[PATCH] Kill PF_SYNCWRITE flag
[linux-3.10.git] / drivers / usb / gadget / file_storage.c
1 /*
2  * file_storage.c -- File-backed USB Storage Gadget, for USB development
3  *
4  * Copyright (C) 2003-2005 Alan Stern
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The names of the above-listed copyright holders may not be used
17  *    to endorse or promote products derived from this software without
18  *    specific prior written permission.
19  *
20  * ALTERNATIVELY, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") as published by the Free Software
22  * Foundation, either version 2 of that License or (at your option) any
23  * later version.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
26  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
27  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
29  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
32  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37
38
39 /*
40  * The File-backed Storage Gadget acts as a USB Mass Storage device,
41  * appearing to the host as a disk drive.  In addition to providing an
42  * example of a genuinely useful gadget driver for a USB device, it also
43  * illustrates a technique of double-buffering for increased throughput.
44  * Last but not least, it gives an easy way to probe the behavior of the
45  * Mass Storage drivers in a USB host.
46  *
47  * Backing storage is provided by a regular file or a block device, specified
48  * by the "file" module parameter.  Access can be limited to read-only by
49  * setting the optional "ro" module parameter.  The gadget will indicate that
50  * it has removable media if the optional "removable" module parameter is set.
51  *
52  * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI),
53  * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected
54  * by the optional "transport" module parameter.  It also supports the
55  * following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03),
56  * UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
57  * the optional "protocol" module parameter.  In addition, the default
58  * Vendor ID, Product ID, and release number can be overridden.
59  *
60  * There is support for multiple logical units (LUNs), each of which has
61  * its own backing file.  The number of LUNs can be set using the optional
62  * "luns" module parameter (anywhere from 1 to 8), and the corresponding
63  * files are specified using comma-separated lists for "file" and "ro".
64  * The default number of LUNs is taken from the number of "file" elements;
65  * it is 1 if "file" is not given.  If "removable" is not set then a backing
66  * file must be specified for each LUN.  If it is set, then an unspecified
67  * or empty backing filename means the LUN's medium is not loaded.
68  *
69  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
70  * needed (an interrupt-out endpoint is also needed for CBI).  The memory
71  * requirement amounts to two 16K buffers, size configurable by a parameter.
72  * Support is included for both full-speed and high-speed operation.
73  *
74  * Note that the driver is slightly non-portable in that it assumes a
75  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
76  * interrupt-in endpoints.  With most device controllers this isn't an
77  * issue, but there may be some with hardware restrictions that prevent
78  * a buffer from being used by more than one endpoint.
79  *
80  * Module options:
81  *
82  *      file=filename[,filename...]
83  *                              Required if "removable" is not set, names of
84  *                                      the files or block devices used for
85  *                                      backing storage
86  *      ro=b[,b...]             Default false, booleans for read-only access
87  *      removable               Default false, boolean for removable media
88  *      luns=N                  Default N = number of filenames, number of
89  *                                      LUNs to support
90  *      stall                   Default determined according to the type of
91  *                                      USB device controller (usually true),
92  *                                      boolean to permit the driver to halt
93  *                                      bulk endpoints
94  *      transport=XXX           Default BBB, transport name (CB, CBI, or BBB)
95  *      protocol=YYY            Default SCSI, protocol name (RBC, 8020 or
96  *                                      ATAPI, QIC, UFI, 8070, or SCSI;
97  *                                      also 1 - 6)
98  *      vendor=0xVVVV           Default 0x0525 (NetChip), USB Vendor ID
99  *      product=0xPPPP          Default 0xa4a5 (FSG), USB Product ID
100  *      release=0xRRRR          Override the USB release number (bcdDevice)
101  *      buflen=N                Default N=16384, buffer size used (will be
102  *                                      rounded down to a multiple of
103  *                                      PAGE_CACHE_SIZE)
104  *
105  * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro",
106  * "removable", "luns", and "stall" options are available; default values
107  * are used for everything else.
108  *
109  * The pathnames of the backing files and the ro settings are available in
110  * the attribute files "file" and "ro" in the lun<n> subdirectory of the
111  * gadget's sysfs directory.  If the "removable" option is set, writing to
112  * these files will simulate ejecting/loading the medium (writing an empty
113  * line means eject) and adjusting a write-enable tab.  Changes to the ro
114  * setting are not allowed when the medium is loaded.
115  *
116  * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
117  * The driver's SCSI command interface was based on the "Information
118  * technology - Small Computer System Interface - 2" document from
119  * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
120  * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.  The single exception
121  * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
122  * "Universal Serial Bus Mass Storage Class UFI Command Specification"
123  * document, Revision 1.0, December 14, 1998, available at
124  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
125  */
126
127
128 /*
129  *                              Driver Design
130  *
131  * The FSG driver is fairly straightforward.  There is a main kernel
132  * thread that handles most of the work.  Interrupt routines field
133  * callbacks from the controller driver: bulk- and interrupt-request
134  * completion notifications, endpoint-0 events, and disconnect events.
135  * Completion events are passed to the main thread by wakeup calls.  Many
136  * ep0 requests are handled at interrupt time, but SetInterface,
137  * SetConfiguration, and device reset requests are forwarded to the
138  * thread in the form of "exceptions" using SIGUSR1 signals (since they
139  * should interrupt any ongoing file I/O operations).
140  *
141  * The thread's main routine implements the standard command/data/status
142  * parts of a SCSI interaction.  It and its subroutines are full of tests
143  * for pending signals/exceptions -- all this polling is necessary since
144  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
145  * indication that the driver really wants to be running in userspace.)
146  * An important point is that so long as the thread is alive it keeps an
147  * open reference to the backing file.  This will prevent unmounting
148  * the backing file's underlying filesystem and could cause problems
149  * during system shutdown, for example.  To prevent such problems, the
150  * thread catches INT, TERM, and KILL signals and converts them into
151  * an EXIT exception.
152  *
153  * In normal operation the main thread is started during the gadget's
154  * fsg_bind() callback and stopped during fsg_unbind().  But it can also
155  * exit when it receives a signal, and there's no point leaving the
156  * gadget running when the thread is dead.  So just before the thread
157  * exits, it deregisters the gadget driver.  This makes things a little
158  * tricky: The driver is deregistered at two places, and the exiting
159  * thread can indirectly call fsg_unbind() which in turn can tell the
160  * thread to exit.  The first problem is resolved through the use of the
161  * REGISTERED atomic bitflag; the driver will only be deregistered once.
162  * The second problem is resolved by having fsg_unbind() check
163  * fsg->state; it won't try to stop the thread if the state is already
164  * FSG_STATE_TERMINATED.
165  *
166  * To provide maximum throughput, the driver uses a circular pipeline of
167  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
168  * arbitrarily long; in practice the benefits don't justify having more
169  * than 2 stages (i.e., double buffering).  But it helps to think of the
170  * pipeline as being a long one.  Each buffer head contains a bulk-in and
171  * a bulk-out request pointer (since the buffer can be used for both
172  * output and input -- directions always are given from the host's
173  * point of view) as well as a pointer to the buffer and various state
174  * variables.
175  *
176  * Use of the pipeline follows a simple protocol.  There is a variable
177  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
178  * At any time that buffer head may still be in use from an earlier
179  * request, so each buffer head has a state variable indicating whether
180  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
181  * buffer head to be EMPTY, filling the buffer either by file I/O or by
182  * USB I/O (during which the buffer head is BUSY), and marking the buffer
183  * head FULL when the I/O is complete.  Then the buffer will be emptied
184  * (again possibly by USB I/O, during which it is marked BUSY) and
185  * finally marked EMPTY again (possibly by a completion routine).
186  *
187  * A module parameter tells the driver to avoid stalling the bulk
188  * endpoints wherever the transport specification allows.  This is
189  * necessary for some UDCs like the SuperH, which cannot reliably clear a
190  * halt on a bulk endpoint.  However, under certain circumstances the
191  * Bulk-only specification requires a stall.  In such cases the driver
192  * will halt the endpoint and set a flag indicating that it should clear
193  * the halt in software during the next device reset.  Hopefully this
194  * will permit everything to work correctly.  Furthermore, although the
195  * specification allows the bulk-out endpoint to halt when the host sends
196  * too much data, implementing this would cause an unavoidable race.
197  * The driver will always use the "no-stall" approach for OUT transfers.
198  *
199  * One subtle point concerns sending status-stage responses for ep0
200  * requests.  Some of these requests, such as device reset, can involve
201  * interrupting an ongoing file I/O operation, which might take an
202  * arbitrarily long time.  During that delay the host might give up on
203  * the original ep0 request and issue a new one.  When that happens the
204  * driver should not notify the host about completion of the original
205  * request, as the host will no longer be waiting for it.  So the driver
206  * assigns to each ep0 request a unique tag, and it keeps track of the
207  * tag value of the request associated with a long-running exception
208  * (device-reset, interface-change, or configuration-change).  When the
209  * exception handler is finished, the status-stage response is submitted
210  * only if the current ep0 request tag is equal to the exception request
211  * tag.  Thus only the most recently received ep0 request will get a
212  * status-stage response.
213  *
214  * Warning: This driver source file is too long.  It ought to be split up
215  * into a header file plus about 3 separate .c files, to handle the details
216  * of the Gadget, USB Mass Storage, and SCSI protocols.
217  */
218
219
220 #undef DEBUG
221 #undef VERBOSE
222 #undef DUMP_MSGS
223
224 #include <linux/config.h>
225
226 #include <asm/system.h>
227 #include <asm/uaccess.h>
228
229 #include <linux/bitops.h>
230 #include <linux/blkdev.h>
231 #include <linux/compiler.h>
232 #include <linux/completion.h>
233 #include <linux/dcache.h>
234 #include <linux/delay.h>
235 #include <linux/device.h>
236 #include <linux/fcntl.h>
237 #include <linux/file.h>
238 #include <linux/fs.h>
239 #include <linux/init.h>
240 #include <linux/kernel.h>
241 #include <linux/kref.h>
242 #include <linux/kthread.h>
243 #include <linux/limits.h>
244 #include <linux/list.h>
245 #include <linux/module.h>
246 #include <linux/moduleparam.h>
247 #include <linux/pagemap.h>
248 #include <linux/rwsem.h>
249 #include <linux/sched.h>
250 #include <linux/signal.h>
251 #include <linux/slab.h>
252 #include <linux/spinlock.h>
253 #include <linux/string.h>
254 #include <linux/suspend.h>
255 #include <linux/utsname.h>
256
257 #include <linux/usb_ch9.h>
258 #include <linux/usb_gadget.h>
259
260 #include "gadget_chips.h"
261
262
263 /*-------------------------------------------------------------------------*/
264
265 #define DRIVER_DESC             "File-backed Storage Gadget"
266 #define DRIVER_NAME             "g_file_storage"
267 #define DRIVER_VERSION          "28 November 2005"
268
269 static const char longname[] = DRIVER_DESC;
270 static const char shortname[] = DRIVER_NAME;
271
272 MODULE_DESCRIPTION(DRIVER_DESC);
273 MODULE_AUTHOR("Alan Stern");
274 MODULE_LICENSE("Dual BSD/GPL");
275
276 /* Thanks to NetChip Technologies for donating this product ID.
277  *
278  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
279  * Instead:  allocate your own, using normal USB-IF procedures. */
280 #define DRIVER_VENDOR_ID        0x0525  // NetChip
281 #define DRIVER_PRODUCT_ID       0xa4a5  // Linux-USB File-backed Storage Gadget
282
283
284 /*
285  * This driver assumes self-powered hardware and has no way for users to
286  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
287  * and endpoint addresses.
288  */
289
290
291 /*-------------------------------------------------------------------------*/
292
293 #define xprintk(f,level,fmt,args...) \
294         dev_printk(level , &(f)->gadget->dev , fmt , ## args)
295 #define yprintk(l,level,fmt,args...) \
296         dev_printk(level , &(l)->dev , fmt , ## args)
297
298 #ifdef DEBUG
299 #define DBG(fsg,fmt,args...) \
300         xprintk(fsg , KERN_DEBUG , fmt , ## args)
301 #define LDBG(lun,fmt,args...) \
302         yprintk(lun , KERN_DEBUG , fmt , ## args)
303 #define MDBG(fmt,args...) \
304         printk(KERN_DEBUG DRIVER_NAME ": " fmt , ## args)
305 #else
306 #define DBG(fsg,fmt,args...) \
307         do { } while (0)
308 #define LDBG(lun,fmt,args...) \
309         do { } while (0)
310 #define MDBG(fmt,args...) \
311         do { } while (0)
312 #undef VERBOSE
313 #undef DUMP_MSGS
314 #endif /* DEBUG */
315
316 #ifdef VERBOSE
317 #define VDBG    DBG
318 #define VLDBG   LDBG
319 #else
320 #define VDBG(fsg,fmt,args...) \
321         do { } while (0)
322 #define VLDBG(lun,fmt,args...) \
323         do { } while (0)
324 #endif /* VERBOSE */
325
326 #define ERROR(fsg,fmt,args...) \
327         xprintk(fsg , KERN_ERR , fmt , ## args)
328 #define LERROR(lun,fmt,args...) \
329         yprintk(lun , KERN_ERR , fmt , ## args)
330
331 #define WARN(fsg,fmt,args...) \
332         xprintk(fsg , KERN_WARNING , fmt , ## args)
333 #define LWARN(lun,fmt,args...) \
334         yprintk(lun , KERN_WARNING , fmt , ## args)
335
336 #define INFO(fsg,fmt,args...) \
337         xprintk(fsg , KERN_INFO , fmt , ## args)
338 #define LINFO(lun,fmt,args...) \
339         yprintk(lun , KERN_INFO , fmt , ## args)
340
341 #define MINFO(fmt,args...) \
342         printk(KERN_INFO DRIVER_NAME ": " fmt , ## args)
343
344
345 /*-------------------------------------------------------------------------*/
346
347 /* Encapsulate the module parameter settings */
348
349 #define MAX_LUNS        8
350
351 static struct {
352         char            *file[MAX_LUNS];
353         int             ro[MAX_LUNS];
354         int             num_filenames;
355         int             num_ros;
356         unsigned int    nluns;
357
358         int             removable;
359         int             can_stall;
360
361         char            *transport_parm;
362         char            *protocol_parm;
363         unsigned short  vendor;
364         unsigned short  product;
365         unsigned short  release;
366         unsigned int    buflen;
367
368         int             transport_type;
369         char            *transport_name;
370         int             protocol_type;
371         char            *protocol_name;
372
373 } mod_data = {                                  // Default values
374         .transport_parm         = "BBB",
375         .protocol_parm          = "SCSI",
376         .removable              = 0,
377         .can_stall              = 1,
378         .vendor                 = DRIVER_VENDOR_ID,
379         .product                = DRIVER_PRODUCT_ID,
380         .release                = 0xffff,       // Use controller chip type
381         .buflen                 = 16384,
382         };
383
384
385 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
386                 S_IRUGO);
387 MODULE_PARM_DESC(file, "names of backing files or devices");
388
389 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
390 MODULE_PARM_DESC(ro, "true to force read-only");
391
392 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
393 MODULE_PARM_DESC(luns, "number of LUNs");
394
395 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
396 MODULE_PARM_DESC(removable, "true to simulate removable media");
397
398 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
399 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
400
401
402 /* In the non-TEST version, only the module parameters listed above
403  * are available. */
404 #ifdef CONFIG_USB_FILE_STORAGE_TEST
405
406 module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
407 MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
408
409 module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
410 MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
411                 "8070, or SCSI)");
412
413 module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
414 MODULE_PARM_DESC(vendor, "USB Vendor ID");
415
416 module_param_named(product, mod_data.product, ushort, S_IRUGO);
417 MODULE_PARM_DESC(product, "USB Product ID");
418
419 module_param_named(release, mod_data.release, ushort, S_IRUGO);
420 MODULE_PARM_DESC(release, "USB release number");
421
422 module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
423 MODULE_PARM_DESC(buflen, "I/O buffer size");
424
425 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
426
427
428 /*-------------------------------------------------------------------------*/
429
430 /* USB protocol value = the transport method */
431 #define USB_PR_CBI      0x00            // Control/Bulk/Interrupt
432 #define USB_PR_CB       0x01            // Control/Bulk w/o interrupt
433 #define USB_PR_BULK     0x50            // Bulk-only
434
435 /* USB subclass value = the protocol encapsulation */
436 #define USB_SC_RBC      0x01            // Reduced Block Commands (flash)
437 #define USB_SC_8020     0x02            // SFF-8020i, MMC-2, ATAPI (CD-ROM)
438 #define USB_SC_QIC      0x03            // QIC-157 (tape)
439 #define USB_SC_UFI      0x04            // UFI (floppy)
440 #define USB_SC_8070     0x05            // SFF-8070i (removable)
441 #define USB_SC_SCSI     0x06            // Transparent SCSI
442
443 /* Bulk-only data structures */
444
445 /* Command Block Wrapper */
446 struct bulk_cb_wrap {
447         __le32  Signature;              // Contains 'USBC'
448         u32     Tag;                    // Unique per command id
449         __le32  DataTransferLength;     // Size of the data
450         u8      Flags;                  // Direction in bit 7
451         u8      Lun;                    // LUN (normally 0)
452         u8      Length;                 // Of the CDB, <= MAX_COMMAND_SIZE
453         u8      CDB[16];                // Command Data Block
454 };
455
456 #define USB_BULK_CB_WRAP_LEN    31
457 #define USB_BULK_CB_SIG         0x43425355      // Spells out USBC
458 #define USB_BULK_IN_FLAG        0x80
459
460 /* Command Status Wrapper */
461 struct bulk_cs_wrap {
462         __le32  Signature;              // Should = 'USBS'
463         u32     Tag;                    // Same as original command
464         __le32  Residue;                // Amount not transferred
465         u8      Status;                 // See below
466 };
467
468 #define USB_BULK_CS_WRAP_LEN    13
469 #define USB_BULK_CS_SIG         0x53425355      // Spells out 'USBS'
470 #define USB_STATUS_PASS         0
471 #define USB_STATUS_FAIL         1
472 #define USB_STATUS_PHASE_ERROR  2
473
474 /* Bulk-only class specific requests */
475 #define USB_BULK_RESET_REQUEST          0xff
476 #define USB_BULK_GET_MAX_LUN_REQUEST    0xfe
477
478
479 /* CBI Interrupt data structure */
480 struct interrupt_data {
481         u8      bType;
482         u8      bValue;
483 };
484
485 #define CBI_INTERRUPT_DATA_LEN          2
486
487 /* CBI Accept Device-Specific Command request */
488 #define USB_CBI_ADSC_REQUEST            0x00
489
490
491 #define MAX_COMMAND_SIZE        16      // Length of a SCSI Command Data Block
492
493 /* SCSI commands that we recognize */
494 #define SC_FORMAT_UNIT                  0x04
495 #define SC_INQUIRY                      0x12
496 #define SC_MODE_SELECT_6                0x15
497 #define SC_MODE_SELECT_10               0x55
498 #define SC_MODE_SENSE_6                 0x1a
499 #define SC_MODE_SENSE_10                0x5a
500 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
501 #define SC_READ_6                       0x08
502 #define SC_READ_10                      0x28
503 #define SC_READ_12                      0xa8
504 #define SC_READ_CAPACITY                0x25
505 #define SC_READ_FORMAT_CAPACITIES       0x23
506 #define SC_RELEASE                      0x17
507 #define SC_REQUEST_SENSE                0x03
508 #define SC_RESERVE                      0x16
509 #define SC_SEND_DIAGNOSTIC              0x1d
510 #define SC_START_STOP_UNIT              0x1b
511 #define SC_SYNCHRONIZE_CACHE            0x35
512 #define SC_TEST_UNIT_READY              0x00
513 #define SC_VERIFY                       0x2f
514 #define SC_WRITE_6                      0x0a
515 #define SC_WRITE_10                     0x2a
516 #define SC_WRITE_12                     0xaa
517
518 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
519 #define SS_NO_SENSE                             0
520 #define SS_COMMUNICATION_FAILURE                0x040800
521 #define SS_INVALID_COMMAND                      0x052000
522 #define SS_INVALID_FIELD_IN_CDB                 0x052400
523 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
524 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
525 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
526 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
527 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
528 #define SS_RESET_OCCURRED                       0x062900
529 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
530 #define SS_UNRECOVERED_READ_ERROR               0x031100
531 #define SS_WRITE_ERROR                          0x030c02
532 #define SS_WRITE_PROTECTED                      0x072700
533
534 #define SK(x)           ((u8) ((x) >> 16))      // Sense Key byte, etc.
535 #define ASC(x)          ((u8) ((x) >> 8))
536 #define ASCQ(x)         ((u8) (x))
537
538
539 /*-------------------------------------------------------------------------*/
540
541 /*
542  * These definitions will permit the compiler to avoid generating code for
543  * parts of the driver that aren't used in the non-TEST version.  Even gcc
544  * can recognize when a test of a constant expression yields a dead code
545  * path.
546  */
547
548 #ifdef CONFIG_USB_FILE_STORAGE_TEST
549
550 #define transport_is_bbb()      (mod_data.transport_type == USB_PR_BULK)
551 #define transport_is_cbi()      (mod_data.transport_type == USB_PR_CBI)
552 #define protocol_is_scsi()      (mod_data.protocol_type == USB_SC_SCSI)
553
554 #else
555
556 #define transport_is_bbb()      1
557 #define transport_is_cbi()      0
558 #define protocol_is_scsi()      1
559
560 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
561
562
563 struct lun {
564         struct file     *filp;
565         loff_t          file_length;
566         loff_t          num_sectors;
567
568         unsigned int    ro : 1;
569         unsigned int    prevent_medium_removal : 1;
570         unsigned int    registered : 1;
571
572         u32             sense_data;
573         u32             sense_data_info;
574         u32             unit_attention_data;
575
576         struct device   dev;
577 };
578
579 #define backing_file_is_open(curlun)    ((curlun)->filp != NULL)
580
581 static inline struct lun *dev_to_lun(struct device *dev)
582 {
583         return container_of(dev, struct lun, dev);
584 }
585
586
587 /* Big enough to hold our biggest descriptor */
588 #define EP0_BUFSIZE     256
589 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     // An impossibly large value
590
591 /* Number of buffers we will use.  2 is enough for double-buffering */
592 #define NUM_BUFFERS     2
593
594 enum fsg_buffer_state {
595         BUF_STATE_EMPTY = 0,
596         BUF_STATE_FULL,
597         BUF_STATE_BUSY
598 };
599
600 struct fsg_buffhd {
601         void                            *buf;
602         dma_addr_t                      dma;
603         enum fsg_buffer_state           state;
604         struct fsg_buffhd               *next;
605
606         /* The NetChip 2280 is faster, and handles some protocol faults
607          * better, if we don't submit any short bulk-out read requests.
608          * So we will record the intended request length here. */
609         unsigned int                    bulk_out_intended_length;
610
611         struct usb_request              *inreq;
612         int                             inreq_busy;
613         struct usb_request              *outreq;
614         int                             outreq_busy;
615 };
616
617 enum fsg_state {
618         FSG_STATE_COMMAND_PHASE = -10,          // This one isn't used anywhere
619         FSG_STATE_DATA_PHASE,
620         FSG_STATE_STATUS_PHASE,
621
622         FSG_STATE_IDLE = 0,
623         FSG_STATE_ABORT_BULK_OUT,
624         FSG_STATE_RESET,
625         FSG_STATE_INTERFACE_CHANGE,
626         FSG_STATE_CONFIG_CHANGE,
627         FSG_STATE_DISCONNECT,
628         FSG_STATE_EXIT,
629         FSG_STATE_TERMINATED
630 };
631
632 enum data_direction {
633         DATA_DIR_UNKNOWN = 0,
634         DATA_DIR_FROM_HOST,
635         DATA_DIR_TO_HOST,
636         DATA_DIR_NONE
637 };
638
639 struct fsg_dev {
640         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
641         spinlock_t              lock;
642         struct usb_gadget       *gadget;
643
644         /* filesem protects: backing files in use */
645         struct rw_semaphore     filesem;
646
647         /* reference counting: wait until all LUNs are released */
648         struct kref             ref;
649
650         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
651         struct usb_request      *ep0req;        // For control responses
652         unsigned int            ep0_req_tag;
653         const char              *ep0req_name;
654
655         struct usb_request      *intreq;        // For interrupt responses
656         int                     intreq_busy;
657         struct fsg_buffhd       *intr_buffhd;
658
659         unsigned int            bulk_out_maxpacket;
660         enum fsg_state          state;          // For exception handling
661         unsigned int            exception_req_tag;
662
663         u8                      config, new_config;
664
665         unsigned int            running : 1;
666         unsigned int            bulk_in_enabled : 1;
667         unsigned int            bulk_out_enabled : 1;
668         unsigned int            intr_in_enabled : 1;
669         unsigned int            phase_error : 1;
670         unsigned int            short_packet_received : 1;
671         unsigned int            bad_lun_okay : 1;
672
673         unsigned long           atomic_bitflags;
674 #define REGISTERED              0
675 #define CLEAR_BULK_HALTS        1
676 #define SUSPENDED               2
677
678         struct usb_ep           *bulk_in;
679         struct usb_ep           *bulk_out;
680         struct usb_ep           *intr_in;
681
682         struct fsg_buffhd       *next_buffhd_to_fill;
683         struct fsg_buffhd       *next_buffhd_to_drain;
684         struct fsg_buffhd       buffhds[NUM_BUFFERS];
685
686         int                     thread_wakeup_needed;
687         struct completion       thread_notifier;
688         struct task_struct      *thread_task;
689         sigset_t                thread_signal_mask;
690
691         int                     cmnd_size;
692         u8                      cmnd[MAX_COMMAND_SIZE];
693         enum data_direction     data_dir;
694         u32                     data_size;
695         u32                     data_size_from_cmnd;
696         u32                     tag;
697         unsigned int            lun;
698         u32                     residue;
699         u32                     usb_amount_left;
700
701         /* The CB protocol offers no way for a host to know when a command
702          * has completed.  As a result the next command may arrive early,
703          * and we will still have to handle it.  For that reason we need
704          * a buffer to store new commands when using CB (or CBI, which
705          * does not oblige a host to wait for command completion either). */
706         int                     cbbuf_cmnd_size;
707         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
708
709         unsigned int            nluns;
710         struct lun              *luns;
711         struct lun              *curlun;
712 };
713
714 typedef void (*fsg_routine_t)(struct fsg_dev *);
715
716 static int inline exception_in_progress(struct fsg_dev *fsg)
717 {
718         return (fsg->state > FSG_STATE_IDLE);
719 }
720
721 /* Make bulk-out requests be divisible by the maxpacket size */
722 static void inline set_bulk_out_req_length(struct fsg_dev *fsg,
723                 struct fsg_buffhd *bh, unsigned int length)
724 {
725         unsigned int    rem;
726
727         bh->bulk_out_intended_length = length;
728         rem = length % fsg->bulk_out_maxpacket;
729         if (rem > 0)
730                 length += fsg->bulk_out_maxpacket - rem;
731         bh->outreq->length = length;
732 }
733
734 static struct fsg_dev                   *the_fsg;
735 static struct usb_gadget_driver         fsg_driver;
736
737 static void     close_backing_file(struct lun *curlun);
738 static void     close_all_backing_files(struct fsg_dev *fsg);
739
740
741 /*-------------------------------------------------------------------------*/
742
743 #ifdef DUMP_MSGS
744
745 static void dump_msg(struct fsg_dev *fsg, const char *label,
746                 const u8 *buf, unsigned int length)
747 {
748         unsigned int    start, num, i;
749         char            line[52], *p;
750
751         if (length >= 512)
752                 return;
753         DBG(fsg, "%s, length %u:\n", label, length);
754
755         start = 0;
756         while (length > 0) {
757                 num = min(length, 16u);
758                 p = line;
759                 for (i = 0; i < num; ++i) {
760                         if (i == 8)
761                                 *p++ = ' ';
762                         sprintf(p, " %02x", buf[i]);
763                         p += 3;
764                 }
765                 *p = 0;
766                 printk(KERN_DEBUG "%6x: %s\n", start, line);
767                 buf += num;
768                 start += num;
769                 length -= num;
770         }
771 }
772
773 static void inline dump_cdb(struct fsg_dev *fsg)
774 {}
775
776 #else
777
778 static void inline dump_msg(struct fsg_dev *fsg, const char *label,
779                 const u8 *buf, unsigned int length)
780 {}
781
782 static void inline dump_cdb(struct fsg_dev *fsg)
783 {
784         int     i;
785         char    cmdbuf[3*MAX_COMMAND_SIZE + 1];
786
787         for (i = 0; i < fsg->cmnd_size; ++i)
788                 sprintf(cmdbuf + i*3, " %02x", fsg->cmnd[i]);
789         VDBG(fsg, "SCSI CDB: %s\n", cmdbuf);
790 }
791
792 #endif /* DUMP_MSGS */
793
794
795 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
796 {
797         const char      *name;
798
799         if (ep == fsg->bulk_in)
800                 name = "bulk-in";
801         else if (ep == fsg->bulk_out)
802                 name = "bulk-out";
803         else
804                 name = ep->name;
805         DBG(fsg, "%s set halt\n", name);
806         return usb_ep_set_halt(ep);
807 }
808
809
810 /*-------------------------------------------------------------------------*/
811
812 /* Routines for unaligned data access */
813
814 static u16 inline get_be16(u8 *buf)
815 {
816         return ((u16) buf[0] << 8) | ((u16) buf[1]);
817 }
818
819 static u32 inline get_be32(u8 *buf)
820 {
821         return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) |
822                         ((u32) buf[2] << 8) | ((u32) buf[3]);
823 }
824
825 static void inline put_be16(u8 *buf, u16 val)
826 {
827         buf[0] = val >> 8;
828         buf[1] = val;
829 }
830
831 static void inline put_be32(u8 *buf, u32 val)
832 {
833         buf[0] = val >> 24;
834         buf[1] = val >> 16;
835         buf[2] = val >> 8;
836         buf[3] = val & 0xff;
837 }
838
839
840 /*-------------------------------------------------------------------------*/
841
842 /*
843  * DESCRIPTORS ... most are static, but strings and (full) configuration
844  * descriptors are built on demand.  Also the (static) config and interface
845  * descriptors are adjusted during fsg_bind().
846  */
847 #define STRING_MANUFACTURER     1
848 #define STRING_PRODUCT          2
849 #define STRING_SERIAL           3
850 #define STRING_CONFIG           4
851 #define STRING_INTERFACE        5
852
853 /* There is only one configuration. */
854 #define CONFIG_VALUE            1
855
856 static struct usb_device_descriptor
857 device_desc = {
858         .bLength =              sizeof device_desc,
859         .bDescriptorType =      USB_DT_DEVICE,
860
861         .bcdUSB =               __constant_cpu_to_le16(0x0200),
862         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
863
864         /* The next three values can be overridden by module parameters */
865         .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_ID),
866         .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
867         .bcdDevice =            __constant_cpu_to_le16(0xffff),
868
869         .iManufacturer =        STRING_MANUFACTURER,
870         .iProduct =             STRING_PRODUCT,
871         .iSerialNumber =        STRING_SERIAL,
872         .bNumConfigurations =   1,
873 };
874
875 static struct usb_config_descriptor
876 config_desc = {
877         .bLength =              sizeof config_desc,
878         .bDescriptorType =      USB_DT_CONFIG,
879
880         /* wTotalLength computed by usb_gadget_config_buf() */
881         .bNumInterfaces =       1,
882         .bConfigurationValue =  CONFIG_VALUE,
883         .iConfiguration =       STRING_CONFIG,
884         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
885         .bMaxPower =            1,      // self-powered
886 };
887
888 static struct usb_otg_descriptor
889 otg_desc = {
890         .bLength =              sizeof(otg_desc),
891         .bDescriptorType =      USB_DT_OTG,
892
893         .bmAttributes =         USB_OTG_SRP,
894 };
895
896 /* There is only one interface. */
897
898 static struct usb_interface_descriptor
899 intf_desc = {
900         .bLength =              sizeof intf_desc,
901         .bDescriptorType =      USB_DT_INTERFACE,
902
903         .bNumEndpoints =        2,              // Adjusted during fsg_bind()
904         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
905         .bInterfaceSubClass =   USB_SC_SCSI,    // Adjusted during fsg_bind()
906         .bInterfaceProtocol =   USB_PR_BULK,    // Adjusted during fsg_bind()
907         .iInterface =           STRING_INTERFACE,
908 };
909
910 /* Three full-speed endpoint descriptors: bulk-in, bulk-out,
911  * and interrupt-in. */
912
913 static struct usb_endpoint_descriptor
914 fs_bulk_in_desc = {
915         .bLength =              USB_DT_ENDPOINT_SIZE,
916         .bDescriptorType =      USB_DT_ENDPOINT,
917
918         .bEndpointAddress =     USB_DIR_IN,
919         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
920         /* wMaxPacketSize set by autoconfiguration */
921 };
922
923 static struct usb_endpoint_descriptor
924 fs_bulk_out_desc = {
925         .bLength =              USB_DT_ENDPOINT_SIZE,
926         .bDescriptorType =      USB_DT_ENDPOINT,
927
928         .bEndpointAddress =     USB_DIR_OUT,
929         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
930         /* wMaxPacketSize set by autoconfiguration */
931 };
932
933 static struct usb_endpoint_descriptor
934 fs_intr_in_desc = {
935         .bLength =              USB_DT_ENDPOINT_SIZE,
936         .bDescriptorType =      USB_DT_ENDPOINT,
937
938         .bEndpointAddress =     USB_DIR_IN,
939         .bmAttributes =         USB_ENDPOINT_XFER_INT,
940         .wMaxPacketSize =       __constant_cpu_to_le16(2),
941         .bInterval =            32,     // frames -> 32 ms
942 };
943
944 static const struct usb_descriptor_header *fs_function[] = {
945         (struct usb_descriptor_header *) &otg_desc,
946         (struct usb_descriptor_header *) &intf_desc,
947         (struct usb_descriptor_header *) &fs_bulk_in_desc,
948         (struct usb_descriptor_header *) &fs_bulk_out_desc,
949         (struct usb_descriptor_header *) &fs_intr_in_desc,
950         NULL,
951 };
952 #define FS_FUNCTION_PRE_EP_ENTRIES      2
953
954
955 #ifdef  CONFIG_USB_GADGET_DUALSPEED
956
957 /*
958  * USB 2.0 devices need to expose both high speed and full speed
959  * descriptors, unless they only run at full speed.
960  *
961  * That means alternate endpoint descriptors (bigger packets)
962  * and a "device qualifier" ... plus more construction options
963  * for the config descriptor.
964  */
965 static struct usb_qualifier_descriptor
966 dev_qualifier = {
967         .bLength =              sizeof dev_qualifier,
968         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
969
970         .bcdUSB =               __constant_cpu_to_le16(0x0200),
971         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
972
973         .bNumConfigurations =   1,
974 };
975
976 static struct usb_endpoint_descriptor
977 hs_bulk_in_desc = {
978         .bLength =              USB_DT_ENDPOINT_SIZE,
979         .bDescriptorType =      USB_DT_ENDPOINT,
980
981         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
982         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
983         .wMaxPacketSize =       __constant_cpu_to_le16(512),
984 };
985
986 static struct usb_endpoint_descriptor
987 hs_bulk_out_desc = {
988         .bLength =              USB_DT_ENDPOINT_SIZE,
989         .bDescriptorType =      USB_DT_ENDPOINT,
990
991         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
992         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
993         .wMaxPacketSize =       __constant_cpu_to_le16(512),
994         .bInterval =            1,      // NAK every 1 uframe
995 };
996
997 static struct usb_endpoint_descriptor
998 hs_intr_in_desc = {
999         .bLength =              USB_DT_ENDPOINT_SIZE,
1000         .bDescriptorType =      USB_DT_ENDPOINT,
1001
1002         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
1003         .bmAttributes =         USB_ENDPOINT_XFER_INT,
1004         .wMaxPacketSize =       __constant_cpu_to_le16(2),
1005         .bInterval =            9,      // 2**(9-1) = 256 uframes -> 32 ms
1006 };
1007
1008 static const struct usb_descriptor_header *hs_function[] = {
1009         (struct usb_descriptor_header *) &otg_desc,
1010         (struct usb_descriptor_header *) &intf_desc,
1011         (struct usb_descriptor_header *) &hs_bulk_in_desc,
1012         (struct usb_descriptor_header *) &hs_bulk_out_desc,
1013         (struct usb_descriptor_header *) &hs_intr_in_desc,
1014         NULL,
1015 };
1016 #define HS_FUNCTION_PRE_EP_ENTRIES      2
1017
1018 /* Maxpacket and other transfer characteristics vary by speed. */
1019 #define ep_desc(g,fs,hs)        (((g)->speed==USB_SPEED_HIGH) ? (hs) : (fs))
1020
1021 #else
1022
1023 /* If there's no high speed support, always use the full-speed descriptor. */
1024 #define ep_desc(g,fs,hs)        fs
1025
1026 #endif  /* !CONFIG_USB_GADGET_DUALSPEED */
1027
1028
1029 /* The CBI specification limits the serial string to 12 uppercase hexadecimal
1030  * characters. */
1031 static char                             manufacturer[64];
1032 static char                             serial[13];
1033
1034 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
1035 static struct usb_string                strings[] = {
1036         {STRING_MANUFACTURER,   manufacturer},
1037         {STRING_PRODUCT,        longname},
1038         {STRING_SERIAL,         serial},
1039         {STRING_CONFIG,         "Self-powered"},
1040         {STRING_INTERFACE,      "Mass Storage"},
1041         {}
1042 };
1043
1044 static struct usb_gadget_strings        stringtab = {
1045         .language       = 0x0409,               // en-us
1046         .strings        = strings,
1047 };
1048
1049
1050 /*
1051  * Config descriptors must agree with the code that sets configurations
1052  * and with code managing interfaces and their altsettings.  They must
1053  * also handle different speeds and other-speed requests.
1054  */
1055 static int populate_config_buf(struct usb_gadget *gadget,
1056                 u8 *buf, u8 type, unsigned index)
1057 {
1058 #ifdef CONFIG_USB_GADGET_DUALSPEED
1059         enum usb_device_speed                   speed = gadget->speed;
1060 #endif
1061         int                                     len;
1062         const struct usb_descriptor_header      **function;
1063
1064         if (index > 0)
1065                 return -EINVAL;
1066
1067 #ifdef CONFIG_USB_GADGET_DUALSPEED
1068         if (type == USB_DT_OTHER_SPEED_CONFIG)
1069                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
1070         if (speed == USB_SPEED_HIGH)
1071                 function = hs_function;
1072         else
1073 #endif
1074                 function = fs_function;
1075
1076         /* for now, don't advertise srp-only devices */
1077         if (!gadget->is_otg)
1078                 function++;
1079
1080         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
1081         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
1082         return len;
1083 }
1084
1085
1086 /*-------------------------------------------------------------------------*/
1087
1088 /* These routines may be called in process context or in_irq */
1089
1090 /* Caller must hold fsg->lock */
1091 static void wakeup_thread(struct fsg_dev *fsg)
1092 {
1093         /* Tell the main thread that something has happened */
1094         fsg->thread_wakeup_needed = 1;
1095         if (fsg->thread_task)
1096                 wake_up_process(fsg->thread_task);
1097 }
1098
1099
1100 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
1101 {
1102         unsigned long           flags;
1103
1104         /* Do nothing if a higher-priority exception is already in progress.
1105          * If a lower-or-equal priority exception is in progress, preempt it
1106          * and notify the main thread by sending it a signal. */
1107         spin_lock_irqsave(&fsg->lock, flags);
1108         if (fsg->state <= new_state) {
1109                 fsg->exception_req_tag = fsg->ep0_req_tag;
1110                 fsg->state = new_state;
1111                 if (fsg->thread_task)
1112                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
1113                                         fsg->thread_task);
1114         }
1115         spin_unlock_irqrestore(&fsg->lock, flags);
1116 }
1117
1118
1119 /*-------------------------------------------------------------------------*/
1120
1121 /* The disconnect callback and ep0 routines.  These always run in_irq,
1122  * except that ep0_queue() is called in the main thread to acknowledge
1123  * completion of various requests: set config, set interface, and
1124  * Bulk-only device reset. */
1125
1126 static void fsg_disconnect(struct usb_gadget *gadget)
1127 {
1128         struct fsg_dev          *fsg = get_gadget_data(gadget);
1129
1130         DBG(fsg, "disconnect or port reset\n");
1131         raise_exception(fsg, FSG_STATE_DISCONNECT);
1132 }
1133
1134
1135 static int ep0_queue(struct fsg_dev *fsg)
1136 {
1137         int     rc;
1138
1139         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
1140         if (rc != 0 && rc != -ESHUTDOWN) {
1141
1142                 /* We can't do much more than wait for a reset */
1143                 WARN(fsg, "error in submission: %s --> %d\n",
1144                                 fsg->ep0->name, rc);
1145         }
1146         return rc;
1147 }
1148
1149 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
1150 {
1151         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1152
1153         if (req->actual > 0)
1154                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
1155         if (req->status || req->actual != req->length)
1156                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1157                                 req->status, req->actual, req->length);
1158         if (req->status == -ECONNRESET)         // Request was cancelled
1159                 usb_ep_fifo_flush(ep);
1160
1161         if (req->status == 0 && req->context)
1162                 ((fsg_routine_t) (req->context))(fsg);
1163 }
1164
1165
1166 /*-------------------------------------------------------------------------*/
1167
1168 /* Bulk and interrupt endpoint completion handlers.
1169  * These always run in_irq. */
1170
1171 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
1172 {
1173         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1174         struct fsg_buffhd       *bh = (struct fsg_buffhd *) req->context;
1175
1176         if (req->status || req->actual != req->length)
1177                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1178                                 req->status, req->actual, req->length);
1179         if (req->status == -ECONNRESET)         // Request was cancelled
1180                 usb_ep_fifo_flush(ep);
1181
1182         /* Hold the lock while we update the request and buffer states */
1183         smp_wmb();
1184         spin_lock(&fsg->lock);
1185         bh->inreq_busy = 0;
1186         bh->state = BUF_STATE_EMPTY;
1187         wakeup_thread(fsg);
1188         spin_unlock(&fsg->lock);
1189 }
1190
1191 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
1192 {
1193         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1194         struct fsg_buffhd       *bh = (struct fsg_buffhd *) req->context;
1195
1196         dump_msg(fsg, "bulk-out", req->buf, req->actual);
1197         if (req->status || req->actual != bh->bulk_out_intended_length)
1198                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1199                                 req->status, req->actual,
1200                                 bh->bulk_out_intended_length);
1201         if (req->status == -ECONNRESET)         // Request was cancelled
1202                 usb_ep_fifo_flush(ep);
1203
1204         /* Hold the lock while we update the request and buffer states */
1205         smp_wmb();
1206         spin_lock(&fsg->lock);
1207         bh->outreq_busy = 0;
1208         bh->state = BUF_STATE_FULL;
1209         wakeup_thread(fsg);
1210         spin_unlock(&fsg->lock);
1211 }
1212
1213
1214 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1215 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1216 {
1217         struct fsg_dev          *fsg = (struct fsg_dev *) ep->driver_data;
1218         struct fsg_buffhd       *bh = (struct fsg_buffhd *) req->context;
1219
1220         if (req->status || req->actual != req->length)
1221                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1222                                 req->status, req->actual, req->length);
1223         if (req->status == -ECONNRESET)         // Request was cancelled
1224                 usb_ep_fifo_flush(ep);
1225
1226         /* Hold the lock while we update the request and buffer states */
1227         smp_wmb();
1228         spin_lock(&fsg->lock);
1229         fsg->intreq_busy = 0;
1230         bh->state = BUF_STATE_EMPTY;
1231         wakeup_thread(fsg);
1232         spin_unlock(&fsg->lock);
1233 }
1234
1235 #else
1236 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1237 {}
1238 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1239
1240
1241 /*-------------------------------------------------------------------------*/
1242
1243 /* Ep0 class-specific handlers.  These always run in_irq. */
1244
1245 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1246 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1247 {
1248         struct usb_request      *req = fsg->ep0req;
1249         static u8               cbi_reset_cmnd[6] = {
1250                         SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
1251
1252         /* Error in command transfer? */
1253         if (req->status || req->length != req->actual ||
1254                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
1255
1256                 /* Not all controllers allow a protocol stall after
1257                  * receiving control-out data, but we'll try anyway. */
1258                 fsg_set_halt(fsg, fsg->ep0);
1259                 return;                 // Wait for reset
1260         }
1261
1262         /* Is it the special reset command? */
1263         if (req->actual >= sizeof cbi_reset_cmnd &&
1264                         memcmp(req->buf, cbi_reset_cmnd,
1265                                 sizeof cbi_reset_cmnd) == 0) {
1266
1267                 /* Raise an exception to stop the current operation
1268                  * and reinitialize our state. */
1269                 DBG(fsg, "cbi reset request\n");
1270                 raise_exception(fsg, FSG_STATE_RESET);
1271                 return;
1272         }
1273
1274         VDBG(fsg, "CB[I] accept device-specific command\n");
1275         spin_lock(&fsg->lock);
1276
1277         /* Save the command for later */
1278         if (fsg->cbbuf_cmnd_size)
1279                 WARN(fsg, "CB[I] overwriting previous command\n");
1280         fsg->cbbuf_cmnd_size = req->actual;
1281         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
1282
1283         wakeup_thread(fsg);
1284         spin_unlock(&fsg->lock);
1285 }
1286
1287 #else
1288 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1289 {}
1290 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1291
1292
1293 static int class_setup_req(struct fsg_dev *fsg,
1294                 const struct usb_ctrlrequest *ctrl)
1295 {
1296         struct usb_request      *req = fsg->ep0req;
1297         int                     value = -EOPNOTSUPP;
1298         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1299         u16                     w_length = le16_to_cpu(ctrl->wLength);
1300
1301         if (!fsg->config)
1302                 return value;
1303
1304         /* Handle Bulk-only class-specific requests */
1305         if (transport_is_bbb()) {
1306                 switch (ctrl->bRequest) {
1307
1308                 case USB_BULK_RESET_REQUEST:
1309                         if (ctrl->bRequestType != (USB_DIR_OUT |
1310                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1311                                 break;
1312                         if (w_index != 0) {
1313                                 value = -EDOM;
1314                                 break;
1315                         }
1316
1317                         /* Raise an exception to stop the current operation
1318                          * and reinitialize our state. */
1319                         DBG(fsg, "bulk reset request\n");
1320                         raise_exception(fsg, FSG_STATE_RESET);
1321                         value = DELAYED_STATUS;
1322                         break;
1323
1324                 case USB_BULK_GET_MAX_LUN_REQUEST:
1325                         if (ctrl->bRequestType != (USB_DIR_IN |
1326                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1327                                 break;
1328                         if (w_index != 0) {
1329                                 value = -EDOM;
1330                                 break;
1331                         }
1332                         VDBG(fsg, "get max LUN\n");
1333                         *(u8 *) req->buf = fsg->nluns - 1;
1334                         value = 1;
1335                         break;
1336                 }
1337         }
1338
1339         /* Handle CBI class-specific requests */
1340         else {
1341                 switch (ctrl->bRequest) {
1342
1343                 case USB_CBI_ADSC_REQUEST:
1344                         if (ctrl->bRequestType != (USB_DIR_OUT |
1345                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1346                                 break;
1347                         if (w_index != 0) {
1348                                 value = -EDOM;
1349                                 break;
1350                         }
1351                         if (w_length > MAX_COMMAND_SIZE) {
1352                                 value = -EOVERFLOW;
1353                                 break;
1354                         }
1355                         value = w_length;
1356                         fsg->ep0req->context = received_cbi_adsc;
1357                         break;
1358                 }
1359         }
1360
1361         if (value == -EOPNOTSUPP)
1362                 VDBG(fsg,
1363                         "unknown class-specific control req "
1364                         "%02x.%02x v%04x i%04x l%u\n",
1365                         ctrl->bRequestType, ctrl->bRequest,
1366                         le16_to_cpu(ctrl->wValue), w_index, w_length);
1367         return value;
1368 }
1369
1370
1371 /*-------------------------------------------------------------------------*/
1372
1373 /* Ep0 standard request handlers.  These always run in_irq. */
1374
1375 static int standard_setup_req(struct fsg_dev *fsg,
1376                 const struct usb_ctrlrequest *ctrl)
1377 {
1378         struct usb_request      *req = fsg->ep0req;
1379         int                     value = -EOPNOTSUPP;
1380         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1381         u16                     w_value = le16_to_cpu(ctrl->wValue);
1382
1383         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
1384          * but config change events will also reconfigure hardware. */
1385         switch (ctrl->bRequest) {
1386
1387         case USB_REQ_GET_DESCRIPTOR:
1388                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1389                                 USB_RECIP_DEVICE))
1390                         break;
1391                 switch (w_value >> 8) {
1392
1393                 case USB_DT_DEVICE:
1394                         VDBG(fsg, "get device descriptor\n");
1395                         value = sizeof device_desc;
1396                         memcpy(req->buf, &device_desc, value);
1397                         break;
1398 #ifdef CONFIG_USB_GADGET_DUALSPEED
1399                 case USB_DT_DEVICE_QUALIFIER:
1400                         VDBG(fsg, "get device qualifier\n");
1401                         if (!fsg->gadget->is_dualspeed)
1402                                 break;
1403                         value = sizeof dev_qualifier;
1404                         memcpy(req->buf, &dev_qualifier, value);
1405                         break;
1406
1407                 case USB_DT_OTHER_SPEED_CONFIG:
1408                         VDBG(fsg, "get other-speed config descriptor\n");
1409                         if (!fsg->gadget->is_dualspeed)
1410                                 break;
1411                         goto get_config;
1412 #endif
1413                 case USB_DT_CONFIG:
1414                         VDBG(fsg, "get configuration descriptor\n");
1415 #ifdef CONFIG_USB_GADGET_DUALSPEED
1416                 get_config:
1417 #endif
1418                         value = populate_config_buf(fsg->gadget,
1419                                         req->buf,
1420                                         w_value >> 8,
1421                                         w_value & 0xff);
1422                         break;
1423
1424                 case USB_DT_STRING:
1425                         VDBG(fsg, "get string descriptor\n");
1426
1427                         /* wIndex == language code */
1428                         value = usb_gadget_get_string(&stringtab,
1429                                         w_value & 0xff, req->buf);
1430                         break;
1431                 }
1432                 break;
1433
1434         /* One config, two speeds */
1435         case USB_REQ_SET_CONFIGURATION:
1436                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
1437                                 USB_RECIP_DEVICE))
1438                         break;
1439                 VDBG(fsg, "set configuration\n");
1440                 if (w_value == CONFIG_VALUE || w_value == 0) {
1441                         fsg->new_config = w_value;
1442
1443                         /* Raise an exception to wipe out previous transaction
1444                          * state (queued bufs, etc) and set the new config. */
1445                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
1446                         value = DELAYED_STATUS;
1447                 }
1448                 break;
1449         case USB_REQ_GET_CONFIGURATION:
1450                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1451                                 USB_RECIP_DEVICE))
1452                         break;
1453                 VDBG(fsg, "get configuration\n");
1454                 *(u8 *) req->buf = fsg->config;
1455                 value = 1;
1456                 break;
1457
1458         case USB_REQ_SET_INTERFACE:
1459                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
1460                                 USB_RECIP_INTERFACE))
1461                         break;
1462                 if (fsg->config && w_index == 0) {
1463
1464                         /* Raise an exception to wipe out previous transaction
1465                          * state (queued bufs, etc) and install the new
1466                          * interface altsetting. */
1467                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
1468                         value = DELAYED_STATUS;
1469                 }
1470                 break;
1471         case USB_REQ_GET_INTERFACE:
1472                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1473                                 USB_RECIP_INTERFACE))
1474                         break;
1475                 if (!fsg->config)
1476                         break;
1477                 if (w_index != 0) {
1478                         value = -EDOM;
1479                         break;
1480                 }
1481                 VDBG(fsg, "get interface\n");
1482                 *(u8 *) req->buf = 0;
1483                 value = 1;
1484                 break;
1485
1486         default:
1487                 VDBG(fsg,
1488                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1489                         ctrl->bRequestType, ctrl->bRequest,
1490                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1491         }
1492
1493         return value;
1494 }
1495
1496
1497 static int fsg_setup(struct usb_gadget *gadget,
1498                 const struct usb_ctrlrequest *ctrl)
1499 {
1500         struct fsg_dev          *fsg = get_gadget_data(gadget);
1501         int                     rc;
1502         int                     w_length = le16_to_cpu(ctrl->wLength);
1503
1504         ++fsg->ep0_req_tag;             // Record arrival of a new request
1505         fsg->ep0req->context = NULL;
1506         fsg->ep0req->length = 0;
1507         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1508
1509         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1510                 rc = class_setup_req(fsg, ctrl);
1511         else
1512                 rc = standard_setup_req(fsg, ctrl);
1513
1514         /* Respond with data/status or defer until later? */
1515         if (rc >= 0 && rc != DELAYED_STATUS) {
1516                 rc = min(rc, w_length);
1517                 fsg->ep0req->length = rc;
1518                 fsg->ep0req->zero = rc < w_length;
1519                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1520                                 "ep0-in" : "ep0-out");
1521                 rc = ep0_queue(fsg);
1522         }
1523
1524         /* Device either stalls (rc < 0) or reports success */
1525         return rc;
1526 }
1527
1528
1529 /*-------------------------------------------------------------------------*/
1530
1531 /* All the following routines run in process context */
1532
1533
1534 /* Use this for bulk or interrupt transfers, not ep0 */
1535 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1536                 struct usb_request *req, int *pbusy,
1537                 enum fsg_buffer_state *state)
1538 {
1539         int     rc;
1540
1541         if (ep == fsg->bulk_in)
1542                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1543         else if (ep == fsg->intr_in)
1544                 dump_msg(fsg, "intr-in", req->buf, req->length);
1545
1546         spin_lock_irq(&fsg->lock);
1547         *pbusy = 1;
1548         *state = BUF_STATE_BUSY;
1549         spin_unlock_irq(&fsg->lock);
1550         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1551         if (rc != 0) {
1552                 *pbusy = 0;
1553                 *state = BUF_STATE_EMPTY;
1554
1555                 /* We can't do much more than wait for a reset */
1556
1557                 /* Note: currently the net2280 driver fails zero-length
1558                  * submissions if DMA is enabled. */
1559                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1560                                                 req->length == 0))
1561                         WARN(fsg, "error in submission: %s --> %d\n",
1562                                         ep->name, rc);
1563         }
1564 }
1565
1566
1567 static int sleep_thread(struct fsg_dev *fsg)
1568 {
1569         int     rc = 0;
1570
1571         /* Wait until a signal arrives or we are woken up */
1572         for (;;) {
1573                 try_to_freeze();
1574                 set_current_state(TASK_INTERRUPTIBLE);
1575                 if (signal_pending(current)) {
1576                         rc = -EINTR;
1577                         break;
1578                 }
1579                 if (fsg->thread_wakeup_needed)
1580                         break;
1581                 schedule();
1582         }
1583         __set_current_state(TASK_RUNNING);
1584         fsg->thread_wakeup_needed = 0;
1585         return rc;
1586 }
1587
1588
1589 /*-------------------------------------------------------------------------*/
1590
1591 static int do_read(struct fsg_dev *fsg)
1592 {
1593         struct lun              *curlun = fsg->curlun;
1594         u32                     lba;
1595         struct fsg_buffhd       *bh;
1596         int                     rc;
1597         u32                     amount_left;
1598         loff_t                  file_offset, file_offset_tmp;
1599         unsigned int            amount;
1600         unsigned int            partial_page;
1601         ssize_t                 nread;
1602
1603         /* Get the starting Logical Block Address and check that it's
1604          * not too big */
1605         if (fsg->cmnd[0] == SC_READ_6)
1606                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1607         else {
1608                 lba = get_be32(&fsg->cmnd[2]);
1609
1610                 /* We allow DPO (Disable Page Out = don't save data in the
1611                  * cache) and FUA (Force Unit Access = don't read from the
1612                  * cache), but we don't implement them. */
1613                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1614                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1615                         return -EINVAL;
1616                 }
1617         }
1618         if (lba >= curlun->num_sectors) {
1619                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1620                 return -EINVAL;
1621         }
1622         file_offset = ((loff_t) lba) << 9;
1623
1624         /* Carry out the file reads */
1625         amount_left = fsg->data_size_from_cmnd;
1626         if (unlikely(amount_left == 0))
1627                 return -EIO;            // No default reply
1628
1629         for (;;) {
1630
1631                 /* Figure out how much we need to read:
1632                  * Try to read the remaining amount.
1633                  * But don't read more than the buffer size.
1634                  * And don't try to read past the end of the file.
1635                  * Finally, if we're not at a page boundary, don't read past
1636                  *      the next page.
1637                  * If this means reading 0 then we were asked to read past
1638                  *      the end of file. */
1639                 amount = min((unsigned int) amount_left, mod_data.buflen);
1640                 amount = min((loff_t) amount,
1641                                 curlun->file_length - file_offset);
1642                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1643                 if (partial_page > 0)
1644                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1645                                         partial_page);
1646
1647                 /* Wait for the next buffer to become available */
1648                 bh = fsg->next_buffhd_to_fill;
1649                 while (bh->state != BUF_STATE_EMPTY) {
1650                         if ((rc = sleep_thread(fsg)) != 0)
1651                                 return rc;
1652                 }
1653
1654                 /* If we were asked to read past the end of file,
1655                  * end with an empty buffer. */
1656                 if (amount == 0) {
1657                         curlun->sense_data =
1658                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1659                         curlun->sense_data_info = file_offset >> 9;
1660                         bh->inreq->length = 0;
1661                         bh->state = BUF_STATE_FULL;
1662                         break;
1663                 }
1664
1665                 /* Perform the read */
1666                 file_offset_tmp = file_offset;
1667                 nread = vfs_read(curlun->filp,
1668                                 (char __user *) bh->buf,
1669                                 amount, &file_offset_tmp);
1670                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1671                                 (unsigned long long) file_offset,
1672                                 (int) nread);
1673                 if (signal_pending(current))
1674                         return -EINTR;
1675
1676                 if (nread < 0) {
1677                         LDBG(curlun, "error in file read: %d\n",
1678                                         (int) nread);
1679                         nread = 0;
1680                 } else if (nread < amount) {
1681                         LDBG(curlun, "partial file read: %d/%u\n",
1682                                         (int) nread, amount);
1683                         nread -= (nread & 511); // Round down to a block
1684                 }
1685                 file_offset  += nread;
1686                 amount_left  -= nread;
1687                 fsg->residue -= nread;
1688                 bh->inreq->length = nread;
1689                 bh->state = BUF_STATE_FULL;
1690
1691                 /* If an error occurred, report it and its position */
1692                 if (nread < amount) {
1693                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1694                         curlun->sense_data_info = file_offset >> 9;
1695                         break;
1696                 }
1697
1698                 if (amount_left == 0)
1699                         break;          // No more left to read
1700
1701                 /* Send this buffer and go read some more */
1702                 bh->inreq->zero = 0;
1703                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1704                                 &bh->inreq_busy, &bh->state);
1705                 fsg->next_buffhd_to_fill = bh->next;
1706         }
1707
1708         return -EIO;            // No default reply
1709 }
1710
1711
1712 /*-------------------------------------------------------------------------*/
1713
1714 static int do_write(struct fsg_dev *fsg)
1715 {
1716         struct lun              *curlun = fsg->curlun;
1717         u32                     lba;
1718         struct fsg_buffhd       *bh;
1719         int                     get_some_more;
1720         u32                     amount_left_to_req, amount_left_to_write;
1721         loff_t                  usb_offset, file_offset, file_offset_tmp;
1722         unsigned int            amount;
1723         unsigned int            partial_page;
1724         ssize_t                 nwritten;
1725         int                     rc;
1726
1727         if (curlun->ro) {
1728                 curlun->sense_data = SS_WRITE_PROTECTED;
1729                 return -EINVAL;
1730         }
1731         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1732
1733         /* Get the starting Logical Block Address and check that it's
1734          * not too big */
1735         if (fsg->cmnd[0] == SC_WRITE_6)
1736                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1737         else {
1738                 lba = get_be32(&fsg->cmnd[2]);
1739
1740                 /* We allow DPO (Disable Page Out = don't save data in the
1741                  * cache) and FUA (Force Unit Access = write directly to the
1742                  * medium).  We don't implement DPO; we implement FUA by
1743                  * performing synchronous output. */
1744                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1745                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1746                         return -EINVAL;
1747                 }
1748                 if (fsg->cmnd[1] & 0x08)        // FUA
1749                         curlun->filp->f_flags |= O_SYNC;
1750         }
1751         if (lba >= curlun->num_sectors) {
1752                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1753                 return -EINVAL;
1754         }
1755
1756         /* Carry out the file writes */
1757         get_some_more = 1;
1758         file_offset = usb_offset = ((loff_t) lba) << 9;
1759         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1760
1761         while (amount_left_to_write > 0) {
1762
1763                 /* Queue a request for more data from the host */
1764                 bh = fsg->next_buffhd_to_fill;
1765                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1766
1767                         /* Figure out how much we want to get:
1768                          * Try to get the remaining amount.
1769                          * But don't get more than the buffer size.
1770                          * And don't try to go past the end of the file.
1771                          * If we're not at a page boundary,
1772                          *      don't go past the next page.
1773                          * If this means getting 0, then we were asked
1774                          *      to write past the end of file.
1775                          * Finally, round down to a block boundary. */
1776                         amount = min(amount_left_to_req, mod_data.buflen);
1777                         amount = min((loff_t) amount, curlun->file_length -
1778                                         usb_offset);
1779                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1780                         if (partial_page > 0)
1781                                 amount = min(amount,
1782         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1783
1784                         if (amount == 0) {
1785                                 get_some_more = 0;
1786                                 curlun->sense_data =
1787                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1788                                 curlun->sense_data_info = usb_offset >> 9;
1789                                 continue;
1790                         }
1791                         amount -= (amount & 511);
1792                         if (amount == 0) {
1793
1794                                 /* Why were we were asked to transfer a
1795                                  * partial block? */
1796                                 get_some_more = 0;
1797                                 continue;
1798                         }
1799
1800                         /* Get the next buffer */
1801                         usb_offset += amount;
1802                         fsg->usb_amount_left -= amount;
1803                         amount_left_to_req -= amount;
1804                         if (amount_left_to_req == 0)
1805                                 get_some_more = 0;
1806
1807                         /* amount is always divisible by 512, hence by
1808                          * the bulk-out maxpacket size */
1809                         bh->outreq->length = bh->bulk_out_intended_length =
1810                                         amount;
1811                         bh->outreq->short_not_ok = 1;
1812                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1813                                         &bh->outreq_busy, &bh->state);
1814                         fsg->next_buffhd_to_fill = bh->next;
1815                         continue;
1816                 }
1817
1818                 /* Write the received data to the backing file */
1819                 bh = fsg->next_buffhd_to_drain;
1820                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1821                         break;                  // We stopped early
1822                 if (bh->state == BUF_STATE_FULL) {
1823                         smp_rmb();
1824                         fsg->next_buffhd_to_drain = bh->next;
1825                         bh->state = BUF_STATE_EMPTY;
1826
1827                         /* Did something go wrong with the transfer? */
1828                         if (bh->outreq->status != 0) {
1829                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1830                                 curlun->sense_data_info = file_offset >> 9;
1831                                 break;
1832                         }
1833
1834                         amount = bh->outreq->actual;
1835                         if (curlun->file_length - file_offset < amount) {
1836                                 LERROR(curlun,
1837         "write %u @ %llu beyond end %llu\n",
1838         amount, (unsigned long long) file_offset,
1839         (unsigned long long) curlun->file_length);
1840                                 amount = curlun->file_length - file_offset;
1841                         }
1842
1843                         /* Perform the write */
1844                         file_offset_tmp = file_offset;
1845                         nwritten = vfs_write(curlun->filp,
1846                                         (char __user *) bh->buf,
1847                                         amount, &file_offset_tmp);
1848                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1849                                         (unsigned long long) file_offset,
1850                                         (int) nwritten);
1851                         if (signal_pending(current))
1852                                 return -EINTR;          // Interrupted!
1853
1854                         if (nwritten < 0) {
1855                                 LDBG(curlun, "error in file write: %d\n",
1856                                                 (int) nwritten);
1857                                 nwritten = 0;
1858                         } else if (nwritten < amount) {
1859                                 LDBG(curlun, "partial file write: %d/%u\n",
1860                                                 (int) nwritten, amount);
1861                                 nwritten -= (nwritten & 511);
1862                                                 // Round down to a block
1863                         }
1864                         file_offset += nwritten;
1865                         amount_left_to_write -= nwritten;
1866                         fsg->residue -= nwritten;
1867
1868                         /* If an error occurred, report it and its position */
1869                         if (nwritten < amount) {
1870                                 curlun->sense_data = SS_WRITE_ERROR;
1871                                 curlun->sense_data_info = file_offset >> 9;
1872                                 break;
1873                         }
1874
1875                         /* Did the host decide to stop early? */
1876                         if (bh->outreq->actual != bh->outreq->length) {
1877                                 fsg->short_packet_received = 1;
1878                                 break;
1879                         }
1880                         continue;
1881                 }
1882
1883                 /* Wait for something to happen */
1884                 if ((rc = sleep_thread(fsg)) != 0)
1885                         return rc;
1886         }
1887
1888         return -EIO;            // No default reply
1889 }
1890
1891
1892 /*-------------------------------------------------------------------------*/
1893
1894 /* Sync the file data, don't bother with the metadata.
1895  * This code was copied from fs/buffer.c:sys_fdatasync(). */
1896 static int fsync_sub(struct lun *curlun)
1897 {
1898         struct file     *filp = curlun->filp;
1899         struct inode    *inode;
1900         int             rc, err;
1901
1902         if (curlun->ro || !filp)
1903                 return 0;
1904         if (!filp->f_op->fsync)
1905                 return -EINVAL;
1906
1907         inode = filp->f_dentry->d_inode;
1908         mutex_lock(&inode->i_mutex);
1909         rc = filemap_fdatawrite(inode->i_mapping);
1910         err = filp->f_op->fsync(filp, filp->f_dentry, 1);
1911         if (!rc)
1912                 rc = err;
1913         err = filemap_fdatawait(inode->i_mapping);
1914         if (!rc)
1915                 rc = err;
1916         mutex_unlock(&inode->i_mutex);
1917         VLDBG(curlun, "fdatasync -> %d\n", rc);
1918         return rc;
1919 }
1920
1921 static void fsync_all(struct fsg_dev *fsg)
1922 {
1923         int     i;
1924
1925         for (i = 0; i < fsg->nluns; ++i)
1926                 fsync_sub(&fsg->luns[i]);
1927 }
1928
1929 static int do_synchronize_cache(struct fsg_dev *fsg)
1930 {
1931         struct lun      *curlun = fsg->curlun;
1932         int             rc;
1933
1934         /* We ignore the requested LBA and write out all file's
1935          * dirty data buffers. */
1936         rc = fsync_sub(curlun);
1937         if (rc)
1938                 curlun->sense_data = SS_WRITE_ERROR;
1939         return 0;
1940 }
1941
1942
1943 /*-------------------------------------------------------------------------*/
1944
1945 static void invalidate_sub(struct lun *curlun)
1946 {
1947         struct file     *filp = curlun->filp;
1948         struct inode    *inode = filp->f_dentry->d_inode;
1949         unsigned long   rc;
1950
1951         rc = invalidate_inode_pages(inode->i_mapping);
1952         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
1953 }
1954
1955 static int do_verify(struct fsg_dev *fsg)
1956 {
1957         struct lun              *curlun = fsg->curlun;
1958         u32                     lba;
1959         u32                     verification_length;
1960         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1961         loff_t                  file_offset, file_offset_tmp;
1962         u32                     amount_left;
1963         unsigned int            amount;
1964         ssize_t                 nread;
1965
1966         /* Get the starting Logical Block Address and check that it's
1967          * not too big */
1968         lba = get_be32(&fsg->cmnd[2]);
1969         if (lba >= curlun->num_sectors) {
1970                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1971                 return -EINVAL;
1972         }
1973
1974         /* We allow DPO (Disable Page Out = don't save data in the
1975          * cache) but we don't implement it. */
1976         if ((fsg->cmnd[1] & ~0x10) != 0) {
1977                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1978                 return -EINVAL;
1979         }
1980
1981         verification_length = get_be16(&fsg->cmnd[7]);
1982         if (unlikely(verification_length == 0))
1983                 return -EIO;            // No default reply
1984
1985         /* Prepare to carry out the file verify */
1986         amount_left = verification_length << 9;
1987         file_offset = ((loff_t) lba) << 9;
1988
1989         /* Write out all the dirty buffers before invalidating them */
1990         fsync_sub(curlun);
1991         if (signal_pending(current))
1992                 return -EINTR;
1993
1994         invalidate_sub(curlun);
1995         if (signal_pending(current))
1996                 return -EINTR;
1997
1998         /* Just try to read the requested blocks */
1999         while (amount_left > 0) {
2000
2001                 /* Figure out how much we need to read:
2002                  * Try to read the remaining amount, but not more than
2003                  * the buffer size.
2004                  * And don't try to read past the end of the file.
2005                  * If this means reading 0 then we were asked to read
2006                  * past the end of file. */
2007                 amount = min((unsigned int) amount_left, mod_data.buflen);
2008                 amount = min((loff_t) amount,
2009                                 curlun->file_length - file_offset);
2010                 if (amount == 0) {
2011                         curlun->sense_data =
2012                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
2013                         curlun->sense_data_info = file_offset >> 9;
2014                         break;
2015                 }
2016
2017                 /* Perform the read */
2018                 file_offset_tmp = file_offset;
2019                 nread = vfs_read(curlun->filp,
2020                                 (char __user *) bh->buf,
2021                                 amount, &file_offset_tmp);
2022                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
2023                                 (unsigned long long) file_offset,
2024                                 (int) nread);
2025                 if (signal_pending(current))
2026                         return -EINTR;
2027
2028                 if (nread < 0) {
2029                         LDBG(curlun, "error in file verify: %d\n",
2030                                         (int) nread);
2031                         nread = 0;
2032                 } else if (nread < amount) {
2033                         LDBG(curlun, "partial file verify: %d/%u\n",
2034                                         (int) nread, amount);
2035                         nread -= (nread & 511); // Round down to a sector
2036                 }
2037                 if (nread == 0) {
2038                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
2039                         curlun->sense_data_info = file_offset >> 9;
2040                         break;
2041                 }
2042                 file_offset += nread;
2043                 amount_left -= nread;
2044         }
2045         return 0;
2046 }
2047
2048
2049 /*-------------------------------------------------------------------------*/
2050
2051 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2052 {
2053         u8      *buf = (u8 *) bh->buf;
2054
2055         static char vendor_id[] = "Linux   ";
2056         static char product_id[] = "File-Stor Gadget";
2057
2058         if (!fsg->curlun) {             // Unsupported LUNs are okay
2059                 fsg->bad_lun_okay = 1;
2060                 memset(buf, 0, 36);
2061                 buf[0] = 0x7f;          // Unsupported, no device-type
2062                 return 36;
2063         }
2064
2065         memset(buf, 0, 8);      // Non-removable, direct-access device
2066         if (mod_data.removable)
2067                 buf[1] = 0x80;
2068         buf[2] = 2;             // ANSI SCSI level 2
2069         buf[3] = 2;             // SCSI-2 INQUIRY data format
2070         buf[4] = 31;            // Additional length
2071                                 // No special options
2072         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, product_id,
2073                         mod_data.release);
2074         return 36;
2075 }
2076
2077
2078 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2079 {
2080         struct lun      *curlun = fsg->curlun;
2081         u8              *buf = (u8 *) bh->buf;
2082         u32             sd, sdinfo;
2083
2084         /*
2085          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
2086          *
2087          * If a REQUEST SENSE command is received from an initiator
2088          * with a pending unit attention condition (before the target
2089          * generates the contingent allegiance condition), then the
2090          * target shall either:
2091          *   a) report any pending sense data and preserve the unit
2092          *      attention condition on the logical unit, or,
2093          *   b) report the unit attention condition, may discard any
2094          *      pending sense data, and clear the unit attention
2095          *      condition on the logical unit for that initiator.
2096          *
2097          * FSG normally uses option a); enable this code to use option b).
2098          */
2099 #if 0
2100         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
2101                 curlun->sense_data = curlun->unit_attention_data;
2102                 curlun->unit_attention_data = SS_NO_SENSE;
2103         }
2104 #endif
2105
2106         if (!curlun) {          // Unsupported LUNs are okay
2107                 fsg->bad_lun_okay = 1;
2108                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2109                 sdinfo = 0;
2110         } else {
2111                 sd = curlun->sense_data;
2112                 sdinfo = curlun->sense_data_info;
2113                 curlun->sense_data = SS_NO_SENSE;
2114                 curlun->sense_data_info = 0;
2115         }
2116
2117         memset(buf, 0, 18);
2118         buf[0] = 0x80 | 0x70;                   // Valid, current error
2119         buf[2] = SK(sd);
2120         put_be32(&buf[3], sdinfo);              // Sense information
2121         buf[7] = 18 - 8;                        // Additional sense length
2122         buf[12] = ASC(sd);
2123         buf[13] = ASCQ(sd);
2124         return 18;
2125 }
2126
2127
2128 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2129 {
2130         struct lun      *curlun = fsg->curlun;
2131         u32             lba = get_be32(&fsg->cmnd[2]);
2132         int             pmi = fsg->cmnd[8];
2133         u8              *buf = (u8 *) bh->buf;
2134
2135         /* Check the PMI and LBA fields */
2136         if (pmi > 1 || (pmi == 0 && lba != 0)) {
2137                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2138                 return -EINVAL;
2139         }
2140
2141         put_be32(&buf[0], curlun->num_sectors - 1);     // Max logical block
2142         put_be32(&buf[4], 512);                         // Block length
2143         return 8;
2144 }
2145
2146
2147 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2148 {
2149         struct lun      *curlun = fsg->curlun;
2150         int             mscmnd = fsg->cmnd[0];
2151         u8              *buf = (u8 *) bh->buf;
2152         u8              *buf0 = buf;
2153         int             pc, page_code;
2154         int             changeable_values, all_pages;
2155         int             valid_page = 0;
2156         int             len, limit;
2157
2158         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
2159                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2160                 return -EINVAL;
2161         }
2162         pc = fsg->cmnd[2] >> 6;
2163         page_code = fsg->cmnd[2] & 0x3f;
2164         if (pc == 3) {
2165                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
2166                 return -EINVAL;
2167         }
2168         changeable_values = (pc == 1);
2169         all_pages = (page_code == 0x3f);
2170
2171         /* Write the mode parameter header.  Fixed values are: default
2172          * medium type, no cache control (DPOFUA), and no block descriptors.
2173          * The only variable value is the WriteProtect bit.  We will fill in
2174          * the mode data length later. */
2175         memset(buf, 0, 8);
2176         if (mscmnd == SC_MODE_SENSE_6) {
2177                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2178                 buf += 4;
2179                 limit = 255;
2180         } else {                        // SC_MODE_SENSE_10
2181                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2182                 buf += 8;
2183                 limit = 65535;          // Should really be mod_data.buflen
2184         }
2185
2186         /* No block descriptors */
2187
2188         /* The mode pages, in numerical order.  The only page we support
2189          * is the Caching page. */
2190         if (page_code == 0x08 || all_pages) {
2191                 valid_page = 1;
2192                 buf[0] = 0x08;          // Page code
2193                 buf[1] = 10;            // Page length
2194                 memset(buf+2, 0, 10);   // None of the fields are changeable
2195
2196                 if (!changeable_values) {
2197                         buf[2] = 0x04;  // Write cache enable,
2198                                         // Read cache not disabled
2199                                         // No cache retention priorities
2200                         put_be16(&buf[4], 0xffff);  // Don't disable prefetch
2201                                         // Minimum prefetch = 0
2202                         put_be16(&buf[8], 0xffff);  // Maximum prefetch
2203                         put_be16(&buf[10], 0xffff); // Maximum prefetch ceiling
2204                 }
2205                 buf += 12;
2206         }
2207
2208         /* Check that a valid page was requested and the mode data length
2209          * isn't too long. */
2210         len = buf - buf0;
2211         if (!valid_page || len > limit) {
2212                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2213                 return -EINVAL;
2214         }
2215
2216         /*  Store the mode data length */
2217         if (mscmnd == SC_MODE_SENSE_6)
2218                 buf0[0] = len - 1;
2219         else
2220                 put_be16(buf0, len - 2);
2221         return len;
2222 }
2223
2224
2225 static int do_start_stop(struct fsg_dev *fsg)
2226 {
2227         struct lun      *curlun = fsg->curlun;
2228         int             loej, start;
2229
2230         if (!mod_data.removable) {
2231                 curlun->sense_data = SS_INVALID_COMMAND;
2232                 return -EINVAL;
2233         }
2234
2235         // int immed = fsg->cmnd[1] & 0x01;
2236         loej = fsg->cmnd[4] & 0x02;
2237         start = fsg->cmnd[4] & 0x01;
2238
2239 #ifdef CONFIG_USB_FILE_STORAGE_TEST
2240         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
2241                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
2242                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2243                 return -EINVAL;
2244         }
2245
2246         if (!start) {
2247
2248                 /* Are we allowed to unload the media? */
2249                 if (curlun->prevent_medium_removal) {
2250                         LDBG(curlun, "unload attempt prevented\n");
2251                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
2252                         return -EINVAL;
2253                 }
2254                 if (loej) {             // Simulate an unload/eject
2255                         up_read(&fsg->filesem);
2256                         down_write(&fsg->filesem);
2257                         close_backing_file(curlun);
2258                         up_write(&fsg->filesem);
2259                         down_read(&fsg->filesem);
2260                 }
2261         } else {
2262
2263                 /* Our emulation doesn't support mounting; the medium is
2264                  * available for use as soon as it is loaded. */
2265                 if (!backing_file_is_open(curlun)) {
2266                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2267                         return -EINVAL;
2268                 }
2269         }
2270 #endif
2271         return 0;
2272 }
2273
2274
2275 static int do_prevent_allow(struct fsg_dev *fsg)
2276 {
2277         struct lun      *curlun = fsg->curlun;
2278         int             prevent;
2279
2280         if (!mod_data.removable) {
2281                 curlun->sense_data = SS_INVALID_COMMAND;
2282                 return -EINVAL;
2283         }
2284
2285         prevent = fsg->cmnd[4] & 0x01;
2286         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
2287                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2288                 return -EINVAL;
2289         }
2290
2291         if (curlun->prevent_medium_removal && !prevent)
2292                 fsync_sub(curlun);
2293         curlun->prevent_medium_removal = prevent;
2294         return 0;
2295 }
2296
2297
2298 static int do_read_format_capacities(struct fsg_dev *fsg,
2299                         struct fsg_buffhd *bh)
2300 {
2301         struct lun      *curlun = fsg->curlun;
2302         u8              *buf = (u8 *) bh->buf;
2303
2304         buf[0] = buf[1] = buf[2] = 0;
2305         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
2306         buf += 4;
2307
2308         put_be32(&buf[0], curlun->num_sectors);         // Number of blocks
2309         put_be32(&buf[4], 512);                         // Block length
2310         buf[4] = 0x02;                                  // Current capacity
2311         return 12;
2312 }
2313
2314
2315 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2316 {
2317         struct lun      *curlun = fsg->curlun;
2318
2319         /* We don't support MODE SELECT */
2320         curlun->sense_data = SS_INVALID_COMMAND;
2321         return -EINVAL;
2322 }
2323
2324
2325 /*-------------------------------------------------------------------------*/
2326
2327 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
2328 {
2329         int     rc;
2330
2331         rc = fsg_set_halt(fsg, fsg->bulk_in);
2332         if (rc == -EAGAIN)
2333                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
2334         while (rc != 0) {
2335                 if (rc != -EAGAIN) {
2336                         WARN(fsg, "usb_ep_set_halt -> %d\n", rc);
2337                         rc = 0;
2338                         break;
2339                 }
2340
2341                 /* Wait for a short time and then try again */
2342                 if (msleep_interruptible(100) != 0)
2343                         return -EINTR;
2344                 rc = usb_ep_set_halt(fsg->bulk_in);
2345         }
2346         return rc;
2347 }
2348
2349 static int pad_with_zeros(struct fsg_dev *fsg)
2350 {
2351         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2352         u32                     nkeep = bh->inreq->length;
2353         u32                     nsend;
2354         int                     rc;
2355
2356         bh->state = BUF_STATE_EMPTY;            // For the first iteration
2357         fsg->usb_amount_left = nkeep + fsg->residue;
2358         while (fsg->usb_amount_left > 0) {
2359
2360                 /* Wait for the next buffer to be free */
2361                 while (bh->state != BUF_STATE_EMPTY) {
2362                         if ((rc = sleep_thread(fsg)) != 0)
2363                                 return rc;
2364                 }
2365
2366                 nsend = min(fsg->usb_amount_left, (u32) mod_data.buflen);
2367                 memset(bh->buf + nkeep, 0, nsend - nkeep);
2368                 bh->inreq->length = nsend;
2369                 bh->inreq->zero = 0;
2370                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2371                                 &bh->inreq_busy, &bh->state);
2372                 bh = fsg->next_buffhd_to_fill = bh->next;
2373                 fsg->usb_amount_left -= nsend;
2374                 nkeep = 0;
2375         }
2376         return 0;
2377 }
2378
2379 static int throw_away_data(struct fsg_dev *fsg)
2380 {
2381         struct fsg_buffhd       *bh;
2382         u32                     amount;
2383         int                     rc;
2384
2385         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
2386                         fsg->usb_amount_left > 0) {
2387
2388                 /* Throw away the data in a filled buffer */
2389                 if (bh->state == BUF_STATE_FULL) {
2390                         smp_rmb();
2391                         bh->state = BUF_STATE_EMPTY;
2392                         fsg->next_buffhd_to_drain = bh->next;
2393
2394                         /* A short packet or an error ends everything */
2395                         if (bh->outreq->actual != bh->outreq->length ||
2396                                         bh->outreq->status != 0) {
2397                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2398                                 return -EINTR;
2399                         }
2400                         continue;
2401                 }
2402
2403                 /* Try to submit another request if we need one */
2404                 bh = fsg->next_buffhd_to_fill;
2405                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
2406                         amount = min(fsg->usb_amount_left,
2407                                         (u32) mod_data.buflen);
2408
2409                         /* amount is always divisible by 512, hence by
2410                          * the bulk-out maxpacket size */
2411                         bh->outreq->length = bh->bulk_out_intended_length =
2412                                         amount;
2413                         bh->outreq->short_not_ok = 1;
2414                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2415                                         &bh->outreq_busy, &bh->state);
2416                         fsg->next_buffhd_to_fill = bh->next;
2417                         fsg->usb_amount_left -= amount;
2418                         continue;
2419                 }
2420
2421                 /* Otherwise wait for something to happen */
2422                 if ((rc = sleep_thread(fsg)) != 0)
2423                         return rc;
2424         }
2425         return 0;
2426 }
2427
2428
2429 static int finish_reply(struct fsg_dev *fsg)
2430 {
2431         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2432         int                     rc = 0;
2433
2434         switch (fsg->data_dir) {
2435         case DATA_DIR_NONE:
2436                 break;                  // Nothing to send
2437
2438         /* If we don't know whether the host wants to read or write,
2439          * this must be CB or CBI with an unknown command.  We mustn't
2440          * try to send or receive any data.  So stall both bulk pipes
2441          * if we can and wait for a reset. */
2442         case DATA_DIR_UNKNOWN:
2443                 if (mod_data.can_stall) {
2444                         fsg_set_halt(fsg, fsg->bulk_out);
2445                         rc = halt_bulk_in_endpoint(fsg);
2446                 }
2447                 break;
2448
2449         /* All but the last buffer of data must have already been sent */
2450         case DATA_DIR_TO_HOST:
2451                 if (fsg->data_size == 0)
2452                         ;               // Nothing to send
2453
2454                 /* If there's no residue, simply send the last buffer */
2455                 else if (fsg->residue == 0) {
2456                         bh->inreq->zero = 0;
2457                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2458                                         &bh->inreq_busy, &bh->state);
2459                         fsg->next_buffhd_to_fill = bh->next;
2460                 }
2461
2462                 /* There is a residue.  For CB and CBI, simply mark the end
2463                  * of the data with a short packet.  However, if we are
2464                  * allowed to stall, there was no data at all (residue ==
2465                  * data_size), and the command failed (invalid LUN or
2466                  * sense data is set), then halt the bulk-in endpoint
2467                  * instead. */
2468                 else if (!transport_is_bbb()) {
2469                         if (mod_data.can_stall &&
2470                                         fsg->residue == fsg->data_size &&
2471         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2472                                 bh->state = BUF_STATE_EMPTY;
2473                                 rc = halt_bulk_in_endpoint(fsg);
2474                         } else {
2475                                 bh->inreq->zero = 1;
2476                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2477                                                 &bh->inreq_busy, &bh->state);
2478                                 fsg->next_buffhd_to_fill = bh->next;
2479                         }
2480                 }
2481
2482                 /* For Bulk-only, if we're allowed to stall then send the
2483                  * short packet and halt the bulk-in endpoint.  If we can't
2484                  * stall, pad out the remaining data with 0's. */
2485                 else {
2486                         if (mod_data.can_stall) {
2487                                 bh->inreq->zero = 1;
2488                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2489                                                 &bh->inreq_busy, &bh->state);
2490                                 fsg->next_buffhd_to_fill = bh->next;
2491                                 rc = halt_bulk_in_endpoint(fsg);
2492                         } else
2493                                 rc = pad_with_zeros(fsg);
2494                 }
2495                 break;
2496
2497         /* We have processed all we want from the data the host has sent.
2498          * There may still be outstanding bulk-out requests. */
2499         case DATA_DIR_FROM_HOST:
2500                 if (fsg->residue == 0)
2501                         ;               // Nothing to receive
2502
2503                 /* Did the host stop sending unexpectedly early? */
2504                 else if (fsg->short_packet_received) {
2505                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2506                         rc = -EINTR;
2507                 }
2508
2509                 /* We haven't processed all the incoming data.  Even though
2510                  * we may be allowed to stall, doing so would cause a race.
2511                  * The controller may already have ACK'ed all the remaining
2512                  * bulk-out packets, in which case the host wouldn't see a
2513                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2514                  * clear the halt -- leading to problems later on. */
2515 #if 0
2516                 else if (mod_data.can_stall) {
2517                         fsg_set_halt(fsg, fsg->bulk_out);
2518                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2519                         rc = -EINTR;
2520                 }
2521 #endif
2522
2523                 /* We can't stall.  Read in the excess data and throw it
2524                  * all away. */
2525                 else
2526                         rc = throw_away_data(fsg);
2527                 break;
2528         }
2529         return rc;
2530 }
2531
2532
2533 static int send_status(struct fsg_dev *fsg)
2534 {
2535         struct lun              *curlun = fsg->curlun;
2536         struct fsg_buffhd       *bh;
2537         int                     rc;
2538         u8                      status = USB_STATUS_PASS;
2539         u32                     sd, sdinfo = 0;
2540
2541         /* Wait for the next buffer to become available */
2542         bh = fsg->next_buffhd_to_fill;
2543         while (bh->state != BUF_STATE_EMPTY) {
2544                 if ((rc = sleep_thread(fsg)) != 0)
2545                         return rc;
2546         }
2547
2548         if (curlun) {
2549                 sd = curlun->sense_data;
2550                 sdinfo = curlun->sense_data_info;
2551         } else if (fsg->bad_lun_okay)
2552                 sd = SS_NO_SENSE;
2553         else
2554                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2555
2556         if (fsg->phase_error) {
2557                 DBG(fsg, "sending phase-error status\n");
2558                 status = USB_STATUS_PHASE_ERROR;
2559                 sd = SS_INVALID_COMMAND;
2560         } else if (sd != SS_NO_SENSE) {
2561                 DBG(fsg, "sending command-failure status\n");
2562                 status = USB_STATUS_FAIL;
2563                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2564                                 "  info x%x\n",
2565                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2566         }
2567
2568         if (transport_is_bbb()) {
2569                 struct bulk_cs_wrap     *csw = (struct bulk_cs_wrap *) bh->buf;
2570
2571                 /* Store and send the Bulk-only CSW */
2572                 csw->Signature = __constant_cpu_to_le32(USB_BULK_CS_SIG);
2573                 csw->Tag = fsg->tag;
2574                 csw->Residue = cpu_to_le32(fsg->residue);
2575                 csw->Status = status;
2576
2577                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2578                 bh->inreq->zero = 0;
2579                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2580                                 &bh->inreq_busy, &bh->state);
2581
2582         } else if (mod_data.transport_type == USB_PR_CB) {
2583
2584                 /* Control-Bulk transport has no status phase! */
2585                 return 0;
2586
2587         } else {                        // USB_PR_CBI
2588                 struct interrupt_data   *buf = (struct interrupt_data *)
2589                                                 bh->buf;
2590
2591                 /* Store and send the Interrupt data.  UFI sends the ASC
2592                  * and ASCQ bytes.  Everything else sends a Type (which
2593                  * is always 0) and the status Value. */
2594                 if (mod_data.protocol_type == USB_SC_UFI) {
2595                         buf->bType = ASC(sd);
2596                         buf->bValue = ASCQ(sd);
2597                 } else {
2598                         buf->bType = 0;
2599                         buf->bValue = status;
2600                 }
2601                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2602
2603                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2604                 fsg->intreq->buf = bh->inreq->buf;
2605                 fsg->intreq->dma = bh->inreq->dma;
2606                 fsg->intreq->context = bh;
2607                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2608                                 &fsg->intreq_busy, &bh->state);
2609         }
2610
2611         fsg->next_buffhd_to_fill = bh->next;
2612         return 0;
2613 }
2614
2615
2616 /*-------------------------------------------------------------------------*/
2617
2618 /* Check whether the command is properly formed and whether its data size
2619  * and direction agree with the values we already have. */
2620 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2621                 enum data_direction data_dir, unsigned int mask,
2622                 int needs_medium, const char *name)
2623 {
2624         int                     i;
2625         int                     lun = fsg->cmnd[1] >> 5;
2626         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2627         char                    hdlen[20];
2628         struct lun              *curlun;
2629
2630         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2631          * Transparent SCSI doesn't pad. */
2632         if (protocol_is_scsi())
2633                 ;
2634
2635         /* There's some disagreement as to whether RBC pads commands or not.
2636          * We'll play it safe and accept either form. */
2637         else if (mod_data.protocol_type == USB_SC_RBC) {
2638                 if (fsg->cmnd_size == 12)
2639                         cmnd_size = 12;
2640
2641         /* All the other protocols pad to 12 bytes */
2642         } else
2643                 cmnd_size = 12;
2644
2645         hdlen[0] = 0;
2646         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2647                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2648                                 fsg->data_size);
2649         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2650                         name, cmnd_size, dirletter[(int) data_dir],
2651                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2652
2653         /* We can't reply at all until we know the correct data direction
2654          * and size. */
2655         if (fsg->data_size_from_cmnd == 0)
2656                 data_dir = DATA_DIR_NONE;
2657         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2658                 fsg->data_dir = data_dir;
2659                 fsg->data_size = fsg->data_size_from_cmnd;
2660
2661         } else {                                        // Bulk-only
2662                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2663
2664                         /* Host data size < Device data size is a phase error.
2665                          * Carry out the command, but only transfer as much
2666                          * as we are allowed. */
2667                         fsg->data_size_from_cmnd = fsg->data_size;
2668                         fsg->phase_error = 1;
2669                 }
2670         }
2671         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2672
2673         /* Conflicting data directions is a phase error */
2674         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2675                 fsg->phase_error = 1;
2676                 return -EINVAL;
2677         }
2678
2679         /* Verify the length of the command itself */
2680         if (cmnd_size != fsg->cmnd_size) {
2681
2682                 /* Special case workaround: MS-Windows issues REQUEST SENSE
2683                  * with cbw->Length == 12 (it should be 6). */
2684                 if (fsg->cmnd[0] == SC_REQUEST_SENSE && fsg->cmnd_size == 12)
2685                         cmnd_size = fsg->cmnd_size;
2686                 else {
2687                         fsg->phase_error = 1;
2688                         return -EINVAL;
2689                 }
2690         }
2691
2692         /* Check that the LUN values are consistent */
2693         if (transport_is_bbb()) {
2694                 if (fsg->lun != lun)
2695                         DBG(fsg, "using LUN %d from CBW, "
2696                                         "not LUN %d from CDB\n",
2697                                         fsg->lun, lun);
2698         } else
2699                 fsg->lun = lun;         // Use LUN from the command
2700
2701         /* Check the LUN */
2702         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
2703                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2704                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
2705                         curlun->sense_data = SS_NO_SENSE;
2706                         curlun->sense_data_info = 0;
2707                 }
2708         } else {
2709                 fsg->curlun = curlun = NULL;
2710                 fsg->bad_lun_okay = 0;
2711
2712                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2713                  * to use unsupported LUNs; all others may not. */
2714                 if (fsg->cmnd[0] != SC_INQUIRY &&
2715                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2716                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2717                         return -EINVAL;
2718                 }
2719         }
2720
2721         /* If a unit attention condition exists, only INQUIRY and
2722          * REQUEST SENSE commands are allowed; anything else must fail. */
2723         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2724                         fsg->cmnd[0] != SC_INQUIRY &&
2725                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2726                 curlun->sense_data = curlun->unit_attention_data;
2727                 curlun->unit_attention_data = SS_NO_SENSE;
2728                 return -EINVAL;
2729         }
2730
2731         /* Check that only command bytes listed in the mask are non-zero */
2732         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2733         for (i = 1; i < cmnd_size; ++i) {
2734                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2735                         if (curlun)
2736                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2737                         return -EINVAL;
2738                 }
2739         }
2740
2741         /* If the medium isn't mounted and the command needs to access
2742          * it, return an error. */
2743         if (curlun && !backing_file_is_open(curlun) && needs_medium) {
2744                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2745                 return -EINVAL;
2746         }
2747
2748         return 0;
2749 }
2750
2751
2752 static int do_scsi_command(struct fsg_dev *fsg)
2753 {
2754         struct fsg_buffhd       *bh;
2755         int                     rc;
2756         int                     reply = -EINVAL;
2757         int                     i;
2758         static char             unknown[16];
2759
2760         dump_cdb(fsg);
2761
2762         /* Wait for the next buffer to become available for data or status */
2763         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2764         while (bh->state != BUF_STATE_EMPTY) {
2765                 if ((rc = sleep_thread(fsg)) != 0)
2766                         return rc;
2767                 }
2768         fsg->phase_error = 0;
2769         fsg->short_packet_received = 0;
2770
2771         down_read(&fsg->filesem);       // We're using the backing file
2772         switch (fsg->cmnd[0]) {
2773
2774         case SC_INQUIRY:
2775                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2776                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2777                                 (1<<4), 0,
2778                                 "INQUIRY")) == 0)
2779                         reply = do_inquiry(fsg, bh);
2780                 break;
2781
2782         case SC_MODE_SELECT_6:
2783                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2784                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2785                                 (1<<1) | (1<<4), 0,
2786                                 "MODE SELECT(6)")) == 0)
2787                         reply = do_mode_select(fsg, bh);
2788                 break;
2789
2790         case SC_MODE_SELECT_10:
2791                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2792                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2793                                 (1<<1) | (3<<7), 0,
2794                                 "MODE SELECT(10)")) == 0)
2795                         reply = do_mode_select(fsg, bh);
2796                 break;
2797
2798         case SC_MODE_SENSE_6:
2799                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2800                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2801                                 (1<<1) | (1<<2) | (1<<4), 0,
2802                                 "MODE SENSE(6)")) == 0)
2803                         reply = do_mode_sense(fsg, bh);
2804                 break;
2805
2806         case SC_MODE_SENSE_10:
2807                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2808                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2809                                 (1<<1) | (1<<2) | (3<<7), 0,
2810                                 "MODE SENSE(10)")) == 0)
2811                         reply = do_mode_sense(fsg, bh);
2812                 break;
2813
2814         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2815                 fsg->data_size_from_cmnd = 0;
2816                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2817                                 (1<<4), 0,
2818                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2819                         reply = do_prevent_allow(fsg);
2820                 break;
2821
2822         case SC_READ_6:
2823                 i = fsg->cmnd[4];
2824                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2825                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2826                                 (7<<1) | (1<<4), 1,
2827                                 "READ(6)")) == 0)
2828                         reply = do_read(fsg);
2829                 break;
2830
2831         case SC_READ_10:
2832                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2833                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2834                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2835                                 "READ(10)")) == 0)
2836                         reply = do_read(fsg);
2837                 break;
2838
2839         case SC_READ_12:
2840                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2841                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2842                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2843                                 "READ(12)")) == 0)
2844                         reply = do_read(fsg);
2845                 break;
2846
2847         case SC_READ_CAPACITY:
2848                 fsg->data_size_from_cmnd = 8;
2849                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2850                                 (0xf<<2) | (1<<8), 1,
2851                                 "READ CAPACITY")) == 0)
2852                         reply = do_read_capacity(fsg, bh);
2853                 break;
2854
2855         case SC_READ_FORMAT_CAPACITIES:
2856                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2857                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2858                                 (3<<7), 1,
2859                                 "READ FORMAT CAPACITIES")) == 0)
2860                         reply = do_read_format_capacities(fsg, bh);
2861                 break;
2862
2863         case SC_REQUEST_SENSE:
2864                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2865                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2866                                 (1<<4), 0,
2867                                 "REQUEST SENSE")) == 0)
2868                         reply = do_request_sense(fsg, bh);
2869                 break;
2870
2871         case SC_START_STOP_UNIT:
2872                 fsg->data_size_from_cmnd = 0;
2873                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2874                                 (1<<1) | (1<<4), 0,
2875                                 "START-STOP UNIT")) == 0)
2876                         reply = do_start_stop(fsg);
2877                 break;
2878
2879         case SC_SYNCHRONIZE_CACHE:
2880                 fsg->data_size_from_cmnd = 0;
2881                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2882                                 (0xf<<2) | (3<<7), 1,
2883                                 "SYNCHRONIZE CACHE")) == 0)
2884                         reply = do_synchronize_cache(fsg);
2885                 break;
2886
2887         case SC_TEST_UNIT_READY:
2888                 fsg->data_size_from_cmnd = 0;
2889                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2890                                 0, 1,
2891                                 "TEST UNIT READY");
2892                 break;
2893
2894         /* Although optional, this command is used by MS-Windows.  We
2895          * support a minimal version: BytChk must be 0. */
2896         case SC_VERIFY:
2897                 fsg->data_size_from_cmnd = 0;
2898                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2899                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2900                                 "VERIFY")) == 0)
2901                         reply = do_verify(fsg);
2902                 break;
2903
2904         case SC_WRITE_6:
2905                 i = fsg->cmnd[4];
2906                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2907                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2908                                 (7<<1) | (1<<4), 1,
2909                                 "WRITE(6)")) == 0)
2910                         reply = do_write(fsg);
2911                 break;
2912
2913         case SC_WRITE_10:
2914                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2915                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2916                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2917                                 "WRITE(10)")) == 0)
2918                         reply = do_write(fsg);
2919                 break;
2920
2921         case SC_WRITE_12:
2922                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2923                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2924                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2925                                 "WRITE(12)")) == 0)
2926                         reply = do_write(fsg);
2927                 break;
2928
2929         /* Some mandatory commands that we recognize but don't implement.
2930          * They don't mean much in this setting.  It's left as an exercise
2931          * for anyone interested to implement RESERVE and RELEASE in terms
2932          * of Posix locks. */
2933         case SC_FORMAT_UNIT:
2934         case SC_RELEASE:
2935         case SC_RESERVE:
2936         case SC_SEND_DIAGNOSTIC:
2937                 // Fall through
2938
2939         default:
2940                 fsg->data_size_from_cmnd = 0;
2941                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2942                 if ((reply = check_command(fsg, fsg->cmnd_size,
2943                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2944                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2945                         reply = -EINVAL;
2946                 }
2947                 break;
2948         }
2949         up_read(&fsg->filesem);
2950
2951         if (reply == -EINTR || signal_pending(current))
2952                 return -EINTR;
2953
2954         /* Set up the single reply buffer for finish_reply() */
2955         if (reply == -EINVAL)
2956                 reply = 0;              // Error reply length
2957         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2958                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2959                 bh->inreq->length = reply;
2960                 bh->state = BUF_STATE_FULL;
2961                 fsg->residue -= reply;
2962         }                               // Otherwise it's already set
2963
2964         return 0;
2965 }
2966
2967
2968 /*-------------------------------------------------------------------------*/
2969
2970 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2971 {
2972         struct usb_request      *req = bh->outreq;
2973         struct bulk_cb_wrap     *cbw = (struct bulk_cb_wrap *) req->buf;
2974
2975         /* Was this a real packet? */
2976         if (req->status)
2977                 return -EINVAL;
2978
2979         /* Is the CBW valid? */
2980         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2981                         cbw->Signature != __constant_cpu_to_le32(
2982                                 USB_BULK_CB_SIG)) {
2983                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2984                                 req->actual,
2985                                 le32_to_cpu(cbw->Signature));
2986
2987                 /* The Bulk-only spec says we MUST stall the bulk pipes!
2988                  * If we want to avoid stalls, set a flag so that we will
2989                  * clear the endpoint halts at the next reset. */
2990                 if (!mod_data.can_stall)
2991                         set_bit(CLEAR_BULK_HALTS, &fsg->atomic_bitflags);
2992                 fsg_set_halt(fsg, fsg->bulk_out);
2993                 halt_bulk_in_endpoint(fsg);
2994                 return -EINVAL;
2995         }
2996
2997         /* Is the CBW meaningful? */
2998         if (cbw->Lun >= MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2999                         cbw->Length < 6 || cbw->Length > MAX_COMMAND_SIZE) {
3000                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
3001                                 "cmdlen %u\n",
3002                                 cbw->Lun, cbw->Flags, cbw->Length);
3003
3004                 /* We can do anything we want here, so let's stall the
3005                  * bulk pipes if we are allowed to. */
3006                 if (mod_data.can_stall) {
3007                         fsg_set_halt(fsg, fsg->bulk_out);
3008                         halt_bulk_in_endpoint(fsg);
3009                 }
3010                 return -EINVAL;
3011         }
3012
3013         /* Save the command for later */
3014         fsg->cmnd_size = cbw->Length;
3015         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
3016         if (cbw->Flags & USB_BULK_IN_FLAG)
3017                 fsg->data_dir = DATA_DIR_TO_HOST;
3018         else
3019                 fsg->data_dir = DATA_DIR_FROM_HOST;
3020         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
3021         if (fsg->data_size == 0)
3022                 fsg->data_dir = DATA_DIR_NONE;
3023         fsg->lun = cbw->Lun;
3024         fsg->tag = cbw->Tag;
3025         return 0;
3026 }
3027
3028
3029 static int get_next_command(struct fsg_dev *fsg)
3030 {
3031         struct fsg_buffhd       *bh;
3032         int                     rc = 0;
3033
3034         if (transport_is_bbb()) {
3035
3036                 /* Wait for the next buffer to become available */
3037                 bh = fsg->next_buffhd_to_fill;
3038                 while (bh->state != BUF_STATE_EMPTY) {
3039                         if ((rc = sleep_thread(fsg)) != 0)
3040                                 return rc;
3041                         }
3042
3043                 /* Queue a request to read a Bulk-only CBW */
3044                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
3045                 bh->outreq->short_not_ok = 1;
3046                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
3047                                 &bh->outreq_busy, &bh->state);
3048
3049                 /* We will drain the buffer in software, which means we
3050                  * can reuse it for the next filling.  No need to advance
3051                  * next_buffhd_to_fill. */
3052
3053                 /* Wait for the CBW to arrive */
3054                 while (bh->state != BUF_STATE_FULL) {
3055                         if ((rc = sleep_thread(fsg)) != 0)
3056                                 return rc;
3057                         }
3058                 smp_rmb();
3059                 rc = received_cbw(fsg, bh);
3060                 bh->state = BUF_STATE_EMPTY;
3061
3062         } else {                // USB_PR_CB or USB_PR_CBI
3063
3064                 /* Wait for the next command to arrive */
3065                 while (fsg->cbbuf_cmnd_size == 0) {
3066                         if ((rc = sleep_thread(fsg)) != 0)
3067                                 return rc;
3068                         }
3069
3070                 /* Is the previous status interrupt request still busy?
3071                  * The host is allowed to skip reading the status,
3072                  * so we must cancel it. */
3073                 if (fsg->intreq_busy)
3074                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3075
3076                 /* Copy the command and mark the buffer empty */
3077                 fsg->data_dir = DATA_DIR_UNKNOWN;
3078                 spin_lock_irq(&fsg->lock);
3079                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
3080                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
3081                 fsg->cbbuf_cmnd_size = 0;
3082                 spin_unlock_irq(&fsg->lock);
3083         }
3084         return rc;
3085 }
3086
3087
3088 /*-------------------------------------------------------------------------*/
3089
3090 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
3091                 const struct usb_endpoint_descriptor *d)
3092 {
3093         int     rc;
3094
3095         ep->driver_data = fsg;
3096         rc = usb_ep_enable(ep, d);
3097         if (rc)
3098                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
3099         return rc;
3100 }
3101
3102 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
3103                 struct usb_request **preq)
3104 {
3105         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
3106         if (*preq)
3107                 return 0;
3108         ERROR(fsg, "can't allocate request for %s\n", ep->name);
3109         return -ENOMEM;
3110 }
3111
3112 /*
3113  * Reset interface setting and re-init endpoint state (toggle etc).
3114  * Call with altsetting < 0 to disable the interface.  The only other
3115  * available altsetting is 0, which enables the interface.
3116  */
3117 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
3118 {
3119         int     rc = 0;
3120         int     i;
3121         const struct usb_endpoint_descriptor    *d;
3122
3123         if (fsg->running)
3124                 DBG(fsg, "reset interface\n");
3125
3126 reset:
3127         /* Deallocate the requests */
3128         for (i = 0; i < NUM_BUFFERS; ++i) {
3129                 struct fsg_buffhd *bh = &fsg->buffhds[i];
3130
3131                 if (bh->inreq) {
3132                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
3133                         bh->inreq = NULL;
3134                 }
3135                 if (bh->outreq) {
3136                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
3137                         bh->outreq = NULL;
3138                 }
3139         }
3140         if (fsg->intreq) {
3141                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
3142                 fsg->intreq = NULL;
3143         }
3144
3145         /* Disable the endpoints */
3146         if (fsg->bulk_in_enabled) {
3147                 usb_ep_disable(fsg->bulk_in);
3148                 fsg->bulk_in_enabled = 0;
3149         }
3150         if (fsg->bulk_out_enabled) {
3151                 usb_ep_disable(fsg->bulk_out);
3152                 fsg->bulk_out_enabled = 0;
3153         }
3154         if (fsg->intr_in_enabled) {
3155                 usb_ep_disable(fsg->intr_in);
3156                 fsg->intr_in_enabled = 0;
3157         }
3158
3159         fsg->running = 0;
3160         if (altsetting < 0 || rc != 0)
3161                 return rc;
3162
3163         DBG(fsg, "set interface %d\n", altsetting);
3164
3165         /* Enable the endpoints */
3166         d = ep_desc(fsg->gadget, &fs_bulk_in_desc, &hs_bulk_in_desc);
3167         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
3168                 goto reset;
3169         fsg->bulk_in_enabled = 1;
3170
3171         d = ep_desc(fsg->gadget, &fs_bulk_out_desc, &hs_bulk_out_desc);
3172         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
3173                 goto reset;
3174         fsg->bulk_out_enabled = 1;
3175         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
3176
3177         if (transport_is_cbi()) {
3178                 d = ep_desc(fsg->gadget, &fs_intr_in_desc, &hs_intr_in_desc);
3179                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
3180                         goto reset;
3181                 fsg->intr_in_enabled = 1;
3182         }
3183
3184         /* Allocate the requests */
3185         for (i = 0; i < NUM_BUFFERS; ++i) {
3186                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3187
3188                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
3189                         goto reset;
3190                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
3191                         goto reset;
3192                 bh->inreq->buf = bh->outreq->buf = bh->buf;
3193                 bh->inreq->dma = bh->outreq->dma = bh->dma;
3194                 bh->inreq->context = bh->outreq->context = bh;
3195                 bh->inreq->complete = bulk_in_complete;
3196                 bh->outreq->complete = bulk_out_complete;
3197         }
3198         if (transport_is_cbi()) {
3199                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
3200                         goto reset;
3201                 fsg->intreq->complete = intr_in_complete;
3202         }
3203
3204         fsg->running = 1;
3205         for (i = 0; i < fsg->nluns; ++i)
3206                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3207         return rc;
3208 }
3209
3210
3211 /*
3212  * Change our operational configuration.  This code must agree with the code
3213  * that returns config descriptors, and with interface altsetting code.
3214  *
3215  * It's also responsible for power management interactions.  Some
3216  * configurations might not work with our current power sources.
3217  * For now we just assume the gadget is always self-powered.
3218  */
3219 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
3220 {
3221         int     rc = 0;
3222
3223         /* Disable the single interface */
3224         if (fsg->config != 0) {
3225                 DBG(fsg, "reset config\n");
3226                 fsg->config = 0;
3227                 rc = do_set_interface(fsg, -1);
3228         }
3229
3230         /* Enable the interface */
3231         if (new_config != 0) {
3232                 fsg->config = new_config;
3233                 if ((rc = do_set_interface(fsg, 0)) != 0)
3234                         fsg->config = 0;        // Reset on errors
3235                 else {
3236                         char *speed;
3237
3238                         switch (fsg->gadget->speed) {
3239                         case USB_SPEED_LOW:     speed = "low";  break;
3240                         case USB_SPEED_FULL:    speed = "full"; break;
3241                         case USB_SPEED_HIGH:    speed = "high"; break;
3242                         default:                speed = "?";    break;
3243                         }
3244                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
3245                 }
3246         }
3247         return rc;
3248 }
3249
3250
3251 /*-------------------------------------------------------------------------*/
3252
3253 static void handle_exception(struct fsg_dev *fsg)
3254 {
3255         siginfo_t               info;
3256         int                     sig;
3257         int                     i;
3258         int                     num_active;
3259         struct fsg_buffhd       *bh;
3260         enum fsg_state          old_state;
3261         u8                      new_config;
3262         struct lun              *curlun;
3263         unsigned int            exception_req_tag;
3264         int                     rc;
3265
3266         /* Clear the existing signals.  Anything but SIGUSR1 is converted
3267          * into a high-priority EXIT exception. */
3268         for (;;) {
3269                 sig = dequeue_signal_lock(current, &fsg->thread_signal_mask,
3270                                 &info);
3271                 if (!sig)
3272                         break;
3273                 if (sig != SIGUSR1) {
3274                         if (fsg->state < FSG_STATE_EXIT)
3275                                 DBG(fsg, "Main thread exiting on signal\n");
3276                         raise_exception(fsg, FSG_STATE_EXIT);
3277                 }
3278         }
3279
3280         /* Cancel all the pending transfers */
3281         if (fsg->intreq_busy)
3282                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3283         for (i = 0; i < NUM_BUFFERS; ++i) {
3284                 bh = &fsg->buffhds[i];
3285                 if (bh->inreq_busy)
3286                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
3287                 if (bh->outreq_busy)
3288                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
3289         }
3290
3291         /* Wait until everything is idle */
3292         for (;;) {
3293                 num_active = fsg->intreq_busy;
3294                 for (i = 0; i < NUM_BUFFERS; ++i) {
3295                         bh = &fsg->buffhds[i];
3296                         num_active += bh->inreq_busy + bh->outreq_busy;
3297                 }
3298                 if (num_active == 0)
3299                         break;
3300                 if (sleep_thread(fsg))
3301                         return;
3302         }
3303
3304         /* Clear out the controller's fifos */
3305         if (fsg->bulk_in_enabled)
3306                 usb_ep_fifo_flush(fsg->bulk_in);
3307         if (fsg->bulk_out_enabled)
3308                 usb_ep_fifo_flush(fsg->bulk_out);
3309         if (fsg->intr_in_enabled)
3310                 usb_ep_fifo_flush(fsg->intr_in);
3311
3312         /* Reset the I/O buffer states and pointers, the SCSI
3313          * state, and the exception.  Then invoke the handler. */
3314         spin_lock_irq(&fsg->lock);
3315
3316         for (i = 0; i < NUM_BUFFERS; ++i) {
3317                 bh = &fsg->buffhds[i];
3318                 bh->state = BUF_STATE_EMPTY;
3319         }
3320         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
3321                         &fsg->buffhds[0];
3322
3323         exception_req_tag = fsg->exception_req_tag;
3324         new_config = fsg->new_config;
3325         old_state = fsg->state;
3326
3327         if (old_state == FSG_STATE_ABORT_BULK_OUT)
3328                 fsg->state = FSG_STATE_STATUS_PHASE;
3329         else {
3330                 for (i = 0; i < fsg->nluns; ++i) {
3331                         curlun = &fsg->luns[i];
3332                         curlun->prevent_medium_removal = 0;
3333                         curlun->sense_data = curlun->unit_attention_data =
3334                                         SS_NO_SENSE;
3335                         curlun->sense_data_info = 0;
3336                 }
3337                 fsg->state = FSG_STATE_IDLE;
3338         }
3339         spin_unlock_irq(&fsg->lock);
3340
3341         /* Carry out any extra actions required for the exception */
3342         switch (old_state) {
3343         default:
3344                 break;
3345
3346         case FSG_STATE_ABORT_BULK_OUT:
3347                 send_status(fsg);
3348                 spin_lock_irq(&fsg->lock);
3349                 if (fsg->state == FSG_STATE_STATUS_PHASE)
3350                         fsg->state = FSG_STATE_IDLE;
3351                 spin_unlock_irq(&fsg->lock);
3352                 break;
3353
3354         case FSG_STATE_RESET:
3355                 /* In case we were forced against our will to halt a
3356                  * bulk endpoint, clear the halt now.  (The SuperH UDC
3357                  * requires this.) */
3358                 if (test_and_clear_bit(CLEAR_BULK_HALTS,
3359                                 &fsg->atomic_bitflags)) {
3360                         usb_ep_clear_halt(fsg->bulk_in);
3361                         usb_ep_clear_halt(fsg->bulk_out);
3362                 }
3363
3364                 if (transport_is_bbb()) {
3365                         if (fsg->ep0_req_tag == exception_req_tag)
3366                                 ep0_queue(fsg); // Complete the status stage
3367
3368                 } else if (transport_is_cbi())
3369                         send_status(fsg);       // Status by interrupt pipe
3370
3371                 /* Technically this should go here, but it would only be
3372                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
3373                  * CONFIG_CHANGE cases. */
3374                 // for (i = 0; i < fsg->nluns; ++i)
3375                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3376                 break;
3377
3378         case FSG_STATE_INTERFACE_CHANGE:
3379                 rc = do_set_interface(fsg, 0);
3380                 if (fsg->ep0_req_tag != exception_req_tag)
3381                         break;
3382                 if (rc != 0)                    // STALL on errors
3383                         fsg_set_halt(fsg, fsg->ep0);
3384                 else                            // Complete the status stage
3385                         ep0_queue(fsg);
3386                 break;
3387
3388         case FSG_STATE_CONFIG_CHANGE:
3389                 rc = do_set_config(fsg, new_config);
3390                 if (fsg->ep0_req_tag != exception_req_tag)
3391                         break;
3392                 if (rc != 0)                    // STALL on errors
3393                         fsg_set_halt(fsg, fsg->ep0);
3394                 else                            // Complete the status stage
3395                         ep0_queue(fsg);
3396                 break;
3397
3398         case FSG_STATE_DISCONNECT:
3399                 fsync_all(fsg);
3400                 do_set_config(fsg, 0);          // Unconfigured state
3401                 break;
3402
3403         case FSG_STATE_EXIT:
3404         case FSG_STATE_TERMINATED:
3405                 do_set_config(fsg, 0);                  // Free resources
3406                 spin_lock_irq(&fsg->lock);
3407                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3408                 spin_unlock_irq(&fsg->lock);
3409                 break;
3410         }
3411 }
3412
3413
3414 /*-------------------------------------------------------------------------*/
3415
3416 static int fsg_main_thread(void *fsg_)
3417 {
3418         struct fsg_dev          *fsg = (struct fsg_dev *) fsg_;
3419
3420         /* Allow the thread to be killed by a signal, but set the signal mask
3421          * to block everything but INT, TERM, KILL, and USR1. */
3422         siginitsetinv(&fsg->thread_signal_mask, sigmask(SIGINT) |
3423                         sigmask(SIGTERM) | sigmask(SIGKILL) |
3424                         sigmask(SIGUSR1));
3425         sigprocmask(SIG_SETMASK, &fsg->thread_signal_mask, NULL);
3426
3427         /* Arrange for userspace references to be interpreted as kernel
3428          * pointers.  That way we can pass a kernel pointer to a routine
3429          * that expects a __user pointer and it will work okay. */
3430         set_fs(get_ds());
3431
3432         /* The main loop */
3433         while (fsg->state != FSG_STATE_TERMINATED) {
3434                 if (exception_in_progress(fsg) || signal_pending(current)) {
3435                         handle_exception(fsg);
3436                         continue;
3437                 }
3438
3439                 if (!fsg->running) {
3440                         sleep_thread(fsg);
3441                         continue;
3442                 }
3443
3444                 if (get_next_command(fsg))
3445                         continue;
3446
3447                 spin_lock_irq(&fsg->lock);
3448                 if (!exception_in_progress(fsg))
3449                         fsg->state = FSG_STATE_DATA_PHASE;
3450                 spin_unlock_irq(&fsg->lock);
3451
3452                 if (do_scsi_command(fsg) || finish_reply(fsg))
3453                         continue;
3454
3455                 spin_lock_irq(&fsg->lock);
3456                 if (!exception_in_progress(fsg))
3457                         fsg->state = FSG_STATE_STATUS_PHASE;
3458                 spin_unlock_irq(&fsg->lock);
3459
3460                 if (send_status(fsg))
3461                         continue;
3462
3463                 spin_lock_irq(&fsg->lock);
3464                 if (!exception_in_progress(fsg))
3465                         fsg->state = FSG_STATE_IDLE;
3466                 spin_unlock_irq(&fsg->lock);
3467                 }
3468
3469         spin_lock_irq(&fsg->lock);
3470         fsg->thread_task = NULL;
3471         spin_unlock_irq(&fsg->lock);
3472
3473         /* In case we are exiting because of a signal, unregister the
3474          * gadget driver and close the backing file. */
3475         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags)) {
3476                 usb_gadget_unregister_driver(&fsg_driver);
3477                 close_all_backing_files(fsg);
3478         }
3479
3480         /* Let the unbind and cleanup routines know the thread has exited */
3481         complete_and_exit(&fsg->thread_notifier, 0);
3482 }
3483
3484
3485 /*-------------------------------------------------------------------------*/
3486
3487 /* If the next two routines are called while the gadget is registered,
3488  * the caller must own fsg->filesem for writing. */
3489
3490 static int open_backing_file(struct lun *curlun, const char *filename)
3491 {
3492         int                             ro;
3493         struct file                     *filp = NULL;
3494         int                             rc = -EINVAL;
3495         struct inode                    *inode = NULL;
3496         loff_t                          size;
3497         loff_t                          num_sectors;
3498
3499         /* R/W if we can, R/O if we must */
3500         ro = curlun->ro;
3501         if (!ro) {
3502                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
3503                 if (-EROFS == PTR_ERR(filp))
3504                         ro = 1;
3505         }
3506         if (ro)
3507                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
3508         if (IS_ERR(filp)) {
3509                 LINFO(curlun, "unable to open backing file: %s\n", filename);
3510                 return PTR_ERR(filp);
3511         }
3512
3513         if (!(filp->f_mode & FMODE_WRITE))
3514                 ro = 1;
3515
3516         if (filp->f_dentry)
3517                 inode = filp->f_dentry->d_inode;
3518         if (inode && S_ISBLK(inode->i_mode)) {
3519                 if (bdev_read_only(inode->i_bdev))
3520                         ro = 1;
3521         } else if (!inode || !S_ISREG(inode->i_mode)) {
3522                 LINFO(curlun, "invalid file type: %s\n", filename);
3523                 goto out;
3524         }
3525
3526         /* If we can't read the file, it's no good.
3527          * If we can't write the file, use it read-only. */
3528         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
3529                 LINFO(curlun, "file not readable: %s\n", filename);
3530                 goto out;
3531         }
3532         if (!(filp->f_op->write || filp->f_op->aio_write))
3533                 ro = 1;
3534
3535         size = i_size_read(inode->i_mapping->host);
3536         if (size < 0) {
3537                 LINFO(curlun, "unable to find file size: %s\n", filename);
3538                 rc = (int) size;
3539                 goto out;
3540         }
3541         num_sectors = size >> 9;        // File size in 512-byte sectors
3542         if (num_sectors == 0) {
3543                 LINFO(curlun, "file too small: %s\n", filename);
3544                 rc = -ETOOSMALL;
3545                 goto out;
3546         }
3547
3548         get_file(filp);
3549         curlun->ro = ro;
3550         curlun->filp = filp;
3551         curlun->file_length = size;
3552         curlun->num_sectors = num_sectors;
3553         LDBG(curlun, "open backing file: %s\n", filename);
3554         rc = 0;
3555
3556 out:
3557         filp_close(filp, current->files);
3558         return rc;
3559 }
3560
3561
3562 static void close_backing_file(struct lun *curlun)
3563 {
3564         if (curlun->filp) {
3565                 LDBG(curlun, "close backing file\n");
3566                 fput(curlun->filp);
3567                 curlun->filp = NULL;
3568         }
3569 }
3570
3571 static void close_all_backing_files(struct fsg_dev *fsg)
3572 {
3573         int     i;
3574
3575         for (i = 0; i < fsg->nluns; ++i)
3576                 close_backing_file(&fsg->luns[i]);
3577 }
3578
3579
3580 static ssize_t show_ro(struct device *dev, struct device_attribute *attr, char *buf)
3581 {
3582         struct lun      *curlun = dev_to_lun(dev);
3583
3584         return sprintf(buf, "%d\n", curlun->ro);
3585 }
3586
3587 static ssize_t show_file(struct device *dev, struct device_attribute *attr, char *buf)
3588 {
3589         struct lun      *curlun = dev_to_lun(dev);
3590         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3591         char            *p;
3592         ssize_t         rc;
3593
3594         down_read(&fsg->filesem);
3595         if (backing_file_is_open(curlun)) {     // Get the complete pathname
3596                 p = d_path(curlun->filp->f_dentry, curlun->filp->f_vfsmnt,
3597                                 buf, PAGE_SIZE - 1);
3598                 if (IS_ERR(p))
3599                         rc = PTR_ERR(p);
3600                 else {
3601                         rc = strlen(p);
3602                         memmove(buf, p, rc);
3603                         buf[rc] = '\n';         // Add a newline
3604                         buf[++rc] = 0;
3605                 }
3606         } else {                                // No file, return 0 bytes
3607                 *buf = 0;
3608                 rc = 0;
3609         }
3610         up_read(&fsg->filesem);
3611         return rc;
3612 }
3613
3614
3615 static ssize_t store_ro(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
3616 {
3617         ssize_t         rc = count;
3618         struct lun      *curlun = dev_to_lun(dev);
3619         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3620         int             i;
3621
3622         if (sscanf(buf, "%d", &i) != 1)
3623                 return -EINVAL;
3624
3625         /* Allow the write-enable status to change only while the backing file
3626          * is closed. */
3627         down_read(&fsg->filesem);
3628         if (backing_file_is_open(curlun)) {
3629                 LDBG(curlun, "read-only status change prevented\n");
3630                 rc = -EBUSY;
3631         } else {
3632                 curlun->ro = !!i;
3633                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
3634         }
3635         up_read(&fsg->filesem);
3636         return rc;
3637 }
3638
3639 static ssize_t store_file(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
3640 {
3641         struct lun      *curlun = dev_to_lun(dev);
3642         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3643         int             rc = 0;
3644
3645         if (curlun->prevent_medium_removal && backing_file_is_open(curlun)) {
3646                 LDBG(curlun, "eject attempt prevented\n");
3647                 return -EBUSY;                          // "Door is locked"
3648         }
3649
3650         /* Remove a trailing newline */
3651         if (count > 0 && buf[count-1] == '\n')
3652                 ((char *) buf)[count-1] = 0;            // Ugh!
3653
3654         /* Eject current medium */
3655         down_write(&fsg->filesem);
3656         if (backing_file_is_open(curlun)) {
3657                 close_backing_file(curlun);
3658                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
3659         }
3660
3661         /* Load new medium */
3662         if (count > 0 && buf[0]) {
3663                 rc = open_backing_file(curlun, buf);
3664                 if (rc == 0)
3665                         curlun->unit_attention_data =
3666                                         SS_NOT_READY_TO_READY_TRANSITION;
3667         }
3668         up_write(&fsg->filesem);
3669         return (rc < 0 ? rc : count);
3670 }
3671
3672
3673 /* The write permissions and store_xxx pointers are set in fsg_bind() */
3674 static DEVICE_ATTR(ro, 0444, show_ro, NULL);
3675 static DEVICE_ATTR(file, 0444, show_file, NULL);
3676
3677
3678 /*-------------------------------------------------------------------------*/
3679
3680 static void fsg_release(struct kref *ref)
3681 {
3682         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
3683
3684         kfree(fsg->luns);
3685         kfree(fsg);
3686 }
3687
3688 static void lun_release(struct device *dev)
3689 {
3690         struct fsg_dev  *fsg = (struct fsg_dev *) dev_get_drvdata(dev);
3691
3692         kref_put(&fsg->ref, fsg_release);
3693 }
3694
3695 static void __exit fsg_unbind(struct usb_gadget *gadget)
3696 {
3697         struct fsg_dev          *fsg = get_gadget_data(gadget);
3698         int                     i;
3699         struct lun              *curlun;
3700         struct usb_request      *req = fsg->ep0req;
3701
3702         DBG(fsg, "unbind\n");
3703         clear_bit(REGISTERED, &fsg->atomic_bitflags);
3704
3705         /* Unregister the sysfs attribute files and the LUNs */
3706         for (i = 0; i < fsg->nluns; ++i) {
3707                 curlun = &fsg->luns[i];
3708                 if (curlun->registered) {
3709                         device_remove_file(&curlun->dev, &dev_attr_ro);
3710                         device_remove_file(&curlun->dev, &dev_attr_file);
3711                         device_unregister(&curlun->dev);
3712                         curlun->registered = 0;
3713                 }
3714         }
3715
3716         /* If the thread isn't already dead, tell it to exit now */
3717         if (fsg->state != FSG_STATE_TERMINATED) {
3718                 raise_exception(fsg, FSG_STATE_EXIT);
3719                 wait_for_completion(&fsg->thread_notifier);
3720
3721                 /* The cleanup routine waits for this completion also */
3722                 complete(&fsg->thread_notifier);
3723         }
3724
3725         /* Free the data buffers */
3726         for (i = 0; i < NUM_BUFFERS; ++i) {
3727                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3728
3729                 if (bh->buf)
3730                         usb_ep_free_buffer(fsg->bulk_in, bh->buf, bh->dma,
3731                                         mod_data.buflen);
3732         }
3733
3734         /* Free the request and buffer for endpoint 0 */
3735         if (req) {
3736                 if (req->buf)
3737                         usb_ep_free_buffer(fsg->ep0, req->buf,
3738                                         req->dma, EP0_BUFSIZE);
3739                 usb_ep_free_request(fsg->ep0, req);
3740         }
3741
3742         set_gadget_data(gadget, NULL);
3743 }
3744
3745
3746 static int __init check_parameters(struct fsg_dev *fsg)
3747 {
3748         int     prot;
3749         int     gcnum;
3750
3751         /* Store the default values */
3752         mod_data.transport_type = USB_PR_BULK;
3753         mod_data.transport_name = "Bulk-only";
3754         mod_data.protocol_type = USB_SC_SCSI;
3755         mod_data.protocol_name = "Transparent SCSI";
3756
3757         if (gadget_is_sh(fsg->gadget))
3758                 mod_data.can_stall = 0;
3759
3760         if (mod_data.release == 0xffff) {       // Parameter wasn't set
3761                 /* The sa1100 controller is not supported */
3762                 if (gadget_is_sa1100(fsg->gadget))
3763                         gcnum = -1;
3764                 else
3765                         gcnum = usb_gadget_controller_number(fsg->gadget);
3766                 if (gcnum >= 0)
3767                         mod_data.release = 0x0300 + gcnum;
3768                 else {
3769                         WARN(fsg, "controller '%s' not recognized\n",
3770                                 fsg->gadget->name);
3771                         mod_data.release = 0x0399;
3772                 }
3773         }
3774
3775         prot = simple_strtol(mod_data.protocol_parm, NULL, 0);
3776
3777 #ifdef CONFIG_USB_FILE_STORAGE_TEST
3778         if (strnicmp(mod_data.transport_parm, "BBB", 10) == 0) {
3779                 ;               // Use default setting
3780         } else if (strnicmp(mod_data.transport_parm, "CB", 10) == 0) {
3781                 mod_data.transport_type = USB_PR_CB;
3782                 mod_data.transport_name = "Control-Bulk";
3783         } else if (strnicmp(mod_data.transport_parm, "CBI", 10) == 0) {
3784                 mod_data.transport_type = USB_PR_CBI;
3785                 mod_data.transport_name = "Control-Bulk-Interrupt";
3786         } else {
3787                 ERROR(fsg, "invalid transport: %s\n", mod_data.transport_parm);
3788                 return -EINVAL;
3789         }
3790
3791         if (strnicmp(mod_data.protocol_parm, "SCSI", 10) == 0 ||
3792                         prot == USB_SC_SCSI) {
3793                 ;               // Use default setting
3794         } else if (strnicmp(mod_data.protocol_parm, "RBC", 10) == 0 ||
3795                         prot == USB_SC_RBC) {
3796                 mod_data.protocol_type = USB_SC_RBC;
3797                 mod_data.protocol_name = "RBC";
3798         } else if (strnicmp(mod_data.protocol_parm, "8020", 4) == 0 ||
3799                         strnicmp(mod_data.protocol_parm, "ATAPI", 10) == 0 ||
3800                         prot == USB_SC_8020) {
3801                 mod_data.protocol_type = USB_SC_8020;
3802                 mod_data.protocol_name = "8020i (ATAPI)";
3803         } else if (strnicmp(mod_data.protocol_parm, "QIC", 3) == 0 ||
3804                         prot == USB_SC_QIC) {
3805                 mod_data.protocol_type = USB_SC_QIC;
3806                 mod_data.protocol_name = "QIC-157";
3807         } else if (strnicmp(mod_data.protocol_parm, "UFI", 10) == 0 ||
3808                         prot == USB_SC_UFI) {
3809                 mod_data.protocol_type = USB_SC_UFI;
3810                 mod_data.protocol_name = "UFI";
3811         } else if (strnicmp(mod_data.protocol_parm, "8070", 4) == 0 ||
3812                         prot == USB_SC_8070) {
3813                 mod_data.protocol_type = USB_SC_8070;
3814                 mod_data.protocol_name = "8070i";
3815         } else {
3816                 ERROR(fsg, "invalid protocol: %s\n", mod_data.protocol_parm);
3817                 return -EINVAL;
3818         }
3819
3820         mod_data.buflen &= PAGE_CACHE_MASK;
3821         if (mod_data.buflen <= 0) {
3822                 ERROR(fsg, "invalid buflen\n");
3823                 return -ETOOSMALL;
3824         }
3825 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
3826
3827         return 0;
3828 }
3829
3830
3831 static int __init fsg_bind(struct usb_gadget *gadget)
3832 {
3833         struct fsg_dev          *fsg = the_fsg;
3834         int                     rc;
3835         int                     i;
3836         struct lun              *curlun;
3837         struct usb_ep           *ep;
3838         struct usb_request      *req;
3839         char                    *pathbuf, *p;
3840
3841         fsg->gadget = gadget;
3842         set_gadget_data(gadget, fsg);
3843         fsg->ep0 = gadget->ep0;
3844         fsg->ep0->driver_data = fsg;
3845
3846         if ((rc = check_parameters(fsg)) != 0)
3847                 goto out;
3848
3849         if (mod_data.removable) {       // Enable the store_xxx attributes
3850                 dev_attr_ro.attr.mode = dev_attr_file.attr.mode = 0644;
3851                 dev_attr_ro.store = store_ro;
3852                 dev_attr_file.store = store_file;
3853         }
3854
3855         /* Find out how many LUNs there should be */
3856         i = mod_data.nluns;
3857         if (i == 0)
3858                 i = max(mod_data.num_filenames, 1);
3859         if (i > MAX_LUNS) {
3860                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
3861                 rc = -EINVAL;
3862                 goto out;
3863         }
3864
3865         /* Create the LUNs, open their backing files, and register the
3866          * LUN devices in sysfs. */
3867         fsg->luns = kzalloc(i * sizeof(struct lun), GFP_KERNEL);
3868         if (!fsg->luns) {
3869                 rc = -ENOMEM;
3870                 goto out;
3871         }
3872         fsg->nluns = i;
3873
3874         for (i = 0; i < fsg->nluns; ++i) {
3875                 curlun = &fsg->luns[i];
3876                 curlun->ro = mod_data.ro[i];
3877                 curlun->dev.parent = &gadget->dev;
3878                 curlun->dev.driver = &fsg_driver.driver;
3879                 dev_set_drvdata(&curlun->dev, fsg);
3880                 snprintf(curlun->dev.bus_id, BUS_ID_SIZE,
3881                                 "%s-lun%d", gadget->dev.bus_id, i);
3882
3883                 if ((rc = device_register(&curlun->dev)) != 0)
3884                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
3885                 else {
3886                         curlun->registered = 1;
3887                         curlun->dev.release = lun_release;
3888                         device_create_file(&curlun->dev, &dev_attr_ro);
3889                         device_create_file(&curlun->dev, &dev_attr_file);
3890                         kref_get(&fsg->ref);
3891                 }
3892
3893                 if (mod_data.file[i] && *mod_data.file[i]) {
3894                         if ((rc = open_backing_file(curlun,
3895                                         mod_data.file[i])) != 0)
3896                                 goto out;
3897                 } else if (!mod_data.removable) {
3898                         ERROR(fsg, "no file given for LUN%d\n", i);
3899                         rc = -EINVAL;
3900                         goto out;
3901                 }
3902         }
3903
3904         /* Find all the endpoints we will use */
3905         usb_ep_autoconfig_reset(gadget);
3906         ep = usb_ep_autoconfig(gadget, &fs_bulk_in_desc);
3907         if (!ep)
3908                 goto autoconf_fail;
3909         ep->driver_data = fsg;          // claim the endpoint
3910         fsg->bulk_in = ep;
3911
3912         ep = usb_ep_autoconfig(gadget, &fs_bulk_out_desc);
3913         if (!ep)
3914                 goto autoconf_fail;
3915         ep->driver_data = fsg;          // claim the endpoint
3916         fsg->bulk_out = ep;
3917
3918         if (transport_is_cbi()) {
3919                 ep = usb_ep_autoconfig(gadget, &fs_intr_in_desc);
3920                 if (!ep)
3921                         goto autoconf_fail;
3922                 ep->driver_data = fsg;          // claim the endpoint
3923                 fsg->intr_in = ep;
3924         }
3925
3926         /* Fix up the descriptors */
3927         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
3928         device_desc.idVendor = cpu_to_le16(mod_data.vendor);
3929         device_desc.idProduct = cpu_to_le16(mod_data.product);
3930         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
3931
3932         i = (transport_is_cbi() ? 3 : 2);       // Number of endpoints
3933         intf_desc.bNumEndpoints = i;
3934         intf_desc.bInterfaceSubClass = mod_data.protocol_type;
3935         intf_desc.bInterfaceProtocol = mod_data.transport_type;
3936         fs_function[i + FS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3937
3938 #ifdef CONFIG_USB_GADGET_DUALSPEED
3939         hs_function[i + HS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3940
3941         /* Assume ep0 uses the same maxpacket value for both speeds */
3942         dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
3943
3944         /* Assume that all endpoint addresses are the same for both speeds */
3945         hs_bulk_in_desc.bEndpointAddress = fs_bulk_in_desc.bEndpointAddress;
3946         hs_bulk_out_desc.bEndpointAddress = fs_bulk_out_desc.bEndpointAddress;
3947         hs_intr_in_desc.bEndpointAddress = fs_intr_in_desc.bEndpointAddress;
3948 #endif
3949
3950         if (gadget->is_otg) {
3951                 otg_desc.bmAttributes |= USB_OTG_HNP,
3952                 config_desc.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
3953         }
3954
3955         rc = -ENOMEM;
3956
3957         /* Allocate the request and buffer for endpoint 0 */
3958         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
3959         if (!req)
3960                 goto out;
3961         req->buf = usb_ep_alloc_buffer(fsg->ep0, EP0_BUFSIZE,
3962                         &req->dma, GFP_KERNEL);
3963         if (!req->buf)
3964                 goto out;
3965         req->complete = ep0_complete;
3966
3967         /* Allocate the data buffers */
3968         for (i = 0; i < NUM_BUFFERS; ++i) {
3969                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3970
3971                 /* Allocate for the bulk-in endpoint.  We assume that
3972                  * the buffer will also work with the bulk-out (and
3973                  * interrupt-in) endpoint. */
3974                 bh->buf = usb_ep_alloc_buffer(fsg->bulk_in, mod_data.buflen,
3975                                 &bh->dma, GFP_KERNEL);
3976                 if (!bh->buf)
3977                         goto out;
3978                 bh->next = bh + 1;
3979         }
3980         fsg->buffhds[NUM_BUFFERS - 1].next = &fsg->buffhds[0];
3981
3982         /* This should reflect the actual gadget power source */
3983         usb_gadget_set_selfpowered(gadget);
3984
3985         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
3986                         system_utsname.sysname, system_utsname.release,
3987                         gadget->name);
3988
3989         /* On a real device, serial[] would be loaded from permanent
3990          * storage.  We just encode it from the driver version string. */
3991         for (i = 0; i < sizeof(serial) - 2; i += 2) {
3992                 unsigned char           c = DRIVER_VERSION[i / 2];
3993
3994                 if (!c)
3995                         break;
3996                 sprintf(&serial[i], "%02X", c);
3997         }
3998
3999         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
4000                         "file-storage-gadget");
4001         if (IS_ERR(fsg->thread_task)) {
4002                 rc = PTR_ERR(fsg->thread_task);
4003                 goto out;
4004         }
4005
4006         INFO(fsg, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
4007         INFO(fsg, "Number of LUNs=%d\n", fsg->nluns);
4008
4009         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
4010         for (i = 0; i < fsg->nluns; ++i) {
4011                 curlun = &fsg->luns[i];
4012                 if (backing_file_is_open(curlun)) {
4013                         p = NULL;
4014                         if (pathbuf) {
4015                                 p = d_path(curlun->filp->f_dentry,
4016                                         curlun->filp->f_vfsmnt,
4017                                         pathbuf, PATH_MAX);
4018                                 if (IS_ERR(p))
4019                                         p = NULL;
4020                         }
4021                         LINFO(curlun, "ro=%d, file: %s\n",
4022                                         curlun->ro, (p ? p : "(error)"));
4023                 }
4024         }
4025         kfree(pathbuf);
4026
4027         DBG(fsg, "transport=%s (x%02x)\n",
4028                         mod_data.transport_name, mod_data.transport_type);
4029         DBG(fsg, "protocol=%s (x%02x)\n",
4030                         mod_data.protocol_name, mod_data.protocol_type);
4031         DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n",
4032                         mod_data.vendor, mod_data.product, mod_data.release);
4033         DBG(fsg, "removable=%d, stall=%d, buflen=%u\n",
4034                         mod_data.removable, mod_data.can_stall,
4035                         mod_data.buflen);
4036         DBG(fsg, "I/O thread pid: %d\n", fsg->thread_task->pid);
4037
4038         set_bit(REGISTERED, &fsg->atomic_bitflags);
4039
4040         /* Tell the thread to start working */
4041         wake_up_process(fsg->thread_task);
4042         return 0;
4043
4044 autoconf_fail:
4045         ERROR(fsg, "unable to autoconfigure all endpoints\n");
4046         rc = -ENOTSUPP;
4047
4048 out:
4049         fsg->state = FSG_STATE_TERMINATED;      // The thread is dead
4050         fsg_unbind(gadget);
4051         close_all_backing_files(fsg);
4052         return rc;
4053 }
4054
4055
4056 /*-------------------------------------------------------------------------*/
4057
4058 static void fsg_suspend(struct usb_gadget *gadget)
4059 {
4060         struct fsg_dev          *fsg = get_gadget_data(gadget);
4061
4062         DBG(fsg, "suspend\n");
4063         set_bit(SUSPENDED, &fsg->atomic_bitflags);
4064 }
4065
4066 static void fsg_resume(struct usb_gadget *gadget)
4067 {
4068         struct fsg_dev          *fsg = get_gadget_data(gadget);
4069
4070         DBG(fsg, "resume\n");
4071         clear_bit(SUSPENDED, &fsg->atomic_bitflags);
4072 }
4073
4074
4075 /*-------------------------------------------------------------------------*/
4076
4077 static struct usb_gadget_driver         fsg_driver = {
4078 #ifdef CONFIG_USB_GADGET_DUALSPEED
4079         .speed          = USB_SPEED_HIGH,
4080 #else
4081         .speed          = USB_SPEED_FULL,
4082 #endif
4083         .function       = (char *) longname,
4084         .bind           = fsg_bind,
4085         .unbind         = __exit_p(fsg_unbind),
4086         .disconnect     = fsg_disconnect,
4087         .setup          = fsg_setup,
4088         .suspend        = fsg_suspend,
4089         .resume         = fsg_resume,
4090
4091         .driver         = {
4092                 .name           = (char *) shortname,
4093                 .owner          = THIS_MODULE,
4094                 // .release = ...
4095                 // .suspend = ...
4096                 // .resume = ...
4097         },
4098 };
4099
4100
4101 static int __init fsg_alloc(void)
4102 {
4103         struct fsg_dev          *fsg;
4104
4105         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
4106         if (!fsg)
4107                 return -ENOMEM;
4108         spin_lock_init(&fsg->lock);
4109         init_rwsem(&fsg->filesem);
4110         kref_init(&fsg->ref);
4111         init_completion(&fsg->thread_notifier);
4112
4113         the_fsg = fsg;
4114         return 0;
4115 }
4116
4117
4118 static int __init fsg_init(void)
4119 {
4120         int             rc;
4121         struct fsg_dev  *fsg;
4122
4123         if ((rc = fsg_alloc()) != 0)
4124                 return rc;
4125         fsg = the_fsg;
4126         if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
4127                 kref_put(&fsg->ref, fsg_release);
4128         return rc;
4129 }
4130 module_init(fsg_init);
4131
4132
4133 static void __exit fsg_cleanup(void)
4134 {
4135         struct fsg_dev  *fsg = the_fsg;
4136
4137         /* Unregister the driver iff the thread hasn't already done so */
4138         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
4139                 usb_gadget_unregister_driver(&fsg_driver);
4140
4141         /* Wait for the thread to finish up */
4142         wait_for_completion(&fsg->thread_notifier);
4143
4144         close_all_backing_files(fsg);
4145         kref_put(&fsg->ref, fsg_release);
4146 }
4147 module_exit(fsg_cleanup);