DMA on a device
 190  *      @drive: drive to disable DMA on
 191  *
 192  *      Disable IDE DMA for a device on this IDE controller.
 193  *      Inform the user that DMA has been disabled.
 194  */
 195 
 196 void ide_dma_off(ide_drive_t *drive)
 197 {
 198         printk(KERN_INFO "%s: DMA disabled\n", drive->name);
 199         ide_dma_off_quietly(drive);
 200 }
 201 EXPORT_SYMBOL(ide_dma_off);
 202 
 203 /**
 204  *      ide_dma_on              -       Enable DMA on a device
 205  *      @drive: drive to enable DMA on
 206  *
 207  *      Enable IDE DMA for a device on this IDE controller.
 208  */
 209 
 210 void ide_dma_on(ide_drive_t *drive)
 211 {
 212         drive->dev_flags |= IDE_DFLAG_USING_DMA;
 213 
 214         drive->hwif->dma_ops->dma_host_set(drive, 1);
 215 }
 216 
 217 int __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 }
 229 EXPORT_SYMBOL(__ide_dma_bad_drive);
 230 
 231 static const u8 xfer_mode_bases[] = {
 232         XFER_UDMA_0,
 233         XFER_MW_DMA_0,
 234         XFER_SW_DMA_0,
 235 };
 236 
 237 static 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 
 311 u8 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 }
 350 
 351 static int ide_tune_dma(ide_drive_t *drive)
 352 {
 353         ide_hwif_t *hwif = drive->hwif;
 354         u8 speed;
 355 
 356         if (ata_id_has_dma(drive->id) == 0 ||
 357             (drive->dev_flags & IDE_DFLAG_NODMA))
 358                 return 0;
 359 
 360         /* consult the list of known "bad" drives */
 361         if (__ide_dma_bad_drive(drive))
 362                 return 0;
 363 
 364         if (hwif->host_flags & IDE_HFLAG_TRUST_BIOS_FOR_DMA)
 365                 return config_drive_for_dma(drive);
 366 
 367         speed = ide_max_dma_mode(drive);
 368 
 369         if (!speed)
 370                 return 0;
 371 
 372         if (ide_set_dma_mode(drive, speed))
 373                 return 0;
 374 
 375         return 1;
 376 }
 377 
 378 static int ide_dma_check(ide_drive_t *drive)
 379 {
 380         ide_hwif_t *hwif = drive->hwif;
 381 
 382         if (ide_tune_dma(drive))
 383                 return 0;
 384 
 385         /* TODO: always do PIO fallback */
 386         if (hwif->host_flags & IDE_HFLAG_TRUST_BIOS_FOR_DMA)
 387                 return -1;
 388 
 389         ide_set_max_pio(drive);
 390 
 391         return -1;
 392 }
 393 
 394 int ide_set_dma(ide_drive_t *drive)
 395 {
 396         int rc;
 397 
 398         /*
 399          * Force DMAing for the beginning of the check.
 400          * Some chipsets appear to do interesting
 401          * things, if not checked and cleared.
 402          *   PARANOIA!!!
 403          */
 404         ide_dma_off_quietly(drive);
 405 
 406         rc = ide_dma_check(drive);
 407         if (rc)
 408                 return rc;
 409 
 410         ide_dma_on(drive);
 411 
 412         return 0;
 413 }
 414 
 415 void ide_check_dma_crc(ide_drive_t *drive)
 416 {
 417         u8 mode;
 418 
 419         ide_dma_off_quietly(drive);
 420         drive->crc_count = 0;
 421         mode = drive->current_speed;
 422         /*
 423          * Don't try non Ultra-DMA modes without iCRC's.  Force the
 424          * device to PIO and make the user enable SWDMA/MWDMA modes.
 425          */
 426         if (mode > XFER_UDMA_0 && mode <= XFER_UDMA_7)
 427                 mode--;
 428         else
 429                 mode = XFER_PIO_4;
 430         ide_set_xfer_rate(drive, mode);
 431         if (drive->current_speed >= XFER_SW_DMA_0)
 432                 ide_dma_on(drive);
 433 }
 434 
 435 void ide_dma_lost_irq(ide_drive_t *drive)
 436 {
 437         printk(KERN_ERR "%s: DMA interrupt recovery\n", drive->name);
 438 }
 439 EXPORT_SYMBOL_GPL(ide_dma_lost_irq);
 440 
 441 /*
 442  * un-busy the port etc, and clear any pending DMA status. we want to
 443  * retry the current request in pio mode instead of risking tossing it
 444  * all away
 445  */
 446 ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
 447 {
 448         ide_hwif_t *hwif = drive->hwif;
 449         const struct ide_dma_ops *dma_ops = hwif->dma_ops;
 450         struct ide_cmd *cmd = &hwif->cmd;
 451         ide_startstop_t ret = ide_stopped;
 452 
 453         /*
 454          * end current dma transaction
 455          */
 456 
 457         if (error < 0) {
 458                 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
 459                 drive->waiting_for_dma = 0;
 460                 (void)dma_ops->dma_end(drive);
 461                 ide_dma_unmap_sg(drive, cmd);
 462                 ret = ide_error(drive, "dma timeout error",
 463                                 hwif->tp_ops->read_status(hwif));
 464         } else {
 465                 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
 466                 if (dma_ops->dma_clear)
 467                         dma_ops->dma_clear(drive);
 468                 printk(KERN_ERR "%s: timeout waiting for DMA\n", drive->name);
 469                 if (dma_ops->dma_test_irq(drive) == 0) {
 470                         ide_dump_status(drive, "DMA timeout",
 471                                         hwif->tp_ops->read_status(hwif));
 472                         drive->waiting_for_dma = 0;
 473                         (void)dma_ops->dma_end(drive);
 474                         ide_dma_unmap_sg(drive, cmd);
 475                 }
 476         }
 477 
 478         /*
 479          * disable dma for now, but remember that we did so because of
 480          * a timeout -- we'll reenable after we finish this next request
 481          * (or rather the first chunk of it) in pio.
 482          */
 483         drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY;
 484         drive->retry_pio++;
 485         ide_dma_off_quietly(drive);
 486 
 487         /*
 488          * make sure request is sane
 489          */
 490         if (hwif->rq)
 491                 scsi_req(hwif->rq)->result = 0;
 492         return ret;
 493 }
 494 
 495 void ide_release_dma_engine(ide_hwif_t *hwif)
 496 {
 497         if (hwif->dmatable_cpu) {
 498                 int prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
 499 
 500                 dma_free_coherent(hwif->dev, prd_size,
 501                                   hwif->dmatable_cpu, hwif->dmatable_dma);
 502                 hwif->dmatable_cpu = NULL;
 503         }
 504 }
 505 EXPORT_SYMBOL_GPL(ide_release_dma_engine);
 506 
 507 int ide_allocate_dma_engine(ide_hwif_t *hwif)
 508 {
 509         int prd_size;
 510 
 511         if (hwif->prd_max_nents == 0)
 512                 hwif->prd_max_nents = PRD_ENTRIES;
 513         if (hwif->prd_ent_size == 0)
 514                 hwif->prd_ent_size = PRD_BYTES;
 515 
 516         prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
 517 
 518         hwif->dmatable_cpu = dma_alloc_coherent(hwif->dev, prd_size,
 519                                                 &hwif->dmatable_dma,
 520                                                 GFP_ATOMIC);
 521         if (hwif->dmatable_cpu == NULL) {
 522                 printk(KERN_ERR "%s: unable to allocate PRD table\n",
 523                         hwif->name);
 524                 return -ENOMEM;
 525         }
 526 
 527         return 0;
 528 }
 529 EXPORT_SYMBOL_GPL(ide_allocate_dma_engine);
 530 
 531 int ide_dma_prepare(ide_drive_t *drive, struct ide_cmd *cmd)
 532 {
 533         const struct ide_dma_ops *dma_ops = drive->hwif->dma_ops;
 534 
 535         if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
 536             (dma_ops->dma_check && dma_ops->dma_check(drive, cmd)))
 537                 goto out;
 538         ide_map_sg(drive, cmd);
 539         if (ide_dma_map_sg(drive, cmd) == 0)
 540                 goto out_map;
 541         if (dma_ops->dma_setup(drive, cmd))
 542                 goto out_dma_unmap;
 543         drive->waiting_for_dma = 1;
 544         return 0;
 545 out_dma_unmap:
 546         ide_dma_unmap_sg(drive, cmd);
 547 out_map:
 548         ide_map_sg(drive, cmd);
 549 out:
 550         return 1;
 551 }