bf3f946fd45544e04cc1549ab68d71f2f2b8f0f2
[linux-2.6.git] / drivers / usb / gadget / file_storage.c
1 /*
2  * file_storage.c -- File-backed USB Storage Gadget, for USB development
3  *
4  * Copyright (C) 2003-2007 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 /* #define VERBOSE_DEBUG */
221 /* #define DUMP_MSGS */
222
223
224 #include <linux/blkdev.h>
225 #include <linux/completion.h>
226 #include <linux/dcache.h>
227 #include <linux/delay.h>
228 #include <linux/device.h>
229 #include <linux/fcntl.h>
230 #include <linux/file.h>
231 #include <linux/fs.h>
232 #include <linux/kref.h>
233 #include <linux/kthread.h>
234 #include <linux/limits.h>
235 #include <linux/rwsem.h>
236 #include <linux/slab.h>
237 #include <linux/spinlock.h>
238 #include <linux/string.h>
239 #include <linux/freezer.h>
240 #include <linux/utsname.h>
241
242 #include <linux/usb/ch9.h>
243 #include <linux/usb/gadget.h>
244
245 #include "gadget_chips.h"
246
247
248 /*-------------------------------------------------------------------------*/
249
250 #define DRIVER_DESC             "File-backed Storage Gadget"
251 #define DRIVER_NAME             "g_file_storage"
252 #define DRIVER_VERSION          "7 August 2007"
253
254 static const char longname[] = DRIVER_DESC;
255 static const char shortname[] = DRIVER_NAME;
256
257 MODULE_DESCRIPTION(DRIVER_DESC);
258 MODULE_AUTHOR("Alan Stern");
259 MODULE_LICENSE("Dual BSD/GPL");
260
261 /* Thanks to NetChip Technologies for donating this product ID.
262  *
263  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
264  * Instead:  allocate your own, using normal USB-IF procedures. */
265 #define DRIVER_VENDOR_ID        0x0525  // NetChip
266 #define DRIVER_PRODUCT_ID       0xa4a5  // Linux-USB File-backed Storage Gadget
267
268
269 /*
270  * This driver assumes self-powered hardware and has no way for users to
271  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
272  * and endpoint addresses.
273  */
274
275
276 /*-------------------------------------------------------------------------*/
277
278 #define LDBG(lun,fmt,args...) \
279         dev_dbg(&(lun)->dev , fmt , ## args)
280 #define MDBG(fmt,args...) \
281         pr_debug(DRIVER_NAME ": " fmt , ## args)
282
283 #ifndef DEBUG
284 #undef VERBOSE_DEBUG
285 #undef DUMP_MSGS
286 #endif /* !DEBUG */
287
288 #ifdef VERBOSE_DEBUG
289 #define VLDBG   LDBG
290 #else
291 #define VLDBG(lun,fmt,args...) \
292         do { } while (0)
293 #endif /* VERBOSE_DEBUG */
294
295 #define LERROR(lun,fmt,args...) \
296         dev_err(&(lun)->dev , fmt , ## args)
297 #define LWARN(lun,fmt,args...) \
298         dev_warn(&(lun)->dev , fmt , ## args)
299 #define LINFO(lun,fmt,args...) \
300         dev_info(&(lun)->dev , fmt , ## args)
301
302 #define MINFO(fmt,args...) \
303         pr_info(DRIVER_NAME ": " fmt , ## args)
304
305 #define DBG(d, fmt, args...) \
306         dev_dbg(&(d)->gadget->dev , fmt , ## args)
307 #define VDBG(d, fmt, args...) \
308         dev_vdbg(&(d)->gadget->dev , fmt , ## args)
309 #define ERROR(d, fmt, args...) \
310         dev_err(&(d)->gadget->dev , fmt , ## args)
311 #define WARN(d, fmt, args...) \
312         dev_warn(&(d)->gadget->dev , fmt , ## args)
313 #define INFO(d, fmt, args...) \
314         dev_info(&(d)->gadget->dev , fmt , ## args)
315
316
317 /*-------------------------------------------------------------------------*/
318
319 /* Encapsulate the module parameter settings */
320
321 #define MAX_LUNS        8
322
323 static struct {
324         char            *file[MAX_LUNS];
325         int             ro[MAX_LUNS];
326         unsigned int    num_filenames;
327         unsigned int    num_ros;
328         unsigned int    nluns;
329
330         int             removable;
331         int             can_stall;
332
333         char            *transport_parm;
334         char            *protocol_parm;
335         unsigned short  vendor;
336         unsigned short  product;
337         unsigned short  release;
338         unsigned int    buflen;
339
340         int             transport_type;
341         char            *transport_name;
342         int             protocol_type;
343         char            *protocol_name;
344
345 } mod_data = {                                  // Default values
346         .transport_parm         = "BBB",
347         .protocol_parm          = "SCSI",
348         .removable              = 0,
349         .can_stall              = 1,
350         .vendor                 = DRIVER_VENDOR_ID,
351         .product                = DRIVER_PRODUCT_ID,
352         .release                = 0xffff,       // Use controller chip type
353         .buflen                 = 16384,
354         };
355
356
357 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
358                 S_IRUGO);
359 MODULE_PARM_DESC(file, "names of backing files or devices");
360
361 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
362 MODULE_PARM_DESC(ro, "true to force read-only");
363
364 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
365 MODULE_PARM_DESC(luns, "number of LUNs");
366
367 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
368 MODULE_PARM_DESC(removable, "true to simulate removable media");
369
370 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
371 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
372
373
374 /* In the non-TEST version, only the module parameters listed above
375  * are available. */
376 #ifdef CONFIG_USB_FILE_STORAGE_TEST
377
378 module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
379 MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
380
381 module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
382 MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
383                 "8070, or SCSI)");
384
385 module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
386 MODULE_PARM_DESC(vendor, "USB Vendor ID");
387
388 module_param_named(product, mod_data.product, ushort, S_IRUGO);
389 MODULE_PARM_DESC(product, "USB Product ID");
390
391 module_param_named(release, mod_data.release, ushort, S_IRUGO);
392 MODULE_PARM_DESC(release, "USB release number");
393
394 module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
395 MODULE_PARM_DESC(buflen, "I/O buffer size");
396
397 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
398
399
400 /*-------------------------------------------------------------------------*/
401
402 /* USB protocol value = the transport method */
403 #define USB_PR_CBI      0x00            // Control/Bulk/Interrupt
404 #define USB_PR_CB       0x01            // Control/Bulk w/o interrupt
405 #define USB_PR_BULK     0x50            // Bulk-only
406
407 /* USB subclass value = the protocol encapsulation */
408 #define USB_SC_RBC      0x01            // Reduced Block Commands (flash)
409 #define USB_SC_8020     0x02            // SFF-8020i, MMC-2, ATAPI (CD-ROM)
410 #define USB_SC_QIC      0x03            // QIC-157 (tape)
411 #define USB_SC_UFI      0x04            // UFI (floppy)
412 #define USB_SC_8070     0x05            // SFF-8070i (removable)
413 #define USB_SC_SCSI     0x06            // Transparent SCSI
414
415 /* Bulk-only data structures */
416
417 /* Command Block Wrapper */
418 struct bulk_cb_wrap {
419         __le32  Signature;              // Contains 'USBC'
420         u32     Tag;                    // Unique per command id
421         __le32  DataTransferLength;     // Size of the data
422         u8      Flags;                  // Direction in bit 7
423         u8      Lun;                    // LUN (normally 0)
424         u8      Length;                 // Of the CDB, <= MAX_COMMAND_SIZE
425         u8      CDB[16];                // Command Data Block
426 };
427
428 #define USB_BULK_CB_WRAP_LEN    31
429 #define USB_BULK_CB_SIG         0x43425355      // Spells out USBC
430 #define USB_BULK_IN_FLAG        0x80
431
432 /* Command Status Wrapper */
433 struct bulk_cs_wrap {
434         __le32  Signature;              // Should = 'USBS'
435         u32     Tag;                    // Same as original command
436         __le32  Residue;                // Amount not transferred
437         u8      Status;                 // See below
438 };
439
440 #define USB_BULK_CS_WRAP_LEN    13
441 #define USB_BULK_CS_SIG         0x53425355      // Spells out 'USBS'
442 #define USB_STATUS_PASS         0
443 #define USB_STATUS_FAIL         1
444 #define USB_STATUS_PHASE_ERROR  2
445
446 /* Bulk-only class specific requests */
447 #define USB_BULK_RESET_REQUEST          0xff
448 #define USB_BULK_GET_MAX_LUN_REQUEST    0xfe
449
450
451 /* CBI Interrupt data structure */
452 struct interrupt_data {
453         u8      bType;
454         u8      bValue;
455 };
456
457 #define CBI_INTERRUPT_DATA_LEN          2
458
459 /* CBI Accept Device-Specific Command request */
460 #define USB_CBI_ADSC_REQUEST            0x00
461
462
463 #define MAX_COMMAND_SIZE        16      // Length of a SCSI Command Data Block
464
465 /* SCSI commands that we recognize */
466 #define SC_FORMAT_UNIT                  0x04
467 #define SC_INQUIRY                      0x12
468 #define SC_MODE_SELECT_6                0x15
469 #define SC_MODE_SELECT_10               0x55
470 #define SC_MODE_SENSE_6                 0x1a
471 #define SC_MODE_SENSE_10                0x5a
472 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
473 #define SC_READ_6                       0x08
474 #define SC_READ_10                      0x28
475 #define SC_READ_12                      0xa8
476 #define SC_READ_CAPACITY                0x25
477 #define SC_READ_FORMAT_CAPACITIES       0x23
478 #define SC_RELEASE                      0x17
479 #define SC_REQUEST_SENSE                0x03
480 #define SC_RESERVE                      0x16
481 #define SC_SEND_DIAGNOSTIC              0x1d
482 #define SC_START_STOP_UNIT              0x1b
483 #define SC_SYNCHRONIZE_CACHE            0x35
484 #define SC_TEST_UNIT_READY              0x00
485 #define SC_VERIFY                       0x2f
486 #define SC_WRITE_6                      0x0a
487 #define SC_WRITE_10                     0x2a
488 #define SC_WRITE_12                     0xaa
489
490 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
491 #define SS_NO_SENSE                             0
492 #define SS_COMMUNICATION_FAILURE                0x040800
493 #define SS_INVALID_COMMAND                      0x052000
494 #define SS_INVALID_FIELD_IN_CDB                 0x052400
495 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
496 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
497 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
498 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
499 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
500 #define SS_RESET_OCCURRED                       0x062900
501 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
502 #define SS_UNRECOVERED_READ_ERROR               0x031100
503 #define SS_WRITE_ERROR                          0x030c02
504 #define SS_WRITE_PROTECTED                      0x072700
505
506 #define SK(x)           ((u8) ((x) >> 16))      // Sense Key byte, etc.
507 #define ASC(x)          ((u8) ((x) >> 8))
508 #define ASCQ(x)         ((u8) (x))
509
510
511 /*-------------------------------------------------------------------------*/
512
513 /*
514  * These definitions will permit the compiler to avoid generating code for
515  * parts of the driver that aren't used in the non-TEST version.  Even gcc
516  * can recognize when a test of a constant expression yields a dead code
517  * path.
518  */
519
520 #ifdef CONFIG_USB_FILE_STORAGE_TEST
521
522 #define transport_is_bbb()      (mod_data.transport_type == USB_PR_BULK)
523 #define transport_is_cbi()      (mod_data.transport_type == USB_PR_CBI)
524 #define protocol_is_scsi()      (mod_data.protocol_type == USB_SC_SCSI)
525
526 #else
527
528 #define transport_is_bbb()      1
529 #define transport_is_cbi()      0
530 #define protocol_is_scsi()      1
531
532 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
533
534
535 struct lun {
536         struct file     *filp;
537         loff_t          file_length;
538         loff_t          num_sectors;
539
540         unsigned int    ro : 1;
541         unsigned int    prevent_medium_removal : 1;
542         unsigned int    registered : 1;
543         unsigned int    info_valid : 1;
544
545         u32             sense_data;
546         u32             sense_data_info;
547         u32             unit_attention_data;
548
549         struct device   dev;
550 };
551
552 #define backing_file_is_open(curlun)    ((curlun)->filp != NULL)
553
554 static struct lun *dev_to_lun(struct device *dev)
555 {
556         return container_of(dev, struct lun, dev);
557 }
558
559
560 /* Big enough to hold our biggest descriptor */
561 #define EP0_BUFSIZE     256
562 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     // An impossibly large value
563
564 /* Number of buffers we will use.  2 is enough for double-buffering */
565 #define NUM_BUFFERS     2
566
567 enum fsg_buffer_state {
568         BUF_STATE_EMPTY = 0,
569         BUF_STATE_FULL,
570         BUF_STATE_BUSY
571 };
572
573 struct fsg_buffhd {
574         void                            *buf;
575         enum fsg_buffer_state           state;
576         struct fsg_buffhd               *next;
577
578         /* The NetChip 2280 is faster, and handles some protocol faults
579          * better, if we don't submit any short bulk-out read requests.
580          * So we will record the intended request length here. */
581         unsigned int                    bulk_out_intended_length;
582
583         struct usb_request              *inreq;
584         int                             inreq_busy;
585         struct usb_request              *outreq;
586         int                             outreq_busy;
587 };
588
589 enum fsg_state {
590         FSG_STATE_COMMAND_PHASE = -10,          // This one isn't used anywhere
591         FSG_STATE_DATA_PHASE,
592         FSG_STATE_STATUS_PHASE,
593
594         FSG_STATE_IDLE = 0,
595         FSG_STATE_ABORT_BULK_OUT,
596         FSG_STATE_RESET,
597         FSG_STATE_INTERFACE_CHANGE,
598         FSG_STATE_CONFIG_CHANGE,
599         FSG_STATE_DISCONNECT,
600         FSG_STATE_EXIT,
601         FSG_STATE_TERMINATED
602 };
603
604 enum data_direction {
605         DATA_DIR_UNKNOWN = 0,
606         DATA_DIR_FROM_HOST,
607         DATA_DIR_TO_HOST,
608         DATA_DIR_NONE
609 };
610
611 struct fsg_dev {
612         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
613         spinlock_t              lock;
614         struct usb_gadget       *gadget;
615
616         /* filesem protects: backing files in use */
617         struct rw_semaphore     filesem;
618
619         /* reference counting: wait until all LUNs are released */
620         struct kref             ref;
621
622         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
623         struct usb_request      *ep0req;        // For control responses
624         unsigned int            ep0_req_tag;
625         const char              *ep0req_name;
626
627         struct usb_request      *intreq;        // For interrupt responses
628         int                     intreq_busy;
629         struct fsg_buffhd       *intr_buffhd;
630
631         unsigned int            bulk_out_maxpacket;
632         enum fsg_state          state;          // For exception handling
633         unsigned int            exception_req_tag;
634
635         u8                      config, new_config;
636
637         unsigned int            running : 1;
638         unsigned int            bulk_in_enabled : 1;
639         unsigned int            bulk_out_enabled : 1;
640         unsigned int            intr_in_enabled : 1;
641         unsigned int            phase_error : 1;
642         unsigned int            short_packet_received : 1;
643         unsigned int            bad_lun_okay : 1;
644
645         unsigned long           atomic_bitflags;
646 #define REGISTERED              0
647 #define IGNORE_BULK_OUT         1
648 #define SUSPENDED               2
649
650         struct usb_ep           *bulk_in;
651         struct usb_ep           *bulk_out;
652         struct usb_ep           *intr_in;
653
654         struct fsg_buffhd       *next_buffhd_to_fill;
655         struct fsg_buffhd       *next_buffhd_to_drain;
656         struct fsg_buffhd       buffhds[NUM_BUFFERS];
657
658         int                     thread_wakeup_needed;
659         struct completion       thread_notifier;
660         struct task_struct      *thread_task;
661
662         int                     cmnd_size;
663         u8                      cmnd[MAX_COMMAND_SIZE];
664         enum data_direction     data_dir;
665         u32                     data_size;
666         u32                     data_size_from_cmnd;
667         u32                     tag;
668         unsigned int            lun;
669         u32                     residue;
670         u32                     usb_amount_left;
671
672         /* The CB protocol offers no way for a host to know when a command
673          * has completed.  As a result the next command may arrive early,
674          * and we will still have to handle it.  For that reason we need
675          * a buffer to store new commands when using CB (or CBI, which
676          * does not oblige a host to wait for command completion either). */
677         int                     cbbuf_cmnd_size;
678         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
679
680         unsigned int            nluns;
681         struct lun              *luns;
682         struct lun              *curlun;
683 };
684
685 typedef void (*fsg_routine_t)(struct fsg_dev *);
686
687 static int exception_in_progress(struct fsg_dev *fsg)
688 {
689         return (fsg->state > FSG_STATE_IDLE);
690 }
691
692 /* Make bulk-out requests be divisible by the maxpacket size */
693 static void set_bulk_out_req_length(struct fsg_dev *fsg,
694                 struct fsg_buffhd *bh, unsigned int length)
695 {
696         unsigned int    rem;
697
698         bh->bulk_out_intended_length = length;
699         rem = length % fsg->bulk_out_maxpacket;
700         if (rem > 0)
701                 length += fsg->bulk_out_maxpacket - rem;
702         bh->outreq->length = length;
703 }
704
705 static struct fsg_dev                   *the_fsg;
706 static struct usb_gadget_driver         fsg_driver;
707
708 static void     close_backing_file(struct lun *curlun);
709 static void     close_all_backing_files(struct fsg_dev *fsg);
710
711
712 /*-------------------------------------------------------------------------*/
713
714 #ifdef DUMP_MSGS
715
716 static void dump_msg(struct fsg_dev *fsg, const char *label,
717                 const u8 *buf, unsigned int length)
718 {
719         if (length < 512) {
720                 DBG(fsg, "%s, length %u:\n", label, length);
721                 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,
722                                 16, 1, buf, length, 0);
723         }
724 }
725
726 static void dump_cdb(struct fsg_dev *fsg)
727 {}
728
729 #else
730
731 static void dump_msg(struct fsg_dev *fsg, const char *label,
732                 const u8 *buf, unsigned int length)
733 {}
734
735 #ifdef VERBOSE_DEBUG
736
737 static void dump_cdb(struct fsg_dev *fsg)
738 {
739         print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,
740                         16, 1, fsg->cmnd, fsg->cmnd_size, 0);
741 }
742
743 #else
744
745 static void dump_cdb(struct fsg_dev *fsg)
746 {}
747
748 #endif /* VERBOSE_DEBUG */
749 #endif /* DUMP_MSGS */
750
751
752 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
753 {
754         const char      *name;
755
756         if (ep == fsg->bulk_in)
757                 name = "bulk-in";
758         else if (ep == fsg->bulk_out)
759                 name = "bulk-out";
760         else
761                 name = ep->name;
762         DBG(fsg, "%s set halt\n", name);
763         return usb_ep_set_halt(ep);
764 }
765
766
767 /*-------------------------------------------------------------------------*/
768
769 /* Routines for unaligned data access */
770
771 static u16 get_be16(u8 *buf)
772 {
773         return ((u16) buf[0] << 8) | ((u16) buf[1]);
774 }
775
776 static u32 get_be32(u8 *buf)
777 {
778         return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) |
779                         ((u32) buf[2] << 8) | ((u32) buf[3]);
780 }
781
782 static void put_be16(u8 *buf, u16 val)
783 {
784         buf[0] = val >> 8;
785         buf[1] = val;
786 }
787
788 static void put_be32(u8 *buf, u32 val)
789 {
790         buf[0] = val >> 24;
791         buf[1] = val >> 16;
792         buf[2] = val >> 8;
793         buf[3] = val & 0xff;
794 }
795
796
797 /*-------------------------------------------------------------------------*/
798
799 /*
800  * DESCRIPTORS ... most are static, but strings and (full) configuration
801  * descriptors are built on demand.  Also the (static) config and interface
802  * descriptors are adjusted during fsg_bind().
803  */
804 #define STRING_MANUFACTURER     1
805 #define STRING_PRODUCT          2
806 #define STRING_SERIAL           3
807 #define STRING_CONFIG           4
808 #define STRING_INTERFACE        5
809
810 /* There is only one configuration. */
811 #define CONFIG_VALUE            1
812
813 static struct usb_device_descriptor
814 device_desc = {
815         .bLength =              sizeof device_desc,
816         .bDescriptorType =      USB_DT_DEVICE,
817
818         .bcdUSB =               __constant_cpu_to_le16(0x0200),
819         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
820
821         /* The next three values can be overridden by module parameters */
822         .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_ID),
823         .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
824         .bcdDevice =            __constant_cpu_to_le16(0xffff),
825
826         .iManufacturer =        STRING_MANUFACTURER,
827         .iProduct =             STRING_PRODUCT,
828         .iSerialNumber =        STRING_SERIAL,
829         .bNumConfigurations =   1,
830 };
831
832 static struct usb_config_descriptor
833 config_desc = {
834         .bLength =              sizeof config_desc,
835         .bDescriptorType =      USB_DT_CONFIG,
836
837         /* wTotalLength computed by usb_gadget_config_buf() */
838         .bNumInterfaces =       1,
839         .bConfigurationValue =  CONFIG_VALUE,
840         .iConfiguration =       STRING_CONFIG,
841         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
842         .bMaxPower =            1,      // self-powered
843 };
844
845 static struct usb_otg_descriptor
846 otg_desc = {
847         .bLength =              sizeof(otg_desc),
848         .bDescriptorType =      USB_DT_OTG,
849
850         .bmAttributes =         USB_OTG_SRP,
851 };
852
853 /* There is only one interface. */
854
855 static struct usb_interface_descriptor
856 intf_desc = {
857         .bLength =              sizeof intf_desc,
858         .bDescriptorType =      USB_DT_INTERFACE,
859
860         .bNumEndpoints =        2,              // Adjusted during fsg_bind()
861         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
862         .bInterfaceSubClass =   USB_SC_SCSI,    // Adjusted during fsg_bind()
863         .bInterfaceProtocol =   USB_PR_BULK,    // Adjusted during fsg_bind()
864         .iInterface =           STRING_INTERFACE,
865 };
866
867 /* Three full-speed endpoint descriptors: bulk-in, bulk-out,
868  * and interrupt-in. */
869
870 static struct usb_endpoint_descriptor
871 fs_bulk_in_desc = {
872         .bLength =              USB_DT_ENDPOINT_SIZE,
873         .bDescriptorType =      USB_DT_ENDPOINT,
874
875         .bEndpointAddress =     USB_DIR_IN,
876         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
877         /* wMaxPacketSize set by autoconfiguration */
878 };
879
880 static struct usb_endpoint_descriptor
881 fs_bulk_out_desc = {
882         .bLength =              USB_DT_ENDPOINT_SIZE,
883         .bDescriptorType =      USB_DT_ENDPOINT,
884
885         .bEndpointAddress =     USB_DIR_OUT,
886         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
887         /* wMaxPacketSize set by autoconfiguration */
888 };
889
890 static struct usb_endpoint_descriptor
891 fs_intr_in_desc = {
892         .bLength =              USB_DT_ENDPOINT_SIZE,
893         .bDescriptorType =      USB_DT_ENDPOINT,
894
895         .bEndpointAddress =     USB_DIR_IN,
896         .bmAttributes =         USB_ENDPOINT_XFER_INT,
897         .wMaxPacketSize =       __constant_cpu_to_le16(2),
898         .bInterval =            32,     // frames -> 32 ms
899 };
900
901 static const struct usb_descriptor_header *fs_function[] = {
902         (struct usb_descriptor_header *) &otg_desc,
903         (struct usb_descriptor_header *) &intf_desc,
904         (struct usb_descriptor_header *) &fs_bulk_in_desc,
905         (struct usb_descriptor_header *) &fs_bulk_out_desc,
906         (struct usb_descriptor_header *) &fs_intr_in_desc,
907         NULL,
908 };
909 #define FS_FUNCTION_PRE_EP_ENTRIES      2
910
911
912 /*
913  * USB 2.0 devices need to expose both high speed and full speed
914  * descriptors, unless they only run at full speed.
915  *
916  * That means alternate endpoint descriptors (bigger packets)
917  * and a "device qualifier" ... plus more construction options
918  * for the config descriptor.
919  */
920 static struct usb_qualifier_descriptor
921 dev_qualifier = {
922         .bLength =              sizeof dev_qualifier,
923         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
924
925         .bcdUSB =               __constant_cpu_to_le16(0x0200),
926         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
927
928         .bNumConfigurations =   1,
929 };
930
931 static struct usb_endpoint_descriptor
932 hs_bulk_in_desc = {
933         .bLength =              USB_DT_ENDPOINT_SIZE,
934         .bDescriptorType =      USB_DT_ENDPOINT,
935
936         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
937         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
938         .wMaxPacketSize =       __constant_cpu_to_le16(512),
939 };
940
941 static struct usb_endpoint_descriptor
942 hs_bulk_out_desc = {
943         .bLength =              USB_DT_ENDPOINT_SIZE,
944         .bDescriptorType =      USB_DT_ENDPOINT,
945
946         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
947         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
948         .wMaxPacketSize =       __constant_cpu_to_le16(512),
949         .bInterval =            1,      // NAK every 1 uframe
950 };
951
952 static struct usb_endpoint_descriptor
953 hs_intr_in_desc = {
954         .bLength =              USB_DT_ENDPOINT_SIZE,
955         .bDescriptorType =      USB_DT_ENDPOINT,
956
957         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
958         .bmAttributes =         USB_ENDPOINT_XFER_INT,
959         .wMaxPacketSize =       __constant_cpu_to_le16(2),
960         .bInterval =            9,      // 2**(9-1) = 256 uframes -> 32 ms
961 };
962
963 static const struct usb_descriptor_header *hs_function[] = {
964         (struct usb_descriptor_header *) &otg_desc,
965         (struct usb_descriptor_header *) &intf_desc,
966         (struct usb_descriptor_header *) &hs_bulk_in_desc,
967         (struct usb_descriptor_header *) &hs_bulk_out_desc,
968         (struct usb_descriptor_header *) &hs_intr_in_desc,
969         NULL,
970 };
971 #define HS_FUNCTION_PRE_EP_ENTRIES      2
972
973 /* Maxpacket and other transfer characteristics vary by speed. */
974 static struct usb_endpoint_descriptor *
975 ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
976                 struct usb_endpoint_descriptor *hs)
977 {
978         if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
979                 return hs;
980         return fs;
981 }
982
983
984 /* The CBI specification limits the serial string to 12 uppercase hexadecimal
985  * characters. */
986 static char                             manufacturer[64];
987 static char                             serial[13];
988
989 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
990 static struct usb_string                strings[] = {
991         {STRING_MANUFACTURER,   manufacturer},
992         {STRING_PRODUCT,        longname},
993         {STRING_SERIAL,         serial},
994         {STRING_CONFIG,         "Self-powered"},
995         {STRING_INTERFACE,      "Mass Storage"},
996         {}
997 };
998
999 static struct usb_gadget_strings        stringtab = {
1000         .language       = 0x0409,               // en-us
1001         .strings        = strings,
1002 };
1003
1004
1005 /*
1006  * Config descriptors must agree with the code that sets configurations
1007  * and with code managing interfaces and their altsettings.  They must
1008  * also handle different speeds and other-speed requests.
1009  */
1010 static int populate_config_buf(struct usb_gadget *gadget,
1011                 u8 *buf, u8 type, unsigned index)
1012 {
1013         enum usb_device_speed                   speed = gadget->speed;
1014         int                                     len;
1015         const struct usb_descriptor_header      **function;
1016
1017         if (index > 0)
1018                 return -EINVAL;
1019
1020         if (gadget_is_dualspeed(gadget) && type == USB_DT_OTHER_SPEED_CONFIG)
1021                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
1022         if (gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH)
1023                 function = hs_function;
1024         else
1025                 function = fs_function;
1026
1027         /* for now, don't advertise srp-only devices */
1028         if (!gadget_is_otg(gadget))
1029                 function++;
1030
1031         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
1032         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
1033         return len;
1034 }
1035
1036
1037 /*-------------------------------------------------------------------------*/
1038
1039 /* These routines may be called in process context or in_irq */
1040
1041 /* Caller must hold fsg->lock */
1042 static void wakeup_thread(struct fsg_dev *fsg)
1043 {
1044         /* Tell the main thread that something has happened */
1045         fsg->thread_wakeup_needed = 1;
1046         if (fsg->thread_task)
1047                 wake_up_process(fsg->thread_task);
1048 }
1049
1050
1051 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
1052 {
1053         unsigned long           flags;
1054
1055         /* Do nothing if a higher-priority exception is already in progress.
1056          * If a lower-or-equal priority exception is in progress, preempt it
1057          * and notify the main thread by sending it a signal. */
1058         spin_lock_irqsave(&fsg->lock, flags);
1059         if (fsg->state <= new_state) {
1060                 fsg->exception_req_tag = fsg->ep0_req_tag;
1061                 fsg->state = new_state;
1062                 if (fsg->thread_task)
1063                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
1064                                         fsg->thread_task);
1065         }
1066         spin_unlock_irqrestore(&fsg->lock, flags);
1067 }
1068
1069
1070 /*-------------------------------------------------------------------------*/
1071
1072 /* The disconnect callback and ep0 routines.  These always run in_irq,
1073  * except that ep0_queue() is called in the main thread to acknowledge
1074  * completion of various requests: set config, set interface, and
1075  * Bulk-only device reset. */
1076
1077 static void fsg_disconnect(struct usb_gadget *gadget)
1078 {
1079         struct fsg_dev          *fsg = get_gadget_data(gadget);
1080
1081         DBG(fsg, "disconnect or port reset\n");
1082         raise_exception(fsg, FSG_STATE_DISCONNECT);
1083 }
1084
1085
1086 static int ep0_queue(struct fsg_dev *fsg)
1087 {
1088         int     rc;
1089
1090         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
1091         if (rc != 0 && rc != -ESHUTDOWN) {
1092
1093                 /* We can't do much more than wait for a reset */
1094                 WARN(fsg, "error in submission: %s --> %d\n",
1095                                 fsg->ep0->name, rc);
1096         }
1097         return rc;
1098 }
1099
1100 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
1101 {
1102         struct fsg_dev          *fsg = ep->driver_data;
1103
1104         if (req->actual > 0)
1105                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
1106         if (req->status || req->actual != req->length)
1107                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1108                                 req->status, req->actual, req->length);
1109         if (req->status == -ECONNRESET)         // Request was cancelled
1110                 usb_ep_fifo_flush(ep);
1111
1112         if (req->status == 0 && req->context)
1113                 ((fsg_routine_t) (req->context))(fsg);
1114 }
1115
1116
1117 /*-------------------------------------------------------------------------*/
1118
1119 /* Bulk and interrupt endpoint completion handlers.
1120  * These always run in_irq. */
1121
1122 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
1123 {
1124         struct fsg_dev          *fsg = ep->driver_data;
1125         struct fsg_buffhd       *bh = req->context;
1126
1127         if (req->status || req->actual != req->length)
1128                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1129                                 req->status, req->actual, req->length);
1130         if (req->status == -ECONNRESET)         // Request was cancelled
1131                 usb_ep_fifo_flush(ep);
1132
1133         /* Hold the lock while we update the request and buffer states */
1134         smp_wmb();
1135         spin_lock(&fsg->lock);
1136         bh->inreq_busy = 0;
1137         bh->state = BUF_STATE_EMPTY;
1138         wakeup_thread(fsg);
1139         spin_unlock(&fsg->lock);
1140 }
1141
1142 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
1143 {
1144         struct fsg_dev          *fsg = ep->driver_data;
1145         struct fsg_buffhd       *bh = req->context;
1146
1147         dump_msg(fsg, "bulk-out", req->buf, req->actual);
1148         if (req->status || req->actual != bh->bulk_out_intended_length)
1149                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1150                                 req->status, req->actual,
1151                                 bh->bulk_out_intended_length);
1152         if (req->status == -ECONNRESET)         // Request was cancelled
1153                 usb_ep_fifo_flush(ep);
1154
1155         /* Hold the lock while we update the request and buffer states */
1156         smp_wmb();
1157         spin_lock(&fsg->lock);
1158         bh->outreq_busy = 0;
1159         bh->state = BUF_STATE_FULL;
1160         wakeup_thread(fsg);
1161         spin_unlock(&fsg->lock);
1162 }
1163
1164
1165 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1166 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1167 {
1168         struct fsg_dev          *fsg = ep->driver_data;
1169         struct fsg_buffhd       *bh = req->context;
1170
1171         if (req->status || req->actual != req->length)
1172                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
1173                                 req->status, req->actual, req->length);
1174         if (req->status == -ECONNRESET)         // Request was cancelled
1175                 usb_ep_fifo_flush(ep);
1176
1177         /* Hold the lock while we update the request and buffer states */
1178         smp_wmb();
1179         spin_lock(&fsg->lock);
1180         fsg->intreq_busy = 0;
1181         bh->state = BUF_STATE_EMPTY;
1182         wakeup_thread(fsg);
1183         spin_unlock(&fsg->lock);
1184 }
1185
1186 #else
1187 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1188 {}
1189 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1190
1191
1192 /*-------------------------------------------------------------------------*/
1193
1194 /* Ep0 class-specific handlers.  These always run in_irq. */
1195
1196 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1197 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1198 {
1199         struct usb_request      *req = fsg->ep0req;
1200         static u8               cbi_reset_cmnd[6] = {
1201                         SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
1202
1203         /* Error in command transfer? */
1204         if (req->status || req->length != req->actual ||
1205                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
1206
1207                 /* Not all controllers allow a protocol stall after
1208                  * receiving control-out data, but we'll try anyway. */
1209                 fsg_set_halt(fsg, fsg->ep0);
1210                 return;                 // Wait for reset
1211         }
1212
1213         /* Is it the special reset command? */
1214         if (req->actual >= sizeof cbi_reset_cmnd &&
1215                         memcmp(req->buf, cbi_reset_cmnd,
1216                                 sizeof cbi_reset_cmnd) == 0) {
1217
1218                 /* Raise an exception to stop the current operation
1219                  * and reinitialize our state. */
1220                 DBG(fsg, "cbi reset request\n");
1221                 raise_exception(fsg, FSG_STATE_RESET);
1222                 return;
1223         }
1224
1225         VDBG(fsg, "CB[I] accept device-specific command\n");
1226         spin_lock(&fsg->lock);
1227
1228         /* Save the command for later */
1229         if (fsg->cbbuf_cmnd_size)
1230                 WARN(fsg, "CB[I] overwriting previous command\n");
1231         fsg->cbbuf_cmnd_size = req->actual;
1232         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
1233
1234         wakeup_thread(fsg);
1235         spin_unlock(&fsg->lock);
1236 }
1237
1238 #else
1239 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1240 {}
1241 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1242
1243
1244 static int class_setup_req(struct fsg_dev *fsg,
1245                 const struct usb_ctrlrequest *ctrl)
1246 {
1247         struct usb_request      *req = fsg->ep0req;
1248         int                     value = -EOPNOTSUPP;
1249         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1250         u16                     w_value = le16_to_cpu(ctrl->wValue);
1251         u16                     w_length = le16_to_cpu(ctrl->wLength);
1252
1253         if (!fsg->config)
1254                 return value;
1255
1256         /* Handle Bulk-only class-specific requests */
1257         if (transport_is_bbb()) {
1258                 switch (ctrl->bRequest) {
1259
1260                 case USB_BULK_RESET_REQUEST:
1261                         if (ctrl->bRequestType != (USB_DIR_OUT |
1262                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1263                                 break;
1264                         if (w_index != 0 || w_value != 0) {
1265                                 value = -EDOM;
1266                                 break;
1267                         }
1268
1269                         /* Raise an exception to stop the current operation
1270                          * and reinitialize our state. */
1271                         DBG(fsg, "bulk reset request\n");
1272                         raise_exception(fsg, FSG_STATE_RESET);
1273                         value = DELAYED_STATUS;
1274                         break;
1275
1276                 case USB_BULK_GET_MAX_LUN_REQUEST:
1277                         if (ctrl->bRequestType != (USB_DIR_IN |
1278                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1279                                 break;
1280                         if (w_index != 0 || w_value != 0) {
1281                                 value = -EDOM;
1282                                 break;
1283                         }
1284                         VDBG(fsg, "get max LUN\n");
1285                         *(u8 *) req->buf = fsg->nluns - 1;
1286                         value = 1;
1287                         break;
1288                 }
1289         }
1290
1291         /* Handle CBI class-specific requests */
1292         else {
1293                 switch (ctrl->bRequest) {
1294
1295                 case USB_CBI_ADSC_REQUEST:
1296                         if (ctrl->bRequestType != (USB_DIR_OUT |
1297                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1298                                 break;
1299                         if (w_index != 0 || w_value != 0) {
1300                                 value = -EDOM;
1301                                 break;
1302                         }
1303                         if (w_length > MAX_COMMAND_SIZE) {
1304                                 value = -EOVERFLOW;
1305                                 break;
1306                         }
1307                         value = w_length;
1308                         fsg->ep0req->context = received_cbi_adsc;
1309                         break;
1310                 }
1311         }
1312
1313         if (value == -EOPNOTSUPP)
1314                 VDBG(fsg,
1315                         "unknown class-specific control req "
1316                         "%02x.%02x v%04x i%04x l%u\n",
1317                         ctrl->bRequestType, ctrl->bRequest,
1318                         le16_to_cpu(ctrl->wValue), w_index, w_length);
1319         return value;
1320 }
1321
1322
1323 /*-------------------------------------------------------------------------*/
1324
1325 /* Ep0 standard request handlers.  These always run in_irq. */
1326
1327 static int standard_setup_req(struct fsg_dev *fsg,
1328                 const struct usb_ctrlrequest *ctrl)
1329 {
1330         struct usb_request      *req = fsg->ep0req;
1331         int                     value = -EOPNOTSUPP;
1332         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1333         u16                     w_value = le16_to_cpu(ctrl->wValue);
1334
1335         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
1336          * but config change events will also reconfigure hardware. */
1337         switch (ctrl->bRequest) {
1338
1339         case USB_REQ_GET_DESCRIPTOR:
1340                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1341                                 USB_RECIP_DEVICE))
1342                         break;
1343                 switch (w_value >> 8) {
1344
1345                 case USB_DT_DEVICE:
1346                         VDBG(fsg, "get device descriptor\n");
1347                         value = sizeof device_desc;
1348                         memcpy(req->buf, &device_desc, value);
1349                         break;
1350                 case USB_DT_DEVICE_QUALIFIER:
1351                         VDBG(fsg, "get device qualifier\n");
1352                         if (!gadget_is_dualspeed(fsg->gadget))
1353                                 break;
1354                         value = sizeof dev_qualifier;
1355                         memcpy(req->buf, &dev_qualifier, value);
1356                         break;
1357
1358                 case USB_DT_OTHER_SPEED_CONFIG:
1359                         VDBG(fsg, "get other-speed config descriptor\n");
1360                         if (!gadget_is_dualspeed(fsg->gadget))
1361                                 break;
1362                         goto get_config;
1363                 case USB_DT_CONFIG:
1364                         VDBG(fsg, "get configuration descriptor\n");
1365 get_config:
1366                         value = populate_config_buf(fsg->gadget,
1367                                         req->buf,
1368                                         w_value >> 8,
1369                                         w_value & 0xff);
1370                         break;
1371
1372                 case USB_DT_STRING:
1373                         VDBG(fsg, "get string descriptor\n");
1374
1375                         /* wIndex == language code */
1376                         value = usb_gadget_get_string(&stringtab,
1377                                         w_value & 0xff, req->buf);
1378                         break;
1379                 }
1380                 break;
1381
1382         /* One config, two speeds */
1383         case USB_REQ_SET_CONFIGURATION:
1384                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
1385                                 USB_RECIP_DEVICE))
1386                         break;
1387                 VDBG(fsg, "set configuration\n");
1388                 if (w_value == CONFIG_VALUE || w_value == 0) {
1389                         fsg->new_config = w_value;
1390
1391                         /* Raise an exception to wipe out previous transaction
1392                          * state (queued bufs, etc) and set the new config. */
1393                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
1394                         value = DELAYED_STATUS;
1395                 }
1396                 break;
1397         case USB_REQ_GET_CONFIGURATION:
1398                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1399                                 USB_RECIP_DEVICE))
1400                         break;
1401                 VDBG(fsg, "get configuration\n");
1402                 *(u8 *) req->buf = fsg->config;
1403                 value = 1;
1404                 break;
1405
1406         case USB_REQ_SET_INTERFACE:
1407                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
1408                                 USB_RECIP_INTERFACE))
1409                         break;
1410                 if (fsg->config && w_index == 0) {
1411
1412                         /* Raise an exception to wipe out previous transaction
1413                          * state (queued bufs, etc) and install the new
1414                          * interface altsetting. */
1415                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
1416                         value = DELAYED_STATUS;
1417                 }
1418                 break;
1419         case USB_REQ_GET_INTERFACE:
1420                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1421                                 USB_RECIP_INTERFACE))
1422                         break;
1423                 if (!fsg->config)
1424                         break;
1425                 if (w_index != 0) {
1426                         value = -EDOM;
1427                         break;
1428                 }
1429                 VDBG(fsg, "get interface\n");
1430                 *(u8 *) req->buf = 0;
1431                 value = 1;
1432                 break;
1433
1434         default:
1435                 VDBG(fsg,
1436                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1437                         ctrl->bRequestType, ctrl->bRequest,
1438                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1439         }
1440
1441         return value;
1442 }
1443
1444
1445 static int fsg_setup(struct usb_gadget *gadget,
1446                 const struct usb_ctrlrequest *ctrl)
1447 {
1448         struct fsg_dev          *fsg = get_gadget_data(gadget);
1449         int                     rc;
1450         int                     w_length = le16_to_cpu(ctrl->wLength);
1451
1452         ++fsg->ep0_req_tag;             // Record arrival of a new request
1453         fsg->ep0req->context = NULL;
1454         fsg->ep0req->length = 0;
1455         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1456
1457         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1458                 rc = class_setup_req(fsg, ctrl);
1459         else
1460                 rc = standard_setup_req(fsg, ctrl);
1461
1462         /* Respond with data/status or defer until later? */
1463         if (rc >= 0 && rc != DELAYED_STATUS) {
1464                 rc = min(rc, w_length);
1465                 fsg->ep0req->length = rc;
1466                 fsg->ep0req->zero = rc < w_length;
1467                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1468                                 "ep0-in" : "ep0-out");
1469                 rc = ep0_queue(fsg);
1470         }
1471
1472         /* Device either stalls (rc < 0) or reports success */
1473         return rc;
1474 }
1475
1476
1477 /*-------------------------------------------------------------------------*/
1478
1479 /* All the following routines run in process context */
1480
1481
1482 /* Use this for bulk or interrupt transfers, not ep0 */
1483 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1484                 struct usb_request *req, int *pbusy,
1485                 enum fsg_buffer_state *state)
1486 {
1487         int     rc;
1488
1489         if (ep == fsg->bulk_in)
1490                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1491         else if (ep == fsg->intr_in)
1492                 dump_msg(fsg, "intr-in", req->buf, req->length);
1493
1494         spin_lock_irq(&fsg->lock);
1495         *pbusy = 1;
1496         *state = BUF_STATE_BUSY;
1497         spin_unlock_irq(&fsg->lock);
1498         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1499         if (rc != 0) {
1500                 *pbusy = 0;
1501                 *state = BUF_STATE_EMPTY;
1502
1503                 /* We can't do much more than wait for a reset */
1504
1505                 /* Note: currently the net2280 driver fails zero-length
1506                  * submissions if DMA is enabled. */
1507                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1508                                                 req->length == 0))
1509                         WARN(fsg, "error in submission: %s --> %d\n",
1510                                         ep->name, rc);
1511         }
1512 }
1513
1514
1515 static int sleep_thread(struct fsg_dev *fsg)
1516 {
1517         int     rc = 0;
1518
1519         /* Wait until a signal arrives or we are woken up */
1520         for (;;) {
1521                 try_to_freeze();
1522                 set_current_state(TASK_INTERRUPTIBLE);
1523                 if (signal_pending(current)) {
1524                         rc = -EINTR;
1525                         break;
1526                 }
1527                 if (fsg->thread_wakeup_needed)
1528                         break;
1529                 schedule();
1530         }
1531         __set_current_state(TASK_RUNNING);
1532         fsg->thread_wakeup_needed = 0;
1533         return rc;
1534 }
1535
1536
1537 /*-------------------------------------------------------------------------*/
1538
1539 static int do_read(struct fsg_dev *fsg)
1540 {
1541         struct lun              *curlun = fsg->curlun;
1542         u32                     lba;
1543         struct fsg_buffhd       *bh;
1544         int                     rc;
1545         u32                     amount_left;
1546         loff_t                  file_offset, file_offset_tmp;
1547         unsigned int            amount;
1548         unsigned int            partial_page;
1549         ssize_t                 nread;
1550
1551         /* Get the starting Logical Block Address and check that it's
1552          * not too big */
1553         if (fsg->cmnd[0] == SC_READ_6)
1554                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1555         else {
1556                 lba = get_be32(&fsg->cmnd[2]);
1557
1558                 /* We allow DPO (Disable Page Out = don't save data in the
1559                  * cache) and FUA (Force Unit Access = don't read from the
1560                  * cache), but we don't implement them. */
1561                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1562                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1563                         return -EINVAL;
1564                 }
1565         }
1566         if (lba >= curlun->num_sectors) {
1567                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1568                 return -EINVAL;
1569         }
1570         file_offset = ((loff_t) lba) << 9;
1571
1572         /* Carry out the file reads */
1573         amount_left = fsg->data_size_from_cmnd;
1574         if (unlikely(amount_left == 0))
1575                 return -EIO;            // No default reply
1576
1577         for (;;) {
1578
1579                 /* Figure out how much we need to read:
1580                  * Try to read the remaining amount.
1581                  * But don't read more than the buffer size.
1582                  * And don't try to read past the end of the file.
1583                  * Finally, if we're not at a page boundary, don't read past
1584                  *      the next page.
1585                  * If this means reading 0 then we were asked to read past
1586                  *      the end of file. */
1587                 amount = min((unsigned int) amount_left, mod_data.buflen);
1588                 amount = min((loff_t) amount,
1589                                 curlun->file_length - file_offset);
1590                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1591                 if (partial_page > 0)
1592                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1593                                         partial_page);
1594
1595                 /* Wait for the next buffer to become available */
1596                 bh = fsg->next_buffhd_to_fill;
1597                 while (bh->state != BUF_STATE_EMPTY) {
1598                         rc = sleep_thread(fsg);
1599                         if (rc)
1600                                 return rc;
1601                 }
1602
1603                 /* If we were asked to read past the end of file,
1604                  * end with an empty buffer. */
1605                 if (amount == 0) {
1606                         curlun->sense_data =
1607                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1608                         curlun->sense_data_info = file_offset >> 9;
1609                         curlun->info_valid = 1;
1610                         bh->inreq->length = 0;
1611                         bh->state = BUF_STATE_FULL;
1612                         break;
1613                 }
1614
1615                 /* Perform the read */
1616                 file_offset_tmp = file_offset;
1617                 nread = vfs_read(curlun->filp,
1618                                 (char __user *) bh->buf,
1619                                 amount, &file_offset_tmp);
1620                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1621                                 (unsigned long long) file_offset,
1622                                 (int) nread);
1623                 if (signal_pending(current))
1624                         return -EINTR;
1625
1626                 if (nread < 0) {
1627                         LDBG(curlun, "error in file read: %d\n",
1628                                         (int) nread);
1629                         nread = 0;
1630                 } else if (nread < amount) {
1631                         LDBG(curlun, "partial file read: %d/%u\n",
1632                                         (int) nread, amount);
1633                         nread -= (nread & 511); // Round down to a block
1634                 }
1635                 file_offset  += nread;
1636                 amount_left  -= nread;
1637                 fsg->residue -= nread;
1638                 bh->inreq->length = nread;
1639                 bh->state = BUF_STATE_FULL;
1640
1641                 /* If an error occurred, report it and its position */
1642                 if (nread < amount) {
1643                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1644                         curlun->sense_data_info = file_offset >> 9;
1645                         curlun->info_valid = 1;
1646                         break;
1647                 }
1648
1649                 if (amount_left == 0)
1650                         break;          // No more left to read
1651
1652                 /* Send this buffer and go read some more */
1653                 bh->inreq->zero = 0;
1654                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1655                                 &bh->inreq_busy, &bh->state);
1656                 fsg->next_buffhd_to_fill = bh->next;
1657         }
1658
1659         return -EIO;            // No default reply
1660 }
1661
1662
1663 /*-------------------------------------------------------------------------*/
1664
1665 static int do_write(struct fsg_dev *fsg)
1666 {
1667         struct lun              *curlun = fsg->curlun;
1668         u32                     lba;
1669         struct fsg_buffhd       *bh;
1670         int                     get_some_more;
1671         u32                     amount_left_to_req, amount_left_to_write;
1672         loff_t                  usb_offset, file_offset, file_offset_tmp;
1673         unsigned int            amount;
1674         unsigned int            partial_page;
1675         ssize_t                 nwritten;
1676         int                     rc;
1677
1678         if (curlun->ro) {
1679                 curlun->sense_data = SS_WRITE_PROTECTED;
1680                 return -EINVAL;
1681         }
1682         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1683
1684         /* Get the starting Logical Block Address and check that it's
1685          * not too big */
1686         if (fsg->cmnd[0] == SC_WRITE_6)
1687                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1688         else {
1689                 lba = get_be32(&fsg->cmnd[2]);
1690
1691                 /* We allow DPO (Disable Page Out = don't save data in the
1692                  * cache) and FUA (Force Unit Access = write directly to the
1693                  * medium).  We don't implement DPO; we implement FUA by
1694                  * performing synchronous output. */
1695                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1696                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1697                         return -EINVAL;
1698                 }
1699                 if (fsg->cmnd[1] & 0x08)        // FUA
1700                         curlun->filp->f_flags |= O_SYNC;
1701         }
1702         if (lba >= curlun->num_sectors) {
1703                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1704                 return -EINVAL;
1705         }
1706
1707         /* Carry out the file writes */
1708         get_some_more = 1;
1709         file_offset = usb_offset = ((loff_t) lba) << 9;
1710         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1711
1712         while (amount_left_to_write > 0) {
1713
1714                 /* Queue a request for more data from the host */
1715                 bh = fsg->next_buffhd_to_fill;
1716                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1717
1718                         /* Figure out how much we want to get:
1719                          * Try to get the remaining amount.
1720                          * But don't get more than the buffer size.
1721                          * And don't try to go past the end of the file.
1722                          * If we're not at a page boundary,
1723                          *      don't go past the next page.
1724                          * If this means getting 0, then we were asked
1725                          *      to write past the end of file.
1726                          * Finally, round down to a block boundary. */
1727                         amount = min(amount_left_to_req, mod_data.buflen);
1728                         amount = min((loff_t) amount, curlun->file_length -
1729                                         usb_offset);
1730                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1731                         if (partial_page > 0)
1732                                 amount = min(amount,
1733         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1734
1735                         if (amount == 0) {
1736                                 get_some_more = 0;
1737                                 curlun->sense_data =
1738                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1739                                 curlun->sense_data_info = usb_offset >> 9;
1740                                 curlun->info_valid = 1;
1741                                 continue;
1742                         }
1743                         amount -= (amount & 511);
1744                         if (amount == 0) {
1745
1746                                 /* Why were we were asked to transfer a
1747                                  * partial block? */
1748                                 get_some_more = 0;
1749                                 continue;
1750                         }
1751
1752                         /* Get the next buffer */
1753                         usb_offset += amount;
1754                         fsg->usb_amount_left -= amount;
1755                         amount_left_to_req -= amount;
1756                         if (amount_left_to_req == 0)
1757                                 get_some_more = 0;
1758
1759                         /* amount is always divisible by 512, hence by
1760                          * the bulk-out maxpacket size */
1761                         bh->outreq->length = bh->bulk_out_intended_length =
1762                                         amount;
1763                         bh->outreq->short_not_ok = 1;
1764                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1765                                         &bh->outreq_busy, &bh->state);
1766                         fsg->next_buffhd_to_fill = bh->next;
1767                         continue;
1768                 }
1769
1770                 /* Write the received data to the backing file */
1771                 bh = fsg->next_buffhd_to_drain;
1772                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1773                         break;                  // We stopped early
1774                 if (bh->state == BUF_STATE_FULL) {
1775                         smp_rmb();
1776                         fsg->next_buffhd_to_drain = bh->next;
1777                         bh->state = BUF_STATE_EMPTY;
1778
1779                         /* Did something go wrong with the transfer? */
1780                         if (bh->outreq->status != 0) {
1781                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1782                                 curlun->sense_data_info = file_offset >> 9;
1783                                 curlun->info_valid = 1;
1784                                 break;
1785                         }
1786
1787                         amount = bh->outreq->actual;
1788                         if (curlun->file_length - file_offset < amount) {
1789                                 LERROR(curlun,
1790         "write %u @ %llu beyond end %llu\n",
1791         amount, (unsigned long long) file_offset,
1792         (unsigned long long) curlun->file_length);
1793                                 amount = curlun->file_length - file_offset;
1794                         }
1795
1796                         /* Perform the write */
1797                         file_offset_tmp = file_offset;
1798                         nwritten = vfs_write(curlun->filp,
1799                                         (char __user *) bh->buf,
1800                                         amount, &file_offset_tmp);
1801                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1802                                         (unsigned long long) file_offset,
1803                                         (int) nwritten);
1804                         if (signal_pending(current))
1805                                 return -EINTR;          // Interrupted!
1806
1807                         if (nwritten < 0) {
1808                                 LDBG(curlun, "error in file write: %d\n",
1809                                                 (int) nwritten);
1810                                 nwritten = 0;
1811                         } else if (nwritten < amount) {
1812                                 LDBG(curlun, "partial file write: %d/%u\n",
1813                                                 (int) nwritten, amount);
1814                                 nwritten -= (nwritten & 511);
1815                                                 // Round down to a block
1816                         }
1817                         file_offset += nwritten;
1818                         amount_left_to_write -= nwritten;
1819                         fsg->residue -= nwritten;
1820
1821                         /* If an error occurred, report it and its position */
1822                         if (nwritten < amount) {
1823                                 curlun->sense_data = SS_WRITE_ERROR;
1824                                 curlun->sense_data_info = file_offset >> 9;
1825                                 curlun->info_valid = 1;
1826                                 break;
1827                         }
1828
1829                         /* Did the host decide to stop early? */
1830                         if (bh->outreq->actual != bh->outreq->length) {
1831                                 fsg->short_packet_received = 1;
1832                                 break;
1833                         }
1834                         continue;
1835                 }
1836
1837                 /* Wait for something to happen */
1838                 rc = sleep_thread(fsg);
1839                 if (rc)
1840                         return rc;
1841         }
1842
1843         return -EIO;            // No default reply
1844 }
1845
1846
1847 /*-------------------------------------------------------------------------*/
1848
1849 /* Sync the file data, don't bother with the metadata.
1850  * This code was copied from fs/buffer.c:sys_fdatasync(). */
1851 static int fsync_sub(struct lun *curlun)
1852 {
1853         struct file     *filp = curlun->filp;
1854         struct inode    *inode;
1855         int             rc, err;
1856
1857         if (curlun->ro || !filp)
1858                 return 0;
1859         if (!filp->f_op->fsync)
1860                 return -EINVAL;
1861
1862         inode = filp->f_path.dentry->d_inode;
1863         mutex_lock(&inode->i_mutex);
1864         rc = filemap_fdatawrite(inode->i_mapping);
1865         err = filp->f_op->fsync(filp, filp->f_path.dentry, 1);
1866         if (!rc)
1867                 rc = err;
1868         err = filemap_fdatawait(inode->i_mapping);
1869         if (!rc)
1870                 rc = err;
1871         mutex_unlock(&inode->i_mutex);
1872         VLDBG(curlun, "fdatasync -> %d\n", rc);
1873         return rc;
1874 }
1875
1876 static void fsync_all(struct fsg_dev *fsg)
1877 {
1878         int     i;
1879
1880         for (i = 0; i < fsg->nluns; ++i)
1881                 fsync_sub(&fsg->luns[i]);
1882 }
1883
1884 static int do_synchronize_cache(struct fsg_dev *fsg)
1885 {
1886         struct lun      *curlun = fsg->curlun;
1887         int             rc;
1888
1889         /* We ignore the requested LBA and write out all file's
1890          * dirty data buffers. */
1891         rc = fsync_sub(curlun);
1892         if (rc)
1893                 curlun->sense_data = SS_WRITE_ERROR;
1894         return 0;
1895 }
1896
1897
1898 /*-------------------------------------------------------------------------*/
1899
1900 static void invalidate_sub(struct lun *curlun)
1901 {
1902         struct file     *filp = curlun->filp;
1903         struct inode    *inode = filp->f_path.dentry->d_inode;
1904         unsigned long   rc;
1905
1906         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1907         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
1908 }
1909
1910 static int do_verify(struct fsg_dev *fsg)
1911 {
1912         struct lun              *curlun = fsg->curlun;
1913         u32                     lba;
1914         u32                     verification_length;
1915         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1916         loff_t                  file_offset, file_offset_tmp;
1917         u32                     amount_left;
1918         unsigned int            amount;
1919         ssize_t                 nread;
1920
1921         /* Get the starting Logical Block Address and check that it's
1922          * not too big */
1923         lba = get_be32(&fsg->cmnd[2]);
1924         if (lba >= curlun->num_sectors) {
1925                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1926                 return -EINVAL;
1927         }
1928
1929         /* We allow DPO (Disable Page Out = don't save data in the
1930          * cache) but we don't implement it. */
1931         if ((fsg->cmnd[1] & ~0x10) != 0) {
1932                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1933                 return -EINVAL;
1934         }
1935
1936         verification_length = get_be16(&fsg->cmnd[7]);
1937         if (unlikely(verification_length == 0))
1938                 return -EIO;            // No default reply
1939
1940         /* Prepare to carry out the file verify */
1941         amount_left = verification_length << 9;
1942         file_offset = ((loff_t) lba) << 9;
1943
1944         /* Write out all the dirty buffers before invalidating them */
1945         fsync_sub(curlun);
1946         if (signal_pending(current))
1947                 return -EINTR;
1948
1949         invalidate_sub(curlun);
1950         if (signal_pending(current))
1951                 return -EINTR;
1952
1953         /* Just try to read the requested blocks */
1954         while (amount_left > 0) {
1955
1956                 /* Figure out how much we need to read:
1957                  * Try to read the remaining amount, but not more than
1958                  * the buffer size.
1959                  * And don't try to read past the end of the file.
1960                  * If this means reading 0 then we were asked to read
1961                  * past the end of file. */
1962                 amount = min((unsigned int) amount_left, mod_data.buflen);
1963                 amount = min((loff_t) amount,
1964                                 curlun->file_length - file_offset);
1965                 if (amount == 0) {
1966                         curlun->sense_data =
1967                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1968                         curlun->sense_data_info = file_offset >> 9;
1969                         curlun->info_valid = 1;
1970                         break;
1971                 }
1972
1973                 /* Perform the read */
1974                 file_offset_tmp = file_offset;
1975                 nread = vfs_read(curlun->filp,
1976                                 (char __user *) bh->buf,
1977                                 amount, &file_offset_tmp);
1978                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1979                                 (unsigned long long) file_offset,
1980                                 (int) nread);
1981                 if (signal_pending(current))
1982                         return -EINTR;
1983
1984                 if (nread < 0) {
1985                         LDBG(curlun, "error in file verify: %d\n",
1986                                         (int) nread);
1987                         nread = 0;
1988                 } else if (nread < amount) {
1989                         LDBG(curlun, "partial file verify: %d/%u\n",
1990                                         (int) nread, amount);
1991                         nread -= (nread & 511); // Round down to a sector
1992                 }
1993                 if (nread == 0) {
1994                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1995                         curlun->sense_data_info = file_offset >> 9;
1996                         curlun->info_valid = 1;
1997                         break;
1998                 }
1999                 file_offset += nread;
2000                 amount_left -= nread;
2001         }
2002         return 0;
2003 }
2004
2005
2006 /*-------------------------------------------------------------------------*/
2007
2008 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2009 {
2010         u8      *buf = (u8 *) bh->buf;
2011
2012         static char vendor_id[] = "Linux   ";
2013         static char product_id[] = "File-Stor Gadget";
2014
2015         if (!fsg->curlun) {             // Unsupported LUNs are okay
2016                 fsg->bad_lun_okay = 1;
2017                 memset(buf, 0, 36);
2018                 buf[0] = 0x7f;          // Unsupported, no device-type
2019                 return 36;
2020         }
2021
2022         memset(buf, 0, 8);      // Non-removable, direct-access device
2023         if (mod_data.removable)
2024                 buf[1] = 0x80;
2025         buf[2] = 2;             // ANSI SCSI level 2
2026         buf[3] = 2;             // SCSI-2 INQUIRY data format
2027         buf[4] = 31;            // Additional length
2028                                 // No special options
2029         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, product_id,
2030                         mod_data.release);
2031         return 36;
2032 }
2033
2034
2035 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2036 {
2037         struct lun      *curlun = fsg->curlun;
2038         u8              *buf = (u8 *) bh->buf;
2039         u32             sd, sdinfo;
2040         int             valid;
2041
2042         /*
2043          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
2044          *
2045          * If a REQUEST SENSE command is received from an initiator
2046          * with a pending unit attention condition (before the target
2047          * generates the contingent allegiance condition), then the
2048          * target shall either:
2049          *   a) report any pending sense data and preserve the unit
2050          *      attention condition on the logical unit, or,
2051          *   b) report the unit attention condition, may discard any
2052          *      pending sense data, and clear the unit attention
2053          *      condition on the logical unit for that initiator.
2054          *
2055          * FSG normally uses option a); enable this code to use option b).
2056          */
2057 #if 0
2058         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
2059                 curlun->sense_data = curlun->unit_attention_data;
2060                 curlun->unit_attention_data = SS_NO_SENSE;
2061         }
2062 #endif
2063
2064         if (!curlun) {          // Unsupported LUNs are okay
2065                 fsg->bad_lun_okay = 1;
2066                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2067                 sdinfo = 0;
2068                 valid = 0;
2069         } else {
2070                 sd = curlun->sense_data;
2071                 sdinfo = curlun->sense_data_info;
2072                 valid = curlun->info_valid << 7;
2073                 curlun->sense_data = SS_NO_SENSE;
2074                 curlun->sense_data_info = 0;
2075                 curlun->info_valid = 0;
2076         }
2077
2078         memset(buf, 0, 18);
2079         buf[0] = valid | 0x70;                  // Valid, current error
2080         buf[2] = SK(sd);
2081         put_be32(&buf[3], sdinfo);              // Sense information
2082         buf[7] = 18 - 8;                        // Additional sense length
2083         buf[12] = ASC(sd);
2084         buf[13] = ASCQ(sd);
2085         return 18;
2086 }
2087
2088
2089 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2090 {
2091         struct lun      *curlun = fsg->curlun;
2092         u32             lba = get_be32(&fsg->cmnd[2]);
2093         int             pmi = fsg->cmnd[8];
2094         u8              *buf = (u8 *) bh->buf;
2095
2096         /* Check the PMI and LBA fields */
2097         if (pmi > 1 || (pmi == 0 && lba != 0)) {
2098                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2099                 return -EINVAL;
2100         }
2101
2102         put_be32(&buf[0], curlun->num_sectors - 1);     // Max logical block
2103         put_be32(&buf[4], 512);                         // Block length
2104         return 8;
2105 }
2106
2107
2108 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2109 {
2110         struct lun      *curlun = fsg->curlun;
2111         int             mscmnd = fsg->cmnd[0];
2112         u8              *buf = (u8 *) bh->buf;
2113         u8              *buf0 = buf;
2114         int             pc, page_code;
2115         int             changeable_values, all_pages;
2116         int             valid_page = 0;
2117         int             len, limit;
2118
2119         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
2120                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2121                 return -EINVAL;
2122         }
2123         pc = fsg->cmnd[2] >> 6;
2124         page_code = fsg->cmnd[2] & 0x3f;
2125         if (pc == 3) {
2126                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
2127                 return -EINVAL;
2128         }
2129         changeable_values = (pc == 1);
2130         all_pages = (page_code == 0x3f);
2131
2132         /* Write the mode parameter header.  Fixed values are: default
2133          * medium type, no cache control (DPOFUA), and no block descriptors.
2134          * The only variable value is the WriteProtect bit.  We will fill in
2135          * the mode data length later. */
2136         memset(buf, 0, 8);
2137         if (mscmnd == SC_MODE_SENSE_6) {
2138                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2139                 buf += 4;
2140                 limit = 255;
2141         } else {                        // SC_MODE_SENSE_10
2142                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2143                 buf += 8;
2144                 limit = 65535;          // Should really be mod_data.buflen
2145         }
2146
2147         /* No block descriptors */
2148
2149         /* The mode pages, in numerical order.  The only page we support
2150          * is the Caching page. */
2151         if (page_code == 0x08 || all_pages) {
2152                 valid_page = 1;
2153                 buf[0] = 0x08;          // Page code
2154                 buf[1] = 10;            // Page length
2155                 memset(buf+2, 0, 10);   // None of the fields are changeable
2156
2157                 if (!changeable_values) {
2158                         buf[2] = 0x04;  // Write cache enable,
2159                                         // Read cache not disabled
2160                                         // No cache retention priorities
2161                         put_be16(&buf[4], 0xffff);  // Don't disable prefetch
2162                                         // Minimum prefetch = 0
2163                         put_be16(&buf[8], 0xffff);  // Maximum prefetch
2164                         put_be16(&buf[10], 0xffff); // Maximum prefetch ceiling
2165                 }
2166                 buf += 12;
2167         }
2168
2169         /* Check that a valid page was requested and the mode data length
2170          * isn't too long. */
2171         len = buf - buf0;
2172         if (!valid_page || len > limit) {
2173                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2174                 return -EINVAL;
2175         }
2176
2177         /*  Store the mode data length */
2178         if (mscmnd == SC_MODE_SENSE_6)
2179                 buf0[0] = len - 1;
2180         else
2181                 put_be16(buf0, len - 2);
2182         return len;
2183 }
2184
2185
2186 static int do_start_stop(struct fsg_dev *fsg)
2187 {
2188         struct lun      *curlun = fsg->curlun;
2189         int             loej, start;
2190
2191         if (!mod_data.removable) {
2192                 curlun->sense_data = SS_INVALID_COMMAND;
2193                 return -EINVAL;
2194         }
2195
2196         // int immed = fsg->cmnd[1] & 0x01;
2197         loej = fsg->cmnd[4] & 0x02;
2198         start = fsg->cmnd[4] & 0x01;
2199
2200 #ifdef CONFIG_USB_FILE_STORAGE_TEST
2201         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
2202                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
2203                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2204                 return -EINVAL;
2205         }
2206
2207         if (!start) {
2208
2209                 /* Are we allowed to unload the media? */
2210                 if (curlun->prevent_medium_removal) {
2211                         LDBG(curlun, "unload attempt prevented\n");
2212                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
2213                         return -EINVAL;
2214                 }
2215                 if (loej) {             // Simulate an unload/eject
2216                         up_read(&fsg->filesem);
2217                         down_write(&fsg->filesem);
2218                         close_backing_file(curlun);
2219                         up_write(&fsg->filesem);
2220                         down_read(&fsg->filesem);
2221                 }
2222         } else {
2223
2224                 /* Our emulation doesn't support mounting; the medium is
2225                  * available for use as soon as it is loaded. */
2226                 if (!backing_file_is_open(curlun)) {
2227                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2228                         return -EINVAL;
2229                 }
2230         }
2231 #endif
2232         return 0;
2233 }
2234
2235
2236 static int do_prevent_allow(struct fsg_dev *fsg)
2237 {
2238         struct lun      *curlun = fsg->curlun;
2239         int             prevent;
2240
2241         if (!mod_data.removable) {
2242                 curlun->sense_data = SS_INVALID_COMMAND;
2243                 return -EINVAL;
2244         }
2245
2246         prevent = fsg->cmnd[4] & 0x01;
2247         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
2248                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2249                 return -EINVAL;
2250         }
2251
2252         if (curlun->prevent_medium_removal && !prevent)
2253                 fsync_sub(curlun);
2254         curlun->prevent_medium_removal = prevent;
2255         return 0;
2256 }
2257
2258
2259 static int do_read_format_capacities(struct fsg_dev *fsg,
2260                         struct fsg_buffhd *bh)
2261 {
2262         struct lun      *curlun = fsg->curlun;
2263         u8              *buf = (u8 *) bh->buf;
2264
2265         buf[0] = buf[1] = buf[2] = 0;
2266         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
2267         buf += 4;
2268
2269         put_be32(&buf[0], curlun->num_sectors);         // Number of blocks
2270         put_be32(&buf[4], 512);                         // Block length
2271         buf[4] = 0x02;                                  // Current capacity
2272         return 12;
2273 }
2274
2275
2276 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2277 {
2278         struct lun      *curlun = fsg->curlun;
2279
2280         /* We don't support MODE SELECT */
2281         curlun->sense_data = SS_INVALID_COMMAND;
2282         return -EINVAL;
2283 }
2284
2285
2286 /*-------------------------------------------------------------------------*/
2287
2288 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
2289 {
2290         int     rc;
2291
2292         rc = fsg_set_halt(fsg, fsg->bulk_in);
2293         if (rc == -EAGAIN)
2294                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
2295         while (rc != 0) {
2296                 if (rc != -EAGAIN) {
2297                         WARN(fsg, "usb_ep_set_halt -> %d\n", rc);
2298                         rc = 0;
2299                         break;
2300                 }
2301
2302                 /* Wait for a short time and then try again */
2303                 if (msleep_interruptible(100) != 0)
2304                         return -EINTR;
2305                 rc = usb_ep_set_halt(fsg->bulk_in);
2306         }
2307         return rc;
2308 }
2309
2310 static int pad_with_zeros(struct fsg_dev *fsg)
2311 {
2312         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2313         u32                     nkeep = bh->inreq->length;
2314         u32                     nsend;
2315         int                     rc;
2316
2317         bh->state = BUF_STATE_EMPTY;            // For the first iteration
2318         fsg->usb_amount_left = nkeep + fsg->residue;
2319         while (fsg->usb_amount_left > 0) {
2320
2321                 /* Wait for the next buffer to be free */
2322                 while (bh->state != BUF_STATE_EMPTY) {
2323                         rc = sleep_thread(fsg);
2324                         if (rc)
2325                                 return rc;
2326                 }
2327
2328                 nsend = min(fsg->usb_amount_left, (u32) mod_data.buflen);
2329                 memset(bh->buf + nkeep, 0, nsend - nkeep);
2330                 bh->inreq->length = nsend;
2331                 bh->inreq->zero = 0;
2332                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2333                                 &bh->inreq_busy, &bh->state);
2334                 bh = fsg->next_buffhd_to_fill = bh->next;
2335                 fsg->usb_amount_left -= nsend;
2336                 nkeep = 0;
2337         }
2338         return 0;
2339 }
2340
2341 static int throw_away_data(struct fsg_dev *fsg)
2342 {
2343         struct fsg_buffhd       *bh;
2344         u32                     amount;
2345         int                     rc;
2346
2347         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
2348                         fsg->usb_amount_left > 0) {
2349
2350                 /* Throw away the data in a filled buffer */
2351                 if (bh->state == BUF_STATE_FULL) {
2352                         smp_rmb();
2353                         bh->state = BUF_STATE_EMPTY;
2354                         fsg->next_buffhd_to_drain = bh->next;
2355
2356                         /* A short packet or an error ends everything */
2357                         if (bh->outreq->actual != bh->outreq->length ||
2358                                         bh->outreq->status != 0) {
2359                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2360                                 return -EINTR;
2361                         }
2362                         continue;
2363                 }
2364
2365                 /* Try to submit another request if we need one */
2366                 bh = fsg->next_buffhd_to_fill;
2367                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
2368                         amount = min(fsg->usb_amount_left,
2369                                         (u32) mod_data.buflen);
2370
2371                         /* amount is always divisible by 512, hence by
2372                          * the bulk-out maxpacket size */
2373                         bh->outreq->length = bh->bulk_out_intended_length =
2374                                         amount;
2375                         bh->outreq->short_not_ok = 1;
2376                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2377                                         &bh->outreq_busy, &bh->state);
2378                         fsg->next_buffhd_to_fill = bh->next;
2379                         fsg->usb_amount_left -= amount;
2380                         continue;
2381                 }
2382
2383                 /* Otherwise wait for something to happen */
2384                 rc = sleep_thread(fsg);
2385                 if (rc)
2386                         return rc;
2387         }
2388         return 0;
2389 }
2390
2391
2392 static int finish_reply(struct fsg_dev *fsg)
2393 {
2394         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2395         int                     rc = 0;
2396
2397         switch (fsg->data_dir) {
2398         case DATA_DIR_NONE:
2399                 break;                  // Nothing to send
2400
2401         /* If we don't know whether the host wants to read or write,
2402          * this must be CB or CBI with an unknown command.  We mustn't
2403          * try to send or receive any data.  So stall both bulk pipes
2404          * if we can and wait for a reset. */
2405         case DATA_DIR_UNKNOWN:
2406                 if (mod_data.can_stall) {
2407                         fsg_set_halt(fsg, fsg->bulk_out);
2408                         rc = halt_bulk_in_endpoint(fsg);
2409                 }
2410                 break;
2411
2412         /* All but the last buffer of data must have already been sent */
2413         case DATA_DIR_TO_HOST:
2414                 if (fsg->data_size == 0)
2415                         ;               // Nothing to send
2416
2417                 /* If there's no residue, simply send the last buffer */
2418                 else if (fsg->residue == 0) {
2419                         bh->inreq->zero = 0;
2420                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2421                                         &bh->inreq_busy, &bh->state);
2422                         fsg->next_buffhd_to_fill = bh->next;
2423                 }
2424
2425                 /* There is a residue.  For CB and CBI, simply mark the end
2426                  * of the data with a short packet.  However, if we are
2427                  * allowed to stall, there was no data at all (residue ==
2428                  * data_size), and the command failed (invalid LUN or
2429                  * sense data is set), then halt the bulk-in endpoint
2430                  * instead. */
2431                 else if (!transport_is_bbb()) {
2432                         if (mod_data.can_stall &&
2433                                         fsg->residue == fsg->data_size &&
2434         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2435                                 bh->state = BUF_STATE_EMPTY;
2436                                 rc = halt_bulk_in_endpoint(fsg);
2437                         } else {
2438                                 bh->inreq->zero = 1;
2439                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2440                                                 &bh->inreq_busy, &bh->state);
2441                                 fsg->next_buffhd_to_fill = bh->next;
2442                         }
2443                 }
2444
2445                 /* For Bulk-only, if we're allowed to stall then send the
2446                  * short packet and halt the bulk-in endpoint.  If we can't
2447                  * stall, pad out the remaining data with 0's. */
2448                 else {
2449                         if (mod_data.can_stall) {
2450                                 bh->inreq->zero = 1;
2451                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2452                                                 &bh->inreq_busy, &bh->state);
2453                                 fsg->next_buffhd_to_fill = bh->next;
2454                                 rc = halt_bulk_in_endpoint(fsg);
2455                         } else
2456                                 rc = pad_with_zeros(fsg);
2457                 }
2458                 break;
2459
2460         /* We have processed all we want from the data the host has sent.
2461          * There may still be outstanding bulk-out requests. */
2462         case DATA_DIR_FROM_HOST:
2463                 if (fsg->residue == 0)
2464                         ;               // Nothing to receive
2465
2466                 /* Did the host stop sending unexpectedly early? */
2467                 else if (fsg->short_packet_received) {
2468                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2469                         rc = -EINTR;
2470                 }
2471
2472                 /* We haven't processed all the incoming data.  Even though
2473                  * we may be allowed to stall, doing so would cause a race.
2474                  * The controller may already have ACK'ed all the remaining
2475                  * bulk-out packets, in which case the host wouldn't see a
2476                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2477                  * clear the halt -- leading to problems later on. */
2478 #if 0
2479                 else if (mod_data.can_stall) {
2480                         fsg_set_halt(fsg, fsg->bulk_out);
2481                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2482                         rc = -EINTR;
2483                 }
2484 #endif
2485
2486                 /* We can't stall.  Read in the excess data and throw it
2487                  * all away. */
2488                 else
2489                         rc = throw_away_data(fsg);
2490                 break;
2491         }
2492         return rc;
2493 }
2494
2495
2496 static int send_status(struct fsg_dev *fsg)
2497 {
2498         struct lun              *curlun = fsg->curlun;
2499         struct fsg_buffhd       *bh;
2500         int                     rc;
2501         u8                      status = USB_STATUS_PASS;
2502         u32                     sd, sdinfo = 0;
2503
2504         /* Wait for the next buffer to become available */
2505         bh = fsg->next_buffhd_to_fill;
2506         while (bh->state != BUF_STATE_EMPTY) {
2507                 rc = sleep_thread(fsg);
2508                 if (rc)
2509                         return rc;
2510         }
2511
2512         if (curlun) {
2513                 sd = curlun->sense_data;
2514                 sdinfo = curlun->sense_data_info;
2515         } else if (fsg->bad_lun_okay)
2516                 sd = SS_NO_SENSE;
2517         else
2518                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2519
2520         if (fsg->phase_error) {
2521                 DBG(fsg, "sending phase-error status\n");
2522                 status = USB_STATUS_PHASE_ERROR;
2523                 sd = SS_INVALID_COMMAND;
2524         } else if (sd != SS_NO_SENSE) {
2525                 DBG(fsg, "sending command-failure status\n");
2526                 status = USB_STATUS_FAIL;
2527                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2528                                 "  info x%x\n",
2529                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2530         }
2531
2532         if (transport_is_bbb()) {
2533                 struct bulk_cs_wrap     *csw = bh->buf;
2534
2535                 /* Store and send the Bulk-only CSW */
2536                 csw->Signature = __constant_cpu_to_le32(USB_BULK_CS_SIG);
2537                 csw->Tag = fsg->tag;
2538                 csw->Residue = cpu_to_le32(fsg->residue);
2539                 csw->Status = status;
2540
2541                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2542                 bh->inreq->zero = 0;
2543                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2544                                 &bh->inreq_busy, &bh->state);
2545
2546         } else if (mod_data.transport_type == USB_PR_CB) {
2547
2548                 /* Control-Bulk transport has no status phase! */
2549                 return 0;
2550
2551         } else {                        // USB_PR_CBI
2552                 struct interrupt_data   *buf = bh->buf;
2553
2554                 /* Store and send the Interrupt data.  UFI sends the ASC
2555                  * and ASCQ bytes.  Everything else sends a Type (which
2556                  * is always 0) and the status Value. */
2557                 if (mod_data.protocol_type == USB_SC_UFI) {
2558                         buf->bType = ASC(sd);
2559                         buf->bValue = ASCQ(sd);
2560                 } else {
2561                         buf->bType = 0;
2562                         buf->bValue = status;
2563                 }
2564                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2565
2566                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2567                 fsg->intreq->buf = bh->inreq->buf;
2568                 fsg->intreq->context = bh;
2569                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2570                                 &fsg->intreq_busy, &bh->state);
2571         }
2572
2573         fsg->next_buffhd_to_fill = bh->next;
2574         return 0;
2575 }
2576
2577
2578 /*-------------------------------------------------------------------------*/
2579
2580 /* Check whether the command is properly formed and whether its data size
2581  * and direction agree with the values we already have. */
2582 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2583                 enum data_direction data_dir, unsigned int mask,
2584                 int needs_medium, const char *name)
2585 {
2586         int                     i;
2587         int                     lun = fsg->cmnd[1] >> 5;
2588         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2589         char                    hdlen[20];
2590         struct lun              *curlun;
2591
2592         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2593          * Transparent SCSI doesn't pad. */
2594         if (protocol_is_scsi())
2595                 ;
2596
2597         /* There's some disagreement as to whether RBC pads commands or not.
2598          * We'll play it safe and accept either form. */
2599         else if (mod_data.protocol_type == USB_SC_RBC) {
2600                 if (fsg->cmnd_size == 12)
2601                         cmnd_size = 12;
2602
2603         /* All the other protocols pad to 12 bytes */
2604         } else
2605                 cmnd_size = 12;
2606
2607         hdlen[0] = 0;
2608         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2609                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2610                                 fsg->data_size);
2611         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2612                         name, cmnd_size, dirletter[(int) data_dir],
2613                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2614
2615         /* We can't reply at all until we know the correct data direction
2616          * and size. */
2617         if (fsg->data_size_from_cmnd == 0)
2618                 data_dir = DATA_DIR_NONE;
2619         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2620                 fsg->data_dir = data_dir;
2621                 fsg->data_size = fsg->data_size_from_cmnd;
2622
2623         } else {                                        // Bulk-only
2624                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2625
2626                         /* Host data size < Device data size is a phase error.
2627                          * Carry out the command, but only transfer as much
2628                          * as we are allowed. */
2629                         fsg->data_size_from_cmnd = fsg->data_size;
2630                         fsg->phase_error = 1;
2631                 }
2632         }
2633         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2634
2635         /* Conflicting data directions is a phase error */
2636         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2637                 fsg->phase_error = 1;
2638                 return -EINVAL;
2639         }
2640
2641         /* Verify the length of the command itself */
2642         if (cmnd_size != fsg->cmnd_size) {
2643
2644                 /* Special case workaround: MS-Windows issues REQUEST SENSE
2645                  * with cbw->Length == 12 (it should be 6). */
2646                 if (fsg->cmnd[0] == SC_REQUEST_SENSE && fsg->cmnd_size == 12)
2647                         cmnd_size = fsg->cmnd_size;
2648                 else {
2649                         fsg->phase_error = 1;
2650                         return -EINVAL;
2651                 }
2652         }
2653
2654         /* Check that the LUN values are consistent */
2655         if (transport_is_bbb()) {
2656                 if (fsg->lun != lun)
2657                         DBG(fsg, "using LUN %d from CBW, "
2658                                         "not LUN %d from CDB\n",
2659                                         fsg->lun, lun);
2660         } else
2661                 fsg->lun = lun;         // Use LUN from the command
2662
2663         /* Check the LUN */
2664         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
2665                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2666                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
2667                         curlun->sense_data = SS_NO_SENSE;
2668                         curlun->sense_data_info = 0;
2669                         curlun->info_valid = 0;
2670                 }
2671         } else {
2672                 fsg->curlun = curlun = NULL;
2673                 fsg->bad_lun_okay = 0;
2674
2675                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2676                  * to use unsupported LUNs; all others may not. */
2677                 if (fsg->cmnd[0] != SC_INQUIRY &&
2678                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2679                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2680                         return -EINVAL;
2681                 }
2682         }
2683
2684         /* If a unit attention condition exists, only INQUIRY and
2685          * REQUEST SENSE commands are allowed; anything else must fail. */
2686         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2687                         fsg->cmnd[0] != SC_INQUIRY &&
2688                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2689                 curlun->sense_data = curlun->unit_attention_data;
2690                 curlun->unit_attention_data = SS_NO_SENSE;
2691                 return -EINVAL;
2692         }
2693
2694         /* Check that only command bytes listed in the mask are non-zero */
2695         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2696         for (i = 1; i < cmnd_size; ++i) {
2697                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2698                         if (curlun)
2699                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2700                         return -EINVAL;
2701                 }
2702         }
2703
2704         /* If the medium isn't mounted and the command needs to access
2705          * it, return an error. */
2706         if (curlun && !backing_file_is_open(curlun) && needs_medium) {
2707                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2708                 return -EINVAL;
2709         }
2710
2711         return 0;
2712 }
2713
2714
2715 static int do_scsi_command(struct fsg_dev *fsg)
2716 {
2717         struct fsg_buffhd       *bh;
2718         int                     rc;
2719         int                     reply = -EINVAL;
2720         int                     i;
2721         static char             unknown[16];
2722
2723         dump_cdb(fsg);
2724
2725         /* Wait for the next buffer to become available for data or status */
2726         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2727         while (bh->state != BUF_STATE_EMPTY) {
2728                 rc = sleep_thread(fsg);
2729                 if (rc)
2730                         return rc;
2731         }
2732         fsg->phase_error = 0;
2733         fsg->short_packet_received = 0;
2734
2735         down_read(&fsg->filesem);       // We're using the backing file
2736         switch (fsg->cmnd[0]) {
2737
2738         case SC_INQUIRY:
2739                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2740                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2741                                 (1<<4), 0,
2742                                 "INQUIRY")) == 0)
2743                         reply = do_inquiry(fsg, bh);
2744                 break;
2745
2746         case SC_MODE_SELECT_6:
2747                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2748                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2749                                 (1<<1) | (1<<4), 0,
2750                                 "MODE SELECT(6)")) == 0)
2751                         reply = do_mode_select(fsg, bh);
2752                 break;
2753
2754         case SC_MODE_SELECT_10:
2755                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2756                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2757                                 (1<<1) | (3<<7), 0,
2758                                 "MODE SELECT(10)")) == 0)
2759                         reply = do_mode_select(fsg, bh);
2760                 break;
2761
2762         case SC_MODE_SENSE_6:
2763                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2764                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2765                                 (1<<1) | (1<<2) | (1<<4), 0,
2766                                 "MODE SENSE(6)")) == 0)
2767                         reply = do_mode_sense(fsg, bh);
2768                 break;
2769
2770         case SC_MODE_SENSE_10:
2771                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2772                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2773                                 (1<<1) | (1<<2) | (3<<7), 0,
2774                                 "MODE SENSE(10)")) == 0)
2775                         reply = do_mode_sense(fsg, bh);
2776                 break;
2777
2778         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2779                 fsg->data_size_from_cmnd = 0;
2780                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2781                                 (1<<4), 0,
2782                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2783                         reply = do_prevent_allow(fsg);
2784                 break;
2785
2786         case SC_READ_6:
2787                 i = fsg->cmnd[4];
2788                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2789                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2790                                 (7<<1) | (1<<4), 1,
2791                                 "READ(6)")) == 0)
2792                         reply = do_read(fsg);
2793                 break;
2794
2795         case SC_READ_10:
2796                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2797                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2798                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2799                                 "READ(10)")) == 0)
2800                         reply = do_read(fsg);
2801                 break;
2802
2803         case SC_READ_12:
2804                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2805                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2806                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2807                                 "READ(12)")) == 0)
2808                         reply = do_read(fsg);
2809                 break;
2810
2811         case SC_READ_CAPACITY:
2812                 fsg->data_size_from_cmnd = 8;
2813                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2814                                 (0xf<<2) | (1<<8), 1,
2815                                 "READ CAPACITY")) == 0)
2816                         reply = do_read_capacity(fsg, bh);
2817                 break;
2818
2819         case SC_READ_FORMAT_CAPACITIES:
2820                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2821                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2822                                 (3<<7), 1,
2823                                 "READ FORMAT CAPACITIES")) == 0)
2824                         reply = do_read_format_capacities(fsg, bh);
2825                 break;
2826
2827         case SC_REQUEST_SENSE:
2828                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2829                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2830                                 (1<<4), 0,
2831                                 "REQUEST SENSE")) == 0)
2832                         reply = do_request_sense(fsg, bh);
2833                 break;
2834
2835         case SC_START_STOP_UNIT:
2836                 fsg->data_size_from_cmnd = 0;
2837                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2838                                 (1<<1) | (1<<4), 0,
2839                                 "START-STOP UNIT")) == 0)
2840                         reply = do_start_stop(fsg);
2841                 break;
2842
2843         case SC_SYNCHRONIZE_CACHE:
2844                 fsg->data_size_from_cmnd = 0;
2845                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2846                                 (0xf<<2) | (3<<7), 1,
2847                                 "SYNCHRONIZE CACHE")) == 0)
2848                         reply = do_synchronize_cache(fsg);
2849                 break;
2850
2851         case SC_TEST_UNIT_READY:
2852                 fsg->data_size_from_cmnd = 0;
2853                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2854                                 0, 1,
2855                                 "TEST UNIT READY");
2856                 break;
2857
2858         /* Although optional, this command is used by MS-Windows.  We
2859          * support a minimal version: BytChk must be 0. */
2860         case SC_VERIFY:
2861                 fsg->data_size_from_cmnd = 0;
2862                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2863                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2864                                 "VERIFY")) == 0)
2865                         reply = do_verify(fsg);
2866                 break;
2867
2868         case SC_WRITE_6:
2869                 i = fsg->cmnd[4];
2870                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2871                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2872                                 (7<<1) | (1<<4), 1,
2873                                 "WRITE(6)")) == 0)
2874                         reply = do_write(fsg);
2875                 break;
2876
2877         case SC_WRITE_10:
2878                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2879                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2880                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2881                                 "WRITE(10)")) == 0)
2882                         reply = do_write(fsg);
2883                 break;
2884
2885         case SC_WRITE_12:
2886                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2887                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2888                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2889                                 "WRITE(12)")) == 0)
2890                         reply = do_write(fsg);
2891                 break;
2892
2893         /* Some mandatory commands that we recognize but don't implement.
2894          * They don't mean much in this setting.  It's left as an exercise
2895          * for anyone interested to implement RESERVE and RELEASE in terms
2896          * of Posix locks. */
2897         case SC_FORMAT_UNIT:
2898         case SC_RELEASE:
2899         case SC_RESERVE:
2900         case SC_SEND_DIAGNOSTIC:
2901                 // Fall through
2902
2903         default:
2904                 fsg->data_size_from_cmnd = 0;
2905                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2906                 if ((reply = check_command(fsg, fsg->cmnd_size,
2907                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2908                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2909                         reply = -EINVAL;
2910                 }
2911                 break;
2912         }
2913         up_read(&fsg->filesem);
2914
2915         if (reply == -EINTR || signal_pending(current))
2916                 return -EINTR;
2917
2918         /* Set up the single reply buffer for finish_reply() */
2919         if (reply == -EINVAL)
2920                 reply = 0;              // Error reply length
2921         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2922                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2923                 bh->inreq->length = reply;
2924                 bh->state = BUF_STATE_FULL;
2925                 fsg->residue -= reply;
2926         }                               // Otherwise it's already set
2927
2928         return 0;
2929 }
2930
2931
2932 /*-------------------------------------------------------------------------*/
2933
2934 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2935 {
2936         struct usb_request      *req = bh->outreq;
2937         struct bulk_cb_wrap     *cbw = req->buf;
2938
2939         /* Was this a real packet?  Should it be ignored? */
2940         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2941                 return -EINVAL;
2942
2943         /* Is the CBW valid? */
2944         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2945                         cbw->Signature != __constant_cpu_to_le32(
2946                                 USB_BULK_CB_SIG)) {
2947                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2948                                 req->actual,
2949                                 le32_to_cpu(cbw->Signature));
2950
2951                 /* The Bulk-only spec says we MUST stall the IN endpoint
2952                  * (6.6.1), so it's unavoidable.  It also says we must
2953                  * retain this state until the next reset, but there's
2954                  * no way to tell the controller driver it should ignore
2955                  * Clear-Feature(HALT) requests.
2956                  *
2957                  * We aren't required to halt the OUT endpoint; instead
2958                  * we can simply accept and discard any data received
2959                  * until the next reset. */
2960                 halt_bulk_in_endpoint(fsg);
2961                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2962                 return -EINVAL;
2963         }
2964
2965         /* Is the CBW meaningful? */
2966         if (cbw->Lun >= MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2967                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2968                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2969                                 "cmdlen %u\n",
2970                                 cbw->Lun, cbw->Flags, cbw->Length);
2971
2972                 /* We can do anything we want here, so let's stall the
2973                  * bulk pipes if we are allowed to. */
2974                 if (mod_data.can_stall) {
2975                         fsg_set_halt(fsg, fsg->bulk_out);
2976                         halt_bulk_in_endpoint(fsg);
2977                 }
2978                 return -EINVAL;
2979         }
2980
2981         /* Save the command for later */
2982         fsg->cmnd_size = cbw->Length;
2983         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
2984         if (cbw->Flags & USB_BULK_IN_FLAG)
2985                 fsg->data_dir = DATA_DIR_TO_HOST;
2986         else
2987                 fsg->data_dir = DATA_DIR_FROM_HOST;
2988         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
2989         if (fsg->data_size == 0)
2990                 fsg->data_dir = DATA_DIR_NONE;
2991         fsg->lun = cbw->Lun;
2992         fsg->tag = cbw->Tag;
2993         return 0;
2994 }
2995
2996
2997 static int get_next_command(struct fsg_dev *fsg)
2998 {
2999         struct fsg_buffhd       *bh;
3000         int                     rc = 0;
3001
3002         if (transport_is_bbb()) {
3003
3004                 /* Wait for the next buffer to become available */
3005                 bh = fsg->next_buffhd_to_fill;
3006                 while (bh->state != BUF_STATE_EMPTY) {
3007                         rc = sleep_thread(fsg);
3008                         if (rc)
3009                                 return rc;
3010                 }
3011
3012                 /* Queue a request to read a Bulk-only CBW */
3013                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
3014                 bh->outreq->short_not_ok = 1;
3015                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
3016                                 &bh->outreq_busy, &bh->state);
3017
3018                 /* We will drain the buffer in software, which means we
3019                  * can reuse it for the next filling.  No need to advance
3020                  * next_buffhd_to_fill. */
3021
3022                 /* Wait for the CBW to arrive */
3023                 while (bh->state != BUF_STATE_FULL) {
3024                         rc = sleep_thread(fsg);
3025                         if (rc)
3026                                 return rc;
3027                 }
3028                 smp_rmb();
3029                 rc = received_cbw(fsg, bh);
3030                 bh->state = BUF_STATE_EMPTY;
3031
3032         } else {                // USB_PR_CB or USB_PR_CBI
3033
3034                 /* Wait for the next command to arrive */
3035                 while (fsg->cbbuf_cmnd_size == 0) {
3036                         rc = sleep_thread(fsg);
3037                         if (rc)
3038                                 return rc;
3039                 }
3040
3041                 /* Is the previous status interrupt request still busy?
3042                  * The host is allowed to skip reading the status,
3043                  * so we must cancel it. */
3044                 if (fsg->intreq_busy)
3045                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3046
3047                 /* Copy the command and mark the buffer empty */
3048                 fsg->data_dir = DATA_DIR_UNKNOWN;
3049                 spin_lock_irq(&fsg->lock);
3050                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
3051                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
3052                 fsg->cbbuf_cmnd_size = 0;
3053                 spin_unlock_irq(&fsg->lock);
3054         }
3055         return rc;
3056 }
3057
3058
3059 /*-------------------------------------------------------------------------*/
3060
3061 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
3062                 const struct usb_endpoint_descriptor *d)
3063 {
3064         int     rc;
3065
3066         ep->driver_data = fsg;
3067         rc = usb_ep_enable(ep, d);
3068         if (rc)
3069                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
3070         return rc;
3071 }
3072
3073 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
3074                 struct usb_request **preq)
3075 {
3076         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
3077         if (*preq)
3078                 return 0;
3079         ERROR(fsg, "can't allocate request for %s\n", ep->name);
3080         return -ENOMEM;
3081 }
3082
3083 /*
3084  * Reset interface setting and re-init endpoint state (toggle etc).
3085  * Call with altsetting < 0 to disable the interface.  The only other
3086  * available altsetting is 0, which enables the interface.
3087  */
3088 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
3089 {
3090         int     rc = 0;
3091         int     i;
3092         const struct usb_endpoint_descriptor    *d;
3093
3094         if (fsg->running)
3095                 DBG(fsg, "reset interface\n");
3096
3097 reset:
3098         /* Deallocate the requests */
3099         for (i = 0; i < NUM_BUFFERS; ++i) {
3100                 struct fsg_buffhd *bh = &fsg->buffhds[i];
3101
3102                 if (bh->inreq) {
3103                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
3104                         bh->inreq = NULL;
3105                 }
3106                 if (bh->outreq) {
3107                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
3108                         bh->outreq = NULL;
3109                 }
3110         }
3111         if (fsg->intreq) {
3112                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
3113                 fsg->intreq = NULL;
3114         }
3115
3116         /* Disable the endpoints */
3117         if (fsg->bulk_in_enabled) {
3118                 usb_ep_disable(fsg->bulk_in);
3119                 fsg->bulk_in_enabled = 0;
3120         }
3121         if (fsg->bulk_out_enabled) {
3122                 usb_ep_disable(fsg->bulk_out);
3123                 fsg->bulk_out_enabled = 0;
3124         }
3125         if (fsg->intr_in_enabled) {
3126                 usb_ep_disable(fsg->intr_in);
3127                 fsg->intr_in_enabled = 0;
3128         }
3129
3130         fsg->running = 0;
3131         if (altsetting < 0 || rc != 0)
3132                 return rc;
3133
3134         DBG(fsg, "set interface %d\n", altsetting);
3135
3136         /* Enable the endpoints */
3137         d = ep_desc(fsg->gadget, &fs_bulk_in_desc, &hs_bulk_in_desc);
3138         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
3139                 goto reset;
3140         fsg->bulk_in_enabled = 1;
3141
3142         d = ep_desc(fsg->gadget, &fs_bulk_out_desc, &hs_bulk_out_desc);
3143         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
3144                 goto reset;
3145         fsg->bulk_out_enabled = 1;
3146         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
3147         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
3148
3149         if (transport_is_cbi()) {
3150                 d = ep_desc(fsg->gadget, &fs_intr_in_desc, &hs_intr_in_desc);
3151                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
3152                         goto reset;
3153                 fsg->intr_in_enabled = 1;
3154         }
3155
3156         /* Allocate the requests */
3157         for (i = 0; i < NUM_BUFFERS; ++i) {
3158                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3159
3160                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
3161                         goto reset;
3162                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
3163                         goto reset;
3164                 bh->inreq->buf = bh->outreq->buf = bh->buf;
3165                 bh->inreq->context = bh->outreq->context = bh;
3166                 bh->inreq->complete = bulk_in_complete;
3167                 bh->outreq->complete = bulk_out_complete;
3168         }
3169         if (transport_is_cbi()) {
3170                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
3171                         goto reset;
3172                 fsg->intreq->complete = intr_in_complete;
3173         }
3174
3175         fsg->running = 1;
3176         for (i = 0; i < fsg->nluns; ++i)
3177                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3178         return rc;
3179 }
3180
3181
3182 /*
3183  * Change our operational configuration.  This code must agree with the code
3184  * that returns config descriptors, and with interface altsetting code.
3185  *
3186  * It's also responsible for power management interactions.  Some
3187  * configurations might not work with our current power sources.
3188  * For now we just assume the gadget is always self-powered.
3189  */
3190 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
3191 {
3192         int     rc = 0;
3193
3194         /* Disable the single interface */
3195         if (fsg->config != 0) {
3196                 DBG(fsg, "reset config\n");
3197                 fsg->config = 0;
3198                 rc = do_set_interface(fsg, -1);
3199         }
3200
3201         /* Enable the interface */
3202         if (new_config != 0) {
3203                 fsg->config = new_config;
3204                 if ((rc = do_set_interface(fsg, 0)) != 0)
3205                         fsg->config = 0;        // Reset on errors
3206                 else {
3207                         char *speed;
3208
3209                         switch (fsg->gadget->speed) {
3210                         case USB_SPEED_LOW:     speed = "low";  break;
3211                         case USB_SPEED_FULL:    speed = "full"; break;
3212                         case USB_SPEED_HIGH:    speed = "high"; break;
3213                         default:                speed = "?";    break;
3214                         }
3215                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
3216                 }
3217         }
3218         return rc;
3219 }
3220
3221
3222 /*-------------------------------------------------------------------------*/
3223
3224 static void handle_exception(struct fsg_dev *fsg)
3225 {
3226         siginfo_t               info;
3227         int                     sig;
3228         int                     i;
3229         int                     num_active;
3230         struct fsg_buffhd       *bh;
3231         enum fsg_state          old_state;
3232         u8                      new_config;
3233         struct lun              *curlun;
3234         unsigned int            exception_req_tag;
3235         int                     rc;
3236
3237         /* Clear the existing signals.  Anything but SIGUSR1 is converted
3238          * into a high-priority EXIT exception. */
3239         for (;;) {
3240                 sig = dequeue_signal_lock(current, &current->blocked, &info);
3241                 if (!sig)
3242                         break;
3243                 if (sig != SIGUSR1) {
3244                         if (fsg->state < FSG_STATE_EXIT)
3245                                 DBG(fsg, "Main thread exiting on signal\n");
3246                         raise_exception(fsg, FSG_STATE_EXIT);
3247                 }
3248         }
3249
3250         /* Cancel all the pending transfers */
3251         if (fsg->intreq_busy)
3252                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3253         for (i = 0; i < NUM_BUFFERS; ++i) {
3254                 bh = &fsg->buffhds[i];
3255                 if (bh->inreq_busy)
3256                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
3257                 if (bh->outreq_busy)
3258                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
3259         }
3260
3261         /* Wait until everything is idle */
3262         for (;;) {
3263                 num_active = fsg->intreq_busy;
3264                 for (i = 0; i < NUM_BUFFERS; ++i) {
3265                         bh = &fsg->buffhds[i];
3266                         num_active += bh->inreq_busy + bh->outreq_busy;
3267                 }
3268                 if (num_active == 0)
3269                         break;
3270                 if (sleep_thread(fsg))
3271                         return;
3272         }
3273
3274         /* Clear out the controller's fifos */
3275         if (fsg->bulk_in_enabled)
3276                 usb_ep_fifo_flush(fsg->bulk_in);
3277         if (fsg->bulk_out_enabled)
3278                 usb_ep_fifo_flush(fsg->bulk_out);
3279         if (fsg->intr_in_enabled)
3280                 usb_ep_fifo_flush(fsg->intr_in);
3281
3282         /* Reset the I/O buffer states and pointers, the SCSI
3283          * state, and the exception.  Then invoke the handler. */
3284         spin_lock_irq(&fsg->lock);
3285
3286         for (i = 0; i < NUM_BUFFERS; ++i) {
3287                 bh = &fsg->buffhds[i];
3288                 bh->state = BUF_STATE_EMPTY;
3289         }
3290         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
3291                         &fsg->buffhds[0];
3292
3293         exception_req_tag = fsg->exception_req_tag;
3294         new_config = fsg->new_config;
3295         old_state = fsg->state;
3296
3297         if (old_state == FSG_STATE_ABORT_BULK_OUT)
3298                 fsg->state = FSG_STATE_STATUS_PHASE;
3299         else {
3300                 for (i = 0; i < fsg->nluns; ++i) {
3301                         curlun = &fsg->luns[i];
3302                         curlun->prevent_medium_removal = 0;
3303                         curlun->sense_data = curlun->unit_attention_data =
3304                                         SS_NO_SENSE;
3305                         curlun->sense_data_info = 0;
3306                         curlun->info_valid = 0;
3307                 }
3308                 fsg->state = FSG_STATE_IDLE;
3309         }
3310         spin_unlock_irq(&fsg->lock);
3311
3312         /* Carry out any extra actions required for the exception */
3313         switch (old_state) {
3314         default:
3315                 break;
3316
3317         case FSG_STATE_ABORT_BULK_OUT:
3318                 send_status(fsg);
3319                 spin_lock_irq(&fsg->lock);
3320                 if (fsg->state == FSG_STATE_STATUS_PHASE)
3321                         fsg->state = FSG_STATE_IDLE;
3322                 spin_unlock_irq(&fsg->lock);
3323                 break;
3324
3325         case FSG_STATE_RESET:
3326                 /* In case we were forced against our will to halt a
3327                  * bulk endpoint, clear the halt now.  (The SuperH UDC
3328                  * requires this.) */
3329                 if (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
3330                         usb_ep_clear_halt(fsg->bulk_in);
3331
3332                 if (transport_is_bbb()) {
3333                         if (fsg->ep0_req_tag == exception_req_tag)
3334                                 ep0_queue(fsg); // Complete the status stage
3335
3336                 } else if (transport_is_cbi())
3337                         send_status(fsg);       // Status by interrupt pipe
3338
3339                 /* Technically this should go here, but it would only be
3340                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
3341                  * CONFIG_CHANGE cases. */
3342                 // for (i = 0; i < fsg->nluns; ++i)
3343                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3344                 break;
3345
3346         case FSG_STATE_INTERFACE_CHANGE:
3347                 rc = do_set_interface(fsg, 0);
3348                 if (fsg->ep0_req_tag != exception_req_tag)
3349                         break;
3350                 if (rc != 0)                    // STALL on errors
3351                         fsg_set_halt(fsg, fsg->ep0);
3352                 else                            // Complete the status stage
3353                         ep0_queue(fsg);
3354                 break;
3355
3356         case FSG_STATE_CONFIG_CHANGE:
3357                 rc = do_set_config(fsg, new_config);
3358                 if (fsg->ep0_req_tag != exception_req_tag)
3359                         break;
3360                 if (rc != 0)                    // STALL on errors
3361                         fsg_set_halt(fsg, fsg->ep0);
3362                 else                            // Complete the status stage
3363                         ep0_queue(fsg);
3364                 break;
3365
3366         case FSG_STATE_DISCONNECT:
3367                 fsync_all(fsg);
3368                 do_set_config(fsg, 0);          // Unconfigured state
3369                 break;
3370
3371         case FSG_STATE_EXIT:
3372         case FSG_STATE_TERMINATED:
3373                 do_set_config(fsg, 0);                  // Free resources
3374                 spin_lock_irq(&fsg->lock);
3375                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3376                 spin_unlock_irq(&fsg->lock);
3377                 break;
3378         }
3379 }
3380
3381
3382 /*-------------------------------------------------------------------------*/
3383
3384 static int fsg_main_thread(void *fsg_)
3385 {
3386         struct fsg_dev          *fsg = fsg_;
3387
3388         /* Allow the thread to be killed by a signal, but set the signal mask
3389          * to block everything but INT, TERM, KILL, and USR1. */
3390         allow_signal(SIGINT);
3391         allow_signal(SIGTERM);
3392         allow_signal(SIGKILL);
3393         allow_signal(SIGUSR1);
3394
3395         /* Allow the thread to be frozen */
3396         set_freezable();
3397
3398         /* Arrange for userspace references to be interpreted as kernel
3399          * pointers.  That way we can pass a kernel pointer to a routine
3400          * that expects a __user pointer and it will work okay. */
3401         set_fs(get_ds());
3402
3403         /* The main loop */
3404         while (fsg->state != FSG_STATE_TERMINATED) {
3405                 if (exception_in_progress(fsg) || signal_pending(current)) {
3406                         handle_exception(fsg);
3407                         continue;
3408                 }
3409
3410                 if (!fsg->running) {
3411                         sleep_thread(fsg);
3412                         continue;
3413                 }
3414
3415                 if (get_next_command(fsg))
3416                         continue;
3417
3418                 spin_lock_irq(&fsg->lock);
3419                 if (!exception_in_progress(fsg))
3420                         fsg->state = FSG_STATE_DATA_PHASE;
3421                 spin_unlock_irq(&fsg->lock);
3422
3423                 if (do_scsi_command(fsg) || finish_reply(fsg))
3424                         continue;
3425
3426                 spin_lock_irq(&fsg->lock);
3427                 if (!exception_in_progress(fsg))
3428                         fsg->state = FSG_STATE_STATUS_PHASE;
3429                 spin_unlock_irq(&fsg->lock);
3430
3431                 if (send_status(fsg))
3432                         continue;
3433
3434                 spin_lock_irq(&fsg->lock);
3435                 if (!exception_in_progress(fsg))
3436                         fsg->state = FSG_STATE_IDLE;
3437                 spin_unlock_irq(&fsg->lock);
3438                 }
3439
3440         spin_lock_irq(&fsg->lock);
3441         fsg->thread_task = NULL;
3442         spin_unlock_irq(&fsg->lock);
3443
3444         /* In case we are exiting because of a signal, unregister the
3445          * gadget driver and close the backing file. */
3446         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags)) {
3447                 usb_gadget_unregister_driver(&fsg_driver);
3448                 close_all_backing_files(fsg);
3449         }
3450
3451         /* Let the unbind and cleanup routines know the thread has exited */
3452         complete_and_exit(&fsg->thread_notifier, 0);
3453 }
3454
3455
3456 /*-------------------------------------------------------------------------*/
3457
3458 /* If the next two routines are called while the gadget is registered,
3459  * the caller must own fsg->filesem for writing. */
3460
3461 static int open_backing_file(struct lun *curlun, const char *filename)
3462 {
3463         int                             ro;
3464         struct file                     *filp = NULL;
3465         int                             rc = -EINVAL;
3466         struct inode                    *inode = NULL;
3467         loff_t                          size;
3468         loff_t                          num_sectors;
3469
3470         /* R/W if we can, R/O if we must */
3471         ro = curlun->ro;
3472         if (!ro) {
3473                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
3474                 if (-EROFS == PTR_ERR(filp))
3475                         ro = 1;
3476         }
3477         if (ro)
3478                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
3479         if (IS_ERR(filp)) {
3480                 LINFO(curlun, "unable to open backing file: %s\n", filename);
3481                 return PTR_ERR(filp);
3482         }
3483
3484         if (!(filp->f_mode & FMODE_WRITE))
3485                 ro = 1;
3486
3487         if (filp->f_path.dentry)
3488                 inode = filp->f_path.dentry->d_inode;
3489         if (inode && S_ISBLK(inode->i_mode)) {
3490                 if (bdev_read_only(inode->i_bdev))
3491                         ro = 1;
3492         } else if (!inode || !S_ISREG(inode->i_mode)) {
3493                 LINFO(curlun, "invalid file type: %s\n", filename);
3494                 goto out;
3495         }
3496
3497         /* If we can't read the file, it's no good.
3498          * If we can't write the file, use it read-only. */
3499         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
3500                 LINFO(curlun, "file not readable: %s\n", filename);
3501                 goto out;
3502         }
3503         if (!(filp->f_op->write || filp->f_op->aio_write))
3504                 ro = 1;
3505
3506         size = i_size_read(inode->i_mapping->host);
3507         if (size < 0) {
3508                 LINFO(curlun, "unable to find file size: %s\n", filename);
3509                 rc = (int) size;
3510                 goto out;
3511         }
3512         num_sectors = size >> 9;        // File size in 512-byte sectors
3513         if (num_sectors == 0) {
3514                 LINFO(curlun, "file too small: %s\n", filename);
3515                 rc = -ETOOSMALL;
3516                 goto out;
3517         }
3518
3519         get_file(filp);
3520         curlun->ro = ro;