drivers/usb/gadget/file_storage.c

   1 /*
   2  * file_storage.c -- File-backed USB Storage Gadget, for USB development
   3  *
   4  * Copyright (C) 2003-2008 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 or as a CD-ROM drive.  In addition
  42  * to providing an example of a genuinely useful gadget driver for a USB
  43  * device, it also illustrates a technique of double-buffering for increased
  44  * throughput.  Last but not least, it gives an easy way to probe the
  45  * behavior of the 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.  (For CD-ROM emulation,
  50  * access is always read-only.)  The gadget will indicate that it has
  51  * removable media if the optional "removable" module parameter is set.
  52  *
  53  * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI),
  54  * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected
  55  * by the optional "transport" module parameter.  It also supports the
  56  * following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03),
  57  * UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
  58  * the optional "protocol" module parameter.  In addition, the default
  59  * Vendor ID, Product ID, release number and serial number can be overridden.
  60  *
  61  * There is support for multiple logical units (LUNs), each of which has
  62  * its own backing file.  The number of LUNs can be set using the optional
  63  * "luns" module parameter (anywhere from 1 to 8), and the corresponding
  64  * files are specified using comma-separated lists for "file" and "ro".
  65  * The default number of LUNs is taken from the number of "file" elements;
  66  * it is 1 if "file" is not given.  If "removable" is not set then a backing
  67  * file must be specified for each LUN.  If it is set, then an unspecified
  68  * or empty backing filename means the LUN's medium is not loaded.  Ideally
  69  * each LUN would be settable independently as a disk drive or a CD-ROM
  70  * drive, but currently all LUNs have to be the same type.  The CD-ROM
  71  * emulation includes a single data track and no audio tracks; hence there
  72  * need be only one backing file per LUN.  Note also that the CD-ROM block
  73  * length is set to 512 rather than the more common value 2048.
  74  *
  75  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
  76  * needed (an interrupt-out endpoint is also needed for CBI).  The memory
  77  * requirement amounts to two 16K buffers, size configurable by a parameter.
  78  * Support is included for both full-speed and high-speed operation.
  79  *
  80  * Note that the driver is slightly non-portable in that it assumes a
  81  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
  82  * interrupt-in endpoints.  With most device controllers this isn't an
  83  * issue, but there may be some with hardware restrictions that prevent
  84  * a buffer from being used by more than one endpoint.
  85  *
  86  * Module options:
  87  *
  88  *      file=filename[,filename...]
  89  *                              Required if "removable" is not set, names of
  90  *                                      the files or block devices used for
  91  *                                      backing storage
  92  *      serial=HHHH...          Required serial number (string of hex chars)
  93  *      ro=b[,b...]             Default false, booleans for read-only access
  94  *      removable               Default false, boolean for removable media
  95  *      luns=N                  Default N = number of filenames, number of
  96  *                                      LUNs to support
  97  *      nofua=b[,b...]          Default false, booleans for ignore FUA flag
  98  *                                      in SCSI WRITE(10,12) commands
  99  *      stall                   Default determined according to the type of
 100  *                                      USB device controller (usually true),
 101  *                                      boolean to permit the driver to halt
 102  *                                      bulk endpoints
 103  *      cdrom                   Default false, boolean for whether to emulate
 104  *                                      a CD-ROM drive
 105  *      transport=XXX           Default BBB, transport name (CB, CBI, or BBB)
 106  *      protocol=YYY            Default SCSI, protocol name (RBC, 8020 or
 107  *                                      ATAPI, QIC, UFI, 8070, or SCSI;
 108  *                                      also 1 - 6)
 109  *      vendor=0xVVVV           Default 0x0525 (NetChip), USB Vendor ID
 110  *      product=0xPPPP          Default 0xa4a5 (FSG), USB Product ID
 111  *      release=0xRRRR          Override the USB release number (bcdDevice)
 112  *      buflen=N                Default N=16384, buffer size used (will be
 113  *                                      rounded down to a multiple of
 114  *                                      PAGE_CACHE_SIZE)
 115  *
 116  * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "serial", "ro",
 117  * "removable", "luns", "nofua", "stall", and "cdrom" options are available;
 118  * default values are used for everything else.
 119  *
 120  * The pathnames of the backing files and the ro settings are available in
 121  * the attribute files "file", "nofua", and "ro" in the lun<n> subdirectory of
 122  * the gadget's sysfs directory.  If the "removable" option is set, writing to
 123  * these files will simulate ejecting/loading the medium (writing an empty
 124  * line means eject) and adjusting a write-enable tab.  Changes to the ro
 125  * setting are not allowed when the medium is loaded or if CD-ROM emulation
 126  * is being used.
 127  *
 128  * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
 129  * The driver's SCSI command interface was based on the "Information
 130  * technology - Small Computer System Interface - 2" document from
 131  * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
 132  * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.  The single exception
 133  * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
 134  * "Universal Serial Bus Mass Storage Class UFI Command Specification"
 135  * document, Revision 1.0, December 14, 1998, available at
 136  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
 137  */
 138
 139
 140 /*
 141  *                              Driver Design
 142  *
 143  * The FSG driver is fairly straightforward.  There is a main kernel
 144  * thread that handles most of the work.  Interrupt routines field
 145  * callbacks from the controller driver: bulk- and interrupt-request
 146  * completion notifications, endpoint-0 events, and disconnect events.
 147  * Completion events are passed to the main thread by wakeup calls.  Many
 148  * ep0 requests are handled at interrupt time, but SetInterface,
 149  * SetConfiguration, and device reset requests are forwarded to the
 150  * thread in the form of "exceptions" using SIGUSR1 signals (since they
 151  * should interrupt any ongoing file I/O operations).
 152  *
 153  * The thread's main routine implements the standard command/data/status
 154  * parts of a SCSI interaction.  It and its subroutines are full of tests
 155  * for pending signals/exceptions -- all this polling is necessary since
 156  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
 157  * indication that the driver really wants to be running in userspace.)
 158  * An important point is that so long as the thread is alive it keeps an
 159  * open reference to the backing file.  This will prevent unmounting
 160  * the backing file's underlying filesystem and could cause problems
 161  * during system shutdown, for example.  To prevent such problems, the
 162  * thread catches INT, TERM, and KILL signals and converts them into
 163  * an EXIT exception.
 164  *
 165  * In normal operation the main thread is started during the gadget's
 166  * fsg_bind() callback and stopped during fsg_unbind().  But it can also
 167  * exit when it receives a signal, and there's no point leaving the
 168  * gadget running when the thread is dead.  So just before the thread
 169  * exits, it deregisters the gadget driver.  This makes things a little
 170  * tricky: The driver is deregistered at two places, and the exiting
 171  * thread can indirectly call fsg_unbind() which in turn can tell the
 172  * thread to exit.  The first problem is resolved through the use of the
 173  * REGISTERED atomic bitflag; the driver will only be deregistered once.
 174  * The second problem is resolved by having fsg_unbind() check
 175  * fsg->state; it won't try to stop the thread if the state is already
 176  * FSG_STATE_TERMINATED.
 177  *
 178  * To provide maximum throughput, the driver uses a circular pipeline of
 179  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
 180  * arbitrarily long; in practice the benefits don't justify having more
 181  * than 2 stages (i.e., double buffering).  But it helps to think of the
 182  * pipeline as being a long one.  Each buffer head contains a bulk-in and
 183  * a bulk-out request pointer (since the buffer can be used for both
 184  * output and input -- directions always are given from the host's
 185  * point of view) as well as a pointer to the buffer and various state
 186  * variables.
 187  *
 188  * Use of the pipeline follows a simple protocol.  There is a variable
 189  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
 190  * At any time that buffer head may still be in use from an earlier
 191  * request, so each buffer head has a state variable indicating whether
 192  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
 193  * buffer head to be EMPTY, filling the buffer either by file I/O or by
 194  * USB I/O (during which the buffer head is BUSY), and marking the buffer
 195  * head FULL when the I/O is complete.  Then the buffer will be emptied
 196  * (again possibly by USB I/O, during which it is marked BUSY) and
 197  * finally marked EMPTY again (possibly by a completion routine).
 198  *
 199  * A module parameter tells the driver to avoid stalling the bulk
 200  * endpoints wherever the transport specification allows.  This is
 201  * necessary for some UDCs like the SuperH, which cannot reliably clear a
 202  * halt on a bulk endpoint.  However, under certain circumstances the
 203  * Bulk-only specification requires a stall.  In such cases the driver
 204  * will halt the endpoint and set a flag indicating that it should clear
 205  * the halt in software during the next device reset.  Hopefully this
 206  * will permit everything to work correctly.  Furthermore, although the
 207  * specification allows the bulk-out endpoint to halt when the host sends
 208  * too much data, implementing this would cause an unavoidable race.
 209  * The driver will always use the "no-stall" approach for OUT transfers.
 210  *
 211  * One subtle point concerns sending status-stage responses for ep0
 212  * requests.  Some of these requests, such as device reset, can involve
 213  * interrupting an ongoing file I/O operation, which might take an
 214  * arbitrarily long time.  During that delay the host might give up on
 215  * the original ep0 request and issue a new one.  When that happens the
 216  * driver should not notify the host about completion of the original
 217  * request, as the host will no longer be waiting for it.  So the driver
 218  * assigns to each ep0 request a unique tag, and it keeps track of the
 219  * tag value of the request associated with a long-running exception
 220  * (device-reset, interface-change, or configuration-change).  When the
 221  * exception handler is finished, the status-stage response is submitted
 222  * only if the current ep0 request tag is equal to the exception request
 223  * tag.  Thus only the most recently received ep0 request will get a
 224  * status-stage response.
 225  *
 226  * Warning: This driver source file is too long.  It ought to be split up
 227  * into a header file plus about 3 separate .c files, to handle the details
 228  * of the Gadget, USB Mass Storage, and SCSI protocols.
 229  */
 230
 231
 232 /* #define VERBOSE_DEBUG */
 233 /* #define DUMP_MSGS */
 234
 235
 236 #include <linux/blkdev.h>
 237 #include <linux/completion.h>
 238 #include <linux/dcache.h>
 239 #include <linux/delay.h>
 240 #include <linux/device.h>
 241 #include <linux/fcntl.h>
 242 #include <linux/file.h>
 243 #include <linux/fs.h>
 244 #include <linux/kref.h>
 245 #include <linux/kthread.h>
 246 #include <linux/limits.h>
 247 #include <linux/rwsem.h>
 248 #include <linux/slab.h>
 249 #include <linux/spinlock.h>
 250 #include <linux/string.h>
 251 #include <linux/freezer.h>
 252 #include <linux/utsname.h>
 253
 254 #include <linux/usb/ch9.h>
 255 #include <linux/usb/gadget.h>
 256
 257 #include "gadget_chips.h"
 258
 259
 260
 261 /*
 262  * Kbuild is not very cooperative with respect to linking separately
 263  * compiled library objects into one module.  So for now we won't use
 264  * separate compilation ... ensuring init/exit sections work to shrink
 265  * the runtime footprint, and giving us at least some parts of what
 266  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 267  */
 268 #include "usbstring.c"
 269 #include "config.c"
 270 #include "epautoconf.c"
 271
 272 /*-------------------------------------------------------------------------*/
 273
 274 #define DRIVER_DESC             "File-backed Storage Gadget"
 275 #define DRIVER_NAME             "g_file_storage"
 276 #define DRIVER_VERSION          "1 September 2010"
 277
 278 static       char fsg_string_manufacturer[64];
 279 static const char fsg_string_product[] = DRIVER_DESC;
 280 static const char fsg_string_config[] = "Self-powered";
 281 static const char fsg_string_interface[] = "Mass Storage";
 282
 283
 284 #include "storage_common.c"
 285
 286
 287 MODULE_DESCRIPTION(DRIVER_DESC);
 288 MODULE_AUTHOR("Alan Stern");
 289 MODULE_LICENSE("Dual BSD/GPL");
 290
 291 /*
 292  * This driver assumes self-powered hardware and has no way for users to
 293  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
 294  * and endpoint addresses.
 295  */
 296
 297
 298 /*-------------------------------------------------------------------------*/
 299
 300
 301 /* Encapsulate the module parameter settings */
 302
 303 static struct {
 304         char            *file[FSG_MAX_LUNS];
 305         char            *serial;
 306         int             ro[FSG_MAX_LUNS];
 307         int             nofua[FSG_MAX_LUNS];
 308         unsigned int    num_filenames;
 309         unsigned int    num_ros;
 310         unsigned int    num_nofuas;
 311         unsigned int    nluns;
 312
 313         int             removable;
 314         int             can_stall;
 315         int             cdrom;
 316
 317         char            *transport_parm;
 318         char            *protocol_parm;
 319         unsigned short  vendor;
 320         unsigned short  product;
 321         unsigned short  release;
 322         unsigned int    buflen;
 323
 324         int             transport_type;
 325         char            *transport_name;
 326         int             protocol_type;
 327         char            *protocol_name;
 328
 329 } mod_data = {                                  // Default values
 330         .transport_parm         = "BBB",
 331         .protocol_parm          = "SCSI",
 332         .removable              = 0,
 333         .can_stall              = 1,
 334         .cdrom                  = 0,
 335         .vendor                 = FSG_VENDOR_ID,
 336         .product                = FSG_PRODUCT_ID,
 337         .release                = 0xffff,       // Use controller chip type
 338         .buflen                 = 16384,
 339         };
 340
 341
 342 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
 343                 S_IRUGO);
 344 MODULE_PARM_DESC(file, "names of backing files or devices");
 345
 346 module_param_named(serial, mod_data.serial, charp, S_IRUGO);
 347 MODULE_PARM_DESC(serial, "USB serial number");
 348
 349 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
 350 MODULE_PARM_DESC(ro, "true to force read-only");
 351
 352 module_param_array_named(nofua, mod_data.nofua, bool, &mod_data.num_nofuas,
 353                 S_IRUGO);
 354 MODULE_PARM_DESC(nofua, "true to ignore SCSI WRITE(10,12) FUA bit");
 355
 356 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
 357 MODULE_PARM_DESC(luns, "number of LUNs");
 358
 359 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
 360 MODULE_PARM_DESC(removable, "true to simulate removable media");
 361
 362 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
 363 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
 364
 365 module_param_named(cdrom, mod_data.cdrom, bool, S_IRUGO);
 366 MODULE_PARM_DESC(cdrom, "true to emulate cdrom instead of disk");
 367
 368 /* In the non-TEST version, only the module parameters listed above
 369  * are available. */
 370 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 371
 372 module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
 373 MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
 374
 375 module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
 376 MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
 377                 "8070, or SCSI)");
 378
 379 module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
 380 MODULE_PARM_DESC(vendor, "USB Vendor ID");
 381
 382 module_param_named(product, mod_data.product, ushort, S_IRUGO);
 383 MODULE_PARM_DESC(product, "USB Product ID");
 384
 385 module_param_named(release, mod_data.release, ushort, S_IRUGO);
 386 MODULE_PARM_DESC(release, "USB release number");
 387
 388 module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
 389 MODULE_PARM_DESC(buflen, "I/O buffer size");
 390
 391 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 392
 393
 394 /*
 395  * These definitions will permit the compiler to avoid generating code for
 396  * parts of the driver that aren't used in the non-TEST version.  Even gcc
 397  * can recognize when a test of a constant expression yields a dead code
 398  * path.
 399  */
 400
 401 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 402
 403 #define transport_is_bbb()      (mod_data.transport_type == USB_PR_BULK)
 404 #define transport_is_cbi()      (mod_data.transport_type == USB_PR_CBI)
 405 #define protocol_is_scsi()      (mod_data.protocol_type == USB_SC_SCSI)
 406
 407 #else
 408
 409 #define transport_is_bbb()      1
 410 #define transport_is_cbi()      0
 411 #define protocol_is_scsi()      1
 412
 413 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 414
 415
 416 /*-------------------------------------------------------------------------*/
 417
 418
 419 struct fsg_dev {
 420         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
 421         spinlock_t              lock;
 422         struct usb_gadget       *gadget;
 423
 424         /* filesem protects: backing files in use */
 425         struct rw_semaphore     filesem;
 426
 427         /* reference counting: wait until all LUNs are released */
 428         struct kref             ref;
 429
 430         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
 431         struct usb_request      *ep0req;        // For control responses
 432         unsigned int            ep0_req_tag;
 433         const char              *ep0req_name;
 434
 435         struct usb_request      *intreq;        // For interrupt responses
 436         int                     intreq_busy;
 437         struct fsg_buffhd       *intr_buffhd;
 438
 439         unsigned int            bulk_out_maxpacket;
 440         enum fsg_state          state;          // For exception handling
 441         unsigned int            exception_req_tag;
 442
 443         u8                      config, new_config;
 444
 445         unsigned int            running : 1;
 446         unsigned int            bulk_in_enabled : 1;
 447         unsigned int            bulk_out_enabled : 1;
 448         unsigned int            intr_in_enabled : 1;
 449         unsigned int            phase_error : 1;
 450         unsigned int            short_packet_received : 1;
 451         unsigned int            bad_lun_okay : 1;
 452
 453         unsigned long           atomic_bitflags;
 454 #define REGISTERED              0
 455 #define IGNORE_BULK_OUT         1
 456 #define SUSPENDED               2
 457
 458         struct usb_ep           *bulk_in;
 459         struct usb_ep           *bulk_out;
 460         struct usb_ep           *intr_in;
 461
 462         struct fsg_buffhd       *next_buffhd_to_fill;
 463         struct fsg_buffhd       *next_buffhd_to_drain;
 464         struct fsg_buffhd       buffhds[FSG_NUM_BUFFERS];
 465
 466         int                     thread_wakeup_needed;
 467         struct completion       thread_notifier;
 468         struct task_struct      *thread_task;
 469
 470         int                     cmnd_size;
 471         u8                      cmnd[MAX_COMMAND_SIZE];
 472         enum data_direction     data_dir;
 473         u32                     data_size;
 474         u32                     data_size_from_cmnd;
 475         u32                     tag;
 476         unsigned int            lun;
 477         u32                     residue;
 478         u32                     usb_amount_left;
 479
 480         /* The CB protocol offers no way for a host to know when a command
 481          * has completed.  As a result the next command may arrive early,
 482          * and we will still have to handle it.  For that reason we need
 483          * a buffer to store new commands when using CB (or CBI, which
 484          * does not oblige a host to wait for command completion either). */
 485         int                     cbbuf_cmnd_size;
 486         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
 487
 488         unsigned int            nluns;
 489         struct fsg_lun          *luns;
 490         struct fsg_lun          *curlun;
 491 };
 492
 493 typedef void (*fsg_routine_t)(struct fsg_dev *);
 494
 495 static int exception_in_progress(struct fsg_dev *fsg)
 496 {
 497         return (fsg->state > FSG_STATE_IDLE);
 498 }
 499
 500 /* Make bulk-out requests be divisible by the maxpacket size */
 501 static void set_bulk_out_req_length(struct fsg_dev *fsg,
 502                 struct fsg_buffhd *bh, unsigned int length)
 503 {
 504         unsigned int    rem;
 505
 506         bh->bulk_out_intended_length = length;
 507         rem = length % fsg->bulk_out_maxpacket;
 508         if (rem > 0)
 509                 length += fsg->bulk_out_maxpacket - rem;
 510         bh->outreq->length = length;
 511 }
 512
 513 static struct fsg_dev                   *the_fsg;
 514 static struct usb_gadget_driver         fsg_driver;
 515
 516
 517 /*-------------------------------------------------------------------------*/
 518
 519 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 520 {
 521         const char      *name;
 522
 523         if (ep == fsg->bulk_in)
 524                 name = "bulk-in";
 525         else if (ep == fsg->bulk_out)
 526                 name = "bulk-out";
 527         else
 528                 name = ep->name;
 529         DBG(fsg, "%s set halt\n", name);
 530         return usb_ep_set_halt(ep);
 531 }
 532
 533
 534 /*-------------------------------------------------------------------------*/
 535
 536 /*
 537  * DESCRIPTORS ... most are static, but strings and (full) configuration
 538  * descriptors are built on demand.  Also the (static) config and interface
 539  * descriptors are adjusted during fsg_bind().
 540  */
 541
 542 /* There is only one configuration. */
 543 #define CONFIG_VALUE            1
 544
 545 static struct usb_device_descriptor
 546 device_desc = {
 547         .bLength =              sizeof device_desc,
 548         .bDescriptorType =      USB_DT_DEVICE,
 549
 550         .bcdUSB =               cpu_to_le16(0x0200),
 551         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
 552
 553         /* The next three values can be overridden by module parameters */
 554         .idVendor =             cpu_to_le16(FSG_VENDOR_ID),
 555         .idProduct =            cpu_to_le16(FSG_PRODUCT_ID),
 556         .bcdDevice =            cpu_to_le16(0xffff),
 557
 558         .iManufacturer =        FSG_STRING_MANUFACTURER,
 559         .iProduct =             FSG_STRING_PRODUCT,
 560         .iSerialNumber =        FSG_STRING_SERIAL,
 561         .bNumConfigurations =   1,
 562 };
 563
 564 static struct usb_config_descriptor
 565 config_desc = {
 566         .bLength =              sizeof config_desc,
 567         .bDescriptorType =      USB_DT_CONFIG,
 568
 569         /* wTotalLength computed by usb_gadget_config_buf() */
 570         .bNumInterfaces =       1,
 571         .bConfigurationValue =  CONFIG_VALUE,
 572         .iConfiguration =       FSG_STRING_CONFIG,
 573         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
 574         .bMaxPower =            CONFIG_USB_GADGET_VBUS_DRAW / 2,
 575 };
 576
 577
 578 static struct usb_qualifier_descriptor
 579 dev_qualifier = {
 580         .bLength =              sizeof dev_qualifier,
 581         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
 582
 583         .bcdUSB =               cpu_to_le16(0x0200),
 584         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
 585
 586         .bNumConfigurations =   1,
 587 };
 588
 589
 590
 591 /*
 592  * Config descriptors must agree with the code that sets configurations
 593  * and with code managing interfaces and their altsettings.  They must
 594  * also handle different speeds and other-speed requests.
 595  */
 596 static int populate_config_buf(struct usb_gadget *gadget,
 597                 u8 *buf, u8 type, unsigned index)
 598 {
 599         enum usb_device_speed                   speed = gadget->speed;
 600         int                                     len;
 601         const struct usb_descriptor_header      **function;
 602
 603         if (index > 0)
 604                 return -EINVAL;
 605
 606         if (gadget_is_dualspeed(gadget) && type == USB_DT_OTHER_SPEED_CONFIG)
 607                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
 608         function = gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH
 609                 ? (const struct usb_descriptor_header **)fsg_hs_function
 610                 : (const struct usb_descriptor_header **)fsg_fs_function;
 611
 612         /* for now, don't advertise srp-only devices */
 613         if (!gadget_is_otg(gadget))
 614                 function++;
 615
 616         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
 617         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
 618         return len;
 619 }
 620
 621
 622 /*-------------------------------------------------------------------------*/
 623
 624 /* These routines may be called in process context or in_irq */
 625
 626 /* Caller must hold fsg->lock */
 627 static void wakeup_thread(struct fsg_dev *fsg)
 628 {
 629         /* Tell the main thread that something has happened */
 630         fsg->thread_wakeup_needed = 1;
 631         if (fsg->thread_task)
 632                 wake_up_process(fsg->thread_task);
 633 }
 634
 635
 636 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
 637 {
 638         unsigned long           flags;
 639
 640         /* Do nothing if a higher-priority exception is already in progress.
 641          * If a lower-or-equal priority exception is in progress, preempt it
 642          * and notify the main thread by sending it a signal. */
 643         spin_lock_irqsave(&fsg->lock, flags);
 644         if (fsg->state <= new_state) {
 645                 fsg->exception_req_tag = fsg->ep0_req_tag;
 646                 fsg->state = new_state;
 647                 if (fsg->thread_task)
 648                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
 649                                         fsg->thread_task);
 650         }
 651         spin_unlock_irqrestore(&fsg->lock, flags);
 652 }
 653
 654
 655 /*-------------------------------------------------------------------------*/
 656
 657 /* The disconnect callback and ep0 routines.  These always run in_irq,
 658  * except that ep0_queue() is called in the main thread to acknowledge
 659  * completion of various requests: set config, set interface, and
 660  * Bulk-only device reset. */
 661
 662 static void fsg_disconnect(struct usb_gadget *gadget)
 663 {
 664         struct fsg_dev          *fsg = get_gadget_data(gadget);
 665
 666         DBG(fsg, "disconnect or port reset\n");
 667         raise_exception(fsg, FSG_STATE_DISCONNECT);
 668 }
 669
 670
 671 static int ep0_queue(struct fsg_dev *fsg)
 672 {
 673         int     rc;
 674
 675         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
 676         if (rc != 0 && rc != -ESHUTDOWN) {
 677
 678                 /* We can't do much more than wait for a reset */
 679                 WARNING(fsg, "error in submission: %s --> %d\n",
 680                                 fsg->ep0->name, rc);
 681         }
 682         return rc;
 683 }
 684
 685 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
 686 {
 687         struct fsg_dev          *fsg = ep->driver_data;
 688
 689         if (req->actual > 0)
 690                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
 691         if (req->status || req->actual != req->length)
 692                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 693                                 req->status, req->actual, req->length);
 694         if (req->status == -ECONNRESET)         // Request was cancelled
 695                 usb_ep_fifo_flush(ep);
 696
 697         if (req->status == 0 && req->context)
 698                 ((fsg_routine_t) (req->context))(fsg);
 699 }
 700
 701
 702 /*-------------------------------------------------------------------------*/
 703
 704 /* Bulk and interrupt endpoint completion handlers.
 705  * These always run in_irq. */
 706
 707 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 708 {
 709         struct fsg_dev          *fsg = ep->driver_data;
 710         struct fsg_buffhd       *bh = req->context;
 711
 712         if (req->status || req->actual != req->length)
 713                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 714                                 req->status, req->actual, req->length);
 715         if (req->status == -ECONNRESET)         // Request was cancelled
 716                 usb_ep_fifo_flush(ep);
 717
 718         /* Hold the lock while we update the request and buffer states */
 719         smp_wmb();
 720         spin_lock(&fsg->lock);
 721         bh->inreq_busy = 0;
 722         bh->state = BUF_STATE_EMPTY;
 723         wakeup_thread(fsg);
 724         spin_unlock(&fsg->lock);
 725 }
 726
 727 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 728 {
 729         struct fsg_dev          *fsg = ep->driver_data;
 730         struct fsg_buffhd       *bh = req->context;
 731
 732         dump_msg(fsg, "bulk-out", req->buf, req->actual);
 733         if (req->status || req->actual != bh->bulk_out_intended_length)
 734                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 735                                 req->status, req->actual,
 736                                 bh->bulk_out_intended_length);
 737         if (req->status == -ECONNRESET)         // Request was cancelled
 738                 usb_ep_fifo_flush(ep);
 739
 740         /* Hold the lock while we update the request and buffer states */
 741         smp_wmb();
 742         spin_lock(&fsg->lock);
 743         bh->outreq_busy = 0;
 744         bh->state = BUF_STATE_FULL;
 745         wakeup_thread(fsg);
 746         spin_unlock(&fsg->lock);
 747 }
 748
 749
 750 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 751 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
 752 {
 753         struct fsg_dev          *fsg = ep->driver_data;
 754         struct fsg_buffhd       *bh = req->context;
 755
 756         if (req->status || req->actual != req->length)
 757                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 758                                 req->status, req->actual, req->length);
 759         if (req->status == -ECONNRESET)         // Request was cancelled
 760                 usb_ep_fifo_flush(ep);
 761
 762         /* Hold the lock while we update the request and buffer states */
 763         smp_wmb();
 764         spin_lock(&fsg->lock);
 765         fsg->intreq_busy = 0;
 766         bh->state = BUF_STATE_EMPTY;
 767         wakeup_thread(fsg);
 768         spin_unlock(&fsg->lock);
 769 }
 770
 771 #else
 772 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
 773 {}
 774 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 775
 776
 777 /*-------------------------------------------------------------------------*/
 778
 779 /* Ep0 class-specific handlers.  These always run in_irq. */
 780
 781 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 782 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 783 {
 784         struct usb_request      *req = fsg->ep0req;
 785         static u8               cbi_reset_cmnd[6] = {
 786                         SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
 787
 788         /* Error in command transfer? */
 789         if (req->status || req->length != req->actual ||
 790                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
 791
 792                 /* Not all controllers allow a protocol stall after
 793                  * receiving control-out data, but we'll try anyway. */
 794                 fsg_set_halt(fsg, fsg->ep0);
 795                 return;                 // Wait for reset
 796         }
 797
 798         /* Is it the special reset command? */
 799         if (req->actual >= sizeof cbi_reset_cmnd &&
 800                         memcmp(req->buf, cbi_reset_cmnd,
 801                                 sizeof cbi_reset_cmnd) == 0) {
 802
 803                 /* Raise an exception to stop the current operation
 804                  * and reinitialize our state. */
 805                 DBG(fsg, "cbi reset request\n");
 806                 raise_exception(fsg, FSG_STATE_RESET);
 807                 return;
 808         }
 809
 810         VDBG(fsg, "CB[I] accept device-specific command\n");
 811         spin_lock(&fsg->lock);
 812
 813         /* Save the command for later */
 814         if (fsg->cbbuf_cmnd_size)
 815                 WARNING(fsg, "CB[I] overwriting previous command\n");
 816         fsg->cbbuf_cmnd_size = req->actual;
 817         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
 818
 819         wakeup_thread(fsg);
 820         spin_unlock(&fsg->lock);
 821 }
 822
 823 #else
 824 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 825 {}
 826 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 827
 828
 829 static int class_setup_req(struct fsg_dev *fsg,
 830                 const struct usb_ctrlrequest *ctrl)
 831 {
 832         struct usb_request      *req = fsg->ep0req;
 833         int                     value = -EOPNOTSUPP;
 834         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 835         u16                     w_value = le16_to_cpu(ctrl->wValue);
 836         u16                     w_length = le16_to_cpu(ctrl->wLength);
 837
 838         if (!fsg->config)
 839                 return value;
 840
 841         /* Handle Bulk-only class-specific requests */
 842         if (transport_is_bbb()) {
 843                 switch (ctrl->bRequest) {
 844
 845                 case USB_BULK_RESET_REQUEST:
 846                         if (ctrl->bRequestType != (USB_DIR_OUT |
 847                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 848                                 break;
 849                         if (w_index != 0 || w_value != 0) {
 850                                 value = -EDOM;
 851                                 break;
 852                         }
 853
 854                         /* Raise an exception to stop the current operation
 855                          * and reinitialize our state. */
 856                         DBG(fsg, "bulk reset request\n");
 857                         raise_exception(fsg, FSG_STATE_RESET);
 858                         value = DELAYED_STATUS;
 859                         break;
 860
 861                 case USB_BULK_GET_MAX_LUN_REQUEST:
 862                         if (ctrl->bRequestType != (USB_DIR_IN |
 863                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 864                                 break;
 865                         if (w_index != 0 || w_value != 0) {
 866                                 value = -EDOM;
 867                                 break;
 868                         }
 869                         VDBG(fsg, "get max LUN\n");
 870                         *(u8 *) req->buf = fsg->nluns - 1;
 871                         value = 1;
 872                         break;
 873                 }
 874         }
 875
 876         /* Handle CBI class-specific requests */
 877         else {
 878                 switch (ctrl->bRequest) {
 879
 880                 case USB_CBI_ADSC_REQUEST:
 881                         if (ctrl->bRequestType != (USB_DIR_OUT |
 882                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 883                                 break;
 884                         if (w_index != 0 || w_value != 0) {
 885                                 value = -EDOM;
 886                                 break;
 887                         }
 888                         if (w_length > MAX_COMMAND_SIZE) {
 889                                 value = -EOVERFLOW;
 890                                 break;
 891                         }
 892                         value = w_length;
 893                         fsg->ep0req->context = received_cbi_adsc;
 894                         break;
 895                 }
 896         }
 897
 898         if (value == -EOPNOTSUPP)
 899                 VDBG(fsg,
 900                         "unknown class-specific control req "
 901                         "%02x.%02x v%04x i%04x l%u\n",
 902                         ctrl->bRequestType, ctrl->bRequest,
 903                         le16_to_cpu(ctrl->wValue), w_index, w_length);
 904         return value;
 905 }
 906
 907
 908 /*-------------------------------------------------------------------------*/
 909
 910 /* Ep0 standard request handlers.  These always run in_irq. */
 911
 912 static int standard_setup_req(struct fsg_dev *fsg,
 913                 const struct usb_ctrlrequest *ctrl)
 914 {
 915         struct usb_request      *req = fsg->ep0req;
 916         int                     value = -EOPNOTSUPP;
 917         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 918         u16                     w_value = le16_to_cpu(ctrl->wValue);
 919
 920         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
 921          * but config change events will also reconfigure hardware. */
 922         switch (ctrl->bRequest) {
 923
 924         case USB_REQ_GET_DESCRIPTOR:
 925                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
 926                                 USB_RECIP_DEVICE))
 927                         break;
 928                 switch (w_value >> 8) {
 929
 930                 case USB_DT_DEVICE:
 931                         VDBG(fsg, "get device descriptor\n");
 932                         value = sizeof device_desc;
 933                         memcpy(req->buf, &device_desc, value);
 934                         break;
 935                 case USB_DT_DEVICE_QUALIFIER:
 936                         VDBG(fsg, "get device qualifier\n");
 937                         if (!gadget_is_dualspeed(fsg->gadget))
 938                                 break;
 939                         value = sizeof dev_qualifier;
 940                         memcpy(req->buf, &dev_qualifier, value);
 941                         break;
 942
 943                 case USB_DT_OTHER_SPEED_CONFIG:
 944                         VDBG(fsg, "get other-speed config descriptor\n");
 945                         if (!gadget_is_dualspeed(fsg->gadget))
 946                                 break;
 947                         goto get_config;
 948                 case USB_DT_CONFIG:
 949                         VDBG(fsg, "get configuration descriptor\n");
 950 get_config:
 951                         value = populate_config_buf(fsg->gadget,
 952                                         req->buf,
 953                                         w_value >> 8,
 954                                         w_value & 0xff);
 955                         break;
 956
 957                 case USB_DT_STRING:
 958                         VDBG(fsg, "get string descriptor\n");
 959
 960                         /* wIndex == language code */
 961                         value = usb_gadget_get_string(&fsg_stringtab,
 962                                         w_value & 0xff, req->buf);
 963                         break;
 964                 }
 965                 break;
 966
 967         /* One config, two speeds */
 968         case USB_REQ_SET_CONFIGURATION:
 969                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
 970                                 USB_RECIP_DEVICE))
 971                         break;
 972                 VDBG(fsg, "set configuration\n");
 973                 if (w_value == CONFIG_VALUE || w_value == 0) {
 974                         fsg->new_config = w_value;
 975
 976                         /* Raise an exception to wipe out previous transaction
 977                          * state (queued bufs, etc) and set the new config. */
 978                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
 979                         value = DELAYED_STATUS;
 980                 }
 981                 break;
 982         case USB_REQ_GET_CONFIGURATION:
 983                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
 984                                 USB_RECIP_DEVICE))
 985                         break;
 986                 VDBG(fsg, "get configuration\n");
 987                 *(u8 *) req->buf = fsg->config;
 988                 value = 1;
 989                 break;
 990
 991         case USB_REQ_SET_INTERFACE:
 992                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
 993                                 USB_RECIP_INTERFACE))
 994                         break;
 995                 if (fsg->config && w_index == 0) {
 996
 997                         /* Raise an exception to wipe out previous transaction
 998                          * state (queued bufs, etc) and install the new
 999                          * interface altsetting. */
1000                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
1001                         value = DELAYED_STATUS;
1002                 }
1003                 break;
1004         case USB_REQ_GET_INTERFACE:
1005                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
1006                                 USB_RECIP_INTERFACE))
1007                         break;
1008                 if (!fsg->config)
1009                         break;
1010                 if (w_index != 0) {
1011                         value = -EDOM;
1012                         break;
1013                 }
1014                 VDBG(fsg, "get interface\n");
1015                 *(u8 *) req->buf = 0;
1016                 value = 1;
1017                 break;
1018
1019         default:
1020                 VDBG(fsg,
1021                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1022                         ctrl->bRequestType, ctrl->bRequest,
1023                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1024         }
1025
1026         return value;
1027 }
1028
1029
1030 static int fsg_setup(struct usb_gadget *gadget,
1031                 const struct usb_ctrlrequest *ctrl)
1032 {
1033         struct fsg_dev          *fsg = get_gadget_data(gadget);
1034         int                     rc;
1035         int                     w_length = le16_to_cpu(ctrl->wLength);
1036
1037         ++fsg->ep0_req_tag;             // Record arrival of a new request
1038         fsg->ep0req->context = NULL;
1039         fsg->ep0req->length = 0;
1040         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1041
1042         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1043                 rc = class_setup_req(fsg, ctrl);
1044         else
1045                 rc = standard_setup_req(fsg, ctrl);
1046
1047         /* Respond with data/status or defer until later? */
1048         if (rc >= 0 && rc != DELAYED_STATUS) {
1049                 rc = min(rc, w_length);
1050                 fsg->ep0req->length = rc;
1051                 fsg->ep0req->zero = rc < w_length;
1052                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1053                                 "ep0-in" : "ep0-out");
1054                 rc = ep0_queue(fsg);
1055         }
1056
1057         /* Device either stalls (rc < 0) or reports success */
1058         return rc;
1059 }
1060
1061
1062 /*-------------------------------------------------------------------------*/
1063
1064 /* All the following routines run in process context */
1065
1066
1067 /* Use this for bulk or interrupt transfers, not ep0 */
1068 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1069                 struct usb_request *req, int *pbusy,
1070                 enum fsg_buffer_state *state)
1071 {
1072         int     rc;
1073
1074         if (ep == fsg->bulk_in)
1075                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1076         else if (ep == fsg->intr_in)
1077                 dump_msg(fsg, "intr-in", req->buf, req->length);
1078
1079         spin_lock_irq(&fsg->lock);
1080         *pbusy = 1;
1081         *state = BUF_STATE_BUSY;
1082         spin_unlock_irq(&fsg->lock);
1083         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1084         if (rc != 0) {
1085                 *pbusy = 0;
1086                 *state = BUF_STATE_EMPTY;
1087
1088                 /* We can't do much more than wait for a reset */
1089
1090                 /* Note: currently the net2280 driver fails zero-length
1091                  * submissions if DMA is enabled. */
1092                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1093                                                 req->length == 0))
1094                         WARNING(fsg, "error in submission: %s --> %d\n",
1095                                         ep->name, rc);
1096         }
1097 }
1098
1099
1100 static int sleep_thread(struct fsg_dev *fsg)
1101 {
1102         int     rc = 0;
1103
1104         /* Wait until a signal arrives or we are woken up */
1105         for (;;) {
1106                 try_to_freeze();
1107                 set_current_state(TASK_INTERRUPTIBLE);
1108                 if (signal_pending(current)) {
1109                         rc = -EINTR;
1110                         break;
1111                 }
1112                 if (fsg->thread_wakeup_needed)
1113                         break;
1114                 schedule();
1115         }
1116         __set_current_state(TASK_RUNNING);
1117         fsg->thread_wakeup_needed = 0;
1118         return rc;
1119 }
1120
1121
1122 /*-------------------------------------------------------------------------*/
1123
1124 static int do_read(struct fsg_dev *fsg)
1125 {
1126         struct fsg_lun          *curlun = fsg->curlun;
1127         u32                     lba;
1128         struct fsg_buffhd       *bh;
1129         int                     rc;
1130         u32                     amount_left;
1131         loff_t                  file_offset, file_offset_tmp;
1132         unsigned int            amount;
1133         unsigned int            partial_page;
1134         ssize_t                 nread;
1135
1136         /* Get the starting Logical Block Address and check that it's
1137          * not too big */
1138         if (fsg->cmnd[0] == READ_6)
1139                 lba = get_unaligned_be24(&fsg->cmnd[1]);
1140         else {
1141                 lba = get_unaligned_be32(&fsg->cmnd[2]);
1142
1143                 /* We allow DPO (Disable Page Out = don't save data in the
1144                  * cache) and FUA (Force Unit Access = don't read from the
1145                  * cache), but we don't implement them. */
1146                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1147                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1148                         return -EINVAL;
1149                 }
1150         }
1151         if (lba >= curlun->num_sectors) {
1152                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1153                 return -EINVAL;
1154         }
1155         file_offset = ((loff_t) lba) << 9;
1156
1157         /* Carry out the file reads */
1158         amount_left = fsg->data_size_from_cmnd;
1159         if (unlikely(amount_left == 0))
1160                 return -EIO;            // No default reply
1161
1162         for (;;) {
1163
1164                 /* Figure out how much we need to read:
1165                  * Try to read the remaining amount.
1166                  * But don't read more than the buffer size.
1167                  * And don't try to read past the end of the file.
1168                  * Finally, if we're not at a page boundary, don't read past
1169                  *      the next page.
1170                  * If this means reading 0 then we were asked to read past
1171                  *      the end of file. */
1172                 amount = min((unsigned int) amount_left, mod_data.buflen);
1173                 amount = min((loff_t) amount,
1174                                 curlun->file_length - file_offset);
1175                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1176                 if (partial_page > 0)
1177                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1178                                         partial_page);
1179
1180                 /* Wait for the next buffer to become available */
1181                 bh = fsg->next_buffhd_to_fill;
1182                 while (bh->state != BUF_STATE_EMPTY) {
1183                         rc = sleep_thread(fsg);
1184                         if (rc)
1185                                 return rc;
1186                 }
1187
1188                 /* If we were asked to read past the end of file,
1189                  * end with an empty buffer. */
1190                 if (amount == 0) {
1191                         curlun->sense_data =
1192                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1193                         curlun->sense_data_info = file_offset >> 9;
1194                         curlun->info_valid = 1;
1195                         bh->inreq->length = 0;
1196                         bh->state = BUF_STATE_FULL;
1197                         break;
1198                 }
1199
1200                 /* Perform the read */
1201                 file_offset_tmp = file_offset;
1202                 nread = vfs_read(curlun->filp,
1203                                 (char __user *) bh->buf,
1204                                 amount, &file_offset_tmp);
1205                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1206                                 (unsigned long long) file_offset,
1207                                 (int) nread);
1208                 if (signal_pending(current))
1209                         return -EINTR;
1210
1211                 if (nread < 0) {
1212                         LDBG(curlun, "error in file read: %d\n",
1213                                         (int) nread);
1214                         nread = 0;
1215                 } else if (nread < amount) {
1216                         LDBG(curlun, "partial file read: %d/%u\n",
1217                                         (int) nread, amount);
1218                         nread -= (nread & 511); // Round down to a block
1219                 }
1220                 file_offset  += nread;
1221                 amount_left  -= nread;
1222                 fsg->residue -= nread;
1223                 bh->inreq->length = nread;
1224                 bh->state = BUF_STATE_FULL;
1225
1226                 /* If an error occurred, report it and its position */
1227                 if (nread < amount) {
1228                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1229                         curlun->sense_data_info = file_offset >> 9;
1230                         curlun->info_valid = 1;
1231                         break;
1232                 }
1233
1234                 if (amount_left == 0)
1235                         break;          // No more left to read
1236
1237                 /* Send this buffer and go read some more */
1238                 bh->inreq->zero = 0;
1239                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1240                                 &bh->inreq_busy, &bh->state);
1241                 fsg->next_buffhd_to_fill = bh->next;
1242         }
1243
1244         return -EIO;            // No default reply
1245 }
1246
1247
1248 /*-------------------------------------------------------------------------*/
1249
1250 static int do_write(struct fsg_dev *fsg)
1251 {
1252         struct fsg_lun          *curlun = fsg->curlun;
1253         u32                     lba;
1254         struct fsg_buffhd       *bh;
1255         int                     get_some_more;
1256         u32                     amount_left_to_req, amount_left_to_write;
1257         loff_t                  usb_offset, file_offset, file_offset_tmp;
1258         unsigned int            amount;
1259         unsigned int            partial_page;
1260         ssize_t                 nwritten;
1261         int                     rc;
1262
1263         if (curlun->ro) {
1264                 curlun->sense_data = SS_WRITE_PROTECTED;
1265                 return -EINVAL;
1266         }
1267         spin_lock(&curlun->filp->f_lock);
1268         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1269         spin_unlock(&curlun->filp->f_lock);
1270
1271         /* Get the starting Logical Block Address and check that it's
1272          * not too big */
1273         if (fsg->cmnd[0] == WRITE_6)
1274                 lba = get_unaligned_be24(&fsg->cmnd[1]);
1275         else {
1276                 lba = get_unaligned_be32(&fsg->cmnd[2]);
1277
1278                 /* We allow DPO (Disable Page Out = don't save data in the
1279                  * cache) and FUA (Force Unit Access = write directly to the
1280                  * medium).  We don't implement DPO; we implement FUA by
1281                  * performing synchronous output. */
1282                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1283                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1284                         return -EINVAL;
1285                 }
1286                 /* FUA */
1287                 if (!curlun->nofua && (fsg->cmnd[1] & 0x08)) {
1288                         spin_lock(&curlun->filp->f_lock);
1289                         curlun->filp->f_flags |= O_DSYNC;
1290                         spin_unlock(&curlun->filp->f_lock);
1291                 }
1292         }
1293         if (lba >= curlun->num_sectors) {
1294                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1295                 return -EINVAL;
1296         }
1297
1298         /* Carry out the file writes */
1299         get_some_more = 1;
1300         file_offset = usb_offset = ((loff_t) lba) << 9;
1301         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1302
1303         while (amount_left_to_write > 0) {
1304
1305                 /* Queue a request for more data from the host */
1306                 bh = fsg->next_buffhd_to_fill;
1307                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1308
1309                         /* Figure out how much we want to get:
1310                          * Try to get the remaining amount.
1311                          * But don't get more than the buffer size.
1312                          * And don't try to go past the end of the file.
1313                          * If we're not at a page boundary,
1314                          *      don't go past the next page.
1315                          * If this means getting 0, then we were asked
1316                          *      to write past the end of file.
1317                          * Finally, round down to a block boundary. */
1318                         amount = min(amount_left_to_req, mod_data.buflen);
1319                         amount = min((loff_t) amount, curlun->file_length -
1320                                         usb_offset);
1321                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1322                         if (partial_page > 0)
1323                                 amount = min(amount,
1324         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1325
1326                         if (amount == 0) {
1327                                 get_some_more = 0;
1328                                 curlun->sense_data =
1329                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1330                                 curlun->sense_data_info = usb_offset >> 9;
1331                                 curlun->info_valid = 1;
1332                                 continue;
1333                         }
1334                         amount -= (amount & 511);
1335                         if (amount == 0) {
1336
1337                                 /* Why were we were asked to transfer a
1338                                  * partial block? */
1339                                 get_some_more = 0;
1340                                 continue;
1341                         }
1342
1343                         /* Get the next buffer */
1344                         usb_offset += amount;
1345                         fsg->usb_amount_left -= amount;
1346                         amount_left_to_req -= amount;
1347                         if (amount_left_to_req == 0)
1348                                 get_some_more = 0;
1349
1350                         /* amount is always divisible by 512, hence by
1351                          * the bulk-out maxpacket size */
1352                         bh->outreq->length = bh->bulk_out_intended_length =
1353                                         amount;
1354                         bh->outreq->short_not_ok = 1;
1355                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1356                                         &bh->outreq_busy, &bh->state);
1357                         fsg->next_buffhd_to_fill = bh->next;
1358                         continue;
1359                 }
1360
1361                 /* Write the received data to the backing file */
1362                 bh = fsg->next_buffhd_to_drain;
1363                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1364                         break;                  // We stopped early
1365                 if (bh->state == BUF_STATE_FULL) {
1366                         smp_rmb();
1367                         fsg->next_buffhd_to_drain = bh->next;
1368                         bh->state = BUF_STATE_EMPTY;
1369
1370                         /* Did something go wrong with the transfer? */
1371                         if (bh->outreq->status != 0) {
1372                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1373                                 curlun->sense_data_info = file_offset >> 9;
1374                                 curlun->info_valid = 1;
1375                                 break;
1376                         }
1377
1378                         amount = bh->outreq->actual;
1379                         if (curlun->file_length - file_offset < amount) {
1380                                 LERROR(curlun,
1381         "write %u @ %llu beyond end %llu\n",
1382         amount, (unsigned long long) file_offset,
1383         (unsigned long long) curlun->file_length);
1384                                 amount = curlun->file_length - file_offset;
1385                         }
1386
1387                         /* Perform the write */
1388                         file_offset_tmp = file_offset;
1389                         nwritten = vfs_write(curlun->filp,
1390                                         (char __user *) bh->buf,
1391                                         amount, &file_offset_tmp);
1392                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1393                                         (unsigned long long) file_offset,
1394                                         (int) nwritten);
1395                         if (signal_pending(current))
1396                                 return -EINTR;          // Interrupted!
1397
1398                         if (nwritten < 0) {
1399                                 LDBG(curlun, "error in file write: %d\n",
1400                                                 (int) nwritten);
1401                                 nwritten = 0;
1402                         } else if (nwritten < amount) {
1403                                 LDBG(curlun, "partial file write: %d/%u\n",
1404                                                 (int) nwritten, amount);
1405                                 nwritten -= (nwritten & 511);
1406                                                 // Round down to a block
1407                         }
1408                         file_offset += nwritten;
1409                         amount_left_to_write -= nwritten;
1410                         fsg->residue -= nwritten;
1411
1412                         /* If an error occurred, report it and its position */
1413                         if (nwritten < amount) {
1414                                 curlun->sense_data = SS_WRITE_ERROR;
1415                                 curlun->sense_data_info = file_offset >> 9;
1416                                 curlun->info_valid = 1;
1417                                 break;
1418                         }
1419
1420                         /* Did the host decide to stop early? */
1421                         if (bh->outreq->actual != bh->outreq->length) {
1422                                 fsg->short_packet_received = 1;
1423                                 break;
1424                         }
1425                         continue;
1426                 }
1427
1428                 /* Wait for something to happen */
1429                 rc = sleep_thread(fsg);
1430                 if (rc)
1431                         return rc;
1432         }
1433
1434         return -EIO;            // No default reply
1435 }
1436
1437
1438 /*-------------------------------------------------------------------------*/
1439
1440 static int do_synchronize_cache(struct fsg_dev *fsg)
1441 {
1442         struct fsg_lun  *curlun = fsg->curlun;
1443         int             rc;
1444
1445         /* We ignore the requested LBA and write out all file's
1446          * dirty data buffers. */
1447         rc = fsg_lun_fsync_sub(curlun);
1448         if (rc)
1449                 curlun->sense_data = SS_WRITE_ERROR;
1450         return 0;
1451 }
1452
1453
1454 /*-------------------------------------------------------------------------*/
1455
1456 static void invalidate_sub(struct fsg_lun *curlun)
1457 {
1458         struct file     *filp = curlun->filp;
1459         struct inode    *inode = filp->f_path.dentry->d_inode;
1460         unsigned long   rc;
1461
1462         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1463         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1464 }
1465
1466 static int do_verify(struct fsg_dev *fsg)
1467 {
1468         struct fsg_lun          *curlun = fsg->curlun;
1469         u32                     lba;
1470         u32                     verification_length;
1471         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1472         loff_t                  file_offset, file_offset_tmp;
1473         u32                     amount_left;
1474         unsigned int            amount;
1475         ssize_t                 nread;
1476
1477         /* Get the starting Logical Block Address and check that it's
1478          * not too big */
1479         lba = get_unaligned_be32(&fsg->cmnd[2]);
1480         if (lba >= curlun->num_sectors) {
1481                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1482                 return -EINVAL;
1483         }
1484
1485         /* We allow DPO (Disable Page Out = don't save data in the
1486          * cache) but we don't implement it. */
1487         if ((fsg->cmnd[1] & ~0x10) != 0) {
1488                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1489                 return -EINVAL;
1490         }
1491
1492         verification_length = get_unaligned_be16(&fsg->cmnd[7]);
1493         if (unlikely(verification_length == 0))
1494                 return -EIO;            // No default reply
1495
1496         /* Prepare to carry out the file verify */
1497         amount_left = verification_length << 9;
1498         file_offset = ((loff_t) lba) << 9;
1499
1500         /* Write out all the dirty buffers before invalidating them */
1501         fsg_lun_fsync_sub(curlun);
1502         if (signal_pending(current))
1503                 return -EINTR;
1504
1505         invalidate_sub(curlun);
1506         if (signal_pending(current))
1507                 return -EINTR;
1508
1509         /* Just try to read the requested blocks */
1510         while (amount_left > 0) {
1511
1512                 /* Figure out how much we need to read:
1513                  * Try to read the remaining amount, but not more than
1514                  * the buffer size.
1515                  * And don't try to read past the end of the file.
1516                  * If this means reading 0 then we were asked to read
1517                  * past the end of file. */
1518                 amount = min((unsigned int) amount_left, mod_data.buflen);
1519                 amount = min((loff_t) amount,
1520                                 curlun->file_length - file_offset);
1521                 if (amount == 0) {
1522                         curlun->sense_data =
1523                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1524                         curlun->sense_data_info = file_offset >> 9;
1525                         curlun->info_valid = 1;
1526                         break;
1527                 }
1528
1529                 /* Perform the read */
1530                 file_offset_tmp = file_offset;
1531                 nread = vfs_read(curlun->filp,
1532                                 (char __user *) bh->buf,
1533                                 amount, &file_offset_tmp);
1534                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1535                                 (unsigned long long) file_offset,
1536                                 (int) nread);
1537                 if (signal_pending(current))
1538                         return -EINTR;
1539
1540                 if (nread < 0) {
1541                         LDBG(curlun, "error in file verify: %d\n",
1542                                         (int) nread);
1543                         nread = 0;
1544                 } else if (nread < amount) {
1545                         LDBG(curlun, "partial file verify: %d/%u\n",
1546                                         (int) nread, amount);
1547                         nread -= (nread & 511); // Round down to a sector
1548                 }
1549                 if (nread == 0) {
1550                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1551                         curlun->sense_data_info = file_offset >> 9;
1552                         curlun->info_valid = 1;
1553                         break;
1554                 }
1555                 file_offset += nread;
1556                 amount_left -= nread;
1557         }
1558         return 0;
1559 }
1560
1561
1562 /*-------------------------------------------------------------------------*/
1563
1564 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1565 {
1566         u8      *buf = (u8 *) bh->buf;
1567
1568         static char vendor_id[] = "Linux   ";
1569         static char product_disk_id[] = "File-Stor Gadget";
1570         static char product_cdrom_id[] = "File-CD Gadget  ";
1571
1572         if (!fsg->curlun) {             // Unsupported LUNs are okay
1573                 fsg->bad_lun_okay = 1;
1574                 memset(buf, 0, 36);
1575                 buf[0] = 0x7f;          // Unsupported, no device-type
1576                 buf[4] = 31;            // Additional length
1577                 return 36;
1578         }
1579
1580         memset(buf, 0, 8);
1581         buf[0] = (mod_data.cdrom ? TYPE_ROM : TYPE_DISK);
1582         if (mod_data.removable)
1583                 buf[1] = 0x80;
1584         buf[2] = 2;             // ANSI SCSI level 2
1585         buf[3] = 2;             // SCSI-2 INQUIRY data format
1586         buf[4] = 31;            // Additional length
1587                                 // No special options
1588         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id,
1589                         (mod_data.cdrom ? product_cdrom_id :
1590                                 product_disk_id),
1591                         mod_data.release);
1592         return 36;
1593 }
1594
1595
1596 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1597 {
1598         struct fsg_lun  *curlun = fsg->curlun;
1599         u8              *buf = (u8 *) bh->buf;
1600         u32             sd, sdinfo;
1601         int             valid;
1602
1603         /*
1604          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1605          *
1606          * If a REQUEST SENSE command is received from an initiator
1607          * with a pending unit attention condition (before the target
1608          * generates the contingent allegiance condition), then the
1609          * target shall either:
1610          *   a) report any pending sense data and preserve the unit
1611          *      attention condition on the logical unit, or,
1612          *   b) report the unit attention condition, may discard any
1613          *      pending sense data, and clear the unit attention
1614          *      condition on the logical unit for that initiator.
1615          *
1616          * FSG normally uses option a); enable this code to use option b).
1617          */
1618 #if 0
1619         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1620                 curlun->sense_data = curlun->unit_attention_data;
1621                 curlun->unit_attention_data = SS_NO_SENSE;
1622         }
1623 #endif
1624
1625         if (!curlun) {          // Unsupported LUNs are okay
1626                 fsg->bad_lun_okay = 1;
1627                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1628                 sdinfo = 0;
1629                 valid = 0;
1630         } else {
1631                 sd = curlun->sense_data;
1632                 sdinfo = curlun->sense_data_info;
1633                 valid = curlun->info_valid << 7;
1634                 curlun->sense_data = SS_NO_SENSE;
1635                 curlun->sense_data_info = 0;
1636                 curlun->info_valid = 0;
1637         }
1638
1639         memset(buf, 0, 18);
1640         buf[0] = valid | 0x70;                  // Valid, current error
1641         buf[2] = SK(sd);
1642         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1643         buf[7] = 18 - 8;                        // Additional sense length
1644         buf[12] = ASC(sd);
1645         buf[13] = ASCQ(sd);
1646         return 18;
1647 }
1648
1649
1650 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1651 {
1652         struct fsg_lun  *curlun = fsg->curlun;
1653         u32             lba = get_unaligned_be32(&fsg->cmnd[2]);
1654         int             pmi = fsg->cmnd[8];
1655         u8              *buf = (u8 *) bh->buf;
1656
1657         /* Check the PMI and LBA fields */
1658         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1659                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1660                 return -EINVAL;
1661         }
1662
1663         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1664                                                 /* Max logical block */
1665         put_unaligned_be32(512, &buf[4]);       /* Block length */
1666         return 8;
1667 }
1668
1669
1670 static int do_read_header(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1671 {
1672         struct fsg_lun  *curlun = fsg->curlun;
1673         int             msf = fsg->cmnd[1] & 0x02;
1674         u32             lba = get_unaligned_be32(&fsg->cmnd[2]);
1675         u8              *buf = (u8 *) bh->buf;
1676
1677         if ((fsg->cmnd[1] & ~0x02) != 0) {              /* Mask away MSF */
1678                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1679                 return -EINVAL;
1680         }
1681         if (lba >= curlun->num_sectors) {
1682                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1683                 return -EINVAL;
1684         }
1685
1686         memset(buf, 0, 8);
1687         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1688         store_cdrom_address(&buf[4], msf, lba);
1689         return 8;
1690 }
1691
1692
1693 static int do_read_toc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1694 {
1695         struct fsg_lun  *curlun = fsg->curlun;
1696         int             msf = fsg->cmnd[1] & 0x02;
1697         int             start_track = fsg->cmnd[6];
1698         u8              *buf = (u8 *) bh->buf;
1699
1700         if ((fsg->cmnd[1] & ~0x02) != 0 ||              /* Mask away MSF */
1701                         start_track > 1) {
1702                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1703                 return -EINVAL;
1704         }
1705
1706         memset(buf, 0, 20);
1707         buf[1] = (20-2);                /* TOC data length */
1708         buf[2] = 1;                     /* First track number */
1709         buf[3] = 1;                     /* Last track number */
1710         buf[5] = 0x16;                  /* Data track, copying allowed */
1711         buf[6] = 0x01;                  /* Only track is number 1 */
1712         store_cdrom_address(&buf[8], msf, 0);
1713
1714         buf[13] = 0x16;                 /* Lead-out track is data */
1715         buf[14] = 0xAA;                 /* Lead-out track number */
1716         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1717         return 20;
1718 }
1719
1720
1721 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1722 {
1723         struct fsg_lun  *curlun = fsg->curlun;
1724         int             mscmnd = fsg->cmnd[0];
1725         u8              *buf = (u8 *) bh->buf;
1726         u8              *buf0 = buf;
1727         int             pc, page_code;
1728         int             changeable_values, all_pages;
1729         int             valid_page = 0;
1730         int             len, limit;
1731
1732         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
1733                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1734                 return -EINVAL;
1735         }
1736         pc = fsg->cmnd[2] >> 6;
1737         page_code = fsg->cmnd[2] & 0x3f;
1738         if (pc == 3) {
1739                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1740                 return -EINVAL;
1741         }
1742         changeable_values = (pc == 1);
1743         all_pages = (page_code == 0x3f);
1744
1745         /* Write the mode parameter header.  Fixed values are: default
1746          * medium type, no cache control (DPOFUA), and no block descriptors.
1747          * The only variable value is the WriteProtect bit.  We will fill in
1748          * the mode data length later. */
1749         memset(buf, 0, 8);
1750         if (mscmnd == MODE_SENSE) {
1751                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
1752                 buf += 4;
1753                 limit = 255;
1754         } else {                        // MODE_SENSE_10
1755                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
1756                 buf += 8;
1757                 limit = 65535;          // Should really be mod_data.buflen
1758         }
1759
1760         /* No block descriptors */
1761
1762         /* The mode pages, in numerical order.  The only page we support
1763          * is the Caching page. */
1764         if (page_code == 0x08 || all_pages) {
1765                 valid_page = 1;
1766                 buf[0] = 0x08;          // Page code
1767                 buf[1] = 10;            // Page length
1768                 memset(buf+2, 0, 10);   // None of the fields are changeable
1769
1770                 if (!changeable_values) {
1771                         buf[2] = 0x04;  // Write cache enable,
1772                                         // Read cache not disabled
1773                                         // No cache retention priorities
1774                         put_unaligned_be16(0xffff, &buf[4]);
1775                                         /* Don't disable prefetch */
1776                                         /* Minimum prefetch = 0 */
1777                         put_unaligned_be16(0xffff, &buf[8]);
1778                                         /* Maximum prefetch */
1779                         put_unaligned_be16(0xffff, &buf[10]);
1780                                         /* Maximum prefetch ceiling */
1781                 }
1782                 buf += 12;
1783         }
1784
1785         /* Check that a valid page was requested and the mode data length
1786          * isn't too long. */
1787         len = buf - buf0;
1788         if (!valid_page || len > limit) {
1789                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1790                 return -EINVAL;
1791         }
1792
1793         /*  Store the mode data length */
1794         if (mscmnd == MODE_SENSE)
1795                 buf0[0] = len - 1;
1796         else
1797                 put_unaligned_be16(len - 2, buf0);
1798         return len;
1799 }
1800
1801
1802 static int do_start_stop(struct fsg_dev *fsg)
1803 {
1804         struct fsg_lun  *curlun = fsg->curlun;
1805         int             loej, start;
1806
1807         if (!mod_data.removable) {
1808                 curlun->sense_data = SS_INVALID_COMMAND;
1809                 return -EINVAL;
1810         }
1811
1812         // int immed = fsg->cmnd[1] & 0x01;
1813         loej = fsg->cmnd[4] & 0x02;
1814         start = fsg->cmnd[4] & 0x01;
1815
1816 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1817         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
1818                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
1819                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1820                 return -EINVAL;
1821         }
1822
1823         if (!start) {
1824
1825                 /* Are we allowed to unload the media? */
1826                 if (curlun->prevent_medium_removal) {
1827                         LDBG(curlun, "unload attempt prevented\n");
1828                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1829                         return -EINVAL;
1830                 }
1831                 if (loej) {             // Simulate an unload/eject
1832                         up_read(&fsg->filesem);
1833                         down_write(&fsg->filesem);
1834                         fsg_lun_close(curlun);
1835                         up_write(&fsg->filesem);
1836                         down_read(&fsg->filesem);
1837                 }
1838         } else {
1839
1840                 /* Our emulation doesn't support mounting; the medium is
1841                  * available for use as soon as it is loaded. */
1842                 if (!fsg_lun_is_open(curlun)) {
1843                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1844                         return -EINVAL;
1845                 }
1846         }
1847 #endif
1848         return 0;
1849 }
1850
1851
1852 static int do_prevent_allow(struct fsg_dev *fsg)
1853 {
1854         struct fsg_lun  *curlun = fsg->curlun;
1855         int             prevent;
1856
1857         if (!mod_data.removable) {
1858                 curlun->sense_data = SS_INVALID_COMMAND;
1859                 return -EINVAL;
1860         }
1861
1862         prevent = fsg->cmnd[4] & 0x01;
1863         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
1864                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1865                 return -EINVAL;
1866         }
1867
1868         if (curlun->prevent_medium_removal && !prevent)
1869                 fsg_lun_fsync_sub(curlun);
1870         curlun->prevent_medium_removal = prevent;
1871         return 0;
1872 }
1873
1874
1875 static int do_read_format_capacities(struct fsg_dev *fsg,
1876                         struct fsg_buffhd *bh)
1877 {
1878         struct fsg_lun  *curlun = fsg->curlun;
1879         u8              *buf = (u8 *) bh->buf;
1880
1881         buf[0] = buf[1] = buf[2] = 0;
1882         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
1883         buf += 4;
1884
1885         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1886                                                 /* Number of blocks */
1887         put_unaligned_be32(512, &buf[4]);       /* Block length */
1888         buf[4] = 0x02;                          /* Current capacity */
1889         return 12;
1890 }
1891
1892
1893 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1894 {
1895         struct fsg_lun  *curlun = fsg->curlun;
1896
1897         /* We don't support MODE SELECT */
1898         curlun->sense_data = SS_INVALID_COMMAND;
1899         return -EINVAL;
1900 }
1901
1902
1903 /*-------------------------------------------------------------------------*/
1904
1905 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1906 {
1907         int     rc;
1908
1909         rc = fsg_set_halt(fsg, fsg->bulk_in);
1910         if (rc == -EAGAIN)
1911                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1912         while (rc != 0) {
1913                 if (rc != -EAGAIN) {
1914                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1915                         rc = 0;
1916                         break;
1917                 }
1918
1919                 /* Wait for a short time and then try again */
1920                 if (msleep_interruptible(100) != 0)
1921                         return -EINTR;
1922                 rc = usb_ep_set_halt(fsg->bulk_in);
1923         }
1924         return rc;
1925 }
1926
1927 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1928 {
1929         int     rc;
1930
1931         DBG(fsg, "bulk-in set wedge\n");
1932         rc = usb_ep_set_wedge(fsg->bulk_in);
1933         if (rc == -EAGAIN)
1934                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1935         while (rc != 0) {
1936                 if (rc != -EAGAIN) {
1937                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1938                         rc = 0;
1939                         break;
1940                 }
1941
1942                 /* Wait for a short time and then try again */
1943                 if (msleep_interruptible(100) != 0)
1944                         return -EINTR;
1945                 rc = usb_ep_set_wedge(fsg->bulk_in);
1946         }
1947         return rc;
1948 }
1949
1950 static int throw_away_data(struct fsg_dev *fsg)
1951 {
1952         struct fsg_buffhd       *bh;
1953         u32                     amount;
1954         int                     rc;
1955
1956         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
1957                         fsg->usb_amount_left > 0) {
1958
1959                 /* Throw away the data in a filled buffer */
1960                 if (bh->state == BUF_STATE_FULL) {
1961                         smp_rmb();
1962                         bh->state = BUF_STATE_EMPTY;
1963                         fsg->next_buffhd_to_drain = bh->next;
1964
1965                         /* A short packet or an error ends everything */
1966                         if (bh->outreq->actual != bh->outreq->length ||
1967                                         bh->outreq->status != 0) {
1968                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
1969                                 return -EINTR;
1970                         }
1971                         continue;
1972                 }
1973
1974                 /* Try to submit another request if we need one */
1975                 bh = fsg->next_buffhd_to_fill;
1976                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
1977                         amount = min(fsg->usb_amount_left,
1978                                         (u32) mod_data.buflen);
1979
1980                         /* amount is always divisible by 512, hence by
1981                          * the bulk-out maxpacket size */
1982                         bh->outreq->length = bh->bulk_out_intended_length =
1983                                         amount;
1984                         bh->outreq->short_not_ok = 1;
1985                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1986                                         &bh->outreq_busy, &bh->state);
1987                         fsg->next_buffhd_to_fill = bh->next;
1988                         fsg->usb_amount_left -= amount;
1989                         continue;
1990                 }
1991
1992                 /* Otherwise wait for something to happen */
1993                 rc = sleep_thread(fsg);
1994                 if (rc)
1995                         return rc;
1996         }
1997         return 0;
1998 }
1999
2000
2001 static int finish_reply(struct fsg_dev *fsg)
2002 {
2003         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2004         int                     rc = 0;
2005
2006         switch (fsg->data_dir) {
2007         case DATA_DIR_NONE:
2008                 break;                  // Nothing to send
2009
2010         /* If we don't know whether the host wants to read or write,
2011          * this must be CB or CBI with an unknown command.  We mustn't
2012          * try to send or receive any data.  So stall both bulk pipes
2013          * if we can and wait for a reset. */
2014         case DATA_DIR_UNKNOWN:
2015                 if (mod_data.can_stall) {
2016                         fsg_set_halt(fsg, fsg->bulk_out);
2017                         rc = halt_bulk_in_endpoint(fsg);
2018                 }
2019                 break;
2020
2021         /* All but the last buffer of data must have already been sent */
2022         case DATA_DIR_TO_HOST:
2023                 if (fsg->data_size == 0)
2024                         ;               // Nothing to send
2025
2026                 /* If there's no residue, simply send the last buffer */
2027                 else if (fsg->residue == 0) {
2028                         bh->inreq->zero = 0;
2029                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2030                                         &bh->inreq_busy, &bh->state);
2031                         fsg->next_buffhd_to_fill = bh->next;
2032                 }
2033
2034                 /* There is a residue.  For CB and CBI, simply mark the end
2035                  * of the data with a short packet.  However, if we are
2036                  * allowed to stall, there was no data at all (residue ==
2037                  * data_size), and the command failed (invalid LUN or
2038                  * sense data is set), then halt the bulk-in endpoint
2039                  * instead. */
2040                 else if (!transport_is_bbb()) {
2041                         if (mod_data.can_stall &&
2042                                         fsg->residue == fsg->data_size &&
2043         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2044                                 bh->state = BUF_STATE_EMPTY;
2045                                 rc = halt_bulk_in_endpoint(fsg);
2046                         } else {
2047                                 bh->inreq->zero = 1;
2048                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2049                                                 &bh->inreq_busy, &bh->state);
2050                                 fsg->next_buffhd_to_fill = bh->next;
2051                         }
2052                 }
2053
2054                 /*
2055                  * For Bulk-only, mark the end of the data with a short
2056                  * packet.  If we are allowed to stall, halt the bulk-in
2057                  * endpoint.  (Note: This violates the Bulk-Only Transport
2058                  * specification, which requires us to pad the data if we
2059                  * don't halt the endpoint.  Presumably nobody will mind.)
2060                  */
2061                 else {
2062                         bh->inreq->zero = 1;
2063                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
2064                                         &bh->inreq_busy, &bh->state);
2065                         fsg->next_buffhd_to_fill = bh->next;
2066                         if (mod_data.can_stall)
2067                                 rc = halt_bulk_in_endpoint(fsg);
2068                 }
2069                 break;
2070
2071         /* We have processed all we want from the data the host has sent.
2072          * There may still be outstanding bulk-out requests. */
2073         case DATA_DIR_FROM_HOST:
2074                 if (fsg->residue == 0)
2075                         ;               // Nothing to receive
2076
2077                 /* Did the host stop sending unexpectedly early? */
2078                 else if (fsg->short_packet_received) {
2079                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2080                         rc = -EINTR;
2081                 }
2082
2083                 /* We haven't processed all the incoming data.  Even though
2084                  * we may be allowed to stall, doing so would cause a race.
2085                  * The controller may already have ACK'ed all the remaining
2086                  * bulk-out packets, in which case the host wouldn't see a
2087                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2088                  * clear the halt -- leading to problems later on. */
2089 #if 0
2090                 else if (mod_data.can_stall) {
2091                         fsg_set_halt(fsg, fsg->bulk_out);
2092                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2093                         rc = -EINTR;
2094                 }
2095 #endif
2096
2097                 /* We can't stall.  Read in the excess data and throw it
2098                  * all away. */
2099                 else
2100                         rc = throw_away_data(fsg);
2101                 break;
2102         }
2103         return rc;
2104 }
2105
2106
2107 static int send_status(struct fsg_dev *fsg)
2108 {
2109         struct fsg_lun          *curlun = fsg->curlun;
2110         struct fsg_buffhd       *bh;
2111         int                     rc;
2112         u8                      status = USB_STATUS_PASS;
2113         u32                     sd, sdinfo = 0;
2114
2115         /* Wait for the next buffer to become available */
2116         bh = fsg->next_buffhd_to_fill;
2117         while (bh->state != BUF_STATE_EMPTY) {
2118                 rc = sleep_thread(fsg);
2119                 if (rc)
2120                         return rc;
2121         }
2122
2123         if (curlun) {
2124                 sd = curlun->sense_data;
2125                 sdinfo = curlun->sense_data_info;
2126         } else if (fsg->bad_lun_okay)
2127                 sd = SS_NO_SENSE;
2128         else
2129                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2130
2131         if (fsg->phase_error) {
2132                 DBG(fsg, "sending phase-error status\n");
2133                 status = USB_STATUS_PHASE_ERROR;
2134                 sd = SS_INVALID_COMMAND;
2135         } else if (sd != SS_NO_SENSE) {
2136                 DBG(fsg, "sending command-failure status\n");
2137                 status = USB_STATUS_FAIL;
2138                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2139                                 "  info x%x\n",
2140                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2141         }
2142
2143         if (transport_is_bbb()) {
2144                 struct bulk_cs_wrap     *csw = bh->buf;
2145
2146                 /* Store and send the Bulk-only CSW */
2147                 csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
2148                 csw->Tag = fsg->tag;
2149                 csw->Residue = cpu_to_le32(fsg->residue);
2150                 csw->Status = status;
2151
2152                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2153                 bh->inreq->zero = 0;
2154                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2155                                 &bh->inreq_busy, &bh->state);
2156
2157         } else if (mod_data.transport_type == USB_PR_CB) {
2158
2159                 /* Control-Bulk transport has no status phase! */
2160                 return 0;
2161
2162         } else {                        // USB_PR_CBI
2163                 struct interrupt_data   *buf = bh->buf;
2164
2165                 /* Store and send the Interrupt data.  UFI sends the ASC
2166                  * and ASCQ bytes.  Everything else sends a Type (which
2167                  * is always 0) and the status Value. */
2168                 if (mod_data.protocol_type == USB_SC_UFI) {
2169                         buf->bType = ASC(sd);
2170                         buf->bValue = ASCQ(sd);
2171                 } else {
2172                         buf->bType = 0;
2173                         buf->bValue = status;
2174                 }
2175                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2176
2177                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2178                 fsg->intreq->buf = bh->inreq->buf;
2179                 fsg->intreq->context = bh;
2180                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2181                                 &fsg->intreq_busy, &bh->state);
2182         }
2183
2184         fsg->next_buffhd_to_fill = bh->next;
2185         return 0;
2186 }
2187
2188
2189 /*-------------------------------------------------------------------------*/
2190
2191 /* Check whether the command is properly formed and whether its data size
2192  * and direction agree with the values we already have. */
2193 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2194                 enum data_direction data_dir, unsigned int mask,
2195                 int needs_medium, const char *name)
2196 {
2197         int                     i;
2198         int                     lun = fsg->cmnd[1] >> 5;
2199         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2200         char                    hdlen[20];
2201         struct fsg_lun          *curlun;
2202
2203         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2204          * Transparent SCSI doesn't pad. */
2205         if (protocol_is_scsi())
2206                 ;
2207
2208         /* There's some disagreement as to whether RBC pads commands or not.
2209          * We'll play it safe and accept either form. */
2210         else if (mod_data.protocol_type == USB_SC_RBC) {
2211                 if (fsg->cmnd_size == 12)
2212                         cmnd_size = 12;
2213
2214         /* All the other protocols pad to 12 bytes */
2215         } else
2216                 cmnd_size = 12;
2217
2218         hdlen[0] = 0;
2219         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2220                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2221                                 fsg->data_size);
2222         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2223                         name, cmnd_size, dirletter[(int) data_dir],
2224                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2225
2226         /* We can't reply at all until we know the correct data direction
2227          * and size. */
2228         if (fsg->data_size_from_cmnd == 0)
2229                 data_dir = DATA_DIR_NONE;
2230         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2231                 fsg->data_dir = data_dir;
2232                 fsg->data_size = fsg->data_size_from_cmnd;
2233
2234         } else {                                        // Bulk-only
2235                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2236
2237                         /* Host data size < Device data size is a phase error.
2238                          * Carry out the command, but only transfer as much
2239                          * as we are allowed. */
2240                         fsg->data_size_from_cmnd = fsg->data_size;
2241                         fsg->phase_error = 1;
2242                 }
2243         }
2244         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2245
2246         /* Conflicting data directions is a phase error */
2247         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2248                 fsg->phase_error = 1;
2249                 return -EINVAL;
2250         }
2251
2252         /* Verify the length of the command itself */
2253         if (cmnd_size != fsg->cmnd_size) {
2254
2255                 /* Special case workaround: There are plenty of buggy SCSI
2256                  * implementations. Many have issues with cbw->Length
2257                  * field passing a wrong command size. For those cases we
2258                  * always try to work around the problem by using the length
2259                  * sent by the host side provided it is at least as large
2260                  * as the correct command length.
2261                  * Examples of such cases would be MS-Windows, which issues
2262                  * REQUEST SENSE with cbw->Length == 12 where it should
2263                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
2264                  * REQUEST SENSE with cbw->Length == 10 where it should
2265                  * be 6 as well.
2266                  */
2267                 if (cmnd_size <= fsg->cmnd_size) {
2268                         DBG(fsg, "%s is buggy! Expected length %d "
2269                                         "but we got %d\n", name,
2270                                         cmnd_size, fsg->cmnd_size);
2271                         cmnd_size = fsg->cmnd_size;
2272                 } else {
2273                         fsg->phase_error = 1;
2274                         return -EINVAL;
2275                 }
2276         }
2277
2278         /* Check that the LUN values are consistent */
2279         if (transport_is_bbb()) {
2280                 if (fsg->lun != lun)
2281                         DBG(fsg, "using LUN %d from CBW, "
2282                                         "not LUN %d from CDB\n",
2283                                         fsg->lun, lun);
2284         } else
2285                 fsg->lun = lun;         // Use LUN from the command
2286
2287         /* Check the LUN */
2288         if (fsg->lun < fsg->nluns) {
2289                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2290                 if (fsg->cmnd[0] != REQUEST_SENSE) {
2291                         curlun->sense_data = SS_NO_SENSE;
2292                         curlun->sense_data_info = 0;
2293                         curlun->info_valid = 0;
2294                 }
2295         } else {
2296                 fsg->curlun = curlun = NULL;
2297                 fsg->bad_lun_okay = 0;
2298
2299                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2300                  * to use unsupported LUNs; all others may not. */
2301                 if (fsg->cmnd[0] != INQUIRY &&
2302                                 fsg->cmnd[0] != REQUEST_SENSE) {
2303                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2304                         return -EINVAL;
2305                 }
2306         }
2307
2308         /* If a unit attention condition exists, only INQUIRY and
2309          * REQUEST SENSE commands are allowed; anything else must fail. */
2310         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2311                         fsg->cmnd[0] != INQUIRY &&
2312                         fsg->cmnd[0] != REQUEST_SENSE) {
2313                 curlun->sense_data = curlun->unit_attention_data;
2314                 curlun->unit_attention_data = SS_NO_SENSE;
2315                 return -EINVAL;
2316         }
2317
2318         /* Check that only command bytes listed in the mask are non-zero */
2319         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2320         for (i = 1; i < cmnd_size; ++i) {
2321                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2322                         if (curlun)
2323                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2324                         return -EINVAL;
2325                 }
2326         }
2327
2328         /* If the medium isn't mounted and the command needs to access
2329          * it, return an error. */
2330         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
2331                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2332                 return -EINVAL;
2333         }
2334
2335         return 0;
2336 }
2337
2338
2339 static int do_scsi_command(struct fsg_dev *fsg)
2340 {
2341         struct fsg_buffhd       *bh;
2342         int                     rc;
2343         int                     reply = -EINVAL;
2344         int                     i;
2345         static char             unknown[16];
2346
2347         dump_cdb(fsg);
2348
2349         /* Wait for the next buffer to become available for data or status */
2350         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2351         while (bh->state != BUF_STATE_EMPTY) {
2352                 rc = sleep_thread(fsg);
2353                 if (rc)
2354                         return rc;
2355         }
2356         fsg->phase_error = 0;
2357         fsg->short_packet_received = 0;
2358
2359         down_read(&fsg->filesem);       // We're using the backing file
2360         switch (fsg->cmnd[0]) {
2361
2362         case INQUIRY:
2363                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2364                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2365                                 (1<<4), 0,
2366                                 "INQUIRY")) == 0)
2367                         reply = do_inquiry(fsg, bh);
2368                 break;
2369
2370         case MODE_SELECT:
2371                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2372                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2373                                 (1<<1) | (1<<4), 0,
2374                                 "MODE SELECT(6)")) == 0)
2375                         reply = do_mode_select(fsg, bh);
2376                 break;
2377
2378         case MODE_SELECT_10:
2379                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2380                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2381                                 (1<<1) | (3<<7), 0,
2382                                 "MODE SELECT(10)")) == 0)
2383                         reply = do_mode_select(fsg, bh);
2384                 break;
2385
2386         case MODE_SENSE:
2387                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2388                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2389                                 (1<<1) | (1<<2) | (1<<4), 0,
2390                                 "MODE SENSE(6)")) == 0)
2391                         reply = do_mode_sense(fsg, bh);
2392                 break;
2393
2394         case MODE_SENSE_10:
2395                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2396                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2397                                 (1<<1) | (1<<2) | (3<<7), 0,
2398                                 "MODE SENSE(10)")) == 0)
2399                         reply = do_mode_sense(fsg, bh);
2400                 break;
2401
2402         case ALLOW_MEDIUM_REMOVAL:
2403                 fsg->data_size_from_cmnd = 0;
2404                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2405                                 (1<<4), 0,
2406                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2407                         reply = do_prevent_allow(fsg);
2408                 break;
2409
2410         case READ_6:
2411                 i = fsg->cmnd[4];
2412                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2413                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2414                                 (7<<1) | (1<<4), 1,
2415                                 "READ(6)")) == 0)
2416                         reply = do_read(fsg);
2417                 break;
2418
2419         case READ_10:
2420                 fsg->data_size_from_cmnd =
2421                                 get_unaligned_be16(&fsg->cmnd[7]) << 9;
2422                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2423                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2424                                 "READ(10)")) == 0)
2425                         reply = do_read(fsg);
2426                 break;
2427
2428         case READ_12:
2429                 fsg->data_size_from_cmnd =
2430                                 get_unaligned_be32(&fsg->cmnd[6]) << 9;
2431                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2432                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2433                                 "READ(12)")) == 0)
2434                         reply = do_read(fsg);
2435                 break;
2436
2437         case READ_CAPACITY:
2438                 fsg->data_size_from_cmnd = 8;
2439                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2440                                 (0xf<<2) | (1<<8), 1,
2441                                 "READ CAPACITY")) == 0)
2442                         reply = do_read_capacity(fsg, bh);
2443                 break;
2444
2445         case READ_HEADER:
2446                 if (!mod_data.cdrom)
2447                         goto unknown_cmnd;
2448                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2449                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2450                                 (3<<7) | (0x1f<<1), 1,
2451                                 "READ HEADER")) == 0)
2452                         reply = do_read_header(fsg, bh);
2453                 break;
2454
2455         case READ_TOC:
2456                 if (!mod_data.cdrom)
2457                         goto unknown_cmnd;
2458                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2459                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2460                                 (7<<6) | (1<<1), 1,
2461                                 "READ TOC")) == 0)
2462                         reply = do_read_toc(fsg, bh);
2463                 break;
2464
2465         case READ_FORMAT_CAPACITIES:
2466                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2467                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2468                                 (3<<7), 1,
2469                                 "READ FORMAT CAPACITIES")) == 0)
2470                         reply = do_read_format_capacities(fsg, bh);
2471                 break;
2472
2473         case REQUEST_SENSE:
2474                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2475                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2476                                 (1<<4), 0,
2477                                 "REQUEST SENSE")) == 0)
2478                         reply = do_request_sense(fsg, bh);
2479                 break;
2480
2481         case START_STOP:
2482                 fsg->data_size_from_cmnd = 0;
2483                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2484                                 (1<<1) | (1<<4), 0,
2485                                 "START-STOP UNIT")) == 0)
2486                         reply = do_start_stop(fsg);
2487                 break;
2488
2489         case SYNCHRONIZE_CACHE:
2490                 fsg->data_size_from_cmnd = 0;
2491                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2492                                 (0xf<<2) | (3<<7), 1,
2493                                 "SYNCHRONIZE CACHE")) == 0)
2494                         reply = do_synchronize_cache(fsg);
2495                 break;
2496
2497         case TEST_UNIT_READY:
2498                 fsg->data_size_from_cmnd = 0;
2499                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2500                                 0, 1,
2501                                 "TEST UNIT READY");
2502                 break;
2503
2504         /* Although optional, this command is used by MS-Windows.  We
2505          * support a minimal version: BytChk must be 0. */
2506         case VERIFY:
2507                 fsg->data_size_from_cmnd = 0;
2508                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2509                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2510                                 "VERIFY")) == 0)
2511                         reply = do_verify(fsg);
2512                 break;
2513
2514         case WRITE_6:
2515                 i = fsg->cmnd[4];
2516                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2517                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2518                                 (7<<1) | (1<<4), 1,
2519                                 "WRITE(6)")) == 0)
2520                         reply = do_write(fsg);
2521                 break;
2522
2523         case WRITE_10:
2524                 fsg->data_size_from_cmnd =
2525                                 get_unaligned_be16(&fsg->cmnd[7]) << 9;
2526                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2527                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2528                                 "WRITE(10)")) == 0)
2529                         reply = do_write(fsg);
2530                 break;
2531
2532         case WRITE_12:
2533                 fsg->data_size_from_cmnd =
2534                                 get_unaligned_be32(&fsg->cmnd[6]) << 9;
2535                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2536                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2537                                 "WRITE(12)")) == 0)
2538                         reply = do_write(fsg);
2539                 break;
2540
2541         /* Some mandatory commands that we recognize but don't implement.
2542          * They don't mean much in this setting.  It's left as an exercise
2543          * for anyone interested to implement RESERVE and RELEASE in terms
2544          * of Posix locks. */
2545         case FORMAT_UNIT:
2546         case RELEASE:
2547         case RESERVE:
2548         case SEND_DIAGNOSTIC:
2549                 // Fall through
2550
2551         default:
2552  unknown_cmnd:
2553                 fsg->data_size_from_cmnd = 0;
2554                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2555                 if ((reply = check_command(fsg, fsg->cmnd_size,
2556                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2557                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2558                         reply = -EINVAL;
2559                 }
2560                 break;
2561         }
2562         up_read(&fsg->filesem);
2563
2564         if (reply == -EINTR || signal_pending(current))
2565                 return -EINTR;
2566
2567         /* Set up the single reply buffer for finish_reply() */
2568         if (reply == -EINVAL)
2569                 reply = 0;              // Error reply length
2570         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2571                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2572                 bh->inreq->length = reply;
2573                 bh->state = BUF_STATE_FULL;
2574                 fsg->residue -= reply;
2575         }                               // Otherwise it's already set
2576
2577         return 0;
2578 }
2579
2580
2581 /*-------------------------------------------------------------------------*/
2582
2583 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2584 {
2585         struct usb_request              *req = bh->outreq;
2586         struct fsg_bulk_cb_wrap *cbw = req->buf;
2587
2588         /* Was this a real packet?  Should it be ignored? */
2589         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2590                 return -EINVAL;
2591
2592         /* Is the CBW valid? */
2593         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2594                         cbw->Signature != cpu_to_le32(
2595                                 USB_BULK_CB_SIG)) {
2596                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2597                                 req->actual,
2598                                 le32_to_cpu(cbw->Signature));
2599
2600                 /* The Bulk-only spec says we MUST stall the IN endpoint
2601                  * (6.6.1), so it's unavoidable.  It also says we must
2602                  * retain this state until the next reset, but there's
2603                  * no way to tell the controller driver it should ignore
2604                  * Clear-Feature(HALT) requests.
2605                  *
2606                  * We aren't required to halt the OUT endpoint; instead
2607                  * we can simply accept and discard any data received
2608                  * until the next reset. */
2609                 wedge_bulk_in_endpoint(fsg);
2610                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2611                 return -EINVAL;
2612         }
2613
2614         /* Is the CBW meaningful? */
2615         if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2616                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2617                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2618                                 "cmdlen %u\n",
2619                                 cbw->Lun, cbw->Flags, cbw->Length);
2620
2621                 /* We can do anything we want here, so let's stall the
2622                  * bulk pipes if we are allowed to. */
2623                 if (mod_data.can_stall) {
2624                         fsg_set_halt(fsg, fsg->bulk_out);
2625                         halt_bulk_in_endpoint(fsg);
2626                 }
2627                 return -EINVAL;
2628         }
2629
2630         /* Save the command for later */
2631         fsg->cmnd_size = cbw->Length;
2632         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
2633         if (cbw->Flags & USB_BULK_IN_FLAG)
2634                 fsg->data_dir = DATA_DIR_TO_HOST;
2635         else
2636                 fsg->data_dir = DATA_DIR_FROM_HOST;
2637         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
2638         if (fsg->data_size == 0)
2639                 fsg->data_dir = DATA_DIR_NONE;
2640         fsg->lun = cbw->Lun;
2641         fsg->tag = cbw->Tag;
2642         return 0;
2643 }
2644
2645
2646 static int get_next_command(struct fsg_dev *fsg)
2647 {
2648         struct fsg_buffhd       *bh;
2649         int                     rc = 0;
2650
2651         if (transport_is_bbb()) {
2652
2653                 /* Wait for the next buffer to become available */
2654                 bh = fsg->next_buffhd_to_fill;
2655                 while (bh->state != BUF_STATE_EMPTY) {
2656                         rc = sleep_thread(fsg);
2657                         if (rc)
2658                                 return rc;
2659                 }
2660
2661                 /* Queue a request to read a Bulk-only CBW */
2662                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
2663                 bh->outreq->short_not_ok = 1;
2664                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
2665                                 &bh->outreq_busy, &bh->state);
2666
2667                 /* We will drain the buffer in software, which means we
2668                  * can reuse it for the next filling.  No need to advance
2669                  * next_buffhd_to_fill. */
2670
2671                 /* Wait for the CBW to arrive */
2672                 while (bh->state != BUF_STATE_FULL) {
2673                         rc = sleep_thread(fsg);
2674                         if (rc)
2675                                 return rc;
2676                 }
2677                 smp_rmb();
2678                 rc = received_cbw(fsg, bh);
2679                 bh->state = BUF_STATE_EMPTY;
2680
2681         } else {                // USB_PR_CB or USB_PR_CBI
2682
2683                 /* Wait for the next command to arrive */
2684                 while (fsg->cbbuf_cmnd_size == 0) {
2685                         rc = sleep_thread(fsg);
2686                         if (rc)
2687                                 return rc;
2688                 }
2689
2690                 /* Is the previous status interrupt request still busy?
2691                  * The host is allowed to skip reading the status,
2692                  * so we must cancel it. */
2693                 if (fsg->intreq_busy)
2694                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
2695
2696                 /* Copy the command and mark the buffer empty */
2697                 fsg->data_dir = DATA_DIR_UNKNOWN;
2698                 spin_lock_irq(&fsg->lock);
2699                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
2700                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
2701                 fsg->cbbuf_cmnd_size = 0;
2702                 spin_unlock_irq(&fsg->lock);
2703         }
2704         return rc;
2705 }
2706
2707
2708 /*-------------------------------------------------------------------------*/
2709
2710 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
2711                 const struct usb_endpoint_descriptor *d)
2712 {
2713         int     rc;
2714
2715         ep->driver_data = fsg;
2716         rc = usb_ep_enable(ep, d);
2717         if (rc)
2718                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
2719         return rc;
2720 }
2721
2722 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
2723                 struct usb_request **preq)
2724 {
2725         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2726         if (*preq)
2727                 return 0;
2728         ERROR(fsg, "can't allocate request for %s\n", ep->name);
2729         return -ENOMEM;
2730 }
2731
2732 /*
2733  * Reset interface setting and re-init endpoint state (toggle etc).
2734  * Call with altsetting < 0 to disable the interface.  The only other
2735  * available altsetting is 0, which enables the interface.
2736  */
2737 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
2738 {
2739         int     rc = 0;
2740         int     i;
2741         const struct usb_endpoint_descriptor    *d;
2742
2743         if (fsg->running)
2744                 DBG(fsg, "reset interface\n");
2745
2746 reset:
2747         /* Deallocate the requests */
2748         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2749                 struct fsg_buffhd *bh = &fsg->buffhds[i];
2750
2751                 if (bh->inreq) {
2752                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
2753                         bh->inreq = NULL;
2754                 }
2755                 if (bh->outreq) {
2756                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
2757                         bh->outreq = NULL;
2758                 }
2759         }
2760         if (fsg->intreq) {
2761                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
2762                 fsg->intreq = NULL;
2763         }
2764
2765         /* Disable the endpoints */
2766         if (fsg->bulk_in_enabled) {
2767                 usb_ep_disable(fsg->bulk_in);
2768                 fsg->bulk_in_enabled = 0;
2769         }
2770         if (fsg->bulk_out_enabled) {
2771                 usb_ep_disable(fsg->bulk_out);
2772                 fsg->bulk_out_enabled = 0;
2773         }
2774         if (fsg->intr_in_enabled) {
2775                 usb_ep_disable(fsg->intr_in);
2776                 fsg->intr_in_enabled = 0;
2777         }
2778
2779         fsg->running = 0;
2780         if (altsetting < 0 || rc != 0)
2781                 return rc;
2782
2783         DBG(fsg, "set interface %d\n", altsetting);
2784
2785         /* Enable the endpoints */
2786         d = fsg_ep_desc(fsg->gadget,
2787                         &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
2788         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
2789                 goto reset;
2790         fsg->bulk_in_enabled = 1;
2791
2792         d = fsg_ep_desc(fsg->gadget,
2793                         &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
2794         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
2795                 goto reset;
2796         fsg->bulk_out_enabled = 1;
2797         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
2798         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2799
2800         if (transport_is_cbi()) {
2801                 d = fsg_ep_desc(fsg->gadget,
2802                                 &fsg_fs_intr_in_desc, &fsg_hs_intr_in_desc);
2803                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
2804                         goto reset;
2805                 fsg->intr_in_enabled = 1;
2806         }
2807
2808         /* Allocate the requests */
2809         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2810                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
2811
2812                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
2813                         goto reset;
2814                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
2815                         goto reset;
2816                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2817                 bh->inreq->context = bh->outreq->context = bh;
2818                 bh->inreq->complete = bulk_in_complete;
2819                 bh->outreq->complete = bulk_out_complete;
2820         }
2821         if (transport_is_cbi()) {
2822                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
2823                         goto reset;
2824                 fsg->intreq->complete = intr_in_complete;
2825         }
2826
2827         fsg->running = 1;
2828         for (i = 0; i < fsg->nluns; ++i)
2829                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2830         return rc;
2831 }
2832
2833
2834 /*
2835  * Change our operational configuration.  This code must agree with the code
2836  * that returns config descriptors, and with interface altsetting code.
2837  *
2838  * It's also responsible for power management interactions.  Some
2839  * configurations might not work with our current power sources.
2840  * For now we just assume the gadget is always self-powered.
2841  */
2842 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
2843 {
2844         int     rc = 0;
2845
2846         /* Disable the single interface */
2847         if (fsg->config != 0) {
2848                 DBG(fsg, "reset config\n");
2849                 fsg->config = 0;
2850                 rc = do_set_interface(fsg, -1);
2851         }
2852
2853         /* Enable the interface */
2854         if (new_config != 0) {
2855                 fsg->config = new_config;
2856                 if ((rc = do_set_interface(fsg, 0)) != 0)
2857                         fsg->config = 0;        // Reset on errors
2858                 else {
2859                         char *speed;
2860
2861                         switch (fsg->gadget->speed) {
2862                         case USB_SPEED_LOW:     speed = "low";  break;
2863                         case USB_SPEED_FULL:    speed = "full"; break;
2864                         case USB_SPEED_HIGH:    speed = "high"; break;
2865                         default:                speed = "?";    break;
2866                         }
2867                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
2868                 }
2869         }
2870         return rc;
2871 }
2872
2873
2874 /*-------------------------------------------------------------------------*/
2875
2876 static void handle_exception(struct fsg_dev *fsg)
2877 {
2878         siginfo_t               info;
2879         int                     sig;
2880         int                     i;
2881         int                     num_active;
2882         struct fsg_buffhd       *bh;
2883         enum fsg_state          old_state;
2884         u8                      new_config;
2885         struct fsg_lun          *curlun;
2886         unsigned int            exception_req_tag;
2887         int                     rc;
2888
2889         /* Clear the existing signals.  Anything but SIGUSR1 is converted
2890          * into a high-priority EXIT exception. */
2891         for (;;) {
2892                 sig = dequeue_signal_lock(current, &current->blocked, &info);
2893                 if (!sig)
2894                         break;
2895                 if (sig != SIGUSR1) {
2896                         if (fsg->state < FSG_STATE_EXIT)
2897                                 DBG(fsg, "Main thread exiting on signal\n");
2898                         raise_exception(fsg, FSG_STATE_EXIT);
2899                 }
2900         }
2901
2902         /* Cancel all the pending transfers */
2903         if (fsg->intreq_busy)
2904                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
2905         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2906                 bh = &fsg->buffhds[i];
2907                 if (bh->inreq_busy)
2908                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
2909                 if (bh->outreq_busy)
2910                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
2911         }
2912
2913         /* Wait until everything is idle */
2914         for (;;) {
2915                 num_active = fsg->intreq_busy;
2916                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2917                         bh = &fsg->buffhds[i];
2918                         num_active += bh->inreq_busy + bh->outreq_busy;
2919                 }
2920                 if (num_active == 0)
2921                         break;
2922                 if (sleep_thread(fsg))
2923                         return;
2924         }
2925
2926         /* Clear out the controller's fifos */
2927         if (fsg->bulk_in_enabled)
2928                 usb_ep_fifo_flush(fsg->bulk_in);
2929         if (fsg->bulk_out_enabled)
2930                 usb_ep_fifo_flush(fsg->bulk_out);
2931         if (fsg->intr_in_enabled)
2932                 usb_ep_fifo_flush(fsg->intr_in);
2933
2934         /* Reset the I/O buffer states and pointers, the SCSI
2935          * state, and the exception.  Then invoke the handler. */
2936         spin_lock_irq(&fsg->lock);
2937
2938         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2939                 bh = &fsg->buffhds[i];
2940                 bh->state = BUF_STATE_EMPTY;
2941         }
2942         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
2943                         &fsg->buffhds[0];
2944
2945         exception_req_tag = fsg->exception_req_tag;
2946         new_config = fsg->new_config;
2947         old_state = fsg->state;
2948
2949         if (old_state == FSG_STATE_ABORT_BULK_OUT)
2950                 fsg->state = FSG_STATE_STATUS_PHASE;
2951         else {
2952                 for (i = 0; i < fsg->nluns; ++i) {
2953                         curlun = &fsg->luns[i];
2954                         curlun->prevent_medium_removal = 0;
2955                         curlun->sense_data = curlun->unit_attention_data =
2956                                         SS_NO_SENSE;
2957                         curlun->sense_data_info = 0;
2958                         curlun->info_valid = 0;
2959                 }
2960                 fsg->state = FSG_STATE_IDLE;
2961         }
2962         spin_unlock_irq(&fsg->lock);
2963
2964         /* Carry out any extra actions required for the exception */
2965         switch (old_state) {
2966         default:
2967                 break;
2968
2969         case FSG_STATE_ABORT_BULK_OUT:
2970                 send_status(fsg);
2971                 spin_lock_irq(&fsg->lock);
2972                 if (fsg->state == FSG_STATE_STATUS_PHASE)
2973                         fsg->state = FSG_STATE_IDLE;
2974                 spin_unlock_irq(&fsg->lock);
2975                 break;
2976
2977         case FSG_STATE_RESET:
2978                 /* In case we were forced against our will to halt a
2979                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2980                  * requires this.) */
2981                 if (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2982                         usb_ep_clear_halt(fsg->bulk_in);
2983
2984                 if (transport_is_bbb()) {
2985                         if (fsg->ep0_req_tag == exception_req_tag)
2986                                 ep0_queue(fsg); // Complete the status stage
2987
2988                 } else if (transport_is_cbi())
2989                         send_status(fsg);       // Status by interrupt pipe
2990
2991                 /* Technically this should go here, but it would only be
2992                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2993                  * CONFIG_CHANGE cases. */
2994                 // for (i = 0; i < fsg->nluns; ++i)
2995                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2996                 break;
2997
2998         case FSG_STATE_INTERFACE_CHANGE:
2999                 rc = do_set_interface(fsg, 0);
3000                 if (fsg->ep0_req_tag != exception_req_tag)
3001                         break;
3002                 if (rc != 0)                    // STALL on errors
3003                         fsg_set_halt(fsg, fsg->ep0);
3004                 else                            // Complete the status stage
3005                         ep0_queue(fsg);
3006                 break;
3007
3008         case FSG_STATE_CONFIG_CHANGE:
3009                 rc = do_set_config(fsg, new_config);
3010                 if (fsg->ep0_req_tag != exception_req_tag)
3011                         break;
3012                 if (rc != 0)                    // STALL on errors
3013                         fsg_set_halt(fsg, fsg->ep0);
3014                 else                            // Complete the status stage
3015                         ep0_queue(fsg);
3016                 break;
3017
3018         case FSG_STATE_DISCONNECT:
3019                 for (i = 0; i < fsg->nluns; ++i)
3020                         fsg_lun_fsync_sub(fsg->luns + i);
3021                 do_set_config(fsg, 0);          // Unconfigured state
3022                 break;
3023
3024         case FSG_STATE_EXIT:
3025         case FSG_STATE_TERMINATED:
3026                 do_set_config(fsg, 0);                  // Free resources
3027                 spin_lock_irq(&fsg->lock);
3028                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3029                 spin_unlock_irq(&fsg->lock);
3030                 break;
3031         }
3032 }
3033
3034
3035 /*-------------------------------------------------------------------------*/
3036
3037 static int fsg_main_thread(void *fsg_)
3038 {
3039         struct fsg_dev          *fsg = fsg_;
3040
3041         /* Allow the thread to be killed by a signal, but set the signal mask
3042          * to block everything but INT, TERM, KILL, and USR1. */
3043         allow_signal(SIGINT);
3044         allow_signal(SIGTERM);
3045         allow_signal(SIGKILL);
3046         allow_signal(SIGUSR1);
3047
3048         /* Allow the thread to be frozen */
3049         set_freezable();
3050
3051         /* Arrange for userspace references to be interpreted as kernel
3052          * pointers.  That way we can pass a kernel pointer to a routine
3053          * that expects a __user pointer and it will work okay. */
3054         set_fs(get_ds());
3055
3056         /* The main loop */
3057         while (fsg->state != FSG_STATE_TERMINATED) {
3058                 if (exception_in_progress(fsg) || signal_pending(current)) {
3059                         handle_exception(fsg);
3060                         continue;
3061                 }
3062
3063                 if (!fsg->running) {
3064                         sleep_thread(fsg);
3065                         continue;
3066                 }
3067
3068                 if (get_next_command(fsg))
3069                         continue;
3070
3071                 spin_lock_irq(&fsg->lock);
3072                 if (!exception_in_progress(fsg))
3073                         fsg->state = FSG_STATE_DATA_PHASE;
3074                 spin_unlock_irq(&fsg->lock);
3075
3076                 if (do_scsi_command(fsg) || finish_reply(fsg))
3077                         continue;
3078
3079                 spin_lock_irq(&fsg->lock);
3080                 if (!exception_in_progress(fsg))
3081                         fsg->state = FSG_STATE_STATUS_PHASE;
3082                 spin_unlock_irq(&fsg->lock);
3083
3084                 if (send_status(fsg))
3085                         continue;
3086
3087                 spin_lock_irq(&fsg->lock);
3088                 if (!exception_in_progress(fsg))
3089                         fsg->state = FSG_STATE_IDLE;
3090                 spin_unlock_irq(&fsg->lock);
3091                 }
3092
3093         spin_lock_irq(&fsg->lock);
3094         fsg->thread_task = NULL;
3095         spin_unlock_irq(&fsg->lock);
3096
3097         /* If we are exiting because of a signal, unregister the
3098          * gadget driver. */
3099         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
3100                 usb_gadget_unregister_driver(&fsg_driver);
3101
3102         /* Let the unbind and cleanup routines know the thread has exited */
3103         complete_and_exit(&fsg->thread_notifier, 0);
3104 }
3105
3106
3107 /*-------------------------------------------------------------------------*/
3108
3109
3110 /* The write permissions and store_xxx pointers are set in fsg_bind() */
3111 static DEVICE_ATTR(ro, 0444, fsg_show_ro, NULL);
3112 static DEVICE_ATTR(nofua, 0644, fsg_show_nofua, NULL);
3113 static DEVICE_ATTR(file, 0444, fsg_show_file, NULL);
3114
3115
3116 /*-------------------------------------------------------------------------*/
3117
3118 static void fsg_release(struct kref *ref)
3119 {
3120         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
3121
3122         kfree(fsg->luns);
3123         kfree(fsg);
3124 }
3125
3126 static void lun_release(struct device *dev)
3127 {
3128         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
3129         struct fsg_dev          *fsg =
3130                 container_of(filesem, struct fsg_dev, filesem);
3131
3132         kref_put(&fsg->ref, fsg_release);
3133 }
3134
3135 static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
3136 {
3137         struct fsg_dev          *fsg = get_gadget_data(gadget);
3138         int                     i;
3139         struct fsg_lun          *curlun;
3140         struct usb_request      *req = fsg->ep0req;
3141
3142         DBG(fsg, "unbind\n");
3143         clear_bit(REGISTERED, &fsg->atomic_bitflags);
3144
3145         /* Unregister the sysfs attribute files and the LUNs */
3146         for (i = 0; i < fsg->nluns; ++i) {
3147                 curlun = &fsg->luns[i];
3148                 if (curlun->registered) {
3149                         device_remove_file(&curlun->dev, &dev_attr_nofua);
3150                         device_remove_file(&curlun->dev, &dev_attr_ro);
3151                         device_remove_file(&curlun->dev, &dev_attr_file);
3152                         fsg_lun_close(curlun);
3153                         device_unregister(&curlun->dev);
3154                         curlun->registered = 0;
3155                 }
3156         }
3157
3158         /* If the thread isn't already dead, tell it to exit now */
3159         if (fsg->state != FSG_STATE_TERMINATED) {
3160                 raise_exception(fsg, FSG_STATE_EXIT);
3161                 wait_for_completion(&fsg->thread_notifier);
3162
3163                 /* The cleanup routine waits for this completion also */
3164                 complete(&fsg->thread_notifier);
3165         }
3166
3167         /* Free the data buffers */
3168         for (i = 0; i < FSG_NUM_BUFFERS; ++i)
3169                 kfree(fsg->buffhds[i].buf);
3170
3171         /* Free the request and buffer for endpoint 0 */
3172         if (req) {
3173                 kfree(req->buf);
3174                 usb_ep_free_request(fsg->ep0, req);
3175         }
3176
3177         set_gadget_data(gadget, NULL);
3178 }
3179
3180
3181 static int __init check_parameters(struct fsg_dev *fsg)
3182 {
3183         int     prot;
3184         int     gcnum;
3185
3186         /* Store the default values */
3187         mod_data.transport_type = USB_PR_BULK;
3188         mod_data.transport_name = "Bulk-only";
3189         mod_data.protocol_type = USB_SC_SCSI;
3190         mod_data.protocol_name = "Transparent SCSI";
3191
3192         /* Some peripheral controllers are known not to be able to
3193          * halt bulk endpoints correctly.  If one of them is present,
3194          * disable stalls.
3195          */
3196         if (gadget_is_at91(fsg->gadget))
3197                 mod_data.can_stall = 0;
3198
3199         if (mod_data.release == 0xffff) {       // Parameter wasn't set
3200                 gcnum = usb_gadget_controller_number(fsg->gadget);
3201                 if (gcnum >= 0)
3202                         mod_data.release = 0x0300 + gcnum;
3203                 else {
3204                         WARNING(fsg, "controller '%s' not recognized\n",
3205                                 fsg->gadget->name);
3206                         mod_data.release = 0x0399;
3207                 }
3208         }
3209
3210         prot = simple_strtol(mod_data.protocol_parm, NULL, 0);
3211
3212 #ifdef CONFIG_USB_FILE_STORAGE_TEST
3213         if (strnicmp(mod_data.transport_parm, "BBB", 10) == 0) {
3214                 ;               // Use default setting
3215         } else if (strnicmp(mod_data.transport_parm, "CB", 10) == 0) {
3216                 mod_data.transport_type = USB_PR_CB;
3217                 mod_data.transport_name = "Control-Bulk";
3218         } else if (strnicmp(mod_data.transport_parm, "CBI", 10) == 0) {
3219                 mod_data.transport_type = USB_PR_CBI;
3220                 mod_data.transport_name = "Control-Bulk-Interrupt";
3221         } else {
3222                 ERROR(fsg, "invalid transport: %s\n", mod_data.transport_parm);
3223                 return -EINVAL;
3224         }
3225
3226         if (strnicmp(mod_data.protocol_parm, "SCSI", 10) == 0 ||
3227                         prot == USB_SC_SCSI) {
3228                 ;               // Use default setting
3229         } else if (strnicmp(mod_data.protocol_parm, "RBC", 10) == 0 ||
3230                         prot == USB_SC_RBC) {
3231                 mod_data.protocol_type = USB_SC_RBC;
3232                 mod_data.protocol_name = "RBC";
3233         } else if (strnicmp(mod_data.protocol_parm, "8020", 4) == 0 ||
3234                         strnicmp(mod_data.protocol_parm, "ATAPI", 10) == 0 ||
3235                         prot == USB_SC_8020) {
3236                 mod_data.protocol_type = USB_SC_8020;
3237                 mod_data.protocol_name = "8020i (ATAPI)";
3238         } else if (strnicmp(mod_data.protocol_parm, "QIC", 3) == 0 ||
3239                         prot == USB_SC_QIC) {
3240                 mod_data.protocol_type = USB_SC_QIC;
3241                 mod_data.protocol_name = "QIC-157";
3242         } else if (strnicmp(mod_data.protocol_parm, "UFI", 10) == 0 ||
3243                         prot == USB_SC_UFI) {
3244                 mod_data.protocol_type = USB_SC_UFI;
3245                 mod_data.protocol_name = "UFI";
3246         } else if (strnicmp(mod_data.protocol_parm, "8070", 4) == 0 ||
3247                         prot == USB_SC_8070) {
3248                 mod_data.protocol_type = USB_SC_8070;
3249                 mod_data.protocol_name = "8070i";
3250         } else {
3251                 ERROR(fsg, "invalid protocol: %s\n", mod_data.protocol_parm);
3252                 return -EINVAL;
3253         }
3254
3255         mod_data.buflen &= PAGE_CACHE_MASK;
3256         if (mod_data.buflen <= 0) {
3257                 ERROR(fsg, "invalid buflen\n");
3258                 return -ETOOSMALL;
3259         }
3260
3261 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
3262
3263         /* Serial string handling.
3264          * On a real device, the serial string would be loaded
3265          * from permanent storage. */
3266         if (mod_data.serial) {
3267                 const char *ch;
3268                 unsigned len = 0;
3269
3270                 /* Sanity check :
3271                  * The CB[I] specification limits the serial string to
3272                  * 12 uppercase hexadecimal characters.
3273                  * BBB need at least 12 uppercase hexadecimal characters,
3274                  * with a maximum of 126. */
3275                 for (ch = mod_data.serial; *ch; ++ch) {
3276                         ++len;
3277                         if ((*ch < '0' || *ch > '9') &&
3278                             (*ch < 'A' || *ch > 'F')) { /* not uppercase hex */
3279                                 WARNING(fsg,
3280                                         "Invalid serial string character: %c\n",
3281                                         *ch);
3282                                 goto no_serial;
3283                         }
3284                 }
3285                 if (len > 126 ||
3286                     (mod_data.transport_type == USB_PR_BULK && len < 12) ||
3287                     (mod_data.transport_type != USB_PR_BULK && len > 12)) {
3288                         WARNING(fsg, "Invalid serial string length!\n");
3289                         goto no_serial;
3290                 }
3291                 fsg_strings[FSG_STRING_SERIAL - 1].s = mod_data.serial;
3292         } else {
3293                 WARNING(fsg, "No serial-number string provided!\n");
3294  no_serial:
3295                 device_desc.iSerialNumber = 0;
3296         }
3297
3298         return 0;
3299 }
3300
3301
3302 static int __init fsg_bind(struct usb_gadget *gadget)
3303 {
3304         struct fsg_dev          *fsg = the_fsg;
3305         int                     rc;
3306         int                     i;
3307         struct fsg_lun          *curlun;
3308         struct usb_ep           *ep;
3309         struct usb_request      *req;
3310         char                    *pathbuf, *p;
3311
3312         fsg->gadget = gadget;
3313         set_gadget_data(gadget, fsg);
3314         fsg->ep0 = gadget->ep0;
3315         fsg->ep0->driver_data = fsg;
3316
3317         if ((rc = check_parameters(fsg)) != 0)
3318                 goto out;
3319
3320         if (mod_data.removable) {       // Enable the store_xxx attributes
3321                 dev_attr_file.attr.mode = 0644;
3322                 dev_attr_file.store = fsg_store_file;
3323                 if (!mod_data.cdrom) {
3324                         dev_attr_ro.attr.mode = 0644;
3325                         dev_attr_ro.store = fsg_store_ro;
3326                 }
3327         }
3328
3329         /* Only for removable media? */
3330         dev_attr_nofua.attr.mode = 0644;
3331         dev_attr_nofua.store = fsg_store_nofua;
3332
3333         /* Find out how many LUNs there should be */
3334         i = mod_data.nluns;
3335         if (i == 0)
3336                 i = max(mod_data.num_filenames, 1u);
3337         if (i > FSG_MAX_LUNS) {
3338                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
3339                 rc = -EINVAL;
3340                 goto out;
3341         }
3342
3343         /* Create the LUNs, open their backing files, and register the
3344          * LUN devices in sysfs. */
3345         fsg->luns = kzalloc(i * sizeof(struct fsg_lun), GFP_KERNEL);
3346         if (!fsg->luns) {
3347                 rc = -ENOMEM;
3348                 goto out;
3349         }
3350         fsg->nluns = i;
3351
3352         for (i = 0; i < fsg->nluns; ++i) {
3353                 curlun = &fsg->luns[i];
3354                 curlun->cdrom = !!mod_data.cdrom;
3355                 curlun->ro = mod_data.cdrom || mod_data.ro[i];
3356                 curlun->initially_ro = curlun->ro;
3357                 curlun->removable = mod_data.removable;
3358                 curlun->nofua = mod_data.nofua[i];
3359                 curlun->dev.release = lun_release;
3360                 curlun->dev.parent = &gadget->dev;
3361                 curlun->dev.driver = &fsg_driver.driver;
3362                 dev_set_drvdata(&curlun->dev, &fsg->filesem);
3363                 dev_set_name(&curlun->dev,"%s-lun%d",
3364                              dev_name(&gadget->dev), i);
3365
3366                 kref_get(&fsg->ref);
3367                 rc = device_register(&curlun->dev);
3368                 if (rc) {
3369                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
3370                         put_device(&curlun->dev);
3371                         goto out;
3372                 }
3373                 curlun->registered = 1;
3374
3375                 rc = device_create_file(&curlun->dev, &dev_attr_ro);
3376                 if (rc)
3377                         goto out;
3378                 rc = device_create_file(&curlun->dev, &dev_attr_nofua);
3379                 if (rc)
3380                         goto out;
3381                 rc = device_create_file(&curlun->dev, &dev_attr_file);
3382                 if (rc)
3383                         goto out;
3384
3385                 if (mod_data.file[i] && *mod_data.file[i]) {
3386                         rc = fsg_lun_open(curlun, mod_data.file[i]);
3387                         if (rc)
3388                                 goto out;
3389                 } else if (!mod_data.removable) {
3390                         ERROR(fsg, "no file given for LUN%d\n", i);
3391                         rc = -EINVAL;
3392                         goto out;
3393                 }
3394         }
3395
3396         /* Find all the endpoints we will use */
3397         usb_ep_autoconfig_reset(gadget);
3398         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
3399         if (!ep)
3400                 goto autoconf_fail;
3401         ep->driver_data = fsg;          // claim the endpoint
3402         fsg->bulk_in = ep;
3403
3404         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
3405         if (!ep)
3406                 goto autoconf_fail;
3407         ep->driver_data = fsg;          // claim the endpoint
3408         fsg->bulk_out = ep;
3409
3410         if (transport_is_cbi()) {
3411                 ep = usb_ep_autoconfig(gadget, &fsg_fs_intr_in_desc);
3412                 if (!ep)
3413                         goto autoconf_fail;
3414                 ep->driver_data = fsg;          // claim the endpoint
3415                 fsg->intr_in = ep;
3416         }
3417
3418         /* Fix up the descriptors */
3419         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
3420         device_desc.idVendor = cpu_to_le16(mod_data.vendor);
3421         device_desc.idProduct = cpu_to_le16(mod_data.product);
3422         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
3423
3424         i = (transport_is_cbi() ? 3 : 2);       // Number of endpoints
3425         fsg_intf_desc.bNumEndpoints = i;
3426         fsg_intf_desc.bInterfaceSubClass = mod_data.protocol_type;
3427         fsg_intf_desc.bInterfaceProtocol = mod_data.transport_type;
3428         fsg_fs_function[i + FSG_FS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3429
3430         if (gadget_is_dualspeed(gadget)) {
3431                 fsg_hs_function[i + FSG_HS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3432
3433                 /* Assume ep0 uses the same maxpacket value for both speeds */
3434                 dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
3435
3436                 /* Assume endpoint addresses are the same for both speeds */
3437                 fsg_hs_bulk_in_desc.bEndpointAddress =
3438                         fsg_fs_bulk_in_desc.bEndpointAddress;
3439                 fsg_hs_bulk_out_desc.bEndpointAddress =
3440                         fsg_fs_bulk_out_desc.bEndpointAddress;
3441                 fsg_hs_intr_in_desc.bEndpointAddress =
3442                         fsg_fs_intr_in_desc.bEndpointAddress;
3443         }
3444
3445         if (gadget_is_otg(gadget))
3446                 fsg_otg_desc.bmAttributes |= USB_OTG_HNP;
3447
3448         rc = -ENOMEM;
3449
3450         /* Allocate the request and buffer for endpoint 0 */
3451         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
3452         if (!req)
3453                 goto out;
3454         req->buf = kmalloc(EP0_BUFSIZE, GFP_KERNEL);
3455         if (!req->buf)
3456                 goto out;
3457         req->complete = ep0_complete;
3458
3459         /* Allocate the data buffers */
3460         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
3461                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3462
3463                 /* Allocate for the bulk-in endpoint.  We assume that
3464                  * the buffer will also work with the bulk-out (and
3465                  * interrupt-in) endpoint. */
3466                 bh->buf = kmalloc(mod_data.buflen, GFP_KERNEL);
3467                 if (!bh->buf)
3468                         goto out;
3469                 bh->next = bh + 1;
3470         }
3471         fsg->buffhds[FSG_NUM_BUFFERS - 1].next = &fsg->buffhds[0];
3472
3473         /* This should reflect the actual gadget power source */
3474         usb_gadget_set_selfpowered(gadget);
3475
3476         snprintf(fsg_string_manufacturer, sizeof fsg_string_manufacturer,
3477                         "%s %s with %s",
3478                         init_utsname()->sysname, init_utsname()->release,
3479                         gadget->name);
3480
3481         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
3482                         "file-storage-gadget");
3483         if (IS_ERR(fsg->thread_task)) {
3484                 rc = PTR_ERR(fsg->thread_task);
3485                 goto out;
3486         }
3487
3488         INFO(fsg, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
3489         INFO(fsg, "Number of LUNs=%d\n", fsg->nluns);
3490
3491         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
3492         for (i = 0; i < fsg->nluns; ++i) {
3493                 curlun = &fsg->luns[i];
3494                 if (fsg_lun_is_open(curlun)) {
3495                         p = NULL;
3496                         if (pathbuf) {
3497                                 p = d_path(&curlun->filp->f_path,
3498                                            pathbuf, PATH_MAX);
3499                                 if (IS_ERR(p))
3500                                         p = NULL;
3501                         }
3502                         LINFO(curlun, "ro=%d, nofua=%d, file: %s\n",
3503                               curlun->ro, curlun->nofua, (p ? p : "(error)"));
3504                 }
3505         }
3506         kfree(pathbuf);
3507
3508         DBG(fsg, "transport=%s (x%02x)\n",
3509                         mod_data.transport_name, mod_data.transport_type);
3510         DBG(fsg, "protocol=%s (x%02x)\n",
3511                         mod_data.protocol_name, mod_data.protocol_type);
3512         DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n",
3513                         mod_data.vendor, mod_data.product, mod_data.release);
3514         DBG(fsg, "removable=%d, stall=%d, cdrom=%d, buflen=%u\n",
3515                         mod_data.removable, mod_data.can_stall,
3516                         mod_data.cdrom, mod_data.buflen);
3517         DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task));
3518
3519         set_bit(REGISTERED, &fsg->atomic_bitflags);
3520
3521         /* Tell the thread to start working */
3522         wake_up_process(fsg->thread_task);
3523         return 0;
3524
3525 autoconf_fail:
3526         ERROR(fsg, "unable to autoconfigure all endpoints\n");
3527         rc = -ENOTSUPP;
3528
3529 out:
3530         fsg->state = FSG_STATE_TERMINATED;      // The thread is dead
3531         fsg_unbind(gadget);
3532         complete(&fsg->thread_notifier);
3533         return rc;
3534 }
3535
3536
3537 /*-------------------------------------------------------------------------*/
3538
3539 static void fsg_suspend(struct usb_gadget *gadget)
3540 {
3541         struct fsg_dev          *fsg = get_gadget_data(gadget);
3542
3543         DBG(fsg, "suspend\n");
3544         set_bit(SUSPENDED, &fsg->atomic_bitflags);
3545 }
3546
3547 static void fsg_resume(struct usb_gadget *gadget)
3548 {
3549         struct fsg_dev          *fsg = get_gadget_data(gadget);
3550
3551         DBG(fsg, "resume\n");
3552         clear_bit(SUSPENDED, &fsg->atomic_bitflags);
3553 }
3554
3555
3556 /*-------------------------------------------------------------------------*/
3557
3558 static struct usb_gadget_driver         fsg_driver = {
3559 #ifdef CONFIG_USB_GADGET_DUALSPEED
3560         .speed          = USB_SPEED_HIGH,
3561 #else
3562         .speed          = USB_SPEED_FULL,
3563 #endif
3564         .function       = (char *) fsg_string_product,
3565         .unbind         = fsg_unbind,
3566         .disconnect     = fsg_disconnect,
3567         .setup          = fsg_setup,
3568         .suspend        = fsg_suspend,
3569         .resume         = fsg_resume,
3570
3571         .driver         = {
3572                 .name           = DRIVER_NAME,
3573                 .owner          = THIS_MODULE,
3574                 // .release = ...
3575                 // .suspend = ...
3576                 // .resume = ...
3577         },
3578 };
3579
3580
3581 static int __init fsg_alloc(void)
3582 {
3583         struct fsg_dev          *fsg;
3584
3585         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
3586         if (!fsg)
3587                 return -ENOMEM;
3588         spin_lock_init(&fsg->lock);
3589         init_rwsem(&fsg->filesem);
3590         kref_init(&fsg->ref);
3591         init_completion(&fsg->thread_notifier);
3592
3593         the_fsg = fsg;
3594         return 0;
3595 }
3596
3597
3598 static int __init fsg_init(void)
3599 {
3600         int             rc;
3601         struct fsg_dev  *fsg;
3602
3603         if ((rc = fsg_alloc()) != 0)
3604                 return rc;
3605         fsg = the_fsg;
3606         if ((rc = usb_gadget_probe_driver(&fsg_driver, fsg_bind)) != 0)
3607                 kref_put(&fsg->ref, fsg_release);
3608         return rc;
3609 }
3610 module_init(fsg_init);
3611
3612
3613 static void __exit fsg_cleanup(void)
3614 {
3615         struct fsg_dev  *fsg = the_fsg;
3616
3617         /* Unregister the driver iff the thread hasn't already done so */
3618         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
3619                 usb_gadget_unregister_driver(&fsg_driver);
3620
3621         /* Wait for the thread to finish up */
3622         wait_for_completion(&fsg->thread_notifier);
3623
3624         kref_put(&fsg->ref, fsg_release);
3625 }
3626 module_exit(fsg_cleanup);