drivers/usb/gadget/storage_common.c

   1 /*
   2  * storage_common.c -- Common definitions for mass storage functionality
   3  *
   4  * Copyright (C) 2003-2008 Alan Stern
   5  * Copyeight (C) 2009 Samsung Electronics
   6  * Author: Michal Nazarewicz (mina86@mina86.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14
  15 /*
  16  * This file requires the following identifiers used in USB strings to
  17  * be defined (each of type pointer to char):
  18  *  - fsg_string_manufacturer -- name of the manufacturer
  19  *  - fsg_string_product      -- name of the product
  20  *  - fsg_string_config       -- name of the configuration
  21  *  - fsg_string_interface    -- name of the interface
  22  * The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
  23  * macro is defined prior to including this file.
  24  */
  25
  26 /*
  27  * When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
  28  * fsg_hs_intr_in_desc objects as well as
  29  * FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
  30  * macros are not defined.
  31  *
  32  * When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
  33  * FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
  34  * defined (as well as corresponding entries in string tables are
  35  * missing) and FSG_STRING_INTERFACE has value of zero.
  36  *
  37  * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
  38  */
  39
  40 /*
  41  * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
  42  * sets the number of pipeline buffers (length of the fsg_buffhd array).
  43  * The valid range of num_buffers is: num >= 2 && num <= 4.
  44  */
  45
  46
  47 #include <linux/usb/storage.h>
  48 #include <scsi/scsi.h>
  49 #include <asm/unaligned.h>
  50
  51
  52 /*
  53  * Thanks to NetChip Technologies for donating this product ID.
  54  *
  55  * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
  56  * Instead:  allocate your own, using normal USB-IF procedures.
  57  */
  58 #define FSG_VENDOR_ID   0x0525  /* NetChip */
  59 #define FSG_PRODUCT_ID  0xa4a5  /* Linux-USB File-backed Storage Gadget */
  60
  61
  62 /*-------------------------------------------------------------------------*/
  63
  64
  65 #ifndef DEBUG
  66 #undef VERBOSE_DEBUG
  67 #undef DUMP_MSGS
  68 #endif /* !DEBUG */
  69
  70 #ifdef VERBOSE_DEBUG
  71 #define VLDBG   LDBG
  72 #else
  73 #define VLDBG(lun, fmt, args...) do { } while (0)
  74 #endif /* VERBOSE_DEBUG */
  75
  76 #define LDBG(lun, fmt, args...)   dev_dbg (&(lun)->dev, fmt, ## args)
  77 #define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
  78 #define LWARN(lun, fmt, args...)  dev_warn(&(lun)->dev, fmt, ## args)
  79 #define LINFO(lun, fmt, args...)  dev_info(&(lun)->dev, fmt, ## args)
  80
  81
  82 #ifdef DUMP_MSGS
  83
  84 #  define dump_msg(fsg, /* const char * */ label,                       \
  85                    /* const u8 * */ buf, /* unsigned */ length) do {    \
  86         if (length < 512) {                                             \
  87                 DBG(fsg, "%s, length %u:\n", label, length);            \
  88                 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,      \
  89                                16, 1, buf, length, 0);                  \
  90         }                                                               \
  91 } while (0)
  92
  93 #  define dump_cdb(fsg) do { } while (0)
  94
  95 #else
  96
  97 #  define dump_msg(fsg, /* const char * */ label, \
  98                    /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
  99
 100 #  ifdef VERBOSE_DEBUG
 101
 102 #    define dump_cdb(fsg)                                               \
 103         print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,      \
 104                        16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)         \
 105
 106 #  else
 107
 108 #    define dump_cdb(fsg) do { } while (0)
 109
 110 #  endif /* VERBOSE_DEBUG */
 111
 112 #endif /* DUMP_MSGS */
 113
 114 /*-------------------------------------------------------------------------*/
 115
 116 /* CBI Interrupt data structure */
 117 struct interrupt_data {
 118         u8      bType;
 119         u8      bValue;
 120 };
 121
 122 #define CBI_INTERRUPT_DATA_LEN          2
 123
 124 /* CBI Accept Device-Specific Command request */
 125 #define USB_CBI_ADSC_REQUEST            0x00
 126
 127
 128 /* Length of a SCSI Command Data Block */
 129 #define MAX_COMMAND_SIZE        16
 130
 131 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
 132 #define SS_NO_SENSE                             0
 133 #define SS_COMMUNICATION_FAILURE                0x040800
 134 #define SS_INVALID_COMMAND                      0x052000
 135 #define SS_INVALID_FIELD_IN_CDB                 0x052400
 136 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
 137 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
 138 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
 139 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
 140 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
 141 #define SS_RESET_OCCURRED                       0x062900
 142 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
 143 #define SS_UNRECOVERED_READ_ERROR               0x031100
 144 #define SS_WRITE_ERROR                          0x030c02
 145 #define SS_WRITE_PROTECTED                      0x072700
 146
 147 #define SK(x)           ((u8) ((x) >> 16))      /* Sense Key byte, etc. */
 148 #define ASC(x)          ((u8) ((x) >> 8))
 149 #define ASCQ(x)         ((u8) (x))
 150
 151
 152 /*-------------------------------------------------------------------------*/
 153
 154
 155 struct fsg_lun {
 156         struct file     *filp;
 157         loff_t          file_length;
 158         loff_t          num_sectors;
 159
 160         unsigned int    initially_ro:1;
 161         unsigned int    ro:1;
 162         unsigned int    removable:1;
 163         unsigned int    cdrom:1;
 164         unsigned int    prevent_medium_removal:1;
 165         unsigned int    registered:1;
 166         unsigned int    info_valid:1;
 167         unsigned int    nofua:1;
 168
 169         u32             sense_data;
 170         u32             sense_data_info;
 171         u32             unit_attention_data;
 172
 173         unsigned int    blkbits;        /* Bits of logical block size of bound block device */
 174         unsigned int    blksize;        /* logical block size of bound block device */
 175         struct device   dev;
 176 };
 177
 178 #define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
 179
 180 static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
 181 {
 182         return container_of(dev, struct fsg_lun, dev);
 183 }
 184
 185
 186 /* Big enough to hold our biggest descriptor */
 187 #define EP0_BUFSIZE     256
 188 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     /* An impossibly large value */
 189
 190 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
 191
 192 static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
 193 module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);
 194 MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
 195
 196 #else
 197
 198 /*
 199  * Number of buffers we will use.
 200  * 2 is usually enough for good buffering pipeline
 201  */
 202 #define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
 203
 204 #endif /* CONFIG_USB_DEBUG */
 205
 206 /* check if fsg_num_buffers is within a valid range */
 207 static inline int fsg_num_buffers_validate(void)
 208 {
 209         if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
 210                 return 0;
 211         pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
 212                fsg_num_buffers, 2 ,4);
 213         return -EINVAL;
 214 }
 215
 216 /* Default size of buffer length. */
 217 #define FSG_BUFLEN      ((u32)16384)
 218
 219 /* Maximal number of LUNs supported in mass storage function */
 220 #define FSG_MAX_LUNS    8
 221
 222 enum fsg_buffer_state {
 223         BUF_STATE_EMPTY = 0,
 224         BUF_STATE_FULL,
 225         BUF_STATE_BUSY
 226 };
 227
 228 struct fsg_buffhd {
 229         void                            *buf;
 230         enum fsg_buffer_state           state;
 231         struct fsg_buffhd               *next;
 232
 233         /*
 234          * The NetChip 2280 is faster, and handles some protocol faults
 235          * better, if we don't submit any short bulk-out read requests.
 236          * So we will record the intended request length here.
 237          */
 238         unsigned int                    bulk_out_intended_length;
 239
 240         struct usb_request              *inreq;
 241         int                             inreq_busy;
 242         struct usb_request              *outreq;
 243         int                             outreq_busy;
 244 };
 245
 246 enum fsg_state {
 247         /* This one isn't used anywhere */
 248         FSG_STATE_COMMAND_PHASE = -10,
 249         FSG_STATE_DATA_PHASE,
 250         FSG_STATE_STATUS_PHASE,
 251
 252         FSG_STATE_IDLE = 0,
 253         FSG_STATE_ABORT_BULK_OUT,
 254         FSG_STATE_RESET,
 255         FSG_STATE_INTERFACE_CHANGE,
 256         FSG_STATE_CONFIG_CHANGE,
 257         FSG_STATE_DISCONNECT,
 258         FSG_STATE_EXIT,
 259         FSG_STATE_TERMINATED
 260 };
 261
 262 enum data_direction {
 263         DATA_DIR_UNKNOWN = 0,
 264         DATA_DIR_FROM_HOST,
 265         DATA_DIR_TO_HOST,
 266         DATA_DIR_NONE
 267 };
 268
 269
 270 /*-------------------------------------------------------------------------*/
 271
 272
 273 static inline u32 get_unaligned_be24(u8 *buf)
 274 {
 275         return 0xffffff & (u32) get_unaligned_be32(buf - 1);
 276 }
 277
 278
 279 /*-------------------------------------------------------------------------*/
 280
 281
 282 enum {
 283 #ifndef FSG_NO_DEVICE_STRINGS
 284         FSG_STRING_MANUFACTURER = 1,
 285         FSG_STRING_PRODUCT,
 286         FSG_STRING_SERIAL,
 287         FSG_STRING_CONFIG,
 288 #endif
 289         FSG_STRING_INTERFACE
 290 };
 291
 292
 293 #ifndef FSG_NO_OTG
 294 static struct usb_otg_descriptor
 295 fsg_otg_desc = {
 296         .bLength =              sizeof fsg_otg_desc,
 297         .bDescriptorType =      USB_DT_OTG,
 298
 299         .bmAttributes =         USB_OTG_SRP,
 300 };
 301 #endif
 302
 303 /* There is only one interface. */
 304
 305 static struct usb_interface_descriptor
 306 fsg_intf_desc = {
 307         .bLength =              sizeof fsg_intf_desc,
 308         .bDescriptorType =      USB_DT_INTERFACE,
 309
 310         .bNumEndpoints =        2,              /* Adjusted during fsg_bind() */
 311         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
 312         .bInterfaceSubClass =   USB_SC_SCSI,    /* Adjusted during fsg_bind() */
 313         .bInterfaceProtocol =   USB_PR_BULK,    /* Adjusted during fsg_bind() */
 314         .iInterface =           FSG_STRING_INTERFACE,
 315 };
 316
 317 /*
 318  * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
 319  * interrupt-in.
 320  */
 321
 322 static struct usb_endpoint_descriptor
 323 fsg_fs_bulk_in_desc = {
 324         .bLength =              USB_DT_ENDPOINT_SIZE,
 325         .bDescriptorType =      USB_DT_ENDPOINT,
 326
 327         .bEndpointAddress =     USB_DIR_IN,
 328         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 329         /* wMaxPacketSize set by autoconfiguration */
 330 };
 331
 332 static struct usb_endpoint_descriptor
 333 fsg_fs_bulk_out_desc = {
 334         .bLength =              USB_DT_ENDPOINT_SIZE,
 335         .bDescriptorType =      USB_DT_ENDPOINT,
 336
 337         .bEndpointAddress =     USB_DIR_OUT,
 338         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 339         /* wMaxPacketSize set by autoconfiguration */
 340 };
 341
 342 #ifndef FSG_NO_INTR_EP
 343
 344 static struct usb_endpoint_descriptor
 345 fsg_fs_intr_in_desc = {
 346         .bLength =              USB_DT_ENDPOINT_SIZE,
 347         .bDescriptorType =      USB_DT_ENDPOINT,
 348
 349         .bEndpointAddress =     USB_DIR_IN,
 350         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 351         .wMaxPacketSize =       cpu_to_le16(2),
 352         .bInterval =            32,     /* frames -> 32 ms */
 353 };
 354
 355 #ifndef FSG_NO_OTG
 356 #  define FSG_FS_FUNCTION_PRE_EP_ENTRIES        2
 357 #else
 358 #  define FSG_FS_FUNCTION_PRE_EP_ENTRIES        1
 359 #endif
 360
 361 #endif
 362
 363 static struct usb_descriptor_header *fsg_fs_function[] = {
 364 #ifndef FSG_NO_OTG
 365         (struct usb_descriptor_header *) &fsg_otg_desc,
 366 #endif
 367         (struct usb_descriptor_header *) &fsg_intf_desc,
 368         (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
 369         (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
 370 #ifndef FSG_NO_INTR_EP
 371         (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
 372 #endif
 373         NULL,
 374 };
 375
 376
 377 /*
 378  * USB 2.0 devices need to expose both high speed and full speed
 379  * descriptors, unless they only run at full speed.
 380  *
 381  * That means alternate endpoint descriptors (bigger packets)
 382  * and a "device qualifier" ... plus more construction options
 383  * for the configuration descriptor.
 384  */
 385 static struct usb_endpoint_descriptor
 386 fsg_hs_bulk_in_desc = {
 387         .bLength =              USB_DT_ENDPOINT_SIZE,
 388         .bDescriptorType =      USB_DT_ENDPOINT,
 389
 390         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
 391         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 392         .wMaxPacketSize =       cpu_to_le16(512),
 393 };
 394
 395 static struct usb_endpoint_descriptor
 396 fsg_hs_bulk_out_desc = {
 397         .bLength =              USB_DT_ENDPOINT_SIZE,
 398         .bDescriptorType =      USB_DT_ENDPOINT,
 399
 400         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
 401         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 402         .wMaxPacketSize =       cpu_to_le16(512),
 403         .bInterval =            1,      /* NAK every 1 uframe */
 404 };
 405
 406 #ifndef FSG_NO_INTR_EP
 407
 408 static struct usb_endpoint_descriptor
 409 fsg_hs_intr_in_desc = {
 410         .bLength =              USB_DT_ENDPOINT_SIZE,
 411         .bDescriptorType =      USB_DT_ENDPOINT,
 412
 413         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
 414         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 415         .wMaxPacketSize =       cpu_to_le16(2),
 416         .bInterval =            USB_MS_TO_HS_INTERVAL(32),      /* 32 ms */
 417 };
 418
 419 #ifndef FSG_NO_OTG
 420 #  define FSG_HS_FUNCTION_PRE_EP_ENTRIES        2
 421 #else
 422 #  define FSG_HS_FUNCTION_PRE_EP_ENTRIES        1
 423 #endif
 424
 425 #endif
 426
 427 static struct usb_descriptor_header *fsg_hs_function[] = {
 428 #ifndef FSG_NO_OTG
 429         (struct usb_descriptor_header *) &fsg_otg_desc,
 430 #endif
 431         (struct usb_descriptor_header *) &fsg_intf_desc,
 432         (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
 433         (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
 434 #ifndef FSG_NO_INTR_EP
 435         (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
 436 #endif
 437         NULL,
 438 };
 439
 440 static struct usb_endpoint_descriptor
 441 fsg_ss_bulk_in_desc = {
 442         .bLength =              USB_DT_ENDPOINT_SIZE,
 443         .bDescriptorType =      USB_DT_ENDPOINT,
 444
 445         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
 446         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 447         .wMaxPacketSize =       cpu_to_le16(1024),
 448 };
 449
 450 static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
 451         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 452         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 453
 454         /*.bMaxBurst =          DYNAMIC, */
 455 };
 456
 457 static struct usb_endpoint_descriptor
 458 fsg_ss_bulk_out_desc = {
 459         .bLength =              USB_DT_ENDPOINT_SIZE,
 460         .bDescriptorType =      USB_DT_ENDPOINT,
 461
 462         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
 463         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 464         .wMaxPacketSize =       cpu_to_le16(1024),
 465 };
 466
 467 static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
 468         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 469         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 470
 471         /*.bMaxBurst =          DYNAMIC, */
 472 };
 473
 474 #ifndef FSG_NO_INTR_EP
 475
 476 static struct usb_endpoint_descriptor
 477 fsg_ss_intr_in_desc = {
 478         .bLength =              USB_DT_ENDPOINT_SIZE,
 479         .bDescriptorType =      USB_DT_ENDPOINT,
 480
 481         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
 482         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 483         .wMaxPacketSize =       cpu_to_le16(2),
 484         .bInterval =            USB_MS_TO_HS_INTERVAL(32),      /* 32 ms */
 485 };
 486
 487 static struct usb_ss_ep_comp_descriptor fsg_ss_intr_in_comp_desc = {
 488         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 489         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 490
 491         .wBytesPerInterval =    cpu_to_le16(2),
 492 };
 493
 494 #ifndef FSG_NO_OTG
 495 #  define FSG_SS_FUNCTION_PRE_EP_ENTRIES        2
 496 #else
 497 #  define FSG_SS_FUNCTION_PRE_EP_ENTRIES        1
 498 #endif
 499
 500 #endif
 501
 502 static __maybe_unused struct usb_ext_cap_descriptor fsg_ext_cap_desc = {
 503         .bLength =              USB_DT_USB_EXT_CAP_SIZE,
 504         .bDescriptorType =      USB_DT_DEVICE_CAPABILITY,
 505         .bDevCapabilityType =   USB_CAP_TYPE_EXT,
 506
 507         .bmAttributes =         cpu_to_le32(USB_LPM_SUPPORT),
 508 };
 509
 510 static __maybe_unused struct usb_ss_cap_descriptor fsg_ss_cap_desc = {
 511         .bLength =              USB_DT_USB_SS_CAP_SIZE,
 512         .bDescriptorType =      USB_DT_DEVICE_CAPABILITY,
 513         .bDevCapabilityType =   USB_SS_CAP_TYPE,
 514
 515         /* .bmAttributes = LTM is not supported yet */
 516
 517         .wSpeedSupported =      cpu_to_le16(USB_LOW_SPEED_OPERATION
 518                 | USB_FULL_SPEED_OPERATION
 519                 | USB_HIGH_SPEED_OPERATION
 520                 | USB_5GBPS_OPERATION),
 521         .bFunctionalitySupport = USB_LOW_SPEED_OPERATION,
 522         .bU1devExitLat =        USB_DEFAULT_U1_DEV_EXIT_LAT,
 523         .bU2DevExitLat =        cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT),
 524 };
 525
 526 static __maybe_unused struct usb_bos_descriptor fsg_bos_desc = {
 527         .bLength =              USB_DT_BOS_SIZE,
 528         .bDescriptorType =      USB_DT_BOS,
 529
 530         .wTotalLength =         cpu_to_le16(USB_DT_BOS_SIZE
 531                                 + USB_DT_USB_EXT_CAP_SIZE
 532                                 + USB_DT_USB_SS_CAP_SIZE),
 533
 534         .bNumDeviceCaps =       2,
 535 };
 536
 537 static struct usb_descriptor_header *fsg_ss_function[] = {
 538 #ifndef FSG_NO_OTG
 539         (struct usb_descriptor_header *) &fsg_otg_desc,
 540 #endif
 541         (struct usb_descriptor_header *) &fsg_intf_desc,
 542         (struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
 543         (struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
 544         (struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
 545         (struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
 546 #ifndef FSG_NO_INTR_EP
 547         (struct usb_descriptor_header *) &fsg_ss_intr_in_desc,
 548         (struct usb_descriptor_header *) &fsg_ss_intr_in_comp_desc,
 549 #endif
 550         NULL,
 551 };
 552
 553 /* Maxpacket and other transfer characteristics vary by speed. */
 554 static __maybe_unused struct usb_endpoint_descriptor *
 555 fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
 556                 struct usb_endpoint_descriptor *hs,
 557                 struct usb_endpoint_descriptor *ss)
 558 {
 559         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
 560                 return ss;
 561         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
 562                 return hs;
 563         return fs;
 564 }
 565
 566
 567 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 568 static struct usb_string                fsg_strings[] = {
 569 #ifndef FSG_NO_DEVICE_STRINGS
 570         {FSG_STRING_MANUFACTURER,       fsg_string_manufacturer},
 571         {FSG_STRING_PRODUCT,            fsg_string_product},
 572         {FSG_STRING_SERIAL,             ""},
 573         {FSG_STRING_CONFIG,             fsg_string_config},
 574 #endif
 575         {FSG_STRING_INTERFACE,          fsg_string_interface},
 576         {}
 577 };
 578
 579 static struct usb_gadget_strings        fsg_stringtab = {
 580         .language       = 0x0409,               /* en-us */
 581         .strings        = fsg_strings,
 582 };
 583
 584
 585  /*-------------------------------------------------------------------------*/
 586
 587 /*
 588  * If the next two routines are called while the gadget is registered,
 589  * the caller must own fsg->filesem for writing.
 590  */
 591
 592 static void fsg_lun_close(struct fsg_lun *curlun)
 593 {
 594         if (curlun->filp) {
 595                 LDBG(curlun, "close backing file\n");
 596                 fput(curlun->filp);
 597                 curlun->filp = NULL;
 598         }
 599 }
 600
 601
 602 static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 603 {
 604         int                             ro;
 605         struct file                     *filp = NULL;
 606         int                             rc = -EINVAL;
 607         struct inode                    *inode = NULL;
 608         loff_t                          size;
 609         loff_t                          num_sectors;
 610         loff_t                          min_sectors;
 611         unsigned int                    blkbits;
 612         unsigned int                    blksize;
 613
 614         /* R/W if we can, R/O if we must */
 615         ro = curlun->initially_ro;
 616         if (!ro) {
 617                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
 618                 if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
 619                         ro = 1;
 620         }
 621         if (ro)
 622                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
 623         if (IS_ERR(filp)) {
 624                 LINFO(curlun, "unable to open backing file: %s\n", filename);
 625                 return PTR_ERR(filp);
 626         }
 627
 628         if (!(filp->f_mode & FMODE_WRITE))
 629                 ro = 1;
 630
 631         inode = filp->f_path.dentry->d_inode;
 632         if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
 633                 LINFO(curlun, "invalid file type: %s\n", filename);
 634                 goto out;
 635         }
 636
 637         /*
 638          * If we can't read the file, it's no good.
 639          * If we can't write the file, use it read-only.
 640          */
 641         if (!(filp->f_op->read || filp->f_op->aio_read)) {
 642                 LINFO(curlun, "file not readable: %s\n", filename);
 643                 goto out;
 644         }
 645         if (!(filp->f_op->write || filp->f_op->aio_write))
 646                 ro = 1;
 647
 648         size = i_size_read(inode->i_mapping->host);
 649         if (size < 0) {
 650                 LINFO(curlun, "unable to find file size: %s\n", filename);
 651                 rc = (int) size;
 652                 goto out;
 653         }
 654
 655         if (curlun->cdrom) {
 656                 blksize = 2048;
 657                 blkbits = 11;
 658         } else if (inode->i_bdev) {
 659                 blksize = bdev_logical_block_size(inode->i_bdev);
 660                 blkbits = blksize_bits(blksize);
 661         } else {
 662                 blksize = 512;
 663                 blkbits = 9;
 664         }
 665
 666         num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
 667         min_sectors = 1;
 668         if (curlun->cdrom) {
 669                 min_sectors = 300;      /* Smallest track is 300 frames */
 670                 if (num_sectors >= 256*60*75) {
 671                         num_sectors = 256*60*75 - 1;
 672                         LINFO(curlun, "file too big: %s\n", filename);
 673                         LINFO(curlun, "using only first %d blocks\n",
 674                                         (int) num_sectors);
 675                 }
 676         }
 677         if (num_sectors < min_sectors) {
 678                 LINFO(curlun, "file too small: %s\n", filename);
 679                 rc = -ETOOSMALL;
 680                 goto out;
 681         }
 682
 683         if (fsg_lun_is_open(curlun))
 684                 fsg_lun_close(curlun);
 685
 686         curlun->blksize = blksize;
 687         curlun->blkbits = blkbits;
 688         curlun->ro = ro;
 689         curlun->filp = filp;
 690         curlun->file_length = size;
 691         curlun->num_sectors = num_sectors;
 692         LDBG(curlun, "open backing file: %s\n", filename);
 693         return 0;
 694
 695 out:
 696         fput(filp);
 697         return rc;
 698 }
 699
 700
 701 /*-------------------------------------------------------------------------*/
 702
 703 /*
 704  * Sync the file data, don't bother with the metadata.
 705  * This code was copied from fs/buffer.c:sys_fdatasync().
 706  */
 707 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
 708 {
 709         struct file     *filp = curlun->filp;
 710
 711         if (curlun->ro || !filp)
 712                 return 0;
 713         return vfs_fsync(filp, 1);
 714 }
 715
 716 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
 717 {
 718         if (msf) {
 719                 /* Convert to Minutes-Seconds-Frames */
 720                 addr >>= 2;             /* Convert to 2048-byte frames */
 721                 addr += 2*75;           /* Lead-in occupies 2 seconds */
 722                 dest[3] = addr % 75;    /* Frames */
 723                 addr /= 75;
 724                 dest[2] = addr % 60;    /* Seconds */
 725                 addr /= 60;
 726                 dest[1] = addr;         /* Minutes */
 727                 dest[0] = 0;            /* Reserved */
 728         } else {
 729                 /* Absolute sector */
 730                 put_unaligned_be32(addr, dest);
 731         }
 732 }
 733
 734
 735 /*-------------------------------------------------------------------------*/
 736
 737
 738 static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
 739                            char *buf)
 740 {
 741         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 742
 743         return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
 744                                   ? curlun->ro
 745                                   : curlun->initially_ro);
 746 }
 747
 748 static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
 749                               char *buf)
 750 {
 751         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 752
 753         return sprintf(buf, "%u\n", curlun->nofua);
 754 }
 755
 756 static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
 757                              char *buf)
 758 {
 759         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 760         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 761         char            *p;
 762         ssize_t         rc;
 763
 764         down_read(filesem);
 765         if (fsg_lun_is_open(curlun)) {  /* Get the complete pathname */
 766                 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
 767                 if (IS_ERR(p))
 768                         rc = PTR_ERR(p);
 769                 else {
 770                         rc = strlen(p);
 771                         memmove(buf, p, rc);
 772                         buf[rc] = '\n';         /* Add a newline */
 773                         buf[++rc] = 0;
 774                 }
 775         } else {                                /* No file, return 0 bytes */
 776                 *buf = 0;
 777                 rc = 0;
 778         }
 779         up_read(filesem);
 780         return rc;
 781 }
 782
 783
 784 static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
 785                             const char *buf, size_t count)
 786 {
 787         ssize_t         rc;
 788         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 789         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 790         unsigned        ro;
 791
 792         rc = kstrtouint(buf, 2, &ro);
 793         if (rc)
 794                 return rc;
 795
 796         /*
 797          * Allow the write-enable status to change only while the
 798          * backing file is closed.
 799          */
 800         down_read(filesem);
 801         if (fsg_lun_is_open(curlun)) {
 802                 LDBG(curlun, "read-only status change prevented\n");
 803                 rc = -EBUSY;
 804         } else {
 805                 curlun->ro = ro;
 806                 curlun->initially_ro = ro;
 807                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
 808                 rc = count;
 809         }
 810         up_read(filesem);
 811         return rc;
 812 }
 813
 814 static ssize_t fsg_store_nofua(struct device *dev,
 815                                struct device_attribute *attr,
 816                                const char *buf, size_t count)
 817 {
 818         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 819         unsigned        nofua;
 820         int             ret;
 821
 822         ret = kstrtouint(buf, 2, &nofua);
 823         if (ret)
 824                 return ret;
 825
 826         /* Sync data when switching from async mode to sync */
 827         if (!nofua && curlun->nofua)
 828                 fsg_lun_fsync_sub(curlun);
 829
 830         curlun->nofua = nofua;
 831
 832         return count;
 833 }
 834
 835 static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
 836                               const char *buf, size_t count)
 837 {
 838         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 839         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 840         int             rc = 0;
 841
 842         if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
 843                 LDBG(curlun, "eject attempt prevented\n");
 844                 return -EBUSY;                          /* "Door is locked" */
 845         }
 846
 847         /* Remove a trailing newline */
 848         if (count > 0 && buf[count-1] == '\n')
 849                 ((char *) buf)[count-1] = 0;            /* Ugh! */
 850
 851         /* Load new medium */
 852         down_write(filesem);
 853         if (count > 0 && buf[0]) {
 854                 /* fsg_lun_open() will close existing file if any. */
 855                 rc = fsg_lun_open(curlun, buf);
 856                 if (rc == 0)
 857                         curlun->unit_attention_data =
 858                                         SS_NOT_READY_TO_READY_TRANSITION;
 859         } else if (fsg_lun_is_open(curlun)) {
 860                 fsg_lun_close(curlun);
 861                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
 862         }
 863         up_write(filesem);
 864         return (rc < 0 ? rc : count);
 865 }