xref: /openbmc/linux/drivers/usb/storage/scsiglue.c (revision 6774def6)
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 
73 static 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 
79 static int slave_alloc (struct scsi_device *sdev)
80 {
81 	struct us_data *us = host_to_us(sdev->host);
82 
83 	/*
84 	 * Set the INQUIRY transfer length to 36.  We don't use any of
85 	 * the extra data and many devices choke if asked for more or
86 	 * less than 36 bytes.
87 	 */
88 	sdev->inquiry_len = 36;
89 
90 	/* USB has unusual DMA-alignment requirements: Although the
91 	 * starting address of each scatter-gather element doesn't matter,
92 	 * the length of each element except the last must be divisible
93 	 * by the Bulk maxpacket value.  There's currently no way to
94 	 * express this by block-layer constraints, so we'll cop out
95 	 * and simply require addresses to be aligned at 512-byte
96 	 * boundaries.  This is okay since most block I/O involves
97 	 * hardware sectors that are multiples of 512 bytes in length,
98 	 * and since host controllers up through USB 2.0 have maxpacket
99 	 * values no larger than 512.
100 	 *
101 	 * But it doesn't suffice for Wireless USB, where Bulk maxpacket
102 	 * values can be as large as 2048.  To make that work properly
103 	 * will require changes to the block layer.
104 	 */
105 	blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
106 
107 	/* 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 
114 static 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_CACHE_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 
295 static 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 */
324 static 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 
352 static DEF_SCSI_QCMD(queuecommand)
353 
354 /***********************************************************************
355  * Error handling functions
356  ***********************************************************************/
357 
358 /* Command timeout and abort */
359 static 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 */
395 static 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. */
411 static 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. */
425 void 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. */
440 void 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 
453 static 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 
459 /* we use this macro to help us write into the buffer */
460 #undef SPRINTF
461 #define SPRINTF(args...) seq_printf(m, ## args)
462 
463 static int show_info (struct seq_file *m, struct Scsi_Host *host)
464 {
465 	struct us_data *us = host_to_us(host);
466 	const char *string;
467 
468 	/* print the controller name */
469 	SPRINTF("   Host scsi%d: usb-storage\n", host->host_no);
470 
471 	/* print product, vendor, and serial number strings */
472 	if (us->pusb_dev->manufacturer)
473 		string = us->pusb_dev->manufacturer;
474 	else if (us->unusual_dev->vendorName)
475 		string = us->unusual_dev->vendorName;
476 	else
477 		string = "Unknown";
478 	SPRINTF("       Vendor: %s\n", string);
479 	if (us->pusb_dev->product)
480 		string = us->pusb_dev->product;
481 	else if (us->unusual_dev->productName)
482 		string = us->unusual_dev->productName;
483 	else
484 		string = "Unknown";
485 	SPRINTF("      Product: %s\n", string);
486 	if (us->pusb_dev->serial)
487 		string = us->pusb_dev->serial;
488 	else
489 		string = "None";
490 	SPRINTF("Serial Number: %s\n", string);
491 
492 	/* show the protocol and transport */
493 	SPRINTF("     Protocol: %s\n", us->protocol_name);
494 	SPRINTF("    Transport: %s\n", us->transport_name);
495 
496 	/* show the device flags */
497 	SPRINTF("       Quirks:");
498 
499 #define US_FLAG(name, value) \
500 	if (us->fflags & value) seq_printf(m, " " #name);
501 US_DO_ALL_FLAGS
502 #undef US_FLAG
503 	seq_putc(m, '\n');
504 	return 0;
505 }
506 
507 /***********************************************************************
508  * Sysfs interface
509  ***********************************************************************/
510 
511 /* Output routine for the sysfs max_sectors file */
512 static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
513 {
514 	struct scsi_device *sdev = to_scsi_device(dev);
515 
516 	return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
517 }
518 
519 /* Input routine for the sysfs max_sectors file */
520 static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
521 		size_t count)
522 {
523 	struct scsi_device *sdev = to_scsi_device(dev);
524 	unsigned short ms;
525 
526 	if (sscanf(buf, "%hu", &ms) > 0) {
527 		blk_queue_max_hw_sectors(sdev->request_queue, ms);
528 		return count;
529 	}
530 	return -EINVAL;
531 }
532 static DEVICE_ATTR_RW(max_sectors);
533 
534 static struct device_attribute *sysfs_device_attr_list[] = {
535 	&dev_attr_max_sectors,
536 	NULL,
537 };
538 
539 /*
540  * this defines our host template, with which we'll allocate hosts
541  */
542 
543 struct scsi_host_template usb_stor_host_template = {
544 	/* basic userland interface stuff */
545 	.name =				"usb-storage",
546 	.proc_name =			"usb-storage",
547 	.show_info =			show_info,
548 	.write_info =			write_info,
549 	.info =				host_info,
550 
551 	/* command interface -- queued only */
552 	.queuecommand =			queuecommand,
553 
554 	/* error and abort handlers */
555 	.eh_abort_handler =		command_abort,
556 	.eh_device_reset_handler =	device_reset,
557 	.eh_bus_reset_handler =		bus_reset,
558 
559 	/* queue commands only, only one command per LUN */
560 	.can_queue =			1,
561 	.cmd_per_lun =			1,
562 
563 	/* unknown initiator id */
564 	.this_id =			-1,
565 
566 	.slave_alloc =			slave_alloc,
567 	.slave_configure =		slave_configure,
568 	.target_alloc =			target_alloc,
569 
570 	/* lots of sg segments can be handled */
571 	.sg_tablesize =			SCSI_MAX_SG_CHAIN_SEGMENTS,
572 
573 	/* limit the total size of a transfer to 120 KB */
574 	.max_sectors =                  240,
575 
576 	/* merge commands... this seems to help performance, but
577 	 * periodically someone should test to see which setting is more
578 	 * optimal.
579 	 */
580 	.use_clustering =		1,
581 
582 	/* emulated HBA */
583 	.emulated =			1,
584 
585 	/* we do our own delay after a device or bus reset */
586 	.skip_settle_delay =		1,
587 
588 	/* sysfs device attributes */
589 	.sdev_attrs =			sysfs_device_attr_list,
590 
591 	/* module management */
592 	.module =			THIS_MODULE
593 };
594 
595 /* To Report "Illegal Request: Invalid Field in CDB */
596 unsigned char usb_stor_sense_invalidCDB[18] = {
597 	[0]	= 0x70,			    /* current error */
598 	[2]	= ILLEGAL_REQUEST,	    /* Illegal Request = 0x05 */
599 	[7]	= 0x0a,			    /* additional length */
600 	[12]	= 0x24			    /* Invalid Field in CDB */
601 };
602 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);
603