release/src-rt-6.x/linux/linux-2.6/drivers/usb/storage/scsiglue.c

   1 /* Driver for USB Mass Storage compliant devices
   2  * SCSI layer glue code
   3  *
   4  * $Id: scsiglue.c,v 1.26 2002/04/22 03:39:43 mdharm Exp $
   5  *
   6  * Current development and maintenance by:
   7  *   (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
   8  *
   9  * Developed with the assistance of:
  10  *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
  11  *   (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
  12  *
  13  * Initial work by:
  14  *   (c) 1999 Michael Gee (michael@linuxspecific.com)
  15  *
  16  * This driver is based on the 'USB Mass Storage Class' document. This
  17  * describes in detail the protocol used to communicate with such
  18  * devices.  Clearly, the designers had SCSI and ATAPI commands in
  19  * mind when they created this document.  The commands are all very
  20  * similar to commands in the SCSI-II and ATAPI specifications.
  21  *
  22  * It is important to note that in a number of cases this class
  23  * exhibits class-specific exemptions from the USB specification.
  24  * Notably the usage of NAK, STALL and ACK differs from the norm, in
  25  * that they are used to communicate wait, failed and OK on commands.
  26  *
  27  * Also, for certain devices, the interrupt endpoint is used to convey
  28  * status of a command.
  29  *
  30  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
  31  * information about this driver.
  32  *
  33  * This program is free software; you can redistribute it and/or modify it
  34  * under the terms of the GNU General Public License as published by the
  35  * Free Software Foundation; either version 2, or (at your option) any
  36  * later version.
  37  *
  38  * This program is distributed in the hope that it will be useful, but
  39  * WITHOUT ANY WARRANTY; without even the implied warranty of
  40  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  41  * General Public License for more details.
  42  *
  43  * You should have received a copy of the GNU General Public License along
  44  * with this program; if not, write to the Free Software Foundation, Inc.,
  45  * 675 Mass Ave, Cambridge, MA 02139, USA.
  46  */
  47
  48 #include <linux/slab.h>
  49 #include <linux/module.h>
  50 #include <linux/mutex.h>
  51
  52 #include <scsi/scsi.h>
  53 #include <scsi/scsi_cmnd.h>
  54 #include <scsi/scsi_devinfo.h>
  55 #include <scsi/scsi_device.h>
  56 #include <scsi/scsi_eh.h>
  57
  58 #include "usb.h"
  59 #include "scsiglue.h"
  60 #include "debug.h"
  61 #include "transport.h"
  62 #include "protocol.h"
  63
  64 /* Vendor IDs for companies that seem to include the READ CAPACITY bug
  65  * in all their devices
  66  */
  67 #define VENDOR_ID_NOKIA         0x0421
  68 #define VENDOR_ID_NIKON         0x04b0
  69 #define VENDOR_ID_PENTAX        0x0a17
  70 #define VENDOR_ID_MOTOROLA      0x22b8
  71
  72 /***********************************************************************
  73  * Host functions
  74  ***********************************************************************/
  75
  76 static const char* host_info(struct Scsi_Host *host)
  77 {
  78         return "SCSI emulation for USB Mass Storage devices";
  79 }
  80
  81 static int slave_alloc (struct scsi_device *sdev)
  82 {
  83         struct us_data *us = host_to_us(sdev->host);
  84         struct usb_host_endpoint *bulk_in_ep;
  85
  86         /*
  87          * Set the INQUIRY transfer length to 36.  We don't use any of
  88          * the extra data and many devices choke if asked for more or
  89          * less than 36 bytes.
  90          */
  91         sdev->inquiry_len = 36;
  92
  93         /* Scatter-gather buffers (all but the last) must have a length
  94          * divisible by the bulk maxpacket size.  Otherwise a data packet
  95          * would end up being short, causing a premature end to the data
  96          * transfer.  We'll use the maxpacket value of the bulk-IN pipe
  97          * to set the SCSI device queue's DMA alignment mask.
  98          */
  99         bulk_in_ep = us->pusb_dev->ep_in[usb_pipeendpoint(us->recv_bulk_pipe)];
 100         blk_queue_update_dma_alignment(sdev->request_queue,
 101                         le16_to_cpu(bulk_in_ep->desc.wMaxPacketSize) - 1);
 102                         /* wMaxPacketSize must be a power of 2 */
 103
 104         /*
 105          * The UFI spec treates the Peripheral Qualifier bits in an
 106          * INQUIRY result as reserved and requires devices to set them
 107          * to 0.  However the SCSI spec requires these bits to be set
 108          * to 3 to indicate when a LUN is not present.
 109          *
 110          * Let the scanning code know if this target merely sets
 111          * Peripheral Device Type to 0x1f to indicate no LUN.
 112          */
 113         if (us->subclass == US_SC_UFI)
 114                 sdev->sdev_target->pdt_1f_for_no_lun = 1;
 115
 116         return 0;
 117 }
 118
 119 static int slave_configure(struct scsi_device *sdev)
 120 {
 121         struct us_data *us = host_to_us(sdev->host);
 122
 123         /* Many devices have trouble transfering more than 32KB at a time,
 124          * while others have trouble with more than 64K. At this time we
 125          * are limiting both to 32K (64 sectores).
 126          */
 127         if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
 128                 unsigned int max_sectors = 64;
 129
 130                 if (us->fflags & US_FL_MAX_SECTORS_MIN)
 131                         max_sectors = PAGE_CACHE_SIZE >> 9;
 132                 if (sdev->request_queue->max_sectors > max_sectors)
 133                         blk_queue_max_sectors(sdev->request_queue,
 134                                               max_sectors);
 135         } else if (sdev->type == TYPE_TAPE) {
 136                 /* Tapes need much higher max_sector limits, so just
 137                  * raise it to the maximum possible (4 GB / 512) and
 138                  * let the queue segment size sort out the real limit.
 139                  */
 140                 blk_queue_max_sectors(sdev->request_queue, 0x7FFFFF);
 141         }
 142
 143         /* Some USB host controllers can't do DMA; they have to use PIO.
 144          * They indicate this by setting their dma_mask to NULL.  For
 145          * such controllers we need to make sure the block layer sets
 146          * up bounce buffers in addressable memory.
 147          */
 148         if (!us->pusb_dev->bus->controller->dma_mask)
 149                 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
 150
 151         /* We can't put these settings in slave_alloc() because that gets
 152          * called before the device type is known.  Consequently these
 153          * settings can't be overridden via the scsi devinfo mechanism. */
 154         if (sdev->type == TYPE_DISK) {
 155
 156                 /* Some vendors seem to put the READ CAPACITY bug into
 157                  * all their devices -- primarily makers of cell phones
 158                  * and digital cameras.  Since these devices always use
 159                  * flash media and can be expected to have an even number
 160                  * of sectors, we will always enable the CAPACITY_HEURISTICS
 161                  * flag unless told otherwise. */
 162                 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
 163                 case VENDOR_ID_NOKIA:
 164                 case VENDOR_ID_NIKON:
 165                 case VENDOR_ID_PENTAX:
 166                 case VENDOR_ID_MOTOROLA:
 167                         if (!(us->fflags & (US_FL_FIX_CAPACITY |
 168                                         US_FL_CAPACITY_OK)))
 169                                 us->fflags |= US_FL_CAPACITY_HEURISTICS;
 170                         break;
 171                 }
 172
 173                 /* Disk-type devices use MODE SENSE(6) if the protocol
 174                  * (SubClass) is Transparent SCSI, otherwise they use
 175                  * MODE SENSE(10). */
 176                 if (us->subclass != US_SC_SCSI)
 177                         sdev->use_10_for_ms = 1;
 178
 179                 /* Many disks only accept MODE SENSE transfer lengths of
 180                  * 192 bytes (that's what Windows uses). */
 181                 sdev->use_192_bytes_for_3f = 1;
 182
 183                 /* Some devices don't like MODE SENSE with page=0x3f,
 184                  * which is the command used for checking if a device
 185                  * is write-protected.  Now that we tell the sd driver
 186                  * to do a 192-byte transfer with this command the
 187                  * majority of devices work fine, but a few still can't
 188                  * handle it.  The sd driver will simply assume those
 189                  * devices are write-enabled. */
 190                 if (us->fflags & US_FL_NO_WP_DETECT)
 191                         sdev->skip_ms_page_3f = 1;
 192
 193                 /* A number of devices have problems with MODE SENSE for
 194                  * page x08, so we will skip it. */
 195                 sdev->skip_ms_page_8 = 1;
 196
 197                 /* Some disks return the total number of blocks in response
 198                  * to READ CAPACITY rather than the highest block number.
 199                  * If this device makes that mistake, tell the sd driver. */
 200                 if (us->fflags & US_FL_FIX_CAPACITY)
 201                         sdev->fix_capacity = 1;
 202
 203                 /* A few disks have two indistinguishable version, one of
 204                  * which reports the correct capacity and the other does not.
 205                  * The sd driver has to guess which is the case. */
 206                 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
 207                         sdev->guess_capacity = 1;
 208
 209                 /* assume SPC3 or latter devices support sense size > 18 */
 210                 if (sdev->scsi_level > SCSI_SPC_2)
 211                         us->fflags |= US_FL_SANE_SENSE;
 212
 213                 /* Some devices report a SCSI revision level above 2 but are
 214                  * unable to handle the REPORT LUNS command (for which
 215                  * support is mandatory at level 3).  Since we already have
 216                  * a Get-Max-LUN request, we won't lose much by setting the
 217                  * revision level down to 2.  The only devices that would be
 218                  * affected are those with sparse LUNs. */
 219                 if (sdev->scsi_level > SCSI_2)
 220                         sdev->sdev_target->scsi_level =
 221                                         sdev->scsi_level = SCSI_2;
 222
 223                 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
 224                  * Hardware Error) when any low-level error occurs,
 225                  * recoverable or not.  Setting this flag tells the SCSI
 226                  * midlayer to retry such commands, which frequently will
 227                  * succeed and fix the error.  The worst this can lead to
 228                  * is an occasional series of retries that will all fail. */
 229                 sdev->retry_hwerror = 1;
 230
 231                 /* USB disks should allow restart.  Some drives spin down
 232                  * automatically, requiring a START-STOP UNIT command. */
 233                 sdev->allow_restart = 1;
 234
 235                 /* Some USB cardreaders have trouble reading an sdcard's last
 236                  * sector in a larger then 1 sector read, since the performance
 237                  * impact is negible we set this flag for all USB disks */
 238                 sdev->last_sector_bug = 1;
 239
 240                 /* Enable last-sector hacks for single-target devices using
 241                  * the Bulk-only transport, unless we already know the
 242                  * capacity will be decremented or is correct. */
 243                 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
 244                                         US_FL_SCM_MULT_TARG)) &&
 245                                 us->protocol == US_PR_BULK)
 246                         us->use_last_sector_hacks = 1;
 247         } else {
 248
 249                 /* Non-disk-type devices don't need to blacklist any pages
 250                  * or to force 192-byte transfer lengths for MODE SENSE.
 251                  * But they do need to use MODE SENSE(10). */
 252                 sdev->use_10_for_ms = 1;
 253         }
 254
 255         /* The CB and CBI transports have no way to pass LUN values
 256          * other than the bits in the second byte of a CDB.  But those
 257          * bits don't get set to the LUN value if the device reports
 258          * scsi_level == 0 (UNKNOWN).  Hence such devices must necessarily
 259          * be single-LUN.
 260          */
 261         if ((us->protocol == US_PR_CB || us->protocol == US_PR_CBI) &&
 262                         sdev->scsi_level == SCSI_UNKNOWN)
 263                 us->max_lun = 0;
 264
 265         /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
 266          * REMOVAL command, so suppress those commands. */
 267         if (us->fflags & US_FL_NOT_LOCKABLE)
 268                 sdev->lockable = 0;
 269
 270         /* this is to satisfy the compiler, tho I don't think the
 271          * return code is ever checked anywhere. */
 272         return 0;
 273 }
 274
 275 /* queue a command */
 276 /* This is always called with scsi_lock(host) held */
 277 static int queuecommand(struct scsi_cmnd *srb,
 278                         void (*done)(struct scsi_cmnd *))
 279 {
 280         struct us_data *us = host_to_us(srb->device->host);
 281
 282         US_DEBUGP("%s called\n", __FUNCTION__);
 283
 284         /* check for state-transition errors */
 285         if (us->srb != NULL) {
 286                 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
 287                         __FUNCTION__, us->srb);
 288                 return SCSI_MLQUEUE_HOST_BUSY;
 289         }
 290
 291         /* fail the command if we are disconnecting */
 292         if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
 293                 US_DEBUGP("Fail command during disconnect\n");
 294                 srb->result = DID_NO_CONNECT << 16;
 295                 done(srb);
 296                 return 0;
 297         }
 298
 299         /* enqueue the command and wake up the control thread */
 300         srb->scsi_done = done;
 301         us->srb = srb;
 302         complete(&us->cmnd_ready);
 303
 304         return 0;
 305 }
 306
 307 /***********************************************************************
 308  * Error handling functions
 309  ***********************************************************************/
 310
 311 /* Command timeout and abort */
 312 static int command_abort(struct scsi_cmnd *srb)
 313 {
 314         struct us_data *us = host_to_us(srb->device->host);
 315
 316         US_DEBUGP("%s called\n", __FUNCTION__);
 317
 318         /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
 319          * bits are protected by the host lock. */
 320         scsi_lock(us_to_host(us));
 321
 322         /* Is this command still active? */
 323         if (us->srb != srb) {
 324                 scsi_unlock(us_to_host(us));
 325                 US_DEBUGP ("-- nothing to abort\n");
 326                 return FAILED;
 327         }
 328
 329         /* Set the TIMED_OUT bit.  Also set the ABORTING bit, but only if
 330          * a device reset isn't already in progress (to avoid interfering
 331          * with the reset).  Note that we must retain the host lock while
 332          * calling usb_stor_stop_transport(); otherwise it might interfere
 333          * with an auto-reset that begins as soon as we release the lock. */
 334         set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
 335         if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
 336                 set_bit(US_FLIDX_ABORTING, &us->dflags);
 337                 usb_stor_stop_transport(us);
 338         }
 339         scsi_unlock(us_to_host(us));
 340
 341         /* Wait for the aborted command to finish */
 342         wait_for_completion(&us->notify);
 343         return SUCCESS;
 344 }
 345
 346 /* This invokes the transport reset mechanism to reset the state of the
 347  * device */
 348 static int device_reset(struct scsi_cmnd *srb)
 349 {
 350         struct us_data *us = host_to_us(srb->device->host);
 351         int result;
 352
 353         US_DEBUGP("%s called\n", __FUNCTION__);
 354
 355         /* lock the device pointers and do the reset */
 356         mutex_lock(&(us->dev_mutex));
 357         result = us->transport_reset(us);
 358         mutex_unlock(&us->dev_mutex);
 359
 360         return result < 0 ? FAILED : SUCCESS;
 361 }
 362
 363 /* Simulate a SCSI bus reset by resetting the device's USB port. */
 364 static int bus_reset(struct scsi_cmnd *srb)
 365 {
 366         struct us_data *us = host_to_us(srb->device->host);
 367         int result;
 368
 369         US_DEBUGP("%s called\n", __FUNCTION__);
 370         result = usb_stor_port_reset(us);
 371         return result < 0 ? FAILED : SUCCESS;
 372 }
 373
 374 /* Report a driver-initiated device reset to the SCSI layer.
 375  * Calling this for a SCSI-initiated reset is unnecessary but harmless.
 376  * The caller must own the SCSI host lock. */
 377 void usb_stor_report_device_reset(struct us_data *us)
 378 {
 379         int i;
 380         struct Scsi_Host *host = us_to_host(us);
 381
 382         scsi_report_device_reset(host, 0, 0);
 383         if (us->fflags & US_FL_SCM_MULT_TARG) {
 384                 for (i = 1; i < host->max_id; ++i)
 385                         scsi_report_device_reset(host, 0, i);
 386         }
 387 }
 388
 389 /* Report a driver-initiated bus reset to the SCSI layer.
 390  * Calling this for a SCSI-initiated reset is unnecessary but harmless.
 391  * The caller must not own the SCSI host lock. */
 392 void usb_stor_report_bus_reset(struct us_data *us)
 393 {
 394         struct Scsi_Host *host = us_to_host(us);
 395
 396         scsi_lock(host);
 397         scsi_report_bus_reset(host, 0);
 398         scsi_unlock(host);
 399 }
 400
 401 /***********************************************************************
 402  * /proc/scsi/ functions
 403  ***********************************************************************/
 404
 405 /* we use this macro to help us write into the buffer */
 406 #undef SPRINTF
 407 #define SPRINTF(args...) \
 408         do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
 409
 410 static int proc_info (struct Scsi_Host *host, char *buffer,
 411                 char **start, off_t offset, int length, int inout)
 412 {
 413         struct us_data *us = host_to_us(host);
 414         char *pos = buffer;
 415         const char *string;
 416
 417         /* if someone is sending us data, just throw it away */
 418         if (inout)
 419                 return length;
 420
 421         /* print the controller name */
 422         SPRINTF("   Host scsi%d: usb-storage\n", host->host_no);
 423
 424         /* print product, vendor, and serial number strings */
 425         if (us->pusb_dev->manufacturer)
 426                 string = us->pusb_dev->manufacturer;
 427         else if (us->unusual_dev->vendorName)
 428                 string = us->unusual_dev->vendorName;
 429         else
 430                 string = "Unknown";
 431         SPRINTF("       Vendor: %s\n", string);
 432         if (us->pusb_dev->product)
 433                 string = us->pusb_dev->product;
 434         else if (us->unusual_dev->productName)
 435                 string = us->unusual_dev->productName;
 436         else
 437                 string = "Unknown";
 438         SPRINTF("      Product: %s\n", string);
 439         if (us->pusb_dev->serial)
 440                 string = us->pusb_dev->serial;
 441         else
 442                 string = "None";
 443         SPRINTF("Serial Number: %s\n", string);
 444
 445         /* show the protocol and transport */
 446         SPRINTF("     Protocol: %s\n", us->protocol_name);
 447         SPRINTF("    Transport: %s\n", us->transport_name);
 448
 449         /* show the device flags */
 450         if (pos < buffer + length) {
 451                 pos += sprintf(pos, "       Quirks:");
 452
 453 #define US_FLAG(name, value) \
 454         if (us->fflags & value) pos += sprintf(pos, " " #name);
 455 US_DO_ALL_FLAGS
 456 #undef US_FLAG
 457
 458                 *(pos++) = '\n';
 459         }
 460
 461
 462         SPRINTF("         Port: %s\n", us->pusb_dev->devpath);
 463         // Added Port descriptor
 464
 465         /*
 466          * Calculate start of next buffer, and return value.
 467          */
 468         *start = buffer + offset;
 469
 470         if ((pos - buffer) < offset)
 471                 return (0);
 472         else if ((pos - buffer - offset) < length)
 473                 return (pos - buffer - offset);
 474         else
 475                 return (length);
 476 }
 477
 478 /***********************************************************************
 479  * Sysfs interface
 480  ***********************************************************************/
 481
 482 /* Output routine for the sysfs max_sectors file */
 483 static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf)
 484 {
 485         struct scsi_device *sdev = to_scsi_device(dev);
 486
 487         return sprintf(buf, "%u\n", sdev->request_queue->max_sectors);
 488 }
 489
 490 /* Input routine for the sysfs max_sectors file */
 491 static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf,
 492                 size_t count)
 493 {
 494         struct scsi_device *sdev = to_scsi_device(dev);
 495         unsigned short ms;
 496
 497         if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
 498                 blk_queue_max_sectors(sdev->request_queue, ms);
 499                 return strlen(buf);
 500         }
 501         return -EINVAL;
 502 }
 503
 504 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
 505                 store_max_sectors);
 506
 507 static struct device_attribute *sysfs_device_attr_list[] = {
 508                 &dev_attr_max_sectors,
 509                 NULL,
 510                 };
 511
 512 /*
 513  * this defines our host template, with which we'll allocate hosts
 514  */
 515
 516 struct scsi_host_template usb_stor_host_template = {
 517         /* basic userland interface stuff */
 518         .name =                         "usb-storage",
 519         .proc_name =                    "usb-storage",
 520         .proc_info =                    proc_info,
 521         .info =                         host_info,
 522
 523         /* command interface -- queued only */
 524         .queuecommand =                 queuecommand,
 525
 526         /* error and abort handlers */
 527         .eh_abort_handler =             command_abort,
 528         .eh_device_reset_handler =      device_reset,
 529         .eh_bus_reset_handler =         bus_reset,
 530
 531         /* queue commands only, only one command per LUN */
 532         .can_queue =                    1,
 533         .cmd_per_lun =                  1,
 534
 535         /* unknown initiator id */
 536         .this_id =                      -1,
 537
 538         .slave_alloc =                  slave_alloc,
 539         .slave_configure =              slave_configure,
 540
 541         /* lots of sg segments can be handled */
 542         .sg_tablesize =                 SG_ALL,
 543
 544         /* limit the total size of a transfer to 120 KB */
 545         .max_sectors =                  240,
 546
 547         /* merge commands... this seems to help performance, but
 548          * periodically someone should test to see which setting is more
 549          * optimal.
 550          */
 551         .use_clustering =               1,
 552
 553         /* emulated HBA */
 554         .emulated =                     1,
 555
 556         /* we do our own delay after a device or bus reset */
 557         .skip_settle_delay =            1,
 558
 559         /* sysfs device attributes */
 560         .sdev_attrs =                   sysfs_device_attr_list,
 561
 562         /* module management */
 563         .module =                       THIS_MODULE
 564 };
 565
 566 /* To Report "Illegal Request: Invalid Field in CDB */
 567 unsigned char usb_stor_sense_invalidCDB[18] = {
 568         [0]     = 0x70,                     /* current error */
 569         [2]     = ILLEGAL_REQUEST,          /* Illegal Request = 0x05 */
 570         [7]     = 0x0a,                     /* additional length */
 571         [12]    = 0x24                      /* Invalid Field in CDB */
 572 };
 573