Linux Audio

Check our new training course

Loading...
v4.6
  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
 73static 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
 79static 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
114static 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_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		/* assume SPC3 or latter devices support sense size > 18 */
227		if (sdev->scsi_level > SCSI_SPC_2)
 
 
 
 
228			us->fflags |= US_FL_SANE_SENSE;
229
230		/* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
 
231		 * Hardware Error) when any low-level error occurs,
232		 * recoverable or not.  Setting this flag tells the SCSI
233		 * midlayer to retry such commands, which frequently will
234		 * succeed and fix the error.  The worst this can lead to
235		 * is an occasional series of retries that will all fail. */
 
236		sdev->retry_hwerror = 1;
237
238		/* USB disks should allow restart.  Some drives spin down
239		 * automatically, requiring a START-STOP UNIT command. */
 
 
240		sdev->allow_restart = 1;
241
242		/* Some USB cardreaders have trouble reading an sdcard's last
 
243		 * sector in a larger then 1 sector read, since the performance
244		 * impact is negligible we set this flag for all USB disks */
 
245		sdev->last_sector_bug = 1;
246
247		/* Enable last-sector hacks for single-target devices using
 
248		 * the Bulk-only transport, unless we already know the
249		 * capacity will be decremented or is correct. */
 
250		if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
251					US_FL_SCM_MULT_TARG)) &&
252				us->protocol == USB_PR_BULK)
253			us->use_last_sector_hacks = 1;
254
255		/* Check if write cache default on flag is set or not */
256		if (us->fflags & US_FL_WRITE_CACHE)
257			sdev->wce_default_on = 1;
258
259		/* A few buggy USB-ATA bridges don't understand FUA */
260		if (us->fflags & US_FL_BROKEN_FUA)
261			sdev->broken_fua = 1;
262
 
 
 
 
 
 
 
 
263	} else {
264
265		/* Non-disk-type devices don't need to blacklist any pages
 
266		 * or to force 192-byte transfer lengths for MODE SENSE.
267		 * But they do need to use MODE SENSE(10). */
 
268		sdev->use_10_for_ms = 1;
269
270		/* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
271		if (us->fflags & US_FL_NO_READ_DISC_INFO)
272			sdev->no_read_disc_info = 1;
273	}
274
275	/* The CB and CBI transports have no way to pass LUN values
 
276	 * other than the bits in the second byte of a CDB.  But those
277	 * bits don't get set to the LUN value if the device reports
278	 * scsi_level == 0 (UNKNOWN).  Hence such devices must necessarily
279	 * be single-LUN.
280	 */
281	if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
282			sdev->scsi_level == SCSI_UNKNOWN)
283		us->max_lun = 0;
284
285	/* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
286	 * REMOVAL command, so suppress those commands. */
 
 
287	if (us->fflags & US_FL_NOT_LOCKABLE)
288		sdev->lockable = 0;
289
290	/* this is to satisfy the compiler, tho I don't think the 
291	 * return code is ever checked anywhere. */
 
 
292	return 0;
293}
294
295static int target_alloc(struct scsi_target *starget)
296{
297	struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
298
299	/*
300	 * Some USB drives don't support REPORT LUNS, even though they
301	 * report a SCSI revision level above 2.  Tell the SCSI layer
302	 * not to issue that command; it will perform a normal sequential
303	 * scan instead.
304	 */
305	starget->no_report_luns = 1;
306
307	/*
308	 * The UFI spec treats the Peripheral Qualifier bits in an
309	 * INQUIRY result as reserved and requires devices to set them
310	 * to 0.  However the SCSI spec requires these bits to be set
311	 * to 3 to indicate when a LUN is not present.
312	 *
313	 * Let the scanning code know if this target merely sets
314	 * Peripheral Device Type to 0x1f to indicate no LUN.
315	 */
316	if (us->subclass == USB_SC_UFI)
317		starget->pdt_1f_for_no_lun = 1;
318
319	return 0;
320}
321
322/* queue a command */
323/* This is always called with scsi_lock(host) held */
324static int queuecommand_lck(struct scsi_cmnd *srb,
325			void (*done)(struct scsi_cmnd *))
326{
 
327	struct us_data *us = host_to_us(srb->device->host);
328
329	/* check for state-transition errors */
330	if (us->srb != NULL) {
331		printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
332			__func__, us->srb);
333		return SCSI_MLQUEUE_HOST_BUSY;
334	}
335
336	/* fail the command if we are disconnecting */
337	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
338		usb_stor_dbg(us, "Fail command during disconnect\n");
339		srb->result = DID_NO_CONNECT << 16;
340		done(srb);
341		return 0;
342	}
343
 
 
 
 
 
 
 
 
 
344	/* enqueue the command and wake up the control thread */
345	srb->scsi_done = done;
346	us->srb = srb;
347	complete(&us->cmnd_ready);
348
349	return 0;
350}
351
352static DEF_SCSI_QCMD(queuecommand)
353
354/***********************************************************************
355 * Error handling functions
356 ***********************************************************************/
357
358/* Command timeout and abort */
359static int command_abort(struct scsi_cmnd *srb)
360{
361	struct us_data *us = host_to_us(srb->device->host);
362
363	usb_stor_dbg(us, "%s called\n", __func__);
364
365	/* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
366	 * bits are protected by the host lock. */
 
 
367	scsi_lock(us_to_host(us));
368
369	/* Is this command still active? */
370	if (us->srb != srb) {
371		scsi_unlock(us_to_host(us));
372		usb_stor_dbg(us, "-- nothing to abort\n");
373		return FAILED;
374	}
375
376	/* Set the TIMED_OUT bit.  Also set the ABORTING bit, but only if
 
377	 * a device reset isn't already in progress (to avoid interfering
378	 * with the reset).  Note that we must retain the host lock while
379	 * calling usb_stor_stop_transport(); otherwise it might interfere
380	 * with an auto-reset that begins as soon as we release the lock. */
 
381	set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
382	if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
383		set_bit(US_FLIDX_ABORTING, &us->dflags);
384		usb_stor_stop_transport(us);
385	}
386	scsi_unlock(us_to_host(us));
387
388	/* Wait for the aborted command to finish */
389	wait_for_completion(&us->notify);
390	return SUCCESS;
391}
392
393/* This invokes the transport reset mechanism to reset the state of the
394 * device */
 
 
395static int device_reset(struct scsi_cmnd *srb)
396{
397	struct us_data *us = host_to_us(srb->device->host);
398	int result;
399
400	usb_stor_dbg(us, "%s called\n", __func__);
401
402	/* lock the device pointers and do the reset */
403	mutex_lock(&(us->dev_mutex));
404	result = us->transport_reset(us);
405	mutex_unlock(&us->dev_mutex);
406
407	return result < 0 ? FAILED : SUCCESS;
408}
409
410/* Simulate a SCSI bus reset by resetting the device's USB port. */
411static int bus_reset(struct scsi_cmnd *srb)
412{
413	struct us_data *us = host_to_us(srb->device->host);
414	int result;
415
416	usb_stor_dbg(us, "%s called\n", __func__);
417
418	result = usb_stor_port_reset(us);
419	return result < 0 ? FAILED : SUCCESS;
420}
421
422/* Report a driver-initiated device reset to the SCSI layer.
 
423 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
424 * The caller must own the SCSI host lock. */
 
425void usb_stor_report_device_reset(struct us_data *us)
426{
427	int i;
428	struct Scsi_Host *host = us_to_host(us);
429
430	scsi_report_device_reset(host, 0, 0);
431	if (us->fflags & US_FL_SCM_MULT_TARG) {
432		for (i = 1; i < host->max_id; ++i)
433			scsi_report_device_reset(host, 0, i);
434	}
435}
436
437/* Report a driver-initiated bus reset to the SCSI layer.
 
438 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
439 * The caller must not own the SCSI host lock. */
 
440void usb_stor_report_bus_reset(struct us_data *us)
441{
442	struct Scsi_Host *host = us_to_host(us);
443
444	scsi_lock(host);
445	scsi_report_bus_reset(host, 0);
446	scsi_unlock(host);
447}
448
449/***********************************************************************
450 * /proc/scsi/ functions
451 ***********************************************************************/
452
453static int write_info(struct Scsi_Host *host, char *buffer, int length)
454{
455	/* if someone is sending us data, just throw it away */
456	return length;
457}
458
459static int show_info (struct seq_file *m, struct Scsi_Host *host)
460{
461	struct us_data *us = host_to_us(host);
462	const char *string;
463
464	/* print the controller name */
465	seq_printf(m, "   Host scsi%d: usb-storage\n", host->host_no);
466
467	/* print product, vendor, and serial number strings */
468	if (us->pusb_dev->manufacturer)
469		string = us->pusb_dev->manufacturer;
470	else if (us->unusual_dev->vendorName)
471		string = us->unusual_dev->vendorName;
472	else
473		string = "Unknown";
474	seq_printf(m, "       Vendor: %s\n", string);
475	if (us->pusb_dev->product)
476		string = us->pusb_dev->product;
477	else if (us->unusual_dev->productName)
478		string = us->unusual_dev->productName;
479	else
480		string = "Unknown";
481	seq_printf(m, "      Product: %s\n", string);
482	if (us->pusb_dev->serial)
483		string = us->pusb_dev->serial;
484	else
485		string = "None";
486	seq_printf(m, "Serial Number: %s\n", string);
487
488	/* show the protocol and transport */
489	seq_printf(m, "     Protocol: %s\n", us->protocol_name);
490	seq_printf(m, "    Transport: %s\n", us->transport_name);
491
492	/* show the device flags */
493	seq_printf(m, "       Quirks:");
494
495#define US_FLAG(name, value) \
496	if (us->fflags & value) seq_printf(m, " " #name);
497US_DO_ALL_FLAGS
498#undef US_FLAG
499	seq_putc(m, '\n');
500	return 0;
501}
502
503/***********************************************************************
504 * Sysfs interface
505 ***********************************************************************/
506
507/* Output routine for the sysfs max_sectors file */
508static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
509{
510	struct scsi_device *sdev = to_scsi_device(dev);
511
512	return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
513}
514
515/* Input routine for the sysfs max_sectors file */
516static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
517		size_t count)
518{
519	struct scsi_device *sdev = to_scsi_device(dev);
520	unsigned short ms;
521
522	if (sscanf(buf, "%hu", &ms) > 0) {
523		blk_queue_max_hw_sectors(sdev->request_queue, ms);
524		return count;
525	}
526	return -EINVAL;
527}
528static DEVICE_ATTR_RW(max_sectors);
529
530static struct device_attribute *sysfs_device_attr_list[] = {
531	&dev_attr_max_sectors,
532	NULL,
533};
534
 
 
535/*
536 * this defines our host template, with which we'll allocate hosts
537 */
538
539static const struct scsi_host_template usb_stor_host_template = {
540	/* basic userland interface stuff */
541	.name =				"usb-storage",
542	.proc_name =			"usb-storage",
543	.show_info =			show_info,
544	.write_info =			write_info,
545	.info =				host_info,
546
547	/* command interface -- queued only */
548	.queuecommand =			queuecommand,
549
550	/* error and abort handlers */
551	.eh_abort_handler =		command_abort,
552	.eh_device_reset_handler =	device_reset,
553	.eh_bus_reset_handler =		bus_reset,
554
555	/* queue commands only, only one command per LUN */
556	.can_queue =			1,
557
558	/* unknown initiator id */
559	.this_id =			-1,
560
561	.slave_alloc =			slave_alloc,
562	.slave_configure =		slave_configure,
563	.target_alloc =			target_alloc,
564
565	/* lots of sg segments can be handled */
566	.sg_tablesize =			SCSI_MAX_SG_CHAIN_SEGMENTS,
567
568	/* limit the total size of a transfer to 120 KB */
569	.max_sectors =                  240,
570
571	/* merge commands... this seems to help performance, but
572	 * periodically someone should test to see which setting is more
573	 * optimal.
 
 
 
 
 
 
 
 
 
 
 
 
 
574	 */
575	.use_clustering =		1,
576
577	/* emulated HBA */
578	.emulated =			1,
579
580	/* we do our own delay after a device or bus reset */
581	.skip_settle_delay =		1,
582
583	/* sysfs device attributes */
584	.sdev_attrs =			sysfs_device_attr_list,
585
586	/* module management */
587	.module =			THIS_MODULE
588};
589
590void usb_stor_host_template_init(struct scsi_host_template *sht,
591				 const char *name, struct module *owner)
592{
593	*sht = usb_stor_host_template;
594	sht->name = name;
595	sht->proc_name = name;
596	sht->module = owner;
597}
598EXPORT_SYMBOL_GPL(usb_stor_host_template_init);
599
600/* To Report "Illegal Request: Invalid Field in CDB */
601unsigned char usb_stor_sense_invalidCDB[18] = {
602	[0]	= 0x70,			    /* current error */
603	[2]	= ILLEGAL_REQUEST,	    /* Illegal Request = 0x05 */
604	[7]	= 0x0a,			    /* additional length */
605	[12]	= 0x24			    /* Invalid Field in CDB */
606};
607EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);
v6.2
  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
 62static 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
 68static int slave_alloc (struct scsi_device *sdev)
 69{
 70	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	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
 92static int slave_configure(struct scsi_device *sdev)
 93{
 94	struct us_data *us = host_to_us(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(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(bus_to_hcd(us->pusb_dev->bus)) ||
139			(bus_to_hcd(us->pusb_dev->bus)->localmem_pool != NULL))
140		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	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
337static int target_alloc(struct scsi_target *starget)
338{
339	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	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 */
366static int queuecommand_lck(struct scsi_cmnd *srb)
 
367{
368	void (*done)(struct scsi_cmnd *) = scsi_done;
369	struct us_data *us = host_to_us(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, "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
402static DEF_SCSI_QCMD(queuecommand)
403
404/***********************************************************************
405 * Error handling functions
406 ***********************************************************************/
407
408/* Command timeout and abort */
409static int command_abort(struct scsi_cmnd *srb)
410{
411	struct us_data *us = host_to_us(srb->device->host);
412
413	usb_stor_dbg(us, "%s called\n", __func__);
414
415	/*
416	 * us->srb together with the TIMED_OUT, RESETTING, and ABORTING
417	 * bits are protected by the host lock.
418	 */
419	scsi_lock(us_to_host(us));
420
421	/* Is this command still active? */
422	if (us->srb != srb) {
423		scsi_unlock(us_to_host(us));
424		usb_stor_dbg(us, "-- nothing to abort\n");
425		return FAILED;
426	}
427
428	/*
429	 * Set the TIMED_OUT bit.  Also set the ABORTING bit, but only if
430	 * a device reset isn't already in progress (to avoid interfering
431	 * with the reset).  Note that we must retain the host lock while
432	 * calling usb_stor_stop_transport(); otherwise it might interfere
433	 * with an auto-reset that begins as soon as we release the lock.
434	 */
435	set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
436	if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
437		set_bit(US_FLIDX_ABORTING, &us->dflags);
438		usb_stor_stop_transport(us);
439	}
440	scsi_unlock(us_to_host(us));
441
442	/* Wait for the aborted command to finish */
443	wait_for_completion(&us->notify);
444	return SUCCESS;
445}
446
447/*
448 * This invokes the transport reset mechanism to reset the state of the
449 * device
450 */
451static int device_reset(struct scsi_cmnd *srb)
452{
453	struct us_data *us = host_to_us(srb->device->host);
454	int result;
455
456	usb_stor_dbg(us, "%s called\n", __func__);
457
458	/* lock the device pointers and do the reset */
459	mutex_lock(&(us->dev_mutex));
460	result = us->transport_reset(us);
461	mutex_unlock(&us->dev_mutex);
462
463	return result < 0 ? FAILED : SUCCESS;
464}
465
466/* Simulate a SCSI bus reset by resetting the device's USB port. */
467static int bus_reset(struct scsi_cmnd *srb)
468{
469	struct us_data *us = host_to_us(srb->device->host);
470	int result;
471
472	usb_stor_dbg(us, "%s called\n", __func__);
473
474	result = usb_stor_port_reset(us);
475	return result < 0 ? FAILED : SUCCESS;
476}
477
478/*
479 * Report a driver-initiated device reset to the SCSI layer.
480 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
481 * The caller must own the SCSI host lock.
482 */
483void usb_stor_report_device_reset(struct us_data *us)
484{
485	int i;
486	struct Scsi_Host *host = us_to_host(us);
487
488	scsi_report_device_reset(host, 0, 0);
489	if (us->fflags & US_FL_SCM_MULT_TARG) {
490		for (i = 1; i < host->max_id; ++i)
491			scsi_report_device_reset(host, 0, i);
492	}
493}
494
495/*
496 * Report a driver-initiated bus reset to the SCSI layer.
497 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
498 * The caller must not own the SCSI host lock.
499 */
500void usb_stor_report_bus_reset(struct us_data *us)
501{
502	struct Scsi_Host *host = us_to_host(us);
503
504	scsi_lock(host);
505	scsi_report_bus_reset(host, 0);
506	scsi_unlock(host);
507}
508
509/***********************************************************************
510 * /proc/scsi/ functions
511 ***********************************************************************/
512
513static int write_info(struct Scsi_Host *host, char *buffer, int length)
514{
515	/* if someone is sending us data, just throw it away */
516	return length;
517}
518
519static int show_info (struct seq_file *m, struct Scsi_Host *host)
520{
521	struct us_data *us = host_to_us(host);
522	const char *string;
523
524	/* print the controller name */
525	seq_printf(m, "   Host scsi%d: usb-storage\n", host->host_no);
526
527	/* print product, vendor, and serial number strings */
528	if (us->pusb_dev->manufacturer)
529		string = us->pusb_dev->manufacturer;
530	else if (us->unusual_dev->vendorName)
531		string = us->unusual_dev->vendorName;
532	else
533		string = "Unknown";
534	seq_printf(m, "       Vendor: %s\n", string);
535	if (us->pusb_dev->product)
536		string = us->pusb_dev->product;
537	else if (us->unusual_dev->productName)
538		string = us->unusual_dev->productName;
539	else
540		string = "Unknown";
541	seq_printf(m, "      Product: %s\n", string);
542	if (us->pusb_dev->serial)
543		string = us->pusb_dev->serial;
544	else
545		string = "None";
546	seq_printf(m, "Serial Number: %s\n", string);
547
548	/* show the protocol and transport */
549	seq_printf(m, "     Protocol: %s\n", us->protocol_name);
550	seq_printf(m, "    Transport: %s\n", us->transport_name);
551
552	/* show the device flags */
553	seq_printf(m, "       Quirks:");
554
555#define US_FLAG(name, value) \
556	if (us->fflags & value) seq_printf(m, " " #name);
557US_DO_ALL_FLAGS
558#undef US_FLAG
559	seq_putc(m, '\n');
560	return 0;
561}
562
563/***********************************************************************
564 * Sysfs interface
565 ***********************************************************************/
566
567/* Output routine for the sysfs max_sectors file */
568static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
569{
570	struct scsi_device *sdev = to_scsi_device(dev);
571
572	return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
573}
574
575/* Input routine for the sysfs max_sectors file */
576static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
577		size_t count)
578{
579	struct scsi_device *sdev = to_scsi_device(dev);
580	unsigned short ms;
581
582	if (sscanf(buf, "%hu", &ms) > 0) {
583		blk_queue_max_hw_sectors(sdev->request_queue, ms);
584		return count;
585	}
586	return -EINVAL;
587}
588static DEVICE_ATTR_RW(max_sectors);
589
590static struct attribute *usb_sdev_attrs[] = {
591	&dev_attr_max_sectors.attr,
592	NULL,
593};
594
595ATTRIBUTE_GROUPS(usb_sdev);
596
597/*
598 * this defines our host template, with which we'll allocate hosts
599 */
600
601static const struct scsi_host_template usb_stor_host_template = {
602	/* basic userland interface stuff */
603	.name =				"usb-storage",
604	.proc_name =			"usb-storage",
605	.show_info =			show_info,
606	.write_info =			write_info,
607	.info =				host_info,
608
609	/* command interface -- queued only */
610	.queuecommand =			queuecommand,
611
612	/* error and abort handlers */
613	.eh_abort_handler =		command_abort,
614	.eh_device_reset_handler =	device_reset,
615	.eh_bus_reset_handler =		bus_reset,
616
617	/* queue commands only, only one command per LUN */
618	.can_queue =			1,
619
620	/* unknown initiator id */
621	.this_id =			-1,
622
623	.slave_alloc =			slave_alloc,
624	.slave_configure =		slave_configure,
625	.target_alloc =			target_alloc,
626
627	/* lots of sg segments can be handled */
628	.sg_tablesize =			SG_MAX_SEGMENTS,
629
 
 
630
631	/*
632	 * Limit the total size of a transfer to 120 KB.
633	 *
634	 * Some devices are known to choke with anything larger. It seems like
635	 * the problem stems from the fact that original IDE controllers had
636	 * only an 8-bit register to hold the number of sectors in one transfer
637	 * and even those couldn't handle a full 256 sectors.
638	 *
639	 * Because we want to make sure we interoperate with as many devices as
640	 * possible, we will maintain a 240 sector transfer size limit for USB
641	 * Mass Storage devices.
642	 *
643	 * Tests show that other operating have similar limits with Microsoft
644	 * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
645	 * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
646	 * and 2048 for USB3 devices.
647	 */
648	.max_sectors =                  240,
649
650	/* emulated HBA */
651	.emulated =			1,
652
653	/* we do our own delay after a device or bus reset */
654	.skip_settle_delay =		1,
655
656	/* sysfs device attributes */
657	.sdev_groups =			usb_sdev_groups,
658
659	/* module management */
660	.module =			THIS_MODULE
661};
662
663void usb_stor_host_template_init(struct scsi_host_template *sht,
664				 const char *name, struct module *owner)
665{
666	*sht = usb_stor_host_template;
667	sht->name = name;
668	sht->proc_name = name;
669	sht->module = owner;
670}
671EXPORT_SYMBOL_GPL(usb_stor_host_template_init);
672
673/* To Report "Illegal Request: Invalid Field in CDB */
674unsigned char usb_stor_sense_invalidCDB[18] = {
675	[0]	= 0x70,			    /* current error */
676	[2]	= ILLEGAL_REQUEST,	    /* Illegal Request = 0x05 */
677	[7]	= 0x0a,			    /* additional length */
678	[12]	= 0x24			    /* Invalid Field in CDB */
679};
680EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);