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 <m.nazarewicz@samsung.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 <asm/unaligned.h>
  24
  25 #include <linux/usb/composite.h>
  26 #include <linux/usb/functionfs.h>
  27
  28
  29 #define FUNCTIONFS_MAGIC        0xa647361 /* Chosen by a honest dice roll ;) */
  30
  31
  32 /* Debugging ****************************************************************/
  33
  34 #ifdef VERBOSE_DEBUG
  35 #  define pr_vdebug pr_debug
  36 #  define ffs_dump_mem(prefix, ptr, len) \
  37         print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
  38 #else
  39 #  define pr_vdebug(...)                 do { } while (0)
  40 #  define ffs_dump_mem(prefix, ptr, len) do { } while (0)
  41 #endif /* VERBOSE_DEBUG */
  42
  43 #define ENTER()    pr_vdebug("%s()\n", __func__)
  44
  45
  46 /* The data structure and setup file ****************************************/
  47
  48 enum ffs_state {
  49         /*
  50          * Waiting for descriptors and strings.
  51          *
  52          * In this state no open(2), read(2) or write(2) on epfiles
  53          * may succeed (which should not be the problem as there
  54          * should be no such files opened in the first place).
  55          */
  56         FFS_READ_DESCRIPTORS,
  57         FFS_READ_STRINGS,
  58
  59         /*
  60          * We've got descriptors and strings.  We are or have called
  61          * functionfs_ready_callback().  functionfs_bind() may have
  62          * been called but we don't know.
  63          *
  64          * This is the only state in which operations on epfiles may
  65          * succeed.
  66          */
  67         FFS_ACTIVE,
  68
  69         /*
  70          * All endpoints have been closed.  This state is also set if
  71          * we encounter an unrecoverable error.  The only
  72          * unrecoverable error is situation when after reading strings
  73          * from user space we fail to initialise epfiles or
  74          * functionfs_ready_callback() returns with error (<0).
  75          *
  76          * In this state no open(2), read(2) or write(2) (both on ep0
  77          * as well as epfile) may succeed (at this point epfiles are
  78          * unlinked and all closed so this is not a problem; ep0 is
  79          * also closed but ep0 file exists and so open(2) on ep0 must
  80          * fail).
  81          */
  82         FFS_CLOSING
  83 };
  84
  85
  86 enum ffs_setup_state {
  87         /* There is no setup request pending. */
  88         FFS_NO_SETUP,
  89         /*
  90          * User has read events and there was a setup request event
  91          * there.  The next read/write on ep0 will handle the
  92          * request.
  93          */
  94         FFS_SETUP_PENDING,
  95         /*
  96          * There was event pending but before user space handled it
  97          * some other event was introduced which canceled existing
  98          * setup.  If this state is set read/write on ep0 return
  99          * -EIDRM.  This state is only set when adding event.
 100          */
 101         FFS_SETUP_CANCELED
 102 };
 103
 104
 105
 106 struct ffs_epfile;
 107 struct ffs_function;
 108
 109 struct ffs_data {
 110         struct usb_gadget               *gadget;
 111
 112         /*
 113          * Protect access read/write operations, only one read/write
 114          * at a time.  As a consequence protects ep0req and company.
 115          * While setup request is being processed (queued) this is
 116          * held.
 117          */
 118         struct mutex                    mutex;
 119
 120         /*
 121          * Protect access to endpoint related structures (basically
 122          * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
 123          * endpoint zero.
 124          */
 125         spinlock_t                      eps_lock;
 126
 127         /*
 128          * XXX REVISIT do we need our own request? Since we are not
 129          * handling setup requests immediately user space may be so
 130          * slow that another setup will be sent to the gadget but this
 131          * time not to us but another function and then there could be
 132          * a race.  Is that the case? Or maybe we can use cdev->req
 133          * after all, maybe we just need some spinlock for that?
 134          */
 135         struct usb_request              *ep0req;                /* P: mutex */
 136         struct completion               ep0req_completion;      /* P: mutex */
 137         int                             ep0req_status;          /* P: mutex */
 138
 139         /* reference counter */
 140         atomic_t                        ref;
 141         /* how many files are opened (EP0 and others) */
 142         atomic_t                        opened;
 143
 144         /* EP0 state */
 145         enum ffs_state                  state;
 146
 147         /*
 148          * Possible transitions:
 149          * + FFS_NO_SETUP       -> FFS_SETUP_PENDING  -- P: ev.waitq.lock
 150          *               happens only in ep0 read which is P: mutex
 151          * + FFS_SETUP_PENDING  -> FFS_NO_SETUP       -- P: ev.waitq.lock
 152          *               happens only in ep0 i/o  which is P: mutex
 153          * + FFS_SETUP_PENDING  -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
 154          * + FFS_SETUP_CANCELED -> FFS_NO_SETUP       -- cmpxchg
 155          */
 156         enum ffs_setup_state            setup_state;
 157
 158 #define FFS_SETUP_STATE(ffs)                                    \
 159         ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state,     \
 160                                        FFS_SETUP_CANCELED, FFS_NO_SETUP))
 161
 162         /* Events & such. */
 163         struct {
 164                 u8                              types[4];
 165                 unsigned short                  count;
 166                 /* XXX REVISIT need to update it in some places, or do we? */
 167                 unsigned short                  can_stall;
 168                 struct usb_ctrlrequest          setup;
 169
 170                 wait_queue_head_t               waitq;
 171         } ev; /* the whole structure, P: ev.waitq.lock */
 172
 173         /* Flags */
 174         unsigned long                   flags;
 175 #define FFS_FL_CALL_CLOSED_CALLBACK 0
 176 #define FFS_FL_BOUND                1
 177
 178         /* Active function */
 179         struct ffs_function             *func;
 180
 181         /*
 182          * Device name, write once when file system is mounted.
 183          * Intended for user to read if she wants.
 184          */
 185         const char                      *dev_name;
 186         /* Private data for our user (ie. gadget).  Managed by user. */
 187         void                            *private_data;
 188
 189         /* filled by __ffs_data_got_descs() */
 190         /*
 191          * Real descriptors are 16 bytes after raw_descs (so you need
 192          * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
 193          * first full speed descriptor).  raw_descs_length and
 194          * raw_fs_descs_length do not have those 16 bytes added.
 195          */
 196         const void                      *raw_descs;
 197         unsigned                        raw_descs_length;
 198         unsigned                        raw_fs_descs_length;
 199         unsigned                        fs_descs_count;
 200         unsigned                        hs_descs_count;
 201
 202         unsigned short                  strings_count;
 203         unsigned short                  interfaces_count;
 204         unsigned short                  eps_count;
 205         unsigned short                  _pad1;
 206
 207         /* filled by __ffs_data_got_strings() */
 208         /* ids in stringtabs are set in functionfs_bind() */
 209         const void                      *raw_strings;
 210         struct usb_gadget_strings       **stringtabs;
 211
 212         /*
 213          * File system's super block, write once when file system is
 214          * mounted.
 215          */
 216         struct super_block              *sb;
 217
 218         /* File permissions, written once when fs is mounted */
 219         struct ffs_file_perms {
 220                 umode_t                         mode;
 221                 uid_t                           uid;
 222                 gid_t                           gid;
 223         }                               file_perms;
 224
 225         /*
 226          * The endpoint files, filled by ffs_epfiles_create(),
 227          * destroyed by ffs_epfiles_destroy().
 228          */
 229         struct ffs_epfile               *epfiles;
 230 };
 231
 232 /* Reference counter handling */
 233 static void ffs_data_get(struct ffs_data *ffs);
 234 static void ffs_data_put(struct ffs_data *ffs);
 235 /* Creates new ffs_data object. */
 236 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
 237
 238 /* Opened counter handling. */
 239 static void ffs_data_opened(struct ffs_data *ffs);
 240 static void ffs_data_closed(struct ffs_data *ffs);
 241
 242 /* Called with ffs->mutex held; take over ownership of data. */
 243 static int __must_check
 244 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
 245 static int __must_check
 246 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
 247
 248
 249 /* The function structure ***************************************************/
 250
 251 struct ffs_ep;
 252
 253 struct ffs_function {
 254         struct usb_configuration        *conf;
 255         struct usb_gadget               *gadget;
 256         struct ffs_data                 *ffs;
 257
 258         struct ffs_ep                   *eps;
 259         u8                              eps_revmap[16];
 260         short                           *interfaces_nums;
 261
 262         struct usb_function             function;
 263 };
 264
 265
 266 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
 267 {
 268         return container_of(f, struct ffs_function, function);
 269 }
 270
 271 static void ffs_func_free(struct ffs_function *func);
 272
 273 static void ffs_func_eps_disable(struct ffs_function *func);
 274 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
 275
 276 static int ffs_func_bind(struct usb_configuration *,
 277                          struct usb_function *);
 278 static void ffs_func_unbind(struct usb_configuration *,
 279                             struct usb_function *);
 280 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
 281 static void ffs_func_disable(struct usb_function *);
 282 static int ffs_func_setup(struct usb_function *,
 283                           const struct usb_ctrlrequest *);
 284 static void ffs_func_suspend(struct usb_function *);
 285 static void ffs_func_resume(struct usb_function *);
 286
 287
 288 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
 289 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
 290
 291
 292 /* The endpoints structures *************************************************/
 293
 294 struct ffs_ep {
 295         struct usb_ep                   *ep;    /* P: ffs->eps_lock */
 296         struct usb_request              *req;   /* P: epfile->mutex */
 297
 298         /* [0]: full speed, [1]: high speed */
 299         struct usb_endpoint_descriptor  *descs[2];
 300
 301         u8                              num;
 302
 303         int                             status; /* P: epfile->mutex */
 304 };
 305
 306 struct ffs_epfile {
 307         /* Protects ep->ep and ep->req. */
 308         struct mutex                    mutex;
 309         wait_queue_head_t               wait;
 310
 311         struct ffs_data                 *ffs;
 312         struct ffs_ep                   *ep;    /* P: ffs->eps_lock */
 313
 314         struct dentry                   *dentry;
 315
 316         char                            name[5];
 317
 318         unsigned char                   in;     /* P: ffs->eps_lock */
 319         unsigned char                   isoc;   /* P: ffs->eps_lock */
 320
 321         unsigned char                   _pad;
 322 };
 323
 324 static int  __must_check ffs_epfiles_create(struct ffs_data *ffs);
 325 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
 326
 327 static struct inode *__must_check
 328 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
 329                    const struct file_operations *fops,
 330                    struct dentry **dentry_p);
 331
 332
 333 /* Misc helper functions ****************************************************/
 334
 335 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
 336         __attribute__((warn_unused_result, nonnull));
 337 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
 338         __attribute__((warn_unused_result, nonnull));
 339
 340
 341 /* Control file aka ep0 *****************************************************/
 342
 343 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
 344 {
 345         struct ffs_data *ffs = req->context;
 346
 347         complete_all(&ffs->ep0req_completion);
 348 }
 349
 350 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 351 {
 352         struct usb_request *req = ffs->ep0req;
 353         int ret;
 354
 355         req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
 356
 357         spin_unlock_irq(&ffs->ev.waitq.lock);
 358
 359         req->buf      = data;
 360         req->length   = len;
 361
 362         /*
 363          * UDC layer requires to provide a buffer even for ZLP, but should
 364          * not use it at all. Let's provide some poisoned pointer to catch
 365          * possible bug in the driver.
 366          */
 367         if (req->buf == NULL)
 368                 req->buf = (void *)0xDEADBABE;
 369
 370         INIT_COMPLETION(ffs->ep0req_completion);
 371
 372         ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
 373         if (unlikely(ret < 0))
 374                 return ret;
 375
 376         ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
 377         if (unlikely(ret)) {
 378                 usb_ep_dequeue(ffs->gadget->ep0, req);
 379                 return -EINTR;
 380         }
 381
 382         ffs->setup_state = FFS_NO_SETUP;
 383         return ffs->ep0req_status;
 384 }
 385
 386 static int __ffs_ep0_stall(struct ffs_data *ffs)
 387 {
 388         if (ffs->ev.can_stall) {
 389                 pr_vdebug("ep0 stall\n");
 390                 usb_ep_set_halt(ffs->gadget->ep0);
 391                 ffs->setup_state = FFS_NO_SETUP;
 392                 return -EL2HLT;
 393         } else {
 394                 pr_debug("bogus ep0 stall!\n");
 395                 return -ESRCH;
 396         }
 397 }
 398
 399 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 400                              size_t len, loff_t *ptr)
 401 {
 402         struct ffs_data *ffs = file->private_data;
 403         ssize_t ret;
 404         char *data;
 405
 406         ENTER();
 407
 408         /* Fast check if setup was canceled */
 409         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 410                 return -EIDRM;
 411
 412         /* Acquire mutex */
 413         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 414         if (unlikely(ret < 0))
 415                 return ret;
 416
 417         /* Check state */
 418         switch (ffs->state) {
 419         case FFS_READ_DESCRIPTORS:
 420         case FFS_READ_STRINGS:
 421                 /* Copy data */
 422                 if (unlikely(len < 16)) {
 423                         ret = -EINVAL;
 424                         break;
 425                 }
 426
 427                 data = ffs_prepare_buffer(buf, len);
 428                 if (IS_ERR(data)) {
 429                         ret = PTR_ERR(data);
 430                         break;
 431                 }
 432
 433                 /* Handle data */
 434                 if (ffs->state == FFS_READ_DESCRIPTORS) {
 435                         pr_info("read descriptors\n");
 436                         ret = __ffs_data_got_descs(ffs, data, len);
 437                         if (unlikely(ret < 0))
 438                                 break;
 439
 440                         ffs->state = FFS_READ_STRINGS;
 441                         ret = len;
 442                 } else {
 443                         pr_info("read strings\n");
 444                         ret = __ffs_data_got_strings(ffs, data, len);
 445                         if (unlikely(ret < 0))
 446                                 break;
 447
 448                         ret = ffs_epfiles_create(ffs);
 449                         if (unlikely(ret)) {
 450                                 ffs->state = FFS_CLOSING;
 451                                 break;
 452                         }
 453
 454                         ffs->state = FFS_ACTIVE;
 455                         mutex_unlock(&ffs->mutex);
 456
 457                         ret = functionfs_ready_callback(ffs);
 458                         if (unlikely(ret < 0)) {
 459                                 ffs->state = FFS_CLOSING;
 460                                 return ret;
 461                         }
 462
 463                         set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
 464                         return len;
 465                 }
 466                 break;
 467
 468         case FFS_ACTIVE:
 469                 data = NULL;
 470                 /*
 471                  * We're called from user space, we can use _irq
 472                  * rather then _irqsave
 473                  */
 474                 spin_lock_irq(&ffs->ev.waitq.lock);
 475                 switch (FFS_SETUP_STATE(ffs)) {
 476                 case FFS_SETUP_CANCELED:
 477                         ret = -EIDRM;
 478                         goto done_spin;
 479
 480                 case FFS_NO_SETUP:
 481                         ret = -ESRCH;
 482                         goto done_spin;
 483
 484                 case FFS_SETUP_PENDING:
 485                         break;
 486                 }
 487
 488                 /* FFS_SETUP_PENDING */
 489                 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
 490                         spin_unlock_irq(&ffs->ev.waitq.lock);
 491                         ret = __ffs_ep0_stall(ffs);
 492                         break;
 493                 }
 494
 495                 /* FFS_SETUP_PENDING and not stall */
 496                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 497
 498                 spin_unlock_irq(&ffs->ev.waitq.lock);
 499
 500                 data = ffs_prepare_buffer(buf, len);
 501                 if (IS_ERR(data)) {
 502                         ret = PTR_ERR(data);
 503                         break;
 504                 }
 505
 506                 spin_lock_irq(&ffs->ev.waitq.lock);
 507
 508                 /*
 509                  * We are guaranteed to be still in FFS_ACTIVE state
 510                  * but the state of setup could have changed from
 511                  * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need
 512                  * to check for that.  If that happened we copied data
 513                  * from user space in vain but it's unlikely.
 514                  *
 515                  * For sure we are not in FFS_NO_SETUP since this is
 516                  * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
 517                  * transition can be performed and it's protected by
 518                  * mutex.
 519                  */
 520                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 521                         ret = -EIDRM;
 522 done_spin:
 523                         spin_unlock_irq(&ffs->ev.waitq.lock);
 524                 } else {
 525                         /* unlocks spinlock */
 526                         ret = __ffs_ep0_queue_wait(ffs, data, len);
 527                 }
 528                 kfree(data);
 529                 break;
 530
 531         default:
 532                 ret = -EBADFD;
 533                 break;
 534         }
 535
 536         mutex_unlock(&ffs->mutex);
 537         return ret;
 538 }
 539
 540 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
 541                                      size_t n)
 542 {
 543         /*
 544          * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
 545          * to release them.
 546          */
 547         struct usb_functionfs_event events[n];
 548         unsigned i = 0;
 549
 550         memset(events, 0, sizeof events);
 551
 552         do {
 553                 events[i].type = ffs->ev.types[i];
 554                 if (events[i].type == FUNCTIONFS_SETUP) {
 555                         events[i].u.setup = ffs->ev.setup;
 556                         ffs->setup_state = FFS_SETUP_PENDING;
 557                 }
 558         } while (++i < n);
 559
 560         if (n < ffs->ev.count) {
 561                 ffs->ev.count -= n;
 562                 memmove(ffs->ev.types, ffs->ev.types + n,
 563                         ffs->ev.count * sizeof *ffs->ev.types);
 564         } else {
 565                 ffs->ev.count = 0;
 566         }
 567
 568         spin_unlock_irq(&ffs->ev.waitq.lock);
 569         mutex_unlock(&ffs->mutex);
 570
 571         return unlikely(__copy_to_user(buf, events, sizeof events))
 572                 ? -EFAULT : sizeof events;
 573 }
 574
 575 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 576                             size_t len, loff_t *ptr)
 577 {
 578         struct ffs_data *ffs = file->private_data;
 579         char *data = NULL;
 580         size_t n;
 581         int ret;
 582
 583         ENTER();
 584
 585         /* Fast check if setup was canceled */
 586         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 587                 return -EIDRM;
 588
 589         /* Acquire mutex */
 590         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 591         if (unlikely(ret < 0))
 592                 return ret;
 593
 594         /* Check state */
 595         if (ffs->state != FFS_ACTIVE) {
 596                 ret = -EBADFD;
 597                 goto done_mutex;
 598         }
 599
 600         /*
 601          * We're called from user space, we can use _irq rather then
 602          * _irqsave
 603          */
 604         spin_lock_irq(&ffs->ev.waitq.lock);
 605
 606         switch (FFS_SETUP_STATE(ffs)) {
 607         case FFS_SETUP_CANCELED:
 608                 ret = -EIDRM;
 609                 break;
 610
 611         case FFS_NO_SETUP:
 612                 n = len / sizeof(struct usb_functionfs_event);
 613                 if (unlikely(!n)) {
 614                         ret = -EINVAL;
 615                         break;
 616                 }
 617
 618                 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
 619                         ret = -EAGAIN;
 620                         break;
 621                 }
 622
 623                 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
 624                                                         ffs->ev.count)) {
 625                         ret = -EINTR;
 626                         break;
 627                 }
 628
 629                 return __ffs_ep0_read_events(ffs, buf,
 630                                              min(n, (size_t)ffs->ev.count));
 631
 632         case FFS_SETUP_PENDING:
 633                 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
 634                         spin_unlock_irq(&ffs->ev.waitq.lock);
 635                         ret = __ffs_ep0_stall(ffs);
 636                         goto done_mutex;
 637                 }
 638
 639                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 640
 641                 spin_unlock_irq(&ffs->ev.waitq.lock);
 642
 643                 if (likely(len)) {
 644                         data = kmalloc(len, GFP_KERNEL);
 645                         if (unlikely(!data)) {
 646                                 ret = -ENOMEM;
 647                                 goto done_mutex;
 648                         }
 649                 }
 650
 651                 spin_lock_irq(&ffs->ev.waitq.lock);
 652
 653                 /* See ffs_ep0_write() */
 654                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 655                         ret = -EIDRM;
 656                         break;
 657                 }
 658
 659                 /* unlocks spinlock */
 660                 ret = __ffs_ep0_queue_wait(ffs, data, len);
 661                 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
 662                         ret = -EFAULT;
 663                 goto done_mutex;
 664
 665         default:
 666                 ret = -EBADFD;
 667                 break;
 668         }
 669
 670         spin_unlock_irq(&ffs->ev.waitq.lock);
 671 done_mutex:
 672         mutex_unlock(&ffs->mutex);
 673         kfree(data);
 674         return ret;
 675 }
 676
 677 static int ffs_ep0_open(struct inode *inode, struct file *file)
 678 {
 679         struct ffs_data *ffs = inode->i_private;
 680
 681         ENTER();
 682
 683         if (unlikely(ffs->state == FFS_CLOSING))
 684                 return -EBUSY;
 685
 686         file->private_data = ffs;
 687         ffs_data_opened(ffs);
 688
 689         return 0;
 690 }
 691
 692 static int ffs_ep0_release(struct inode *inode, struct file *file)
 693 {
 694         struct ffs_data *ffs = file->private_data;
 695
 696         ENTER();
 697
 698         ffs_data_closed(ffs);
 699
 700         return 0;
 701 }
 702
 703 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
 704 {
 705         struct ffs_data *ffs = file->private_data;
 706         struct usb_gadget *gadget = ffs->gadget;
 707         long ret;
 708
 709         ENTER();
 710
 711         if (code == FUNCTIONFS_INTERFACE_REVMAP) {
 712                 struct ffs_function *func = ffs->func;
 713                 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
 714         } else if (gadget->ops->ioctl) {
 715                 ret = gadget->ops->ioctl(gadget, code, value);
 716         } else {
 717                 ret = -ENOTTY;
 718         }
 719
 720         return ret;
 721 }
 722
 723 static const struct file_operations ffs_ep0_operations = {
 724         .owner =        THIS_MODULE,
 725         .llseek =       no_llseek,
 726
 727         .open =         ffs_ep0_open,
 728         .write =        ffs_ep0_write,
 729         .read =         ffs_ep0_read,
 730         .release =      ffs_ep0_release,
 731         .unlocked_ioctl =       ffs_ep0_ioctl,
 732 };
 733
 734
 735 /* "Normal" endpoints operations ********************************************/
 736
 737 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
 738 {
 739         ENTER();
 740         if (likely(req->context)) {
 741                 struct ffs_ep *ep = _ep->driver_data;
 742                 ep->status = req->status ? req->status : req->actual;
 743                 complete(req->context);
 744         }
 745 }
 746
 747 static ssize_t ffs_epfile_io(struct file *file,
 748                              char __user *buf, size_t len, int read)
 749 {
 750         struct ffs_epfile *epfile = file->private_data;
 751         struct ffs_ep *ep;
 752         char *data = NULL;
 753         ssize_t ret;
 754         int halt;
 755
 756         goto first_try;
 757         do {
 758                 spin_unlock_irq(&epfile->ffs->eps_lock);
 759                 mutex_unlock(&epfile->mutex);
 760
 761 first_try:
 762                 /* Are we still active? */
 763                 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
 764                         ret = -ENODEV;
 765                         goto error;
 766                 }
 767
 768                 /* Wait for endpoint to be enabled */
 769                 ep = epfile->ep;
 770                 if (!ep) {
 771                         if (file->f_flags & O_NONBLOCK) {
 772                                 ret = -EAGAIN;
 773                                 goto error;
 774                         }
 775
 776                         if (wait_event_interruptible(epfile->wait,
 777                                                      (ep = epfile->ep))) {
 778                                 ret = -EINTR;
 779                                 goto error;
 780                         }
 781                 }
 782
 783                 /* Do we halt? */
 784                 halt = !read == !epfile->in;
 785                 if (halt && epfile->isoc) {
 786                         ret = -EINVAL;
 787                         goto error;
 788                 }
 789
 790                 /* Allocate & copy */
 791                 if (!halt && !data) {
 792                         data = kzalloc(len, GFP_KERNEL);
 793                         if (unlikely(!data))
 794                                 return -ENOMEM;
 795
 796                         if (!read &&
 797                             unlikely(__copy_from_user(data, buf, len))) {
 798                                 ret = -EFAULT;
 799                                 goto error;
 800                         }
 801                 }
 802
 803                 /* We will be using request */
 804                 ret = ffs_mutex_lock(&epfile->mutex,
 805                                      file->f_flags & O_NONBLOCK);
 806                 if (unlikely(ret))
 807                         goto error;
 808
 809                 /*
 810                  * We're called from user space, we can use _irq rather then
 811                  * _irqsave
 812                  */
 813                 spin_lock_irq(&epfile->ffs->eps_lock);
 814
 815                 /*
 816                  * While we were acquiring mutex endpoint got disabled
 817                  * or changed?
 818                  */
 819         } while (unlikely(epfile->ep != ep));
 820
 821         /* Halt */
 822         if (unlikely(halt)) {
 823                 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
 824                         usb_ep_set_halt(ep->ep);
 825                 spin_unlock_irq(&epfile->ffs->eps_lock);
 826                 ret = -EBADMSG;
 827         } else {
 828                 /* Fire the request */
 829                 DECLARE_COMPLETION_ONSTACK(done);
 830
 831                 struct usb_request *req = ep->req;
 832                 req->context  = &done;
 833                 req->complete = ffs_epfile_io_complete;
 834                 req->buf      = data;
 835                 req->length   = len;
 836
 837                 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 838
 839                 spin_unlock_irq(&epfile->ffs->eps_lock);
 840
 841                 if (unlikely(ret < 0)) {
 842                         /* nop */
 843                 } else if (unlikely(wait_for_completion_interruptible(&done))) {
 844                         ret = -EINTR;
 845                         usb_ep_dequeue(ep->ep, req);
 846                 } else {
 847                         ret = ep->status;
 848                         if (read && ret > 0 &&
 849                             unlikely(copy_to_user(buf, data, ret)))
 850                                 ret = -EFAULT;
 851                 }
 852         }
 853
 854         mutex_unlock(&epfile->mutex);
 855 error:
 856         kfree(data);
 857         return ret;
 858 }
 859
 860 static ssize_t
 861 ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
 862                  loff_t *ptr)
 863 {
 864         ENTER();
 865
 866         return ffs_epfile_io(file, (char __user *)buf, len, 0);
 867 }
 868
 869 static ssize_t
 870 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
 871 {
 872         ENTER();
 873
 874         return ffs_epfile_io(file, buf, len, 1);
 875 }
 876
 877 static int
 878 ffs_epfile_open(struct inode *inode, struct file *file)
 879 {
 880         struct ffs_epfile *epfile = inode->i_private;
 881
 882         ENTER();
 883
 884         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 885                 return -ENODEV;
 886
 887         file->private_data = epfile;
 888         ffs_data_opened(epfile->ffs);
 889
 890         return 0;
 891 }
 892
 893 static int
 894 ffs_epfile_release(struct inode *inode, struct file *file)
 895 {
 896         struct ffs_epfile *epfile = inode->i_private;
 897
 898         ENTER();
 899
 900         ffs_data_closed(epfile->ffs);
 901
 902         return 0;
 903 }
 904
 905 static long ffs_epfile_ioctl(struct file *file, unsigned code,
 906                              unsigned long value)
 907 {
 908         struct ffs_epfile *epfile = file->private_data;
 909         int ret;
 910
 911         ENTER();
 912
 913         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 914                 return -ENODEV;
 915
 916         spin_lock_irq(&epfile->ffs->eps_lock);
 917         if (likely(epfile->ep)) {
 918                 switch (code) {
 919                 case FUNCTIONFS_FIFO_STATUS:
 920                         ret = usb_ep_fifo_status(epfile->ep->ep);
 921                         break;
 922                 case FUNCTIONFS_FIFO_FLUSH:
 923                         usb_ep_fifo_flush(epfile->ep->ep);
 924                         ret = 0;
 925                         break;
 926                 case FUNCTIONFS_CLEAR_HALT:
 927                         ret = usb_ep_clear_halt(epfile->ep->ep);
 928                         break;
 929                 case FUNCTIONFS_ENDPOINT_REVMAP:
 930                         ret = epfile->ep->num;
 931                         break;
 932                 default:
 933                         ret = -ENOTTY;
 934                 }
 935         } else {
 936                 ret = -ENODEV;
 937         }
 938         spin_unlock_irq(&epfile->ffs->eps_lock);
 939
 940         return ret;
 941 }
 942
 943 static const struct file_operations ffs_epfile_operations = {
 944         .owner =        THIS_MODULE,
 945         .llseek =       no_llseek,
 946
 947         .open =         ffs_epfile_open,
 948         .write =        ffs_epfile_write,
 949         .read =         ffs_epfile_read,
 950         .release =      ffs_epfile_release,
 951         .unlocked_ioctl =       ffs_epfile_ioctl,
 952 };
 953
 954
 955 /* File system and super block operations ***********************************/
 956
 957 /*
 958  * Mounting the file system creates a controller file, used first for
 959  * function configuration then later for event monitoring.
 960  */
 961
 962 static struct inode *__must_check
 963 ffs_sb_make_inode(struct super_block *sb, void *data,
 964                   const struct file_operations *fops,
 965                   const struct inode_operations *iops,
 966                   struct ffs_file_perms *perms)
 967 {
 968         struct inode *inode;
 969
 970         ENTER();
 971
 972         inode = new_inode(sb);
 973
 974         if (likely(inode)) {
 975                 struct timespec current_time = CURRENT_TIME;
 976
 977                 inode->i_ino     = get_next_ino();
 978                 inode->i_mode    = perms->mode;
 979                 inode->i_uid     = perms->uid;
 980                 inode->i_gid     = perms->gid;
 981                 inode->i_atime   = current_time;
 982                 inode->i_mtime   = current_time;
 983                 inode->i_ctime   = current_time;
 984                 inode->i_private = data;
 985                 if (fops)
 986                         inode->i_fop = fops;
 987                 if (iops)
 988                         inode->i_op  = iops;
 989         }
 990
 991         return inode;
 992 }
 993
 994 /* Create "regular" file */
 995 static struct inode *ffs_sb_create_file(struct super_block *sb,
 996                                         const char *name, void *data,
 997                                         const struct file_operations *fops,
 998                                         struct dentry **dentry_p)
 999 {
1000         struct ffs_data *ffs = sb->s_fs_info;
1001         struct dentry   *dentry;
1002         struct inode    *inode;
1003
1004         ENTER();
1005
1006         dentry = d_alloc_name(sb->s_root, name);
1007         if (unlikely(!dentry))
1008                 return NULL;
1009
1010         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1011         if (unlikely(!inode)) {
1012                 dput(dentry);
1013                 return NULL;
1014         }
1015
1016         d_add(dentry, inode);
1017         if (dentry_p)
1018                 *dentry_p = dentry;
1019
1020         return inode;
1021 }
1022
1023 /* Super block */
1024 static const struct super_operations ffs_sb_operations = {
1025         .statfs =       simple_statfs,
1026         .drop_inode =   generic_delete_inode,
1027 };
1028
1029 struct ffs_sb_fill_data {
1030         struct ffs_file_perms perms;
1031         umode_t root_mode;
1032         const char *dev_name;
1033 };
1034
1035 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1036 {
1037         struct ffs_sb_fill_data *data = _data;
1038         struct inode    *inode;
1039         struct dentry   *d;
1040         struct ffs_data *ffs;
1041
1042         ENTER();
1043
1044         /* Initialise data */
1045         ffs = ffs_data_new();
1046         if (unlikely(!ffs))
1047                 goto enomem0;
1048
1049         ffs->sb              = sb;
1050         ffs->dev_name        = data->dev_name;
1051         ffs->file_perms      = data->perms;
1052
1053         sb->s_fs_info        = ffs;
1054         sb->s_blocksize      = PAGE_CACHE_SIZE;
1055         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1056         sb->s_magic          = FUNCTIONFS_MAGIC;
1057         sb->s_op             = &ffs_sb_operations;
1058         sb->s_time_gran      = 1;
1059
1060         /* Root inode */
1061         data->perms.mode = data->root_mode;
1062         inode = ffs_sb_make_inode(sb, NULL,
1063                                   &simple_dir_operations,
1064                                   &simple_dir_inode_operations,
1065                                   &data->perms);
1066         if (unlikely(!inode))
1067                 goto enomem1;
1068         d = d_alloc_root(inode);
1069         if (unlikely(!d))
1070                 goto enomem2;
1071         sb->s_root = d;
1072
1073         /* EP0 file */
1074         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1075                                          &ffs_ep0_operations, NULL)))
1076                 goto enomem3;
1077
1078         return 0;
1079
1080 enomem3:
1081         dput(d);
1082 enomem2:
1083         iput(inode);
1084 enomem1:
1085         ffs_data_put(ffs);
1086 enomem0:
1087         return -ENOMEM;
1088 }
1089
1090 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1091 {
1092         ENTER();
1093
1094         if (!opts || !*opts)
1095                 return 0;
1096
1097         for (;;) {
1098                 char *end, *eq, *comma;
1099                 unsigned long value;
1100
1101                 /* Option limit */
1102                 comma = strchr(opts, ',');
1103                 if (comma)
1104                         *comma = 0;
1105
1106                 /* Value limit */
1107                 eq = strchr(opts, '=');
1108                 if (unlikely(!eq)) {
1109                         pr_err("'=' missing in %s\n", opts);
1110                         return -EINVAL;
1111                 }
1112                 *eq = 0;
1113
1114                 /* Parse value */
1115                 value = simple_strtoul(eq + 1, &end, 0);
1116                 if (unlikely(*end != ',' && *end != 0)) {
1117                         pr_err("%s: invalid value: %s\n", opts, eq + 1);
1118                         return -EINVAL;
1119                 }
1120
1121                 /* Interpret option */
1122                 switch (eq - opts) {
1123                 case 5:
1124                         if (!memcmp(opts, "rmode", 5))
1125                                 data->root_mode  = (value & 0555) | S_IFDIR;
1126                         else if (!memcmp(opts, "fmode", 5))
1127                                 data->perms.mode = (value & 0666) | S_IFREG;
1128                         else
1129                                 goto invalid;
1130                         break;
1131
1132                 case 4:
1133                         if (!memcmp(opts, "mode", 4)) {
1134                                 data->root_mode  = (value & 0555) | S_IFDIR;
1135                                 data->perms.mode = (value & 0666) | S_IFREG;
1136                         } else {
1137                                 goto invalid;
1138                         }
1139                         break;
1140
1141                 case 3:
1142                         if (!memcmp(opts, "uid", 3))
1143                                 data->perms.uid = value;
1144                         else if (!memcmp(opts, "gid", 3))
1145                                 data->perms.gid = value;
1146                         else
1147                                 goto invalid;
1148                         break;
1149
1150                 default:
1151 invalid:
1152                         pr_err("%s: invalid option\n", opts);
1153                         return -EINVAL;
1154                 }
1155
1156                 /* Next iteration */
1157                 if (!comma)
1158                         break;
1159                 opts = comma + 1;
1160         }
1161
1162         return 0;
1163 }
1164
1165 /* "mount -t functionfs dev_name /dev/function" ends up here */
1166
1167 static struct dentry *
1168 ffs_fs_mount(struct file_system_type *t, int flags,
1169               const char *dev_name, void *opts)
1170 {
1171         struct ffs_sb_fill_data data = {
1172                 .perms = {
1173                         .mode = S_IFREG | 0600,
1174                         .uid = 0,
1175                         .gid = 0
1176                 },
1177                 .root_mode = S_IFDIR | 0500,
1178         };
1179         int ret;
1180
1181         ENTER();
1182
1183         ret = functionfs_check_dev_callback(dev_name);
1184         if (unlikely(ret < 0))
1185                 return ERR_PTR(ret);
1186
1187         ret = ffs_fs_parse_opts(&data, opts);
1188         if (unlikely(ret < 0))
1189                 return ERR_PTR(ret);
1190
1191         data.dev_name = dev_name;
1192         return mount_single(t, flags, &data, ffs_sb_fill);
1193 }
1194
1195 static void
1196 ffs_fs_kill_sb(struct super_block *sb)
1197 {
1198         void *ptr;
1199
1200         ENTER();
1201
1202         kill_litter_super(sb);
1203         ptr = xchg(&sb->s_fs_info, NULL);
1204         if (ptr)
1205                 ffs_data_put(ptr);
1206 }
1207
1208 static struct file_system_type ffs_fs_type = {
1209         .owner          = THIS_MODULE,
1210         .name           = "functionfs",
1211         .mount          = ffs_fs_mount,
1212         .kill_sb        = ffs_fs_kill_sb,
1213 };
1214
1215
1216 /* Driver's main init/cleanup functions *************************************/
1217
1218 static int functionfs_init(void)
1219 {
1220         int ret;
1221
1222         ENTER();
1223
1224         ret = register_filesystem(&ffs_fs_type);
1225         if (likely(!ret))
1226                 pr_info("file system registered\n");
1227         else
1228                 pr_err("failed registering file system (%d)\n", ret);
1229
1230         return ret;
1231 }
1232
1233 static void functionfs_cleanup(void)
1234 {
1235         ENTER();
1236
1237         pr_info("unloading\n");
1238         unregister_filesystem(&ffs_fs_type);
1239 }
1240
1241
1242 /* ffs_data and ffs_function construction and destruction code **************/
1243
1244 static void ffs_data_clear(struct ffs_data *ffs);
1245 static void ffs_data_reset(struct ffs_data *ffs);
1246
1247 static void ffs_data_get(struct ffs_data *ffs)
1248 {
1249         ENTER();
1250
1251         atomic_inc(&ffs->ref);
1252 }
1253
1254 static void ffs_data_opened(struct ffs_data *ffs)
1255 {
1256         ENTER();
1257
1258         atomic_inc(&ffs->ref);
1259         atomic_inc(&ffs->opened);
1260 }
1261
1262 static void ffs_data_put(struct ffs_data *ffs)
1263 {
1264         ENTER();
1265
1266         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1267                 pr_info("%s(): freeing\n", __func__);
1268                 ffs_data_clear(ffs);
1269                 BUG_ON(mutex_is_locked(&ffs->mutex) ||
1270                        spin_is_locked(&ffs->ev.waitq.lock) ||
1271                        waitqueue_active(&ffs->ev.waitq) ||
1272                        waitqueue_active(&ffs->ep0req_completion.wait));
1273                 kfree(ffs);
1274         }
1275 }
1276
1277 static void ffs_data_closed(struct ffs_data *ffs)
1278 {
1279         ENTER();
1280
1281         if (atomic_dec_and_test(&ffs->opened)) {
1282                 ffs->state = FFS_CLOSING;
1283                 ffs_data_reset(ffs);
1284         }
1285
1286         ffs_data_put(ffs);
1287 }
1288
1289 static struct ffs_data *ffs_data_new(void)
1290 {
1291         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1292         if (unlikely(!ffs))
1293                 return 0;
1294
1295         ENTER();
1296
1297         atomic_set(&ffs->ref, 1);
1298         atomic_set(&ffs->opened, 0);
1299         ffs->state = FFS_READ_DESCRIPTORS;
1300         mutex_init(&ffs->mutex);
1301         spin_lock_init(&ffs->eps_lock);
1302         init_waitqueue_head(&ffs->ev.waitq);
1303         init_completion(&ffs->ep0req_completion);
1304
1305         /* XXX REVISIT need to update it in some places, or do we? */
1306         ffs->ev.can_stall = 1;
1307
1308         return ffs;
1309 }
1310
1311 static void ffs_data_clear(struct ffs_data *ffs)
1312 {
1313         ENTER();
1314
1315         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1316                 functionfs_closed_callback(ffs);
1317
1318         BUG_ON(ffs->gadget);
1319
1320         if (ffs->epfiles)
1321                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1322
1323         kfree(ffs->raw_descs);
1324         kfree(ffs->raw_strings);
1325         kfree(ffs->stringtabs);
1326 }
1327
1328 static void ffs_data_reset(struct ffs_data *ffs)
1329 {
1330         ENTER();
1331
1332         ffs_data_clear(ffs);
1333
1334         ffs->epfiles = NULL;
1335         ffs->raw_descs = NULL;
1336         ffs->raw_strings = NULL;
1337         ffs->stringtabs = NULL;
1338
1339         ffs->raw_descs_length = 0;
1340         ffs->raw_fs_descs_length = 0;
1341         ffs->fs_descs_count = 0;
1342         ffs->hs_descs_count = 0;
1343
1344         ffs->strings_count = 0;
1345         ffs->interfaces_count = 0;
1346         ffs->eps_count = 0;
1347
1348         ffs->ev.count = 0;
1349
1350         ffs->state = FFS_READ_DESCRIPTORS;
1351         ffs->setup_state = FFS_NO_SETUP;
1352         ffs->flags = 0;
1353 }
1354
1355
1356 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1357 {
1358         struct usb_gadget_strings **lang;
1359         int first_id;
1360
1361         ENTER();
1362
1363         if (WARN_ON(ffs->state != FFS_ACTIVE
1364                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1365                 return -EBADFD;
1366
1367         first_id = usb_string_ids_n(cdev, ffs->strings_count);
1368         if (unlikely(first_id < 0))
1369                 return first_id;
1370
1371         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1372         if (unlikely(!ffs->ep0req))
1373                 return -ENOMEM;
1374         ffs->ep0req->complete = ffs_ep0_complete;
1375         ffs->ep0req->context = ffs;
1376
1377         lang = ffs->stringtabs;
1378         for (lang = ffs->stringtabs; *lang; ++lang) {
1379                 struct usb_string *str = (*lang)->strings;
1380                 int id = first_id;
1381                 for (; str->s; ++id, ++str)
1382                         str->id = id;
1383         }
1384
1385         ffs->gadget = cdev->gadget;
1386         ffs_data_get(ffs);
1387         return 0;
1388 }
1389
1390 static void functionfs_unbind(struct ffs_data *ffs)
1391 {
1392         ENTER();
1393
1394         if (!WARN_ON(!ffs->gadget)) {
1395                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1396                 ffs->ep0req = NULL;
1397                 ffs->gadget = NULL;
1398                 ffs_data_put(ffs);
1399         }
1400 }
1401
1402 static int ffs_epfiles_create(struct ffs_data *ffs)
1403 {
1404         struct ffs_epfile *epfile, *epfiles;
1405         unsigned i, count;
1406
1407         ENTER();
1408
1409         count = ffs->eps_count;
1410         epfiles = kzalloc(count * sizeof *epfiles, GFP_KERNEL);
1411         if (!epfiles)
1412                 return -ENOMEM;
1413
1414         epfile = epfiles;
1415         for (i = 1; i <= count; ++i, ++epfile) {
1416                 epfile->ffs = ffs;
1417                 mutex_init(&epfile->mutex);
1418                 init_waitqueue_head(&epfile->wait);
1419                 sprintf(epfiles->name, "ep%u",  i);
1420                 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1421                                                  &ffs_epfile_operations,
1422                                                  &epfile->dentry))) {
1423                         ffs_epfiles_destroy(epfiles, i - 1);
1424                         return -ENOMEM;
1425                 }
1426         }
1427
1428         ffs->epfiles = epfiles;
1429         return 0;
1430 }
1431
1432 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1433 {
1434         struct ffs_epfile *epfile = epfiles;
1435
1436         ENTER();
1437
1438         for (; count; --count, ++epfile) {
1439                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1440                        waitqueue_active(&epfile->wait));
1441                 if (epfile->dentry) {
1442                         d_delete(epfile->dentry);
1443                         dput(epfile->dentry);
1444                         epfile->dentry = NULL;
1445                 }
1446         }
1447
1448         kfree(epfiles);
1449 }
1450
1451 static int functionfs_bind_config(struct usb_composite_dev *cdev,
1452                                   struct usb_configuration *c,
1453                                   struct ffs_data *ffs)
1454 {
1455         struct ffs_function *func;
1456         int ret;
1457
1458         ENTER();
1459
1460         func = kzalloc(sizeof *func, GFP_KERNEL);
1461         if (unlikely(!func))
1462                 return -ENOMEM;
1463
1464         func->function.name    = "Function FS Gadget";
1465         func->function.strings = ffs->stringtabs;
1466
1467         func->function.bind    = ffs_func_bind;
1468         func->function.unbind  = ffs_func_unbind;
1469         func->function.set_alt = ffs_func_set_alt;
1470         func->function.disable = ffs_func_disable;
1471         func->function.setup   = ffs_func_setup;
1472         func->function.suspend = ffs_func_suspend;
1473         func->function.resume  = ffs_func_resume;
1474
1475         func->conf   = c;
1476         func->gadget = cdev->gadget;
1477         func->ffs = ffs;
1478         ffs_data_get(ffs);
1479
1480         ret = usb_add_function(c, &func->function);
1481         if (unlikely(ret))
1482                 ffs_func_free(func);
1483
1484         return ret;
1485 }
1486
1487 static void ffs_func_free(struct ffs_function *func)
1488 {
1489         ENTER();
1490
1491         ffs_data_put(func->ffs);
1492
1493         kfree(func->eps);
1494         /*
1495          * eps and interfaces_nums are allocated in the same chunk so
1496          * only one free is required.  Descriptors are also allocated
1497          * in the same chunk.
1498          */
1499
1500         kfree(func);
1501 }
1502
1503 static void ffs_func_eps_disable(struct ffs_function *func)
1504 {
1505         struct ffs_ep *ep         = func->eps;
1506         struct ffs_epfile *epfile = func->ffs->epfiles;
1507         unsigned count            = func->ffs->eps_count;
1508         unsigned long flags;
1509
1510         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1511         do {
1512                 /* pending requests get nuked */
1513                 if (likely(ep->ep))
1514                         usb_ep_disable(ep->ep);
1515                 epfile->ep = NULL;
1516
1517                 ++ep;
1518                 ++epfile;
1519         } while (--count);
1520         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1521 }
1522
1523 static int ffs_func_eps_enable(struct ffs_function *func)
1524 {
1525         struct ffs_data *ffs      = func->ffs;
1526         struct ffs_ep *ep         = func->eps;
1527         struct ffs_epfile *epfile = ffs->epfiles;
1528         unsigned count            = ffs->eps_count;
1529         unsigned long flags;
1530         int ret = 0;
1531
1532         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1533         do {
1534                 struct usb_endpoint_descriptor *ds;
1535                 ds = ep->descs[ep->descs[1] ? 1 : 0];
1536
1537                 ep->ep->driver_data = ep;
1538                 ep->ep->desc = ds;
1539                 ret = usb_ep_enable(ep->ep);
1540                 if (likely(!ret)) {
1541                         epfile->ep = ep;
1542                         epfile->in = usb_endpoint_dir_in(ds);
1543                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1544                 } else {
1545                         break;
1546                 }
1547
1548                 wake_up(&epfile->wait);
1549
1550                 ++ep;
1551                 ++epfile;
1552         } while (--count);
1553         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1554
1555         return ret;
1556 }
1557
1558
1559 /* Parsing and building descriptors and strings *****************************/
1560
1561 /*
1562  * This validates if data pointed by data is a valid USB descriptor as
1563  * well as record how many interfaces, endpoints and strings are
1564  * required by given configuration.  Returns address after the
1565  * descriptor or NULL if data is invalid.
1566  */
1567
1568 enum ffs_entity_type {
1569         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1570 };
1571
1572 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1573                                    u8 *valuep,
1574                                    struct usb_descriptor_header *desc,
1575                                    void *priv);
1576
1577 static int __must_check ffs_do_desc(char *data, unsigned len,
1578                                     ffs_entity_callback entity, void *priv)
1579 {
1580         struct usb_descriptor_header *_ds = (void *)data;
1581         u8 length;
1582         int ret;
1583
1584         ENTER();
1585
1586         /* At least two bytes are required: length and type */
1587         if (len < 2) {
1588                 pr_vdebug("descriptor too short\n");
1589                 return -EINVAL;
1590         }
1591
1592         /* If we have at least as many bytes as the descriptor takes? */
1593         length = _ds->bLength;
1594         if (len < length) {
1595                 pr_vdebug("descriptor longer then available data\n");
1596                 return -EINVAL;
1597         }
1598
1599 #define __entity_check_INTERFACE(val)  1
1600 #define __entity_check_STRING(val)     (val)
1601 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1602 #define __entity(type, val) do {                                        \
1603                 pr_vdebug("entity " #type "(%02x)\n", (val));           \
1604                 if (unlikely(!__entity_check_ ##type(val))) {           \
1605                         pr_vdebug("invalid entity's value\n");          \
1606                         return -EINVAL;                                 \
1607                 }                                                       \
1608                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1609                 if (unlikely(ret < 0)) {                                \
1610                         pr_debug("entity " #type "(%02x); ret = %d\n",  \
1611                                  (val), ret);                           \
1612                         return ret;                                     \
1613                 }                                                       \
1614         } while (0)
1615
1616         /* Parse descriptor depending on type. */
1617         switch (_ds->bDescriptorType) {
1618         case USB_DT_DEVICE:
1619         case USB_DT_CONFIG:
1620         case USB_DT_STRING:
1621         case USB_DT_DEVICE_QUALIFIER:
1622                 /* function can't have any of those */
1623                 pr_vdebug("descriptor reserved for gadget: %d\n",
1624                       _ds->bDescriptorType);
1625                 return -EINVAL;
1626
1627         case USB_DT_INTERFACE: {
1628                 struct usb_interface_descriptor *ds = (void *)_ds;
1629                 pr_vdebug("interface descriptor\n");
1630                 if (length != sizeof *ds)
1631                         goto inv_length;
1632
1633                 __entity(INTERFACE, ds->bInterfaceNumber);
1634                 if (ds->iInterface)
1635                         __entity(STRING, ds->iInterface);
1636         }
1637                 break;
1638
1639         case USB_DT_ENDPOINT: {
1640                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1641                 pr_vdebug("endpoint descriptor\n");
1642                 if (length != USB_DT_ENDPOINT_SIZE &&
1643                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1644                         goto inv_length;
1645                 __entity(ENDPOINT, ds->bEndpointAddress);
1646         }
1647                 break;
1648
1649         case USB_DT_OTG:
1650                 if (length != sizeof(struct usb_otg_descriptor))
1651                         goto inv_length;
1652                 break;
1653
1654         case USB_DT_INTERFACE_ASSOCIATION: {
1655                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1656                 pr_vdebug("interface association descriptor\n");
1657                 if (length != sizeof *ds)
1658                         goto inv_length;
1659                 if (ds->iFunction)
1660                         __entity(STRING, ds->iFunction);
1661         }
1662                 break;
1663
1664         case USB_DT_OTHER_SPEED_CONFIG:
1665         case USB_DT_INTERFACE_POWER:
1666         case USB_DT_DEBUG:
1667         case USB_DT_SECURITY:
1668         case USB_DT_CS_RADIO_CONTROL:
1669                 /* TODO */
1670                 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1671                 return -EINVAL;
1672
1673         default:
1674                 /* We should never be here */
1675                 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1676                 return -EINVAL;
1677
1678 inv_length:
1679                 pr_vdebug("invalid length: %d (descriptor %d)\n",
1680                           _ds->bLength, _ds->bDescriptorType);
1681                 return -EINVAL;
1682         }
1683
1684 #undef __entity
1685 #undef __entity_check_DESCRIPTOR
1686 #undef __entity_check_INTERFACE
1687 #undef __entity_check_STRING
1688 #undef __entity_check_ENDPOINT
1689
1690         return length;
1691 }
1692
1693 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1694                                      ffs_entity_callback entity, void *priv)
1695 {
1696         const unsigned _len = len;
1697         unsigned long num = 0;
1698
1699         ENTER();
1700
1701         for (;;) {
1702                 int ret;
1703
1704                 if (num == count)
1705                         data = NULL;
1706
1707                 /* Record "descriptor" entity */
1708                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1709                 if (unlikely(ret < 0)) {
1710                         pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1711                                  num, ret);
1712                         return ret;
1713                 }
1714
1715                 if (!data)
1716                         return _len - len;
1717
1718                 ret = ffs_do_desc(data, len, entity, priv);
1719                 if (unlikely(ret < 0)) {
1720                         pr_debug("%s returns %d\n", __func__, ret);
1721                         return ret;
1722                 }
1723
1724                 len -= ret;
1725                 data += ret;
1726                 ++num;
1727         }
1728 }
1729
1730 static int __ffs_data_do_entity(enum ffs_entity_type type,
1731                                 u8 *valuep, struct usb_descriptor_header *desc,
1732                                 void *priv)
1733 {
1734         struct ffs_data *ffs = priv;
1735
1736         ENTER();
1737
1738         switch (type) {
1739         case FFS_DESCRIPTOR:
1740                 break;
1741
1742         case FFS_INTERFACE:
1743                 /*
1744                  * Interfaces are indexed from zero so if we
1745                  * encountered interface "n" then there are at least
1746                  * "n+1" interfaces.
1747                  */
1748                 if (*valuep >= ffs->interfaces_count)
1749                         ffs->interfaces_count = *valuep + 1;
1750                 break;
1751
1752         case FFS_STRING:
1753                 /*
1754                  * Strings are indexed from 1 (0 is magic ;) reserved
1755                  * for languages list or some such)
1756                  */
1757                 if (*valuep > ffs->strings_count)
1758                         ffs->strings_count = *valuep;
1759                 break;
1760
1761         case FFS_ENDPOINT:
1762                 /* Endpoints are indexed from 1 as well. */
1763                 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1764                         ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1765                 break;
1766         }
1767
1768         return 0;
1769 }
1770
1771 static int __ffs_data_got_descs(struct ffs_data *ffs,
1772                                 char *const _data, size_t len)
1773 {
1774         unsigned fs_count, hs_count;
1775         int fs_len, ret = -EINVAL;
1776         char *data = _data;
1777
1778         ENTER();
1779
1780         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1781                      get_unaligned_le32(data + 4) != len))
1782                 goto error;
1783         fs_count = get_unaligned_le32(data +  8);
1784         hs_count = get_unaligned_le32(data + 12);
1785
1786         if (!fs_count && !hs_count)
1787                 goto einval;
1788
1789         data += 16;
1790         len  -= 16;
1791
1792         if (likely(fs_count)) {
1793                 fs_len = ffs_do_descs(fs_count, data, len,
1794                                       __ffs_data_do_entity, ffs);
1795                 if (unlikely(fs_len < 0)) {
1796                         ret = fs_len;
1797                         goto error;
1798                 }
1799
1800                 data += fs_len;
1801                 len  -= fs_len;
1802         } else {
1803                 fs_len = 0;
1804         }
1805
1806         if (likely(hs_count)) {
1807                 ret = ffs_do_descs(hs_count, data, len,
1808                                    __ffs_data_do_entity, ffs);
1809                 if (unlikely(ret < 0))
1810                         goto error;
1811         } else {
1812                 ret = 0;
1813         }
1814
1815         if (unlikely(len != ret))
1816                 goto einval;
1817
1818         ffs->raw_fs_descs_length = fs_len;
1819         ffs->raw_descs_length    = fs_len + ret;
1820         ffs->raw_descs           = _data;
1821         ffs->fs_descs_count      = fs_count;
1822         ffs->hs_descs_count      = hs_count;
1823
1824         return 0;
1825
1826 einval:
1827         ret = -EINVAL;
1828 error:
1829         kfree(_data);
1830         return ret;
1831 }
1832
1833 static int __ffs_data_got_strings(struct ffs_data *ffs,
1834                                   char *const _data, size_t len)
1835 {
1836         u32 str_count, needed_count, lang_count;
1837         struct usb_gadget_strings **stringtabs, *t;
1838         struct usb_string *strings, *s;
1839         const char *data = _data;
1840
1841         ENTER();
1842
1843         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1844                      get_unaligned_le32(data + 4) != len))
1845                 goto error;
1846         str_count  = get_unaligned_le32(data + 8);
1847         lang_count = get_unaligned_le32(data + 12);
1848
1849         /* if one is zero the other must be zero */
1850         if (unlikely(!str_count != !lang_count))
1851                 goto error;
1852
1853         /* Do we have at least as many strings as descriptors need? */
1854         needed_count = ffs->strings_count;
1855         if (unlikely(str_count < needed_count))
1856                 goto error;
1857
1858         /*
1859          * If we don't need any strings just return and free all
1860          * memory.
1861          */
1862         if (!needed_count) {
1863                 kfree(_data);
1864                 return 0;
1865         }
1866
1867         /* Allocate everything in one chunk so there's less maintenance. */
1868         {
1869                 struct {
1870                         struct usb_gadget_strings *stringtabs[lang_count + 1];
1871                         struct usb_gadget_strings stringtab[lang_count];
1872                         struct usb_string strings[lang_count*(needed_count+1)];
1873                 } *d;
1874                 unsigned i = 0;
1875
1876                 d = kmalloc(sizeof *d, GFP_KERNEL);
1877                 if (unlikely(!d)) {
1878                         kfree(_data);
1879                         return -ENOMEM;
1880                 }
1881
1882                 stringtabs = d->stringtabs;
1883                 t = d->stringtab;
1884                 i = lang_count;
1885                 do {
1886                         *stringtabs++ = t++;
1887                 } while (--i);
1888                 *stringtabs = NULL;
1889
1890                 stringtabs = d->stringtabs;
1891                 t = d->stringtab;
1892                 s = d->strings;
1893                 strings = s;
1894         }
1895
1896         /* For each language */
1897         data += 16;
1898         len -= 16;
1899
1900         do { /* lang_count > 0 so we can use do-while */
1901                 unsigned needed = needed_count;
1902
1903                 if (unlikely(len < 3))
1904                         goto error_free;
1905                 t->language = get_unaligned_le16(data);
1906                 t->strings  = s;
1907                 ++t;
1908
1909                 data += 2;
1910                 len -= 2;
1911
1912                 /* For each string */
1913                 do { /* str_count > 0 so we can use do-while */
1914                         size_t length = strnlen(data, len);
1915
1916                         if (unlikely(length == len))
1917                                 goto error_free;
1918
1919                         /*
1920                          * User may provide more strings then we need,
1921                          * if that's the case we simply ignore the
1922                          * rest
1923                          */
1924                         if (likely(needed)) {
1925                                 /*
1926                                  * s->id will be set while adding
1927                                  * function to configuration so for
1928                                  * now just leave garbage here.
1929                                  */
1930                                 s->s = data;
1931                                 --needed;
1932                                 ++s;
1933                         }
1934
1935                         data += length + 1;
1936                         len -= length + 1;
1937                 } while (--str_count);
1938
1939                 s->id = 0;   /* terminator */
1940                 s->s = NULL;
1941                 ++s;
1942
1943         } while (--lang_count);
1944
1945         /* Some garbage left? */
1946         if (unlikely(len))
1947                 goto error_free;
1948
1949         /* Done! */
1950         ffs->stringtabs = stringtabs;
1951         ffs->raw_strings = _data;
1952
1953         return 0;
1954
1955 error_free:
1956         kfree(stringtabs);
1957 error:
1958         kfree(_data);
1959         return -EINVAL;
1960 }
1961
1962
1963 /* Events handling and management *******************************************/
1964
1965 static void __ffs_event_add(struct ffs_data *ffs,
1966                             enum usb_functionfs_event_type type)
1967 {
1968         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
1969         int neg = 0;
1970
1971         /*
1972          * Abort any unhandled setup
1973          *
1974          * We do not need to worry about some cmpxchg() changing value
1975          * of ffs->setup_state without holding the lock because when
1976          * state is FFS_SETUP_PENDING cmpxchg() in several places in
1977          * the source does nothing.
1978          */
1979         if (ffs->setup_state == FFS_SETUP_PENDING)
1980                 ffs->setup_state = FFS_SETUP_CANCELED;
1981
1982         switch (type) {
1983         case FUNCTIONFS_RESUME:
1984                 rem_type2 = FUNCTIONFS_SUSPEND;
1985                 /* FALL THROUGH */
1986         case FUNCTIONFS_SUSPEND:
1987         case FUNCTIONFS_SETUP:
1988                 rem_type1 = type;
1989                 /* Discard all similar events */
1990                 break;
1991
1992         case FUNCTIONFS_BIND:
1993         case FUNCTIONFS_UNBIND:
1994         case FUNCTIONFS_DISABLE:
1995         case FUNCTIONFS_ENABLE:
1996                 /* Discard everything other then power management. */
1997                 rem_type1 = FUNCTIONFS_SUSPEND;
1998                 rem_type2 = FUNCTIONFS_RESUME;
1999                 neg = 1;
2000                 break;
2001
2002         default:
2003                 BUG();
2004         }
2005
2006         {
2007                 u8 *ev  = ffs->ev.types, *out = ev;
2008                 unsigned n = ffs->ev.count;
2009                 for (; n; --n, ++ev)
2010                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2011                                 *out++ = *ev;
2012                         else
2013                                 pr_vdebug("purging event %d\n", *ev);
2014                 ffs->ev.count = out - ffs->ev.types;
2015         }
2016
2017         pr_vdebug("adding event %d\n", type);
2018         ffs->ev.types[ffs->ev.count++] = type;
2019         wake_up_locked(&ffs->ev.waitq);
2020 }
2021
2022 static void ffs_event_add(struct ffs_data *ffs,
2023                           enum usb_functionfs_event_type type)
2024 {
2025         unsigned long flags;
2026         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2027         __ffs_event_add(ffs, type);
2028         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2029 }
2030
2031
2032 /* Bind/unbind USB function hooks *******************************************/
2033
2034 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2035                                     struct usb_descriptor_header *desc,
2036                                     void *priv)
2037 {
2038         struct usb_endpoint_descriptor *ds = (void *)desc;
2039         struct ffs_function *func = priv;
2040         struct ffs_ep *ffs_ep;
2041
2042         /*
2043          * If hs_descriptors is not NULL then we are reading hs
2044          * descriptors now
2045          */
2046         const int isHS = func->function.hs_descriptors != NULL;
2047         unsigned idx;
2048
2049         if (type != FFS_DESCRIPTOR)
2050                 return 0;
2051
2052         if (isHS)
2053                 func->function.hs_descriptors[(long)valuep] = desc;
2054         else
2055                 func->function.descriptors[(long)valuep]    = desc;
2056
2057         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2058                 return 0;
2059
2060         idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2061         ffs_ep = func->eps + idx;
2062
2063         if (unlikely(ffs_ep->descs[isHS])) {
2064                 pr_vdebug("two %sspeed descriptors for EP %d\n",
2065                           isHS ? "high" : "full",
2066                           ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2067                 return -EINVAL;
2068         }
2069         ffs_ep->descs[isHS] = ds;
2070
2071         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2072         if (ffs_ep->ep) {
2073                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2074                 if (!ds->wMaxPacketSize)
2075                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2076         } else {
2077                 struct usb_request *req;
2078                 struct usb_ep *ep;
2079
2080                 pr_vdebug("autoconfig\n");
2081                 ep = usb_ep_autoconfig(func->gadget, ds);
2082                 if (unlikely(!ep))
2083                         return -ENOTSUPP;
2084                 ep->driver_data = func->eps + idx;
2085
2086                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2087                 if (unlikely(!req))
2088                         return -ENOMEM;
2089
2090                 ffs_ep->ep  = ep;
2091                 ffs_ep->req = req;
2092                 func->eps_revmap[ds->bEndpointAddress &
2093                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2094         }
2095         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2096
2097         return 0;
2098 }
2099
2100 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2101                                    struct usb_descriptor_header *desc,
2102                                    void *priv)
2103 {
2104         struct ffs_function *func = priv;
2105         unsigned idx;
2106         u8 newValue;
2107
2108         switch (type) {
2109         default:
2110         case FFS_DESCRIPTOR:
2111                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2112                 return 0;
2113
2114         case FFS_INTERFACE:
2115                 idx = *valuep;
2116                 if (func->interfaces_nums[idx] < 0) {
2117                         int id = usb_interface_id(func->conf, &func->function);
2118                         if (unlikely(id < 0))
2119                                 return id;
2120                         func->interfaces_nums[idx] = id;
2121                 }
2122                 newValue = func->interfaces_nums[idx];
2123                 break;
2124
2125         case FFS_STRING:
2126                 /* String' IDs are allocated when fsf_data is bound to cdev */
2127                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2128                 break;
2129
2130         case FFS_ENDPOINT:
2131                 /*
2132                  * USB_DT_ENDPOINT are handled in
2133                  * __ffs_func_bind_do_descs().
2134                  */
2135                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2136                         return 0;
2137
2138                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2139                 if (unlikely(!func->eps[idx].ep))
2140                         return -EINVAL;
2141
2142                 {
2143                         struct usb_endpoint_descriptor **descs;
2144                         descs = func->eps[idx].descs;
2145                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2146                 }
2147                 break;
2148         }
2149
2150         pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2151         *valuep = newValue;
2152         return 0;
2153 }
2154
2155 static int ffs_func_bind(struct usb_configuration *c,
2156                          struct usb_function *f)
2157 {
2158         struct ffs_function *func = ffs_func_from_usb(f);
2159         struct ffs_data *ffs = func->ffs;
2160
2161         const int full = !!func->ffs->fs_descs_count;
2162         const int high = gadget_is_dualspeed(func->gadget) &&
2163                 func->ffs->hs_descs_count;
2164
2165         int ret;
2166
2167         /* Make it a single chunk, less management later on */
2168         struct {
2169                 struct ffs_ep eps[ffs->eps_count];
2170                 struct usb_descriptor_header
2171                         *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2172                 struct usb_descriptor_header
2173                         *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2174                 short inums[ffs->interfaces_count];
2175                 char raw_descs[high ? ffs->raw_descs_length
2176                                     : ffs->raw_fs_descs_length];
2177         } *data;
2178
2179         ENTER();
2180
2181         /* Only high speed but not supported by gadget? */
2182         if (unlikely(!(full | high)))
2183                 return -ENOTSUPP;
2184
2185         /* Allocate */
2186         data = kmalloc(sizeof *data, GFP_KERNEL);
2187         if (unlikely(!data))
2188                 return -ENOMEM;
2189
2190         /* Zero */
2191         memset(data->eps, 0, sizeof data->eps);
2192         memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2193         memset(data->inums, 0xff, sizeof data->inums);
2194         for (ret = ffs->eps_count; ret; --ret)
2195                 data->eps[ret].num = -1;
2196
2197         /* Save pointers */
2198         func->eps             = data->eps;
2199         func->interfaces_nums = data->inums;
2200
2201         /*
2202          * Go through all the endpoint descriptors and allocate
2203          * endpoints first, so that later we can rewrite the endpoint
2204          * numbers without worrying that it may be described later on.
2205          */
2206         if (likely(full)) {
2207                 func->function.descriptors = data->fs_descs;
2208                 ret = ffs_do_descs(ffs->fs_descs_count,
2209                                    data->raw_descs,
2210                                    sizeof data->raw_descs,
2211                                    __ffs_func_bind_do_descs, func);
2212                 if (unlikely(ret < 0))
2213                         goto error;
2214         } else {
2215                 ret = 0;
2216         }
2217
2218         if (likely(high)) {
2219                 func->function.hs_descriptors = data->hs_descs;
2220                 ret = ffs_do_descs(ffs->hs_descs_count,
2221                                    data->raw_descs + ret,
2222                                    (sizeof data->raw_descs) - ret,
2223                                    __ffs_func_bind_do_descs, func);
2224         }
2225
2226         /*
2227          * Now handle interface numbers allocation and interface and
2228          * endpoint numbers rewriting.  We can do that in one go
2229          * now.
2230          */
2231         ret = ffs_do_descs(ffs->fs_descs_count +
2232                            (high ? ffs->hs_descs_count : 0),
2233                            data->raw_descs, sizeof data->raw_descs,
2234                            __ffs_func_bind_do_nums, func);
2235         if (unlikely(ret < 0))
2236                 goto error;
2237
2238         /* And we're done */
2239         ffs_event_add(ffs, FUNCTIONFS_BIND);
2240         return 0;
2241
2242 error:
2243         /* XXX Do we need to release all claimed endpoints here? */
2244         return ret;
2245 }
2246
2247
2248 /* Other USB function hooks *************************************************/
2249
2250 static void ffs_func_unbind(struct usb_configuration *c,
2251                             struct usb_function *f)
2252 {
2253         struct ffs_function *func = ffs_func_from_usb(f);
2254         struct ffs_data *ffs = func->ffs;
2255
2256         ENTER();
2257
2258         if (ffs->func == func) {
2259                 ffs_func_eps_disable(func);
2260                 ffs->func = NULL;
2261         }
2262
2263         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2264
2265         ffs_func_free(func);
2266 }
2267
2268 static int ffs_func_set_alt(struct usb_function *f,
2269                             unsigned interface, unsigned alt)
2270 {
2271         struct ffs_function *func = ffs_func_from_usb(f);
2272         struct ffs_data *ffs = func->ffs;
2273         int ret = 0, intf;
2274
2275         if (alt != (unsigned)-1) {
2276                 intf = ffs_func_revmap_intf(func, interface);
2277                 if (unlikely(intf < 0))
2278                         return intf;
2279         }
2280
2281         if (ffs->func)
2282                 ffs_func_eps_disable(ffs->func);
2283
2284         if (ffs->state != FFS_ACTIVE)
2285                 return -ENODEV;
2286
2287         if (alt == (unsigned)-1) {
2288                 ffs->func = NULL;
2289                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2290                 return 0;
2291         }
2292
2293         ffs->func = func;
2294         ret = ffs_func_eps_enable(func);
2295         if (likely(ret >= 0))
2296                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2297         return ret;
2298 }
2299
2300 static void ffs_func_disable(struct usb_function *f)
2301 {
2302         ffs_func_set_alt(f, 0, (unsigned)-1);
2303 }
2304
2305 static int ffs_func_setup(struct usb_function *f,
2306                           const struct usb_ctrlrequest *creq)
2307 {
2308         struct ffs_function *func = ffs_func_from_usb(f);
2309         struct ffs_data *ffs = func->ffs;
2310         unsigned long flags;
2311         int ret;
2312
2313         ENTER();
2314
2315         pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2316         pr_vdebug("creq->bRequest     = %02x\n", creq->bRequest);
2317         pr_vdebug("creq->wValue       = %04x\n", le16_to_cpu(creq->wValue));
2318         pr_vdebug("creq->wIndex       = %04x\n", le16_to_cpu(creq->wIndex));
2319         pr_vdebug("creq->wLength      = %04x\n", le16_to_cpu(creq->wLength));
2320
2321         /*
2322          * Most requests directed to interface go through here
2323          * (notable exceptions are set/get interface) so we need to
2324          * handle them.  All other either handled by composite or
2325          * passed to usb_configuration->setup() (if one is set).  No
2326          * matter, we will handle requests directed to endpoint here
2327          * as well (as it's straightforward) but what to do with any
2328          * other request?
2329          */
2330         if (ffs->state != FFS_ACTIVE)
2331                 return -ENODEV;
2332
2333         switch (creq->bRequestType & USB_RECIP_MASK) {
2334         case USB_RECIP_INTERFACE:
2335                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2336                 if (unlikely(ret < 0))
2337                         return ret;
2338                 break;
2339
2340         case USB_RECIP_ENDPOINT:
2341                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2342                 if (unlikely(ret < 0))
2343                         return ret;
2344                 break;
2345
2346         default:
2347                 return -EOPNOTSUPP;
2348         }
2349
2350         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2351         ffs->ev.setup = *creq;
2352         ffs->ev.setup.wIndex = cpu_to_le16(ret);
2353         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2354         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2355
2356         return 0;
2357 }
2358
2359 static void ffs_func_suspend(struct usb_function *f)
2360 {
2361         ENTER();
2362         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2363 }
2364
2365 static void ffs_func_resume(struct usb_function *f)
2366 {
2367         ENTER();
2368         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2369 }
2370
2371
2372 /* Endpoint and interface numbers reverse mapping ***************************/
2373
2374 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2375 {
2376         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2377         return num ? num : -EDOM;
2378 }
2379
2380 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2381 {
2382         short *nums = func->interfaces_nums;
2383         unsigned count = func->ffs->interfaces_count;
2384
2385         for (; count; --count, ++nums) {
2386                 if (*nums >= 0 && *nums == intf)
2387                         return nums - func->interfaces_nums;
2388         }
2389
2390         return -EDOM;
2391 }
2392
2393
2394 /* Misc helper functions ****************************************************/
2395
2396 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2397 {
2398         return nonblock
2399                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2400                 : mutex_lock_interruptible(mutex);
2401 }
2402
2403 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
2404 {
2405         char *data;
2406
2407         if (unlikely(!len))
2408                 return NULL;
2409
2410         data = kmalloc(len, GFP_KERNEL);
2411         if (unlikely(!data))
2412                 return ERR_PTR(-ENOMEM);
2413
2414         if (unlikely(__copy_from_user(data, buf, len))) {
2415                 kfree(data);
2416                 return ERR_PTR(-EFAULT);
2417         }
2418
2419         pr_vdebug("Buffer from user space:\n");
2420         ffs_dump_mem("", data, len);
2421
2422         return data;
2423 }