Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw
[linux-2.6] / drivers / usb / gadget / file_storage.c
1 /*
2  * file_storage.c -- File-backed USB Storage Gadget, for USB development
3  *
4  * Copyright (C) 2003-2008 Alan Stern
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The names of the above-listed copyright holders may not be used
17  *    to endorse or promote products derived from this software without
18  *    specific prior written permission.
19  *
20  * ALTERNATIVELY, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") as published by the Free Software
22  * Foundation, either version 2 of that License or (at your option) any
23  * later version.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
26  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
27  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
29  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
32  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37
38
39 /*
40  * The File-backed Storage Gadget acts as a USB Mass Storage device,
41  * appearing to the host as a disk drive or as a CD-ROM drive.  In addition
42  * to providing an example of a genuinely useful gadget driver for a USB
43  * device, it also illustrates a technique of double-buffering for increased
44  * throughput.  Last but not least, it gives an easy way to probe the
45  * behavior of the Mass Storage drivers in a USB host.
46  *
47  * Backing storage is provided by a regular file or a block device, specified
48  * by the "file" module parameter.  Access can be limited to read-only by
49  * setting the optional "ro" module parameter.  (For CD-ROM emulation,
50  * access is always read-only.)  The gadget will indicate that it has
51  * removable media if the optional "removable" module parameter is set.
52  *
53  * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI),
54  * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected
55  * by the optional "transport" module parameter.  It also supports the
56  * following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03),
57  * UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
58  * the optional "protocol" module parameter.  In addition, the default
59  * Vendor ID, Product ID, and release number can be overridden.
60  *
61  * There is support for multiple logical units (LUNs), each of which has
62  * its own backing file.  The number of LUNs can be set using the optional
63  * "luns" module parameter (anywhere from 1 to 8), and the corresponding
64  * files are specified using comma-separated lists for "file" and "ro".
65  * The default number of LUNs is taken from the number of "file" elements;
66  * it is 1 if "file" is not given.  If "removable" is not set then a backing
67  * file must be specified for each LUN.  If it is set, then an unspecified
68  * or empty backing filename means the LUN's medium is not loaded.  Ideally
69  * each LUN would be settable independently as a disk drive or a CD-ROM
70  * drive, but currently all LUNs have to be the same type.  The CD-ROM
71  * emulation includes a single data track and no audio tracks; hence there
72  * need be only one backing file per LUN.  Note also that the CD-ROM block
73  * length is set to 512 rather than the more common value 2048.
74  *
75  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
76  * needed (an interrupt-out endpoint is also needed for CBI).  The memory
77  * requirement amounts to two 16K buffers, size configurable by a parameter.
78  * Support is included for both full-speed and high-speed operation.
79  *
80  * Note that the driver is slightly non-portable in that it assumes a
81  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
82  * interrupt-in endpoints.  With most device controllers this isn't an
83  * issue, but there may be some with hardware restrictions that prevent
84  * a buffer from being used by more than one endpoint.
85  *
86  * Module options:
87  *
88  *      file=filename[,filename...]
89  *                              Required if "removable" is not set, names of
90  *                                      the files or block devices used for
91  *                                      backing storage
92  *      ro=b[,b...]             Default false, booleans for read-only access
93  *      removable               Default false, boolean for removable media
94  *      luns=N                  Default N = number of filenames, number of
95  *                                      LUNs to support
96  *      stall                   Default determined according to the type of
97  *                                      USB device controller (usually true),
98  *                                      boolean to permit the driver to halt
99  *                                      bulk endpoints
100  *      cdrom                   Default false, boolean for whether to emulate
101  *                                      a CD-ROM drive
102  *      transport=XXX           Default BBB, transport name (CB, CBI, or BBB)
103  *      protocol=YYY            Default SCSI, protocol name (RBC, 8020 or
104  *                                      ATAPI, QIC, UFI, 8070, or SCSI;
105  *                                      also 1 - 6)
106  *      vendor=0xVVVV           Default 0x0525 (NetChip), USB Vendor ID
107  *      product=0xPPPP          Default 0xa4a5 (FSG), USB Product ID
108  *      release=0xRRRR          Override the USB release number (bcdDevice)
109  *      buflen=N                Default N=16384, buffer size used (will be
110  *                                      rounded down to a multiple of
111  *                                      PAGE_CACHE_SIZE)
112  *
113  * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro",
114  * "removable", "luns", "stall", and "cdrom" options are available; default
115  * values are used for everything else.
116  *
117  * The pathnames of the backing files and the ro settings are available in
118  * the attribute files "file" and "ro" in the lun<n> subdirectory of the
119  * gadget's sysfs directory.  If the "removable" option is set, writing to
120  * these files will simulate ejecting/loading the medium (writing an empty
121  * line means eject) and adjusting a write-enable tab.  Changes to the ro
122  * setting are not allowed when the medium is loaded or if CD-ROM emulation
123  * is being used.
124  *
125  * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
126  * The driver's SCSI command interface was based on the "Information
127  * technology - Small Computer System Interface - 2" document from
128  * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
129  * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.  The single exception
130  * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
131  * "Universal Serial Bus Mass Storage Class UFI Command Specification"
132  * document, Revision 1.0, December 14, 1998, available at
133  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
134  */
135
136
137 /*
138  *                              Driver Design
139  *
140  * The FSG driver is fairly straightforward.  There is a main kernel
141  * thread that handles most of the work.  Interrupt routines field
142  * callbacks from the controller driver: bulk- and interrupt-request
143  * completion notifications, endpoint-0 events, and disconnect events.
144  * Completion events are passed to the main thread by wakeup calls.  Many
145  * ep0 requests are handled at interrupt time, but SetInterface,
146  * SetConfiguration, and device reset requests are forwarded to the
147  * thread in the form of "exceptions" using SIGUSR1 signals (since they
148  * should interrupt any ongoing file I/O operations).
149  *
150  * The thread's main routine implements the standard command/data/status
151  * parts of a SCSI interaction.  It and its subroutines are full of tests
152  * for pending signals/exceptions -- all this polling is necessary since
153  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
154  * indication that the driver really wants to be running in userspace.)
155  * An important point is that so long as the thread is alive it keeps an
156  * open reference to the backing file.  This will prevent unmounting
157  * the backing file's underlying filesystem and could cause problems
158  * during system shutdown, for example.  To prevent such problems, the
159  * thread catches INT, TERM, and KILL signals and converts them into
160  * an EXIT exception.
161  *
162  * In normal operation the main thread is started during the gadget's
163  * fsg_bind() callback and stopped during fsg_unbind().  But it can also
164  * exit when it receives a signal, and there's no point leaving the
165  * gadget running when the thread is dead.  So just before the thread
166  * exits, it deregisters the gadget driver.  This makes things a little
167  * tricky: The driver is deregistered at two places, and the exiting
168  * thread can indirectly call fsg_unbind() which in turn can tell the
169  * thread to exit.  The first problem is resolved through the use of the
170  * REGISTERED atomic bitflag; the driver will only be deregistered once.
171  * The second problem is resolved by having fsg_unbind() check
172  * fsg->state; it won't try to stop the thread if the state is already
173  * FSG_STATE_TERMINATED.
174  *
175  * To provide maximum throughput, the driver uses a circular pipeline of
176  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
177  * arbitrarily long; in practice the benefits don't justify having more
178  * than 2 stages (i.e., double buffering).  But it helps to think of the
179  * pipeline as being a long one.  Each buffer head contains a bulk-in and
180  * a bulk-out request pointer (since the buffer can be used for both
181  * output and input -- directions always are given from the host's
182  * point of view) as well as a pointer to the buffer and various state
183  * variables.
184  *
185  * Use of the pipeline follows a simple protocol.  There is a variable
186  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
187  * At any time that buffer head may still be in use from an earlier
188  * request, so each buffer head has a state variable indicating whether
189  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
190  * buffer head to be EMPTY, filling the buffer either by file I/O or by
191  * USB I/O (during which the buffer head is BUSY), and marking the buffer
192  * head FULL when the I/O is complete.  Then the buffer will be emptied
193  * (again possibly by USB I/O, during which it is marked BUSY) and
194  * finally marked EMPTY again (possibly by a completion routine).
195  *
196  * A module parameter tells the driver to avoid stalling the bulk
197  * endpoints wherever the transport specification allows.  This is
198  * necessary for some UDCs like the SuperH, which cannot reliably clear a
199  * halt on a bulk endpoint.  However, under certain circumstances the
200  * Bulk-only specification requires a stall.  In such cases the driver
201  * will halt the endpoint and set a flag indicating that it should clear
202  * the halt in software during the next device reset.  Hopefully this
203  * will permit everything to work correctly.  Furthermore, although the
204  * specification allows the bulk-out endpoint to halt when the host sends
205  * too much data, implementing this would cause an unavoidable race.
206  * The driver will always use the "no-stall" approach for OUT transfers.
207  *
208  * One subtle point concerns sending status-stage responses for ep0
209  * requests.  Some of these requests, such as device reset, can involve
210  * interrupting an ongoing file I/O operation, which might take an
211  * arbitrarily long time.  During that delay the host might give up on
212  * the original ep0 request and issue a new one.  When that happens the
213  * driver should not notify the host about completion of the original
214  * request, as the host will no longer be waiting for it.  So the driver
215  * assigns to each ep0 request a unique tag, and it keeps track of the
216  * tag value of the request associated with a long-running exception
217  * (device-reset, interface-change, or configuration-change).  When the
218  * exception handler is finished, the status-stage response is submitted
219  * only if the current ep0 request tag is equal to the exception request
220  * tag.  Thus only the most recently received ep0 request will get a
221  * status-stage response.
222  *
223  * Warning: This driver source file is too long.  It ought to be split up
224  * into a header file plus about 3 separate .c files, to handle the details
225  * of the Gadget, USB Mass Storage, and SCSI protocols.
226  */
227
228
229 /* #define VERBOSE_DEBUG */
230 /* #define DUMP_MSGS */
231
232
233 #include <linux/blkdev.h>
234 #include <linux/completion.h>
235 #include <linux/dcache.h>
236 #include <linux/delay.h>
237 #include <linux/device.h>
238 #include <linux/fcntl.h>
239 #include <linux/file.h>
240 #include <linux/fs.h>
241 #include <linux/kref.h>
242 #include <linux/kthread.h>
243 #include <linux/limits.h>
244 #include <linux/rwsem.h>
245 #include <linux/slab.h>
246 #include <linux/spinlock.h>
247 #include <linux/string.h>
248 #include <linux/freezer.h>
249 #include <linux/utsname.h>
250
251 #include <linux/usb/ch9.h>
252 #include <linux/usb/gadget.h>
253
254 #include "gadget_chips.h"
255
256
257
258 /*
259  * Kbuild is not very cooperative with respect to linking separately
260  * compiled library objects into one module.  So for now we won't use
261  * separate compilation ... ensuring init/exit sections work to shrink
262  * the runtime footprint, and giving us at least some parts of what
263  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
264  */
265 #include "usbstring.c"
266 #include "config.c"
267 #include "epautoconf.c"
268
269 /*-------------------------------------------------------------------------*/
270
271 #define DRIVER_DESC             "File-backed Storage Gadget"
272 #define DRIVER_NAME             "g_file_storage"
273 #define DRIVER_VERSION          "20 November 2008"
274
275 static const char longname[] = DRIVER_DESC;
276 static const char shortname[] = DRIVER_NAME;
277
278 MODULE_DESCRIPTION(DRIVER_DESC);
279 MODULE_AUTHOR("Alan Stern");
280 MODULE_LICENSE("Dual BSD/GPL");
281
282 /* Thanks to NetChip Technologies for donating this product ID.
283  *
284  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
285  * Instead:  allocate your own, using normal USB-IF procedures. */
286 #define DRIVER_VENDOR_ID        0x0525  // NetChip
287 #define DRIVER_PRODUCT_ID       0xa4a5  // Linux-USB File-backed Storage Gadget
288
289
290 /*
291  * This driver assumes self-powered hardware and has no way for users to
292  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
293  * and endpoint addresses.
294  */
295
296
297 /*-------------------------------------------------------------------------*/
298
299 #define LDBG(lun,fmt,args...) \
300         dev_dbg(&(lun)->dev , fmt , ## args)
301 #define MDBG(fmt,args...) \
302         pr_debug(DRIVER_NAME ": " fmt , ## args)
303
304 #ifndef DEBUG
305 #undef VERBOSE_DEBUG
306 #undef DUMP_MSGS
307 #endif /* !DEBUG */
308
309 #ifdef VERBOSE_DEBUG
310 #define VLDBG   LDBG
311 #else
312 #define VLDBG(lun,fmt,args...) \
313         do { } while (0)
314 #endif /* VERBOSE_DEBUG */
315
316 #define LERROR(lun,fmt,args...) \
317         dev_err(&(lun)->dev , fmt , ## args)
318 #define LWARN(lun,fmt,args...) \
319         dev_warn(&(lun)->dev , fmt , ## args)
320 #define LINFO(lun,fmt,args...) \
321         dev_info(&(lun)->dev , fmt , ## args)
322
323 #define MINFO(fmt,args...) \
324         pr_info(DRIVER_NAME ": " fmt , ## args)
325
326 #define DBG(d, fmt, args...) \
327         dev_dbg(&(d)->gadget->dev , fmt , ## args)
328 #define VDBG(d, fmt, args...) \
329         dev_vdbg(&(d)->gadget->dev , fmt , ## args)
330 #define ERROR(d, fmt, args...) \
331         dev_err(&(d)->gadget->dev , fmt , ## args)
332 #define WARNING(d, fmt, args...) \
333         dev_warn(&(d)->gadget->dev , fmt , ## args)
334 #define INFO(d, fmt, args...) \
335         dev_info(&(d)->gadget->dev , fmt , ## args)
336
337
338 /*-------------------------------------------------------------------------*/
339
340 /* Encapsulate the module parameter settings */
341
342 #define MAX_LUNS        8
343
344 static struct {
345         char            *file[MAX_LUNS];
346         int             ro[MAX_LUNS];
347         unsigned int    num_filenames;
348         unsigned int    num_ros;
349         unsigned int    nluns;
350
351         int             removable;
352         int             can_stall;
353         int             cdrom;
354
355         char            *transport_parm;
356         char            *protocol_parm;
357         unsigned short  vendor;
358         unsigned short  product;
359         unsigned short  release;
360         unsigned int    buflen;
361
362         int             transport_type;
363         char            *transport_name;
364         int             protocol_type;
365         char            *protocol_name;
366
367 } mod_data = {                                  // Default values
368         .transport_parm         = "BBB",
369         .protocol_parm          = "SCSI",
370         .removable              = 0,
371         .can_stall              = 1,
372         .cdrom                  = 0,
373         .vendor                 = DRIVER_VENDOR_ID,
374         .product                = DRIVER_PRODUCT_ID,
375         .release                = 0xffff,       // Use controller chip type
376         .buflen                 = 16384,
377         };
378
379
380 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
381                 S_IRUGO);
382 MODULE_PARM_DESC(file, "names of backing files or devices");
383
384 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
385 MODULE_PARM_DESC(ro, "true to force read-only");
386
387 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
388 MODULE_PARM_DESC(luns, "number of LUNs");
389
390 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
391 MODULE_PARM_DESC(removable, "true to simulate removable media");
392
393 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
394 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
395
396 module_param_named(cdrom, mod_data.cdrom, bool, S_IRUGO);
397 MODULE_PARM_DESC(cdrom, "true to emulate cdrom instead of disk");
398
399
400 /* In the non-TEST version, only the module parameters listed above
401  * are available. */
402 #ifdef CONFIG_USB_FILE_STORAGE_TEST
403
404 module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
405 MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
406
407 module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
408 MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
409                 "8070, or SCSI)");
410
411 module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
412 MODULE_PARM_DESC(vendor, "USB Vendor ID");
413
414 module_param_named(product, mod_data.product, ushort, S_IRUGO);
415 MODULE_PARM_DESC(product, "USB Product ID");
416
417 module_param_named(release, mod_data.release, ushort, S_IRUGO);
418 MODULE_PARM_DESC(release, "USB release number");
419
420 module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
421 MODULE_PARM_DESC(buflen, "I/O buffer size");
422
423 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
424
425
426 /*-------------------------------------------------------------------------*/
427
428 /* SCSI device types */
429 #define TYPE_DISK       0x00
430 #define TYPE_CDROM      0x05
431
432 /* USB protocol value = the transport method */
433 #define USB_PR_CBI      0x00            // Control/Bulk/Interrupt
434 #define USB_PR_CB       0x01            // Control/Bulk w/o interrupt
435 #define USB_PR_BULK     0x50            // Bulk-only
436
437 /* USB subclass value = the protocol encapsulation */
438 #define USB_SC_RBC      0x01            // Reduced Block Commands (flash)
439 #define USB_SC_8020     0x02            // SFF-8020i, MMC-2, ATAPI (CD-ROM)
440 #define USB_SC_QIC      0x03            // QIC-157 (tape)
441 #define USB_SC_UFI      0x04            // UFI (floppy)
442 #define USB_SC_8070     0x05            // SFF-8070i (removable)
443 #define USB_SC_SCSI     0x06            // Transparent SCSI
444
445 /* Bulk-only data structures */
446
447 /* Command Block Wrapper */
448 struct bulk_cb_wrap {
449         __le32  Signature;              // Contains 'USBC'
450         u32     Tag;                    // Unique per command id
451         __le32  DataTransferLength;     // Size of the data
452         u8      Flags;                  // Direction in bit 7
453         u8      Lun;                    // LUN (normally 0)
454         u8      Length;                 // Of the CDB, <= MAX_COMMAND_SIZE
455         u8      CDB[16];                // Command Data Block
456 };
457
458 #define USB_BULK_CB_WRAP_LEN    31
459 #define USB_BULK_CB_SIG         0x43425355      // Spells out USBC
460 #define USB_BULK_IN_FLAG        0x80
461
462 /* Command Status Wrapper */
463 struct bulk_cs_wrap {
464         __le32  Signature;              // Should = 'USBS'
465         u32     Tag;                    // Same as original command
466         __le32  Residue;                // Amount not transferred
467         u8      Status;                 // See below
468 };
469
470 #define USB_BULK_CS_WRAP_LEN    13
471 #define USB_BULK_CS_SIG         0x53425355      // Spells out 'USBS'
472 #define USB_STATUS_PASS         0
473 #define USB_STATUS_FAIL         1
474 #define USB_STATUS_PHASE_ERROR  2
475
476 /* Bulk-only class specific requests */
477 #define USB_BULK_RESET_REQUEST          0xff
478 #define USB_BULK_GET_MAX_LUN_REQUEST    0xfe
479
480
481 /* CBI Interrupt data structure */
482 struct interrupt_data {
483         u8      bType;
484         u8      bValue;
485 };
486
487 #define CBI_INTERRUPT_DATA_LEN          2
488
489 /* CBI Accept Device-Specific Command request */
490 #define USB_CBI_ADSC_REQUEST            0x00
491
492
493 #define MAX_COMMAND_SIZE        16      // Length of a SCSI Command Data Block
494
495 /* SCSI commands that we recognize */
496 #define SC_FORMAT_UNIT                  0x04
497 #define SC_INQUIRY                      0x12
498 #define SC_MODE_SELECT_6                0x15
499 #define SC_MODE_SELECT_10               0x55
500 #define SC_MODE_SENSE_6                 0x1a
501 #define SC_MODE_SENSE_10                0x5a
502 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
503 #define SC_READ_6                       0x08
504 #define SC_READ_10                      0x28
505 #define SC_READ_12                      0xa8
506 #define SC_READ_CAPACITY                0x25
507 #define SC_READ_FORMAT_CAPACITIES       0x23
508 #define SC_READ_HEADER                  0x44
509 #define SC_READ_TOC                     0x43
510 #define SC_RELEASE                      0x17
511 #define SC_REQUEST_SENSE                0x03
512 #define SC_RESERVE                      0x16
513 #define SC_SEND_DIAGNOSTIC              0x1d
514 #define SC_START_STOP_UNIT              0x1b
515 #define SC_SYNCHRONIZE_CACHE            0x35
516 #define SC_TEST_UNIT_READY              0x00
517 #define SC_VERIFY                       0x2f
518 #define SC_WRITE_6                      0x0a
519 #define SC_WRITE_10                     0x2a
520 #define SC_WRITE_12                     0xaa
521
522 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
523 #define SS_NO_SENSE                             0
524 #define SS_COMMUNICATION_FAILURE                0x040800
525 #define SS_INVALID_COMMAND                      0x052000
526 #define SS_INVALID_FIELD_IN_CDB                 0x052400
527 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
528 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
529 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
530 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
531 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
532 #define SS_RESET_OCCURRED                       0x062900
533 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
534 #define SS_UNRECOVERED_READ_ERROR               0x031100
535 #define SS_WRITE_ERROR                          0x030c02
536 #define SS_WRITE_PROTECTED                      0x072700
537
538 #define SK(x)           ((u8) ((x) >> 16))      // Sense Key byte, etc.
539 #define ASC(x)          ((u8) ((x) >> 8))
540 #define ASCQ(x)         ((u8) (x))
541
542
543 /*-------------------------------------------------------------------------*/
544
545 /*
546  * These definitions will permit the compiler to avoid generating code for
547  * parts of the driver that aren't used in the non-TEST version.  Even gcc
548  * can recognize when a test of a constant expression yields a dead code
549  * path.
550  */
551
552 #ifdef CONFIG_USB_FILE_STORAGE_TEST
553
554 #define transport_is_bbb()      (mod_data.transport_type == USB_PR_BULK)
555 #define transport_is_cbi()      (mod_data.transport_type == USB_PR_CBI)
556 #define protocol_is_scsi()      (mod_data.protocol_type == USB_SC_SCSI)
557
558 #else
559
560 #define transport_is_bbb()      1
561 #define transport_is_cbi()      0
562 #define protocol_is_scsi()      1
563
564 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
565
566
567 struct lun {
568         struct file     *filp;
569         loff_t          file_length;
570         loff_t          num_sectors;
571
572         unsigned int    ro : 1;
573         unsigned int    prevent_medium_removal : 1;
574         unsigned int    registered : 1;
575         unsigned int    info_valid : 1;
576
577         u32             sense_data;
578         u32             sense_data_info;
579         u32             unit_attention_data;
580
581         struct device   dev;
582 };
583
584 #define backing_file_is_open(curlun)    ((curlun)->filp != NULL)
585
586 static struct lun *dev_to_lun(struct device *dev)
587 {
588         return container_of(dev, struct lun, dev);
589 }
590
591
592 /* Big enough to hold our biggest descriptor */
593 #define EP0_BUFSIZE     256
594 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     // An impossibly large value
595
596 /* Number of buffers we will use.  2 is enough for double-buffering */
597 #define NUM_BUFFERS     2
598
599 enum fsg_buffer_state {
600         BUF_STATE_EMPTY = 0,
601         BUF_STATE_FULL,
602         BUF_STATE_BUSY
603 };
604
605 struct fsg_buffhd {
606         void                            *buf;
607         enum fsg_buffer_state           state;
608         struct fsg_buffhd               *next;
609
610         /* The NetChip 2280 is faster, and handles some protocol faults
611          * better, if we don't submit any short bulk-out read requests.
612          * So we will record the intended request length here. */
613         unsigned int                    bulk_out_intended_length;
614
615         struct usb_request              *inreq;
616         int                             inreq_busy;
617         struct usb_request              *outreq;
618         int                             outreq_busy;
619 };
620
621 enum fsg_state {
622         FSG_STATE_COMMAND_PHASE = -10,          // This one isn't used anywhere
623         FSG_STATE_DATA_PHASE,
624         FSG_STATE_STATUS_PHASE,
625
626         FSG_STATE_IDLE = 0,
627         FSG_STATE_ABORT_BULK_OUT,
628         FSG_STATE_RESET,
629         FSG_STATE_INTERFACE_CHANGE,
630         FSG_STATE_CONFIG_CHANGE,
631         FSG_STATE_DISCONNECT,
632         FSG_STATE_EXIT,
633         FSG_STATE_TERMINATED
634 };
635
636 enum data_direction {
637         DATA_DIR_UNKNOWN = 0,
638         DATA_DIR_FROM_HOST,
639         DATA_DIR_TO_HOST,
640         DATA_DIR_NONE
641 };
642
643 struct fsg_dev {
644         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
645         spinlock_t              lock;
646         struct usb_gadget       *gadget;
647
648         /* filesem protects: backing files in use */
649         struct rw_semaphore     filesem;
650
651         /* reference counting: wait until all LUNs are released */
652         struct kref             ref;
653
654         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
655         struct usb_request      *ep0req;        // For control responses
656         unsigned int            ep0_req_tag;
657         const char              *ep0req_name;
658
659         struct usb_request      *intreq;        // For interrupt responses
660         int                     intreq_busy;
661         struct fsg_buffhd       *intr_buffhd;
662
663         unsigned int            bulk_out_maxpacket;
664         enum fsg_state          state;          // For exception handling
665         unsigned int            exception_req_tag;
666
667         u8                      config, new_config;
668
669         unsigned int            running : 1;
670         unsigned int            bulk_in_enabled : 1;
671         unsigned int            bulk_out_enabled : 1;
672         unsigned int            intr_in_enabled : 1;
673         unsigned int            phase_error : 1;
674         unsigned int            short_packet_received : 1;
675         unsigned int            bad_lun_okay : 1;
676
677         unsigned long           atomic_bitflags;
678 #define REGISTERED              0
679 #define IGNORE_BULK_OUT         1
680 #define SUSPENDED               2
681
682         struct usb_ep           *bulk_in;
683         struct usb_ep           *bulk_out;
684         struct usb_ep           *intr_in;
685
686         struct fsg_buffhd       *next_buffhd_to_fill;
687         struct fsg_buffhd       *next_buffhd_to_drain;
688         struct fsg_buffhd       buffhds[NUM_BUFFERS];
689
690         int                     thread_wakeup_needed;
691         struct completion       thread_notifier;
692         struct task_struct      *thread_task;
693
694         int                     cmnd_size;
695         u8                      cmnd[MAX_COMMAND_SIZE];
696         enum data_direction     data_dir;
697         u32                     data_size;
698         u32                     data_size_from_cmnd;
699         u32                     tag;
700         unsigned int            lun;
701         u32                     residue;
702         u32                     usb_amount_left;
703
704         /* The CB protocol offers no way for a host to know when a command
705          * has completed.  As a result the next command may arrive early,
706          * and we will still have to handle it.  For that reason we need
707          * a buffer to store new commands when using CB (or CBI, which
708          * does not oblige a host to wait for command completion either). */
709         int                     cbbuf_cmnd_size;
710         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
711
712         unsigned int            nluns;
713         struct lun              *luns;
714         struct lun              *curlun;
715 };
716
717 typedef void (*fsg_routine_t)(struct fsg_dev *);
718
719 static int exception_in_progress(struct fsg_dev *fsg)
720 {
721         return (fsg->state > FSG_STATE_IDLE);
722 }
723
724 /* Make bulk-out requests be divisible by the maxpacket size */
725 static void set_bulk_out_req_length(struct fsg_dev *fsg,
726                 struct fsg_buffhd *bh, unsigned int length)
727 {
728         unsigned int    rem;
729
730         bh->bulk_out_intended_length = length;
731         rem = length % fsg->bulk_out_maxpacket;
732         if (rem > 0)
733                 length += fsg->bulk_out_maxpacket - rem;
734         bh->outreq->length = length;
735 }
736
737 static struct fsg_dev                   *the_fsg;
738 static struct usb_gadget_driver         fsg_driver;
739
740 static void     close_backing_file(struct lun *curlun);
741
742
743 /*-------------------------------------------------------------------------*/
744
745 #ifdef DUMP_MSGS
746
747 static void dump_msg(struct fsg_dev *fsg, const char *label,
748                 const u8 *buf, unsigned int length)
749 {
750         if (length < 512) {
751                 DBG(fsg, "%s, length %u:\n", label, length);
752                 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,
753                                 16, 1, buf, length, 0);
754         }
755 }
756
757 static void dump_cdb(struct fsg_dev *fsg)
758 {}
759
760 #else
761
762 static void dump_msg(struct fsg_dev *fsg, const char *label,
763                 const u8 *buf, unsigned int length)
764 {}
765
766 #ifdef VERBOSE_DEBUG
767
768 static void dump_cdb(struct fsg_dev *fsg)
769 {
770         print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,
771                         16, 1, fsg->cmnd, fsg->cmnd_size, 0);
772 }
773
774 #else
775
776 static void dump_cdb(struct fsg_dev *fsg)
777 {}
778
779 #endif /* VERBOSE_DEBUG */
780 #endif /* DUMP_MSGS */
781
782
783 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
784 {
785         const char      *name;
786
787         if (ep == fsg->bulk_in)
788                 name = "bulk-in";
789         else if (ep == fsg->bulk_out)
790                 name = "bulk-out";
791         else
792                 name = ep->name;
793         DBG(fsg, "%s set halt\n", name);
794         return usb_ep_set_halt(ep);
795 }
796
797
798 /*-------------------------------------------------------------------------*/
799
800 /* Routines for unaligned data access */
801
802 static u16 get_be16(u8 *buf)
803 {
804         return ((u16) buf[0] << 8) | ((u16) buf[1]);
805 }
806
807 static u32 get_be32(u8 *buf)
808 {
809         return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) |
810                         ((u32) buf[2] << 8) | ((u32) buf[3]);
811 }
812
813 static void put_be16(u8 *buf, u16 val)
814 {
815         buf[0] = val >> 8;
816         buf[1] = val;
817 }
818
819 static void put_be32(u8 *buf, u32 val)
820 {
821         buf[0] = val >> 24;
822         buf[1] = val >> 16;
823         buf[2] = val >> 8;
824         buf[3] = val & 0xff;
825 }
826
827
828 /*-------------------------------------------------------------------------*/
829
830 /*
831  * DESCRIPTORS ... most are static, but strings and (full) configuration
832  * descriptors are built on demand.  Also the (static) config and interface
833  * descriptors are adjusted during fsg_bind().
834  */
835 #define STRING_MANUFACTURER     1
836 #define STRING_PRODUCT          2
837 #define STRING_SERIAL           3
838 #define STRING_CONFIG           4
839 #define STRING_INTERFACE        5
840
841 /* There is only one configuration. */
842 #define CONFIG_VALUE            1
843
844 static struct usb_device_descriptor
845 device_desc = {
846         .bLength =              sizeof device_desc,
847         .bDescriptorType =      USB_DT_DEVICE,
848
849         .bcdUSB =               cpu_to_le16(0x0200),
850         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
851
852         /* The next three values can be overridden by module parameters */
853         .idVendor =             cpu_to_le16(DRIVER_VENDOR_ID),
854         .idProduct =            cpu_to_le16(DRIVER_PRODUCT_ID),
855         .bcdDevice =            cpu_to_le16(0xffff),
856
857         .iManufacturer =        STRING_MANUFACTURER,
858         .iProduct =             STRING_PRODUCT,
859         .iSerialNumber =        STRING_SERIAL,
860         .bNumConfigurations =   1,
861 };
862
863 static struct usb_config_descriptor
864 config_desc = {
865         .bLength =              sizeof config_desc,
866         .bDescriptorType =      USB_DT_CONFIG,
867
868         /* wTotalLength computed by usb_gadget_config_buf() */
869         .bNumInterfaces =       1,
870         .bConfigurationValue =  CONFIG_VALUE,
871         .iConfiguration =       STRING_CONFIG,
872         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
873         .bMaxPower =            CONFIG_USB_GADGET_VBUS_DRAW / 2,
874 };
875
876 static struct usb_otg_descriptor
877 otg_desc = {
878         .bLength =              sizeof(otg_desc),
879         .bDescriptorType =      USB_DT_OTG,
880
881         .bmAttributes =         USB_OTG_SRP,
882 };
883
884 /* There is only one interface. */
885
886 static struct usb_interface_descriptor
887 intf_desc = {
888         .bLength =              sizeof intf_desc,
889         .bDescriptorType =      USB_DT_INTERFACE,
890
891         .bNumEndpoints =        2,              // Adjusted during fsg_bind()
892         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
893         .bInterfaceSubClass =   USB_SC_SCSI,    // Adjusted during fsg_bind()
894         .bInterfaceProtocol =   USB_PR_BULK,    // Adjusted during fsg_bind()
895         .iInterface =           STRING_INTERFACE,
896 };
897
898 /* Three full-speed endpoint descriptors: bulk-in, bulk-out,
899  * and interrupt-in. */
900
901 static struct usb_endpoint_descriptor
902 fs_bulk_in_desc = {
903         .bLength =              USB_DT_ENDPOINT_SIZE,
904         .bDescriptorType =      USB_DT_ENDPOINT,
905
906         .bEndpointAddress =     USB_DIR_IN,
907         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
908         /* wMaxPacketSize set by autoconfiguration */
909 };
910
911 static struct usb_endpoint_descriptor
912 fs_bulk_out_desc = {
913         .bLength =              USB_DT_ENDPOINT_SIZE,
914         .bDescriptorType =      USB_DT_ENDPOINT,
915
916         .bEndpointAddress =     USB_DIR_OUT,
917         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
918         /* wMaxPacketSize set by autoconfiguration */
919 };
920
921 static struct usb_endpoint_descriptor
922 fs_intr_in_desc = {
923         .bLength =              USB_DT_ENDPOINT_SIZE,
924         .bDescriptorType =      USB_DT_ENDPOINT,
925
926         .bEndpointAddress =     USB_DIR_IN,
927         .bmAttributes =         USB_ENDPOINT_XFER_INT,
928         .wMaxPacketSize =       cpu_to_le16(2),
929         .bInterval =            32,     // frames -> 32 ms
930 };
931
932 static const struct usb_descriptor_header *fs_function[] = {
933         (struct usb_descriptor_header *) &otg_desc,
934         (struct usb_descriptor_header *) &intf_desc,
935         (struct usb_descriptor_header *) &fs_bulk_in_desc,
936         (struct usb_descriptor_header *) &fs_bulk_out_desc,
937         (struct usb_descriptor_header *) &fs_intr_in_desc,
938         NULL,
939 };
940 #define FS_FUNCTION_PRE_EP_ENTRIES      2
941
942
943 /*
944  * USB 2.0 devices need to expose both high speed and full speed
945  * descriptors, unless they only run at full speed.
946  *
947  * That means alternate endpoint descriptors (bigger packets)
948  * and a "device qualifier" ... plus more construction options
949  * for the config descriptor.
950  */
951 static struct usb_qualifier_descriptor
952 dev_qualifier = {
953         .bLength =              sizeof dev_qualifier,
954         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
955
956         .bcdUSB =               cpu_to_le16(0x0200),
957         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
958
959         .bNumConfigurations =   1,
960 };
961
962 static struct usb_endpoint_descriptor
963 hs_bulk_in_desc = {
964         .bLength =              USB_DT_ENDPOINT_SIZE,
965         .bDescriptorType =      USB_DT_ENDPOINT,
966
967         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
968         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
969         .wMaxPacketSize =       cpu_to_le16(512),
970 };
971
972 static struct usb_endpoint_descriptor
973 hs_bulk_out_desc = {
974         .bLength =              USB_DT_ENDPOINT_SIZE,
975         .bDescriptorType =      USB_DT_ENDPOINT,
976
977         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
978         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
979         .wMaxPacketSize =       cpu_to_le16(512),
980         .bInterval =            1,      // NAK every 1 uframe
981 };
982
983 static struct usb_endpoint_descriptor
984 hs_intr_in_desc = {
985         .bLength =              USB_DT_ENDPOINT_SIZE,
986         .bDescriptorType =      USB_DT_ENDPOINT,
987
988         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
989         .bmAttributes =         USB_ENDPOINT_XFER_INT,
990         .wMaxPacketSize =       cpu_to_le16(2),
991         .bInterval =            9,      // 2**(9-1) = 256 uframes -> 32 ms
992 };
993
994 static const struct usb_descriptor_header *hs_function[] = {
995         (struct usb_descriptor_header *) &otg_desc,
996         (struct usb_descriptor_header *) &intf_desc,
997         (struct usb_descriptor_header *) &hs_bulk_in_desc,
998         (struct usb_descriptor_header *) &hs_bulk_out_desc,
999         (struct usb_descriptor_header *) &hs_intr_in_desc,
1000         NULL,
1001 };
1002 #define HS_FUNCTION_PRE_EP_ENTRIES      2
1003
1004 /* Maxpacket and other transfer characteristics vary by speed. */
1005 static struct usb_endpoint_descriptor *
1006 ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
1007                 struct usb_endpoint_descriptor *hs)
1008 {
1009         if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
1010                 return hs;
1011         return fs;
1012 }
1013
1014
1015 /* The CBI specification limits the serial string to 12 uppercase hexadecimal
1016  * characters. */
1017 static char                             manufacturer[64];
1018 static char                             serial[13];
1019
1020 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
1021 static struct usb_string                strings[] = {
1022         {STRING_MANUFACTURER,   manufacturer},
1023         {STRING_PRODUCT,        longname},
1024         {STRING_SERIAL,         serial},
1025         {STRING_CONFIG,         "Self-powered"},
1026         {STRING_INTERFACE,      "Mass Storage"},
1027         {}
1028 };
1029
1030 static struct usb_gadget_strings        stringtab = {
1031         .language       = 0x0409,               // en-us
1032         .strings        = strings,
1033 };
1034
1035
1036 /*
1037  * Config descriptors must agree with the code that sets configurations
1038  * and with code managing interfaces and their altsettings.  They must
1039  * also handle different speeds and other-speed requests.
1040  */
1041 static int populate_config_buf(struct usb_gadget *gadget,
1042                 u8 *buf, u8 type, unsigned index)
1043 {
1044         enum usb_device_speed                   speed = gadget->speed;
1045         int                                     len;
1046         const struct usb_descriptor_header      **function;
1047
1048         if (index > 0)
1049                 return -EINVAL;
1050
1051         if (gadget_is_dualspeed(gadget) && type == USB_DT_OTHER_SPEED_CONFIG)
1052                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
1053         if (gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH)
1054                 function = hs_function;
1055         else
1056                 function = fs_function;
1057
1058         /* for now, don't advertise srp-only devices */
1059         if (!gadget_is_otg(gadget))
1060                 function++;
1061
1062         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
1063         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
1064         return len;
1065 }
1066
1067
1068 /*-------------------------------------------------------------------------*/
1069
1070 /* These routines may be called in process context or in_irq */
1071
1072 /* Caller must hold fsg->lock */
1073 static void wakeup_thread(struct fsg_dev *fsg)
1074 {
1075         /* Tell the main thread that something has happened */
1076         fsg->thread_wakeup_needed = 1;
1077         if (fsg->thread_task)
1078                 wake_up_process(fsg->thread_task);
1079 }
1080
1081
1082 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
1083 {
1084         unsigned long           flags;
1085
1086         /* Do nothing if a higher-priority exception is already in progress.
1087          * If a lower-or-equal priority exception is in progress, preempt it
1088          * and notify the main thread by sending it a signal. */
1089         spin_lock_irqsave(&fsg->lock, flags);
1090         if (fsg->state <= new_state) {
1091                 fsg->exception_req_tag = fsg->ep0_req_tag;
1092                 fsg->state = new_state;
1093                 if (fsg->thread_task)
1094                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
1095                                         fsg->thread_task);
1096         }
1097         spin_unlock_irqrestore(&fsg->lock, flags);
1098 }
1099
1100
1101 /*-------------------------------------------------------------------------*/
1102
1103 /* The disconnect callback and ep0 routines.  These always run in_irq,
1104  * except that ep0_queue() is called in the main thread to acknowledge
1105  * completion of various requests: set config, set interface, and
1106  * Bulk-only device reset. */
1107
1108 static void fsg_disconnect(struct usb_gadget *gadget)
1109 {
1110         struct fsg_dev          *fsg = get_gadget_data(gadget);
1111
1112         DBG(fsg, "disconnect or port reset\n");
1113         raise_exception(fsg, FSG_STATE_DISCONNECT);
1114 }
1115
1116
1117 static int ep0_queue(struct fsg_dev *fsg)
1118 {
1119         int     rc;
1120
1121         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
1122         if (rc != 0 && rc != -ESHUTDOWN) {
1123
1124                 /* We can't do much more than wait for a reset */
1125                 WARNING(fsg, "error in submission: %s --> %d\n",
1126                                 fsg->ep0->name, rc);
1127         }
1128         return rc;
1129 }
1130
1131 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
1132 {
1133         struct fsg_dev          *fsg = ep->driver_data;
1134
1135         if (req->actual > 0)
1136                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
1137         if (req->status || req->actual != req->length)
1138                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1139                                 req->status, req->actual, req->length);
1140         if (req->status == -ECONNRESET)         // Request was cancelled
1141                 usb_ep_fifo_flush(ep);
1142
1143         if (req->status == 0 && req->context)
1144                 ((fsg_routine_t) (req->context))(fsg);
1145 }
1146
1147
1148 /*-------------------------------------------------------------------------*/
1149
1150 /* Bulk and interrupt endpoint completion handlers.
1151  * These always run in_irq. */
1152
1153 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
1154 {
1155         struct fsg_dev          *fsg = ep->driver_data;
1156         struct fsg_buffhd       *bh = req->context;
1157
1158         if (req->status || req->actual != req->length)
1159                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1160                                 req->status, req->actual, req->length);
1161         if (req->status == -ECONNRESET)         // Request was cancelled
1162                 usb_ep_fifo_flush(ep);
1163
1164         /* Hold the lock while we update the request and buffer states */
1165         smp_wmb();
1166         spin_lock(&fsg->lock);
1167         bh->inreq_busy = 0;
1168         bh->state = BUF_STATE_EMPTY;
1169         wakeup_thread(fsg);
1170         spin_unlock(&fsg->lock);
1171 }
1172
1173 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
1174 {
1175         struct fsg_dev          *fsg = ep->driver_data;
1176         struct fsg_buffhd       *bh = req->context;
1177
1178         dump_msg(fsg, "bulk-out", req->buf, req->actual);
1179         if (req->status || req->actual != bh->bulk_out_intended_length)
1180                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1181                                 req->status, req->actual,
1182                                 bh->bulk_out_intended_length);
1183         if (req->status == -ECONNRESET)         // Request was cancelled
1184                 usb_ep_fifo_flush(ep);
1185
1186         /* Hold the lock while we update the request and buffer states */
1187         smp_wmb();
1188         spin_lock(&fsg->lock);
1189         bh->outreq_busy = 0;
1190         bh->state = BUF_STATE_FULL;
1191         wakeup_thread(fsg);
1192         spin_unlock(&fsg->lock);
1193 }
1194
1195
1196 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1197 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1198 {
1199         struct fsg_dev          *fsg = ep->driver_data;
1200         struct fsg_buffhd       *bh = req->context;
1201
1202         if (req->status || req->actual != req->length)
1203                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1204                                 req->status, req->actual, req->length);
1205         if (req->status == -ECONNRESET)         // Request was cancelled
1206                 usb_ep_fifo_flush(ep);
1207
1208         /* Hold the lock while we update the request and buffer states */
1209         smp_wmb();
1210         spin_lock(&fsg->lock);
1211         fsg->intreq_busy = 0;
1212         bh->state = BUF_STATE_EMPTY;
1213         wakeup_thread(fsg);
1214         spin_unlock(&fsg->lock);
1215 }
1216
1217 #else
1218 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1219 {}
1220 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1221
1222
1223 /*-------------------------------------------------------------------------*/
1224
1225 /* Ep0 class-specific handlers.  These always run in_irq. */
1226
1227 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1228 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1229 {
1230         struct usb_request      *req = fsg->ep0req;
1231         static u8               cbi_reset_cmnd[6] = {
1232                         SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
1233
1234         /* Error in command transfer? */
1235         if (req->status || req->length != req->actual ||
1236                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
1237
1238                 /* Not all controllers allow a protocol stall after
1239                  * receiving control-out data, but we'll try anyway. */
1240                 fsg_set_halt(fsg, fsg->ep0);
1241                 return;                 // Wait for reset
1242         }
1243
1244         /* Is it the special reset command? */
1245         if (req->actual >= sizeof cbi_reset_cmnd &&
1246                         memcmp(req->buf, cbi_reset_cmnd,
1247                                 sizeof cbi_reset_cmnd) == 0) {
1248
1249                 /* Raise an exception to stop the current operation
1250                  * and reinitialize our state. */
1251                 DBG(fsg, "cbi reset request\n");
1252                 raise_exception(fsg, FSG_STATE_RESET);
1253                 return;
1254         }
1255
1256         VDBG(fsg, "CB[I] accept device-specific command\n");
1257         spin_lock(&fsg->lock);
1258
1259         /* Save the command for later */
1260         if (fsg->cbbuf_cmnd_size)
1261                 WARNING(fsg, "CB[I] overwriting previous command\n");
1262         fsg->cbbuf_cmnd_size = req->actual;
1263         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
1264
1265         wakeup_thread(fsg);
1266         spin_unlock(&fsg->lock);
1267 }
1268
1269 #else
1270 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1271 {}
1272 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1273
1274
1275 static int class_setup_req(struct fsg_dev *fsg,
1276                 const struct usb_ctrlrequest *ctrl)
1277 {
1278         struct usb_request      *req = fsg->ep0req;
1279         int                     value = -EOPNOTSUPP;
1280         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1281         u16                     w_value = le16_to_cpu(ctrl->wValue);
1282         u16                     w_length = le16_to_cpu(ctrl->wLength);
1283
1284         if (!fsg->config)
1285                 return value;
1286
1287         /* Handle Bulk-only class-specific requests */
1288         if (transport_is_bbb()) {
1289                 switch (ctrl->bRequest) {
1290
1291                 case USB_BULK_RESET_REQUEST:
1292                         if (ctrl->bRequestType != (USB_DIR_OUT |
1293                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1294                                 break;
1295                         if (w_index != 0 || w_value != 0) {
1296                                 value = -EDOM;
1297                                 break;
1298                         }
1299
1300                         /* Raise an exception to stop the current operation
1301                          * and reinitialize our state. */
1302                         DBG(fsg, "bulk reset request\n");
1303                         raise_exception(fsg, FSG_STATE_RESET);
1304                         value = DELAYED_STATUS;
1305                         break;
1306
1307                 case USB_BULK_GET_MAX_LUN_REQUEST:
1308                         if (ctrl->bRequestType != (USB_DIR_IN |
1309                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1310                                 break;
1311                         if (w_index != 0 || w_value != 0) {
1312                                 value = -EDOM;
1313                                 break;
1314                         }
1315                         VDBG(fsg, "get max LUN\n");
1316                         *(u8 *) req->buf = fsg->nluns - 1;
1317                         value = 1;
1318                         break;
1319                 }
1320         }
1321
1322         /* Handle CBI class-specific requests */
1323         else {
1324                 switch (ctrl->bRequest) {
1325
1326                 case USB_CBI_ADSC_REQUEST:
1327                         if (ctrl->bRequestType != (USB_DIR_OUT |
1328                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1329                                 break;
1330                         if (w_index != 0 || w_value != 0) {
1331                                 value = -EDOM;
1332                                 break;
1333                         }
1334                         if (w_length > MAX_COMMAND_SIZE) {
1335                                 value = -EOVERFLOW;
1336                                 break;
1337                         }
1338                         value = w_length;
1339                         fsg->ep0req->context = received_cbi_adsc;
1340                         break;
1341                 }
1342         }
1343
1344         if (value == -EOPNOTSUPP)
1345                 VDBG(fsg,
1346                         "unknown class-specific control req "
1347                         "%02x.%02x v%04x i%04x l%u\n",
1348                         ctrl->bRequestType, ctrl->bRequest,
1349                         le16_to_cpu(ctrl->wValue), w_index, w_length);
1350         return value;
1351 }
1352
1353
1354 /*-------------------------------------------------------------------------*/
1355
1356 /* Ep0 standard request handlers.  These always run in_irq. */
1357
1358 static int standard_setup_req(struct fsg_dev *fsg,
1359                 const struct usb_ctrlrequest *ctrl)
1360 {
1361         struct usb_request      *req = fsg->ep0req;
1362         int                     value = -EOPNOTSUPP;
1363         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1364         u16                     w_value = le16_to_cpu(ctrl->wValue);
1365
1366         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
1367          * but config change events will also reconfigure hardware. */
1368         switch (ctrl->bRequest) {
1369
1370         case USB_REQ_GET_DESCRIPTOR:
1371                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1372                                 USB_RECIP_DEVICE))
1373                         break;
1374                 switch (w_value >> 8) {
1375
1376                 case USB_DT_DEVICE:
1377                         VDBG(fsg, "get device descriptor\n");
1378                         value = sizeof device_desc;
1379                         memcpy(req->buf, &device_desc, value);
1380                         break;
1381                 case USB_DT_DEVICE_QUALIFIER:
1382                         VDBG(fsg, "get device qualifier\n");
1383                         if (!gadget_is_dualspeed(fsg->gadget))
1384                                 break;
1385                         value = sizeof dev_qualifier;
1386                         memcpy(req->buf, &dev_qualifier, value);
1387                         break;
1388
1389                 case USB_DT_OTHER_SPEED_CONFIG:
1390                         VDBG(fsg, "get other-speed config descriptor\n");
1391                         if (!gadget_is_dualspeed(fsg->gadget))
1392                                 break;
1393                         goto get_config;
1394                 case USB_DT_CONFIG:
1395                         VDBG(fsg, "get configuration descriptor\n");
1396 get_config:
1397                         value = populate_config_buf(fsg->gadget,
1398                                         req->buf,
1399                                         w_value >> 8,
1400                                         w_value & 0xff);
1401                         break;
1402
1403                 case USB_DT_STRING:
1404                         VDBG(fsg, "get string descriptor\n");
1405
1406                         /* wIndex == language code */
1407                         value = usb_gadget_get_string(&stringtab,
1408                                         w_value & 0xff, req->buf);
1409                         break;
1410                 }
1411                 break;
1412
1413         /* One config, two speeds */
1414         case USB_REQ_SET_CONFIGURATION:
1415                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
1416                                 USB_RECIP_DEVICE))
1417                         break;
1418                 VDBG(fsg, "set configuration\n");
1419                 if (w_value == CONFIG_VALUE || w_value == 0) {
1420                         fsg->new_config = w_value;
1421
1422                         /* Raise an exception to wipe out previous transaction
1423                          * state (queued bufs, etc) and set the new config. */
1424                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
1425                         value = DELAYED_STATUS;
1426                 }
1427                 break;
1428         case USB_REQ_GET_CONFIGURATION:
1429                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1430                                 USB_RECIP_DEVICE))
1431                         break;
1432                 VDBG(fsg, "get configuration\n");
1433                 *(u8 *) req->buf = fsg->config;
1434                 value = 1;
1435                 break;
1436
1437         case USB_REQ_SET_INTERFACE:
1438                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
1439                                 USB_RECIP_INTERFACE))
1440                         break;
1441                 if (fsg->config && w_index == 0) {
1442
1443                         /* Raise an exception to wipe out previous transaction
1444                          * state (queued bufs, etc) and install the new
1445                          * interface altsetting. */
1446                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
1447                         value = DELAYED_STATUS;
1448                 }
1449                 break;
1450         case USB_REQ_GET_INTERFACE:
1451                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1452                                 USB_RECIP_INTERFACE))
1453                         break;
1454                 if (!fsg->config)
1455                         break;
1456                 if (w_index != 0) {
1457                         value = -EDOM;
1458                         break;
1459                 }
1460                 VDBG(fsg, "get interface\n");
1461                 *(u8 *) req->buf = 0;
1462                 value = 1;
1463                 break;
1464
1465         default:
1466                 VDBG(fsg,
1467                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1468                         ctrl->bRequestType, ctrl->bRequest,
1469                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1470         }
1471
1472         return value;
1473 }
1474
1475
1476 static int fsg_setup(struct usb_gadget *gadget,
1477                 const struct usb_ctrlrequest *ctrl)
1478 {
1479         struct fsg_dev          *fsg = get_gadget_data(gadget);
1480         int                     rc;
1481         int                     w_length = le16_to_cpu(ctrl->wLength);
1482
1483         ++fsg->ep0_req_tag;             // Record arrival of a new request
1484         fsg->ep0req->context = NULL;
1485         fsg->ep0req->length = 0;
1486         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1487
1488         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1489                 rc = class_setup_req(fsg, ctrl);
1490         else
1491                 rc = standard_setup_req(fsg, ctrl);
1492
1493         /* Respond with data/status or defer until later? */
1494         if (rc >= 0 && rc != DELAYED_STATUS) {
1495                 rc = min(rc, w_length);
1496                 fsg->ep0req->length = rc;
1497                 fsg->ep0req->zero = rc < w_length;
1498                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1499                                 "ep0-in" : "ep0-out");
1500                 rc = ep0_queue(fsg);
1501         }
1502
1503         /* Device either stalls (rc < 0) or reports success */
1504         return rc;
1505 }
1506
1507
1508 /*-------------------------------------------------------------------------*/
1509
1510 /* All the following routines run in process context */
1511
1512
1513 /* Use this for bulk or interrupt transfers, not ep0 */
1514 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1515                 struct usb_request *req, int *pbusy,
1516                 enum fsg_buffer_state *state)
1517 {
1518         int     rc;
1519
1520         if (ep == fsg->bulk_in)
1521                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1522         else if (ep == fsg->intr_in)
1523                 dump_msg(fsg, "intr-in", req->buf, req->length);
1524
1525         spin_lock_irq(&fsg->lock);
1526         *pbusy = 1;
1527         *state = BUF_STATE_BUSY;
1528         spin_unlock_irq(&fsg->lock);
1529         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1530         if (rc != 0) {
1531                 *pbusy = 0;
1532                 *state = BUF_STATE_EMPTY;
1533
1534                 /* We can't do much more than wait for a reset */
1535
1536                 /* Note: currently the net2280 driver fails zero-length
1537                  * submissions if DMA is enabled. */
1538                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1539                                                 req->length == 0))
1540                         WARNING(fsg, "error in submission: %s --> %d\n",
1541                                         ep->name, rc);
1542         }
1543 }
1544
1545
1546 static int sleep_thread(struct fsg_dev *fsg)
1547 {
1548         int     rc = 0;
1549
1550         /* Wait until a signal arrives or we are woken up */
1551         for (;;) {
1552                 try_to_freeze();
1553                 set_current_state(TASK_INTERRUPTIBLE);
1554                 if (signal_pending(current)) {
1555                         rc = -EINTR;
1556                         break;
1557                 }
1558                 if (fsg->thread_wakeup_needed)
1559                         break;
1560                 schedule();
1561         }
1562         __set_current_state(TASK_RUNNING);
1563         fsg->thread_wakeup_needed = 0;
1564         return rc;
1565 }
1566
1567
1568 /*-------------------------------------------------------------------------*/
1569
1570 static int do_read(struct fsg_dev *fsg)
1571 {
1572         struct lun              *curlun = fsg->curlun;
1573         u32                     lba;
1574         struct fsg_buffhd       *bh;
1575         int                     rc;
1576         u32                     amount_left;
1577         loff_t                  file_offset, file_offset_tmp;
1578         unsigned int            amount;
1579         unsigned int            partial_page;
1580         ssize_t                 nread;
1581
1582         /* Get the starting Logical Block Address and check that it's
1583          * not too big */
1584         if (fsg->cmnd[0] == SC_READ_6)
1585                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1586         else {
1587                 lba = get_be32(&fsg->cmnd[2]);
1588
1589                 /* We allow DPO (Disable Page Out = don't save data in the
1590                  * cache) and FUA (Force Unit Access = don't read from the
1591                  * cache), but we don't implement them. */
1592                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1593                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1594                         return -EINVAL;
1595                 }
1596         }
1597         if (lba >= curlun->num_sectors) {
1598                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1599                 return -EINVAL;
1600         }
1601         file_offset = ((loff_t) lba) << 9;
1602
1603         /* Carry out the file reads */
1604         amount_left = fsg->data_size_from_cmnd;
1605         if (unlikely(amount_left == 0))
1606                 return -EIO;            // No default reply
1607
1608         for (;;) {
1609
1610                 /* Figure out how much we need to read:
1611                  * Try to read the remaining amount.
1612                  * But don't read more than the buffer size.
1613                  * And don't try to read past the end of the file.
1614                  * Finally, if we're not at a page boundary, don't read past
1615                  *      the next page.
1616                  * If this means reading 0 then we were asked to read past
1617                  *      the end of file. */
1618                 amount = min((unsigned int) amount_left, mod_data.buflen);
1619                 amount = min((loff_t) amount,
1620                                 curlun->file_length - file_offset);
1621                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1622                 if (partial_page > 0)
1623                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1624                                         partial_page);
1625
1626                 /* Wait for the next buffer to become available */
1627                 bh = fsg->next_buffhd_to_fill;
1628                 while (bh->state != BUF_STATE_EMPTY) {
1629                         rc = sleep_thread(fsg);
1630                         if (rc)
1631                                 return rc;
1632                 }
1633
1634                 /* If we were asked to read past the end of file,
1635                  * end with an empty buffer. */
1636                 if (amount == 0) {
1637                         curlun->sense_data =
1638                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1639                         curlun->sense_data_info = file_offset >> 9;
1640                         curlun->info_valid = 1;
1641                         bh->inreq->length = 0;
1642                         bh->state = BUF_STATE_FULL;
1643                         break;
1644                 }
1645
1646                 /* Perform the read */
1647                 file_offset_tmp = file_offset;
1648                 nread = vfs_read(curlun->filp,
1649                                 (char __user *) bh->buf,
1650                                 amount, &file_offset_tmp);
1651                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1652                                 (unsigned long long) file_offset,
1653                                 (int) nread);
1654                 if (signal_pending(current))
1655                         return -EINTR;
1656
1657                 if (nread < 0) {
1658                         LDBG(curlun, "error in file read: %d\n",
1659                                         (int) nread);
1660                         nread = 0;
1661                 } else if (nread < amount) {
1662                         LDBG(curlun, "partial file read: %d/%u\n",
1663                                         (int) nread, amount);
1664                         nread -= (nread & 511); // Round down to a block
1665                 }
1666                 file_offset  += nread;
1667                 amount_left  -= nread;
1668                 fsg->residue -= nread;
1669                 bh->inreq->length = nread;
1670                 bh->state = BUF_STATE_FULL;
1671
1672                 /* If an error occurred, report it and its position */
1673                 if (nread < amount) {
1674                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1675                         curlun->sense_data_info = file_offset >> 9;
1676                         curlun->info_valid = 1;
1677                         break;
1678                 }
1679
1680                 if (amount_left == 0)
1681                         break;          // No more left to read
1682
1683                 /* Send this buffer and go read some more */
1684                 bh->inreq->zero = 0;
1685                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1686                                 &bh->inreq_busy, &bh->state);
1687                 fsg->next_buffhd_to_fill = bh->next;
1688         }
1689
1690         return -EIO;            // No default reply
1691 }
1692
1693
1694 /*-------------------------------------------------------------------------*/
1695
1696 static int do_write(struct fsg_dev *fsg)
1697 {
1698         struct lun              *curlun = fsg->curlun;
1699         u32                     lba;
1700         struct fsg_buffhd       *bh;
1701         int                     get_some_more;
1702         u32                     amount_left_to_req, amount_left_to_write;
1703         loff_t                  usb_offset, file_offset, file_offset_tmp;
1704         unsigned int            amount;
1705         unsigned int            partial_page;
1706         ssize_t                 nwritten;
1707         int                     rc;
1708
1709         if (curlun->ro) {
1710                 curlun->sense_data = SS_WRITE_PROTECTED;
1711                 return -EINVAL;
1712         }
1713         spin_lock(&curlun->filp->f_lock);
1714         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1715         spin_unlock(&curlun->filp->f_lock);
1716
1717         /* Get the starting Logical Block Address and check that it's
1718          * not too big */
1719         if (fsg->cmnd[0] == SC_WRITE_6)
1720                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1721         else {
1722                 lba = get_be32(&fsg->cmnd[2]);
1723
1724                 /* We allow DPO (Disable Page Out = don't save data in the
1725                  * cache) and FUA (Force Unit Access = write directly to the
1726                  * medium).  We don't implement DPO; we implement FUA by
1727                  * performing synchronous output. */
1728                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1729                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1730                         return -EINVAL;
1731                 }
1732                 if (fsg->cmnd[1] & 0x08) {      // FUA
1733                         spin_lock(&curlun->filp->f_lock);
1734                         curlun->filp->f_flags |= O_SYNC;
1735                         spin_unlock(&curlun->filp->f_lock);
1736                 }
1737         }
1738         if (lba >= curlun->num_sectors) {
1739                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1740                 return -EINVAL;
1741         }
1742
1743         /* Carry out the file writes */
1744         get_some_more = 1;
1745         file_offset = usb_offset = ((loff_t) lba) << 9;
1746         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1747
1748         while (amount_left_to_write > 0) {
1749
1750                 /* Queue a request for more data from the host */
1751                 bh = fsg->next_buffhd_to_fill;
1752                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1753
1754                         /* Figure out how much we want to get:
1755                          * Try to get the remaining amount.
1756                          * But don't get more than the buffer size.
1757                          * And don't try to go past the end of the file.
1758                          * If we're not at a page boundary,
1759                          *      don't go past the next page.
1760                          * If this means getting 0, then we were asked
1761                          *      to write past the end of file.
1762                          * Finally, round down to a block boundary. */
1763                         amount = min(amount_left_to_req, mod_data.buflen);
1764                         amount = min((loff_t) amount, curlun->file_length -
1765                                         usb_offset);
1766                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1767                         if (partial_page > 0)
1768                                 amount = min(amount,
1769         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1770
1771                         if (amount == 0) {
1772                                 get_some_more = 0;
1773                                 curlun->sense_data =
1774                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1775                                 curlun->sense_data_info = usb_offset >> 9;
1776                                 curlun->info_valid = 1;
1777                                 continue;
1778                         }
1779                         amount -= (amount & 511);
1780                         if (amount == 0) {
1781
1782                                 /* Why were we were asked to transfer a
1783                                  * partial block? */
1784                                 get_some_more = 0;
1785                                 continue;
1786                         }
1787
1788                         /* Get the next buffer */
1789                         usb_offset += amount;
1790                         fsg->usb_amount_left -= amount;
1791                         amount_left_to_req -= amount;
1792                         if (amount_left_to_req == 0)
1793                                 get_some_more = 0;
1794
1795                         /* amount is always divisible by 512, hence by
1796                          * the bulk-out maxpacket size */
1797                         bh->outreq->length = bh->bulk_out_intended_length =
1798                                         amount;
1799                         bh->outreq->short_not_ok = 1;
1800                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1801                                         &bh->outreq_busy, &bh->state);
1802                         fsg->next_buffhd_to_fill = bh->next;
1803                         continue;
1804                 }
1805
1806                 /* Write the received data to the backing file */
1807                 bh = fsg->next_buffhd_to_drain;
1808                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1809                         break;                  // We stopped early
1810                 if (bh->state == BUF_STATE_FULL) {
1811                         smp_rmb();
1812                         fsg->next_buffhd_to_drain = bh->next;
1813                         bh->state = BUF_STATE_EMPTY;
1814
1815                         /* Did something go wrong with the transfer? */
1816                         if (bh->outreq->status != 0) {
1817                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1818                                 curlun->sense_data_info = file_offset >> 9;
1819                                 curlun->info_valid = 1;
1820                                 break;
1821                         }
1822
1823                         amount = bh->outreq->actual;
1824                         if (curlun->file_length - file_offset < amount) {
1825                                 LERROR(curlun,
1826         "write %u @ %llu beyond end %llu\n",
1827         amount, (unsigned long long) file_offset,
1828         (unsigned long long) curlun->file_length);
1829                                 amount = curlun->file_length - file_offset;
1830                         }
1831
1832                         /* Perform the write */
1833                         file_offset_tmp = file_offset;
1834                         nwritten = vfs_write(curlun->filp,
1835                                         (char __user *) bh->buf,
1836                                         amount, &file_offset_tmp);
1837                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1838                                         (unsigned long long) file_offset,
1839                                         (int) nwritten);
1840                         if (signal_pending(current))
1841                                 return -EINTR;          // Interrupted!
1842
1843                         if (nwritten < 0) {
1844                                 LDBG(curlun, "error in file write: %d\n",
1845                                                 (int) nwritten);
1846                                 nwritten = 0;
1847                         } else if (nwritten < amount) {
1848                                 LDBG(curlun, "partial file write: %d/%u\n",
1849                                                 (int) nwritten, amount);
1850                                 nwritten -= (nwritten & 511);
1851                                                 // Round down to a block
1852                         }
1853                         file_offset += nwritten;
1854                         amount_left_to_write -= nwritten;
1855                         fsg->residue -= nwritten;
1856
1857                         /* If an error occurred, report it and its position */
1858                         if (nwritten < amount) {
1859                                 curlun->sense_data = SS_WRITE_ERROR;
1860                                 curlun->sense_data_info = file_offset >> 9;
1861                                 curlun->info_valid = 1;
1862                                 break;
1863                         }
1864
1865                         /* Did the host decide to stop early? */
1866                         if (bh->outreq->actual != bh->outreq->length) {
1867                                 fsg->short_packet_received = 1;
1868                                 break;
1869                         }
1870                         continue;
1871                 }
1872
1873                 /* Wait for something to happen */
1874                 rc = sleep_thread(fsg);
1875                 if (rc)
1876                         return rc;
1877         }
1878
1879         return -EIO;            // No default reply
1880 }
1881
1882
1883 /*-------------------------------------------------------------------------*/
1884
1885 /* Sync the file data, don't bother with the metadata.
1886  * This code was copied from fs/buffer.c:sys_fdatasync(). */
1887 static int fsync_sub(struct lun *curlun)
1888 {
1889         struct file     *filp = curlun->filp;
1890
1891         if (curlun->ro || !filp)
1892                 return 0;
1893         return vfs_fsync(filp, filp->f_path.dentry, 1);
1894 }
1895
1896 static void fsync_all(struct fsg_dev *fsg)
1897 {
1898         int     i;
1899
1900         for (i = 0; i < fsg->nluns; ++i)
1901                 fsync_sub(&fsg->luns[i]);
1902 }
1903
1904 static int do_synchronize_cache(struct fsg_dev *fsg)
1905 {
1906         struct lun      *curlun = fsg->curlun;
1907         int             rc;
1908
1909         /* We ignore the requested LBA and write out all file's
1910          * dirty data buffers. */
1911         rc = fsync_sub(curlun);
1912         if (rc)
1913                 curlun->sense_data = SS_WRITE_ERROR;
1914         return 0;
1915 }
1916
1917
1918 /*-------------------------------------------------------------------------*/
1919
1920 static void invalidate_sub(struct lun *curlun)
1921 {
1922         struct file     *filp = curlun->filp;
1923         struct inode    *inode = filp->f_path.dentry->d_inode;
1924         unsigned long   rc;
1925
1926         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1927         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
1928 }
1929
1930 static int do_verify(struct fsg_dev *fsg)
1931 {
1932         struct lun              *curlun = fsg->curlun;
1933         u32                     lba;
1934         u32                     verification_length;
1935         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1936         loff_t                  file_offset, file_offset_tmp;
1937         u32                     amount_left;
1938         unsigned int            amount;
1939         ssize_t                 nread;
1940
1941         /* Get the starting Logical Block Address and check that it's
1942          * not too big */
1943         lba = get_be32(&fsg->cmnd[2]);
1944         if (lba >= curlun->num_sectors) {
1945                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1946                 return -EINVAL;
1947         }
1948
1949         /* We allow DPO (Disable Page Out = don't save data in the
1950          * cache) but we don't implement it. */
1951         if ((fsg->cmnd[1] & ~0x10) != 0) {
1952                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1953                 return -EINVAL;
1954         }
1955
1956         verification_length = get_be16(&fsg->cmnd[7]);
1957         if (unlikely(verification_length == 0))
1958                 return -EIO;            // No default reply
1959
1960         /* Prepare to carry out the file verify */
1961         amount_left = verification_length << 9;
1962         file_offset = ((loff_t) lba) << 9;
1963
1964         /* Write out all the dirty buffers before invalidating them */
1965         fsync_sub(curlun);
1966         if (signal_pending(current))
1967                 return -EINTR;
1968
1969         invalidate_sub(curlun);
1970         if (signal_pending(current))
1971                 return -EINTR;
1972
1973         /* Just try to read the requested blocks */
1974         while (amount_left > 0) {
1975
1976                 /* Figure out how much we need to read:
1977                  * Try to read the remaining amount, but not more than
1978                  * the buffer size.
1979                  * And don't try to read past the end of the file.
1980                  * If this means reading 0 then we were asked to read
1981                  * past the end of file. */
1982                 amount = min((unsigned int) amount_left, mod_data.buflen);
1983                 amount = min((loff_t) amount,
1984                                 curlun->file_length - file_offset);
1985                 if (amount == 0) {
1986                         curlun->sense_data =
1987                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1988                         curlun->sense_data_info = file_offset >> 9;
1989                         curlun->info_valid = 1;
1990                         break;
1991                 }
1992
1993                 /* Perform the read */
1994                 file_offset_tmp = file_offset;
1995                 nread = vfs_read(curlun->filp,
1996                                 (char __user *) bh->buf,
1997                                 amount, &file_offset_tmp);
1998                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1999                                 (unsigned long long) file_offset,
2000                                 (int) nread);
2001                 if (signal_pending(current))
2002                         return -EINTR;
2003
2004                 if (nread < 0) {
2005                         LDBG(curlun, "error in file verify: %d\n",
2006                                         (int) nread);
2007                         nread = 0;
2008                 } else if (nread < amount) {
2009                         LDBG(curlun, "partial file verify: %d/%u\n",
2010                                         (int) nread, amount);
2011                         nread -= (nread & 511); // Round down to a sector
2012                 }
2013                 if (nread == 0) {
2014                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
2015                         curlun->sense_data_info = file_offset >> 9;
2016                         curlun->info_valid = 1;
2017                         break;
2018                 }
2019                 file_offset += nread;
2020                 amount_left -= nread;
2021         }
2022         return 0;
2023 }
2024
2025
2026 /*-------------------------------------------------------------------------*/
2027
2028 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2029 {
2030         u8      *buf = (u8 *) bh->buf;
2031
2032         static char vendor_id[] = "Linux   ";
2033         static char product_disk_id[] = "File-Stor Gadget";
2034         static char product_cdrom_id[] = "File-CD Gadget  ";
2035
2036         if (!fsg->curlun) {             // Unsupported LUNs are okay
2037                 fsg->bad_lun_okay = 1;
2038                 memset(buf, 0, 36);
2039                 buf[0] = 0x7f;          // Unsupported, no device-type
2040                 buf[4] = 31;            // Additional length
2041                 return 36;
2042         }
2043
2044         memset(buf, 0, 8);
2045         buf[0] = (mod_data.cdrom ? TYPE_CDROM : TYPE_DISK);
2046         if (mod_data.removable)
2047                 buf[1] = 0x80;
2048         buf[2] = 2;             // ANSI SCSI level 2
2049         buf[3] = 2;             // SCSI-2 INQUIRY data format
2050         buf[4] = 31;            // Additional length
2051                                 // No special options
2052         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id,
2053                         (mod_data.cdrom ? product_cdrom_id :
2054                                 product_disk_id),
2055                         mod_data.release);
2056         return 36;
2057 }
2058
2059
2060 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2061 {
2062         struct lun      *curlun = fsg->curlun;
2063         u8              *buf = (u8 *) bh->buf;
2064         u32             sd, sdinfo;
2065         int             valid;
2066
2067         /*
2068          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
2069          *
2070          * If a REQUEST SENSE command is received from an initiator
2071          * with a pending unit attention condition (before the target
2072          * generates the contingent allegiance condition), then the
2073          * target shall either:
2074          *   a) report any pending sense data and preserve the unit
2075          *      attention condition on the logical unit, or,
2076          *   b) report the unit attention condition, may discard any
2077          *      pending sense data, and clear the unit attention
2078          *      condition on the logical unit for that initiator.
2079          *
2080          * FSG normally uses option a); enable this code to use option b).
2081          */
2082 #if 0
2083         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
2084                 curlun->sense_data = curlun->unit_attention_data;
2085                 curlun->unit_attention_data = SS_NO_SENSE;
2086         }
2087 #endif
2088
2089         if (!curlun) {          // Unsupported LUNs are okay
2090                 fsg->bad_lun_okay = 1;
2091                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2092                 sdinfo = 0;
2093                 valid = 0;
2094         } else {
2095                 sd = curlun->sense_data;
2096                 sdinfo = curlun->sense_data_info;
2097                 valid = curlun->info_valid << 7;
2098                 curlun->sense_data = SS_NO_SENSE;
2099                 curlun->sense_data_info = 0;
2100                 curlun->info_valid = 0;
2101         }
2102
2103         memset(buf, 0, 18);
2104         buf[0] = valid | 0x70;                  // Valid, current error
2105         buf[2] = SK(sd);
2106         put_be32(&buf[3], sdinfo);              // Sense information
2107         buf[7] = 18 - 8;                        // Additional sense length
2108         buf[12] = ASC(sd);
2109         buf[13] = ASCQ(sd);
2110         return 18;
2111 }
2112
2113
2114 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2115 {
2116         struct lun      *curlun = fsg->curlun;
2117         u32             lba = get_be32(&fsg->cmnd[2]);
2118         int             pmi = fsg->cmnd[8];
2119         u8              *buf = (u8 *) bh->buf;
2120
2121         /* Check the PMI and LBA fields */
2122         if (pmi > 1 || (pmi == 0 && lba != 0)) {
2123                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2124                 return -EINVAL;
2125         }
2126
2127         put_be32(&buf[0], curlun->num_sectors - 1);     // Max logical block
2128         put_be32(&buf[4], 512);                         // Block length
2129         return 8;
2130 }
2131
2132
2133 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
2134 {
2135         if (msf) {
2136                 /* Convert to Minutes-Seconds-Frames */
2137                 addr >>= 2;             /* Convert to 2048-byte frames */
2138                 addr += 2*75;           /* Lead-in occupies 2 seconds */
2139                 dest[3] = addr % 75;    /* Frames */
2140                 addr /= 75;
2141                 dest[2] = addr % 60;    /* Seconds */
2142                 addr /= 60;
2143                 dest[1] = addr;         /* Minutes */
2144                 dest[0] = 0;            /* Reserved */
2145         } else {
2146                 /* Absolute sector */
2147                 put_be32(dest, addr);
2148         }
2149 }
2150
2151 static int do_read_header(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2152 {
2153         struct lun      *curlun = fsg->curlun;
2154         int             msf = fsg->cmnd[1] & 0x02;
2155         u32             lba = get_be32(&fsg->cmnd[2]);
2156         u8              *buf = (u8 *) bh->buf;
2157
2158         if ((fsg->cmnd[1] & ~0x02) != 0) {              /* Mask away MSF */
2159                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2160                 return -EINVAL;
2161         }
2162         if (lba >= curlun->num_sectors) {
2163                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
2164                 return -EINVAL;
2165         }
2166
2167         memset(buf, 0, 8);
2168         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
2169         store_cdrom_address(&buf[4], msf, lba);
2170         return 8;
2171 }
2172
2173
2174 static int do_read_toc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2175 {
2176         struct lun      *curlun = fsg->curlun;
2177         int             msf = fsg->cmnd[1] & 0x02;
2178         int             start_track = fsg->cmnd[6];
2179         u8              *buf = (u8 *) bh->buf;
2180
2181         if ((fsg->cmnd[1] & ~0x02) != 0 ||              /* Mask away MSF */
2182                         start_track > 1) {
2183                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2184                 return -EINVAL;
2185         }
2186
2187         memset(buf, 0, 20);
2188         buf[1] = (20-2);                /* TOC data length */
2189         buf[2] = 1;                     /* First track number */
2190         buf[3] = 1;                     /* Last track number */
2191         buf[5] = 0x16;                  /* Data track, copying allowed */
2192         buf[6] = 0x01;                  /* Only track is number 1 */
2193         store_cdrom_address(&buf[8], msf, 0);
2194
2195         buf[13] = 0x16;                 /* Lead-out track is data */
2196         buf[14] = 0xAA;                 /* Lead-out track number */
2197         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
2198         return 20;
2199 }
2200
2201
2202 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2203 {
2204         struct lun      *curlun = fsg->curlun;
2205         int             mscmnd = fsg->cmnd[0];
2206         u8              *buf = (u8 *) bh->buf;
2207         u8              *buf0 = buf;
2208         int             pc, page_code;
2209         int             changeable_values, all_pages;
2210         int             valid_page = 0;
2211         int             len, limit;
2212
2213         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
2214                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2215                 return -EINVAL;
2216         }
2217         pc = fsg->cmnd[2] >> 6;
2218         page_code = fsg->cmnd[2] & 0x3f;
2219         if (pc == 3) {
2220                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
2221                 return -EINVAL;
2222         }
2223         changeable_values = (pc == 1);
2224         all_pages = (page_code == 0x3f);
2225
2226         /* Write the mode parameter header.  Fixed values are: default
2227          * medium type, no cache control (DPOFUA), and no block descriptors.
2228          * The only variable value is the WriteProtect bit.  We will fill in
2229          * the mode data length later. */
2230         memset(buf, 0, 8);
2231         if (mscmnd == SC_MODE_SENSE_6) {
2232                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2233                 buf += 4;
2234                 limit = 255;
2235         } else {                        // SC_MODE_SENSE_10
2236                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2237                 buf += 8;
2238                 limit = 65535;          // Should really be mod_data.buflen
2239         }
2240
2241         /* No block descriptors */
2242
2243         /* The mode pages, in numerical order.  The only page we support
2244          * is the Caching page. */
2245         if (page_code == 0x08 || all_pages) {
2246                 valid_page = 1;
2247                 buf[0] = 0x08;          // Page code
2248                 buf[1] = 10;            // Page length
2249                 memset(buf+2, 0, 10);   // None of the fields are changeable
2250
2251                 if (!changeable_values) {
2252                         buf[2] = 0x04;  // Write cache enable,
2253                                         // Read cache not disabled
2254                                         // No cache retention priorities
2255                         put_be16(&buf[4], 0xffff);  // Don't disable prefetch
2256                                         // Minimum prefetch = 0
2257                         put_be16(&buf[8], 0xffff);  // Maximum prefetch
2258                         put_be16(&buf[10], 0xffff); // Maximum prefetch ceiling
2259                 }
2260                 buf += 12;
2261         }
2262
2263         /* Check that a valid page was requested and the mode data length
2264          * isn't too long. */
2265         len = buf - buf0;
2266         if (!valid_page || len > limit) {
2267                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2268                 return -EINVAL;
2269         }
2270
2271         /*  Store the mode data length */
2272         if (mscmnd == SC_MODE_SENSE_6)
2273                 buf0[0] = len - 1;
2274         else
2275                 put_be16(buf0, len - 2);
2276         return len;
2277 }
2278
2279
2280 static int do_start_stop(struct fsg_dev *fsg)
2281 {
2282         struct lun      *curlun = fsg->curlun;
2283         int             loej, start;
2284
2285         if (!mod_data.removable) {
2286                 curlun->sense_data = SS_INVALID_COMMAND;
2287                 return -EINVAL;
2288         }
2289
2290         // int immed = fsg->cmnd[1] & 0x01;
2291         loej = fsg->cmnd[4] & 0x02;
2292         start = fsg->cmnd[4] & 0x01;
2293
2294 #ifdef CONFIG_USB_FILE_STORAGE_TEST
2295         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
2296                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
2297                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2298                 return -EINVAL;
2299         }
2300
2301         if (!start) {
2302
2303                 /* Are we allowed to unload the media? */
2304                 if (curlun->prevent_medium_removal) {
2305                         LDBG(curlun, "unload attempt prevented\n");
2306                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
2307                         return -EINVAL;
2308                 }
2309                 if (loej) {             // Simulate an unload/eject
2310                         up_read(&fsg->filesem);
2311                         down_write(&fsg->filesem);
2312                         close_backing_file(curlun);
2313                         up_write(&fsg->filesem);
2314                         down_read(&fsg->filesem);
2315                 }
2316         } else {
2317
2318                 /* Our emulation doesn't support mounting; the medium is
2319                  * available for use as soon as it is loaded. */
2320                 if (!backing_file_is_open(curlun)) {
2321                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2322                         return -EINVAL;
2323                 }
2324         }
2325 #endif
2326         return 0;
2327 }
2328
2329
2330 static int do_prevent_allow(struct fsg_dev *fsg)
2331 {
2332         struct lun      *curlun = fsg->curlun;
2333         int             prevent;
2334
2335         if (!mod_data.removable) {
2336                 curlun->sense_data = SS_INVALID_COMMAND;
2337                 return -EINVAL;
2338         }
2339
2340         prevent = fsg->cmnd[4] & 0x01;
2341         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
2342                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2343                 return -EINVAL;
2344         }
2345
2346         if (curlun->prevent_medium_removal && !prevent)
2347                 fsync_sub(curlun);
2348         curlun->prevent_medium_removal = prevent;
2349         return 0;
2350 }
2351
2352
2353 static int do_read_format_capacities(struct fsg_dev *fsg,
2354                         struct fsg_buffhd *bh)
2355 {
2356         struct lun      *curlun = fsg->curlun;
2357         u8              *buf = (u8 *) bh->buf;
2358
2359         buf[0] = buf[1] = buf[2] = 0;
2360         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
2361         buf += 4;
2362
2363         put_be32(&buf[0], curlun->num_sectors);         // Number of blocks
2364         put_be32(&buf[4], 512);                         // Block length
2365         buf[4] = 0x02;                                  // Current capacity
2366         return 12;
2367 }
2368
2369
2370 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2371 {
2372         struct lun      *curlun = fsg->curlun;
2373
2374         /* We don't support MODE SELECT */
2375         curlun->sense_data = SS_INVALID_COMMAND;
2376         return -EINVAL;
2377 }
2378
2379
2380 /*-------------------------------------------------------------------------*/
2381
2382 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
2383 {
2384         int     rc;
2385
2386         rc = fsg_set_halt(fsg, fsg->bulk_in);
2387         if (rc == -EAGAIN)
2388                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
2389         while (rc != 0) {
2390                 if (rc != -EAGAIN) {
2391                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
2392                         rc = 0;
2393                         break;
2394                 }
2395
2396                 /* Wait for a short time and then try again */
2397                 if (msleep_interruptible(100) != 0)
2398                         return -EINTR;
2399                 rc = usb_ep_set_halt(fsg->bulk_in);
2400         }
2401         return rc;
2402 }
2403
2404 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
2405 {
2406         int     rc;
2407
2408         DBG(fsg, "bulk-in set wedge\n");
2409         rc = usb_ep_set_wedge(fsg->bulk_in);
2410         if (rc == -EAGAIN)
2411                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
2412         while (rc != 0) {
2413                 if (rc != -EAGAIN) {
2414                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
2415                         rc = 0;
2416                         break;
2417                 }
2418
2419                 /* Wait for a short time and then try again */
2420                 if (msleep_interruptible(100) != 0)
2421                         return -EINTR;
2422                 rc = usb_ep_set_wedge(fsg->bulk_in);
2423         }
2424         return rc;
2425 }
2426
2427 static int pad_with_zeros(struct fsg_dev *fsg)
2428 {
2429         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2430         u32                     nkeep = bh->inreq->length;
2431         u32                     nsend;
2432         int                     rc;
2433
2434         bh->state = BUF_STATE_EMPTY;            // For the first iteration
2435         fsg->usb_amount_left = nkeep + fsg->residue;
2436         while (fsg->usb_amount_left > 0) {
2437
2438                 /* Wait for the next buffer to be free */
2439                 while (bh->state != BUF_STATE_EMPTY) {
2440                         rc = sleep_thread(fsg);
2441                         if (rc)
2442                                 return rc;
2443                 }
2444
2445                 nsend = min(fsg->usb_amount_left, (u32) mod_data.buflen);
2446                 memset(bh->buf + nkeep, 0, nsend - nkeep);
2447                 bh->inreq->length = nsend;
2448                 bh->inreq->zero = 0;
2449                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2450                                 &bh->inreq_busy, &bh->state);
2451                 bh = fsg->next_buffhd_to_fill = bh->next;
2452                 fsg->usb_amount_left -= nsend;
2453                 nkeep = 0;
2454         }
2455         return 0;
2456 }
2457
2458 static int throw_away_data(struct fsg_dev *fsg)
2459 {
2460         struct fsg_buffhd       *bh;
2461         u32                     amount;
2462         int                     rc;
2463
2464         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
2465                         fsg->usb_amount_left > 0) {
2466
2467                 /* Throw away the data in a filled buffer */
2468                 if (bh->state == BUF_STATE_FULL) {
2469                         smp_rmb();
2470                         bh->state = BUF_STATE_EMPTY;
2471                         fsg->next_buffhd_to_drain = bh->next;
2472
2473                         /* A short packet or an error ends everything */
2474                         if (bh->outreq->actual != bh->outreq->length ||
2475                                         bh->outreq->status != 0) {
2476                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2477                                 return -EINTR;
2478                         }
2479                         continue;
2480                 }
2481
2482                 /* Try to submit another request if we need one */
2483                 bh = fsg->next_buffhd_to_fill;
2484                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
2485                         amount = min(fsg->usb_amount_left,
2486                                         (u32) mod_data.buflen);
2487
2488                         /* amount is always divisible by 512, hence by
2489                          * the bulk-out maxpacket size */
2490                         bh->outreq->length = bh->bulk_out_intended_length =
2491                                         amount;
2492                         bh->outreq->short_not_ok = 1;
2493                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2494                                         &bh->outreq_busy, &bh->state);
2495                         fsg->next_buffhd_to_fill = bh->next;
2496                         fsg->usb_amount_left -= amount;
2497                         continue;
2498                 }
2499
2500                 /* Otherwise wait for something to happen */
2501                 rc = sleep_thread(fsg);
2502                 if (rc)
2503                         return rc;
2504         }
2505         return 0;
2506 }
2507
2508
2509 static int finish_reply(struct fsg_dev *fsg)
2510 {
2511         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2512         int                     rc = 0;
2513
2514         switch (fsg->data_dir) {
2515         case DATA_DIR_NONE:
2516                 break;                  // Nothing to send
2517
2518         /* If we don't know whether the host wants to read or write,
2519          * this must be CB or CBI with an unknown command.  We mustn't
2520          * try to send or receive any data.  So stall both bulk pipes
2521          * if we can and wait for a reset. */
2522         case DATA_DIR_UNKNOWN:
2523                 if (mod_data.can_stall) {
2524                         fsg_set_halt(fsg, fsg->bulk_out);
2525                         rc = halt_bulk_in_endpoint(fsg);
2526                 }
2527                 break;
2528
2529         /* All but the last buffer of data must have already been sent */
2530         case DATA_DIR_TO_HOST:
2531                 if (fsg->data_size == 0)
2532                         ;               // Nothing to send
2533
2534                 /* If there's no residue, simply send the last buffer */
2535                 else if (fsg->residue == 0) {
2536                         bh->inreq->zero = 0;
2537                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2538                                         &bh->inreq_busy, &bh->state);
2539                         fsg->next_buffhd_to_fill = bh->next;
2540                 }
2541
2542                 /* There is a residue.  For CB and CBI, simply mark the end
2543                  * of the data with a short packet.  However, if we are
2544                  * allowed to stall, there was no data at all (residue ==
2545                  * data_size), and the command failed (invalid LUN or
2546                  * sense data is set), then halt the bulk-in endpoint
2547                  * instead. */
2548                 else if (!transport_is_bbb()) {
2549                         if (mod_data.can_stall &&
2550                                         fsg->residue == fsg->data_size &&
2551         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2552                                 bh->state = BUF_STATE_EMPTY;
2553                                 rc = halt_bulk_in_endpoint(fsg);
2554                         } else {
2555                                 bh->inreq->zero = 1;
2556                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2557                                                 &bh->inreq_busy, &bh->state);
2558                                 fsg->next_buffhd_to_fill = bh->next;
2559                         }
2560                 }
2561
2562                 /* For Bulk-only, if we're allowed to stall then send the
2563                  * short packet and halt the bulk-in endpoint.  If we can't
2564                  * stall, pad out the remaining data with 0's. */
2565                 else {
2566                         if (mod_data.can_stall) {
2567                                 bh->inreq->zero = 1;
2568                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2569                                                 &bh->inreq_busy, &bh->state);
2570                                 fsg->next_buffhd_to_fill = bh->next;
2571                                 rc = halt_bulk_in_endpoint(fsg);
2572                         } else
2573                                 rc = pad_with_zeros(fsg);
2574                 }
2575                 break;
2576
2577         /* We have processed all we want from the data the host has sent.
2578          * There may still be outstanding bulk-out requests. */
2579         case DATA_DIR_FROM_HOST:
2580                 if (fsg->residue == 0)
2581                         ;               // Nothing to receive
2582
2583                 /* Did the host stop sending unexpectedly early? */
2584                 else if (fsg->short_packet_received) {
2585                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2586                         rc = -EINTR;
2587                 }
2588
2589                 /* We haven't processed all the incoming data.  Even though
2590                  * we may be allowed to stall, doing so would cause a race.
2591                  * The controller may already have ACK'ed all the remaining
2592                  * bulk-out packets, in which case the host wouldn't see a
2593                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2594                  * clear the halt -- leading to problems later on. */
2595 #if 0
2596                 else if (mod_data.can_stall) {
2597                         fsg_set_halt(fsg, fsg->bulk_out);
2598                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2599                         rc = -EINTR;
2600                 }
2601 #endif
2602
2603                 /* We can't stall.  Read in the excess data and throw it
2604                  * all away. */
2605                 else
2606                         rc = throw_away_data(fsg);
2607                 break;
2608         }
2609         return rc;
2610 }
2611
2612
2613 static int send_status(struct fsg_dev *fsg)
2614 {
2615         struct lun              *curlun = fsg->curlun;
2616         struct fsg_buffhd       *bh;
2617         int                     rc;
2618         u8                      status = USB_STATUS_PASS;
2619         u32                     sd, sdinfo = 0;
2620
2621         /* Wait for the next buffer to become available */
2622         bh = fsg->next_buffhd_to_fill;
2623         while (bh->state != BUF_STATE_EMPTY) {
2624                 rc = sleep_thread(fsg);
2625                 if (rc)
2626                         return rc;
2627         }
2628
2629         if (curlun) {
2630                 sd = curlun->sense_data;
2631                 sdinfo = curlun->sense_data_info;
2632         } else if (fsg->bad_lun_okay)
2633                 sd = SS_NO_SENSE;
2634         else
2635                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2636
2637         if (fsg->phase_error) {
2638                 DBG(fsg, "sending phase-error status\n");
2639                 status = USB_STATUS_PHASE_ERROR;
2640                 sd = SS_INVALID_COMMAND;
2641         } else if (sd != SS_NO_SENSE) {
2642                 DBG(fsg, "sending command-failure status\n");
2643                 status = USB_STATUS_FAIL;
2644                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2645                                 "  info x%x\n",
2646                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2647         }
2648
2649         if (transport_is_bbb()) {
2650                 struct bulk_cs_wrap     *csw = bh->buf;
2651
2652                 /* Store and send the Bulk-only CSW */
2653                 csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
2654                 csw->Tag = fsg->tag;
2655                 csw->Residue = cpu_to_le32(fsg->residue);
2656                 csw->Status = status;
2657
2658                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2659                 bh->inreq->zero = 0;
2660                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2661                                 &bh->inreq_busy, &bh->state);
2662
2663         } else if (mod_data.transport_type == USB_PR_CB) {
2664
2665                 /* Control-Bulk transport has no status phase! */
2666                 return 0;
2667
2668         } else {                        // USB_PR_CBI
2669                 struct interrupt_data   *buf = bh->buf;
2670
2671                 /* Store and send the Interrupt data.  UFI sends the ASC
2672                  * and ASCQ bytes.  Everything else sends a Type (which
2673                  * is always 0) and the status Value. */
2674                 if (mod_data.protocol_type == USB_SC_UFI) {
2675                         buf->bType = ASC(sd);
2676                         buf->bValue = ASCQ(sd);
2677                 } else {
2678                         buf->bType = 0;
2679                         buf->bValue = status;
2680                 }
2681                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2682
2683                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2684                 fsg->intreq->buf = bh->inreq->buf;
2685                 fsg->intreq->context = bh;
2686                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2687                                 &fsg->intreq_busy, &bh->state);
2688         }
2689
2690         fsg->next_buffhd_to_fill = bh->next;
2691         return 0;
2692 }
2693
2694
2695 /*-------------------------------------------------------------------------*/
2696
2697 /* Check whether the command is properly formed and whether its data size
2698  * and direction agree with the values we already have. */
2699 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2700                 enum data_direction data_dir, unsigned int mask,
2701                 int needs_medium, const char *name)
2702 {
2703         int                     i;
2704         int                     lun = fsg->cmnd[1] >> 5;
2705         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2706         char                    hdlen[20];
2707         struct lun              *curlun;
2708
2709         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2710          * Transparent SCSI doesn't pad. */
2711         if (protocol_is_scsi())
2712                 ;
2713
2714         /* There's some disagreement as to whether RBC pads commands or not.
2715          * We'll play it safe and accept either form. */
2716         else if (mod_data.protocol_type == USB_SC_RBC) {
2717                 if (fsg->cmnd_size == 12)
2718                         cmnd_size = 12;
2719
2720         /* All the other protocols pad to 12 bytes */
2721         } else
2722                 cmnd_size = 12;
2723
2724         hdlen[0] = 0;
2725         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2726                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2727                                 fsg->data_size);
2728         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2729                         name, cmnd_size, dirletter[(int) data_dir],
2730                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2731
2732         /* We can't reply at all until we know the correct data direction
2733          * and size. */
2734         if (fsg->data_size_from_cmnd == 0)
2735                 data_dir = DATA_DIR_NONE;
2736         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2737                 fsg->data_dir = data_dir;
2738                 fsg->data_size = fsg->data_size_from_cmnd;
2739
2740         } else {                                        // Bulk-only
2741                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2742
2743                         /* Host data size < Device data size is a phase error.
2744                          * Carry out the command, but only transfer as much
2745                          * as we are allowed. */
2746                         fsg->data_size_from_cmnd = fsg->data_size;
2747                         fsg->phase_error = 1;
2748                 }
2749         }
2750         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2751
2752         /* Conflicting data directions is a phase error */
2753         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2754                 fsg->phase_error = 1;
2755                 return -EINVAL;
2756         }
2757
2758         /* Verify the length of the command itself */
2759         if (cmnd_size != fsg->cmnd_size) {
2760
2761                 /* Special case workaround: There are plenty of buggy SCSI
2762                  * implementations. Many have issues with cbw->Length
2763                  * field passing a wrong command size. For those cases we
2764                  * always try to work around the problem by using the length
2765                  * sent by the host side provided it is at least as large
2766                  * as the correct command length.
2767                  * Examples of such cases would be MS-Windows, which issues
2768                  * REQUEST SENSE with cbw->Length == 12 where it should
2769                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
2770                  * REQUEST SENSE with cbw->Length == 10 where it should
2771                  * be 6 as well.
2772                  */
2773                 if (cmnd_size <= fsg->cmnd_size) {
2774                         DBG(fsg, "%s is buggy! Expected length %d "
2775                                         "but we got %d\n", name,
2776                                         cmnd_size, fsg->cmnd_size);
2777                         cmnd_size = fsg->cmnd_size;
2778                 } else {
2779                         fsg->phase_error = 1;
2780                         return -EINVAL;
2781                 }
2782         }
2783
2784         /* Check that the LUN values are consistent */
2785         if (transport_is_bbb()) {
2786                 if (fsg->lun != lun)
2787                         DBG(fsg, "using LUN %d from CBW, "
2788                                         "not LUN %d from CDB\n",
2789                                         fsg->lun, lun);
2790         } else
2791                 fsg->lun = lun;         // Use LUN from the command
2792
2793         /* Check the LUN */
2794         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
2795                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2796                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
2797                         curlun->sense_data = SS_NO_SENSE;
2798                         curlun->sense_data_info = 0;
2799                         curlun->info_valid = 0;
2800                 }
2801         } else {
2802                 fsg->curlun = curlun = NULL;
2803                 fsg->bad_lun_okay = 0;
2804
2805                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2806                  * to use unsupported LUNs; all others may not. */
2807                 if (fsg->cmnd[0] != SC_INQUIRY &&
2808                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2809                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2810                         return -EINVAL;
2811                 }
2812         }
2813
2814         /* If a unit attention condition exists, only INQUIRY and
2815          * REQUEST SENSE commands are allowed; anything else must fail. */
2816         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2817                         fsg->cmnd[0] != SC_INQUIRY &&
2818                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2819                 curlun->sense_data = curlun->unit_attention_data;
2820                 curlun->unit_attention_data = SS_NO_SENSE;
2821                 return -EINVAL;
2822         }
2823
2824         /* Check that only command bytes listed in the mask are non-zero */
2825         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2826         for (i = 1; i < cmnd_size; ++i) {
2827                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2828                         if (curlun)
2829                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2830                         return -EINVAL;
2831                 }
2832         }
2833
2834         /* If the medium isn't mounted and the command needs to access
2835          * it, return an error. */
2836         if (curlun && !backing_file_is_open(curlun) && needs_medium) {
2837                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2838                 return -EINVAL;
2839         }
2840
2841         return 0;
2842 }
2843
2844
2845 static int do_scsi_command(struct fsg_dev *fsg)
2846 {
2847         struct fsg_buffhd       *bh;
2848         int                     rc;
2849         int                     reply = -EINVAL;
2850         int                     i;
2851         static char             unknown[16];
2852
2853         dump_cdb(fsg);
2854
2855         /* Wait for the next buffer to become available for data or status */
2856         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2857         while (bh->state != BUF_STATE_EMPTY) {
2858                 rc = sleep_thread(fsg);
2859                 if (rc)
2860                         return rc;
2861         }
2862         fsg->phase_error = 0;
2863         fsg->short_packet_received = 0;
2864
2865         down_read(&fsg->filesem);       // We're using the backing file
2866         switch (fsg->cmnd[0]) {
2867
2868         case SC_INQUIRY:
2869                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2870                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2871                                 (1<<4), 0,
2872                                 "INQUIRY")) == 0)
2873                         reply = do_inquiry(fsg, bh);
2874                 break;
2875
2876         case SC_MODE_SELECT_6:
2877                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2878                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2879                                 (1<<1) | (1<<4), 0,
2880                                 "MODE SELECT(6)")) == 0)
2881                         reply = do_mode_select(fsg, bh);
2882                 break;
2883
2884         case SC_MODE_SELECT_10:
2885                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2886                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2887                                 (1<<1) | (3<<7), 0,
2888                                 "MODE SELECT(10)")) == 0)
2889                         reply = do_mode_select(fsg, bh);
2890                 break;
2891
2892         case SC_MODE_SENSE_6:
2893                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2894                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2895                                 (1<<1) | (1<<2) | (1<<4), 0,
2896                                 "MODE SENSE(6)")) == 0)
2897                         reply = do_mode_sense(fsg, bh);
2898                 break;
2899
2900         case SC_MODE_SENSE_10:
2901                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2902                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2903                                 (1<<1) | (1<<2) | (3<<7), 0,
2904                                 "MODE SENSE(10)")) == 0)
2905                         reply = do_mode_sense(fsg, bh);
2906                 break;
2907
2908         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2909                 fsg->data_size_from_cmnd = 0;
2910                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2911                                 (1<<4), 0,
2912                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2913                         reply = do_prevent_allow(fsg);
2914                 break;
2915
2916         case SC_READ_6:
2917                 i = fsg->cmnd[4];
2918                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2919                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2920                                 (7<<1) | (1<<4), 1,
2921                                 "READ(6)")) == 0)
2922                         reply = do_read(fsg);
2923                 break;
2924
2925         case SC_READ_10:
2926                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2927                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2928                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2929                                 "READ(10)")) == 0)
2930                         reply = do_read(fsg);
2931                 break;
2932
2933         case SC_READ_12:
2934                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2935                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2936                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2937                                 "READ(12)")) == 0)
2938                         reply = do_read(fsg);
2939                 break;
2940
2941         case SC_READ_CAPACITY:
2942                 fsg->data_size_from_cmnd = 8;
2943                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2944                                 (0xf<<2) | (1<<8), 1,
2945                                 "READ CAPACITY")) == 0)
2946                         reply = do_read_capacity(fsg, bh);
2947                 break;
2948
2949         case SC_READ_HEADER:
2950                 if (!mod_data.cdrom)
2951                         goto unknown_cmnd;
2952                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2953                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2954                                 (3<<7) | (0x1f<<1), 1,
2955                                 "READ HEADER")) == 0)
2956                         reply = do_read_header(fsg, bh);
2957                 break;
2958
2959         case SC_READ_TOC:
2960                 if (!mod_data.cdrom)
2961                         goto unknown_cmnd;
2962                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2963                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2964                                 (7<<6) | (1<<1), 1,
2965                                 "READ TOC")) == 0)
2966                         reply = do_read_toc(fsg, bh);
2967                 break;
2968
2969         case SC_READ_FORMAT_CAPACITIES:
2970                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2971                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2972                                 (3<<7), 1,
2973                                 "READ FORMAT CAPACITIES")) == 0)
2974                         reply = do_read_format_capacities(fsg, bh);
2975                 break;
2976
2977         case SC_REQUEST_SENSE:
2978                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2979                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2980                                 (1<<4), 0,
2981                                 "REQUEST SENSE")) == 0)
2982                         reply = do_request_sense(fsg, bh);
2983                 break;
2984
2985         case SC_START_STOP_UNIT:
2986                 fsg->data_size_from_cmnd = 0;
2987                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2988                                 (1<<1) | (1<<4), 0,
2989                                 "START-STOP UNIT")) == 0)
2990                         reply = do_start_stop(fsg);
2991                 break;
2992
2993         case SC_SYNCHRONIZE_CACHE:
2994                 fsg->data_size_from_cmnd = 0;
2995                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2996                                 (0xf<<2) | (3<<7), 1,
2997                                 "SYNCHRONIZE CACHE")) == 0)
2998                         reply = do_synchronize_cache(fsg);
2999                 break;
3000
3001         case SC_TEST_UNIT_READY:
3002                 fsg->data_size_from_cmnd = 0;
3003                 reply = check_command(fsg, 6, DATA_DIR_NONE,
3004                                 0, 1,
3005                                 "TEST UNIT READY");
3006                 break;
3007
3008         /* Although optional, this command is used by MS-Windows.  We
3009          * support a minimal version: BytChk must be 0. */
3010         case SC_VERIFY:
3011                 fsg->data_size_from_cmnd = 0;
3012                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
3013                                 (1<<1) | (0xf<<2) | (3<<7), 1,
3014                                 "VERIFY")) == 0)
3015                         reply = do_verify(fsg);
3016                 break;
3017
3018         case SC_WRITE_6:
3019                 i = fsg->cmnd[4];
3020                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
3021                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
3022                                 (7<<1) | (1<<4), 1,
3023                                 "WRITE(6)")) == 0)
3024                         reply = do_write(fsg);
3025                 break;
3026
3027         case SC_WRITE_10:
3028                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
3029                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
3030                                 (1<<1) | (0xf<<2) | (3<<7), 1,
3031                                 "WRITE(10)")) == 0)
3032                         reply = do_write(fsg);
3033                 break;
3034
3035         case SC_WRITE_12:
3036                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
3037                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
3038                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
3039                                 "WRITE(12)")) == 0)
3040                         reply = do_write(fsg);
3041                 break;
3042
3043         /* Some mandatory commands that we recognize but don't implement.
3044          * They don't mean much in this setting.  It's left as an exercise
3045          * for anyone interested to implement RESERVE and RELEASE in terms
3046          * of Posix locks. */
3047         case SC_FORMAT_UNIT:
3048         case SC_RELEASE:
3049         case SC_RESERVE:
3050         case SC_SEND_DIAGNOSTIC:
3051                 // Fall through
3052
3053         default:
3054  unknown_cmnd:
3055                 fsg->data_size_from_cmnd = 0;
3056                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
3057                 if ((reply = check_command(fsg, fsg->cmnd_size,
3058                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
3059                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
3060                         reply = -EINVAL;
3061                 }
3062                 break;
3063         }
3064         up_read(&fsg->filesem);
3065
3066         if (reply == -EINTR || signal_pending(current))
3067                 return -EINTR;
3068
3069         /* Set up the single reply buffer for finish_reply() */
3070         if (reply == -EINVAL)
3071                 reply = 0;              // Error reply length
3072         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
3073                 reply = min((u32) reply, fsg->data_size_from_cmnd);
3074                 bh->inreq->length = reply;
3075                 bh->state = BUF_STATE_FULL;
3076                 fsg->residue -= reply;
3077         }                               // Otherwise it's already set
3078
3079         return 0;
3080 }
3081
3082
3083 /*-------------------------------------------------------------------------*/
3084
3085 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
3086 {
3087         struct usb_request      *req = bh->outreq;
3088         struct bulk_cb_wrap     *cbw = req->buf;
3089
3090         /* Was this a real packet?  Should it be ignored? */
3091         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
3092                 return -EINVAL;
3093
3094         /* Is the CBW valid? */
3095         if (req->actual != USB_BULK_CB_WRAP_LEN ||
3096                         cbw->Signature != cpu_to_le32(
3097                                 USB_BULK_CB_SIG)) {
3098                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
3099                                 req->actual,
3100                                 le32_to_cpu(cbw->Signature));
3101
3102                 /* The Bulk-only spec says we MUST stall the IN endpoint
3103                  * (6.6.1), so it's unavoidable.  It also says we must
3104                  * retain this state until the next reset, but there's
3105                  * no way to tell the controller driver it should ignore
3106                  * Clear-Feature(HALT) requests.
3107                  *
3108                  * We aren't required to halt the OUT endpoint; instead
3109                  * we can simply accept and discard any data received
3110                  * until the next reset. */
3111                 wedge_bulk_in_endpoint(fsg);
3112                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
3113                 return -EINVAL;
3114         }
3115
3116         /* Is the CBW meaningful? */
3117         if (cbw->Lun >= MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
3118                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
3119                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
3120                                 "cmdlen %u\n",
3121                                 cbw->Lun, cbw->Flags, cbw->Length);
3122
3123                 /* We can do anything we want here, so let's stall the
3124                  * bulk pipes if we are allowed to. */
3125                 if (mod_data.can_stall) {
3126                         fsg_set_halt(fsg, fsg->bulk_out);
3127                         halt_bulk_in_endpoint(fsg);
3128                 }
3129                 return -EINVAL;
3130         }
3131
3132         /* Save the command for later */
3133         fsg->cmnd_size = cbw->Length;
3134         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
3135         if (cbw->Flags & USB_BULK_IN_FLAG)
3136                 fsg->data_dir = DATA_DIR_TO_HOST;
3137         else
3138                 fsg->data_dir = DATA_DIR_FROM_HOST;
3139         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
3140         if (fsg->data_size == 0)
3141                 fsg->data_dir = DATA_DIR_NONE;
3142         fsg->lun = cbw->Lun;
3143         fsg->tag = cbw->Tag;
3144         return 0;
3145 }
3146
3147
3148 static int get_next_command(struct fsg_dev *fsg)
3149 {
3150         struct fsg_buffhd       *bh;
3151         int                     rc = 0;
3152
3153         if (transport_is_bbb()) {
3154
3155                 /* Wait for the next buffer to become available */
3156                 bh = fsg->next_buffhd_to_fill;
3157                 while (bh->state != BUF_STATE_EMPTY) {
3158                         rc = sleep_thread(fsg);
3159                         if (rc)
3160                                 return rc;
3161                 }
3162
3163                 /* Queue a request to read a Bulk-only CBW */
3164                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
3165                 bh->outreq->short_not_ok = 1;
3166                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
3167                                 &bh->outreq_busy, &bh->state);
3168
3169                 /* We will drain the buffer in software, which means we
3170                  * can reuse it for the next filling.  No need to advance
3171                  * next_buffhd_to_fill. */
3172
3173                 /* Wait for the CBW to arrive */
3174                 while (bh->state != BUF_STATE_FULL) {
3175                         rc = sleep_thread(fsg);
3176                         if (rc)
3177                                 return rc;
3178                 }
3179                 smp_rmb();
3180                 rc = received_cbw(fsg, bh);
3181                 bh->state = BUF_STATE_EMPTY;
3182
3183         } else {                // USB_PR_CB or USB_PR_CBI
3184
3185                 /* Wait for the next command to arrive */
3186                 while (fsg->cbbuf_cmnd_size == 0) {
3187                         rc = sleep_thread(fsg);
3188                         if (rc)
3189                                 return rc;
3190                 }
3191
3192                 /* Is the previous status interrupt request still busy?
3193                  * The host is allowed to skip reading the status,
3194                  * so we must cancel it. */
3195                 if (fsg->intreq_busy)
3196                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3197
3198                 /* Copy the command and mark the buffer empty */
3199                 fsg->data_dir = DATA_DIR_UNKNOWN;
3200                 spin_lock_irq(&fsg->lock);
3201                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
3202                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
3203                 fsg->cbbuf_cmnd_size = 0;
3204                 spin_unlock_irq(&fsg->lock);
3205         }
3206         return rc;
3207 }
3208
3209
3210 /*-------------------------------------------------------------------------*/
3211
3212 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
3213                 const struct usb_endpoint_descriptor *d)
3214 {
3215         int     rc;
3216
3217         ep->driver_data = fsg;
3218         rc = usb_ep_enable(ep, d);
3219         if (rc)
3220                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
3221         return rc;
3222 }
3223
3224 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
3225                 struct usb_request **preq)
3226 {
3227         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
3228         if (*preq)
3229                 return 0;
3230         ERROR(fsg, "can't allocate request for %s\n", ep->name);
3231         return -ENOMEM;
3232 }
3233
3234 /*
3235  * Reset interface setting and re-init endpoint state (toggle etc).
3236  * Call with altsetting < 0 to disable the interface.  The only other
3237  * available altsetting is 0, which enables the interface.
3238  */
3239 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
3240 {
3241         int     rc = 0;
3242         int     i;
3243         const struct usb_endpoint_descriptor    *d;
3244
3245         if (fsg->running)
3246                 DBG(fsg, "reset interface\n");
3247
3248 reset:
3249         /* Deallocate the requests */
3250         for (i = 0; i < NUM_BUFFERS; ++i) {
3251                 struct fsg_buffhd *bh = &fsg->buffhds[i];
3252
3253                 if (bh->inreq) {
3254                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
3255                         bh->inreq = NULL;
3256                 }
3257                 if (bh->outreq) {
3258                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
3259                         bh->outreq = NULL;
3260                 }
3261         }
3262         if (fsg->intreq) {
3263                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
3264                 fsg->intreq = NULL;
3265         }
3266
3267         /* Disable the endpoints */
3268         if (fsg->bulk_in_enabled) {
3269                 usb_ep_disable(fsg->bulk_in);
3270                 fsg->bulk_in_enabled = 0;
3271         }
3272         if (fsg->bulk_out_enabled) {
3273                 usb_ep_disable(fsg->bulk_out);
3274                 fsg->bulk_out_enabled = 0;
3275         }
3276         if (fsg->intr_in_enabled) {
3277                 usb_ep_disable(fsg->intr_in);
3278                 fsg->intr_in_enabled = 0;
3279         }
3280
3281         fsg->running = 0;
3282         if (altsetting < 0 || rc != 0)
3283                 return rc;
3284
3285         DBG(fsg, "set interface %d\n", altsetting);
3286
3287         /* Enable the endpoints */
3288         d = ep_desc(fsg->gadget, &fs_bulk_in_desc, &hs_bulk_in_desc);
3289         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
3290                 goto reset;
3291         fsg->bulk_in_enabled = 1;
3292
3293         d = ep_desc(fsg->gadget, &fs_bulk_out_desc, &hs_bulk_out_desc);
3294         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
3295                 goto reset;
3296         fsg->bulk_out_enabled = 1;
3297         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
3298         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
3299
3300         if (transport_is_cbi()) {
3301                 d = ep_desc(fsg->gadget, &fs_intr_in_desc, &hs_intr_in_desc);
3302                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
3303                         goto reset;
3304                 fsg->intr_in_enabled = 1;
3305         }
3306
3307         /* Allocate the requests */
3308         for (i = 0; i < NUM_BUFFERS; ++i) {
3309                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3310
3311                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
3312                         goto reset;
3313                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
3314                         goto reset;
3315                 bh->inreq->buf = bh->outreq->buf = bh->buf;
3316                 bh->inreq->context = bh->outreq->context = bh;
3317                 bh->inreq->complete = bulk_in_complete;
3318                 bh->outreq->complete = bulk_out_complete;
3319         }
3320         if (transport_is_cbi()) {
3321                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
3322                         goto reset;
3323                 fsg->intreq->complete = intr_in_complete;
3324         }
3325
3326         fsg->running = 1;
3327         for (i = 0; i < fsg->nluns; ++i)
3328                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3329         return rc;
3330 }
3331
3332
3333 /*
3334  * Change our operational configuration.  This code must agree with the code
3335  * that returns config descriptors, and with interface altsetting code.
3336  *
3337  * It's also responsible for power management interactions.  Some
3338  * configurations might not work with our current power sources.
3339  * For now we just assume the gadget is always self-powered.
3340  */
3341 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
3342 {
3343         int     rc = 0;
3344
3345         /* Disable the single interface */
3346         if (fsg->config != 0) {
3347                 DBG(fsg, "reset config\n");
3348                 fsg->config = 0;
3349                 rc = do_set_interface(fsg, -1);
3350         }
3351
3352         /* Enable the interface */
3353         if (new_config != 0) {
3354                 fsg->config = new_config;
3355                 if ((rc = do_set_interface(fsg, 0)) != 0)
3356                         fsg->config = 0;        // Reset on errors
3357                 else {
3358                         char *speed;
3359
3360                         switch (fsg->gadget->speed) {
3361                         case USB_SPEED_LOW:     speed = "low";  break;
3362                         case USB_SPEED_FULL:    speed = "full"; break;
3363                         case USB_SPEED_HIGH:    speed = "high"; break;
3364                         default:                speed = "?";    break;
3365                         }
3366                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
3367                 }
3368         }
3369         return rc;
3370 }
3371
3372
3373 /*-------------------------------------------------------------------------*/
3374
3375 static void handle_exception(struct fsg_dev *fsg)
3376 {
3377         siginfo_t               info;
3378         int                     sig;
3379         int                     i;
3380         int                     num_active;
3381         struct fsg_buffhd       *bh;
3382         enum fsg_state          old_state;
3383         u8                      new_config;
3384         struct lun              *curlun;
3385         unsigned int            exception_req_tag;
3386         int                     rc;
3387
3388         /* Clear the existing signals.  Anything but SIGUSR1 is converted
3389          * into a high-priority EXIT exception. */
3390         for (;;) {
3391                 sig = dequeue_signal_lock(current, &current->blocked, &info);
3392                 if (!sig)
3393                         break;
3394                 if (sig != SIGUSR1) {
3395                         if (fsg->state < FSG_STATE_EXIT)
3396                                 DBG(fsg, "Main thread exiting on signal\n");
3397                         raise_exception(fsg, FSG_STATE_EXIT);
3398                 }
3399         }
3400
3401         /* Cancel all the pending transfers */
3402         if (fsg->intreq_busy)
3403                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3404         for (i = 0; i < NUM_BUFFERS; ++i) {
3405                 bh = &fsg->buffhds[i];
3406                 if (bh->inreq_busy)
3407                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
3408                 if (bh->outreq_busy)
3409                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
3410         }
3411
3412         /* Wait until everything is idle */
3413         for (;;) {
3414                 num_active = fsg->intreq_busy;
3415                 for (i = 0; i < NUM_BUFFERS; ++i) {
3416                         bh = &fsg->buffhds[i];
3417                         num_active += bh->inreq_busy + bh->outreq_busy;
3418                 }
3419                 if (num_active == 0)
3420                         break;
3421                 if (sleep_thread(fsg))
3422                         return;
3423         }
3424
3425         /* Clear out the controller's fifos */
3426         if (fsg->bulk_in_enabled)
3427                 usb_ep_fifo_flush(fsg->bulk_in);
3428         if (fsg->bulk_out_enabled)
3429                 usb_ep_fifo_flush(fsg->bulk_out);
3430         if (fsg->intr_in_enabled)
3431                 usb_ep_fifo_flush(fsg->intr_in);
3432
3433         /* Reset the I/O buffer states and pointers, the SCSI
3434          * state, and the exception.  Then invoke the handler. */
3435         spin_lock_irq(&fsg->lock);
3436
3437         for (i = 0; i < NUM_BUFFERS; ++i) {
3438                 bh = &fsg->buffhds[i];
3439                 bh->state = BUF_STATE_EMPTY;
3440         }
3441         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
3442                         &fsg->buffhds[0];
3443
3444         exception_req_tag = fsg->exception_req_tag;
3445         new_config = fsg->new_config;
3446         old_state = fsg->state;
3447
3448         if (old_state == FSG_STATE_ABORT_BULK_OUT)
3449                 fsg->state = FSG_STATE_STATUS_PHASE;
3450         else {
3451                 for (i = 0; i < fsg->nluns; ++i) {
3452                         curlun = &fsg->luns[i];
3453                         curlun->prevent_medium_removal = 0;
3454                         curlun->sense_data = curlun->unit_attention_data =
3455                                         SS_NO_SENSE;
3456                         curlun->sense_data_info = 0;
3457                         curlun->info_valid = 0;
3458                 }
3459                 fsg->state = FSG_STATE_IDLE;
3460         }
3461         spin_unlock_irq(&fsg->lock);
3462
3463         /* Carry out any extra actions required for the exception */
3464         switch (old_state) {
3465         default:
3466                 break;
3467
3468         case FSG_STATE_ABORT_BULK_OUT:
3469                 send_status(fsg);
3470                 spin_lock_irq(&fsg->lock);
3471                 if (fsg->state == FSG_STATE_STATUS_PHASE)
3472                         fsg->state = FSG_STATE_IDLE;
3473                 spin_unlock_irq(&fsg->lock);
3474                 break;
3475
3476         case FSG_STATE_RESET:
3477                 /* In case we were forced against our will to halt a
3478                  * bulk endpoint, clear the halt now.  (The SuperH UDC
3479                  * requires this.) */
3480                 if (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
3481                         usb_ep_clear_halt(fsg->bulk_in);
3482
3483                 if (transport_is_bbb()) {
3484                         if (fsg->ep0_req_tag == exception_req_tag)
3485                                 ep0_queue(fsg); // Complete the status stage
3486
3487                 } else if (transport_is_cbi())
3488                         send_status(fsg);       // Status by interrupt pipe
3489
3490                 /* Technically this should go here, but it would only be
3491                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
3492                  * CONFIG_CHANGE cases. */
3493                 // for (i = 0; i < fsg->nluns; ++i)
3494                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3495                 break;
3496
3497         case FSG_STATE_INTERFACE_CHANGE:
3498                 rc = do_set_interface(fsg, 0);
3499                 if (fsg->ep0_req_tag != exception_req_tag)
3500                         break;
3501                 if (rc != 0)                    // STALL on errors
3502                         fsg_set_halt(fsg, fsg->ep0);
3503                 else                            // Complete the status stage
3504                         ep0_queue(fsg);
3505                 break;
3506
3507         case FSG_STATE_CONFIG_CHANGE:
3508                 rc = do_set_config(fsg, new_config);
3509                 if (fsg->ep0_req_tag != exception_req_tag)
3510                         break;
3511                 if (rc != 0)                    // STALL on errors
3512                         fsg_set_halt(fsg, fsg->ep0);
3513                 else                            // Complete the status stage
3514                         ep0_queue(fsg);
3515                 break;
3516
3517         case FSG_STATE_DISCONNECT:
3518                 fsync_all(fsg);
3519                 do_set_config(fsg, 0);          // Unconfigured state
3520                 break;
3521
3522         case FSG_STATE_EXIT:
3523         case FSG_STATE_TERMINATED:
3524                 do_set_config(fsg, 0);                  // Free resources
3525                 spin_lock_irq(&fsg->lock);
3526                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3527                 spin_unlock_irq(&fsg->lock);
3528                 break;
3529         }
3530 }
3531
3532
3533 /*-------------------------------------------------------------------------*/
3534
3535 static int fsg_main_thread(void *fsg_)
3536 {
3537         struct fsg_dev          *fsg = fsg_;
3538
3539         /* Allow the thread to be killed by a signal, but set the signal mask
3540          * to block everything but INT, TERM, KILL, and USR1. */
3541         allow_signal(SIGINT);
3542         allow_signal(SIGTERM);
3543         allow_signal(SIGKILL);
3544         allow_signal(SIGUSR1);
3545
3546         /* Allow the thread to be frozen */
3547         set_freezable();
3548
3549         /* Arrange for userspace references to be interpreted as kernel
3550          * pointers.  That way we can pass a kernel pointer to a routine
3551          * that expects a __user pointer and it will work okay. */
3552         set_fs(get_ds());
3553
3554         /* The main loop */
3555         while (fsg->state != FSG_STATE_TERMINATED) {
3556                 if (exception_in_progress(fsg) || signal_pending(current)) {
3557                         handle_exception(fsg);
3558                         continue;
3559                 }
3560
3561                 if (!fsg->running) {
3562                         sleep_thread(fsg);
3563                         continue;
3564                 }
3565
3566                 if (get_next_command(fsg))
3567                         continue;
3568
3569                 spin_lock_irq(&fsg->lock);
3570                 if (!exception_in_progress(fsg))
3571                         fsg->state = FSG_STATE_DATA_PHASE;
3572                 spin_unlock_irq(&fsg->lock);
3573
3574                 if (do_scsi_command(fsg) || finish_reply(fsg))
3575                         continue;
3576
3577                 spin_lock_irq(&fsg->lock);
3578                 if (!exception_in_progress(fsg))
3579                         fsg->state = FSG_STATE_STATUS_PHASE;
3580                 spin_unlock_irq(&fsg->lock);
3581
3582                 if (send_status(fsg))
3583                         continue;
3584
3585                 spin_lock_irq(&fsg->lock);
3586                 if (!exception_in_progress(fsg))
3587                         fsg->state = FSG_STATE_IDLE;
3588                 spin_unlock_irq(&fsg->lock);
3589                 }
3590
3591         spin_lock_irq(&fsg->lock);
3592         fsg->thread_task = NULL;
3593         spin_unlock_irq(&fsg->lock);
3594
3595         /* If we are exiting because of a signal, unregister the
3596          * gadget driver. */
3597         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
3598                 usb_gadget_unregister_driver(&fsg_driver);
3599
3600         /* Let the unbind and cleanup routines know the thread has exited */
3601         complete_and_exit(&fsg->thread_notifier, 0);
3602 }
3603
3604
3605 /*-------------------------------------------------------------------------*/
3606
3607 /* If the next two routines are called while the gadget is registered,
3608  * the caller must own fsg->filesem for writing. */
3609
3610 static int open_backing_file(struct lun *curlun, const char *filename)
3611 {
3612         int                             ro;
3613         struct file                     *filp = NULL;
3614         int                             rc = -EINVAL;
3615         struct inode                    *inode = NULL;
3616         loff_t                          size;
3617         loff_t                          num_sectors;
3618         loff_t                          min_sectors;
3619
3620         /* R/W if we can, R/O if we must */
3621         ro = curlun->ro;
3622         if (!ro) {
3623                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
3624                 if (-EROFS == PTR_ERR(filp))
3625                         ro = 1;
3626         }
3627         if (ro)
3628                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
3629         if (IS_ERR(filp)) {
3630                 LINFO(curlun, "unable to open backing file: %s\n", filename);
3631                 return PTR_ERR(filp);
3632         }
3633
3634         if (!(filp->f_mode & FMODE_WRITE))
3635                 ro = 1;
3636
3637         if (filp->f_path.dentry)
3638                 inode = filp->f_path.dentry->d_inode;
3639         if (inode && S_ISBLK(inode->i_mode)) {
3640                 if (bdev_read_only(inode->i_bdev))
3641                         ro = 1;
3642         } else if (!inode || !S_ISREG(inode->i_mode)) {
3643                 LINFO(curlun, "invalid file type: %s\n", filename);
3644                 goto out;
3645         }
3646
3647         /* If we can't read the file, it's no good.
3648          * If we can't write the file, use it read-only. */
3649         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
3650                 LINFO(curlun, "file not readable: %s\n", filename);
3651                 goto out;
3652         }
3653         if (!(filp->f_op->write || filp->f_op->aio_write))
3654                 ro = 1;
3655
3656         size = i_size_read(inode->i_mapping->host);
3657         if (size < 0) {
3658                 LINFO(curlun, "unable to find file size: %s\n", filename);
3659                 rc = (int) size;
3660                 goto out;
3661         }
3662         num_sectors = size >> 9;        // File size in 512-byte blocks
3663         min_sectors = 1;
3664         if (mod_data.cdrom) {
3665                 num_sectors &= ~3;      // Reduce to a multiple of 2048
3666                 min_sectors = 300*4;    // Smallest track is 300 frames
3667                 if (num_sectors >= 256*60*75*4) {
3668                         num_sectors = (256*60*75 - 1) * 4;
3669                         LINFO(curlun, "file too big: %s\n", filename);
3670                         LINFO(curlun, "using only first %d blocks\n",
3671                                         (int) num_sectors);
3672                 }
3673         }
3674         if (num_sectors < min_sectors) {
3675                 LINFO(curlun, "file too small: %s\n", filename);
3676                 rc = -ETOOSMALL;
3677                 goto out;
3678         }
3679
3680         get_file(filp);
3681         curlun->ro = ro;
3682         curlun->filp = filp;
3683         curlun->file_length = size;
3684         curlun->num_sectors = num_sectors;
3685         LDBG(curlun, "open backing file: %s\n", filename);
3686         rc = 0;
3687
3688 out:
3689         filp_close(filp, current->files);
3690         return rc;
3691 }
3692
3693
3694 static void close_backing_file(struct lun *curlun)
3695 {
3696         if (curlun->filp) {
3697                 LDBG(curlun, "close backing file\n");
3698                 fput(curlun->filp);
3699                 curlun->filp = NULL;
3700         }
3701 }
3702
3703
3704 static ssize_t show_ro(struct device *dev, struct device_attribute *attr, char *buf)
3705 {
3706         struct lun      *curlun = dev_to_lun(dev);
3707
3708         return sprintf(buf, "%d\n", curlun->ro);
3709 }
3710
3711 static ssize_t show_file(struct device *dev, struct device_attribute *attr,
3712                 char *buf)
3713 {
3714         struct lun      *curlun = dev_to_lun(dev);
3715         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3716         char            *p;
3717         ssize_t         rc;
3718
3719         down_read(&fsg->filesem);
3720         if (backing_file_is_open(curlun)) {     // Get the complete pathname
3721                 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
3722                 if (IS_ERR(p))
3723                         rc = PTR_ERR(p);
3724                 else {
3725                         rc = strlen(p);
3726                         memmove(buf, p, rc);
3727                         buf[rc] = '\n';         // Add a newline
3728                         buf[++rc] = 0;
3729                 }
3730         } else {                                // No file, return 0 bytes
3731                 *buf = 0;
3732                 rc = 0;
3733         }
3734         up_read(&fsg->filesem);
3735         return rc;
3736 }
3737
3738
3739 static ssize_t store_ro(struct device *dev, struct device_attribute *attr,
3740                 const char *buf, size_t count)
3741 {
3742         ssize_t         rc = count;
3743         struct lun      *curlun = dev_to_lun(dev);
3744         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3745         int             i;
3746
3747         if (sscanf(buf, "%d", &i) != 1)
3748                 return -EINVAL;
3749
3750         /* Allow the write-enable status to change only while the backing file
3751          * is closed. */
3752         down_read(&fsg->filesem);
3753         if (backing_file_is_open(curlun)) {
3754                 LDBG(curlun, "read-only status change prevented\n");
3755                 rc = -EBUSY;
3756         } else {
3757                 curlun->ro = !!i;
3758                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
3759         }
3760         up_read(&fsg->filesem);
3761         return rc;
3762 }
3763
3764 static ssize_t store_file(struct device *dev, struct device_attribute *attr,
3765                 const char *buf, size_t count)
3766 {
3767         struct lun      *curlun = dev_to_lun(dev);
3768         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3769         int             rc = 0;
3770
3771         if (curlun->prevent_medium_removal && backing_file_is_open(curlun)) {
3772                 LDBG(curlun, "eject attempt prevented\n");
3773                 return -EBUSY;                          // "Door is locked"
3774         }
3775
3776         /* Remove a trailing newline */
3777         if (count > 0 && buf[count-1] == '\n')
3778                 ((char *) buf)[count-1] = 0;            // Ugh!
3779
3780         /* Eject current medium */
3781         down_write(&fsg->filesem);
3782         if (backing_file_is_open(curlun)) {
3783                 close_backing_file(curlun);
3784                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
3785         }
3786
3787         /* Load new medium */
3788         if (count > 0 && buf[0]) {
3789                 rc = open_backing_file(curlun, buf);
3790                 if (rc == 0)
3791                         curlun->unit_attention_data =
3792                                         SS_NOT_READY_TO_READY_TRANSITION;
3793         }
3794         up_write(&fsg->filesem);
3795         return (rc < 0 ? rc : count);
3796 }
3797
3798
3799 /* The write permissions and store_xxx pointers are set in fsg_bind() */
3800 static DEVICE_ATTR(ro, 0444, show_ro, NULL);
3801 static DEVICE_ATTR(file, 0444, show_file, NULL);
3802
3803
3804 /*-------------------------------------------------------------------------*/
3805
3806 static void fsg_release(struct kref *ref)
3807 {
3808         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
3809
3810         kfree(fsg->luns);
3811         kfree(fsg);
3812 }
3813
3814 static void lun_release(struct device *dev)
3815 {
3816         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3817
3818         kref_put(&fsg->ref, fsg_release);
3819 }
3820
3821 static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
3822 {
3823         struct fsg_dev          *fsg = get_gadget_data(gadget);
3824         int                     i;
3825         struct lun              *curlun;
3826         struct usb_request      *req = fsg->ep0req;
3827
3828         DBG(fsg, "unbind\n");
3829         clear_bit(REGISTERED, &fsg->atomic_bitflags);
3830
3831         /* Unregister the sysfs attribute files and the LUNs */
3832         for (i = 0; i < fsg->nluns; ++i) {
3833                 curlun = &fsg->luns[i];
3834                 if (curlun->registered) {
3835                         device_remove_file(&curlun->dev, &dev_attr_ro);
3836                         device_remove_file(&curlun->dev, &dev_attr_file);
3837                         close_backing_file(curlun);
3838                         device_unregister(&curlun->dev);
3839                         curlun->registered = 0;
3840                 }
3841         }
3842
3843         /* If the thread isn't already dead, tell it to exit now */
3844         if (fsg->state != FSG_STATE_TERMINATED) {
3845                 raise_exception(fsg, FSG_STATE_EXIT);
3846                 wait_for_completion(&fsg->thread_notifier);
3847
3848                 /* The cleanup routine waits for this completion also */
3849                 complete(&fsg->thread_notifier);
3850         }
3851
3852         /* Free the data buffers */
3853         for (i = 0; i < NUM_BUFFERS; ++i)
3854                 kfree(fsg->buffhds[i].buf);
3855
3856         /* Free the request and buffer for endpoint 0 */
3857         if (req) {
3858                 kfree(req->buf);
3859                 usb_ep_free_request(fsg->ep0, req);
3860         }
3861
3862         set_gadget_data(gadget, NULL);
3863 }
3864
3865
3866 static int __init check_parameters(struct fsg_dev *fsg)
3867 {
3868         int     prot;
3869         int     gcnum;
3870
3871         /* Store the default values */
3872         mod_data.transport_type = USB_PR_BULK;
3873         mod_data.transport_name = "Bulk-only";
3874         mod_data.protocol_type = USB_SC_SCSI;
3875         mod_data.protocol_name = "Transparent SCSI";
3876
3877         /* Some peripheral controllers are known not to be able to
3878          * halt bulk endpoints correctly.  If one of them is present,
3879          * disable stalls.
3880          */
3881         if (gadget_is_sh(fsg->gadget) || gadget_is_at91(fsg->gadget))
3882                 mod_data.can_stall = 0;
3883
3884         if (mod_data.release == 0xffff) {       // Parameter wasn't set
3885                 /* The sa1100 controller is not supported */
3886                 if (gadget_is_sa1100(fsg->gadget))
3887                         gcnum = -1;
3888                 else
3889                         gcnum = usb_gadget_controller_number(fsg->gadget);
3890                 if (gcnum >= 0)
3891                         mod_data.release = 0x0300 + gcnum;
3892                 else {
3893                         WARNING(fsg, "controller '%s' not recognized\n",
3894                                 fsg->gadget->name);
3895                         mod_data.release = 0x0399;
3896                 }
3897         }
3898
3899         prot = simple_strtol(mod_data.protocol_parm, NULL, 0);
3900
3901 #ifdef CONFIG_USB_FILE_STORAGE_TEST
3902         if (strnicmp(mod_data.transport_parm, "BBB", 10) == 0) {
3903                 ;               // Use default setting
3904         } else if (strnicmp(mod_data.transport_parm, "CB", 10) == 0) {
3905                 mod_data.transport_type = USB_PR_CB;
3906                 mod_data.transport_name = "Control-Bulk";
3907         } else if (strnicmp(mod_data.transport_parm, "CBI", 10) == 0) {
3908                 mod_data.transport_type = USB_PR_CBI;
3909                 mod_data.transport_name = "Control-Bulk-Interrupt";
3910         } else {
3911                 ERROR(fsg, "invalid transport: %s\n", mod_data.transport_parm);
3912                 return -EINVAL;
3913         }
3914
3915         if (strnicmp(mod_data.protocol_parm, "SCSI", 10) == 0 ||
3916                         prot == USB_SC_SCSI) {
3917                 ;               // Use default setting
3918         } else if (strnicmp(mod_data.protocol_parm, "RBC", 10) == 0 ||
3919                         prot == USB_SC_RBC) {
3920                 mod_data.protocol_type = USB_SC_RBC;
3921                 mod_data.protocol_name = "RBC";
3922         } else if (strnicmp(mod_data.protocol_parm, "8020", 4) == 0 ||
3923                         strnicmp(mod_data.protocol_parm, "ATAPI", 10) == 0 ||
3924                         prot == USB_SC_8020) {
3925                 mod_data.protocol_type = USB_SC_8020;
3926                 mod_data.protocol_name = "8020i (ATAPI)";
3927         } else if (strnicmp(mod_data.protocol_parm, "QIC", 3) == 0 ||
3928                         prot == USB_SC_QIC) {
3929                 mod_data.protocol_type = USB_SC_QIC;
3930                 mod_data.protocol_name = "QIC-157";
3931         } else if (strnicmp(mod_data.protocol_parm, "UFI", 10) == 0 ||
3932                         prot == USB_SC_UFI) {
3933                 mod_data.protocol_type = USB_SC_UFI;
3934                 mod_data.protocol_name = "UFI";
3935         } else if (strnicmp(mod_data.protocol_parm, "8070", 4) == 0 ||
3936                         prot == USB_SC_8070) {
3937                 mod_data.protocol_type = USB_SC_8070;
3938                 mod_data.protocol_name = "8070i";
3939         } else {
3940                 ERROR(fsg, "invalid protocol: %s\n", mod_data.protocol_parm);
3941                 return -EINVAL;
3942         }
3943
3944         mod_data.buflen &= PAGE_CACHE_MASK;
3945         if (mod_data.buflen <= 0) {
3946                 ERROR(fsg, "invalid buflen\n");
3947                 return -ETOOSMALL;
3948         }
3949 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
3950
3951         return 0;
3952 }
3953
3954
3955 static int __init fsg_bind(struct usb_gadget *gadget)
3956 {
3957         struct fsg_dev          *fsg = the_fsg;
3958         int                     rc;
3959         int                     i;
3960         struct lun              *curlun;
3961         struct usb_ep           *ep;
3962         struct usb_request      *req;
3963         char                    *pathbuf, *p;
3964
3965         fsg->gadget = gadget;
3966         set_gadget_data(gadget, fsg);
3967         fsg->ep0 = gadget->ep0;
3968         fsg->ep0->driver_data = fsg;
3969
3970         if ((rc = check_parameters(fsg)) != 0)
3971                 goto out;
3972
3973         if (mod_data.removable) {       // Enable the store_xxx attributes
3974                 dev_attr_file.attr.mode = 0644;
3975                 dev_attr_file.store = store_file;
3976                 if (!mod_data.cdrom) {
3977                         dev_attr_ro.attr.mode = 0644;
3978                         dev_attr_ro.store = store_ro;
3979                 }
3980         }
3981
3982         /* Find out how many LUNs there should be */
3983         i = mod_data.nluns;
3984         if (i == 0)
3985                 i = max(mod_data.num_filenames, 1u);
3986         if (i > MAX_LUNS) {
3987                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
3988                 rc = -EINVAL;
3989                 goto out;
3990         }
3991
3992         /* Create the LUNs, open their backing files, and register the
3993          * LUN devices in sysfs. */
3994         fsg->luns = kzalloc(i * sizeof(struct lun), GFP_KERNEL);
3995         if (!fsg->luns) {
3996                 rc = -ENOMEM;
3997                 goto out;
3998         }
3999         fsg->nluns = i;
4000
4001         for (i = 0; i < fsg->nluns; ++i) {
4002                 curlun = &fsg->luns[i];
4003                 curlun->ro = mod_data.ro[i];
4004                 if (mod_data.cdrom)
4005                         curlun->ro = 1;
4006                 curlun->dev.release = lun_release;
4007                 curlun->dev.parent = &gadget->dev;
4008                 curlun->dev.driver = &fsg_driver.driver;
4009                 dev_set_drvdata(&curlun->dev, fsg);
4010                 dev_set_name(&curlun->dev,"%s-lun%d",
4011                              dev_name(&gadget->dev), i);
4012
4013                 if ((rc = device_register(&curlun->dev)) != 0) {
4014                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
4015                         goto out;
4016                 }
4017                 if ((rc = device_create_file(&curlun->dev,
4018                                         &dev_attr_ro)) != 0 ||
4019                                 (rc = device_create_file(&curlun->dev,
4020                                         &dev_attr_file)) != 0) {
4021                         device_unregister(&curlun->dev);
4022                         goto out;
4023                 }
4024                 curlun->registered = 1;
4025                 kref_get(&fsg->ref);
4026
4027                 if (mod_data.file[i] && *mod_data.file[i]) {
4028                         if ((rc = open_backing_file(curlun,
4029                                         mod_data.file[i])) != 0)
4030                                 goto out;
4031                 } else if (!mod_data.removable) {
4032                         ERROR(fsg, "no file given for LUN%d\n", i);
4033                         rc = -EINVAL;
4034                         goto out;
4035                 }
4036         }
4037
4038         /* Find all the endpoints we will use */
4039         usb_ep_autoconfig_reset(gadget);
4040         ep = usb_ep_autoconfig(gadget, &fs_bulk_in_desc);
4041         if (!ep)
4042                 goto autoconf_fail;
4043         ep->driver_data = fsg;          // claim the endpoint
4044         fsg->bulk_in = ep;
4045
4046         ep = usb_ep_autoconfig(gadget, &fs_bulk_out_desc);
4047         if (!ep)
4048                 goto autoconf_fail;
4049         ep->driver_data = fsg;          // claim the endpoint
4050         fsg->bulk_out = ep;
4051
4052         if (transport_is_cbi()) {
4053                 ep = usb_ep_autoconfig(gadget, &fs_intr_in_desc);
4054                 if (!ep)
4055                         goto autoconf_fail;
4056                 ep->driver_data = fsg;          // claim the endpoint
4057                 fsg->intr_in = ep;
4058         }
4059
4060         /* Fix up the descriptors */
4061         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
4062         device_desc.idVendor = cpu_to_le16(mod_data.vendor);
4063         device_desc.idProduct = cpu_to_le16(mod_data.product);
4064         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
4065
4066         i = (transport_is_cbi() ? 3 : 2);       // Number of endpoints
4067         intf_desc.bNumEndpoints = i;
4068         intf_desc.bInterfaceSubClass = mod_data.protocol_type;
4069         intf_desc.bInterfaceProtocol = mod_data.transport_type;
4070         fs_function[i + FS_FUNCTION_PRE_EP_ENTRIES] = NULL;
4071
4072         if (gadget_is_dualspeed(gadget)) {
4073                 hs_function[i + HS_FUNCTION_PRE_EP_ENTRIES] = NULL;
4074
4075                 /* Assume ep0 uses the same maxpacket value for both speeds */
4076                 dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
4077
4078                 /* Assume endpoint addresses are the same for both speeds */
4079                 hs_bulk_in_desc.bEndpointAddress =
4080                                 fs_bulk_in_desc.bEndpointAddress;
4081                 hs_bulk_out_desc.bEndpointAddress =
4082                                 fs_bulk_out_desc.bEndpointAddress;
4083                 hs_intr_in_desc.bEndpointAddress =
4084                                 fs_intr_in_desc.bEndpointAddress;
4085         }
4086
4087         if (gadget_is_otg(gadget))
4088                 otg_desc.bmAttributes |= USB_OTG_HNP;
4089
4090         rc = -ENOMEM;
4091
4092         /* Allocate the request and buffer for endpoint 0 */
4093         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
4094         if (!req)
4095                 goto out;
4096         req->buf = kmalloc(EP0_BUFSIZE, GFP_KERNEL);
4097         if (!req->buf)
4098                 goto out;
4099         req->complete = ep0_complete;
4100
4101         /* Allocate the data buffers */
4102         for (i = 0; i < NUM_BUFFERS; ++i) {
4103                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
4104
4105                 /* Allocate for the bulk-in endpoint.  We assume that
4106                  * the buffer will also work with the bulk-out (and
4107                  * interrupt-in) endpoint. */
4108                 bh->buf = kmalloc(mod_data.buflen, GFP_KERNEL);
4109                 if (!bh->buf)
4110                         goto out;
4111                 bh->next = bh + 1;
4112         }
4113         fsg->buffhds[NUM_BUFFERS - 1].next = &fsg->buffhds[0];
4114
4115         /* This should reflect the actual gadget power source */
4116         usb_gadget_set_selfpowered(gadget);
4117
4118         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
4119                         init_utsname()->sysname, init_utsname()->release,
4120                         gadget->name);
4121
4122         /* On a real device, serial[] would be loaded from permanent
4123          * storage.  We just encode it from the driver version string. */
4124         for (i = 0; i < sizeof(serial) - 2; i += 2) {
4125                 unsigned char           c = DRIVER_VERSION[i / 2];
4126
4127                 if (!c)
4128                         break;
4129                 sprintf(&serial[i], "%02X", c);
4130         }
4131
4132         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
4133                         "file-storage-gadget");
4134         if (IS_ERR(fsg->thread_task)) {
4135                 rc = PTR_ERR(fsg->thread_task);
4136                 goto out;
4137         }
4138
4139         INFO(fsg, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
4140         INFO(fsg, "Number of LUNs=%d\n", fsg->nluns);
4141
4142         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
4143         for (i = 0; i < fsg->nluns; ++i) {
4144                 curlun = &fsg->luns[i];
4145                 if (backing_file_is_open(curlun)) {
4146                         p = NULL;
4147                         if (pathbuf) {
4148                                 p = d_path(&curlun->filp->f_path,
4149                                            pathbuf, PATH_MAX);
4150                                 if (IS_ERR(p))
4151                                         p = NULL;
4152                         }
4153                         LINFO(curlun, "ro=%d, file: %s\n",
4154                                         curlun->ro, (p ? p : "(error)"));
4155                 }
4156         }
4157         kfree(pathbuf);
4158
4159         DBG(fsg, "transport=%s (x%02x)\n",
4160                         mod_data.transport_name, mod_data.transport_type);
4161         DBG(fsg, "protocol=%s (x%02x)\n",
4162                         mod_data.protocol_name, mod_data.protocol_type);
4163         DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n",
4164                         mod_data.vendor, mod_data.product, mod_data.release);
4165         DBG(fsg, "removable=%d, stall=%d, cdrom=%d, buflen=%u\n",
4166                         mod_data.removable, mod_data.can_stall,
4167                         mod_data.cdrom, mod_data.buflen);
4168         DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task));
4169
4170         set_bit(REGISTERED, &fsg->atomic_bitflags);
4171
4172         /* Tell the thread to start working */
4173         wake_up_process(fsg->thread_task);
4174         return 0;
4175
4176 autoconf_fail:
4177         ERROR(fsg, "unable to autoconfigure all endpoints\n");
4178         rc = -ENOTSUPP;
4179
4180 out:
4181         fsg->state = FSG_STATE_TERMINATED;      // The thread is dead
4182         fsg_unbind(gadget);
4183         complete(&fsg->thread_notifier);
4184         return rc;
4185 }
4186
4187
4188 /*-------------------------------------------------------------------------*/
4189
4190 static void fsg_suspend(struct usb_gadget *gadget)
4191 {
4192         struct fsg_dev          *fsg = get_gadget_data(gadget);
4193
4194         DBG(fsg, "suspend\n");
4195         set_bit(SUSPENDED, &fsg->atomic_bitflags);
4196 }
4197
4198 static void fsg_resume(struct usb_gadget *gadget)
4199 {
4200         struct fsg_dev          *fsg = get_gadget_data(gadget);
4201
4202         DBG(fsg, "resume\n");
4203         clear_bit(SUSPENDED, &fsg->atomic_bitflags);
4204 }
4205
4206
4207 /*-------------------------------------------------------------------------*/
4208
4209 static struct usb_gadget_driver         fsg_driver = {
4210 #ifdef CONFIG_USB_GADGET_DUALSPEED
4211         .speed          = USB_SPEED_HIGH,
4212 #else
4213         .speed          = USB_SPEED_FULL,
4214 #endif
4215         .function       = (char *) longname,
4216         .bind           = fsg_bind,
4217         .unbind         = fsg_unbind,
4218         .disconnect     = fsg_disconnect,
4219         .setup          = fsg_setup,
4220         .suspend        = fsg_suspend,
4221         .resume         = fsg_resume,
4222
4223         .driver         = {
4224                 .name           = (char *) shortname,
4225                 .owner          = THIS_MODULE,
4226                 // .release = ...
4227                 // .suspend = ...
4228                 // .resume = ...
4229         },
4230 };
4231
4232
4233 static int __init fsg_alloc(void)
4234 {
4235         struct fsg_dev          *fsg;
4236
4237         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
4238         if (!fsg)
4239                 return -ENOMEM;
4240         spin_lock_init(&fsg->lock);
4241         init_rwsem(&fsg->filesem);
4242         kref_init(&fsg->ref);
4243         init_completion(&fsg->thread_notifier);
4244
4245         the_fsg = fsg;
4246         return 0;
4247 }
4248
4249
4250 static int __init fsg_init(void)
4251 {
4252         int             rc;
4253         struct fsg_dev  *fsg;
4254
4255         if ((rc = fsg_alloc()) != 0)
4256                 return rc;
4257         fsg = the_fsg;
4258         if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
4259                 kref_put(&fsg->ref, fsg_release);
4260         return rc;
4261 }
4262 module_init(fsg_init);
4263
4264
4265 static void __exit fsg_cleanup(void)
4266 {
4267         struct fsg_dev  *fsg = the_fsg;
4268
4269         /* Unregister the driver iff the thread hasn't already done so */
4270         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
4271                 usb_gadget_unregister_driver(&fsg_driver);
4272
4273         /* Wait for the thread to finish up */
4274         wait_for_completion(&fsg->thread_notifier);
4275
4276         kref_put(&fsg->ref, fsg_release);
4277 }
4278 module_exit(fsg_cleanup);