xref: /openbmc/linux/drivers/usb/storage/usb.c (revision 12eb4683)
1 /* Driver for USB Mass Storage compliant devices
2  *
3  * Current development and maintenance by:
4  *   (c) 1999-2003 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
5  *
6  * Developed with the assistance of:
7  *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
8  *   (c) 2003-2009 Alan Stern (stern@rowland.harvard.edu)
9  *
10  * Initial work by:
11  *   (c) 1999 Michael Gee (michael@linuxspecific.com)
12  *
13  * usb_device_id support by Adam J. Richter (adam@yggdrasil.com):
14  *   (c) 2000 Yggdrasil Computing, Inc.
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  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
31  * information about this driver.
32  *
33  * This program is free software; you can redistribute it and/or modify it
34  * under the terms of the GNU General Public License as published by the
35  * Free Software Foundation; either version 2, or (at your option) any
36  * later version.
37  *
38  * This program is distributed in the hope that it will be useful, but
39  * WITHOUT ANY WARRANTY; without even the implied warranty of
40  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
41  * General Public License for more details.
42  *
43  * You should have received a copy of the GNU General Public License along
44  * with this program; if not, write to the Free Software Foundation, Inc.,
45  * 675 Mass Ave, Cambridge, MA 02139, USA.
46  */
47 
48 #ifdef CONFIG_USB_STORAGE_DEBUG
49 #define DEBUG
50 #endif
51 
52 #include <linux/sched.h>
53 #include <linux/errno.h>
54 #include <linux/freezer.h>
55 #include <linux/module.h>
56 #include <linux/init.h>
57 #include <linux/slab.h>
58 #include <linux/kthread.h>
59 #include <linux/mutex.h>
60 #include <linux/utsname.h>
61 
62 #include <scsi/scsi.h>
63 #include <scsi/scsi_cmnd.h>
64 #include <scsi/scsi_device.h>
65 
66 #include "usb.h"
67 #include "scsiglue.h"
68 #include "transport.h"
69 #include "protocol.h"
70 #include "debug.h"
71 #include "initializers.h"
72 
73 #include "sierra_ms.h"
74 #include "option_ms.h"
75 
76 /* Some informational data */
77 MODULE_AUTHOR("Matthew Dharm <mdharm-usb@one-eyed-alien.net>");
78 MODULE_DESCRIPTION("USB Mass Storage driver for Linux");
79 MODULE_LICENSE("GPL");
80 
81 static unsigned int delay_use = 1;
82 module_param(delay_use, uint, S_IRUGO | S_IWUSR);
83 MODULE_PARM_DESC(delay_use, "seconds to delay before using a new device");
84 
85 static char quirks[128];
86 module_param_string(quirks, quirks, sizeof(quirks), S_IRUGO | S_IWUSR);
87 MODULE_PARM_DESC(quirks, "supplemental list of device IDs and their quirks");
88 
89 
90 /*
91  * The entries in this table correspond, line for line,
92  * with the entries in usb_storage_usb_ids[], defined in usual-tables.c.
93  */
94 
95 /* The vendor name should be kept at eight characters or less, and
96  * the product name should be kept at 16 characters or less. If a device
97  * has the US_FL_FIX_INQUIRY flag, then the vendor and product names
98  * normally generated by a device thorugh the INQUIRY response will be
99  * taken from this list, and this is the reason for the above size
100  * restriction. However, if the flag is not present, then you
101  * are free to use as many characters as you like.
102  */
103 
104 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
105 		    vendor_name, product_name, use_protocol, use_transport, \
106 		    init_function, Flags) \
107 { \
108 	.vendorName = vendor_name,	\
109 	.productName = product_name,	\
110 	.useProtocol = use_protocol,	\
111 	.useTransport = use_transport,	\
112 	.initFunction = init_function,	\
113 }
114 
115 #define COMPLIANT_DEV	UNUSUAL_DEV
116 
117 #define USUAL_DEV(use_protocol, use_transport) \
118 { \
119 	.useProtocol = use_protocol,	\
120 	.useTransport = use_transport,	\
121 }
122 
123 #define UNUSUAL_VENDOR_INTF(idVendor, cl, sc, pr, \
124 		vendor_name, product_name, use_protocol, use_transport, \
125 		init_function, Flags) \
126 { \
127 	.vendorName = vendor_name,	\
128 	.productName = product_name,	\
129 	.useProtocol = use_protocol,	\
130 	.useTransport = use_transport,	\
131 	.initFunction = init_function,	\
132 }
133 
134 static struct us_unusual_dev us_unusual_dev_list[] = {
135 #	include "unusual_devs.h"
136 	{ }		/* Terminating entry */
137 };
138 
139 static struct us_unusual_dev for_dynamic_ids =
140 		USUAL_DEV(USB_SC_SCSI, USB_PR_BULK);
141 
142 #undef UNUSUAL_DEV
143 #undef COMPLIANT_DEV
144 #undef USUAL_DEV
145 #undef UNUSUAL_VENDOR_INTF
146 
147 #ifdef CONFIG_LOCKDEP
148 
149 static struct lock_class_key us_interface_key[USB_MAXINTERFACES];
150 
151 static void us_set_lock_class(struct mutex *mutex,
152 		struct usb_interface *intf)
153 {
154 	struct usb_device *udev = interface_to_usbdev(intf);
155 	struct usb_host_config *config = udev->actconfig;
156 	int i;
157 
158 	for (i = 0; i < config->desc.bNumInterfaces; i++) {
159 		if (config->interface[i] == intf)
160 			break;
161 	}
162 
163 	BUG_ON(i == config->desc.bNumInterfaces);
164 
165 	lockdep_set_class(mutex, &us_interface_key[i]);
166 }
167 
168 #else
169 
170 static void us_set_lock_class(struct mutex *mutex,
171 		struct usb_interface *intf)
172 {
173 }
174 
175 #endif
176 
177 #ifdef CONFIG_PM	/* Minimal support for suspend and resume */
178 
179 int usb_stor_suspend(struct usb_interface *iface, pm_message_t message)
180 {
181 	struct us_data *us = usb_get_intfdata(iface);
182 
183 	/* Wait until no command is running */
184 	mutex_lock(&us->dev_mutex);
185 
186 	if (us->suspend_resume_hook)
187 		(us->suspend_resume_hook)(us, US_SUSPEND);
188 
189 	/* When runtime PM is working, we'll set a flag to indicate
190 	 * whether we should autoresume when a SCSI request arrives. */
191 
192 	mutex_unlock(&us->dev_mutex);
193 	return 0;
194 }
195 EXPORT_SYMBOL_GPL(usb_stor_suspend);
196 
197 int usb_stor_resume(struct usb_interface *iface)
198 {
199 	struct us_data *us = usb_get_intfdata(iface);
200 
201 	mutex_lock(&us->dev_mutex);
202 
203 	if (us->suspend_resume_hook)
204 		(us->suspend_resume_hook)(us, US_RESUME);
205 
206 	mutex_unlock(&us->dev_mutex);
207 	return 0;
208 }
209 EXPORT_SYMBOL_GPL(usb_stor_resume);
210 
211 int usb_stor_reset_resume(struct usb_interface *iface)
212 {
213 	struct us_data *us = usb_get_intfdata(iface);
214 
215 	/* Report the reset to the SCSI core */
216 	usb_stor_report_bus_reset(us);
217 
218 	/* FIXME: Notify the subdrivers that they need to reinitialize
219 	 * the device */
220 	return 0;
221 }
222 EXPORT_SYMBOL_GPL(usb_stor_reset_resume);
223 
224 #endif /* CONFIG_PM */
225 
226 /*
227  * The next two routines get called just before and just after
228  * a USB port reset, whether from this driver or a different one.
229  */
230 
231 int usb_stor_pre_reset(struct usb_interface *iface)
232 {
233 	struct us_data *us = usb_get_intfdata(iface);
234 
235 	/* Make sure no command runs during the reset */
236 	mutex_lock(&us->dev_mutex);
237 	return 0;
238 }
239 EXPORT_SYMBOL_GPL(usb_stor_pre_reset);
240 
241 int usb_stor_post_reset(struct usb_interface *iface)
242 {
243 	struct us_data *us = usb_get_intfdata(iface);
244 
245 	/* Report the reset to the SCSI core */
246 	usb_stor_report_bus_reset(us);
247 
248 	/* FIXME: Notify the subdrivers that they need to reinitialize
249 	 * the device */
250 
251 	mutex_unlock(&us->dev_mutex);
252 	return 0;
253 }
254 EXPORT_SYMBOL_GPL(usb_stor_post_reset);
255 
256 /*
257  * fill_inquiry_response takes an unsigned char array (which must
258  * be at least 36 characters) and populates the vendor name,
259  * product name, and revision fields. Then the array is copied
260  * into the SCSI command's response buffer (oddly enough
261  * called request_buffer). data_len contains the length of the
262  * data array, which again must be at least 36.
263  */
264 
265 void fill_inquiry_response(struct us_data *us, unsigned char *data,
266 		unsigned int data_len)
267 {
268 	if (data_len < 36) /* You lose. */
269 		return;
270 
271 	memset(data+8, ' ', 28);
272 	if (data[0]&0x20) { /* USB device currently not connected. Return
273 			      peripheral qualifier 001b ("...however, the
274 			      physical device is not currently connected
275 			      to this logical unit") and leave vendor and
276 			      product identification empty. ("If the target
277 			      does store some of the INQUIRY data on the
278 			      device, it may return zeros or ASCII spaces
279 			      (20h) in those fields until the data is
280 			      available from the device."). */
281 	} else {
282 		u16 bcdDevice = le16_to_cpu(us->pusb_dev->descriptor.bcdDevice);
283 		int n;
284 
285 		n = strlen(us->unusual_dev->vendorName);
286 		memcpy(data+8, us->unusual_dev->vendorName, min(8, n));
287 		n = strlen(us->unusual_dev->productName);
288 		memcpy(data+16, us->unusual_dev->productName, min(16, n));
289 
290 		data[32] = 0x30 + ((bcdDevice>>12) & 0x0F);
291 		data[33] = 0x30 + ((bcdDevice>>8) & 0x0F);
292 		data[34] = 0x30 + ((bcdDevice>>4) & 0x0F);
293 		data[35] = 0x30 + ((bcdDevice) & 0x0F);
294 	}
295 
296 	usb_stor_set_xfer_buf(data, data_len, us->srb);
297 }
298 EXPORT_SYMBOL_GPL(fill_inquiry_response);
299 
300 static int usb_stor_control_thread(void * __us)
301 {
302 	struct us_data *us = (struct us_data *)__us;
303 	struct Scsi_Host *host = us_to_host(us);
304 
305 	for (;;) {
306 		usb_stor_dbg(us, "*** thread sleeping\n");
307 		if (wait_for_completion_interruptible(&us->cmnd_ready))
308 			break;
309 
310 		usb_stor_dbg(us, "*** thread awakened\n");
311 
312 		/* lock the device pointers */
313 		mutex_lock(&(us->dev_mutex));
314 
315 		/* lock access to the state */
316 		scsi_lock(host);
317 
318 		/* When we are called with no command pending, we're done */
319 		if (us->srb == NULL) {
320 			scsi_unlock(host);
321 			mutex_unlock(&us->dev_mutex);
322 			usb_stor_dbg(us, "-- exiting\n");
323 			break;
324 		}
325 
326 		/* has the command timed out *already* ? */
327 		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
328 			us->srb->result = DID_ABORT << 16;
329 			goto SkipForAbort;
330 		}
331 
332 		scsi_unlock(host);
333 
334 		/* reject the command if the direction indicator
335 		 * is UNKNOWN
336 		 */
337 		if (us->srb->sc_data_direction == DMA_BIDIRECTIONAL) {
338 			usb_stor_dbg(us, "UNKNOWN data direction\n");
339 			us->srb->result = DID_ERROR << 16;
340 		}
341 
342 		/* reject if target != 0 or if LUN is higher than
343 		 * the maximum known LUN
344 		 */
345 		else if (us->srb->device->id &&
346 				!(us->fflags & US_FL_SCM_MULT_TARG)) {
347 			usb_stor_dbg(us, "Bad target number (%d:%d)\n",
348 				     us->srb->device->id, us->srb->device->lun);
349 			us->srb->result = DID_BAD_TARGET << 16;
350 		}
351 
352 		else if (us->srb->device->lun > us->max_lun) {
353 			usb_stor_dbg(us, "Bad LUN (%d:%d)\n",
354 				     us->srb->device->id, us->srb->device->lun);
355 			us->srb->result = DID_BAD_TARGET << 16;
356 		}
357 
358 		/* Handle those devices which need us to fake
359 		 * their inquiry data */
360 		else if ((us->srb->cmnd[0] == INQUIRY) &&
361 			    (us->fflags & US_FL_FIX_INQUIRY)) {
362 			unsigned char data_ptr[36] = {
363 			    0x00, 0x80, 0x02, 0x02,
364 			    0x1F, 0x00, 0x00, 0x00};
365 
366 			usb_stor_dbg(us, "Faking INQUIRY command\n");
367 			fill_inquiry_response(us, data_ptr, 36);
368 			us->srb->result = SAM_STAT_GOOD;
369 		}
370 
371 		/* we've got a command, let's do it! */
372 		else {
373 			US_DEBUG(usb_stor_show_command(us, us->srb));
374 			us->proto_handler(us->srb, us);
375 			usb_mark_last_busy(us->pusb_dev);
376 		}
377 
378 		/* lock access to the state */
379 		scsi_lock(host);
380 
381 		/* indicate that the command is done */
382 		if (us->srb->result != DID_ABORT << 16) {
383 			usb_stor_dbg(us, "scsi cmd done, result=0x%x\n",
384 				     us->srb->result);
385 			us->srb->scsi_done(us->srb);
386 		} else {
387 SkipForAbort:
388 			usb_stor_dbg(us, "scsi command aborted\n");
389 		}
390 
391 		/* If an abort request was received we need to signal that
392 		 * the abort has finished.  The proper test for this is
393 		 * the TIMED_OUT flag, not srb->result == DID_ABORT, because
394 		 * the timeout might have occurred after the command had
395 		 * already completed with a different result code. */
396 		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
397 			complete(&(us->notify));
398 
399 			/* Allow USB transfers to resume */
400 			clear_bit(US_FLIDX_ABORTING, &us->dflags);
401 			clear_bit(US_FLIDX_TIMED_OUT, &us->dflags);
402 		}
403 
404 		/* finished working on this command */
405 		us->srb = NULL;
406 		scsi_unlock(host);
407 
408 		/* unlock the device pointers */
409 		mutex_unlock(&us->dev_mutex);
410 	} /* for (;;) */
411 
412 	/* Wait until we are told to stop */
413 	for (;;) {
414 		set_current_state(TASK_INTERRUPTIBLE);
415 		if (kthread_should_stop())
416 			break;
417 		schedule();
418 	}
419 	__set_current_state(TASK_RUNNING);
420 	return 0;
421 }
422 
423 /***********************************************************************
424  * Device probing and disconnecting
425  ***********************************************************************/
426 
427 /* Associate our private data with the USB device */
428 static int associate_dev(struct us_data *us, struct usb_interface *intf)
429 {
430 	/* Fill in the device-related fields */
431 	us->pusb_dev = interface_to_usbdev(intf);
432 	us->pusb_intf = intf;
433 	us->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
434 	usb_stor_dbg(us, "Vendor: 0x%04x, Product: 0x%04x, Revision: 0x%04x\n",
435 		     le16_to_cpu(us->pusb_dev->descriptor.idVendor),
436 		     le16_to_cpu(us->pusb_dev->descriptor.idProduct),
437 		     le16_to_cpu(us->pusb_dev->descriptor.bcdDevice));
438 	usb_stor_dbg(us, "Interface Subclass: 0x%02x, Protocol: 0x%02x\n",
439 		     intf->cur_altsetting->desc.bInterfaceSubClass,
440 		     intf->cur_altsetting->desc.bInterfaceProtocol);
441 
442 	/* Store our private data in the interface */
443 	usb_set_intfdata(intf, us);
444 
445 	/* Allocate the control/setup and DMA-mapped buffers */
446 	us->cr = kmalloc(sizeof(*us->cr), GFP_KERNEL);
447 	if (!us->cr)
448 		return -ENOMEM;
449 
450 	us->iobuf = usb_alloc_coherent(us->pusb_dev, US_IOBUF_SIZE,
451 			GFP_KERNEL, &us->iobuf_dma);
452 	if (!us->iobuf) {
453 		usb_stor_dbg(us, "I/O buffer allocation failed\n");
454 		return -ENOMEM;
455 	}
456 	return 0;
457 }
458 
459 /* Works only for digits and letters, but small and fast */
460 #define TOLOWER(x) ((x) | 0x20)
461 
462 /* Adjust device flags based on the "quirks=" module parameter */
463 static void adjust_quirks(struct us_data *us)
464 {
465 	char *p;
466 	u16 vid = le16_to_cpu(us->pusb_dev->descriptor.idVendor);
467 	u16 pid = le16_to_cpu(us->pusb_dev->descriptor.idProduct);
468 	unsigned f = 0;
469 	unsigned int mask = (US_FL_SANE_SENSE | US_FL_BAD_SENSE |
470 			US_FL_FIX_CAPACITY |
471 			US_FL_CAPACITY_HEURISTICS | US_FL_IGNORE_DEVICE |
472 			US_FL_NOT_LOCKABLE | US_FL_MAX_SECTORS_64 |
473 			US_FL_CAPACITY_OK | US_FL_IGNORE_RESIDUE |
474 			US_FL_SINGLE_LUN | US_FL_NO_WP_DETECT |
475 			US_FL_NO_READ_DISC_INFO | US_FL_NO_READ_CAPACITY_16 |
476 			US_FL_INITIAL_READ10 | US_FL_WRITE_CACHE);
477 
478 	p = quirks;
479 	while (*p) {
480 		/* Each entry consists of VID:PID:flags */
481 		if (vid == simple_strtoul(p, &p, 16) &&
482 				*p == ':' &&
483 				pid == simple_strtoul(p+1, &p, 16) &&
484 				*p == ':')
485 			break;
486 
487 		/* Move forward to the next entry */
488 		while (*p) {
489 			if (*p++ == ',')
490 				break;
491 		}
492 	}
493 	if (!*p)	/* No match */
494 		return;
495 
496 	/* Collect the flags */
497 	while (*++p && *p != ',') {
498 		switch (TOLOWER(*p)) {
499 		case 'a':
500 			f |= US_FL_SANE_SENSE;
501 			break;
502 		case 'b':
503 			f |= US_FL_BAD_SENSE;
504 			break;
505 		case 'c':
506 			f |= US_FL_FIX_CAPACITY;
507 			break;
508 		case 'd':
509 			f |= US_FL_NO_READ_DISC_INFO;
510 			break;
511 		case 'e':
512 			f |= US_FL_NO_READ_CAPACITY_16;
513 			break;
514 		case 'h':
515 			f |= US_FL_CAPACITY_HEURISTICS;
516 			break;
517 		case 'i':
518 			f |= US_FL_IGNORE_DEVICE;
519 			break;
520 		case 'l':
521 			f |= US_FL_NOT_LOCKABLE;
522 			break;
523 		case 'm':
524 			f |= US_FL_MAX_SECTORS_64;
525 			break;
526 		case 'n':
527 			f |= US_FL_INITIAL_READ10;
528 			break;
529 		case 'o':
530 			f |= US_FL_CAPACITY_OK;
531 			break;
532 		case 'p':
533 			f |= US_FL_WRITE_CACHE;
534 			break;
535 		case 'r':
536 			f |= US_FL_IGNORE_RESIDUE;
537 			break;
538 		case 's':
539 			f |= US_FL_SINGLE_LUN;
540 			break;
541 		case 'w':
542 			f |= US_FL_NO_WP_DETECT;
543 			break;
544 		/* Ignore unrecognized flag characters */
545 		}
546 	}
547 	us->fflags = (us->fflags & ~mask) | f;
548 }
549 
550 /* Get the unusual_devs entries and the string descriptors */
551 static int get_device_info(struct us_data *us, const struct usb_device_id *id,
552 		struct us_unusual_dev *unusual_dev)
553 {
554 	struct usb_device *dev = us->pusb_dev;
555 	struct usb_interface_descriptor *idesc =
556 		&us->pusb_intf->cur_altsetting->desc;
557 	struct device *pdev = &us->pusb_intf->dev;
558 
559 	/* Store the entries */
560 	us->unusual_dev = unusual_dev;
561 	us->subclass = (unusual_dev->useProtocol == USB_SC_DEVICE) ?
562 			idesc->bInterfaceSubClass :
563 			unusual_dev->useProtocol;
564 	us->protocol = (unusual_dev->useTransport == USB_PR_DEVICE) ?
565 			idesc->bInterfaceProtocol :
566 			unusual_dev->useTransport;
567 	us->fflags = id->driver_info;
568 	adjust_quirks(us);
569 
570 	if (us->fflags & US_FL_IGNORE_DEVICE) {
571 		dev_info(pdev, "device ignored\n");
572 		return -ENODEV;
573 	}
574 
575 	/*
576 	 * This flag is only needed when we're in high-speed, so let's
577 	 * disable it if we're in full-speed
578 	 */
579 	if (dev->speed != USB_SPEED_HIGH)
580 		us->fflags &= ~US_FL_GO_SLOW;
581 
582 	if (us->fflags)
583 		dev_info(pdev, "Quirks match for vid %04x pid %04x: %lx\n",
584 				le16_to_cpu(dev->descriptor.idVendor),
585 				le16_to_cpu(dev->descriptor.idProduct),
586 				us->fflags);
587 
588 	/* Log a message if a non-generic unusual_dev entry contains an
589 	 * unnecessary subclass or protocol override.  This may stimulate
590 	 * reports from users that will help us remove unneeded entries
591 	 * from the unusual_devs.h table.
592 	 */
593 	if (id->idVendor || id->idProduct) {
594 		static const char *msgs[3] = {
595 			"an unneeded SubClass entry",
596 			"an unneeded Protocol entry",
597 			"unneeded SubClass and Protocol entries"};
598 		struct usb_device_descriptor *ddesc = &dev->descriptor;
599 		int msg = -1;
600 
601 		if (unusual_dev->useProtocol != USB_SC_DEVICE &&
602 			us->subclass == idesc->bInterfaceSubClass)
603 			msg += 1;
604 		if (unusual_dev->useTransport != USB_PR_DEVICE &&
605 			us->protocol == idesc->bInterfaceProtocol)
606 			msg += 2;
607 		if (msg >= 0 && !(us->fflags & US_FL_NEED_OVERRIDE))
608 			dev_notice(pdev, "This device "
609 					"(%04x,%04x,%04x S %02x P %02x)"
610 					" has %s in unusual_devs.h (kernel"
611 					" %s)\n"
612 					"   Please send a copy of this message to "
613 					"<linux-usb@vger.kernel.org> and "
614 					"<usb-storage@lists.one-eyed-alien.net>\n",
615 					le16_to_cpu(ddesc->idVendor),
616 					le16_to_cpu(ddesc->idProduct),
617 					le16_to_cpu(ddesc->bcdDevice),
618 					idesc->bInterfaceSubClass,
619 					idesc->bInterfaceProtocol,
620 					msgs[msg],
621 					utsname()->release);
622 	}
623 
624 	return 0;
625 }
626 
627 /* Get the transport settings */
628 static void get_transport(struct us_data *us)
629 {
630 	switch (us->protocol) {
631 	case USB_PR_CB:
632 		us->transport_name = "Control/Bulk";
633 		us->transport = usb_stor_CB_transport;
634 		us->transport_reset = usb_stor_CB_reset;
635 		us->max_lun = 7;
636 		break;
637 
638 	case USB_PR_CBI:
639 		us->transport_name = "Control/Bulk/Interrupt";
640 		us->transport = usb_stor_CB_transport;
641 		us->transport_reset = usb_stor_CB_reset;
642 		us->max_lun = 7;
643 		break;
644 
645 	case USB_PR_BULK:
646 		us->transport_name = "Bulk";
647 		us->transport = usb_stor_Bulk_transport;
648 		us->transport_reset = usb_stor_Bulk_reset;
649 		break;
650 	}
651 }
652 
653 /* Get the protocol settings */
654 static void get_protocol(struct us_data *us)
655 {
656 	switch (us->subclass) {
657 	case USB_SC_RBC:
658 		us->protocol_name = "Reduced Block Commands (RBC)";
659 		us->proto_handler = usb_stor_transparent_scsi_command;
660 		break;
661 
662 	case USB_SC_8020:
663 		us->protocol_name = "8020i";
664 		us->proto_handler = usb_stor_pad12_command;
665 		us->max_lun = 0;
666 		break;
667 
668 	case USB_SC_QIC:
669 		us->protocol_name = "QIC-157";
670 		us->proto_handler = usb_stor_pad12_command;
671 		us->max_lun = 0;
672 		break;
673 
674 	case USB_SC_8070:
675 		us->protocol_name = "8070i";
676 		us->proto_handler = usb_stor_pad12_command;
677 		us->max_lun = 0;
678 		break;
679 
680 	case USB_SC_SCSI:
681 		us->protocol_name = "Transparent SCSI";
682 		us->proto_handler = usb_stor_transparent_scsi_command;
683 		break;
684 
685 	case USB_SC_UFI:
686 		us->protocol_name = "Uniform Floppy Interface (UFI)";
687 		us->proto_handler = usb_stor_ufi_command;
688 		break;
689 	}
690 }
691 
692 /* Get the pipe settings */
693 static int get_pipes(struct us_data *us)
694 {
695 	struct usb_host_interface *altsetting =
696 		us->pusb_intf->cur_altsetting;
697 	int i;
698 	struct usb_endpoint_descriptor *ep;
699 	struct usb_endpoint_descriptor *ep_in = NULL;
700 	struct usb_endpoint_descriptor *ep_out = NULL;
701 	struct usb_endpoint_descriptor *ep_int = NULL;
702 
703 	/*
704 	 * Find the first endpoint of each type we need.
705 	 * We are expecting a minimum of 2 endpoints - in and out (bulk).
706 	 * An optional interrupt-in is OK (necessary for CBI protocol).
707 	 * We will ignore any others.
708 	 */
709 	for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
710 		ep = &altsetting->endpoint[i].desc;
711 
712 		if (usb_endpoint_xfer_bulk(ep)) {
713 			if (usb_endpoint_dir_in(ep)) {
714 				if (!ep_in)
715 					ep_in = ep;
716 			} else {
717 				if (!ep_out)
718 					ep_out = ep;
719 			}
720 		}
721 
722 		else if (usb_endpoint_is_int_in(ep)) {
723 			if (!ep_int)
724 				ep_int = ep;
725 		}
726 	}
727 
728 	if (!ep_in || !ep_out || (us->protocol == USB_PR_CBI && !ep_int)) {
729 		usb_stor_dbg(us, "Endpoint sanity check failed! Rejecting dev.\n");
730 		return -EIO;
731 	}
732 
733 	/* Calculate and store the pipe values */
734 	us->send_ctrl_pipe = usb_sndctrlpipe(us->pusb_dev, 0);
735 	us->recv_ctrl_pipe = usb_rcvctrlpipe(us->pusb_dev, 0);
736 	us->send_bulk_pipe = usb_sndbulkpipe(us->pusb_dev,
737 		usb_endpoint_num(ep_out));
738 	us->recv_bulk_pipe = usb_rcvbulkpipe(us->pusb_dev,
739 		usb_endpoint_num(ep_in));
740 	if (ep_int) {
741 		us->recv_intr_pipe = usb_rcvintpipe(us->pusb_dev,
742 			usb_endpoint_num(ep_int));
743 		us->ep_bInterval = ep_int->bInterval;
744 	}
745 	return 0;
746 }
747 
748 /* Initialize all the dynamic resources we need */
749 static int usb_stor_acquire_resources(struct us_data *us)
750 {
751 	int p;
752 	struct task_struct *th;
753 
754 	us->current_urb = usb_alloc_urb(0, GFP_KERNEL);
755 	if (!us->current_urb) {
756 		usb_stor_dbg(us, "URB allocation failed\n");
757 		return -ENOMEM;
758 	}
759 
760 	/* Just before we start our control thread, initialize
761 	 * the device if it needs initialization */
762 	if (us->unusual_dev->initFunction) {
763 		p = us->unusual_dev->initFunction(us);
764 		if (p)
765 			return p;
766 	}
767 
768 	/* Start up our control thread */
769 	th = kthread_run(usb_stor_control_thread, us, "usb-storage");
770 	if (IS_ERR(th)) {
771 		dev_warn(&us->pusb_intf->dev,
772 				"Unable to start control thread\n");
773 		return PTR_ERR(th);
774 	}
775 	us->ctl_thread = th;
776 
777 	return 0;
778 }
779 
780 /* Release all our dynamic resources */
781 static void usb_stor_release_resources(struct us_data *us)
782 {
783 	/* Tell the control thread to exit.  The SCSI host must
784 	 * already have been removed and the DISCONNECTING flag set
785 	 * so that we won't accept any more commands.
786 	 */
787 	usb_stor_dbg(us, "-- sending exit command to thread\n");
788 	complete(&us->cmnd_ready);
789 	if (us->ctl_thread)
790 		kthread_stop(us->ctl_thread);
791 
792 	/* Call the destructor routine, if it exists */
793 	if (us->extra_destructor) {
794 		usb_stor_dbg(us, "-- calling extra_destructor()\n");
795 		us->extra_destructor(us->extra);
796 	}
797 
798 	/* Free the extra data and the URB */
799 	kfree(us->extra);
800 	usb_free_urb(us->current_urb);
801 }
802 
803 /* Dissociate from the USB device */
804 static void dissociate_dev(struct us_data *us)
805 {
806 	/* Free the buffers */
807 	kfree(us->cr);
808 	usb_free_coherent(us->pusb_dev, US_IOBUF_SIZE, us->iobuf, us->iobuf_dma);
809 
810 	/* Remove our private data from the interface */
811 	usb_set_intfdata(us->pusb_intf, NULL);
812 }
813 
814 /* First stage of disconnect processing: stop SCSI scanning,
815  * remove the host, and stop accepting new commands
816  */
817 static void quiesce_and_remove_host(struct us_data *us)
818 {
819 	struct Scsi_Host *host = us_to_host(us);
820 
821 	/* If the device is really gone, cut short reset delays */
822 	if (us->pusb_dev->state == USB_STATE_NOTATTACHED) {
823 		set_bit(US_FLIDX_DISCONNECTING, &us->dflags);
824 		wake_up(&us->delay_wait);
825 	}
826 
827 	/* Prevent SCSI scanning (if it hasn't started yet)
828 	 * or wait for the SCSI-scanning routine to stop.
829 	 */
830 	cancel_delayed_work_sync(&us->scan_dwork);
831 
832 	/* Balance autopm calls if scanning was cancelled */
833 	if (test_bit(US_FLIDX_SCAN_PENDING, &us->dflags))
834 		usb_autopm_put_interface_no_suspend(us->pusb_intf);
835 
836 	/* Removing the host will perform an orderly shutdown: caches
837 	 * synchronized, disks spun down, etc.
838 	 */
839 	scsi_remove_host(host);
840 
841 	/* Prevent any new commands from being accepted and cut short
842 	 * reset delays.
843 	 */
844 	scsi_lock(host);
845 	set_bit(US_FLIDX_DISCONNECTING, &us->dflags);
846 	scsi_unlock(host);
847 	wake_up(&us->delay_wait);
848 }
849 
850 /* Second stage of disconnect processing: deallocate all resources */
851 static void release_everything(struct us_data *us)
852 {
853 	usb_stor_release_resources(us);
854 	dissociate_dev(us);
855 
856 	/* Drop our reference to the host; the SCSI core will free it
857 	 * (and "us" along with it) when the refcount becomes 0. */
858 	scsi_host_put(us_to_host(us));
859 }
860 
861 /* Delayed-work routine to carry out SCSI-device scanning */
862 static void usb_stor_scan_dwork(struct work_struct *work)
863 {
864 	struct us_data *us = container_of(work, struct us_data,
865 			scan_dwork.work);
866 	struct device *dev = &us->pusb_intf->dev;
867 
868 	dev_dbg(dev, "starting scan\n");
869 
870 	/* For bulk-only devices, determine the max LUN value */
871 	if (us->protocol == USB_PR_BULK && !(us->fflags & US_FL_SINGLE_LUN)) {
872 		mutex_lock(&us->dev_mutex);
873 		us->max_lun = usb_stor_Bulk_max_lun(us);
874 		mutex_unlock(&us->dev_mutex);
875 	}
876 	scsi_scan_host(us_to_host(us));
877 	dev_dbg(dev, "scan complete\n");
878 
879 	/* Should we unbind if no devices were detected? */
880 
881 	usb_autopm_put_interface(us->pusb_intf);
882 	clear_bit(US_FLIDX_SCAN_PENDING, &us->dflags);
883 }
884 
885 static unsigned int usb_stor_sg_tablesize(struct usb_interface *intf)
886 {
887 	struct usb_device *usb_dev = interface_to_usbdev(intf);
888 
889 	if (usb_dev->bus->sg_tablesize) {
890 		return usb_dev->bus->sg_tablesize;
891 	}
892 	return SG_ALL;
893 }
894 
895 /* First part of general USB mass-storage probing */
896 int usb_stor_probe1(struct us_data **pus,
897 		struct usb_interface *intf,
898 		const struct usb_device_id *id,
899 		struct us_unusual_dev *unusual_dev)
900 {
901 	struct Scsi_Host *host;
902 	struct us_data *us;
903 	int result;
904 
905 	dev_info(&intf->dev, "USB Mass Storage device detected\n");
906 
907 	/*
908 	 * Ask the SCSI layer to allocate a host structure, with extra
909 	 * space at the end for our private us_data structure.
910 	 */
911 	host = scsi_host_alloc(&usb_stor_host_template, sizeof(*us));
912 	if (!host) {
913 		dev_warn(&intf->dev, "Unable to allocate the scsi host\n");
914 		return -ENOMEM;
915 	}
916 
917 	/*
918 	 * Allow 16-byte CDBs and thus > 2TB
919 	 */
920 	host->max_cmd_len = 16;
921 	host->sg_tablesize = usb_stor_sg_tablesize(intf);
922 	*pus = us = host_to_us(host);
923 	mutex_init(&(us->dev_mutex));
924 	us_set_lock_class(&us->dev_mutex, intf);
925 	init_completion(&us->cmnd_ready);
926 	init_completion(&(us->notify));
927 	init_waitqueue_head(&us->delay_wait);
928 	INIT_DELAYED_WORK(&us->scan_dwork, usb_stor_scan_dwork);
929 
930 	/* Associate the us_data structure with the USB device */
931 	result = associate_dev(us, intf);
932 	if (result)
933 		goto BadDevice;
934 
935 	/* Get the unusual_devs entries and the descriptors */
936 	result = get_device_info(us, id, unusual_dev);
937 	if (result)
938 		goto BadDevice;
939 
940 	/* Get standard transport and protocol settings */
941 	get_transport(us);
942 	get_protocol(us);
943 
944 	/* Give the caller a chance to fill in specialized transport
945 	 * or protocol settings.
946 	 */
947 	return 0;
948 
949 BadDevice:
950 	usb_stor_dbg(us, "storage_probe() failed\n");
951 	release_everything(us);
952 	return result;
953 }
954 EXPORT_SYMBOL_GPL(usb_stor_probe1);
955 
956 /* Second part of general USB mass-storage probing */
957 int usb_stor_probe2(struct us_data *us)
958 {
959 	int result;
960 	struct device *dev = &us->pusb_intf->dev;
961 
962 	/* Make sure the transport and protocol have both been set */
963 	if (!us->transport || !us->proto_handler) {
964 		result = -ENXIO;
965 		goto BadDevice;
966 	}
967 	usb_stor_dbg(us, "Transport: %s\n", us->transport_name);
968 	usb_stor_dbg(us, "Protocol: %s\n", us->protocol_name);
969 
970 	/* fix for single-lun devices */
971 	if (us->fflags & US_FL_SINGLE_LUN)
972 		us->max_lun = 0;
973 
974 	if (!(us->fflags & US_FL_SCM_MULT_TARG))
975 		us_to_host(us)->max_id = 1;
976 
977 	/* Find the endpoints and calculate pipe values */
978 	result = get_pipes(us);
979 	if (result)
980 		goto BadDevice;
981 
982 	/*
983 	 * If the device returns invalid data for the first READ(10)
984 	 * command, indicate the command should be retried.
985 	 */
986 	if (us->fflags & US_FL_INITIAL_READ10)
987 		set_bit(US_FLIDX_REDO_READ10, &us->dflags);
988 
989 	/* Acquire all the other resources and add the host */
990 	result = usb_stor_acquire_resources(us);
991 	if (result)
992 		goto BadDevice;
993 	snprintf(us->scsi_name, sizeof(us->scsi_name), "usb-storage %s",
994 					dev_name(&us->pusb_intf->dev));
995 	result = scsi_add_host(us_to_host(us), dev);
996 	if (result) {
997 		dev_warn(dev,
998 				"Unable to add the scsi host\n");
999 		goto BadDevice;
1000 	}
1001 
1002 	/* Submit the delayed_work for SCSI-device scanning */
1003 	usb_autopm_get_interface_no_resume(us->pusb_intf);
1004 	set_bit(US_FLIDX_SCAN_PENDING, &us->dflags);
1005 
1006 	if (delay_use > 0)
1007 		dev_dbg(dev, "waiting for device to settle before scanning\n");
1008 	queue_delayed_work(system_freezable_wq, &us->scan_dwork,
1009 			delay_use * HZ);
1010 	return 0;
1011 
1012 	/* We come here if there are any problems */
1013 BadDevice:
1014 	usb_stor_dbg(us, "storage_probe() failed\n");
1015 	release_everything(us);
1016 	return result;
1017 }
1018 EXPORT_SYMBOL_GPL(usb_stor_probe2);
1019 
1020 /* Handle a USB mass-storage disconnect */
1021 void usb_stor_disconnect(struct usb_interface *intf)
1022 {
1023 	struct us_data *us = usb_get_intfdata(intf);
1024 
1025 	quiesce_and_remove_host(us);
1026 	release_everything(us);
1027 }
1028 EXPORT_SYMBOL_GPL(usb_stor_disconnect);
1029 
1030 /* The main probe routine for standard devices */
1031 static int storage_probe(struct usb_interface *intf,
1032 			 const struct usb_device_id *id)
1033 {
1034 	struct us_unusual_dev *unusual_dev;
1035 	struct us_data *us;
1036 	int result;
1037 	int size;
1038 
1039 	/*
1040 	 * If the device isn't standard (is handled by a subdriver
1041 	 * module) then don't accept it.
1042 	 */
1043 	if (usb_usual_ignore_device(intf))
1044 		return -ENXIO;
1045 
1046 	/*
1047 	 * Call the general probe procedures.
1048 	 *
1049 	 * The unusual_dev_list array is parallel to the usb_storage_usb_ids
1050 	 * table, so we use the index of the id entry to find the
1051 	 * corresponding unusual_devs entry.
1052 	 */
1053 
1054 	size = ARRAY_SIZE(us_unusual_dev_list);
1055 	if (id >= usb_storage_usb_ids && id < usb_storage_usb_ids + size) {
1056 		unusual_dev = (id - usb_storage_usb_ids) + us_unusual_dev_list;
1057 	} else {
1058 		unusual_dev = &for_dynamic_ids;
1059 
1060 		dev_dbg(&intf->dev, "Use Bulk-Only transport with the Transparent SCSI protocol for dynamic id: 0x%04x 0x%04x\n",
1061 			id->idVendor, id->idProduct);
1062 	}
1063 
1064 	result = usb_stor_probe1(&us, intf, id, unusual_dev);
1065 	if (result)
1066 		return result;
1067 
1068 	/* No special transport or protocol settings in the main module */
1069 
1070 	result = usb_stor_probe2(us);
1071 	return result;
1072 }
1073 
1074 static struct usb_driver usb_storage_driver = {
1075 	.name =		"usb-storage",
1076 	.probe =	storage_probe,
1077 	.disconnect =	usb_stor_disconnect,
1078 	.suspend =	usb_stor_suspend,
1079 	.resume =	usb_stor_resume,
1080 	.reset_resume =	usb_stor_reset_resume,
1081 	.pre_reset =	usb_stor_pre_reset,
1082 	.post_reset =	usb_stor_post_reset,
1083 	.id_table =	usb_storage_usb_ids,
1084 	.supports_autosuspend = 1,
1085 	.soft_unbind =	1,
1086 };
1087 
1088 module_usb_driver(usb_storage_driver);
1089