drivers/usb/gadget/file_storage.c

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