drivers/usb/gadget/f_fs.c

   1 /*
   2  * f_fs.c -- user mode file system API for USB composite function controllers
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  * Author: Michal Nazarewicz <mina86@mina86.com>
   6  *
   7  * Based on inode.c (GadgetFS) which was:
   8  * Copyright (C) 2003-2004 David Brownell
   9  * Copyright (C) 2003 Agilent Technologies
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  */
  16
  17
  18 /* #define DEBUG */
  19 /* #define VERBOSE_DEBUG */
  20
  21 #include <linux/blkdev.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/export.h>
  24 #include <linux/hid.h>
  25 #include <asm/unaligned.h>
  26
  27 #include <linux/usb/composite.h>
  28 #include <linux/usb/functionfs.h>
  29
  30
  31 #define FUNCTIONFS_MAGIC        0xa647361 /* Chosen by a honest dice roll ;) */
  32
  33
  34 /* Debugging ****************************************************************/
  35
  36 #ifdef VERBOSE_DEBUG
  37 #  define pr_vdebug pr_debug
  38 #  define ffs_dump_mem(prefix, ptr, len) \
  39         print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
  40 #else
  41 #  define pr_vdebug(...)                 do { } while (0)
  42 #  define ffs_dump_mem(prefix, ptr, len) do { } while (0)
  43 #endif /* VERBOSE_DEBUG */
  44
  45 #define ENTER()    pr_vdebug("%s()\n", __func__)
  46
  47
  48 /* The data structure and setup file ****************************************/
  49
  50 enum ffs_state {
  51         /*
  52          * Waiting for descriptors and strings.
  53          *
  54          * In this state no open(2), read(2) or write(2) on epfiles
  55          * may succeed (which should not be the problem as there
  56          * should be no such files opened in the first place).
  57          */
  58         FFS_READ_DESCRIPTORS,
  59         FFS_READ_STRINGS,
  60
  61         /*
  62          * We've got descriptors and strings.  We are or have called
  63          * functionfs_ready_callback().  functionfs_bind() may have
  64          * been called but we don't know.
  65          *
  66          * This is the only state in which operations on epfiles may
  67          * succeed.
  68          */
  69         FFS_ACTIVE,
  70
  71         /*
  72          * All endpoints have been closed.  This state is also set if
  73          * we encounter an unrecoverable error.  The only
  74          * unrecoverable error is situation when after reading strings
  75          * from user space we fail to initialise epfiles or
  76          * functionfs_ready_callback() returns with error (<0).
  77          *
  78          * In this state no open(2), read(2) or write(2) (both on ep0
  79          * as well as epfile) may succeed (at this point epfiles are
  80          * unlinked and all closed so this is not a problem; ep0 is
  81          * also closed but ep0 file exists and so open(2) on ep0 must
  82          * fail).
  83          */
  84         FFS_CLOSING
  85 };
  86
  87
  88 enum ffs_setup_state {
  89         /* There is no setup request pending. */
  90         FFS_NO_SETUP,
  91         /*
  92          * User has read events and there was a setup request event
  93          * there.  The next read/write on ep0 will handle the
  94          * request.
  95          */
  96         FFS_SETUP_PENDING,
  97         /*
  98          * There was event pending but before user space handled it
  99          * some other event was introduced which canceled existing
 100          * setup.  If this state is set read/write on ep0 return
 101          * -EIDRM.  This state is only set when adding event.
 102          */
 103         FFS_SETUP_CANCELED
 104 };
 105
 106
 107
 108 struct ffs_epfile;
 109 struct ffs_function;
 110
 111 struct ffs_data {
 112         struct usb_gadget               *gadget;
 113
 114         /*
 115          * Protect access read/write operations, only one read/write
 116          * at a time.  As a consequence protects ep0req and company.
 117          * While setup request is being processed (queued) this is
 118          * held.
 119          */
 120         struct mutex                    mutex;
 121
 122         /*
 123          * Protect access to endpoint related structures (basically
 124          * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
 125          * endpoint zero.
 126          */
 127         spinlock_t                      eps_lock;
 128
 129         /*
 130          * XXX REVISIT do we need our own request? Since we are not
 131          * handling setup requests immediately user space may be so
 132          * slow that another setup will be sent to the gadget but this
 133          * time not to us but another function and then there could be
 134          * a race.  Is that the case? Or maybe we can use cdev->req
 135          * after all, maybe we just need some spinlock for that?
 136          */
 137         struct usb_request              *ep0req;                /* P: mutex */
 138         struct completion               ep0req_completion;      /* P: mutex */
 139         int                             ep0req_status;          /* P: mutex */
 140
 141         /* reference counter */
 142         atomic_t                        ref;
 143         /* how many files are opened (EP0 and others) */
 144         atomic_t                        opened;
 145
 146         /* EP0 state */
 147         enum ffs_state                  state;
 148
 149         /*
 150          * Possible transitions:
 151          * + FFS_NO_SETUP       -> FFS_SETUP_PENDING  -- P: ev.waitq.lock
 152          *               happens only in ep0 read which is P: mutex
 153          * + FFS_SETUP_PENDING  -> FFS_NO_SETUP       -- P: ev.waitq.lock
 154          *               happens only in ep0 i/o  which is P: mutex
 155          * + FFS_SETUP_PENDING  -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
 156          * + FFS_SETUP_CANCELED -> FFS_NO_SETUP       -- cmpxchg
 157          */
 158         enum ffs_setup_state            setup_state;
 159
 160 #define FFS_SETUP_STATE(ffs)                                    \
 161         ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state,     \
 162                                        FFS_SETUP_CANCELED, FFS_NO_SETUP))
 163
 164         /* Events & such. */
 165         struct {
 166                 u8                              types[4];
 167                 unsigned short                  count;
 168                 /* XXX REVISIT need to update it in some places, or do we? */
 169                 unsigned short                  can_stall;
 170                 struct usb_ctrlrequest          setup;
 171
 172                 wait_queue_head_t               waitq;
 173         } ev; /* the whole structure, P: ev.waitq.lock */
 174
 175         /* Flags */
 176         unsigned long                   flags;
 177 #define FFS_FL_CALL_CLOSED_CALLBACK 0
 178 #define FFS_FL_BOUND                1
 179
 180         /* Active function */
 181         struct ffs_function             *func;
 182
 183         /*
 184          * Device name, write once when file system is mounted.
 185          * Intended for user to read if she wants.
 186          */
 187         const char                      *dev_name;
 188         /* Private data for our user (ie. gadget).  Managed by user. */
 189         void                            *private_data;
 190
 191         /* filled by __ffs_data_got_descs() */
 192         /*
 193          * Real descriptors are 16 bytes after raw_descs (so you need
 194          * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
 195          * first full speed descriptor).  raw_descs_length and
 196          * raw_fs_descs_length do not have those 16 bytes added.
 197          */
 198         const void                      *raw_descs;
 199         unsigned                        raw_descs_length;
 200         unsigned                        raw_fs_descs_length;
 201         unsigned                        fs_descs_count;
 202         unsigned                        hs_descs_count;
 203
 204         unsigned short                  strings_count;
 205         unsigned short                  interfaces_count;
 206         unsigned short                  eps_count;
 207         unsigned short                  _pad1;
 208
 209         /* filled by __ffs_data_got_strings() */
 210         /* ids in stringtabs are set in functionfs_bind() */
 211         const void                      *raw_strings;
 212         struct usb_gadget_strings       **stringtabs;
 213
 214         /*
 215          * File system's super block, write once when file system is
 216          * mounted.
 217          */
 218         struct super_block              *sb;
 219
 220         /* File permissions, written once when fs is mounted */
 221         struct ffs_file_perms {
 222                 umode_t                         mode;
 223                 uid_t                           uid;
 224                 gid_t                           gid;
 225         }                               file_perms;
 226
 227         /*
 228          * The endpoint files, filled by ffs_epfiles_create(),
 229          * destroyed by ffs_epfiles_destroy().
 230          */
 231         struct ffs_epfile               *epfiles;
 232 };
 233
 234 /* Reference counter handling */
 235 static void ffs_data_get(struct ffs_data *ffs);
 236 static void ffs_data_put(struct ffs_data *ffs);
 237 /* Creates new ffs_data object. */
 238 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
 239
 240 /* Opened counter handling. */
 241 static void ffs_data_opened(struct ffs_data *ffs);
 242 static void ffs_data_closed(struct ffs_data *ffs);
 243
 244 /* Called with ffs->mutex held; take over ownership of data. */
 245 static int __must_check
 246 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
 247 static int __must_check
 248 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
 249
 250
 251 /* The function structure ***************************************************/
 252
 253 struct ffs_ep;
 254
 255 struct ffs_function {
 256         struct usb_configuration        *conf;
 257         struct usb_gadget               *gadget;
 258         struct ffs_data                 *ffs;
 259
 260         struct ffs_ep                   *eps;
 261         u8                              eps_revmap[16];
 262         short                           *interfaces_nums;
 263
 264         struct usb_function             function;
 265 };
 266
 267
 268 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
 269 {
 270         return container_of(f, struct ffs_function, function);
 271 }
 272
 273 static void ffs_func_free(struct ffs_function *func);
 274
 275 static void ffs_func_eps_disable(struct ffs_function *func);
 276 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
 277
 278 static int ffs_func_bind(struct usb_configuration *,
 279                          struct usb_function *);
 280 static void ffs_func_unbind(struct usb_configuration *,
 281                             struct usb_function *);
 282 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
 283 static void ffs_func_disable(struct usb_function *);
 284 static int ffs_func_setup(struct usb_function *,
 285                           const struct usb_ctrlrequest *);
 286 static void ffs_func_suspend(struct usb_function *);
 287 static void ffs_func_resume(struct usb_function *);
 288
 289
 290 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
 291 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
 292
 293
 294 /* The endpoints structures *************************************************/
 295
 296 struct ffs_ep {
 297         struct usb_ep                   *ep;    /* P: ffs->eps_lock */
 298         struct usb_request              *req;   /* P: epfile->mutex */
 299
 300         /* [0]: full speed, [1]: high speed */
 301         struct usb_endpoint_descriptor  *descs[2];
 302
 303         u8                              num;
 304
 305         int                             status; /* P: epfile->mutex */
 306 };
 307
 308 struct ffs_epfile {
 309         /* Protects ep->ep and ep->req. */
 310         struct mutex                    mutex;
 311         wait_queue_head_t               wait;
 312
 313         struct ffs_data                 *ffs;
 314         struct ffs_ep                   *ep;    /* P: ffs->eps_lock */
 315
 316         struct dentry                   *dentry;
 317
 318         char                            name[5];
 319
 320         unsigned char                   in;     /* P: ffs->eps_lock */
 321         unsigned char                   isoc;   /* P: ffs->eps_lock */
 322
 323         unsigned char                   _pad;
 324 };
 325
 326 static int  __must_check ffs_epfiles_create(struct ffs_data *ffs);
 327 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
 328
 329 static struct inode *__must_check
 330 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
 331                    const struct file_operations *fops,
 332                    struct dentry **dentry_p);
 333
 334
 335 /* Misc helper functions ****************************************************/
 336
 337 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
 338         __attribute__((warn_unused_result, nonnull));
 339 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
 340         __attribute__((warn_unused_result, nonnull));
 341
 342
 343 /* Control file aka ep0 *****************************************************/
 344
 345 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
 346 {
 347         struct ffs_data *ffs = req->context;
 348
 349         complete_all(&ffs->ep0req_completion);
 350 }
 351
 352 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 353 {
 354         struct usb_request *req = ffs->ep0req;
 355         int ret;
 356
 357         req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
 358
 359         spin_unlock_irq(&ffs->ev.waitq.lock);
 360
 361         req->buf      = data;
 362         req->length   = len;
 363
 364         /*
 365          * UDC layer requires to provide a buffer even for ZLP, but should
 366          * not use it at all. Let's provide some poisoned pointer to catch
 367          * possible bug in the driver.
 368          */
 369         if (req->buf == NULL)
 370                 req->buf = (void *)0xDEADBABE;
 371
 372         INIT_COMPLETION(ffs->ep0req_completion);
 373
 374         ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
 375         if (unlikely(ret < 0))
 376                 return ret;
 377
 378         ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
 379         if (unlikely(ret)) {
 380                 usb_ep_dequeue(ffs->gadget->ep0, req);
 381                 return -EINTR;
 382         }
 383
 384         ffs->setup_state = FFS_NO_SETUP;
 385         return ffs->ep0req_status;
 386 }
 387
 388 static int __ffs_ep0_stall(struct ffs_data *ffs)
 389 {
 390         if (ffs->ev.can_stall) {
 391                 pr_vdebug("ep0 stall\n");
 392                 usb_ep_set_halt(ffs->gadget->ep0);
 393                 ffs->setup_state = FFS_NO_SETUP;
 394                 return -EL2HLT;
 395         } else {
 396                 pr_debug("bogus ep0 stall!\n");
 397                 return -ESRCH;
 398         }
 399 }
 400
 401 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 402                              size_t len, loff_t *ptr)
 403 {
 404         struct ffs_data *ffs = file->private_data;
 405         ssize_t ret;
 406         char *data;
 407
 408         ENTER();
 409
 410         /* Fast check if setup was canceled */
 411         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 412                 return -EIDRM;
 413
 414         /* Acquire mutex */
 415         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 416         if (unlikely(ret < 0))
 417                 return ret;
 418
 419         /* Check state */
 420         switch (ffs->state) {
 421         case FFS_READ_DESCRIPTORS:
 422         case FFS_READ_STRINGS:
 423                 /* Copy data */
 424                 if (unlikely(len < 16)) {
 425                         ret = -EINVAL;
 426                         break;
 427                 }
 428
 429                 data = ffs_prepare_buffer(buf, len);
 430                 if (IS_ERR(data)) {
 431                         ret = PTR_ERR(data);
 432                         break;
 433                 }
 434
 435                 /* Handle data */
 436                 if (ffs->state == FFS_READ_DESCRIPTORS) {
 437                         pr_info("read descriptors\n");
 438                         ret = __ffs_data_got_descs(ffs, data, len);
 439                         if (unlikely(ret < 0))
 440                                 break;
 441
 442                         ffs->state = FFS_READ_STRINGS;
 443                         ret = len;
 444                 } else {
 445                         pr_info("read strings\n");
 446                         ret = __ffs_data_got_strings(ffs, data, len);
 447                         if (unlikely(ret < 0))
 448                                 break;
 449
 450                         ret = ffs_epfiles_create(ffs);
 451                         if (unlikely(ret)) {
 452                                 ffs->state = FFS_CLOSING;
 453                                 break;
 454                         }
 455
 456                         ffs->state = FFS_ACTIVE;
 457                         mutex_unlock(&ffs->mutex);
 458
 459                         ret = functionfs_ready_callback(ffs);
 460                         if (unlikely(ret < 0)) {
 461                                 ffs->state = FFS_CLOSING;
 462                                 return ret;
 463                         }
 464
 465                         set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
 466                         return len;
 467                 }
 468                 break;
 469
 470         case FFS_ACTIVE:
 471                 data = NULL;
 472                 /*
 473                  * We're called from user space, we can use _irq
 474                  * rather then _irqsave
 475                  */
 476                 spin_lock_irq(&ffs->ev.waitq.lock);
 477                 switch (FFS_SETUP_STATE(ffs)) {
 478                 case FFS_SETUP_CANCELED:
 479                         ret = -EIDRM;
 480                         goto done_spin;
 481
 482                 case FFS_NO_SETUP:
 483                         ret = -ESRCH;
 484                         goto done_spin;
 485
 486                 case FFS_SETUP_PENDING:
 487                         break;
 488                 }
 489
 490                 /* FFS_SETUP_PENDING */
 491                 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
 492                         spin_unlock_irq(&ffs->ev.waitq.lock);
 493                         ret = __ffs_ep0_stall(ffs);
 494                         break;
 495                 }
 496
 497                 /* FFS_SETUP_PENDING and not stall */
 498                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 499
 500                 spin_unlock_irq(&ffs->ev.waitq.lock);
 501
 502                 data = ffs_prepare_buffer(buf, len);
 503                 if (IS_ERR(data)) {
 504                         ret = PTR_ERR(data);
 505                         break;
 506                 }
 507
 508                 spin_lock_irq(&ffs->ev.waitq.lock);
 509
 510                 /*
 511                  * We are guaranteed to be still in FFS_ACTIVE state
 512                  * but the state of setup could have changed from
 513                  * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need
 514                  * to check for that.  If that happened we copied data
 515                  * from user space in vain but it's unlikely.
 516                  *
 517                  * For sure we are not in FFS_NO_SETUP since this is
 518                  * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
 519                  * transition can be performed and it's protected by
 520                  * mutex.
 521                  */
 522                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 523                         ret = -EIDRM;
 524 done_spin:
 525                         spin_unlock_irq(&ffs->ev.waitq.lock);
 526                 } else {
 527                         /* unlocks spinlock */
 528                         ret = __ffs_ep0_queue_wait(ffs, data, len);
 529                 }
 530                 kfree(data);
 531                 break;
 532
 533         default:
 534                 ret = -EBADFD;
 535                 break;
 536         }
 537
 538         mutex_unlock(&ffs->mutex);
 539         return ret;
 540 }
 541
 542 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
 543                                      size_t n)
 544 {
 545         /*
 546          * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
 547          * to release them.
 548          */
 549         struct usb_functionfs_event events[n];
 550         unsigned i = 0;
 551
 552         memset(events, 0, sizeof events);
 553
 554         do {
 555                 events[i].type = ffs->ev.types[i];
 556                 if (events[i].type == FUNCTIONFS_SETUP) {
 557                         events[i].u.setup = ffs->ev.setup;
 558                         ffs->setup_state = FFS_SETUP_PENDING;
 559                 }
 560         } while (++i < n);
 561
 562         if (n < ffs->ev.count) {
 563                 ffs->ev.count -= n;
 564                 memmove(ffs->ev.types, ffs->ev.types + n,
 565                         ffs->ev.count * sizeof *ffs->ev.types);
 566         } else {
 567                 ffs->ev.count = 0;
 568         }
 569
 570         spin_unlock_irq(&ffs->ev.waitq.lock);
 571         mutex_unlock(&ffs->mutex);
 572
 573         return unlikely(__copy_to_user(buf, events, sizeof events))
 574                 ? -EFAULT : sizeof events;
 575 }
 576
 577 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 578                             size_t len, loff_t *ptr)
 579 {
 580         struct ffs_data *ffs = file->private_data;
 581         char *data = NULL;
 582         size_t n;
 583         int ret;
 584
 585         ENTER();
 586
 587         /* Fast check if setup was canceled */
 588         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 589                 return -EIDRM;
 590
 591         /* Acquire mutex */
 592         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 593         if (unlikely(ret < 0))
 594                 return ret;
 595
 596         /* Check state */
 597         if (ffs->state != FFS_ACTIVE) {
 598                 ret = -EBADFD;
 599                 goto done_mutex;
 600         }
 601
 602         /*
 603          * We're called from user space, we can use _irq rather then
 604          * _irqsave
 605          */
 606         spin_lock_irq(&ffs->ev.waitq.lock);
 607
 608         switch (FFS_SETUP_STATE(ffs)) {
 609         case FFS_SETUP_CANCELED:
 610                 ret = -EIDRM;
 611                 break;
 612
 613         case FFS_NO_SETUP:
 614                 n = len / sizeof(struct usb_functionfs_event);
 615                 if (unlikely(!n)) {
 616                         ret = -EINVAL;
 617                         break;
 618                 }
 619
 620                 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
 621                         ret = -EAGAIN;
 622                         break;
 623                 }
 624
 625                 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
 626                                                         ffs->ev.count)) {
 627                         ret = -EINTR;
 628                         break;
 629                 }
 630
 631                 return __ffs_ep0_read_events(ffs, buf,
 632                                              min(n, (size_t)ffs->ev.count));
 633
 634         case FFS_SETUP_PENDING:
 635                 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
 636                         spin_unlock_irq(&ffs->ev.waitq.lock);
 637                         ret = __ffs_ep0_stall(ffs);
 638                         goto done_mutex;
 639                 }
 640
 641                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 642
 643                 spin_unlock_irq(&ffs->ev.waitq.lock);
 644
 645                 if (likely(len)) {
 646                         data = kmalloc(len, GFP_KERNEL);
 647                         if (unlikely(!data)) {
 648                                 ret = -ENOMEM;
 649                                 goto done_mutex;
 650                         }
 651                 }
 652
 653                 spin_lock_irq(&ffs->ev.waitq.lock);
 654
 655                 /* See ffs_ep0_write() */
 656                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 657                         ret = -EIDRM;
 658                         break;
 659                 }
 660
 661                 /* unlocks spinlock */
 662                 ret = __ffs_ep0_queue_wait(ffs, data, len);
 663                 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
 664                         ret = -EFAULT;
 665                 goto done_mutex;
 666
 667         default:
 668                 ret = -EBADFD;
 669                 break;
 670         }
 671
 672         spin_unlock_irq(&ffs->ev.waitq.lock);
 673 done_mutex:
 674         mutex_unlock(&ffs->mutex);
 675         kfree(data);
 676         return ret;
 677 }
 678
 679 static int ffs_ep0_open(struct inode *inode, struct file *file)
 680 {
 681         struct ffs_data *ffs = inode->i_private;
 682
 683         ENTER();
 684
 685         if (unlikely(ffs->state == FFS_CLOSING))
 686                 return -EBUSY;
 687
 688         file->private_data = ffs;
 689         ffs_data_opened(ffs);
 690
 691         return 0;
 692 }
 693
 694 static int ffs_ep0_release(struct inode *inode, struct file *file)
 695 {
 696         struct ffs_data *ffs = file->private_data;
 697
 698         ENTER();
 699
 700         ffs_data_closed(ffs);
 701
 702         return 0;
 703 }
 704
 705 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
 706 {
 707         struct ffs_data *ffs = file->private_data;
 708         struct usb_gadget *gadget = ffs->gadget;
 709         long ret;
 710
 711         ENTER();
 712
 713         if (code == FUNCTIONFS_INTERFACE_REVMAP) {
 714                 struct ffs_function *func = ffs->func;
 715                 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
 716         } else if (gadget && gadget->ops->ioctl) {
 717                 ret = gadget->ops->ioctl(gadget, code, value);
 718         } else {
 719                 ret = -ENOTTY;
 720         }
 721
 722         return ret;
 723 }
 724
 725 static const struct file_operations ffs_ep0_operations = {
 726         .owner =        THIS_MODULE,
 727         .llseek =       no_llseek,
 728
 729         .open =         ffs_ep0_open,
 730         .write =        ffs_ep0_write,
 731         .read =         ffs_ep0_read,
 732         .release =      ffs_ep0_release,
 733         .unlocked_ioctl =       ffs_ep0_ioctl,
 734 };
 735
 736
 737 /* "Normal" endpoints operations ********************************************/
 738
 739 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
 740 {
 741         ENTER();
 742         if (likely(req->context)) {
 743                 struct ffs_ep *ep = _ep->driver_data;
 744                 ep->status = req->status ? req->status : req->actual;
 745                 complete(req->context);
 746         }
 747 }
 748
 749 static ssize_t ffs_epfile_io(struct file *file,
 750                              char __user *buf, size_t len, int read)
 751 {
 752         struct ffs_epfile *epfile = file->private_data;
 753         struct ffs_ep *ep;
 754         char *data = NULL;
 755         ssize_t ret;
 756         int halt;
 757
 758         goto first_try;
 759         do {
 760                 spin_unlock_irq(&epfile->ffs->eps_lock);
 761                 mutex_unlock(&epfile->mutex);
 762
 763 first_try:
 764                 /* Are we still active? */
 765                 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
 766                         ret = -ENODEV;
 767                         goto error;
 768                 }
 769
 770                 /* Wait for endpoint to be enabled */
 771                 ep = epfile->ep;
 772                 if (!ep) {
 773                         if (file->f_flags & O_NONBLOCK) {
 774                                 ret = -EAGAIN;
 775                                 goto error;
 776                         }
 777
 778                         if (wait_event_interruptible(epfile->wait,
 779                                                      (ep = epfile->ep))) {
 780                                 ret = -EINTR;
 781                                 goto error;
 782                         }
 783                 }
 784
 785                 /* Do we halt? */
 786                 halt = !read == !epfile->in;
 787                 if (halt && epfile->isoc) {
 788                         ret = -EINVAL;
 789                         goto error;
 790                 }
 791
 792                 /* Allocate & copy */
 793                 if (!halt && !data) {
 794                         data = kzalloc(len, GFP_KERNEL);
 795                         if (unlikely(!data))
 796                                 return -ENOMEM;
 797
 798                         if (!read &&
 799                             unlikely(__copy_from_user(data, buf, len))) {
 800                                 ret = -EFAULT;
 801                                 goto error;
 802                         }
 803                 }
 804
 805                 /* We will be using request */
 806                 ret = ffs_mutex_lock(&epfile->mutex,
 807                                      file->f_flags & O_NONBLOCK);
 808                 if (unlikely(ret))
 809                         goto error;
 810
 811                 /*
 812                  * We're called from user space, we can use _irq rather then
 813                  * _irqsave
 814                  */
 815                 spin_lock_irq(&epfile->ffs->eps_lock);
 816
 817                 /*
 818                  * While we were acquiring mutex endpoint got disabled
 819                  * or changed?
 820                  */
 821         } while (unlikely(epfile->ep != ep));
 822
 823         /* Halt */
 824         if (unlikely(halt)) {
 825                 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
 826                         usb_ep_set_halt(ep->ep);
 827                 spin_unlock_irq(&epfile->ffs->eps_lock);
 828                 ret = -EBADMSG;
 829         } else {
 830                 /* Fire the request */
 831                 DECLARE_COMPLETION_ONSTACK(done);
 832
 833                 struct usb_request *req = ep->req;
 834                 req->context  = &done;
 835                 req->complete = ffs_epfile_io_complete;
 836                 req->buf      = data;
 837                 req->length   = len;
 838
 839                 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 840
 841                 spin_unlock_irq(&epfile->ffs->eps_lock);
 842
 843                 if (unlikely(ret < 0)) {
 844                         /* nop */
 845                 } else if (unlikely(wait_for_completion_interruptible(&done))) {
 846                         ret = -EINTR;
 847                         usb_ep_dequeue(ep->ep, req);
 848                 } else {
 849                         ret = ep->status;
 850                         if (read && ret > 0 &&
 851                             unlikely(copy_to_user(buf, data, ret)))
 852                                 ret = -EFAULT;
 853                 }
 854         }
 855
 856         mutex_unlock(&epfile->mutex);
 857 error:
 858         kfree(data);
 859         return ret;
 860 }
 861
 862 static ssize_t
 863 ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
 864                  loff_t *ptr)
 865 {
 866         ENTER();
 867
 868         return ffs_epfile_io(file, (char __user *)buf, len, 0);
 869 }
 870
 871 static ssize_t
 872 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
 873 {
 874         ENTER();
 875
 876         return ffs_epfile_io(file, buf, len, 1);
 877 }
 878
 879 static int
 880 ffs_epfile_open(struct inode *inode, struct file *file)
 881 {
 882         struct ffs_epfile *epfile = inode->i_private;
 883
 884         ENTER();
 885
 886         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 887                 return -ENODEV;
 888
 889         file->private_data = epfile;
 890         ffs_data_opened(epfile->ffs);
 891
 892         return 0;
 893 }
 894
 895 static int
 896 ffs_epfile_release(struct inode *inode, struct file *file)
 897 {
 898         struct ffs_epfile *epfile = inode->i_private;
 899
 900         ENTER();
 901
 902         ffs_data_closed(epfile->ffs);
 903
 904         return 0;
 905 }
 906
 907 static long ffs_epfile_ioctl(struct file *file, unsigned code,
 908                              unsigned long value)
 909 {
 910         struct ffs_epfile *epfile = file->private_data;
 911         int ret;
 912
 913         ENTER();
 914
 915         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 916                 return -ENODEV;
 917
 918         spin_lock_irq(&epfile->ffs->eps_lock);
 919         if (likely(epfile->ep)) {
 920                 switch (code) {
 921                 case FUNCTIONFS_FIFO_STATUS:
 922                         ret = usb_ep_fifo_status(epfile->ep->ep);
 923                         break;
 924                 case FUNCTIONFS_FIFO_FLUSH:
 925                         usb_ep_fifo_flush(epfile->ep->ep);
 926                         ret = 0;
 927                         break;
 928                 case FUNCTIONFS_CLEAR_HALT:
 929                         ret = usb_ep_clear_halt(epfile->ep->ep);
 930                         break;
 931                 case FUNCTIONFS_ENDPOINT_REVMAP:
 932                         ret = epfile->ep->num;
 933                         break;
 934                 default:
 935                         ret = -ENOTTY;
 936                 }
 937         } else {
 938                 ret = -ENODEV;
 939         }
 940         spin_unlock_irq(&epfile->ffs->eps_lock);
 941
 942         return ret;
 943 }
 944
 945 static const struct file_operations ffs_epfile_operations = {
 946         .owner =        THIS_MODULE,
 947         .llseek =       no_llseek,
 948
 949         .open =         ffs_epfile_open,
 950         .write =        ffs_epfile_write,
 951         .read =         ffs_epfile_read,
 952         .release =      ffs_epfile_release,
 953         .unlocked_ioctl =       ffs_epfile_ioctl,
 954 };
 955
 956
 957 /* File system and super block operations ***********************************/
 958
 959 /*
 960  * Mounting the file system creates a controller file, used first for
 961  * function configuration then later for event monitoring.
 962  */
 963
 964 static struct inode *__must_check
 965 ffs_sb_make_inode(struct super_block *sb, void *data,
 966                   const struct file_operations *fops,
 967                   const struct inode_operations *iops,
 968                   struct ffs_file_perms *perms)
 969 {
 970         struct inode *inode;
 971
 972         ENTER();
 973
 974         inode = new_inode(sb);
 975
 976         if (likely(inode)) {
 977                 struct timespec current_time = CURRENT_TIME;
 978
 979                 inode->i_ino     = get_next_ino();
 980                 inode->i_mode    = perms->mode;
 981                 inode->i_uid     = perms->uid;
 982                 inode->i_gid     = perms->gid;
 983                 inode->i_atime   = current_time;
 984                 inode->i_mtime   = current_time;
 985                 inode->i_ctime   = current_time;
 986                 inode->i_private = data;
 987                 if (fops)
 988                         inode->i_fop = fops;
 989                 if (iops)
 990                         inode->i_op  = iops;
 991         }
 992
 993         return inode;
 994 }
 995
 996 /* Create "regular" file */
 997 static struct inode *ffs_sb_create_file(struct super_block *sb,
 998                                         const char *name, void *data,
 999                                         const struct file_operations *fops,
1000                                         struct dentry **dentry_p)
1001 {
1002         struct ffs_data *ffs = sb->s_fs_info;
1003         struct dentry   *dentry;
1004         struct inode    *inode;
1005
1006         ENTER();
1007
1008         dentry = d_alloc_name(sb->s_root, name);
1009         if (unlikely(!dentry))
1010                 return NULL;
1011
1012         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1013         if (unlikely(!inode)) {
1014                 dput(dentry);
1015                 return NULL;
1016         }
1017
1018         d_add(dentry, inode);
1019         if (dentry_p)
1020                 *dentry_p = dentry;
1021
1022         return inode;
1023 }
1024
1025 /* Super block */
1026 static const struct super_operations ffs_sb_operations = {
1027         .statfs =       simple_statfs,
1028         .drop_inode =   generic_delete_inode,
1029 };
1030
1031 struct ffs_sb_fill_data {
1032         struct ffs_file_perms perms;
1033         umode_t root_mode;
1034         const char *dev_name;
1035         union {
1036                 /* set by ffs_fs_mount(), read by ffs_sb_fill() */
1037                 void *private_data;
1038                 /* set by ffs_sb_fill(), read by ffs_fs_mount */
1039                 struct ffs_data *ffs_data;
1040         };
1041 };
1042
1043 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1044 {
1045         struct ffs_sb_fill_data *data = _data;
1046         struct inode    *inode;
1047         struct ffs_data *ffs;
1048
1049         ENTER();
1050
1051         /* Initialise data */
1052         ffs = ffs_data_new();
1053         if (unlikely(!ffs))
1054                 goto Enomem;
1055
1056         ffs->sb              = sb;
1057         ffs->dev_name        = kstrdup(data->dev_name, GFP_KERNEL);
1058         if (unlikely(!ffs->dev_name))
1059                 goto Enomem;
1060         ffs->file_perms      = data->perms;
1061         ffs->private_data    = data->private_data;
1062
1063         /* used by the caller of this function */
1064         data->ffs_data       = ffs;
1065
1066         sb->s_fs_info        = ffs;
1067         sb->s_blocksize      = PAGE_CACHE_SIZE;
1068         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1069         sb->s_magic          = FUNCTIONFS_MAGIC;
1070         sb->s_op             = &ffs_sb_operations;
1071         sb->s_time_gran      = 1;
1072
1073         /* Root inode */
1074         data->perms.mode = data->root_mode;
1075         inode = ffs_sb_make_inode(sb, NULL,
1076                                   &simple_dir_operations,
1077                                   &simple_dir_inode_operations,
1078                                   &data->perms);
1079         sb->s_root = d_make_root(inode);
1080         if (unlikely(!sb->s_root))
1081                 goto Enomem;
1082
1083         /* EP0 file */
1084         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1085                                          &ffs_ep0_operations, NULL)))
1086                 goto Enomem;
1087
1088         return 0;
1089
1090 Enomem:
1091         return -ENOMEM;
1092 }
1093
1094 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1095 {
1096         ENTER();
1097
1098         if (!opts || !*opts)
1099                 return 0;
1100
1101         for (;;) {
1102                 char *end, *eq, *comma;
1103                 unsigned long value;
1104
1105                 /* Option limit */
1106                 comma = strchr(opts, ',');
1107                 if (comma)
1108                         *comma = 0;
1109
1110                 /* Value limit */
1111                 eq = strchr(opts, '=');
1112                 if (unlikely(!eq)) {
1113                         pr_err("'=' missing in %s\n", opts);
1114                         return -EINVAL;
1115                 }
1116                 *eq = 0;
1117
1118                 /* Parse value */
1119                 value = simple_strtoul(eq + 1, &end, 0);
1120                 if (unlikely(*end != ',' && *end != 0)) {
1121                         pr_err("%s: invalid value: %s\n", opts, eq + 1);
1122                         return -EINVAL;
1123                 }
1124
1125                 /* Interpret option */
1126                 switch (eq - opts) {
1127                 case 5:
1128                         if (!memcmp(opts, "rmode", 5))
1129                                 data->root_mode  = (value & 0555) | S_IFDIR;
1130                         else if (!memcmp(opts, "fmode", 5))
1131                                 data->perms.mode = (value & 0666) | S_IFREG;
1132                         else
1133                                 goto invalid;
1134                         break;
1135
1136                 case 4:
1137                         if (!memcmp(opts, "mode", 4)) {
1138                                 data->root_mode  = (value & 0555) | S_IFDIR;
1139                                 data->perms.mode = (value & 0666) | S_IFREG;
1140                         } else {
1141                                 goto invalid;
1142                         }
1143                         break;
1144
1145                 case 3:
1146                         if (!memcmp(opts, "uid", 3))
1147                                 data->perms.uid = value;
1148                         else if (!memcmp(opts, "gid", 3))
1149                                 data->perms.gid = value;
1150                         else
1151                                 goto invalid;
1152                         break;
1153
1154                 default:
1155 invalid:
1156                         pr_err("%s: invalid option\n", opts);
1157                         return -EINVAL;
1158                 }
1159
1160                 /* Next iteration */
1161                 if (!comma)
1162                         break;
1163                 opts = comma + 1;
1164         }
1165
1166         return 0;
1167 }
1168
1169 /* "mount -t functionfs dev_name /dev/function" ends up here */
1170
1171 static struct dentry *
1172 ffs_fs_mount(struct file_system_type *t, int flags,
1173               const char *dev_name, void *opts)
1174 {
1175         struct ffs_sb_fill_data data = {
1176                 .perms = {
1177                         .mode = S_IFREG | 0600,
1178                         .uid = 0,
1179                         .gid = 0
1180                 },
1181                 .root_mode = S_IFDIR | 0500,
1182         };
1183         struct dentry *rv;
1184         int ret;
1185         void *ffs_dev;
1186
1187         ENTER();
1188
1189         ret = ffs_fs_parse_opts(&data, opts);
1190         if (unlikely(ret < 0))
1191                 return ERR_PTR(ret);
1192
1193         ffs_dev = functionfs_acquire_dev_callback(dev_name);
1194         if (IS_ERR(ffs_dev))
1195                 return ffs_dev;
1196
1197         data.dev_name = dev_name;
1198         data.private_data = ffs_dev;
1199         rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1200
1201         /* data.ffs_data is set by ffs_sb_fill */
1202         if (IS_ERR(rv))
1203                 functionfs_release_dev_callback(data.ffs_data);
1204
1205         return rv;
1206 }
1207
1208 static void
1209 ffs_fs_kill_sb(struct super_block *sb)
1210 {
1211         ENTER();
1212
1213         kill_litter_super(sb);
1214         if (sb->s_fs_info) {
1215                 functionfs_release_dev_callback(sb->s_fs_info);
1216                 ffs_data_put(sb->s_fs_info);
1217         }
1218 }
1219
1220 static struct file_system_type ffs_fs_type = {
1221         .owner          = THIS_MODULE,
1222         .name           = "functionfs",
1223         .mount          = ffs_fs_mount,
1224         .kill_sb        = ffs_fs_kill_sb,
1225 };
1226
1227
1228 /* Driver's main init/cleanup functions *************************************/
1229
1230 static int functionfs_init(void)
1231 {
1232         int ret;
1233
1234         ENTER();
1235
1236         ret = register_filesystem(&ffs_fs_type);
1237         if (likely(!ret))
1238                 pr_info("file system registered\n");
1239         else
1240                 pr_err("failed registering file system (%d)\n", ret);
1241
1242         return ret;
1243 }
1244
1245 static void functionfs_cleanup(void)
1246 {
1247         ENTER();
1248
1249         pr_info("unloading\n");
1250         unregister_filesystem(&ffs_fs_type);
1251 }
1252
1253
1254 /* ffs_data and ffs_function construction and destruction code **************/
1255
1256 static void ffs_data_clear(struct ffs_data *ffs);
1257 static void ffs_data_reset(struct ffs_data *ffs);
1258
1259 static void ffs_data_get(struct ffs_data *ffs)
1260 {
1261         ENTER();
1262
1263         atomic_inc(&ffs->ref);
1264 }
1265
1266 static void ffs_data_opened(struct ffs_data *ffs)
1267 {
1268         ENTER();
1269
1270         atomic_inc(&ffs->ref);
1271         atomic_inc(&ffs->opened);
1272 }
1273
1274 static void ffs_data_put(struct ffs_data *ffs)
1275 {
1276         ENTER();
1277
1278         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1279                 pr_info("%s(): freeing\n", __func__);
1280                 ffs_data_clear(ffs);
1281                 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1282                        waitqueue_active(&ffs->ep0req_completion.wait));
1283                 kfree(ffs->dev_name);
1284                 kfree(ffs);
1285         }
1286 }
1287
1288 static void ffs_data_closed(struct ffs_data *ffs)
1289 {
1290         ENTER();
1291
1292         if (atomic_dec_and_test(&ffs->opened)) {
1293                 ffs->state = FFS_CLOSING;
1294                 ffs_data_reset(ffs);
1295         }
1296
1297         ffs_data_put(ffs);
1298 }
1299
1300 static struct ffs_data *ffs_data_new(void)
1301 {
1302         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1303         if (unlikely(!ffs))
1304                 return 0;
1305
1306         ENTER();
1307
1308         atomic_set(&ffs->ref, 1);
1309         atomic_set(&ffs->opened, 0);
1310         ffs->state = FFS_READ_DESCRIPTORS;
1311         mutex_init(&ffs->mutex);
1312         spin_lock_init(&ffs->eps_lock);
1313         init_waitqueue_head(&ffs->ev.waitq);
1314         init_completion(&ffs->ep0req_completion);
1315
1316         /* XXX REVISIT need to update it in some places, or do we? */
1317         ffs->ev.can_stall = 1;
1318
1319         return ffs;
1320 }
1321
1322 static void ffs_data_clear(struct ffs_data *ffs)
1323 {
1324         ENTER();
1325
1326         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1327                 functionfs_closed_callback(ffs);
1328
1329         BUG_ON(ffs->gadget);
1330
1331         if (ffs->epfiles)
1332                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1333
1334         kfree(ffs->raw_descs);
1335         kfree(ffs->raw_strings);
1336         kfree(ffs->stringtabs);
1337 }
1338
1339 static void ffs_data_reset(struct ffs_data *ffs)
1340 {
1341         ENTER();
1342
1343         ffs_data_clear(ffs);
1344
1345         ffs->epfiles = NULL;
1346         ffs->raw_descs = NULL;
1347         ffs->raw_strings = NULL;
1348         ffs->stringtabs = NULL;
1349
1350         ffs->raw_descs_length = 0;
1351         ffs->raw_fs_descs_length = 0;
1352         ffs->fs_descs_count = 0;
1353         ffs->hs_descs_count = 0;
1354
1355         ffs->strings_count = 0;
1356         ffs->interfaces_count = 0;
1357         ffs->eps_count = 0;
1358
1359         ffs->ev.count = 0;
1360
1361         ffs->state = FFS_READ_DESCRIPTORS;
1362         ffs->setup_state = FFS_NO_SETUP;
1363         ffs->flags = 0;
1364 }
1365
1366
1367 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1368 {
1369         struct usb_gadget_strings **lang;
1370         int first_id;
1371
1372         ENTER();
1373
1374         if (WARN_ON(ffs->state != FFS_ACTIVE
1375                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1376                 return -EBADFD;
1377
1378         first_id = usb_string_ids_n(cdev, ffs->strings_count);
1379         if (unlikely(first_id < 0))
1380                 return first_id;
1381
1382         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1383         if (unlikely(!ffs->ep0req))
1384                 return -ENOMEM;
1385         ffs->ep0req->complete = ffs_ep0_complete;
1386         ffs->ep0req->context = ffs;
1387
1388         lang = ffs->stringtabs;
1389         for (lang = ffs->stringtabs; *lang; ++lang) {
1390                 struct usb_string *str = (*lang)->strings;
1391                 int id = first_id;
1392                 for (; str->s; ++id, ++str)
1393                         str->id = id;
1394         }
1395
1396         ffs->gadget = cdev->gadget;
1397         ffs_data_get(ffs);
1398         return 0;
1399 }
1400
1401 static void functionfs_unbind(struct ffs_data *ffs)
1402 {
1403         ENTER();
1404
1405         if (!WARN_ON(!ffs->gadget)) {
1406                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1407                 ffs->ep0req = NULL;
1408                 ffs->gadget = NULL;
1409                 ffs_data_put(ffs);
1410                 clear_bit(FFS_FL_BOUND, &ffs->flags);
1411         }
1412 }
1413
1414 static int ffs_epfiles_create(struct ffs_data *ffs)
1415 {
1416         struct ffs_epfile *epfile, *epfiles;
1417         unsigned i, count;
1418
1419         ENTER();
1420
1421         count = ffs->eps_count;
1422         epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1423         if (!epfiles)
1424                 return -ENOMEM;
1425
1426         epfile = epfiles;
1427         for (i = 1; i <= count; ++i, ++epfile) {
1428                 epfile->ffs = ffs;
1429                 mutex_init(&epfile->mutex);
1430                 init_waitqueue_head(&epfile->wait);
1431                 sprintf(epfiles->name, "ep%u",  i);
1432                 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1433                                                  &ffs_epfile_operations,
1434                                                  &epfile->dentry))) {
1435                         ffs_epfiles_destroy(epfiles, i - 1);
1436                         return -ENOMEM;
1437                 }
1438         }
1439
1440         ffs->epfiles = epfiles;
1441         return 0;
1442 }
1443
1444 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1445 {
1446         struct ffs_epfile *epfile = epfiles;
1447
1448         ENTER();
1449
1450         for (; count; --count, ++epfile) {
1451                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1452                        waitqueue_active(&epfile->wait));
1453                 if (epfile->dentry) {
1454                         d_delete(epfile->dentry);
1455                         dput(epfile->dentry);
1456                         epfile->dentry = NULL;
1457                 }
1458         }
1459
1460         kfree(epfiles);
1461 }
1462
1463 static int functionfs_bind_config(struct usb_composite_dev *cdev,
1464                                   struct usb_configuration *c,
1465                                   struct ffs_data *ffs)
1466 {
1467         struct ffs_function *func;
1468         int ret;
1469
1470         ENTER();
1471
1472         func = kzalloc(sizeof *func, GFP_KERNEL);
1473         if (unlikely(!func))
1474                 return -ENOMEM;
1475
1476         func->function.name    = "Function FS Gadget";
1477         func->function.strings = ffs->stringtabs;
1478
1479         func->function.bind    = ffs_func_bind;
1480         func->function.unbind  = ffs_func_unbind;
1481         func->function.set_alt = ffs_func_set_alt;
1482         func->function.disable = ffs_func_disable;
1483         func->function.setup   = ffs_func_setup;
1484         func->function.suspend = ffs_func_suspend;
1485         func->function.resume  = ffs_func_resume;
1486
1487         func->conf   = c;
1488         func->gadget = cdev->gadget;
1489         func->ffs = ffs;
1490         ffs_data_get(ffs);
1491
1492         ret = usb_add_function(c, &func->function);
1493         if (unlikely(ret))
1494                 ffs_func_free(func);
1495
1496         return ret;
1497 }
1498
1499 static void ffs_func_free(struct ffs_function *func)
1500 {
1501         struct ffs_ep *ep         = func->eps;
1502         unsigned count            = func->ffs->eps_count;
1503         unsigned long flags;
1504
1505         ENTER();
1506
1507         /* cleanup after autoconfig */
1508         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1509         do {
1510                 if (ep->ep && ep->req)
1511                         usb_ep_free_request(ep->ep, ep->req);
1512                 ep->req = NULL;
1513                 ++ep;
1514         } while (--count);
1515         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1516
1517         ffs_data_put(func->ffs);
1518
1519         kfree(func->eps);
1520         /*
1521          * eps and interfaces_nums are allocated in the same chunk so
1522          * only one free is required.  Descriptors are also allocated
1523          * in the same chunk.
1524          */
1525
1526         kfree(func);
1527 }
1528
1529 static void ffs_func_eps_disable(struct ffs_function *func)
1530 {
1531         struct ffs_ep *ep         = func->eps;
1532         struct ffs_epfile *epfile = func->ffs->epfiles;
1533         unsigned count            = func->ffs->eps_count;
1534         unsigned long flags;
1535
1536         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1537         do {
1538                 /* pending requests get nuked */
1539                 if (likely(ep->ep))
1540                         usb_ep_disable(ep->ep);
1541                 epfile->ep = NULL;
1542
1543                 ++ep;
1544                 ++epfile;
1545         } while (--count);
1546         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1547 }
1548
1549 static int ffs_func_eps_enable(struct ffs_function *func)
1550 {
1551         struct ffs_data *ffs      = func->ffs;
1552         struct ffs_ep *ep         = func->eps;
1553         struct ffs_epfile *epfile = ffs->epfiles;
1554         unsigned count            = ffs->eps_count;
1555         unsigned long flags;
1556         int ret = 0;
1557
1558         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1559         do {
1560                 struct usb_endpoint_descriptor *ds;
1561                 ds = ep->descs[ep->descs[1] ? 1 : 0];
1562
1563                 ep->ep->driver_data = ep;
1564                 ep->ep->desc = ds;
1565                 ret = usb_ep_enable(ep->ep);
1566                 if (likely(!ret)) {
1567                         epfile->ep = ep;
1568                         epfile->in = usb_endpoint_dir_in(ds);
1569                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1570                 } else {
1571                         break;
1572                 }
1573
1574                 wake_up(&epfile->wait);
1575
1576                 ++ep;
1577                 ++epfile;
1578         } while (--count);
1579         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1580
1581         return ret;
1582 }
1583
1584
1585 /* Parsing and building descriptors and strings *****************************/
1586
1587 /*
1588  * This validates if data pointed by data is a valid USB descriptor as
1589  * well as record how many interfaces, endpoints and strings are
1590  * required by given configuration.  Returns address after the
1591  * descriptor or NULL if data is invalid.
1592  */
1593
1594 enum ffs_entity_type {
1595         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1596 };
1597
1598 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1599                                    u8 *valuep,
1600                                    struct usb_descriptor_header *desc,
1601                                    void *priv);
1602
1603 static int __must_check ffs_do_desc(char *data, unsigned len,
1604                                     ffs_entity_callback entity, void *priv)
1605 {
1606         struct usb_descriptor_header *_ds = (void *)data;
1607         u8 length;
1608         int ret;
1609
1610         ENTER();
1611
1612         /* At least two bytes are required: length and type */
1613         if (len < 2) {
1614                 pr_vdebug("descriptor too short\n");
1615                 return -EINVAL;
1616         }
1617
1618         /* If we have at least as many bytes as the descriptor takes? */
1619         length = _ds->bLength;
1620         if (len < length) {
1621                 pr_vdebug("descriptor longer then available data\n");
1622                 return -EINVAL;
1623         }
1624
1625 #define __entity_check_INTERFACE(val)  1
1626 #define __entity_check_STRING(val)     (val)
1627 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1628 #define __entity(type, val) do {                                        \
1629                 pr_vdebug("entity " #type "(%02x)\n", (val));           \
1630                 if (unlikely(!__entity_check_ ##type(val))) {           \
1631                         pr_vdebug("invalid entity's value\n");          \
1632                         return -EINVAL;                                 \
1633                 }                                                       \
1634                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1635                 if (unlikely(ret < 0)) {                                \
1636                         pr_debug("entity " #type "(%02x); ret = %d\n",  \
1637                                  (val), ret);                           \
1638                         return ret;                                     \
1639                 }                                                       \
1640         } while (0)
1641
1642         /* Parse descriptor depending on type. */
1643         switch (_ds->bDescriptorType) {
1644         case USB_DT_DEVICE:
1645         case USB_DT_CONFIG:
1646         case USB_DT_STRING:
1647         case USB_DT_DEVICE_QUALIFIER:
1648                 /* function can't have any of those */
1649                 pr_vdebug("descriptor reserved for gadget: %d\n",
1650                       _ds->bDescriptorType);
1651                 return -EINVAL;
1652
1653         case USB_DT_INTERFACE: {
1654                 struct usb_interface_descriptor *ds = (void *)_ds;
1655                 pr_vdebug("interface descriptor\n");
1656                 if (length != sizeof *ds)
1657                         goto inv_length;
1658
1659                 __entity(INTERFACE, ds->bInterfaceNumber);
1660                 if (ds->iInterface)
1661                         __entity(STRING, ds->iInterface);
1662         }
1663                 break;
1664
1665         case USB_DT_ENDPOINT: {
1666                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1667                 pr_vdebug("endpoint descriptor\n");
1668                 if (length != USB_DT_ENDPOINT_SIZE &&
1669                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1670                         goto inv_length;
1671                 __entity(ENDPOINT, ds->bEndpointAddress);
1672         }
1673                 break;
1674
1675         case HID_DT_HID:
1676                 pr_vdebug("hid descriptor\n");
1677                 if (length != sizeof(struct hid_descriptor))
1678                         goto inv_length;
1679                 break;
1680
1681         case USB_DT_OTG:
1682                 if (length != sizeof(struct usb_otg_descriptor))
1683                         goto inv_length;
1684                 break;
1685
1686         case USB_DT_INTERFACE_ASSOCIATION: {
1687                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1688                 pr_vdebug("interface association descriptor\n");
1689                 if (length != sizeof *ds)
1690                         goto inv_length;
1691                 if (ds->iFunction)
1692                         __entity(STRING, ds->iFunction);
1693         }
1694                 break;
1695
1696         case USB_DT_OTHER_SPEED_CONFIG:
1697         case USB_DT_INTERFACE_POWER:
1698         case USB_DT_DEBUG:
1699         case USB_DT_SECURITY:
1700         case USB_DT_CS_RADIO_CONTROL:
1701                 /* TODO */
1702                 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1703                 return -EINVAL;
1704
1705         default:
1706                 /* We should never be here */
1707                 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1708                 return -EINVAL;
1709
1710 inv_length:
1711                 pr_vdebug("invalid length: %d (descriptor %d)\n",
1712                           _ds->bLength, _ds->bDescriptorType);
1713                 return -EINVAL;
1714         }
1715
1716 #undef __entity
1717 #undef __entity_check_DESCRIPTOR
1718 #undef __entity_check_INTERFACE
1719 #undef __entity_check_STRING
1720 #undef __entity_check_ENDPOINT
1721
1722         return length;
1723 }
1724
1725 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1726                                      ffs_entity_callback entity, void *priv)
1727 {
1728         const unsigned _len = len;
1729         unsigned long num = 0;
1730
1731         ENTER();
1732
1733         for (;;) {
1734                 int ret;
1735
1736                 if (num == count)
1737                         data = NULL;
1738
1739                 /* Record "descriptor" entity */
1740                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1741                 if (unlikely(ret < 0)) {
1742                         pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1743                                  num, ret);
1744                         return ret;
1745                 }
1746
1747                 if (!data)
1748                         return _len - len;
1749
1750                 ret = ffs_do_desc(data, len, entity, priv);
1751                 if (unlikely(ret < 0)) {
1752                         pr_debug("%s returns %d\n", __func__, ret);
1753                         return ret;
1754                 }
1755
1756                 len -= ret;
1757                 data += ret;
1758                 ++num;
1759         }
1760 }
1761
1762 static int __ffs_data_do_entity(enum ffs_entity_type type,
1763                                 u8 *valuep, struct usb_descriptor_header *desc,
1764                                 void *priv)
1765 {
1766         struct ffs_data *ffs = priv;
1767
1768         ENTER();
1769
1770         switch (type) {
1771         case FFS_DESCRIPTOR:
1772                 break;
1773
1774         case FFS_INTERFACE:
1775                 /*
1776                  * Interfaces are indexed from zero so if we
1777                  * encountered interface "n" then there are at least
1778                  * "n+1" interfaces.
1779                  */
1780                 if (*valuep >= ffs->interfaces_count)
1781                         ffs->interfaces_count = *valuep + 1;
1782                 break;
1783
1784         case FFS_STRING:
1785                 /*
1786                  * Strings are indexed from 1 (0 is magic ;) reserved
1787                  * for languages list or some such)
1788                  */
1789                 if (*valuep > ffs->strings_count)
1790                         ffs->strings_count = *valuep;
1791                 break;
1792
1793         case FFS_ENDPOINT:
1794                 /* Endpoints are indexed from 1 as well. */
1795                 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1796                         ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1797                 break;
1798         }
1799
1800         return 0;
1801 }
1802
1803 static int __ffs_data_got_descs(struct ffs_data *ffs,
1804                                 char *const _data, size_t len)
1805 {
1806         unsigned fs_count, hs_count;
1807         int fs_len, ret = -EINVAL;
1808         char *data = _data;
1809
1810         ENTER();
1811
1812         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1813                      get_unaligned_le32(data + 4) != len))
1814                 goto error;
1815         fs_count = get_unaligned_le32(data +  8);
1816         hs_count = get_unaligned_le32(data + 12);
1817
1818         if (!fs_count && !hs_count)
1819                 goto einval;
1820
1821         data += 16;
1822         len  -= 16;
1823
1824         if (likely(fs_count)) {
1825                 fs_len = ffs_do_descs(fs_count, data, len,
1826                                       __ffs_data_do_entity, ffs);
1827                 if (unlikely(fs_len < 0)) {
1828                         ret = fs_len;
1829                         goto error;
1830                 }
1831
1832                 data += fs_len;
1833                 len  -= fs_len;
1834         } else {
1835                 fs_len = 0;
1836         }
1837
1838         if (likely(hs_count)) {
1839                 ret = ffs_do_descs(hs_count, data, len,
1840                                    __ffs_data_do_entity, ffs);
1841                 if (unlikely(ret < 0))
1842                         goto error;
1843         } else {
1844                 ret = 0;
1845         }
1846
1847         if (unlikely(len != ret))
1848                 goto einval;
1849
1850         ffs->raw_fs_descs_length = fs_len;
1851         ffs->raw_descs_length    = fs_len + ret;
1852         ffs->raw_descs           = _data;
1853         ffs->fs_descs_count      = fs_count;
1854         ffs->hs_descs_count      = hs_count;
1855
1856         return 0;
1857
1858 einval:
1859         ret = -EINVAL;
1860 error:
1861         kfree(_data);
1862         return ret;
1863 }
1864
1865 static int __ffs_data_got_strings(struct ffs_data *ffs,
1866                                   char *const _data, size_t len)
1867 {
1868         u32 str_count, needed_count, lang_count;
1869         struct usb_gadget_strings **stringtabs, *t;
1870         struct usb_string *strings, *s;
1871         const char *data = _data;
1872
1873         ENTER();
1874
1875         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1876                      get_unaligned_le32(data + 4) != len))
1877                 goto error;
1878         str_count  = get_unaligned_le32(data + 8);
1879         lang_count = get_unaligned_le32(data + 12);
1880
1881         /* if one is zero the other must be zero */
1882         if (unlikely(!str_count != !lang_count))
1883                 goto error;
1884
1885         /* Do we have at least as many strings as descriptors need? */
1886         needed_count = ffs->strings_count;
1887         if (unlikely(str_count < needed_count))
1888                 goto error;
1889
1890         /*
1891          * If we don't need any strings just return and free all
1892          * memory.
1893          */
1894         if (!needed_count) {
1895                 kfree(_data);
1896                 return 0;
1897         }
1898
1899         /* Allocate everything in one chunk so there's less maintenance. */
1900         {
1901                 struct {
1902                         struct usb_gadget_strings *stringtabs[lang_count + 1];
1903                         struct usb_gadget_strings stringtab[lang_count];
1904                         struct usb_string strings[lang_count*(needed_count+1)];
1905                 } *d;
1906                 unsigned i = 0;
1907
1908                 d = kmalloc(sizeof *d, GFP_KERNEL);
1909                 if (unlikely(!d)) {
1910                         kfree(_data);
1911                         return -ENOMEM;
1912                 }
1913
1914                 stringtabs = d->stringtabs;
1915                 t = d->stringtab;
1916                 i = lang_count;
1917                 do {
1918                         *stringtabs++ = t++;
1919                 } while (--i);
1920                 *stringtabs = NULL;
1921
1922                 stringtabs = d->stringtabs;
1923                 t = d->stringtab;
1924                 s = d->strings;
1925                 strings = s;
1926         }
1927
1928         /* For each language */
1929         data += 16;
1930         len -= 16;
1931
1932         do { /* lang_count > 0 so we can use do-while */
1933                 unsigned needed = needed_count;
1934
1935                 if (unlikely(len < 3))
1936                         goto error_free;
1937                 t->language = get_unaligned_le16(data);
1938                 t->strings  = s;
1939                 ++t;
1940
1941                 data += 2;
1942                 len -= 2;
1943
1944                 /* For each string */
1945                 do { /* str_count > 0 so we can use do-while */
1946                         size_t length = strnlen(data, len);
1947
1948                         if (unlikely(length == len))
1949                                 goto error_free;
1950
1951                         /*
1952                          * User may provide more strings then we need,
1953                          * if that's the case we simply ignore the
1954                          * rest
1955                          */
1956                         if (likely(needed)) {
1957                                 /*
1958                                  * s->id will be set while adding
1959                                  * function to configuration so for
1960                                  * now just leave garbage here.
1961                                  */
1962                                 s->s = data;
1963                                 --needed;
1964                                 ++s;
1965                         }
1966
1967                         data += length + 1;
1968                         len -= length + 1;
1969                 } while (--str_count);
1970
1971                 s->id = 0;   /* terminator */
1972                 s->s = NULL;
1973                 ++s;
1974
1975         } while (--lang_count);
1976
1977         /* Some garbage left? */
1978         if (unlikely(len))
1979                 goto error_free;
1980
1981         /* Done! */
1982         ffs->stringtabs = stringtabs;
1983         ffs->raw_strings = _data;
1984
1985         return 0;
1986
1987 error_free:
1988         kfree(stringtabs);
1989 error:
1990         kfree(_data);
1991         return -EINVAL;
1992 }
1993
1994
1995 /* Events handling and management *******************************************/
1996
1997 static void __ffs_event_add(struct ffs_data *ffs,
1998                             enum usb_functionfs_event_type type)
1999 {
2000         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2001         int neg = 0;
2002
2003         /*
2004          * Abort any unhandled setup
2005          *
2006          * We do not need to worry about some cmpxchg() changing value
2007          * of ffs->setup_state without holding the lock because when
2008          * state is FFS_SETUP_PENDING cmpxchg() in several places in
2009          * the source does nothing.
2010          */
2011         if (ffs->setup_state == FFS_SETUP_PENDING)
2012                 ffs->setup_state = FFS_SETUP_CANCELED;
2013
2014         switch (type) {
2015         case FUNCTIONFS_RESUME:
2016                 rem_type2 = FUNCTIONFS_SUSPEND;
2017                 /* FALL THROUGH */
2018         case FUNCTIONFS_SUSPEND:
2019         case FUNCTIONFS_SETUP:
2020                 rem_type1 = type;
2021                 /* Discard all similar events */
2022                 break;
2023
2024         case FUNCTIONFS_BIND:
2025         case FUNCTIONFS_UNBIND:
2026         case FUNCTIONFS_DISABLE:
2027         case FUNCTIONFS_ENABLE:
2028                 /* Discard everything other then power management. */
2029                 rem_type1 = FUNCTIONFS_SUSPEND;
2030                 rem_type2 = FUNCTIONFS_RESUME;
2031                 neg = 1;
2032                 break;
2033
2034         default:
2035                 BUG();
2036         }
2037
2038         {
2039                 u8 *ev  = ffs->ev.types, *out = ev;
2040                 unsigned n = ffs->ev.count;
2041                 for (; n; --n, ++ev)
2042                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2043                                 *out++ = *ev;
2044                         else
2045                                 pr_vdebug("purging event %d\n", *ev);
2046                 ffs->ev.count = out - ffs->ev.types;
2047         }
2048
2049         pr_vdebug("adding event %d\n", type);
2050         ffs->ev.types[ffs->ev.count++] = type;
2051         wake_up_locked(&ffs->ev.waitq);
2052 }
2053
2054 static void ffs_event_add(struct ffs_data *ffs,
2055                           enum usb_functionfs_event_type type)
2056 {
2057         unsigned long flags;
2058         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2059         __ffs_event_add(ffs, type);
2060         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2061 }
2062
2063
2064 /* Bind/unbind USB function hooks *******************************************/
2065
2066 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2067                                     struct usb_descriptor_header *desc,
2068                                     void *priv)
2069 {
2070         struct usb_endpoint_descriptor *ds = (void *)desc;
2071         struct ffs_function *func = priv;
2072         struct ffs_ep *ffs_ep;
2073
2074         /*
2075          * If hs_descriptors is not NULL then we are reading hs
2076          * descriptors now
2077          */
2078         const int isHS = func->function.hs_descriptors != NULL;
2079         unsigned idx;
2080
2081         if (type != FFS_DESCRIPTOR)
2082                 return 0;
2083
2084         if (isHS)
2085                 func->function.hs_descriptors[(long)valuep] = desc;
2086         else
2087                 func->function.descriptors[(long)valuep]    = desc;
2088
2089         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2090                 return 0;
2091
2092         idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2093         ffs_ep = func->eps + idx;
2094
2095         if (unlikely(ffs_ep->descs[isHS])) {
2096                 pr_vdebug("two %sspeed descriptors for EP %d\n",
2097                           isHS ? "high" : "full",
2098                           ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2099                 return -EINVAL;
2100         }
2101         ffs_ep->descs[isHS] = ds;
2102
2103         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2104         if (ffs_ep->ep) {
2105                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2106                 if (!ds->wMaxPacketSize)
2107                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2108         } else {
2109                 struct usb_request *req;
2110                 struct usb_ep *ep;
2111
2112                 pr_vdebug("autoconfig\n");
2113                 ep = usb_ep_autoconfig(func->gadget, ds);
2114                 if (unlikely(!ep))
2115                         return -ENOTSUPP;
2116                 ep->driver_data = func->eps + idx;
2117
2118                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2119                 if (unlikely(!req))
2120                         return -ENOMEM;
2121
2122                 ffs_ep->ep  = ep;
2123                 ffs_ep->req = req;
2124                 func->eps_revmap[ds->bEndpointAddress &
2125                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2126         }
2127         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2128
2129         return 0;
2130 }
2131
2132 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2133                                    struct usb_descriptor_header *desc,
2134                                    void *priv)
2135 {
2136         struct ffs_function *func = priv;
2137         unsigned idx;
2138         u8 newValue;
2139
2140         switch (type) {
2141         default:
2142         case FFS_DESCRIPTOR:
2143                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2144                 return 0;
2145
2146         case FFS_INTERFACE:
2147                 idx = *valuep;
2148                 if (func->interfaces_nums[idx] < 0) {
2149                         int id = usb_interface_id(func->conf, &func->function);
2150                         if (unlikely(id < 0))
2151                                 return id;
2152                         func->interfaces_nums[idx] = id;
2153                 }
2154                 newValue = func->interfaces_nums[idx];
2155                 break;
2156
2157         case FFS_STRING:
2158                 /* String' IDs are allocated when fsf_data is bound to cdev */
2159                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2160                 break;
2161
2162         case FFS_ENDPOINT:
2163                 /*
2164                  * USB_DT_ENDPOINT are handled in
2165                  * __ffs_func_bind_do_descs().
2166                  */
2167                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2168                         return 0;
2169
2170                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2171                 if (unlikely(!func->eps[idx].ep))
2172                         return -EINVAL;
2173
2174                 {
2175                         struct usb_endpoint_descriptor **descs;
2176                         descs = func->eps[idx].descs;
2177                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2178                 }
2179                 break;
2180         }
2181
2182         pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2183         *valuep = newValue;
2184         return 0;
2185 }
2186
2187 static int ffs_func_bind(struct usb_configuration *c,
2188                          struct usb_function *f)
2189 {
2190         struct ffs_function *func = ffs_func_from_usb(f);
2191         struct ffs_data *ffs = func->ffs;
2192
2193         const int full = !!func->ffs->fs_descs_count;
2194         const int high = gadget_is_dualspeed(func->gadget) &&
2195                 func->ffs->hs_descs_count;
2196
2197         int ret;
2198
2199         /* Make it a single chunk, less management later on */
2200         struct {
2201                 struct ffs_ep eps[ffs->eps_count];
2202                 struct usb_descriptor_header
2203                         *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2204                 struct usb_descriptor_header
2205                         *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2206                 short inums[ffs->interfaces_count];
2207                 char raw_descs[high ? ffs->raw_descs_length
2208                                     : ffs->raw_fs_descs_length];
2209         } *data;
2210
2211         ENTER();
2212
2213         /* Only high speed but not supported by gadget? */
2214         if (unlikely(!(full | high)))
2215                 return -ENOTSUPP;
2216
2217         /* Allocate */
2218         data = kmalloc(sizeof *data, GFP_KERNEL);
2219         if (unlikely(!data))
2220                 return -ENOMEM;
2221
2222         /* Zero */
2223         memset(data->eps, 0, sizeof data->eps);
2224         memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2225         memset(data->inums, 0xff, sizeof data->inums);
2226         for (ret = ffs->eps_count; ret; --ret)
2227                 data->eps[ret].num = -1;
2228
2229         /* Save pointers */
2230         func->eps             = data->eps;
2231         func->interfaces_nums = data->inums;
2232
2233         /*
2234          * Go through all the endpoint descriptors and allocate
2235          * endpoints first, so that later we can rewrite the endpoint
2236          * numbers without worrying that it may be described later on.
2237          */
2238         if (likely(full)) {
2239                 func->function.descriptors = data->fs_descs;
2240                 ret = ffs_do_descs(ffs->fs_descs_count,
2241                                    data->raw_descs,
2242                                    sizeof data->raw_descs,
2243                                    __ffs_func_bind_do_descs, func);
2244                 if (unlikely(ret < 0))
2245                         goto error;
2246         } else {
2247                 ret = 0;
2248         }
2249
2250         if (likely(high)) {
2251                 func->function.hs_descriptors = data->hs_descs;
2252                 ret = ffs_do_descs(ffs->hs_descs_count,
2253                                    data->raw_descs + ret,
2254                                    (sizeof data->raw_descs) - ret,
2255                                    __ffs_func_bind_do_descs, func);
2256         }
2257
2258         /*
2259          * Now handle interface numbers allocation and interface and
2260          * endpoint numbers rewriting.  We can do that in one go
2261          * now.
2262          */
2263         ret = ffs_do_descs(ffs->fs_descs_count +
2264                            (high ? ffs->hs_descs_count : 0),
2265                            data->raw_descs, sizeof data->raw_descs,
2266                            __ffs_func_bind_do_nums, func);
2267         if (unlikely(ret < 0))
2268                 goto error;
2269
2270         /* And we're done */
2271         ffs_event_add(ffs, FUNCTIONFS_BIND);
2272         return 0;
2273
2274 error:
2275         /* XXX Do we need to release all claimed endpoints here? */
2276         return ret;
2277 }
2278
2279
2280 /* Other USB function hooks *************************************************/
2281
2282 static void ffs_func_unbind(struct usb_configuration *c,
2283                             struct usb_function *f)
2284 {
2285         struct ffs_function *func = ffs_func_from_usb(f);
2286         struct ffs_data *ffs = func->ffs;
2287
2288         ENTER();
2289
2290         if (ffs->func == func) {
2291                 ffs_func_eps_disable(func);
2292                 ffs->func = NULL;
2293         }
2294
2295         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2296
2297         ffs_func_free(func);
2298 }
2299
2300 static int ffs_func_set_alt(struct usb_function *f,
2301                             unsigned interface, unsigned alt)
2302 {
2303         struct ffs_function *func = ffs_func_from_usb(f);
2304         struct ffs_data *ffs = func->ffs;
2305         int ret = 0, intf;
2306
2307         if (alt != (unsigned)-1) {
2308                 intf = ffs_func_revmap_intf(func, interface);
2309                 if (unlikely(intf < 0))
2310                         return intf;
2311         }
2312
2313         if (ffs->func)
2314                 ffs_func_eps_disable(ffs->func);
2315
2316         if (ffs->state != FFS_ACTIVE)
2317                 return -ENODEV;
2318
2319         if (alt == (unsigned)-1) {
2320                 ffs->func = NULL;
2321                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2322                 return 0;
2323         }
2324
2325         ffs->func = func;
2326         ret = ffs_func_eps_enable(func);
2327         if (likely(ret >= 0))
2328                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2329         return ret;
2330 }
2331
2332 static void ffs_func_disable(struct usb_function *f)
2333 {
2334         ffs_func_set_alt(f, 0, (unsigned)-1);
2335 }
2336
2337 static int ffs_func_setup(struct usb_function *f,
2338                           const struct usb_ctrlrequest *creq)
2339 {
2340         struct ffs_function *func = ffs_func_from_usb(f);
2341         struct ffs_data *ffs = func->ffs;
2342         unsigned long flags;
2343         int ret;
2344
2345         ENTER();
2346
2347         pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2348         pr_vdebug("creq->bRequest     = %02x\n", creq->bRequest);
2349         pr_vdebug("creq->wValue       = %04x\n", le16_to_cpu(creq->wValue));
2350         pr_vdebug("creq->wIndex       = %04x\n", le16_to_cpu(creq->wIndex));
2351         pr_vdebug("creq->wLength      = %04x\n", le16_to_cpu(creq->wLength));
2352
2353         /*
2354          * Most requests directed to interface go through here
2355          * (notable exceptions are set/get interface) so we need to
2356          * handle them.  All other either handled by composite or
2357          * passed to usb_configuration->setup() (if one is set).  No
2358          * matter, we will handle requests directed to endpoint here
2359          * as well (as it's straightforward) but what to do with any
2360          * other request?
2361          */
2362         if (ffs->state != FFS_ACTIVE)
2363                 return -ENODEV;
2364
2365         switch (creq->bRequestType & USB_RECIP_MASK) {
2366         case USB_RECIP_INTERFACE:
2367                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2368                 if (unlikely(ret < 0))
2369                         return ret;
2370                 break;
2371
2372         case USB_RECIP_ENDPOINT:
2373                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2374                 if (unlikely(ret < 0))
2375                         return ret;
2376                 break;
2377
2378         default:
2379                 return -EOPNOTSUPP;
2380         }
2381
2382         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2383         ffs->ev.setup = *creq;
2384         ffs->ev.setup.wIndex = cpu_to_le16(ret);
2385         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2386         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2387
2388         return 0;
2389 }
2390
2391 static void ffs_func_suspend(struct usb_function *f)
2392 {
2393         ENTER();
2394         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2395 }
2396
2397 static void ffs_func_resume(struct usb_function *f)
2398 {
2399         ENTER();
2400         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2401 }
2402
2403
2404 /* Endpoint and interface numbers reverse mapping ***************************/
2405
2406 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2407 {
2408         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2409         return num ? num : -EDOM;
2410 }
2411
2412 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2413 {
2414         short *nums = func->interfaces_nums;
2415         unsigned count = func->ffs->interfaces_count;
2416
2417         for (; count; --count, ++nums) {
2418                 if (*nums >= 0 && *nums == intf)
2419                         return nums - func->interfaces_nums;
2420         }
2421
2422         return -EDOM;
2423 }
2424
2425
2426 /* Misc helper functions ****************************************************/
2427
2428 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2429 {
2430         return nonblock
2431                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2432                 : mutex_lock_interruptible(mutex);
2433 }
2434
2435 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
2436 {
2437         char *data;
2438
2439         if (unlikely(!len))
2440                 return NULL;
2441
2442         data = kmalloc(len, GFP_KERNEL);
2443         if (unlikely(!data))
2444                 return ERR_PTR(-ENOMEM);
2445
2446         if (unlikely(__copy_from_user(data, buf, len))) {
2447                 kfree(data);
2448                 return ERR_PTR(-EFAULT);
2449         }
2450
2451         pr_vdebug("Buffer from user space:\n");
2452         ffs_dump_mem("", data, len);
2453
2454         return data;
2455 }