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/slab.h>
47 #include <linux/module.h>
48 #include <linux/mutex.h>
49
50 #include <scsi/scsi.h>
51 #include <scsi/scsi_cmnd.h>
52 #include <scsi/scsi_devinfo.h>
53 #include <scsi/scsi_device.h>
54 #include <scsi/scsi_eh.h>
55
56 #include "usb.h"
57 #include "scsiglue.h"
58 #include "debug.h"
59 #include "transport.h"
60 #include "protocol.h"
61
62 /* Vendor IDs for companies that seem to include the READ CAPACITY bug
63 * in all their devices
64 */
65 #define VENDOR_ID_NOKIA 0x0421
66 #define VENDOR_ID_NIKON 0x04b0
67 #define VENDOR_ID_PENTAX 0x0a17
68 #define VENDOR_ID_MOTOROLA 0x22b8
69
70 /***********************************************************************
71 * Host functions
72 ***********************************************************************/
73
host_info(struct Scsi_Host * host)74 static const char* host_info(struct Scsi_Host *host)
75 {
76 return "SCSI emulation for USB Mass Storage devices";
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 /*
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
slave_configure(struct scsi_device * sdev)122 static 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 (sdev->request_queue->max_sectors > max_sectors)
136 blk_queue_max_sectors(sdev->request_queue,
137 max_sectors);
138 }
139
140 /* Some USB host controllers can't do DMA; they have to use PIO.
141 * They indicate this by setting their dma_mask to NULL. For
142 * such controllers we need to make sure the block layer sets
143 * up bounce buffers in addressable memory.
144 */
145 if (!us->pusb_dev->bus->controller->dma_mask)
146 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
147
148 /* We can't put these settings in slave_alloc() because that gets
149 * called before the device type is known. Consequently these
150 * settings can't be overridden via the scsi devinfo mechanism. */
151 if (sdev->type == TYPE_DISK) {
152
153 /* Some vendors seem to put the READ CAPACITY bug into
154 * all their devices -- primarily makers of cell phones
155 * and digital cameras. Since these devices always use
156 * flash media and can be expected to have an even number
157 * of sectors, we will always enable the CAPACITY_HEURISTICS
158 * flag unless told otherwise. */
159 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
160 case VENDOR_ID_NOKIA:
161 case VENDOR_ID_NIKON:
162 case VENDOR_ID_PENTAX:
163 case VENDOR_ID_MOTOROLA:
164 if (!(us->fflags & (US_FL_FIX_CAPACITY |
165 US_FL_CAPACITY_OK)))
166 us->fflags |= US_FL_CAPACITY_HEURISTICS;
167 break;
168 }
169
170 /* Disk-type devices use MODE SENSE(6) if the protocol
171 * (SubClass) is Transparent SCSI, otherwise they use
172 * MODE SENSE(10). */
173 if (us->subclass != US_SC_SCSI && us->subclass != US_SC_CYP_ATACB)
174 sdev->use_10_for_ms = 1;
175
176 /* Many disks only accept MODE SENSE transfer lengths of
177 * 192 bytes (that's what Windows uses). */
178 sdev->use_192_bytes_for_3f = 1;
179
180 /* Some devices don't like MODE SENSE with page=0x3f,
181 * which is the command used for checking if a device
182 * is write-protected. Now that we tell the sd driver
183 * to do a 192-byte transfer with this command the
184 * majority of devices work fine, but a few still can't
185 * handle it. The sd driver will simply assume those
186 * devices are write-enabled. */
187 if (us->fflags & US_FL_NO_WP_DETECT)
188 sdev->skip_ms_page_3f = 1;
189
190 /* A number of devices have problems with MODE SENSE for
191 * page x08, so we will skip it. */
192 sdev->skip_ms_page_8 = 1;
193
194 /* Some disks return the total number of blocks in response
195 * to READ CAPACITY rather than the highest block number.
196 * If this device makes that mistake, tell the sd driver. */
197 if (us->fflags & US_FL_FIX_CAPACITY)
198 sdev->fix_capacity = 1;
199
200 /* A few disks have two indistinguishable version, one of
201 * which reports the correct capacity and the other does not.
202 * The sd driver has to guess which is the case. */
203 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
204 sdev->guess_capacity = 1;
205
206 /* assume SPC3 or latter devices support sense size > 18 */
207 if (sdev->scsi_level > SCSI_SPC_2)
208 us->fflags |= US_FL_SANE_SENSE;
209
210 /* Some devices report a SCSI revision level above 2 but are
211 * unable to handle the REPORT LUNS command (for which
212 * support is mandatory at level 3). Since we already have
213 * a Get-Max-LUN request, we won't lose much by setting the
214 * revision level down to 2. The only devices that would be
215 * affected are those with sparse LUNs. */
216 if (sdev->scsi_level > SCSI_2)
217 sdev->sdev_target->scsi_level =
218 sdev->scsi_level = SCSI_2;
219
220 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
221 * Hardware Error) when any low-level error occurs,
222 * recoverable or not. Setting this flag tells the SCSI
223 * midlayer to retry such commands, which frequently will
224 * succeed and fix the error. The worst this can lead to
225 * is an occasional series of retries that will all fail. */
226 sdev->retry_hwerror = 1;
227
228 /* USB disks should allow restart. Some drives spin down
229 * automatically, requiring a START-STOP UNIT command. */
230 sdev->allow_restart = 1;
231
232 /* Some USB cardreaders have trouble reading an sdcard's last
233 * sector in a larger then 1 sector read, since the performance
234 * impact is negible we set this flag for all USB disks */
235 sdev->last_sector_bug = 1;
236
237 /* Enable last-sector hacks for single-target devices using
238 * the Bulk-only transport, unless we already know the
239 * capacity will be decremented or is correct. */
240 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
241 US_FL_SCM_MULT_TARG)) &&
242 us->protocol == US_PR_BULK)
243 us->use_last_sector_hacks = 1;
244 } else {
245
246 /* Non-disk-type devices don't need to blacklist any pages
247 * or to force 192-byte transfer lengths for MODE SENSE.
248 * But they do need to use MODE SENSE(10). */
249 sdev->use_10_for_ms = 1;
250 }
251
252 /* The CB and CBI transports have no way to pass LUN values
253 * other than the bits in the second byte of a CDB. But those
254 * bits don't get set to the LUN value if the device reports
255 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
256 * be single-LUN.
257 */
258 if ((us->protocol == US_PR_CB || us->protocol == US_PR_CBI) &&
259 sdev->scsi_level == SCSI_UNKNOWN)
260 us->max_lun = 0;
261
262 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
263 * REMOVAL command, so suppress those commands. */
264 if (us->fflags & US_FL_NOT_LOCKABLE)
265 sdev->lockable = 0;
266
267 /* this is to satisfy the compiler, tho I don't think the
268 * return code is ever checked anywhere. */
269 return 0;
270 }
271
272 /* queue a command */
273 /* This is always called with scsi_lock(host) held */
queuecommand(struct scsi_cmnd * srb,void (* done)(struct scsi_cmnd *))274 static int queuecommand(struct scsi_cmnd *srb,
275 void (*done)(struct scsi_cmnd *))
276 {
277 struct us_data *us = host_to_us(srb->device->host);
278
279 US_DEBUGP("%s called\n", __func__);
280
281 /* check for state-transition errors */
282 if (us->srb != NULL) {
283 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
284 __func__, us->srb);
285 return SCSI_MLQUEUE_HOST_BUSY;
286 }
287
288 /* fail the command if we are disconnecting */
289 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
290 US_DEBUGP("Fail command during disconnect\n");
291 srb->result = DID_NO_CONNECT << 16;
292 done(srb);
293 return 0;
294 }
295
296 /* enqueue the command and wake up the control thread */
297 srb->scsi_done = done;
298 us->srb = srb;
299 complete(&us->cmnd_ready);
300
301 return 0;
302 }
303
304 /***********************************************************************
305 * Error handling functions
306 ***********************************************************************/
307
308 /* Command timeout and abort */
command_abort(struct scsi_cmnd * srb)309 static int command_abort(struct scsi_cmnd *srb)
310 {
311 struct us_data *us = host_to_us(srb->device->host);
312
313 US_DEBUGP("%s called\n", __func__);
314
315 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
316 * bits are protected by the host lock. */
317 scsi_lock(us_to_host(us));
318
319 /* Is this command still active? */
320 if (us->srb != srb) {
321 scsi_unlock(us_to_host(us));
322 US_DEBUGP ("-- nothing to abort\n");
323 return FAILED;
324 }
325
326 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
327 * a device reset isn't already in progress (to avoid interfering
328 * with the reset). Note that we must retain the host lock while
329 * calling usb_stor_stop_transport(); otherwise it might interfere
330 * with an auto-reset that begins as soon as we release the lock. */
331 set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
332 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
333 set_bit(US_FLIDX_ABORTING, &us->dflags);
334 usb_stor_stop_transport(us);
335 }
336 scsi_unlock(us_to_host(us));
337
338 /* Wait for the aborted command to finish */
339 wait_for_completion(&us->notify);
340 return SUCCESS;
341 }
342
343 /* This invokes the transport reset mechanism to reset the state of the
344 * device */
device_reset(struct scsi_cmnd * srb)345 static int device_reset(struct scsi_cmnd *srb)
346 {
347 struct us_data *us = host_to_us(srb->device->host);
348 int result;
349
350 US_DEBUGP("%s called\n", __func__);
351
352 /* lock the device pointers and do the reset */
353 mutex_lock(&(us->dev_mutex));
354 result = us->transport_reset(us);
355 mutex_unlock(&us->dev_mutex);
356
357 return result < 0 ? FAILED : SUCCESS;
358 }
359
360 /* Simulate a SCSI bus reset by resetting the device's USB port. */
bus_reset(struct scsi_cmnd * srb)361 static int bus_reset(struct scsi_cmnd *srb)
362 {
363 struct us_data *us = host_to_us(srb->device->host);
364 int result;
365
366 US_DEBUGP("%s called\n", __func__);
367 result = usb_stor_port_reset(us);
368 return result < 0 ? FAILED : SUCCESS;
369 }
370
371 /* Report a driver-initiated device reset to the SCSI layer.
372 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
373 * The caller must own the SCSI host lock. */
usb_stor_report_device_reset(struct us_data * us)374 void usb_stor_report_device_reset(struct us_data *us)
375 {
376 int i;
377 struct Scsi_Host *host = us_to_host(us);
378
379 scsi_report_device_reset(host, 0, 0);
380 if (us->fflags & US_FL_SCM_MULT_TARG) {
381 for (i = 1; i < host->max_id; ++i)
382 scsi_report_device_reset(host, 0, i);
383 }
384 }
385
386 /* Report a driver-initiated bus reset to the SCSI layer.
387 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
388 * The caller must not own the SCSI host lock. */
usb_stor_report_bus_reset(struct us_data * us)389 void usb_stor_report_bus_reset(struct us_data *us)
390 {
391 struct Scsi_Host *host = us_to_host(us);
392
393 scsi_lock(host);
394 scsi_report_bus_reset(host, 0);
395 scsi_unlock(host);
396 }
397
398 /***********************************************************************
399 * /proc/scsi/ functions
400 ***********************************************************************/
401
402 /* we use this macro to help us write into the buffer */
403 #undef SPRINTF
404 #define SPRINTF(args...) \
405 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
406
proc_info(struct Scsi_Host * host,char * buffer,char ** start,off_t offset,int length,int inout)407 static int proc_info (struct Scsi_Host *host, char *buffer,
408 char **start, off_t offset, int length, int inout)
409 {
410 struct us_data *us = host_to_us(host);
411 char *pos = buffer;
412 const char *string;
413
414 /* if someone is sending us data, just throw it away */
415 if (inout)
416 return length;
417
418 /* print the controller name */
419 SPRINTF(" Host scsi%d: usb-storage\n", host->host_no);
420
421 /* print product, vendor, and serial number strings */
422 if (us->pusb_dev->manufacturer)
423 string = us->pusb_dev->manufacturer;
424 else if (us->unusual_dev->vendorName)
425 string = us->unusual_dev->vendorName;
426 else
427 string = "Unknown";
428 SPRINTF(" Vendor: %s\n", string);
429 if (us->pusb_dev->product)
430 string = us->pusb_dev->product;
431 else if (us->unusual_dev->productName)
432 string = us->unusual_dev->productName;
433 else
434 string = "Unknown";
435 SPRINTF(" Product: %s\n", string);
436 if (us->pusb_dev->serial)
437 string = us->pusb_dev->serial;
438 else
439 string = "None";
440 SPRINTF("Serial Number: %s\n", string);
441
442 /* show the protocol and transport */
443 SPRINTF(" Protocol: %s\n", us->protocol_name);
444 SPRINTF(" Transport: %s\n", us->transport_name);
445
446 /* show the device flags */
447 if (pos < buffer + length) {
448 pos += sprintf(pos, " Quirks:");
449
450 #define US_FLAG(name, value) \
451 if (us->fflags & value) pos += sprintf(pos, " " #name);
452 US_DO_ALL_FLAGS
453 #undef US_FLAG
454
455 *(pos++) = '\n';
456 }
457
458 /*
459 * Calculate start of next buffer, and return value.
460 */
461 *start = buffer + offset;
462
463 if ((pos - buffer) < offset)
464 return (0);
465 else if ((pos - buffer - offset) < length)
466 return (pos - buffer - offset);
467 else
468 return (length);
469 }
470
471 /***********************************************************************
472 * Sysfs interface
473 ***********************************************************************/
474
475 /* Output routine for the sysfs max_sectors file */
show_max_sectors(struct device * dev,struct device_attribute * attr,char * buf)476 static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf)
477 {
478 struct scsi_device *sdev = to_scsi_device(dev);
479
480 return sprintf(buf, "%u\n", sdev->request_queue->max_sectors);
481 }
482
483 /* Input routine for the sysfs max_sectors file */
store_max_sectors(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)484 static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf,
485 size_t count)
486 {
487 struct scsi_device *sdev = to_scsi_device(dev);
488 unsigned short ms;
489
490 if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
491 blk_queue_max_sectors(sdev->request_queue, ms);
492 return strlen(buf);
493 }
494 return -EINVAL;
495 }
496
497 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
498 store_max_sectors);
499
500 static struct device_attribute *sysfs_device_attr_list[] = {
501 &dev_attr_max_sectors,
502 NULL,
503 };
504
505 /*
506 * this defines our host template, with which we'll allocate hosts
507 */
508
509 struct scsi_host_template usb_stor_host_template = {
510 /* basic userland interface stuff */
511 .name = "usb-storage",
512 .proc_name = "usb-storage",
513 .proc_info = proc_info,
514 .info = host_info,
515
516 /* command interface -- queued only */
517 .queuecommand = queuecommand,
518
519 /* error and abort handlers */
520 .eh_abort_handler = command_abort,
521 .eh_device_reset_handler = device_reset,
522 .eh_bus_reset_handler = bus_reset,
523
524 /* queue commands only, only one command per LUN */
525 .can_queue = 1,
526 .cmd_per_lun = 1,
527
528 /* unknown initiator id */
529 .this_id = -1,
530
531 .slave_alloc = slave_alloc,
532 .slave_configure = slave_configure,
533
534 /* lots of sg segments can be handled */
535 .sg_tablesize = SG_ALL,
536
537 /* limit the total size of a transfer to 120 KB */
538 .max_sectors = 240,
539
540 /* merge commands... this seems to help performance, but
541 * periodically someone should test to see which setting is more
542 * optimal.
543 */
544 .use_clustering = 1,
545
546 /* emulated HBA */
547 .emulated = 1,
548
549 /* we do our own delay after a device or bus reset */
550 .skip_settle_delay = 1,
551
552 /* sysfs device attributes */
553 .sdev_attrs = sysfs_device_attr_list,
554
555 /* module management */
556 .module = THIS_MODULE
557 };
558
559 /* To Report "Illegal Request: Invalid Field in CDB */
560 unsigned char usb_stor_sense_invalidCDB[18] = {
561 [0] = 0x70, /* current error */
562 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
563 [7] = 0x0a, /* additional length */
564 [12] = 0x24 /* Invalid Field in CDB */
565 };
566
567