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 73static 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 79static 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 /* 108 * The UFI spec treates the Peripheral Qualifier bits in an 109 * INQUIRY result as reserved and requires devices to set them 110 * to 0. However the SCSI spec requires these bits to be set 111 * to 3 to indicate when a LUN is not present. 112 * 113 * Let the scanning code know if this target merely sets 114 * Peripheral Device Type to 0x1f to indicate no LUN. 115 */ 116 if (us->subclass == US_SC_UFI) 117 sdev->sdev_target->pdt_1f_for_no_lun = 1; 118 119 return 0; 120} 121 122static int slave_configure(struct scsi_device *sdev) 123{ 124 struct us_data *us = host_to_us(sdev->host); 125 126 /* Many devices have trouble transfering more than 32KB at a time, 127 * while others have trouble with more than 64K. At this time we 128 * are limiting both to 32K (64 sectores). 129 */ 130 if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) { 131 unsigned int max_sectors = 64; 132 133 if (us->fflags & US_FL_MAX_SECTORS_MIN) 134 max_sectors = PAGE_CACHE_SIZE >> 9; 135 if (queue_max_hw_sectors(sdev->request_queue) > max_sectors) 136 blk_queue_max_hw_sectors(sdev->request_queue, 137 max_sectors); 138 } else if (sdev->type == TYPE_TAPE) { 139 /* Tapes need much higher max_sector limits, so just 140 * raise it to the maximum possible (4 GB / 512) and 141 * let the queue segment size sort out the real limit. 142 */ 143 blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF); 144 } 145 146 /* Some USB host controllers can't do DMA; they have to use PIO. 147 * They indicate this by setting their dma_mask to NULL. For 148 * such controllers we need to make sure the block layer sets 149 * up bounce buffers in addressable memory. 150 */ 151 if (!us->pusb_dev->bus->controller->dma_mask) 152 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH); 153 154 /* We can't put these settings in slave_alloc() because that gets 155 * called before the device type is known. Consequently these 156 * settings can't be overridden via the scsi devinfo mechanism. */ 157 if (sdev->type == TYPE_DISK) { 158 159 /* Some vendors seem to put the READ CAPACITY bug into 160 * all their devices -- primarily makers of cell phones 161 * and digital cameras. Since these devices always use 162 * flash media and can be expected to have an even number 163 * of sectors, we will always enable the CAPACITY_HEURISTICS 164 * flag unless told otherwise. */ 165 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) { 166 case VENDOR_ID_NOKIA: 167 case VENDOR_ID_NIKON: 168 case VENDOR_ID_PENTAX: 169 case VENDOR_ID_MOTOROLA: 170 if (!(us->fflags & (US_FL_FIX_CAPACITY | 171 US_FL_CAPACITY_OK))) 172 us->fflags |= US_FL_CAPACITY_HEURISTICS; 173 break; 174 } 175 176 /* Disk-type devices use MODE SENSE(6) if the protocol 177 * (SubClass) is Transparent SCSI, otherwise they use 178 * MODE SENSE(10). */ 179 if (us->subclass != US_SC_SCSI && us->subclass != US_SC_CYP_ATACB) 180 sdev->use_10_for_ms = 1; 181 182 /* Many disks only accept MODE SENSE transfer lengths of 183 * 192 bytes (that's what Windows uses). */ 184 sdev->use_192_bytes_for_3f = 1; 185 186 /* Some devices don't like MODE SENSE with page=0x3f, 187 * which is the command used for checking if a device 188 * is write-protected. Now that we tell the sd driver 189 * to do a 192-byte transfer with this command the 190 * majority of devices work fine, but a few still can't 191 * handle it. The sd driver will simply assume those 192 * devices are write-enabled. */ 193 if (us->fflags & US_FL_NO_WP_DETECT) 194 sdev->skip_ms_page_3f = 1; 195 196 /* A number of devices have problems with MODE SENSE for 197 * page x08, so we will skip it. */ 198 sdev->skip_ms_page_8 = 1; 199 200 /* Some disks return the total number of blocks in response 201 * to READ CAPACITY rather than the highest block number. 202 * If this device makes that mistake, tell the sd driver. */ 203 if (us->fflags & US_FL_FIX_CAPACITY) 204 sdev->fix_capacity = 1; 205 206 /* A few disks have two indistinguishable version, one of 207 * which reports the correct capacity and the other does not. 208 * The sd driver has to guess which is the case. */ 209 if (us->fflags & US_FL_CAPACITY_HEURISTICS) 210 sdev->guess_capacity = 1; 211 212 /* assume SPC3 or latter devices support sense size > 18 */ 213 if (sdev->scsi_level > SCSI_SPC_2) 214 us->fflags |= US_FL_SANE_SENSE; 215 216 /* Some devices report a SCSI revision level above 2 but are 217 * unable to handle the REPORT LUNS command (for which 218 * support is mandatory at level 3). Since we already have 219 * a Get-Max-LUN request, we won't lose much by setting the 220 * revision level down to 2. The only devices that would be 221 * affected are those with sparse LUNs. */ 222 if (sdev->scsi_level > SCSI_2) 223 sdev->sdev_target->scsi_level = 224 sdev->scsi_level = SCSI_2; 225 226 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable 227 * Hardware Error) when any low-level error occurs, 228 * recoverable or not. Setting this flag tells the SCSI 229 * midlayer to retry such commands, which frequently will 230 * succeed and fix the error. The worst this can lead to 231 * is an occasional series of retries that will all fail. */ 232 sdev->retry_hwerror = 1; 233 234 /* USB disks should allow restart. Some drives spin down 235 * automatically, requiring a START-STOP UNIT command. */ 236 sdev->allow_restart = 1; 237 238 /* Some USB cardreaders have trouble reading an sdcard's last 239 * sector in a larger then 1 sector read, since the performance 240 * impact is negible we set this flag for all USB disks */ 241 sdev->last_sector_bug = 1; 242 243 /* Enable last-sector hacks for single-target devices using 244 * the Bulk-only transport, unless we already know the 245 * capacity will be decremented or is correct. */ 246 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK | 247 US_FL_SCM_MULT_TARG)) && 248 us->protocol == US_PR_BULK) 249 us->use_last_sector_hacks = 1; 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 } 257 258 /* The CB and CBI transports have no way to pass LUN values 259 * other than the bits in the second byte of a CDB. But those 260 * bits don't get set to the LUN value if the device reports 261 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily 262 * be single-LUN. 263 */ 264 if ((us->protocol == US_PR_CB || us->protocol == US_PR_CBI) && 265 sdev->scsi_level == SCSI_UNKNOWN) 266 us->max_lun = 0; 267 268 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM 269 * REMOVAL command, so suppress those commands. */ 270 if (us->fflags & US_FL_NOT_LOCKABLE) 271 sdev->lockable = 0; 272 273 /* this is to satisfy the compiler, tho I don't think the 274 * return code is ever checked anywhere. */ 275 return 0; 276} 277 278/* queue a command */ 279/* This is always called with scsi_lock(host) held */ 280static int queuecommand(struct scsi_cmnd *srb, 281 void (*done)(struct scsi_cmnd *)) 282{ 283 struct us_data *us = host_to_us(srb->device->host); 284 285 US_DEBUGP("%s called\n", __func__); 286 287 /* check for state-transition errors */ 288 if (us->srb != NULL) { 289 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n", 290 __func__, us->srb); 291 return SCSI_MLQUEUE_HOST_BUSY; 292 } 293 294 /* fail the command if we are disconnecting */ 295 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) { 296 US_DEBUGP("Fail command during disconnect\n"); 297 srb->result = DID_NO_CONNECT << 16; 298 done(srb); 299 return 0; 300 } 301 302 /* enqueue the command and wake up the control thread */ 303 srb->scsi_done = done; 304 us->srb = srb; 305 complete(&us->cmnd_ready); 306 307 return 0; 308} 309 310/*********************************************************************** 311 * Error handling functions 312 ***********************************************************************/ 313 314/* Command timeout and abort */ 315static int command_abort(struct scsi_cmnd *srb) 316{ 317 struct us_data *us = host_to_us(srb->device->host); 318 319 US_DEBUGP("%s called\n", __func__); 320 321 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING 322 * bits are protected by the host lock. */ 323 scsi_lock(us_to_host(us)); 324 325 /* Is this command still active? */ 326 if (us->srb != srb) { 327 scsi_unlock(us_to_host(us)); 328 US_DEBUGP ("-- nothing to abort\n"); 329 return FAILED; 330 } 331 332 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if 333 * a device reset isn't already in progress (to avoid interfering 334 * with the reset). Note that we must retain the host lock while 335 * calling usb_stor_stop_transport(); otherwise it might interfere 336 * with an auto-reset that begins as soon as we release the lock. */ 337 set_bit(US_FLIDX_TIMED_OUT, &us->dflags); 338 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) { 339 set_bit(US_FLIDX_ABORTING, &us->dflags); 340 usb_stor_stop_transport(us); 341 } 342 scsi_unlock(us_to_host(us)); 343 344 /* Wait for the aborted command to finish */ 345 wait_for_completion(&us->notify); 346 return SUCCESS; 347} 348 349/* This invokes the transport reset mechanism to reset the state of the 350 * device */ 351static int device_reset(struct scsi_cmnd *srb) 352{ 353 struct us_data *us = host_to_us(srb->device->host); 354 int result; 355 356 US_DEBUGP("%s called\n", __func__); 357 358 /* lock the device pointers and do the reset */ 359 mutex_lock(&(us->dev_mutex)); 360 result = us->transport_reset(us); 361 mutex_unlock(&us->dev_mutex); 362 363 return result < 0 ? FAILED : SUCCESS; 364} 365 366/* Simulate a SCSI bus reset by resetting the device's USB port. */ 367static int bus_reset(struct scsi_cmnd *srb) 368{ 369 struct us_data *us = host_to_us(srb->device->host); 370 int result; 371 372 US_DEBUGP("%s called\n", __func__); 373 result = usb_stor_port_reset(us); 374 return result < 0 ? FAILED : SUCCESS; 375} 376 377/* Report a driver-initiated device reset to the SCSI layer. 378 * Calling this for a SCSI-initiated reset is unnecessary but harmless. 379 * The caller must own the SCSI host lock. */ 380void usb_stor_report_device_reset(struct us_data *us) 381{ 382 int i; 383 struct Scsi_Host *host = us_to_host(us); 384 385 scsi_report_device_reset(host, 0, 0); 386 if (us->fflags & US_FL_SCM_MULT_TARG) { 387 for (i = 1; i < host->max_id; ++i) 388 scsi_report_device_reset(host, 0, i); 389 } 390} 391 392/* Report a driver-initiated bus reset to the SCSI layer. 393 * Calling this for a SCSI-initiated reset is unnecessary but harmless. 394 * The caller must not own the SCSI host lock. */ 395void usb_stor_report_bus_reset(struct us_data *us) 396{ 397 struct Scsi_Host *host = us_to_host(us); 398 399 scsi_lock(host); 400 scsi_report_bus_reset(host, 0); 401 scsi_unlock(host); 402} 403 404/*********************************************************************** 405 * /proc/scsi/ functions 406 ***********************************************************************/ 407 408/* we use this macro to help us write into the buffer */ 409#undef SPRINTF 410#define SPRINTF(args...) \ 411 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0) 412 413static int proc_info (struct Scsi_Host *host, char *buffer, 414 char **start, off_t offset, int length, int inout) 415{ 416 struct us_data *us = host_to_us(host); 417 char *pos = buffer; 418 const char *string; 419 420 /* if someone is sending us data, just throw it away */ 421 if (inout) 422 return length; 423 424 /* print the controller name */ 425 SPRINTF(" Host scsi%d: usb-storage\n", host->host_no); 426 427 /* print product, vendor, and serial number strings */ 428 if (us->pusb_dev->manufacturer) 429 string = us->pusb_dev->manufacturer; 430 else if (us->unusual_dev->vendorName) 431 string = us->unusual_dev->vendorName; 432 else 433 string = "Unknown"; 434 SPRINTF(" Vendor: %s\n", string); 435 if (us->pusb_dev->product) 436 string = us->pusb_dev->product; 437 else if (us->unusual_dev->productName) 438 string = us->unusual_dev->productName; 439 else 440 string = "Unknown"; 441 SPRINTF(" Product: %s\n", string); 442 if (us->pusb_dev->serial) 443 string = us->pusb_dev->serial; 444 else 445 string = "None"; 446 SPRINTF("Serial Number: %s\n", string); 447 448 /* show the protocol and transport */ 449 SPRINTF(" Protocol: %s\n", us->protocol_name); 450 SPRINTF(" Transport: %s\n", us->transport_name); 451 452 /* show the device flags */ 453 if (pos < buffer + length) { 454 pos += sprintf(pos, " Quirks:"); 455 456#define US_FLAG(name, value) \ 457 if (us->fflags & value) pos += sprintf(pos, " " #name); 458US_DO_ALL_FLAGS 459#undef US_FLAG 460 461 *(pos++) = '\n'; 462 } 463 464 /* 465 * Calculate start of next buffer, and return value. 466 */ 467 *start = buffer + offset; 468 469 if ((pos - buffer) < offset) 470 return (0); 471 else if ((pos - buffer - offset) < length) 472 return (pos - buffer - offset); 473 else 474 return (length); 475} 476 477/*********************************************************************** 478 * Sysfs interface 479 ***********************************************************************/ 480 481/* Output routine for the sysfs max_sectors file */ 482static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf) 483{ 484 struct scsi_device *sdev = to_scsi_device(dev); 485 486 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue)); 487} 488 489/* Input routine for the sysfs max_sectors file */ 490static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf, 491 size_t count) 492{ 493 struct scsi_device *sdev = to_scsi_device(dev); 494 unsigned short ms; 495 496 if (sscanf(buf, "%hu", &ms) > 0) { 497 blk_queue_max_hw_sectors(sdev->request_queue, ms); 498 return count; 499 } 500 return -EINVAL; 501} 502 503static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors, 504 store_max_sectors); 505 506static struct device_attribute *sysfs_device_attr_list[] = { 507 &dev_attr_max_sectors, 508 NULL, 509 }; 510 511/* 512 * this defines our host template, with which we'll allocate hosts 513 */ 514 515struct scsi_host_template usb_stor_host_template = { 516 /* basic userland interface stuff */ 517 .name = "usb-storage", 518 .proc_name = "usb-storage", 519 .proc_info = proc_info, 520 .info = host_info, 521 522 /* command interface -- queued only */ 523 .queuecommand = queuecommand, 524 525 /* error and abort handlers */ 526 .eh_abort_handler = command_abort, 527 .eh_device_reset_handler = device_reset, 528 .eh_bus_reset_handler = bus_reset, 529 530 /* queue commands only, only one command per LUN */ 531 .can_queue = 1, 532 .cmd_per_lun = 1, 533 534 /* unknown initiator id */ 535 .this_id = -1, 536 537 .slave_alloc = slave_alloc, 538 .slave_configure = slave_configure, 539 540 /* lots of sg segments can be handled */ 541 .sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS, 542 543#ifdef CONFIG_BCM47XX 544 .max_sectors = 960, 545#else 546 /* limit the total size of a transfer to 120 KB */ 547 .max_sectors = 240, 548#endif 549 550 /* merge commands... this seems to help performance, but 551 * periodically someone should test to see which setting is more 552 * optimal. 553 */ 554 .use_clustering = 1, 555 556 /* emulated HBA */ 557 .emulated = 1, 558 559 /* we do our own delay after a device or bus reset */ 560 .skip_settle_delay = 1, 561 562 /* sysfs device attributes */ 563 .sdev_attrs = sysfs_device_attr_list, 564 565 /* module management */ 566 .module = THIS_MODULE 567}; 568 569/* To Report "Illegal Request: Invalid Field in CDB */ 570unsigned char usb_stor_sense_invalidCDB[18] = { 571 [0] = 0x70, /* current error */ 572 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */ 573 [7] = 0x0a, /* additional length */ 574 [12] = 0x24 /* Invalid Field in CDB */ 575}; 576EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB); 577