drivers/usb/storage/scsiglue.c

   1 /* Driver for USB Mass Storage compliant devices
   2  * SCSI layer glue code
   3  *
   4  * Current development and maintenance by:
   5  *   (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
   6  *
   7  * Developed with the assistance of:
   8  *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
   9  *   (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
  10  *
  11  * Initial work by:
  12  *   (c) 1999 Michael Gee (michael@linuxspecific.com)
  13  *
  14  * This driver is based on the 'USB Mass Storage Class' document. This
  15  * describes in detail the protocol used to communicate with such
  16  * devices.  Clearly, the designers had SCSI and ATAPI commands in
  17  * mind when they created this document.  The commands are all very
  18  * similar to commands in the SCSI-II and ATAPI specifications.
  19  *
  20  * It is important to note that in a number of cases this class
  21  * exhibits class-specific exemptions from the USB specification.
  22  * Notably the usage of NAK, STALL and ACK differs from the norm, in
  23  * that they are used to communicate wait, failed and OK on commands.
  24  *
  25  * Also, for certain devices, the interrupt endpoint is used to convey
  26  * status of a command.
  27  *
  28  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
  29  * information about this driver.
  30  *
  31  * This program is free software; you can redistribute it and/or modify it
  32  * under the terms of the GNU General Public License as published by the
  33  * Free Software Foundation; either version 2, or (at your option) any
  34  * later version.
  35  *
  36  * This program is distributed in the hope that it will be useful, but
  37  * WITHOUT ANY WARRANTY; without even the implied warranty of
  38  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  39  * General Public License for more details.
  40  *
  41  * You should have received a copy of the GNU General Public License along
  42  * with this program; if not, write to the Free Software Foundation, Inc.,
  43  * 675 Mass Ave, Cambridge, MA 02139, USA.
  44  */
  45
  46 #include <linux/module.h>
  47 #include <linux/mutex.h>
  48
  49 #include <scsi/scsi.h>
  50 #include <scsi/scsi_cmnd.h>
  51 #include <scsi/scsi_devinfo.h>
  52 #include <scsi/scsi_device.h>
  53 #include <scsi/scsi_eh.h>
  54
  55 #include "usb.h"
  56 #include "scsiglue.h"
  57 #include "debug.h"
  58 #include "transport.h"
  59 #include "protocol.h"
  60
  61 /* Vendor IDs for companies that seem to include the READ CAPACITY bug
  62  * in all their devices
  63  */
  64 #define VENDOR_ID_NOKIA         0x0421
  65 #define VENDOR_ID_NIKON         0x04b0
  66 #define VENDOR_ID_PENTAX        0x0a17
  67 #define VENDOR_ID_MOTOROLA      0x22b8
  68
  69 /***********************************************************************
  70  * Host functions
  71  ***********************************************************************/
  72
  73 static const char* host_info(struct Scsi_Host *host)
  74 {
  75         struct us_data *us = host_to_us(host);
  76         return us->scsi_name;
  77 }
  78
  79 static int slave_alloc (struct scsi_device *sdev)
  80 {
  81         /*
  82          * Set the INQUIRY transfer length to 36.  We don't use any of
  83          * the extra data and many devices choke if asked for more or
  84          * less than 36 bytes.
  85          */
  86         sdev->inquiry_len = 36;
  87
  88         /* USB has unusual DMA-alignment requirements: Although the
  89          * starting address of each scatter-gather element doesn't matter,
  90          * the length of each element except the last must be divisible
  91          * by the Bulk maxpacket value.  There's currently no way to
  92          * express this by block-layer constraints, so we'll cop out
  93          * and simply require addresses to be aligned at 512-byte
  94          * boundaries.  This is okay since most block I/O involves
  95          * hardware sectors that are multiples of 512 bytes in length,
  96          * and since host controllers up through USB 2.0 have maxpacket
  97          * values no larger than 512.
  98          *
  99          * But it doesn't suffice for Wireless USB, where Bulk maxpacket
 100          * values can be as large as 2048.  To make that work properly
 101          * will require changes to the block layer.
 102          */
 103         blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
 104
 105         return 0;
 106 }
 107
 108 static int slave_configure(struct scsi_device *sdev)
 109 {
 110         struct us_data *us = host_to_us(sdev->host);
 111
 112         /* Many devices have trouble transferring more than 32KB at a time,
 113          * while others have trouble with more than 64K. At this time we
 114          * are limiting both to 32K (64 sectores).
 115          */
 116         if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
 117                 unsigned int max_sectors = 64;
 118
 119                 if (us->fflags & US_FL_MAX_SECTORS_MIN)
 120                         max_sectors = PAGE_CACHE_SIZE >> 9;
 121                 if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
 122                         blk_queue_max_hw_sectors(sdev->request_queue,
 123                                               max_sectors);
 124         } else if (sdev->type == TYPE_TAPE) {
 125                 /* Tapes need much higher max_sector limits, so just
 126                  * raise it to the maximum possible (4 GB / 512) and
 127                  * let the queue segment size sort out the real limit.
 128                  */
 129                 blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
 130         }
 131
 132         /* Some USB host controllers can't do DMA; they have to use PIO.
 133          * They indicate this by setting their dma_mask to NULL.  For
 134          * such controllers we need to make sure the block layer sets
 135          * up bounce buffers in addressable memory.
 136          */
 137         if (!us->pusb_dev->bus->controller->dma_mask)
 138                 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
 139
 140         /* We can't put these settings in slave_alloc() because that gets
 141          * called before the device type is known.  Consequently these
 142          * settings can't be overridden via the scsi devinfo mechanism. */
 143         if (sdev->type == TYPE_DISK) {
 144
 145                 /* Some vendors seem to put the READ CAPACITY bug into
 146                  * all their devices -- primarily makers of cell phones
 147                  * and digital cameras.  Since these devices always use
 148                  * flash media and can be expected to have an even number
 149                  * of sectors, we will always enable the CAPACITY_HEURISTICS
 150                  * flag unless told otherwise. */
 151                 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
 152                 case VENDOR_ID_NOKIA:
 153                 case VENDOR_ID_NIKON:
 154                 case VENDOR_ID_PENTAX:
 155                 case VENDOR_ID_MOTOROLA:
 156                         if (!(us->fflags & (US_FL_FIX_CAPACITY |
 157                                         US_FL_CAPACITY_OK)))
 158                                 us->fflags |= US_FL_CAPACITY_HEURISTICS;
 159                         break;
 160                 }
 161
 162                 /* Disk-type devices use MODE SENSE(6) if the protocol
 163                  * (SubClass) is Transparent SCSI, otherwise they use
 164                  * MODE SENSE(10). */
 165                 if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
 166                         sdev->use_10_for_ms = 1;
 167
 168                 /* Many disks only accept MODE SENSE transfer lengths of
 169                  * 192 bytes (that's what Windows uses). */
 170                 sdev->use_192_bytes_for_3f = 1;
 171
 172                 /* Some devices don't like MODE SENSE with page=0x3f,
 173                  * which is the command used for checking if a device
 174                  * is write-protected.  Now that we tell the sd driver
 175                  * to do a 192-byte transfer with this command the
 176                  * majority of devices work fine, but a few still can't
 177                  * handle it.  The sd driver will simply assume those
 178                  * devices are write-enabled. */
 179                 if (us->fflags & US_FL_NO_WP_DETECT)
 180                         sdev->skip_ms_page_3f = 1;
 181
 182                 /* A number of devices have problems with MODE SENSE for
 183                  * page x08, so we will skip it. */
 184                 sdev->skip_ms_page_8 = 1;
 185
 186                 /* Some devices don't handle VPD pages correctly */
 187                 sdev->skip_vpd_pages = 1;
 188
 189                 /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
 190                 sdev->no_report_opcodes = 1;
 191
 192                 /* Do not attempt to use WRITE SAME */
 193                 sdev->no_write_same = 1;
 194
 195                 /* Some disks return the total number of blocks in response
 196                  * to READ CAPACITY rather than the highest block number.
 197                  * If this device makes that mistake, tell the sd driver. */
 198                 if (us->fflags & US_FL_FIX_CAPACITY)
 199                         sdev->fix_capacity = 1;
 200
 201                 /* A few disks have two indistinguishable version, one of
 202                  * which reports the correct capacity and the other does not.
 203                  * The sd driver has to guess which is the case. */
 204                 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
 205                         sdev->guess_capacity = 1;
 206
 207                 /* Some devices cannot handle READ_CAPACITY_16 */
 208                 if (us->fflags & US_FL_NO_READ_CAPACITY_16)
 209                         sdev->no_read_capacity_16 = 1;
 210
 211                 /*
 212                  * Many devices do not respond properly to READ_CAPACITY_16.
 213                  * Tell the SCSI layer to try READ_CAPACITY_10 first.
 214                  */
 215                 sdev->try_rc_10_first = 1;
 216
 217                 /* assume SPC3 or latter devices support sense size > 18 */
 218                 if (sdev->scsi_level > SCSI_SPC_2)
 219                         us->fflags |= US_FL_SANE_SENSE;
 220
 221                 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
 222                  * Hardware Error) when any low-level error occurs,
 223                  * recoverable or not.  Setting this flag tells the SCSI
 224                  * midlayer to retry such commands, which frequently will
 225                  * succeed and fix the error.  The worst this can lead to
 226                  * is an occasional series of retries that will all fail. */
 227                 sdev->retry_hwerror = 1;
 228
 229                 /* USB disks should allow restart.  Some drives spin down
 230                  * automatically, requiring a START-STOP UNIT command. */
 231                 sdev->allow_restart = 1;
 232
 233                 /* Some USB cardreaders have trouble reading an sdcard's last
 234                  * sector in a larger then 1 sector read, since the performance
 235                  * impact is negible we set this flag for all USB disks */
 236                 sdev->last_sector_bug = 1;
 237
 238                 /* Enable last-sector hacks for single-target devices using
 239                  * the Bulk-only transport, unless we already know the
 240                  * capacity will be decremented or is correct. */
 241                 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
 242                                         US_FL_SCM_MULT_TARG)) &&
 243                                 us->protocol == USB_PR_BULK)
 244                         us->use_last_sector_hacks = 1;
 245
 246                 /* Check if write cache default on flag is set or not */
 247                 if (us->fflags & US_FL_WRITE_CACHE)
 248                         sdev->wce_default_on = 1;
 249
 250         } else {
 251
 252                 /* Non-disk-type devices don't need to blacklist any pages
 253                  * or to force 192-byte transfer lengths for MODE SENSE.
 254                  * But they do need to use MODE SENSE(10). */
 255                 sdev->use_10_for_ms = 1;
 256
 257                 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
 258                 if (us->fflags & US_FL_NO_READ_DISC_INFO)
 259                         sdev->no_read_disc_info = 1;
 260         }
 261
 262         /* The CB and CBI transports have no way to pass LUN values
 263          * other than the bits in the second byte of a CDB.  But those
 264          * bits don't get set to the LUN value if the device reports
 265          * scsi_level == 0 (UNKNOWN).  Hence such devices must necessarily
 266          * be single-LUN.
 267          */
 268         if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
 269                         sdev->scsi_level == SCSI_UNKNOWN)
 270                 us->max_lun = 0;
 271
 272         /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
 273          * REMOVAL command, so suppress those commands. */
 274         if (us->fflags & US_FL_NOT_LOCKABLE)
 275                 sdev->lockable = 0;
 276
 277         /* this is to satisfy the compiler, tho I don't think the
 278          * return code is ever checked anywhere. */
 279         return 0;
 280 }
 281
 282 static int target_alloc(struct scsi_target *starget)
 283 {
 284         struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
 285
 286         /*
 287          * Some USB drives don't support REPORT LUNS, even though they
 288          * report a SCSI revision level above 2.  Tell the SCSI layer
 289          * not to issue that command; it will perform a normal sequential
 290          * scan instead.
 291          */
 292         starget->no_report_luns = 1;
 293
 294         /*
 295          * The UFI spec treats the Peripheral Qualifier bits in an
 296          * INQUIRY result as reserved and requires devices to set them
 297          * to 0.  However the SCSI spec requires these bits to be set
 298          * to 3 to indicate when a LUN is not present.
 299          *
 300          * Let the scanning code know if this target merely sets
 301          * Peripheral Device Type to 0x1f to indicate no LUN.
 302          */
 303         if (us->subclass == USB_SC_UFI)
 304                 starget->pdt_1f_for_no_lun = 1;
 305
 306         return 0;
 307 }
 308
 309 /* queue a command */
 310 /* This is always called with scsi_lock(host) held */
 311 static int queuecommand_lck(struct scsi_cmnd *srb,
 312                         void (*done)(struct scsi_cmnd *))
 313 {
 314         struct us_data *us = host_to_us(srb->device->host);
 315
 316         /* check for state-transition errors */
 317         if (us->srb != NULL) {
 318                 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
 319                         __func__, us->srb);
 320                 return SCSI_MLQUEUE_HOST_BUSY;
 321         }
 322
 323         /* fail the command if we are disconnecting */
 324         if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
 325                 usb_stor_dbg(us, "Fail command during disconnect\n");
 326                 srb->result = DID_NO_CONNECT << 16;
 327                 done(srb);
 328                 return 0;
 329         }
 330
 331         /* enqueue the command and wake up the control thread */
 332         srb->scsi_done = done;
 333         us->srb = srb;
 334         complete(&us->cmnd_ready);
 335
 336         return 0;
 337 }
 338
 339 static DEF_SCSI_QCMD(queuecommand)
 340
 341 /***********************************************************************
 342  * Error handling functions
 343  ***********************************************************************/
 344
 345 /* Command timeout and abort */
 346 static int command_abort(struct scsi_cmnd *srb)
 347 {
 348         struct us_data *us = host_to_us(srb->device->host);
 349
 350         usb_stor_dbg(us, "%s called\n", __func__);
 351
 352         /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
 353          * bits are protected by the host lock. */
 354         scsi_lock(us_to_host(us));
 355
 356         /* Is this command still active? */
 357         if (us->srb != srb) {
 358                 scsi_unlock(us_to_host(us));
 359                 usb_stor_dbg(us, "-- nothing to abort\n");
 360                 return FAILED;
 361         }
 362
 363         /* Set the TIMED_OUT bit.  Also set the ABORTING bit, but only if
 364          * a device reset isn't already in progress (to avoid interfering
 365          * with the reset).  Note that we must retain the host lock while
 366          * calling usb_stor_stop_transport(); otherwise it might interfere
 367          * with an auto-reset that begins as soon as we release the lock. */
 368         set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
 369         if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
 370                 set_bit(US_FLIDX_ABORTING, &us->dflags);
 371                 usb_stor_stop_transport(us);
 372         }
 373         scsi_unlock(us_to_host(us));
 374
 375         /* Wait for the aborted command to finish */
 376         wait_for_completion(&us->notify);
 377         return SUCCESS;
 378 }
 379
 380 /* This invokes the transport reset mechanism to reset the state of the
 381  * device */
 382 static int device_reset(struct scsi_cmnd *srb)
 383 {
 384         struct us_data *us = host_to_us(srb->device->host);
 385         int result;
 386
 387         usb_stor_dbg(us, "%s called\n", __func__);
 388
 389         /* lock the device pointers and do the reset */
 390         mutex_lock(&(us->dev_mutex));
 391         result = us->transport_reset(us);
 392         mutex_unlock(&us->dev_mutex);
 393
 394         return result < 0 ? FAILED : SUCCESS;
 395 }
 396
 397 /* Simulate a SCSI bus reset by resetting the device's USB port. */
 398 static int bus_reset(struct scsi_cmnd *srb)
 399 {
 400         struct us_data *us = host_to_us(srb->device->host);
 401         int result;
 402
 403         usb_stor_dbg(us, "%s called\n", __func__);
 404
 405         result = usb_stor_port_reset(us);
 406         return result < 0 ? FAILED : SUCCESS;
 407 }
 408
 409 /* Report a driver-initiated device reset to the SCSI layer.
 410  * Calling this for a SCSI-initiated reset is unnecessary but harmless.
 411  * The caller must own the SCSI host lock. */
 412 void usb_stor_report_device_reset(struct us_data *us)
 413 {
 414         int i;
 415         struct Scsi_Host *host = us_to_host(us);
 416
 417         scsi_report_device_reset(host, 0, 0);
 418         if (us->fflags & US_FL_SCM_MULT_TARG) {
 419                 for (i = 1; i < host->max_id; ++i)
 420                         scsi_report_device_reset(host, 0, i);
 421         }
 422 }
 423
 424 /* Report a driver-initiated bus reset to the SCSI layer.
 425  * Calling this for a SCSI-initiated reset is unnecessary but harmless.
 426  * The caller must not own the SCSI host lock. */
 427 void usb_stor_report_bus_reset(struct us_data *us)
 428 {
 429         struct Scsi_Host *host = us_to_host(us);
 430
 431         scsi_lock(host);
 432         scsi_report_bus_reset(host, 0);
 433         scsi_unlock(host);
 434 }
 435
 436 /***********************************************************************
 437  * /proc/scsi/ functions
 438  ***********************************************************************/
 439
 440 static int write_info(struct Scsi_Host *host, char *buffer, int length)
 441 {
 442         /* if someone is sending us data, just throw it away */
 443         return length;
 444 }
 445
 446 /* we use this macro to help us write into the buffer */
 447 #undef SPRINTF
 448 #define SPRINTF(args...) seq_printf(m, ## args)
 449
 450 static int show_info (struct seq_file *m, struct Scsi_Host *host)
 451 {
 452         struct us_data *us = host_to_us(host);
 453         const char *string;
 454
 455         /* print the controller name */
 456         SPRINTF("   Host scsi%d: usb-storage\n", host->host_no);
 457
 458         /* print product, vendor, and serial number strings */
 459         if (us->pusb_dev->manufacturer)
 460                 string = us->pusb_dev->manufacturer;
 461         else if (us->unusual_dev->vendorName)
 462                 string = us->unusual_dev->vendorName;
 463         else
 464                 string = "Unknown";
 465         SPRINTF("       Vendor: %s\n", string);
 466         if (us->pusb_dev->product)
 467                 string = us->pusb_dev->product;
 468         else if (us->unusual_dev->productName)
 469                 string = us->unusual_dev->productName;
 470         else
 471                 string = "Unknown";
 472         SPRINTF("      Product: %s\n", string);
 473         if (us->pusb_dev->serial)
 474                 string = us->pusb_dev->serial;
 475         else
 476                 string = "None";
 477         SPRINTF("Serial Number: %s\n", string);
 478
 479         /* show the protocol and transport */
 480         SPRINTF("     Protocol: %s\n", us->protocol_name);
 481         SPRINTF("    Transport: %s\n", us->transport_name);
 482
 483         /* show the device flags */
 484         SPRINTF("       Quirks:");
 485
 486 #define US_FLAG(name, value) \
 487         if (us->fflags & value) seq_printf(m, " " #name);
 488 US_DO_ALL_FLAGS
 489 #undef US_FLAG
 490         seq_putc(m, '\n');
 491         return 0;
 492 }
 493
 494 /***********************************************************************
 495  * Sysfs interface
 496  ***********************************************************************/
 497
 498 /* Output routine for the sysfs max_sectors file */
 499 static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf)
 500 {
 501         struct scsi_device *sdev = to_scsi_device(dev);
 502
 503         return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
 504 }
 505
 506 /* Input routine for the sysfs max_sectors file */
 507 static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf,
 508                 size_t count)
 509 {
 510         struct scsi_device *sdev = to_scsi_device(dev);
 511         unsigned short ms;
 512
 513         if (sscanf(buf, "%hu", &ms) > 0) {
 514                 blk_queue_max_hw_sectors(sdev->request_queue, ms);
 515                 return count;
 516         }
 517         return -EINVAL;
 518 }
 519
 520 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
 521                 store_max_sectors);
 522
 523 static struct device_attribute *sysfs_device_attr_list[] = {
 524                 &dev_attr_max_sectors,
 525                 NULL,
 526                 };
 527
 528 /*
 529  * this defines our host template, with which we'll allocate hosts
 530  */
 531
 532 struct scsi_host_template usb_stor_host_template = {
 533         /* basic userland interface stuff */
 534         .name =                         "usb-storage",
 535         .proc_name =                    "usb-storage",
 536         .show_info =                    show_info,
 537         .write_info =                   write_info,
 538         .info =                         host_info,
 539
 540         /* command interface -- queued only */
 541         .queuecommand =                 queuecommand,
 542
 543         /* error and abort handlers */
 544         .eh_abort_handler =             command_abort,
 545         .eh_device_reset_handler =      device_reset,
 546         .eh_bus_reset_handler =         bus_reset,
 547
 548         /* queue commands only, only one command per LUN */
 549         .can_queue =                    1,
 550         .cmd_per_lun =                  1,
 551
 552         /* unknown initiator id */
 553         .this_id =                      -1,
 554
 555         .slave_alloc =                  slave_alloc,
 556         .slave_configure =              slave_configure,
 557         .target_alloc =                 target_alloc,
 558
 559         /* lots of sg segments can be handled */
 560         .sg_tablesize =                 SCSI_MAX_SG_CHAIN_SEGMENTS,
 561
 562         /* limit the total size of a transfer to 120 KB */
 563         .max_sectors =                  240,
 564
 565         /* merge commands... this seems to help performance, but
 566          * periodically someone should test to see which setting is more
 567          * optimal.
 568          */
 569         .use_clustering =               1,
 570
 571         /* emulated HBA */
 572         .emulated =                     1,
 573
 574         /* we do our own delay after a device or bus reset */
 575         .skip_settle_delay =            1,
 576
 577         /* sysfs device attributes */
 578         .sdev_attrs =                   sysfs_device_attr_list,
 579
 580         /* module management */
 581         .module =                       THIS_MODULE
 582 };
 583
 584 /* To Report "Illegal Request: Invalid Field in CDB */
 585 unsigned char usb_stor_sense_invalidCDB[18] = {
 586         [0]     = 0x70,                     /* current error */
 587         [2]     = ILLEGAL_REQUEST,          /* Illegal Request = 0x05 */
 588         [7]     = 0x0a,                     /* additional length */
 589         [12]    = 0x24                      /* Invalid Field in CDB */
 590 };
 591 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);