1 // SPDX-License-Identifier: GPL-2.0+
3 * Driver for USB Mass Storage compliant devices
6 * Current development and maintenance by:
7 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
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)
14 * (c) 1999 Michael Gee (michael@linuxspecific.com)
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.
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.
27 * Also, for certain devices, the interrupt endpoint is used to convey
28 * status of a command.
31 #include <linux/module.h>
32 #include <linux/mutex.h>
34 #include <scsi/scsi.h>
35 #include <scsi/scsi_cmnd.h>
36 #include <scsi/scsi_devinfo.h>
37 #include <scsi/scsi_device.h>
38 #include <scsi/scsi_eh.h>
43 #include "transport.h"
47 * Vendor IDs for companies that seem to include the READ CAPACITY bug
48 * in all their devices
50 #define VENDOR_ID_NOKIA 0x0421
51 #define VENDOR_ID_NIKON 0x04b0
52 #define VENDOR_ID_PENTAX 0x0a17
53 #define VENDOR_ID_MOTOROLA 0x22b8
55 /***********************************************************************
57 ***********************************************************************/
59 static const char* host_info(struct Scsi_Host *host)
61 struct us_data *us = host_to_us(host);
65 static int slave_alloc (struct scsi_device *sdev)
67 struct us_data *us = host_to_us(sdev->host);
71 * Set the INQUIRY transfer length to 36. We don't use any of
72 * the extra data and many devices choke if asked for more or
75 sdev->inquiry_len = 36;
78 * USB has unusual scatter-gather requirements: the length of each
79 * scatterlist element except the last must be divisible by the
80 * Bulk maxpacket value. Fortunately this value is always a
81 * power of 2. Inform the block layer about this requirement.
83 maxp = usb_maxpacket(us->pusb_dev, us->recv_bulk_pipe, 0);
84 blk_queue_virt_boundary(sdev->request_queue, maxp - 1);
87 * Some host controllers may have alignment requirements.
88 * We'll play it safe by requiring 512-byte alignment always.
90 blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
92 /* Tell the SCSI layer if we know there is more than one LUN */
93 if (us->protocol == USB_PR_BULK && us->max_lun > 0)
94 sdev->sdev_bflags |= BLIST_FORCELUN;
99 static int slave_configure(struct scsi_device *sdev)
101 struct us_data *us = host_to_us(sdev->host);
104 * Many devices have trouble transferring more than 32KB at a time,
105 * while others have trouble with more than 64K. At this time we
106 * are limiting both to 32K (64 sectores).
108 if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
109 unsigned int max_sectors = 64;
111 if (us->fflags & US_FL_MAX_SECTORS_MIN)
112 max_sectors = PAGE_SIZE >> 9;
113 if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
114 blk_queue_max_hw_sectors(sdev->request_queue,
116 } else if (sdev->type == TYPE_TAPE) {
118 * Tapes need much higher max_sector limits, so just
119 * raise it to the maximum possible (4 GB / 512) and
120 * let the queue segment size sort out the real limit.
122 blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
123 } else if (us->pusb_dev->speed >= USB_SPEED_SUPER) {
125 * USB3 devices will be limited to 2048 sectors. This gives us
126 * better throughput on most devices.
128 blk_queue_max_hw_sectors(sdev->request_queue, 2048);
132 * Some USB host controllers can't do DMA; they have to use PIO.
133 * They indicate this by setting their dma_mask to NULL. For
134 * such controllers we need to make sure the block layer sets
135 * up bounce buffers in addressable memory.
137 if (!us->pusb_dev->bus->controller->dma_mask)
138 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
141 * We can't put these settings in slave_alloc() because that gets
142 * called before the device type is known. Consequently these
143 * settings can't be overridden via the scsi devinfo mechanism.
145 if (sdev->type == TYPE_DISK) {
148 * Some vendors seem to put the READ CAPACITY bug into
149 * all their devices -- primarily makers of cell phones
150 * and digital cameras. Since these devices always use
151 * flash media and can be expected to have an even number
152 * of sectors, we will always enable the CAPACITY_HEURISTICS
153 * flag unless told otherwise.
155 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
156 case VENDOR_ID_NOKIA:
157 case VENDOR_ID_NIKON:
158 case VENDOR_ID_PENTAX:
159 case VENDOR_ID_MOTOROLA:
160 if (!(us->fflags & (US_FL_FIX_CAPACITY |
162 us->fflags |= US_FL_CAPACITY_HEURISTICS;
167 * Disk-type devices use MODE SENSE(6) if the protocol
168 * (SubClass) is Transparent SCSI, otherwise they use
171 if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
172 sdev->use_10_for_ms = 1;
175 *Many disks only accept MODE SENSE transfer lengths of
176 * 192 bytes (that's what Windows uses).
178 sdev->use_192_bytes_for_3f = 1;
181 * Some devices don't like MODE SENSE with page=0x3f,
182 * which is the command used for checking if a device
183 * is write-protected. Now that we tell the sd driver
184 * to do a 192-byte transfer with this command the
185 * majority of devices work fine, but a few still can't
186 * handle it. The sd driver will simply assume those
187 * devices are write-enabled.
189 if (us->fflags & US_FL_NO_WP_DETECT)
190 sdev->skip_ms_page_3f = 1;
193 * A number of devices have problems with MODE SENSE for
194 * page x08, so we will skip it.
196 sdev->skip_ms_page_8 = 1;
199 * Some devices don't handle VPD pages correctly, so skip vpd
200 * pages if not forced by SCSI layer.
202 sdev->skip_vpd_pages = !sdev->try_vpd_pages;
204 /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
205 sdev->no_report_opcodes = 1;
207 /* Do not attempt to use WRITE SAME */
208 sdev->no_write_same = 1;
211 * Some disks return the total number of blocks in response
212 * to READ CAPACITY rather than the highest block number.
213 * If this device makes that mistake, tell the sd driver.
215 if (us->fflags & US_FL_FIX_CAPACITY)
216 sdev->fix_capacity = 1;
219 * A few disks have two indistinguishable version, one of
220 * which reports the correct capacity and the other does not.
221 * The sd driver has to guess which is the case.
223 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
224 sdev->guess_capacity = 1;
226 /* Some devices cannot handle READ_CAPACITY_16 */
227 if (us->fflags & US_FL_NO_READ_CAPACITY_16)
228 sdev->no_read_capacity_16 = 1;
231 * Many devices do not respond properly to READ_CAPACITY_16.
232 * Tell the SCSI layer to try READ_CAPACITY_10 first.
233 * However some USB 3.0 drive enclosures return capacity
234 * modulo 2TB. Those must use READ_CAPACITY_16
236 if (!(us->fflags & US_FL_NEEDS_CAP16))
237 sdev->try_rc_10_first = 1;
240 * assume SPC3 or latter devices support sense size > 18
241 * unless US_FL_BAD_SENSE quirk is specified.
243 if (sdev->scsi_level > SCSI_SPC_2 &&
244 !(us->fflags & US_FL_BAD_SENSE))
245 us->fflags |= US_FL_SANE_SENSE;
248 * USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
249 * Hardware Error) when any low-level error occurs,
250 * recoverable or not. Setting this flag tells the SCSI
251 * midlayer to retry such commands, which frequently will
252 * succeed and fix the error. The worst this can lead to
253 * is an occasional series of retries that will all fail.
255 sdev->retry_hwerror = 1;
258 * USB disks should allow restart. Some drives spin down
259 * automatically, requiring a START-STOP UNIT command.
261 sdev->allow_restart = 1;
264 * Some USB cardreaders have trouble reading an sdcard's last
265 * sector in a larger then 1 sector read, since the performance
266 * impact is negligible we set this flag for all USB disks
268 sdev->last_sector_bug = 1;
271 * Enable last-sector hacks for single-target devices using
272 * the Bulk-only transport, unless we already know the
273 * capacity will be decremented or is correct.
275 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
276 US_FL_SCM_MULT_TARG)) &&
277 us->protocol == USB_PR_BULK)
278 us->use_last_sector_hacks = 1;
280 /* Check if write cache default on flag is set or not */
281 if (us->fflags & US_FL_WRITE_CACHE)
282 sdev->wce_default_on = 1;
284 /* A few buggy USB-ATA bridges don't understand FUA */
285 if (us->fflags & US_FL_BROKEN_FUA)
286 sdev->broken_fua = 1;
288 /* Some even totally fail to indicate a cache */
289 if (us->fflags & US_FL_ALWAYS_SYNC) {
290 /* don't read caching information */
291 sdev->skip_ms_page_8 = 1;
292 sdev->skip_ms_page_3f = 1;
293 /* assume sync is needed */
294 sdev->wce_default_on = 1;
299 * Non-disk-type devices don't need to blacklist any pages
300 * or to force 192-byte transfer lengths for MODE SENSE.
301 * But they do need to use MODE SENSE(10).
303 sdev->use_10_for_ms = 1;
305 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
306 if (us->fflags & US_FL_NO_READ_DISC_INFO)
307 sdev->no_read_disc_info = 1;
311 * The CB and CBI transports have no way to pass LUN values
312 * other than the bits in the second byte of a CDB. But those
313 * bits don't get set to the LUN value if the device reports
314 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
317 if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
318 sdev->scsi_level == SCSI_UNKNOWN)
322 * Some devices choke when they receive a PREVENT-ALLOW MEDIUM
323 * REMOVAL command, so suppress those commands.
325 if (us->fflags & US_FL_NOT_LOCKABLE)
329 * this is to satisfy the compiler, tho I don't think the
330 * return code is ever checked anywhere.
335 static int target_alloc(struct scsi_target *starget)
337 struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
340 * Some USB drives don't support REPORT LUNS, even though they
341 * report a SCSI revision level above 2. Tell the SCSI layer
342 * not to issue that command; it will perform a normal sequential
345 starget->no_report_luns = 1;
348 * The UFI spec treats the Peripheral Qualifier bits in an
349 * INQUIRY result as reserved and requires devices to set them
350 * to 0. However the SCSI spec requires these bits to be set
351 * to 3 to indicate when a LUN is not present.
353 * Let the scanning code know if this target merely sets
354 * Peripheral Device Type to 0x1f to indicate no LUN.
356 if (us->subclass == USB_SC_UFI)
357 starget->pdt_1f_for_no_lun = 1;
362 /* queue a command */
363 /* This is always called with scsi_lock(host) held */
364 static int queuecommand_lck(struct scsi_cmnd *srb,
365 void (*done)(struct scsi_cmnd *))
367 struct us_data *us = host_to_us(srb->device->host);
369 /* check for state-transition errors */
370 if (us->srb != NULL) {
371 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
373 return SCSI_MLQUEUE_HOST_BUSY;
376 /* fail the command if we are disconnecting */
377 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
378 usb_stor_dbg(us, "Fail command during disconnect\n");
379 srb->result = DID_NO_CONNECT << 16;
384 if ((us->fflags & US_FL_NO_ATA_1X) &&
385 (srb->cmnd[0] == ATA_12 || srb->cmnd[0] == ATA_16)) {
386 memcpy(srb->sense_buffer, usb_stor_sense_invalidCDB,
387 sizeof(usb_stor_sense_invalidCDB));
388 srb->result = SAM_STAT_CHECK_CONDITION;
393 /* enqueue the command and wake up the control thread */
394 srb->scsi_done = done;
396 complete(&us->cmnd_ready);
401 static DEF_SCSI_QCMD(queuecommand)
403 /***********************************************************************
404 * Error handling functions
405 ***********************************************************************/
407 /* Command timeout and abort */
408 static int command_abort(struct scsi_cmnd *srb)
410 struct us_data *us = host_to_us(srb->device->host);
412 usb_stor_dbg(us, "%s called\n", __func__);
415 * us->srb together with the TIMED_OUT, RESETTING, and ABORTING
416 * bits are protected by the host lock.
418 scsi_lock(us_to_host(us));
420 /* Is this command still active? */
421 if (us->srb != srb) {
422 scsi_unlock(us_to_host(us));
423 usb_stor_dbg(us, "-- nothing to abort\n");
428 * Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
429 * a device reset isn't already in progress (to avoid interfering
430 * with the reset). Note that we must retain the host lock while
431 * calling usb_stor_stop_transport(); otherwise it might interfere
432 * with an auto-reset that begins as soon as we release the lock.
434 set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
435 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
436 set_bit(US_FLIDX_ABORTING, &us->dflags);
437 usb_stor_stop_transport(us);
439 scsi_unlock(us_to_host(us));
441 /* Wait for the aborted command to finish */
442 wait_for_completion(&us->notify);
447 * This invokes the transport reset mechanism to reset the state of the
450 static int device_reset(struct scsi_cmnd *srb)
452 struct us_data *us = host_to_us(srb->device->host);
455 usb_stor_dbg(us, "%s called\n", __func__);
457 /* lock the device pointers and do the reset */
458 mutex_lock(&(us->dev_mutex));
459 result = us->transport_reset(us);
460 mutex_unlock(&us->dev_mutex);
462 return result < 0 ? FAILED : SUCCESS;
465 /* Simulate a SCSI bus reset by resetting the device's USB port. */
466 static int bus_reset(struct scsi_cmnd *srb)
468 struct us_data *us = host_to_us(srb->device->host);
471 usb_stor_dbg(us, "%s called\n", __func__);
473 result = usb_stor_port_reset(us);
474 return result < 0 ? FAILED : SUCCESS;
478 * Report a driver-initiated device reset to the SCSI layer.
479 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
480 * The caller must own the SCSI host lock.
482 void usb_stor_report_device_reset(struct us_data *us)
485 struct Scsi_Host *host = us_to_host(us);
487 scsi_report_device_reset(host, 0, 0);
488 if (us->fflags & US_FL_SCM_MULT_TARG) {
489 for (i = 1; i < host->max_id; ++i)
490 scsi_report_device_reset(host, 0, i);
495 * Report a driver-initiated bus reset to the SCSI layer.
496 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
497 * The caller must not own the SCSI host lock.
499 void usb_stor_report_bus_reset(struct us_data *us)
501 struct Scsi_Host *host = us_to_host(us);
504 scsi_report_bus_reset(host, 0);
508 /***********************************************************************
509 * /proc/scsi/ functions
510 ***********************************************************************/
512 static int write_info(struct Scsi_Host *host, char *buffer, int length)
514 /* if someone is sending us data, just throw it away */
518 static int show_info (struct seq_file *m, struct Scsi_Host *host)
520 struct us_data *us = host_to_us(host);
523 /* print the controller name */
524 seq_printf(m, " Host scsi%d: usb-storage\n", host->host_no);
526 /* print product, vendor, and serial number strings */
527 if (us->pusb_dev->manufacturer)
528 string = us->pusb_dev->manufacturer;
529 else if (us->unusual_dev->vendorName)
530 string = us->unusual_dev->vendorName;
533 seq_printf(m, " Vendor: %s\n", string);
534 if (us->pusb_dev->product)
535 string = us->pusb_dev->product;
536 else if (us->unusual_dev->productName)
537 string = us->unusual_dev->productName;
540 seq_printf(m, " Product: %s\n", string);
541 if (us->pusb_dev->serial)
542 string = us->pusb_dev->serial;
545 seq_printf(m, "Serial Number: %s\n", string);
547 /* show the protocol and transport */
548 seq_printf(m, " Protocol: %s\n", us->protocol_name);
549 seq_printf(m, " Transport: %s\n", us->transport_name);
551 /* show the device flags */
552 seq_printf(m, " Quirks:");
554 #define US_FLAG(name, value) \
555 if (us->fflags & value) seq_printf(m, " " #name);
562 /***********************************************************************
564 ***********************************************************************/
566 /* Output routine for the sysfs max_sectors file */
567 static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
569 struct scsi_device *sdev = to_scsi_device(dev);
571 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
574 /* Input routine for the sysfs max_sectors file */
575 static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
578 struct scsi_device *sdev = to_scsi_device(dev);
581 if (sscanf(buf, "%hu", &ms) > 0) {
582 blk_queue_max_hw_sectors(sdev->request_queue, ms);
587 static DEVICE_ATTR_RW(max_sectors);
589 static struct device_attribute *sysfs_device_attr_list[] = {
590 &dev_attr_max_sectors,
595 * this defines our host template, with which we'll allocate hosts
598 static const struct scsi_host_template usb_stor_host_template = {
599 /* basic userland interface stuff */
600 .name = "usb-storage",
601 .proc_name = "usb-storage",
602 .show_info = show_info,
603 .write_info = write_info,
606 /* command interface -- queued only */
607 .queuecommand = queuecommand,
609 /* error and abort handlers */
610 .eh_abort_handler = command_abort,
611 .eh_device_reset_handler = device_reset,
612 .eh_bus_reset_handler = bus_reset,
614 /* queue commands only, only one command per LUN */
617 /* unknown initiator id */
620 .slave_alloc = slave_alloc,
621 .slave_configure = slave_configure,
622 .target_alloc = target_alloc,
624 /* lots of sg segments can be handled */
625 .sg_tablesize = SG_MAX_SEGMENTS,
629 * Limit the total size of a transfer to 120 KB.
631 * Some devices are known to choke with anything larger. It seems like
632 * the problem stems from the fact that original IDE controllers had
633 * only an 8-bit register to hold the number of sectors in one transfer
634 * and even those couldn't handle a full 256 sectors.
636 * Because we want to make sure we interoperate with as many devices as
637 * possible, we will maintain a 240 sector transfer size limit for USB
638 * Mass Storage devices.
640 * Tests show that other operating have similar limits with Microsoft
641 * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
642 * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
643 * and 2048 for USB3 devices.
650 /* we do our own delay after a device or bus reset */
651 .skip_settle_delay = 1,
653 /* sysfs device attributes */
654 .sdev_attrs = sysfs_device_attr_list,
656 /* module management */
657 .module = THIS_MODULE
660 void usb_stor_host_template_init(struct scsi_host_template *sht,
661 const char *name, struct module *owner)
663 *sht = usb_stor_host_template;
665 sht->proc_name = name;
668 EXPORT_SYMBOL_GPL(usb_stor_host_template_init);
670 /* To Report "Illegal Request: Invalid Field in CDB */
671 unsigned char usb_stor_sense_invalidCDB[18] = {
672 [0] = 0x70, /* current error */
673 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
674 [7] = 0x0a, /* additional length */
675 [12] = 0x24 /* Invalid Field in CDB */
677 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);