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 US_DEBUGP("%s called\n", __func__); 317 318 /* check for state-transition errors */ 319 if (us->srb != NULL) { 320 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n", 321 __func__, us->srb); 322 return SCSI_MLQUEUE_HOST_BUSY; 323 } 324 325 /* fail the command if we are disconnecting */ 326 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) { 327 US_DEBUGP("Fail command during disconnect\n"); 328 srb->result = DID_NO_CONNECT << 16; 329 done(srb); 330 return 0; 331 } 332 333 /* enqueue the command and wake up the control thread */ 334 srb->scsi_done = done; 335 us->srb = srb; 336 complete(&us->cmnd_ready); 337 338 return 0; 339 } 340 341 static DEF_SCSI_QCMD(queuecommand) 342 343 /*********************************************************************** 344 * Error handling functions 345 ***********************************************************************/ 346 347 /* Command timeout and abort */ 348 static int command_abort(struct scsi_cmnd *srb) 349 { 350 struct us_data *us = host_to_us(srb->device->host); 351 352 US_DEBUGP("%s called\n", __func__); 353 354 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING 355 * bits are protected by the host lock. */ 356 scsi_lock(us_to_host(us)); 357 358 /* Is this command still active? */ 359 if (us->srb != srb) { 360 scsi_unlock(us_to_host(us)); 361 US_DEBUGP ("-- nothing to abort\n"); 362 return FAILED; 363 } 364 365 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if 366 * a device reset isn't already in progress (to avoid interfering 367 * with the reset). Note that we must retain the host lock while 368 * calling usb_stor_stop_transport(); otherwise it might interfere 369 * with an auto-reset that begins as soon as we release the lock. */ 370 set_bit(US_FLIDX_TIMED_OUT, &us->dflags); 371 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) { 372 set_bit(US_FLIDX_ABORTING, &us->dflags); 373 usb_stor_stop_transport(us); 374 } 375 scsi_unlock(us_to_host(us)); 376 377 /* Wait for the aborted command to finish */ 378 wait_for_completion(&us->notify); 379 return SUCCESS; 380 } 381 382 /* This invokes the transport reset mechanism to reset the state of the 383 * device */ 384 static int device_reset(struct scsi_cmnd *srb) 385 { 386 struct us_data *us = host_to_us(srb->device->host); 387 int result; 388 389 US_DEBUGP("%s called\n", __func__); 390 391 /* lock the device pointers and do the reset */ 392 mutex_lock(&(us->dev_mutex)); 393 result = us->transport_reset(us); 394 mutex_unlock(&us->dev_mutex); 395 396 return result < 0 ? FAILED : SUCCESS; 397 } 398 399 /* Simulate a SCSI bus reset by resetting the device's USB port. */ 400 static int bus_reset(struct scsi_cmnd *srb) 401 { 402 struct us_data *us = host_to_us(srb->device->host); 403 int result; 404 405 US_DEBUGP("%s called\n", __func__); 406 result = usb_stor_port_reset(us); 407 return result < 0 ? FAILED : SUCCESS; 408 } 409 410 /* Report a driver-initiated device reset to the SCSI layer. 411 * Calling this for a SCSI-initiated reset is unnecessary but harmless. 412 * The caller must own the SCSI host lock. */ 413 void usb_stor_report_device_reset(struct us_data *us) 414 { 415 int i; 416 struct Scsi_Host *host = us_to_host(us); 417 418 scsi_report_device_reset(host, 0, 0); 419 if (us->fflags & US_FL_SCM_MULT_TARG) { 420 for (i = 1; i < host->max_id; ++i) 421 scsi_report_device_reset(host, 0, i); 422 } 423 } 424 425 /* Report a driver-initiated bus reset to the SCSI layer. 426 * Calling this for a SCSI-initiated reset is unnecessary but harmless. 427 * The caller must not own the SCSI host lock. */ 428 void usb_stor_report_bus_reset(struct us_data *us) 429 { 430 struct Scsi_Host *host = us_to_host(us); 431 432 scsi_lock(host); 433 scsi_report_bus_reset(host, 0); 434 scsi_unlock(host); 435 } 436 437 /*********************************************************************** 438 * /proc/scsi/ functions 439 ***********************************************************************/ 440 441 /* we use this macro to help us write into the buffer */ 442 #undef SPRINTF 443 #define SPRINTF(args...) \ 444 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0) 445 446 static int proc_info (struct Scsi_Host *host, char *buffer, 447 char **start, off_t offset, int length, int inout) 448 { 449 struct us_data *us = host_to_us(host); 450 char *pos = buffer; 451 const char *string; 452 453 /* if someone is sending us data, just throw it away */ 454 if (inout) 455 return length; 456 457 /* print the controller name */ 458 SPRINTF(" Host scsi%d: usb-storage\n", host->host_no); 459 460 /* print product, vendor, and serial number strings */ 461 if (us->pusb_dev->manufacturer) 462 string = us->pusb_dev->manufacturer; 463 else if (us->unusual_dev->vendorName) 464 string = us->unusual_dev->vendorName; 465 else 466 string = "Unknown"; 467 SPRINTF(" Vendor: %s\n", string); 468 if (us->pusb_dev->product) 469 string = us->pusb_dev->product; 470 else if (us->unusual_dev->productName) 471 string = us->unusual_dev->productName; 472 else 473 string = "Unknown"; 474 SPRINTF(" Product: %s\n", string); 475 if (us->pusb_dev->serial) 476 string = us->pusb_dev->serial; 477 else 478 string = "None"; 479 SPRINTF("Serial Number: %s\n", string); 480 481 /* show the protocol and transport */ 482 SPRINTF(" Protocol: %s\n", us->protocol_name); 483 SPRINTF(" Transport: %s\n", us->transport_name); 484 485 /* show the device flags */ 486 if (pos < buffer + length) { 487 pos += sprintf(pos, " Quirks:"); 488 489 #define US_FLAG(name, value) \ 490 if (us->fflags & value) pos += sprintf(pos, " " #name); 491 US_DO_ALL_FLAGS 492 #undef US_FLAG 493 494 *(pos++) = '\n'; 495 } 496 497 /* 498 * Calculate start of next buffer, and return value. 499 */ 500 *start = buffer + offset; 501 502 if ((pos - buffer) < offset) 503 return (0); 504 else if ((pos - buffer - offset) < length) 505 return (pos - buffer - offset); 506 else 507 return (length); 508 } 509 510 /*********************************************************************** 511 * Sysfs interface 512 ***********************************************************************/ 513 514 /* Output routine for the sysfs max_sectors file */ 515 static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf) 516 { 517 struct scsi_device *sdev = to_scsi_device(dev); 518 519 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue)); 520 } 521 522 /* Input routine for the sysfs max_sectors file */ 523 static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf, 524 size_t count) 525 { 526 struct scsi_device *sdev = to_scsi_device(dev); 527 unsigned short ms; 528 529 if (sscanf(buf, "%hu", &ms) > 0) { 530 blk_queue_max_hw_sectors(sdev->request_queue, ms); 531 return count; 532 } 533 return -EINVAL; 534 } 535 536 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors, 537 store_max_sectors); 538 539 static struct device_attribute *sysfs_device_attr_list[] = { 540 &dev_attr_max_sectors, 541 NULL, 542 }; 543 544 /* 545 * this defines our host template, with which we'll allocate hosts 546 */ 547 548 struct scsi_host_template usb_stor_host_template = { 549 /* basic userland interface stuff */ 550 .name = "usb-storage", 551 .proc_name = "usb-storage", 552 .proc_info = proc_info, 553 .info = host_info, 554 555 /* command interface -- queued only */ 556 .queuecommand = queuecommand, 557 558 /* error and abort handlers */ 559 .eh_abort_handler = command_abort, 560 .eh_device_reset_handler = device_reset, 561 .eh_bus_reset_handler = bus_reset, 562 563 /* queue commands only, only one command per LUN */ 564 .can_queue = 1, 565 .cmd_per_lun = 1, 566 567 /* unknown initiator id */ 568 .this_id = -1, 569 570 .slave_alloc = slave_alloc, 571 .slave_configure = slave_configure, 572 .target_alloc = target_alloc, 573 574 /* lots of sg segments can be handled */ 575 .sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS, 576 577 /* limit the total size of a transfer to 120 KB */ 578 .max_sectors = 240, 579 580 /* merge commands... this seems to help performance, but 581 * periodically someone should test to see which setting is more 582 * optimal. 583 */ 584 .use_clustering = 1, 585 586 /* emulated HBA */ 587 .emulated = 1, 588 589 /* we do our own delay after a device or bus reset */ 590 .skip_settle_delay = 1, 591 592 /* sysfs device attributes */ 593 .sdev_attrs = sysfs_device_attr_list, 594 595 /* module management */ 596 .module = THIS_MODULE 597 }; 598 599 /* To Report "Illegal Request: Invalid Field in CDB */ 600 unsigned char usb_stor_sense_invalidCDB[18] = { 601 [0] = 0x70, /* current error */ 602 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */ 603 [7] = 0x0a, /* additional length */ 604 [12] = 0x24 /* Invalid Field in CDB */ 605 }; 606 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB); 607