Branch data Line data Source code
1 : : // SPDX-License-Identifier: GPL-2.0+
2 : : /*
3 : : * Driver for USB Mass Storage compliant devices
4 : : * SCSI layer glue code
5 : : *
6 : : * Current development and maintenance by:
7 : : * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
8 : : *
9 : : * Developed with the assistance of:
10 : : * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
11 : : * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
12 : : *
13 : : * Initial work by:
14 : : * (c) 1999 Michael Gee (michael@linuxspecific.com)
15 : : *
16 : : * This driver is based on the 'USB Mass Storage Class' document. This
17 : : * describes in detail the protocol used to communicate with such
18 : : * devices. Clearly, the designers had SCSI and ATAPI commands in
19 : : * mind when they created this document. The commands are all very
20 : : * similar to commands in the SCSI-II and ATAPI specifications.
21 : : *
22 : : * It is important to note that in a number of cases this class
23 : : * exhibits class-specific exemptions from the USB specification.
24 : : * Notably the usage of NAK, STALL and ACK differs from the norm, in
25 : : * that they are used to communicate wait, failed and OK on commands.
26 : : *
27 : : * Also, for certain devices, the interrupt endpoint is used to convey
28 : : * status of a command.
29 : : */
30 : :
31 : : #include <linux/blkdev.h>
32 : : #include <linux/dma-mapping.h>
33 : : #include <linux/module.h>
34 : : #include <linux/mutex.h>
35 : :
36 : : #include <scsi/scsi.h>
37 : : #include <scsi/scsi_cmnd.h>
38 : : #include <scsi/scsi_devinfo.h>
39 : : #include <scsi/scsi_device.h>
40 : : #include <scsi/scsi_eh.h>
41 : :
42 : : #include "usb.h"
43 : : #include <linux/usb/hcd.h>
44 : : #include "scsiglue.h"
45 : : #include "debug.h"
46 : : #include "transport.h"
47 : : #include "protocol.h"
48 : :
49 : : /*
50 : : * Vendor IDs for companies that seem to include the READ CAPACITY bug
51 : : * in all their devices
52 : : */
53 : : #define VENDOR_ID_NOKIA 0x0421
54 : : #define VENDOR_ID_NIKON 0x04b0
55 : : #define VENDOR_ID_PENTAX 0x0a17
56 : : #define VENDOR_ID_MOTOROLA 0x22b8
57 : :
58 : : /***********************************************************************
59 : : * Host functions
60 : : ***********************************************************************/
61 : :
62 : 0 : static const char* host_info(struct Scsi_Host *host)
63 : : {
64 : : struct us_data *us = host_to_us(host);
65 : 0 : return us->scsi_name;
66 : : }
67 : :
68 : 0 : static int slave_alloc (struct scsi_device *sdev)
69 : : {
70 : 0 : struct us_data *us = host_to_us(sdev->host);
71 : :
72 : : /*
73 : : * Set the INQUIRY transfer length to 36. We don't use any of
74 : : * the extra data and many devices choke if asked for more or
75 : : * less than 36 bytes.
76 : : */
77 : 0 : sdev->inquiry_len = 36;
78 : :
79 : : /*
80 : : * Some host controllers may have alignment requirements.
81 : : * We'll play it safe by requiring 512-byte alignment always.
82 : : */
83 : 0 : blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
84 : :
85 : : /* Tell the SCSI layer if we know there is more than one LUN */
86 : 0 : if (us->protocol == USB_PR_BULK && us->max_lun > 0)
87 : 0 : sdev->sdev_bflags |= BLIST_FORCELUN;
88 : :
89 : 0 : return 0;
90 : : }
91 : :
92 : 0 : static int slave_configure(struct scsi_device *sdev)
93 : : {
94 : 0 : struct us_data *us = host_to_us(sdev->host);
95 : 0 : struct device *dev = us->pusb_dev->bus->sysdev;
96 : :
97 : : /*
98 : : * Many devices have trouble transferring more than 32KB at a time,
99 : : * while others have trouble with more than 64K. At this time we
100 : : * are limiting both to 32K (64 sectores).
101 : : */
102 : 0 : if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
103 : : unsigned int max_sectors = 64;
104 : :
105 : 0 : if (us->fflags & US_FL_MAX_SECTORS_MIN)
106 : : max_sectors = PAGE_SIZE >> 9;
107 : 0 : if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
108 : 0 : blk_queue_max_hw_sectors(sdev->request_queue,
109 : : max_sectors);
110 : 0 : } else if (sdev->type == TYPE_TAPE) {
111 : : /*
112 : : * Tapes need much higher max_sector limits, so just
113 : : * raise it to the maximum possible (4 GB / 512) and
114 : : * let the queue segment size sort out the real limit.
115 : : */
116 : 0 : blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
117 : 0 : } else if (us->pusb_dev->speed >= USB_SPEED_SUPER) {
118 : : /*
119 : : * USB3 devices will be limited to 2048 sectors. This gives us
120 : : * better throughput on most devices.
121 : : */
122 : 0 : blk_queue_max_hw_sectors(sdev->request_queue, 2048);
123 : : }
124 : :
125 : : /*
126 : : * The max_hw_sectors should be up to maximum size of a mapping for
127 : : * the device. Otherwise, a DMA API might fail on swiotlb environment.
128 : : */
129 : 0 : blk_queue_max_hw_sectors(sdev->request_queue,
130 : 0 : min_t(size_t, queue_max_hw_sectors(sdev->request_queue),
131 : : dma_max_mapping_size(dev) >> SECTOR_SHIFT));
132 : :
133 : : /*
134 : : * Some USB host controllers can't do DMA; they have to use PIO.
135 : : * For such controllers we need to make sure the block layer sets
136 : : * up bounce buffers in addressable memory.
137 : : */
138 : 0 : if (!hcd_uses_dma(bus_to_hcd(us->pusb_dev->bus)) ||
139 : 0 : (bus_to_hcd(us->pusb_dev->bus)->localmem_pool != NULL))
140 : 0 : blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
141 : :
142 : : /*
143 : : * We can't put these settings in slave_alloc() because that gets
144 : : * called before the device type is known. Consequently these
145 : : * settings can't be overridden via the scsi devinfo mechanism.
146 : : */
147 : 0 : if (sdev->type == TYPE_DISK) {
148 : :
149 : : /*
150 : : * Some vendors seem to put the READ CAPACITY bug into
151 : : * all their devices -- primarily makers of cell phones
152 : : * and digital cameras. Since these devices always use
153 : : * flash media and can be expected to have an even number
154 : : * of sectors, we will always enable the CAPACITY_HEURISTICS
155 : : * flag unless told otherwise.
156 : : */
157 : 0 : 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 : 0 : if (!(us->fflags & (US_FL_FIX_CAPACITY |
163 : : US_FL_CAPACITY_OK)))
164 : 0 : us->fflags |= US_FL_CAPACITY_HEURISTICS;
165 : : break;
166 : : }
167 : :
168 : : /*
169 : : * Disk-type devices use MODE SENSE(6) if the protocol
170 : : * (SubClass) is Transparent SCSI, otherwise they use
171 : : * MODE SENSE(10).
172 : : */
173 : 0 : if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
174 : 0 : sdev->use_10_for_ms = 1;
175 : :
176 : : /*
177 : : *Many disks only accept MODE SENSE transfer lengths of
178 : : * 192 bytes (that's what Windows uses).
179 : : */
180 : 0 : sdev->use_192_bytes_for_3f = 1;
181 : :
182 : : /*
183 : : * Some devices don't like MODE SENSE with page=0x3f,
184 : : * which is the command used for checking if a device
185 : : * is write-protected. Now that we tell the sd driver
186 : : * to do a 192-byte transfer with this command the
187 : : * majority of devices work fine, but a few still can't
188 : : * handle it. The sd driver will simply assume those
189 : : * devices are write-enabled.
190 : : */
191 : 0 : if (us->fflags & US_FL_NO_WP_DETECT)
192 : 0 : sdev->skip_ms_page_3f = 1;
193 : :
194 : : /*
195 : : * A number of devices have problems with MODE SENSE for
196 : : * page x08, so we will skip it.
197 : : */
198 : 0 : sdev->skip_ms_page_8 = 1;
199 : :
200 : : /*
201 : : * Some devices don't handle VPD pages correctly, so skip vpd
202 : : * pages if not forced by SCSI layer.
203 : : */
204 : 0 : sdev->skip_vpd_pages = !sdev->try_vpd_pages;
205 : :
206 : : /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
207 : 0 : sdev->no_report_opcodes = 1;
208 : :
209 : : /* Do not attempt to use WRITE SAME */
210 : 0 : sdev->no_write_same = 1;
211 : :
212 : : /*
213 : : * Some disks return the total number of blocks in response
214 : : * to READ CAPACITY rather than the highest block number.
215 : : * If this device makes that mistake, tell the sd driver.
216 : : */
217 : 0 : if (us->fflags & US_FL_FIX_CAPACITY)
218 : 0 : sdev->fix_capacity = 1;
219 : :
220 : : /*
221 : : * A few disks have two indistinguishable version, one of
222 : : * which reports the correct capacity and the other does not.
223 : : * The sd driver has to guess which is the case.
224 : : */
225 : 0 : if (us->fflags & US_FL_CAPACITY_HEURISTICS)
226 : 0 : sdev->guess_capacity = 1;
227 : :
228 : : /* Some devices cannot handle READ_CAPACITY_16 */
229 : 0 : if (us->fflags & US_FL_NO_READ_CAPACITY_16)
230 : 0 : sdev->no_read_capacity_16 = 1;
231 : :
232 : : /*
233 : : * Many devices do not respond properly to READ_CAPACITY_16.
234 : : * Tell the SCSI layer to try READ_CAPACITY_10 first.
235 : : * However some USB 3.0 drive enclosures return capacity
236 : : * modulo 2TB. Those must use READ_CAPACITY_16
237 : : */
238 : 0 : if (!(us->fflags & US_FL_NEEDS_CAP16))
239 : 0 : sdev->try_rc_10_first = 1;
240 : :
241 : : /*
242 : : * assume SPC3 or latter devices support sense size > 18
243 : : * unless US_FL_BAD_SENSE quirk is specified.
244 : : */
245 : 0 : if (sdev->scsi_level > SCSI_SPC_2 &&
246 : 0 : !(us->fflags & US_FL_BAD_SENSE))
247 : 0 : us->fflags |= US_FL_SANE_SENSE;
248 : :
249 : : /*
250 : : * USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
251 : : * Hardware Error) when any low-level error occurs,
252 : : * recoverable or not. Setting this flag tells the SCSI
253 : : * midlayer to retry such commands, which frequently will
254 : : * succeed and fix the error. The worst this can lead to
255 : : * is an occasional series of retries that will all fail.
256 : : */
257 : 0 : sdev->retry_hwerror = 1;
258 : :
259 : : /*
260 : : * USB disks should allow restart. Some drives spin down
261 : : * automatically, requiring a START-STOP UNIT command.
262 : : */
263 : 0 : sdev->allow_restart = 1;
264 : :
265 : : /*
266 : : * Some USB cardreaders have trouble reading an sdcard's last
267 : : * sector in a larger then 1 sector read, since the performance
268 : : * impact is negligible we set this flag for all USB disks
269 : : */
270 : 0 : sdev->last_sector_bug = 1;
271 : :
272 : : /*
273 : : * Enable last-sector hacks for single-target devices using
274 : : * the Bulk-only transport, unless we already know the
275 : : * capacity will be decremented or is correct.
276 : : */
277 : 0 : if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
278 : 0 : US_FL_SCM_MULT_TARG)) &&
279 : 0 : us->protocol == USB_PR_BULK)
280 : 0 : us->use_last_sector_hacks = 1;
281 : :
282 : : /* Check if write cache default on flag is set or not */
283 : 0 : if (us->fflags & US_FL_WRITE_CACHE)
284 : 0 : sdev->wce_default_on = 1;
285 : :
286 : : /* A few buggy USB-ATA bridges don't understand FUA */
287 : 0 : if (us->fflags & US_FL_BROKEN_FUA)
288 : 0 : sdev->broken_fua = 1;
289 : :
290 : : /* Some even totally fail to indicate a cache */
291 : 0 : if (us->fflags & US_FL_ALWAYS_SYNC) {
292 : : /* don't read caching information */
293 : 0 : sdev->skip_ms_page_8 = 1;
294 : 0 : sdev->skip_ms_page_3f = 1;
295 : : /* assume sync is needed */
296 : 0 : sdev->wce_default_on = 1;
297 : : }
298 : : } else {
299 : :
300 : : /*
301 : : * Non-disk-type devices don't need to blacklist any pages
302 : : * or to force 192-byte transfer lengths for MODE SENSE.
303 : : * But they do need to use MODE SENSE(10).
304 : : */
305 : 0 : sdev->use_10_for_ms = 1;
306 : :
307 : : /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
308 : 0 : if (us->fflags & US_FL_NO_READ_DISC_INFO)
309 : 0 : sdev->no_read_disc_info = 1;
310 : : }
311 : :
312 : : /*
313 : : * The CB and CBI transports have no way to pass LUN values
314 : : * other than the bits in the second byte of a CDB. But those
315 : : * bits don't get set to the LUN value if the device reports
316 : : * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
317 : : * be single-LUN.
318 : : */
319 : 0 : if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
320 : 0 : sdev->scsi_level == SCSI_UNKNOWN)
321 : 0 : us->max_lun = 0;
322 : :
323 : : /*
324 : : * Some devices choke when they receive a PREVENT-ALLOW MEDIUM
325 : : * REMOVAL command, so suppress those commands.
326 : : */
327 : 0 : if (us->fflags & US_FL_NOT_LOCKABLE)
328 : 0 : sdev->lockable = 0;
329 : :
330 : : /*
331 : : * this is to satisfy the compiler, tho I don't think the
332 : : * return code is ever checked anywhere.
333 : : */
334 : 0 : return 0;
335 : : }
336 : :
337 : 0 : static int target_alloc(struct scsi_target *starget)
338 : : {
339 : 0 : struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
340 : :
341 : : /*
342 : : * Some USB drives don't support REPORT LUNS, even though they
343 : : * report a SCSI revision level above 2. Tell the SCSI layer
344 : : * not to issue that command; it will perform a normal sequential
345 : : * scan instead.
346 : : */
347 : 0 : starget->no_report_luns = 1;
348 : :
349 : : /*
350 : : * The UFI spec treats the Peripheral Qualifier bits in an
351 : : * INQUIRY result as reserved and requires devices to set them
352 : : * to 0. However the SCSI spec requires these bits to be set
353 : : * to 3 to indicate when a LUN is not present.
354 : : *
355 : : * Let the scanning code know if this target merely sets
356 : : * Peripheral Device Type to 0x1f to indicate no LUN.
357 : : */
358 : 0 : if (us->subclass == USB_SC_UFI)
359 : 0 : starget->pdt_1f_for_no_lun = 1;
360 : :
361 : 0 : return 0;
362 : : }
363 : :
364 : : /* queue a command */
365 : : /* This is always called with scsi_lock(host) held */
366 : 0 : static int queuecommand_lck(struct scsi_cmnd *srb,
367 : : void (*done)(struct scsi_cmnd *))
368 : : {
369 : 0 : struct us_data *us = host_to_us(srb->device->host);
370 : :
371 : : /* check for state-transition errors */
372 : 0 : if (us->srb != NULL) {
373 : 0 : printk(KERN_ERR "usb-storage: Error in %s: us->srb = %p\n",
374 : : __func__, us->srb);
375 : 0 : return SCSI_MLQUEUE_HOST_BUSY;
376 : : }
377 : :
378 : : /* fail the command if we are disconnecting */
379 : 0 : if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
380 : : usb_stor_dbg(us, "Fail command during disconnect\n");
381 : 0 : srb->result = DID_NO_CONNECT << 16;
382 : 0 : done(srb);
383 : 0 : return 0;
384 : : }
385 : :
386 : 0 : if ((us->fflags & US_FL_NO_ATA_1X) &&
387 : 0 : (srb->cmnd[0] == ATA_12 || srb->cmnd[0] == ATA_16)) {
388 : 0 : memcpy(srb->sense_buffer, usb_stor_sense_invalidCDB,
389 : : sizeof(usb_stor_sense_invalidCDB));
390 : 0 : srb->result = SAM_STAT_CHECK_CONDITION;
391 : 0 : done(srb);
392 : 0 : return 0;
393 : : }
394 : :
395 : : /* enqueue the command and wake up the control thread */
396 : 0 : srb->scsi_done = done;
397 : 0 : us->srb = srb;
398 : 0 : complete(&us->cmnd_ready);
399 : :
400 : 0 : return 0;
401 : : }
402 : :
403 : 0 : static DEF_SCSI_QCMD(queuecommand)
404 : :
405 : : /***********************************************************************
406 : : * Error handling functions
407 : : ***********************************************************************/
408 : :
409 : : /* Command timeout and abort */
410 : 0 : static int command_abort(struct scsi_cmnd *srb)
411 : : {
412 : 0 : struct us_data *us = host_to_us(srb->device->host);
413 : :
414 : : usb_stor_dbg(us, "%s called\n", __func__);
415 : :
416 : : /*
417 : : * us->srb together with the TIMED_OUT, RESETTING, and ABORTING
418 : : * bits are protected by the host lock.
419 : : */
420 : 0 : scsi_lock(us_to_host(us));
421 : :
422 : : /* Is this command still active? */
423 : 0 : if (us->srb != srb) {
424 : 0 : scsi_unlock(us_to_host(us));
425 : : usb_stor_dbg(us, "-- nothing to abort\n");
426 : 0 : return FAILED;
427 : : }
428 : :
429 : : /*
430 : : * Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
431 : : * a device reset isn't already in progress (to avoid interfering
432 : : * with the reset). Note that we must retain the host lock while
433 : : * calling usb_stor_stop_transport(); otherwise it might interfere
434 : : * with an auto-reset that begins as soon as we release the lock.
435 : : */
436 : 0 : set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
437 : 0 : if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
438 : 0 : set_bit(US_FLIDX_ABORTING, &us->dflags);
439 : 0 : usb_stor_stop_transport(us);
440 : : }
441 : 0 : scsi_unlock(us_to_host(us));
442 : :
443 : : /* Wait for the aborted command to finish */
444 : 0 : wait_for_completion(&us->notify);
445 : 0 : return SUCCESS;
446 : : }
447 : :
448 : : /*
449 : : * This invokes the transport reset mechanism to reset the state of the
450 : : * device
451 : : */
452 : 0 : static int device_reset(struct scsi_cmnd *srb)
453 : : {
454 : 0 : struct us_data *us = host_to_us(srb->device->host);
455 : : int result;
456 : :
457 : : usb_stor_dbg(us, "%s called\n", __func__);
458 : :
459 : : /* lock the device pointers and do the reset */
460 : 0 : mutex_lock(&(us->dev_mutex));
461 : 0 : result = us->transport_reset(us);
462 : 0 : mutex_unlock(&us->dev_mutex);
463 : :
464 : 0 : return result < 0 ? FAILED : SUCCESS;
465 : : }
466 : :
467 : : /* Simulate a SCSI bus reset by resetting the device's USB port. */
468 : 0 : static int bus_reset(struct scsi_cmnd *srb)
469 : : {
470 : 0 : struct us_data *us = host_to_us(srb->device->host);
471 : : int result;
472 : :
473 : : usb_stor_dbg(us, "%s called\n", __func__);
474 : :
475 : 0 : result = usb_stor_port_reset(us);
476 : 0 : return result < 0 ? FAILED : SUCCESS;
477 : : }
478 : :
479 : : /*
480 : : * Report a driver-initiated device reset to the SCSI layer.
481 : : * Calling this for a SCSI-initiated reset is unnecessary but harmless.
482 : : * The caller must own the SCSI host lock.
483 : : */
484 : 0 : void usb_stor_report_device_reset(struct us_data *us)
485 : : {
486 : : int i;
487 : : struct Scsi_Host *host = us_to_host(us);
488 : :
489 : 0 : scsi_report_device_reset(host, 0, 0);
490 : 0 : if (us->fflags & US_FL_SCM_MULT_TARG) {
491 : 0 : for (i = 1; i < host->max_id; ++i)
492 : 0 : scsi_report_device_reset(host, 0, i);
493 : : }
494 : 0 : }
495 : :
496 : : /*
497 : : * Report a driver-initiated bus reset to the SCSI layer.
498 : : * Calling this for a SCSI-initiated reset is unnecessary but harmless.
499 : : * The caller must not own the SCSI host lock.
500 : : */
501 : 0 : void usb_stor_report_bus_reset(struct us_data *us)
502 : : {
503 : : struct Scsi_Host *host = us_to_host(us);
504 : :
505 : 0 : scsi_lock(host);
506 : 0 : scsi_report_bus_reset(host, 0);
507 : 0 : scsi_unlock(host);
508 : 0 : }
509 : :
510 : : /***********************************************************************
511 : : * /proc/scsi/ functions
512 : : ***********************************************************************/
513 : :
514 : 0 : static int write_info(struct Scsi_Host *host, char *buffer, int length)
515 : : {
516 : : /* if someone is sending us data, just throw it away */
517 : 0 : return length;
518 : : }
519 : :
520 : 0 : static int show_info (struct seq_file *m, struct Scsi_Host *host)
521 : : {
522 : : struct us_data *us = host_to_us(host);
523 : : const char *string;
524 : :
525 : : /* print the controller name */
526 : 0 : seq_printf(m, " Host scsi%d: usb-storage\n", host->host_no);
527 : :
528 : : /* print product, vendor, and serial number strings */
529 : 0 : if (us->pusb_dev->manufacturer)
530 : : string = us->pusb_dev->manufacturer;
531 : 0 : else if (us->unusual_dev->vendorName)
532 : : string = us->unusual_dev->vendorName;
533 : : else
534 : : string = "Unknown";
535 : 0 : seq_printf(m, " Vendor: %s\n", string);
536 : 0 : if (us->pusb_dev->product)
537 : : string = us->pusb_dev->product;
538 : 0 : else if (us->unusual_dev->productName)
539 : : string = us->unusual_dev->productName;
540 : : else
541 : : string = "Unknown";
542 : 0 : seq_printf(m, " Product: %s\n", string);
543 : 0 : if (us->pusb_dev->serial)
544 : : string = us->pusb_dev->serial;
545 : : else
546 : : string = "None";
547 : 0 : seq_printf(m, "Serial Number: %s\n", string);
548 : :
549 : : /* show the protocol and transport */
550 : 0 : seq_printf(m, " Protocol: %s\n", us->protocol_name);
551 : 0 : seq_printf(m, " Transport: %s\n", us->transport_name);
552 : :
553 : : /* show the device flags */
554 : 0 : seq_printf(m, " Quirks:");
555 : :
556 : : #define US_FLAG(name, value) \
557 : : if (us->fflags & value) seq_printf(m, " " #name);
558 : 0 : US_DO_ALL_FLAGS
559 : : #undef US_FLAG
560 : 0 : seq_putc(m, '\n');
561 : 0 : return 0;
562 : : }
563 : :
564 : : /***********************************************************************
565 : : * Sysfs interface
566 : : ***********************************************************************/
567 : :
568 : : /* Output routine for the sysfs max_sectors file */
569 : 0 : static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
570 : : {
571 : : struct scsi_device *sdev = to_scsi_device(dev);
572 : :
573 : 0 : return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
574 : : }
575 : :
576 : : /* Input routine for the sysfs max_sectors file */
577 : 0 : static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
578 : : size_t count)
579 : : {
580 : : struct scsi_device *sdev = to_scsi_device(dev);
581 : : unsigned short ms;
582 : :
583 : 0 : if (sscanf(buf, "%hu", &ms) > 0) {
584 : 0 : blk_queue_max_hw_sectors(sdev->request_queue, ms);
585 : 0 : return count;
586 : : }
587 : : return -EINVAL;
588 : : }
589 : : static DEVICE_ATTR_RW(max_sectors);
590 : :
591 : : static struct device_attribute *sysfs_device_attr_list[] = {
592 : : &dev_attr_max_sectors,
593 : : NULL,
594 : : };
595 : :
596 : : /*
597 : : * this defines our host template, with which we'll allocate hosts
598 : : */
599 : :
600 : : static const struct scsi_host_template usb_stor_host_template = {
601 : : /* basic userland interface stuff */
602 : : .name = "usb-storage",
603 : : .proc_name = "usb-storage",
604 : : .show_info = show_info,
605 : : .write_info = write_info,
606 : : .info = host_info,
607 : :
608 : : /* command interface -- queued only */
609 : : .queuecommand = queuecommand,
610 : :
611 : : /* error and abort handlers */
612 : : .eh_abort_handler = command_abort,
613 : : .eh_device_reset_handler = device_reset,
614 : : .eh_bus_reset_handler = bus_reset,
615 : :
616 : : /* queue commands only, only one command per LUN */
617 : : .can_queue = 1,
618 : :
619 : : /* unknown initiator id */
620 : : .this_id = -1,
621 : :
622 : : .slave_alloc = slave_alloc,
623 : : .slave_configure = slave_configure,
624 : : .target_alloc = target_alloc,
625 : :
626 : : /* lots of sg segments can be handled */
627 : : .sg_tablesize = SG_MAX_SEGMENTS,
628 : :
629 : :
630 : : /*
631 : : * Limit the total size of a transfer to 120 KB.
632 : : *
633 : : * Some devices are known to choke with anything larger. It seems like
634 : : * the problem stems from the fact that original IDE controllers had
635 : : * only an 8-bit register to hold the number of sectors in one transfer
636 : : * and even those couldn't handle a full 256 sectors.
637 : : *
638 : : * Because we want to make sure we interoperate with as many devices as
639 : : * possible, we will maintain a 240 sector transfer size limit for USB
640 : : * Mass Storage devices.
641 : : *
642 : : * Tests show that other operating have similar limits with Microsoft
643 : : * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
644 : : * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
645 : : * and 2048 for USB3 devices.
646 : : */
647 : : .max_sectors = 240,
648 : :
649 : : /* emulated HBA */
650 : : .emulated = 1,
651 : :
652 : : /* we do our own delay after a device or bus reset */
653 : : .skip_settle_delay = 1,
654 : :
655 : : /* sysfs device attributes */
656 : : .sdev_attrs = sysfs_device_attr_list,
657 : :
658 : : /* module management */
659 : : .module = THIS_MODULE
660 : : };
661 : :
662 : 3 : void usb_stor_host_template_init(struct scsi_host_template *sht,
663 : : const char *name, struct module *owner)
664 : : {
665 : 3 : *sht = usb_stor_host_template;
666 : 3 : sht->name = name;
667 : 3 : sht->proc_name = name;
668 : 3 : sht->module = owner;
669 : 3 : }
670 : : EXPORT_SYMBOL_GPL(usb_stor_host_template_init);
671 : :
672 : : /* To Report "Illegal Request: Invalid Field in CDB */
673 : : unsigned char usb_stor_sense_invalidCDB[18] = {
674 : : [0] = 0x70, /* current error */
675 : : [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
676 : : [7] = 0x0a, /* additional length */
677 : : [12] = 0x24 /* Invalid Field in CDB */
678 : : };
679 : : EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);
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