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, and release 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  *      ro=b[,b...]             Default false, booleans for read-only access
  93  *      removable               Default false, boolean for removable media
  94  *      luns=N                  Default N = number of filenames, number of
  95  *                                      LUNs to support
  96  *      stall                   Default determined according to the type of
  97  *                                      USB device controller (usually true),
  98  *                                      boolean to permit the driver to halt
  99  *                                      bulk endpoints
 100  *      cdrom                   Default false, boolean for whether to emulate
 101  *                                      a CD-ROM drive
 102  *      transport=XXX           Default BBB, transport name (CB, CBI, or BBB)
 103  *      protocol=YYY            Default SCSI, protocol name (RBC, 8020 or
 104  *                                      ATAPI, QIC, UFI, 8070, or SCSI;
 105  *                                      also 1 - 6)
 106  *      vendor=0xVVVV           Default 0x0525 (NetChip), USB Vendor ID
 107  *      product=0xPPPP          Default 0xa4a5 (FSG), USB Product ID
 108  *      release=0xRRRR          Override the USB release number (bcdDevice)
 109  *      buflen=N                Default N=16384, buffer size used (will be
 110  *                                      rounded down to a multiple of
 111  *                                      PAGE_CACHE_SIZE)
 112  *
 113  * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro",
 114  * "removable", "luns", "stall", and "cdrom" options are available; default
 115  * values are used for everything else.
 116  *
 117  * The pathnames of the backing files and the ro settings are available in
 118  * the attribute files "file" and "ro" in the lun<n> subdirectory of the
 119  * gadget's sysfs directory.  If the "removable" option is set, writing to
 120  * these files will simulate ejecting/loading the medium (writing an empty
 121  * line means eject) and adjusting a write-enable tab.  Changes to the ro
 122  * setting are not allowed when the medium is loaded or if CD-ROM emulation
 123  * is being used.
 124  *
 125  * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
 126  * The driver's SCSI command interface was based on the "Information
 127  * technology - Small Computer System Interface - 2" document from
 128  * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
 129  * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.  The single exception
 130  * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
 131  * "Universal Serial Bus Mass Storage Class UFI Command Specification"
 132  * document, Revision 1.0, December 14, 1998, available at
 133  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
 134  */
 135
 136
 137 /*
 138  *                              Driver Design
 139  *
 140  * The FSG driver is fairly straightforward.  There is a main kernel
 141  * thread that handles most of the work.  Interrupt routines field
 142  * callbacks from the controller driver: bulk- and interrupt-request
 143  * completion notifications, endpoint-0 events, and disconnect events.
 144  * Completion events are passed to the main thread by wakeup calls.  Many
 145  * ep0 requests are handled at interrupt time, but SetInterface,
 146  * SetConfiguration, and device reset requests are forwarded to the
 147  * thread in the form of "exceptions" using SIGUSR1 signals (since they
 148  * should interrupt any ongoing file I/O operations).
 149  *
 150  * The thread's main routine implements the standard command/data/status
 151  * parts of a SCSI interaction.  It and its subroutines are full of tests
 152  * for pending signals/exceptions -- all this polling is necessary since
 153  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
 154  * indication that the driver really wants to be running in userspace.)
 155  * An important point is that so long as the thread is alive it keeps an
 156  * open reference to the backing file.  This will prevent unmounting
 157  * the backing file's underlying filesystem and could cause problems
 158  * during system shutdown, for example.  To prevent such problems, the
 159  * thread catches INT, TERM, and KILL signals and converts them into
 160  * an EXIT exception.
 161  *
 162  * In normal operation the main thread is started during the gadget's
 163  * fsg_bind() callback and stopped during fsg_unbind().  But it can also
 164  * exit when it receives a signal, and there's no point leaving the
 165  * gadget running when the thread is dead.  So just before the thread
 166  * exits, it deregisters the gadget driver.  This makes things a little
 167  * tricky: The driver is deregistered at two places, and the exiting
 168  * thread can indirectly call fsg_unbind() which in turn can tell the
 169  * thread to exit.  The first problem is resolved through the use of the
 170  * REGISTERED atomic bitflag; the driver will only be deregistered once.
 171  * The second problem is resolved by having fsg_unbind() check
 172  * fsg->state; it won't try to stop the thread if the state is already
 173  * FSG_STATE_TERMINATED.
 174  *
 175  * To provide maximum throughput, the driver uses a circular pipeline of
 176  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
 177  * arbitrarily long; in practice the benefits don't justify having more
 178  * than 2 stages (i.e., double buffering).  But it helps to think of the
 179  * pipeline as being a long one.  Each buffer head contains a bulk-in and
 180  * a bulk-out request pointer (since the buffer can be used for both
 181  * output and input -- directions always are given from the host's
 182  * point of view) as well as a pointer to the buffer and various state
 183  * variables.
 184  *
 185  * Use of the pipeline follows a simple protocol.  There is a variable
 186  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
 187  * At any time that buffer head may still be in use from an earlier
 188  * request, so each buffer head has a state variable indicating whether
 189  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
 190  * buffer head to be EMPTY, filling the buffer either by file I/O or by
 191  * USB I/O (during which the buffer head is BUSY), and marking the buffer
 192  * head FULL when the I/O is complete.  Then the buffer will be emptied
 193  * (again possibly by USB I/O, during which it is marked BUSY) and
 194  * finally marked EMPTY again (possibly by a completion routine).
 195  *
 196  * A module parameter tells the driver to avoid stalling the bulk
 197  * endpoints wherever the transport specification allows.  This is
 198  * necessary for some UDCs like the SuperH, which cannot reliably clear a
 199  * halt on a bulk endpoint.  However, under certain circumstances the
 200  * Bulk-only specification requires a stall.  In such cases the driver
 201  * will halt the endpoint and set a flag indicating that it should clear
 202  * the halt in software during the next device reset.  Hopefully this
 203  * will permit everything to work correctly.  Furthermore, although the
 204  * specification allows the bulk-out endpoint to halt when the host sends
 205  * too much data, implementing this would cause an unavoidable race.
 206  * The driver will always use the "no-stall" approach for OUT transfers.
 207  *
 208  * One subtle point concerns sending status-stage responses for ep0
 209  * requests.  Some of these requests, such as device reset, can involve
 210  * interrupting an ongoing file I/O operation, which might take an
 211  * arbitrarily long time.  During that delay the host might give up on
 212  * the original ep0 request and issue a new one.  When that happens the
 213  * driver should not notify the host about completion of the original
 214  * request, as the host will no longer be waiting for it.  So the driver
 215  * assigns to each ep0 request a unique tag, and it keeps track of the
 216  * tag value of the request associated with a long-running exception
 217  * (device-reset, interface-change, or configuration-change).  When the
 218  * exception handler is finished, the status-stage response is submitted
 219  * only if the current ep0 request tag is equal to the exception request
 220  * tag.  Thus only the most recently received ep0 request will get a
 221  * status-stage response.
 222  *
 223  * Warning: This driver source file is too long.  It ought to be split up
 224  * into a header file plus about 3 separate .c files, to handle the details
 225  * of the Gadget, USB Mass Storage, and SCSI protocols.
 226  */
 227
 228
 229 /* #define VERBOSE_DEBUG */
 230 /* #define DUMP_MSGS */
 231
 232
 233 #include <linux/blkdev.h>
 234 #include <linux/completion.h>
 235 #include <linux/dcache.h>
 236 #include <linux/delay.h>
 237 #include <linux/device.h>
 238 #include <linux/fcntl.h>
 239 #include <linux/file.h>
 240 #include <linux/fs.h>
 241 #include <linux/kref.h>
 242 #include <linux/kthread.h>
 243 #include <linux/limits.h>
 244 #include <linux/rwsem.h>
 245 #include <linux/slab.h>
 246 #include <linux/spinlock.h>
 247 #include <linux/string.h>
 248 #include <linux/freezer.h>
 249 #include <linux/utsname.h>
 250
 251 #include <linux/usb/ch9.h>
 252 #include <linux/usb/gadget.h>
 253
 254 #include "gadget_chips.h"
 255
 256
 257
 258 /*
 259  * Kbuild is not very cooperative with respect to linking separately
 260  * compiled library objects into one module.  So for now we won't use
 261  * separate compilation ... ensuring init/exit sections work to shrink
 262  * the runtime footprint, and giving us at least some parts of what
 263  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 264  */
 265 #include "usbstring.c"
 266 #include "config.c"
 267 #include "epautoconf.c"
 268
 269 /*-------------------------------------------------------------------------*/
 270
 271 #define DRIVER_DESC             "File-backed Storage Gadget"
 272 #define DRIVER_NAME             "g_file_storage"
 273 #define DRIVER_VERSION          "20 November 2008"
 274
 275 static       char fsg_string_manufacturer[64];
 276 static const char fsg_string_product[] = DRIVER_DESC;
 277 static       char fsg_string_serial[13];
 278 static const char fsg_string_config[] = "Self-powered";
 279 static const char fsg_string_interface[] = "Mass Storage";
 280
 281
 282 #include "storage_common.c"
 283
 284
 285 MODULE_DESCRIPTION(DRIVER_DESC);
 286 MODULE_AUTHOR("Alan Stern");
 287 MODULE_LICENSE("Dual BSD/GPL");
 288
 289 /*
 290  * This driver assumes self-powered hardware and has no way for users to
 291  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
 292  * and endpoint addresses.
 293  */
 294
 295
 296 /*-------------------------------------------------------------------------*/
 297
 298
 299 /* Encapsulate the module parameter settings */
 300
 301 static struct {
 302         char            *file[FSG_MAX_LUNS];
 303         int             ro[FSG_MAX_LUNS];
 304         unsigned int    num_filenames;
 305         unsigned int    num_ros;
 306         unsigned int    nluns;
 307
 308         int             removable;
 309         int             can_stall;
 310         int             cdrom;
 311
 312         char            *transport_parm;
 313         char            *protocol_parm;
 314         unsigned short  vendor;
 315         unsigned short  product;
 316         unsigned short  release;
 317         unsigned int    buflen;
 318
 319         int             transport_type;
 320         char            *transport_name;
 321         int             protocol_type;
 322         char            *protocol_name;
 323
 324 } mod_data = {                                  // Default values
 325         .transport_parm         = "BBB",
 326         .protocol_parm          = "SCSI",
 327         .removable              = 0,
 328         .can_stall              = 1,
 329         .cdrom                  = 0,
 330         .vendor                 = FSG_VENDOR_ID,
 331         .product                = FSG_PRODUCT_ID,
 332         .release                = 0xffff,       // Use controller chip type
 333         .buflen                 = 16384,
 334         };
 335
 336
 337 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
 338                 S_IRUGO);
 339 MODULE_PARM_DESC(file, "names of backing files or devices");
 340
 341 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
 342 MODULE_PARM_DESC(ro, "true to force read-only");
 343
 344 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
 345 MODULE_PARM_DESC(luns, "number of LUNs");
 346
 347 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
 348 MODULE_PARM_DESC(removable, "true to simulate removable media");
 349
 350 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
 351 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
 352
 353 module_param_named(cdrom, mod_data.cdrom, bool, S_IRUGO);
 354 MODULE_PARM_DESC(cdrom, "true to emulate cdrom instead of disk");
 355
 356
 357 /* In the non-TEST version, only the module parameters listed above
 358  * are available. */
 359 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 360
 361 module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
 362 MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
 363
 364 module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
 365 MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
 366                 "8070, or SCSI)");
 367
 368 module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
 369 MODULE_PARM_DESC(vendor, "USB Vendor ID");
 370
 371 module_param_named(product, mod_data.product, ushort, S_IRUGO);
 372 MODULE_PARM_DESC(product, "USB Product ID");
 373
 374 module_param_named(release, mod_data.release, ushort, S_IRUGO);
 375 MODULE_PARM_DESC(release, "USB release number");
 376
 377 module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
 378 MODULE_PARM_DESC(buflen, "I/O buffer size");
 379
 380 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 381
 382
 383 /*
 384  * These definitions will permit the compiler to avoid generating code for
 385  * parts of the driver that aren't used in the non-TEST version.  Even gcc
 386  * can recognize when a test of a constant expression yields a dead code
 387  * path.
 388  */
 389
 390 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 391
 392 #define transport_is_bbb()      (mod_data.transport_type == USB_PR_BULK)
 393 #define transport_is_cbi()      (mod_data.transport_type == USB_PR_CBI)
 394 #define protocol_is_scsi()      (mod_data.protocol_type == USB_SC_SCSI)
 395
 396 #else
 397
 398 #define transport_is_bbb()      1
 399 #define transport_is_cbi()      0
 400 #define protocol_is_scsi()      1
 401
 402 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 403
 404
 405 /*-------------------------------------------------------------------------*/
 406
 407
 408 struct fsg_dev {
 409         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
 410         spinlock_t              lock;
 411         struct usb_gadget       *gadget;
 412
 413         /* filesem protects: backing files in use */
 414         struct rw_semaphore     filesem;
 415
 416         /* reference counting: wait until all LUNs are released */
 417         struct kref             ref;
 418
 419         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
 420         struct usb_request      *ep0req;        // For control responses
 421         unsigned int            ep0_req_tag;
 422         const char              *ep0req_name;
 423
 424         struct usb_request      *intreq;        // For interrupt responses
 425         int                     intreq_busy;
 426         struct fsg_buffhd       *intr_buffhd;
 427
 428         unsigned int            bulk_out_maxpacket;
 429         enum fsg_state          state;          // For exception handling
 430         unsigned int            exception_req_tag;
 431
 432         u8                      config, new_config;
 433
 434         unsigned int            running : 1;
 435         unsigned int            bulk_in_enabled : 1;
 436         unsigned int            bulk_out_enabled : 1;
 437         unsigned int            intr_in_enabled : 1;
 438         unsigned int            phase_error : 1;
 439         unsigned int            short_packet_received : 1;
 440         unsigned int            bad_lun_okay : 1;
 441
 442         unsigned long           atomic_bitflags;
 443 #define REGISTERED              0
 444 #define IGNORE_BULK_OUT         1
 445 #define SUSPENDED               2
 446
 447         struct usb_ep           *bulk_in;
 448         struct usb_ep           *bulk_out;
 449         struct usb_ep           *intr_in;
 450
 451         struct fsg_buffhd       *next_buffhd_to_fill;
 452         struct fsg_buffhd       *next_buffhd_to_drain;
 453         struct fsg_buffhd       buffhds[FSG_NUM_BUFFERS];
 454
 455         int                     thread_wakeup_needed;
 456         struct completion       thread_notifier;
 457         struct task_struct      *thread_task;
 458
 459         int                     cmnd_size;
 460         u8                      cmnd[MAX_COMMAND_SIZE];
 461         enum data_direction     data_dir;
 462         u32                     data_size;
 463         u32                     data_size_from_cmnd;
 464         u32                     tag;
 465         unsigned int            lun;
 466         u32                     residue;
 467         u32                     usb_amount_left;
 468
 469         /* The CB protocol offers no way for a host to know when a command
 470          * has completed.  As a result the next command may arrive early,
 471          * and we will still have to handle it.  For that reason we need
 472          * a buffer to store new commands when using CB (or CBI, which
 473          * does not oblige a host to wait for command completion either). */
 474         int                     cbbuf_cmnd_size;
 475         u8                      cbbuf_cmnd[MAX_COMMAND_SIZE];
 476
 477         unsigned int            nluns;
 478         struct fsg_lun          *luns;
 479         struct fsg_lun          *curlun;
 480 };
 481
 482 typedef void (*fsg_routine_t)(struct fsg_dev *);
 483
 484 static int exception_in_progress(struct fsg_dev *fsg)
 485 {
 486         return (fsg->state > FSG_STATE_IDLE);
 487 }
 488
 489 /* Make bulk-out requests be divisible by the maxpacket size */
 490 static void set_bulk_out_req_length(struct fsg_dev *fsg,
 491                 struct fsg_buffhd *bh, unsigned int length)
 492 {
 493         unsigned int    rem;
 494
 495         bh->bulk_out_intended_length = length;
 496         rem = length % fsg->bulk_out_maxpacket;
 497         if (rem > 0)
 498                 length += fsg->bulk_out_maxpacket - rem;
 499         bh->outreq->length = length;
 500 }
 501
 502 static struct fsg_dev                   *the_fsg;
 503 static struct usb_gadget_driver         fsg_driver;
 504
 505
 506 /*-------------------------------------------------------------------------*/
 507
 508 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 509 {
 510         const char      *name;
 511
 512         if (ep == fsg->bulk_in)
 513                 name = "bulk-in";
 514         else if (ep == fsg->bulk_out)
 515                 name = "bulk-out";
 516         else
 517                 name = ep->name;
 518         DBG(fsg, "%s set halt\n", name);
 519         return usb_ep_set_halt(ep);
 520 }
 521
 522
 523 /*-------------------------------------------------------------------------*/
 524
 525 /*
 526  * DESCRIPTORS ... most are static, but strings and (full) configuration
 527  * descriptors are built on demand.  Also the (static) config and interface
 528  * descriptors are adjusted during fsg_bind().
 529  */
 530
 531 /* There is only one configuration. */
 532 #define CONFIG_VALUE            1
 533
 534 static struct usb_device_descriptor
 535 device_desc = {
 536         .bLength =              sizeof device_desc,
 537         .bDescriptorType =      USB_DT_DEVICE,
 538
 539         .bcdUSB =               cpu_to_le16(0x0200),
 540         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
 541
 542         /* The next three values can be overridden by module parameters */
 543         .idVendor =             cpu_to_le16(FSG_VENDOR_ID),
 544         .idProduct =            cpu_to_le16(FSG_PRODUCT_ID),
 545         .bcdDevice =            cpu_to_le16(0xffff),
 546
 547         .iManufacturer =        FSG_STRING_MANUFACTURER,
 548         .iProduct =             FSG_STRING_PRODUCT,
 549         .iSerialNumber =        FSG_STRING_SERIAL,
 550         .bNumConfigurations =   1,
 551 };
 552
 553 static struct usb_config_descriptor
 554 config_desc = {
 555         .bLength =              sizeof config_desc,
 556         .bDescriptorType =      USB_DT_CONFIG,
 557
 558         /* wTotalLength computed by usb_gadget_config_buf() */
 559         .bNumInterfaces =       1,
 560         .bConfigurationValue =  CONFIG_VALUE,
 561         .iConfiguration =       FSG_STRING_CONFIG,
 562         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
 563         .bMaxPower =            CONFIG_USB_GADGET_VBUS_DRAW / 2,
 564 };
 565
 566
 567 static struct usb_qualifier_descriptor
 568 dev_qualifier = {
 569         .bLength =              sizeof dev_qualifier,
 570         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
 571
 572         .bcdUSB =               cpu_to_le16(0x0200),
 573         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
 574
 575         .bNumConfigurations =   1,
 576 };
 577
 578
 579
 580 /*
 581  * Config descriptors must agree with the code that sets configurations
 582  * and with code managing interfaces and their altsettings.  They must
 583  * also handle different speeds and other-speed requests.
 584  */
 585 static int populate_config_buf(struct usb_gadget *gadget,
 586                 u8 *buf, u8 type, unsigned index)
 587 {
 588         enum usb_device_speed                   speed = gadget->speed;
 589         int                                     len;
 590         const struct usb_descriptor_header      **function;
 591
 592         if (index > 0)
 593                 return -EINVAL;
 594
 595         if (gadget_is_dualspeed(gadget) && type == USB_DT_OTHER_SPEED_CONFIG)
 596                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
 597         function = gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH
 598                 ? (const struct usb_descriptor_header **)fsg_hs_function
 599                 : (const struct usb_descriptor_header **)fsg_fs_function;
 600
 601         /* for now, don't advertise srp-only devices */
 602         if (!gadget_is_otg(gadget))
 603                 function++;
 604
 605         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
 606         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
 607         return len;
 608 }
 609
 610
 611 /*-------------------------------------------------------------------------*/
 612
 613 /* These routines may be called in process context or in_irq */
 614
 615 /* Caller must hold fsg->lock */
 616 static void wakeup_thread(struct fsg_dev *fsg)
 617 {
 618         /* Tell the main thread that something has happened */
 619         fsg->thread_wakeup_needed = 1;
 620         if (fsg->thread_task)
 621                 wake_up_process(fsg->thread_task);
 622 }
 623
 624
 625 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
 626 {
 627         unsigned long           flags;
 628
 629         /* Do nothing if a higher-priority exception is already in progress.
 630          * If a lower-or-equal priority exception is in progress, preempt it
 631          * and notify the main thread by sending it a signal. */
 632         spin_lock_irqsave(&fsg->lock, flags);
 633         if (fsg->state <= new_state) {
 634                 fsg->exception_req_tag = fsg->ep0_req_tag;
 635                 fsg->state = new_state;
 636                 if (fsg->thread_task)
 637                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
 638                                         fsg->thread_task);
 639         }
 640         spin_unlock_irqrestore(&fsg->lock, flags);
 641 }
 642
 643
 644 /*-------------------------------------------------------------------------*/
 645
 646 /* The disconnect callback and ep0 routines.  These always run in_irq,
 647  * except that ep0_queue() is called in the main thread to acknowledge
 648  * completion of various requests: set config, set interface, and
 649  * Bulk-only device reset. */
 650
 651 static void fsg_disconnect(struct usb_gadget *gadget)
 652 {
 653         struct fsg_dev          *fsg = get_gadget_data(gadget);
 654
 655         DBG(fsg, "disconnect or port reset\n");
 656         raise_exception(fsg, FSG_STATE_DISCONNECT);
 657 }
 658
 659
 660 static int ep0_queue(struct fsg_dev *fsg)
 661 {
 662         int     rc;
 663
 664         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
 665         if (rc != 0 && rc != -ESHUTDOWN) {
 666
 667                 /* We can't do much more than wait for a reset */
 668                 WARNING(fsg, "error in submission: %s --> %d\n",
 669                                 fsg->ep0->name, rc);
 670         }
 671         return rc;
 672 }
 673
 674 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
 675 {
 676         struct fsg_dev          *fsg = ep->driver_data;
 677
 678         if (req->actual > 0)
 679                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
 680         if (req->status || req->actual != req->length)
 681                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 682                                 req->status, req->actual, req->length);
 683         if (req->status == -ECONNRESET)         // Request was cancelled
 684                 usb_ep_fifo_flush(ep);
 685
 686         if (req->status == 0 && req->context)
 687                 ((fsg_routine_t) (req->context))(fsg);
 688 }
 689
 690
 691 /*-------------------------------------------------------------------------*/
 692
 693 /* Bulk and interrupt endpoint completion handlers.
 694  * These always run in_irq. */
 695
 696 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 697 {
 698         struct fsg_dev          *fsg = ep->driver_data;
 699         struct fsg_buffhd       *bh = req->context;
 700
 701         if (req->status || req->actual != req->length)
 702                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 703                                 req->status, req->actual, req->length);
 704         if (req->status == -ECONNRESET)         // Request was cancelled
 705                 usb_ep_fifo_flush(ep);
 706
 707         /* Hold the lock while we update the request and buffer states */
 708         smp_wmb();
 709         spin_lock(&fsg->lock);
 710         bh->inreq_busy = 0;
 711         bh->state = BUF_STATE_EMPTY;
 712         wakeup_thread(fsg);
 713         spin_unlock(&fsg->lock);
 714 }
 715
 716 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 717 {
 718         struct fsg_dev          *fsg = ep->driver_data;
 719         struct fsg_buffhd       *bh = req->context;
 720
 721         dump_msg(fsg, "bulk-out", req->buf, req->actual);
 722         if (req->status || req->actual != bh->bulk_out_intended_length)
 723                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 724                                 req->status, req->actual,
 725                                 bh->bulk_out_intended_length);
 726         if (req->status == -ECONNRESET)         // Request was cancelled
 727                 usb_ep_fifo_flush(ep);
 728
 729         /* Hold the lock while we update the request and buffer states */
 730         smp_wmb();
 731         spin_lock(&fsg->lock);
 732         bh->outreq_busy = 0;
 733         bh->state = BUF_STATE_FULL;
 734         wakeup_thread(fsg);
 735         spin_unlock(&fsg->lock);
 736 }
 737
 738
 739 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 740 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
 741 {
 742         struct fsg_dev          *fsg = ep->driver_data;
 743         struct fsg_buffhd       *bh = req->context;
 744
 745         if (req->status || req->actual != req->length)
 746                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
 747                                 req->status, req->actual, req->length);
 748         if (req->status == -ECONNRESET)         // Request was cancelled
 749                 usb_ep_fifo_flush(ep);
 750
 751         /* Hold the lock while we update the request and buffer states */
 752         smp_wmb();
 753         spin_lock(&fsg->lock);
 754         fsg->intreq_busy = 0;
 755         bh->state = BUF_STATE_EMPTY;
 756         wakeup_thread(fsg);
 757         spin_unlock(&fsg->lock);
 758 }
 759
 760 #else
 761 static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
 762 {}
 763 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 764
 765
 766 /*-------------------------------------------------------------------------*/
 767
 768 /* Ep0 class-specific handlers.  These always run in_irq. */
 769
 770 #ifdef CONFIG_USB_FILE_STORAGE_TEST
 771 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 772 {
 773         struct usb_request      *req = fsg->ep0req;
 774         static u8               cbi_reset_cmnd[6] = {
 775                         SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
 776
 777         /* Error in command transfer? */
 778         if (req->status || req->length != req->actual ||
 779                         req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
 780
 781                 /* Not all controllers allow a protocol stall after
 782                  * receiving control-out data, but we'll try anyway. */
 783                 fsg_set_halt(fsg, fsg->ep0);
 784                 return;                 // Wait for reset
 785         }
 786
 787         /* Is it the special reset command? */
 788         if (req->actual >= sizeof cbi_reset_cmnd &&
 789                         memcmp(req->buf, cbi_reset_cmnd,
 790                                 sizeof cbi_reset_cmnd) == 0) {
 791
 792                 /* Raise an exception to stop the current operation
 793                  * and reinitialize our state. */
 794                 DBG(fsg, "cbi reset request\n");
 795                 raise_exception(fsg, FSG_STATE_RESET);
 796                 return;
 797         }
 798
 799         VDBG(fsg, "CB[I] accept device-specific command\n");
 800         spin_lock(&fsg->lock);
 801
 802         /* Save the command for later */
 803         if (fsg->cbbuf_cmnd_size)
 804                 WARNING(fsg, "CB[I] overwriting previous command\n");
 805         fsg->cbbuf_cmnd_size = req->actual;
 806         memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
 807
 808         wakeup_thread(fsg);
 809         spin_unlock(&fsg->lock);
 810 }
 811
 812 #else
 813 static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 814 {}
 815 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 816
 817
 818 static int class_setup_req(struct fsg_dev *fsg,
 819                 const struct usb_ctrlrequest *ctrl)
 820 {
 821         struct usb_request      *req = fsg->ep0req;
 822         int                     value = -EOPNOTSUPP;
 823         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 824         u16                     w_value = le16_to_cpu(ctrl->wValue);
 825         u16                     w_length = le16_to_cpu(ctrl->wLength);
 826
 827         if (!fsg->config)
 828                 return value;
 829
 830         /* Handle Bulk-only class-specific requests */
 831         if (transport_is_bbb()) {
 832                 switch (ctrl->bRequest) {
 833
 834                 case USB_BULK_RESET_REQUEST:
 835                         if (ctrl->bRequestType != (USB_DIR_OUT |
 836                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 837                                 break;
 838                         if (w_index != 0 || w_value != 0) {
 839                                 value = -EDOM;
 840                                 break;
 841                         }
 842
 843                         /* Raise an exception to stop the current operation
 844                          * and reinitialize our state. */
 845                         DBG(fsg, "bulk reset request\n");
 846                         raise_exception(fsg, FSG_STATE_RESET);
 847                         value = DELAYED_STATUS;
 848                         break;
 849
 850                 case USB_BULK_GET_MAX_LUN_REQUEST:
 851                         if (ctrl->bRequestType != (USB_DIR_IN |
 852                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 853                                 break;
 854                         if (w_index != 0 || w_value != 0) {
 855                                 value = -EDOM;
 856                                 break;
 857                         }
 858                         VDBG(fsg, "get max LUN\n");
 859                         *(u8 *) req->buf = fsg->nluns - 1;
 860                         value = 1;
 861                         break;
 862                 }
 863         }
 864
 865         /* Handle CBI class-specific requests */
 866         else {
 867                 switch (ctrl->bRequest) {
 868
 869                 case USB_CBI_ADSC_REQUEST:
 870                         if (ctrl->bRequestType != (USB_DIR_OUT |
 871                                         USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 872                                 break;
 873                         if (w_index != 0 || w_value != 0) {
 874                                 value = -EDOM;
 875                                 break;
 876                         }
 877                         if (w_length > MAX_COMMAND_SIZE) {
 878                                 value = -EOVERFLOW;
 879                                 break;
 880                         }
 881                         value = w_length;
 882                         fsg->ep0req->context = received_cbi_adsc;
 883                         break;
 884                 }
 885         }
 886
 887         if (value == -EOPNOTSUPP)
 888                 VDBG(fsg,
 889                         "unknown class-specific control req "
 890                         "%02x.%02x v%04x i%04x l%u\n",
 891                         ctrl->bRequestType, ctrl->bRequest,
 892                         le16_to_cpu(ctrl->wValue), w_index, w_length);
 893         return value;
 894 }
 895
 896
 897 /*-------------------------------------------------------------------------*/
 898
 899 /* Ep0 standard request handlers.  These always run in_irq. */
 900
 901 static int standard_setup_req(struct fsg_dev *fsg,
 902                 const struct usb_ctrlrequest *ctrl)
 903 {
 904         struct usb_request      *req = fsg->ep0req;
 905         int                     value = -EOPNOTSUPP;
 906         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 907         u16                     w_value = le16_to_cpu(ctrl->wValue);
 908
 909         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
 910          * but config change events will also reconfigure hardware. */
 911         switch (ctrl->bRequest) {
 912
 913         case USB_REQ_GET_DESCRIPTOR:
 914                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
 915                                 USB_RECIP_DEVICE))
 916                         break;
 917                 switch (w_value >> 8) {
 918
 919                 case USB_DT_DEVICE:
 920                         VDBG(fsg, "get device descriptor\n");
 921                         value = sizeof device_desc;
 922                         memcpy(req->buf, &device_desc, value);
 923                         break;
 924                 case USB_DT_DEVICE_QUALIFIER:
 925                         VDBG(fsg, "get device qualifier\n");
 926                         if (!gadget_is_dualspeed(fsg->gadget))
 927                                 break;
 928                         value = sizeof dev_qualifier;
 929                         memcpy(req->buf, &dev_qualifier, value);
 930                         break;
 931
 932                 case USB_DT_OTHER_SPEED_CONFIG:
 933                         VDBG(fsg, "get other-speed config descriptor\n");
 934                         if (!gadget_is_dualspeed(fsg->gadget))
 935                                 break;
 936                         goto get_config;
 937                 case USB_DT_CONFIG:
 938                         VDBG(fsg, "get configuration descriptor\n");
 939 get_config:
 940                         value = populate_config_buf(fsg->gadget,
 941                                         req->buf,
 942                                         w_value >> 8,
 943                                         w_value & 0xff);
 944                         break;
 945
 946                 case USB_DT_STRING:
 947                         VDBG(fsg, "get string descriptor\n");
 948
 949                         /* wIndex == language code */
 950                         value = usb_gadget_get_string(&fsg_stringtab,
 951                                         w_value & 0xff, req->buf);
 952                         break;
 953                 }
 954                 break;
 955
 956         /* One config, two speeds */
 957         case USB_REQ_SET_CONFIGURATION:
 958                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
 959                                 USB_RECIP_DEVICE))
 960                         break;
 961                 VDBG(fsg, "set configuration\n");
 962                 if (w_value == CONFIG_VALUE || w_value == 0) {
 963                         fsg->new_config = w_value;
 964
 965                         /* Raise an exception to wipe out previous transaction
 966                          * state (queued bufs, etc) and set the new config. */
 967                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
 968                         value = DELAYED_STATUS;
 969                 }
 970                 break;
 971         case USB_REQ_GET_CONFIGURATION:
 972                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
 973                                 USB_RECIP_DEVICE))
 974                         break;
 975                 VDBG(fsg, "get configuration\n");
 976                 *(u8 *) req->buf = fsg->config;
 977                 value = 1;
 978                 break;
 979
 980         case USB_REQ_SET_INTERFACE:
 981                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
 982                                 USB_RECIP_INTERFACE))
 983                         break;
 984                 if (fsg->config && w_index == 0) {
 985
 986                         /* Raise an exception to wipe out previous transaction
 987                          * state (queued bufs, etc) and install the new
 988                          * interface altsetting. */
 989                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
 990                         value = DELAYED_STATUS;
 991                 }
 992                 break;
 993         case USB_REQ_GET_INTERFACE:
 994                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
 995                                 USB_RECIP_INTERFACE))
 996                         break;
 997                 if (!fsg->config)
 998                         break;
 999                 if (w_index != 0) {
1000                         value = -EDOM;
1001                         break;
1002                 }
1003                 VDBG(fsg, "get interface\n");
1004                 *(u8 *) req->buf = 0;
1005                 value = 1;
1006                 break;
1007
1008         default:
1009                 VDBG(fsg,
1010                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
1011                         ctrl->bRequestType, ctrl->bRequest,
1012                         w_value, w_index, le16_to_cpu(ctrl->wLength));
1013         }
1014
1015         return value;
1016 }
1017
1018
1019 static int fsg_setup(struct usb_gadget *gadget,
1020                 const struct usb_ctrlrequest *ctrl)
1021 {
1022         struct fsg_dev          *fsg = get_gadget_data(gadget);
1023         int                     rc;
1024         int                     w_length = le16_to_cpu(ctrl->wLength);
1025
1026         ++fsg->ep0_req_tag;             // Record arrival of a new request
1027         fsg->ep0req->context = NULL;
1028         fsg->ep0req->length = 0;
1029         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
1030
1031         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
1032                 rc = class_setup_req(fsg, ctrl);
1033         else
1034                 rc = standard_setup_req(fsg, ctrl);
1035
1036         /* Respond with data/status or defer until later? */
1037         if (rc >= 0 && rc != DELAYED_STATUS) {
1038                 rc = min(rc, w_length);
1039                 fsg->ep0req->length = rc;
1040                 fsg->ep0req->zero = rc < w_length;
1041                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
1042                                 "ep0-in" : "ep0-out");
1043                 rc = ep0_queue(fsg);
1044         }
1045
1046         /* Device either stalls (rc < 0) or reports success */
1047         return rc;
1048 }
1049
1050
1051 /*-------------------------------------------------------------------------*/
1052
1053 /* All the following routines run in process context */
1054
1055
1056 /* Use this for bulk or interrupt transfers, not ep0 */
1057 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
1058                 struct usb_request *req, int *pbusy,
1059                 enum fsg_buffer_state *state)
1060 {
1061         int     rc;
1062
1063         if (ep == fsg->bulk_in)
1064                 dump_msg(fsg, "bulk-in", req->buf, req->length);
1065         else if (ep == fsg->intr_in)
1066                 dump_msg(fsg, "intr-in", req->buf, req->length);
1067
1068         spin_lock_irq(&fsg->lock);
1069         *pbusy = 1;
1070         *state = BUF_STATE_BUSY;
1071         spin_unlock_irq(&fsg->lock);
1072         rc = usb_ep_queue(ep, req, GFP_KERNEL);
1073         if (rc != 0) {
1074                 *pbusy = 0;
1075                 *state = BUF_STATE_EMPTY;
1076
1077                 /* We can't do much more than wait for a reset */
1078
1079                 /* Note: currently the net2280 driver fails zero-length
1080                  * submissions if DMA is enabled. */
1081                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
1082                                                 req->length == 0))
1083                         WARNING(fsg, "error in submission: %s --> %d\n",
1084                                         ep->name, rc);
1085         }
1086 }
1087
1088
1089 static int sleep_thread(struct fsg_dev *fsg)
1090 {
1091         int     rc = 0;
1092
1093         /* Wait until a signal arrives or we are woken up */
1094         for (;;) {
1095                 try_to_freeze();
1096                 set_current_state(TASK_INTERRUPTIBLE);
1097                 if (signal_pending(current)) {
1098                         rc = -EINTR;
1099                         break;
1100                 }
1101                 if (fsg->thread_wakeup_needed)
1102                         break;
1103                 schedule();
1104         }
1105         __set_current_state(TASK_RUNNING);
1106         fsg->thread_wakeup_needed = 0;
1107         return rc;
1108 }
1109
1110
1111 /*-------------------------------------------------------------------------*/
1112
1113 static int do_read(struct fsg_dev *fsg)
1114 {
1115         struct fsg_lun          *curlun = fsg->curlun;
1116         u32                     lba;
1117         struct fsg_buffhd       *bh;
1118         int                     rc;
1119         u32                     amount_left;
1120         loff_t                  file_offset, file_offset_tmp;
1121         unsigned int            amount;
1122         unsigned int            partial_page;
1123         ssize_t                 nread;
1124
1125         /* Get the starting Logical Block Address and check that it's
1126          * not too big */
1127         if (fsg->cmnd[0] == SC_READ_6)
1128                 lba = get_unaligned_be24(&fsg->cmnd[1]);
1129         else {
1130                 lba = get_unaligned_be32(&fsg->cmnd[2]);
1131
1132                 /* We allow DPO (Disable Page Out = don't save data in the
1133                  * cache) and FUA (Force Unit Access = don't read from the
1134                  * cache), but we don't implement them. */
1135                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1136                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1137                         return -EINVAL;
1138                 }
1139         }
1140         if (lba >= curlun->num_sectors) {
1141                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1142                 return -EINVAL;
1143         }
1144         file_offset = ((loff_t) lba) << 9;
1145
1146         /* Carry out the file reads */
1147         amount_left = fsg->data_size_from_cmnd;
1148         if (unlikely(amount_left == 0))
1149                 return -EIO;            // No default reply
1150
1151         for (;;) {
1152
1153                 /* Figure out how much we need to read:
1154                  * Try to read the remaining amount.
1155                  * But don't read more than the buffer size.
1156                  * And don't try to read past the end of the file.
1157                  * Finally, if we're not at a page boundary, don't read past
1158                  *      the next page.
1159                  * If this means reading 0 then we were asked to read past
1160                  *      the end of file. */
1161                 amount = min((unsigned int) amount_left, mod_data.buflen);
1162                 amount = min((loff_t) amount,
1163                                 curlun->file_length - file_offset);
1164                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
1165                 if (partial_page > 0)
1166                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
1167                                         partial_page);
1168
1169                 /* Wait for the next buffer to become available */
1170                 bh = fsg->next_buffhd_to_fill;
1171                 while (bh->state != BUF_STATE_EMPTY) {
1172                         rc = sleep_thread(fsg);
1173                         if (rc)
1174                                 return rc;
1175                 }
1176
1177                 /* If we were asked to read past the end of file,
1178                  * end with an empty buffer. */
1179                 if (amount == 0) {
1180                         curlun->sense_data =
1181                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1182                         curlun->sense_data_info = file_offset >> 9;
1183                         curlun->info_valid = 1;
1184                         bh->inreq->length = 0;
1185                         bh->state = BUF_STATE_FULL;
1186                         break;
1187                 }
1188
1189                 /* Perform the read */
1190                 file_offset_tmp = file_offset;
1191                 nread = vfs_read(curlun->filp,
1192                                 (char __user *) bh->buf,
1193                                 amount, &file_offset_tmp);
1194                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1195                                 (unsigned long long) file_offset,
1196                                 (int) nread);
1197                 if (signal_pending(current))
1198                         return -EINTR;
1199
1200                 if (nread < 0) {
1201                         LDBG(curlun, "error in file read: %d\n",
1202                                         (int) nread);
1203                         nread = 0;
1204                 } else if (nread < amount) {
1205                         LDBG(curlun, "partial file read: %d/%u\n",
1206                                         (int) nread, amount);
1207                         nread -= (nread & 511); // Round down to a block
1208                 }
1209                 file_offset  += nread;
1210                 amount_left  -= nread;
1211                 fsg->residue -= nread;
1212                 bh->inreq->length = nread;
1213                 bh->state = BUF_STATE_FULL;
1214
1215                 /* If an error occurred, report it and its position */
1216                 if (nread < amount) {
1217                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1218                         curlun->sense_data_info = file_offset >> 9;
1219                         curlun->info_valid = 1;
1220                         break;
1221                 }
1222
1223                 if (amount_left == 0)
1224                         break;          // No more left to read
1225
1226                 /* Send this buffer and go read some more */
1227                 bh->inreq->zero = 0;
1228                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1229                                 &bh->inreq_busy, &bh->state);
1230                 fsg->next_buffhd_to_fill = bh->next;
1231         }
1232
1233         return -EIO;            // No default reply
1234 }
1235
1236
1237 /*-------------------------------------------------------------------------*/
1238
1239 static int do_write(struct fsg_dev *fsg)
1240 {
1241         struct fsg_lun          *curlun = fsg->curlun;
1242         u32                     lba;
1243         struct fsg_buffhd       *bh;
1244         int                     get_some_more;
1245         u32                     amount_left_to_req, amount_left_to_write;
1246         loff_t                  usb_offset, file_offset, file_offset_tmp;
1247         unsigned int            amount;
1248         unsigned int            partial_page;
1249         ssize_t                 nwritten;
1250         int                     rc;
1251
1252         if (curlun->ro) {
1253                 curlun->sense_data = SS_WRITE_PROTECTED;
1254                 return -EINVAL;
1255         }
1256         spin_lock(&curlun->filp->f_lock);
1257         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1258         spin_unlock(&curlun->filp->f_lock);
1259
1260         /* Get the starting Logical Block Address and check that it's
1261          * not too big */
1262         if (fsg->cmnd[0] == SC_WRITE_6)
1263                 lba = get_unaligned_be24(&fsg->cmnd[1]);
1264         else {
1265                 lba = get_unaligned_be32(&fsg->cmnd[2]);
1266
1267                 /* We allow DPO (Disable Page Out = don't save data in the
1268                  * cache) and FUA (Force Unit Access = write directly to the
1269                  * medium).  We don't implement DPO; we implement FUA by
1270                  * performing synchronous output. */
1271                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1272                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1273                         return -EINVAL;
1274                 }
1275                 if (fsg->cmnd[1] & 0x08) {      // FUA
1276                         spin_lock(&curlun->filp->f_lock);
1277                         curlun->filp->f_flags |= O_DSYNC;
1278                         spin_unlock(&curlun->filp->f_lock);
1279                 }
1280         }
1281         if (lba >= curlun->num_sectors) {
1282                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1283                 return -EINVAL;
1284         }
1285
1286         /* Carry out the file writes */
1287         get_some_more = 1;
1288         file_offset = usb_offset = ((loff_t) lba) << 9;
1289         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1290
1291         while (amount_left_to_write > 0) {
1292
1293                 /* Queue a request for more data from the host */
1294                 bh = fsg->next_buffhd_to_fill;
1295                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1296
1297                         /* Figure out how much we want to get:
1298                          * Try to get the remaining amount.
1299                          * But don't get more than the buffer size.
1300                          * And don't try to go past the end of the file.
1301                          * If we're not at a page boundary,
1302                          *      don't go past the next page.
1303                          * If this means getting 0, then we were asked
1304                          *      to write past the end of file.
1305                          * Finally, round down to a block boundary. */
1306                         amount = min(amount_left_to_req, mod_data.buflen);
1307                         amount = min((loff_t) amount, curlun->file_length -
1308                                         usb_offset);
1309                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1310                         if (partial_page > 0)
1311                                 amount = min(amount,
1312         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1313
1314                         if (amount == 0) {
1315                                 get_some_more = 0;
1316                                 curlun->sense_data =
1317                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1318                                 curlun->sense_data_info = usb_offset >> 9;
1319                                 curlun->info_valid = 1;
1320                                 continue;
1321                         }
1322                         amount -= (amount & 511);
1323                         if (amount == 0) {
1324
1325                                 /* Why were we were asked to transfer a
1326                                  * partial block? */
1327                                 get_some_more = 0;
1328                                 continue;
1329                         }
1330
1331                         /* Get the next buffer */
1332                         usb_offset += amount;
1333                         fsg->usb_amount_left -= amount;
1334                         amount_left_to_req -= amount;
1335                         if (amount_left_to_req == 0)
1336                                 get_some_more = 0;
1337
1338                         /* amount is always divisible by 512, hence by
1339                          * the bulk-out maxpacket size */
1340                         bh->outreq->length = bh->bulk_out_intended_length =
1341                                         amount;
1342                         bh->outreq->short_not_ok = 1;
1343                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1344                                         &bh->outreq_busy, &bh->state);
1345                         fsg->next_buffhd_to_fill = bh->next;
1346                         continue;
1347                 }
1348
1349                 /* Write the received data to the backing file */
1350                 bh = fsg->next_buffhd_to_drain;
1351                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1352                         break;                  // We stopped early
1353                 if (bh->state == BUF_STATE_FULL) {
1354                         smp_rmb();
1355                         fsg->next_buffhd_to_drain = bh->next;
1356                         bh->state = BUF_STATE_EMPTY;
1357
1358                         /* Did something go wrong with the transfer? */
1359                         if (bh->outreq->status != 0) {
1360                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1361                                 curlun->sense_data_info = file_offset >> 9;
1362                                 curlun->info_valid = 1;
1363                                 break;
1364                         }
1365
1366                         amount = bh->outreq->actual;
1367                         if (curlun->file_length - file_offset < amount) {
1368                                 LERROR(curlun,
1369         "write %u @ %llu beyond end %llu\n",
1370         amount, (unsigned long long) file_offset,
1371         (unsigned long long) curlun->file_length);
1372                                 amount = curlun->file_length - file_offset;
1373                         }
1374
1375                         /* Perform the write */
1376                         file_offset_tmp = file_offset;
1377                         nwritten = vfs_write(curlun->filp,
1378                                         (char __user *) bh->buf,
1379                                         amount, &file_offset_tmp);
1380                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1381                                         (unsigned long long) file_offset,
1382                                         (int) nwritten);
1383                         if (signal_pending(current))
1384                                 return -EINTR;          // Interrupted!
1385
1386                         if (nwritten < 0) {
1387                                 LDBG(curlun, "error in file write: %d\n",
1388                                                 (int) nwritten);
1389                                 nwritten = 0;
1390                         } else if (nwritten < amount) {
1391                                 LDBG(curlun, "partial file write: %d/%u\n",
1392                                                 (int) nwritten, amount);
1393                                 nwritten -= (nwritten & 511);
1394                                                 // Round down to a block
1395                         }
1396                         file_offset += nwritten;
1397                         amount_left_to_write -= nwritten;
1398                         fsg->residue -= nwritten;
1399
1400                         /* If an error occurred, report it and its position */
1401                         if (nwritten < amount) {
1402                                 curlun->sense_data = SS_WRITE_ERROR;
1403                                 curlun->sense_data_info = file_offset >> 9;
1404                                 curlun->info_valid = 1;
1405                                 break;
1406                         }
1407
1408                         /* Did the host decide to stop early? */
1409                         if (bh->outreq->actual != bh->outreq->length) {
1410                                 fsg->short_packet_received = 1;
1411                                 break;
1412                         }
1413                         continue;
1414                 }
1415
1416                 /* Wait for something to happen */
1417                 rc = sleep_thread(fsg);
1418                 if (rc)
1419                         return rc;
1420         }
1421
1422         return -EIO;            // No default reply
1423 }
1424
1425
1426 /*-------------------------------------------------------------------------*/
1427
1428 static int do_synchronize_cache(struct fsg_dev *fsg)
1429 {
1430         struct fsg_lun  *curlun = fsg->curlun;
1431         int             rc;
1432
1433         /* We ignore the requested LBA and write out all file's
1434          * dirty data buffers. */
1435         rc = fsg_lun_fsync_sub(curlun);
1436         if (rc)
1437                 curlun->sense_data = SS_WRITE_ERROR;
1438         return 0;
1439 }
1440
1441
1442 /*-------------------------------------------------------------------------*/
1443
1444 static void invalidate_sub(struct fsg_lun *curlun)
1445 {
1446         struct file     *filp = curlun->filp;
1447         struct inode    *inode = filp->f_path.dentry->d_inode;
1448         unsigned long   rc;
1449
1450         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1451         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1452 }
1453
1454 static int do_verify(struct fsg_dev *fsg)
1455 {
1456         struct fsg_lun          *curlun = fsg->curlun;
1457         u32                     lba;
1458         u32                     verification_length;
1459         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1460         loff_t                  file_offset, file_offset_tmp;
1461         u32                     amount_left;
1462         unsigned int            amount;
1463         ssize_t                 nread;
1464
1465         /* Get the starting Logical Block Address and check that it's
1466          * not too big */
1467         lba = get_unaligned_be32(&fsg->cmnd[2]);
1468         if (lba >= curlun->num_sectors) {
1469                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1470                 return -EINVAL;
1471         }
1472
1473         /* We allow DPO (Disable Page Out = don't save data in the
1474          * cache) but we don't implement it. */
1475         if ((fsg->cmnd[1] & ~0x10) != 0) {
1476                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1477                 return -EINVAL;
1478         }
1479
1480         verification_length = get_unaligned_be16(&fsg->cmnd[7]);
1481         if (unlikely(verification_length == 0))
1482                 return -EIO;            // No default reply
1483
1484         /* Prepare to carry out the file verify */
1485         amount_left = verification_length << 9;
1486         file_offset = ((loff_t) lba) << 9;
1487
1488         /* Write out all the dirty buffers before invalidating them */
1489         fsg_lun_fsync_sub(curlun);
1490         if (signal_pending(current))
1491                 return -EINTR;
1492
1493         invalidate_sub(curlun);
1494         if (signal_pending(current))
1495                 return -EINTR;
1496
1497         /* Just try to read the requested blocks */
1498         while (amount_left > 0) {
1499
1500                 /* Figure out how much we need to read:
1501                  * Try to read the remaining amount, but not more than
1502                  * the buffer size.
1503                  * And don't try to read past the end of the file.
1504                  * If this means reading 0 then we were asked to read
1505                  * past the end of file. */
1506                 amount = min((unsigned int) amount_left, mod_data.buflen);
1507                 amount = min((loff_t) amount,
1508                                 curlun->file_length - file_offset);
1509                 if (amount == 0) {
1510                         curlun->sense_data =
1511                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1512                         curlun->sense_data_info = file_offset >> 9;
1513                         curlun->info_valid = 1;
1514                         break;
1515                 }
1516
1517                 /* Perform the read */
1518                 file_offset_tmp = file_offset;
1519                 nread = vfs_read(curlun->filp,
1520                                 (char __user *) bh->buf,
1521                                 amount, &file_offset_tmp);
1522                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1523                                 (unsigned long long) file_offset,
1524                                 (int) nread);
1525                 if (signal_pending(current))
1526                         return -EINTR;
1527
1528                 if (nread < 0) {
1529                         LDBG(curlun, "error in file verify: %d\n",
1530                                         (int) nread);
1531                         nread = 0;
1532                 } else if (nread < amount) {
1533                         LDBG(curlun, "partial file verify: %d/%u\n",
1534                                         (int) nread, amount);
1535                         nread -= (nread & 511); // Round down to a sector
1536                 }
1537                 if (nread == 0) {
1538                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1539                         curlun->sense_data_info = file_offset >> 9;
1540                         curlun->info_valid = 1;
1541                         break;
1542                 }
1543                 file_offset += nread;
1544                 amount_left -= nread;
1545         }
1546         return 0;
1547 }
1548
1549
1550 /*-------------------------------------------------------------------------*/
1551
1552 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1553 {
1554         u8      *buf = (u8 *) bh->buf;
1555
1556         static char vendor_id[] = "Linux   ";
1557         static char product_disk_id[] = "File-Stor Gadget";
1558         static char product_cdrom_id[] = "File-CD Gadget  ";
1559
1560         if (!fsg->curlun) {             // Unsupported LUNs are okay
1561                 fsg->bad_lun_okay = 1;
1562                 memset(buf, 0, 36);
1563                 buf[0] = 0x7f;          // Unsupported, no device-type
1564                 buf[4] = 31;            // Additional length
1565                 return 36;
1566         }
1567
1568         memset(buf, 0, 8);
1569         buf[0] = (mod_data.cdrom ? TYPE_CDROM : TYPE_DISK);
1570         if (mod_data.removable)
1571                 buf[1] = 0x80;
1572         buf[2] = 2;             // ANSI SCSI level 2
1573         buf[3] = 2;             // SCSI-2 INQUIRY data format
1574         buf[4] = 31;            // Additional length
1575                                 // No special options
1576         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id,
1577                         (mod_data.cdrom ? product_cdrom_id :
1578                                 product_disk_id),
1579                         mod_data.release);
1580         return 36;
1581 }
1582
1583
1584 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1585 {
1586         struct fsg_lun  *curlun = fsg->curlun;
1587         u8              *buf = (u8 *) bh->buf;
1588         u32             sd, sdinfo;
1589         int             valid;
1590
1591         /*
1592          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1593          *
1594          * If a REQUEST SENSE command is received from an initiator
1595          * with a pending unit attention condition (before the target
1596          * generates the contingent allegiance condition), then the
1597          * target shall either:
1598          *   a) report any pending sense data and preserve the unit
1599          *      attention condition on the logical unit, or,
1600          *   b) report the unit attention condition, may discard any
1601          *      pending sense data, and clear the unit attention
1602          *      condition on the logical unit for that initiator.
1603          *
1604          * FSG normally uses option a); enable this code to use option b).
1605          */
1606 #if 0
1607         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1608                 curlun->sense_data = curlun->unit_attention_data;
1609                 curlun->unit_attention_data = SS_NO_SENSE;
1610         }
1611 #endif
1612
1613         if (!curlun) {          // Unsupported LUNs are okay
1614                 fsg->bad_lun_okay = 1;
1615                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1616                 sdinfo = 0;
1617                 valid = 0;
1618         } else {
1619                 sd = curlun->sense_data;
1620                 sdinfo = curlun->sense_data_info;
1621                 valid = curlun->info_valid << 7;
1622                 curlun->sense_data = SS_NO_SENSE;
1623                 curlun->sense_data_info = 0;
1624                 curlun->info_valid = 0;
1625         }
1626
1627         memset(buf, 0, 18);
1628         buf[0] = valid | 0x70;                  // Valid, current error
1629         buf[2] = SK(sd);
1630         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1631         buf[7] = 18 - 8;                        // Additional sense length
1632         buf[12] = ASC(sd);
1633         buf[13] = ASCQ(sd);
1634         return 18;
1635 }
1636
1637
1638 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1639 {
1640         struct fsg_lun  *curlun = fsg->curlun;
1641         u32             lba = get_unaligned_be32(&fsg->cmnd[2]);
1642         int             pmi = fsg->cmnd[8];
1643         u8              *buf = (u8 *) bh->buf;
1644
1645         /* Check the PMI and LBA fields */
1646         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1647                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1648                 return -EINVAL;
1649         }
1650
1651         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1652                                                 /* Max logical block */
1653         put_unaligned_be32(512, &buf[4]);       /* Block length */
1654         return 8;
1655 }
1656
1657
1658 static int do_read_header(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1659 {
1660         struct fsg_lun  *curlun = fsg->curlun;
1661         int             msf = fsg->cmnd[1] & 0x02;
1662         u32             lba = get_unaligned_be32(&fsg->cmnd[2]);
1663         u8              *buf = (u8 *) bh->buf;
1664
1665         if ((fsg->cmnd[1] & ~0x02) != 0) {              /* Mask away MSF */
1666                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1667                 return -EINVAL;
1668         }
1669         if (lba >= curlun->num_sectors) {
1670                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1671                 return -EINVAL;
1672         }
1673
1674         memset(buf, 0, 8);
1675         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1676         store_cdrom_address(&buf[4], msf, lba);
1677         return 8;
1678 }
1679
1680
1681 static int do_read_toc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1682 {
1683         struct fsg_lun  *curlun = fsg->curlun;
1684         int             msf = fsg->cmnd[1] & 0x02;
1685         int             start_track = fsg->cmnd[6];
1686         u8              *buf = (u8 *) bh->buf;
1687
1688         if ((fsg->cmnd[1] & ~0x02) != 0 ||              /* Mask away MSF */
1689                         start_track > 1) {
1690                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1691                 return -EINVAL;
1692         }
1693
1694         memset(buf, 0, 20);
1695         buf[1] = (20-2);                /* TOC data length */
1696         buf[2] = 1;                     /* First track number */
1697         buf[3] = 1;                     /* Last track number */
1698         buf[5] = 0x16;                  /* Data track, copying allowed */
1699         buf[6] = 0x01;                  /* Only track is number 1 */
1700         store_cdrom_address(&buf[8], msf, 0);
1701
1702         buf[13] = 0x16;                 /* Lead-out track is data */
1703         buf[14] = 0xAA;                 /* Lead-out track number */
1704         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1705         return 20;
1706 }
1707
1708
1709 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1710 {
1711         struct fsg_lun  *curlun = fsg->curlun;
1712         int             mscmnd = fsg->cmnd[0];
1713         u8              *buf = (u8 *) bh->buf;
1714         u8              *buf0 = buf;
1715         int             pc, page_code;
1716         int             changeable_values, all_pages;
1717         int             valid_page = 0;
1718         int             len, limit;
1719
1720         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
1721                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1722                 return -EINVAL;
1723         }
1724         pc = fsg->cmnd[2] >> 6;
1725         page_code = fsg->cmnd[2] & 0x3f;
1726         if (pc == 3) {
1727                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1728                 return -EINVAL;
1729         }
1730         changeable_values = (pc == 1);
1731         all_pages = (page_code == 0x3f);
1732
1733         /* Write the mode parameter header.  Fixed values are: default
1734          * medium type, no cache control (DPOFUA), and no block descriptors.
1735          * The only variable value is the WriteProtect bit.  We will fill in
1736          * the mode data length later. */
1737         memset(buf, 0, 8);
1738         if (mscmnd == SC_MODE_SENSE_6) {
1739                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
1740                 buf += 4;
1741                 limit = 255;
1742         } else {                        // SC_MODE_SENSE_10
1743                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
1744                 buf += 8;
1745                 limit = 65535;          // Should really be mod_data.buflen
1746         }
1747
1748         /* No block descriptors */
1749
1750         /* The mode pages, in numerical order.  The only page we support
1751          * is the Caching page. */
1752         if (page_code == 0x08 || all_pages) {
1753                 valid_page = 1;
1754                 buf[0] = 0x08;          // Page code
1755                 buf[1] = 10;            // Page length
1756                 memset(buf+2, 0, 10);   // None of the fields are changeable
1757
1758                 if (!changeable_values) {
1759                         buf[2] = 0x04;  // Write cache enable,
1760                                         // Read cache not disabled
1761                                         // No cache retention priorities
1762                         put_unaligned_be16(0xffff, &buf[4]);
1763                                         /* Don't disable prefetch */
1764                                         /* Minimum prefetch = 0 */
1765                         put_unaligned_be16(0xffff, &buf[8]);
1766                                         /* Maximum prefetch */
1767                         put_unaligned_be16(0xffff, &buf[10]);
1768                                         /* Maximum prefetch ceiling */
1769                 }
1770                 buf += 12;
1771         }
1772
1773         /* Check that a valid page was requested and the mode data length
1774          * isn't too long. */
1775         len = buf - buf0;
1776         if (!valid_page || len > limit) {
1777                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1778                 return -EINVAL;
1779         }
1780
1781         /*  Store the mode data length */
1782         if (mscmnd == SC_MODE_SENSE_6)
1783                 buf0[0] = len - 1;
1784         else
1785                 put_unaligned_be16(len - 2, buf0);
1786         return len;
1787 }
1788
1789
1790 static int do_start_stop(struct fsg_dev *fsg)
1791 {
1792         struct fsg_lun  *curlun = fsg->curlun;
1793         int             loej, start;
1794
1795         if (!mod_data.removable) {
1796                 curlun->sense_data = SS_INVALID_COMMAND;
1797                 return -EINVAL;
1798         }
1799
1800         // int immed = fsg->cmnd[1] & 0x01;
1801         loej = fsg->cmnd[4] & 0x02;
1802         start = fsg->cmnd[4] & 0x01;
1803
1804 #ifdef CONFIG_USB_FILE_STORAGE_TEST
1805         if ((fsg->cmnd[1] & ~0x01) != 0 ||              // Mask away Immed
1806                         (fsg->cmnd[4] & ~0x03) != 0) {  // Mask LoEj, Start
1807                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1808                 return -EINVAL;
1809         }
1810
1811         if (!start) {
1812
1813                 /* Are we allowed to unload the media? */
1814                 if (curlun->prevent_medium_removal) {
1815                         LDBG(curlun, "unload attempt prevented\n");
1816                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1817                         return -EINVAL;
1818                 }
1819                 if (loej) {             // Simulate an unload/eject
1820                         up_read(&fsg->filesem);
1821                         down_write(&fsg->filesem);
1822                         fsg_lun_close(curlun);
1823                         up_write(&fsg->filesem);
1824                         down_read(&fsg->filesem);
1825                 }
1826         } else {
1827
1828                 /* Our emulation doesn't support mounting; the medium is
1829                  * available for use as soon as it is loaded. */
1830                 if (!fsg_lun_is_open(curlun)) {
1831                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1832                         return -EINVAL;
1833                 }
1834         }
1835 #endif
1836         return 0;
1837 }
1838
1839
1840 static int do_prevent_allow(struct fsg_dev *fsg)
1841 {
1842         struct fsg_lun  *curlun = fsg->curlun;
1843         int             prevent;
1844
1845         if (!mod_data.removable) {
1846                 curlun->sense_data = SS_INVALID_COMMAND;
1847                 return -EINVAL;
1848         }
1849
1850         prevent = fsg->cmnd[4] & 0x01;
1851         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
1852                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1853                 return -EINVAL;
1854         }
1855
1856         if (curlun->prevent_medium_removal && !prevent)
1857                 fsg_lun_fsync_sub(curlun);
1858         curlun->prevent_medium_removal = prevent;
1859         return 0;
1860 }
1861
1862
1863 static int do_read_format_capacities(struct fsg_dev *fsg,
1864                         struct fsg_buffhd *bh)
1865 {
1866         struct fsg_lun  *curlun = fsg->curlun;
1867         u8              *buf = (u8 *) bh->buf;
1868
1869         buf[0] = buf[1] = buf[2] = 0;
1870         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
1871         buf += 4;
1872
1873         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1874                                                 /* Number of blocks */
1875         put_unaligned_be32(512, &buf[4]);       /* Block length */
1876         buf[4] = 0x02;                          /* Current capacity */
1877         return 12;
1878 }
1879
1880
1881 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1882 {
1883         struct fsg_lun  *curlun = fsg->curlun;
1884
1885         /* We don't support MODE SELECT */
1886         curlun->sense_data = SS_INVALID_COMMAND;
1887         return -EINVAL;
1888 }
1889
1890
1891 /*-------------------------------------------------------------------------*/
1892
1893 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1894 {
1895         int     rc;
1896
1897         rc = fsg_set_halt(fsg, fsg->bulk_in);
1898         if (rc == -EAGAIN)
1899                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1900         while (rc != 0) {
1901                 if (rc != -EAGAIN) {
1902                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1903                         rc = 0;
1904                         break;
1905                 }
1906
1907                 /* Wait for a short time and then try again */
1908                 if (msleep_interruptible(100) != 0)
1909                         return -EINTR;
1910                 rc = usb_ep_set_halt(fsg->bulk_in);
1911         }
1912         return rc;
1913 }
1914
1915 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1916 {
1917         int     rc;
1918
1919         DBG(fsg, "bulk-in set wedge\n");
1920         rc = usb_ep_set_wedge(fsg->bulk_in);
1921         if (rc == -EAGAIN)
1922                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1923         while (rc != 0) {
1924                 if (rc != -EAGAIN) {
1925                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1926                         rc = 0;
1927                         break;
1928                 }
1929
1930                 /* Wait for a short time and then try again */
1931                 if (msleep_interruptible(100) != 0)
1932                         return -EINTR;
1933                 rc = usb_ep_set_wedge(fsg->bulk_in);
1934         }
1935         return rc;
1936 }
1937
1938 static int pad_with_zeros(struct fsg_dev *fsg)
1939 {
1940         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1941         u32                     nkeep = bh->inreq->length;
1942         u32                     nsend;
1943         int                     rc;
1944
1945         bh->state = BUF_STATE_EMPTY;            // For the first iteration
1946         fsg->usb_amount_left = nkeep + fsg->residue;
1947         while (fsg->usb_amount_left > 0) {
1948
1949                 /* Wait for the next buffer to be free */
1950                 while (bh->state != BUF_STATE_EMPTY) {
1951                         rc = sleep_thread(fsg);
1952                         if (rc)
1953                                 return rc;
1954                 }
1955
1956                 nsend = min(fsg->usb_amount_left, (u32) mod_data.buflen);
1957                 memset(bh->buf + nkeep, 0, nsend - nkeep);
1958                 bh->inreq->length = nsend;
1959                 bh->inreq->zero = 0;
1960                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1961                                 &bh->inreq_busy, &bh->state);
1962                 bh = fsg->next_buffhd_to_fill = bh->next;
1963                 fsg->usb_amount_left -= nsend;
1964                 nkeep = 0;
1965         }
1966         return 0;
1967 }
1968
1969 static int throw_away_data(struct fsg_dev *fsg)
1970 {
1971         struct fsg_buffhd       *bh;
1972         u32                     amount;
1973         int                     rc;
1974
1975         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
1976                         fsg->usb_amount_left > 0) {
1977
1978                 /* Throw away the data in a filled buffer */
1979                 if (bh->state == BUF_STATE_FULL) {
1980                         smp_rmb();
1981                         bh->state = BUF_STATE_EMPTY;
1982                         fsg->next_buffhd_to_drain = bh->next;
1983
1984                         /* A short packet or an error ends everything */
1985                         if (bh->outreq->actual != bh->outreq->length ||
1986                                         bh->outreq->status != 0) {
1987                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
1988                                 return -EINTR;
1989                         }
1990                         continue;
1991                 }
1992
1993                 /* Try to submit another request if we need one */
1994                 bh = fsg->next_buffhd_to_fill;
1995                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
1996                         amount = min(fsg->usb_amount_left,
1997                                         (u32) mod_data.buflen);
1998
1999                         /* amount is always divisible by 512, hence by
2000                          * the bulk-out maxpacket size */
2001                         bh->outreq->length = bh->bulk_out_intended_length =
2002                                         amount;
2003                         bh->outreq->short_not_ok = 1;
2004                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2005                                         &bh->outreq_busy, &bh->state);
2006                         fsg->next_buffhd_to_fill = bh->next;
2007                         fsg->usb_amount_left -= amount;
2008                         continue;
2009                 }
2010
2011                 /* Otherwise wait for something to happen */
2012                 rc = sleep_thread(fsg);
2013                 if (rc)
2014                         return rc;
2015         }
2016         return 0;
2017 }
2018
2019
2020 static int finish_reply(struct fsg_dev *fsg)
2021 {
2022         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
2023         int                     rc = 0;
2024
2025         switch (fsg->data_dir) {
2026         case DATA_DIR_NONE:
2027                 break;                  // Nothing to send
2028
2029         /* If we don't know whether the host wants to read or write,
2030          * this must be CB or CBI with an unknown command.  We mustn't
2031          * try to send or receive any data.  So stall both bulk pipes
2032          * if we can and wait for a reset. */
2033         case DATA_DIR_UNKNOWN:
2034                 if (mod_data.can_stall) {
2035                         fsg_set_halt(fsg, fsg->bulk_out);
2036                         rc = halt_bulk_in_endpoint(fsg);
2037                 }
2038                 break;
2039
2040         /* All but the last buffer of data must have already been sent */
2041         case DATA_DIR_TO_HOST:
2042                 if (fsg->data_size == 0)
2043                         ;               // Nothing to send
2044
2045                 /* If there's no residue, simply send the last buffer */
2046                 else if (fsg->residue == 0) {
2047                         bh->inreq->zero = 0;
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                 /* There is a residue.  For CB and CBI, simply mark the end
2054                  * of the data with a short packet.  However, if we are
2055                  * allowed to stall, there was no data at all (residue ==
2056                  * data_size), and the command failed (invalid LUN or
2057                  * sense data is set), then halt the bulk-in endpoint
2058                  * instead. */
2059                 else if (!transport_is_bbb()) {
2060                         if (mod_data.can_stall &&
2061                                         fsg->residue == fsg->data_size &&
2062         (!fsg->curlun || fsg->curlun->sense_data != SS_NO_SENSE)) {
2063                                 bh->state = BUF_STATE_EMPTY;
2064                                 rc = halt_bulk_in_endpoint(fsg);
2065                         } else {
2066                                 bh->inreq->zero = 1;
2067                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2068                                                 &bh->inreq_busy, &bh->state);
2069                                 fsg->next_buffhd_to_fill = bh->next;
2070                         }
2071                 }
2072
2073                 /* For Bulk-only, if we're allowed to stall then send the
2074                  * short packet and halt the bulk-in endpoint.  If we can't
2075                  * stall, pad out the remaining data with 0's. */
2076                 else {
2077                         if (mod_data.can_stall) {
2078                                 bh->inreq->zero = 1;
2079                                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2080                                                 &bh->inreq_busy, &bh->state);
2081                                 fsg->next_buffhd_to_fill = bh->next;
2082                                 rc = halt_bulk_in_endpoint(fsg);
2083                         } else
2084                                 rc = pad_with_zeros(fsg);
2085                 }
2086                 break;
2087
2088         /* We have processed all we want from the data the host has sent.
2089          * There may still be outstanding bulk-out requests. */
2090         case DATA_DIR_FROM_HOST:
2091                 if (fsg->residue == 0)
2092                         ;               // Nothing to receive
2093
2094                 /* Did the host stop sending unexpectedly early? */
2095                 else if (fsg->short_packet_received) {
2096                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2097                         rc = -EINTR;
2098                 }
2099
2100                 /* We haven't processed all the incoming data.  Even though
2101                  * we may be allowed to stall, doing so would cause a race.
2102                  * The controller may already have ACK'ed all the remaining
2103                  * bulk-out packets, in which case the host wouldn't see a
2104                  * STALL.  Not realizing the endpoint was halted, it wouldn't
2105                  * clear the halt -- leading to problems later on. */
2106 #if 0
2107                 else if (mod_data.can_stall) {
2108                         fsg_set_halt(fsg, fsg->bulk_out);
2109                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
2110                         rc = -EINTR;
2111                 }
2112 #endif
2113
2114                 /* We can't stall.  Read in the excess data and throw it
2115                  * all away. */
2116                 else
2117                         rc = throw_away_data(fsg);
2118                 break;
2119         }
2120         return rc;
2121 }
2122
2123
2124 static int send_status(struct fsg_dev *fsg)
2125 {
2126         struct fsg_lun          *curlun = fsg->curlun;
2127         struct fsg_buffhd       *bh;
2128         int                     rc;
2129         u8                      status = USB_STATUS_PASS;
2130         u32                     sd, sdinfo = 0;
2131
2132         /* Wait for the next buffer to become available */
2133         bh = fsg->next_buffhd_to_fill;
2134         while (bh->state != BUF_STATE_EMPTY) {
2135                 rc = sleep_thread(fsg);
2136                 if (rc)
2137                         return rc;
2138         }
2139
2140         if (curlun) {
2141                 sd = curlun->sense_data;
2142                 sdinfo = curlun->sense_data_info;
2143         } else if (fsg->bad_lun_okay)
2144                 sd = SS_NO_SENSE;
2145         else
2146                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
2147
2148         if (fsg->phase_error) {
2149                 DBG(fsg, "sending phase-error status\n");
2150                 status = USB_STATUS_PHASE_ERROR;
2151                 sd = SS_INVALID_COMMAND;
2152         } else if (sd != SS_NO_SENSE) {
2153                 DBG(fsg, "sending command-failure status\n");
2154                 status = USB_STATUS_FAIL;
2155                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
2156                                 "  info x%x\n",
2157                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
2158         }
2159
2160         if (transport_is_bbb()) {
2161                 struct bulk_cs_wrap     *csw = bh->buf;
2162
2163                 /* Store and send the Bulk-only CSW */
2164                 csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
2165                 csw->Tag = fsg->tag;
2166                 csw->Residue = cpu_to_le32(fsg->residue);
2167                 csw->Status = status;
2168
2169                 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
2170                 bh->inreq->zero = 0;
2171                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
2172                                 &bh->inreq_busy, &bh->state);
2173
2174         } else if (mod_data.transport_type == USB_PR_CB) {
2175
2176                 /* Control-Bulk transport has no status phase! */
2177                 return 0;
2178
2179         } else {                        // USB_PR_CBI
2180                 struct interrupt_data   *buf = bh->buf;
2181
2182                 /* Store and send the Interrupt data.  UFI sends the ASC
2183                  * and ASCQ bytes.  Everything else sends a Type (which
2184                  * is always 0) and the status Value. */
2185                 if (mod_data.protocol_type == USB_SC_UFI) {
2186                         buf->bType = ASC(sd);
2187                         buf->bValue = ASCQ(sd);
2188                 } else {
2189                         buf->bType = 0;
2190                         buf->bValue = status;
2191                 }
2192                 fsg->intreq->length = CBI_INTERRUPT_DATA_LEN;
2193
2194                 fsg->intr_buffhd = bh;          // Point to the right buffhd
2195                 fsg->intreq->buf = bh->inreq->buf;
2196                 fsg->intreq->context = bh;
2197                 start_transfer(fsg, fsg->intr_in, fsg->intreq,
2198                                 &fsg->intreq_busy, &bh->state);
2199         }
2200
2201         fsg->next_buffhd_to_fill = bh->next;
2202         return 0;
2203 }
2204
2205
2206 /*-------------------------------------------------------------------------*/
2207
2208 /* Check whether the command is properly formed and whether its data size
2209  * and direction agree with the values we already have. */
2210 static int check_command(struct fsg_dev *fsg, int cmnd_size,
2211                 enum data_direction data_dir, unsigned int mask,
2212                 int needs_medium, const char *name)
2213 {
2214         int                     i;
2215         int                     lun = fsg->cmnd[1] >> 5;
2216         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
2217         char                    hdlen[20];
2218         struct fsg_lun          *curlun;
2219
2220         /* Adjust the expected cmnd_size for protocol encapsulation padding.
2221          * Transparent SCSI doesn't pad. */
2222         if (protocol_is_scsi())
2223                 ;
2224
2225         /* There's some disagreement as to whether RBC pads commands or not.
2226          * We'll play it safe and accept either form. */
2227         else if (mod_data.protocol_type == USB_SC_RBC) {
2228                 if (fsg->cmnd_size == 12)
2229                         cmnd_size = 12;
2230
2231         /* All the other protocols pad to 12 bytes */
2232         } else
2233                 cmnd_size = 12;
2234
2235         hdlen[0] = 0;
2236         if (fsg->data_dir != DATA_DIR_UNKNOWN)
2237                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
2238                                 fsg->data_size);
2239         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
2240                         name, cmnd_size, dirletter[(int) data_dir],
2241                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
2242
2243         /* We can't reply at all until we know the correct data direction
2244          * and size. */
2245         if (fsg->data_size_from_cmnd == 0)
2246                 data_dir = DATA_DIR_NONE;
2247         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
2248                 fsg->data_dir = data_dir;
2249                 fsg->data_size = fsg->data_size_from_cmnd;
2250
2251         } else {                                        // Bulk-only
2252                 if (fsg->data_size < fsg->data_size_from_cmnd) {
2253
2254                         /* Host data size < Device data size is a phase error.
2255                          * Carry out the command, but only transfer as much
2256                          * as we are allowed. */
2257                         fsg->data_size_from_cmnd = fsg->data_size;
2258                         fsg->phase_error = 1;
2259                 }
2260         }
2261         fsg->residue = fsg->usb_amount_left = fsg->data_size;
2262
2263         /* Conflicting data directions is a phase error */
2264         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
2265                 fsg->phase_error = 1;
2266                 return -EINVAL;
2267         }
2268
2269         /* Verify the length of the command itself */
2270         if (cmnd_size != fsg->cmnd_size) {
2271
2272                 /* Special case workaround: There are plenty of buggy SCSI
2273                  * implementations. Many have issues with cbw->Length
2274                  * field passing a wrong command size. For those cases we
2275                  * always try to work around the problem by using the length
2276                  * sent by the host side provided it is at least as large
2277                  * as the correct command length.
2278                  * Examples of such cases would be MS-Windows, which issues
2279                  * REQUEST SENSE with cbw->Length == 12 where it should
2280                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
2281                  * REQUEST SENSE with cbw->Length == 10 where it should
2282                  * be 6 as well.
2283                  */
2284                 if (cmnd_size <= fsg->cmnd_size) {
2285                         DBG(fsg, "%s is buggy! Expected length %d "
2286                                         "but we got %d\n", name,
2287                                         cmnd_size, fsg->cmnd_size);
2288                         cmnd_size = fsg->cmnd_size;
2289                 } else {
2290                         fsg->phase_error = 1;
2291                         return -EINVAL;
2292                 }
2293         }
2294
2295         /* Check that the LUN values are consistent */
2296         if (transport_is_bbb()) {
2297                 if (fsg->lun != lun)
2298                         DBG(fsg, "using LUN %d from CBW, "
2299                                         "not LUN %d from CDB\n",
2300                                         fsg->lun, lun);
2301         } else
2302                 fsg->lun = lun;         // Use LUN from the command
2303
2304         /* Check the LUN */
2305         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
2306                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
2307                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
2308                         curlun->sense_data = SS_NO_SENSE;
2309                         curlun->sense_data_info = 0;
2310                         curlun->info_valid = 0;
2311                 }
2312         } else {
2313                 fsg->curlun = curlun = NULL;
2314                 fsg->bad_lun_okay = 0;
2315
2316                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2317                  * to use unsupported LUNs; all others may not. */
2318                 if (fsg->cmnd[0] != SC_INQUIRY &&
2319                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2320                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2321                         return -EINVAL;
2322                 }
2323         }
2324
2325         /* If a unit attention condition exists, only INQUIRY and
2326          * REQUEST SENSE commands are allowed; anything else must fail. */
2327         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2328                         fsg->cmnd[0] != SC_INQUIRY &&
2329                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2330                 curlun->sense_data = curlun->unit_attention_data;
2331                 curlun->unit_attention_data = SS_NO_SENSE;
2332                 return -EINVAL;
2333         }
2334
2335         /* Check that only command bytes listed in the mask are non-zero */
2336         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2337         for (i = 1; i < cmnd_size; ++i) {
2338                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2339                         if (curlun)
2340                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2341                         return -EINVAL;
2342                 }
2343         }
2344
2345         /* If the medium isn't mounted and the command needs to access
2346          * it, return an error. */
2347         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
2348                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2349                 return -EINVAL;
2350         }
2351
2352         return 0;
2353 }
2354
2355
2356 static int do_scsi_command(struct fsg_dev *fsg)
2357 {
2358         struct fsg_buffhd       *bh;
2359         int                     rc;
2360         int                     reply = -EINVAL;
2361         int                     i;
2362         static char             unknown[16];
2363
2364         dump_cdb(fsg);
2365
2366         /* Wait for the next buffer to become available for data or status */
2367         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2368         while (bh->state != BUF_STATE_EMPTY) {
2369                 rc = sleep_thread(fsg);
2370                 if (rc)
2371                         return rc;
2372         }
2373         fsg->phase_error = 0;
2374         fsg->short_packet_received = 0;
2375
2376         down_read(&fsg->filesem);       // We're using the backing file
2377         switch (fsg->cmnd[0]) {
2378
2379         case SC_INQUIRY:
2380                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2381                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2382                                 (1<<4), 0,
2383                                 "INQUIRY")) == 0)
2384                         reply = do_inquiry(fsg, bh);
2385                 break;
2386
2387         case SC_MODE_SELECT_6:
2388                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2389                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2390                                 (1<<1) | (1<<4), 0,
2391                                 "MODE SELECT(6)")) == 0)
2392                         reply = do_mode_select(fsg, bh);
2393                 break;
2394
2395         case SC_MODE_SELECT_10:
2396                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2397                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2398                                 (1<<1) | (3<<7), 0,
2399                                 "MODE SELECT(10)")) == 0)
2400                         reply = do_mode_select(fsg, bh);
2401                 break;
2402
2403         case SC_MODE_SENSE_6:
2404                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2405                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2406                                 (1<<1) | (1<<2) | (1<<4), 0,
2407                                 "MODE SENSE(6)")) == 0)
2408                         reply = do_mode_sense(fsg, bh);
2409                 break;
2410
2411         case SC_MODE_SENSE_10:
2412                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2413                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2414                                 (1<<1) | (1<<2) | (3<<7), 0,
2415                                 "MODE SENSE(10)")) == 0)
2416                         reply = do_mode_sense(fsg, bh);
2417                 break;
2418
2419         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2420                 fsg->data_size_from_cmnd = 0;
2421                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2422                                 (1<<4), 0,
2423                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2424                         reply = do_prevent_allow(fsg);
2425                 break;
2426
2427         case SC_READ_6:
2428                 i = fsg->cmnd[4];
2429                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2430                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2431                                 (7<<1) | (1<<4), 1,
2432                                 "READ(6)")) == 0)
2433                         reply = do_read(fsg);
2434                 break;
2435
2436         case SC_READ_10:
2437                 fsg->data_size_from_cmnd =
2438                                 get_unaligned_be16(&fsg->cmnd[7]) << 9;
2439                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2440                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2441                                 "READ(10)")) == 0)
2442                         reply = do_read(fsg);
2443                 break;
2444
2445         case SC_READ_12:
2446                 fsg->data_size_from_cmnd =
2447                                 get_unaligned_be32(&fsg->cmnd[6]) << 9;
2448                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2449                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2450                                 "READ(12)")) == 0)
2451                         reply = do_read(fsg);
2452                 break;
2453
2454         case SC_READ_CAPACITY:
2455                 fsg->data_size_from_cmnd = 8;
2456                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2457                                 (0xf<<2) | (1<<8), 1,
2458                                 "READ CAPACITY")) == 0)
2459                         reply = do_read_capacity(fsg, bh);
2460                 break;
2461
2462         case SC_READ_HEADER:
2463                 if (!mod_data.cdrom)
2464                         goto unknown_cmnd;
2465                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2466                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2467                                 (3<<7) | (0x1f<<1), 1,
2468                                 "READ HEADER")) == 0)
2469                         reply = do_read_header(fsg, bh);
2470                 break;
2471
2472         case SC_READ_TOC:
2473                 if (!mod_data.cdrom)
2474                         goto unknown_cmnd;
2475                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2476                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2477                                 (7<<6) | (1<<1), 1,
2478                                 "READ TOC")) == 0)
2479                         reply = do_read_toc(fsg, bh);
2480                 break;
2481
2482         case SC_READ_FORMAT_CAPACITIES:
2483                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2484                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2485                                 (3<<7), 1,
2486                                 "READ FORMAT CAPACITIES")) == 0)
2487                         reply = do_read_format_capacities(fsg, bh);
2488                 break;
2489
2490         case SC_REQUEST_SENSE:
2491                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2492                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2493                                 (1<<4), 0,
2494                                 "REQUEST SENSE")) == 0)
2495                         reply = do_request_sense(fsg, bh);
2496                 break;
2497
2498         case SC_START_STOP_UNIT:
2499                 fsg->data_size_from_cmnd = 0;
2500                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2501                                 (1<<1) | (1<<4), 0,
2502                                 "START-STOP UNIT")) == 0)
2503                         reply = do_start_stop(fsg);
2504                 break;
2505
2506         case SC_SYNCHRONIZE_CACHE:
2507                 fsg->data_size_from_cmnd = 0;
2508                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2509                                 (0xf<<2) | (3<<7), 1,
2510                                 "SYNCHRONIZE CACHE")) == 0)
2511                         reply = do_synchronize_cache(fsg);
2512                 break;
2513
2514         case SC_TEST_UNIT_READY:
2515                 fsg->data_size_from_cmnd = 0;
2516                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2517                                 0, 1,
2518                                 "TEST UNIT READY");
2519                 break;
2520
2521         /* Although optional, this command is used by MS-Windows.  We
2522          * support a minimal version: BytChk must be 0. */
2523         case SC_VERIFY:
2524                 fsg->data_size_from_cmnd = 0;
2525                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2526                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2527                                 "VERIFY")) == 0)
2528                         reply = do_verify(fsg);
2529                 break;
2530
2531         case SC_WRITE_6:
2532                 i = fsg->cmnd[4];
2533                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2534                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2535                                 (7<<1) | (1<<4), 1,
2536                                 "WRITE(6)")) == 0)
2537                         reply = do_write(fsg);
2538                 break;
2539
2540         case SC_WRITE_10:
2541                 fsg->data_size_from_cmnd =
2542                                 get_unaligned_be16(&fsg->cmnd[7]) << 9;
2543                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2544                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2545                                 "WRITE(10)")) == 0)
2546                         reply = do_write(fsg);
2547                 break;
2548
2549         case SC_WRITE_12:
2550                 fsg->data_size_from_cmnd =
2551                                 get_unaligned_be32(&fsg->cmnd[6]) << 9;
2552                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2553                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2554                                 "WRITE(12)")) == 0)
2555                         reply = do_write(fsg);
2556                 break;
2557
2558         /* Some mandatory commands that we recognize but don't implement.
2559          * They don't mean much in this setting.  It's left as an exercise
2560          * for anyone interested to implement RESERVE and RELEASE in terms
2561          * of Posix locks. */
2562         case SC_FORMAT_UNIT:
2563         case SC_RELEASE:
2564         case SC_RESERVE:
2565         case SC_SEND_DIAGNOSTIC:
2566                 // Fall through
2567
2568         default:
2569  unknown_cmnd:
2570                 fsg->data_size_from_cmnd = 0;
2571                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2572                 if ((reply = check_command(fsg, fsg->cmnd_size,
2573                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2574                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2575                         reply = -EINVAL;
2576                 }
2577                 break;
2578         }
2579         up_read(&fsg->filesem);
2580
2581         if (reply == -EINTR || signal_pending(current))
2582                 return -EINTR;
2583
2584         /* Set up the single reply buffer for finish_reply() */
2585         if (reply == -EINVAL)
2586                 reply = 0;              // Error reply length
2587         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2588                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2589                 bh->inreq->length = reply;
2590                 bh->state = BUF_STATE_FULL;
2591                 fsg->residue -= reply;
2592         }                               // Otherwise it's already set
2593
2594         return 0;
2595 }
2596
2597
2598 /*-------------------------------------------------------------------------*/
2599
2600 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2601 {
2602         struct usb_request              *req = bh->outreq;
2603         struct fsg_bulk_cb_wrap *cbw = req->buf;
2604
2605         /* Was this a real packet?  Should it be ignored? */
2606         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2607                 return -EINVAL;
2608
2609         /* Is the CBW valid? */
2610         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2611                         cbw->Signature != cpu_to_le32(
2612                                 USB_BULK_CB_SIG)) {
2613                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2614                                 req->actual,
2615                                 le32_to_cpu(cbw->Signature));
2616
2617                 /* The Bulk-only spec says we MUST stall the IN endpoint
2618                  * (6.6.1), so it's unavoidable.  It also says we must
2619                  * retain this state until the next reset, but there's
2620                  * no way to tell the controller driver it should ignore
2621                  * Clear-Feature(HALT) requests.
2622                  *
2623                  * We aren't required to halt the OUT endpoint; instead
2624                  * we can simply accept and discard any data received
2625                  * until the next reset. */
2626                 wedge_bulk_in_endpoint(fsg);
2627                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2628                 return -EINVAL;
2629         }
2630
2631         /* Is the CBW meaningful? */
2632         if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2633                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2634                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2635                                 "cmdlen %u\n",
2636                                 cbw->Lun, cbw->Flags, cbw->Length);
2637
2638                 /* We can do anything we want here, so let's stall the
2639                  * bulk pipes if we are allowed to. */
2640                 if (mod_data.can_stall) {
2641                         fsg_set_halt(fsg, fsg->bulk_out);
2642                         halt_bulk_in_endpoint(fsg);
2643                 }
2644                 return -EINVAL;
2645         }
2646
2647         /* Save the command for later */
2648         fsg->cmnd_size = cbw->Length;
2649         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
2650         if (cbw->Flags & USB_BULK_IN_FLAG)
2651                 fsg->data_dir = DATA_DIR_TO_HOST;
2652         else
2653                 fsg->data_dir = DATA_DIR_FROM_HOST;
2654         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
2655         if (fsg->data_size == 0)
2656                 fsg->data_dir = DATA_DIR_NONE;
2657         fsg->lun = cbw->Lun;
2658         fsg->tag = cbw->Tag;
2659         return 0;
2660 }
2661
2662
2663 static int get_next_command(struct fsg_dev *fsg)
2664 {
2665         struct fsg_buffhd       *bh;
2666         int                     rc = 0;
2667
2668         if (transport_is_bbb()) {
2669
2670                 /* Wait for the next buffer to become available */
2671                 bh = fsg->next_buffhd_to_fill;
2672                 while (bh->state != BUF_STATE_EMPTY) {
2673                         rc = sleep_thread(fsg);
2674                         if (rc)
2675                                 return rc;
2676                 }
2677
2678                 /* Queue a request to read a Bulk-only CBW */
2679                 set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
2680                 bh->outreq->short_not_ok = 1;
2681                 start_transfer(fsg, fsg->bulk_out, bh->outreq,
2682                                 &bh->outreq_busy, &bh->state);
2683
2684                 /* We will drain the buffer in software, which means we
2685                  * can reuse it for the next filling.  No need to advance
2686                  * next_buffhd_to_fill. */
2687
2688                 /* Wait for the CBW to arrive */
2689                 while (bh->state != BUF_STATE_FULL) {
2690                         rc = sleep_thread(fsg);
2691                         if (rc)
2692                                 return rc;
2693                 }
2694                 smp_rmb();
2695                 rc = received_cbw(fsg, bh);
2696                 bh->state = BUF_STATE_EMPTY;
2697
2698         } else {                // USB_PR_CB or USB_PR_CBI
2699
2700                 /* Wait for the next command to arrive */
2701                 while (fsg->cbbuf_cmnd_size == 0) {
2702                         rc = sleep_thread(fsg);
2703                         if (rc)
2704                                 return rc;
2705                 }
2706
2707                 /* Is the previous status interrupt request still busy?
2708                  * The host is allowed to skip reading the status,
2709                  * so we must cancel it. */
2710                 if (fsg->intreq_busy)
2711                         usb_ep_dequeue(fsg->intr_in, fsg->intreq);
2712
2713                 /* Copy the command and mark the buffer empty */
2714                 fsg->data_dir = DATA_DIR_UNKNOWN;
2715                 spin_lock_irq(&fsg->lock);
2716                 fsg->cmnd_size = fsg->cbbuf_cmnd_size;
2717                 memcpy(fsg->cmnd, fsg->cbbuf_cmnd, fsg->cmnd_size);
2718                 fsg->cbbuf_cmnd_size = 0;
2719                 spin_unlock_irq(&fsg->lock);
2720         }
2721         return rc;
2722 }
2723
2724
2725 /*-------------------------------------------------------------------------*/
2726
2727 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
2728                 const struct usb_endpoint_descriptor *d)
2729 {
2730         int     rc;
2731
2732         ep->driver_data = fsg;
2733         rc = usb_ep_enable(ep, d);
2734         if (rc)
2735                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
2736         return rc;
2737 }
2738
2739 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
2740                 struct usb_request **preq)
2741 {
2742         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2743         if (*preq)
2744                 return 0;
2745         ERROR(fsg, "can't allocate request for %s\n", ep->name);
2746         return -ENOMEM;
2747 }
2748
2749 /*
2750  * Reset interface setting and re-init endpoint state (toggle etc).
2751  * Call with altsetting < 0 to disable the interface.  The only other
2752  * available altsetting is 0, which enables the interface.
2753  */
2754 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
2755 {
2756         int     rc = 0;
2757         int     i;
2758         const struct usb_endpoint_descriptor    *d;
2759
2760         if (fsg->running)
2761                 DBG(fsg, "reset interface\n");
2762
2763 reset:
2764         /* Deallocate the requests */
2765         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2766                 struct fsg_buffhd *bh = &fsg->buffhds[i];
2767
2768                 if (bh->inreq) {
2769                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
2770                         bh->inreq = NULL;
2771                 }
2772                 if (bh->outreq) {
2773                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
2774                         bh->outreq = NULL;
2775                 }
2776         }
2777         if (fsg->intreq) {
2778                 usb_ep_free_request(fsg->intr_in, fsg->intreq);
2779                 fsg->intreq = NULL;
2780         }
2781
2782         /* Disable the endpoints */
2783         if (fsg->bulk_in_enabled) {
2784                 usb_ep_disable(fsg->bulk_in);
2785                 fsg->bulk_in_enabled = 0;
2786         }
2787         if (fsg->bulk_out_enabled) {
2788                 usb_ep_disable(fsg->bulk_out);
2789                 fsg->bulk_out_enabled = 0;
2790         }
2791         if (fsg->intr_in_enabled) {
2792                 usb_ep_disable(fsg->intr_in);
2793                 fsg->intr_in_enabled = 0;
2794         }
2795
2796         fsg->running = 0;
2797         if (altsetting < 0 || rc != 0)
2798                 return rc;
2799
2800         DBG(fsg, "set interface %d\n", altsetting);
2801
2802         /* Enable the endpoints */
2803         d = fsg_ep_desc(fsg->gadget,
2804                         &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
2805         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
2806                 goto reset;
2807         fsg->bulk_in_enabled = 1;
2808
2809         d = fsg_ep_desc(fsg->gadget,
2810                         &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
2811         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
2812                 goto reset;
2813         fsg->bulk_out_enabled = 1;
2814         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
2815         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2816
2817         if (transport_is_cbi()) {
2818                 d = fsg_ep_desc(fsg->gadget,
2819                                 &fsg_fs_intr_in_desc, &fsg_hs_intr_in_desc);
2820                 if ((rc = enable_endpoint(fsg, fsg->intr_in, d)) != 0)
2821                         goto reset;
2822                 fsg->intr_in_enabled = 1;
2823         }
2824
2825         /* Allocate the requests */
2826         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2827                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
2828
2829                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
2830                         goto reset;
2831                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
2832                         goto reset;
2833                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2834                 bh->inreq->context = bh->outreq->context = bh;
2835                 bh->inreq->complete = bulk_in_complete;
2836                 bh->outreq->complete = bulk_out_complete;
2837         }
2838         if (transport_is_cbi()) {
2839                 if ((rc = alloc_request(fsg, fsg->intr_in, &fsg->intreq)) != 0)
2840                         goto reset;
2841                 fsg->intreq->complete = intr_in_complete;
2842         }
2843
2844         fsg->running = 1;
2845         for (i = 0; i < fsg->nluns; ++i)
2846                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2847         return rc;
2848 }
2849
2850
2851 /*
2852  * Change our operational configuration.  This code must agree with the code
2853  * that returns config descriptors, and with interface altsetting code.
2854  *
2855  * It's also responsible for power management interactions.  Some
2856  * configurations might not work with our current power sources.
2857  * For now we just assume the gadget is always self-powered.
2858  */
2859 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
2860 {
2861         int     rc = 0;
2862
2863         /* Disable the single interface */
2864         if (fsg->config != 0) {
2865                 DBG(fsg, "reset config\n");
2866                 fsg->config = 0;
2867                 rc = do_set_interface(fsg, -1);
2868         }
2869
2870         /* Enable the interface */
2871         if (new_config != 0) {
2872                 fsg->config = new_config;
2873                 if ((rc = do_set_interface(fsg, 0)) != 0)
2874                         fsg->config = 0;        // Reset on errors
2875                 else {
2876                         char *speed;
2877
2878                         switch (fsg->gadget->speed) {
2879                         case USB_SPEED_LOW:     speed = "low";  break;
2880                         case USB_SPEED_FULL:    speed = "full"; break;
2881                         case USB_SPEED_HIGH:    speed = "high"; break;
2882                         default:                speed = "?";    break;
2883                         }
2884                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
2885                 }
2886         }
2887         return rc;
2888 }
2889
2890
2891 /*-------------------------------------------------------------------------*/
2892
2893 static void handle_exception(struct fsg_dev *fsg)
2894 {
2895         siginfo_t               info;
2896         int                     sig;
2897         int                     i;
2898         int                     num_active;
2899         struct fsg_buffhd       *bh;
2900         enum fsg_state          old_state;
2901         u8                      new_config;
2902         struct fsg_lun          *curlun;
2903         unsigned int            exception_req_tag;
2904         int                     rc;
2905
2906         /* Clear the existing signals.  Anything but SIGUSR1 is converted
2907          * into a high-priority EXIT exception. */
2908         for (;;) {
2909                 sig = dequeue_signal_lock(current, &current->blocked, &info);
2910                 if (!sig)
2911                         break;
2912                 if (sig != SIGUSR1) {
2913                         if (fsg->state < FSG_STATE_EXIT)
2914                                 DBG(fsg, "Main thread exiting on signal\n");
2915                         raise_exception(fsg, FSG_STATE_EXIT);
2916                 }
2917         }
2918
2919         /* Cancel all the pending transfers */
2920         if (fsg->intreq_busy)
2921                 usb_ep_dequeue(fsg->intr_in, fsg->intreq);
2922         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2923                 bh = &fsg->buffhds[i];
2924                 if (bh->inreq_busy)
2925                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
2926                 if (bh->outreq_busy)
2927                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
2928         }
2929
2930         /* Wait until everything is idle */
2931         for (;;) {
2932                 num_active = fsg->intreq_busy;
2933                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2934                         bh = &fsg->buffhds[i];
2935                         num_active += bh->inreq_busy + bh->outreq_busy;
2936                 }
2937                 if (num_active == 0)
2938                         break;
2939                 if (sleep_thread(fsg))
2940                         return;
2941         }
2942
2943         /* Clear out the controller's fifos */
2944         if (fsg->bulk_in_enabled)
2945                 usb_ep_fifo_flush(fsg->bulk_in);
2946         if (fsg->bulk_out_enabled)
2947                 usb_ep_fifo_flush(fsg->bulk_out);
2948         if (fsg->intr_in_enabled)
2949                 usb_ep_fifo_flush(fsg->intr_in);
2950
2951         /* Reset the I/O buffer states and pointers, the SCSI
2952          * state, and the exception.  Then invoke the handler. */
2953         spin_lock_irq(&fsg->lock);
2954
2955         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2956                 bh = &fsg->buffhds[i];
2957                 bh->state = BUF_STATE_EMPTY;
2958         }
2959         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
2960                         &fsg->buffhds[0];
2961
2962         exception_req_tag = fsg->exception_req_tag;
2963         new_config = fsg->new_config;
2964         old_state = fsg->state;
2965
2966         if (old_state == FSG_STATE_ABORT_BULK_OUT)
2967                 fsg->state = FSG_STATE_STATUS_PHASE;
2968         else {
2969                 for (i = 0; i < fsg->nluns; ++i) {
2970                         curlun = &fsg->luns[i];
2971                         curlun->prevent_medium_removal = 0;
2972                         curlun->sense_data = curlun->unit_attention_data =
2973                                         SS_NO_SENSE;
2974                         curlun->sense_data_info = 0;
2975                         curlun->info_valid = 0;
2976                 }
2977                 fsg->state = FSG_STATE_IDLE;
2978         }
2979         spin_unlock_irq(&fsg->lock);
2980
2981         /* Carry out any extra actions required for the exception */
2982         switch (old_state) {
2983         default:
2984                 break;
2985
2986         case FSG_STATE_ABORT_BULK_OUT:
2987                 send_status(fsg);
2988                 spin_lock_irq(&fsg->lock);
2989                 if (fsg->state == FSG_STATE_STATUS_PHASE)
2990                         fsg->state = FSG_STATE_IDLE;
2991                 spin_unlock_irq(&fsg->lock);
2992                 break;
2993
2994         case FSG_STATE_RESET:
2995                 /* In case we were forced against our will to halt a
2996                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2997                  * requires this.) */
2998                 if (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2999                         usb_ep_clear_halt(fsg->bulk_in);
3000
3001                 if (transport_is_bbb()) {
3002                         if (fsg->ep0_req_tag == exception_req_tag)
3003                                 ep0_queue(fsg); // Complete the status stage
3004
3005                 } else if (transport_is_cbi())
3006                         send_status(fsg);       // Status by interrupt pipe
3007
3008                 /* Technically this should go here, but it would only be
3009                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
3010                  * CONFIG_CHANGE cases. */
3011                 // for (i = 0; i < fsg->nluns; ++i)
3012                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
3013                 break;
3014
3015         case FSG_STATE_INTERFACE_CHANGE:
3016                 rc = do_set_interface(fsg, 0);
3017                 if (fsg->ep0_req_tag != exception_req_tag)
3018                         break;
3019                 if (rc != 0)                    // STALL on errors
3020                         fsg_set_halt(fsg, fsg->ep0);
3021                 else                            // Complete the status stage
3022                         ep0_queue(fsg);
3023                 break;
3024
3025         case FSG_STATE_CONFIG_CHANGE:
3026                 rc = do_set_config(fsg, new_config);
3027                 if (fsg->ep0_req_tag != exception_req_tag)
3028                         break;
3029                 if (rc != 0)                    // STALL on errors
3030                         fsg_set_halt(fsg, fsg->ep0);
3031                 else                            // Complete the status stage
3032                         ep0_queue(fsg);
3033                 break;
3034
3035         case FSG_STATE_DISCONNECT:
3036                 for (i = 0; i < fsg->nluns; ++i)
3037                         fsg_lun_fsync_sub(fsg->luns + i);
3038                 do_set_config(fsg, 0);          // Unconfigured state
3039                 break;
3040
3041         case FSG_STATE_EXIT:
3042         case FSG_STATE_TERMINATED:
3043                 do_set_config(fsg, 0);                  // Free resources
3044                 spin_lock_irq(&fsg->lock);
3045                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
3046                 spin_unlock_irq(&fsg->lock);
3047                 break;
3048         }
3049 }
3050
3051
3052 /*-------------------------------------------------------------------------*/
3053
3054 static int fsg_main_thread(void *fsg_)
3055 {
3056         struct fsg_dev          *fsg = fsg_;
3057
3058         /* Allow the thread to be killed by a signal, but set the signal mask
3059          * to block everything but INT, TERM, KILL, and USR1. */
3060         allow_signal(SIGINT);
3061         allow_signal(SIGTERM);
3062         allow_signal(SIGKILL);
3063         allow_signal(SIGUSR1);
3064
3065         /* Allow the thread to be frozen */
3066         set_freezable();
3067
3068         /* Arrange for userspace references to be interpreted as kernel
3069          * pointers.  That way we can pass a kernel pointer to a routine
3070          * that expects a __user pointer and it will work okay. */
3071         set_fs(get_ds());
3072
3073         /* The main loop */
3074         while (fsg->state != FSG_STATE_TERMINATED) {
3075                 if (exception_in_progress(fsg) || signal_pending(current)) {
3076                         handle_exception(fsg);
3077                         continue;
3078                 }
3079
3080                 if (!fsg->running) {
3081                         sleep_thread(fsg);
3082                         continue;
3083                 }
3084
3085                 if (get_next_command(fsg))
3086                         continue;
3087
3088                 spin_lock_irq(&fsg->lock);
3089                 if (!exception_in_progress(fsg))
3090                         fsg->state = FSG_STATE_DATA_PHASE;
3091                 spin_unlock_irq(&fsg->lock);
3092
3093                 if (do_scsi_command(fsg) || finish_reply(fsg))
3094                         continue;
3095
3096                 spin_lock_irq(&fsg->lock);
3097                 if (!exception_in_progress(fsg))
3098                         fsg->state = FSG_STATE_STATUS_PHASE;
3099                 spin_unlock_irq(&fsg->lock);
3100
3101                 if (send_status(fsg))
3102                         continue;
3103
3104                 spin_lock_irq(&fsg->lock);
3105                 if (!exception_in_progress(fsg))
3106                         fsg->state = FSG_STATE_IDLE;
3107                 spin_unlock_irq(&fsg->lock);
3108                 }
3109
3110         spin_lock_irq(&fsg->lock);
3111         fsg->thread_task = NULL;
3112         spin_unlock_irq(&fsg->lock);
3113
3114         /* If we are exiting because of a signal, unregister the
3115          * gadget driver. */
3116         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
3117                 usb_gadget_unregister_driver(&fsg_driver);
3118
3119         /* Let the unbind and cleanup routines know the thread has exited */
3120         complete_and_exit(&fsg->thread_notifier, 0);
3121 }
3122
3123
3124 /*-------------------------------------------------------------------------*/
3125
3126
3127 /* The write permissions and store_xxx pointers are set in fsg_bind() */
3128 static DEVICE_ATTR(ro, 0444, fsg_show_ro, NULL);
3129 static DEVICE_ATTR(file, 0444, fsg_show_file, NULL);
3130
3131
3132 /*-------------------------------------------------------------------------*/
3133
3134 static void fsg_release(struct kref *ref)
3135 {
3136         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
3137
3138         kfree(fsg->luns);
3139         kfree(fsg);
3140 }
3141
3142 static void lun_release(struct device *dev)
3143 {
3144         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
3145         struct fsg_dev          *fsg =
3146                 container_of(filesem, struct fsg_dev, filesem);
3147
3148         kref_put(&fsg->ref, fsg_release);
3149 }
3150
3151 static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
3152 {
3153         struct fsg_dev          *fsg = get_gadget_data(gadget);
3154         int                     i;
3155         struct fsg_lun          *curlun;
3156         struct usb_request      *req = fsg->ep0req;
3157
3158         DBG(fsg, "unbind\n");
3159         clear_bit(REGISTERED, &fsg->atomic_bitflags);
3160
3161         /* Unregister the sysfs attribute files and the LUNs */
3162         for (i = 0; i < fsg->nluns; ++i) {
3163                 curlun = &fsg->luns[i];
3164                 if (curlun->registered) {
3165                         device_remove_file(&curlun->dev, &dev_attr_ro);
3166                         device_remove_file(&curlun->dev, &dev_attr_file);
3167                         fsg_lun_close(curlun);
3168                         device_unregister(&curlun->dev);
3169                         curlun->registered = 0;
3170                 }
3171         }
3172
3173         /* If the thread isn't already dead, tell it to exit now */
3174         if (fsg->state != FSG_STATE_TERMINATED) {
3175                 raise_exception(fsg, FSG_STATE_EXIT);
3176                 wait_for_completion(&fsg->thread_notifier);
3177
3178                 /* The cleanup routine waits for this completion also */
3179                 complete(&fsg->thread_notifier);
3180         }
3181
3182         /* Free the data buffers */
3183         for (i = 0; i < FSG_NUM_BUFFERS; ++i)
3184                 kfree(fsg->buffhds[i].buf);
3185
3186         /* Free the request and buffer for endpoint 0 */
3187         if (req) {
3188                 kfree(req->buf);
3189                 usb_ep_free_request(fsg->ep0, req);
3190         }
3191
3192         set_gadget_data(gadget, NULL);
3193 }
3194
3195
3196 static int __init check_parameters(struct fsg_dev *fsg)
3197 {
3198         int     prot;
3199         int     gcnum;
3200
3201         /* Store the default values */
3202         mod_data.transport_type = USB_PR_BULK;
3203         mod_data.transport_name = "Bulk-only";
3204         mod_data.protocol_type = USB_SC_SCSI;
3205         mod_data.protocol_name = "Transparent SCSI";
3206
3207         /* Some peripheral controllers are known not to be able to
3208          * halt bulk endpoints correctly.  If one of them is present,
3209          * disable stalls.
3210          */
3211         if (gadget_is_at91(fsg->gadget))
3212                 mod_data.can_stall = 0;
3213
3214         if (mod_data.release == 0xffff) {       // Parameter wasn't set
3215                 gcnum = usb_gadget_controller_number(fsg->gadget);
3216                 if (gcnum >= 0)
3217                         mod_data.release = 0x0300 + gcnum;
3218                 else {
3219                         WARNING(fsg, "controller '%s' not recognized\n",
3220                                 fsg->gadget->name);
3221                         mod_data.release = 0x0399;
3222                 }
3223         }
3224
3225         prot = simple_strtol(mod_data.protocol_parm, NULL, 0);
3226
3227 #ifdef CONFIG_USB_FILE_STORAGE_TEST
3228         if (strnicmp(mod_data.transport_parm, "BBB", 10) == 0) {
3229                 ;               // Use default setting
3230         } else if (strnicmp(mod_data.transport_parm, "CB", 10) == 0) {
3231                 mod_data.transport_type = USB_PR_CB;
3232                 mod_data.transport_name = "Control-Bulk";
3233         } else if (strnicmp(mod_data.transport_parm, "CBI", 10) == 0) {
3234                 mod_data.transport_type = USB_PR_CBI;
3235                 mod_data.transport_name = "Control-Bulk-Interrupt";
3236         } else {
3237                 ERROR(fsg, "invalid transport: %s\n", mod_data.transport_parm);
3238                 return -EINVAL;
3239         }
3240
3241         if (strnicmp(mod_data.protocol_parm, "SCSI", 10) == 0 ||
3242                         prot == USB_SC_SCSI) {
3243                 ;               // Use default setting
3244         } else if (strnicmp(mod_data.protocol_parm, "RBC", 10) == 0 ||
3245                         prot == USB_SC_RBC) {
3246                 mod_data.protocol_type = USB_SC_RBC;
3247                 mod_data.protocol_name = "RBC";
3248         } else if (strnicmp(mod_data.protocol_parm, "8020", 4) == 0 ||
3249                         strnicmp(mod_data.protocol_parm, "ATAPI", 10) == 0 ||
3250                         prot == USB_SC_8020) {
3251                 mod_data.protocol_type = USB_SC_8020;
3252                 mod_data.protocol_name = "8020i (ATAPI)";
3253         } else if (strnicmp(mod_data.protocol_parm, "QIC", 3) == 0 ||
3254                         prot == USB_SC_QIC) {
3255                 mod_data.protocol_type = USB_SC_QIC;
3256                 mod_data.protocol_name = "QIC-157";
3257         } else if (strnicmp(mod_data.protocol_parm, "UFI", 10) == 0 ||
3258                         prot == USB_SC_UFI) {
3259                 mod_data.protocol_type = USB_SC_UFI;
3260                 mod_data.protocol_name = "UFI";
3261         } else if (strnicmp(mod_data.protocol_parm, "8070", 4) == 0 ||
3262                         prot == USB_SC_8070) {
3263                 mod_data.protocol_type = USB_SC_8070;
3264                 mod_data.protocol_name = "8070i";
3265         } else {
3266                 ERROR(fsg, "invalid protocol: %s\n", mod_data.protocol_parm);
3267                 return -EINVAL;
3268         }
3269
3270         mod_data.buflen &= PAGE_CACHE_MASK;
3271         if (mod_data.buflen <= 0) {
3272                 ERROR(fsg, "invalid buflen\n");
3273                 return -ETOOSMALL;
3274         }
3275 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
3276
3277         return 0;
3278 }
3279
3280
3281 static int __init fsg_bind(struct usb_gadget *gadget)
3282 {
3283         struct fsg_dev          *fsg = the_fsg;
3284         int                     rc;
3285         int                     i;
3286         struct fsg_lun          *curlun;
3287         struct usb_ep           *ep;
3288         struct usb_request      *req;
3289         char                    *pathbuf, *p;
3290
3291         fsg->gadget = gadget;
3292         set_gadget_data(gadget, fsg);
3293         fsg->ep0 = gadget->ep0;
3294         fsg->ep0->driver_data = fsg;
3295
3296         if ((rc = check_parameters(fsg)) != 0)
3297                 goto out;
3298
3299         if (mod_data.removable) {       // Enable the store_xxx attributes
3300                 dev_attr_file.attr.mode = 0644;
3301                 dev_attr_file.store = fsg_store_file;
3302                 if (!mod_data.cdrom) {
3303                         dev_attr_ro.attr.mode = 0644;
3304                         dev_attr_ro.store = fsg_store_ro;
3305                 }
3306         }
3307
3308         /* Find out how many LUNs there should be */
3309         i = mod_data.nluns;
3310         if (i == 0)
3311                 i = max(mod_data.num_filenames, 1u);
3312         if (i > FSG_MAX_LUNS) {
3313                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
3314                 rc = -EINVAL;
3315                 goto out;
3316         }
3317
3318         /* Create the LUNs, open their backing files, and register the
3319          * LUN devices in sysfs. */
3320         fsg->luns = kzalloc(i * sizeof(struct fsg_lun), GFP_KERNEL);
3321         if (!fsg->luns) {
3322                 rc = -ENOMEM;
3323                 goto out;
3324         }
3325         fsg->nluns = i;
3326
3327         for (i = 0; i < fsg->nluns; ++i) {
3328                 curlun = &fsg->luns[i];
3329                 curlun->cdrom = !!mod_data.cdrom;
3330                 curlun->ro = mod_data.cdrom || mod_data.ro[i];
3331                 curlun->initially_ro = curlun->ro;
3332                 curlun->removable = mod_data.removable;
3333                 curlun->dev.release = lun_release;
3334                 curlun->dev.parent = &gadget->dev;
3335                 curlun->dev.driver = &fsg_driver.driver;
3336                 dev_set_drvdata(&curlun->dev, &fsg->filesem);
3337                 dev_set_name(&curlun->dev,"%s-lun%d",
3338                              dev_name(&gadget->dev), i);
3339
3340                 if ((rc = device_register(&curlun->dev)) != 0) {
3341                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
3342                         goto out;
3343                 }
3344                 if ((rc = device_create_file(&curlun->dev,
3345                                         &dev_attr_ro)) != 0 ||
3346                                 (rc = device_create_file(&curlun->dev,
3347                                         &dev_attr_file)) != 0) {
3348                         device_unregister(&curlun->dev);
3349                         goto out;
3350                 }
3351                 curlun->registered = 1;
3352                 kref_get(&fsg->ref);
3353
3354                 if (mod_data.file[i] && *mod_data.file[i]) {
3355                         if ((rc = fsg_lun_open(curlun,
3356                                         mod_data.file[i])) != 0)
3357                                 goto out;
3358                 } else if (!mod_data.removable) {
3359                         ERROR(fsg, "no file given for LUN%d\n", i);
3360                         rc = -EINVAL;
3361                         goto out;
3362                 }
3363         }
3364
3365         /* Find all the endpoints we will use */
3366         usb_ep_autoconfig_reset(gadget);
3367         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
3368         if (!ep)
3369                 goto autoconf_fail;
3370         ep->driver_data = fsg;          // claim the endpoint
3371         fsg->bulk_in = ep;
3372
3373         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
3374         if (!ep)
3375                 goto autoconf_fail;
3376         ep->driver_data = fsg;          // claim the endpoint
3377         fsg->bulk_out = ep;
3378
3379         if (transport_is_cbi()) {
3380                 ep = usb_ep_autoconfig(gadget, &fsg_fs_intr_in_desc);
3381                 if (!ep)
3382                         goto autoconf_fail;
3383                 ep->driver_data = fsg;          // claim the endpoint
3384                 fsg->intr_in = ep;
3385         }
3386
3387         /* Fix up the descriptors */
3388         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
3389         device_desc.idVendor = cpu_to_le16(mod_data.vendor);
3390         device_desc.idProduct = cpu_to_le16(mod_data.product);
3391         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
3392
3393         i = (transport_is_cbi() ? 3 : 2);       // Number of endpoints
3394         fsg_intf_desc.bNumEndpoints = i;
3395         fsg_intf_desc.bInterfaceSubClass = mod_data.protocol_type;
3396         fsg_intf_desc.bInterfaceProtocol = mod_data.transport_type;
3397         fsg_fs_function[i + FSG_FS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3398
3399         if (gadget_is_dualspeed(gadget)) {
3400                 fsg_hs_function[i + FSG_HS_FUNCTION_PRE_EP_ENTRIES] = NULL;
3401
3402                 /* Assume ep0 uses the same maxpacket value for both speeds */
3403                 dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
3404
3405                 /* Assume endpoint addresses are the same for both speeds */
3406                 fsg_hs_bulk_in_desc.bEndpointAddress =
3407                         fsg_fs_bulk_in_desc.bEndpointAddress;
3408                 fsg_hs_bulk_out_desc.bEndpointAddress =
3409                         fsg_fs_bulk_out_desc.bEndpointAddress;
3410                 fsg_hs_intr_in_desc.bEndpointAddress =
3411                         fsg_fs_intr_in_desc.bEndpointAddress;
3412         }
3413
3414         if (gadget_is_otg(gadget))
3415                 fsg_otg_desc.bmAttributes |= USB_OTG_HNP;
3416
3417         rc = -ENOMEM;
3418
3419         /* Allocate the request and buffer for endpoint 0 */
3420         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
3421         if (!req)
3422                 goto out;
3423         req->buf = kmalloc(EP0_BUFSIZE, GFP_KERNEL);
3424         if (!req->buf)
3425                 goto out;
3426         req->complete = ep0_complete;
3427
3428         /* Allocate the data buffers */
3429         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
3430                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
3431
3432                 /* Allocate for the bulk-in endpoint.  We assume that
3433                  * the buffer will also work with the bulk-out (and
3434                  * interrupt-in) endpoint. */
3435                 bh->buf = kmalloc(mod_data.buflen, GFP_KERNEL);
3436                 if (!bh->buf)
3437                         goto out;
3438                 bh->next = bh + 1;
3439         }
3440         fsg->buffhds[FSG_NUM_BUFFERS - 1].next = &fsg->buffhds[0];
3441
3442         /* This should reflect the actual gadget power source */
3443         usb_gadget_set_selfpowered(gadget);
3444
3445         snprintf(fsg_string_manufacturer, sizeof fsg_string_manufacturer,
3446                         "%s %s with %s",
3447                         init_utsname()->sysname, init_utsname()->release,
3448                         gadget->name);
3449
3450         /* On a real device, serial[] would be loaded from permanent
3451          * storage.  We just encode it from the driver version string. */
3452         for (i = 0; i < sizeof fsg_string_serial - 2; i += 2) {
3453                 unsigned char           c = DRIVER_VERSION[i / 2];
3454
3455                 if (!c)
3456                         break;
3457                 sprintf(&fsg_string_serial[i], "%02X", c);
3458         }
3459
3460         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
3461                         "file-storage-gadget");
3462         if (IS_ERR(fsg->thread_task)) {
3463                 rc = PTR_ERR(fsg->thread_task);
3464                 goto out;
3465         }
3466
3467         INFO(fsg, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
3468         INFO(fsg, "Number of LUNs=%d\n", fsg->nluns);
3469
3470         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
3471         for (i = 0; i < fsg->nluns; ++i) {
3472                 curlun = &fsg->luns[i];
3473                 if (fsg_lun_is_open(curlun)) {
3474                         p = NULL;
3475                         if (pathbuf) {
3476                                 p = d_path(&curlun->filp->f_path,
3477                                            pathbuf, PATH_MAX);
3478                                 if (IS_ERR(p))
3479                                         p = NULL;
3480                         }
3481                         LINFO(curlun, "ro=%d, file: %s\n",
3482                                         curlun->ro, (p ? p : "(error)"));
3483                 }
3484         }
3485         kfree(pathbuf);
3486
3487         DBG(fsg, "transport=%s (x%02x)\n",
3488                         mod_data.transport_name, mod_data.transport_type);
3489         DBG(fsg, "protocol=%s (x%02x)\n",
3490                         mod_data.protocol_name, mod_data.protocol_type);
3491         DBG(fsg, "VendorID=x%04x, ProductID=x%04x, Release=x%04x\n",
3492                         mod_data.vendor, mod_data.product, mod_data.release);
3493         DBG(fsg, "removable=%d, stall=%d, cdrom=%d, buflen=%u\n",
3494                         mod_data.removable, mod_data.can_stall,
3495                         mod_data.cdrom, mod_data.buflen);
3496         DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task));
3497
3498         set_bit(REGISTERED, &fsg->atomic_bitflags);
3499
3500         /* Tell the thread to start working */
3501         wake_up_process(fsg->thread_task);
3502         return 0;
3503
3504 autoconf_fail:
3505         ERROR(fsg, "unable to autoconfigure all endpoints\n");
3506         rc = -ENOTSUPP;
3507
3508 out:
3509         fsg->state = FSG_STATE_TERMINATED;      // The thread is dead
3510         fsg_unbind(gadget);
3511         complete(&fsg->thread_notifier);
3512         return rc;
3513 }
3514
3515
3516 /*-------------------------------------------------------------------------*/
3517
3518 static void fsg_suspend(struct usb_gadget *gadget)
3519 {
3520         struct fsg_dev          *fsg = get_gadget_data(gadget);
3521
3522         DBG(fsg, "suspend\n");
3523         set_bit(SUSPENDED, &fsg->atomic_bitflags);
3524 }
3525
3526 static void fsg_resume(struct usb_gadget *gadget)
3527 {
3528         struct fsg_dev          *fsg = get_gadget_data(gadget);
3529
3530         DBG(fsg, "resume\n");
3531         clear_bit(SUSPENDED, &fsg->atomic_bitflags);
3532 }
3533
3534
3535 /*-------------------------------------------------------------------------*/
3536
3537 static struct usb_gadget_driver         fsg_driver = {
3538 #ifdef CONFIG_USB_GADGET_DUALSPEED
3539         .speed          = USB_SPEED_HIGH,
3540 #else
3541         .speed          = USB_SPEED_FULL,
3542 #endif
3543         .function       = (char *) fsg_string_product,
3544         .bind           = fsg_bind,
3545         .unbind         = fsg_unbind,
3546         .disconnect     = fsg_disconnect,
3547         .setup          = fsg_setup,
3548         .suspend        = fsg_suspend,
3549         .resume         = fsg_resume,
3550
3551         .driver         = {
3552                 .name           = DRIVER_NAME,
3553                 .owner          = THIS_MODULE,
3554                 // .release = ...
3555                 // .suspend = ...
3556                 // .resume = ...
3557         },
3558 };
3559
3560
3561 static int __init fsg_alloc(void)
3562 {
3563         struct fsg_dev          *fsg;
3564
3565         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
3566         if (!fsg)
3567                 return -ENOMEM;
3568         spin_lock_init(&fsg->lock);
3569         init_rwsem(&fsg->filesem);
3570         kref_init(&fsg->ref);
3571         init_completion(&fsg->thread_notifier);
3572
3573         the_fsg = fsg;
3574         return 0;
3575 }
3576
3577
3578 static int __init fsg_init(void)
3579 {
3580         int             rc;
3581         struct fsg_dev  *fsg;
3582
3583         if ((rc = fsg_alloc()) != 0)
3584                 return rc;
3585         fsg = the_fsg;
3586         if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
3587                 kref_put(&fsg->ref, fsg_release);
3588         return rc;
3589 }
3590 module_init(fsg_init);
3591
3592
3593 static void __exit fsg_cleanup(void)
3594 {
3595         struct fsg_dev  *fsg = the_fsg;
3596
3597         /* Unregister the driver iff the thread hasn't already done so */
3598         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
3599                 usb_gadget_unregister_driver(&fsg_driver);
3600
3601         /* Wait for the thread to finish up */
3602         wait_for_completion(&fsg->thread_notifier);
3603
3604         kref_put(&fsg->ref, fsg_release);
3605 }
3606 module_exit(fsg_cleanup);