xref: /linux/drivers/usb/storage/usb.c (revision 12871a0bd67dd4db4418e1daafcd46e9d329ef10)
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, use_type) \
118 { \
119 	.useProtocol = use_protocol,	\
120 	.useTransport = use_transport,	\
121 }
122 
123 static struct us_unusual_dev us_unusual_dev_list[] = {
124 #	include "unusual_devs.h"
125 	{ }		/* Terminating entry */
126 };
127 
128 #undef UNUSUAL_DEV
129 #undef COMPLIANT_DEV
130 #undef USUAL_DEV
131 
132 
133 #ifdef CONFIG_PM	/* Minimal support for suspend and resume */
134 
135 int usb_stor_suspend(struct usb_interface *iface, pm_message_t message)
136 {
137 	struct us_data *us = usb_get_intfdata(iface);
138 
139 	/* Wait until no command is running */
140 	mutex_lock(&us->dev_mutex);
141 
142 	US_DEBUGP("%s\n", __func__);
143 	if (us->suspend_resume_hook)
144 		(us->suspend_resume_hook)(us, US_SUSPEND);
145 
146 	/* When runtime PM is working, we'll set a flag to indicate
147 	 * whether we should autoresume when a SCSI request arrives. */
148 
149 	mutex_unlock(&us->dev_mutex);
150 	return 0;
151 }
152 EXPORT_SYMBOL_GPL(usb_stor_suspend);
153 
154 int usb_stor_resume(struct usb_interface *iface)
155 {
156 	struct us_data *us = usb_get_intfdata(iface);
157 
158 	mutex_lock(&us->dev_mutex);
159 
160 	US_DEBUGP("%s\n", __func__);
161 	if (us->suspend_resume_hook)
162 		(us->suspend_resume_hook)(us, US_RESUME);
163 
164 	mutex_unlock(&us->dev_mutex);
165 	return 0;
166 }
167 EXPORT_SYMBOL_GPL(usb_stor_resume);
168 
169 int usb_stor_reset_resume(struct usb_interface *iface)
170 {
171 	struct us_data *us = usb_get_intfdata(iface);
172 
173 	US_DEBUGP("%s\n", __func__);
174 
175 	/* Report the reset to the SCSI core */
176 	usb_stor_report_bus_reset(us);
177 
178 	/* FIXME: Notify the subdrivers that they need to reinitialize
179 	 * the device */
180 	return 0;
181 }
182 EXPORT_SYMBOL_GPL(usb_stor_reset_resume);
183 
184 #endif /* CONFIG_PM */
185 
186 /*
187  * The next two routines get called just before and just after
188  * a USB port reset, whether from this driver or a different one.
189  */
190 
191 int usb_stor_pre_reset(struct usb_interface *iface)
192 {
193 	struct us_data *us = usb_get_intfdata(iface);
194 
195 	US_DEBUGP("%s\n", __func__);
196 
197 	/* Make sure no command runs during the reset */
198 	mutex_lock(&us->dev_mutex);
199 	return 0;
200 }
201 EXPORT_SYMBOL_GPL(usb_stor_pre_reset);
202 
203 int usb_stor_post_reset(struct usb_interface *iface)
204 {
205 	struct us_data *us = usb_get_intfdata(iface);
206 
207 	US_DEBUGP("%s\n", __func__);
208 
209 	/* Report the reset to the SCSI core */
210 	usb_stor_report_bus_reset(us);
211 
212 	/* FIXME: Notify the subdrivers that they need to reinitialize
213 	 * the device */
214 
215 	mutex_unlock(&us->dev_mutex);
216 	return 0;
217 }
218 EXPORT_SYMBOL_GPL(usb_stor_post_reset);
219 
220 /*
221  * fill_inquiry_response takes an unsigned char array (which must
222  * be at least 36 characters) and populates the vendor name,
223  * product name, and revision fields. Then the array is copied
224  * into the SCSI command's response buffer (oddly enough
225  * called request_buffer). data_len contains the length of the
226  * data array, which again must be at least 36.
227  */
228 
229 void fill_inquiry_response(struct us_data *us, unsigned char *data,
230 		unsigned int data_len)
231 {
232 	if (data_len<36) // You lose.
233 		return;
234 
235 	memset(data+8, ' ', 28);
236 	if(data[0]&0x20) { /* USB device currently not connected. Return
237 			      peripheral qualifier 001b ("...however, the
238 			      physical device is not currently connected
239 			      to this logical unit") and leave vendor and
240 			      product identification empty. ("If the target
241 			      does store some of the INQUIRY data on the
242 			      device, it may return zeros or ASCII spaces
243 			      (20h) in those fields until the data is
244 			      available from the device."). */
245 	} else {
246 		u16 bcdDevice = le16_to_cpu(us->pusb_dev->descriptor.bcdDevice);
247 		int n;
248 
249 		n = strlen(us->unusual_dev->vendorName);
250 		memcpy(data+8, us->unusual_dev->vendorName, min(8, n));
251 		n = strlen(us->unusual_dev->productName);
252 		memcpy(data+16, us->unusual_dev->productName, min(16, n));
253 
254 		data[32] = 0x30 + ((bcdDevice>>12) & 0x0F);
255 		data[33] = 0x30 + ((bcdDevice>>8) & 0x0F);
256 		data[34] = 0x30 + ((bcdDevice>>4) & 0x0F);
257 		data[35] = 0x30 + ((bcdDevice) & 0x0F);
258 	}
259 
260 	usb_stor_set_xfer_buf(data, data_len, us->srb);
261 }
262 EXPORT_SYMBOL_GPL(fill_inquiry_response);
263 
264 static int usb_stor_control_thread(void * __us)
265 {
266 	struct us_data *us = (struct us_data *)__us;
267 	struct Scsi_Host *host = us_to_host(us);
268 
269 	for(;;) {
270 		US_DEBUGP("*** thread sleeping.\n");
271 		if (wait_for_completion_interruptible(&us->cmnd_ready))
272 			break;
273 
274 		US_DEBUGP("*** thread awakened.\n");
275 
276 		/* lock the device pointers */
277 		mutex_lock(&(us->dev_mutex));
278 
279 		/* lock access to the state */
280 		scsi_lock(host);
281 
282 		/* When we are called with no command pending, we're done */
283 		if (us->srb == NULL) {
284 			scsi_unlock(host);
285 			mutex_unlock(&us->dev_mutex);
286 			US_DEBUGP("-- exiting\n");
287 			break;
288 		}
289 
290 		/* has the command timed out *already* ? */
291 		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
292 			us->srb->result = DID_ABORT << 16;
293 			goto SkipForAbort;
294 		}
295 
296 		scsi_unlock(host);
297 
298 		/* reject the command if the direction indicator
299 		 * is UNKNOWN
300 		 */
301 		if (us->srb->sc_data_direction == DMA_BIDIRECTIONAL) {
302 			US_DEBUGP("UNKNOWN data direction\n");
303 			us->srb->result = DID_ERROR << 16;
304 		}
305 
306 		/* reject if target != 0 or if LUN is higher than
307 		 * the maximum known LUN
308 		 */
309 		else if (us->srb->device->id &&
310 				!(us->fflags & US_FL_SCM_MULT_TARG)) {
311 			US_DEBUGP("Bad target number (%d:%d)\n",
312 				  us->srb->device->id, us->srb->device->lun);
313 			us->srb->result = DID_BAD_TARGET << 16;
314 		}
315 
316 		else if (us->srb->device->lun > us->max_lun) {
317 			US_DEBUGP("Bad LUN (%d:%d)\n",
318 				  us->srb->device->id, us->srb->device->lun);
319 			us->srb->result = DID_BAD_TARGET << 16;
320 		}
321 
322 		/* Handle those devices which need us to fake
323 		 * their inquiry data */
324 		else if ((us->srb->cmnd[0] == INQUIRY) &&
325 			    (us->fflags & US_FL_FIX_INQUIRY)) {
326 			unsigned char data_ptr[36] = {
327 			    0x00, 0x80, 0x02, 0x02,
328 			    0x1F, 0x00, 0x00, 0x00};
329 
330 			US_DEBUGP("Faking INQUIRY command\n");
331 			fill_inquiry_response(us, data_ptr, 36);
332 			us->srb->result = SAM_STAT_GOOD;
333 		}
334 
335 		/* we've got a command, let's do it! */
336 		else {
337 			US_DEBUG(usb_stor_show_command(us->srb));
338 			us->proto_handler(us->srb, us);
339 			usb_mark_last_busy(us->pusb_dev);
340 		}
341 
342 		/* lock access to the state */
343 		scsi_lock(host);
344 
345 		/* indicate that the command is done */
346 		if (us->srb->result != DID_ABORT << 16) {
347 			US_DEBUGP("scsi cmd done, result=0x%x\n",
348 				   us->srb->result);
349 			us->srb->scsi_done(us->srb);
350 		} else {
351 SkipForAbort:
352 			US_DEBUGP("scsi command aborted\n");
353 		}
354 
355 		/* If an abort request was received we need to signal that
356 		 * the abort has finished.  The proper test for this is
357 		 * the TIMED_OUT flag, not srb->result == DID_ABORT, because
358 		 * the timeout might have occurred after the command had
359 		 * already completed with a different result code. */
360 		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
361 			complete(&(us->notify));
362 
363 			/* Allow USB transfers to resume */
364 			clear_bit(US_FLIDX_ABORTING, &us->dflags);
365 			clear_bit(US_FLIDX_TIMED_OUT, &us->dflags);
366 		}
367 
368 		/* finished working on this command */
369 		us->srb = NULL;
370 		scsi_unlock(host);
371 
372 		/* unlock the device pointers */
373 		mutex_unlock(&us->dev_mutex);
374 	} /* for (;;) */
375 
376 	/* Wait until we are told to stop */
377 	for (;;) {
378 		set_current_state(TASK_INTERRUPTIBLE);
379 		if (kthread_should_stop())
380 			break;
381 		schedule();
382 	}
383 	__set_current_state(TASK_RUNNING);
384 	return 0;
385 }
386 
387 /***********************************************************************
388  * Device probing and disconnecting
389  ***********************************************************************/
390 
391 /* Associate our private data with the USB device */
392 static int associate_dev(struct us_data *us, struct usb_interface *intf)
393 {
394 	US_DEBUGP("-- %s\n", __func__);
395 
396 	/* Fill in the device-related fields */
397 	us->pusb_dev = interface_to_usbdev(intf);
398 	us->pusb_intf = intf;
399 	us->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
400 	US_DEBUGP("Vendor: 0x%04x, Product: 0x%04x, Revision: 0x%04x\n",
401 			le16_to_cpu(us->pusb_dev->descriptor.idVendor),
402 			le16_to_cpu(us->pusb_dev->descriptor.idProduct),
403 			le16_to_cpu(us->pusb_dev->descriptor.bcdDevice));
404 	US_DEBUGP("Interface Subclass: 0x%02x, Protocol: 0x%02x\n",
405 			intf->cur_altsetting->desc.bInterfaceSubClass,
406 			intf->cur_altsetting->desc.bInterfaceProtocol);
407 
408 	/* Store our private data in the interface */
409 	usb_set_intfdata(intf, us);
410 
411 	/* Allocate the control/setup and DMA-mapped buffers */
412 	us->cr = kmalloc(sizeof(*us->cr), GFP_KERNEL);
413 	if (!us->cr) {
414 		US_DEBUGP("usb_ctrlrequest allocation failed\n");
415 		return -ENOMEM;
416 	}
417 
418 	us->iobuf = usb_alloc_coherent(us->pusb_dev, US_IOBUF_SIZE,
419 			GFP_KERNEL, &us->iobuf_dma);
420 	if (!us->iobuf) {
421 		US_DEBUGP("I/O buffer allocation failed\n");
422 		return -ENOMEM;
423 	}
424 	return 0;
425 }
426 
427 /* Works only for digits and letters, but small and fast */
428 #define TOLOWER(x) ((x) | 0x20)
429 
430 /* Adjust device flags based on the "quirks=" module parameter */
431 static void adjust_quirks(struct us_data *us)
432 {
433 	char *p;
434 	u16 vid = le16_to_cpu(us->pusb_dev->descriptor.idVendor);
435 	u16 pid = le16_to_cpu(us->pusb_dev->descriptor.idProduct);
436 	unsigned f = 0;
437 	unsigned int mask = (US_FL_SANE_SENSE | US_FL_BAD_SENSE |
438 			US_FL_FIX_CAPACITY |
439 			US_FL_CAPACITY_HEURISTICS | US_FL_IGNORE_DEVICE |
440 			US_FL_NOT_LOCKABLE | US_FL_MAX_SECTORS_64 |
441 			US_FL_CAPACITY_OK | US_FL_IGNORE_RESIDUE |
442 			US_FL_SINGLE_LUN | US_FL_NO_WP_DETECT |
443 			US_FL_NO_READ_DISC_INFO | US_FL_NO_READ_CAPACITY_16);
444 
445 	p = quirks;
446 	while (*p) {
447 		/* Each entry consists of VID:PID:flags */
448 		if (vid == simple_strtoul(p, &p, 16) &&
449 				*p == ':' &&
450 				pid == simple_strtoul(p+1, &p, 16) &&
451 				*p == ':')
452 			break;
453 
454 		/* Move forward to the next entry */
455 		while (*p) {
456 			if (*p++ == ',')
457 				break;
458 		}
459 	}
460 	if (!*p)	/* No match */
461 		return;
462 
463 	/* Collect the flags */
464 	while (*++p && *p != ',') {
465 		switch (TOLOWER(*p)) {
466 		case 'a':
467 			f |= US_FL_SANE_SENSE;
468 			break;
469 		case 'b':
470 			f |= US_FL_BAD_SENSE;
471 			break;
472 		case 'c':
473 			f |= US_FL_FIX_CAPACITY;
474 			break;
475 		case 'd':
476 			f |= US_FL_NO_READ_DISC_INFO;
477 			break;
478 		case 'e':
479 			f |= US_FL_NO_READ_CAPACITY_16;
480 			break;
481 		case 'h':
482 			f |= US_FL_CAPACITY_HEURISTICS;
483 			break;
484 		case 'i':
485 			f |= US_FL_IGNORE_DEVICE;
486 			break;
487 		case 'l':
488 			f |= US_FL_NOT_LOCKABLE;
489 			break;
490 		case 'm':
491 			f |= US_FL_MAX_SECTORS_64;
492 			break;
493 		case 'o':
494 			f |= US_FL_CAPACITY_OK;
495 			break;
496 		case 'r':
497 			f |= US_FL_IGNORE_RESIDUE;
498 			break;
499 		case 's':
500 			f |= US_FL_SINGLE_LUN;
501 			break;
502 		case 'w':
503 			f |= US_FL_NO_WP_DETECT;
504 			break;
505 		/* Ignore unrecognized flag characters */
506 		}
507 	}
508 	us->fflags = (us->fflags & ~mask) | f;
509 }
510 
511 /* Get the unusual_devs entries and the string descriptors */
512 static int get_device_info(struct us_data *us, const struct usb_device_id *id,
513 		struct us_unusual_dev *unusual_dev)
514 {
515 	struct usb_device *dev = us->pusb_dev;
516 	struct usb_interface_descriptor *idesc =
517 		&us->pusb_intf->cur_altsetting->desc;
518 	struct device *pdev = &us->pusb_intf->dev;
519 
520 	/* Store the entries */
521 	us->unusual_dev = unusual_dev;
522 	us->subclass = (unusual_dev->useProtocol == USB_SC_DEVICE) ?
523 			idesc->bInterfaceSubClass :
524 			unusual_dev->useProtocol;
525 	us->protocol = (unusual_dev->useTransport == USB_PR_DEVICE) ?
526 			idesc->bInterfaceProtocol :
527 			unusual_dev->useTransport;
528 	us->fflags = USB_US_ORIG_FLAGS(id->driver_info);
529 	adjust_quirks(us);
530 
531 	if (us->fflags & US_FL_IGNORE_DEVICE) {
532 		dev_info(pdev, "device ignored\n");
533 		return -ENODEV;
534 	}
535 
536 	/*
537 	 * This flag is only needed when we're in high-speed, so let's
538 	 * disable it if we're in full-speed
539 	 */
540 	if (dev->speed != USB_SPEED_HIGH)
541 		us->fflags &= ~US_FL_GO_SLOW;
542 
543 	if (us->fflags)
544 		dev_info(pdev, "Quirks match for vid %04x pid %04x: %lx\n",
545 				le16_to_cpu(dev->descriptor.idVendor),
546 				le16_to_cpu(dev->descriptor.idProduct),
547 				us->fflags);
548 
549 	/* Log a message if a non-generic unusual_dev entry contains an
550 	 * unnecessary subclass or protocol override.  This may stimulate
551 	 * reports from users that will help us remove unneeded entries
552 	 * from the unusual_devs.h table.
553 	 */
554 	if (id->idVendor || id->idProduct) {
555 		static const char *msgs[3] = {
556 			"an unneeded SubClass entry",
557 			"an unneeded Protocol entry",
558 			"unneeded SubClass and Protocol entries"};
559 		struct usb_device_descriptor *ddesc = &dev->descriptor;
560 		int msg = -1;
561 
562 		if (unusual_dev->useProtocol != USB_SC_DEVICE &&
563 			us->subclass == idesc->bInterfaceSubClass)
564 			msg += 1;
565 		if (unusual_dev->useTransport != USB_PR_DEVICE &&
566 			us->protocol == idesc->bInterfaceProtocol)
567 			msg += 2;
568 		if (msg >= 0 && !(us->fflags & US_FL_NEED_OVERRIDE))
569 			dev_notice(pdev, "This device "
570 					"(%04x,%04x,%04x S %02x P %02x)"
571 					" has %s in unusual_devs.h (kernel"
572 					" %s)\n"
573 					"   Please send a copy of this message to "
574 					"<linux-usb@vger.kernel.org> and "
575 					"<usb-storage@lists.one-eyed-alien.net>\n",
576 					le16_to_cpu(ddesc->idVendor),
577 					le16_to_cpu(ddesc->idProduct),
578 					le16_to_cpu(ddesc->bcdDevice),
579 					idesc->bInterfaceSubClass,
580 					idesc->bInterfaceProtocol,
581 					msgs[msg],
582 					utsname()->release);
583 	}
584 
585 	return 0;
586 }
587 
588 /* Get the transport settings */
589 static void get_transport(struct us_data *us)
590 {
591 	switch (us->protocol) {
592 	case USB_PR_CB:
593 		us->transport_name = "Control/Bulk";
594 		us->transport = usb_stor_CB_transport;
595 		us->transport_reset = usb_stor_CB_reset;
596 		us->max_lun = 7;
597 		break;
598 
599 	case USB_PR_CBI:
600 		us->transport_name = "Control/Bulk/Interrupt";
601 		us->transport = usb_stor_CB_transport;
602 		us->transport_reset = usb_stor_CB_reset;
603 		us->max_lun = 7;
604 		break;
605 
606 	case USB_PR_BULK:
607 		us->transport_name = "Bulk";
608 		us->transport = usb_stor_Bulk_transport;
609 		us->transport_reset = usb_stor_Bulk_reset;
610 		break;
611 	}
612 }
613 
614 /* Get the protocol settings */
615 static void get_protocol(struct us_data *us)
616 {
617 	switch (us->subclass) {
618 	case USB_SC_RBC:
619 		us->protocol_name = "Reduced Block Commands (RBC)";
620 		us->proto_handler = usb_stor_transparent_scsi_command;
621 		break;
622 
623 	case USB_SC_8020:
624 		us->protocol_name = "8020i";
625 		us->proto_handler = usb_stor_pad12_command;
626 		us->max_lun = 0;
627 		break;
628 
629 	case USB_SC_QIC:
630 		us->protocol_name = "QIC-157";
631 		us->proto_handler = usb_stor_pad12_command;
632 		us->max_lun = 0;
633 		break;
634 
635 	case USB_SC_8070:
636 		us->protocol_name = "8070i";
637 		us->proto_handler = usb_stor_pad12_command;
638 		us->max_lun = 0;
639 		break;
640 
641 	case USB_SC_SCSI:
642 		us->protocol_name = "Transparent SCSI";
643 		us->proto_handler = usb_stor_transparent_scsi_command;
644 		break;
645 
646 	case USB_SC_UFI:
647 		us->protocol_name = "Uniform Floppy Interface (UFI)";
648 		us->proto_handler = usb_stor_ufi_command;
649 		break;
650 	}
651 }
652 
653 /* Get the pipe settings */
654 static int get_pipes(struct us_data *us)
655 {
656 	struct usb_host_interface *altsetting =
657 		us->pusb_intf->cur_altsetting;
658 	int i;
659 	struct usb_endpoint_descriptor *ep;
660 	struct usb_endpoint_descriptor *ep_in = NULL;
661 	struct usb_endpoint_descriptor *ep_out = NULL;
662 	struct usb_endpoint_descriptor *ep_int = NULL;
663 
664 	/*
665 	 * Find the first endpoint of each type we need.
666 	 * We are expecting a minimum of 2 endpoints - in and out (bulk).
667 	 * An optional interrupt-in is OK (necessary for CBI protocol).
668 	 * We will ignore any others.
669 	 */
670 	for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
671 		ep = &altsetting->endpoint[i].desc;
672 
673 		if (usb_endpoint_xfer_bulk(ep)) {
674 			if (usb_endpoint_dir_in(ep)) {
675 				if (!ep_in)
676 					ep_in = ep;
677 			} else {
678 				if (!ep_out)
679 					ep_out = ep;
680 			}
681 		}
682 
683 		else if (usb_endpoint_is_int_in(ep)) {
684 			if (!ep_int)
685 				ep_int = ep;
686 		}
687 	}
688 
689 	if (!ep_in || !ep_out || (us->protocol == USB_PR_CBI && !ep_int)) {
690 		US_DEBUGP("Endpoint sanity check failed! Rejecting dev.\n");
691 		return -EIO;
692 	}
693 
694 	/* Calculate and store the pipe values */
695 	us->send_ctrl_pipe = usb_sndctrlpipe(us->pusb_dev, 0);
696 	us->recv_ctrl_pipe = usb_rcvctrlpipe(us->pusb_dev, 0);
697 	us->send_bulk_pipe = usb_sndbulkpipe(us->pusb_dev,
698 		usb_endpoint_num(ep_out));
699 	us->recv_bulk_pipe = usb_rcvbulkpipe(us->pusb_dev,
700 		usb_endpoint_num(ep_in));
701 	if (ep_int) {
702 		us->recv_intr_pipe = usb_rcvintpipe(us->pusb_dev,
703 			usb_endpoint_num(ep_int));
704 		us->ep_bInterval = ep_int->bInterval;
705 	}
706 	return 0;
707 }
708 
709 /* Initialize all the dynamic resources we need */
710 static int usb_stor_acquire_resources(struct us_data *us)
711 {
712 	int p;
713 	struct task_struct *th;
714 
715 	us->current_urb = usb_alloc_urb(0, GFP_KERNEL);
716 	if (!us->current_urb) {
717 		US_DEBUGP("URB allocation failed\n");
718 		return -ENOMEM;
719 	}
720 
721 	/* Just before we start our control thread, initialize
722 	 * the device if it needs initialization */
723 	if (us->unusual_dev->initFunction) {
724 		p = us->unusual_dev->initFunction(us);
725 		if (p)
726 			return p;
727 	}
728 
729 	/* Start up our control thread */
730 	th = kthread_run(usb_stor_control_thread, us, "usb-storage");
731 	if (IS_ERR(th)) {
732 		dev_warn(&us->pusb_intf->dev,
733 				"Unable to start control thread\n");
734 		return PTR_ERR(th);
735 	}
736 	us->ctl_thread = th;
737 
738 	return 0;
739 }
740 
741 /* Release all our dynamic resources */
742 static void usb_stor_release_resources(struct us_data *us)
743 {
744 	US_DEBUGP("-- %s\n", __func__);
745 
746 	/* Tell the control thread to exit.  The SCSI host must
747 	 * already have been removed and the DISCONNECTING flag set
748 	 * so that we won't accept any more commands.
749 	 */
750 	US_DEBUGP("-- sending exit command to thread\n");
751 	complete(&us->cmnd_ready);
752 	if (us->ctl_thread)
753 		kthread_stop(us->ctl_thread);
754 
755 	/* Call the destructor routine, if it exists */
756 	if (us->extra_destructor) {
757 		US_DEBUGP("-- calling extra_destructor()\n");
758 		us->extra_destructor(us->extra);
759 	}
760 
761 	/* Free the extra data and the URB */
762 	kfree(us->extra);
763 	usb_free_urb(us->current_urb);
764 }
765 
766 /* Dissociate from the USB device */
767 static void dissociate_dev(struct us_data *us)
768 {
769 	US_DEBUGP("-- %s\n", __func__);
770 
771 	/* Free the buffers */
772 	kfree(us->cr);
773 	usb_free_coherent(us->pusb_dev, US_IOBUF_SIZE, us->iobuf, us->iobuf_dma);
774 
775 	/* Remove our private data from the interface */
776 	usb_set_intfdata(us->pusb_intf, NULL);
777 }
778 
779 /* First stage of disconnect processing: stop SCSI scanning,
780  * remove the host, and stop accepting new commands
781  */
782 static void quiesce_and_remove_host(struct us_data *us)
783 {
784 	struct Scsi_Host *host = us_to_host(us);
785 
786 	/* If the device is really gone, cut short reset delays */
787 	if (us->pusb_dev->state == USB_STATE_NOTATTACHED)
788 		set_bit(US_FLIDX_DISCONNECTING, &us->dflags);
789 
790 	/* Prevent SCSI-scanning (if it hasn't started yet)
791 	 * and wait for the SCSI-scanning thread to stop.
792 	 */
793 	set_bit(US_FLIDX_DONT_SCAN, &us->dflags);
794 	wake_up(&us->delay_wait);
795 	wait_for_completion(&us->scanning_done);
796 
797 	/* Removing the host will perform an orderly shutdown: caches
798 	 * synchronized, disks spun down, etc.
799 	 */
800 	scsi_remove_host(host);
801 
802 	/* Prevent any new commands from being accepted and cut short
803 	 * reset delays.
804 	 */
805 	scsi_lock(host);
806 	set_bit(US_FLIDX_DISCONNECTING, &us->dflags);
807 	scsi_unlock(host);
808 	wake_up(&us->delay_wait);
809 }
810 
811 /* Second stage of disconnect processing: deallocate all resources */
812 static void release_everything(struct us_data *us)
813 {
814 	usb_stor_release_resources(us);
815 	dissociate_dev(us);
816 
817 	/* Drop our reference to the host; the SCSI core will free it
818 	 * (and "us" along with it) when the refcount becomes 0. */
819 	scsi_host_put(us_to_host(us));
820 }
821 
822 /* Thread to carry out delayed SCSI-device scanning */
823 static int usb_stor_scan_thread(void * __us)
824 {
825 	struct us_data *us = (struct us_data *)__us;
826 	struct device *dev = &us->pusb_intf->dev;
827 
828 	dev_dbg(dev, "device found\n");
829 
830 	set_freezable();
831 	/* Wait for the timeout to expire or for a disconnect */
832 	if (delay_use > 0) {
833 		dev_dbg(dev, "waiting for device to settle "
834 				"before scanning\n");
835 		wait_event_freezable_timeout(us->delay_wait,
836 				test_bit(US_FLIDX_DONT_SCAN, &us->dflags),
837 				delay_use * HZ);
838 	}
839 
840 	/* If the device is still connected, perform the scanning */
841 	if (!test_bit(US_FLIDX_DONT_SCAN, &us->dflags)) {
842 
843 		/* For bulk-only devices, determine the max LUN value */
844 		if (us->protocol == USB_PR_BULK &&
845 				!(us->fflags & US_FL_SINGLE_LUN)) {
846 			mutex_lock(&us->dev_mutex);
847 			us->max_lun = usb_stor_Bulk_max_lun(us);
848 			mutex_unlock(&us->dev_mutex);
849 		}
850 		scsi_scan_host(us_to_host(us));
851 		dev_dbg(dev, "scan complete\n");
852 
853 		/* Should we unbind if no devices were detected? */
854 	}
855 
856 	usb_autopm_put_interface(us->pusb_intf);
857 	complete_and_exit(&us->scanning_done, 0);
858 }
859 
860 static unsigned int usb_stor_sg_tablesize(struct usb_interface *intf)
861 {
862 	struct usb_device *usb_dev = interface_to_usbdev(intf);
863 
864 	if (usb_dev->bus->sg_tablesize) {
865 		return usb_dev->bus->sg_tablesize;
866 	}
867 	return SG_ALL;
868 }
869 
870 /* First part of general USB mass-storage probing */
871 int usb_stor_probe1(struct us_data **pus,
872 		struct usb_interface *intf,
873 		const struct usb_device_id *id,
874 		struct us_unusual_dev *unusual_dev)
875 {
876 	struct Scsi_Host *host;
877 	struct us_data *us;
878 	int result;
879 
880 	US_DEBUGP("USB Mass Storage device detected\n");
881 
882 	/*
883 	 * Ask the SCSI layer to allocate a host structure, with extra
884 	 * space at the end for our private us_data structure.
885 	 */
886 	host = scsi_host_alloc(&usb_stor_host_template, sizeof(*us));
887 	if (!host) {
888 		dev_warn(&intf->dev,
889 				"Unable to allocate the scsi host\n");
890 		return -ENOMEM;
891 	}
892 
893 	/*
894 	 * Allow 16-byte CDBs and thus > 2TB
895 	 */
896 	host->max_cmd_len = 16;
897 	host->sg_tablesize = usb_stor_sg_tablesize(intf);
898 	*pus = us = host_to_us(host);
899 	memset(us, 0, sizeof(struct us_data));
900 	mutex_init(&(us->dev_mutex));
901 	init_completion(&us->cmnd_ready);
902 	init_completion(&(us->notify));
903 	init_waitqueue_head(&us->delay_wait);
904 	init_completion(&us->scanning_done);
905 
906 	/* Associate the us_data structure with the USB device */
907 	result = associate_dev(us, intf);
908 	if (result)
909 		goto BadDevice;
910 
911 	/* Get the unusual_devs entries and the descriptors */
912 	result = get_device_info(us, id, unusual_dev);
913 	if (result)
914 		goto BadDevice;
915 
916 	/* Get standard transport and protocol settings */
917 	get_transport(us);
918 	get_protocol(us);
919 
920 	/* Give the caller a chance to fill in specialized transport
921 	 * or protocol settings.
922 	 */
923 	return 0;
924 
925 BadDevice:
926 	US_DEBUGP("storage_probe() failed\n");
927 	release_everything(us);
928 	return result;
929 }
930 EXPORT_SYMBOL_GPL(usb_stor_probe1);
931 
932 /* Second part of general USB mass-storage probing */
933 int usb_stor_probe2(struct us_data *us)
934 {
935 	struct task_struct *th;
936 	int result;
937 	struct device *dev = &us->pusb_intf->dev;
938 
939 	/* Make sure the transport and protocol have both been set */
940 	if (!us->transport || !us->proto_handler) {
941 		result = -ENXIO;
942 		goto BadDevice;
943 	}
944 	US_DEBUGP("Transport: %s\n", us->transport_name);
945 	US_DEBUGP("Protocol: %s\n", us->protocol_name);
946 
947 	/* fix for single-lun devices */
948 	if (us->fflags & US_FL_SINGLE_LUN)
949 		us->max_lun = 0;
950 
951 	/* Find the endpoints and calculate pipe values */
952 	result = get_pipes(us);
953 	if (result)
954 		goto BadDevice;
955 
956 	/* Acquire all the other resources and add the host */
957 	result = usb_stor_acquire_resources(us);
958 	if (result)
959 		goto BadDevice;
960 	snprintf(us->scsi_name, sizeof(us->scsi_name), "usb-storage %s",
961 					dev_name(&us->pusb_intf->dev));
962 	result = scsi_add_host(us_to_host(us), dev);
963 	if (result) {
964 		dev_warn(dev,
965 				"Unable to add the scsi host\n");
966 		goto BadDevice;
967 	}
968 
969 	/* Start up the thread for delayed SCSI-device scanning */
970 	th = kthread_create(usb_stor_scan_thread, us, "usb-stor-scan");
971 	if (IS_ERR(th)) {
972 		dev_warn(dev,
973 				"Unable to start the device-scanning thread\n");
974 		complete(&us->scanning_done);
975 		quiesce_and_remove_host(us);
976 		result = PTR_ERR(th);
977 		goto BadDevice;
978 	}
979 
980 	usb_autopm_get_interface_no_resume(us->pusb_intf);
981 	wake_up_process(th);
982 
983 	return 0;
984 
985 	/* We come here if there are any problems */
986 BadDevice:
987 	US_DEBUGP("storage_probe() failed\n");
988 	release_everything(us);
989 	return result;
990 }
991 EXPORT_SYMBOL_GPL(usb_stor_probe2);
992 
993 /* Handle a USB mass-storage disconnect */
994 void usb_stor_disconnect(struct usb_interface *intf)
995 {
996 	struct us_data *us = usb_get_intfdata(intf);
997 
998 	US_DEBUGP("storage_disconnect() called\n");
999 	quiesce_and_remove_host(us);
1000 	release_everything(us);
1001 }
1002 EXPORT_SYMBOL_GPL(usb_stor_disconnect);
1003 
1004 /* The main probe routine for standard devices */
1005 static int storage_probe(struct usb_interface *intf,
1006 			 const struct usb_device_id *id)
1007 {
1008 	struct us_data *us;
1009 	int result;
1010 
1011 	/*
1012 	 * If libusual is configured, let it decide whether a standard
1013 	 * device should be handled by usb-storage or by ub.
1014 	 * If the device isn't standard (is handled by a subdriver
1015 	 * module) then don't accept it.
1016 	 */
1017 	if (usb_usual_check_type(id, USB_US_TYPE_STOR) ||
1018 			usb_usual_ignore_device(intf))
1019 		return -ENXIO;
1020 
1021 	/*
1022 	 * Call the general probe procedures.
1023 	 *
1024 	 * The unusual_dev_list array is parallel to the usb_storage_usb_ids
1025 	 * table, so we use the index of the id entry to find the
1026 	 * corresponding unusual_devs entry.
1027 	 */
1028 	result = usb_stor_probe1(&us, intf, id,
1029 			(id - usb_storage_usb_ids) + us_unusual_dev_list);
1030 	if (result)
1031 		return result;
1032 
1033 	/* No special transport or protocol settings in the main module */
1034 
1035 	result = usb_stor_probe2(us);
1036 	return result;
1037 }
1038 
1039 /***********************************************************************
1040  * Initialization and registration
1041  ***********************************************************************/
1042 
1043 static struct usb_driver usb_storage_driver = {
1044 	.name =		"usb-storage",
1045 	.probe =	storage_probe,
1046 	.disconnect =	usb_stor_disconnect,
1047 	.suspend =	usb_stor_suspend,
1048 	.resume =	usb_stor_resume,
1049 	.reset_resume =	usb_stor_reset_resume,
1050 	.pre_reset =	usb_stor_pre_reset,
1051 	.post_reset =	usb_stor_post_reset,
1052 	.id_table =	usb_storage_usb_ids,
1053 	.supports_autosuspend = 1,
1054 	.soft_unbind =	1,
1055 };
1056 
1057 static int __init usb_stor_init(void)
1058 {
1059 	int retval;
1060 
1061 	pr_info("Initializing USB Mass Storage driver...\n");
1062 
1063 	/* register the driver, return usb_register return code if error */
1064 	retval = usb_register(&usb_storage_driver);
1065 	if (retval == 0) {
1066 		pr_info("USB Mass Storage support registered.\n");
1067 		usb_usual_set_present(USB_US_TYPE_STOR);
1068 	}
1069 	return retval;
1070 }
1071 
1072 static void __exit usb_stor_exit(void)
1073 {
1074 	US_DEBUGP("usb_stor_exit() called\n");
1075 
1076 	/* Deregister the driver
1077 	 * This will cause disconnect() to be called for each
1078 	 * attached unit
1079 	 */
1080 	US_DEBUGP("-- calling usb_deregister()\n");
1081 	usb_deregister(&usb_storage_driver) ;
1082 
1083 	usb_usual_clear_present(USB_US_TYPE_STOR);
1084 }
1085 
1086 module_init(usb_stor_init);
1087 module_exit(usb_stor_exit);
1088