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
host_info(struct Scsi_Host * host)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
slave_alloc(struct scsi_device * sdev)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
slave_configure(struct scsi_device * sdev)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 /*
227 * assume SPC3 or latter devices support sense size > 18
228 * unless US_FL_BAD_SENSE quirk is specified.
229 */
230 if (sdev->scsi_level > SCSI_SPC_2 &&
231 !(us->fflags & US_FL_BAD_SENSE))
232 us->fflags |= US_FL_SANE_SENSE;
233
234 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
235 * Hardware Error) when any low-level error occurs,
236 * recoverable or not. Setting this flag tells the SCSI
237 * midlayer to retry such commands, which frequently will
238 * succeed and fix the error. The worst this can lead to
239 * is an occasional series of retries that will all fail. */
240 sdev->retry_hwerror = 1;
241
242 /* USB disks should allow restart. Some drives spin down
243 * automatically, requiring a START-STOP UNIT command. */
244 sdev->allow_restart = 1;
245
246 /* Some USB cardreaders have trouble reading an sdcard's last
247 * sector in a larger then 1 sector read, since the performance
248 * impact is negligible we set this flag for all USB disks */
249 sdev->last_sector_bug = 1;
250
251 /* Enable last-sector hacks for single-target devices using
252 * the Bulk-only transport, unless we already know the
253 * capacity will be decremented or is correct. */
254 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
255 US_FL_SCM_MULT_TARG)) &&
256 us->protocol == USB_PR_BULK)
257 us->use_last_sector_hacks = 1;
258
259 /* Check if write cache default on flag is set or not */
260 if (us->fflags & US_FL_WRITE_CACHE)
261 sdev->wce_default_on = 1;
262
263 /* A few buggy USB-ATA bridges don't understand FUA */
264 if (us->fflags & US_FL_BROKEN_FUA)
265 sdev->broken_fua = 1;
266
267 } else {
268
269 /* Non-disk-type devices don't need to blacklist any pages
270 * or to force 192-byte transfer lengths for MODE SENSE.
271 * But they do need to use MODE SENSE(10). */
272 sdev->use_10_for_ms = 1;
273
274 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
275 if (us->fflags & US_FL_NO_READ_DISC_INFO)
276 sdev->no_read_disc_info = 1;
277 }
278
279 /* The CB and CBI transports have no way to pass LUN values
280 * other than the bits in the second byte of a CDB. But those
281 * bits don't get set to the LUN value if the device reports
282 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
283 * be single-LUN.
284 */
285 if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
286 sdev->scsi_level == SCSI_UNKNOWN)
287 us->max_lun = 0;
288
289 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
290 * REMOVAL command, so suppress those commands. */
291 if (us->fflags & US_FL_NOT_LOCKABLE)
292 sdev->lockable = 0;
293
294 /* this is to satisfy the compiler, tho I don't think the
295 * return code is ever checked anywhere. */
296 return 0;
297 }
298
target_alloc(struct scsi_target * starget)299 static int target_alloc(struct scsi_target *starget)
300 {
301 struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
302
303 /*
304 * Some USB drives don't support REPORT LUNS, even though they
305 * report a SCSI revision level above 2. Tell the SCSI layer
306 * not to issue that command; it will perform a normal sequential
307 * scan instead.
308 */
309 starget->no_report_luns = 1;
310
311 /*
312 * The UFI spec treats the Peripheral Qualifier bits in an
313 * INQUIRY result as reserved and requires devices to set them
314 * to 0. However the SCSI spec requires these bits to be set
315 * to 3 to indicate when a LUN is not present.
316 *
317 * Let the scanning code know if this target merely sets
318 * Peripheral Device Type to 0x1f to indicate no LUN.
319 */
320 if (us->subclass == USB_SC_UFI)
321 starget->pdt_1f_for_no_lun = 1;
322
323 return 0;
324 }
325
326 /* queue a command */
327 /* This is always called with scsi_lock(host) held */
queuecommand_lck(struct scsi_cmnd * srb,void (* done)(struct scsi_cmnd *))328 static int queuecommand_lck(struct scsi_cmnd *srb,
329 void (*done)(struct scsi_cmnd *))
330 {
331 struct us_data *us = host_to_us(srb->device->host);
332
333 /* check for state-transition errors */
334 if (us->srb != NULL) {
335 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
336 __func__, us->srb);
337 return SCSI_MLQUEUE_HOST_BUSY;
338 }
339
340 /* fail the command if we are disconnecting */
341 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
342 usb_stor_dbg(us, "Fail command during disconnect\n");
343 srb->result = DID_NO_CONNECT << 16;
344 done(srb);
345 return 0;
346 }
347
348 if ((us->fflags & US_FL_NO_ATA_1X) &&
349 (srb->cmnd[0] == ATA_12 || srb->cmnd[0] == ATA_16)) {
350 memcpy(srb->sense_buffer, usb_stor_sense_invalidCDB,
351 sizeof(usb_stor_sense_invalidCDB));
352 srb->result = SAM_STAT_CHECK_CONDITION;
353 done(srb);
354 return 0;
355 }
356
357 /* enqueue the command and wake up the control thread */
358 srb->scsi_done = done;
359 us->srb = srb;
360 complete(&us->cmnd_ready);
361
362 return 0;
363 }
364
DEF_SCSI_QCMD(queuecommand)365 static DEF_SCSI_QCMD(queuecommand)
366
367 /***********************************************************************
368 * Error handling functions
369 ***********************************************************************/
370
371 /* Command timeout and abort */
372 static int command_abort(struct scsi_cmnd *srb)
373 {
374 struct us_data *us = host_to_us(srb->device->host);
375
376 usb_stor_dbg(us, "%s called\n", __func__);
377
378 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
379 * bits are protected by the host lock. */
380 scsi_lock(us_to_host(us));
381
382 /* Is this command still active? */
383 if (us->srb != srb) {
384 scsi_unlock(us_to_host(us));
385 usb_stor_dbg(us, "-- nothing to abort\n");
386 return FAILED;
387 }
388
389 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
390 * a device reset isn't already in progress (to avoid interfering
391 * with the reset). Note that we must retain the host lock while
392 * calling usb_stor_stop_transport(); otherwise it might interfere
393 * with an auto-reset that begins as soon as we release the lock. */
394 set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
395 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
396 set_bit(US_FLIDX_ABORTING, &us->dflags);
397 usb_stor_stop_transport(us);
398 }
399 scsi_unlock(us_to_host(us));
400
401 /* Wait for the aborted command to finish */
402 wait_for_completion(&us->notify);
403 return SUCCESS;
404 }
405
406 /* This invokes the transport reset mechanism to reset the state of the
407 * device */
device_reset(struct scsi_cmnd * srb)408 static int device_reset(struct scsi_cmnd *srb)
409 {
410 struct us_data *us = host_to_us(srb->device->host);
411 int result;
412
413 usb_stor_dbg(us, "%s called\n", __func__);
414
415 /* lock the device pointers and do the reset */
416 mutex_lock(&(us->dev_mutex));
417 result = us->transport_reset(us);
418 mutex_unlock(&us->dev_mutex);
419
420 return result < 0 ? FAILED : SUCCESS;
421 }
422
423 /* Simulate a SCSI bus reset by resetting the device's USB port. */
bus_reset(struct scsi_cmnd * srb)424 static int bus_reset(struct scsi_cmnd *srb)
425 {
426 struct us_data *us = host_to_us(srb->device->host);
427 int result;
428
429 usb_stor_dbg(us, "%s called\n", __func__);
430
431 result = usb_stor_port_reset(us);
432 return result < 0 ? FAILED : SUCCESS;
433 }
434
435 /* Report a driver-initiated device reset to the SCSI layer.
436 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
437 * The caller must own the SCSI host lock. */
usb_stor_report_device_reset(struct us_data * us)438 void usb_stor_report_device_reset(struct us_data *us)
439 {
440 int i;
441 struct Scsi_Host *host = us_to_host(us);
442
443 scsi_report_device_reset(host, 0, 0);
444 if (us->fflags & US_FL_SCM_MULT_TARG) {
445 for (i = 1; i < host->max_id; ++i)
446 scsi_report_device_reset(host, 0, i);
447 }
448 }
449
450 /* Report a driver-initiated bus reset to the SCSI layer.
451 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
452 * The caller must not own the SCSI host lock. */
usb_stor_report_bus_reset(struct us_data * us)453 void usb_stor_report_bus_reset(struct us_data *us)
454 {
455 struct Scsi_Host *host = us_to_host(us);
456
457 scsi_lock(host);
458 scsi_report_bus_reset(host, 0);
459 scsi_unlock(host);
460 }
461
462 /***********************************************************************
463 * /proc/scsi/ functions
464 ***********************************************************************/
465
write_info(struct Scsi_Host * host,char * buffer,int length)466 static int write_info(struct Scsi_Host *host, char *buffer, int length)
467 {
468 /* if someone is sending us data, just throw it away */
469 return length;
470 }
471
show_info(struct seq_file * m,struct Scsi_Host * host)472 static int show_info (struct seq_file *m, struct Scsi_Host *host)
473 {
474 struct us_data *us = host_to_us(host);
475 const char *string;
476
477 /* print the controller name */
478 seq_printf(m, " Host scsi%d: usb-storage\n", host->host_no);
479
480 /* print product, vendor, and serial number strings */
481 if (us->pusb_dev->manufacturer)
482 string = us->pusb_dev->manufacturer;
483 else if (us->unusual_dev->vendorName)
484 string = us->unusual_dev->vendorName;
485 else
486 string = "Unknown";
487 seq_printf(m, " Vendor: %s\n", string);
488 if (us->pusb_dev->product)
489 string = us->pusb_dev->product;
490 else if (us->unusual_dev->productName)
491 string = us->unusual_dev->productName;
492 else
493 string = "Unknown";
494 seq_printf(m, " Product: %s\n", string);
495 if (us->pusb_dev->serial)
496 string = us->pusb_dev->serial;
497 else
498 string = "None";
499 seq_printf(m, "Serial Number: %s\n", string);
500
501 /* show the protocol and transport */
502 seq_printf(m, " Protocol: %s\n", us->protocol_name);
503 seq_printf(m, " Transport: %s\n", us->transport_name);
504
505 /* show the device flags */
506 seq_printf(m, " Quirks:");
507
508 #define US_FLAG(name, value) \
509 if (us->fflags & value) seq_printf(m, " " #name);
510 US_DO_ALL_FLAGS
511 #undef US_FLAG
512 seq_putc(m, '\n');
513 return 0;
514 }
515
516 /***********************************************************************
517 * Sysfs interface
518 ***********************************************************************/
519
520 /* Output routine for the sysfs max_sectors file */
max_sectors_show(struct device * dev,struct device_attribute * attr,char * buf)521 static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
522 {
523 struct scsi_device *sdev = to_scsi_device(dev);
524
525 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
526 }
527
528 /* Input routine for the sysfs max_sectors file */
max_sectors_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)529 static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
530 size_t count)
531 {
532 struct scsi_device *sdev = to_scsi_device(dev);
533 unsigned short ms;
534
535 if (sscanf(buf, "%hu", &ms) > 0) {
536 blk_queue_max_hw_sectors(sdev->request_queue, ms);
537 return count;
538 }
539 return -EINVAL;
540 }
541 static DEVICE_ATTR_RW(max_sectors);
542
543 static struct device_attribute *sysfs_device_attr_list[] = {
544 &dev_attr_max_sectors,
545 NULL,
546 };
547
548 /*
549 * this defines our host template, with which we'll allocate hosts
550 */
551
552 static const struct scsi_host_template usb_stor_host_template = {
553 /* basic userland interface stuff */
554 .name = "usb-storage",
555 .proc_name = "usb-storage",
556 .show_info = show_info,
557 .write_info = write_info,
558 .info = host_info,
559
560 /* command interface -- queued only */
561 .queuecommand = queuecommand,
562
563 /* error and abort handlers */
564 .eh_abort_handler = command_abort,
565 .eh_device_reset_handler = device_reset,
566 .eh_bus_reset_handler = bus_reset,
567
568 /* queue commands only, only one command per LUN */
569 .can_queue = 1,
570
571 /* unknown initiator id */
572 .this_id = -1,
573
574 .slave_alloc = slave_alloc,
575 .slave_configure = slave_configure,
576 .target_alloc = target_alloc,
577
578 /* lots of sg segments can be handled */
579 .sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS,
580
581 /* limit the total size of a transfer to 120 KB */
582 .max_sectors = 240,
583
584 /* merge commands... this seems to help performance, but
585 * periodically someone should test to see which setting is more
586 * optimal.
587 */
588 .use_clustering = 1,
589
590 /* emulated HBA */
591 .emulated = 1,
592
593 /* we do our own delay after a device or bus reset */
594 .skip_settle_delay = 1,
595
596 /* sysfs device attributes */
597 .sdev_attrs = sysfs_device_attr_list,
598
599 /* module management */
600 .module = THIS_MODULE
601 };
602
usb_stor_host_template_init(struct scsi_host_template * sht,const char * name,struct module * owner)603 void usb_stor_host_template_init(struct scsi_host_template *sht,
604 const char *name, struct module *owner)
605 {
606 *sht = usb_stor_host_template;
607 sht->name = name;
608 sht->proc_name = name;
609 sht->module = owner;
610 }
611 EXPORT_SYMBOL_GPL(usb_stor_host_template_init);
612
613 /* To Report "Illegal Request: Invalid Field in CDB */
614 unsigned char usb_stor_sense_invalidCDB[18] = {
615 [0] = 0x70, /* current error */
616 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
617 [7] = 0x0a, /* additional length */
618 [12] = 0x24 /* Invalid Field in CDB */
619 };
620 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);
621