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  * Keep those macros in sync with those in
  83  * include/linux/usb/composite.h or else GCC will complain.  If they
  84  * are identical (the same names of arguments, white spaces in the
  85  * same places) GCC will allow redefinition otherwise (even if some
  86  * white space is removed or added) warning will be issued.
  87  *
  88  * Those macros are needed here because File Storage Gadget does not
  89  * include the composite.h header.  For composite gadgets those macros
  90  * are redundant since composite.h is included any way.
  91  *
  92  * One could check whether those macros are already defined (which
  93  * would indicate composite.h had been included) or not (which would
  94  * indicate we were in FSG) but this is not done because a warning is
  95  * desired if definitions here differ from the ones in composite.h.
  96  *
  97  * We want the definitions to match and be the same in File Storage
  98  * Gadget as well as Mass Storage Function (and so composite gadgets
  99  * using MSF).  If someone changes them in composite.h it will produce
 100  * a warning in this file when building MSF.
 101  */
 102 #define DBG(d, fmt, args...)     dev_dbg(&(d)->gadget->dev , fmt , ## args)
 103 #define VDBG(d, fmt, args...)    dev_vdbg(&(d)->gadget->dev , fmt , ## args)
 104 #define ERROR(d, fmt, args...)   dev_err(&(d)->gadget->dev , fmt , ## args)
 105 #define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
 106 #define INFO(d, fmt, args...)    dev_info(&(d)->gadget->dev , fmt , ## args)
 107
 108
 109
 110 #ifdef DUMP_MSGS
 111
 112 #  define dump_msg(fsg, /* const char * */ label,                       \
 113                    /* const u8 * */ buf, /* unsigned */ length) do {    \
 114         if (length < 512) {                                             \
 115                 DBG(fsg, "%s, length %u:\n", label, length);            \
 116                 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,      \
 117                                16, 1, buf, length, 0);                  \
 118         }                                                               \
 119 } while (0)
 120
 121 #  define dump_cdb(fsg) do { } while (0)
 122
 123 #else
 124
 125 #  define dump_msg(fsg, /* const char * */ label, \
 126                    /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
 127
 128 #  ifdef VERBOSE_DEBUG
 129
 130 #    define dump_cdb(fsg)                                               \
 131         print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,      \
 132                        16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0)         \
 133
 134 #  else
 135
 136 #    define dump_cdb(fsg) do { } while (0)
 137
 138 #  endif /* VERBOSE_DEBUG */
 139
 140 #endif /* DUMP_MSGS */
 141
 142 /*-------------------------------------------------------------------------*/
 143
 144 /* CBI Interrupt data structure */
 145 struct interrupt_data {
 146         u8      bType;
 147         u8      bValue;
 148 };
 149
 150 #define CBI_INTERRUPT_DATA_LEN          2
 151
 152 /* CBI Accept Device-Specific Command request */
 153 #define USB_CBI_ADSC_REQUEST            0x00
 154
 155
 156 /* Length of a SCSI Command Data Block */
 157 #define MAX_COMMAND_SIZE        16
 158
 159 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
 160 #define SS_NO_SENSE                             0
 161 #define SS_COMMUNICATION_FAILURE                0x040800
 162 #define SS_INVALID_COMMAND                      0x052000
 163 #define SS_INVALID_FIELD_IN_CDB                 0x052400
 164 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE   0x052100
 165 #define SS_LOGICAL_UNIT_NOT_SUPPORTED           0x052500
 166 #define SS_MEDIUM_NOT_PRESENT                   0x023a00
 167 #define SS_MEDIUM_REMOVAL_PREVENTED             0x055302
 168 #define SS_NOT_READY_TO_READY_TRANSITION        0x062800
 169 #define SS_RESET_OCCURRED                       0x062900
 170 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED      0x053900
 171 #define SS_UNRECOVERED_READ_ERROR               0x031100
 172 #define SS_WRITE_ERROR                          0x030c02
 173 #define SS_WRITE_PROTECTED                      0x072700
 174
 175 #define SK(x)           ((u8) ((x) >> 16))      /* Sense Key byte, etc. */
 176 #define ASC(x)          ((u8) ((x) >> 8))
 177 #define ASCQ(x)         ((u8) (x))
 178
 179
 180 /*-------------------------------------------------------------------------*/
 181
 182
 183 struct fsg_lun {
 184         struct file     *filp;
 185         loff_t          file_length;
 186         loff_t          num_sectors;
 187
 188         unsigned int    initially_ro:1;
 189         unsigned int    ro:1;
 190         unsigned int    removable:1;
 191         unsigned int    cdrom:1;
 192         unsigned int    prevent_medium_removal:1;
 193         unsigned int    registered:1;
 194         unsigned int    info_valid:1;
 195         unsigned int    nofua:1;
 196
 197         u32             sense_data;
 198         u32             sense_data_info;
 199         u32             unit_attention_data;
 200
 201         unsigned int    blkbits;        /* Bits of logical block size of bound block device */
 202         unsigned int    blksize;        /* logical block size of bound block device */
 203         struct device   dev;
 204 };
 205
 206 #define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
 207
 208 static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
 209 {
 210         return container_of(dev, struct fsg_lun, dev);
 211 }
 212
 213
 214 /* Big enough to hold our biggest descriptor */
 215 #define EP0_BUFSIZE     256
 216 #define DELAYED_STATUS  (EP0_BUFSIZE + 999)     /* An impossibly large value */
 217
 218 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
 219
 220 static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
 221 module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);
 222 MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
 223
 224 #else
 225
 226 /*
 227  * Number of buffers we will use.
 228  * 2 is usually enough for good buffering pipeline
 229  */
 230 #define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
 231
 232 #endif /* CONFIG_USB_DEBUG */
 233
 234 /* check if fsg_num_buffers is within a valid range */
 235 static inline int fsg_num_buffers_validate(void)
 236 {
 237         if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
 238                 return 0;
 239         pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
 240                fsg_num_buffers, 2 ,4);
 241         return -EINVAL;
 242 }
 243
 244 /* Default size of buffer length. */
 245 #define FSG_BUFLEN      ((u32)16384)
 246
 247 /* Maximal number of LUNs supported in mass storage function */
 248 #define FSG_MAX_LUNS    8
 249
 250 enum fsg_buffer_state {
 251         BUF_STATE_EMPTY = 0,
 252         BUF_STATE_FULL,
 253         BUF_STATE_BUSY
 254 };
 255
 256 struct fsg_buffhd {
 257         void                            *buf;
 258         enum fsg_buffer_state           state;
 259         struct fsg_buffhd               *next;
 260
 261         /*
 262          * The NetChip 2280 is faster, and handles some protocol faults
 263          * better, if we don't submit any short bulk-out read requests.
 264          * So we will record the intended request length here.
 265          */
 266         unsigned int                    bulk_out_intended_length;
 267
 268         struct usb_request              *inreq;
 269         int                             inreq_busy;
 270         struct usb_request              *outreq;
 271         int                             outreq_busy;
 272 };
 273
 274 enum fsg_state {
 275         /* This one isn't used anywhere */
 276         FSG_STATE_COMMAND_PHASE = -10,
 277         FSG_STATE_DATA_PHASE,
 278         FSG_STATE_STATUS_PHASE,
 279
 280         FSG_STATE_IDLE = 0,
 281         FSG_STATE_ABORT_BULK_OUT,
 282         FSG_STATE_RESET,
 283         FSG_STATE_INTERFACE_CHANGE,
 284         FSG_STATE_CONFIG_CHANGE,
 285         FSG_STATE_DISCONNECT,
 286         FSG_STATE_EXIT,
 287         FSG_STATE_TERMINATED
 288 };
 289
 290 enum data_direction {
 291         DATA_DIR_UNKNOWN = 0,
 292         DATA_DIR_FROM_HOST,
 293         DATA_DIR_TO_HOST,
 294         DATA_DIR_NONE
 295 };
 296
 297
 298 /*-------------------------------------------------------------------------*/
 299
 300
 301 static inline u32 get_unaligned_be24(u8 *buf)
 302 {
 303         return 0xffffff & (u32) get_unaligned_be32(buf - 1);
 304 }
 305
 306
 307 /*-------------------------------------------------------------------------*/
 308
 309
 310 enum {
 311 #ifndef FSG_NO_DEVICE_STRINGS
 312         FSG_STRING_MANUFACTURER = 1,
 313         FSG_STRING_PRODUCT,
 314         FSG_STRING_SERIAL,
 315         FSG_STRING_CONFIG,
 316 #endif
 317         FSG_STRING_INTERFACE
 318 };
 319
 320
 321 #ifndef FSG_NO_OTG
 322 static struct usb_otg_descriptor
 323 fsg_otg_desc = {
 324         .bLength =              sizeof fsg_otg_desc,
 325         .bDescriptorType =      USB_DT_OTG,
 326
 327         .bmAttributes =         USB_OTG_SRP,
 328 };
 329 #endif
 330
 331 /* There is only one interface. */
 332
 333 static struct usb_interface_descriptor
 334 fsg_intf_desc = {
 335         .bLength =              sizeof fsg_intf_desc,
 336         .bDescriptorType =      USB_DT_INTERFACE,
 337
 338         .bNumEndpoints =        2,              /* Adjusted during fsg_bind() */
 339         .bInterfaceClass =      USB_CLASS_MASS_STORAGE,
 340         .bInterfaceSubClass =   USB_SC_SCSI,    /* Adjusted during fsg_bind() */
 341         .bInterfaceProtocol =   USB_PR_BULK,    /* Adjusted during fsg_bind() */
 342         .iInterface =           FSG_STRING_INTERFACE,
 343 };
 344
 345 /*
 346  * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
 347  * interrupt-in.
 348  */
 349
 350 static struct usb_endpoint_descriptor
 351 fsg_fs_bulk_in_desc = {
 352         .bLength =              USB_DT_ENDPOINT_SIZE,
 353         .bDescriptorType =      USB_DT_ENDPOINT,
 354
 355         .bEndpointAddress =     USB_DIR_IN,
 356         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 357         /* wMaxPacketSize set by autoconfiguration */
 358 };
 359
 360 static struct usb_endpoint_descriptor
 361 fsg_fs_bulk_out_desc = {
 362         .bLength =              USB_DT_ENDPOINT_SIZE,
 363         .bDescriptorType =      USB_DT_ENDPOINT,
 364
 365         .bEndpointAddress =     USB_DIR_OUT,
 366         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 367         /* wMaxPacketSize set by autoconfiguration */
 368 };
 369
 370 #ifndef FSG_NO_INTR_EP
 371
 372 static struct usb_endpoint_descriptor
 373 fsg_fs_intr_in_desc = {
 374         .bLength =              USB_DT_ENDPOINT_SIZE,
 375         .bDescriptorType =      USB_DT_ENDPOINT,
 376
 377         .bEndpointAddress =     USB_DIR_IN,
 378         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 379         .wMaxPacketSize =       cpu_to_le16(2),
 380         .bInterval =            32,     /* frames -> 32 ms */
 381 };
 382
 383 #ifndef FSG_NO_OTG
 384 #  define FSG_FS_FUNCTION_PRE_EP_ENTRIES        2
 385 #else
 386 #  define FSG_FS_FUNCTION_PRE_EP_ENTRIES        1
 387 #endif
 388
 389 #endif
 390
 391 static struct usb_descriptor_header *fsg_fs_function[] = {
 392 #ifndef FSG_NO_OTG
 393         (struct usb_descriptor_header *) &fsg_otg_desc,
 394 #endif
 395         (struct usb_descriptor_header *) &fsg_intf_desc,
 396         (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
 397         (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
 398 #ifndef FSG_NO_INTR_EP
 399         (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
 400 #endif
 401         NULL,
 402 };
 403
 404
 405 /*
 406  * USB 2.0 devices need to expose both high speed and full speed
 407  * descriptors, unless they only run at full speed.
 408  *
 409  * That means alternate endpoint descriptors (bigger packets)
 410  * and a "device qualifier" ... plus more construction options
 411  * for the configuration descriptor.
 412  */
 413 static struct usb_endpoint_descriptor
 414 fsg_hs_bulk_in_desc = {
 415         .bLength =              USB_DT_ENDPOINT_SIZE,
 416         .bDescriptorType =      USB_DT_ENDPOINT,
 417
 418         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
 419         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 420         .wMaxPacketSize =       cpu_to_le16(512),
 421 };
 422
 423 static struct usb_endpoint_descriptor
 424 fsg_hs_bulk_out_desc = {
 425         .bLength =              USB_DT_ENDPOINT_SIZE,
 426         .bDescriptorType =      USB_DT_ENDPOINT,
 427
 428         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
 429         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 430         .wMaxPacketSize =       cpu_to_le16(512),
 431         .bInterval =            1,      /* NAK every 1 uframe */
 432 };
 433
 434 #ifndef FSG_NO_INTR_EP
 435
 436 static struct usb_endpoint_descriptor
 437 fsg_hs_intr_in_desc = {
 438         .bLength =              USB_DT_ENDPOINT_SIZE,
 439         .bDescriptorType =      USB_DT_ENDPOINT,
 440
 441         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
 442         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 443         .wMaxPacketSize =       cpu_to_le16(2),
 444         .bInterval =            9,      /* 2**(9-1) = 256 uframes -> 32 ms */
 445 };
 446
 447 #ifndef FSG_NO_OTG
 448 #  define FSG_HS_FUNCTION_PRE_EP_ENTRIES        2
 449 #else
 450 #  define FSG_HS_FUNCTION_PRE_EP_ENTRIES        1
 451 #endif
 452
 453 #endif
 454
 455 static struct usb_descriptor_header *fsg_hs_function[] = {
 456 #ifndef FSG_NO_OTG
 457         (struct usb_descriptor_header *) &fsg_otg_desc,
 458 #endif
 459         (struct usb_descriptor_header *) &fsg_intf_desc,
 460         (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
 461         (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
 462 #ifndef FSG_NO_INTR_EP
 463         (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
 464 #endif
 465         NULL,
 466 };
 467
 468 static struct usb_endpoint_descriptor
 469 fsg_ss_bulk_in_desc = {
 470         .bLength =              USB_DT_ENDPOINT_SIZE,
 471         .bDescriptorType =      USB_DT_ENDPOINT,
 472
 473         /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
 474         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 475         .wMaxPacketSize =       cpu_to_le16(1024),
 476 };
 477
 478 static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
 479         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 480         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 481
 482         /*.bMaxBurst =          DYNAMIC, */
 483 };
 484
 485 static struct usb_endpoint_descriptor
 486 fsg_ss_bulk_out_desc = {
 487         .bLength =              USB_DT_ENDPOINT_SIZE,
 488         .bDescriptorType =      USB_DT_ENDPOINT,
 489
 490         /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
 491         .bmAttributes =         USB_ENDPOINT_XFER_BULK,
 492         .wMaxPacketSize =       cpu_to_le16(1024),
 493 };
 494
 495 static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
 496         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 497         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 498
 499         /*.bMaxBurst =          DYNAMIC, */
 500 };
 501
 502 #ifndef FSG_NO_INTR_EP
 503
 504 static struct usb_endpoint_descriptor
 505 fsg_ss_intr_in_desc = {
 506         .bLength =              USB_DT_ENDPOINT_SIZE,
 507         .bDescriptorType =      USB_DT_ENDPOINT,
 508
 509         /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
 510         .bmAttributes =         USB_ENDPOINT_XFER_INT,
 511         .wMaxPacketSize =       cpu_to_le16(2),
 512         .bInterval =            9,      /* 2**(9-1) = 256 uframes -> 32 ms */
 513 };
 514
 515 static struct usb_ss_ep_comp_descriptor fsg_ss_intr_in_comp_desc = {
 516         .bLength =              sizeof(fsg_ss_bulk_in_comp_desc),
 517         .bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
 518
 519         .wBytesPerInterval =    cpu_to_le16(2),
 520 };
 521
 522 #ifndef FSG_NO_OTG
 523 #  define FSG_SS_FUNCTION_PRE_EP_ENTRIES        2
 524 #else
 525 #  define FSG_SS_FUNCTION_PRE_EP_ENTRIES        1
 526 #endif
 527
 528 #endif
 529
 530 static __maybe_unused struct usb_ext_cap_descriptor fsg_ext_cap_desc = {
 531         .bLength =              USB_DT_USB_EXT_CAP_SIZE,
 532         .bDescriptorType =      USB_DT_DEVICE_CAPABILITY,
 533         .bDevCapabilityType =   USB_CAP_TYPE_EXT,
 534
 535         .bmAttributes =         cpu_to_le32(USB_LPM_SUPPORT),
 536 };
 537
 538 static __maybe_unused struct usb_ss_cap_descriptor fsg_ss_cap_desc = {
 539         .bLength =              USB_DT_USB_SS_CAP_SIZE,
 540         .bDescriptorType =      USB_DT_DEVICE_CAPABILITY,
 541         .bDevCapabilityType =   USB_SS_CAP_TYPE,
 542
 543         /* .bmAttributes = LTM is not supported yet */
 544
 545         .wSpeedSupported =      cpu_to_le16(USB_LOW_SPEED_OPERATION
 546                 | USB_FULL_SPEED_OPERATION
 547                 | USB_HIGH_SPEED_OPERATION
 548                 | USB_5GBPS_OPERATION),
 549         .bFunctionalitySupport = USB_LOW_SPEED_OPERATION,
 550         .bU1devExitLat =        USB_DEFAULT_U1_DEV_EXIT_LAT,
 551         .bU2DevExitLat =        cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT),
 552 };
 553
 554 static __maybe_unused struct usb_bos_descriptor fsg_bos_desc = {
 555         .bLength =              USB_DT_BOS_SIZE,
 556         .bDescriptorType =      USB_DT_BOS,
 557
 558         .wTotalLength =         cpu_to_le16(USB_DT_BOS_SIZE
 559                                 + USB_DT_USB_EXT_CAP_SIZE
 560                                 + USB_DT_USB_SS_CAP_SIZE),
 561
 562         .bNumDeviceCaps =       2,
 563 };
 564
 565 static struct usb_descriptor_header *fsg_ss_function[] = {
 566 #ifndef FSG_NO_OTG
 567         (struct usb_descriptor_header *) &fsg_otg_desc,
 568 #endif
 569         (struct usb_descriptor_header *) &fsg_intf_desc,
 570         (struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
 571         (struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
 572         (struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
 573         (struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
 574 #ifndef FSG_NO_INTR_EP
 575         (struct usb_descriptor_header *) &fsg_ss_intr_in_desc,
 576         (struct usb_descriptor_header *) &fsg_ss_intr_in_comp_desc,
 577 #endif
 578         NULL,
 579 };
 580
 581 /* Maxpacket and other transfer characteristics vary by speed. */
 582 static __maybe_unused struct usb_endpoint_descriptor *
 583 fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
 584                 struct usb_endpoint_descriptor *hs,
 585                 struct usb_endpoint_descriptor *ss)
 586 {
 587         if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
 588                 return ss;
 589         else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
 590                 return hs;
 591         return fs;
 592 }
 593
 594
 595 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 596 static struct usb_string                fsg_strings[] = {
 597 #ifndef FSG_NO_DEVICE_STRINGS
 598         {FSG_STRING_MANUFACTURER,       fsg_string_manufacturer},
 599         {FSG_STRING_PRODUCT,            fsg_string_product},
 600         {FSG_STRING_SERIAL,             ""},
 601         {FSG_STRING_CONFIG,             fsg_string_config},
 602 #endif
 603         {FSG_STRING_INTERFACE,          fsg_string_interface},
 604         {}
 605 };
 606
 607 static struct usb_gadget_strings        fsg_stringtab = {
 608         .language       = 0x0409,               /* en-us */
 609         .strings        = fsg_strings,
 610 };
 611
 612
 613  /*-------------------------------------------------------------------------*/
 614
 615 /*
 616  * If the next two routines are called while the gadget is registered,
 617  * the caller must own fsg->filesem for writing.
 618  */
 619
 620 static void fsg_lun_close(struct fsg_lun *curlun)
 621 {
 622         if (curlun->filp) {
 623                 LDBG(curlun, "close backing file\n");
 624                 fput(curlun->filp);
 625                 curlun->filp = NULL;
 626         }
 627 }
 628
 629
 630 static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 631 {
 632         int                             ro;
 633         struct file                     *filp = NULL;
 634         int                             rc = -EINVAL;
 635         struct inode                    *inode = NULL;
 636         loff_t                          size;
 637         loff_t                          num_sectors;
 638         loff_t                          min_sectors;
 639         unsigned int                    blkbits;
 640         unsigned int                    blksize;
 641
 642         /* R/W if we can, R/O if we must */
 643         ro = curlun->initially_ro;
 644         if (!ro) {
 645                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
 646                 if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
 647                         ro = 1;
 648         }
 649         if (ro)
 650                 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
 651         if (IS_ERR(filp)) {
 652                 LINFO(curlun, "unable to open backing file: %s\n", filename);
 653                 return PTR_ERR(filp);
 654         }
 655
 656         if (!(filp->f_mode & FMODE_WRITE))
 657                 ro = 1;
 658
 659         if (filp->f_path.dentry)
 660                 inode = filp->f_path.dentry->d_inode;
 661         if (!inode || (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
 662                 LINFO(curlun, "invalid file type: %s\n", filename);
 663                 goto out;
 664         }
 665
 666         /*
 667          * If we can't read the file, it's no good.
 668          * If we can't write the file, use it read-only.
 669          */
 670         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
 671                 LINFO(curlun, "file not readable: %s\n", filename);
 672                 goto out;
 673         }
 674         if (!(filp->f_op->write || filp->f_op->aio_write))
 675                 ro = 1;
 676
 677         size = i_size_read(inode->i_mapping->host);
 678         if (size < 0) {
 679                 LINFO(curlun, "unable to find file size: %s\n", filename);
 680                 rc = (int) size;
 681                 goto out;
 682         }
 683
 684         if (curlun->cdrom) {
 685                 blksize = 2048;
 686                 blkbits = 11;
 687         } else if (inode->i_bdev) {
 688                 blksize = bdev_logical_block_size(inode->i_bdev);
 689                 blkbits = blksize_bits(blksize);
 690         } else {
 691                 blksize = 512;
 692                 blkbits = 9;
 693         }
 694
 695         num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
 696         min_sectors = 1;
 697         if (curlun->cdrom) {
 698                 min_sectors = 300;      /* Smallest track is 300 frames */
 699                 if (num_sectors >= 256*60*75) {
 700                         num_sectors = 256*60*75 - 1;
 701                         LINFO(curlun, "file too big: %s\n", filename);
 702                         LINFO(curlun, "using only first %d blocks\n",
 703                                         (int) num_sectors);
 704                 }
 705         }
 706         if (num_sectors < min_sectors) {
 707                 LINFO(curlun, "file too small: %s\n", filename);
 708                 rc = -ETOOSMALL;
 709                 goto out;
 710         }
 711
 712         if (fsg_lun_is_open(curlun))
 713                 fsg_lun_close(curlun);
 714
 715         get_file(filp);
 716         curlun->blksize = blksize;
 717         curlun->blkbits = blkbits;
 718         curlun->ro = ro;
 719         curlun->filp = filp;
 720         curlun->file_length = size;
 721         curlun->num_sectors = num_sectors;
 722         LDBG(curlun, "open backing file: %s\n", filename);
 723         rc = 0;
 724
 725 out:
 726         filp_close(filp, current->files);
 727         return rc;
 728 }
 729
 730
 731 /*-------------------------------------------------------------------------*/
 732
 733 /*
 734  * Sync the file data, don't bother with the metadata.
 735  * This code was copied from fs/buffer.c:sys_fdatasync().
 736  */
 737 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
 738 {
 739         struct file     *filp = curlun->filp;
 740
 741         if (curlun->ro || !filp)
 742                 return 0;
 743         return vfs_fsync(filp, 1);
 744 }
 745
 746 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
 747 {
 748         if (msf) {
 749                 /* Convert to Minutes-Seconds-Frames */
 750                 addr >>= 2;             /* Convert to 2048-byte frames */
 751                 addr += 2*75;           /* Lead-in occupies 2 seconds */
 752                 dest[3] = addr % 75;    /* Frames */
 753                 addr /= 75;
 754                 dest[2] = addr % 60;    /* Seconds */
 755                 addr /= 60;
 756                 dest[1] = addr;         /* Minutes */
 757                 dest[0] = 0;            /* Reserved */
 758         } else {
 759                 /* Absolute sector */
 760                 put_unaligned_be32(addr, dest);
 761         }
 762 }
 763
 764
 765 /*-------------------------------------------------------------------------*/
 766
 767
 768 static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
 769                            char *buf)
 770 {
 771         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 772
 773         return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
 774                                   ? curlun->ro
 775                                   : curlun->initially_ro);
 776 }
 777
 778 static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
 779                               char *buf)
 780 {
 781         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 782
 783         return sprintf(buf, "%u\n", curlun->nofua);
 784 }
 785
 786 static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
 787                              char *buf)
 788 {
 789         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 790         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 791         char            *p;
 792         ssize_t         rc;
 793
 794         down_read(filesem);
 795         if (fsg_lun_is_open(curlun)) {  /* Get the complete pathname */
 796                 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
 797                 if (IS_ERR(p))
 798                         rc = PTR_ERR(p);
 799                 else {
 800                         rc = strlen(p);
 801                         memmove(buf, p, rc);
 802                         buf[rc] = '\n';         /* Add a newline */
 803                         buf[++rc] = 0;
 804                 }
 805         } else {                                /* No file, return 0 bytes */
 806                 *buf = 0;
 807                 rc = 0;
 808         }
 809         up_read(filesem);
 810         return rc;
 811 }
 812
 813
 814 static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
 815                             const char *buf, size_t count)
 816 {
 817         ssize_t         rc;
 818         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 819         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 820         unsigned        ro;
 821
 822         rc = kstrtouint(buf, 2, &ro);
 823         if (rc)
 824                 return rc;
 825
 826         /*
 827          * Allow the write-enable status to change only while the
 828          * backing file is closed.
 829          */
 830         down_read(filesem);
 831         if (fsg_lun_is_open(curlun)) {
 832                 LDBG(curlun, "read-only status change prevented\n");
 833                 rc = -EBUSY;
 834         } else {
 835                 curlun->ro = ro;
 836                 curlun->initially_ro = ro;
 837                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
 838                 rc = count;
 839         }
 840         up_read(filesem);
 841         return rc;
 842 }
 843
 844 static ssize_t fsg_store_nofua(struct device *dev,
 845                                struct device_attribute *attr,
 846                                const char *buf, size_t count)
 847 {
 848         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 849         unsigned        nofua;
 850         int             ret;
 851
 852         ret = kstrtouint(buf, 2, &nofua);
 853         if (ret)
 854                 return ret;
 855
 856         /* Sync data when switching from async mode to sync */
 857         if (!nofua && curlun->nofua)
 858                 fsg_lun_fsync_sub(curlun);
 859
 860         curlun->nofua = nofua;
 861
 862         return count;
 863 }
 864
 865 static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
 866                               const char *buf, size_t count)
 867 {
 868         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 869         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
 870         int             rc = 0;
 871
 872         if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
 873                 LDBG(curlun, "eject attempt prevented\n");
 874                 return -EBUSY;                          /* "Door is locked" */
 875         }
 876
 877         /* Remove a trailing newline */
 878         if (count > 0 && buf[count-1] == '\n')
 879                 ((char *) buf)[count-1] = 0;            /* Ugh! */
 880
 881
 882         /* Load new medium */
 883         down_write(filesem);
 884         if (count > 0 && buf[0]) {
 885                 /* fsg_lun_open() will close existing file if any. */
 886                 rc = fsg_lun_open(curlun, buf);
 887                 if (rc == 0)
 888                         curlun->unit_attention_data =
 889                                         SS_NOT_READY_TO_READY_TRANSITION;
 890         } else if (fsg_lun_is_open(curlun)) {
 891                 fsg_lun_close(curlun);
 892                 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
 893         }
 894         up_write(filesem);
 895         return (rc < 0 ? rc : count);
 896 }