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 | static const char* host_info(struct Scsi_Host *host) |
63 | { |
64 | struct us_data *us = host_to_us(host); |
65 | return us->scsi_name; |
66 | } |
67 | |
68 | static int slave_alloc (struct scsi_device *sdev) |
69 | { |
70 | struct us_data *us = host_to_us(host: 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 | 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 | 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 | if (us->protocol == USB_PR_BULK && us->max_lun > 0) |
87 | sdev->sdev_bflags |= BLIST_FORCELUN; |
88 | |
89 | return 0; |
90 | } |
91 | |
92 | static int slave_configure(struct scsi_device *sdev) |
93 | { |
94 | struct us_data *us = host_to_us(host: sdev->host); |
95 | 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 | if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) { |
103 | unsigned int max_sectors = 64; |
104 | |
105 | if (us->fflags & US_FL_MAX_SECTORS_MIN) |
106 | max_sectors = PAGE_SIZE >> 9; |
107 | if (queue_max_hw_sectors(q: sdev->request_queue) > max_sectors) |
108 | blk_queue_max_hw_sectors(sdev->request_queue, |
109 | max_sectors); |
110 | } 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 | blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF); |
117 | } 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 | 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 | blk_queue_max_hw_sectors(sdev->request_queue, |
130 | 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 | if (!hcd_uses_dma(hcd: bus_to_hcd(bus: us->pusb_dev->bus)) || |
139 | (bus_to_hcd(bus: us->pusb_dev->bus)->localmem_pool != NULL)) |
140 | blk_queue_bounce_limit(q: sdev->request_queue, limit: 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 | 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 | 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 | /* |
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 | if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB) |
174 | 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 | 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 | if (us->fflags & US_FL_NO_WP_DETECT) |
192 | 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 | 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 | sdev->skip_vpd_pages = !sdev->try_vpd_pages; |
205 | |
206 | /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */ |
207 | sdev->no_report_opcodes = 1; |
208 | |
209 | /* Do not attempt to use WRITE SAME */ |
210 | 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 | if (us->fflags & US_FL_FIX_CAPACITY) |
218 | 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 | if (us->fflags & US_FL_CAPACITY_HEURISTICS) |
226 | sdev->guess_capacity = 1; |
227 | |
228 | /* Some devices cannot handle READ_CAPACITY_16 */ |
229 | if (us->fflags & US_FL_NO_READ_CAPACITY_16) |
230 | 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 | if (!(us->fflags & US_FL_NEEDS_CAP16)) |
239 | 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 | if (sdev->scsi_level > SCSI_SPC_2 && |
246 | !(us->fflags & US_FL_BAD_SENSE)) |
247 | 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 | 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 | 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 | 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 | if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK | |
278 | US_FL_SCM_MULT_TARG)) && |
279 | us->protocol == USB_PR_BULK) |
280 | us->use_last_sector_hacks = 1; |
281 | |
282 | /* Check if write cache default on flag is set or not */ |
283 | if (us->fflags & US_FL_WRITE_CACHE) |
284 | sdev->wce_default_on = 1; |
285 | |
286 | /* A few buggy USB-ATA bridges don't understand FUA */ |
287 | if (us->fflags & US_FL_BROKEN_FUA) |
288 | sdev->broken_fua = 1; |
289 | |
290 | /* Some even totally fail to indicate a cache */ |
291 | if (us->fflags & US_FL_ALWAYS_SYNC) { |
292 | /* don't read caching information */ |
293 | sdev->skip_ms_page_8 = 1; |
294 | sdev->skip_ms_page_3f = 1; |
295 | /* assume sync is needed */ |
296 | sdev->wce_default_on = 1; |
297 | } |
298 | } else { |
299 | |
300 | /* |
301 | * Non-disk-type devices don't need to ignore 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 | sdev->use_10_for_ms = 1; |
306 | |
307 | /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */ |
308 | if (us->fflags & US_FL_NO_READ_DISC_INFO) |
309 | 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 | if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) && |
320 | sdev->scsi_level == SCSI_UNKNOWN) |
321 | 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 | if (us->fflags & US_FL_NOT_LOCKABLE) |
328 | 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 | return 0; |
335 | } |
336 | |
337 | static int target_alloc(struct scsi_target *starget) |
338 | { |
339 | struct us_data *us = host_to_us(host: dev_to_shost(dev: 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 | 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 | if (us->subclass == USB_SC_UFI) |
359 | starget->pdt_1f_for_no_lun = 1; |
360 | |
361 | return 0; |
362 | } |
363 | |
364 | /* queue a command */ |
365 | /* This is always called with scsi_lock(host) held */ |
366 | static int queuecommand_lck(struct scsi_cmnd *srb) |
367 | { |
368 | void (*done)(struct scsi_cmnd *) = scsi_done; |
369 | struct us_data *us = host_to_us(host: srb->device->host); |
370 | |
371 | /* check for state-transition errors */ |
372 | if (us->srb != NULL) { |
373 | dev_err(&us->pusb_intf->dev, |
374 | "Error in %s: us->srb = %p\n" , __func__, us->srb); |
375 | return SCSI_MLQUEUE_HOST_BUSY; |
376 | } |
377 | |
378 | /* fail the command if we are disconnecting */ |
379 | if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) { |
380 | usb_stor_dbg(us, fmt: "Fail command during disconnect\n" ); |
381 | srb->result = DID_NO_CONNECT << 16; |
382 | done(srb); |
383 | return 0; |
384 | } |
385 | |
386 | if ((us->fflags & US_FL_NO_ATA_1X) && |
387 | (srb->cmnd[0] == ATA_12 || srb->cmnd[0] == ATA_16)) { |
388 | memcpy(srb->sense_buffer, usb_stor_sense_invalidCDB, |
389 | sizeof(usb_stor_sense_invalidCDB)); |
390 | srb->result = SAM_STAT_CHECK_CONDITION; |
391 | done(srb); |
392 | return 0; |
393 | } |
394 | |
395 | /* enqueue the command and wake up the control thread */ |
396 | us->srb = srb; |
397 | complete(&us->cmnd_ready); |
398 | |
399 | return 0; |
400 | } |
401 | |
402 | static DEF_SCSI_QCMD(queuecommand) |
403 | |
404 | /*********************************************************************** |
405 | * Error handling functions |
406 | ***********************************************************************/ |
407 | |
408 | /* Command timeout and abort */ |
409 | static int command_abort_matching(struct us_data *us, struct scsi_cmnd *srb_match) |
410 | { |
411 | /* |
412 | * us->srb together with the TIMED_OUT, RESETTING, and ABORTING |
413 | * bits are protected by the host lock. |
414 | */ |
415 | scsi_lock(us_to_host(us)); |
416 | |
417 | /* is there any active pending command to abort ? */ |
418 | if (!us->srb) { |
419 | scsi_unlock(us_to_host(us)); |
420 | usb_stor_dbg(us, fmt: "-- nothing to abort\n" ); |
421 | return SUCCESS; |
422 | } |
423 | |
424 | /* Does the command match the passed srb if any ? */ |
425 | if (srb_match && us->srb != srb_match) { |
426 | scsi_unlock(us_to_host(us)); |
427 | usb_stor_dbg(us, fmt: "-- pending command mismatch\n" ); |
428 | return FAILED; |
429 | } |
430 | |
431 | /* |
432 | * Set the TIMED_OUT bit. Also set the ABORTING bit, but only if |
433 | * a device reset isn't already in progress (to avoid interfering |
434 | * with the reset). Note that we must retain the host lock while |
435 | * calling usb_stor_stop_transport(); otherwise it might interfere |
436 | * with an auto-reset that begins as soon as we release the lock. |
437 | */ |
438 | set_bit(US_FLIDX_TIMED_OUT, addr: &us->dflags); |
439 | if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) { |
440 | set_bit(US_FLIDX_ABORTING, addr: &us->dflags); |
441 | usb_stor_stop_transport(us); |
442 | } |
443 | scsi_unlock(us_to_host(us)); |
444 | |
445 | /* Wait for the aborted command to finish */ |
446 | wait_for_completion(&us->notify); |
447 | return SUCCESS; |
448 | } |
449 | |
450 | static int command_abort(struct scsi_cmnd *srb) |
451 | { |
452 | struct us_data *us = host_to_us(host: srb->device->host); |
453 | |
454 | usb_stor_dbg(us, fmt: "%s called\n" , __func__); |
455 | return command_abort_matching(us, srb_match: srb); |
456 | } |
457 | |
458 | /* |
459 | * This invokes the transport reset mechanism to reset the state of the |
460 | * device |
461 | */ |
462 | static int device_reset(struct scsi_cmnd *srb) |
463 | { |
464 | struct us_data *us = host_to_us(host: srb->device->host); |
465 | int result; |
466 | |
467 | usb_stor_dbg(us, fmt: "%s called\n" , __func__); |
468 | |
469 | /* abort any pending command before reset */ |
470 | command_abort_matching(us, NULL); |
471 | |
472 | /* lock the device pointers and do the reset */ |
473 | mutex_lock(&(us->dev_mutex)); |
474 | result = us->transport_reset(us); |
475 | mutex_unlock(lock: &us->dev_mutex); |
476 | |
477 | return result < 0 ? FAILED : SUCCESS; |
478 | } |
479 | |
480 | /* Simulate a SCSI bus reset by resetting the device's USB port. */ |
481 | static int bus_reset(struct scsi_cmnd *srb) |
482 | { |
483 | struct us_data *us = host_to_us(host: srb->device->host); |
484 | int result; |
485 | |
486 | usb_stor_dbg(us, fmt: "%s called\n" , __func__); |
487 | |
488 | result = usb_stor_port_reset(us); |
489 | return result < 0 ? FAILED : SUCCESS; |
490 | } |
491 | |
492 | /* |
493 | * Report a driver-initiated device reset to the SCSI layer. |
494 | * Calling this for a SCSI-initiated reset is unnecessary but harmless. |
495 | * The caller must own the SCSI host lock. |
496 | */ |
497 | void usb_stor_report_device_reset(struct us_data *us) |
498 | { |
499 | int i; |
500 | struct Scsi_Host *host = us_to_host(us); |
501 | |
502 | scsi_report_device_reset(host, 0, 0); |
503 | if (us->fflags & US_FL_SCM_MULT_TARG) { |
504 | for (i = 1; i < host->max_id; ++i) |
505 | scsi_report_device_reset(host, 0, i); |
506 | } |
507 | } |
508 | |
509 | /* |
510 | * Report a driver-initiated bus reset to the SCSI layer. |
511 | * Calling this for a SCSI-initiated reset is unnecessary but harmless. |
512 | * The caller must not own the SCSI host lock. |
513 | */ |
514 | void usb_stor_report_bus_reset(struct us_data *us) |
515 | { |
516 | struct Scsi_Host *host = us_to_host(us); |
517 | |
518 | scsi_lock(host); |
519 | scsi_report_bus_reset(host, 0); |
520 | scsi_unlock(host); |
521 | } |
522 | |
523 | /*********************************************************************** |
524 | * /proc/scsi/ functions |
525 | ***********************************************************************/ |
526 | |
527 | static int write_info(struct Scsi_Host *host, char *buffer, int length) |
528 | { |
529 | /* if someone is sending us data, just throw it away */ |
530 | return length; |
531 | } |
532 | |
533 | static int show_info (struct seq_file *m, struct Scsi_Host *host) |
534 | { |
535 | struct us_data *us = host_to_us(host); |
536 | const char *string; |
537 | |
538 | /* print the controller name */ |
539 | seq_printf(m, fmt: " Host scsi%d: usb-storage\n" , host->host_no); |
540 | |
541 | /* print product, vendor, and serial number strings */ |
542 | if (us->pusb_dev->manufacturer) |
543 | string = us->pusb_dev->manufacturer; |
544 | else if (us->unusual_dev->vendorName) |
545 | string = us->unusual_dev->vendorName; |
546 | else |
547 | string = "Unknown" ; |
548 | seq_printf(m, fmt: " Vendor: %s\n" , string); |
549 | if (us->pusb_dev->product) |
550 | string = us->pusb_dev->product; |
551 | else if (us->unusual_dev->productName) |
552 | string = us->unusual_dev->productName; |
553 | else |
554 | string = "Unknown" ; |
555 | seq_printf(m, fmt: " Product: %s\n" , string); |
556 | if (us->pusb_dev->serial) |
557 | string = us->pusb_dev->serial; |
558 | else |
559 | string = "None" ; |
560 | seq_printf(m, fmt: "Serial Number: %s\n" , string); |
561 | |
562 | /* show the protocol and transport */ |
563 | seq_printf(m, fmt: " Protocol: %s\n" , us->protocol_name); |
564 | seq_printf(m, fmt: " Transport: %s\n" , us->transport_name); |
565 | |
566 | /* show the device flags */ |
567 | seq_printf(m, fmt: " Quirks:" ); |
568 | |
569 | #define US_FLAG(name, value) \ |
570 | if (us->fflags & value) seq_printf(m, " " #name); |
571 | US_DO_ALL_FLAGS |
572 | #undef US_FLAG |
573 | seq_putc(m, c: '\n'); |
574 | return 0; |
575 | } |
576 | |
577 | /*********************************************************************** |
578 | * Sysfs interface |
579 | ***********************************************************************/ |
580 | |
581 | /* Output routine for the sysfs max_sectors file */ |
582 | static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf) |
583 | { |
584 | struct scsi_device *sdev = to_scsi_device(dev); |
585 | |
586 | return sprintf(buf, fmt: "%u\n" , queue_max_hw_sectors(q: sdev->request_queue)); |
587 | } |
588 | |
589 | /* Input routine for the sysfs max_sectors file */ |
590 | static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf, |
591 | size_t count) |
592 | { |
593 | struct scsi_device *sdev = to_scsi_device(dev); |
594 | unsigned short ms; |
595 | |
596 | if (sscanf(buf, "%hu" , &ms) > 0) { |
597 | blk_queue_max_hw_sectors(sdev->request_queue, ms); |
598 | return count; |
599 | } |
600 | return -EINVAL; |
601 | } |
602 | static DEVICE_ATTR_RW(max_sectors); |
603 | |
604 | static struct attribute *usb_sdev_attrs[] = { |
605 | &dev_attr_max_sectors.attr, |
606 | NULL, |
607 | }; |
608 | |
609 | ATTRIBUTE_GROUPS(usb_sdev); |
610 | |
611 | /* |
612 | * this defines our host template, with which we'll allocate hosts |
613 | */ |
614 | |
615 | static const struct scsi_host_template usb_stor_host_template = { |
616 | /* basic userland interface stuff */ |
617 | .name = "usb-storage" , |
618 | .proc_name = "usb-storage" , |
619 | .show_info = show_info, |
620 | .write_info = write_info, |
621 | .info = host_info, |
622 | |
623 | /* command interface -- queued only */ |
624 | .queuecommand = queuecommand, |
625 | |
626 | /* error and abort handlers */ |
627 | .eh_abort_handler = command_abort, |
628 | .eh_device_reset_handler = device_reset, |
629 | .eh_bus_reset_handler = bus_reset, |
630 | |
631 | /* queue commands only, only one command per LUN */ |
632 | .can_queue = 1, |
633 | |
634 | /* unknown initiator id */ |
635 | .this_id = -1, |
636 | |
637 | .slave_alloc = slave_alloc, |
638 | .slave_configure = slave_configure, |
639 | .target_alloc = target_alloc, |
640 | |
641 | /* lots of sg segments can be handled */ |
642 | .sg_tablesize = SG_MAX_SEGMENTS, |
643 | |
644 | |
645 | /* |
646 | * Limit the total size of a transfer to 120 KB. |
647 | * |
648 | * Some devices are known to choke with anything larger. It seems like |
649 | * the problem stems from the fact that original IDE controllers had |
650 | * only an 8-bit register to hold the number of sectors in one transfer |
651 | * and even those couldn't handle a full 256 sectors. |
652 | * |
653 | * Because we want to make sure we interoperate with as many devices as |
654 | * possible, we will maintain a 240 sector transfer size limit for USB |
655 | * Mass Storage devices. |
656 | * |
657 | * Tests show that other operating have similar limits with Microsoft |
658 | * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3 |
659 | * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2 |
660 | * and 2048 for USB3 devices. |
661 | */ |
662 | .max_sectors = 240, |
663 | |
664 | /* emulated HBA */ |
665 | .emulated = 1, |
666 | |
667 | /* we do our own delay after a device or bus reset */ |
668 | .skip_settle_delay = 1, |
669 | |
670 | /* sysfs device attributes */ |
671 | .sdev_groups = usb_sdev_groups, |
672 | |
673 | /* module management */ |
674 | .module = THIS_MODULE |
675 | }; |
676 | |
677 | void usb_stor_host_template_init(struct scsi_host_template *sht, |
678 | const char *name, struct module *owner) |
679 | { |
680 | *sht = usb_stor_host_template; |
681 | sht->name = name; |
682 | sht->proc_name = name; |
683 | sht->module = owner; |
684 | } |
685 | EXPORT_SYMBOL_GPL(usb_stor_host_template_init); |
686 | |
687 | /* To Report "Illegal Request: Invalid Field in CDB */ |
688 | unsigned char usb_stor_sense_invalidCDB[18] = { |
689 | [0] = 0x70, /* current error */ |
690 | [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */ |
691 | [7] = 0x0a, /* additional length */ |
692 | [12] = 0x24 /* Invalid Field in CDB */ |
693 | }; |
694 | EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB); |
695 | |