drivers/usb/gadget/file_storage.c

   1 /*
   2  * file_storage.c -- File-backed USB Storage Gadget, for USB development
   3  *
   4  * Copyright (C) 2003-2007 Alan Stern
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions, and the following disclaimer,
  12  *    without modification.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The names of the above-listed copyright holders may not be used
  17  *    to endorse or promote products derived from this software without
  18  *    specific prior written permission.
  19  *
  20  * ALTERNATIVELY, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") as published by the Free Software
  22  * Foundation, either version 2 of that License or (at your option) any
  23  * later version.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  26  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  27  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  29  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  30  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  32  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  35  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 /*
  40  * The File-backed Storage Gadget acts as a USB Mass Storage device,
  41  * appearing to the host as a disk drive.  In addition to providing an
  42  * example of a genuinely useful gadget driver for a USB device, it also
  43  * illustrates a technique of double-buffering for increased throughput.
  44  * Last but not least, it gives an easy way to probe the behavior of the
  45  * Mass Storage drivers in a USB host.
  46  *
  47  * Backing storage is provided by a regular file or a block device, specified
  48  * by the "file" module parameter.  Access can be limited to read-only by
  49  * setting the optional "ro" module parameter.  The gadget will indicate that
  50  * it has removable media if the optional "removable" module parameter is set.
  51  *
  52  * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI),
  53  * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected
  54  * by the optional "transport" module parameter.  It also supports the
  55  * following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03),
  56  * UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
  57  * the optional "protocol" module parameter.  In addition, the default
  58  * Vendor ID, Product ID, and release number can be overridden.
  59  *
  60  * There is support for multiple logical units (LUNs), each of which has
  61  * its own backing file.  The number of LUNs can be set using the optional
  62  * "luns" module parameter (anywhere from 1 to 8), and the corresponding
  63  * files are specified using comma-separated lists for "file" and "ro".
  64  * The default number of LUNs is taken from the number of "file" elements;
  65  * it is 1 if "file" is not given.  If "removable" is not set then a backing
  66  * file must be specified for each LUN.  If it is set, then an unspecified
  67  * or empty backing filename means the LUN's medium is not loaded.
  68  *
  69  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
  70  * needed (an interrupt-out endpoint is also needed for CBI).  The memory
  71  * requirement amounts to two 16K buffers, size configurable by a parameter.
  72  * Support is included for both full-speed and high-speed operation.
  73  *
  74  * Note that the driver is slightly non-portable in that it assumes a
  75  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
  76  * interrupt-in endpoints.  With most device controllers this isn't an
  77  * issue, but there may be some with hardware restrictions that prevent
  78  * a buffer from being used by more than one endpoint.
  79  *
  80  * Module options:
  81  *
  82  *      file=filename[,filename...]
  83  *                              Required if "removable" is not set, names of
  84  *                                      the files or block devices used for
  85  *                                      backing storage
  86  *      ro=b[,b...]             Default false, booleans for read-only access
  87  *      removable               Default false, boolean for removable media
  88  *      luns=N                  Default N = number of filenames, number of
  89  *                                      LUNs to support
  90  *      stall                   Default determined according to the type of
  91  *                                      USB device controller (usually true),
  92  *                                      boolean to permit the driver to halt
  93  *                                      bulk endpoints
  94  *      transport=XXX           Default BBB, transport name (CB, CBI, or BBB)
  95  *      protocol=YYY            Default SCSI, protocol name (RBC, 8020 or
  96  *                                      ATAPI, QIC, UFI, 8070, or SCSI;
  97  *                                      also 1 - 6)
  98  *      vendor=0xVVVV           Default 0x0525 (NetChip), USB Vendor ID
  99  *      product=0xPPPP          Default 0xa4a5 (FSG), USB Product ID
 100  *      release=0xRRRR          Override the USB release number (bcdDevice)
 101  *      buflen=N                Default N=16384, buffer size used (will be
 102  *                                      rounded down to a multiple of
 103  *                                      PAGE_CACHE_SIZE)
 104  *
 105  * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro",
 106  * "removable", "luns", and "stall" options are available; default values
 107  * are used for everything else.
 108  *
 109  * The pathnames of the backing files and the ro settings are available in
 110  * the attribute files "file" and "ro" in the lun<n> subdirectory of the
 111  * gadget's sysfs directory.  If the "removable" option is set, writing to
 112  * these files will simulate ejecting/loading the medium (writing an empty
 113  * line means eject) and adjusting a write-enable tab.  Changes to the ro
 114  * setting are not allowed when the medium is loaded.
 115  *
 116  * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
 117  * The driver's SCSI command interface was based on the "Information
 118  * technology - Small Computer System Interface - 2" document from
 119  * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
 120  * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.  The single exception
 121  * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
 122  * "Universal Serial Bus Mass Storage Class UFI Command Specification"
 123  * document, Revision 1.0, December 14, 1998, available at
 124  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
 125  */
 126
 127
 128 /*
 129  *                              Driver Design
 130  *
 131  * The FSG driver is fairly straightforward.  There is a main kernel
 132  * thread that handles most of the work.  Interrupt routines field
 133  * callbacks from the controller driver: bulk- and interrupt-request
 134  * completion notifications, endpoint-0 events, and disconnect events.
 135  * Completion events are passed to the main thread by wakeup calls.  Many
 136  * ep0 requests are handled at interrupt time, but SetInterface,
 137  * SetConfiguration, and device reset requests are forwarded to the
 138  * thread in the form of "exceptions" using SIGUSR1 signals (since they
 139  * should interrupt any ongoing file I/O operations).
 140  *
 141  * The thread's main routine implements the standard command/data/status
 142  * parts of a SCSI interaction.  It and its subroutines are full of tests
 143  * for pending signals/exceptions -- all this polling is necessary since
 144  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
 145  * indication that the driver really wants to be running in userspace.)
 146  * An important point is that so long as the thread is alive it keeps an
 147  * open reference to the backing file.  This will prevent unmounting
 148  * the backing file's underlying filesystem and could cause problems
 149  * during system shutdown, for example.  To prevent such problems, the
 150  * thread catches INT, TERM, and KILL signals and converts them into
 151  * an EXIT exception.
 152  *
 153  * In normal operation the main thread is started during the gadget's
 154  * fsg_bind() callback and stopped during fsg_unbind().  But it can also
 155  * exit when it receives a signal, and there's no point leaving the
 156  * gadget running when the thread is dead.  So just before the thread
 157  * exits, it deregisters the gadget driver.  This makes things a little
 158  * tricky: The driver is deregistered at two places, and the exiting
 159  * thread can indirectly call fsg_unbind() which in turn can tell the
 160  * thread to exit.  The first problem is resolved through the use of the
 161  * REGISTERED atomic bitflag; the driver will only be deregistered once.
 162  * The second problem is resolved by having fsg_unbind() check
 163  * fsg->state; it won't try to stop the thread if the state is already
 164  * FSG_STATE_TERMINATED.
 165  *
 166  * To provide maximum throughput, the driver uses a circular pipeline of
 167  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
 168  * arbitrarily long; in practice the benefits don't justify having more
 169  * than 2 stages (i.e., double buffering).  But it helps to think of the
 170  * pipeline as being a long one.  Each buffer head contains a bulk-in and
 171  * a bulk-out request pointer (since the buffer can be used for both
 172  * output and input -- directions always are given from the host's
 173  * point of view) as well as a pointer to the buffer and various state
 174  * variables.
 175  *
 176  * Use of the pipeline follows a simple protocol.  There is a variable
 177  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
 178  * At any time that buffer head may still be in use from an earlier
 179  * request, so each buffer head has a state variable indicating whether
 180  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
 181  * buffer head to be EMPTY, filling the buffer either by file I/O or by
 182  * USB I/O (during which the buffer head is BUSY), and marking the buffer
 183  * head FULL when the I/O is complete.  Then the buffer will be emptied
 184  * (again possibly by USB I/O, during which it is marked BUSY) and
 185  * finally marked EMPTY again (possibly by a completion routine).
 186  *
 187  * A module parameter tells the driver to avoid stalling the bulk
 188  * endpoints wherever the transport specification allows.  This is
 189  * necessary for some UDCs like the SuperH, which cannot reliably clear a
 190  * halt on a bulk endpoint.  However, under certain circumstances the
 191  * Bulk-only specification requires a stall.  In such cases the driver
 192  * will halt the endpoint and set a flag indicating that it should clear
 193  * the halt in software during the next device reset.  Hopefully this
 194  * will permit everything to work correctly.  Furthermore, although the
 195  * specification allows the bulk-out endpoint to halt when the host sends
 196  * too much data, implementing this would cause an unavoidable race.
 197  * The driver will always use the "no-stall" approach for OUT transfers.
 198  *
 199  * One subtle point concerns sending status-stage responses for ep0
 200  * requests.  Some of these requests, such as device reset, can involve
 201  * interrupting an ongoing file I/O operation, which might take an
 202  * arbitrarily long time.  During that delay the host might give up on
 203  * the original ep0 request and issue a new one.  When that happens the
 204  * driver should not notify the host about completion of the original
 205  * request, as the host will no longer be waiting for it.  So the driver
 206  * assigns to each ep0 request a unique tag, and it keeps track of the
 207  * tag value of the request associated with a long-running exception
 208  * (device-reset, interface-change, or configuration-change).  When the
 209  * exception handler is finished, the status-stage response is submitted
 210  * only if the current ep0 request tag is equal to the exception request
 211  * tag.  Thus only the most recently received ep0 request will get a
 212  * status-stage response.
 213  *
 214  * Warning: This driver source file is too long.  It ought to be split up
 215  * into a header file plus about 3 separate .c files, to handle the details
 216  * of the Gadget, USB Mass Storage, and SCSI protocols.
 217  */
 218
 219
 220 /* #define VERBOSE_DEBUG */
 221 /* #define DUMP_MSGS */
 222
 223
 224 #include <linux/blkdev.h>
 225 #include <linux/completion.h>
 226 #include <linux/dcache.h>
 227 #include <linux/delay.h>
 228 #include <linux/device.h>
 229 #include <linux/fcntl.h>
 230 #include <linux/file.h>
 231 #include <linux/fs.h>
 232 #include <linux/kref.h>
 233 #include <linux/kthread.h>
 234 #include <linux/limits.h>
 235 #include <linux/rwsem.h>
 236 #include <linux/slab.h>
 237 #include <linux/spinlock.h>
 238 #include <linux/string.h>
 239 #include <linux/freezer.h>
 240 #include <linux/utsname.h>
 241
 242 #include <linux/usb/ch9.h>
 243 #include <linux/usb/gadget.h>
 244
 245 #include "gadget_chips.h"
 246
 247
 248 /*-------------------------------------------------------------------------*/
 249
 250 #define DRIVER_DESC             "File-backed Storage Gadget"
 251 #define DRIVER_NAME             "g_file_storage"
 252 #define DRIVER_VERSION          "7 August 2007"
 253
 254 static const char longname[] = DRIVER_DESC;
 255 static const char shortname[] = DRIVER_NAME;
 256
 257 MODULE_DESCRIPTION(DRIVER_DESC);
 258 MODULE_AUTHOR("Alan Stern");
 259 MODULE_LICENSE("Dual BSD/GPL");
 260
 261 /* Thanks to NetChip Technologies for donating this product ID.
 262  *
 263  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
 264  * Instead:  allocate your own, using normal USB-IF procedures. */
 265 #define DRIVER_VENDOR_ID        0x0525  // NetChip
 266 #define DRIVER_PRODUCT_ID       0xa4a5  // Linux-USB File-backed Storage Gadget
 267
 268
 269 /*
 270  * This driver assumes self-powered hardware and has no way for users to
 271  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
 272  * and endpoint addresses.
 273  */
 274
 275
 276 /*-------------------------------------------------------------------------*/
 277
 278 #define LDBG(lun,fmt,args...) \
 279         dev_dbg(&(lun)->dev , fmt , ## args)
 280 #define MDBG(fmt,args...) \
 281         pr_debug(DRIVER_NAME ": " fmt , ## args)
 282
 283 #ifndef DEBUG
 284 #undef VERBOSE_DEBUG
 285 #undef DUMP_MSGS
 286 #endif /* !DEBUG */
 287
 288 #ifdef VERBOSE_DEBUG
 289 #define VLDBG   LDBG
 290 #else
 291 #define VLDBG(lun,fmt,args...) \
 292         do { } while (0)
 293 #endif /* VERBOSE_DEBUG */
 294
 295 #define LERROR(lun,fmt,args...) \
 296         dev_err(&(lun)->dev , fmt , ## args)
 297 #define LWARN(lun,fmt,args...) \
 298         dev_warn(&(lun)->dev , fmt , ## args)
 299 #define LINFO(lun,fmt,args...) \
 300         dev_info(&(lun)->dev , fmt , ## args)
 301
 302 #define MINFO(fmt,args...) \
 303         pr_info(DRIVER_NAME ": " fmt , ## args)
 304
 305 #define DBG(d, fmt, args...) \
 306         dev_dbg(&(d)->gadget->dev , fmt , ## args)
 307 #define VDBG(d, fmt, args...) \
 308         dev_vdbg(&(d)->gadget->dev , fmt , ## args)
 309 #define ERROR(d, fmt, args...) \
 310         dev_err(&(d)->gadget->dev , fmt , ## args)
 311 #define WARN(d, fmt, args...) \
 312         dev_warn(&(d)->gadget->dev , fmt , ## args)
 313 #define INFO(d, fmt, args...) \
 314         dev_info(&(d)->gadget->dev , fmt , ## args)
 315
 316
 317 /*-------------------------------------------------------------------------*/
 318
 319 /* Encapsulate the module parameter settings */
 320
 321 #define MAX_LUNS        8
 322
 323 static struct {
 324         char            *file[MAX_LUNS];
 325         int             ro[MAX_LUNS];
 326         unsigned int    num_filenames;
 327         unsigned int    num_ros;
 328         unsigned int    nluns;
 329
 330         int             removable;
 331         int             can_stall;
 332
 333         char            *transport_parm;
 334         char            *protocol_parm;
 335         unsigned short  vendor;
 336         unsigned short  product;
 337         unsigned short  release;
 338         unsigned int    buflen;
 339
 340         int             transport_type;
 341         char            *transport_name;
 342         int             protocol_type;
 343         char            *protocol_name;
 344
 345 } mod_data = {                                  // Default values
 346         .transport_parm         = "BBB",
 347         .protocol_parm          = "SCSI",
 348         .removable              = 0,
 349         .can_stall              = 1,
 350         .vendor                 = DRIVER_VENDOR_ID,
 351         .product                = DRIVER_PRODUCT_ID,
 352         .release                = 0xffff,       // Use controller chip type
 353         .buflen                 = 16384,
 354         };
 355
 356
 357 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
 358                 S_IRUGO);
 359 MODULE_PARM_DESC(file, "names of backing files or devices");
 360
 361 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
 362 MODULE_PARM_DESC(ro, "true to force read-only");
 363
 364 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
 365 MODULE_PARM_DESC(luns, "number of LUNs");
 366
 367 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
 368 MODULE_PARM_DESC(removable, "true to simulate removable media");
 369
 370 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
 371 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
 372
 373
 374 /* In the non-TEST version, only the module parameters listed above
 375  * are available. */
 376 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 377
 378 module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
 379 MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
 380
 381 module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
 382 MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
 383                 "8070, or SCSI)");
 384
 385 module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
 386 MODULE_PARM_DESC(vendor, "USB Vendor ID");
 387
 388 module_param_named(product, mod_data.product, ushort, S_IRUGO);
 389 MODULE_PARM_DESC(product, "USB Product ID");
 390
 391 module_param_named(release, mod_data.release, ushort, S_IRUGO);
 392 MODULE_PARM_DESC(release, "USB release number");
 393
 394 module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
 395 MODULE_PARM_DESC(buflen, "I/O buffer size");
 396
 397 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 398
 399
 400 /*-------------------------------------------------------------------------*/
 401
 402 /* USB protocol value = the transport method */
 403 #define USB_PR_CBI      0x00            // Control/Bulk/Interrupt
 404 #define USB_PR_CB       0x01            // Control/Bulk w/o interrupt
 405 #define USB_PR_BULK     0x50            // Bulk-only
 406
 407 /* USB subclass value = the protocol encapsulation */
 408 #define USB_SC_RBC      0x01            // Reduced Block Commands (flash)
 409 #define USB_SC_8020     0x02            // SFF-8020i, MMC-2, ATAPI (CD-ROM)
 410 #define USB_SC_QIC      0x03            // QIC-157 (tape)
 411 #define USB_SC_UFI      0x04            // UFI (floppy)
 412 #define USB_SC_8070     0x05            // SFF-8070i (removable)
 413 #define USB_SC_SCSI     0x06            // Transparent SCSI
 414
 415 /* Bulk-only data structures */
 416
 417 /* Command Block Wrapper */
 418 struct bulk_cb_wrap {
 419         __le32  Signature;              // Contains 'USBC'
 420         u32     Tag;                    // Unique per command id
 421         __le32  DataTransferLength;     // Size of the data
 422         u8      Flags;                  // Direction in bit 7
 423         u8      Lun;                    // LUN (normally 0)
 424         u8      Length;                 // Of the CDB, <= MAX_COMMAND_SIZE
 425         u8      CDB[16];                // Command Data Block
 426 };
 427
 428 #define USB_BULK_CB_WRAP_LEN    31
 429 #define USB_BULK_CB_SIG         0x43425355      // Spells out USBC
 430 #define USB_BULK_IN_FLAG        0x80
 431
 432 /* Command Status Wrapper */
 433 struct bulk_cs_wrap {
 434         __le32  Signature;              // Should = 'USBS'
 435         u32     Tag;                    // Same as original command
 436         __le32  Residue;                // Amount not transferred
 437         u8      Status;                 // See below
 438 };
 439
 440 #define USB_BULK_CS_WRAP_LEN    13
 441 #define USB_BULK_CS_SIG         0x53425355      // Spells out 'USBS'
 442 #define USB_STATUS_PASS         0
 443 #define USB_STATUS_FAIL         1
 444 #define USB_STATUS_PHASE_ERROR  2
 445
 446 /* Bulk-only class specific requests */
 447 #define USB_BULK_RESET_REQUEST          0xff
 448 #define USB_BULK_GET_MAX_LUN_REQUEST    0xfe
 449
 450
 451 /* CBI Interrupt data structure */
 452 struct interrupt_data {
 453         u8      bType;
 454         u8      bValue;
 455 };
 456
 457 #define CBI_INTERRUPT_DATA_LEN          2
 458
 459 /* CBI Accept Device-Specific Command request */
 460 #define USB_CBI_ADSC_REQUEST            0x00
 461
 462
 463 #define MAX_COMMAND_SIZE        16      // Length of a SCSI Command Data Block
 464
 465 /* SCSI commands that we recognize */
 466 #define SC_FORMAT_UNIT                  0x04
 467 #define SC_INQUIRY                      0x12
 468 #define SC_MODE_SELECT_6                0x15
 469 #define SC_MODE_SELECT_10               0x55
 470 #define SC_MODE_SENSE_6                 0x1a
 471 #define SC_MODE_SENSE_10                0x5a
 472 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
 473 #define SC_READ_6                       0x08
 474 #define SC_READ_10                      0x28
 475 #define SC_READ_12                      0xa8
 476 #define SC_READ_CAPACITY                0x25
 477 #define SC_READ_FORMAT_CAPACITIES       0x23
 478 #define SC_RELEASE                      0x17
 479 #define SC_REQUEST_SENSE                0x03
 480 #define SC_RESERVE                      0x16
 481 #define SC_SEND_DIAGNOSTIC              0x1d
 482 #define SC_START_STOP_UNIT              0x1b
 483 #define SC_SYNCHRONIZE_CACHE            0x35
 484 #define SC_TEST_UNIT_READY              0x00
 485 #define SC_VERIFY                       0x2f
 486 #define SC_WRITE_6                      0x0a
 487 #define SC_WRITE_10                     0x2a
 488 #define SC_WRITE_12                     0xaa
 489
 490 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
 491 #define SS_NO_SENSE                             0
 492 #define SS_COMMUNICATION_FAILURE                0x040800
 493 #define SS_INVALID_COMMAND                      0x052000
 494 #define SS_INVALID_FIELD_IN_CDB                 0x052400
 495 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
 496 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
 497 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
 498 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
 499 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
 500 #define SS_RESET_OCCURRED                       0x062900
 501 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
 502 #define SS_UNRECOVERED_READ_ERROR               0x031100
 503 #define SS_WRITE_ERROR                          0x030c02
 504 #define SS_WRITE_PROTECTED                      0x072700
 505
 506 #define SK(x)           ((u8) ((x) >> 16))      // Sense Key byte, etc.
 507 #define ASC(x)          ((u8) ((x) >> 8))
 508 #define ASCQ(x)         ((u8) (x))
 509
 510
 511 /*-------------------------------------------------------------------------*/
 512
 513 /*
 514  * These definitions will permit the compiler to avoid generating code for
 515  * parts of the driver that aren't used in the non-TEST version.  Even gcc
 516  * can recognize when a test of a constant expression yields a dead code
 517  * path.
 518  */
 519
 520 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 521
 522 #define transport_is_bbb()      (mod_data.transport_type == USB_PR_BULK)
 523 #define transport_is_cbi()      (mod_data.transport_type == USB_PR_CBI)
 524 #define protocol_is_scsi()      (mod_data.protocol_type == USB_SC_SCSI)
 525
 526 #else
 527
 528 #define transport_is_bbb()      1
 529 #define transport_is_cbi()      0
 530 #define protocol_is_scsi()      1
 531
 532 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 533
 534
 535 struct lun {
 536         struct file     *filp;
 537         loff_t          file_length;
 538         loff_t          num_sectors;
 539
 540         unsigned int    ro : 1;
 541         unsigned int    prevent_medium_removal : 1;
 542         unsigned int    registered : 1;
 543         unsigned int    info_valid : 1;
 544
 545         u32             sense_data;
 546         u32             sense_data_info;
 547         u32             unit_attention_data;
 548
 549         struct device   dev;
 550 };
 551
 552 #define backing_file_is_open(curlun)    ((curlun)->filp != NULL)
 553
 554 static struct lun *dev_to_lun(struct device *dev)
 555 {
 556         return container_of(dev, struct lun, dev);
 557 }
 558
 559
 560 /* Big enough to hold our biggest descriptor */
 561 #define EP0_BUFSIZE     256
 562 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     // An impossibly large value
 563
 564 /* Number of buffers we will use.  2 is enough for double-buffering */
 565 #define NUM_BUFFERS     2
 566
 567 enum fsg_buffer_state {
 568         BUF_STATE_EMPTY = 0,
 569         BUF_STATE_FULL,
 570         BUF_STATE_BUSY
 571 };
 572
 573 struct fsg_buffhd {
 574         void                            *buf;
 575         enum fsg_buffer_state           state;
 576         struct fsg_buffhd               *next;
 577
 578         /* The NetChip 2280 is faster, and handles some protocol faults
 579          * better, if we don't submit any short bulk-out read requests.
 580          * So we will record the intended request length here. */
 581         unsigned int                    bulk_out_intended_length;
 582
 583         struct usb_request              *inreq;
 584         int                             inreq_busy;
 585         struct usb_request              *outreq;
 586         int                             outreq_busy;
 587 };
 588
 589 enum fsg_state {
 590         FSG_STATE_COMMAND_PHASE = -10,          // This one isn't used anywhere
 591         FSG_STATE_DATA_PHASE,
 592         FSG_STATE_STATUS_PHASE,
 593
 594         FSG_STATE_IDLE = 0,
 595         FSG_STATE_ABORT_BULK_OUT,
 596         FSG_STATE_RESET,
 597         FSG_STATE_INTERFACE_CHANGE,
 598         FSG_STATE_CONFIG_CHANGE,
 599         FSG_STATE_DISCONNECT,
 600         FSG_STATE_EXIT,
 601         FSG_STATE_TERMINATED
 602 };
 603
 604 enum data_direction {
 605         DATA_DIR_UNKNOWN = 0,
 606         DATA_DIR_FROM_HOST,
 607         DATA_DIR_TO_HOST,
 608         DATA_DIR_NONE
 609 };
 610
 611 struct fsg_dev {
 612         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
 613         spinlock_t              lock;
 614         struct usb_gadget       *gadget;
 615
 616         /* filesem protects: backing files in use */
 617         struct rw_semaphore     filesem;
 618
 619         /* reference counting: wait until all LUNs are released */
 620         struct kref             ref;
 621
 622         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
 623         struct usb_request      *ep0req;        // For control responses
 624         unsigned int            ep0_req_tag;
 625         const char              *ep0req_name;
 626
 627         struct usb_request      *intreq;        // For interrupt responses
 628         int                     intreq_busy;
 629         struct fsg_buffhd       *intr_buffhd;
 630
 631         unsigned int            bulk_out_maxpacket;
 632         enum fsg_state          state;          // For exception handling
 633         unsigned int            exception_req_tag;
 634
 635         u8                      config, new_config;
 636
 637         unsigned int            running : 1;
 638         unsigned int            bulk_in_enabled : 1;
 639         unsigned int            bulk_out_enabled : 1;
 640         unsigned int            intr_in_enabled : 1;
 641         unsigned int            phase_error : 1;
 642         unsigned int            short_packet_received : 1;
 643         unsigned int            bad_lun_okay : 1;
 644
 645         unsigned long           atomic_bitflags;
 646 #define REGISTERED              0
 647 #define CLEAR_BULK_HALTS        1
 648 #define SUSPENDED               2
 649
 650         struct usb_ep           *bulk_in;
 651         struct usb_ep           *bulk_out;
 652         struct usb_ep           *intr_in;
 653
 654         struct fsg_buffhd       *next_buffhd_to_fill;
 655         struct fsg_buffhd       *next_buffhd_to_drain;
 656         struct fsg_buffhd       buffhds[NUM_BUFFERS];
 657
 658         int                     thread_wakeup_needed;
 659         struct completion       thread_notifier;
 660         struct task_struct      *thread_task;
 661
 662         int                     cmnd_size;
 663         u8                      cmnd[MAX_COMMAND_SIZE];
 664         enum data_direction     data_dir;
 665         u32                     data_size;
 666         u32                     data_size_from_cmnd;
 667         u32                     tag;
 668         unsigned int            lun;
 669         u32                     residue;
 670         u32                     usb_amount_left;
 671
 672         /* The CB protocol offers no way for a host to know when a command
 673          * has completed.  As a result the next command may arrive early,
 674          * and we will still have to handle it.  For that reason we need
 675          * a buffer to store new commands when using CB (or CBI, which
 676          * does not oblige a host to wait for command completion either). */
 677         int                     cbbuf_cmnd_size;
 678         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
 679
 680         unsigned int            nluns;
 681         struct lun              *luns;
 682         struct lun              *curlun;
 683 };
 684
 685 typedef void (*fsg_routine_t)(struct fsg_dev *);
 686
 687 static int exception_in_progress(struct fsg_dev *fsg)
 688 {
 689         return (fsg->state > FSG_STATE_IDLE);
 690 }
 691
 692 /* Make bulk-out requests be divisible by the maxpacket size */
 693 static void set_bulk_out_req_length(struct fsg_dev *fsg,
 694                 struct fsg_buffhd *bh, unsigned int length)
 695 {
 696         unsigned int    rem;
 697
 698         bh->bulk_out_intended_length = length;
 699         rem = length % fsg->bulk_out_maxpacket;
 700         if (rem > 0)
 701                 length += fsg->bulk_out_maxpacket - rem;
 702         bh->outreq->length = length;
 703 }
 704
 705 static struct fsg_dev                   *the_fsg;
 706 static struct usb_gadget_driver         fsg_driver;
 707
 708 static void     close_backing_file(struct lun *curlun);
 709 static void     close_all_backing_files(struct fsg_dev *fsg);
 710
 711
 712 /*-------------------------------------------------------------------------*/
 713
 714 #ifdef DUMP_MSGS
 715
 716 static void dump_msg(struct fsg_dev *fsg, const char *label,
 717                 const u8 *buf, unsigned int length)
 718 {
 719         if (length < 512) {
 720                 DBG(fsg, "%s, length %u:\n", label, length);
 721                 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,
 722                                 16, 1, buf, length, 0);
 723         }
 724 }
 725
 726 static void dump_cdb(struct fsg_dev *fsg)
 727 {}
 728
 729 #else
 730
 731 static void dump_msg(struct fsg_dev *fsg, const char *label,
 732                 const u8 *buf, unsigned int length)
 733 {}
 734
 735 #ifdef VERBOSE_DEBUG
 736
 737 static void dump_cdb(struct fsg_dev *fsg)
 738 {
 739         print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,
 740                         16, 1, fsg->cmnd, fsg->cmnd_size, 0);
 741 }
 742
 743 #else
 744
 745 static void dump_cdb(struct fsg_dev *fsg)
 746 {}
 747
 748 #endif /* VERBOSE_DEBUG */
 749 #endif /* DUMP_MSGS */
 750
 751
 752 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 753 {
 754         const char      *name;
 755
 756         if (ep == fsg->bulk_in)
 757                 name = "bulk-in";
 758         else if (ep == fsg->bulk_out)
 759                 name = "bulk-out";
 760         else
 761                 name = ep->name;
 762         DBG(fsg, "%s set halt\n", name);
 763         return usb_ep_set_halt(ep);
 764 }
 765
 766
 767 /*-------------------------------------------------------------------------*/
 768
 769 /* Routines for unaligned data access */
 770
 771 static u16 get_be16(u8 *buf)
 772 {
 773         return ((u16) buf[0] << 8) | ((u16) buf[1]);
 774 }
 775
 776 static u32 get_be32(u8 *buf)
 777 {
 778         return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) |
 779                         ((u32) buf[2] << 8) | ((u32) buf[3]);
 780 }
 781
 782 static void put_be16(u8 *buf, u16 val)
 783 {
 784         buf[0] = val >> 8;
 785         buf[1] = val;
 786 }
 787
 788 static void put_be32(u8 *buf, u32 val)
 789 {
 790         buf[0] = val >> 24;
 791         buf[1] = val >> 16;
 792         buf[2] = val >> 8;
 793         buf[3] = val & 0xff;
 794 }
 795
 796
 797 /*-------------------------------------------------------------------------*/
 798
 799 /*
 800  * DESCRIPTORS ... most are static, but strings and (full) configuration
 801  * descriptors are built on demand.  Also the (static) config and interface
 802  * descriptors are adjusted during fsg_bind().
 803  */
 804 #define STRING_MANUFACTURER     1
 805 #define STRING_PRODUCT          2
 806 #define STRING_SERIAL           3
 807 #define STRING_CONFIG           4
 808 #define STRING_INTERFACE        5
 809
 810 /* There is only one configuration. */
 811 #define CONFIG_VALUE            1
 812
 813 static struct usb_device_descriptor
 814 device_desc = {
 815         .bLength =              sizeof device_desc,
 816         .bDescriptorType =      USB_DT_DEVICE,
 817
 818         .bcdUSB =               __constant_cpu_to_le16(0x0200),
 819         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
 820
 821         /* The next three values can be overridden by module parameters */
 822         .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_ID),
 823         .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
 824         .bcdDevice =            __constant_cpu_to_le16(0xffff),
 825
 826         .iManufacturer =        STRING_MANUFACTURER,
 827         .iProduct =             STRING_PRODUCT,
 828         .iSerialNumber =        STRING_SERIAL,
 829         .bNumConfigurations =   1,
 830 };
 831
 832 static struct usb_config_descriptor
 833 config_desc = {
 834         .bLength =              sizeof config_desc,
 835         .bDescriptorType =      USB_DT_CONFIG,
 836
 837         /* wTotalLength computed by usb_gadget_config_buf() */
 838         .bNumInterfaces =       1,
 839         .bConfigurationValue =  CONFIG_VALUE,
 840         .iConfiguration =       STRING_CONFIG,
 841         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
 842         .bMaxPower =            1,      // self-powered
 843 };
 844
 845 static struct usb_otg_descriptor
 846 otg_desc = {
 847         .bLength =              sizeof(otg_desc),
 848         .bDescriptorType =      USB_DT_OTG,
 849
 850         .bmAttributes =         USB_OTG_SRP,
 851 };
 852
 853 /* There is only one interface. */
 854
 855 static struct usb_interface_descriptor
 856 intf_desc = {
 857         .bLength =              sizeof intf_desc,
 858         .bDescriptorType =      USB_DT_INTERFACE,
 859
 860         .bNumEndpoints =        2,              // Adjusted during fsg_bind()
 861         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
 862         .bInterfaceSubClass =   USB_SC_SCSI,    // Adjusted during fsg_bind()
 863         .bInterfaceProtocol =   USB_PR_BULK,    // Adjusted during fsg_bind()
 864         .iInterface =           STRING_INTERFACE,
 865 };
 866
 867 /* Three full-speed endpoint descriptors: bulk-in, bulk-out,
 868  * and interrupt-in. */
 869
 870 static struct usb_endpoint_descriptor
 871 fs_bulk_in_desc = {
 872         .bLength =              USB_DT_ENDPOINT_SIZE,
 873         .bDescriptorType =      USB_DT_ENDPOINT,
 874
 875         .bEndpointAddress =     USB_DIR_IN,
 876         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 877         /* wMaxPacketSize set by autoconfiguration */
 878 };
 879
 880 static struct usb_endpoint_descriptor
 881 fs_bulk_out_desc = {
 882         .bLength =              USB_DT_ENDPOINT_SIZE,
 883         .bDescriptorType =      USB_DT_ENDPOINT,
 884
 885         .bEndpointAddress =     USB_DIR_OUT,
 886         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 887         /* wMaxPacketSize set by autoconfiguration */
 888 };
 889
 890 static struct usb_endpoint_descriptor
 891 fs_intr_in_desc = {
 892         .bLength =              USB_DT_ENDPOINT_SIZE,
 893         .bDescriptorType =      USB_DT_ENDPOINT,
 894
 895         .bEndpointAddress =     USB_DIR_IN,
 896         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 897         .wMaxPacketSize =       __constant_cpu_to_le16(2),
 898         .bInterval =            32,     // frames -> 32 ms
 899 };
 900
 901 static const struct usb_descriptor_header *fs_function[] = {
 902         (struct usb_descriptor_header *) &otg_desc,
 903         (struct usb_descriptor_header *) &intf_desc,
 904         (struct usb_descriptor_header *) &fs_bulk_in_desc,
 905         (struct usb_descriptor_header *) &fs_bulk_out_desc,
 906         (struct usb_descriptor_header *) &fs_intr_in_desc,
 907         NULL,
 908 };
 909 #define FS_FUNCTION_PRE_EP_ENTRIES      2
 910
 911
 912 /*
 913  * USB 2.0 devices need to expose both high speed and full speed
 914  * descriptors, unless they only run at full speed.
 915  *
 916  * That means alternate endpoint descriptors (bigger packets)
 917  * and a "device qualifier" ... plus more construction options
 918  * for the config descriptor.
 919  */
 920 static struct usb_qualifier_descriptor
 921 dev_qualifier = {
 922         .bLength =              sizeof dev_qualifier,
 923         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
 924
 925         .bcdUSB =               __constant_cpu_to_le16(0x0200),
 926         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
 927
 928         .bNumConfigurations =   1,
 929 };
 930
 931 static struct usb_endpoint_descriptor
 932 hs_bulk_in_desc = {
 933         .bLength =              USB_DT_ENDPOINT_SIZE,
 934         .bDescriptorType =      USB_DT_ENDPOINT,
 935
 936         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
 937         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 938         .wMaxPacketSize =       __constant_cpu_to_le16(512),
 939 };
 940
 941 static struct usb_endpoint_descriptor
 942 hs_bulk_out_desc = {
 943         .bLength =              USB_DT_ENDPOINT_SIZE,
 944         .bDescriptorType =      USB_DT_ENDPOINT,
 945
 946         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
 947         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 948         .wMaxPacketSize =       __constant_cpu_to_le16(512),
 949         .bInterval =            1,      // NAK every 1 uframe
 950 };
 951
 952 static struct usb_endpoint_descriptor
 953 hs_intr_in_desc = {
 954         .bLength =              USB_DT_ENDPOINT_SIZE,
 955         .bDescriptorType =      USB_DT_ENDPOINT,
 956
 957         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
 958         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 959         .wMaxPacketSize =       __constant_cpu_to_le16(2),
 960         .bInterval =            9,      // 2**(9-1) = 256 uframes -> 32 ms
 961 };
 962
 963 static const struct usb_descriptor_header *hs_function[] = {
 964         (struct usb_descriptor_header *) &otg_desc,
 965         (struct usb_descriptor_header *) &intf_desc,
 966         (struct usb_descriptor_header *) &hs_bulk_in_desc,
 967         (struct usb_descriptor_header *) &hs_bulk_out_desc,
 968         (struct usb_descriptor_header *) &hs_intr_in_desc,
 969         NULL,
 970 };
 971 #define HS_FUNCTION_PRE_EP_ENTRIES      2
 972
 973 /* Maxpacket and other transfer characteristics vary by speed. */
 974 static struct usb_endpoint_descriptor *
 975 ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
 976                 struct usb_endpoint_descriptor *hs)
 977 {
 978         if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
 979                 return hs;
 980         return fs;
 981 }
 982
 983
 984 /* The CBI specification limits the serial string to 12 uppercase hexadecimal
 985  * characters. */
 986 static char                             manufacturer[64];
 987 static char                             serial[13];
 988
 989 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 990 static struct usb_string                strings[] = {
 991         {STRING_MANUFACTURER,   manufacturer},
 992         {STRING_PRODUCT,        longname},
 993         {STRING_SERIAL,         serial},
 994         {STRING_CONFIG,         "Self-powered"},
 995         {STRING_INTERFACE,      "Mass Storage"},
 996         {}
 997 };
 998
 999 static struct usb_gadget_strings        stringtab = {
1000         .language       = 0x0409,               // en-us
1001         .strings        = strings,
1002 };
1003
1004
1005 /*
1006  * Config descriptors must agree with the code that sets configurations
1007  * and with code managing interfaces and their altsettings.  They must
1008  * also handle different speeds and other-speed requests.
1009  */
1010 static int populate_config_buf(struct usb_gadget *gadget,
1011                 u8 *buf, u8 type, unsigned index)
1012 {
1013         enum usb_device_speed                   speed = gadget->speed;
1014         int                                     len;
1015         const struct usb_descriptor_header      **function;
1016
1017         if (index > 0)
1018                 return -EINVAL;
1019
1020         if (gadget_is_dualspeed(gadget) && type == USB_DT_OTHER_SPEED_CONFIG)
1021                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
1022         if (gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH)
1023                 function = hs_function;
1024         else
1025                 function = fs_function;
1026
1027         /* for now, don't advertise srp-only devices */
1028         if (!gadget_is_otg(gadget))
1029                 function++;
1030
1031         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
1032         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
1033         return len;
1034 }
1035
1036
1037 /*-------------------------------------------------------------------------*/
1038
1039 /* These routines may be called in process context or in_irq */
1040
1041 /* Caller must hold fsg->lock */
1042 static void wakeup_thread(struct fsg_dev *fsg)
1043 {
1044         /* Tell the main thread that something has happened */
1045         fsg->thread_wakeup_needed = 1;
1046         if (fsg->thread_task)
1047                 wake_up_process(fsg->thread_task);
1048 }
1049
1050
1051 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
1052 {
1053         unsigned long           flags;
1054
1055         /* Do nothing if a higher-priority exception is already in progress.
1056          * If a lower-or-equal priority exception is in progress, preempt it
1057          * and notify the main thread by sending it a signal. */
1058         spin_lock_irqsave(&fsg->lock, flags);
1059         if (fsg->state <= new_state) {
1060                 fsg->exception_req_tag = fsg->ep0_req_tag;
1061                 fsg->state = new_state;
1062                 if (fsg->thread_task)
1063                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
1064                                         fsg->thread_task);
1065         }
1066         spin_unlock_irqrestore(&fsg->lock, flags);
1067 }
1068
1069
1070 /*-------------------------------------------------------------------------*/
1071
1072 /* The disconnect callback and ep0 routines.  These always run in_irq,
1073  * except that ep0_queue() is called in the main thread to acknowledge
1074  * completion of various requests: set config, set interface, and
1075  * Bulk-only device reset. */
1076
1077 static void fsg_disconnect(struct usb_gadget *gadget)
1078 {
1079         struct fsg_dev          *fsg = get_gadget_data(gadget);
1080
1081         DBG(fsg, "disconnect or port reset\n");
1082         raise_exception(fsg, FSG_STATE_DISCONNECT);
1083 }
1084
1085
1086 static int ep0_queue(struct fsg_dev *fsg)
1087 {
1088         int     rc;
1089
1090         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
1091         if (rc != 0 && rc != -ESHUTDOWN) {
1092
1093                 /* We can't do much more than wait for a reset */
1094                 WARN(fsg, "error in submission: %s --> %d\n",
1095                                 fsg->ep0->name, rc);
1096         }
1097         return rc;
1098 }
1099
1100 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
1101 {
1102         struct fsg_dev          *fsg = ep->driver_data;
1103
1104         if (req->actual > 0)
1105                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
1106         if (req->status || req->actual != req->length)
1107                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1108                                 req->status, req->actual, req->length);
1109         if (req->status == -ECONNRESET)         // Request was cancelled
1110                 usb_ep_fifo_flush(ep);
1111
1112         if (req->status == 0 && req->context)
1113                 ((fsg_routine_t) (req->context))(fsg);
1114 }
1115
1116
1117 /*-------------------------------------------------------------------------*/
1118
1119 /* Bulk and interrupt endpoint completion handlers.
1120  * These always run in_irq. */
1121
1122 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
1123 {
1124         struct fsg_dev          *fsg = ep->driver_data;
1125         struct fsg_buffhd       *bh = req->context;
1126
1127         if (req->status || req->actual != req->length)
1128                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1129                                 req->status, req->actual, req->length);
1130         if (req->status == -ECONNRESET)         // Request was cancelled
1131                 usb_ep_fifo_flush(ep);
1132
1133         /* Hold the lock while we update the request and buffer states */
1134         smp_wmb();
1135         spin_lock(&fsg->lock);
1136         bh->inreq_busy = 0;
1137         bh->state = BUF_STATE_EMPTY;
1138         wakeup_thread(fsg);
1139         spin_unlock(&fsg->lock);
1140 }
1141
1142 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
1143 {
1144         struct fsg_dev          *fsg = ep->driver_data;
1145         struct fsg_buffhd       *bh = req->context;
1146
1147         dump_msg(fsg, "bulk-out", req->buf, req->actual);
1148         if (req->status || req->actual != bh->bulk_out_intended_length)
1149                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1150                                 req->status, req->actual,
1151                                 bh->bulk_out_intended_length);
1152         if (req->status == -ECONNRESET)         // Request was cancelled
1153                 usb_ep_fifo_flush(ep);
1154
1155         /* Hold the lock while we update the request and buffer states */
1156         smp_wmb();
1157         spin_lock(&fsg->lock);
1158         bh->outreq_busy = 0;
1159         bh->state = BUF_STATE_FULL;
1160         wakeup_thread(fsg);
1161         spin_unlock(&fsg->lock);
1162 }
1163
1164
1165 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1166 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1167 {
1168         struct fsg_dev          *fsg = ep->driver_data;
1169         struct fsg_buffhd       *bh = req->context;
1170
1171         if (req->status || req->actual != req->length)
1172                 DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__,
1173                                 req->status, req->actual, req->length);
1174         if (req->status == -ECONNRESET)         // Request was cancelled
1175                 usb_ep_fifo_flush(ep);
1176
1177         /* Hold the lock while we update the request and buffer states */
1178         smp_wmb();
1179         spin_lock(&fsg->lock);
1180         fsg->intreq_busy = 0;
1181         bh->state = BUF_STATE_EMPTY;
1182         wakeup_thread(fsg);
1183         spin_unlock(&fsg->lock);
1184 }
1185
1186 #else
1187 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
1188 {}
1189 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1190
1191
1192 /*-------------------------------------------------------------------------*/
1193
1194 /* Ep0 class-specific handlers.  These always run in_irq. */
1195
1196 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1197 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1198 {
1199         struct usb_request      *req = fsg->ep0req;
1200         static u8               cbi_reset_cmnd[6] = {
1201                         SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
1202
1203         /* Error in command transfer? */
1204         if (req->status || req->length != req->actual ||
1205                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
1206
1207                 /* Not all controllers allow a protocol stall after
1208                  * receiving control-out data, but we'll try anyway. */
1209                 fsg_set_halt(fsg, fsg->ep0);
1210                 return;                 // Wait for reset
1211         }
1212
1213         /* Is it the special reset command? */
1214         if (req->actual >= sizeof cbi_reset_cmnd &&
1215                         memcmp(req->buf, cbi_reset_cmnd,
1216                                 sizeof cbi_reset_cmnd) == 0) {
1217
1218                 /* Raise an exception to stop the current operation
1219                  * and reinitialize our state. */
1220                 DBG(fsg, "cbi reset request\n");
1221                 raise_exception(fsg, FSG_STATE_RESET);
1222                 return;
1223         }
1224
1225         VDBG(fsg, "CB[I] accept device-specific command\n");
1226         spin_lock(&fsg->lock);
1227
1228         /* Save the command for later */
1229         if (fsg->cbbuf_cmnd_size)
1230                 WARN(fsg, "CB[I] overwriting previous command\n");
1231         fsg->cbbuf_cmnd_size = req->actual;
1232         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
1233
1234         wakeup_thread(fsg);
1235         spin_unlock(&fsg->lock);
1236 }
1237
1238 #else
1239 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1240 {}
1241 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
1242
1243
1244 static int class_setup_req(struct fsg_dev *fsg,
1245                 const struct usb_ctrlrequest *ctrl)
1246 {
1247         struct usb_request      *req = fsg->ep0req;
1248         int                     value = -EOPNOTSUPP;
1249         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1250         u16                     w_value = le16_to_cpu(ctrl->wValue);
1251         u16                     w_length = le16_to_cpu(ctrl->wLength);
1252
1253         if (!fsg->config)
1254                 return value;
1255
1256         /* Handle Bulk-only class-specific requests */
1257         if (transport_is_bbb()) {
1258                 switch (ctrl->bRequest) {
1259
1260                 case USB_BULK_RESET_REQUEST:
1261                         if (ctrl->bRequestType != (USB_DIR_OUT |
1262                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1263                                 break;
1264                         if (w_index != 0 || w_value != 0) {
1265                                 value = -EDOM;
1266                                 break;
1267                         }
1268
1269                         /* Raise an exception to stop the current operation
1270                          * and reinitialize our state. */
1271                         DBG(fsg, "bulk reset request\n");
1272                         raise_exception(fsg, FSG_STATE_RESET);
1273                         value = DELAYED_STATUS;
1274                         break;
1275
1276                 case USB_BULK_GET_MAX_LUN_REQUEST:
1277                         if (ctrl->bRequestType != (USB_DIR_IN |
1278                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1279                                 break;
1280                         if (w_index != 0 || w_value != 0) {
1281                                 value = -EDOM;
1282                                 break;
1283                         }
1284                         VDBG(fsg, "get max LUN\n");
1285                         *(u8 *) req->buf = fsg->nluns - 1;
1286                         value = 1;
1287                         break;
1288                 }
1289         }
1290
1291         /* Handle CBI class-specific requests */
1292         else {
1293                 switch (ctrl->bRequest) {
1294
1295                 case USB_CBI_ADSC_REQUEST:
1296                         if (ctrl->bRequestType != (USB_DIR_OUT |
1297                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
1298                                 break;
1299                         if (w_index != 0 || w_value != 0) {
1300                                 value = -EDOM;
1301                                 break;
1302                         }
1303                         if (w_length > MAX_COMMAND_SIZE) {
1304                                 value = -EOVERFLOW;
1305                                 break;
1306                         }
1307                         value = w_length;
1308                         fsg->ep0req->context = received_cbi_adsc;
1309                         break;
1310                 }
1311         }
1312
1313         if (value == -EOPNOTSUPP)
1314                 VDBG(fsg,
1315                         "unknown class-specific control req "
1316                         "%02x.%02x v%04x i%04x l%u\n",
1317                         ctrl->bRequestType, ctrl->bRequest,
1318                         le16_to_cpu(ctrl->wValue), w_index, w_length);
1319         return value;
1320 }
1321
1322
1323 /*-------------------------------------------------------------------------*/
1324
1325 /* Ep0 standard request handlers.  These always run in_irq. */
1326
1327 static int standard_setup_req(struct fsg_dev *fsg,
1328                 const struct usb_ctrlrequest *ctrl)
1329 {
1330         struct usb_request      *req = fsg->ep0req;
1331         int                     value = -EOPNOTSUPP;
1332         u16                     w_index = le16_to_cpu(ctrl->wIndex);
1333         u16                     w_value = le16_to_cpu(ctrl->wValue);
1334
1335         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
1336          * but config change events will also reconfigure hardware. */
1337         switch (ctrl->bRequest) {
1338
1339         case USB_REQ_GET_DESCRIPTOR:
1340                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1341                                 USB_RECIP_DEVICE))
1342                         break;
1343                 switch (w_value >> 8) {
1344
1345                 case USB_DT_DEVICE:
1346                         VDBG(fsg, "get device descriptor\n");
1347                         value = sizeof device_desc;
1348                         memcpy(req->buf, &device_desc, value);
1349                         break;
1350                 case USB_DT_DEVICE_QUALIFIER:
1351                         VDBG(fsg, "get device qualifier\n");
1352                         if (!gadget_is_dualspeed(fsg->gadget))
1353                                 break;
1354                         value = sizeof dev_qualifier;
1355                         memcpy(req->buf, &dev_qualifier, value);
1356                         break;
1357
1358                 case USB_DT_OTHER_SPEED_CONFIG:
1359                         VDBG(fsg, "get other-speed config descriptor\n");
1360                         if (!gadget_is_dualspeed(fsg->gadget))
1361                                 break;
1362                         goto get_config;
1363                 case USB_DT_CONFIG:
1364                         VDBG(fsg, "get configuration descriptor\n");
1365 get_config:
1366                         value = populate_config_buf(fsg->gadget,
1367                                         req->buf,
1368                                         w_value >> 8,
1369                                         w_value & 0xff);
1370                         break;
1371
1372                 case USB_DT_STRING:
1373                         VDBG(fsg, "get string descriptor\n");
1374
1375                         /* wIndex == language code */
1376                         value = usb_gadget_get_string(&stringtab,
1377                                         w_value & 0xff, req->buf);
1378                         break;
1379                 }
1380                 break;
1381
1382         /* One config, two speeds */
1383         case USB_REQ_SET_CONFIGURATION:
1384                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
1385                                 USB_RECIP_DEVICE))
1386                         break;
1387                 VDBG(fsg, "set configuration\n");
1388                 if (w_value == CONFIG_VALUE || w_value == 0) {
1389                         fsg->new_config = w_value;
1390
1391                         /* Raise an exception to wipe out previous transaction
1392                          * state (queued bufs, etc) and set the new config. */
1393                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
1394                         value = DELAYED_STATUS;
1395                 }
1396                 break;
1397         case USB_REQ_GET_CONFIGURATION:
1398                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1399                                 USB_RECIP_DEVICE))
1400                         break;
1401                 VDBG(fsg, "get configuration\n");
1402                 *(u8 *) req->buf = fsg->config;
1403                 value = 1;
1404                 break;
1405
1406         case USB_REQ_SET_INTERFACE:
1407                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
1408                                 USB_RECIP_INTERFACE))
1409                         break;
1410                 if (fsg->config && w_index == 0) {
1411
1412                         /* Raise an exception to wipe out previous transaction
1413                          * state (queued bufs, etc) and install the new
1414                          * interface altsetting. */
1415                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
1416                         value = DELAYED_STATUS;
1417                 }
1418                 break;
1419         case USB_REQ_GET_INTERFACE:
1420                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1421                                 USB_RECIP_INTERFACE))
1422                         break;
1423                 if (!fsg->config)
1424                         break;
1425                 if (w_index != 0) {
1426                         value = -EDOM;
1427                         break;
1428                 }
1429                 VDBG(fsg, "get interface\n");
1430                 *(u8 *) req->buf = 0;
1431                 value = 1;
1432                 break;
1433
1434         default:
1435                 VDBG(fsg,
1436                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1437                         ctrl->bRequestType, ctrl->bRequest,
1438                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1439         }
1440
1441         return value;
1442 }
1443
1444
1445 static int fsg_setup(struct usb_gadget *gadget,
1446                 const struct usb_ctrlrequest *ctrl)
1447 {
1448         struct fsg_dev          *fsg = get_gadget_data(gadget);
1449         int                     rc;
1450         int                     w_length = le16_to_cpu(ctrl->wLength);
1451
1452         ++fsg->ep0_req_tag;             // Record arrival of a new request
1453         fsg->ep0req->context = NULL;
1454         fsg->ep0req->length = 0;
1455         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1456
1457         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1458                 rc = class_setup_req(fsg, ctrl);
1459         else
1460                 rc = standard_setup_req(fsg, ctrl);
1461
1462         /* Respond with data/status or defer until later? */
1463         if (rc >= 0 && rc != DELAYED_STATUS) {
1464                 rc = min(rc, w_length);
1465                 fsg->ep0req->length = rc;
1466                 fsg->ep0req->zero = rc < w_length;
1467                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1468                                 "ep0-in" : "ep0-out");
1469                 rc = ep0_queue(fsg);
1470         }
1471
1472         /* Device either stalls (rc < 0) or reports success */
1473         return rc;
1474 }
1475
1476
1477 /*-------------------------------------------------------------------------*/
1478
1479 /* All the following routines run in process context */
1480
1481
1482 /* Use this for bulk or interrupt transfers, not ep0 */
1483 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1484                 struct usb_request *req, int *pbusy,
1485                 enum fsg_buffer_state *state)
1486 {
1487         int     rc;
1488
1489         if (ep == fsg->bulk_in)
1490                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1491         else if (ep == fsg->intr_in)
1492                 dump_msg(fsg, "intr-in", req->buf, req->length);
1493
1494         spin_lock_irq(&fsg->lock);
1495         *pbusy = 1;
1496         *state = BUF_STATE_BUSY;
1497         spin_unlock_irq(&fsg->lock);
1498         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1499         if (rc != 0) {
1500                 *pbusy = 0;
1501                 *state = BUF_STATE_EMPTY;
1502
1503                 /* We can't do much more than wait for a reset */
1504
1505                 /* Note: currently the net2280 driver fails zero-length
1506                  * submissions if DMA is enabled. */
1507                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1508                                                 req->length == 0))
1509                         WARN(fsg, "error in submission: %s --> %d\n",
1510                                         ep->name, rc);
1511         }
1512 }
1513
1514
1515 static int sleep_thread(struct fsg_dev *fsg)
1516 {
1517         int     rc = 0;
1518
1519         /* Wait until a signal arrives or we are woken up */
1520         for (;;) {
1521                 try_to_freeze();
1522                 set_current_state(TASK_INTERRUPTIBLE);
1523                 if (signal_pending(current)) {
1524                         rc = -EINTR;
1525                         break;
1526                 }
1527                 if (fsg->thread_wakeup_needed)
1528                         break;
1529                 schedule();
1530         }
1531         __set_current_state(TASK_RUNNING);
1532         fsg->thread_wakeup_needed = 0;
1533         return rc;
1534 }
1535
1536
1537 /*-------------------------------------------------------------------------*/
1538
1539 static int do_read(struct fsg_dev *fsg)
1540 {
1541         struct lun              *curlun = fsg->curlun;
1542         u32                     lba;
1543         struct fsg_buffhd       *bh;
1544         int                     rc;
1545         u32                     amount_left;
1546         loff_t                  file_offset, file_offset_tmp;
1547         unsigned int            amount;
1548         unsigned int            partial_page;
1549         ssize_t                 nread;
1550
1551         /* Get the starting Logical Block Address and check that it's
1552          * not too big */
1553         if (fsg->cmnd[0] == SC_READ_6)
1554                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1555         else {
1556                 lba = get_be32(&fsg->cmnd[2]);
1557
1558                 /* We allow DPO (Disable Page Out = don't save data in the
1559                  * cache) and FUA (Force Unit Access = don't read from the
1560                  * cache), but we don't implement them. */
1561                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1562                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1563                         return -EINVAL;
1564                 }
1565         }
1566         if (lba >= curlun->num_sectors) {
1567                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1568                 return -EINVAL;
1569         }
1570         file_offset = ((loff_t) lba) << 9;
1571
1572         /* Carry out the file reads */
1573         amount_left = fsg->data_size_from_cmnd;
1574         if (unlikely(amount_left == 0))
1575                 return -EIO;            // No default reply
1576
1577         for (;;) {
1578
1579                 /* Figure out how much we need to read:
1580                  * Try to read the remaining amount.
1581                  * But don't read more than the buffer size.
1582                  * And don't try to read past the end of the file.
1583                  * Finally, if we're not at a page boundary, don't read past
1584                  *      the next page.
1585                  * If this means reading 0 then we were asked to read past
1586                  *      the end of file. */
1587                 amount = min((unsigned int) amount_left, mod_data.buflen);
1588                 amount = min((loff_t) amount,
1589                                 curlun->file_length - file_offset);
1590                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1591                 if (partial_page > 0)
1592                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1593                                         partial_page);
1594
1595                 /* Wait for the next buffer to become available */
1596                 bh = fsg->next_buffhd_to_fill;
1597                 while (bh->state != BUF_STATE_EMPTY) {
1598                         rc = sleep_thread(fsg);
1599                         if (rc)
1600                                 return rc;
1601                 }
1602
1603                 /* If we were asked to read past the end of file,
1604                  * end with an empty buffer. */
1605                 if (amount == 0) {
1606                         curlun->sense_data =
1607                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1608                         curlun->sense_data_info = file_offset >> 9;
1609                         curlun->info_valid = 1;
1610                         bh->inreq->length = 0;
1611                         bh->state = BUF_STATE_FULL;
1612                         break;
1613                 }
1614
1615                 /* Perform the read */
1616                 file_offset_tmp = file_offset;
1617                 nread = vfs_read(curlun->filp,
1618                                 (char __user *) bh->buf,
1619                                 amount, &file_offset_tmp);
1620                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1621                                 (unsigned long long) file_offset,
1622                                 (int) nread);
1623                 if (signal_pending(current))
1624                         return -EINTR;
1625
1626                 if (nread < 0) {
1627                         LDBG(curlun, "error in file read: %d\n",
1628                                         (int) nread);
1629                         nread = 0;
1630                 } else if (nread < amount) {
1631                         LDBG(curlun, "partial file read: %d/%u\n",
1632                                         (int) nread, amount);
1633                         nread -= (nread & 511); // Round down to a block
1634                 }
1635                 file_offset  += nread;
1636                 amount_left  -= nread;
1637                 fsg->residue -= nread;
1638                 bh->inreq->length = nread;
1639                 bh->state = BUF_STATE_FULL;
1640
1641                 /* If an error occurred, report it and its position */
1642                 if (nread < amount) {
1643                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1644                         curlun->sense_data_info = file_offset >> 9;
1645                         curlun->info_valid = 1;
1646                         break;
1647                 }
1648
1649                 if (amount_left == 0)
1650                         break;          // No more left to read
1651
1652                 /* Send this buffer and go read some more */
1653                 bh->inreq->zero = 0;
1654                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1655                                 &bh->inreq_busy, &bh->state);
1656                 fsg->next_buffhd_to_fill = bh->next;
1657         }
1658
1659         return -EIO;            // No default reply
1660 }
1661
1662
1663 /*-------------------------------------------------------------------------*/
1664
1665 static int do_write(struct fsg_dev *fsg)
1666 {
1667         struct lun              *curlun = fsg->curlun;
1668         u32                     lba;
1669         struct fsg_buffhd       *bh;
1670         int                     get_some_more;
1671         u32                     amount_left_to_req, amount_left_to_write;
1672         loff_t                  usb_offset, file_offset, file_offset_tmp;
1673         unsigned int            amount;
1674         unsigned int            partial_page;
1675         ssize_t                 nwritten;
1676         int                     rc;
1677
1678         if (curlun->ro) {
1679                 curlun->sense_data = SS_WRITE_PROTECTED;
1680                 return -EINVAL;
1681         }
1682         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1683
1684         /* Get the starting Logical Block Address and check that it's
1685          * not too big */
1686         if (fsg->cmnd[0] == SC_WRITE_6)
1687                 lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]);
1688         else {
1689                 lba = get_be32(&fsg->cmnd[2]);
1690
1691                 /* We allow DPO (Disable Page Out = don't save data in the
1692                  * cache) and FUA (Force Unit Access = write directly to the
1693                  * medium).  We don't implement DPO; we implement FUA by
1694                  * performing synchronous output. */
1695                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1696                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1697                         return -EINVAL;
1698                 }
1699                 if (fsg->cmnd[1] & 0x08)        // FUA
1700                         curlun->filp->f_flags |= O_SYNC;
1701         }
1702         if (lba >= curlun->num_sectors) {
1703                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1704                 return -EINVAL;
1705         }
1706
1707         /* Carry out the file writes */
1708         get_some_more = 1;
1709         file_offset = usb_offset = ((loff_t) lba) << 9;
1710         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1711
1712         while (amount_left_to_write > 0) {
1713
1714                 /* Queue a request for more data from the host */
1715                 bh = fsg->next_buffhd_to_fill;
1716                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1717
1718                         /* Figure out how much we want to get:
1719                          * Try to get the remaining amount.
1720                          * But don't get more than the buffer size.
1721                          * And don't try to go past the end of the file.
1722                          * If we're not at a page boundary,
1723                          *      don't go past the next page.
1724                          * If this means getting 0, then we were asked
1725                          *      to write past the end of file.
1726                          * Finally, round down to a block boundary. */
1727                         amount = min(amount_left_to_req, mod_data.buflen);
1728                         amount = min((loff_t) amount, curlun->file_length -
1729                                         usb_offset);
1730                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1731                         if (partial_page > 0)
1732                                 amount = min(amount,
1733         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1734
1735                         if (amount == 0) {
1736                                 get_some_more = 0;
1737                                 curlun->sense_data =
1738                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1739                                 curlun->sense_data_info = usb_offset >> 9;
1740                                 curlun->info_valid = 1;
1741                                 continue;
1742                         }
1743                         amount -= (amount & 511);
1744                         if (amount == 0) {
1745
1746                                 /* Why were we were asked to transfer a
1747                                  * partial block? */
1748                                 get_some_more = 0;
1749                                 continue;
1750                         }
1751
1752                         /* Get the next buffer */
1753                         usb_offset += amount;
1754                         fsg->usb_amount_left -= amount;
1755                         amount_left_to_req -= amount;
1756                         if (amount_left_to_req == 0)
1757                                 get_some_more = 0;
1758
1759                         /* amount is always divisible by 512, hence by
1760                          * the bulk-out maxpacket size */
1761                         bh->outreq->length = bh->bulk_out_intended_length =
1762                                         amount;
1763                         bh->outreq->short_not_ok = 1;
1764                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1765                                         &bh->outreq_busy, &bh->state);
1766                         fsg->next_buffhd_to_fill = bh->next;
1767                         continue;
1768                 }
1769
1770                 /* Write the received data to the backing file */
1771                 bh = fsg->next_buffhd_to_drain;
1772                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1773                         break;                  // We stopped early
1774                 if (bh->state == BUF_STATE_FULL) {
1775                         smp_rmb();
1776                         fsg->next_buffhd_to_drain = bh->next;
1777                         bh->state = BUF_STATE_EMPTY;
1778
1779                         /* Did something go wrong with the transfer? */
1780                         if (bh->outreq->status != 0) {
1781                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1782                                 curlun->sense_data_info = file_offset >> 9;
1783                                 curlun->info_valid = 1;
1784                                 break;
1785                         }
1786
1787                         amount = bh->outreq->actual;
1788                         if (curlun->file_length - file_offset < amount) {
1789                                 LERROR(curlun,
1790         "write %u @ %llu beyond end %llu\n",
1791         amount, (unsigned long long) file_offset,
1792         (unsigned long long) curlun->file_length);
1793                                 amount = curlun->file_length - file_offset;
1794                         }
1795
1796                         /* Perform the write */
1797                         file_offset_tmp = file_offset;
1798                         nwritten = vfs_write(curlun->filp,
1799                                         (char __user *) bh->buf,
1800                                         amount, &file_offset_tmp);
1801                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1802                                         (unsigned long long) file_offset,
1803                                         (int) nwritten);
1804                         if (signal_pending(current))
1805                                 return -EINTR;          // Interrupted!
1806
1807                         if (nwritten < 0) {
1808                                 LDBG(curlun, "error in file write: %d\n",
1809                                                 (int) nwritten);
1810                                 nwritten = 0;
1811                         } else if (nwritten < amount) {
1812                                 LDBG(curlun, "partial file write: %d/%u\n",
1813                                                 (int) nwritten, amount);
1814                                 nwritten -= (nwritten & 511);
1815                                                 // Round down to a block
1816                         }
1817                         file_offset += nwritten;
1818                         amount_left_to_write -= nwritten;
1819                         fsg->residue -= nwritten;
1820
1821                         /* If an error occurred, report it and its position */
1822                         if (nwritten < amount) {
1823                                 curlun->sense_data = SS_WRITE_ERROR;
1824                                 curlun->sense_data_info = file_offset >> 9;
1825                                 curlun->info_valid = 1;
1826                                 break;
1827                         }
1828
1829                         /* Did the host decide to stop early? */
1830                         if (bh->outreq->actual != bh->outreq->length) {
1831                                 fsg->short_packet_received = 1;
1832                                 break;
1833                         }
1834                         continue;
1835                 }
1836
1837                 /* Wait for something to happen */
1838                 rc = sleep_thread(fsg);
1839                 if (rc)
1840                         return rc;
1841         }
1842
1843         return -EIO;            // No default reply
1844 }
1845
1846
1847 /*-------------------------------------------------------------------------*/
1848
1849 /* Sync the file data, don't bother with the metadata.
1850  * This code was copied from fs/buffer.c:sys_fdatasync(). */
1851 static int fsync_sub(struct lun *curlun)
1852 {
1853         struct file     *filp = curlun->filp;
1854         struct inode    *inode;
1855         int             rc, err;
1856
1857         if (curlun->ro || !filp)
1858                 return 0;
1859         if (!filp->f_op->fsync)
1860                 return -EINVAL;
1861
1862         inode = filp->f_path.dentry->d_inode;
1863         mutex_lock(&inode->i_mutex);
1864         rc = filemap_fdatawrite(inode->i_mapping);
1865         err = filp->f_op->fsync(filp, filp->f_path.dentry, 1);
1866         if (!rc)
1867                 rc = err;
1868         err = filemap_fdatawait(inode->i_mapping);
1869         if (!rc)
1870                 rc = err;
1871         mutex_unlock(&inode->i_mutex);
1872         VLDBG(curlun, "fdatasync -> %d\n", rc);
1873         return rc;
1874 }
1875
1876 static void fsync_all(struct fsg_dev *fsg)
1877 {
1878         int     i;
1879
1880         for (i = 0; i < fsg->nluns; ++i)
1881                 fsync_sub(&fsg->luns[i]);
1882 }
1883
1884 static int do_synchronize_cache(struct fsg_dev *fsg)
1885 {
1886         struct lun      *curlun = fsg->curlun;
1887         int             rc;
1888
1889         /* We ignore the requested LBA and write out all file's
1890          * dirty data buffers. */
1891         rc = fsync_sub(curlun);
1892         if (rc)
1893                 curlun->sense_data = SS_WRITE_ERROR;
1894         return 0;
1895 }
1896
1897
1898 /*-------------------------------------------------------------------------*/
1899
1900 static void invalidate_sub(struct lun *curlun)
1901 {
1902         struct file     *filp = curlun->filp;
1903         struct inode    *inode = filp->f_path.dentry->d_inode;
1904         unsigned long   rc;
1905
1906         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1907         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
1908 }
1909
1910 static int do_verify(struct fsg_dev *fsg)
1911 {
1912         struct lun              *curlun = fsg->curlun;
1913         u32                     lba;
1914         u32                     verification_length;
1915         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1916         loff_t                  file_offset, file_offset_tmp;
1917         u32                     amount_left;
1918         unsigned int            amount;
1919         ssize_t                 nread;
1920
1921         /* Get the starting Logical Block Address and check that it's
1922          * not too big */
1923         lba = get_be32(&fsg->cmnd[2]);
1924         if (lba >= curlun->num_sectors) {
1925                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1926                 return -EINVAL;
1927         }
1928
1929         /* We allow DPO (Disable Page Out = don't save data in the
1930          * cache) but we don't implement it. */
1931         if ((fsg->cmnd[1] & ~0x10) != 0) {
1932                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1933                 return -EINVAL;
1934         }
1935
1936         verification_length = get_be16(&fsg->cmnd[7]);
1937         if (unlikely(verification_length == 0))
1938                 return -EIO;            // No default reply
1939
1940         /* Prepare to carry out the file verify */
1941         amount_left = verification_length << 9;
1942         file_offset = ((loff_t) lba) << 9;
1943
1944         /* Write out all the dirty buffers before invalidating them */
1945         fsync_sub(curlun);
1946         if (signal_pending(current))
1947                 return -EINTR;
1948
1949         invalidate_sub(curlun);
1950         if (signal_pending(current))
1951                 return -EINTR;
1952
1953         /* Just try to read the requested blocks */
1954         while (amount_left > 0) {
1955
1956                 /* Figure out how much we need to read:
1957                  * Try to read the remaining amount, but not more than
1958                  * the buffer size.
1959                  * And don't try to read past the end of the file.
1960                  * If this means reading 0 then we were asked to read
1961                  * past the end of file. */
1962                 amount = min((unsigned int) amount_left, mod_data.buflen);
1963                 amount = min((loff_t) amount,
1964                                 curlun->file_length - file_offset);
1965                 if (amount == 0) {
1966                         curlun->sense_data =
1967                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1968                         curlun->sense_data_info = file_offset >> 9;
1969                         curlun->info_valid = 1;
1970                         break;
1971                 }
1972
1973                 /* Perform the read */
1974                 file_offset_tmp = file_offset;
1975                 nread = vfs_read(curlun->filp,
1976                                 (char __user *) bh->buf,
1977                                 amount, &file_offset_tmp);
1978                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1979                                 (unsigned long long) file_offset,
1980                                 (int) nread);
1981                 if (signal_pending(current))
1982                         return -EINTR;
1983
1984                 if (nread < 0) {
1985                         LDBG(curlun, "error in file verify: %d\n",
1986                                         (int) nread);
1987                         nread = 0;
1988                 } else if (nread < amount) {
1989                         LDBG(curlun, "partial file verify: %d/%u\n",
1990                                         (int) nread, amount);
1991                         nread -= (nread & 511); // Round down to a sector
1992                 }
1993                 if (nread == 0) {
1994                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1995                         curlun->sense_data_info = file_offset >> 9;
1996                         curlun->info_valid = 1;
1997                         break;
1998                 }
1999                 file_offset += nread;
2000                 amount_left -= nread;
2001         }
2002         return 0;
2003 }
2004
2005
2006 /*-------------------------------------------------------------------------*/
2007
2008 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2009 {
2010         u8      *buf = (u8 *) bh->buf;
2011
2012         static char vendor_id[] = "Linux   ";
2013         static char product_id[] = "File-Stor Gadget";
2014
2015         if (!fsg->curlun) {             // Unsupported LUNs are okay
2016                 fsg->bad_lun_okay = 1;
2017                 memset(buf, 0, 36);
2018                 buf[0] = 0x7f;          // Unsupported, no device-type
2019                 return 36;
2020         }
2021
2022         memset(buf, 0, 8);      // Non-removable, direct-access device
2023         if (mod_data.removable)
2024                 buf[1] = 0x80;
2025         buf[2] = 2;             // ANSI SCSI level 2
2026         buf[3] = 2;             // SCSI-2 INQUIRY data format
2027         buf[4] = 31;            // Additional length
2028                                 // No special options
2029         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, product_id,
2030                         mod_data.release);
2031         return 36;
2032 }
2033
2034
2035 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2036 {
2037         struct lun      *curlun = fsg->curlun;
2038         u8              *buf = (u8 *) bh->buf;
2039         u32             sd, sdinfo;
2040         int             valid;
2041
2042         /*
2043          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
2044          *
2045          * If a REQUEST SENSE command is received from an initiator
2046          * with a pending unit attention condition (before the target
2047          * generates the contingent allegiance condition), then the
2048          * target shall either:
2049          *   a) report any pending sense data and preserve the unit
2050          *      attention condition on the logical unit, or,
2051          *   b) report the unit attention condition, may discard any
2052          *      pending sense data, and clear the unit attention
2053          *      condition on the logical unit for that initiator.
2054          *
2055          * FSG normally uses option a); enable this code to use option b).
2056          */
2057 #if 0
2058         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
2059                 curlun->sense_data = curlun->unit_attention_data;
2060                 curlun->unit_attention_data = SS_NO_SENSE;
2061         }
2062 #endif
2063
2064         if (!curlun) {          // Unsupported LUNs are okay
2065                 fsg->bad_lun_okay = 1;
2066                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2067                 sdinfo = 0;
2068                 valid = 0;
2069         } else {
2070                 sd = curlun->sense_data;
2071                 sdinfo = curlun->sense_data_info;
2072                 valid = curlun->info_valid << 7;
2073                 curlun->sense_data = SS_NO_SENSE;
2074                 curlun->sense_data_info = 0;
2075                 curlun->info_valid = 0;
2076         }
2077
2078         memset(buf, 0, 18);
2079         buf[0] = valid | 0x70;                  // Valid, current error
2080         buf[2] = SK(sd);
2081         put_be32(&buf[3], sdinfo);              // Sense information
2082         buf[7] = 18 - 8;                        // Additional sense length
2083         buf[12] = ASC(sd);
2084         buf[13] = ASCQ(sd);
2085         return 18;
2086 }
2087
2088
2089 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2090 {
2091         struct lun      *curlun = fsg->curlun;
2092         u32             lba = get_be32(&fsg->cmnd[2]);
2093         int             pmi = fsg->cmnd[8];
2094         u8              *buf = (u8 *) bh->buf;
2095
2096         /* Check the PMI and LBA fields */
2097         if (pmi > 1 || (pmi == 0 && lba != 0)) {
2098                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2099                 return -EINVAL;
2100         }
2101
2102         put_be32(&buf[0], curlun->num_sectors - 1);     // Max logical block
2103         put_be32(&buf[4], 512);                         // Block length
2104         return 8;
2105 }
2106
2107
2108 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2109 {
2110         struct lun      *curlun = fsg->curlun;
2111         int             mscmnd = fsg->cmnd[0];
2112         u8              *buf = (u8 *) bh->buf;
2113         u8              *buf0 = buf;
2114         int             pc, page_code;
2115         int             changeable_values, all_pages;
2116         int             valid_page = 0;
2117         int             len, limit;
2118
2119         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
2120                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2121                 return -EINVAL;
2122         }
2123         pc = fsg->cmnd[2] >> 6;
2124         page_code = fsg->cmnd[2] & 0x3f;
2125         if (pc == 3) {
2126                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
2127                 return -EINVAL;
2128         }
2129         changeable_values = (pc == 1);
2130         all_pages = (page_code == 0x3f);
2131
2132         /* Write the mode parameter header.  Fixed values are: default
2133          * medium type, no cache control (DPOFUA), and no block descriptors.
2134          * The only variable value is the WriteProtect bit.  We will fill in
2135          * the mode data length later. */
2136         memset(buf, 0, 8);
2137         if (mscmnd == SC_MODE_SENSE_6) {
2138                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2139                 buf += 4;
2140                 limit = 255;
2141         } else {                        // SC_MODE_SENSE_10
2142                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
2143                 buf += 8;
2144                 limit = 65535;          // Should really be mod_data.buflen
2145         }
2146
2147         /* No block descriptors */
2148
2149         /* The mode pages, in numerical order.  The only page we support
2150          * is the Caching page. */
2151         if (page_code == 0x08 || all_pages) {
2152                 valid_page = 1;
2153                 buf[0] = 0x08;          // Page code
2154                 buf[1] = 10;            // Page length
2155                 memset(buf+2, 0, 10);   // None of the fields are changeable
2156
2157                 if (!changeable_values) {
2158                         buf[2] = 0x04;  // Write cache enable,
2159                                         // Read cache not disabled
2160                                         // No cache retention priorities
2161                         put_be16(&buf[4], 0xffff);  // Don't disable prefetch
2162                                         // Minimum prefetch = 0
2163                         put_be16(&buf[8], 0xffff);  // Maximum prefetch
2164                         put_be16(&buf[10], 0xffff); // Maximum prefetch ceiling
2165                 }
2166                 buf += 12;
2167         }
2168
2169         /* Check that a valid page was requested and the mode data length
2170          * isn't too long. */
2171         len = buf - buf0;
2172         if (!valid_page || len > limit) {
2173                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2174                 return -EINVAL;
2175         }
2176
2177         /*  Store the mode data length */
2178         if (mscmnd == SC_MODE_SENSE_6)
2179                 buf0[0] = len - 1;
2180         else
2181                 put_be16(buf0, len - 2);
2182         return len;
2183 }
2184
2185
2186 static int do_start_stop(struct fsg_dev *fsg)
2187 {
2188         struct lun      *curlun = fsg->curlun;
2189         int             loej, start;
2190
2191         if (!mod_data.removable) {
2192                 curlun->sense_data = SS_INVALID_COMMAND;
2193                 return -EINVAL;
2194         }
2195
2196         // int immed = fsg->cmnd[1] & 0x01;
2197         loej = fsg->cmnd[4] & 0x02;
2198         start = fsg->cmnd[4] & 0x01;
2199
2200 #ifdef CONFIG_USB_FILE_STORAGE_TEST
2201         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
2202                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
2203                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2204                 return -EINVAL;
2205         }
2206
2207         if (!start) {
2208
2209                 /* Are we allowed to unload the media? */
2210                 if (curlun->prevent_medium_removal) {
2211                         LDBG(curlun, "unload attempt prevented\n");
2212                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
2213                         return -EINVAL;
2214                 }
2215                 if (loej) {             // Simulate an unload/eject
2216                         up_read(&fsg->filesem);
2217                         down_write(&fsg->filesem);
2218                         close_backing_file(curlun);
2219                         up_write(&fsg->filesem);
2220                         down_read(&fsg->filesem);
2221                 }
2222         } else {
2223
2224                 /* Our emulation doesn't support mounting; the medium is
2225                  * available for use as soon as it is loaded. */
2226                 if (!backing_file_is_open(curlun)) {
2227                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2228                         return -EINVAL;
2229                 }
2230         }
2231 #endif
2232         return 0;
2233 }
2234
2235
2236 static int do_prevent_allow(struct fsg_dev *fsg)
2237 {
2238         struct lun      *curlun = fsg->curlun;
2239         int             prevent;
2240
2241         if (!mod_data.removable) {
2242                 curlun->sense_data = SS_INVALID_COMMAND;
2243                 return -EINVAL;
2244         }
2245
2246         prevent = fsg->cmnd[4] & 0x01;
2247         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
2248                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2249                 return -EINVAL;
2250         }
2251
2252         if (curlun->prevent_medium_removal && !prevent)
2253                 fsync_sub(curlun);
2254         curlun->prevent_medium_removal = prevent;
2255         return 0;
2256 }
2257
2258
2259 static int do_read_format_capacities(struct fsg_dev *fsg,
2260                         struct fsg_buffhd *bh)
2261 {
2262         struct lun      *curlun = fsg->curlun;
2263         u8              *buf = (u8 *) bh->buf;
2264
2265         buf[0] = buf[1] = buf[2] = 0;
2266         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
2267         buf += 4;
2268
2269         put_be32(&buf[0], curlun->num_sectors);         // Number of blocks
2270         put_be32(&buf[4], 512);                         // Block length
2271         buf[4] = 0x02;                                  // Current capacity
2272         return 12;
2273 }
2274
2275
2276 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2277 {
2278         struct lun      *curlun = fsg->curlun;
2279
2280         /* We don't support MODE SELECT */
2281         curlun->sense_data = SS_INVALID_COMMAND;
2282         return -EINVAL;
2283 }
2284
2285
2286 /*-------------------------------------------------------------------------*/
2287
2288 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
2289 {
2290         int     rc;
2291
2292         rc = fsg_set_halt(fsg, fsg->bulk_in);
2293         if (rc == -EAGAIN)
2294                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
2295         while (rc != 0) {
2296                 if (rc != -EAGAIN) {
2297                         WARN(fsg, "usb_ep_set_halt -> %d\n", rc);
2298                         rc = 0;
2299                         break;
2300                 }
2301
2302                 /* Wait for a short time and then try again */
2303                 if (msleep_interruptible(100) != 0)
2304                         return -EINTR;
2305                 rc = usb_ep_set_halt(fsg->bulk_in);
2306         }
2307         return rc;
2308 }
2309
2310 static int pad_with_zeros(struct fsg_dev *fsg)
2311 {
2312         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2313         u32                     nkeep = bh->inreq->length;
2314         u32                     nsend;
2315         int                     rc;
2316
2317         bh->state = BUF_STATE_EMPTY;            // For the first iteration
2318         fsg->usb_amount_left = nkeep + fsg->residue;
2319         while (fsg->usb_amount_left > 0) {
2320
2321                 /* Wait for the next buffer to be free */
2322                 while (bh->state != BUF_STATE_EMPTY) {
2323                         rc = sleep_thread(fsg);
2324                         if (rc)
2325                                 return rc;
2326                 }
2327
2328                 nsend = min(fsg->usb_amount_left, (u32) mod_data.buflen);
2329                 memset(bh->buf + nkeep, 0, nsend - nkeep);
2330                 bh->inreq->length = nsend;
2331                 bh->inreq->zero = 0;
2332                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2333                                 &bh->inreq_busy, &bh->state);
2334                 bh = fsg->next_buffhd_to_fill = bh->next;
2335                 fsg->usb_amount_left -= nsend;
2336                 nkeep = 0;
2337         }
2338         return 0;
2339 }
2340
2341 static int throw_away_data(struct fsg_dev *fsg)
2342 {
2343         struct fsg_buffhd       *bh;
2344         u32                     amount;
2345         int                     rc;
2346
2347         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
2348                         fsg->usb_amount_left > 0) {
2349
2350                 /* Throw away the data in a filled buffer */
2351                 if (bh->state == BUF_STATE_FULL) {
2352                         smp_rmb();
2353                         bh->state = BUF_STATE_EMPTY;
2354                         fsg->next_buffhd_to_drain = bh->next;
2355
2356                         /* A short packet or an error ends everything */
2357                         if (bh->outreq->actual != bh->outreq->length ||
2358                                         bh->outreq->status != 0) {
2359                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2360                                 return -EINTR;
2361                         }
2362                         continue;
2363                 }
2364
2365                 /* Try to submit another request if we need one */
2366                 bh = fsg->next_buffhd_to_fill;
2367                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
2368                         amount = min(fsg->usb_amount_left,
2369                                         (u32) mod_data.buflen);
2370
2371                         /* amount is always divisible by 512, hence by
2372                          * the bulk-out maxpacket size */
2373                         bh->outreq->length = bh->bulk_out_intended_length =
2374                                         amount;
2375                         bh->outreq->short_not_ok = 1;
2376                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2377                                         &bh->outreq_busy, &bh->state);
2378                         fsg->next_buffhd_to_fill = bh->next;
2379                         fsg->usb_amount_left -= amount;
2380                         continue;
2381                 }
2382
2383                 /* Otherwise wait for something to happen */
2384                 rc = sleep_thread(fsg);
2385                 if (rc)
2386                         return rc;
2387         }
2388         return 0;
2389 }
2390
2391
2392 static int finish_reply(struct fsg_dev *fsg)
2393 {
2394         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2395         int                     rc = 0;
2396
2397         switch (fsg->data_dir) {
2398         case DATA_DIR_NONE:
2399                 break;                  // Nothing to send
2400
2401         /* If we don't know whether the host wants to read or write,
2402          * this must be CB or CBI with an unknown command.  We mustn't
2403          * try to send or receive any data.  So stall both bulk pipes
2404          * if we can and wait for a reset. */
2405         case DATA_DIR_UNKNOWN:
2406                 if (mod_data.can_stall) {
2407                         fsg_set_halt(fsg, fsg->bulk_out);
2408                         rc = halt_bulk_in_endpoint(fsg);
2409                 }
2410                 break;
2411
2412         /* All but the last buffer of data must have already been sent */
2413         case DATA_DIR_TO_HOST:
2414                 if (fsg->data_size == 0)
2415                         ;               // Nothing to send
2416
2417                 /* If there's no residue, simply send the last buffer */
2418                 else if (fsg->residue == 0) {
2419                         bh->inreq->zero = 0;
2420                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2421                                         &bh->inreq_busy, &bh->state);
2422                         fsg->next_buffhd_to_fill = bh->next;
2423                 }
2424
2425                 /* There is a residue.  For CB and CBI, simply mark the end
2426                  * of the data with a short packet.  However, if we are
2427                  * allowed to stall, there was no data at all (residue ==
2428                  * data_size), and the command failed (invalid LUN or
2429                  * sense data is set), then halt the bulk-in endpoint
2430                  * instead. */
2431                 else if (!transport_is_bbb()) {
2432                         if (mod_data.can_stall &&
2433                                         fsg->residue == fsg->data_size &&
2434         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2435                                 bh->state = BUF_STATE_EMPTY;
2436                                 rc = halt_bulk_in_endpoint(fsg);
2437                         } else {
2438                                 bh->inreq->zero = 1;
2439                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2440                                                 &bh->inreq_busy, &bh->state);
2441                                 fsg->next_buffhd_to_fill = bh->next;
2442                         }
2443                 }
2444
2445                 /* For Bulk-only, if we're allowed to stall then send the
2446                  * short packet and halt the bulk-in endpoint.  If we can't
2447                  * stall, pad out the remaining data with 0's. */
2448                 else {
2449                         if (mod_data.can_stall) {
2450                                 bh->inreq->zero = 1;
2451                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2452                                                 &bh->inreq_busy, &bh->state);
2453                                 fsg->next_buffhd_to_fill = bh->next;
2454                                 rc = halt_bulk_in_endpoint(fsg);
2455                         } else
2456                                 rc = pad_with_zeros(fsg);
2457                 }
2458                 break;
2459
2460         /* We have processed all we want from the data the host has sent.
2461          * There may still be outstanding bulk-out requests. */
2462         case DATA_DIR_FROM_HOST:
2463                 if (fsg->residue == 0)
2464                         ;               // Nothing to receive
2465
2466                 /* Did the host stop sending unexpectedly early? */
2467                 else if (fsg->short_packet_received) {
2468                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2469                         rc = -EINTR;
2470                 }
2471
2472                 /* We haven't processed all the incoming data.  Even though
2473                  * we may be allowed to stall, doing so would cause a race.
2474                  * The controller may already have ACK'ed all the remaining
2475                  * bulk-out packets, in which case the host wouldn't see a
2476                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2477                  * clear the halt -- leading to problems later on. */
2478 #if 0
2479                 else if (mod_data.can_stall) {
2480                         fsg_set_halt(fsg, fsg->bulk_out);
2481                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2482                         rc = -EINTR;
2483                 }
2484 #endif
2485
2486                 /* We can't stall.  Read in the excess data and throw it
2487                  * all away. */
2488                 else
2489                         rc = throw_away_data(fsg);
2490                 break;
2491         }
2492         return rc;
2493 }
2494
2495
2496 static int send_status(struct fsg_dev *fsg)
2497 {
2498         struct lun              *curlun = fsg->curlun;
2499         struct fsg_buffhd       *bh;
2500         int                     rc;
2501         u8                      status = USB_STATUS_PASS;
2502         u32                     sd, sdinfo = 0;
2503
2504         /* Wait for the next buffer to become available */
2505         bh = fsg->next_buffhd_to_fill;
2506         while (bh->state != BUF_STATE_EMPTY) {
2507                 rc = sleep_thread(fsg);
2508                 if (rc)
2509                         return rc;
2510         }
2511
2512         if (curlun) {
2513                 sd = curlun->sense_data;
2514                 sdinfo = curlun->sense_data_info;
2515         } else if (fsg->bad_lun_okay)
2516                 sd = SS_NO_SENSE;
2517         else
2518                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2519
2520         if (fsg->phase_error) {
2521                 DBG(fsg, "sending phase-error status\n");
2522                 status = USB_STATUS_PHASE_ERROR;
2523                 sd = SS_INVALID_COMMAND;
2524         } else if (sd != SS_NO_SENSE) {
2525                 DBG(fsg, "sending command-failure status\n");
2526                 status = USB_STATUS_FAIL;
2527                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2528                                 "  info x%x\n",
2529                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2530         }
2531
2532         if (transport_is_bbb()) {
2533                 struct bulk_cs_wrap     *csw = bh->buf;
2534
2535                 /* Store and send the Bulk-only CSW */
2536                 csw->Signature = __constant_cpu_to_le32(USB_BULK_CS_SIG);
2537                 csw->Tag = fsg->tag;
2538                 csw->Residue = cpu_to_le32(fsg->residue);
2539                 csw->Status = status;
2540
2541                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2542                 bh->inreq->zero = 0;
2543                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2544                                 &bh->inreq_busy, &bh->state);
2545
2546         } else if (mod_data.transport_type == USB_PR_CB) {
2547
2548                 /* Control-Bulk transport has no status phase! */
2549                 return 0;
2550
2551         } else {                        // USB_PR_CBI
2552                 struct interrupt_data   *buf = bh->buf;
2553
2554                 /* Store and send the Interrupt data.  UFI sends the ASC
2555                  * and ASCQ bytes.  Everything else sends a Type (which
2556                  * is always 0) and the status Value. */
2557                 if (mod_data.protocol_type == USB_SC_UFI) {
2558                         buf->bType = ASC(sd);
2559                         buf->bValue = ASCQ(sd);
2560                 } else {
2561                         buf->bType = 0;
2562                         buf->bValue = status;
2563                 }
2564                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2565
2566                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2567                 fsg->intreq->buf = bh->inreq->buf;
2568                 fsg->intreq->context = bh;
2569                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2570                                 &fsg->intreq_busy, &bh->state);
2571         }
2572
2573         fsg->next_buffhd_to_fill = bh->next;
2574         return 0;
2575 }
2576
2577
2578 /*-------------------------------------------------------------------------*/
2579
2580 /* Check whether the command is properly formed and whether its data size
2581  * and direction agree with the values we already have. */
2582 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2583                 enum data_direction data_dir, unsigned int mask,
2584                 int needs_medium, const char *name)
2585 {
2586         int                     i;
2587         int                     lun = fsg->cmnd[1] >> 5;
2588         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2589         char                    hdlen[20];
2590         struct lun              *curlun;
2591
2592         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2593          * Transparent SCSI doesn't pad. */
2594         if (protocol_is_scsi())
2595                 ;
2596
2597         /* There's some disagreement as to whether RBC pads commands or not.
2598          * We'll play it safe and accept either form. */
2599         else if (mod_data.protocol_type == USB_SC_RBC) {
2600                 if (fsg->cmnd_size == 12)
2601                         cmnd_size = 12;
2602
2603         /* All the other protocols pad to 12 bytes */
2604         } else
2605                 cmnd_size = 12;
2606
2607         hdlen[0] = 0;
2608         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2609                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2610                                 fsg->data_size);
2611         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2612                         name, cmnd_size, dirletter[(int) data_dir],
2613                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2614
2615         /* We can't reply at all until we know the correct data direction
2616          * and size. */
2617         if (fsg->data_size_from_cmnd == 0)
2618                 data_dir = DATA_DIR_NONE;
2619         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2620                 fsg->data_dir = data_dir;
2621                 fsg->data_size = fsg->data_size_from_cmnd;
2622
2623         } else {                                        // Bulk-only
2624                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2625
2626                         /* Host data size < Device data size is a phase error.
2627                          * Carry out the command, but only transfer as much
2628                          * as we are allowed. */
2629                         fsg->data_size_from_cmnd = fsg->data_size;
2630                         fsg->phase_error = 1;
2631                 }
2632         }
2633         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2634
2635         /* Conflicting data directions is a phase error */
2636         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2637                 fsg->phase_error = 1;
2638                 return -EINVAL;
2639         }
2640
2641         /* Verify the length of the command itself */
2642         if (cmnd_size != fsg->cmnd_size) {
2643
2644                 /* Special case workaround: MS-Windows issues REQUEST SENSE
2645                  * with cbw->Length == 12 (it should be 6). */
2646                 if (fsg->cmnd[0] == SC_REQUEST_SENSE && fsg->cmnd_size == 12)
2647                         cmnd_size = fsg->cmnd_size;
2648                 else {
2649                         fsg->phase_error = 1;
2650                         return -EINVAL;
2651                 }
2652         }
2653
2654         /* Check that the LUN values are consistent */
2655         if (transport_is_bbb()) {
2656                 if (fsg->lun != lun)
2657                         DBG(fsg, "using LUN %d from CBW, "
2658                                         "not LUN %d from CDB\n",
2659                                         fsg->lun, lun);
2660         } else
2661                 fsg->lun = lun;         // Use LUN from the command
2662
2663         /* Check the LUN */
2664         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
2665                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2666                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
2667                         curlun->sense_data = SS_NO_SENSE;
2668                         curlun->sense_data_info = 0;
2669                         curlun->info_valid = 0;
2670                 }
2671         } else {
2672                 fsg->curlun = curlun = NULL;
2673                 fsg->bad_lun_okay = 0;
2674
2675                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2676                  * to use unsupported LUNs; all others may not. */
2677                 if (fsg->cmnd[0] != SC_INQUIRY &&
2678                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2679                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2680                         return -EINVAL;
2681                 }
2682         }
2683
2684         /* If a unit attention condition exists, only INQUIRY and
2685          * REQUEST SENSE commands are allowed; anything else must fail. */
2686         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2687                         fsg->cmnd[0] != SC_INQUIRY &&
2688                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2689                 curlun->sense_data = curlun->unit_attention_data;
2690                 curlun->unit_attention_data = SS_NO_SENSE;
2691                 return -EINVAL;
2692         }
2693
2694         /* Check that only command bytes listed in the mask are non-zero */
2695         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2696         for (i = 1; i < cmnd_size; ++i) {
2697                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2698                         if (curlun)
2699                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2700                         return -EINVAL;
2701                 }
2702         }
2703
2704         /* If the medium isn't mounted and the command needs to access
2705          * it, return an error. */
2706         if (curlun && !backing_file_is_open(curlun) && needs_medium) {
2707                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2708                 return -EINVAL;
2709         }
2710
2711         return 0;
2712 }
2713
2714
2715 static int do_scsi_command(struct fsg_dev *fsg)
2716 {
2717         struct fsg_buffhd       *bh;
2718         int                     rc;
2719         int                     reply = -EINVAL;
2720         int                     i;
2721         static char             unknown[16];
2722
2723         dump_cdb(fsg);
2724
2725         /* Wait for the next buffer to become available for data or status */
2726         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2727         while (bh->state != BUF_STATE_EMPTY) {
2728                 rc = sleep_thread(fsg);
2729                 if (rc)
2730                         return rc;
2731         }
2732         fsg->phase_error = 0;
2733         fsg->short_packet_received = 0;
2734
2735         down_read(&fsg->filesem);       // We're using the backing file
2736         switch (fsg->cmnd[0]) {
2737
2738         case SC_INQUIRY:
2739                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2740                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2741                                 (1<<4), 0,
2742                                 "INQUIRY")) == 0)
2743                         reply = do_inquiry(fsg, bh);
2744                 break;
2745
2746         case SC_MODE_SELECT_6:
2747                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2748                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2749                                 (1<<1) | (1<<4), 0,
2750                                 "MODE SELECT(6)")) == 0)
2751                         reply = do_mode_select(fsg, bh);
2752                 break;
2753
2754         case SC_MODE_SELECT_10:
2755                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2756                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2757                                 (1<<1) | (3<<7), 0,
2758                                 "MODE SELECT(10)")) == 0)
2759                         reply = do_mode_select(fsg, bh);
2760                 break;
2761
2762         case SC_MODE_SENSE_6:
2763                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2764                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2765                                 (1<<1) | (1<<2) | (1<<4), 0,
2766                                 "MODE SENSE(6)")) == 0)
2767                         reply = do_mode_sense(fsg, bh);
2768                 break;
2769
2770         case SC_MODE_SENSE_10:
2771                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2772                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2773                                 (1<<1) | (1<<2) | (3<<7), 0,
2774                                 "MODE SENSE(10)")) == 0)
2775                         reply = do_mode_sense(fsg, bh);
2776                 break;
2777
2778         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2779                 fsg->data_size_from_cmnd = 0;
2780                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2781                                 (1<<4), 0,
2782                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2783                         reply = do_prevent_allow(fsg);
2784                 break;
2785
2786         case SC_READ_6:
2787                 i = fsg->cmnd[4];
2788                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2789                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2790                                 (7<<1) | (1<<4), 1,
2791                                 "READ(6)")) == 0)
2792                         reply = do_read(fsg);
2793                 break;
2794
2795         case SC_READ_10:
2796                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2797                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2798                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2799                                 "READ(10)")) == 0)
2800                         reply = do_read(fsg);
2801                 break;
2802
2803         case SC_READ_12:
2804                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2805                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2806                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2807                                 "READ(12)")) == 0)
2808                         reply = do_read(fsg);
2809                 break;
2810
2811         case SC_READ_CAPACITY:
2812                 fsg->data_size_from_cmnd = 8;
2813                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2814                                 (0xf<<2) | (1<<8), 1,
2815                                 "READ CAPACITY")) == 0)
2816                         reply = do_read_capacity(fsg, bh);
2817                 break;
2818
2819         case SC_READ_FORMAT_CAPACITIES:
2820                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]);
2821                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2822                                 (3<<7), 1,
2823                                 "READ FORMAT CAPACITIES")) == 0)
2824                         reply = do_read_format_capacities(fsg, bh);
2825                 break;
2826
2827         case SC_REQUEST_SENSE:
2828                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2829                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2830                                 (1<<4), 0,
2831                                 "REQUEST SENSE")) == 0)
2832                         reply = do_request_sense(fsg, bh);
2833                 break;
2834
2835         case SC_START_STOP_UNIT:
2836                 fsg->data_size_from_cmnd = 0;
2837                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2838                                 (1<<1) | (1<<4), 0,
2839                                 "START-STOP UNIT")) == 0)
2840                         reply = do_start_stop(fsg);
2841                 break;
2842
2843         case SC_SYNCHRONIZE_CACHE:
2844                 fsg->data_size_from_cmnd = 0;
2845                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2846                                 (0xf<<2) | (3<<7), 1,
2847                                 "SYNCHRONIZE CACHE")) == 0)
2848                         reply = do_synchronize_cache(fsg);
2849                 break;
2850
2851         case SC_TEST_UNIT_READY:
2852                 fsg->data_size_from_cmnd = 0;
2853                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2854                                 0, 1,
2855                                 "TEST UNIT READY");
2856                 break;
2857
2858         /* Although optional, this command is used by MS-Windows.  We
2859          * support a minimal version: BytChk must be 0. */
2860         case SC_VERIFY:
2861                 fsg->data_size_from_cmnd = 0;
2862                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2863                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2864                                 "VERIFY")) == 0)
2865                         reply = do_verify(fsg);
2866                 break;
2867
2868         case SC_WRITE_6:
2869                 i = fsg->cmnd[4];
2870                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2871                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2872                                 (7<<1) | (1<<4), 1,
2873                                 "WRITE(6)")) == 0)
2874                         reply = do_write(fsg);
2875                 break;
2876
2877         case SC_WRITE_10:
2878                 fsg->data_size_from_cmnd = get_be16(&fsg->cmnd[7]) << 9;
2879                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2880                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2881                                 "WRITE(10)")) == 0)
2882                         reply = do_write(fsg);
2883                 break;
2884
2885         case SC_WRITE_12:
2886                 fsg->data_size_from_cmnd = get_be32(&fsg->cmnd[6]) << 9;
2887                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2888                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2889                                 "WRITE(12)")) == 0)
2890                         reply = do_write(fsg);
2891                 break;
2892
2893         /* Some mandatory commands that we recognize but don't implement.
2894          * They don't mean much in this setting.  It's left as an exercise
2895          * for anyone interested to implement RESERVE and RELEASE in terms
2896          * of Posix locks. */
2897         case SC_FORMAT_UNIT:
2898         case SC_RELEASE:
2899         case SC_RESERVE:
2900         case SC_SEND_DIAGNOSTIC:
2901                 // Fall through
2902
2903         default:
2904                 fsg->data_size_from_cmnd = 0;
2905                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2906                 if ((reply = check_command(fsg, fsg->cmnd_size,
2907                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2908                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2909                         reply = -EINVAL;
2910                 }
2911                 break;
2912         }
2913         up_read(&fsg->filesem);
2914
2915         if (reply == -EINTR || signal_pending(current))
2916                 return -EINTR;
2917
2918         /* Set up the single reply buffer for finish_reply() */
2919         if (reply == -EINVAL)
2920                 reply = 0;              // Error reply length
2921         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2922                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2923                 bh->inreq->length = reply;
2924                 bh->state = BUF_STATE_FULL;
2925                 fsg->residue -= reply;
2926         }                               // Otherwise it's already set
2927
2928         return 0;
2929 }
2930
2931
2932 /*-------------------------------------------------------------------------*/
2933
2934 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2935 {
2936         struct usb_request      *req = bh->outreq;
2937         struct bulk_cb_wrap     *cbw = req->buf;
2938
2939         /* Was this a real packet? */
2940         if (req->status)
2941                 return -EINVAL;
2942
2943         /* Is the CBW valid? */
2944         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2945                         cbw->Signature != __constant_cpu_to_le32(
2946                                 USB_BULK_CB_SIG)) {
2947                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2948                                 req->actual,
2949                                 le32_to_cpu(cbw->Signature));
2950
2951                 /* The Bulk-only spec says we MUST stall the bulk pipes!
2952                  * If we want to avoid stalls, set a flag so that we will
2953                  * clear the endpoint halts at the next reset. */
2954                 if (!mod_data.can_stall)
2955                         set_bit(CLEAR_BULK_HALTS, &fsg->atomic_bitflags);
2956                 fsg_set_halt(fsg, fsg->bulk_out);
2957                 halt_bulk_in_endpoint(fsg);
2958                 return -EINVAL;
2959         }
2960
2961         /* Is the CBW meaningful? */
2962         if (cbw->Lun >= MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2963                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2964                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2965                                 "cmdlen %u\n",
2966                                 cbw->Lun, cbw->Flags, cbw->Length);
2967
2968                 /* We can do anything we want here, so let's stall the
2969                  * bulk pipes if we are allowed to. */
2970                 if (mod_data.can_stall) {
2971                         fsg_set_halt(fsg, fsg->bulk_out);
2972                         halt_bulk_in_endpoint(fsg);
2973                 }
2974                 return -EINVAL;
2975         }
2976
2977         /* Save the command for later */
2978         fsg->cmnd_size = cbw->Length;
2979         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
2980         if (cbw->Flags & USB_BULK_IN_FLAG)
2981                 fsg->data_dir = DATA_DIR_TO_HOST;
2982         else
2983                 fsg->data_dir = DATA_DIR_FROM_HOST;
2984         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
2985         if (fsg->data_size == 0)
2986                 fsg->data_dir = DATA_DIR_NONE;
2987         fsg->lun = cbw->Lun;
2988         fsg->tag = cbw->Tag;
2989         return 0;
2990 }
2991
2992
2993 static int get_next_command(struct fsg_dev *fsg)
2994 {
2995         struct fsg_buffhd       *bh;
2996         int                     rc = 0;
2997
2998         if (transport_is_bbb()) {
2999
3000                 /* Wait for the next buffer to become available */
3001                 bh = fsg->next_buffhd_to_fill;
3002                 while (bh->state != BUF_STATE_EMPTY) {
3003                         rc = sleep_thread(fsg);
3004                         if (rc)
3005                                 return rc;
3006                 }
3007
3008                 /* Queue a request to read a Bulk-only CBW */
3009                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
3010                 bh->outreq->short_not_ok = 1;
3011                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
3012                                 &bh->outreq_busy, &bh->state);
3013
3014                 /* We will drain the buffer in software, which means we
3015                  * can reuse it for the next filling.  No need to advance
3016                  * next_buffhd_to_fill. */
3017
3018                 /* Wait for the CBW to arrive */
3019                 while (bh->state != BUF_STATE_FULL) {
3020                         rc = sleep_thread(fsg);
3021                         if (rc)
3022                                 return rc;
3023                 }
3024                 smp_rmb();
3025                 rc = received_cbw(fsg, bh);
3026                 bh->state = BUF_STATE_EMPTY;
3027
3028         } else {                // USB_PR_CB or USB_PR_CBI
3029
3030                 /* Wait for the next command to arrive */
3031                 while (fsg->cbbuf_cmnd_size == 0) {
3032                         rc = sleep_thread(fsg);
3033                         if (rc)
3034                                 return rc;
3035                 }
3036
3037                 /* Is the previous status interrupt request still busy?
3038                  * The host is allowed to skip reading the status,
3039                  * so we must cancel it. */
3040                 if (fsg->intreq_busy)
3041                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3042
3043                 /* Copy the command and mark the buffer empty */
3044                 fsg->data_dir = DATA_DIR_UNKNOWN;
3045                 spin_lock_irq(&fsg->lock);
3046                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
3047                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
3048                 fsg->cbbuf_cmnd_size = 0;
3049                 spin_unlock_irq(&fsg->lock);
3050         }
3051         return rc;
3052 }
3053
3054
3055 /*-------------------------------------------------------------------------*/
3056
3057 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
3058                 const struct usb_endpoint_descriptor *d)
3059 {
3060         int     rc;
3061
3062         ep->driver_data = fsg;
3063         rc = usb_ep_enable(ep, d);
3064         if (rc)
3065                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
3066         return rc;
3067 }
3068
3069 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
3070                 struct usb_request **preq)
3071 {
3072         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
3073         if (*preq)
3074                 return 0;
3075         ERROR(fsg, "can't allocate request for %s\n", ep->name);
3076         return -ENOMEM;
3077 }
3078
3079 /*
3080  * Reset interface setting and re-init endpoint state (toggle etc).
3081  * Call with altsetting < 0 to disable the interface.  The only other
3082  * available altsetting is 0, which enables the interface.
3083  */
3084 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
3085 {
3086         int     rc = 0;
3087         int     i;
3088         const struct usb_endpoint_descriptor    *d;
3089
3090         if (fsg->running)
3091                 DBG(fsg, "reset interface\n");
3092
3093 reset:
3094         /* Deallocate the requests */
3095         for (i = 0; i < NUM_BUFFERS; ++i) {
3096                 struct fsg_buffhd *bh = &fsg->buffhds[i];
3097
3098                 if (bh->inreq) {
3099                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
3100                         bh->inreq = NULL;
3101                 }
3102                 if (bh->outreq) {
3103                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
3104                         bh->outreq = NULL;
3105                 }
3106         }
3107         if (fsg->intreq) {
3108                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
3109                 fsg->intreq = NULL;
3110         }
3111
3112         /* Disable the endpoints */
3113         if (fsg->bulk_in_enabled) {
3114                 usb_ep_disable(fsg->bulk_in);
3115                 fsg->bulk_in_enabled = 0;
3116         }
3117         if (fsg->bulk_out_enabled) {
3118                 usb_ep_disable(fsg->bulk_out);
3119                 fsg->bulk_out_enabled = 0;
3120         }
3121         if (fsg->intr_in_enabled) {
3122                 usb_ep_disable(fsg->intr_in);
3123                 fsg->intr_in_enabled = 0;
3124         }
3125
3126         fsg->running = 0;
3127         if (altsetting < 0 || rc != 0)
3128                 return rc;
3129
3130         DBG(fsg, "set interface %d\n", altsetting);
3131
3132         /* Enable the endpoints */
3133         d = ep_desc(fsg->gadget, &fs_bulk_in_desc, &hs_bulk_in_desc);
3134         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
3135                 goto reset;
3136         fsg->bulk_in_enabled = 1;
3137
3138         d = ep_desc(fsg->gadget, &fs_bulk_out_desc, &hs_bulk_out_desc);
3139         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
3140                 goto reset;
3141         fsg->bulk_out_enabled = 1;
3142         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
3143
3144         if (transport_is_cbi()) {
3145                 d = ep_desc(fsg->gadget, &fs_intr_in_desc, &hs_intr_in_desc);
3146                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
3147                         goto reset;
3148                 fsg->intr_in_enabled = 1;
3149         }
3150
3151         /* Allocate the requests */
3152         for (i = 0; i < NUM_BUFFERS; ++i) {
3153                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3154
3155                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
3156                         goto reset;
3157                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
3158                         goto reset;
3159                 bh->inreq->buf = bh->outreq->buf = bh->buf;
3160                 bh->inreq->context = bh->outreq->context = bh;
3161                 bh->inreq->complete = bulk_in_complete;
3162                 bh->outreq->complete = bulk_out_complete;
3163         }
3164         if (transport_is_cbi()) {
3165                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
3166                         goto reset;
3167                 fsg->intreq->complete = intr_in_complete;
3168         }
3169
3170         fsg->running = 1;
3171         for (i = 0; i < fsg->nluns; ++i)
3172                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3173         return rc;
3174 }
3175
3176
3177 /*
3178  * Change our operational configuration.  This code must agree with the code
3179  * that returns config descriptors, and with interface altsetting code.
3180  *
3181  * It's also responsible for power management interactions.  Some
3182  * configurations might not work with our current power sources.
3183  * For now we just assume the gadget is always self-powered.
3184  */
3185 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
3186 {
3187         int     rc = 0;
3188
3189         /* Disable the single interface */
3190         if (fsg->config != 0) {
3191                 DBG(fsg, "reset config\n");
3192                 fsg->config = 0;
3193                 rc = do_set_interface(fsg, -1);
3194         }
3195
3196         /* Enable the interface */
3197         if (new_config != 0) {
3198                 fsg->config = new_config;
3199                 if ((rc = do_set_interface(fsg, 0)) != 0)
3200                         fsg->config = 0;        // Reset on errors
3201                 else {
3202                         char *speed;
3203
3204                         switch (fsg->gadget->speed) {
3205                         case USB_SPEED_LOW:     speed = "low";  break;
3206                         case USB_SPEED_FULL:    speed = "full"; break;
3207                         case USB_SPEED_HIGH:    speed = "high"; break;
3208                         default:                speed = "?";    break;
3209                         }
3210                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
3211                 }
3212         }
3213         return rc;
3214 }
3215
3216
3217 /*-------------------------------------------------------------------------*/
3218
3219 static void handle_exception(struct fsg_dev *fsg)
3220 {
3221         siginfo_t               info;
3222         int                     sig;
3223         int                     i;
3224         int                     num_active;
3225         struct fsg_buffhd       *bh;
3226         enum fsg_state          old_state;
3227         u8                      new_config;
3228         struct lun              *curlun;
3229         unsigned int            exception_req_tag;
3230         int                     rc;
3231
3232         /* Clear the existing signals.  Anything but SIGUSR1 is converted
3233          * into a high-priority EXIT exception. */
3234         for (;;) {
3235                 sig = dequeue_signal_lock(current, &current->blocked, &info);
3236                 if (!sig)
3237                         break;
3238                 if (sig != SIGUSR1) {
3239                         if (fsg->state < FSG_STATE_EXIT)
3240                                 DBG(fsg, "Main thread exiting on signal\n");
3241                         raise_exception(fsg, FSG_STATE_EXIT);
3242                 }
3243         }
3244
3245         /* Cancel all the pending transfers */
3246         if (fsg->intreq_busy)
3247                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
3248         for (i = 0; i < NUM_BUFFERS; ++i) {
3249                 bh = &fsg->buffhds[i];
3250                 if (bh->inreq_busy)
3251                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
3252                 if (bh->outreq_busy)
3253                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
3254         }
3255
3256         /* Wait until everything is idle */
3257         for (;;) {
3258                 num_active = fsg->intreq_busy;
3259                 for (i = 0; i < NUM_BUFFERS; ++i) {
3260                         bh = &fsg->buffhds[i];
3261                         num_active += bh->inreq_busy + bh->outreq_busy;
3262                 }
3263                 if (num_active == 0)
3264                         break;
3265                 if (sleep_thread(fsg))
3266                         return;
3267         }
3268
3269         /* Clear out the controller's fifos */
3270         if (fsg->bulk_in_enabled)
3271                 usb_ep_fifo_flush(fsg->bulk_in);
3272         if (fsg->bulk_out_enabled)
3273                 usb_ep_fifo_flush(fsg->bulk_out);
3274         if (fsg->intr_in_enabled)
3275                 usb_ep_fifo_flush(fsg->intr_in);
3276
3277         /* Reset the I/O buffer states and pointers, the SCSI
3278          * state, and the exception.  Then invoke the handler. */
3279         spin_lock_irq(&fsg->lock);
3280
3281         for (i = 0; i < NUM_BUFFERS; ++i) {
3282                 bh = &fsg->buffhds[i];
3283                 bh->state = BUF_STATE_EMPTY;
3284         }
3285         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
3286                         &fsg->buffhds[0];
3287
3288         exception_req_tag = fsg->exception_req_tag;
3289         new_config = fsg->new_config;
3290         old_state = fsg->state;
3291
3292         if (old_state == FSG_STATE_ABORT_BULK_OUT)
3293                 fsg->state = FSG_STATE_STATUS_PHASE;
3294         else {
3295                 for (i = 0; i < fsg->nluns; ++i) {
3296                         curlun = &fsg->luns[i];
3297                         curlun->prevent_medium_removal = 0;
3298                         curlun->sense_data = curlun->unit_attention_data =
3299                                         SS_NO_SENSE;
3300                         curlun->sense_data_info = 0;
3301                         curlun->info_valid = 0;
3302                 }
3303                 fsg->state = FSG_STATE_IDLE;
3304         }
3305         spin_unlock_irq(&fsg->lock);
3306
3307         /* Carry out any extra actions required for the exception */
3308         switch (old_state) {
3309         default:
3310                 break;
3311
3312         case FSG_STATE_ABORT_BULK_OUT:
3313                 send_status(fsg);
3314                 spin_lock_irq(&fsg->lock);
3315                 if (fsg->state == FSG_STATE_STATUS_PHASE)
3316                         fsg->state = FSG_STATE_IDLE;
3317                 spin_unlock_irq(&fsg->lock);
3318                 break;
3319
3320         case FSG_STATE_RESET:
3321                 /* In case we were forced against our will to halt a
3322                  * bulk endpoint, clear the halt now.  (The SuperH UDC
3323                  * requires this.) */
3324                 if (test_and_clear_bit(CLEAR_BULK_HALTS,
3325                                 &fsg->atomic_bitflags)) {
3326                         usb_ep_clear_halt(fsg->bulk_in);
3327                         usb_ep_clear_halt(fsg->bulk_out);
3328                 }
3329
3330                 if (transport_is_bbb()) {
3331                         if (fsg->ep0_req_tag == exception_req_tag)
3332                                 ep0_queue(fsg); // Complete the status stage
3333
3334                 } else if (transport_is_cbi())
3335                         send_status(fsg);       // Status by interrupt pipe
3336
3337                 /* Technically this should go here, but it would only be
3338                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
3339                  * CONFIG_CHANGE cases. */
3340                 // for (i = 0; i < fsg->nluns; ++i)
3341                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3342                 break;
3343
3344         case FSG_STATE_INTERFACE_CHANGE:
3345                 rc = do_set_interface(fsg, 0);
3346                 if (fsg->ep0_req_tag != exception_req_tag)
3347                         break;
3348                 if (rc != 0)                    // STALL on errors
3349                         fsg_set_halt(fsg, fsg->ep0);
3350                 else                            // Complete the status stage
3351                         ep0_queue(fsg);
3352                 break;
3353
3354         case FSG_STATE_CONFIG_CHANGE:
3355                 rc = do_set_config(fsg, new_config);
3356                 if (fsg->ep0_req_tag != exception_req_tag)
3357                         break;
3358                 if (rc != 0)                    // STALL on errors
3359                         fsg_set_halt(fsg, fsg->ep0);
3360                 else                            // Complete the status stage
3361                         ep0_queue(fsg);
3362                 break;
3363
3364         case FSG_STATE_DISCONNECT:
3365                 fsync_all(fsg);
3366                 do_set_config(fsg, 0);          // Unconfigured state
3367                 break;
3368
3369         case FSG_STATE_EXIT:
3370         case FSG_STATE_TERMINATED:
3371                 do_set_config(fsg, 0);                  // Free resources
3372                 spin_lock_irq(&fsg->lock);
3373                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3374                 spin_unlock_irq(&fsg->lock);
3375                 break;
3376         }
3377 }
3378
3379
3380 /*-------------------------------------------------------------------------*/
3381
3382 static int fsg_main_thread(void *fsg_)
3383 {
3384         struct fsg_dev          *fsg = fsg_;
3385
3386         /* Allow the thread to be killed by a signal, but set the signal mask
3387          * to block everything but INT, TERM, KILL, and USR1. */
3388         allow_signal(SIGINT);
3389         allow_signal(SIGTERM);
3390         allow_signal(SIGKILL);
3391         allow_signal(SIGUSR1);
3392
3393         /* Allow the thread to be frozen */
3394         set_freezable();
3395
3396         /* Arrange for userspace references to be interpreted as kernel
3397          * pointers.  That way we can pass a kernel pointer to a routine
3398          * that expects a __user pointer and it will work okay. */
3399         set_fs(get_ds());
3400
3401         /* The main loop */
3402         while (fsg->state != FSG_STATE_TERMINATED) {
3403                 if (exception_in_progress(fsg) || signal_pending(current)) {
3404                         handle_exception(fsg);
3405                         continue;
3406                 }
3407
3408                 if (!fsg->running) {
3409                         sleep_thread(fsg);
3410                         continue;
3411                 }
3412
3413                 if (get_next_command(fsg))
3414                         continue;
3415
3416                 spin_lock_irq(&fsg->lock);
3417                 if (!exception_in_progress(fsg))
3418                         fsg->state = FSG_STATE_DATA_PHASE;
3419                 spin_unlock_irq(&fsg->lock);
3420
3421                 if (do_scsi_command(fsg) || finish_reply(fsg))
3422                         continue;
3423
3424                 spin_lock_irq(&fsg->lock);
3425                 if (!exception_in_progress(fsg))
3426                         fsg->state = FSG_STATE_STATUS_PHASE;
3427                 spin_unlock_irq(&fsg->lock);
3428
3429                 if (send_status(fsg))
3430                         continue;
3431
3432                 spin_lock_irq(&fsg->lock);
3433                 if (!exception_in_progress(fsg))
3434                         fsg->state = FSG_STATE_IDLE;
3435                 spin_unlock_irq(&fsg->lock);
3436                 }
3437
3438         spin_lock_irq(&fsg->lock);
3439         fsg->thread_task = NULL;
3440         spin_unlock_irq(&fsg->lock);
3441
3442         /* In case we are exiting because of a signal, unregister the
3443          * gadget driver and close the backing file. */
3444         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags)) {
3445                 usb_gadget_unregister_driver(&fsg_driver);
3446                 close_all_backing_files(fsg);
3447         }
3448
3449         /* Let the unbind and cleanup routines know the thread has exited */
3450         complete_and_exit(&fsg->thread_notifier, 0);
3451 }
3452
3453
3454 /*-------------------------------------------------------------------------*/
3455
3456 /* If the next two routines are called while the gadget is registered,
3457  * the caller must own fsg->filesem for writing. */
3458
3459 static int open_backing_file(struct lun *curlun, const char *filename)
3460 {
3461         int                             ro;
3462         struct file                     *filp = NULL;
3463         int                             rc = -EINVAL;
3464         struct inode                    *inode = NULL;
3465         loff_t                          size;
3466         loff_t                          num_sectors;
3467
3468         /* R/W if we can, R/O if we must */
3469         ro = curlun->ro;
3470         if (!ro) {
3471                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
3472                 if (-EROFS == PTR_ERR(filp))
3473                         ro = 1;
3474         }
3475         if (ro)
3476                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
3477         if (IS_ERR(filp)) {
3478                 LINFO(curlun, "unable to open backing file: %s\n", filename);
3479                 return PTR_ERR(filp);
3480         }
3481
3482         if (!(filp->f_mode & FMODE_WRITE))
3483                 ro = 1;
3484
3485         if (filp->f_path.dentry)
3486                 inode = filp->f_path.dentry->d_inode;
3487         if (inode && S_ISBLK(inode->i_mode)) {
3488                 if (bdev_read_only(inode->i_bdev))
3489                         ro = 1;
3490         } else if (!inode || !S_ISREG(inode->i_mode)) {
3491                 LINFO(curlun, "invalid file type: %s\n", filename);
3492                 goto out;
3493         }
3494
3495         /* If we can't read the file, it's no good.
3496          * If we can't write the file, use it read-only. */
3497         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
3498                 LINFO(curlun, "file not readable: %s\n", filename);
3499                 goto out;
3500         }
3501         if (!(filp->f_op->write || filp->f_op->aio_write))
3502                 ro = 1;
3503
3504         size = i_size_read(inode->i_mapping->host);
3505         if (size < 0) {
3506                 LINFO(curlun, "unable to find file size: %s\n", filename);
3507                 rc = (int) size;
3508                 goto out;
3509         }
3510         num_sectors = size >> 9;        // File size in 512-byte sectors
3511         if (num_sectors == 0) {
3512                 LINFO(curlun, "file too small: %s\n", filename);
3513                 rc = -ETOOSMALL;
3514                 goto out;
3515         }
3516
3517         get_file(filp);
3518         curlun->ro = ro;
3519         curlun->filp = filp;
3520         curlun->file_length = size;
3521         curlun->num_sectors = num_sectors;
3522         LDBG(curlun, "open backing file: %s\n", filename);
3523         rc = 0;
3524
3525 out:
3526         filp_close(filp, current->files);
3527         return rc;
3528 }
3529
3530
3531 static void close_backing_file(struct lun *curlun)
3532 {
3533         if (curlun->filp) {
3534                 LDBG(curlun, "close backing file\n");
3535                 fput(curlun->filp);
3536                 curlun->filp = NULL;
3537         }
3538 }
3539
3540 static void close_all_backing_files(struct fsg_dev *fsg)
3541 {
3542         int     i;
3543
3544         for (i = 0; i < fsg->nluns; ++i)
3545                 close_backing_file(&fsg->luns[i]);
3546 }
3547
3548
3549 static ssize_t show_ro(struct device *dev, struct device_attribute *attr, char *buf)
3550 {
3551         struct lun      *curlun = dev_to_lun(dev);
3552
3553         return sprintf(buf, "%d\n", curlun->ro);
3554 }
3555
3556 static ssize_t show_file(struct device *dev, struct device_attribute *attr,
3557                 char *buf)
3558 {
3559         struct lun      *curlun = dev_to_lun(dev);
3560         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3561         char            *p;
3562         ssize_t         rc;
3563
3564         down_read(&fsg->filesem);
3565         if (backing_file_is_open(curlun)) {     // Get the complete pathname
3566                 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
3567                 if (IS_ERR(p))
3568                         rc = PTR_ERR(p);
3569                 else {
3570                         rc = strlen(p);
3571                         memmove(buf, p, rc);
3572                         buf[rc] = '\n';         // Add a newline
3573                         buf[++rc] = 0;
3574                 }
3575         } else {                                // No file, return 0 bytes
3576                 *buf = 0;
3577                 rc = 0;
3578         }
3579         up_read(&fsg->filesem);
3580         return rc;
3581 }
3582
3583
3584 static ssize_t store_ro(struct device *dev, struct device_attribute *attr,
3585                 const char *buf, size_t count)
3586 {
3587         ssize_t         rc = count;
3588         struct lun      *curlun = dev_to_lun(dev);
3589         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3590         int             i;
3591
3592         if (sscanf(buf, "%d", &i) != 1)
3593                 return -EINVAL;
3594
3595         /* Allow the write-enable status to change only while the backing file
3596          * is closed. */
3597         down_read(&fsg->filesem);
3598         if (backing_file_is_open(curlun)) {
3599                 LDBG(curlun, "read-only status change prevented\n");
3600                 rc = -EBUSY;
3601         } else {
3602                 curlun->ro = !!i;
3603                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
3604         }
3605         up_read(&fsg->filesem);
3606         return rc;
3607 }
3608
3609 static ssize_t store_file(struct device *dev, struct device_attribute *attr,
3610                 const char *buf, size_t count)
3611 {
3612         struct lun      *curlun = dev_to_lun(dev);
3613         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3614         int             rc = 0;
3615
3616         if (curlun->prevent_medium_removal && backing_file_is_open(curlun)) {
3617                 LDBG(curlun, "eject attempt prevented\n");
3618                 return -EBUSY;                          // "Door is locked"
3619         }
3620
3621         /* Remove a trailing newline */
3622         if (count > 0 && buf[count-1] == '\n')
3623                 ((char *) buf)[count-1] = 0;            // Ugh!
3624
3625         /* Eject current medium */
3626         down_write(&fsg->filesem);
3627         if (backing_file_is_open(curlun)) {
3628                 close_backing_file(curlun);
3629                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
3630         }
3631
3632         /* Load new medium */
3633         if (count > 0 && buf[0]) {
3634                 rc = open_backing_file(curlun, buf);
3635                 if (rc == 0)
3636                         curlun->unit_attention_data =
3637                                         SS_NOT_READY_TO_READY_TRANSITION;
3638         }
3639         up_write(&fsg->filesem);
3640         return (rc < 0 ? rc : count);
3641 }
3642
3643
3644 /* The write permissions and store_xxx pointers are set in fsg_bind() */
3645 static DEVICE_ATTR(ro, 0444, show_ro, NULL);
3646 static DEVICE_ATTR(file, 0444, show_file, NULL);
3647
3648
3649 /*-------------------------------------------------------------------------*/
3650
3651 static void fsg_release(struct kref *ref)
3652 {
3653         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
3654
3655         kfree(fsg->luns);
3656         kfree(fsg);
3657 }
3658
3659 static void lun_release(struct device *dev)
3660 {
3661         struct fsg_dev  *fsg = dev_get_drvdata(dev);
3662
3663         kref_put(&fsg->ref, fsg_release);
3664 }
3665
3666 static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
3667 {
3668         struct fsg_dev          *fsg = get_gadget_data(gadget);
3669         int                     i;
3670         struct lun              *curlun;
3671         struct usb_request      *req = fsg->ep0req;
3672
3673         DBG(fsg, "unbind\n");
3674         clear_bit(REGISTERED, &fsg->atomic_bitflags);
3675
3676         /* Unregister the sysfs attribute files and the LUNs */
3677         for (i = 0; i < fsg->nluns; ++i) {
3678                 curlun = &fsg->luns[i];
3679                 if (curlun->registered) {
3680                         device_remove_file(&curlun->dev, &dev_attr_ro);
3681                         device_remove_file(&curlun->dev, &dev_attr_file);
3682                         device_unregister(&curlun->dev);
3683                         curlun->registered = 0;
3684                 }
3685         }
3686
3687         /* If the thread isn't already dead, tell it to exit now */
3688         if (fsg->state != FSG_STATE_TERMINATED) {
3689                 raise_exception(fsg, FSG_STATE_EXIT);
3690                 wait_for_completion(&fsg->thread_notifier);
3691
3692                 /* The cleanup routine waits for this completion also */
3693                 complete(&fsg->thread_notifier);
3694         }
3695
3696         /* Free the data buffers */
3697         for (i = 0; i < NUM_BUFFERS; ++i)
3698                 kfree(fsg->buffhds[i].buf);
3699
3700         /* Free the request and buffer for endpoint 0 */
3701         if (req) {
3702                 kfree(req->buf);
3703                 usb_ep_free_request(fsg->ep0, req);
3704         }
3705
3706         set_gadget_data(gadget, NULL);
3707 }
3708
3709
3710 static int __init check_parameters(struct fsg_dev *fsg)
3711 {
3712         int     prot;
3713         int     gcnum;
3714
3715         /* Store the default values */
3716         mod_data.transport_type = USB_PR_BULK;
3717         mod_data.transport_name = "Bulk-only";
3718         mod_data.protocol_type = USB_SC_SCSI;
3719         mod_data.protocol_name = "Transparent SCSI";
3720
3721         if (gadget_is_sh(fsg->gadget))
3722                 mod_data.can_stall = 0;
3723
3724         if (mod_data.release == 0xffff) {       // Parameter wasn't set
3725                 /* The sa1100 controller is not supported */
3726                 if (gadget_is_sa1100(fsg->gadget))
3727                         gcnum = -1;
3728                 else
3729                         gcnum = usb_gadget_controller_number(fsg->gadget);
3730                 if (gcnum >= 0)
3731                         mod_data.release = 0x0300 + gcnum;
3732                 else {
3733                         WARN(fsg, "controller '%s' not recognized\n",
3734                                 fsg->gadget->name);
3735                         mod_data.release = 0x0399;
3736                 }
3737         }
3738
3739         prot = simple_strtol(mod_data.protocol_parm, NULL, 0);
3740
3741 #ifdef CONFIG_USB_FILE_STORAGE_TEST
3742         if (strnicmp(mod_data.transport_parm, "BBB", 10) == 0) {
3743                 ;               // Use default setting
3744         } else if (strnicmp(mod_data.transport_parm, "CB", 10) == 0) {
3745                 mod_data.transport_type = USB_PR_CB;
3746                 mod_data.transport_name = "Control-Bulk";
3747         } else if (strnicmp(mod_data.transport_parm, "CBI", 10) == 0) {
3748                 mod_data.transport_type = USB_PR_CBI;
3749                 mod_data.transport_name = "Control-Bulk-Interrupt";
3750         } else {
3751                 ERROR(fsg, "invalid transport: %s\n", mod_data.transport_parm);
3752                 return -EINVAL;
3753         }
3754
3755         if (strnicmp(mod_data.protocol_parm, "SCSI", 10) == 0 ||
3756                         prot == USB_SC_SCSI) {
3757                 ;               // Use default setting
3758         } else if (strnicmp(mod_data.protocol_parm, "RBC", 10) == 0 ||
3759                         prot == USB_SC_RBC) {
3760                 mod_data.protocol_type = USB_SC_RBC;
3761                 mod_data.protocol_name = "RBC";
3762         } else if (strnicmp(mod_data.protocol_parm, "8020", 4) == 0 ||
3763                         strnicmp(mod_data.protocol_parm, "ATAPI", 10) == 0 ||
3764                         prot == USB_SC_8020) {
3765                 mod_data.protocol_type = USB_SC_8020;
3766                 mod_data.protocol_name = "8020i (ATAPI)";
3767         } else if (strnicmp(mod_data.protocol_parm, "QIC", 3) == 0 ||
3768                         prot == USB_SC_QIC) {
3769                 mod_data.protocol_type = USB_SC_QIC;
3770                 mod_data.protocol_name = "QIC-157";
3771         } else if (strnicmp(mod_data.protocol_parm, "UFI", 10) == 0 ||
3772                         prot == USB_SC_UFI) {
3773                 mod_data.protocol_type = USB_SC_UFI;
3774                 mod_data.protocol_name = "UFI";
3775         } else if (strnicmp(mod_data.protocol_parm, "8070", 4) == 0 ||
3776                         prot == USB_SC_8070) {
3777                 mod_data.protocol_type = USB_SC_8070;
3778                 mod_data.protocol_name = "8070i";
3779         } else {
3780                 ERROR(fsg, "invalid protocol: %s\n", mod_data.protocol_parm);
3781                 return -EINVAL;
3782         }
3783
3784         mod_data.buflen &= PAGE_CACHE_MASK;
3785         if (mod_data.buflen <= 0) {
3786                 ERROR(fsg, "invalid buflen\n");
3787                 return -ETOOSMALL;
3788         }
3789 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
3790
3791         return 0;
3792 }
3793
3794
3795 static int __init fsg_bind(struct usb_gadget *gadget)
3796 {
3797         struct fsg_dev          *fsg = the_fsg;
3798         int                     rc;
3799         int                     i;
3800         struct lun              *curlun;
3801         struct usb_ep           *ep;
3802         struct usb_request      *req;
3803         char                    *pathbuf, *p;
3804
3805         fsg->gadget = gadget;
3806         set_gadget_data(gadget, fsg);
3807         fsg->ep0 = gadget->ep0;
3808         fsg->ep0->driver_data = fsg;
3809
3810         if ((rc = check_parameters(fsg)) != 0)
3811                 goto out;
3812
3813         if (mod_data.removable) {       // Enable the store_xxx attributes
3814                 dev_attr_ro.attr.mode = dev_attr_file.attr.mode = 0644;
3815                 dev_attr_ro.store = store_ro;
3816                 dev_attr_file.store = store_file;
3817         }
3818
3819         /* Find out how many LUNs there should be */
3820         i = mod_data.nluns;
3821         if (i == 0)
3822                 i = max(mod_data.num_filenames, 1u);
3823         if (i > MAX_LUNS) {
3824                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
3825                 rc = -EINVAL;
3826                 goto out;
3827         }
3828
3829         /* Create the LUNs, open their backing files, and register the
3830          * LUN devices in sysfs. */
3831         fsg->luns = kzalloc(i * sizeof(struct lun), GFP_KERNEL);
3832         if (!fsg->luns) {
3833                 rc = -ENOMEM;
3834                 goto out;
3835         }
3836         fsg->nluns = i;
3837
3838         for (i = 0; i < fsg->nluns; ++i) {
3839                 curlun = &fsg->luns[i];
3840                 curlun->ro = mod_data.ro[i];
3841                 curlun->dev.release = lun_release;
3842                 curlun->dev.parent = &gadget->dev;
3843                 curlun->dev.driver = &fsg_driver.driver;
3844                 dev_set_drvdata(&curlun->dev, fsg);
3845                 snprintf(curlun->dev.bus_id, BUS_ID_SIZE,
3846                                 "%s-lun%d", gadget->dev.bus_id, i);
3847
3848                 if ((rc = device_register(&curlun->dev)) != 0) {
3849                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
3850                         goto out;
3851                 }
3852                 if ((rc = device_create_file(&curlun->dev,
3853                                         &dev_attr_ro)) != 0 ||
3854                                 (rc = device_create_file(&curlun->dev,
3855                                         &dev_attr_file)) != 0) {
3856                         device_unregister(&curlun->dev);
3857                         goto out;
3858                 }
3859                 curlun->registered = 1;
3860                 kref_get(&fsg->ref);
3861
3862                 if (mod_data.file[i] && *mod_data.file[i]) {
3863                         if ((rc = open_backing_file(curlun,
3864                                         mod_data.file[i])) != 0)
3865                                 goto out;
3866                 } else if (!mod_data.removable) {
3867                         ERROR(fsg, "no file given for LUN%d\n", i);
3868                         rc = -EINVAL;
3869                         goto out;
3870                 }
3871         }
3872
3873         /* Find all the endpoints we will use */
3874         usb_ep_autoconfig_reset(gadget);
3875         ep = usb_ep_autoconfig(gadget, &fs_bulk_in_desc);
3876         if (!ep)
3877                 goto autoconf_fail;
3878         ep->driver_data = fsg;          // claim the endpoint
3879         fsg->bulk_in = ep;
3880
3881         ep = usb_ep_autoconfig(gadget, &fs_bulk_out_desc);
3882         if (!ep)
3883                 goto autoconf_fail;
3884         ep->driver_data = fsg;          // claim the endpoint
3885         fsg->bulk_out = ep;
3886
3887         if (transport_is_cbi()) {
3888                 ep = usb_ep_autoconfig(gadget, &fs_intr_in_desc);
3889                 if (!ep)
3890                         goto autoconf_fail;
3891                 ep->driver_data = fsg;          // claim the endpoint
3892                 fsg->intr_in = ep;
3893         }
3894
3895         /* Fix up the descriptors */
3896         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
3897         device_desc.idVendor = cpu_to_le16(mod_data.vendor);
3898         device_desc.idProduct = cpu_to_le16(mod_data.product);
3899         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
3900
3901         i = (transport_is_cbi() ? 3 : 2);       // Number of endpoints
3902         intf_desc.bNumEndpoints = i;
3903         intf_desc.bInterfaceSubClass = mod_data.protocol_type;
3904         intf_desc.bInterfaceProtocol = mod_data.transport_type;
3905         fs_function[i + FS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3906
3907         if (gadget_is_dualspeed(gadget)) {
3908                 hs_function[i + HS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3909
3910                 /* Assume ep0 uses the same maxpacket value for both speeds */
3911                 dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
3912
3913                 /* Assume endpoint addresses are the same for both speeds */
3914                 hs_bulk_in_desc.bEndpointAddress =
3915                                 fs_bulk_in_desc.bEndpointAddress;
3916                 hs_bulk_out_desc.bEndpointAddress =
3917                                 fs_bulk_out_desc.bEndpointAddress;
3918                 hs_intr_in_desc.bEndpointAddress =
3919                                 fs_intr_in_desc.bEndpointAddress;
3920         }
3921
3922         if (gadget_is_otg(gadget))
3923                 otg_desc.bmAttributes |= USB_OTG_HNP;
3924
3925         rc = -ENOMEM;
3926
3927         /* Allocate the request and buffer for endpoint 0 */
3928         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
3929         if (!req)
3930                 goto out;
3931         req->buf = kmalloc(EP0_BUFSIZE, GFP_KERNEL);
3932         if (!req->buf)
3933                 goto out;
3934         req->complete = ep0_complete;
3935
3936         /* Allocate the data buffers */
3937         for (i = 0; i < NUM_BUFFERS; ++i) {
3938                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3939
3940                 /* Allocate for the bulk-in endpoint.  We assume that
3941                  * the buffer will also work with the bulk-out (and
3942                  * interrupt-in) endpoint. */
3943                 bh->buf = kmalloc(mod_data.buflen, GFP_KERNEL);
3944                 if (!bh->buf)
3945                         goto out;
3946                 bh->next = bh + 1;
3947         }
3948         fsg->buffhds[NUM_BUFFERS - 1].next = &fsg->buffhds[0];
3949
3950         /* This should reflect the actual gadget power source */
3951         usb_gadget_set_selfpowered(gadget);
3952
3953         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
3954                         init_utsname()->sysname, init_utsname()->release,
3955                         gadget->name);
3956
3957         /* On a real device, serial[] would be loaded from permanent
3958          * storage.  We just encode it from the driver version string. */
3959         for (i = 0; i < sizeof(serial) - 2; i += 2) {
3960                 unsigned char           c = DRIVER_VERSION[i / 2];
3961
3962                 if (!c)
3963                         break;
3964                 sprintf(&serial[i], "%02X", c);
3965         }
3966
3967         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
3968                         "file-storage-gadget");
3969         if (IS_ERR(fsg->thread_task)) {
3970                 rc = PTR_ERR(fsg->thread_task);
3971                 goto out;
3972         }
3973
3974         INFO(fsg, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
3975         INFO(fsg, "Number of LUNs=%d\n", fsg->nluns);
3976
3977         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
3978         for (i = 0; i < fsg->nluns; ++i) {
3979                 curlun = &fsg->luns[i];
3980                 if (backing_file_is_open(curlun)) {
3981                         p = NULL;
3982                         if (pathbuf) {
3983                                 p = d_path(&curlun->filp->f_path,
3984                                            pathbuf, PATH_MAX);
3985                                 if (IS_ERR(p))
3986                                         p = NULL;
3987                         }
3988                         LINFO(curlun, "ro=%d, file: %s\n",
3989                                         curlun->ro, (p ? p : "(error)"));
3990                 }
3991         }
3992         kfree(pathbuf);
3993
3994         DBG(fsg, "transport=%s (x%02x)\n",
3995                         mod_data.transport_name, mod_data.transport_type);
3996         DBG(fsg, "protocol=%s (x%02x)\n",
3997                         mod_data.protocol_name, mod_data.protocol_type);
3998         DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n",
3999                         mod_data.vendor, mod_data.product, mod_data.release);
4000         DBG(fsg, "removable=%d, stall=%d, buflen=%u\n",
4001                         mod_data.removable, mod_data.can_stall,
4002                         mod_data.buflen);
4003         DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task));
4004
4005         set_bit(REGISTERED, &fsg->atomic_bitflags);
4006
4007         /* Tell the thread to start working */
4008         wake_up_process(fsg->thread_task);
4009         return 0;
4010
4011 autoconf_fail:
4012         ERROR(fsg, "unable to autoconfigure all endpoints\n");
4013         rc = -ENOTSUPP;
4014
4015 out:
4016         fsg->state = FSG_STATE_TERMINATED;      // The thread is dead
4017         fsg_unbind(gadget);
4018         close_all_backing_files(fsg);
4019         return rc;
4020 }
4021
4022
4023 /*-------------------------------------------------------------------------*/
4024
4025 static void fsg_suspend(struct usb_gadget *gadget)
4026 {
4027         struct fsg_dev          *fsg = get_gadget_data(gadget);
4028
4029         DBG(fsg, "suspend\n");
4030         set_bit(SUSPENDED, &fsg->atomic_bitflags);
4031 }
4032
4033 static void fsg_resume(struct usb_gadget *gadget)
4034 {
4035         struct fsg_dev          *fsg = get_gadget_data(gadget);
4036
4037         DBG(fsg, "resume\n");
4038         clear_bit(SUSPENDED, &fsg->atomic_bitflags);
4039 }
4040
4041
4042 /*-------------------------------------------------------------------------*/
4043
4044 static struct usb_gadget_driver         fsg_driver = {
4045 #ifdef CONFIG_USB_GADGET_DUALSPEED
4046         .speed          = USB_SPEED_HIGH,
4047 #else
4048         .speed          = USB_SPEED_FULL,
4049 #endif
4050         .function       = (char *) longname,
4051         .bind           = fsg_bind,
4052         .unbind         = fsg_unbind,
4053         .disconnect     = fsg_disconnect,
4054         .setup          = fsg_setup,
4055         .suspend        = fsg_suspend,
4056         .resume         = fsg_resume,
4057
4058         .driver         = {
4059                 .name           = (char *) shortname,
4060                 .owner          = THIS_MODULE,
4061                 // .release = ...
4062                 // .suspend = ...
4063                 // .resume = ...
4064         },
4065 };
4066
4067
4068 static int __init fsg_alloc(void)
4069 {
4070         struct fsg_dev          *fsg;
4071
4072         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
4073         if (!fsg)
4074                 return -ENOMEM;
4075         spin_lock_init(&fsg->lock);
4076         init_rwsem(&fsg->filesem);
4077         kref_init(&fsg->ref);
4078         init_completion(&fsg->thread_notifier);
4079
4080         the_fsg = fsg;
4081         return 0;
4082 }
4083
4084
4085 static int __init fsg_init(void)
4086 {
4087         int             rc;
4088         struct fsg_dev  *fsg;
4089
4090         if ((rc = fsg_alloc()) != 0)
4091                 return rc;
4092         fsg = the_fsg;
4093         if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
4094                 kref_put(&fsg->ref, fsg_release);
4095         return rc;
4096 }
4097 module_init(fsg_init);
4098
4099
4100 static void __exit fsg_cleanup(void)
4101 {
4102         struct fsg_dev  *fsg = the_fsg;
4103
4104         /* Unregister the driver iff the thread hasn't already done so */
4105         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
4106                 usb_gadget_unregister_driver(&fsg_driver);
4107
4108         /* Wait for the thread to finish up */
4109         wait_for_completion(&fsg->thread_notifier);
4110
4111         close_all_backing_files(fsg);
4112         kref_put(&fsg->ref, fsg_release);
4113 }
4114 module_exit(fsg_cleanup);