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 struct us_data *us = host_to_us(sdev->host); 82 83 /* 84 * Set the INQUIRY transfer length to 36. We don't use any of 85 * the extra data and many devices choke if asked for more or 86 * less than 36 bytes. 87 */ 88 sdev->inquiry_len = 36; 89 90 /* USB has unusual DMA-alignment requirements: Although the 91 * starting address of each scatter-gather element doesn't matter, 92 * the length of each element except the last must be divisible 93 * by the Bulk maxpacket value. There's currently no way to 94 * express this by block-layer constraints, so we'll cop out 95 * and simply require addresses to be aligned at 512-byte 96 * boundaries. This is okay since most block I/O involves 97 * hardware sectors that are multiples of 512 bytes in length, 98 * and since host controllers up through USB 2.0 have maxpacket 99 * values no larger than 512. 100 * 101 * But it doesn't suffice for Wireless USB, where Bulk maxpacket 102 * values can be as large as 2048. To make that work properly 103 * will require changes to the block layer. 104 */ 105 blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1)); 106 107 /* Tell the SCSI layer if we know there is more than one LUN */ 108 if (us->protocol == USB_PR_BULK && us->max_lun > 0) 109 sdev->sdev_bflags |= BLIST_FORCELUN; 110 111 return 0; 112 } 113 114 static int slave_configure(struct scsi_device *sdev) 115 { 116 struct us_data *us = host_to_us(sdev->host); 117 118 /* Many devices have trouble transferring more than 32KB at a time, 119 * while others have trouble with more than 64K. At this time we 120 * are limiting both to 32K (64 sectores). 121 */ 122 if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) { 123 unsigned int max_sectors = 64; 124 125 if (us->fflags & US_FL_MAX_SECTORS_MIN) 126 max_sectors = PAGE_CACHE_SIZE >> 9; 127 if (queue_max_hw_sectors(sdev->request_queue) > max_sectors) 128 blk_queue_max_hw_sectors(sdev->request_queue, 129 max_sectors); 130 } else if (sdev->type == TYPE_TAPE) { 131 /* Tapes need much higher max_sector limits, so just 132 * raise it to the maximum possible (4 GB / 512) and 133 * let the queue segment size sort out the real limit. 134 */ 135 blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF); 136 } 137 138 /* Some USB host controllers can't do DMA; they have to use PIO. 139 * They indicate this by setting their dma_mask to NULL. For 140 * such controllers we need to make sure the block layer sets 141 * up bounce buffers in addressable memory. 142 */ 143 if (!us->pusb_dev->bus->controller->dma_mask) 144 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH); 145 146 /* We can't put these settings in slave_alloc() because that gets 147 * called before the device type is known. Consequently these 148 * settings can't be overridden via the scsi devinfo mechanism. */ 149 if (sdev->type == TYPE_DISK) { 150 151 /* Some vendors seem to put the READ CAPACITY bug into 152 * all their devices -- primarily makers of cell phones 153 * and digital cameras. Since these devices always use 154 * flash media and can be expected to have an even number 155 * of sectors, we will always enable the CAPACITY_HEURISTICS 156 * flag unless told otherwise. */ 157 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) { 158 case VENDOR_ID_NOKIA: 159 case VENDOR_ID_NIKON: 160 case VENDOR_ID_PENTAX: 161 case VENDOR_ID_MOTOROLA: 162 if (!(us->fflags & (US_FL_FIX_CAPACITY | 163 US_FL_CAPACITY_OK))) 164 us->fflags |= US_FL_CAPACITY_HEURISTICS; 165 break; 166 } 167 168 /* Disk-type devices use MODE SENSE(6) if the protocol 169 * (SubClass) is Transparent SCSI, otherwise they use 170 * MODE SENSE(10). */ 171 if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB) 172 sdev->use_10_for_ms = 1; 173 174 /* Many disks only accept MODE SENSE transfer lengths of 175 * 192 bytes (that's what Windows uses). */ 176 sdev->use_192_bytes_for_3f = 1; 177 178 /* Some devices don't like MODE SENSE with page=0x3f, 179 * which is the command used for checking if a device 180 * is write-protected. Now that we tell the sd driver 181 * to do a 192-byte transfer with this command the 182 * majority of devices work fine, but a few still can't 183 * handle it. The sd driver will simply assume those 184 * devices are write-enabled. */ 185 if (us->fflags & US_FL_NO_WP_DETECT) 186 sdev->skip_ms_page_3f = 1; 187 188 /* A number of devices have problems with MODE SENSE for 189 * page x08, so we will skip it. */ 190 sdev->skip_ms_page_8 = 1; 191 192 /* Some devices don't handle VPD pages correctly */ 193 sdev->skip_vpd_pages = 1; 194 195 /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */ 196 sdev->no_report_opcodes = 1; 197 198 /* Do not attempt to use WRITE SAME */ 199 sdev->no_write_same = 1; 200 201 /* Some disks return the total number of blocks in response 202 * to READ CAPACITY rather than the highest block number. 203 * If this device makes that mistake, tell the sd driver. */ 204 if (us->fflags & US_FL_FIX_CAPACITY) 205 sdev->fix_capacity = 1; 206 207 /* A few disks have two indistinguishable version, one of 208 * which reports the correct capacity and the other does not. 209 * The sd driver has to guess which is the case. */ 210 if (us->fflags & US_FL_CAPACITY_HEURISTICS) 211 sdev->guess_capacity = 1; 212 213 /* Some devices cannot handle READ_CAPACITY_16 */ 214 if (us->fflags & US_FL_NO_READ_CAPACITY_16) 215 sdev->no_read_capacity_16 = 1; 216 217 /* 218 * Many devices do not respond properly to READ_CAPACITY_16. 219 * Tell the SCSI layer to try READ_CAPACITY_10 first. 220 * However some USB 3.0 drive enclosures return capacity 221 * modulo 2TB. Those must use READ_CAPACITY_16 222 */ 223 if (!(us->fflags & US_FL_NEEDS_CAP16)) 224 sdev->try_rc_10_first = 1; 225 226 /* assume SPC3 or latter devices support sense size > 18 */ 227 if (sdev->scsi_level > SCSI_SPC_2) 228 us->fflags |= US_FL_SANE_SENSE; 229 230 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable 231 * Hardware Error) when any low-level error occurs, 232 * recoverable or not. Setting this flag tells the SCSI 233 * midlayer to retry such commands, which frequently will 234 * succeed and fix the error. The worst this can lead to 235 * is an occasional series of retries that will all fail. */ 236 sdev->retry_hwerror = 1; 237 238 /* USB disks should allow restart. Some drives spin down 239 * automatically, requiring a START-STOP UNIT command. */ 240 sdev->allow_restart = 1; 241 242 /* Some USB cardreaders have trouble reading an sdcard's last 243 * sector in a larger then 1 sector read, since the performance 244 * impact is negligible we set this flag for all USB disks */ 245 sdev->last_sector_bug = 1; 246 247 /* Enable last-sector hacks for single-target devices using 248 * the Bulk-only transport, unless we already know the 249 * capacity will be decremented or is correct. */ 250 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK | 251 US_FL_SCM_MULT_TARG)) && 252 us->protocol == USB_PR_BULK) 253 us->use_last_sector_hacks = 1; 254 255 /* Check if write cache default on flag is set or not */ 256 if (us->fflags & US_FL_WRITE_CACHE) 257 sdev->wce_default_on = 1; 258 259 /* A few buggy USB-ATA bridges don't understand FUA */ 260 if (us->fflags & US_FL_BROKEN_FUA) 261 sdev->broken_fua = 1; 262 263 } else { 264 265 /* Non-disk-type devices don't need to blacklist any pages 266 * or to force 192-byte transfer lengths for MODE SENSE. 267 * But they do need to use MODE SENSE(10). */ 268 sdev->use_10_for_ms = 1; 269 270 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */ 271 if (us->fflags & US_FL_NO_READ_DISC_INFO) 272 sdev->no_read_disc_info = 1; 273 } 274 275 /* The CB and CBI transports have no way to pass LUN values 276 * other than the bits in the second byte of a CDB. But those 277 * bits don't get set to the LUN value if the device reports 278 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily 279 * be single-LUN. 280 */ 281 if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) && 282 sdev->scsi_level == SCSI_UNKNOWN) 283 us->max_lun = 0; 284 285 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM 286 * REMOVAL command, so suppress those commands. */ 287 if (us->fflags & US_FL_NOT_LOCKABLE) 288 sdev->lockable = 0; 289 290 /* this is to satisfy the compiler, tho I don't think the 291 * return code is ever checked anywhere. */ 292 return 0; 293 } 294 295 static int target_alloc(struct scsi_target *starget) 296 { 297 struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent)); 298 299 /* 300 * Some USB drives don't support REPORT LUNS, even though they 301 * report a SCSI revision level above 2. Tell the SCSI layer 302 * not to issue that command; it will perform a normal sequential 303 * scan instead. 304 */ 305 starget->no_report_luns = 1; 306 307 /* 308 * The UFI spec treats the Peripheral Qualifier bits in an 309 * INQUIRY result as reserved and requires devices to set them 310 * to 0. However the SCSI spec requires these bits to be set 311 * to 3 to indicate when a LUN is not present. 312 * 313 * Let the scanning code know if this target merely sets 314 * Peripheral Device Type to 0x1f to indicate no LUN. 315 */ 316 if (us->subclass == USB_SC_UFI) 317 starget->pdt_1f_for_no_lun = 1; 318 319 return 0; 320 } 321 322 /* queue a command */ 323 /* This is always called with scsi_lock(host) held */ 324 static int queuecommand_lck(struct scsi_cmnd *srb, 325 void (*done)(struct scsi_cmnd *)) 326 { 327 struct us_data *us = host_to_us(srb->device->host); 328 329 /* check for state-transition errors */ 330 if (us->srb != NULL) { 331 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n", 332 __func__, us->srb); 333 return SCSI_MLQUEUE_HOST_BUSY; 334 } 335 336 /* fail the command if we are disconnecting */ 337 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) { 338 usb_stor_dbg(us, "Fail command during disconnect\n"); 339 srb->result = DID_NO_CONNECT << 16; 340 done(srb); 341 return 0; 342 } 343 344 /* enqueue the command and wake up the control thread */ 345 srb->scsi_done = done; 346 us->srb = srb; 347 complete(&us->cmnd_ready); 348 349 return 0; 350 } 351 352 static DEF_SCSI_QCMD(queuecommand) 353 354 /*********************************************************************** 355 * Error handling functions 356 ***********************************************************************/ 357 358 /* Command timeout and abort */ 359 static int command_abort(struct scsi_cmnd *srb) 360 { 361 struct us_data *us = host_to_us(srb->device->host); 362 363 usb_stor_dbg(us, "%s called\n", __func__); 364 365 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING 366 * bits are protected by the host lock. */ 367 scsi_lock(us_to_host(us)); 368 369 /* Is this command still active? */ 370 if (us->srb != srb) { 371 scsi_unlock(us_to_host(us)); 372 usb_stor_dbg(us, "-- nothing to abort\n"); 373 return FAILED; 374 } 375 376 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if 377 * a device reset isn't already in progress (to avoid interfering 378 * with the reset). Note that we must retain the host lock while 379 * calling usb_stor_stop_transport(); otherwise it might interfere 380 * with an auto-reset that begins as soon as we release the lock. */ 381 set_bit(US_FLIDX_TIMED_OUT, &us->dflags); 382 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) { 383 set_bit(US_FLIDX_ABORTING, &us->dflags); 384 usb_stor_stop_transport(us); 385 } 386 scsi_unlock(us_to_host(us)); 387 388 /* Wait for the aborted command to finish */ 389 wait_for_completion(&us->notify); 390 return SUCCESS; 391 } 392 393 /* This invokes the transport reset mechanism to reset the state of the 394 * device */ 395 static int device_reset(struct scsi_cmnd *srb) 396 { 397 struct us_data *us = host_to_us(srb->device->host); 398 int result; 399 400 usb_stor_dbg(us, "%s called\n", __func__); 401 402 /* lock the device pointers and do the reset */ 403 mutex_lock(&(us->dev_mutex)); 404 result = us->transport_reset(us); 405 mutex_unlock(&us->dev_mutex); 406 407 return result < 0 ? FAILED : SUCCESS; 408 } 409 410 /* Simulate a SCSI bus reset by resetting the device's USB port. */ 411 static int bus_reset(struct scsi_cmnd *srb) 412 { 413 struct us_data *us = host_to_us(srb->device->host); 414 int result; 415 416 usb_stor_dbg(us, "%s called\n", __func__); 417 418 result = usb_stor_port_reset(us); 419 return result < 0 ? FAILED : SUCCESS; 420 } 421 422 /* Report a driver-initiated device reset to the SCSI layer. 423 * Calling this for a SCSI-initiated reset is unnecessary but harmless. 424 * The caller must own the SCSI host lock. */ 425 void usb_stor_report_device_reset(struct us_data *us) 426 { 427 int i; 428 struct Scsi_Host *host = us_to_host(us); 429 430 scsi_report_device_reset(host, 0, 0); 431 if (us->fflags & US_FL_SCM_MULT_TARG) { 432 for (i = 1; i < host->max_id; ++i) 433 scsi_report_device_reset(host, 0, i); 434 } 435 } 436 437 /* Report a driver-initiated bus reset to the SCSI layer. 438 * Calling this for a SCSI-initiated reset is unnecessary but harmless. 439 * The caller must not own the SCSI host lock. */ 440 void usb_stor_report_bus_reset(struct us_data *us) 441 { 442 struct Scsi_Host *host = us_to_host(us); 443 444 scsi_lock(host); 445 scsi_report_bus_reset(host, 0); 446 scsi_unlock(host); 447 } 448 449 /*********************************************************************** 450 * /proc/scsi/ functions 451 ***********************************************************************/ 452 453 static int write_info(struct Scsi_Host *host, char *buffer, int length) 454 { 455 /* if someone is sending us data, just throw it away */ 456 return length; 457 } 458 459 static int show_info (struct seq_file *m, struct Scsi_Host *host) 460 { 461 struct us_data *us = host_to_us(host); 462 const char *string; 463 464 /* print the controller name */ 465 seq_printf(m, " Host scsi%d: usb-storage\n", host->host_no); 466 467 /* print product, vendor, and serial number strings */ 468 if (us->pusb_dev->manufacturer) 469 string = us->pusb_dev->manufacturer; 470 else if (us->unusual_dev->vendorName) 471 string = us->unusual_dev->vendorName; 472 else 473 string = "Unknown"; 474 seq_printf(m, " Vendor: %s\n", string); 475 if (us->pusb_dev->product) 476 string = us->pusb_dev->product; 477 else if (us->unusual_dev->productName) 478 string = us->unusual_dev->productName; 479 else 480 string = "Unknown"; 481 seq_printf(m, " Product: %s\n", string); 482 if (us->pusb_dev->serial) 483 string = us->pusb_dev->serial; 484 else 485 string = "None"; 486 seq_printf(m, "Serial Number: %s\n", string); 487 488 /* show the protocol and transport */ 489 seq_printf(m, " Protocol: %s\n", us->protocol_name); 490 seq_printf(m, " Transport: %s\n", us->transport_name); 491 492 /* show the device flags */ 493 seq_printf(m, " Quirks:"); 494 495 #define US_FLAG(name, value) \ 496 if (us->fflags & value) seq_printf(m, " " #name); 497 US_DO_ALL_FLAGS 498 #undef US_FLAG 499 seq_putc(m, '\n'); 500 return 0; 501 } 502 503 /*********************************************************************** 504 * Sysfs interface 505 ***********************************************************************/ 506 507 /* Output routine for the sysfs max_sectors file */ 508 static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf) 509 { 510 struct scsi_device *sdev = to_scsi_device(dev); 511 512 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue)); 513 } 514 515 /* Input routine for the sysfs max_sectors file */ 516 static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf, 517 size_t count) 518 { 519 struct scsi_device *sdev = to_scsi_device(dev); 520 unsigned short ms; 521 522 if (sscanf(buf, "%hu", &ms) > 0) { 523 blk_queue_max_hw_sectors(sdev->request_queue, ms); 524 return count; 525 } 526 return -EINVAL; 527 } 528 static DEVICE_ATTR_RW(max_sectors); 529 530 static struct device_attribute *sysfs_device_attr_list[] = { 531 &dev_attr_max_sectors, 532 NULL, 533 }; 534 535 /* 536 * this defines our host template, with which we'll allocate hosts 537 */ 538 539 static const struct scsi_host_template usb_stor_host_template = { 540 /* basic userland interface stuff */ 541 .name = "usb-storage", 542 .proc_name = "usb-storage", 543 .show_info = show_info, 544 .write_info = write_info, 545 .info = host_info, 546 547 /* command interface -- queued only */ 548 .queuecommand = queuecommand, 549 550 /* error and abort handlers */ 551 .eh_abort_handler = command_abort, 552 .eh_device_reset_handler = device_reset, 553 .eh_bus_reset_handler = bus_reset, 554 555 /* queue commands only, only one command per LUN */ 556 .can_queue = 1, 557 558 /* unknown initiator id */ 559 .this_id = -1, 560 561 .slave_alloc = slave_alloc, 562 .slave_configure = slave_configure, 563 .target_alloc = target_alloc, 564 565 /* lots of sg segments can be handled */ 566 .sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS, 567 568 /* limit the total size of a transfer to 120 KB */ 569 .max_sectors = 240, 570 571 /* merge commands... this seems to help performance, but 572 * periodically someone should test to see which setting is more 573 * optimal. 574 */ 575 .use_clustering = 1, 576 577 /* emulated HBA */ 578 .emulated = 1, 579 580 /* we do our own delay after a device or bus reset */ 581 .skip_settle_delay = 1, 582 583 /* sysfs device attributes */ 584 .sdev_attrs = sysfs_device_attr_list, 585 586 /* module management */ 587 .module = THIS_MODULE 588 }; 589 590 void usb_stor_host_template_init(struct scsi_host_template *sht, 591 const char *name, struct module *owner) 592 { 593 *sht = usb_stor_host_template; 594 sht->name = name; 595 sht->proc_name = name; 596 sht->module = owner; 597 } 598 EXPORT_SYMBOL_GPL(usb_stor_host_template_init); 599 600 /* To Report "Illegal Request: Invalid Field in CDB */ 601 unsigned char usb_stor_sense_invalidCDB[18] = { 602 [0] = 0x70, /* current error */ 603 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */ 604 [7] = 0x0a, /* additional length */ 605 [12] = 0x24 /* Invalid Field in CDB */ 606 }; 607 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB); 608