Merge master.kernel.org:/home/rmk/linux-2.6-serial
[pandora-kernel.git] / 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/suspend.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
571         u32             sense_data;
572         u32             sense_data_info;
573         u32             unit_attention_data;
574
575         struct device   dev;
576 };
577
578 #define backing_file_is_open(curlun)    ((curlun)->filp != NULL)
579
580 static inline struct lun *dev_to_lun(struct device *dev)
581 {
582         return container_of(dev, struct lun, dev);
583 }
584
585
586 /* Big enough to hold our biggest descriptor */
587 #define EP0_BUFSIZE     256
588 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     // An impossibly large value
589
590 /* Number of buffers we will use.  2 is enough for double-buffering */
591 #define NUM_BUFFERS     2
592
593 enum fsg_buffer_state {
594         BUF_STATE_EMPTY = 0,
595         BUF_STATE_FULL,
596         BUF_STATE_BUSY
597 };
598
599 struct fsg_buffhd {
600         void                            *buf;
601         dma_addr_t                      dma;
602         enum fsg_buffer_state           state;
603         struct fsg_buffhd               *next;
604
605         /* The NetChip 2280 is faster, and handles some protocol faults
606          * better, if we don't submit any short bulk-out read requests.
607          * So we will record the intended request length here. */
608         unsigned int                    bulk_out_intended_length;
609
610         struct usb_request              *inreq;
611         int                             inreq_busy;
612         struct usb_request              *outreq;
613         int                             outreq_busy;
614 };
615
616 enum fsg_state {
617         FSG_STATE_COMMAND_PHASE = -10,          // This one isn't used anywhere
618         FSG_STATE_DATA_PHASE,
619         FSG_STATE_STATUS_PHASE,
620
621         FSG_STATE_IDLE = 0,
622         FSG_STATE_ABORT_BULK_OUT,
623         FSG_STATE_RESET,
624         FSG_STATE_INTERFACE_CHANGE,
625         FSG_STATE_CONFIG_CHANGE,
626         FSG_STATE_DISCONNECT,
627         FSG_STATE_EXIT,
628         FSG_STATE_TERMINATED
629 };
630
631 enum data_direction {
632         DATA_DIR_UNKNOWN = 0,
633         DATA_DIR_FROM_HOST,
634         DATA_DIR_TO_HOST,
635         DATA_DIR_NONE
636 };
637
638 struct fsg_dev {
639         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
640         spinlock_t              lock;
641         struct usb_gadget       *gadget;
642
643         /* filesem protects: backing files in use */
644         struct rw_semaphore     filesem;
645
646         /* reference counting: wait until all LUNs are released */
647         struct kref             ref;
648
649         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
650         struct usb_request      *ep0req;        // For control responses
651         unsigned int            ep0_req_tag;
652         const char              *ep0req_name;
653
654         struct usb_request      *intreq;        // For interrupt responses
655         int                     intreq_busy;
656         struct fsg_buffhd       *intr_buffhd;
657
658         unsigned int            bulk_out_maxpacket;
659         enum fsg_state          state;          // For exception handling
660         unsigned int            exception_req_tag;
661
662         u8                      config, new_config;
663
664         unsigned int            running : 1;
665         unsigned int            bulk_in_enabled : 1;
666         unsigned int            bulk_out_enabled : 1;
667         unsigned int            intr_in_enabled : 1;
668         unsigned int            phase_error : 1;
669         unsigned int            short_packet_received : 1;
670         unsigned int            bad_lun_okay : 1;
671
672         unsigned long           atomic_bitflags;
673 #define REGISTERED              0
674 #define CLEAR_BULK_HALTS        1
675 #define SUSPENDED               2
676
677         struct usb_ep           *bulk_in;
678         struct usb_ep           *bulk_out;
679         struct usb_ep           *intr_in;
680
681         struct fsg_buffhd       *next_buffhd_to_fill;
682         struct fsg_buffhd       *next_buffhd_to_drain;
683         struct fsg_buffhd       buffhds[NUM_BUFFERS];
684
685         int                     thread_wakeup_needed;
686         struct completion       thread_notifier;
687         struct task_struct      *thread_task;
688         sigset_t                thread_signal_mask;
689
690         int                     cmnd_size;
691         u8                      cmnd[MAX_COMMAND_SIZE];
692         enum data_direction     data_dir;
693         u32                     data_size;
694         u32                     data_size_from_cmnd;
695         u32                     tag;
696         unsigned int            lun;
697         u32                     residue;
698         u32                     usb_amount_left;
699
700         /* The CB protocol offers no way for a host to know when a command
701          * has completed.  As a result the next command may arrive early,
702          * and we will still have to handle it.  For that reason we need
703          * a buffer to store new commands when using CB (or CBI, which
704          * does not oblige a host to wait for command completion either). */
705         int                     cbbuf_cmnd_size;
706         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
707
708         unsigned int            nluns;
709         struct lun              *luns;
710         struct lun              *curlun;
711 };
712
713 typedef void (*fsg_routine_t)(struct fsg_dev *);
714
715 static int inline exception_in_progress(struct fsg_dev *fsg)
716 {
717         return (fsg->state > FSG_STATE_IDLE);
718 }
719
720 /* Make bulk-out requests be divisible by the maxpacket size */
721 static void inline set_bulk_out_req_length(struct fsg_dev *fsg,
722                 struct fsg_buffhd *bh, unsigned int length)
723 {
724         unsigned int    rem;
725
726         bh->bulk_out_intended_length = length;
727         rem = length % fsg->bulk_out_maxpacket;
728         if (rem > 0)
729                 length += fsg->bulk_out_maxpacket - rem;
730         bh->outreq->length = length;
731 }
732
733 static struct fsg_dev                   *the_fsg;
734 static struct usb_gadget_driver         fsg_driver;
735
736 static void     close_backing_file(struct lun *curlun);
737 static void     close_all_backing_files(struct fsg_dev *fsg);
738
739
740 /*-------------------------------------------------------------------------*/
741
742 #ifdef DUMP_MSGS
743
744 static void dump_msg(struct fsg_dev *fsg, const char *label,
745                 const u8 *buf, unsigned int length)
746 {
747         unsigned int    start, num, i;
748         char            line[52], *p;
749
750         if (length >= 512)
751                 return;
752         DBG(fsg, "%s, length %u:\n", label, length);
753
754         start = 0;
755         while (length > 0) {
756                 num = min(length, 16u);
757                 p = line;
758                 for (i = 0; i < num; ++i) {
759                         if (i == 8)
760                                 *p++ = ' ';
761                         sprintf(p, " %02x", buf[i]);
762                         p += 3;
763                 }
764                 *p = 0;
765                 printk(KERN_DEBUG "%6x: %s\n", start, line);
766                 buf += num;
767                 start += num;
768                 length -= num;
769         }
770 }
771
772 static void inline dump_cdb(struct fsg_dev *fsg)
773 {}
774
775 #else
776
777 static void inline dump_msg(struct fsg_dev *fsg, const char *label,
778                 const u8 *buf, unsigned int length)
779 {}
780
781 static void inline dump_cdb(struct fsg_dev *fsg)
782 {
783         int     i;
784         char    cmdbuf[3*MAX_COMMAND_SIZE + 1];
785
786         for (i = 0; i < fsg->cmnd_size; ++i)
787                 sprintf(cmdbuf + i*3, " %02x", fsg->cmnd[i]);
788         VDBG(fsg, "SCSI CDB: %s\n", cmdbuf);
789 }
790
791 #endif /* DUMP_MSGS */
792
793
794 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
795 {
796         const char      *name;
797
798         if (ep == fsg->bulk_in)
799                 name = "bulk-in";
800         else if (ep == fsg->bulk_out)
801                 name = "bulk-out";
802         else
803                 name = ep->name;
804         DBG(fsg, "%s set halt\n", name);
805         return usb_ep_set_halt(ep);
806 }
807
808
809 /*-------------------------------------------------------------------------*/
810
811 /* Routines for unaligned data access */
812
813 static u16 inline get_be16(u8 *buf)
814 {
815         return ((u16) buf[0] << 8) | ((u16) buf[1]);
816 }
817
818 static u32 inline get_be32(u8 *buf)
819 {
820         return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) |
821                         ((u32) buf[2] << 8) | ((u32) buf[3]);
822 }
823
824 static void inline put_be16(u8 *buf, u16 val)
825 {
826         buf[0] = val >> 8;
827         buf[1] = val;
828 }
829
830 static void inline put_be32(u8 *buf, u32 val)
831 {
832         buf[0] = val >> 24;
833         buf[1] = val >> 16;
834         buf[2] = val >> 8;
835         buf[3] = val & 0xff;
836 }
837
838
839 /*-------------------------------------------------------------------------*/
840
841 /*
842  * DESCRIPTORS ... most are static, but strings and (full) configuration
843  * descriptors are built on demand.  Also the (static) config and interface
844  * descriptors are adjusted during fsg_bind().
845  */
846 #define STRING_MANUFACTURER     1
847 #define STRING_PRODUCT          2
848 #define STRING_SERIAL           3
849 #define STRING_CONFIG           4
850 #define STRING_INTERFACE        5
851
852 /* There is only one configuration. */
853 #define CONFIG_VALUE            1
854
855 static struct usb_device_descriptor
856 device_desc = {
857         .bLength =              sizeof device_desc,
858         .bDescriptorType =      USB_DT_DEVICE,
859
860         .bcdUSB =               __constant_cpu_to_le16(0x0200),
861         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
862
863         /* The next three values can be overridden by module parameters */
864         .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_ID),
865         .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
866         .bcdDevice =            __constant_cpu_to_le16(0xffff),
867
868         .iManufacturer =        STRING_MANUFACTURER,
869         .iProduct =             STRING_PRODUCT,
870         .iSerialNumber =        STRING_SERIAL,
871         .bNumConfigurations =   1,
872 };
873
874 static struct usb_config_descriptor
875 config_desc = {
876         .bLength =              sizeof config_desc,
877         .bDescriptorType =      USB_DT_CONFIG,
878
879         /* wTotalLength computed by usb_gadget_config_buf() */
880         .bNumInterfaces =       1,
881         .bConfigurationValue =  CONFIG_VALUE,
882         .iConfiguration =       STRING_CONFIG,
883         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
884         .bMaxPower =            1,      // self-powered
885 };
886
887 static struct usb_otg_descriptor
888 otg_desc = {
889         .bLength =              sizeof(otg_desc),
890         .bDescriptorType =      USB_DT_OTG,
891
892         .bmAttributes =         USB_OTG_SRP,
893 };
894
895 /* There is only one interface. */
896
897 static struct usb_interface_descriptor
898 intf_desc = {
899         .bLength =              sizeof intf_desc,
900         .bDescriptorType =      USB_DT_INTERFACE,
901
902         .bNumEndpoints =        2,              // Adjusted during fsg_bind()
903         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
904         .bInterfaceSubClass =   USB_SC_SCSI,    // Adjusted during fsg_bind()
905         .bInterfaceProtocol =   USB_PR_BULK,    // Adjusted during fsg_bind()
906         .iInterface =           STRING_INTERFACE,
907 };
908
909 /* Three full-speed endpoint descriptors: bulk-in, bulk-out,
910  * and interrupt-in. */
911
912 static struct usb_endpoint_descriptor
913 fs_bulk_in_desc = {
914         .bLength =              USB_DT_ENDPOINT_SIZE,
915         .bDescriptorType =      USB_DT_ENDPOINT,
916
917         .bEndpointAddress =     USB_DIR_IN,
918         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
919         /* wMaxPacketSize set by autoconfiguration */
920 };
921
922 static struct usb_endpoint_descriptor
923 fs_bulk_out_desc = {
924         .bLength =              USB_DT_ENDPOINT_SIZE,
925         .bDescriptorType =      USB_DT_ENDPOINT,
926
927         .bEndpointAddress =     USB_DIR_OUT,
928         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
929         /* wMaxPacketSize set by autoconfiguration */
930 };
931
932 static struct usb_endpoint_descriptor
933 fs_intr_in_desc = {
934         .bLength =              USB_DT_ENDPOINT_SIZE,
935         .bDescriptorType =      USB_DT_ENDPOINT,
936
937         .bEndpointAddress =     USB_DIR_IN,
938         .bmAttributes =         USB_ENDPOINT_XFER_INT,
939         .wMaxPacketSize =       __constant_cpu_to_le16(2),
940         .bInterval =            32,     // frames -> 32 ms
941 };
942
943 static const struct usb_descriptor_header *fs_function[] = {
944         (struct usb_descriptor_header *) &otg_desc,
945         (struct usb_descriptor_header *) &intf_desc,
946         (struct usb_descriptor_header *) &fs_bulk_in_desc,
947         (struct usb_descriptor_header *) &fs_bulk_out_desc,
948         (struct usb_descriptor_header *) &fs_intr_in_desc,
949         NULL,
950 };
951 #define FS_FUNCTION_PRE_EP_ENTRIES      2
952
953
954 #ifdef  CONFIG_USB_GADGET_DUALSPEED
955
956 /*
957  * USB 2.0 devices need to expose both high speed and full speed
958  * descriptors, unless they only run at full speed.
959  *
960  * That means alternate endpoint descriptors (bigger packets)
961  * and a "device qualifier" ... plus more construction options
962  * for the config descriptor.
963  */
964 static struct usb_qualifier_descriptor
965 dev_qualifier = {
966         .bLength =              sizeof dev_qualifier,
967         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
968
969         .bcdUSB =               __constant_cpu_to_le16(0x0200),
970         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
971
972         .bNumConfigurations =   1,
973 };
974
975 static struct usb_endpoint_descriptor
976 hs_bulk_in_desc = {
977         .bLength =              USB_DT_ENDPOINT_SIZE,
978         .bDescriptorType =      USB_DT_ENDPOINT,
979
980         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
981         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
982         .wMaxPacketSize =       __constant_cpu_to_le16(512),
983 };
984
985 static struct usb_endpoint_descriptor
986 hs_bulk_out_desc = {
987         .bLength =              USB_DT_ENDPOINT_SIZE,
988         .bDescriptorType =      USB_DT_ENDPOINT,
989
990         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
991         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
992         .wMaxPacketSize =       __constant_cpu_to_le16(512),
993         .bInterval =            1,      // NAK every 1 uframe
994 };
995
996 static struct usb_endpoint_descriptor
997 hs_intr_in_desc = {
998         .bLength =              USB_DT_ENDPOINT_SIZE,
999         .bDescriptorType =      USB_DT_ENDPOINT,
1000
1001         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
1002         .bmAttributes =         USB_ENDPOINT_XFER_INT,
1003         .wMaxPacketSize =       __constant_cpu_to_le16(2),
1004         .bInterval =            9,      // 2**(9-1) = 256 uframes -> 32 ms
1005 };
1006
1007 static const struct usb_descriptor_header *hs_function[] = {
1008         (struct usb_descriptor_header *) &otg_desc,
1009         (struct usb_descriptor_header *) &intf_desc,
1010         (struct usb_descriptor_header *) &hs_bulk_in_desc,
1011         (struct usb_descriptor_header *) &hs_bulk_out_desc,
1012         (struct usb_descriptor_header *) &hs_intr_in_desc,
1013         NULL,
1014 };
1015 #define HS_FUNCTION_PRE_EP_ENTRIES      2
1016
1017 /* Maxpacket and other transfer characteristics vary by speed. */
1018 #define ep_desc(g,fs,hs)        (((g)->speed==USB_SPEED_HIGH) ? (hs) : (fs))
1019
1020 #else
1021
1022 /* If there's no high speed support, always use the full-speed descriptor. */
1023 #define ep_desc(g,fs,hs)        fs
1024
1025 #endif  /* !CONFIG_USB_GADGET_DUALSPEED */
1026
1027
1028 /* The CBI specification limits the serial string to 12 uppercase hexadecimal
1029  * characters. */
1030 static char                             manufacturer[64];
1031 static char                             serial[13];
1032
1033 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
1034 static struct usb_string                strings[] = {
1035         {STRING_MANUFACTURER,   manufacturer},
1036         {STRING_PRODUCT,        longname},
1037         {STRING_SERIAL,         serial},
1038         {STRING_CONFIG,         "Self-powered"},
1039         {STRING_INTERFACE,      "Mass Storage"},
1040         {}
1041 };
1042
1043 static struct usb_gadget_strings        stringtab = {
1044         .language       = 0x0409,               // en-us
1045         .strings        = strings,
1046 };
1047
1048
1049 /*
1050  * Config descriptors must agree with the code that sets configurations
1051  * and with code managing interfaces and their altsettings.  They must
1052  * also handle different speeds and other-speed requests.
1053  */
1054 static int populate_config_buf(struct usb_gadget *gadget,
1055                 u8 *buf, u8 type, unsigned index)
1056 {
1057 #ifdef CONFIG_USB_GADGET_DUALSPEED
1058         enum usb_device_speed                   speed = gadget->speed;
1059 #endif
1060         int                                     len;
1061         const struct usb_descriptor_header      **function;
1062
1063         if (index > 0)
1064                 return -EINVAL;
1065
1066 #ifdef CONFIG_USB_GADGET_DUALSPEED
1067         if (type == USB_DT_OTHER_SPEED_CONFIG)
1068                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
1069         if (speed == USB_SPEED_HIGH)
1070                 function = hs_function;
1071         else
1072 #endif
1073                 function = fs_function;
1074
1075         /* for now, don't advertise srp-only devices */
1076         if (!gadget->is_otg)
1077                 function++;
1078
1079         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
1080         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
1081         return len;
1082 }
1083
1084
1085 /*-------------------------------------------------------------------------*/
1086
1087 /* These routines may be called in process context or in_irq */
1088
1089 /* Caller must hold fsg->lock */
1090 static void wakeup_thread(struct fsg_dev *fsg)
1091 {
1092         /* Tell the main thread that something has happened */
1093         fsg->thread_wakeup_needed = 1;
1094         if (fsg->thread_task)
1095                 wake_up_process(fsg->thread_task);
1096 }
1097
1098
1099 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
1100 {
1101         unsigned long           flags;
1102
1103         /* Do nothing if a higher-priority exception is already in progress.
1104          * If a lower-or-equal priority exception is in progress, preempt it
1105          * and notify the main thread by sending it a signal. */
1106         spin_lock_irqsave(&fsg->lock, flags);
1107         if (fsg->state <= new_state) {
1108                 fsg->exception_req_tag = fsg->ep0_req_tag;
1109                 fsg->state = new_state;
1110                 if (fsg->thread_task)
1111                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
1112                                         fsg->thread_task);
1113         }
1114         spin_unlock_irqrestore(&fsg->lock, flags);
1115 }
1116
1117
1118 /*-------------------------------------------------------------------------*/
1119
1120 /* The disconnect callback and ep0 routines.  These always run in_irq,
1121  * except that ep0_queue() is called in the main thread to acknowledge
1122  * completion of various requests: set config, set interface, and
1123  * Bulk-only device reset. */
1124
1125 static void fsg_disconnect(struct usb_gadget *gadget)
1126 {
1127         struct fsg_dev          *fsg = get_gadget_data(gadget);
1128
1129         DBG(fsg, "disconnect or port reset\n");
1130         raise_exception(fsg, FSG_STATE_DISCONNECT);
1131 }
1132
1133
1134 static int ep0_queue(struct fsg_dev *fsg)
1135 {
1136         int     rc;
1137
1138         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
1139         if (rc != 0 && rc != -ESHUTDOWN) {
1140
1141                 /* We can't do much more than wait for a reset */
1142                 WARN(fsg, "error in submission: %s --> %d\n",
1143                                 fsg->ep0->name, rc);
1144         }
1145         return rc;
1146 }
1147
1148 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
1149 {
1150         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1151
1152         if (req->actual > 0)
1153                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
1154         if (req->status || req->actual != req->length)
1155                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1156                                 req->status, req->actual, req->length);
1157         if (req->status == -ECONNRESET)         // Request was cancelled
1158                 usb_ep_fifo_flush(ep);
1159
1160         if (req->status == 0 && req->context)
1161                 ((fsg_routine_t) (req->context))(fsg);
1162 }
1163
1164
1165 /*-------------------------------------------------------------------------*/
1166
1167 /* Bulk and interrupt endpoint completion handlers.
1168  * These always run in_irq. */
1169
1170 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
1171 {
1172         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1173         struct fsg_buffhd       *bh = (struct fsg_buffhd *) req->context;
1174
1175         if (req->status || req->actual != req->length)
1176                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1177                                 req->status, req->actual, req->length);
1178         if (req->status == -ECONNRESET)         // Request was cancelled
1179                 usb_ep_fifo_flush(ep);
1180
1181         /* Hold the lock while we update the request and buffer states */
1182         smp_wmb();
1183         spin_lock(&fsg->lock);
1184         bh->inreq_busy = 0;
1185         bh->state = BUF_STATE_EMPTY;
1186         wakeup_thread(fsg);
1187         spin_unlock(&fsg->lock);
1188 }
1189
1190 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
1191 {
1192         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1193         struct fsg_buffhd       *bh = (struct fsg_buffhd *) req->context;
1194
1195         dump_msg(fsg, "bulk-out", req->buf, req->actual);
1196         if (req->status || req->actual != bh->bulk_out_intended_length)
1197                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1198                                 req->status, req->actual,
1199                                 bh->bulk_out_intended_length);
1200         if (req->status == -ECONNRESET)         // Request was cancelled
1201                 usb_ep_fifo_flush(ep);
1202
1203         /* Hold the lock while we update the request and buffer states */
1204         smp_wmb();
1205         spin_lock(&fsg->lock);
1206         bh->outreq_busy = 0;
1207         bh->state = BUF_STATE_FULL;
1208         wakeup_thread(fsg);
1209         spin_unlock(&fsg->lock);
1210 }
1211
1212
1213 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1214 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1215 {
1216         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1217         struct fsg_buffhd       *bh = (struct fsg_buffhd *) req->context;
1218
1219         if (req->status || req->actual != req->length)
1220                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1221                                 req->status, req->actual, req->length);
1222         if (req->status == -ECONNRESET)         // Request was cancelled
1223                 usb_ep_fifo_flush(ep);
1224
1225         /* Hold the lock while we update the request and buffer states */
1226         smp_wmb();
1227         spin_lock(&fsg->lock);
1228         fsg->intreq_busy = 0;
1229         bh->state = BUF_STATE_EMPTY;
1230         wakeup_thread(fsg);
1231         spin_unlock(&fsg->lock);
1232 }
1233
1234 #else
1235 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1236 {}
1237 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1238
1239
1240 /*-------------------------------------------------------------------------*/
1241
1242 /* Ep0 class-specific handlers.  These always run in_irq. */
1243
1244 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1245 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1246 {
1247         struct usb_request      *req = fsg->ep0req;
1248         static u8               cbi_reset_cmnd[6] = {
1249                         SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
1250
1251         /* Error in command transfer? */
1252         if (req->status || req->length != req->actual ||
1253                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
1254
1255                 /* Not all controllers allow a protocol stall after
1256                  * receiving control-out data, but we'll try anyway. */
1257                 fsg_set_halt(fsg, fsg->ep0);
1258                 return;                 // Wait for reset
1259         }
1260
1261         /* Is it the special reset command? */
1262         if (req->actual >= sizeof cbi_reset_cmnd &&
1263                         memcmp(req->buf, cbi_reset_cmnd,
1264                                 sizeof cbi_reset_cmnd) == 0) {
1265
1266                 /* Raise an exception to stop the current operation
1267                  * and reinitialize our state. */
1268                 DBG(fsg, "cbi reset request\n");
1269                 raise_exception(fsg, FSG_STATE_RESET);
1270                 return;
1271         }
1272
1273         VDBG(fsg, "CB[I] accept device-specific command\n");
1274         spin_lock(&fsg->lock);
1275
1276         /* Save the command for later */
1277         if (fsg->cbbuf_cmnd_size)
1278                 WARN(fsg, "CB[I] overwriting previous command\n");
1279         fsg->cbbuf_cmnd_size = req->actual;
1280         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
1281
1282         wakeup_thread(fsg);
1283         spin_unlock(&fsg->lock);
1284 }
1285
1286 #else
1287 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1288 {}
1289 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1290
1291
1292 static int class_setup_req(struct fsg_dev *fsg,
1293                 const struct usb_ctrlrequest *ctrl)
1294 {
1295         struct usb_request      *req = fsg->ep0req;
1296         int                     value = -EOPNOTSUPP;
1297         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1298         u16                     w_length = le16_to_cpu(ctrl->wLength);
1299
1300         if (!fsg->config)
1301                 return value;
1302
1303         /* Handle Bulk-only class-specific requests */
1304         if (transport_is_bbb()) {
1305                 switch (ctrl->bRequest) {
1306
1307                 case USB_BULK_RESET_REQUEST:
1308                         if (ctrl->bRequestType != (USB_DIR_OUT |
1309                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1310                                 break;
1311                         if (w_index != 0) {
1312                                 value = -EDOM;
1313                                 break;
1314                         }
1315
1316                         /* Raise an exception to stop the current operation
1317                          * and reinitialize our state. */
1318                         DBG(fsg, "bulk reset request\n");
1319                         raise_exception(fsg, FSG_STATE_RESET);
1320                         value = DELAYED_STATUS;
1321                         break;
1322
1323                 case USB_BULK_GET_MAX_LUN_REQUEST:
1324                         if (ctrl->bRequestType != (USB_DIR_IN |
1325                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1326                                 break;
1327                         if (w_index != 0) {
1328                                 value = -EDOM;
1329                                 break;
1330                         }
1331                         VDBG(fsg, "get max LUN\n");
1332                         *(u8 *) req->buf = fsg->nluns - 1;
1333                         value = 1;
1334                         break;
1335                 }
1336         }
1337
1338         /* Handle CBI class-specific requests */
1339         else {
1340                 switch (ctrl->bRequest) {
1341
1342                 case USB_CBI_ADSC_REQUEST:
1343                         if (ctrl->bRequestType != (USB_DIR_OUT |
1344                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1345                                 break;
1346                         if (w_index != 0) {
1347                                 value = -EDOM;
1348                                 break;
1349                         }
1350                         if (w_length > MAX_COMMAND_SIZE) {
1351                                 value = -EOVERFLOW;
1352                                 break;
1353                         }
1354                         value = w_length;
1355                         fsg->ep0req->context = received_cbi_adsc;
1356                         break;
1357                 }
1358         }
1359
1360         if (value == -EOPNOTSUPP)
1361                 VDBG(fsg,
1362                         "unknown class-specific control req "
1363                         "%02x.%02x v%04x i%04x l%u\n",
1364                         ctrl->bRequestType, ctrl->bRequest,
1365                         le16_to_cpu(ctrl->wValue), w_index, w_length);
1366         return value;
1367 }
1368
1369
1370 /*-------------------------------------------------------------------------*/
1371
1372 /* Ep0 standard request handlers.  These always run in_irq. */
1373
1374 static int standard_setup_req(struct fsg_dev *fsg,
1375                 const struct usb_ctrlrequest *ctrl)
1376 {
1377         struct usb_request      *req = fsg->ep0req;
1378         int                     value = -EOPNOTSUPP;
1379         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1380         u16                     w_value = le16_to_cpu(ctrl->wValue);
1381
1382         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
1383          * but config change events will also reconfigure hardware. */
1384         switch (ctrl->bRequest) {
1385
1386         case USB_REQ_GET_DESCRIPTOR:
1387                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1388                                 USB_RECIP_DEVICE))
1389                         break;
1390                 switch (w_value >> 8) {
1391
1392                 case USB_DT_DEVICE:
1393                         VDBG(fsg, "get device descriptor\n");
1394                         value = sizeof device_desc;
1395                         memcpy(req->buf, &device_desc, value);
1396                         break;
1397 #ifdef CONFIG_USB_GADGET_DUALSPEED
1398                 case USB_DT_DEVICE_QUALIFIER:
1399                         VDBG(fsg, "get device qualifier\n");
1400                         if (!fsg->gadget->is_dualspeed)
1401                                 break;
1402                         value = sizeof dev_qualifier;
1403                         memcpy(req->buf, &dev_qualifier, value);
1404                         break;
1405
1406                 case USB_DT_OTHER_SPEED_CONFIG:
1407                         VDBG(fsg, "get other-speed config descriptor\n");
1408                         if (!fsg->gadget->is_dualspeed)
1409                                 break;
1410                         goto get_config;
1411 #endif
1412                 case USB_DT_CONFIG:
1413                         VDBG(fsg, "get configuration descriptor\n");
1414 #ifdef CONFIG_USB_GADGET_DUALSPEED
1415                 get_config:
1416 #endif
1417                         value = populate_config_buf(fsg->gadget,
1418                                         req->buf,
1419                                         w_value >> 8,
1420                                         w_value & 0xff);
1421                         break;
1422
1423                 case USB_DT_STRING:
1424                         VDBG(fsg, "get string descriptor\n");
1425
1426                         /* wIndex == language code */
1427                         value = usb_gadget_get_string(&stringtab,
1428                                         w_value & 0xff, req->buf);
1429                         break;
1430                 }
1431                 break;
1432
1433         /* One config, two speeds */
1434         case USB_REQ_SET_CONFIGURATION:
1435                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
1436                                 USB_RECIP_DEVICE))
1437                         break;
1438                 VDBG(fsg, "set configuration\n");
1439                 if (w_value == CONFIG_VALUE || w_value == 0) {
1440                         fsg->new_config = w_value;
1441
1442                         /* Raise an exception to wipe out previous transaction
1443                          * state (queued bufs, etc) and set the new config. */
1444                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
1445                         value = DELAYED_STATUS;
1446                 }
1447                 break;
1448         case USB_REQ_GET_CONFIGURATION:
1449                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1450                                 USB_RECIP_DEVICE))
1451                         break;
1452                 VDBG(fsg, "get configuration\n");
1453                 *(u8 *) req->buf = fsg->config;
1454                 value = 1;
1455                 break;
1456
1457         case USB_REQ_SET_INTERFACE:
1458                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
1459                                 USB_RECIP_INTERFACE))
1460                         break;
1461                 if (fsg->config && w_index == 0) {
1462
1463                         /* Raise an exception to wipe out previous transaction
1464                          * state (queued bufs, etc) and install the new
1465                          * interface altsetting. */
1466                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
1467                         value = DELAYED_STATUS;
1468                 }
1469                 break;
1470         case USB_REQ_GET_INTERFACE:
1471                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1472                                 USB_RECIP_INTERFACE))
1473                         break;
1474                 if (!fsg->config)
1475                         break;
1476                 if (w_index != 0) {
1477                         value = -EDOM;
1478                         break;
1479                 }
1480                 VDBG(fsg, "get interface\n");
1481                 *(u8 *) req->buf = 0;
1482                 value = 1;
1483                 break;
1484
1485         default:
1486                 VDBG(fsg,
1487                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1488                         ctrl->bRequestType, ctrl->bRequest,
1489                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1490         }
1491
1492         return value;
1493 }
1494
1495
1496 static int fsg_setup(struct usb_gadget *gadget,
1497                 const struct usb_ctrlrequest *ctrl)
1498 {
1499         struct fsg_dev          *fsg = get_gadget_data(gadget);
1500         int                     rc;
1501         int                     w_length = le16_to_cpu(ctrl->wLength);
1502
1503         ++fsg->ep0_req_tag;             // Record arrival of a new request
1504         fsg->ep0req->context = NULL;
1505         fsg->ep0req->length = 0;
1506         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1507
1508         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1509                 rc = class_setup_req(fsg, ctrl);
1510         else
1511                 rc = standard_setup_req(fsg, ctrl);
1512
1513         /* Respond with data/status or defer until later? */
1514         if (rc >= 0 && rc != DELAYED_STATUS) {
1515                 rc = min(rc, w_length);
1516                 fsg->ep0req->length = rc;
1517                 fsg->ep0req->zero = rc < w_length;
1518                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1519                                 "ep0-in" : "ep0-out");
1520                 rc = ep0_queue(fsg);
1521         }
1522
1523         /* Device either stalls (rc < 0) or reports success */
1524         return rc;
1525 }
1526
1527
1528 /*-------------------------------------------------------------------------*/
1529
1530 /* All the following routines run in process context */
1531
1532
1533 /* Use this for bulk or interrupt transfers, not ep0 */
1534 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1535                 struct usb_request *req, int *pbusy,
1536                 enum fsg_buffer_state *state)
1537 {
1538         int     rc;
1539
1540         if (ep == fsg->bulk_in)
1541                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1542         else if (ep == fsg->intr_in)
1543                 dump_msg(fsg, "intr-in", req->buf, req->length);
1544
1545         spin_lock_irq(&fsg->lock);
1546         *pbusy = 1;
1547         *state = BUF_STATE_BUSY;
1548         spin_unlock_irq(&fsg->lock);
1549         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1550         if (rc != 0) {
1551                 *pbusy = 0;
1552                 *state = BUF_STATE_EMPTY;
1553
1554                 /* We can't do much more than wait for a reset */
1555
1556                 /* Note: currently the net2280 driver fails zero-length
1557                  * submissions if DMA is enabled. */
1558                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1559                                                 req->length == 0))
1560                         WARN(fsg, "error in submission: %s --> %d\n",
1561                                         ep->name, rc);
1562         }
1563 }
1564
1565
1566 static int sleep_thread(struct fsg_dev *fsg)
1567 {
1568         int     rc = 0;
1569
1570         /* Wait until a signal arrives or we are woken up */
1571         for (;;) {
1572                 try_to_freeze();
1573                 set_current_state(TASK_INTERRUPTIBLE);
1574                 if (signal_pending(current)) {
1575                         rc = -EINTR;
1576                         break;
1577                 }
1578                 if (fsg->thread_wakeup_needed)
1579                         break;
1580                 schedule();
1581         }
1582         __set_current_state(TASK_RUNNING);
1583         fsg->thread_wakeup_needed = 0;
1584         return rc;
1585 }
1586
1587
1588 /*-------------------------------------------------------------------------*/
1589
1590 static int do_read(struct fsg_dev *fsg)
1591 {
1592         struct lun              *curlun = fsg->curlun;
1593         u32                     lba;
1594         struct fsg_buffhd       *bh;
1595         int                     rc;
1596         u32                     amount_left;
1597         loff_t                  file_offset, file_offset_tmp;
1598         unsigned int            amount;
1599         unsigned int            partial_page;
1600         ssize_t                 nread;
1601
1602         /* Get the starting Logical Block Address and check that it's
1603          * not too big */
1604         if (fsg->cmnd[0] == SC_READ_6)
1605                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1606         else {
1607                 lba = get_be32(&fsg->cmnd[2]);
1608
1609                 /* We allow DPO (Disable Page Out = don't save data in the
1610                  * cache) and FUA (Force Unit Access = don't read from the
1611                  * cache), but we don't implement them. */
1612                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1613                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1614                         return -EINVAL;
1615                 }
1616         }
1617         if (lba >= curlun->num_sectors) {
1618                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1619                 return -EINVAL;
1620         }
1621         file_offset = ((loff_t) lba) << 9;
1622
1623         /* Carry out the file reads */
1624         amount_left = fsg->data_size_from_cmnd;
1625         if (unlikely(amount_left == 0))
1626                 return -EIO;            // No default reply
1627
1628         for (;;) {
1629
1630                 /* Figure out how much we need to read:
1631                  * Try to read the remaining amount.
1632                  * But don't read more than the buffer size.
1633                  * And don't try to read past the end of the file.
1634                  * Finally, if we're not at a page boundary, don't read past
1635                  *      the next page.
1636                  * If this means reading 0 then we were asked to read past
1637                  *      the end of file. */
1638                 amount = min((unsigned int) amount_left, mod_data.buflen);
1639                 amount = min((loff_t) amount,
1640                                 curlun->file_length - file_offset);
1641                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1642                 if (partial_page > 0)
1643                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1644                                         partial_page);
1645
1646                 /* Wait for the next buffer to become available */
1647                 bh = fsg->next_buffhd_to_fill;
1648                 while (bh->state != BUF_STATE_EMPTY) {
1649                         if ((rc = sleep_thread(fsg)) != 0)
1650                                 return rc;
1651                 }
1652
1653                 /* If we were asked to read past the end of file,
1654                  * end with an empty buffer. */
1655                 if (amount == 0) {
1656                         curlun->sense_data =
1657                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1658                         curlun->sense_data_info = file_offset >> 9;
1659                         bh->inreq->length = 0;
1660                         bh->state = BUF_STATE_FULL;
1661                         break;
1662                 }
1663
1664                 /* Perform the read */
1665                 file_offset_tmp = file_offset;
1666                 nread = vfs_read(curlun->filp,
1667                                 (char __user *) bh->buf,
1668                                 amount, &file_offset_tmp);
1669                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1670                                 (unsigned long long) file_offset,
1671                                 (int) nread);
1672                 if (signal_pending(current))
1673                         return -EINTR;
1674
1675                 if (nread < 0) {
1676                         LDBG(curlun, "error in file read: %d\n",
1677                                         (int) nread);
1678                         nread = 0;
1679                 } else if (nread < amount) {
1680                         LDBG(curlun, "partial file read: %d/%u\n",
1681                                         (int) nread, amount);
1682                         nread -= (nread & 511); // Round down to a block
1683                 }
1684                 file_offset  += nread;
1685                 amount_left  -= nread;
1686                 fsg->residue -= nread;
1687                 bh->inreq->length = nread;
1688                 bh->state = BUF_STATE_FULL;
1689
1690                 /* If an error occurred, report it and its position */
1691                 if (nread < amount) {
1692                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1693                         curlun->sense_data_info = file_offset >> 9;
1694                         break;
1695                 }
1696
1697                 if (amount_left == 0)
1698                         break;          // No more left to read
1699
1700                 /* Send this buffer and go read some more */
1701                 bh->inreq->zero = 0;
1702                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1703                                 &bh->inreq_busy, &bh->state);
1704                 fsg->next_buffhd_to_fill = bh->next;
1705         }
1706
1707         return -EIO;            // No default reply
1708 }
1709
1710
1711 /*-------------------------------------------------------------------------*/
1712
1713 static int do_write(struct fsg_dev *fsg)
1714 {
1715         struct lun              *curlun = fsg->curlun;
1716         u32                     lba;
1717         struct fsg_buffhd       *bh;
1718         int                     get_some_more;
1719         u32                     amount_left_to_req, amount_left_to_write;
1720         loff_t                  usb_offset, file_offset, file_offset_tmp;
1721         unsigned int            amount;
1722         unsigned int            partial_page;
1723         ssize_t                 nwritten;
1724         int                     rc;
1725
1726         if (curlun->ro) {
1727                 curlun->sense_data = SS_WRITE_PROTECTED;
1728                 return -EINVAL;
1729         }
1730         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1731
1732         /* Get the starting Logical Block Address and check that it's
1733          * not too big */
1734         if (fsg->cmnd[0] == SC_WRITE_6)
1735                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1736         else {
1737                 lba = get_be32(&fsg->cmnd[2]);
1738
1739                 /* We allow DPO (Disable Page Out = don't save data in the
1740                  * cache) and FUA (Force Unit Access = write directly to the
1741                  * medium).  We don't implement DPO; we implement FUA by
1742                  * performing synchronous output. */
1743                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1744                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1745                         return -EINVAL;
1746                 }
1747                 if (fsg->cmnd[1] & 0x08)        // FUA
1748                         curlun->filp->f_flags |= O_SYNC;
1749         }
1750         if (lba >= curlun->num_sectors) {
1751                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1752                 return -EINVAL;
1753         }
1754
1755         /* Carry out the file writes */
1756         get_some_more = 1;
1757         file_offset = usb_offset = ((loff_t) lba) << 9;
1758         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1759
1760         while (amount_left_to_write > 0) {
1761
1762                 /* Queue a request for more data from the host */
1763                 bh = fsg->next_buffhd_to_fill;
1764                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1765
1766                         /* Figure out how much we want to get:
1767                          * Try to get the remaining amount.
1768                          * But don't get more than the buffer size.
1769                          * And don't try to go past the end of the file.
1770                          * If we're not at a page boundary,
1771                          *      don't go past the next page.
1772                          * If this means getting 0, then we were asked
1773                          *      to write past the end of file.
1774                          * Finally, round down to a block boundary. */
1775                         amount = min(amount_left_to_req, mod_data.buflen);
1776                         amount = min((loff_t) amount, curlun->file_length -
1777                                         usb_offset);
1778                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1779                         if (partial_page > 0)
1780                                 amount = min(amount,
1781         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1782
1783                         if (amount == 0) {
1784                                 get_some_more = 0;
1785                                 curlun->sense_data =
1786                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1787                                 curlun->sense_data_info = usb_offset >> 9;
1788                                 continue;
1789                         }
1790                         amount -= (amount & 511);
1791                         if (amount == 0) {
1792
1793                                 /* Why were we were asked to transfer a
1794                                  * partial block? */
1795                                 get_some_more = 0;
1796                                 continue;
1797                         }
1798
1799                         /* Get the next buffer */
1800                         usb_offset += amount;
1801                         fsg->usb_amount_left -= amount;
1802                         amount_left_to_req -= amount;
1803                         if (amount_left_to_req == 0)
1804                                 get_some_more = 0;
1805
1806                         /* amount is always divisible by 512, hence by
1807                          * the bulk-out maxpacket size */
1808                         bh->outreq->length = bh->bulk_out_intended_length =
1809                                         amount;
1810                         bh->outreq->short_not_ok = 1;
1811                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1812                                         &bh->outreq_busy, &bh->state);
1813                         fsg->next_buffhd_to_fill = bh->next;
1814                         continue;
1815                 }
1816
1817                 /* Write the received data to the backing file */
1818                 bh = fsg->next_buffhd_to_drain;
1819                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1820                         break;                  // We stopped early
1821                 if (bh->state == BUF_STATE_FULL) {
1822                         smp_rmb();
1823                         fsg->next_buffhd_to_drain = bh->next;
1824                         bh->state = BUF_STATE_EMPTY;
1825
1826                         /* Did something go wrong with the transfer? */
1827                         if (bh->outreq->status != 0) {
1828                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1829                                 curlun->sense_data_info = file_offset >> 9;
1830                                 break;
1831                         }
1832
1833                         amount = bh->outreq->actual;
1834                         if (curlun->file_length - file_offset < amount) {
1835                                 LERROR(curlun,
1836         "write %u @ %llu beyond end %llu\n",
1837         amount, (unsigned long long) file_offset,
1838         (unsigned long long) curlun->file_length);
1839                                 amount = curlun->file_length - file_offset;
1840                         }
1841
1842                         /* Perform the write */
1843                         file_offset_tmp = file_offset;
1844                         nwritten = vfs_write(curlun->filp,
1845                                         (char __user *) bh->buf,
1846                                         amount, &file_offset_tmp);
1847                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1848                                         (unsigned long long) file_offset,
1849                                         (int) nwritten);
1850                         if (signal_pending(current))
1851                                 return -EINTR;          // Interrupted!
1852
1853                         if (nwritten < 0) {
1854                                 LDBG(curlun, "error in file write: %d\n",
1855                                                 (int) nwritten);
1856                                 nwritten = 0;
1857                         } else if (nwritten < amount) {
1858                                 LDBG(curlun, "partial file write: %d/%u\n",
1859                                                 (int) nwritten, amount);
1860                                 nwritten -= (nwritten & 511);
1861                                                 // Round down to a block
1862                         }
1863                         file_offset += nwritten;
1864                         amount_left_to_write -= nwritten;
1865                         fsg->residue -= nwritten;
1866
1867                         /* If an error occurred, report it and its position */
1868                         if (nwritten < amount) {
1869                                 curlun->sense_data = SS_WRITE_ERROR;
1870                                 curlun->sense_data_info = file_offset >> 9;
1871                                 break;
1872                         }
1873
1874                         /* Did the host decide to stop early? */
1875                         if (bh->outreq->actual != bh->outreq->length) {
1876                                 fsg->short_packet_received = 1;
1877                                 break;
1878                         }
1879                         continue;
1880                 }
1881
1882                 /* Wait for something to happen */
1883                 if ((rc = sleep_thread(fsg)) != 0)
1884                         return rc;
1885         }
1886
1887         return -EIO;            // No default reply
1888 }
1889
1890
1891 /*-------------------------------------------------------------------------*/
1892
1893 /* Sync the file data, don't bother with the metadata.
1894  * This code was copied from fs/buffer.c:sys_fdatasync(). */
1895 static int fsync_sub(struct lun *curlun)
1896 {
1897         struct file     *filp = curlun->filp;
1898         struct inode    *inode;
1899         int             rc, err;
1900
1901         if (curlun->ro || !filp)
1902                 return 0;
1903         if (!filp->f_op->fsync)
1904                 return -EINVAL;
1905
1906         inode = filp->f_dentry->d_inode;
1907         mutex_lock(&inode->i_mutex);
1908         rc = filemap_fdatawrite(inode->i_mapping);
1909         err = filp->f_op->fsync(filp, filp->f_dentry, 1);
1910         if (!rc)
1911                 rc = err;
1912         err = filemap_fdatawait(inode->i_mapping);
1913         if (!rc)
1914                 rc = err;
1915         mutex_unlock(&inode->i_mutex);
1916         VLDBG(curlun, "fdatasync -> %d\n", rc);
1917         return rc;
1918 }
1919
1920 static void fsync_all(struct fsg_dev *fsg)
1921 {
1922         int     i;
1923
1924         for (i = 0; i < fsg->nluns; ++i)
1925                 fsync_sub(&fsg->luns[i]);
1926 }
1927
1928 static int do_synchronize_cache(struct fsg_dev *fsg)
1929 {
1930         struct lun      *curlun = fsg->curlun;
1931         int             rc;
1932
1933         /* We ignore the requested LBA and write out all file's
1934          * dirty data buffers. */
1935         rc = fsync_sub(curlun);
1936         if (rc)
1937                 curlun->sense_data = SS_WRITE_ERROR;
1938         return 0;
1939 }
1940
1941
1942 /*-------------------------------------------------------------------------*/
1943
1944 static void invalidate_sub(struct lun *curlun)
1945 {
1946         struct file     *filp = curlun->filp;
1947         struct inode    *inode = filp->f_dentry->d_inode;
1948         unsigned long   rc;
1949
1950         rc = invalidate_inode_pages(inode->i_mapping);
1951         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
1952 }
1953
1954 static int do_verify(struct fsg_dev *fsg)
1955 {
1956         struct lun              *curlun = fsg->curlun;
1957         u32                     lba;
1958         u32                     verification_length;
1959         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1960         loff_t                  file_offset, file_offset_tmp;
1961         u32                     amount_left;
1962         unsigned int            amount;
1963         ssize_t                 nread;
1964
1965         /* Get the starting Logical Block Address and check that it's
1966          * not too big */
1967         lba = get_be32(&fsg->cmnd[2]);
1968         if (lba >= curlun->num_sectors) {
1969                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1970                 return -EINVAL;
1971         }
1972
1973         /* We allow DPO (Disable Page Out = don't save data in the
1974          * cache) but we don't implement it. */
1975         if ((fsg->cmnd[1] & ~0x10) != 0) {
1976                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1977                 return -EINVAL;
1978         }
1979
1980         verification_length = get_be16(&fsg->cmnd[7]);
1981         if (unlikely(verification_length == 0))
1982                 return -EIO;            // No default reply
1983
1984         /* Prepare to carry out the file verify */
1985         amount_left = verification_length << 9;
1986         file_offset = ((loff_t) lba) << 9;
1987
1988         /* Write out all the dirty buffers before invalidating them */
1989         fsync_sub(curlun);
1990         if (signal_pending(current))
1991                 return -EINTR;
1992
1993         invalidate_sub(curlun);
1994         if (signal_pending(current))
1995                 return -EINTR;
1996
1997         /* Just try to read the requested blocks */
1998         while (amount_left > 0) {
1999
2000                 /* Figure out how much we need to read:
2001                  * Try to read the remaining amount, but not more than
2002                  * the buffer size.
2003                  * And don't try to read past the end of the file.
2004                  * If this means reading 0 then we were asked to read
2005                  * past the end of file. */
2006                 amount = min((unsigned int) amount_left, mod_data.buflen);
2007                 amount = min((loff_t) amount,
2008                                 curlun->file_length - file_offset);
2009                 if (amount == 0) {
2010                         curlun->sense_data =
2011                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
2012                         curlun->sense_data_info = file_offset >> 9;
2013                         break;
2014                 }
2015
2016                 /* Perform the read */
2017                 file_offset_tmp = file_offset;
2018                 nread = vfs_read(curlun->filp,
2019                                 (char __user *) bh->buf,
2020                                 amount, &file_offset_tmp);
2021                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
2022                                 (unsigned long long) file_offset,
2023                                 (int) nread);
2024                 if (signal_pending(current))
2025                         return -EINTR;
2026
2027                 if (nread < 0) {
2028                         LDBG(curlun, "error in file verify: %d\n",
2029                                         (int) nread);
2030                         nread = 0;
2031                 } else if (nread < amount) {
2032                         LDBG(curlun, "partial file verify: %d/%u\n",
2033                                         (int) nread, amount);
2034                         nread -= (nread & 511); // Round down to a sector
2035                 }
2036                 if (nread == 0) {
2037                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
2038                         curlun->sense_data_info = file_offset >> 9;
2039                         break;
2040                 }
2041                 file_offset += nread;
2042                 amount_left -= nread;
2043         }
2044         return 0;
2045 }
2046
2047
2048 /*-------------------------------------------------------------------------*/
2049
2050 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2051 {
2052         u8      *buf = (u8 *) bh->buf;
2053
2054         static char vendor_id[] = "Linux   ";
2055         static char product_id[] = "File-Stor Gadget";
2056
2057         if (!fsg->curlun) {             // Unsupported LUNs are okay
2058                 fsg->bad_lun_okay = 1;
2059                 memset(buf, 0, 36);
2060                 buf[0] = 0x7f;          // Unsupported, no device-type
2061                 return 36;
2062         }
2063
2064         memset(buf, 0, 8);      // Non-removable, direct-access device
2065         if (mod_data.removable)
2066                 buf[1] = 0x80;
2067         buf[2] = 2;             // ANSI SCSI level 2
2068         buf[3] = 2;             // SCSI-2 INQUIRY data format
2069         buf[4] = 31;            // Additional length
2070                                 // No special options
2071         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, product_id,
2072                         mod_data.release);
2073         return 36;
2074 }
2075
2076
2077 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2078 {
2079         struct lun      *curlun = fsg->curlun;
2080         u8              *buf = (u8 *) bh->buf;
2081         u32             sd, sdinfo;
2082
2083         /*
2084          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
2085          *
2086          * If a REQUEST SENSE command is received from an initiator
2087          * with a pending unit attention condition (before the target
2088          * generates the contingent allegiance condition), then the
2089          * target shall either:
2090          *   a) report any pending sense data and preserve the unit
2091          *      attention condition on the logical unit, or,
2092          *   b) report the unit attention condition, may discard any
2093          *      pending sense data, and clear the unit attention
2094          *      condition on the logical unit for that initiator.
2095          *
2096          * FSG normally uses option a); enable this code to use option b).
2097          */
2098 #if 0
2099         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
2100                 curlun->sense_data = curlun->unit_attention_data;
2101                 curlun->unit_attention_data = SS_NO_SENSE;
2102         }
2103 #endif
2104
2105         if (!curlun) {          // Unsupported LUNs are okay
2106                 fsg->bad_lun_okay = 1;
2107                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2108                 sdinfo = 0;
2109         } else {
2110                 sd = curlun->sense_data;
2111                 sdinfo = curlun->sense_data_info;
2112                 curlun->sense_data = SS_NO_SENSE;
2113                 curlun->sense_data_info = 0;
2114         }
2115
2116         memset(buf, 0, 18);
2117         buf[0] = 0x80 | 0x70;                   // Valid, current error
2118         buf[2] = SK(sd);
2119         put_be32(&buf[3], sdinfo);              // Sense information
2120         buf[7] = 18 - 8;                        // Additional sense length
2121         buf[12] = ASC(sd);
2122         buf[13] = ASCQ(sd);
2123         return 18;
2124 }
2125
2126
2127 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2128 {
2129         struct lun      *curlun = fsg->curlun;
2130         u32             lba = get_be32(&fsg->cmnd[2]);
2131         int             pmi = fsg->cmnd[8];
2132         u8              *buf = (u8 *) bh->buf;
2133
2134         /* Check the PMI and LBA fields */
2135         if (pmi > 1 || (pmi == 0 && lba != 0)) {
2136                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2137                 return -EINVAL;
2138         }
2139
2140         put_be32(&buf[0], curlun->num_sectors - 1);     // Max logical block
2141         put_be32(&buf[4], 512);                         // Block length
2142         return 8;
2143 }
2144
2145
2146 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2147 {
2148         struct lun      *curlun = fsg->curlun;
2149         int             mscmnd = fsg->cmnd[0];
2150         u8              *buf = (u8 *) bh->buf;
2151         u8              *buf0 = buf;
2152         int             pc, page_code;
2153         int             changeable_values, all_pages;
2154         int             valid_page = 0;
2155         int             len, limit;
2156
2157         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
2158                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2159                 return -EINVAL;
2160         }
2161         pc = fsg->cmnd[2] >> 6;
2162         page_code = fsg->cmnd[2] & 0x3f;
2163         if (pc == 3) {
2164                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
2165                 return -EINVAL;
2166         }
2167         changeable_values = (pc == 1);
2168         all_pages = (page_code == 0x3f);
2169
2170         /* Write the mode parameter header.  Fixed values are: default
2171          * medium type, no cache control (DPOFUA), and no block descriptors.
2172          * The only variable value is the WriteProtect bit.  We will fill in
2173          * the mode data length later. */
2174         memset(buf, 0, 8);
2175         if (mscmnd == SC_MODE_SENSE_6) {
2176                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2177                 buf += 4;
2178                 limit = 255;
2179         } else {                        // SC_MODE_SENSE_10
2180                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2181                 buf += 8;
2182                 limit = 65535;          // Should really be mod_data.buflen
2183         }
2184
2185         /* No block descriptors */
2186
2187         /* The mode pages, in numerical order.  The only page we support
2188          * is the Caching page. */
2189         if (page_code == 0x08 || all_pages) {
2190                 valid_page = 1;
2191                 buf[0] = 0x08;          // Page code
2192                 buf[1] = 10;            // Page length
2193                 memset(buf+2, 0, 10);   // None of the fields are changeable
2194
2195                 if (!changeable_values) {
2196                         buf[2] = 0x04;  // Write cache enable,
2197                                         // Read cache not disabled
2198                                         // No cache retention priorities
2199                         put_be16(&buf[4], 0xffff);  // Don't disable prefetch
2200                                         // Minimum prefetch = 0
2201                         put_be16(&buf[8], 0xffff);  // Maximum prefetch
2202                         put_be16(&buf[10], 0xffff); // Maximum prefetch ceiling
2203                 }
2204                 buf += 12;
2205         }
2206
2207         /* Check that a valid page was requested and the mode data length
2208          * isn't too long. */
2209         len = buf - buf0;
2210         if (!valid_page || len > limit) {
2211                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2212                 return -EINVAL;
2213         }
2214
2215         /*  Store the mode data length */
2216         if (mscmnd == SC_MODE_SENSE_6)
2217                 buf0[0] = len - 1;
2218         else
2219                 put_be16(buf0, len - 2);
2220         return len;
2221 }
2222
2223
2224 static int do_start_stop(struct fsg_dev *fsg)
2225 {
2226         struct lun      *curlun = fsg->curlun;
2227         int             loej, start;
2228
2229         if (!mod_data.removable) {
2230                 curlun->sense_data = SS_INVALID_COMMAND;
2231                 return -EINVAL;
2232         }
2233
2234         // int immed = fsg->cmnd[1] & 0x01;
2235         loej = fsg->cmnd[4] & 0x02;
2236         start = fsg->cmnd[4] & 0x01;
2237
2238 #ifdef CONFIG_USB_FILE_STORAGE_TEST
2239         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
2240                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
2241                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2242                 return -EINVAL;
2243         }
2244
2245         if (!start) {
2246
2247                 /* Are we allowed to unload the media? */
2248                 if (curlun->prevent_medium_removal) {
2249                         LDBG(curlun, "unload attempt prevented\n");
2250                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
2251                         return -EINVAL;
2252                 }
2253                 if (loej) {             // Simulate an unload/eject
2254                         up_read(&fsg->filesem);
2255                         down_write(&fsg->filesem);
2256                         close_backing_file(curlun);
2257                         up_write(&fsg->filesem);
2258                         down_read(&fsg->filesem);
2259                 }
2260         } else {
2261
2262                 /* Our emulation doesn't support mounting; the medium is
2263                  * available for use as soon as it is loaded. */
2264                 if (!backing_file_is_open(curlun)) {
2265                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2266                         return -EINVAL;
2267                 }
2268         }
2269 #endif
2270         return 0;
2271 }
2272
2273
2274 static int do_prevent_allow(struct fsg_dev *fsg)
2275 {
2276         struct lun      *curlun = fsg->curlun;
2277         int             prevent;
2278
2279         if (!mod_data.removable) {
2280                 curlun->sense_data = SS_INVALID_COMMAND;
2281                 return -EINVAL;
2282         }
2283
2284         prevent = fsg->cmnd[4] & 0x01;
2285         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
2286                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2287                 return -EINVAL;
2288         }
2289
2290         if (curlun->prevent_medium_removal && !prevent)
2291                 fsync_sub(curlun);
2292         curlun->prevent_medium_removal = prevent;
2293         return 0;
2294 }
2295
2296
2297 static int do_read_format_capacities(struct fsg_dev *fsg,
2298                         struct fsg_buffhd *bh)
2299 {
2300         struct lun      *curlun = fsg->curlun;
2301         u8              *buf = (u8 *) bh->buf;
2302
2303         buf[0] = buf[1] = buf[2] = 0;
2304         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
2305         buf += 4;
2306
2307         put_be32(&buf[0], curlun->num_sectors);         // Number of blocks
2308         put_be32(&buf[4], 512);                         // Block length
2309         buf[4] = 0x02;                                  // Current capacity
2310         return 12;
2311 }
2312
2313
2314 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2315 {
2316         struct lun      *curlun = fsg->curlun;
2317
2318         /* We don't support MODE SELECT */
2319         curlun->sense_data = SS_INVALID_COMMAND;
2320         return -EINVAL;
2321 }
2322
2323
2324 /*-------------------------------------------------------------------------*/
2325
2326 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
2327 {
2328         int     rc;
2329
2330         rc = fsg_set_halt(fsg, fsg->bulk_in);
2331         if (rc == -EAGAIN)
2332                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
2333         while (rc != 0) {
2334                 if (rc != -EAGAIN) {
2335                         WARN(fsg, "usb_ep_set_halt -> %d\n", rc);
2336                         rc = 0;
2337                         break;
2338                 }
2339
2340                 /* Wait for a short time and then try again */
2341                 if (msleep_interruptible(100) != 0)
2342                         return -EINTR;
2343                 rc = usb_ep_set_halt(fsg->bulk_in);
2344         }
2345         return rc;
2346 }
2347
2348 static int pad_with_zeros(struct fsg_dev *fsg)
2349 {
2350         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2351         u32                     nkeep = bh->inreq->length;
2352         u32                     nsend;
2353         int                     rc;
2354
2355         bh->state = BUF_STATE_EMPTY;            // For the first iteration
2356         fsg->usb_amount_left = nkeep + fsg->residue;
2357         while (fsg->usb_amount_left > 0) {
2358
2359                 /* Wait for the next buffer to be free */
2360                 while (bh->state != BUF_STATE_EMPTY) {
2361                         if ((rc = sleep_thread(fsg)) != 0)
2362                                 return rc;
2363                 }
2364
2365                 nsend = min(fsg->usb_amount_left, (u32) mod_data.buflen);
2366                 memset(bh->buf + nkeep, 0, nsend - nkeep);
2367                 bh->inreq->length = nsend;
2368                 bh->inreq->zero = 0;
2369                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2370                                 &bh->inreq_busy, &bh->state);
2371                 bh = fsg->next_buffhd_to_fill = bh->next;
2372                 fsg->usb_amount_left -= nsend;
2373                 nkeep = 0;
2374         }
2375         return 0;
2376 }
2377
2378 static int throw_away_data(struct fsg_dev *fsg)
2379 {
2380         struct fsg_buffhd       *bh;
2381         u32                     amount;
2382         int                     rc;
2383
2384         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
2385                         fsg->usb_amount_left > 0) {
2386
2387                 /* Throw away the data in a filled buffer */
2388                 if (bh->state == BUF_STATE_FULL) {
2389                         smp_rmb();
2390                         bh->state = BUF_STATE_EMPTY;
2391                         fsg->next_buffhd_to_drain = bh->next;
2392
2393                         /* A short packet or an error ends everything */
2394                         if (bh->outreq->actual != bh->outreq->length ||
2395                                         bh->outreq->status != 0) {
2396                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2397                                 return -EINTR;
2398                         }
2399                         continue;
2400                 }
2401
2402                 /* Try to submit another request if we need one */
2403                 bh = fsg->next_buffhd_to_fill;
2404                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
2405                         amount = min(fsg->usb_amount_left,
2406                                         (u32) mod_data.buflen);
2407
2408                         /* amount is always divisible by 512, hence by
2409                          * the bulk-out maxpacket size */
2410                         bh->outreq->length = bh->bulk_out_intended_length =
2411                                         amount;
2412                         bh->outreq->short_not_ok = 1;
2413                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2414                                         &bh->outreq_busy, &bh->state);
2415                         fsg->next_buffhd_to_fill = bh->next;
2416                         fsg->usb_amount_left -= amount;
2417                         continue;
2418                 }
2419
2420                 /* Otherwise wait for something to happen */
2421                 if ((rc = sleep_thread(fsg)) != 0)
2422                         return rc;
2423         }
2424         return 0;
2425 }
2426
2427
2428 static int finish_reply(struct fsg_dev *fsg)
2429 {
2430         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2431         int                     rc = 0;
2432
2433         switch (fsg->data_dir) {
2434         case DATA_DIR_NONE:
2435                 break;                  // Nothing to send
2436
2437         /* If we don't know whether the host wants to read or write,
2438          * this must be CB or CBI with an unknown command.  We mustn't
2439          * try to send or receive any data.  So stall both bulk pipes
2440          * if we can and wait for a reset. */
2441         case DATA_DIR_UNKNOWN:
2442                 if (mod_data.can_stall) {
2443                         fsg_set_halt(fsg, fsg->bulk_out);
2444                         rc = halt_bulk_in_endpoint(fsg);
2445                 }
2446                 break;
2447
2448         /* All but the last buffer of data must have already been sent */
2449         case DATA_DIR_TO_HOST:
2450                 if (fsg->data_size == 0)
2451                         ;               // Nothing to send
2452
2453                 /* If there's no residue, simply send the last buffer */
2454                 else if (fsg->residue == 0) {
2455                         bh->inreq->zero = 0;
2456                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2457                                         &bh->inreq_busy, &bh->state);
2458                         fsg->next_buffhd_to_fill = bh->next;
2459                 }
2460
2461                 /* There is a residue.  For CB and CBI, simply mark the end
2462                  * of the data with a short packet.  However, if we are
2463                  * allowed to stall, there was no data at all (residue ==
2464                  * data_size), and the command failed (invalid LUN or
2465                  * sense data is set), then halt the bulk-in endpoint
2466                  * instead. */
2467                 else if (!transport_is_bbb()) {
2468                         if (mod_data.can_stall &&
2469                                         fsg->residue == fsg->data_size &&
2470         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2471                                 bh->state = BUF_STATE_EMPTY;
2472                                 rc = halt_bulk_in_endpoint(fsg);
2473                         } else {
2474                                 bh->inreq->zero = 1;
2475                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2476                                                 &bh->inreq_busy, &bh->state);
2477                                 fsg->next_buffhd_to_fill = bh->next;
2478                         }
2479                 }
2480
2481                 /* For Bulk-only, if we're allowed to stall then send the
2482                  * short packet and halt the bulk-in endpoint.  If we can't
2483                  * stall, pad out the remaining data with 0's. */
2484                 else {
2485                         if (mod_data.can_stall) {
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                                 rc = halt_bulk_in_endpoint(fsg);
2491                         } else
2492                                 rc = pad_with_zeros(fsg);
2493                 }
2494                 break;
2495
2496         /* We have processed all we want from the data the host has sent.
2497          * There may still be outstanding bulk-out requests. */
2498         case DATA_DIR_FROM_HOST:
2499                 if (fsg->residue == 0)
2500                         ;               // Nothing to receive
2501
2502                 /* Did the host stop sending unexpectedly early? */
2503                 else if (fsg->short_packet_received) {
2504                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2505                         rc = -EINTR;
2506                 }
2507
2508                 /* We haven't processed all the incoming data.  Even though
2509                  * we may be allowed to stall, doing so would cause a race.
2510                  * The controller may already have ACK'ed all the remaining
2511                  * bulk-out packets, in which case the host wouldn't see a
2512                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2513                  * clear the halt -- leading to problems later on. */
2514 #if 0
2515                 else if (mod_data.can_stall) {
2516                         fsg_set_halt(fsg, fsg->bulk_out);
2517                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2518                         rc = -EINTR;
2519                 }
2520 #endif
2521
2522                 /* We can't stall.  Read in the excess data and throw it
2523                  * all away. */
2524                 else
2525                         rc = throw_away_data(fsg);
2526                 break;
2527         }
2528         return rc;
2529 }
2530
2531
2532 static int send_status(struct fsg_dev *fsg)
2533 {
2534         struct lun              *curlun = fsg->curlun;
2535         struct fsg_buffhd       *bh;
2536         int                     rc;
2537         u8                      status = USB_STATUS_PASS;
2538         u32                     sd, sdinfo = 0;
2539
2540         /* Wait for the next buffer to become available */
2541         bh = fsg->next_buffhd_to_fill;
2542         while (bh->state != BUF_STATE_EMPTY) {
2543                 if ((rc = sleep_thread(fsg)) != 0)
2544                         return rc;
2545         }
2546
2547         if (curlun) {
2548                 sd = curlun->sense_data;
2549                 sdinfo = curlun->sense_data_info;
2550         } else if (fsg->bad_lun_okay)
2551                 sd = SS_NO_SENSE;
2552         else
2553                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2554
2555         if (fsg->phase_error) {
2556                 DBG(fsg, "sending phase-error status\n");
2557                 status = USB_STATUS_PHASE_ERROR;
2558                 sd = SS_INVALID_COMMAND;
2559         } else if (sd != SS_NO_SENSE) {
2560                 DBG(fsg, "sending command-failure status\n");
2561                 status = USB_STATUS_FAIL;
2562                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2563                                 "  info x%x\n",
2564                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2565         }
2566
2567         if (transport_is_bbb()) {
2568                 struct bulk_cs_wrap     *csw = (struct bulk_cs_wrap *) bh->buf;
2569
2570                 /* Store and send the Bulk-only CSW */
2571                 csw->Signature = __constant_cpu_to_le32(USB_BULK_CS_SIG);
2572                 csw->Tag = fsg->tag;
2573                 csw->Residue = cpu_to_le32(fsg->residue);
2574                 csw->Status = status;
2575
2576                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2577                 bh->inreq->zero = 0;
2578                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2579                                 &bh->inreq_busy, &bh->state);
2580
2581         } else if (mod_data.transport_type == USB_PR_CB) {
2582
2583                 /* Control-Bulk transport has no status phase! */
2584                 return 0;
2585
2586         } else {                        // USB_PR_CBI
2587                 struct interrupt_data   *buf = (struct interrupt_data *)
2588                                                 bh->buf;
2589
2590                 /* Store and send the Interrupt data.  UFI sends the ASC
2591                  * and ASCQ bytes.  Everything else sends a Type (which
2592                  * is always 0) and the status Value. */
2593                 if (mod_data.protocol_type == USB_SC_UFI) {
2594                         buf->bType = ASC(sd);
2595                         buf->bValue = ASCQ(sd);
2596                 } else {
2597                         buf->bType = 0;
2598                         buf->bValue = status;
2599                 }
2600                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2601
2602                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2603                 fsg->intreq->buf = bh->inreq->buf;
2604                 fsg->intreq->dma = bh->inreq->dma;
2605                 fsg->intreq->context = bh;
2606                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2607                                 &fsg->intreq_busy, &bh->state);
2608         }
2609
2610         fsg->next_buffhd_to_fill = bh->next;
2611         return 0;
2612 }
2613
2614
2615 /*-------------------------------------------------------------------------*/
2616
2617 /* Check whether the command is properly formed and whether its data size
2618  * and direction agree with the values we already have. */
2619 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2620                 enum data_direction data_dir, unsigned int mask,
2621                 int needs_medium, const char *name)
2622 {
2623         int                     i;
2624         int                     lun = fsg->cmnd[1] >> 5;
2625         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2626         char                    hdlen[20];
2627         struct lun              *curlun;
2628
2629         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2630          * Transparent SCSI doesn't pad. */
2631         if (protocol_is_scsi())
2632                 ;
2633
2634         /* There's some disagreement as to whether RBC pads commands or not.
2635          * We'll play it safe and accept either form. */
2636         else if (mod_data.protocol_type == USB_SC_RBC) {
2637                 if (fsg->cmnd_size == 12)
2638                         cmnd_size = 12;
2639
2640         /* All the other protocols pad to 12 bytes */
2641         } else
2642                 cmnd_size = 12;
2643
2644         hdlen[0] = 0;
2645         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2646                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2647                                 fsg->data_size);
2648         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2649                         name, cmnd_size, dirletter[(int) data_dir],
2650                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2651
2652         /* We can't reply at all until we know the correct data direction
2653          * and size. */
2654         if (fsg->data_size_from_cmnd == 0)
2655                 data_dir = DATA_DIR_NONE;
2656         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2657                 fsg->data_dir = data_dir;
2658                 fsg->data_size = fsg->data_size_from_cmnd;
2659
2660         } else {                                        // Bulk-only
2661                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2662
2663                         /* Host data size < Device data size is a phase error.
2664                          * Carry out the command, but only transfer as much
2665                          * as we are allowed. */
2666                         fsg->data_size_from_cmnd = fsg->data_size;
2667                         fsg->phase_error = 1;
2668                 }
2669         }
2670         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2671
2672         /* Conflicting data directions is a phase error */
2673         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2674                 fsg->phase_error = 1;
2675                 return -EINVAL;
2676         }
2677
2678         /* Verify the length of the command itself */
2679         if (cmnd_size != fsg->cmnd_size) {
2680
2681                 /* Special case workaround: MS-Windows issues REQUEST SENSE
2682                  * with cbw->Length == 12 (it should be 6). */
2683                 if (fsg->cmnd[0] == SC_REQUEST_SENSE && fsg->cmnd_size == 12)
2684                         cmnd_size = fsg->cmnd_size;
2685                 else {
2686                         fsg->phase_error = 1;
2687                         return -EINVAL;
2688                 }
2689         }
2690
2691         /* Check that the LUN values are consistent */
2692         if (transport_is_bbb()) {
2693                 if (fsg->lun != lun)
2694                         DBG(fsg, "using LUN %d from CBW, "
2695                                         "not LUN %d from CDB\n",
2696                                         fsg->lun, lun);
2697         } else
2698                 fsg->lun = lun;         // Use LUN from the command
2699
2700         /* Check the LUN */
2701         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
2702                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2703                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
2704                         curlun->sense_data = SS_NO_SENSE;
2705                         curlun->sense_data_info = 0;
2706                 }
2707         } else {
2708                 fsg->curlun = curlun = NULL;
2709                 fsg->bad_lun_okay = 0;
2710
2711                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2712                  * to use unsupported LUNs; all others may not. */
2713                 if (fsg->cmnd[0] != SC_INQUIRY &&
2714                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2715                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2716                         return -EINVAL;
2717                 }
2718         }
2719
2720         /* If a unit attention condition exists, only INQUIRY and
2721          * REQUEST SENSE commands are allowed; anything else must fail. */
2722         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2723                         fsg->cmnd[0] != SC_INQUIRY &&
2724                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2725                 curlun->sense_data = curlun->unit_attention_data;
2726                 curlun->unit_attention_data = SS_NO_SENSE;
2727                 return -EINVAL;
2728         }
2729
2730         /* Check that only command bytes listed in the mask are non-zero */
2731         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2732         for (i = 1; i < cmnd_size; ++i) {
2733                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2734                         if (curlun)
2735                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2736                         return -EINVAL;
2737                 }
2738         }
2739
2740         /* If the medium isn't mounted and the command needs to access
2741          * it, return an error. */
2742         if (curlun && !backing_file_is_open(curlun) && needs_medium) {
2743                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2744                 return -EINVAL;
2745         }
2746
2747         return 0;
2748 }
2749
2750
2751 static int do_scsi_command(struct fsg_dev *fsg)
2752 {
2753         struct fsg_buffhd       *bh;
2754         int                     rc;
2755         int                     reply = -EINVAL;
2756         int                     i;
2757         static char             unknown[16];
2758
2759         dump_cdb(fsg);
2760
2761         /* Wait for the next buffer to become available for data or status */
2762         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2763         while (bh->state != BUF_STATE_EMPTY) {
2764                 if ((rc = sleep_thread(fsg)) != 0)
2765                         return rc;
2766                 }
2767         fsg->phase_error = 0;
2768         fsg->short_packet_received = 0;
2769
2770         down_read(&fsg->filesem);       // We're using the backing file
2771         switch (fsg->cmnd[0]) {
2772
2773         case SC_INQUIRY:
2774                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2775                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2776                                 (1<<4), 0,
2777                                 "INQUIRY")) == 0)
2778                         reply = do_inquiry(fsg, bh);
2779                 break;
2780
2781         case SC_MODE_SELECT_6:
2782                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2783                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2784                                 (1<<1) | (1<<4), 0,
2785                                 "MODE SELECT(6)")) == 0)
2786                         reply = do_mode_select(fsg, bh);
2787                 break;
2788
2789         case SC_MODE_SELECT_10:
2790                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2791                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2792                                 (1<<1) | (3<<7), 0,
2793                                 "MODE SELECT(10)")) == 0)
2794                         reply = do_mode_select(fsg, bh);
2795                 break;
2796
2797         case SC_MODE_SENSE_6:
2798                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2799                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2800                                 (1<<1) | (1<<2) | (1<<4), 0,
2801                                 "MODE SENSE(6)")) == 0)
2802                         reply = do_mode_sense(fsg, bh);
2803                 break;
2804
2805         case SC_MODE_SENSE_10:
2806                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2807                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2808                                 (1<<1) | (1<<2) | (3<<7), 0,
2809                                 "MODE SENSE(10)")) == 0)
2810                         reply = do_mode_sense(fsg, bh);
2811                 break;
2812
2813         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2814                 fsg->data_size_from_cmnd = 0;
2815                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2816                                 (1<<4), 0,
2817                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2818                         reply = do_prevent_allow(fsg);
2819                 break;
2820
2821         case SC_READ_6:
2822                 i = fsg->cmnd[4];
2823                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2824                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2825                                 (7<<1) | (1<<4), 1,
2826                                 "READ(6)")) == 0)
2827                         reply = do_read(fsg);
2828                 break;
2829
2830         case SC_READ_10:
2831                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2832                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2833                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2834                                 "READ(10)")) == 0)
2835                         reply = do_read(fsg);
2836                 break;
2837
2838         case SC_READ_12:
2839                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2840                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2841                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2842                                 "READ(12)")) == 0)
2843                         reply = do_read(fsg);
2844                 break;
2845
2846         case SC_READ_CAPACITY:
2847                 fsg->data_size_from_cmnd = 8;
2848                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2849                                 (0xf<<2) | (1<<8), 1,
2850                                 "READ CAPACITY")) == 0)
2851                         reply = do_read_capacity(fsg, bh);
2852                 break;
2853
2854         case SC_READ_FORMAT_CAPACITIES:
2855                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2856                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2857                                 (3<<7), 1,
2858                                 "READ FORMAT CAPACITIES")) == 0)
2859                         reply = do_read_format_capacities(fsg, bh);
2860                 break;
2861
2862         case SC_REQUEST_SENSE:
2863                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2864                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2865                                 (1<<4), 0,
2866                                 "REQUEST SENSE")) == 0)
2867                         reply = do_request_sense(fsg, bh);
2868                 break;
2869
2870         case SC_START_STOP_UNIT:
2871                 fsg->data_size_from_cmnd = 0;
2872                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2873                                 (1<<1) | (1<<4), 0,
2874                                 "START-STOP UNIT")) == 0)
2875                         reply = do_start_stop(fsg);
2876                 break;
2877
2878         case SC_SYNCHRONIZE_CACHE:
2879                 fsg->data_size_from_cmnd = 0;
2880                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2881                                 (0xf<<2) | (3<<7), 1,
2882                                 "SYNCHRONIZE CACHE")) == 0)
2883                         reply = do_synchronize_cache(fsg);
2884                 break;
2885
2886         case SC_TEST_UNIT_READY:
2887                 fsg->data_size_from_cmnd = 0;
2888                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2889                                 0, 1,
2890                                 "TEST UNIT READY");
2891                 break;
2892
2893         /* Although optional, this command is used by MS-Windows.  We
2894          * support a minimal version: BytChk must be 0. */
2895         case SC_VERIFY:
2896                 fsg->data_size_from_cmnd = 0;
2897                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2898                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2899                                 "VERIFY")) == 0)
2900                         reply = do_verify(fsg);
2901                 break;
2902
2903         case SC_WRITE_6:
2904                 i = fsg->cmnd[4];
2905                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2906                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2907                                 (7<<1) | (1<<4), 1,
2908                                 "WRITE(6)")) == 0)
2909                         reply = do_write(fsg);
2910                 break;
2911
2912         case SC_WRITE_10:
2913                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2914                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2915                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2916                                 "WRITE(10)")) == 0)
2917                         reply = do_write(fsg);
2918                 break;
2919
2920         case SC_WRITE_12:
2921                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2922                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2923                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2924                                 "WRITE(12)")) == 0)
2925                         reply = do_write(fsg);
2926                 break;
2927
2928         /* Some mandatory commands that we recognize but don't implement.
2929          * They don't mean much in this setting.  It's left as an exercise
2930          * for anyone interested to implement RESERVE and RELEASE in terms
2931          * of Posix locks. */
2932         case SC_FORMAT_UNIT:
2933         case SC_RELEASE:
2934         case SC_RESERVE:
2935         case SC_SEND_DIAGNOSTIC:
2936                 // Fall through
2937
2938         default:
2939                 fsg->data_size_from_cmnd = 0;
2940                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2941                 if ((reply = check_command(fsg, fsg->cmnd_size,
2942                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2943                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2944                         reply = -EINVAL;
2945                 }
2946                 break;
2947         }
2948         up_read(&fsg->filesem);
2949
2950         if (reply == -EINTR || signal_pending(current))
2951                 return -EINTR;
2952
2953         /* Set up the single reply buffer for finish_reply() */
2954         if (reply == -EINVAL)
2955                 reply = 0;              // Error reply length
2956         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2957                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2958                 bh->inreq->length = reply;
2959                 bh->state = BUF_STATE_FULL;
2960                 fsg->residue -= reply;
2961         }                               // Otherwise it's already set
2962
2963         return 0;
2964 }
2965
2966
2967 /*-------------------------------------------------------------------------*/
2968
2969 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2970 {
2971         struct usb_request      *req = bh->outreq;
2972         struct bulk_cb_wrap     *cbw = (struct bulk_cb_wrap *) req->buf;
2973
2974         /* Was this a real packet? */
2975         if (req->status)
2976                 return -EINVAL;
2977
2978         /* Is the CBW valid? */
2979         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2980                         cbw->Signature != __constant_cpu_to_le32(
2981                                 USB_BULK_CB_SIG)) {
2982                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2983                                 req->actual,
2984                                 le32_to_cpu(cbw->Signature));
2985
2986                 /* The Bulk-only spec says we MUST stall the bulk pipes!
2987                  * If we want to avoid stalls, set a flag so that we will
2988                  * clear the endpoint halts at the next reset. */
2989                 if (!mod_data.can_stall)
2990                         set_bit(CLEAR_BULK_HALTS, &fsg->atomic_bitflags);
2991                 fsg_set_halt(fsg, fsg->bulk_out);
2992                 halt_bulk_in_endpoint(fsg);
2993                 return -EINVAL;
2994         }
2995
2996         /* Is the CBW meaningful? */
2997         if (cbw->Lun >= MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2998                         cbw->Length < 6 || cbw->Length > MAX_COMMAND_SIZE) {
2999                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
3000                                 "cmdlen %u\n",
3001                                 cbw->Lun, cbw->Flags, cbw->Length);
3002
3003                 /* We can do anything we want here, so let's stall the
3004                  * bulk pipes if we are allowed to. */
3005                 if (mod_data.can_stall) {
3006                         fsg_set_halt(fsg, fsg->bulk_out);
3007                         halt_bulk_in_endpoint(fsg);
3008                 }
3009                 return -EINVAL;
3010         }
3011
3012         /* Save the command for later */
3013         fsg->cmnd_size = cbw->Length;
3014         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
3015         if (cbw->Flags & USB_BULK_IN_FLAG)
3016                 fsg->data_dir = DATA_DIR_TO_HOST;
3017         else
3018                 fsg->data_dir = DATA_DIR_FROM_HOST;
3019         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
3020         if (fsg->data_size == 0)
3021                 fsg->data_dir = DATA_DIR_NONE;
3022         fsg->lun = cbw->Lun;
3023         fsg->tag = cbw->Tag;
3024         return 0;
3025 }
3026
3027
3028 static int get_next_command(struct fsg_dev *fsg)
3029 {
3030         struct fsg_buffhd       *bh;
3031         int                     rc = 0;
3032
3033         if (transport_is_bbb()) {
3034
3035                 /* Wait for the next buffer to become available */
3036                 bh = fsg->next_buffhd_to_fill;
3037                 while (bh->state != BUF_STATE_EMPTY) {
3038                         if ((rc = sleep_thread(fsg)) != 0)
3039                                 return rc;
3040                         }
3041
3042                 /* Queue a request to read a Bulk-only CBW */
3043                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
3044                 bh->outreq->short_not_ok = 1;
3045                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
3046                                 &bh->outreq_busy, &bh->state);
3047
3048                 /* We will drain the buffer in software, which means we
3049                  * can reuse it for the next filling.  No need to advance
3050                  * next_buffhd_to_fill. */
3051
3052                 /* Wait for the CBW to arrive */
3053                 while (bh->state != BUF_STATE_FULL) {
3054                         if ((rc = sleep_thread(fsg)) != 0)
3055                                 return rc;
3056                         }
3057                 smp_rmb();
3058                 rc = received_cbw(fsg, bh);
3059                 bh->state = BUF_STATE_EMPTY;
3060
3061         } else {                // USB_PR_CB or USB_PR_CBI
3062
3063                 /* Wait for the next command to arrive */
3064                 while (fsg->cbbuf_cmnd_size == 0) {
3065                         if ((rc = sleep_thread(fsg)) != 0)
3066                                 return rc;
3067                         }
3068
3069                 /* Is the previous status interrupt request still busy?
3070                  * The host is allowed to skip reading the status,
3071                  * so we must cancel it. */
3072                 if (fsg->intreq_busy)
3073                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3074
3075                 /* Copy the command and mark the buffer empty */
3076                 fsg->data_dir = DATA_DIR_UNKNOWN;
3077                 spin_lock_irq(&fsg->lock);
3078                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
3079                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
3080                 fsg->cbbuf_cmnd_size = 0;
3081                 spin_unlock_irq(&fsg->lock);
3082         }
3083         return rc;
3084 }
3085
3086
3087 /*-------------------------------------------------------------------------*/
3088
3089 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
3090                 const struct usb_endpoint_descriptor *d)
3091 {
3092         int     rc;
3093
3094         ep->driver_data = fsg;
3095         rc = usb_ep_enable(ep, d);
3096         if (rc)
3097                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
3098         return rc;
3099 }
3100
3101 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
3102                 struct usb_request **preq)
3103 {
3104         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
3105         if (*preq)
3106                 return 0;
3107         ERROR(fsg, "can't allocate request for %s\n", ep->name);
3108         return -ENOMEM;
3109 }
3110
3111 /*
3112  * Reset interface setting and re-init endpoint state (toggle etc).
3113  * Call with altsetting < 0 to disable the interface.  The only other
3114  * available altsetting is 0, which enables the interface.
3115  */
3116 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
3117 {
3118         int     rc = 0;
3119         int     i;
3120         const struct usb_endpoint_descriptor    *d;
3121
3122         if (fsg->running)
3123                 DBG(fsg, "reset interface\n");
3124
3125 reset:
3126         /* Deallocate the requests */
3127         for (i = 0; i < NUM_BUFFERS; ++i) {
3128                 struct fsg_buffhd *bh = &fsg->buffhds[i];
3129
3130                 if (bh->inreq) {
3131                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
3132                         bh->inreq = NULL;
3133                 }
3134                 if (bh->outreq) {
3135                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
3136                         bh->outreq = NULL;
3137                 }
3138         }
3139         if (fsg->intreq) {
3140                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
3141                 fsg->intreq = NULL;
3142         }
3143
3144         /* Disable the endpoints */
3145         if (fsg->bulk_in_enabled) {
3146                 usb_ep_disable(fsg->bulk_in);
3147                 fsg->bulk_in_enabled = 0;
3148         }
3149         if (fsg->bulk_out_enabled) {
3150                 usb_ep_disable(fsg->bulk_out);
3151                 fsg->bulk_out_enabled = 0;
3152         }
3153         if (fsg->intr_in_enabled) {
3154                 usb_ep_disable(fsg->intr_in);
3155                 fsg->intr_in_enabled = 0;
3156         }
3157
3158         fsg->running = 0;
3159         if (altsetting < 0 || rc != 0)
3160                 return rc;
3161
3162         DBG(fsg, "set interface %d\n", altsetting);
3163
3164         /* Enable the endpoints */
3165         d = ep_desc(fsg->gadget, &fs_bulk_in_desc, &hs_bulk_in_desc);
3166         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
3167                 goto reset;
3168         fsg->bulk_in_enabled = 1;
3169
3170         d = ep_desc(fsg->gadget, &fs_bulk_out_desc, &hs_bulk_out_desc);
3171         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
3172                 goto reset;
3173         fsg->bulk_out_enabled = 1;
3174         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
3175
3176         if (transport_is_cbi()) {
3177                 d = ep_desc(fsg->gadget, &fs_intr_in_desc, &hs_intr_in_desc);
3178                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
3179                         goto reset;
3180                 fsg->intr_in_enabled = 1;
3181         }
3182
3183         /* Allocate the requests */
3184         for (i = 0; i < NUM_BUFFERS; ++i) {
3185                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3186
3187                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
3188                         goto reset;
3189                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
3190                         goto reset;
3191                 bh->inreq->buf = bh->outreq->buf = bh->buf;
3192                 bh->inreq->dma = bh->outreq->dma = bh->dma;
3193                 bh->inreq->context = bh->outreq->context = bh;
3194                 bh->inreq->complete = bulk_in_complete;
3195                 bh->outreq->complete = bulk_out_complete;
3196         }
3197         if (transport_is_cbi()) {
3198                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
3199                         goto reset;
3200                 fsg->intreq->complete = intr_in_complete;
3201         }
3202
3203         fsg->running = 1;
3204         for (i = 0; i < fsg->nluns; ++i)
3205                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3206         return rc;
3207 }
3208
3209
3210 /*
3211  * Change our operational configuration.  This code must agree with the code
3212  * that returns config descriptors, and with interface altsetting code.
3213  *
3214  * It's also responsible for power management interactions.  Some
3215  * configurations might not work with our current power sources.
3216  * For now we just assume the gadget is always self-powered.
3217  */
3218 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
3219 {
3220         int     rc = 0;
3221
3222         /* Disable the single interface */
3223         if (fsg->config != 0) {
3224                 DBG(fsg, "reset config\n");
3225                 fsg->config = 0;
3226                 rc = do_set_interface(fsg, -1);
3227         }
3228
3229         /* Enable the interface */
3230         if (new_config != 0) {
3231                 fsg->config = new_config;
3232                 if ((rc = do_set_interface(fsg, 0)) != 0)
3233                         fsg->config = 0;        // Reset on errors
3234                 else {
3235                         char *speed;
3236
3237                         switch (fsg->gadget->speed) {
3238                         case USB_SPEED_LOW:     speed = "low";  break;
3239                         case USB_SPEED_FULL:    speed = "full"; break;
3240                         case USB_SPEED_HIGH:    speed = "high"; break;
3241                         default:                speed = "?";    break;
3242                         }
3243                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
3244                 }
3245         }
3246         return rc;
3247 }
3248
3249
3250 /*-------------------------------------------------------------------------*/
3251
3252 static void handle_exception(struct fsg_dev *fsg)
3253 {
3254         siginfo_t               info;
3255         int                     sig;
3256         int                     i;
3257         int                     num_active;
3258         struct fsg_buffhd       *bh;
3259         enum fsg_state          old_state;
3260         u8                      new_config;
3261         struct lun              *curlun;
3262         unsigned int            exception_req_tag;
3263         int                     rc;
3264
3265         /* Clear the existing signals.  Anything but SIGUSR1 is converted
3266          * into a high-priority EXIT exception. */
3267         for (;;) {
3268                 sig = dequeue_signal_lock(current, &fsg->thread_signal_mask,
3269                                 &info);
3270                 if (!sig)
3271                         break;
3272                 if (sig != SIGUSR1) {
3273                         if (fsg->state < FSG_STATE_EXIT)
3274                                 DBG(fsg, "Main thread exiting on signal\n");
3275                         raise_exception(fsg, FSG_STATE_EXIT);
3276                 }
3277         }
3278
3279         /* Cancel all the pending transfers */
3280         if (fsg->intreq_busy)
3281                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3282         for (i = 0; i < NUM_BUFFERS; ++i) {
3283                 bh = &fsg->buffhds[i];
3284                 if (bh->inreq_busy)
3285                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
3286                 if (bh->outreq_busy)
3287                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
3288         }
3289
3290         /* Wait until everything is idle */
3291         for (;;) {
3292                 num_active = fsg->intreq_busy;
3293                 for (i = 0; i < NUM_BUFFERS; ++i) {
3294                         bh = &fsg->buffhds[i];
3295                         num_active += bh->inreq_busy + bh->outreq_busy;
3296                 }
3297                 if (num_active == 0)
3298                         break;
3299                 if (sleep_thread(fsg))
3300                         return;
3301         }
3302
3303         /* Clear out the controller's fifos */
3304         if (fsg->bulk_in_enabled)
3305                 usb_ep_fifo_flush(fsg->bulk_in);
3306         if (fsg->bulk_out_enabled)
3307                 usb_ep_fifo_flush(fsg->bulk_out);
3308         if (fsg->intr_in_enabled)
3309                 usb_ep_fifo_flush(fsg->intr_in);
3310
3311         /* Reset the I/O buffer states and pointers, the SCSI
3312          * state, and the exception.  Then invoke the handler. */
3313         spin_lock_irq(&fsg->lock);
3314
3315         for (i = 0; i < NUM_BUFFERS; ++i) {
3316                 bh = &fsg->buffhds[i];
3317                 bh->state = BUF_STATE_EMPTY;
3318         }
3319         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
3320                         &fsg->buffhds[0];
3321
3322         exception_req_tag = fsg->exception_req_tag;
3323         new_config = fsg->new_config;
3324         old_state = fsg->state;
3325
3326         if (old_state == FSG_STATE_ABORT_BULK_OUT)
3327                 fsg->state = FSG_STATE_STATUS_PHASE;
3328         else {
3329                 for (i = 0; i < fsg->nluns; ++i) {
3330                         curlun = &fsg->luns[i];
3331                         curlun->prevent_medium_removal = 0;
3332                         curlun->sense_data = curlun->unit_attention_data =
3333                                         SS_NO_SENSE;
3334                         curlun->sense_data_info = 0;
3335                 }
3336                 fsg->state = FSG_STATE_IDLE;
3337         }
3338         spin_unlock_irq(&fsg->lock);
3339
3340         /* Carry out any extra actions required for the exception */
3341         switch (old_state) {
3342         default:
3343                 break;
3344
3345         case FSG_STATE_ABORT_BULK_OUT:
3346                 send_status(fsg);
3347                 spin_lock_irq(&fsg->lock);
3348                 if (fsg->state == FSG_STATE_STATUS_PHASE)
3349                         fsg->state = FSG_STATE_IDLE;
3350                 spin_unlock_irq(&fsg->lock);
3351                 break;
3352
3353         case FSG_STATE_RESET:
3354                 /* In case we were forced against our will to halt a
3355                  * bulk endpoint, clear the halt now.  (The SuperH UDC
3356                  * requires this.) */
3357                 if (test_and_clear_bit(CLEAR_BULK_HALTS,
3358                                 &fsg->atomic_bitflags)) {
3359                         usb_ep_clear_halt(fsg->bulk_in);
3360                         usb_ep_clear_halt(fsg->bulk_out);
3361                 }
3362
3363                 if (transport_is_bbb()) {
3364                         if (fsg->ep0_req_tag == exception_req_tag)
3365                                 ep0_queue(fsg); // Complete the status stage
3366
3367                 } else if (transport_is_cbi())
3368                         send_status(fsg);       // Status by interrupt pipe
3369
3370                 /* Technically this should go here, but it would only be
3371                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
3372                  * CONFIG_CHANGE cases. */
3373                 // for (i = 0; i < fsg->nluns; ++i)
3374                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3375                 break;
3376
3377         case FSG_STATE_INTERFACE_CHANGE:
3378                 rc = do_set_interface(fsg, 0);
3379                 if (fsg->ep0_req_tag != exception_req_tag)
3380                         break;
3381                 if (rc != 0)                    // STALL on errors
3382                         fsg_set_halt(fsg, fsg->ep0);
3383                 else                            // Complete the status stage
3384                         ep0_queue(fsg);
3385                 break;
3386
3387         case FSG_STATE_CONFIG_CHANGE:
3388                 rc = do_set_config(fsg, new_config);
3389                 if (fsg->ep0_req_tag != exception_req_tag)
3390                         break;
3391                 if (rc != 0)                    // STALL on errors
3392                         fsg_set_halt(fsg, fsg->ep0);
3393                 else                            // Complete the status stage
3394                         ep0_queue(fsg);
3395                 break;
3396
3397         case FSG_STATE_DISCONNECT:
3398                 fsync_all(fsg);
3399                 do_set_config(fsg, 0);          // Unconfigured state
3400                 break;
3401
3402         case FSG_STATE_EXIT:
3403         case FSG_STATE_TERMINATED:
3404                 do_set_config(fsg, 0);                  // Free resources
3405                 spin_lock_irq(&fsg->lock);
3406                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3407                 spin_unlock_irq(&fsg->lock);
3408                 break;
3409         }
3410 }
3411
3412
3413 /*-------------------------------------------------------------------------*/
3414
3415 static int fsg_main_thread(void *fsg_)
3416 {
3417         struct fsg_dev          *fsg = (struct fsg_dev *) fsg_;
3418
3419         /* Allow the thread to be killed by a signal, but set the signal mask
3420          * to block everything but INT, TERM, KILL, and USR1. */
3421         siginitsetinv(&fsg->thread_signal_mask, sigmask(SIGINT) |
3422                         sigmask(SIGTERM) | sigmask(SIGKILL) |
3423                         sigmask(SIGUSR1));
3424         sigprocmask(SIG_SETMASK, &fsg->thread_signal_mask, NULL);
3425
3426         /* Arrange for userspace references to be interpreted as kernel
3427          * pointers.  That way we can pass a kernel pointer to a routine
3428          * that expects a __user pointer and it will work okay. */
3429         set_fs(get_ds());
3430
3431         /* The main loop */
3432         while (fsg->state != FSG_STATE_TERMINATED) {
3433                 if (exception_in_progress(fsg) || signal_pending(current)) {
3434                         handle_exception(fsg);
3435                         continue;
3436                 }
3437
3438                 if (!fsg->running) {
3439                         sleep_thread(fsg);
3440                         continue;
3441                 }
3442
3443                 if (get_next_command(fsg))
3444                         continue;
3445
3446                 spin_lock_irq(&fsg->lock);
3447                 if (!exception_in_progress(fsg))
3448                         fsg->state = FSG_STATE_DATA_PHASE;
3449                 spin_unlock_irq(&fsg->lock);
3450
3451                 if (do_scsi_command(fsg) || finish_reply(fsg))
3452                         continue;
3453
3454                 spin_lock_irq(&fsg->lock);
3455                 if (!exception_in_progress(fsg))
3456                         fsg->state = FSG_STATE_STATUS_PHASE;
3457                 spin_unlock_irq(&fsg->lock);
3458
3459                 if (send_status(fsg))
3460                         continue;
3461
3462                 spin_lock_irq(&fsg->lock);
3463                 if (!exception_in_progress(fsg))
3464                         fsg->state = FSG_STATE_IDLE;
3465                 spin_unlock_irq(&fsg->lock);
3466                 }
3467
3468         spin_lock_irq(&fsg->lock);
3469         fsg->thread_task = NULL;
3470         spin_unlock_irq(&fsg->lock);
3471
3472         /* In case we are exiting because of a signal, unregister the
3473          * gadget driver and close the backing file. */
3474         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags)) {
3475                 usb_gadget_unregister_driver(&fsg_driver);
3476                 close_all_backing_files(fsg);
3477         }
3478
3479         /* Let the unbind and cleanup routines know the thread has exited */
3480         complete_and_exit(&fsg->thread_notifier, 0);
3481 }
3482
3483
3484 /*-------------------------------------------------------------------------*/
3485
3486 /* If the next two routines are called while the gadget is registered,
3487  * the caller must own fsg->filesem for writing. */
3488
3489 static int open_backing_file(struct lun *curlun, const char *filename)
3490 {
3491         int                             ro;
3492         struct file                     *filp = NULL;
3493         int                             rc = -EINVAL;
3494         struct inode                    *inode = NULL;
3495         loff_t                          size;
3496         loff_t                          num_sectors;
3497
3498         /* R/W if we can, R/O if we must */
3499         ro = curlun->ro;
3500         if (!ro) {
3501                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
3502                 if (-EROFS == PTR_ERR(filp))
3503                         ro = 1;
3504         }
3505         if (ro)
3506                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
3507         if (IS_ERR(filp)) {
3508                 LINFO(curlun, "unable to open backing file: %s\n", filename);
3509                 return PTR_ERR(filp);
3510         }
3511
3512         if (!(filp->f_mode & FMODE_WRITE))
3513                 ro = 1;
3514
3515         if (filp->f_dentry)
3516                 inode = filp->f_dentry->d_inode;
3517         if (inode && S_ISBLK(inode->i_mode)) {
3518                 if (bdev_read_only(inode->i_bdev))
3519                         ro = 1;
3520         } else if (!inode || !S_ISREG(inode->i_mode)) {
3521                 LINFO(curlun, "invalid file type: %s\n", filename);
3522                 goto out;
3523         }
3524
3525         /* If we can't read the file, it's no good.
3526          * If we can't write the file, use it read-only. */
3527         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
3528                 LINFO(curlun, "file not readable: %s\n", filename);
3529                 goto out;
3530         }
3531         if (!(filp->f_op->write || filp->f_op->aio_write))
3532                 ro = 1;
3533
3534         size = i_size_read(inode->i_mapping->host);
3535         if (size < 0) {
3536                 LINFO(curlun, "unable to find file size: %s\n", filename);
3537                 rc = (int) size;
3538                 goto out;
3539         }
3540         num_sectors = size >> 9;        // File size in 512-byte sectors
3541         if (num_sectors == 0) {
3542                 LINFO(curlun, "file too small: %s\n", filename);
3543                 rc = -ETOOSMALL;
3544                 goto out;
3545         }
3546
3547         get_file(filp);
3548         curlun->ro = ro;
3549         curlun->filp = filp;
3550         curlun->file_length = size;
3551         curlun->num_sectors = num_sectors;
3552         LDBG(curlun, "open backing file: %s\n", filename);
3553         rc = 0;
3554
3555 out:
3556         filp_close(filp, current->files);
3557         return rc;
3558 }
3559
3560
3561 static void close_backing_file(struct lun *curlun)
3562 {
3563         if (curlun->filp) {
3564                 LDBG(curlun, "close backing file\n");
3565                 fput(curlun->filp);
3566                 curlun->filp = NULL;
3567         }
3568 }
3569
3570 static void close_all_backing_files(struct fsg_dev *fsg)
3571 {
3572         int     i;
3573
3574         for (i = 0; i < fsg->nluns; ++i)
3575                 close_backing_file(&fsg->luns[i]);
3576 }
3577
3578
3579 static ssize_t show_ro(struct device *dev, struct device_attribute *attr, char *buf)
3580 {
3581         struct lun      *curlun = dev_to_lun(dev);
3582
3583         return sprintf(buf, "%d\n", curlun->ro);
3584 }
3585
3586 static ssize_t show_file(struct device *dev, struct device_attribute *attr, char *buf)
3587 {
3588         struct lun      *curlun = dev_to_lun(dev);
3589         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3590         char            *p;
3591         ssize_t         rc;
3592
3593         down_read(&fsg->filesem);
3594         if (backing_file_is_open(curlun)) {     // Get the complete pathname
3595                 p = d_path(curlun->filp->f_dentry, curlun->filp->f_vfsmnt,
3596                                 buf, PAGE_SIZE - 1);
3597                 if (IS_ERR(p))
3598                         rc = PTR_ERR(p);
3599                 else {
3600                         rc = strlen(p);
3601                         memmove(buf, p, rc);
3602                         buf[rc] = '\n';         // Add a newline
3603                         buf[++rc] = 0;
3604                 }
3605         } else {                                // No file, return 0 bytes
3606                 *buf = 0;
3607                 rc = 0;
3608         }
3609         up_read(&fsg->filesem);
3610         return rc;
3611 }
3612
3613
3614 static ssize_t store_ro(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
3615 {
3616         ssize_t         rc = count;
3617         struct lun      *curlun = dev_to_lun(dev);
3618         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3619         int             i;
3620
3621         if (sscanf(buf, "%d", &i) != 1)
3622                 return -EINVAL;
3623
3624         /* Allow the write-enable status to change only while the backing file
3625          * is closed. */
3626         down_read(&fsg->filesem);
3627         if (backing_file_is_open(curlun)) {
3628                 LDBG(curlun, "read-only status change prevented\n");
3629                 rc = -EBUSY;
3630         } else {
3631                 curlun->ro = !!i;
3632                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
3633         }
3634         up_read(&fsg->filesem);
3635         return rc;
3636 }
3637
3638 static ssize_t store_file(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
3639 {
3640         struct lun      *curlun = dev_to_lun(dev);
3641         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3642         int             rc = 0;
3643
3644         if (curlun->prevent_medium_removal && backing_file_is_open(curlun)) {
3645                 LDBG(curlun, "eject attempt prevented\n");
3646                 return -EBUSY;                          // "Door is locked"
3647         }
3648
3649         /* Remove a trailing newline */
3650         if (count > 0 && buf[count-1] == '\n')
3651                 ((char *) buf)[count-1] = 0;            // Ugh!
3652
3653         /* Eject current medium */
3654         down_write(&fsg->filesem);
3655         if (backing_file_is_open(curlun)) {
3656                 close_backing_file(curlun);
3657                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
3658         }
3659
3660         /* Load new medium */
3661         if (count > 0 && buf[0]) {
3662                 rc = open_backing_file(curlun, buf);
3663                 if (rc == 0)
3664                         curlun->unit_attention_data =
3665                                         SS_NOT_READY_TO_READY_TRANSITION;
3666         }
3667         up_write(&fsg->filesem);
3668         return (rc < 0 ? rc : count);
3669 }
3670
3671
3672 /* The write permissions and store_xxx pointers are set in fsg_bind() */
3673 static DEVICE_ATTR(ro, 0444, show_ro, NULL);
3674 static DEVICE_ATTR(file, 0444, show_file, NULL);
3675
3676
3677 /*-------------------------------------------------------------------------*/
3678
3679 static void fsg_release(struct kref *ref)
3680 {
3681         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
3682
3683         kfree(fsg->luns);
3684         kfree(fsg);
3685 }
3686
3687 static void lun_release(struct device *dev)
3688 {
3689         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3690
3691         kref_put(&fsg->ref, fsg_release);
3692 }
3693
3694 static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
3695 {
3696         struct fsg_dev          *fsg = get_gadget_data(gadget);
3697         int                     i;
3698         struct lun              *curlun;
3699         struct usb_request      *req = fsg->ep0req;
3700
3701         DBG(fsg, "unbind\n");
3702         clear_bit(REGISTERED, &fsg->atomic_bitflags);
3703
3704         /* Unregister the sysfs attribute files and the LUNs */
3705         for (i = 0; i < fsg->nluns; ++i) {
3706                 curlun = &fsg->luns[i];
3707                 if (curlun->registered) {
3708                         device_remove_file(&curlun->dev, &dev_attr_ro);
3709                         device_remove_file(&curlun->dev, &dev_attr_file);
3710                         device_unregister(&curlun->dev);
3711                         curlun->registered = 0;
3712                 }
3713         }
3714
3715         /* If the thread isn't already dead, tell it to exit now */
3716         if (fsg->state != FSG_STATE_TERMINATED) {
3717                 raise_exception(fsg, FSG_STATE_EXIT);
3718                 wait_for_completion(&fsg->thread_notifier);
3719
3720                 /* The cleanup routine waits for this completion also */
3721                 complete(&fsg->thread_notifier);
3722         }
3723
3724         /* Free the data buffers */
3725         for (i = 0; i < NUM_BUFFERS; ++i) {
3726                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3727
3728                 if (bh->buf)
3729                         usb_ep_free_buffer(fsg->bulk_in, bh->buf, bh->dma,
3730                                         mod_data.buflen);
3731         }
3732
3733         /* Free the request and buffer for endpoint 0 */
3734         if (req) {
3735                 if (req->buf)
3736                         usb_ep_free_buffer(fsg->ep0, req->buf,
3737                                         req->dma, EP0_BUFSIZE);
3738                 usb_ep_free_request(fsg->ep0, req);
3739         }
3740
3741         set_gadget_data(gadget, NULL);
3742 }
3743
3744
3745 static int __init check_parameters(struct fsg_dev *fsg)
3746 {
3747         int     prot;
3748         int     gcnum;
3749
3750         /* Store the default values */
3751         mod_data.transport_type = USB_PR_BULK;
3752         mod_data.transport_name = "Bulk-only";
3753         mod_data.protocol_type = USB_SC_SCSI;
3754         mod_data.protocol_name = "Transparent SCSI";
3755
3756         if (gadget_is_sh(fsg->gadget))
3757                 mod_data.can_stall = 0;
3758
3759         if (mod_data.release == 0xffff) {       // Parameter wasn't set
3760                 /* The sa1100 controller is not supported */
3761                 if (gadget_is_sa1100(fsg->gadget))
3762                         gcnum = -1;
3763                 else
3764                         gcnum = usb_gadget_controller_number(fsg->gadget);
3765                 if (gcnum >= 0)
3766                         mod_data.release = 0x0300 + gcnum;
3767                 else {
3768                         WARN(fsg, "controller '%s' not recognized\n",
3769                                 fsg->gadget->name);
3770                         mod_data.release = 0x0399;
3771                 }
3772         }
3773
3774         prot = simple_strtol(mod_data.protocol_parm, NULL, 0);
3775
3776 #ifdef CONFIG_USB_FILE_STORAGE_TEST
3777         if (strnicmp(mod_data.transport_parm, "BBB", 10) == 0) {
3778                 ;               // Use default setting
3779         } else if (strnicmp(mod_data.transport_parm, "CB", 10) == 0) {
3780                 mod_data.transport_type = USB_PR_CB;
3781                 mod_data.transport_name = "Control-Bulk";
3782         } else if (strnicmp(mod_data.transport_parm, "CBI", 10) == 0) {
3783                 mod_data.transport_type = USB_PR_CBI;
3784                 mod_data.transport_name = "Control-Bulk-Interrupt";
3785         } else {
3786                 ERROR(fsg, "invalid transport: %s\n", mod_data.transport_parm);
3787                 return -EINVAL;
3788         }
3789
3790         if (strnicmp(mod_data.protocol_parm, "SCSI", 10) == 0 ||
3791                         prot == USB_SC_SCSI) {
3792                 ;               // Use default setting
3793         } else if (strnicmp(mod_data.protocol_parm, "RBC", 10) == 0 ||
3794                         prot == USB_SC_RBC) {
3795                 mod_data.protocol_type = USB_SC_RBC;
3796                 mod_data.protocol_name = "RBC";
3797         } else if (strnicmp(mod_data.protocol_parm, "8020", 4) == 0 ||
3798                         strnicmp(mod_data.protocol_parm, "ATAPI", 10) == 0 ||
3799                         prot == USB_SC_8020) {
3800                 mod_data.protocol_type = USB_SC_8020;
3801                 mod_data.protocol_name = "8020i (ATAPI)";
3802         } else if (strnicmp(mod_data.protocol_parm, "QIC", 3) == 0 ||
3803                         prot == USB_SC_QIC) {
3804                 mod_data.protocol_type = USB_SC_QIC;
3805                 mod_data.protocol_name = "QIC-157";
3806         } else if (strnicmp(mod_data.protocol_parm, "UFI", 10) == 0 ||
3807                         prot == USB_SC_UFI) {
3808                 mod_data.protocol_type = USB_SC_UFI;
3809                 mod_data.protocol_name = "UFI";
3810         } else if (strnicmp(mod_data.protocol_parm, "8070", 4) == 0 ||
3811                         prot == USB_SC_8070) {
3812                 mod_data.protocol_type = USB_SC_8070;
3813                 mod_data.protocol_name = "8070i";
3814         } else {
3815                 ERROR(fsg, "invalid protocol: %s\n", mod_data.protocol_parm);
3816                 return -EINVAL;
3817         }
3818
3819         mod_data.buflen &= PAGE_CACHE_MASK;
3820         if (mod_data.buflen <= 0) {
3821                 ERROR(fsg, "invalid buflen\n");
3822                 return -ETOOSMALL;
3823         }
3824 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
3825
3826         return 0;
3827 }
3828
3829
3830 static int __init fsg_bind(struct usb_gadget *gadget)
3831 {
3832         struct fsg_dev          *fsg = the_fsg;
3833         int                     rc;
3834         int                     i;
3835         struct lun              *curlun;
3836         struct usb_ep           *ep;
3837         struct usb_request      *req;
3838         char                    *pathbuf, *p;
3839
3840         fsg->gadget = gadget;
3841         set_gadget_data(gadget, fsg);
3842         fsg->ep0 = gadget->ep0;
3843         fsg->ep0->driver_data = fsg;
3844
3845         if ((rc = check_parameters(fsg)) != 0)
3846                 goto out;
3847
3848         if (mod_data.removable) {       // Enable the store_xxx attributes
3849                 dev_attr_ro.attr.mode = dev_attr_file.attr.mode = 0644;
3850                 dev_attr_ro.store = store_ro;
3851                 dev_attr_file.store = store_file;
3852         }
3853
3854         /* Find out how many LUNs there should be */
3855         i = mod_data.nluns;
3856         if (i == 0)
3857                 i = max(mod_data.num_filenames, 1);
3858         if (i > MAX_LUNS) {
3859                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
3860                 rc = -EINVAL;
3861                 goto out;
3862         }
3863
3864         /* Create the LUNs, open their backing files, and register the
3865          * LUN devices in sysfs. */
3866         fsg->luns = kzalloc(i * sizeof(struct lun), GFP_KERNEL);
3867         if (!fsg->luns) {
3868                 rc = -ENOMEM;
3869                 goto out;
3870         }
3871         fsg->nluns = i;
3872
3873         for (i = 0; i < fsg->nluns; ++i) {
3874                 curlun = &fsg->luns[i];
3875                 curlun->ro = mod_data.ro[i];
3876                 curlun->dev.parent = &gadget->dev;
3877                 curlun->dev.driver = &fsg_driver.driver;
3878                 dev_set_drvdata(&curlun->dev, fsg);
3879                 snprintf(curlun->dev.bus_id, BUS_ID_SIZE,
3880                                 "%s-lun%d", gadget->dev.bus_id, i);
3881
3882                 if ((rc = device_register(&curlun->dev)) != 0)
3883                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
3884                 else {
3885                         curlun->registered = 1;
3886                         curlun->dev.release = lun_release;
3887                         device_create_file(&curlun->dev, &dev_attr_ro);
3888                         device_create_file(&curlun->dev, &dev_attr_file);
3889                         kref_get(&fsg->ref);
3890                 }
3891
3892                 if (mod_data.file[i] && *mod_data.file[i]) {
3893                         if ((rc = open_backing_file(curlun,
3894                                         mod_data.file[i])) != 0)
3895                                 goto out;
3896                 } else if (!mod_data.removable) {
3897                         ERROR(fsg, "no file given for LUN%d\n", i);
3898                         rc = -EINVAL;
3899                         goto out;
3900                 }
3901         }
3902
3903         /* Find all the endpoints we will use */
3904         usb_ep_autoconfig_reset(gadget);
3905         ep = usb_ep_autoconfig(gadget, &fs_bulk_in_desc);
3906         if (!ep)
3907                 goto autoconf_fail;
3908         ep->driver_data = fsg;          // claim the endpoint
3909         fsg->bulk_in = ep;
3910
3911         ep = usb_ep_autoconfig(gadget, &fs_bulk_out_desc);
3912         if (!ep)
3913                 goto autoconf_fail;
3914         ep->driver_data = fsg;          // claim the endpoint
3915         fsg->bulk_out = ep;
3916
3917         if (transport_is_cbi()) {
3918                 ep = usb_ep_autoconfig(gadget, &fs_intr_in_desc);
3919                 if (!ep)
3920                         goto autoconf_fail;
3921                 ep->driver_data = fsg;          // claim the endpoint
3922                 fsg->intr_in = ep;
3923         }
3924
3925         /* Fix up the descriptors */
3926         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
3927         device_desc.idVendor = cpu_to_le16(mod_data.vendor);
3928         device_desc.idProduct = cpu_to_le16(mod_data.product);
3929         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
3930
3931         i = (transport_is_cbi() ? 3 : 2);       // Number of endpoints
3932         intf_desc.bNumEndpoints = i;
3933         intf_desc.bInterfaceSubClass = mod_data.protocol_type;
3934         intf_desc.bInterfaceProtocol = mod_data.transport_type;
3935         fs_function[i + FS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3936
3937 #ifdef CONFIG_USB_GADGET_DUALSPEED
3938         hs_function[i + HS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3939
3940         /* Assume ep0 uses the same maxpacket value for both speeds */
3941         dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
3942
3943         /* Assume that all endpoint addresses are the same for both speeds */
3944         hs_bulk_in_desc.bEndpointAddress = fs_bulk_in_desc.bEndpointAddress;
3945         hs_bulk_out_desc.bEndpointAddress = fs_bulk_out_desc.bEndpointAddress;
3946         hs_intr_in_desc.bEndpointAddress = fs_intr_in_desc.bEndpointAddress;
3947 #endif
3948
3949         if (gadget->is_otg) {
3950                 otg_desc.bmAttributes |= USB_OTG_HNP,
3951                 config_desc.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
3952         }
3953
3954         rc = -ENOMEM;
3955
3956         /* Allocate the request and buffer for endpoint 0 */
3957         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
3958         if (!req)
3959                 goto out;
3960         req->buf = usb_ep_alloc_buffer(fsg->ep0, EP0_BUFSIZE,
3961                         &req->dma, GFP_KERNEL);
3962         if (!req->buf)
3963                 goto out;
3964         req->complete = ep0_complete;
3965
3966         /* Allocate the data buffers */
3967         for (i = 0; i < NUM_BUFFERS; ++i) {
3968                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3969
3970                 /* Allocate for the bulk-in endpoint.  We assume that
3971                  * the buffer will also work with the bulk-out (and
3972                  * interrupt-in) endpoint. */
3973                 bh->buf = usb_ep_alloc_buffer(fsg->bulk_in, mod_data.buflen,
3974                                 &bh->dma, GFP_KERNEL);
3975                 if (!bh->buf)
3976                         goto out;
3977                 bh->next = bh + 1;
3978         }
3979         fsg->buffhds[NUM_BUFFERS - 1].next = &fsg->buffhds[0];
3980
3981         /* This should reflect the actual gadget power source */
3982         usb_gadget_set_selfpowered(gadget);
3983
3984         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
3985                         system_utsname.sysname, system_utsname.release,
3986                         gadget->name);
3987
3988         /* On a real device, serial[] would be loaded from permanent
3989          * storage.  We just encode it from the driver version string. */
3990         for (i = 0; i < sizeof(serial) - 2; i += 2) {
3991                 unsigned char           c = DRIVER_VERSION[i / 2];
3992
3993                 if (!c)
3994                         break;
3995                 sprintf(&serial[i], "%02X", c);
3996         }
3997
3998         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
3999                         "file-storage-gadget");
4000         if (IS_ERR(fsg->thread_task)) {
4001                 rc = PTR_ERR(fsg->thread_task);
4002                 goto out;
4003         }
4004
4005         INFO(fsg, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
4006         INFO(fsg, "Number of LUNs=%d\n", fsg->nluns);
4007
4008         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
4009         for (i = 0; i < fsg->nluns; ++i) {
4010                 curlun = &fsg->luns[i];
4011                 if (backing_file_is_open(curlun)) {
4012                         p = NULL;
4013                         if (pathbuf) {
4014                                 p = d_path(curlun->filp->f_dentry,
4015                                         curlun->filp->f_vfsmnt,
4016                                         pathbuf, PATH_MAX);
4017                                 if (IS_ERR(p))
4018                                         p = NULL;
4019                         }
4020                         LINFO(curlun, "ro=%d, file: %s\n",
4021                                         curlun->ro, (p ? p : "(error)"));
4022                 }
4023         }
4024         kfree(pathbuf);
4025
4026         DBG(fsg, "transport=%s (x%02x)\n",
4027                         mod_data.transport_name, mod_data.transport_type);
4028         DBG(fsg, "protocol=%s (x%02x)\n",
4029                         mod_data.protocol_name, mod_data.protocol_type);
4030         DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n",
4031                         mod_data.vendor, mod_data.product, mod_data.release);
4032         DBG(fsg, "removable=%d, stall=%d, buflen=%u\n",
4033                         mod_data.removable, mod_data.can_stall,
4034                         mod_data.buflen);
4035         DBG(fsg, "I/O thread pid: %d\n", fsg->thread_task->pid);
4036
4037         set_bit(REGISTERED, &fsg->atomic_bitflags);
4038
4039         /* Tell the thread to start working */
4040         wake_up_process(fsg->thread_task);
4041         return 0;
4042
4043 autoconf_fail:
4044         ERROR(fsg, "unable to autoconfigure all endpoints\n");
4045         rc = -ENOTSUPP;
4046
4047 out:
4048         fsg->state = FSG_STATE_TERMINATED;      // The thread is dead
4049         fsg_unbind(gadget);
4050         close_all_backing_files(fsg);
4051         return rc;
4052 }
4053
4054
4055 /*-------------------------------------------------------------------------*/
4056
4057 static void fsg_suspend(struct usb_gadget *gadget)
4058 {
4059         struct fsg_dev          *fsg = get_gadget_data(gadget);
4060
4061         DBG(fsg, "suspend\n");
4062         set_bit(SUSPENDED, &fsg->atomic_bitflags);
4063 }
4064
4065 static void fsg_resume(struct usb_gadget *gadget)
4066 {
4067         struct fsg_dev          *fsg = get_gadget_data(gadget);
4068
4069         DBG(fsg, "resume\n");
4070         clear_bit(SUSPENDED, &fsg->atomic_bitflags);
4071 }
4072
4073
4074 /*-------------------------------------------------------------------------*/
4075
4076 static struct usb_gadget_driver         fsg_driver = {
4077 #ifdef CONFIG_USB_GADGET_DUALSPEED
4078         .speed          = USB_SPEED_HIGH,
4079 #else
4080         .speed          = USB_SPEED_FULL,
4081 #endif
4082         .function       = (char *) longname,
4083         .bind           = fsg_bind,
4084         .unbind         = __exit_p(fsg_unbind),
4085         .disconnect     = fsg_disconnect,
4086         .setup          = fsg_setup,
4087         .suspend        = fsg_suspend,
4088         .resume         = fsg_resume,
4089
4090         .driver         = {
4091                 .name           = (char *) shortname,
4092                 .owner          = THIS_MODULE,
4093                 // .release = ...
4094                 // .suspend = ...
4095                 // .resume = ...
4096         },
4097 };
4098
4099
4100 static int __init fsg_alloc(void)
4101 {
4102         struct fsg_dev          *fsg;
4103
4104         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
4105         if (!fsg)
4106                 return -ENOMEM;
4107         spin_lock_init(&fsg->lock);
4108         init_rwsem(&fsg->filesem);
4109         kref_init(&fsg->ref);
4110         init_completion(&fsg->thread_notifier);
4111
4112         the_fsg = fsg;
4113         return 0;
4114 }
4115
4116
4117 static int __init fsg_init(void)
4118 {
4119         int             rc;
4120         struct fsg_dev  *fsg;
4121
4122         if ((rc = fsg_alloc()) != 0)
4123                 return rc;
4124         fsg = the_fsg;
4125         if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
4126                 kref_put(&fsg->ref, fsg_release);
4127         return rc;
4128 }
4129 module_init(fsg_init);
4130
4131
4132 static void __exit fsg_cleanup(void)
4133 {
4134         struct fsg_dev  *fsg = the_fsg;
4135
4136         /* Unregister the driver iff the thread hasn't already done so */
4137         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
4138                 usb_gadget_unregister_driver(&fsg_driver);
4139
4140         /* Wait for the thread to finish up */
4141         wait_for_completion(&fsg->thread_notifier);
4142
4143         close_all_backing_files(fsg);
4144         kref_put(&fsg->ref, fsg_release);
4145 }
4146 module_exit(fsg_cleanup);