Merge branch 'upstream-jgarzik' of git://git.kernel.org/pub/scm/linux/kernel/git...
[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) 2003-2005 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.  In addition to providing an
42  * example of a genuinely useful gadget driver for a USB device, it also
43  * illustrates a technique of double-buffering for increased throughput.
44  * Last but not least, it gives an easy way to probe the behavior of the
45  * 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.  The gadget will indicate that
50  * it has removable media if the optional "removable" module parameter is set.
51  *
52  * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI),
53  * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected
54  * by the optional "transport" module parameter.  It also supports the
55  * following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03),
56  * UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
57  * the optional "protocol" module parameter.  In addition, the default
58  * Vendor ID, Product ID, and release number can be overridden.
59  *
60  * There is support for multiple logical units (LUNs), each of which has
61  * its own backing file.  The number of LUNs can be set using the optional
62  * "luns" module parameter (anywhere from 1 to 8), and the corresponding
63  * files are specified using comma-separated lists for "file" and "ro".
64  * The default number of LUNs is taken from the number of "file" elements;
65  * it is 1 if "file" is not given.  If "removable" is not set then a backing
66  * file must be specified for each LUN.  If it is set, then an unspecified
67  * or empty backing filename means the LUN's medium is not loaded.
68  *
69  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
70  * needed (an interrupt-out endpoint is also needed for CBI).  The memory
71  * requirement amounts to two 16K buffers, size configurable by a parameter.
72  * Support is included for both full-speed and high-speed operation.
73  *
74  * Note that the driver is slightly non-portable in that it assumes a
75  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
76  * interrupt-in endpoints.  With most device controllers this isn't an
77  * issue, but there may be some with hardware restrictions that prevent
78  * a buffer from being used by more than one endpoint.
79  *
80  * Module options:
81  *
82  *      file=filename[,filename...]
83  *                              Required if "removable" is not set, names of
84  *                                      the files or block devices used for
85  *                                      backing storage
86  *      ro=b[,b...]             Default false, booleans for read-only access
87  *      removable               Default false, boolean for removable media
88  *      luns=N                  Default N = number of filenames, number of
89  *                                      LUNs to support
90  *      stall                   Default determined according to the type of
91  *                                      USB device controller (usually true),
92  *                                      boolean to permit the driver to halt
93  *                                      bulk endpoints
94  *      transport=XXX           Default BBB, transport name (CB, CBI, or BBB)
95  *      protocol=YYY            Default SCSI, protocol name (RBC, 8020 or
96  *                                      ATAPI, QIC, UFI, 8070, or SCSI;
97  *                                      also 1 - 6)
98  *      vendor=0xVVVV           Default 0x0525 (NetChip), USB Vendor ID
99  *      product=0xPPPP          Default 0xa4a5 (FSG), USB Product ID
100  *      release=0xRRRR          Override the USB release number (bcdDevice)
101  *      buflen=N                Default N=16384, buffer size used (will be
102  *                                      rounded down to a multiple of
103  *                                      PAGE_CACHE_SIZE)
104  *
105  * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro",
106  * "removable", "luns", and "stall" options are available; default values
107  * are used for everything else.
108  *
109  * The pathnames of the backing files and the ro settings are available in
110  * the attribute files "file" and "ro" in the lun<n> subdirectory of the
111  * gadget's sysfs directory.  If the "removable" option is set, writing to
112  * these files will simulate ejecting/loading the medium (writing an empty
113  * line means eject) and adjusting a write-enable tab.  Changes to the ro
114  * setting are not allowed when the medium is loaded.
115  *
116  * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
117  * The driver's SCSI command interface was based on the "Information
118  * technology - Small Computer System Interface - 2" document from
119  * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
120  * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.  The single exception
121  * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
122  * "Universal Serial Bus Mass Storage Class UFI Command Specification"
123  * document, Revision 1.0, December 14, 1998, available at
124  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
125  */
126
127
128 /*
129  *                              Driver Design
130  *
131  * The FSG driver is fairly straightforward.  There is a main kernel
132  * thread that handles most of the work.  Interrupt routines field
133  * callbacks from the controller driver: bulk- and interrupt-request
134  * completion notifications, endpoint-0 events, and disconnect events.
135  * Completion events are passed to the main thread by wakeup calls.  Many
136  * ep0 requests are handled at interrupt time, but SetInterface,
137  * SetConfiguration, and device reset requests are forwarded to the
138  * thread in the form of "exceptions" using SIGUSR1 signals (since they
139  * should interrupt any ongoing file I/O operations).
140  *
141  * The thread's main routine implements the standard command/data/status
142  * parts of a SCSI interaction.  It and its subroutines are full of tests
143  * for pending signals/exceptions -- all this polling is necessary since
144  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
145  * indication that the driver really wants to be running in userspace.)
146  * An important point is that so long as the thread is alive it keeps an
147  * open reference to the backing file.  This will prevent unmounting
148  * the backing file's underlying filesystem and could cause problems
149  * during system shutdown, for example.  To prevent such problems, the
150  * thread catches INT, TERM, and KILL signals and converts them into
151  * an EXIT exception.
152  *
153  * In normal operation the main thread is started during the gadget's
154  * fsg_bind() callback and stopped during fsg_unbind().  But it can also
155  * exit when it receives a signal, and there's no point leaving the
156  * gadget running when the thread is dead.  So just before the thread
157  * exits, it deregisters the gadget driver.  This makes things a little
158  * tricky: The driver is deregistered at two places, and the exiting
159  * thread can indirectly call fsg_unbind() which in turn can tell the
160  * thread to exit.  The first problem is resolved through the use of the
161  * REGISTERED atomic bitflag; the driver will only be deregistered once.
162  * The second problem is resolved by having fsg_unbind() check
163  * fsg->state; it won't try to stop the thread if the state is already
164  * FSG_STATE_TERMINATED.
165  *
166  * To provide maximum throughput, the driver uses a circular pipeline of
167  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
168  * arbitrarily long; in practice the benefits don't justify having more
169  * than 2 stages (i.e., double buffering).  But it helps to think of the
170  * pipeline as being a long one.  Each buffer head contains a bulk-in and
171  * a bulk-out request pointer (since the buffer can be used for both
172  * output and input -- directions always are given from the host's
173  * point of view) as well as a pointer to the buffer and various state
174  * variables.
175  *
176  * Use of the pipeline follows a simple protocol.  There is a variable
177  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
178  * At any time that buffer head may still be in use from an earlier
179  * request, so each buffer head has a state variable indicating whether
180  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
181  * buffer head to be EMPTY, filling the buffer either by file I/O or by
182  * USB I/O (during which the buffer head is BUSY), and marking the buffer
183  * head FULL when the I/O is complete.  Then the buffer will be emptied
184  * (again possibly by USB I/O, during which it is marked BUSY) and
185  * finally marked EMPTY again (possibly by a completion routine).
186  *
187  * A module parameter tells the driver to avoid stalling the bulk
188  * endpoints wherever the transport specification allows.  This is
189  * necessary for some UDCs like the SuperH, which cannot reliably clear a
190  * halt on a bulk endpoint.  However, under certain circumstances the
191  * Bulk-only specification requires a stall.  In such cases the driver
192  * will halt the endpoint and set a flag indicating that it should clear
193  * the halt in software during the next device reset.  Hopefully this
194  * will permit everything to work correctly.  Furthermore, although the
195  * specification allows the bulk-out endpoint to halt when the host sends
196  * too much data, implementing this would cause an unavoidable race.
197  * The driver will always use the "no-stall" approach for OUT transfers.
198  *
199  * One subtle point concerns sending status-stage responses for ep0
200  * requests.  Some of these requests, such as device reset, can involve
201  * interrupting an ongoing file I/O operation, which might take an
202  * arbitrarily long time.  During that delay the host might give up on
203  * the original ep0 request and issue a new one.  When that happens the
204  * driver should not notify the host about completion of the original
205  * request, as the host will no longer be waiting for it.  So the driver
206  * assigns to each ep0 request a unique tag, and it keeps track of the
207  * tag value of the request associated with a long-running exception
208  * (device-reset, interface-change, or configuration-change).  When the
209  * exception handler is finished, the status-stage response is submitted
210  * only if the current ep0 request tag is equal to the exception request
211  * tag.  Thus only the most recently received ep0 request will get a
212  * status-stage response.
213  *
214  * Warning: This driver source file is too long.  It ought to be split up
215  * into a header file plus about 3 separate .c files, to handle the details
216  * of the Gadget, USB Mass Storage, and SCSI protocols.
217  */
218
219
220 #undef DEBUG
221 #undef VERBOSE
222 #undef DUMP_MSGS
223
224
225 #include <asm/system.h>
226 #include <asm/uaccess.h>
227
228 #include <linux/bitops.h>
229 #include <linux/blkdev.h>
230 #include <linux/compiler.h>
231 #include <linux/completion.h>
232 #include <linux/dcache.h>
233 #include <linux/delay.h>
234 #include <linux/device.h>
235 #include <linux/fcntl.h>
236 #include <linux/file.h>
237 #include <linux/fs.h>
238 #include <linux/init.h>
239 #include <linux/kernel.h>
240 #include <linux/kref.h>
241 #include <linux/kthread.h>
242 #include <linux/limits.h>
243 #include <linux/list.h>
244 #include <linux/module.h>
245 #include <linux/moduleparam.h>
246 #include <linux/pagemap.h>
247 #include <linux/rwsem.h>
248 #include <linux/sched.h>
249 #include <linux/signal.h>
250 #include <linux/slab.h>
251 #include <linux/spinlock.h>
252 #include <linux/string.h>
253 #include <linux/freezer.h>
254 #include <linux/utsname.h>
255
256 #include <linux/usb/ch9.h>
257 #include <linux/usb_gadget.h>
258
259 #include "gadget_chips.h"
260
261
262 /*-------------------------------------------------------------------------*/
263
264 #define DRIVER_DESC             "File-backed Storage Gadget"
265 #define DRIVER_NAME             "g_file_storage"
266 #define DRIVER_VERSION          "28 November 2005"
267
268 static const char longname[] = DRIVER_DESC;
269 static const char shortname[] = DRIVER_NAME;
270
271 MODULE_DESCRIPTION(DRIVER_DESC);
272 MODULE_AUTHOR("Alan Stern");
273 MODULE_LICENSE("Dual BSD/GPL");
274
275 /* Thanks to NetChip Technologies for donating this product ID.
276  *
277  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
278  * Instead:  allocate your own, using normal USB-IF procedures. */
279 #define DRIVER_VENDOR_ID        0x0525  // NetChip
280 #define DRIVER_PRODUCT_ID       0xa4a5  // Linux-USB File-backed Storage Gadget
281
282
283 /*
284  * This driver assumes self-powered hardware and has no way for users to
285  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
286  * and endpoint addresses.
287  */
288
289
290 /*-------------------------------------------------------------------------*/
291
292 #define xprintk(f,level,fmt,args...) \
293         dev_printk(level , &(f)->gadget->dev , fmt , ## args)
294 #define yprintk(l,level,fmt,args...) \
295         dev_printk(level , &(l)->dev , fmt , ## args)
296
297 #ifdef DEBUG
298 #define DBG(fsg,fmt,args...) \
299         xprintk(fsg , KERN_DEBUG , fmt , ## args)
300 #define LDBG(lun,fmt,args...) \
301         yprintk(lun , KERN_DEBUG , fmt , ## args)
302 #define MDBG(fmt,args...) \
303         printk(KERN_DEBUG DRIVER_NAME ": " fmt , ## args)
304 #else
305 #define DBG(fsg,fmt,args...) \
306         do { } while (0)
307 #define LDBG(lun,fmt,args...) \
308         do { } while (0)
309 #define MDBG(fmt,args...) \
310         do { } while (0)
311 #undef VERBOSE
312 #undef DUMP_MSGS
313 #endif /* DEBUG */
314
315 #ifdef VERBOSE
316 #define VDBG    DBG
317 #define VLDBG   LDBG
318 #else
319 #define VDBG(fsg,fmt,args...) \
320         do { } while (0)
321 #define VLDBG(lun,fmt,args...) \
322         do { } while (0)
323 #endif /* VERBOSE */
324
325 #define ERROR(fsg,fmt,args...) \
326         xprintk(fsg , KERN_ERR , fmt , ## args)
327 #define LERROR(lun,fmt,args...) \
328         yprintk(lun , KERN_ERR , fmt , ## args)
329
330 #define WARN(fsg,fmt,args...) \
331         xprintk(fsg , KERN_WARNING , fmt , ## args)
332 #define LWARN(lun,fmt,args...) \
333         yprintk(lun , KERN_WARNING , fmt , ## args)
334
335 #define INFO(fsg,fmt,args...) \
336         xprintk(fsg , KERN_INFO , fmt , ## args)
337 #define LINFO(lun,fmt,args...) \
338         yprintk(lun , KERN_INFO , fmt , ## args)
339
340 #define MINFO(fmt,args...) \
341         printk(KERN_INFO DRIVER_NAME ": " fmt , ## args)
342
343
344 /*-------------------------------------------------------------------------*/
345
346 /* Encapsulate the module parameter settings */
347
348 #define MAX_LUNS        8
349
350 static struct {
351         char            *file[MAX_LUNS];
352         int             ro[MAX_LUNS];
353         int             num_filenames;
354         int             num_ros;
355         unsigned int    nluns;
356
357         int             removable;
358         int             can_stall;
359
360         char            *transport_parm;
361         char            *protocol_parm;
362         unsigned short  vendor;
363         unsigned short  product;
364         unsigned short  release;
365         unsigned int    buflen;
366
367         int             transport_type;
368         char            *transport_name;
369         int             protocol_type;
370         char            *protocol_name;
371
372 } mod_data = {                                  // Default values
373         .transport_parm         = "BBB",
374         .protocol_parm          = "SCSI",
375         .removable              = 0,
376         .can_stall              = 1,
377         .vendor                 = DRIVER_VENDOR_ID,
378         .product                = DRIVER_PRODUCT_ID,
379         .release                = 0xffff,       // Use controller chip type
380         .buflen                 = 16384,
381         };
382
383
384 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
385                 S_IRUGO);
386 MODULE_PARM_DESC(file, "names of backing files or devices");
387
388 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
389 MODULE_PARM_DESC(ro, "true to force read-only");
390
391 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
392 MODULE_PARM_DESC(luns, "number of LUNs");
393
394 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
395 MODULE_PARM_DESC(removable, "true to simulate removable media");
396
397 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
398 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
399
400
401 /* In the non-TEST version, only the module parameters listed above
402  * are available. */
403 #ifdef CONFIG_USB_FILE_STORAGE_TEST
404
405 module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
406 MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
407
408 module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
409 MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
410                 "8070, or SCSI)");
411
412 module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
413 MODULE_PARM_DESC(vendor, "USB Vendor ID");
414
415 module_param_named(product, mod_data.product, ushort, S_IRUGO);
416 MODULE_PARM_DESC(product, "USB Product ID");
417
418 module_param_named(release, mod_data.release, ushort, S_IRUGO);
419 MODULE_PARM_DESC(release, "USB release number");
420
421 module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
422 MODULE_PARM_DESC(buflen, "I/O buffer size");
423
424 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
425
426
427 /*-------------------------------------------------------------------------*/
428
429 /* USB protocol value = the transport method */
430 #define USB_PR_CBI      0x00            // Control/Bulk/Interrupt
431 #define USB_PR_CB       0x01            // Control/Bulk w/o interrupt
432 #define USB_PR_BULK     0x50            // Bulk-only
433
434 /* USB subclass value = the protocol encapsulation */
435 #define USB_SC_RBC      0x01            // Reduced Block Commands (flash)
436 #define USB_SC_8020     0x02            // SFF-8020i, MMC-2, ATAPI (CD-ROM)
437 #define USB_SC_QIC      0x03            // QIC-157 (tape)
438 #define USB_SC_UFI      0x04            // UFI (floppy)
439 #define USB_SC_8070     0x05            // SFF-8070i (removable)
440 #define USB_SC_SCSI     0x06            // Transparent SCSI
441
442 /* Bulk-only data structures */
443
444 /* Command Block Wrapper */
445 struct bulk_cb_wrap {
446         __le32  Signature;              // Contains 'USBC'
447         u32     Tag;                    // Unique per command id
448         __le32  DataTransferLength;     // Size of the data
449         u8      Flags;                  // Direction in bit 7
450         u8      Lun;                    // LUN (normally 0)
451         u8      Length;                 // Of the CDB, <= MAX_COMMAND_SIZE
452         u8      CDB[16];                // Command Data Block
453 };
454
455 #define USB_BULK_CB_WRAP_LEN    31
456 #define USB_BULK_CB_SIG         0x43425355      // Spells out USBC
457 #define USB_BULK_IN_FLAG        0x80
458
459 /* Command Status Wrapper */
460 struct bulk_cs_wrap {
461         __le32  Signature;              // Should = 'USBS'
462         u32     Tag;                    // Same as original command
463         __le32  Residue;                // Amount not transferred
464         u8      Status;                 // See below
465 };
466
467 #define USB_BULK_CS_WRAP_LEN    13
468 #define USB_BULK_CS_SIG         0x53425355      // Spells out 'USBS'
469 #define USB_STATUS_PASS         0
470 #define USB_STATUS_FAIL         1
471 #define USB_STATUS_PHASE_ERROR  2
472
473 /* Bulk-only class specific requests */
474 #define USB_BULK_RESET_REQUEST          0xff
475 #define USB_BULK_GET_MAX_LUN_REQUEST    0xfe
476
477
478 /* CBI Interrupt data structure */
479 struct interrupt_data {
480         u8      bType;
481         u8      bValue;
482 };
483
484 #define CBI_INTERRUPT_DATA_LEN          2
485
486 /* CBI Accept Device-Specific Command request */
487 #define USB_CBI_ADSC_REQUEST            0x00
488
489
490 #define MAX_COMMAND_SIZE        16      // Length of a SCSI Command Data Block
491
492 /* SCSI commands that we recognize */
493 #define SC_FORMAT_UNIT                  0x04
494 #define SC_INQUIRY                      0x12
495 #define SC_MODE_SELECT_6                0x15
496 #define SC_MODE_SELECT_10               0x55
497 #define SC_MODE_SENSE_6                 0x1a
498 #define SC_MODE_SENSE_10                0x5a
499 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
500 #define SC_READ_6                       0x08
501 #define SC_READ_10                      0x28
502 #define SC_READ_12                      0xa8
503 #define SC_READ_CAPACITY                0x25
504 #define SC_READ_FORMAT_CAPACITIES       0x23
505 #define SC_RELEASE                      0x17
506 #define SC_REQUEST_SENSE                0x03
507 #define SC_RESERVE                      0x16
508 #define SC_SEND_DIAGNOSTIC              0x1d
509 #define SC_START_STOP_UNIT              0x1b
510 #define SC_SYNCHRONIZE_CACHE            0x35
511 #define SC_TEST_UNIT_READY              0x00
512 #define SC_VERIFY                       0x2f
513 #define SC_WRITE_6                      0x0a
514 #define SC_WRITE_10                     0x2a
515 #define SC_WRITE_12                     0xaa
516
517 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
518 #define SS_NO_SENSE                             0
519 #define SS_COMMUNICATION_FAILURE                0x040800
520 #define SS_INVALID_COMMAND                      0x052000
521 #define SS_INVALID_FIELD_IN_CDB                 0x052400
522 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
523 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
524 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
525 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
526 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
527 #define SS_RESET_OCCURRED                       0x062900
528 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
529 #define SS_UNRECOVERED_READ_ERROR               0x031100
530 #define SS_WRITE_ERROR                          0x030c02
531 #define SS_WRITE_PROTECTED                      0x072700
532
533 #define SK(x)           ((u8) ((x) >> 16))      // Sense Key byte, etc.
534 #define ASC(x)          ((u8) ((x) >> 8))
535 #define ASCQ(x)         ((u8) (x))
536
537
538 /*-------------------------------------------------------------------------*/
539
540 /*
541  * These definitions will permit the compiler to avoid generating code for
542  * parts of the driver that aren't used in the non-TEST version.  Even gcc
543  * can recognize when a test of a constant expression yields a dead code
544  * path.
545  */
546
547 #ifdef CONFIG_USB_FILE_STORAGE_TEST
548
549 #define transport_is_bbb()      (mod_data.transport_type == USB_PR_BULK)
550 #define transport_is_cbi()      (mod_data.transport_type == USB_PR_CBI)
551 #define protocol_is_scsi()      (mod_data.protocol_type == USB_SC_SCSI)
552
553 #else
554
555 #define transport_is_bbb()      1
556 #define transport_is_cbi()      0
557 #define protocol_is_scsi()      1
558
559 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
560
561
562 struct lun {
563         struct file     *filp;
564         loff_t          file_length;
565         loff_t          num_sectors;
566
567         unsigned int    ro : 1;
568         unsigned int    prevent_medium_removal : 1;
569         unsigned int    registered : 1;
570         unsigned int    info_valid : 1;
571
572         u32             sense_data;
573         u32             sense_data_info;
574         u32             unit_attention_data;
575
576         struct device   dev;
577 };
578
579 #define backing_file_is_open(curlun)    ((curlun)->filp != NULL)
580
581 static inline struct lun *dev_to_lun(struct device *dev)
582 {
583         return container_of(dev, struct lun, dev);
584 }
585
586
587 /* Big enough to hold our biggest descriptor */
588 #define EP0_BUFSIZE     256
589 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     // An impossibly large value
590
591 /* Number of buffers we will use.  2 is enough for double-buffering */
592 #define NUM_BUFFERS     2
593
594 enum fsg_buffer_state {
595         BUF_STATE_EMPTY = 0,
596         BUF_STATE_FULL,
597         BUF_STATE_BUSY
598 };
599
600 struct fsg_buffhd {
601         void                            *buf;
602         dma_addr_t                      dma;
603         enum fsg_buffer_state           state;
604         struct fsg_buffhd               *next;
605
606         /* The NetChip 2280 is faster, and handles some protocol faults
607          * better, if we don't submit any short bulk-out read requests.
608          * So we will record the intended request length here. */
609         unsigned int                    bulk_out_intended_length;
610
611         struct usb_request              *inreq;
612         int                             inreq_busy;
613         struct usb_request              *outreq;
614         int                             outreq_busy;
615 };
616
617 enum fsg_state {
618         FSG_STATE_COMMAND_PHASE = -10,          // This one isn't used anywhere
619         FSG_STATE_DATA_PHASE,
620         FSG_STATE_STATUS_PHASE,
621
622         FSG_STATE_IDLE = 0,
623         FSG_STATE_ABORT_BULK_OUT,
624         FSG_STATE_RESET,
625         FSG_STATE_INTERFACE_CHANGE,
626         FSG_STATE_CONFIG_CHANGE,
627         FSG_STATE_DISCONNECT,
628         FSG_STATE_EXIT,
629         FSG_STATE_TERMINATED
630 };
631
632 enum data_direction {
633         DATA_DIR_UNKNOWN = 0,
634         DATA_DIR_FROM_HOST,
635         DATA_DIR_TO_HOST,
636         DATA_DIR_NONE
637 };
638
639 struct fsg_dev {
640         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
641         spinlock_t              lock;
642         struct usb_gadget       *gadget;
643
644         /* filesem protects: backing files in use */
645         struct rw_semaphore     filesem;
646
647         /* reference counting: wait until all LUNs are released */
648         struct kref             ref;
649
650         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
651         struct usb_request      *ep0req;        // For control responses
652         unsigned int            ep0_req_tag;
653         const char              *ep0req_name;
654
655         struct usb_request      *intreq;        // For interrupt responses
656         int                     intreq_busy;
657         struct fsg_buffhd       *intr_buffhd;
658
659         unsigned int            bulk_out_maxpacket;
660         enum fsg_state          state;          // For exception handling
661         unsigned int            exception_req_tag;
662
663         u8                      config, new_config;
664
665         unsigned int            running : 1;
666         unsigned int            bulk_in_enabled : 1;
667         unsigned int            bulk_out_enabled : 1;
668         unsigned int            intr_in_enabled : 1;
669         unsigned int            phase_error : 1;
670         unsigned int            short_packet_received : 1;
671         unsigned int            bad_lun_okay : 1;
672
673         unsigned long           atomic_bitflags;
674 #define REGISTERED              0
675 #define CLEAR_BULK_HALTS        1
676 #define SUSPENDED               2
677
678         struct usb_ep           *bulk_in;
679         struct usb_ep           *bulk_out;
680         struct usb_ep           *intr_in;
681
682         struct fsg_buffhd       *next_buffhd_to_fill;
683         struct fsg_buffhd       *next_buffhd_to_drain;
684         struct fsg_buffhd       buffhds[NUM_BUFFERS];
685
686         int                     thread_wakeup_needed;
687         struct completion       thread_notifier;
688         struct task_struct      *thread_task;
689         sigset_t                thread_signal_mask;
690
691         int                     cmnd_size;
692         u8                      cmnd[MAX_COMMAND_SIZE];
693         enum data_direction     data_dir;
694         u32                     data_size;
695         u32                     data_size_from_cmnd;
696         u32                     tag;
697         unsigned int            lun;
698         u32                     residue;
699         u32                     usb_amount_left;
700
701         /* The CB protocol offers no way for a host to know when a command
702          * has completed.  As a result the next command may arrive early,
703          * and we will still have to handle it.  For that reason we need
704          * a buffer to store new commands when using CB (or CBI, which
705          * does not oblige a host to wait for command completion either). */
706         int                     cbbuf_cmnd_size;
707         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
708
709         unsigned int            nluns;
710         struct lun              *luns;
711         struct lun              *curlun;
712 };
713
714 typedef void (*fsg_routine_t)(struct fsg_dev *);
715
716 static int inline exception_in_progress(struct fsg_dev *fsg)
717 {
718         return (fsg->state > FSG_STATE_IDLE);
719 }
720
721 /* Make bulk-out requests be divisible by the maxpacket size */
722 static void inline set_bulk_out_req_length(struct fsg_dev *fsg,
723                 struct fsg_buffhd *bh, unsigned int length)
724 {
725         unsigned int    rem;
726
727         bh->bulk_out_intended_length = length;
728         rem = length % fsg->bulk_out_maxpacket;
729         if (rem > 0)
730                 length += fsg->bulk_out_maxpacket - rem;
731         bh->outreq->length = length;
732 }
733
734 static struct fsg_dev                   *the_fsg;
735 static struct usb_gadget_driver         fsg_driver;
736
737 static void     close_backing_file(struct lun *curlun);
738 static void     close_all_backing_files(struct fsg_dev *fsg);
739
740
741 /*-------------------------------------------------------------------------*/
742
743 #ifdef DUMP_MSGS
744
745 static void dump_msg(struct fsg_dev *fsg, const char *label,
746                 const u8 *buf, unsigned int length)
747 {
748         unsigned int    start, num, i;
749         char            line[52], *p;
750
751         if (length >= 512)
752                 return;
753         DBG(fsg, "%s, length %u:\n", label, length);
754
755         start = 0;
756         while (length > 0) {
757                 num = min(length, 16u);
758                 p = line;
759                 for (i = 0; i < num; ++i) {
760                         if (i == 8)
761                                 *p++ = ' ';
762                         sprintf(p, " %02x", buf[i]);
763                         p += 3;
764                 }
765                 *p = 0;
766                 printk(KERN_DEBUG "%6x: %s\n", start, line);
767                 buf += num;
768                 start += num;
769                 length -= num;
770         }
771 }
772
773 static void inline dump_cdb(struct fsg_dev *fsg)
774 {}
775
776 #else
777
778 static void inline dump_msg(struct fsg_dev *fsg, const char *label,
779                 const u8 *buf, unsigned int length)
780 {}
781
782 static void inline dump_cdb(struct fsg_dev *fsg)
783 {
784         int     i;
785         char    cmdbuf[3*MAX_COMMAND_SIZE + 1];
786
787         for (i = 0; i < fsg->cmnd_size; ++i)
788                 sprintf(cmdbuf + i*3, " %02x", fsg->cmnd[i]);
789         VDBG(fsg, "SCSI CDB: %s\n", cmdbuf);
790 }
791
792 #endif /* DUMP_MSGS */
793
794
795 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
796 {
797         const char      *name;
798
799         if (ep == fsg->bulk_in)
800                 name = "bulk-in";
801         else if (ep == fsg->bulk_out)
802                 name = "bulk-out";
803         else
804                 name = ep->name;
805         DBG(fsg, "%s set halt\n", name);
806         return usb_ep_set_halt(ep);
807 }
808
809
810 /*-------------------------------------------------------------------------*/
811
812 /* Routines for unaligned data access */
813
814 static u16 inline get_be16(u8 *buf)
815 {
816         return ((u16) buf[0] << 8) | ((u16) buf[1]);
817 }
818
819 static u32 inline get_be32(u8 *buf)
820 {
821         return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) |
822                         ((u32) buf[2] << 8) | ((u32) buf[3]);
823 }
824
825 static void inline put_be16(u8 *buf, u16 val)
826 {
827         buf[0] = val >> 8;
828         buf[1] = val;
829 }
830
831 static void inline put_be32(u8 *buf, u32 val)
832 {
833         buf[0] = val >> 24;
834         buf[1] = val >> 16;
835         buf[2] = val >> 8;
836         buf[3] = val & 0xff;
837 }
838
839
840 /*-------------------------------------------------------------------------*/
841
842 /*
843  * DESCRIPTORS ... most are static, but strings and (full) configuration
844  * descriptors are built on demand.  Also the (static) config and interface
845  * descriptors are adjusted during fsg_bind().
846  */
847 #define STRING_MANUFACTURER     1
848 #define STRING_PRODUCT          2
849 #define STRING_SERIAL           3
850 #define STRING_CONFIG           4
851 #define STRING_INTERFACE        5
852
853 /* There is only one configuration. */
854 #define CONFIG_VALUE            1
855
856 static struct usb_device_descriptor
857 device_desc = {
858         .bLength =              sizeof device_desc,
859         .bDescriptorType =      USB_DT_DEVICE,
860
861         .bcdUSB =               __constant_cpu_to_le16(0x0200),
862         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
863
864         /* The next three values can be overridden by module parameters */
865         .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_ID),
866         .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
867         .bcdDevice =            __constant_cpu_to_le16(0xffff),
868
869         .iManufacturer =        STRING_MANUFACTURER,
870         .iProduct =             STRING_PRODUCT,
871         .iSerialNumber =        STRING_SERIAL,
872         .bNumConfigurations =   1,
873 };
874
875 static struct usb_config_descriptor
876 config_desc = {
877         .bLength =              sizeof config_desc,
878         .bDescriptorType =      USB_DT_CONFIG,
879
880         /* wTotalLength computed by usb_gadget_config_buf() */
881         .bNumInterfaces =       1,
882         .bConfigurationValue =  CONFIG_VALUE,
883         .iConfiguration =       STRING_CONFIG,
884         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
885         .bMaxPower =            1,      // self-powered
886 };
887
888 static struct usb_otg_descriptor
889 otg_desc = {
890         .bLength =              sizeof(otg_desc),
891         .bDescriptorType =      USB_DT_OTG,
892
893         .bmAttributes =         USB_OTG_SRP,
894 };
895
896 /* There is only one interface. */
897
898 static struct usb_interface_descriptor
899 intf_desc = {
900         .bLength =              sizeof intf_desc,
901         .bDescriptorType =      USB_DT_INTERFACE,
902
903         .bNumEndpoints =        2,              // Adjusted during fsg_bind()
904         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
905         .bInterfaceSubClass =   USB_SC_SCSI,    // Adjusted during fsg_bind()
906         .bInterfaceProtocol =   USB_PR_BULK,    // Adjusted during fsg_bind()
907         .iInterface =           STRING_INTERFACE,
908 };
909
910 /* Three full-speed endpoint descriptors: bulk-in, bulk-out,
911  * and interrupt-in. */
912
913 static struct usb_endpoint_descriptor
914 fs_bulk_in_desc = {
915         .bLength =              USB_DT_ENDPOINT_SIZE,
916         .bDescriptorType =      USB_DT_ENDPOINT,
917
918         .bEndpointAddress =     USB_DIR_IN,
919         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
920         /* wMaxPacketSize set by autoconfiguration */
921 };
922
923 static struct usb_endpoint_descriptor
924 fs_bulk_out_desc = {
925         .bLength =              USB_DT_ENDPOINT_SIZE,
926         .bDescriptorType =      USB_DT_ENDPOINT,
927
928         .bEndpointAddress =     USB_DIR_OUT,
929         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
930         /* wMaxPacketSize set by autoconfiguration */
931 };
932
933 static struct usb_endpoint_descriptor
934 fs_intr_in_desc = {
935         .bLength =              USB_DT_ENDPOINT_SIZE,
936         .bDescriptorType =      USB_DT_ENDPOINT,
937
938         .bEndpointAddress =     USB_DIR_IN,
939         .bmAttributes =         USB_ENDPOINT_XFER_INT,
940         .wMaxPacketSize =       __constant_cpu_to_le16(2),
941         .bInterval =            32,     // frames -> 32 ms
942 };
943
944 static const struct usb_descriptor_header *fs_function[] = {
945         (struct usb_descriptor_header *) &otg_desc,
946         (struct usb_descriptor_header *) &intf_desc,
947         (struct usb_descriptor_header *) &fs_bulk_in_desc,
948         (struct usb_descriptor_header *) &fs_bulk_out_desc,
949         (struct usb_descriptor_header *) &fs_intr_in_desc,
950         NULL,
951 };
952 #define FS_FUNCTION_PRE_EP_ENTRIES      2
953
954
955 #ifdef  CONFIG_USB_GADGET_DUALSPEED
956
957 /*
958  * USB 2.0 devices need to expose both high speed and full speed
959  * descriptors, unless they only run at full speed.
960  *
961  * That means alternate endpoint descriptors (bigger packets)
962  * and a "device qualifier" ... plus more construction options
963  * for the config descriptor.
964  */
965 static struct usb_qualifier_descriptor
966 dev_qualifier = {
967         .bLength =              sizeof dev_qualifier,
968         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
969
970         .bcdUSB =               __constant_cpu_to_le16(0x0200),
971         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
972
973         .bNumConfigurations =   1,
974 };
975
976 static struct usb_endpoint_descriptor
977 hs_bulk_in_desc = {
978         .bLength =              USB_DT_ENDPOINT_SIZE,
979         .bDescriptorType =      USB_DT_ENDPOINT,
980
981         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
982         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
983         .wMaxPacketSize =       __constant_cpu_to_le16(512),
984 };
985
986 static struct usb_endpoint_descriptor
987 hs_bulk_out_desc = {
988         .bLength =              USB_DT_ENDPOINT_SIZE,
989         .bDescriptorType =      USB_DT_ENDPOINT,
990
991         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
992         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
993         .wMaxPacketSize =       __constant_cpu_to_le16(512),
994         .bInterval =            1,      // NAK every 1 uframe
995 };
996
997 static struct usb_endpoint_descriptor
998 hs_intr_in_desc = {
999         .bLength =              USB_DT_ENDPOINT_SIZE,
1000         .bDescriptorType =      USB_DT_ENDPOINT,
1001
1002         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
1003         .bmAttributes =         USB_ENDPOINT_XFER_INT,
1004         .wMaxPacketSize =       __constant_cpu_to_le16(2),
1005         .bInterval =            9,      // 2**(9-1) = 256 uframes -> 32 ms
1006 };
1007
1008 static const struct usb_descriptor_header *hs_function[] = {
1009         (struct usb_descriptor_header *) &otg_desc,
1010         (struct usb_descriptor_header *) &intf_desc,
1011         (struct usb_descriptor_header *) &hs_bulk_in_desc,
1012         (struct usb_descriptor_header *) &hs_bulk_out_desc,
1013         (struct usb_descriptor_header *) &hs_intr_in_desc,
1014         NULL,
1015 };
1016 #define HS_FUNCTION_PRE_EP_ENTRIES      2
1017
1018 /* Maxpacket and other transfer characteristics vary by speed. */
1019 #define ep_desc(g,fs,hs)        (((g)->speed==USB_SPEED_HIGH) ? (hs) : (fs))
1020
1021 #else
1022
1023 /* If there's no high speed support, always use the full-speed descriptor. */
1024 #define ep_desc(g,fs,hs)        fs
1025
1026 #endif  /* !CONFIG_USB_GADGET_DUALSPEED */
1027
1028
1029 /* The CBI specification limits the serial string to 12 uppercase hexadecimal
1030  * characters. */
1031 static char                             manufacturer[64];
1032 static char                             serial[13];
1033
1034 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
1035 static struct usb_string                strings[] = {
1036         {STRING_MANUFACTURER,   manufacturer},
1037         {STRING_PRODUCT,        longname},
1038         {STRING_SERIAL,         serial},
1039         {STRING_CONFIG,         "Self-powered"},
1040         {STRING_INTERFACE,      "Mass Storage"},
1041         {}
1042 };
1043
1044 static struct usb_gadget_strings        stringtab = {
1045         .language       = 0x0409,               // en-us
1046         .strings        = strings,
1047 };
1048
1049
1050 /*
1051  * Config descriptors must agree with the code that sets configurations
1052  * and with code managing interfaces and their altsettings.  They must
1053  * also handle different speeds and other-speed requests.
1054  */
1055 static int populate_config_buf(struct usb_gadget *gadget,
1056                 u8 *buf, u8 type, unsigned index)
1057 {
1058 #ifdef CONFIG_USB_GADGET_DUALSPEED
1059         enum usb_device_speed                   speed = gadget->speed;
1060 #endif
1061         int                                     len;
1062         const struct usb_descriptor_header      **function;
1063
1064         if (index > 0)
1065                 return -EINVAL;
1066
1067 #ifdef CONFIG_USB_GADGET_DUALSPEED
1068         if (type == USB_DT_OTHER_SPEED_CONFIG)
1069                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
1070         if (speed == USB_SPEED_HIGH)
1071                 function = hs_function;
1072         else
1073 #endif
1074                 function = fs_function;
1075
1076         /* for now, don't advertise srp-only devices */
1077         if (!gadget->is_otg)
1078                 function++;
1079
1080         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
1081         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
1082         return len;
1083 }
1084
1085
1086 /*-------------------------------------------------------------------------*/
1087
1088 /* These routines may be called in process context or in_irq */
1089
1090 /* Caller must hold fsg->lock */
1091 static void wakeup_thread(struct fsg_dev *fsg)
1092 {
1093         /* Tell the main thread that something has happened */
1094         fsg->thread_wakeup_needed = 1;
1095         if (fsg->thread_task)
1096                 wake_up_process(fsg->thread_task);
1097 }
1098
1099
1100 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
1101 {
1102         unsigned long           flags;
1103
1104         /* Do nothing if a higher-priority exception is already in progress.
1105          * If a lower-or-equal priority exception is in progress, preempt it
1106          * and notify the main thread by sending it a signal. */
1107         spin_lock_irqsave(&fsg->lock, flags);
1108         if (fsg->state <= new_state) {
1109                 fsg->exception_req_tag = fsg->ep0_req_tag;
1110                 fsg->state = new_state;
1111                 if (fsg->thread_task)
1112                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
1113                                         fsg->thread_task);
1114         }
1115         spin_unlock_irqrestore(&fsg->lock, flags);
1116 }
1117
1118
1119 /*-------------------------------------------------------------------------*/
1120
1121 /* The disconnect callback and ep0 routines.  These always run in_irq,
1122  * except that ep0_queue() is called in the main thread to acknowledge
1123  * completion of various requests: set config, set interface, and
1124  * Bulk-only device reset. */
1125
1126 static void fsg_disconnect(struct usb_gadget *gadget)
1127 {
1128         struct fsg_dev          *fsg = get_gadget_data(gadget);
1129
1130         DBG(fsg, "disconnect or port reset\n");
1131         raise_exception(fsg, FSG_STATE_DISCONNECT);
1132 }
1133
1134
1135 static int ep0_queue(struct fsg_dev *fsg)
1136 {
1137         int     rc;
1138
1139         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
1140         if (rc != 0 && rc != -ESHUTDOWN) {
1141
1142                 /* We can't do much more than wait for a reset */
1143                 WARN(fsg, "error in submission: %s --> %d\n",
1144                                 fsg->ep0->name, rc);
1145         }
1146         return rc;
1147 }
1148
1149 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
1150 {
1151         struct fsg_dev          *fsg = ep->driver_data;
1152
1153         if (req->actual > 0)
1154                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
1155         if (req->status || req->actual != req->length)
1156                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1157                                 req->status, req->actual, req->length);
1158         if (req->status == -ECONNRESET)         // Request was cancelled
1159                 usb_ep_fifo_flush(ep);
1160
1161         if (req->status == 0 && req->context)
1162                 ((fsg_routine_t) (req->context))(fsg);
1163 }
1164
1165
1166 /*-------------------------------------------------------------------------*/
1167
1168 /* Bulk and interrupt endpoint completion handlers.
1169  * These always run in_irq. */
1170
1171 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
1172 {
1173         struct fsg_dev          *fsg = ep->driver_data;
1174         struct fsg_buffhd       *bh = req->context;
1175
1176         if (req->status || req->actual != req->length)
1177                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1178                                 req->status, req->actual, req->length);
1179         if (req->status == -ECONNRESET)         // Request was cancelled
1180                 usb_ep_fifo_flush(ep);
1181
1182         /* Hold the lock while we update the request and buffer states */
1183         smp_wmb();
1184         spin_lock(&fsg->lock);
1185         bh->inreq_busy = 0;
1186         bh->state = BUF_STATE_EMPTY;
1187         wakeup_thread(fsg);
1188         spin_unlock(&fsg->lock);
1189 }
1190
1191 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
1192 {
1193         struct fsg_dev          *fsg = ep->driver_data;
1194         struct fsg_buffhd       *bh = req->context;
1195
1196         dump_msg(fsg, "bulk-out", req->buf, req->actual);
1197         if (req->status || req->actual != bh->bulk_out_intended_length)
1198                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1199                                 req->status, req->actual,
1200                                 bh->bulk_out_intended_length);
1201         if (req->status == -ECONNRESET)         // Request was cancelled
1202                 usb_ep_fifo_flush(ep);
1203
1204         /* Hold the lock while we update the request and buffer states */
1205         smp_wmb();
1206         spin_lock(&fsg->lock);
1207         bh->outreq_busy = 0;
1208         bh->state = BUF_STATE_FULL;
1209         wakeup_thread(fsg);
1210         spin_unlock(&fsg->lock);
1211 }
1212
1213
1214 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1215 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1216 {
1217         struct fsg_dev          *fsg = ep->driver_data;
1218         struct fsg_buffhd       *bh = req->context;
1219
1220         if (req->status || req->actual != req->length)
1221                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1222                                 req->status, req->actual, req->length);
1223         if (req->status == -ECONNRESET)         // Request was cancelled
1224                 usb_ep_fifo_flush(ep);
1225
1226         /* Hold the lock while we update the request and buffer states */
1227         smp_wmb();
1228         spin_lock(&fsg->lock);
1229         fsg->intreq_busy = 0;
1230         bh->state = BUF_STATE_EMPTY;
1231         wakeup_thread(fsg);
1232         spin_unlock(&fsg->lock);
1233 }
1234
1235 #else
1236 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1237 {}
1238 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1239
1240
1241 /*-------------------------------------------------------------------------*/
1242
1243 /* Ep0 class-specific handlers.  These always run in_irq. */
1244
1245 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1246 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1247 {
1248         struct usb_request      *req = fsg->ep0req;
1249         static u8               cbi_reset_cmnd[6] = {
1250                         SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
1251
1252         /* Error in command transfer? */
1253         if (req->status || req->length != req->actual ||
1254                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
1255
1256                 /* Not all controllers allow a protocol stall after
1257                  * receiving control-out data, but we'll try anyway. */
1258                 fsg_set_halt(fsg, fsg->ep0);
1259                 return;                 // Wait for reset
1260         }
1261
1262         /* Is it the special reset command? */
1263         if (req->actual >= sizeof cbi_reset_cmnd &&
1264                         memcmp(req->buf, cbi_reset_cmnd,
1265                                 sizeof cbi_reset_cmnd) == 0) {
1266
1267                 /* Raise an exception to stop the current operation
1268                  * and reinitialize our state. */
1269                 DBG(fsg, "cbi reset request\n");
1270                 raise_exception(fsg, FSG_STATE_RESET);
1271                 return;
1272         }
1273
1274         VDBG(fsg, "CB[I] accept device-specific command\n");
1275         spin_lock(&fsg->lock);
1276
1277         /* Save the command for later */
1278         if (fsg->cbbuf_cmnd_size)
1279                 WARN(fsg, "CB[I] overwriting previous command\n");
1280         fsg->cbbuf_cmnd_size = req->actual;
1281         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
1282
1283         wakeup_thread(fsg);
1284         spin_unlock(&fsg->lock);
1285 }
1286
1287 #else
1288 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1289 {}
1290 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1291
1292
1293 static int class_setup_req(struct fsg_dev *fsg,
1294                 const struct usb_ctrlrequest *ctrl)
1295 {
1296         struct usb_request      *req = fsg->ep0req;
1297         int                     value = -EOPNOTSUPP;
1298         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1299         u16                     w_length = le16_to_cpu(ctrl->wLength);
1300
1301         if (!fsg->config)
1302                 return value;
1303
1304         /* Handle Bulk-only class-specific requests */
1305         if (transport_is_bbb()) {
1306                 switch (ctrl->bRequest) {
1307
1308                 case USB_BULK_RESET_REQUEST:
1309                         if (ctrl->bRequestType != (USB_DIR_OUT |
1310                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1311                                 break;
1312                         if (w_index != 0) {
1313                                 value = -EDOM;
1314                                 break;
1315                         }
1316
1317                         /* Raise an exception to stop the current operation
1318                          * and reinitialize our state. */
1319                         DBG(fsg, "bulk reset request\n");
1320                         raise_exception(fsg, FSG_STATE_RESET);
1321                         value = DELAYED_STATUS;
1322                         break;
1323
1324                 case USB_BULK_GET_MAX_LUN_REQUEST:
1325                         if (ctrl->bRequestType != (USB_DIR_IN |
1326                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1327                                 break;
1328                         if (w_index != 0) {
1329                                 value = -EDOM;
1330                                 break;
1331                         }
1332                         VDBG(fsg, "get max LUN\n");
1333                         *(u8 *) req->buf = fsg->nluns - 1;
1334                         value = 1;
1335                         break;
1336                 }
1337         }
1338
1339         /* Handle CBI class-specific requests */
1340         else {
1341                 switch (ctrl->bRequest) {
1342
1343                 case USB_CBI_ADSC_REQUEST:
1344                         if (ctrl->bRequestType != (USB_DIR_OUT |
1345                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1346                                 break;
1347                         if (w_index != 0) {
1348                                 value = -EDOM;
1349                                 break;
1350                         }
1351                         if (w_length > MAX_COMMAND_SIZE) {
1352                                 value = -EOVERFLOW;
1353                                 break;
1354                         }
1355                         value = w_length;
1356                         fsg->ep0req->context = received_cbi_adsc;
1357                         break;
1358                 }
1359         }
1360
1361         if (value == -EOPNOTSUPP)
1362                 VDBG(fsg,
1363                         "unknown class-specific control req "
1364                         "%02x.%02x v%04x i%04x l%u\n",
1365                         ctrl->bRequestType, ctrl->bRequest,
1366                         le16_to_cpu(ctrl->wValue), w_index, w_length);
1367         return value;
1368 }
1369
1370
1371 /*-------------------------------------------------------------------------*/
1372
1373 /* Ep0 standard request handlers.  These always run in_irq. */
1374
1375 static int standard_setup_req(struct fsg_dev *fsg,
1376                 const struct usb_ctrlrequest *ctrl)
1377 {
1378         struct usb_request      *req = fsg->ep0req;
1379         int                     value = -EOPNOTSUPP;
1380         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1381         u16                     w_value = le16_to_cpu(ctrl->wValue);
1382
1383         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
1384          * but config change events will also reconfigure hardware. */
1385         switch (ctrl->bRequest) {
1386
1387         case USB_REQ_GET_DESCRIPTOR:
1388                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1389                                 USB_RECIP_DEVICE))
1390                         break;
1391                 switch (w_value >> 8) {
1392
1393                 case USB_DT_DEVICE:
1394                         VDBG(fsg, "get device descriptor\n");
1395                         value = sizeof device_desc;
1396                         memcpy(req->buf, &device_desc, value);
1397                         break;
1398 #ifdef CONFIG_USB_GADGET_DUALSPEED
1399                 case USB_DT_DEVICE_QUALIFIER:
1400                         VDBG(fsg, "get device qualifier\n");
1401                         if (!fsg->gadget->is_dualspeed)
1402                                 break;
1403                         value = sizeof dev_qualifier;
1404                         memcpy(req->buf, &dev_qualifier, value);
1405                         break;
1406
1407                 case USB_DT_OTHER_SPEED_CONFIG:
1408                         VDBG(fsg, "get other-speed config descriptor\n");
1409                         if (!fsg->gadget->is_dualspeed)
1410                                 break;
1411                         goto get_config;
1412 #endif
1413                 case USB_DT_CONFIG:
1414                         VDBG(fsg, "get configuration descriptor\n");
1415 #ifdef CONFIG_USB_GADGET_DUALSPEED
1416                 get_config:
1417 #endif
1418                         value = populate_config_buf(fsg->gadget,
1419                                         req->buf,
1420                                         w_value >> 8,
1421                                         w_value & 0xff);
1422                         break;
1423
1424                 case USB_DT_STRING:
1425                         VDBG(fsg, "get string descriptor\n");
1426
1427                         /* wIndex == language code */
1428                         value = usb_gadget_get_string(&stringtab,
1429                                         w_value & 0xff, req->buf);
1430                         break;
1431                 }
1432                 break;
1433
1434         /* One config, two speeds */
1435         case USB_REQ_SET_CONFIGURATION:
1436                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
1437                                 USB_RECIP_DEVICE))
1438                         break;
1439                 VDBG(fsg, "set configuration\n");
1440                 if (w_value == CONFIG_VALUE || w_value == 0) {
1441                         fsg->new_config = w_value;
1442
1443                         /* Raise an exception to wipe out previous transaction
1444                          * state (queued bufs, etc) and set the new config. */
1445                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
1446                         value = DELAYED_STATUS;
1447                 }
1448                 break;
1449         case USB_REQ_GET_CONFIGURATION:
1450                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1451                                 USB_RECIP_DEVICE))
1452                         break;
1453                 VDBG(fsg, "get configuration\n");
1454                 *(u8 *) req->buf = fsg->config;
1455                 value = 1;
1456                 break;
1457
1458         case USB_REQ_SET_INTERFACE:
1459                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
1460                                 USB_RECIP_INTERFACE))
1461                         break;
1462                 if (fsg->config && w_index == 0) {
1463
1464                         /* Raise an exception to wipe out previous transaction
1465                          * state (queued bufs, etc) and install the new
1466                          * interface altsetting. */
1467                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
1468                         value = DELAYED_STATUS;
1469                 }
1470                 break;
1471         case USB_REQ_GET_INTERFACE:
1472                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1473                                 USB_RECIP_INTERFACE))
1474                         break;
1475                 if (!fsg->config)
1476                         break;
1477                 if (w_index != 0) {
1478                         value = -EDOM;
1479                         break;
1480                 }
1481                 VDBG(fsg, "get interface\n");
1482                 *(u8 *) req->buf = 0;
1483                 value = 1;
1484                 break;
1485
1486         default:
1487                 VDBG(fsg,
1488                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1489                         ctrl->bRequestType, ctrl->bRequest,
1490                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1491         }
1492
1493         return value;
1494 }
1495
1496
1497 static int fsg_setup(struct usb_gadget *gadget,
1498                 const struct usb_ctrlrequest *ctrl)
1499 {
1500         struct fsg_dev          *fsg = get_gadget_data(gadget);
1501         int                     rc;
1502         int                     w_length = le16_to_cpu(ctrl->wLength);
1503
1504         ++fsg->ep0_req_tag;             // Record arrival of a new request
1505         fsg->ep0req->context = NULL;
1506         fsg->ep0req->length = 0;
1507         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1508
1509         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1510                 rc = class_setup_req(fsg, ctrl);
1511         else
1512                 rc = standard_setup_req(fsg, ctrl);
1513
1514         /* Respond with data/status or defer until later? */
1515         if (rc >= 0 && rc != DELAYED_STATUS) {
1516                 rc = min(rc, w_length);
1517                 fsg->ep0req->length = rc;
1518                 fsg->ep0req->zero = rc < w_length;
1519                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1520                                 "ep0-in" : "ep0-out");
1521                 rc = ep0_queue(fsg);
1522         }
1523
1524         /* Device either stalls (rc < 0) or reports success */
1525         return rc;
1526 }
1527
1528
1529 /*-------------------------------------------------------------------------*/
1530
1531 /* All the following routines run in process context */
1532
1533
1534 /* Use this for bulk or interrupt transfers, not ep0 */
1535 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1536                 struct usb_request *req, int *pbusy,
1537                 enum fsg_buffer_state *state)
1538 {
1539         int     rc;
1540
1541         if (ep == fsg->bulk_in)
1542                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1543         else if (ep == fsg->intr_in)
1544                 dump_msg(fsg, "intr-in", req->buf, req->length);
1545
1546         spin_lock_irq(&fsg->lock);
1547         *pbusy = 1;
1548         *state = BUF_STATE_BUSY;
1549         spin_unlock_irq(&fsg->lock);
1550         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1551         if (rc != 0) {
1552                 *pbusy = 0;
1553                 *state = BUF_STATE_EMPTY;
1554
1555                 /* We can't do much more than wait for a reset */
1556
1557                 /* Note: currently the net2280 driver fails zero-length
1558                  * submissions if DMA is enabled. */
1559                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1560                                                 req->length == 0))
1561                         WARN(fsg, "error in submission: %s --> %d\n",
1562                                         ep->name, rc);
1563         }
1564 }
1565
1566
1567 static int sleep_thread(struct fsg_dev *fsg)
1568 {
1569         int     rc = 0;
1570
1571         /* Wait until a signal arrives or we are woken up */
1572         for (;;) {
1573                 try_to_freeze();
1574                 set_current_state(TASK_INTERRUPTIBLE);
1575                 if (signal_pending(current)) {
1576                         rc = -EINTR;
1577                         break;
1578                 }
1579                 if (fsg->thread_wakeup_needed)
1580                         break;
1581                 schedule();
1582         }
1583         __set_current_state(TASK_RUNNING);
1584         fsg->thread_wakeup_needed = 0;
1585         return rc;
1586 }
1587
1588
1589 /*-------------------------------------------------------------------------*/
1590
1591 static int do_read(struct fsg_dev *fsg)
1592 {
1593         struct lun              *curlun = fsg->curlun;
1594         u32                     lba;
1595         struct fsg_buffhd       *bh;
1596         int                     rc;
1597         u32                     amount_left;
1598         loff_t                  file_offset, file_offset_tmp;
1599         unsigned int            amount;
1600         unsigned int            partial_page;
1601         ssize_t                 nread;
1602
1603         /* Get the starting Logical Block Address and check that it's
1604          * not too big */
1605         if (fsg->cmnd[0] == SC_READ_6)
1606                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1607         else {
1608                 lba = get_be32(&fsg->cmnd[2]);
1609
1610                 /* We allow DPO (Disable Page Out = don't save data in the
1611                  * cache) and FUA (Force Unit Access = don't read from the
1612                  * cache), but we don't implement them. */
1613                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1614                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1615                         return -EINVAL;
1616                 }
1617         }
1618         if (lba >= curlun->num_sectors) {
1619                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1620                 return -EINVAL;
1621         }
1622         file_offset = ((loff_t) lba) << 9;
1623
1624         /* Carry out the file reads */
1625         amount_left = fsg->data_size_from_cmnd;
1626         if (unlikely(amount_left == 0))
1627                 return -EIO;            // No default reply
1628
1629         for (;;) {
1630
1631                 /* Figure out how much we need to read:
1632                  * Try to read the remaining amount.
1633                  * But don't read more than the buffer size.
1634                  * And don't try to read past the end of the file.
1635                  * Finally, if we're not at a page boundary, don't read past
1636                  *      the next page.
1637                  * If this means reading 0 then we were asked to read past
1638                  *      the end of file. */
1639                 amount = min((unsigned int) amount_left, mod_data.buflen);
1640                 amount = min((loff_t) amount,
1641                                 curlun->file_length - file_offset);
1642                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1643                 if (partial_page > 0)
1644                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1645                                         partial_page);
1646
1647                 /* Wait for the next buffer to become available */
1648                 bh = fsg->next_buffhd_to_fill;
1649                 while (bh->state != BUF_STATE_EMPTY) {
1650                         if ((rc = sleep_thread(fsg)) != 0)
1651                                 return rc;
1652                 }
1653
1654                 /* If we were asked to read past the end of file,
1655                  * end with an empty buffer. */
1656                 if (amount == 0) {
1657                         curlun->sense_data =
1658                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1659                         curlun->sense_data_info = file_offset >> 9;
1660                         curlun->info_valid = 1;
1661                         bh->inreq->length = 0;
1662                         bh->state = BUF_STATE_FULL;
1663                         break;
1664                 }
1665
1666                 /* Perform the read */
1667                 file_offset_tmp = file_offset;
1668                 nread = vfs_read(curlun->filp,
1669                                 (char __user *) bh->buf,
1670                                 amount, &file_offset_tmp);
1671                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1672                                 (unsigned long long) file_offset,
1673                                 (int) nread);
1674                 if (signal_pending(current))
1675                         return -EINTR;
1676
1677                 if (nread < 0) {
1678                         LDBG(curlun, "error in file read: %d\n",
1679                                         (int) nread);
1680                         nread = 0;
1681                 } else if (nread < amount) {
1682                         LDBG(curlun, "partial file read: %d/%u\n",
1683                                         (int) nread, amount);
1684                         nread -= (nread & 511); // Round down to a block
1685                 }
1686                 file_offset  += nread;
1687                 amount_left  -= nread;
1688                 fsg->residue -= nread;
1689                 bh->inreq->length = nread;
1690                 bh->state = BUF_STATE_FULL;
1691
1692                 /* If an error occurred, report it and its position */
1693                 if (nread < amount) {
1694                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1695                         curlun->sense_data_info = file_offset >> 9;
1696                         curlun->info_valid = 1;
1697                         break;
1698                 }
1699
1700                 if (amount_left == 0)
1701                         break;          // No more left to read
1702
1703                 /* Send this buffer and go read some more */
1704                 bh->inreq->zero = 0;
1705                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1706                                 &bh->inreq_busy, &bh->state);
1707                 fsg->next_buffhd_to_fill = bh->next;
1708         }
1709
1710         return -EIO;            // No default reply
1711 }
1712
1713
1714 /*-------------------------------------------------------------------------*/
1715
1716 static int do_write(struct fsg_dev *fsg)
1717 {
1718         struct lun              *curlun = fsg->curlun;
1719         u32                     lba;
1720         struct fsg_buffhd       *bh;
1721         int                     get_some_more;
1722         u32                     amount_left_to_req, amount_left_to_write;
1723         loff_t                  usb_offset, file_offset, file_offset_tmp;
1724         unsigned int            amount;
1725         unsigned int            partial_page;
1726         ssize_t                 nwritten;
1727         int                     rc;
1728
1729         if (curlun->ro) {
1730                 curlun->sense_data = SS_WRITE_PROTECTED;
1731                 return -EINVAL;
1732         }
1733         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1734
1735         /* Get the starting Logical Block Address and check that it's
1736          * not too big */
1737         if (fsg->cmnd[0] == SC_WRITE_6)
1738                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1739         else {
1740                 lba = get_be32(&fsg->cmnd[2]);
1741
1742                 /* We allow DPO (Disable Page Out = don't save data in the
1743                  * cache) and FUA (Force Unit Access = write directly to the
1744                  * medium).  We don't implement DPO; we implement FUA by
1745                  * performing synchronous output. */
1746                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1747                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1748                         return -EINVAL;
1749                 }
1750                 if (fsg->cmnd[1] & 0x08)        // FUA
1751                         curlun->filp->f_flags |= O_SYNC;
1752         }
1753         if (lba >= curlun->num_sectors) {
1754                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1755                 return -EINVAL;
1756         }
1757
1758         /* Carry out the file writes */
1759         get_some_more = 1;
1760         file_offset = usb_offset = ((loff_t) lba) << 9;
1761         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1762
1763         while (amount_left_to_write > 0) {
1764
1765                 /* Queue a request for more data from the host */
1766                 bh = fsg->next_buffhd_to_fill;
1767                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1768
1769                         /* Figure out how much we want to get:
1770                          * Try to get the remaining amount.
1771                          * But don't get more than the buffer size.
1772                          * And don't try to go past the end of the file.
1773                          * If we're not at a page boundary,
1774                          *      don't go past the next page.
1775                          * If this means getting 0, then we were asked
1776                          *      to write past the end of file.
1777                          * Finally, round down to a block boundary. */
1778                         amount = min(amount_left_to_req, mod_data.buflen);
1779                         amount = min((loff_t) amount, curlun->file_length -
1780                                         usb_offset);
1781                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1782                         if (partial_page > 0)
1783                                 amount = min(amount,
1784         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1785
1786                         if (amount == 0) {
1787                                 get_some_more = 0;
1788                                 curlun->sense_data =
1789                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1790                                 curlun->sense_data_info = usb_offset >> 9;
1791                                 curlun->info_valid = 1;
1792                                 continue;
1793                         }
1794                         amount -= (amount & 511);
1795                         if (amount == 0) {
1796
1797                                 /* Why were we were asked to transfer a
1798                                  * partial block? */
1799                                 get_some_more = 0;
1800                                 continue;
1801                         }
1802
1803                         /* Get the next buffer */
1804                         usb_offset += amount;
1805                         fsg->usb_amount_left -= amount;
1806                         amount_left_to_req -= amount;
1807                         if (amount_left_to_req == 0)
1808                                 get_some_more = 0;
1809
1810                         /* amount is always divisible by 512, hence by
1811                          * the bulk-out maxpacket size */
1812                         bh->outreq->length = bh->bulk_out_intended_length =
1813                                         amount;
1814                         bh->outreq->short_not_ok = 1;
1815                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1816                                         &bh->outreq_busy, &bh->state);
1817                         fsg->next_buffhd_to_fill = bh->next;
1818                         continue;
1819                 }
1820
1821                 /* Write the received data to the backing file */
1822                 bh = fsg->next_buffhd_to_drain;
1823                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1824                         break;                  // We stopped early
1825                 if (bh->state == BUF_STATE_FULL) {
1826                         smp_rmb();
1827                         fsg->next_buffhd_to_drain = bh->next;
1828                         bh->state = BUF_STATE_EMPTY;
1829
1830                         /* Did something go wrong with the transfer? */
1831                         if (bh->outreq->status != 0) {
1832                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1833                                 curlun->sense_data_info = file_offset >> 9;
1834                                 curlun->info_valid = 1;
1835                                 break;
1836                         }
1837
1838                         amount = bh->outreq->actual;
1839                         if (curlun->file_length - file_offset < amount) {
1840                                 LERROR(curlun,
1841         "write %u @ %llu beyond end %llu\n",
1842         amount, (unsigned long long) file_offset,
1843         (unsigned long long) curlun->file_length);
1844                                 amount = curlun->file_length - file_offset;
1845                         }
1846
1847                         /* Perform the write */
1848                         file_offset_tmp = file_offset;
1849                         nwritten = vfs_write(curlun->filp,
1850                                         (char __user *) bh->buf,
1851                                         amount, &file_offset_tmp);
1852                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1853                                         (unsigned long long) file_offset,
1854                                         (int) nwritten);
1855                         if (signal_pending(current))
1856                                 return -EINTR;          // Interrupted!
1857
1858                         if (nwritten < 0) {
1859                                 LDBG(curlun, "error in file write: %d\n",
1860                                                 (int) nwritten);
1861                                 nwritten = 0;
1862                         } else if (nwritten < amount) {
1863                                 LDBG(curlun, "partial file write: %d/%u\n",
1864                                                 (int) nwritten, amount);
1865                                 nwritten -= (nwritten & 511);
1866                                                 // Round down to a block
1867                         }
1868                         file_offset += nwritten;
1869                         amount_left_to_write -= nwritten;
1870                         fsg->residue -= nwritten;
1871
1872                         /* If an error occurred, report it and its position */
1873                         if (nwritten < amount) {
1874                                 curlun->sense_data = SS_WRITE_ERROR;
1875                                 curlun->sense_data_info = file_offset >> 9;
1876                                 curlun->info_valid = 1;
1877                                 break;
1878                         }
1879
1880                         /* Did the host decide to stop early? */
1881                         if (bh->outreq->actual != bh->outreq->length) {
1882                                 fsg->short_packet_received = 1;
1883                                 break;
1884                         }
1885                         continue;
1886                 }
1887
1888                 /* Wait for something to happen */
1889                 if ((rc = sleep_thread(fsg)) != 0)
1890                         return rc;
1891         }
1892
1893         return -EIO;            // No default reply
1894 }
1895
1896
1897 /*-------------------------------------------------------------------------*/
1898
1899 /* Sync the file data, don't bother with the metadata.
1900  * This code was copied from fs/buffer.c:sys_fdatasync(). */
1901 static int fsync_sub(struct lun *curlun)
1902 {
1903         struct file     *filp = curlun->filp;
1904         struct inode    *inode;
1905         int             rc, err;
1906
1907         if (curlun->ro || !filp)
1908                 return 0;
1909         if (!filp->f_op->fsync)
1910                 return -EINVAL;
1911
1912         inode = filp->f_path.dentry->d_inode;
1913         mutex_lock(&inode->i_mutex);
1914         rc = filemap_fdatawrite(inode->i_mapping);
1915         err = filp->f_op->fsync(filp, filp->f_path.dentry, 1);
1916         if (!rc)
1917                 rc = err;
1918         err = filemap_fdatawait(inode->i_mapping);
1919         if (!rc)
1920                 rc = err;
1921         mutex_unlock(&inode->i_mutex);
1922         VLDBG(curlun, "fdatasync -> %d\n", rc);
1923         return rc;
1924 }
1925
1926 static void fsync_all(struct fsg_dev *fsg)
1927 {
1928         int     i;
1929
1930         for (i = 0; i < fsg->nluns; ++i)
1931                 fsync_sub(&fsg->luns[i]);
1932 }
1933
1934 static int do_synchronize_cache(struct fsg_dev *fsg)
1935 {
1936         struct lun      *curlun = fsg->curlun;
1937         int             rc;
1938
1939         /* We ignore the requested LBA and write out all file's
1940          * dirty data buffers. */
1941         rc = fsync_sub(curlun);
1942         if (rc)
1943                 curlun->sense_data = SS_WRITE_ERROR;
1944         return 0;
1945 }
1946
1947
1948 /*-------------------------------------------------------------------------*/
1949
1950 static void invalidate_sub(struct lun *curlun)
1951 {
1952         struct file     *filp = curlun->filp;
1953         struct inode    *inode = filp->f_path.dentry->d_inode;
1954         unsigned long   rc;
1955
1956         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1957         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
1958 }
1959
1960 static int do_verify(struct fsg_dev *fsg)
1961 {
1962         struct lun              *curlun = fsg->curlun;
1963         u32                     lba;
1964         u32                     verification_length;
1965         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1966         loff_t                  file_offset, file_offset_tmp;
1967         u32                     amount_left;
1968         unsigned int            amount;
1969         ssize_t                 nread;
1970
1971         /* Get the starting Logical Block Address and check that it's
1972          * not too big */
1973         lba = get_be32(&fsg->cmnd[2]);
1974         if (lba >= curlun->num_sectors) {
1975                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1976                 return -EINVAL;
1977         }
1978
1979         /* We allow DPO (Disable Page Out = don't save data in the
1980          * cache) but we don't implement it. */
1981         if ((fsg->cmnd[1] & ~0x10) != 0) {
1982                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1983                 return -EINVAL;
1984         }
1985
1986         verification_length = get_be16(&fsg->cmnd[7]);
1987         if (unlikely(verification_length == 0))
1988                 return -EIO;            // No default reply
1989
1990         /* Prepare to carry out the file verify */
1991         amount_left = verification_length << 9;
1992         file_offset = ((loff_t) lba) << 9;
1993
1994         /* Write out all the dirty buffers before invalidating them */
1995         fsync_sub(curlun);
1996         if (signal_pending(current))
1997                 return -EINTR;
1998
1999         invalidate_sub(curlun);
2000         if (signal_pending(current))
2001                 return -EINTR;
2002
2003         /* Just try to read the requested blocks */
2004         while (amount_left > 0) {
2005
2006                 /* Figure out how much we need to read:
2007                  * Try to read the remaining amount, but not more than
2008                  * the buffer size.
2009                  * And don't try to read past the end of the file.
2010                  * If this means reading 0 then we were asked to read
2011                  * past the end of file. */
2012                 amount = min((unsigned int) amount_left, mod_data.buflen);
2013                 amount = min((loff_t) amount,
2014                                 curlun->file_length - file_offset);
2015                 if (amount == 0) {
2016                         curlun->sense_data =
2017                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
2018                         curlun->sense_data_info = file_offset >> 9;
2019                         curlun->info_valid = 1;
2020                         break;
2021                 }
2022
2023                 /* Perform the read */
2024                 file_offset_tmp = file_offset;
2025                 nread = vfs_read(curlun->filp,
2026                                 (char __user *) bh->buf,
2027                                 amount, &file_offset_tmp);
2028                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
2029                                 (unsigned long long) file_offset,
2030                                 (int) nread);
2031                 if (signal_pending(current))
2032                         return -EINTR;
2033
2034                 if (nread < 0) {
2035                         LDBG(curlun, "error in file verify: %d\n",
2036                                         (int) nread);
2037                         nread = 0;
2038                 } else if (nread < amount) {
2039                         LDBG(curlun, "partial file verify: %d/%u\n",
2040                                         (int) nread, amount);
2041                         nread -= (nread & 511); // Round down to a sector
2042                 }
2043                 if (nread == 0) {
2044                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
2045                         curlun->sense_data_info = file_offset >> 9;
2046                         curlun->info_valid = 1;
2047                         break;
2048                 }
2049                 file_offset += nread;
2050                 amount_left -= nread;
2051         }
2052         return 0;
2053 }
2054
2055
2056 /*-------------------------------------------------------------------------*/
2057
2058 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2059 {
2060         u8      *buf = (u8 *) bh->buf;
2061
2062         static char vendor_id[] = "Linux   ";
2063         static char product_id[] = "File-Stor Gadget";
2064
2065         if (!fsg->curlun) {             // Unsupported LUNs are okay
2066                 fsg->bad_lun_okay = 1;
2067                 memset(buf, 0, 36);
2068                 buf[0] = 0x7f;          // Unsupported, no device-type
2069                 return 36;
2070         }
2071
2072         memset(buf, 0, 8);      // Non-removable, direct-access device
2073         if (mod_data.removable)
2074                 buf[1] = 0x80;
2075         buf[2] = 2;             // ANSI SCSI level 2
2076         buf[3] = 2;             // SCSI-2 INQUIRY data format
2077         buf[4] = 31;            // Additional length
2078                                 // No special options
2079         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, product_id,
2080                         mod_data.release);
2081         return 36;
2082 }
2083
2084
2085 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2086 {
2087         struct lun      *curlun = fsg->curlun;
2088         u8              *buf = (u8 *) bh->buf;
2089         u32             sd, sdinfo;
2090         int             valid;
2091
2092         /*
2093          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
2094          *
2095          * If a REQUEST SENSE command is received from an initiator
2096          * with a pending unit attention condition (before the target
2097          * generates the contingent allegiance condition), then the
2098          * target shall either:
2099          *   a) report any pending sense data and preserve the unit
2100          *      attention condition on the logical unit, or,
2101          *   b) report the unit attention condition, may discard any
2102          *      pending sense data, and clear the unit attention
2103          *      condition on the logical unit for that initiator.
2104          *
2105          * FSG normally uses option a); enable this code to use option b).
2106          */
2107 #if 0
2108         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
2109                 curlun->sense_data = curlun->unit_attention_data;
2110                 curlun->unit_attention_data = SS_NO_SENSE;
2111         }
2112 #endif
2113
2114         if (!curlun) {          // Unsupported LUNs are okay
2115                 fsg->bad_lun_okay = 1;
2116                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2117                 sdinfo = 0;
2118                 valid = 0;
2119         } else {
2120                 sd = curlun->sense_data;
2121                 sdinfo = curlun->sense_data_info;
2122                 valid = curlun->info_valid << 7;
2123                 curlun->sense_data = SS_NO_SENSE;
2124                 curlun->sense_data_info = 0;
2125                 curlun->info_valid = 0;
2126         }
2127
2128         memset(buf, 0, 18);
2129         buf[0] = valid | 0x70;                  // Valid, current error
2130         buf[2] = SK(sd);
2131         put_be32(&buf[3], sdinfo);              // Sense information
2132         buf[7] = 18 - 8;                        // Additional sense length
2133         buf[12] = ASC(sd);
2134         buf[13] = ASCQ(sd);
2135         return 18;
2136 }
2137
2138
2139 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2140 {
2141         struct lun      *curlun = fsg->curlun;
2142         u32             lba = get_be32(&fsg->cmnd[2]);
2143         int             pmi = fsg->cmnd[8];
2144         u8              *buf = (u8 *) bh->buf;
2145
2146         /* Check the PMI and LBA fields */
2147         if (pmi > 1 || (pmi == 0 && lba != 0)) {
2148                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2149                 return -EINVAL;
2150         }
2151
2152         put_be32(&buf[0], curlun->num_sectors - 1);     // Max logical block
2153         put_be32(&buf[4], 512);                         // Block length
2154         return 8;
2155 }
2156
2157
2158 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2159 {
2160         struct lun      *curlun = fsg->curlun;
2161         int             mscmnd = fsg->cmnd[0];
2162         u8              *buf = (u8 *) bh->buf;
2163         u8              *buf0 = buf;
2164         int             pc, page_code;
2165         int             changeable_values, all_pages;
2166         int             valid_page = 0;
2167         int             len, limit;
2168
2169         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
2170                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2171                 return -EINVAL;
2172         }
2173         pc = fsg->cmnd[2] >> 6;
2174         page_code = fsg->cmnd[2] & 0x3f;
2175         if (pc == 3) {
2176                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
2177                 return -EINVAL;
2178         }
2179         changeable_values = (pc == 1);
2180         all_pages = (page_code == 0x3f);
2181
2182         /* Write the mode parameter header.  Fixed values are: default
2183          * medium type, no cache control (DPOFUA), and no block descriptors.
2184          * The only variable value is the WriteProtect bit.  We will fill in
2185          * the mode data length later. */
2186         memset(buf, 0, 8);
2187         if (mscmnd == SC_MODE_SENSE_6) {
2188                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2189                 buf += 4;
2190                 limit = 255;
2191         } else {                        // SC_MODE_SENSE_10
2192                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2193                 buf += 8;
2194                 limit = 65535;          // Should really be mod_data.buflen
2195         }
2196
2197         /* No block descriptors */
2198
2199         /* The mode pages, in numerical order.  The only page we support
2200          * is the Caching page. */
2201         if (page_code == 0x08 || all_pages) {
2202                 valid_page = 1;
2203                 buf[0] = 0x08;          // Page code
2204                 buf[1] = 10;            // Page length
2205                 memset(buf+2, 0, 10);   // None of the fields are changeable
2206
2207                 if (!changeable_values) {
2208                         buf[2] = 0x04;  // Write cache enable,
2209                                         // Read cache not disabled
2210                                         // No cache retention priorities
2211                         put_be16(&buf[4], 0xffff);  // Don't disable prefetch
2212                                         // Minimum prefetch = 0
2213                         put_be16(&buf[8], 0xffff);  // Maximum prefetch
2214                         put_be16(&buf[10], 0xffff); // Maximum prefetch ceiling
2215                 }
2216                 buf += 12;
2217         }
2218
2219         /* Check that a valid page was requested and the mode data length
2220          * isn't too long. */
2221         len = buf - buf0;
2222         if (!valid_page || len > limit) {
2223                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2224                 return -EINVAL;
2225         }
2226
2227         /*  Store the mode data length */
2228         if (mscmnd == SC_MODE_SENSE_6)
2229                 buf0[0] = len - 1;
2230         else
2231                 put_be16(buf0, len - 2);
2232         return len;
2233 }
2234
2235
2236 static int do_start_stop(struct fsg_dev *fsg)
2237 {
2238         struct lun      *curlun = fsg->curlun;
2239         int             loej, start;
2240
2241         if (!mod_data.removable) {
2242                 curlun->sense_data = SS_INVALID_COMMAND;
2243                 return -EINVAL;
2244         }
2245
2246         // int immed = fsg->cmnd[1] & 0x01;
2247         loej = fsg->cmnd[4] & 0x02;
2248         start = fsg->cmnd[4] & 0x01;
2249
2250 #ifdef CONFIG_USB_FILE_STORAGE_TEST
2251         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
2252                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
2253                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2254                 return -EINVAL;
2255         }
2256
2257         if (!start) {
2258
2259                 /* Are we allowed to unload the media? */
2260                 if (curlun->prevent_medium_removal) {
2261                         LDBG(curlun, "unload attempt prevented\n");
2262                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
2263                         return -EINVAL;
2264                 }
2265                 if (loej) {             // Simulate an unload/eject
2266                         up_read(&fsg->filesem);
2267                         down_write(&fsg->filesem);
2268                         close_backing_file(curlun);
2269                         up_write(&fsg->filesem);
2270                         down_read(&fsg->filesem);
2271                 }
2272         } else {
2273
2274                 /* Our emulation doesn't support mounting; the medium is
2275                  * available for use as soon as it is loaded. */
2276                 if (!backing_file_is_open(curlun)) {
2277                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2278                         return -EINVAL;
2279                 }
2280         }
2281 #endif
2282         return 0;
2283 }
2284
2285
2286 static int do_prevent_allow(struct fsg_dev *fsg)
2287 {
2288         struct lun      *curlun = fsg->curlun;
2289         int             prevent;
2290
2291         if (!mod_data.removable) {
2292                 curlun->sense_data = SS_INVALID_COMMAND;
2293                 return -EINVAL;
2294         }
2295
2296         prevent = fsg->cmnd[4] & 0x01;
2297         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
2298                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2299                 return -EINVAL;
2300         }
2301
2302         if (curlun->prevent_medium_removal && !prevent)
2303                 fsync_sub(curlun);
2304         curlun->prevent_medium_removal = prevent;
2305         return 0;
2306 }
2307
2308
2309 static int do_read_format_capacities(struct fsg_dev *fsg,
2310                         struct fsg_buffhd *bh)
2311 {
2312         struct lun      *curlun = fsg->curlun;
2313         u8              *buf = (u8 *) bh->buf;
2314
2315         buf[0] = buf[1] = buf[2] = 0;
2316         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
2317         buf += 4;
2318
2319         put_be32(&buf[0], curlun->num_sectors);         // Number of blocks
2320         put_be32(&buf[4], 512);                         // Block length
2321         buf[4] = 0x02;                                  // Current capacity
2322         return 12;
2323 }
2324
2325
2326 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2327 {
2328         struct lun      *curlun = fsg->curlun;
2329
2330         /* We don't support MODE SELECT */
2331         curlun->sense_data = SS_INVALID_COMMAND;
2332         return -EINVAL;
2333 }
2334
2335
2336 /*-------------------------------------------------------------------------*/
2337
2338 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
2339 {
2340         int     rc;
2341
2342         rc = fsg_set_halt(fsg, fsg->bulk_in);
2343         if (rc == -EAGAIN)
2344                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
2345         while (rc != 0) {
2346                 if (rc != -EAGAIN) {
2347                         WARN(fsg, "usb_ep_set_halt -> %d\n", rc);
2348                         rc = 0;
2349                         break;
2350                 }
2351
2352                 /* Wait for a short time and then try again */
2353                 if (msleep_interruptible(100) != 0)
2354                         return -EINTR;
2355                 rc = usb_ep_set_halt(fsg->bulk_in);
2356         }
2357         return rc;
2358 }
2359
2360 static int pad_with_zeros(struct fsg_dev *fsg)
2361 {
2362         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2363         u32                     nkeep = bh->inreq->length;
2364         u32                     nsend;
2365         int                     rc;
2366
2367         bh->state = BUF_STATE_EMPTY;            // For the first iteration
2368         fsg->usb_amount_left = nkeep + fsg->residue;
2369         while (fsg->usb_amount_left > 0) {
2370
2371                 /* Wait for the next buffer to be free */
2372                 while (bh->state != BUF_STATE_EMPTY) {
2373                         if ((rc = sleep_thread(fsg)) != 0)
2374                                 return rc;
2375                 }
2376
2377                 nsend = min(fsg->usb_amount_left, (u32) mod_data.buflen);
2378                 memset(bh->buf + nkeep, 0, nsend - nkeep);
2379                 bh->inreq->length = nsend;
2380                 bh->inreq->zero = 0;
2381                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2382                                 &bh->inreq_busy, &bh->state);
2383                 bh = fsg->next_buffhd_to_fill = bh->next;
2384                 fsg->usb_amount_left -= nsend;
2385                 nkeep = 0;
2386         }
2387         return 0;
2388 }
2389
2390 static int throw_away_data(struct fsg_dev *fsg)
2391 {
2392         struct fsg_buffhd       *bh;
2393         u32                     amount;
2394         int                     rc;
2395
2396         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
2397                         fsg->usb_amount_left > 0) {
2398
2399                 /* Throw away the data in a filled buffer */
2400                 if (bh->state == BUF_STATE_FULL) {
2401                         smp_rmb();
2402                         bh->state = BUF_STATE_EMPTY;
2403                         fsg->next_buffhd_to_drain = bh->next;
2404
2405                         /* A short packet or an error ends everything */
2406                         if (bh->outreq->actual != bh->outreq->length ||
2407                                         bh->outreq->status != 0) {
2408                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2409                                 return -EINTR;
2410                         }
2411                         continue;
2412                 }
2413
2414                 /* Try to submit another request if we need one */
2415                 bh = fsg->next_buffhd_to_fill;
2416                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
2417                         amount = min(fsg->usb_amount_left,
2418                                         (u32) mod_data.buflen);
2419
2420                         /* amount is always divisible by 512, hence by
2421                          * the bulk-out maxpacket size */
2422                         bh->outreq->length = bh->bulk_out_intended_length =
2423                                         amount;
2424                         bh->outreq->short_not_ok = 1;
2425                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2426                                         &bh->outreq_busy, &bh->state);
2427                         fsg->next_buffhd_to_fill = bh->next;
2428                         fsg->usb_amount_left -= amount;
2429                         continue;
2430                 }
2431
2432                 /* Otherwise wait for something to happen */
2433                 if ((rc = sleep_thread(fsg)) != 0)
2434                         return rc;
2435         }
2436         return 0;
2437 }
2438
2439
2440 static int finish_reply(struct fsg_dev *fsg)
2441 {
2442         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2443         int                     rc = 0;
2444
2445         switch (fsg->data_dir) {
2446         case DATA_DIR_NONE:
2447                 break;                  // Nothing to send
2448
2449         /* If we don't know whether the host wants to read or write,
2450          * this must be CB or CBI with an unknown command.  We mustn't
2451          * try to send or receive any data.  So stall both bulk pipes
2452          * if we can and wait for a reset. */
2453         case DATA_DIR_UNKNOWN:
2454                 if (mod_data.can_stall) {
2455                         fsg_set_halt(fsg, fsg->bulk_out);
2456                         rc = halt_bulk_in_endpoint(fsg);
2457                 }
2458                 break;
2459
2460         /* All but the last buffer of data must have already been sent */
2461         case DATA_DIR_TO_HOST:
2462                 if (fsg->data_size == 0)
2463                         ;               // Nothing to send
2464
2465                 /* If there's no residue, simply send the last buffer */
2466                 else if (fsg->residue == 0) {
2467                         bh->inreq->zero = 0;
2468                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2469                                         &bh->inreq_busy, &bh->state);
2470                         fsg->next_buffhd_to_fill = bh->next;
2471                 }
2472
2473                 /* There is a residue.  For CB and CBI, simply mark the end
2474                  * of the data with a short packet.  However, if we are
2475                  * allowed to stall, there was no data at all (residue ==
2476                  * data_size), and the command failed (invalid LUN or
2477                  * sense data is set), then halt the bulk-in endpoint
2478                  * instead. */
2479                 else if (!transport_is_bbb()) {
2480                         if (mod_data.can_stall &&
2481                                         fsg->residue == fsg->data_size &&
2482         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2483                                 bh->state = BUF_STATE_EMPTY;
2484                                 rc = halt_bulk_in_endpoint(fsg);
2485                         } else {
2486                                 bh->inreq->zero = 1;
2487                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2488                                                 &bh->inreq_busy, &bh->state);
2489                                 fsg->next_buffhd_to_fill = bh->next;
2490                         }
2491                 }
2492
2493                 /* For Bulk-only, if we're allowed to stall then send the
2494                  * short packet and halt the bulk-in endpoint.  If we can't
2495                  * stall, pad out the remaining data with 0's. */
2496                 else {
2497                         if (mod_data.can_stall) {
2498                                 bh->inreq->zero = 1;
2499                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2500                                                 &bh->inreq_busy, &bh->state);
2501                                 fsg->next_buffhd_to_fill = bh->next;
2502                                 rc = halt_bulk_in_endpoint(fsg);
2503                         } else
2504                                 rc = pad_with_zeros(fsg);
2505                 }
2506                 break;
2507
2508         /* We have processed all we want from the data the host has sent.
2509          * There may still be outstanding bulk-out requests. */
2510         case DATA_DIR_FROM_HOST:
2511                 if (fsg->residue == 0)
2512                         ;               // Nothing to receive
2513
2514                 /* Did the host stop sending unexpectedly early? */
2515                 else if (fsg->short_packet_received) {
2516                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2517                         rc = -EINTR;
2518                 }
2519
2520                 /* We haven't processed all the incoming data.  Even though
2521                  * we may be allowed to stall, doing so would cause a race.
2522                  * The controller may already have ACK'ed all the remaining
2523                  * bulk-out packets, in which case the host wouldn't see a
2524                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2525                  * clear the halt -- leading to problems later on. */
2526 #if 0
2527                 else if (mod_data.can_stall) {
2528                         fsg_set_halt(fsg, fsg->bulk_out);
2529                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2530                         rc = -EINTR;
2531                 }
2532 #endif
2533
2534                 /* We can't stall.  Read in the excess data and throw it
2535                  * all away. */
2536                 else
2537                         rc = throw_away_data(fsg);
2538                 break;
2539         }
2540         return rc;
2541 }
2542
2543
2544 static int send_status(struct fsg_dev *fsg)
2545 {
2546         struct lun              *curlun = fsg->curlun;
2547         struct fsg_buffhd       *bh;
2548         int                     rc;
2549         u8                      status = USB_STATUS_PASS;
2550         u32                     sd, sdinfo = 0;
2551
2552         /* Wait for the next buffer to become available */
2553         bh = fsg->next_buffhd_to_fill;
2554         while (bh->state != BUF_STATE_EMPTY) {
2555                 if ((rc = sleep_thread(fsg)) != 0)
2556                         return rc;
2557         }
2558
2559         if (curlun) {
2560                 sd = curlun->sense_data;
2561                 sdinfo = curlun->sense_data_info;
2562         } else if (fsg->bad_lun_okay)
2563                 sd = SS_NO_SENSE;
2564         else
2565                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2566
2567         if (fsg->phase_error) {
2568                 DBG(fsg, "sending phase-error status\n");
2569                 status = USB_STATUS_PHASE_ERROR;
2570                 sd = SS_INVALID_COMMAND;
2571         } else if (sd != SS_NO_SENSE) {
2572                 DBG(fsg, "sending command-failure status\n");
2573                 status = USB_STATUS_FAIL;
2574                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2575                                 "  info x%x\n",
2576                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2577         }
2578
2579         if (transport_is_bbb()) {
2580                 struct bulk_cs_wrap     *csw = bh->buf;
2581
2582                 /* Store and send the Bulk-only CSW */
2583                 csw->Signature = __constant_cpu_to_le32(USB_BULK_CS_SIG);
2584                 csw->Tag = fsg->tag;
2585                 csw->Residue = cpu_to_le32(fsg->residue);
2586                 csw->Status = status;
2587
2588                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2589                 bh->inreq->zero = 0;
2590                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2591                                 &bh->inreq_busy, &bh->state);
2592
2593         } else if (mod_data.transport_type == USB_PR_CB) {
2594
2595                 /* Control-Bulk transport has no status phase! */
2596                 return 0;
2597
2598         } else {                        // USB_PR_CBI
2599                 struct interrupt_data   *buf = bh->buf;
2600
2601                 /* Store and send the Interrupt data.  UFI sends the ASC
2602                  * and ASCQ bytes.  Everything else sends a Type (which
2603                  * is always 0) and the status Value. */
2604                 if (mod_data.protocol_type == USB_SC_UFI) {
2605                         buf->bType = ASC(sd);
2606                         buf->bValue = ASCQ(sd);
2607                 } else {
2608                         buf->bType = 0;
2609                         buf->bValue = status;
2610                 }
2611                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2612
2613                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2614                 fsg->intreq->buf = bh->inreq->buf;
2615                 fsg->intreq->dma = bh->inreq->dma;
2616                 fsg->intreq->context = bh;
2617                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2618                                 &fsg->intreq_busy, &bh->state);
2619         }
2620
2621         fsg->next_buffhd_to_fill = bh->next;
2622         return 0;
2623 }
2624
2625
2626 /*-------------------------------------------------------------------------*/
2627
2628 /* Check whether the command is properly formed and whether its data size
2629  * and direction agree with the values we already have. */
2630 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2631                 enum data_direction data_dir, unsigned int mask,
2632                 int needs_medium, const char *name)
2633 {
2634         int                     i;
2635         int                     lun = fsg->cmnd[1] >> 5;
2636         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2637         char                    hdlen[20];
2638         struct lun              *curlun;
2639
2640         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2641          * Transparent SCSI doesn't pad. */
2642         if (protocol_is_scsi())
2643                 ;
2644
2645         /* There's some disagreement as to whether RBC pads commands or not.
2646          * We'll play it safe and accept either form. */
2647         else if (mod_data.protocol_type == USB_SC_RBC) {
2648                 if (fsg->cmnd_size == 12)
2649                         cmnd_size = 12;
2650
2651         /* All the other protocols pad to 12 bytes */
2652         } else
2653                 cmnd_size = 12;
2654
2655         hdlen[0] = 0;
2656         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2657                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2658                                 fsg->data_size);
2659         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2660                         name, cmnd_size, dirletter[(int) data_dir],
2661                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2662
2663         /* We can't reply at all until we know the correct data direction
2664          * and size. */
2665         if (fsg->data_size_from_cmnd == 0)
2666                 data_dir = DATA_DIR_NONE;
2667         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2668                 fsg->data_dir = data_dir;
2669                 fsg->data_size = fsg->data_size_from_cmnd;
2670
2671         } else {                                        // Bulk-only
2672                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2673
2674                         /* Host data size < Device data size is a phase error.
2675                          * Carry out the command, but only transfer as much
2676                          * as we are allowed. */
2677                         fsg->data_size_from_cmnd = fsg->data_size;
2678                         fsg->phase_error = 1;
2679                 }
2680         }
2681         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2682
2683         /* Conflicting data directions is a phase error */
2684         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2685                 fsg->phase_error = 1;
2686                 return -EINVAL;
2687         }
2688
2689         /* Verify the length of the command itself */
2690         if (cmnd_size != fsg->cmnd_size) {
2691
2692                 /* Special case workaround: MS-Windows issues REQUEST SENSE
2693                  * with cbw->Length == 12 (it should be 6). */
2694                 if (fsg->cmnd[0] == SC_REQUEST_SENSE && fsg->cmnd_size == 12)
2695                         cmnd_size = fsg->cmnd_size;
2696                 else {
2697                         fsg->phase_error = 1;
2698                         return -EINVAL;
2699                 }
2700         }
2701
2702         /* Check that the LUN values are consistent */
2703         if (transport_is_bbb()) {
2704                 if (fsg->lun != lun)
2705                         DBG(fsg, "using LUN %d from CBW, "
2706                                         "not LUN %d from CDB\n",
2707                                         fsg->lun, lun);
2708         } else
2709                 fsg->lun = lun;         // Use LUN from the command
2710
2711         /* Check the LUN */
2712         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
2713                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2714                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
2715                         curlun->sense_data = SS_NO_SENSE;
2716                         curlun->sense_data_info = 0;
2717                         curlun->info_valid = 0;
2718                 }
2719         } else {
2720                 fsg->curlun = curlun = NULL;
2721                 fsg->bad_lun_okay = 0;
2722
2723                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2724                  * to use unsupported LUNs; all others may not. */
2725                 if (fsg->cmnd[0] != SC_INQUIRY &&
2726                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2727                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2728                         return -EINVAL;
2729                 }
2730         }
2731
2732         /* If a unit attention condition exists, only INQUIRY and
2733          * REQUEST SENSE commands are allowed; anything else must fail. */
2734         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2735                         fsg->cmnd[0] != SC_INQUIRY &&
2736                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2737                 curlun->sense_data = curlun->unit_attention_data;
2738                 curlun->unit_attention_data = SS_NO_SENSE;
2739                 return -EINVAL;
2740         }
2741
2742         /* Check that only command bytes listed in the mask are non-zero */
2743         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2744         for (i = 1; i < cmnd_size; ++i) {
2745                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2746                         if (curlun)
2747                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2748                         return -EINVAL;
2749                 }
2750         }
2751
2752         /* If the medium isn't mounted and the command needs to access
2753          * it, return an error. */
2754         if (curlun && !backing_file_is_open(curlun) && needs_medium) {
2755                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2756                 return -EINVAL;
2757         }
2758
2759         return 0;
2760 }
2761
2762
2763 static int do_scsi_command(struct fsg_dev *fsg)
2764 {
2765         struct fsg_buffhd       *bh;
2766         int                     rc;
2767         int                     reply = -EINVAL;
2768         int                     i;
2769         static char             unknown[16];
2770
2771         dump_cdb(fsg);
2772
2773         /* Wait for the next buffer to become available for data or status */
2774         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2775         while (bh->state != BUF_STATE_EMPTY) {
2776                 if ((rc = sleep_thread(fsg)) != 0)
2777                         return rc;
2778                 }
2779         fsg->phase_error = 0;
2780         fsg->short_packet_received = 0;
2781
2782         down_read(&fsg->filesem);       // We're using the backing file
2783         switch (fsg->cmnd[0]) {
2784
2785         case SC_INQUIRY:
2786                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2787                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2788                                 (1<<4), 0,
2789                                 "INQUIRY")) == 0)
2790                         reply = do_inquiry(fsg, bh);
2791                 break;
2792
2793         case SC_MODE_SELECT_6:
2794                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2795                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2796                                 (1<<1) | (1<<4), 0,
2797                                 "MODE SELECT(6)")) == 0)
2798                         reply = do_mode_select(fsg, bh);
2799                 break;
2800
2801         case SC_MODE_SELECT_10:
2802                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2803                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2804                                 (1<<1) | (3<<7), 0,
2805                                 "MODE SELECT(10)")) == 0)
2806                         reply = do_mode_select(fsg, bh);
2807                 break;
2808
2809         case SC_MODE_SENSE_6:
2810                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2811                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2812                                 (1<<1) | (1<<2) | (1<<4), 0,
2813                                 "MODE SENSE(6)")) == 0)
2814                         reply = do_mode_sense(fsg, bh);
2815                 break;
2816
2817         case SC_MODE_SENSE_10:
2818                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2819                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2820                                 (1<<1) | (1<<2) | (3<<7), 0,
2821                                 "MODE SENSE(10)")) == 0)
2822                         reply = do_mode_sense(fsg, bh);
2823                 break;
2824
2825         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2826                 fsg->data_size_from_cmnd = 0;
2827                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2828                                 (1<<4), 0,
2829                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2830                         reply = do_prevent_allow(fsg);
2831                 break;
2832
2833         case SC_READ_6:
2834                 i = fsg->cmnd[4];
2835                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2836                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2837                                 (7<<1) | (1<<4), 1,
2838                                 "READ(6)")) == 0)
2839                         reply = do_read(fsg);
2840                 break;
2841
2842         case SC_READ_10:
2843                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2844                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2845                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2846                                 "READ(10)")) == 0)
2847                         reply = do_read(fsg);
2848                 break;
2849
2850         case SC_READ_12:
2851                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2852                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2853                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2854                                 "READ(12)")) == 0)
2855                         reply = do_read(fsg);
2856                 break;
2857
2858         case SC_READ_CAPACITY:
2859                 fsg->data_size_from_cmnd = 8;
2860                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2861                                 (0xf<<2) | (1<<8), 1,
2862                                 "READ CAPACITY")) == 0)
2863                         reply = do_read_capacity(fsg, bh);
2864                 break;
2865
2866         case SC_READ_FORMAT_CAPACITIES:
2867                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2868                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2869                                 (3<<7), 1,
2870                                 "READ FORMAT CAPACITIES")) == 0)
2871                         reply = do_read_format_capacities(fsg, bh);
2872                 break;
2873
2874         case SC_REQUEST_SENSE:
2875                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2876                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2877                                 (1<<4), 0,
2878                                 "REQUEST SENSE")) == 0)
2879                         reply = do_request_sense(fsg, bh);
2880                 break;
2881
2882         case SC_START_STOP_UNIT:
2883                 fsg->data_size_from_cmnd = 0;
2884                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2885                                 (1<<1) | (1<<4), 0,
2886                                 "START-STOP UNIT")) == 0)
2887                         reply = do_start_stop(fsg);
2888                 break;
2889
2890         case SC_SYNCHRONIZE_CACHE:
2891                 fsg->data_size_from_cmnd = 0;
2892                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2893                                 (0xf<<2) | (3<<7), 1,
2894                                 "SYNCHRONIZE CACHE")) == 0)
2895                         reply = do_synchronize_cache(fsg);
2896                 break;
2897
2898         case SC_TEST_UNIT_READY:
2899                 fsg->data_size_from_cmnd = 0;
2900                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2901                                 0, 1,
2902                                 "TEST UNIT READY");
2903                 break;
2904
2905         /* Although optional, this command is used by MS-Windows.  We
2906          * support a minimal version: BytChk must be 0. */
2907         case SC_VERIFY:
2908                 fsg->data_size_from_cmnd = 0;
2909                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2910                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2911                                 "VERIFY")) == 0)
2912                         reply = do_verify(fsg);
2913                 break;
2914
2915         case SC_WRITE_6:
2916                 i = fsg->cmnd[4];
2917                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2918                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2919                                 (7<<1) | (1<<4), 1,
2920                                 "WRITE(6)")) == 0)
2921                         reply = do_write(fsg);
2922                 break;
2923
2924         case SC_WRITE_10:
2925                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2926                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2927                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2928                                 "WRITE(10)")) == 0)
2929                         reply = do_write(fsg);
2930                 break;
2931
2932         case SC_WRITE_12:
2933                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2934                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2935                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2936                                 "WRITE(12)")) == 0)
2937                         reply = do_write(fsg);
2938                 break;
2939
2940         /* Some mandatory commands that we recognize but don't implement.
2941          * They don't mean much in this setting.  It's left as an exercise
2942          * for anyone interested to implement RESERVE and RELEASE in terms
2943          * of Posix locks. */
2944         case SC_FORMAT_UNIT:
2945         case SC_RELEASE:
2946         case SC_RESERVE:
2947         case SC_SEND_DIAGNOSTIC:
2948                 // Fall through
2949
2950         default:
2951                 fsg->data_size_from_cmnd = 0;
2952                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2953                 if ((reply = check_command(fsg, fsg->cmnd_size,
2954                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2955                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2956                         reply = -EINVAL;
2957                 }
2958                 break;
2959         }
2960         up_read(&fsg->filesem);
2961
2962         if (reply == -EINTR || signal_pending(current))
2963                 return -EINTR;
2964
2965         /* Set up the single reply buffer for finish_reply() */
2966         if (reply == -EINVAL)
2967                 reply = 0;              // Error reply length
2968         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2969                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2970                 bh->inreq->length = reply;
2971                 bh->state = BUF_STATE_FULL;
2972                 fsg->residue -= reply;
2973         }                               // Otherwise it's already set
2974
2975         return 0;
2976 }
2977
2978
2979 /*-------------------------------------------------------------------------*/
2980
2981 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2982 {
2983         struct usb_request      *req = bh->outreq;
2984         struct bulk_cb_wrap     *cbw = req->buf;
2985
2986         /* Was this a real packet? */
2987         if (req->status)
2988                 return -EINVAL;
2989
2990         /* Is the CBW valid? */
2991         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2992                         cbw->Signature != __constant_cpu_to_le32(
2993                                 USB_BULK_CB_SIG)) {
2994                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2995                                 req->actual,
2996                                 le32_to_cpu(cbw->Signature));
2997
2998                 /* The Bulk-only spec says we MUST stall the bulk pipes!
2999                  * If we want to avoid stalls, set a flag so that we will
3000                  * clear the endpoint halts at the next reset. */
3001                 if (!mod_data.can_stall)
3002                         set_bit(CLEAR_BULK_HALTS, &fsg->atomic_bitflags);
3003                 fsg_set_halt(fsg, fsg->bulk_out);
3004                 halt_bulk_in_endpoint(fsg);
3005                 return -EINVAL;
3006         }
3007
3008         /* Is the CBW meaningful? */
3009         if (cbw->Lun >= MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
3010                         cbw->Length < 6 || cbw->Length > MAX_COMMAND_SIZE) {
3011                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
3012                                 "cmdlen %u\n",
3013                                 cbw->Lun, cbw->Flags, cbw->Length);
3014
3015                 /* We can do anything we want here, so let's stall the
3016                  * bulk pipes if we are allowed to. */
3017                 if (mod_data.can_stall) {
3018                         fsg_set_halt(fsg, fsg->bulk_out);
3019                         halt_bulk_in_endpoint(fsg);
3020                 }
3021                 return -EINVAL;
3022         }
3023
3024         /* Save the command for later */
3025         fsg->cmnd_size = cbw->Length;
3026         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
3027         if (cbw->Flags & USB_BULK_IN_FLAG)
3028                 fsg->data_dir = DATA_DIR_TO_HOST;
3029         else
3030                 fsg->data_dir = DATA_DIR_FROM_HOST;
3031         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
3032         if (fsg->data_size == 0)
3033                 fsg->data_dir = DATA_DIR_NONE;
3034         fsg->lun = cbw->Lun;
3035         fsg->tag = cbw->Tag;
3036         return 0;
3037 }
3038
3039
3040 static int get_next_command(struct fsg_dev *fsg)
3041 {
3042         struct fsg_buffhd       *bh;
3043         int                     rc = 0;
3044
3045         if (transport_is_bbb()) {
3046
3047                 /* Wait for the next buffer to become available */
3048                 bh = fsg->next_buffhd_to_fill;
3049                 while (bh->state != BUF_STATE_EMPTY) {
3050                         if ((rc = sleep_thread(fsg)) != 0)
3051                                 return rc;
3052                         }
3053
3054                 /* Queue a request to read a Bulk-only CBW */
3055                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
3056                 bh->outreq->short_not_ok = 1;
3057                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
3058                                 &bh->outreq_busy, &bh->state);
3059
3060                 /* We will drain the buffer in software, which means we
3061                  * can reuse it for the next filling.  No need to advance
3062                  * next_buffhd_to_fill. */
3063
3064                 /* Wait for the CBW to arrive */
3065                 while (bh->state != BUF_STATE_FULL) {
3066                         if ((rc = sleep_thread(fsg)) != 0)
3067                                 return rc;
3068                         }
3069                 smp_rmb();
3070                 rc = received_cbw(fsg, bh);
3071                 bh->state = BUF_STATE_EMPTY;
3072
3073         } else {                // USB_PR_CB or USB_PR_CBI
3074
3075                 /* Wait for the next command to arrive */
3076                 while (fsg->cbbuf_cmnd_size == 0) {
3077                         if ((rc = sleep_thread(fsg)) != 0)
3078                                 return rc;
3079                         }
3080
3081                 /* Is the previous status interrupt request still busy?
3082                  * The host is allowed to skip reading the status,
3083                  * so we must cancel it. */
3084                 if (fsg->intreq_busy)
3085                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3086
3087                 /* Copy the command and mark the buffer empty */
3088                 fsg->data_dir = DATA_DIR_UNKNOWN;
3089                 spin_lock_irq(&fsg->lock);
3090                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
3091                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
3092                 fsg->cbbuf_cmnd_size = 0;
3093                 spin_unlock_irq(&fsg->lock);
3094         }
3095         return rc;
3096 }
3097
3098
3099 /*-------------------------------------------------------------------------*/
3100
3101 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
3102                 const struct usb_endpoint_descriptor *d)
3103 {
3104         int     rc;
3105
3106         ep->driver_data = fsg;
3107         rc = usb_ep_enable(ep, d);
3108         if (rc)
3109                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
3110         return rc;
3111 }
3112
3113 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
3114                 struct usb_request **preq)
3115 {
3116         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
3117         if (*preq)
3118                 return 0;
3119         ERROR(fsg, "can't allocate request for %s\n", ep->name);
3120         return -ENOMEM;
3121 }
3122
3123 /*
3124  * Reset interface setting and re-init endpoint state (toggle etc).
3125  * Call with altsetting < 0 to disable the interface.  The only other
3126  * available altsetting is 0, which enables the interface.
3127  */
3128 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
3129 {
3130         int     rc = 0;
3131         int     i;
3132         const struct usb_endpoint_descriptor    *d;
3133
3134         if (fsg->running)
3135                 DBG(fsg, "reset interface\n");
3136
3137 reset:
3138         /* Deallocate the requests */
3139         for (i = 0; i < NUM_BUFFERS; ++i) {
3140                 struct fsg_buffhd *bh = &fsg->buffhds[i];
3141
3142                 if (bh->inreq) {
3143                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
3144                         bh->inreq = NULL;
3145                 }
3146                 if (bh->outreq) {
3147                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
3148                         bh->outreq = NULL;
3149                 }
3150         }
3151         if (fsg->intreq) {
3152                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
3153                 fsg->intreq = NULL;
3154         }
3155
3156         /* Disable the endpoints */
3157         if (fsg->bulk_in_enabled) {
3158                 usb_ep_disable(fsg->bulk_in);
3159                 fsg->bulk_in_enabled = 0;
3160         }
3161         if (fsg->bulk_out_enabled) {
3162                 usb_ep_disable(fsg->bulk_out);
3163                 fsg->bulk_out_enabled = 0;
3164         }
3165         if (fsg->intr_in_enabled) {
3166                 usb_ep_disable(fsg->intr_in);
3167                 fsg->intr_in_enabled = 0;
3168         }
3169
3170         fsg->running = 0;
3171         if (altsetting < 0 || rc != 0)
3172                 return rc;
3173
3174         DBG(fsg, "set interface %d\n", altsetting);
3175
3176         /* Enable the endpoints */
3177         d = ep_desc(fsg->gadget, &fs_bulk_in_desc, &hs_bulk_in_desc);
3178         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
3179                 goto reset;
3180         fsg->bulk_in_enabled = 1;
3181
3182         d = ep_desc(fsg->gadget, &fs_bulk_out_desc, &hs_bulk_out_desc);
3183         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
3184                 goto reset;
3185         fsg->bulk_out_enabled = 1;
3186         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
3187
3188         if (transport_is_cbi()) {
3189                 d = ep_desc(fsg->gadget, &fs_intr_in_desc, &hs_intr_in_desc);
3190                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
3191                         goto reset;
3192                 fsg->intr_in_enabled = 1;
3193         }
3194
3195         /* Allocate the requests */
3196         for (i = 0; i < NUM_BUFFERS; ++i) {
3197                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3198
3199                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
3200                         goto reset;
3201                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
3202                         goto reset;
3203                 bh->inreq->buf = bh->outreq->buf = bh->buf;
3204                 bh->inreq->dma = bh->outreq->dma = bh->dma;
3205                 bh->inreq->context = bh->outreq->context = bh;
3206                 bh->inreq->complete = bulk_in_complete;
3207                 bh->outreq->complete = bulk_out_complete;
3208         }
3209         if (transport_is_cbi()) {
3210                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
3211                         goto reset;
3212                 fsg->intreq->complete = intr_in_complete;
3213         }
3214
3215         fsg->running = 1;
3216         for (i = 0; i < fsg->nluns; ++i)
3217                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3218         return rc;
3219 }
3220
3221
3222 /*
3223  * Change our operational configuration.  This code must agree with the code
3224  * that returns config descriptors, and with interface altsetting code.
3225  *
3226  * It's also responsible for power management interactions.  Some
3227  * configurations might not work with our current power sources.
3228  * For now we just assume the gadget is always self-powered.
3229  */
3230 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
3231 {
3232         int     rc = 0;
3233
3234         /* Disable the single interface */
3235         if (fsg->config != 0) {
3236                 DBG(fsg, "reset config\n");
3237                 fsg->config = 0;
3238                 rc = do_set_interface(fsg, -1);
3239         }
3240
3241         /* Enable the interface */
3242         if (new_config != 0) {
3243                 fsg->config = new_config;
3244                 if ((rc = do_set_interface(fsg, 0)) != 0)
3245                         fsg->config = 0;        // Reset on errors
3246                 else {
3247                         char *speed;
3248
3249                         switch (fsg->gadget->speed) {
3250                         case USB_SPEED_LOW:     speed = "low";  break;
3251                         case USB_SPEED_FULL:    speed = "full"; break;
3252                         case USB_SPEED_HIGH:    speed = "high"; break;
3253                         default:                speed = "?";    break;
3254                         }
3255                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
3256                 }
3257         }
3258         return rc;
3259 }
3260
3261
3262 /*-------------------------------------------------------------------------*/
3263
3264 static void handle_exception(struct fsg_dev *fsg)
3265 {
3266         siginfo_t               info;
3267         int                     sig;
3268         int                     i;
3269         int                     num_active;
3270         struct fsg_buffhd       *bh;
3271         enum fsg_state          old_state;
3272         u8                      new_config;
3273         struct lun              *curlun;
3274         unsigned int            exception_req_tag;
3275         int                     rc;
3276
3277         /* Clear the existing signals.  Anything but SIGUSR1 is converted
3278          * into a high-priority EXIT exception. */
3279         for (;;) {
3280                 sig = dequeue_signal_lock(current, &fsg->thread_signal_mask,
3281                                 &info);
3282                 if (!sig)
3283                         break;
3284                 if (sig != SIGUSR1) {
3285                         if (fsg->state < FSG_STATE_EXIT)
3286                                 DBG(fsg, "Main thread exiting on signal\n");
3287                         raise_exception(fsg, FSG_STATE_EXIT);
3288                 }
3289         }
3290
3291         /* Cancel all the pending transfers */
3292         if (fsg->intreq_busy)
3293                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3294         for (i = 0; i < NUM_BUFFERS; ++i) {
3295                 bh = &fsg->buffhds[i];
3296                 if (bh->inreq_busy)
3297                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
3298                 if (bh->outreq_busy)
3299                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
3300         }
3301
3302         /* Wait until everything is idle */
3303         for (;;) {
3304                 num_active = fsg->intreq_busy;
3305                 for (i = 0; i < NUM_BUFFERS; ++i) {
3306                         bh = &fsg->buffhds[i];
3307                         num_active += bh->inreq_busy + bh->outreq_busy;
3308                 }
3309                 if (num_active == 0)
3310                         break;
3311                 if (sleep_thread(fsg))
3312                         return;
3313         }
3314
3315         /* Clear out the controller's fifos */
3316         if (fsg->bulk_in_enabled)
3317                 usb_ep_fifo_flush(fsg->bulk_in);
3318         if (fsg->bulk_out_enabled)
3319                 usb_ep_fifo_flush(fsg->bulk_out);
3320         if (fsg->intr_in_enabled)
3321                 usb_ep_fifo_flush(fsg->intr_in);
3322
3323         /* Reset the I/O buffer states and pointers, the SCSI
3324          * state, and the exception.  Then invoke the handler. */
3325         spin_lock_irq(&fsg->lock);
3326
3327         for (i = 0; i < NUM_BUFFERS; ++i) {
3328                 bh = &fsg->buffhds[i];
3329                 bh->state = BUF_STATE_EMPTY;
3330         }
3331         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
3332                         &fsg->buffhds[0];
3333
3334         exception_req_tag = fsg->exception_req_tag;
3335         new_config = fsg->new_config;
3336         old_state = fsg->state;
3337
3338         if (old_state == FSG_STATE_ABORT_BULK_OUT)
3339                 fsg->state = FSG_STATE_STATUS_PHASE;
3340         else {
3341                 for (i = 0; i < fsg->nluns; ++i) {
3342                         curlun = &fsg->luns[i];
3343                         curlun->prevent_medium_removal = 0;
3344                         curlun->sense_data = curlun->unit_attention_data =
3345                                         SS_NO_SENSE;
3346                         curlun->sense_data_info = 0;
3347                         curlun->info_valid = 0;
3348                 }
3349                 fsg->state = FSG_STATE_IDLE;
3350         }
3351         spin_unlock_irq(&fsg->lock);
3352
3353         /* Carry out any extra actions required for the exception */
3354         switch (old_state) {
3355         default:
3356                 break;
3357
3358         case FSG_STATE_ABORT_BULK_OUT:
3359                 send_status(fsg);
3360                 spin_lock_irq(&fsg->lock);
3361                 if (fsg->state == FSG_STATE_STATUS_PHASE)
3362                         fsg->state = FSG_STATE_IDLE;
3363                 spin_unlock_irq(&fsg->lock);
3364                 break;
3365
3366         case FSG_STATE_RESET:
3367                 /* In case we were forced against our will to halt a
3368                  * bulk endpoint, clear the halt now.  (The SuperH UDC
3369                  * requires this.) */
3370                 if (test_and_clear_bit(CLEAR_BULK_HALTS,
3371                                 &fsg->atomic_bitflags)) {
3372                         usb_ep_clear_halt(fsg->bulk_in);
3373                         usb_ep_clear_halt(fsg->bulk_out);
3374                 }
3375
3376                 if (transport_is_bbb()) {
3377                         if (fsg->ep0_req_tag == exception_req_tag)
3378                                 ep0_queue(fsg); // Complete the status stage
3379
3380                 } else if (transport_is_cbi())
3381                         send_status(fsg);       // Status by interrupt pipe
3382
3383                 /* Technically this should go here, but it would only be
3384                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
3385                  * CONFIG_CHANGE cases. */
3386                 // for (i = 0; i < fsg->nluns; ++i)
3387                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3388                 break;
3389
3390         case FSG_STATE_INTERFACE_CHANGE:
3391                 rc = do_set_interface(fsg, 0);
3392                 if (fsg->ep0_req_tag != exception_req_tag)
3393                         break;
3394                 if (rc != 0)                    // STALL on errors
3395                         fsg_set_halt(fsg, fsg->ep0);
3396                 else                            // Complete the status stage
3397                         ep0_queue(fsg);
3398                 break;
3399
3400         case FSG_STATE_CONFIG_CHANGE:
3401                 rc = do_set_config(fsg, new_config);
3402                 if (fsg->ep0_req_tag != exception_req_tag)
3403                         break;
3404                 if (rc != 0)                    // STALL on errors
3405                         fsg_set_halt(fsg, fsg->ep0);
3406                 else                            // Complete the status stage
3407                         ep0_queue(fsg);
3408                 break;
3409
3410         case FSG_STATE_DISCONNECT:
3411                 fsync_all(fsg);
3412                 do_set_config(fsg, 0);          // Unconfigured state
3413                 break;
3414
3415         case FSG_STATE_EXIT:
3416         case FSG_STATE_TERMINATED:
3417                 do_set_config(fsg, 0);                  // Free resources
3418                 spin_lock_irq(&fsg->lock);
3419                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3420                 spin_unlock_irq(&fsg->lock);
3421                 break;
3422         }
3423 }
3424
3425
3426 /*-------------------------------------------------------------------------*/
3427
3428 static int fsg_main_thread(void *fsg_)
3429 {
3430         struct fsg_dev          *fsg = fsg_;
3431
3432         /* Allow the thread to be killed by a signal, but set the signal mask
3433          * to block everything but INT, TERM, KILL, and USR1. */
3434         siginitsetinv(&fsg->thread_signal_mask, sigmask(SIGINT) |
3435                         sigmask(SIGTERM) | sigmask(SIGKILL) |
3436                         sigmask(SIGUSR1));
3437         sigprocmask(SIG_SETMASK, &fsg->thread_signal_mask, NULL);
3438
3439         /* Arrange for userspace references to be interpreted as kernel
3440          * pointers.  That way we can pass a kernel pointer to a routine
3441          * that expects a __user pointer and it will work okay. */
3442         set_fs(get_ds());
3443
3444         /* The main loop */
3445         while (fsg->state != FSG_STATE_TERMINATED) {
3446                 if (exception_in_progress(fsg) || signal_pending(current)) {
3447                         handle_exception(fsg);
3448                         continue;
3449                 }
3450
3451                 if (!fsg->running) {
3452                         sleep_thread(fsg);
3453                         continue;
3454                 }
3455
3456                 if (get_next_command(fsg))
3457                         continue;
3458
3459                 spin_lock_irq(&fsg->lock);
3460                 if (!exception_in_progress(fsg))
3461                         fsg->state = FSG_STATE_DATA_PHASE;
3462                 spin_unlock_irq(&fsg->lock);
3463
3464                 if (do_scsi_command(fsg) || finish_reply(fsg))
3465                         continue;
3466
3467                 spin_lock_irq(&fsg->lock);
3468                 if (!exception_in_progress(fsg))
3469                         fsg->state = FSG_STATE_STATUS_PHASE;
3470                 spin_unlock_irq(&fsg->lock);
3471
3472                 if (send_status(fsg))
3473                         continue;
3474
3475                 spin_lock_irq(&fsg->lock);
3476                 if (!exception_in_progress(fsg))
3477                         fsg->state = FSG_STATE_IDLE;
3478                 spin_unlock_irq(&fsg->lock);
3479                 }
3480
3481         spin_lock_irq(&fsg->lock);
3482         fsg->thread_task = NULL;
3483         spin_unlock_irq(&fsg->lock);
3484
3485         /* In case we are exiting because of a signal, unregister the
3486          * gadget driver and close the backing file. */
3487         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags)) {
3488                 usb_gadget_unregister_driver(&fsg_driver);
3489                 close_all_backing_files(fsg);
3490         }
3491
3492         /* Let the unbind and cleanup routines know the thread has exited */
3493         complete_and_exit(&fsg->thread_notifier, 0);
3494 }
3495
3496
3497 /*-------------------------------------------------------------------------*/
3498
3499 /* If the next two routines are called while the gadget is registered,
3500  * the caller must own fsg->filesem for writing. */
3501
3502 static int open_backing_file(struct lun *curlun, const char *filename)
3503 {
3504         int                             ro;
3505         struct file                     *filp = NULL;
3506         int                             rc = -EINVAL;
3507         struct inode                    *inode = NULL;
3508         loff_t                          size;
3509         loff_t                          num_sectors;
3510
3511         /* R/W if we can, R/O if we must */
3512         ro = curlun->ro;
3513         if (!ro) {
3514                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
3515                 if (-EROFS == PTR_ERR(filp))
3516                         ro = 1;
3517         }
3518         if (ro)
3519                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
3520         if (IS_ERR(filp)) {
3521                 LINFO(curlun, "unable to open backing file: %s\n", filename);
3522                 return PTR_ERR(filp);
3523         }
3524
3525         if (!(filp->f_mode & FMODE_WRITE))
3526                 ro = 1;
3527
3528         if (filp->f_path.dentry)
3529                 inode = filp->f_path.dentry->d_inode;
3530         if (inode && S_ISBLK(inode->i_mode)) {
3531                 if (bdev_read_only(inode->i_bdev))
3532                         ro = 1;
3533         } else if (!inode || !S_ISREG(inode->i_mode)) {
3534                 LINFO(curlun, "invalid file type: %s\n", filename);
3535                 goto out;
3536         }
3537
3538         /* If we can't read the file, it's no good.
3539          * If we can't write the file, use it read-only. */
3540         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
3541                 LINFO(curlun, "file not readable: %s\n", filename);
3542                 goto out;
3543         }
3544         if (!(filp->f_op->write || filp->f_op->aio_write))
3545                 ro = 1;
3546
3547         size = i_size_read(inode->i_mapping->host);
3548         if (size < 0) {
3549                 LINFO(curlun, "unable to find file size: %s\n", filename);
3550                 rc = (int) size;
3551                 goto out;
3552         }
3553         num_sectors = size >> 9;        // File size in 512-byte sectors
3554         if (num_sectors == 0) {
3555                 LINFO(curlun, "file too small: %s\n", filename);
3556                 rc = -ETOOSMALL;
3557                 goto out;
3558         }
3559
3560         get_file(filp);
3561         curlun->ro = ro;
3562         curlun->filp = filp;
3563         curlun->file_length = size;
3564         curlun->num_sectors = num_sectors;
3565         LDBG(curlun, "open backing file: %s\n", filename);
3566         rc = 0;
3567
3568 out:
3569         filp_close(filp, current->files);
3570         return rc;
3571 }
3572
3573
3574 static void close_backing_file(struct lun *curlun)
3575 {
3576         if (curlun->filp) {
3577                 LDBG(curlun, "close backing file\n");
3578                 fput(curlun->filp);
3579                 curlun->filp = NULL;
3580         }
3581 }
3582
3583 static void close_all_backing_files(struct fsg_dev *fsg)
3584 {
3585         int     i;
3586
3587         for (i = 0; i < fsg->nluns; ++i)
3588                 close_backing_file(&fsg->luns[i]);
3589 }
3590
3591
3592 static ssize_t show_ro(struct device *dev, struct device_attribute *attr, char *buf)
3593 {
3594         struct lun      *curlun = dev_to_lun(dev);
3595
3596         return sprintf(buf, "%d\n", curlun->ro);
3597 }
3598
3599 static ssize_t show_file(struct device *dev, struct device_attribute *attr, char *buf)
3600 {
3601         struct lun      *curlun = dev_to_lun(dev);
3602         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3603         char            *p;
3604         ssize_t         rc;
3605
3606         down_read(&fsg->filesem);
3607         if (backing_file_is_open(curlun)) {     // Get the complete pathname
3608                 p = d_path(curlun->filp->f_path.dentry, curlun->filp->f_path.mnt,
3609                                 buf, PAGE_SIZE - 1);
3610                 if (IS_ERR(p))
3611                         rc = PTR_ERR(p);
3612                 else {
3613                         rc = strlen(p);
3614                         memmove(buf, p, rc);
3615                         buf[rc] = '\n';         // Add a newline
3616                         buf[++rc] = 0;
3617                 }
3618         } else {                                // No file, return 0 bytes
3619                 *buf = 0;
3620                 rc = 0;
3621         }
3622         up_read(&fsg->filesem);
3623         return rc;
3624 }
3625
3626
3627 static ssize_t store_ro(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
3628 {
3629         ssize_t         rc = count;
3630         struct lun      *curlun = dev_to_lun(dev);
3631         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3632         int             i;
3633
3634         if (sscanf(buf, "%d", &i) != 1)
3635                 return -EINVAL;
3636
3637         /* Allow the write-enable status to change only while the backing file
3638          * is closed. */
3639         down_read(&fsg->filesem);
3640         if (backing_file_is_open(curlun)) {
3641                 LDBG(curlun, "read-only status change prevented\n");
3642                 rc = -EBUSY;
3643         } else {
3644                 curlun->ro = !!i;
3645                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
3646         }
3647         up_read(&fsg->filesem);
3648         return rc;
3649 }
3650
3651 static ssize_t store_file(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
3652 {
3653         struct lun      *curlun = dev_to_lun(dev);
3654         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3655         int             rc = 0;
3656
3657         if (curlun->prevent_medium_removal && backing_file_is_open(curlun)) {
3658                 LDBG(curlun, "eject attempt prevented\n");
3659                 return -EBUSY;                          // "Door is locked"
3660         }
3661
3662         /* Remove a trailing newline */
3663         if (count > 0 && buf[count-1] == '\n')
3664                 ((char *) buf)[count-1] = 0;            // Ugh!
3665
3666         /* Eject current medium */
3667         down_write(&fsg->filesem);
3668         if (backing_file_is_open(curlun)) {
3669                 close_backing_file(curlun);
3670                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
3671         }
3672
3673         /* Load new medium */
3674         if (count > 0 && buf[0]) {
3675                 rc = open_backing_file(curlun, buf);
3676                 if (rc == 0)
3677                         curlun->unit_attention_data =
3678                                         SS_NOT_READY_TO_READY_TRANSITION;
3679         }
3680         up_write(&fsg->filesem);
3681         return (rc < 0 ? rc : count);
3682 }
3683
3684
3685 /* The write permissions and store_xxx pointers are set in fsg_bind() */
3686 static DEVICE_ATTR(ro, 0444, show_ro, NULL);
3687 static DEVICE_ATTR(file, 0444, show_file, NULL);
3688
3689
3690 /*-------------------------------------------------------------------------*/
3691
3692 static void fsg_release(struct kref *ref)
3693 {
3694         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
3695
3696         kfree(fsg->luns);
3697         kfree(fsg);
3698 }
3699
3700 static void lun_release(struct device *dev)
3701 {
3702         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3703
3704         kref_put(&fsg->ref, fsg_release);
3705 }
3706
3707 static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
3708 {
3709         struct fsg_dev          *fsg = get_gadget_data(gadget);
3710         int                     i;
3711         struct lun              *curlun;
3712         struct usb_request      *req = fsg->ep0req;
3713
3714         DBG(fsg, "unbind\n");
3715         clear_bit(REGISTERED, &fsg->atomic_bitflags);
3716
3717         /* Unregister the sysfs attribute files and the LUNs */
3718         for (i = 0; i < fsg->nluns; ++i) {
3719                 curlun = &fsg->luns[i];
3720                 if (curlun->registered) {
3721                         device_remove_file(&curlun->dev, &dev_attr_ro);
3722                         device_remove_file(&curlun->dev, &dev_attr_file);
3723                         device_unregister(&curlun->dev);
3724                         curlun->registered = 0;
3725                 }
3726         }
3727
3728         /* If the thread isn't already dead, tell it to exit now */
3729         if (fsg->state != FSG_STATE_TERMINATED) {
3730                 raise_exception(fsg, FSG_STATE_EXIT);
3731                 wait_for_completion(&fsg->thread_notifier);
3732
3733                 /* The cleanup routine waits for this completion also */
3734                 complete(&fsg->thread_notifier);
3735         }
3736
3737         /* Free the data buffers */
3738         for (i = 0; i < NUM_BUFFERS; ++i) {
3739                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3740
3741                 if (bh->buf)
3742                         usb_ep_free_buffer(fsg->bulk_in, bh->buf, bh->dma,
3743                                         mod_data.buflen);
3744         }
3745
3746         /* Free the request and buffer for endpoint 0 */
3747         if (req) {
3748                 if (req->buf)
3749                         usb_ep_free_buffer(fsg->ep0, req->buf,
3750                                         req->dma, EP0_BUFSIZE);
3751                 usb_ep_free_request(fsg->ep0, req);
3752         }
3753
3754         set_gadget_data(gadget, NULL);
3755 }
3756
3757
3758 static int __init check_parameters(struct fsg_dev *fsg)
3759 {
3760         int     prot;
3761         int     gcnum;
3762
3763         /* Store the default values */
3764         mod_data.transport_type = USB_PR_BULK;
3765         mod_data.transport_name = "Bulk-only";
3766         mod_data.protocol_type = USB_SC_SCSI;
3767         mod_data.protocol_name = "Transparent SCSI";
3768
3769         if (gadget_is_sh(fsg->gadget))
3770                 mod_data.can_stall = 0;
3771
3772         if (mod_data.release == 0xffff) {       // Parameter wasn't set
3773                 /* The sa1100 controller is not supported */
3774                 if (gadget_is_sa1100(fsg->gadget))
3775                         gcnum = -1;
3776                 else
3777                         gcnum = usb_gadget_controller_number(fsg->gadget);
3778                 if (gcnum >= 0)
3779                         mod_data.release = 0x0300 + gcnum;
3780                 else {
3781                         WARN(fsg, "controller '%s' not recognized\n",
3782                                 fsg->gadget->name);
3783                         mod_data.release = 0x0399;
3784                 }
3785         }
3786
3787         prot = simple_strtol(mod_data.protocol_parm, NULL, 0);
3788
3789 #ifdef CONFIG_USB_FILE_STORAGE_TEST
3790         if (strnicmp(mod_data.transport_parm, "BBB", 10) == 0) {
3791                 ;               // Use default setting
3792         } else if (strnicmp(mod_data.transport_parm, "CB", 10) == 0) {
3793                 mod_data.transport_type = USB_PR_CB;
3794                 mod_data.transport_name = "Control-Bulk";
3795         } else if (strnicmp(mod_data.transport_parm, "CBI", 10) == 0) {
3796                 mod_data.transport_type = USB_PR_CBI;
3797                 mod_data.transport_name = "Control-Bulk-Interrupt";
3798         } else {
3799                 ERROR(fsg, "invalid transport: %s\n", mod_data.transport_parm);
3800                 return -EINVAL;
3801         }
3802
3803         if (strnicmp(mod_data.protocol_parm, "SCSI", 10) == 0 ||
3804                         prot == USB_SC_SCSI) {
3805                 ;               // Use default setting
3806         } else if (strnicmp(mod_data.protocol_parm, "RBC", 10) == 0 ||
3807                         prot == USB_SC_RBC) {
3808                 mod_data.protocol_type = USB_SC_RBC;
3809                 mod_data.protocol_name = "RBC";
3810         } else if (strnicmp(mod_data.protocol_parm, "8020", 4) == 0 ||
3811                         strnicmp(mod_data.protocol_parm, "ATAPI", 10) == 0 ||
3812                         prot == USB_SC_8020) {
3813                 mod_data.protocol_type = USB_SC_8020;
3814                 mod_data.protocol_name = "8020i (ATAPI)";
3815         } else if (strnicmp(mod_data.protocol_parm, "QIC", 3) == 0 ||
3816                         prot == USB_SC_QIC) {
3817                 mod_data.protocol_type = USB_SC_QIC;
3818                 mod_data.protocol_name = "QIC-157";
3819         } else if (strnicmp(mod_data.protocol_parm, "UFI", 10) == 0 ||
3820                         prot == USB_SC_UFI) {
3821                 mod_data.protocol_type = USB_SC_UFI;
3822                 mod_data.protocol_name = "UFI";
3823         } else if (strnicmp(mod_data.protocol_parm, "8070", 4) == 0 ||
3824                         prot == USB_SC_8070) {
3825                 mod_data.protocol_type = USB_SC_8070;
3826                 mod_data.protocol_name = "8070i";
3827         } else {
3828                 ERROR(fsg, "invalid protocol: %s\n", mod_data.protocol_parm);
3829                 return -EINVAL;
3830         }
3831
3832         mod_data.buflen &= PAGE_CACHE_MASK;
3833         if (mod_data.buflen <= 0) {
3834                 ERROR(fsg, "invalid buflen\n");
3835                 return -ETOOSMALL;
3836         }
3837 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
3838
3839         return 0;
3840 }
3841
3842
3843 static int __init fsg_bind(struct usb_gadget *gadget)
3844 {
3845         struct fsg_dev          *fsg = the_fsg;
3846         int                     rc;
3847         int                     i;
3848         struct lun              *curlun;
3849         struct usb_ep           *ep;
3850         struct usb_request      *req;
3851         char                    *pathbuf, *p;
3852
3853         fsg->gadget = gadget;
3854         set_gadget_data(gadget, fsg);
3855         fsg->ep0 = gadget->ep0;
3856         fsg->ep0->driver_data = fsg;
3857
3858         if ((rc = check_parameters(fsg)) != 0)
3859                 goto out;
3860
3861         if (mod_data.removable) {       // Enable the store_xxx attributes
3862                 dev_attr_ro.attr.mode = dev_attr_file.attr.mode = 0644;
3863                 dev_attr_ro.store = store_ro;
3864                 dev_attr_file.store = store_file;
3865         }
3866
3867         /* Find out how many LUNs there should be */
3868         i = mod_data.nluns;
3869         if (i == 0)
3870                 i = max(mod_data.num_filenames, 1);
3871         if (i > MAX_LUNS) {
3872                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
3873                 rc = -EINVAL;
3874                 goto out;
3875         }
3876
3877         /* Create the LUNs, open their backing files, and register the
3878          * LUN devices in sysfs. */
3879         fsg->luns = kzalloc(i * sizeof(struct lun), GFP_KERNEL);
3880         if (!fsg->luns) {
3881                 rc = -ENOMEM;
3882                 goto out;
3883         }
3884         fsg->nluns = i;
3885
3886         for (i = 0; i < fsg->nluns; ++i) {
3887                 curlun = &fsg->luns[i];
3888                 curlun->ro = mod_data.ro[i];
3889                 curlun->dev.release = lun_release;
3890                 curlun->dev.parent = &gadget->dev;
3891                 curlun->dev.driver = &fsg_driver.driver;
3892                 dev_set_drvdata(&curlun->dev, fsg);
3893                 snprintf(curlun->dev.bus_id, BUS_ID_SIZE,
3894                                 "%s-lun%d", gadget->dev.bus_id, i);
3895
3896                 if ((rc = device_register(&curlun->dev)) != 0) {
3897                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
3898                         goto out;
3899                 }
3900                 if ((rc = device_create_file(&curlun->dev,
3901                                         &dev_attr_ro)) != 0 ||
3902                                 (rc = device_create_file(&curlun->dev,
3903                                         &dev_attr_file)) != 0) {
3904                         device_unregister(&curlun->dev);
3905                         goto out;
3906                 }
3907                 curlun->registered = 1;
3908                 kref_get(&fsg->ref);
3909
3910                 if (mod_data.file[i] && *mod_data.file[i]) {
3911                         if ((rc = open_backing_file(curlun,
3912                                         mod_data.file[i])) != 0)
3913                                 goto out;
3914                 } else if (!mod_data.removable) {
3915                         ERROR(fsg, "no file given for LUN%d\n", i);
3916                         rc = -EINVAL;
3917                         goto out;
3918                 }
3919         }
3920
3921         /* Find all the endpoints we will use */
3922         usb_ep_autoconfig_reset(gadget);
3923         ep = usb_ep_autoconfig(gadget, &fs_bulk_in_desc);
3924         if (!ep)
3925                 goto autoconf_fail;
3926         ep->driver_data = fsg;          // claim the endpoint
3927         fsg->bulk_in = ep;
3928
3929         ep = usb_ep_autoconfig(gadget, &fs_bulk_out_desc);
3930         if (!ep)
3931                 goto autoconf_fail;
3932         ep->driver_data = fsg;          // claim the endpoint
3933         fsg->bulk_out = ep;
3934
3935         if (transport_is_cbi()) {
3936                 ep = usb_ep_autoconfig(gadget, &fs_intr_in_desc);
3937                 if (!ep)
3938                         goto autoconf_fail;
3939                 ep->driver_data = fsg;          // claim the endpoint
3940                 fsg->intr_in = ep;
3941         }
3942
3943         /* Fix up the descriptors */
3944         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
3945         device_desc.idVendor = cpu_to_le16(mod_data.vendor);
3946         device_desc.idProduct = cpu_to_le16(mod_data.product);
3947         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
3948
3949         i = (transport_is_cbi() ? 3 : 2);       // Number of endpoints
3950         intf_desc.bNumEndpoints = i;
3951         intf_desc.bInterfaceSubClass = mod_data.protocol_type;
3952         intf_desc.bInterfaceProtocol = mod_data.transport_type;
3953         fs_function[i + FS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3954
3955 #ifdef CONFIG_USB_GADGET_DUALSPEED
3956         hs_function[i + HS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3957
3958         /* Assume ep0 uses the same maxpacket value for both speeds */
3959         dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
3960
3961         /* Assume that all endpoint addresses are the same for both speeds */
3962         hs_bulk_in_desc.bEndpointAddress = fs_bulk_in_desc.bEndpointAddress;
3963         hs_bulk_out_desc.bEndpointAddress = fs_bulk_out_desc.bEndpointAddress;
3964         hs_intr_in_desc.bEndpointAddress = fs_intr_in_desc.bEndpointAddress;
3965 #endif
3966
3967         if (gadget->is_otg) {
3968                 otg_desc.bmAttributes |= USB_OTG_HNP,
3969                 config_desc.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
3970         }
3971
3972         rc = -ENOMEM;
3973
3974         /* Allocate the request and buffer for endpoint 0 */
3975         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
3976         if (!req)
3977                 goto out;
3978         req->buf = usb_ep_alloc_buffer(fsg->ep0, EP0_BUFSIZE,
3979                         &req->dma, GFP_KERNEL);
3980         if (!req->buf)
3981                 goto out;
3982         req->complete = ep0_complete;
3983
3984         /* Allocate the data buffers */
3985         for (i = 0; i < NUM_BUFFERS; ++i) {
3986                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3987
3988                 /* Allocate for the bulk-in endpoint.  We assume that
3989                  * the buffer will also work with the bulk-out (and
3990                  * interrupt-in) endpoint. */
3991                 bh->buf = usb_ep_alloc_buffer(fsg->bulk_in, mod_data.buflen,
3992                                 &bh->dma, GFP_KERNEL);
3993                 if (!bh->buf)
3994                         goto out;
3995                 bh->next = bh + 1;
3996         }
3997         fsg->buffhds[NUM_BUFFERS - 1].next = &fsg->buffhds[0];
3998
3999         /* This should reflect the actual gadget power source */
4000         usb_gadget_set_selfpowered(gadget);
4001
4002         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
4003                         init_utsname()->sysname, init_utsname()->release,
4004                         gadget->name);
4005
4006         /* On a real device, serial[] would be loaded from permanent
4007          * storage.  We just encode it from the driver version string. */
4008         for (i = 0; i < sizeof(serial) - 2; i += 2) {
4009                 unsigned char           c = DRIVER_VERSION[i / 2];
4010
4011                 if (!c)
4012                         break;
4013                 sprintf(&serial[i], "%02X", c);
4014         }
4015
4016         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
4017                         "file-storage-gadget");
4018         if (IS_ERR(fsg->thread_task)) {
4019                 rc = PTR_ERR(fsg->thread_task);
4020                 goto out;
4021         }
4022
4023         INFO(fsg, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
4024         INFO(fsg, "Number of LUNs=%d\n", fsg->nluns);
4025
4026         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
4027         for (i = 0; i < fsg->nluns; ++i) {
4028                 curlun = &fsg->luns[i];
4029                 if (backing_file_is_open(curlun)) {
4030                         p = NULL;
4031                         if (pathbuf) {
4032                                 p = d_path(curlun->filp->f_path.dentry,
4033                                         curlun->filp->f_path.mnt,
4034                                         pathbuf, PATH_MAX);
4035                                 if (IS_ERR(p))
4036                                         p = NULL;
4037                         }
4038                         LINFO(curlun, "ro=%d, file: %s\n",
4039                                         curlun->ro, (p ? p : "(error)"));
4040                 }
4041         }
4042         kfree(pathbuf);
4043
4044         DBG(fsg, "transport=%s (x%02x)\n",
4045                         mod_data.transport_name, mod_data.transport_type);
4046         DBG(fsg, "protocol=%s (x%02x)\n",
4047                         mod_data.protocol_name, mod_data.protocol_type);
4048         DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n",
4049                         mod_data.vendor, mod_data.product, mod_data.release);
4050         DBG(fsg, "removable=%d, stall=%d, buflen=%u\n",
4051                         mod_data.removable, mod_data.can_stall,
4052                         mod_data.buflen);
4053         DBG(fsg, "I/O thread pid: %d\n", fsg->thread_task->pid);
4054
4055         set_bit(REGISTERED, &fsg->atomic_bitflags);
4056
4057         /* Tell the thread to start working */
4058         wake_up_process(fsg->thread_task);
4059         return 0;
4060
4061 autoconf_fail:
4062         ERROR(fsg, "unable to autoconfigure all endpoints\n");
4063         rc = -ENOTSUPP;
4064
4065 out:
4066         fsg->state = FSG_STATE_TERMINATED;      // The thread is dead
4067         fsg_unbind(gadget);
4068         close_all_backing_files(fsg);
4069         return rc;
4070 }
4071
4072
4073 /*-------------------------------------------------------------------------*/
4074
4075 static void fsg_suspend(struct usb_gadget *gadget)
4076 {
4077         struct fsg_dev          *fsg = get_gadget_data(gadget);
4078
4079         DBG(fsg, "suspend\n");
4080         set_bit(SUSPENDED, &fsg->atomic_bitflags);
4081 }
4082
4083 static void fsg_resume(struct usb_gadget *gadget)
4084 {
4085         struct fsg_dev          *fsg = get_gadget_data(gadget);
4086
4087         DBG(fsg, "resume\n");
4088         clear_bit(SUSPENDED, &fsg->atomic_bitflags);
4089 }
4090
4091
4092 /*-------------------------------------------------------------------------*/
4093
4094 static struct usb_gadget_driver         fsg_driver = {
4095 #ifdef CONFIG_USB_GADGET_DUALSPEED
4096         .speed          = USB_SPEED_HIGH,
4097 #else
4098         .speed          = USB_SPEED_FULL,
4099 #endif
4100         .function       = (char *) longname,
4101         .bind           = fsg_bind,
4102         .unbind         = fsg_unbind,
4103         .disconnect     = fsg_disconnect,
4104         .setup          = fsg_setup,
4105         .suspend        = fsg_suspend,
4106         .resume         = fsg_resume,
4107
4108         .driver         = {
4109                 .name           = (char *) shortname,
4110                 .owner          = THIS_MODULE,
4111                 // .release = ...
4112                 // .suspend = ...
4113                 // .resume = ...
4114         },
4115 };
4116
4117
4118 static int __init fsg_alloc(void)
4119 {
4120         struct fsg_dev          *fsg;
4121
4122         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
4123         if (!fsg)
4124                 return -ENOMEM;
4125         spin_lock_init(&fsg->lock);
4126         init_rwsem(&fsg->filesem);
4127         kref_init(&fsg->ref);
4128         init_completion(&fsg->thread_notifier);
4129
4130         the_fsg = fsg;
4131         return 0;
4132 }
4133
4134
4135 static int __init fsg_init(void)
4136 {
4137         int             rc;
4138         struct fsg_dev  *fsg;
4139
4140         if ((rc = fsg_alloc()) != 0)
4141                 return rc;
4142         fsg = the_fsg;
4143         if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
4144                 kref_put(&fsg->ref, fsg_release);
4145         return rc;
4146 }
4147 module_init(fsg_init);
4148
4149
4150 static void __exit fsg_cleanup(void)
4151 {
4152         struct fsg_dev  *fsg = the_fsg;
4153
4154         /* Unregister the driver iff the thread hasn't already done so */
4155         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
4156                 usb_gadget_unregister_driver(&fsg_driver);
4157
4158         /* Wait for the thread to finish up */
4159         wait_for_completion(&fsg->thread_notifier);
4160
4161         close_all_backing_files(fsg);
4162         kref_put(&fsg->ref, fsg_release);
4163 }
4164 module_exit(fsg_cleanup);