drivers/usb/gadget/f_fs.c

   1 /*
   2  * f_fs.c -- user mode filesystem api for usb composite funtcion controllers
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
   6  *
   7  * Based on inode.c (GadgetFS):
   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  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26
  27 /* #define DEBUG */
  28 /* #define VERBOSE_DEBUG */
  29
  30 #include <linux/blkdev.h>
  31 #include <linux/pagemap.h>
  32 #include <asm/unaligned.h>
  33 #include <linux/smp_lock.h>
  34
  35 #include <linux/usb/composite.h>
  36 #include <linux/usb/functionfs.h>
  37
  38
  39 #define FUNCTIONFS_MAGIC        0xa647361 /* Chosen by a honest dice roll ;) */
  40
  41
  42 /* Debuging *****************************************************************/
  43
  44 #define ffs_printk(level, fmt, args...) printk(level "f_fs: " fmt "\n", ## args)
  45
  46 #define FERR(...)  ffs_printk(KERN_ERR,  __VA_ARGS__)
  47 #define FINFO(...) ffs_printk(KERN_INFO, __VA_ARGS__)
  48
  49 #ifdef DEBUG
  50 #  define FDBG(...) ffs_printk(KERN_DEBUG, __VA_ARGS__)
  51 #else
  52 #  define FDBG(...) do { } while (0)
  53 #endif /* DEBUG */
  54
  55 #ifdef VERBOSE_DEBUG
  56 #  define FVDBG FDBG
  57 #else
  58 #  define FVDBG(...) do { } while (0)
  59 #endif /* VERBOSE_DEBUG */
  60
  61 #define ENTER()    FVDBG("%s()", __func__)
  62
  63 #ifdef VERBOSE_DEBUG
  64 #  define ffs_dump_mem(prefix, ptr, len) \
  65         print_hex_dump_bytes("f_fs" prefix ": ", DUMP_PREFIX_NONE, ptr, len)
  66 #else
  67 #  define ffs_dump_mem(prefix, ptr, len) do { } while (0)
  68 #endif
  69
  70
  71 /* The data structure and setup file ****************************************/
  72
  73 enum ffs_state {
  74         /* Waiting for descriptors and strings. */
  75         /* In this state no open(2), read(2) or write(2) on epfiles
  76          * may succeed (which should not be the problem as there
  77          * should be no such files opened in the firts place). */
  78         FFS_READ_DESCRIPTORS,
  79         FFS_READ_STRINGS,
  80
  81         /* We've got descriptors and strings.  We are or have called
  82          * functionfs_ready_callback().  functionfs_bind() may have
  83          * been called but we don't know. */
  84         /* This is the only state in which operations on epfiles may
  85          * succeed. */
  86         FFS_ACTIVE,
  87
  88         /* All endpoints have been closed.  This state is also set if
  89          * we encounter an unrecoverable error.  The only
  90          * unrecoverable error is situation when after reading strings
  91          * from user space we fail to initialise EP files or
  92          * functionfs_ready_callback() returns with error (<0). */
  93         /* In this state no open(2), read(2) or write(2) (both on ep0
  94          * as well as epfile) may succeed (at this point epfiles are
  95          * unlinked and all closed so this is not a problem; ep0 is
  96          * also closed but ep0 file exists and so open(2) on ep0 must
  97          * fail). */
  98         FFS_CLOSING
  99 };
 100
 101
 102 enum ffs_setup_state {
 103         /* There is no setup request pending. */
 104         FFS_NO_SETUP,
 105         /* User has read events and there was a setup request event
 106          * there.  The next read/write on ep0 will handle the
 107          * request. */
 108         FFS_SETUP_PENDING,
 109         /* There was event pending but before user space handled it
 110          * some other event was introduced which canceled existing
 111          * setup.  If this state is set read/write on ep0 return
 112          * -EIDRM.  This state is only set when adding event. */
 113         FFS_SETUP_CANCELED
 114 };
 115
 116
 117
 118 struct ffs_epfile;
 119 struct ffs_function;
 120
 121 struct ffs_data {
 122         struct usb_gadget               *gadget;
 123
 124         /* Protect access read/write operations, only one read/write
 125          * at a time.  As a consequence protects ep0req and company.
 126          * While setup request is being processed (queued) this is
 127          * held. */
 128         struct mutex                    mutex;
 129
 130         /* Protect access to enpoint related structures (basically
 131          * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
 132          * endpint zero. */
 133         spinlock_t                      eps_lock;
 134
 135         /* XXX REVISIT do we need our own request? Since we are not
 136          * handling setup requests immidiatelly user space may be so
 137          * slow that another setup will be sent to the gadget but this
 138          * time not to us but another function and then there could be
 139          * a race.  Is that the case? Or maybe we can use cdev->req
 140          * after all, maybe we just need some spinlock for that? */
 141         struct usb_request              *ep0req;                /* P: mutex */
 142         struct completion               ep0req_completion;      /* P: mutex */
 143         int                             ep0req_status;          /* P: mutex */
 144
 145         /* reference counter */
 146         atomic_t                        ref;
 147         /* how many files are opened (EP0 and others) */
 148         atomic_t                        opened;
 149
 150         /* EP0 state */
 151         enum ffs_state                  state;
 152
 153         /*
 154          * Possible transations:
 155          * + FFS_NO_SETUP       -> FFS_SETUP_PENDING  -- P: ev.waitq.lock
 156          *               happens only in ep0 read which is P: mutex
 157          * + FFS_SETUP_PENDING  -> FFS_NO_SETUP       -- P: ev.waitq.lock
 158          *               happens only in ep0 i/o  which is P: mutex
 159          * + FFS_SETUP_PENDING  -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
 160          * + FFS_SETUP_CANCELED -> FFS_NO_SETUP       -- cmpxchg
 161          */
 162         enum ffs_setup_state            setup_state;
 163
 164 #define FFS_SETUP_STATE(ffs)                                    \
 165         ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state,     \
 166                                        FFS_SETUP_CANCELED, FFS_NO_SETUP))
 167
 168         /* Events & such. */
 169         struct {
 170                 u8                              types[4];
 171                 unsigned short                  count;
 172                 /* XXX REVISIT need to update it in some places, or do we? */
 173                 unsigned short                  can_stall;
 174                 struct usb_ctrlrequest          setup;
 175
 176                 wait_queue_head_t               waitq;
 177         } ev; /* the whole structure, P: ev.waitq.lock */
 178
 179         /* Flags */
 180         unsigned long                   flags;
 181 #define FFS_FL_CALL_CLOSED_CALLBACK 0
 182 #define FFS_FL_BOUND                1
 183
 184         /* Active function */
 185         struct ffs_function             *func;
 186
 187         /* Device name, write once when file system is mounted.
 188          * Intendet for user to read if she wants. */
 189         const char                      *dev_name;
 190         /* Private data for our user (ie. gadget).  Managed by
 191          * user. */
 192         void                            *private_data;
 193
 194         /* filled by __ffs_data_got_descs() */
 195         /* real descriptors are 16 bytes after raw_descs (so you need
 196          * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
 197          * first full speed descriptor).  raw_descs_length and
 198          * raw_fs_descs_length do not have those 16 bytes added. */
 199         const void                      *raw_descs;
 200         unsigned                        raw_descs_length;
 201         unsigned                        raw_fs_descs_length;
 202         unsigned                        fs_descs_count;
 203         unsigned                        hs_descs_count;
 204
 205         unsigned short                  strings_count;
 206         unsigned short                  interfaces_count;
 207         unsigned short                  eps_count;
 208         unsigned short                  _pad1;
 209
 210         /* filled by __ffs_data_got_strings() */
 211         /* ids in stringtabs are set in functionfs_bind() */
 212         const void                      *raw_strings;
 213         struct usb_gadget_strings       **stringtabs;
 214
 215         /* File system's super block, write once when file system is mounted. */
 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         /* The endpoint files, filled by ffs_epfiles_create(),
 226          * destroyed by ffs_epfiles_destroy(). */
 227         struct ffs_epfile               *epfiles;
 228 };
 229
 230 /* Reference counter handling */
 231 static void ffs_data_get(struct ffs_data *ffs);
 232 static void ffs_data_put(struct ffs_data *ffs);
 233 /* Creates new ffs_data object. */
 234 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
 235
 236 /* Opened counter handling. */
 237 static void ffs_data_opened(struct ffs_data *ffs);
 238 static void ffs_data_closed(struct ffs_data *ffs);
 239
 240 /* Called with ffs->mutex held; take over ownerrship of data. */
 241 static int __must_check
 242 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
 243 static int __must_check
 244 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
 245
 246
 247 /* The function structure ***************************************************/
 248
 249 struct ffs_ep;
 250
 251 struct ffs_function {
 252         struct usb_configuration        *conf;
 253         struct usb_gadget               *gadget;
 254         struct ffs_data                 *ffs;
 255
 256         struct ffs_ep                   *eps;
 257         u8                              eps_revmap[16];
 258         short                           *interfaces_nums;
 259
 260         struct usb_function             function;
 261 };
 262
 263
 264 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
 265 {
 266         return container_of(f, struct ffs_function, function);
 267 }
 268
 269 static void ffs_func_free(struct ffs_function *func);
 270
 271
 272 static void ffs_func_eps_disable(struct ffs_function *func);
 273 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
 274
 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
 293 /* The endpoints structures *************************************************/
 294
 295 struct ffs_ep {
 296         struct usb_ep                   *ep;    /* P: ffs->eps_lock */
 297         struct usb_request              *req;   /* P: epfile->mutex */
 298
 299         /* [0]: full speed, [1]: high speed */
 300         struct usb_endpoint_descriptor  *descs[2];
 301
 302         u8                              num;
 303
 304         int                             status; /* P: epfile->mutex */
 305 };
 306
 307 struct ffs_epfile {
 308         /* Protects ep->ep and ep->req. */
 309         struct mutex                    mutex;
 310         wait_queue_head_t               wait;
 311
 312         struct ffs_data                 *ffs;
 313         struct ffs_ep                   *ep;    /* P: ffs->eps_lock */
 314
 315         struct dentry                   *dentry;
 316
 317         char                            name[5];
 318
 319         unsigned char                   in;     /* P: ffs->eps_lock */
 320         unsigned char                   isoc;   /* P: ffs->eps_lock */
 321
 322         unsigned char                   _pad;
 323 };
 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
 353 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 354 {
 355         struct usb_request *req = ffs->ep0req;
 356         int ret;
 357
 358         req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
 359
 360         spin_unlock_irq(&ffs->ev.waitq.lock);
 361
 362         req->buf      = data;
 363         req->length   = len;
 364
 365         INIT_COMPLETION(ffs->ep0req_completion);
 366
 367         ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
 368         if (unlikely(ret < 0))
 369                 return ret;
 370
 371         ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
 372         if (unlikely(ret)) {
 373                 usb_ep_dequeue(ffs->gadget->ep0, req);
 374                 return -EINTR;
 375         }
 376
 377         ffs->setup_state = FFS_NO_SETUP;
 378         return ffs->ep0req_status;
 379 }
 380
 381 static int __ffs_ep0_stall(struct ffs_data *ffs)
 382 {
 383         if (ffs->ev.can_stall) {
 384                 FVDBG("ep0 stall\n");
 385                 usb_ep_set_halt(ffs->gadget->ep0);
 386                 ffs->setup_state = FFS_NO_SETUP;
 387                 return -EL2HLT;
 388         } else {
 389                 FDBG("bogus ep0 stall!\n");
 390                 return -ESRCH;
 391         }
 392 }
 393
 394
 395 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 396                              size_t len, loff_t *ptr)
 397 {
 398         struct ffs_data *ffs = file->private_data;
 399         ssize_t ret;
 400         char *data;
 401
 402         ENTER();
 403
 404         /* Fast check if setup was canceled */
 405         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 406                 return -EIDRM;
 407
 408         /* Acquire mutex */
 409         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 410         if (unlikely(ret < 0))
 411                 return ret;
 412
 413
 414         /* Check state */
 415         switch (ffs->state) {
 416         case FFS_READ_DESCRIPTORS:
 417         case FFS_READ_STRINGS:
 418                 /* Copy data */
 419                 if (unlikely(len < 16)) {
 420                         ret = -EINVAL;
 421                         break;
 422                 }
 423
 424                 data = ffs_prepare_buffer(buf, len);
 425                 if (unlikely(IS_ERR(data))) {
 426                         ret = PTR_ERR(data);
 427                         break;
 428                 }
 429
 430                 /* Handle data */
 431                 if (ffs->state == FFS_READ_DESCRIPTORS) {
 432                         FINFO("read descriptors");
 433                         ret = __ffs_data_got_descs(ffs, data, len);
 434                         if (unlikely(ret < 0))
 435                                 break;
 436
 437                         ffs->state = FFS_READ_STRINGS;
 438                         ret = len;
 439                 } else {
 440                         FINFO("read strings");
 441                         ret = __ffs_data_got_strings(ffs, data, len);
 442                         if (unlikely(ret < 0))
 443                                 break;
 444
 445                         ret = ffs_epfiles_create(ffs);
 446                         if (unlikely(ret)) {
 447                                 ffs->state = FFS_CLOSING;
 448                                 break;
 449                         }
 450
 451                         ffs->state = FFS_ACTIVE;
 452                         mutex_unlock(&ffs->mutex);
 453
 454                         ret = functionfs_ready_callback(ffs);
 455                         if (unlikely(ret < 0)) {
 456                                 ffs->state = FFS_CLOSING;
 457                                 return ret;
 458                         }
 459
 460                         set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
 461                         return len;
 462                 }
 463                 break;
 464
 465
 466         case FFS_ACTIVE:
 467                 data = NULL;
 468                 /* We're called from user space, we can use _irq
 469                  * rather then _irqsave */
 470                 spin_lock_irq(&ffs->ev.waitq.lock);
 471                 switch (FFS_SETUP_STATE(ffs)) {
 472                 case FFS_SETUP_CANCELED:
 473                         ret = -EIDRM;
 474                         goto done_spin;
 475
 476                 case FFS_NO_SETUP:
 477                         ret = -ESRCH;
 478                         goto done_spin;
 479
 480                 case FFS_SETUP_PENDING:
 481                         break;
 482                 }
 483
 484                 /* FFS_SETUP_PENDING */
 485                 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
 486                         spin_unlock_irq(&ffs->ev.waitq.lock);
 487                         ret = __ffs_ep0_stall(ffs);
 488                         break;
 489                 }
 490
 491                 /* FFS_SETUP_PENDING and not stall */
 492                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 493
 494                 spin_unlock_irq(&ffs->ev.waitq.lock);
 495
 496                 data = ffs_prepare_buffer(buf, len);
 497                 if (unlikely(IS_ERR(data))) {
 498                         ret = PTR_ERR(data);
 499                         break;
 500                 }
 501
 502                 spin_lock_irq(&ffs->ev.waitq.lock);
 503
 504                 /* We are guaranteed to be still in FFS_ACTIVE state
 505                  * but the state of setup could have changed from
 506                  * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need
 507                  * to check for that.  If that happened we copied data
 508                  * from user space in vain but it's unlikely. */
 509                 /* For sure we are not in FFS_NO_SETUP since this is
 510                  * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
 511                  * transition can be performed and it's protected by
 512                  * mutex. */
 513
 514                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 515                         ret = -EIDRM;
 516 done_spin:
 517                         spin_unlock_irq(&ffs->ev.waitq.lock);
 518                 } else {
 519                         /* unlocks spinlock */
 520                         ret = __ffs_ep0_queue_wait(ffs, data, len);
 521                 }
 522                 kfree(data);
 523                 break;
 524
 525
 526         default:
 527                 ret = -EBADFD;
 528                 break;
 529         }
 530
 531
 532         mutex_unlock(&ffs->mutex);
 533         return ret;
 534 }
 535
 536
 537
 538 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
 539                                      size_t n)
 540 {
 541         /* We are holding ffs->ev.waitq.lock and ffs->mutex and we need
 542          * to release them. */
 543
 544         struct usb_functionfs_event events[n];
 545         unsigned i = 0;
 546
 547         memset(events, 0, sizeof events);
 548
 549         do {
 550                 events[i].type = ffs->ev.types[i];
 551                 if (events[i].type == FUNCTIONFS_SETUP) {
 552                         events[i].u.setup = ffs->ev.setup;
 553                         ffs->setup_state = FFS_SETUP_PENDING;
 554                 }
 555         } while (++i < n);
 556
 557         if (n < ffs->ev.count) {
 558                 ffs->ev.count -= n;
 559                 memmove(ffs->ev.types, ffs->ev.types + n,
 560                         ffs->ev.count * sizeof *ffs->ev.types);
 561         } else {
 562                 ffs->ev.count = 0;
 563         }
 564
 565         spin_unlock_irq(&ffs->ev.waitq.lock);
 566         mutex_unlock(&ffs->mutex);
 567
 568         return unlikely(__copy_to_user(buf, events, sizeof events))
 569                 ? -EFAULT : sizeof events;
 570 }
 571
 572
 573 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 574                             size_t len, loff_t *ptr)
 575 {
 576         struct ffs_data *ffs = file->private_data;
 577         char *data = NULL;
 578         size_t n;
 579         int ret;
 580
 581         ENTER();
 582
 583         /* Fast check if setup was canceled */
 584         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
 585                 return -EIDRM;
 586
 587         /* Acquire mutex */
 588         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 589         if (unlikely(ret < 0))
 590                 return ret;
 591
 592
 593         /* Check state */
 594         if (ffs->state != FFS_ACTIVE) {
 595                 ret = -EBADFD;
 596                 goto done_mutex;
 597         }
 598
 599
 600         /* We're called from user space, we can use _irq rather then
 601          * _irqsave */
 602         spin_lock_irq(&ffs->ev.waitq.lock);
 603
 604         switch (FFS_SETUP_STATE(ffs)) {
 605         case FFS_SETUP_CANCELED:
 606                 ret = -EIDRM;
 607                 break;
 608
 609         case FFS_NO_SETUP:
 610                 n = len / sizeof(struct usb_functionfs_event);
 611                 if (unlikely(!n)) {
 612                         ret = -EINVAL;
 613                         break;
 614                 }
 615
 616                 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
 617                         ret = -EAGAIN;
 618                         break;
 619                 }
 620
 621                 if (unlikely(wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, ffs->ev.count))) {
 622                         ret = -EINTR;
 623                         break;
 624                 }
 625
 626                 return __ffs_ep0_read_events(ffs, buf,
 627                                              min(n, (size_t)ffs->ev.count));
 628
 629
 630         case FFS_SETUP_PENDING:
 631                 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
 632                         spin_unlock_irq(&ffs->ev.waitq.lock);
 633                         ret = __ffs_ep0_stall(ffs);
 634                         goto done_mutex;
 635                 }
 636
 637                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 638
 639                 spin_unlock_irq(&ffs->ev.waitq.lock);
 640
 641                 if (likely(len)) {
 642                         data = kmalloc(len, GFP_KERNEL);
 643                         if (unlikely(!data)) {
 644                                 ret = -ENOMEM;
 645                                 goto done_mutex;
 646                         }
 647                 }
 648
 649                 spin_lock_irq(&ffs->ev.waitq.lock);
 650
 651                 /* See ffs_ep0_write() */
 652                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
 653                         ret = -EIDRM;
 654                         break;
 655                 }
 656
 657                 /* unlocks spinlock */
 658                 ret = __ffs_ep0_queue_wait(ffs, data, len);
 659                 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
 660                         ret = -EFAULT;
 661                 goto done_mutex;
 662
 663         default:
 664                 ret = -EBADFD;
 665                 break;
 666         }
 667
 668         spin_unlock_irq(&ffs->ev.waitq.lock);
 669 done_mutex:
 670         mutex_unlock(&ffs->mutex);
 671         kfree(data);
 672         return ret;
 673 }
 674
 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
 693 static int ffs_ep0_release(struct inode *inode, struct file *file)
 694 {
 695         struct ffs_data *ffs = file->private_data;
 696
 697         ENTER();
 698
 699         ffs_data_closed(ffs);
 700
 701         return 0;
 702 }
 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->ops->ioctl) {
 717                 ret = gadget->ops->ioctl(gadget, code, value);
 718         } else {
 719                 ret = -ENOTTY;
 720         }
 721
 722         return ret;
 723 }
 724
 725
 726 static const struct file_operations ffs_ep0_operations = {
 727         .owner =        THIS_MODULE,
 728         .llseek =       no_llseek,
 729
 730         .open =         ffs_ep0_open,
 731         .write =        ffs_ep0_write,
 732         .read =         ffs_ep0_read,
 733         .release =      ffs_ep0_release,
 734         .unlocked_ioctl =       ffs_ep0_ioctl,
 735 };
 736
 737
 738 /* "Normal" endpoints operations ********************************************/
 739
 740
 741 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
 742 {
 743         ENTER();
 744         if (likely(req->context)) {
 745                 struct ffs_ep *ep = _ep->driver_data;
 746                 ep->status = req->status ? req->status : req->actual;
 747                 complete(req->context);
 748         }
 749 }
 750
 751
 752 static ssize_t ffs_epfile_io(struct file *file,
 753                              char __user *buf, size_t len, int read)
 754 {
 755         struct ffs_epfile *epfile = file->private_data;
 756         struct ffs_ep *ep;
 757         char *data = NULL;
 758         ssize_t ret;
 759         int halt;
 760
 761         goto first_try;
 762         do {
 763                 spin_unlock_irq(&epfile->ffs->eps_lock);
 764                 mutex_unlock(&epfile->mutex);
 765
 766 first_try:
 767                 /* Are we still active? */
 768                 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
 769                         ret = -ENODEV;
 770                         goto error;
 771                 }
 772
 773                 /* Wait for endpoint to be enabled */
 774                 ep = epfile->ep;
 775                 if (!ep) {
 776                         if (file->f_flags & O_NONBLOCK) {
 777                                 ret = -EAGAIN;
 778                                 goto error;
 779                         }
 780
 781                         if (unlikely(wait_event_interruptible
 782                                      (epfile->wait, (ep = epfile->ep)))) {
 783                                 ret = -EINTR;
 784                                 goto error;
 785                         }
 786                 }
 787
 788                 /* Do we halt? */
 789                 halt = !read == !epfile->in;
 790                 if (halt && epfile->isoc) {
 791                         ret = -EINVAL;
 792                         goto error;
 793                 }
 794
 795                 /* Allocate & copy */
 796                 if (!halt && !data) {
 797                         data = kzalloc(len, GFP_KERNEL);
 798                         if (unlikely(!data))
 799                                 return -ENOMEM;
 800
 801                         if (!read &&
 802                             unlikely(__copy_from_user(data, buf, len))) {
 803                                 ret = -EFAULT;
 804                                 goto error;
 805                         }
 806                 }
 807
 808                 /* We will be using request */
 809                 ret = ffs_mutex_lock(&epfile->mutex,
 810                                      file->f_flags & O_NONBLOCK);
 811                 if (unlikely(ret))
 812                         goto error;
 813
 814                 /* We're called from user space, we can use _irq rather then
 815                  * _irqsave */
 816                 spin_lock_irq(&epfile->ffs->eps_lock);
 817
 818                 /* While we were acquiring mutex endpoint got disabled
 819                  * or changed? */
 820         } while (unlikely(epfile->ep != ep));
 821
 822         /* Halt */
 823         if (unlikely(halt)) {
 824                 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
 825                         usb_ep_set_halt(ep->ep);
 826                 spin_unlock_irq(&epfile->ffs->eps_lock);
 827                 ret = -EBADMSG;
 828         } else {
 829                 /* Fire the request */
 830                 DECLARE_COMPLETION_ONSTACK(done);
 831
 832                 struct usb_request *req = ep->req;
 833                 req->context  = &done;
 834                 req->complete = ffs_epfile_io_complete;
 835                 req->buf      = data;
 836                 req->length   = len;
 837
 838                 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 839
 840                 spin_unlock_irq(&epfile->ffs->eps_lock);
 841
 842                 if (unlikely(ret < 0)) {
 843                         /* nop */
 844                 } else if (unlikely(wait_for_completion_interruptible(&done))) {
 845                         ret = -EINTR;
 846                         usb_ep_dequeue(ep->ep, req);
 847                 } else {
 848                         ret = ep->status;
 849                         if (read && ret > 0 &&
 850                             unlikely(copy_to_user(buf, data, ret)))
 851                                 ret = -EFAULT;
 852                 }
 853         }
 854
 855         mutex_unlock(&epfile->mutex);
 856 error:
 857         kfree(data);
 858         return ret;
 859 }
 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
 908 static long ffs_epfile_ioctl(struct file *file, unsigned code,
 909                              unsigned long value)
 910 {
 911         struct ffs_epfile *epfile = file->private_data;
 912         int ret;
 913
 914         ENTER();
 915
 916         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 917                 return -ENODEV;
 918
 919         spin_lock_irq(&epfile->ffs->eps_lock);
 920         if (likely(epfile->ep)) {
 921                 switch (code) {
 922                 case FUNCTIONFS_FIFO_STATUS:
 923                         ret = usb_ep_fifo_status(epfile->ep->ep);
 924                         break;
 925                 case FUNCTIONFS_FIFO_FLUSH:
 926                         usb_ep_fifo_flush(epfile->ep->ep);
 927                         ret = 0;
 928                         break;
 929                 case FUNCTIONFS_CLEAR_HALT:
 930                         ret = usb_ep_clear_halt(epfile->ep->ep);
 931                         break;
 932                 case FUNCTIONFS_ENDPOINT_REVMAP:
 933                         ret = epfile->ep->num;
 934                         break;
 935                 default:
 936                         ret = -ENOTTY;
 937                 }
 938         } else {
 939                 ret = -ENODEV;
 940         }
 941         spin_unlock_irq(&epfile->ffs->eps_lock);
 942
 943         return ret;
 944 }
 945
 946
 947 static const struct file_operations ffs_epfile_operations = {
 948         .owner =        THIS_MODULE,
 949         .llseek =       no_llseek,
 950
 951         .open =         ffs_epfile_open,
 952         .write =        ffs_epfile_write,
 953         .read =         ffs_epfile_read,
 954         .release =      ffs_epfile_release,
 955         .unlocked_ioctl =       ffs_epfile_ioctl,
 956 };
 957
 958
 959
 960 /* File system and super block operations ***********************************/
 961
 962 /*
 963  * Mounting the filesystem creates a controller file, used first for
 964  * function configuration then later for event monitoring.
 965  */
 966
 967
 968 static struct inode *__must_check
 969 ffs_sb_make_inode(struct super_block *sb, void *data,
 970                   const struct file_operations *fops,
 971                   const struct inode_operations *iops,
 972                   struct ffs_file_perms *perms)
 973 {
 974         struct inode *inode;
 975
 976         ENTER();
 977
 978         inode = new_inode(sb);
 979
 980         if (likely(inode)) {
 981                 struct timespec current_time = CURRENT_TIME;
 982
 983                 inode->i_ino     = usbfs_get_inode();
 984                 inode->i_mode    = perms->mode;
 985                 inode->i_uid     = perms->uid;
 986                 inode->i_gid     = perms->gid;
 987                 inode->i_atime   = current_time;
 988                 inode->i_mtime   = current_time;
 989                 inode->i_ctime   = current_time;
 990                 inode->i_private = data;
 991                 if (fops)
 992                         inode->i_fop = fops;
 993                 if (iops)
 994                         inode->i_op  = iops;
 995         }
 996
 997         return inode;
 998 }
 999
1000
1001 /* Create "regular" file */
1002
1003 static struct inode *ffs_sb_create_file(struct super_block *sb,
1004                                         const char *name, void *data,
1005                                         const struct file_operations *fops,
1006                                         struct dentry **dentry_p)
1007 {
1008         struct ffs_data *ffs = sb->s_fs_info;
1009         struct dentry   *dentry;
1010         struct inode    *inode;
1011
1012         ENTER();
1013
1014         dentry = d_alloc_name(sb->s_root, name);
1015         if (unlikely(!dentry))
1016                 return NULL;
1017
1018         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1019         if (unlikely(!inode)) {
1020                 dput(dentry);
1021                 return NULL;
1022         }
1023
1024         d_add(dentry, inode);
1025         if (dentry_p)
1026                 *dentry_p = dentry;
1027
1028         return inode;
1029 }
1030
1031
1032 /* Super block */
1033
1034 static const struct super_operations ffs_sb_operations = {
1035         .statfs =       simple_statfs,
1036         .drop_inode =   generic_delete_inode,
1037 };
1038
1039 struct ffs_sb_fill_data {
1040         struct ffs_file_perms perms;
1041         umode_t root_mode;
1042         const char *dev_name;
1043 };
1044
1045 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1046 {
1047         struct ffs_sb_fill_data *data = _data;
1048         struct inode    *inode;
1049         struct dentry   *d;
1050         struct ffs_data *ffs;
1051
1052         ENTER();
1053
1054         /* Initialize data */
1055         ffs = ffs_data_new();
1056         if (unlikely(!ffs))
1057                 goto enomem0;
1058
1059         ffs->sb              = sb;
1060         ffs->dev_name        = data->dev_name;
1061         ffs->file_perms      = data->perms;
1062
1063         sb->s_fs_info        = ffs;
1064         sb->s_blocksize      = PAGE_CACHE_SIZE;
1065         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1066         sb->s_magic          = FUNCTIONFS_MAGIC;
1067         sb->s_op             = &ffs_sb_operations;
1068         sb->s_time_gran      = 1;
1069
1070         /* Root inode */
1071         data->perms.mode = data->root_mode;
1072         inode = ffs_sb_make_inode(sb, NULL,
1073                                   &simple_dir_operations,
1074                                   &simple_dir_inode_operations,
1075                                   &data->perms);
1076         if (unlikely(!inode))
1077                 goto enomem1;
1078         d = d_alloc_root(inode);
1079         if (unlikely(!d))
1080                 goto enomem2;
1081         sb->s_root = d;
1082
1083         /* EP0 file */
1084         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1085                                          &ffs_ep0_operations, NULL)))
1086                 goto enomem3;
1087
1088         return 0;
1089
1090 enomem3:
1091         dput(d);
1092 enomem2:
1093         iput(inode);
1094 enomem1:
1095         ffs_data_put(ffs);
1096 enomem0:
1097         return -ENOMEM;
1098 }
1099
1100
1101 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1102 {
1103         ENTER();
1104
1105         if (!opts || !*opts)
1106                 return 0;
1107
1108         for (;;) {
1109                 char *end, *eq, *comma;
1110                 unsigned long value;
1111
1112                 /* Option limit */
1113                 comma = strchr(opts, ',');
1114                 if (comma)
1115                         *comma = 0;
1116
1117                 /* Value limit */
1118                 eq = strchr(opts, '=');
1119                 if (unlikely(!eq)) {
1120                         FERR("'=' missing in %s", opts);
1121                         return -EINVAL;
1122                 }
1123                 *eq = 0;
1124
1125                 /* Parse value */
1126                 value = simple_strtoul(eq + 1, &end, 0);
1127                 if (unlikely(*end != ',' && *end != 0)) {
1128                         FERR("%s: invalid value: %s", opts, eq + 1);
1129                         return -EINVAL;
1130                 }
1131
1132                 /* Interpret option */
1133                 switch (eq - opts) {
1134                 case 5:
1135                         if (!memcmp(opts, "rmode", 5))
1136                                 data->root_mode  = (value & 0555) | S_IFDIR;
1137                         else if (!memcmp(opts, "fmode", 5))
1138                                 data->perms.mode = (value & 0666) | S_IFREG;
1139                         else
1140                                 goto invalid;
1141                         break;
1142
1143                 case 4:
1144                         if (!memcmp(opts, "mode", 4)) {
1145                                 data->root_mode  = (value & 0555) | S_IFDIR;
1146                                 data->perms.mode = (value & 0666) | S_IFREG;
1147                         } else {
1148                                 goto invalid;
1149                         }
1150                         break;
1151
1152                 case 3:
1153                         if (!memcmp(opts, "uid", 3))
1154                                 data->perms.uid = value;
1155                         else if (!memcmp(opts, "gid", 3))
1156                                 data->perms.gid = value;
1157                         else
1158                                 goto invalid;
1159                         break;
1160
1161                 default:
1162 invalid:
1163                         FERR("%s: invalid option", opts);
1164                         return -EINVAL;
1165                 }
1166
1167                 /* Next iteration */
1168                 if (!comma)
1169                         break;
1170                 opts = comma + 1;
1171         }
1172
1173         return 0;
1174 }
1175
1176
1177 /* "mount -t functionfs dev_name /dev/function" ends up here */
1178
1179 static int
1180 ffs_fs_get_sb(struct file_system_type *t, int flags,
1181               const char *dev_name, void *opts, struct vfsmount *mnt)
1182 {
1183         struct ffs_sb_fill_data data = {
1184                 .perms = {
1185                         .mode = S_IFREG | 0600,
1186                         .uid = 0,
1187                         .gid = 0
1188                 },
1189                 .root_mode = S_IFDIR | 0500,
1190         };
1191         int ret;
1192
1193         ENTER();
1194
1195         ret = functionfs_check_dev_callback(dev_name);
1196         if (unlikely(ret < 0))
1197                 return ret;
1198
1199         ret = ffs_fs_parse_opts(&data, opts);
1200         if (unlikely(ret < 0))
1201                 return ret;
1202
1203         data.dev_name = dev_name;
1204         return get_sb_single(t, flags, &data, ffs_sb_fill, mnt);
1205 }
1206
1207 static void
1208 ffs_fs_kill_sb(struct super_block *sb)
1209 {
1210         void *ptr;
1211
1212         ENTER();
1213
1214         kill_litter_super(sb);
1215         ptr = xchg(&sb->s_fs_info, NULL);
1216         if (ptr)
1217                 ffs_data_put(ptr);
1218 }
1219
1220 static struct file_system_type ffs_fs_type = {
1221         .owner          = THIS_MODULE,
1222         .name           = "functionfs",
1223         .get_sb         = ffs_fs_get_sb,
1224         .kill_sb        = ffs_fs_kill_sb,
1225 };
1226
1227
1228
1229 /* Driver's main init/cleanup functions *************************************/
1230
1231
1232 static int functionfs_init(void)
1233 {
1234         int ret;
1235
1236         ENTER();
1237
1238         ret = register_filesystem(&ffs_fs_type);
1239         if (likely(!ret))
1240                 FINFO("file system registered");
1241         else
1242                 FERR("failed registering file system (%d)", ret);
1243
1244         return ret;
1245 }
1246
1247 static void functionfs_cleanup(void)
1248 {
1249         ENTER();
1250
1251         FINFO("unloading");
1252         unregister_filesystem(&ffs_fs_type);
1253 }
1254
1255
1256
1257 /* ffs_data and ffs_function construction and destruction code **************/
1258
1259 static void ffs_data_clear(struct ffs_data *ffs);
1260 static void ffs_data_reset(struct ffs_data *ffs);
1261
1262
1263 static void ffs_data_get(struct ffs_data *ffs)
1264 {
1265         ENTER();
1266
1267         atomic_inc(&ffs->ref);
1268 }
1269
1270 static void ffs_data_opened(struct ffs_data *ffs)
1271 {
1272         ENTER();
1273
1274         atomic_inc(&ffs->ref);
1275         atomic_inc(&ffs->opened);
1276 }
1277
1278 static void ffs_data_put(struct ffs_data *ffs)
1279 {
1280         ENTER();
1281
1282         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1283                 FINFO("%s(): freeing", __func__);
1284                 ffs_data_clear(ffs);
1285                 BUG_ON(mutex_is_locked(&ffs->mutex) ||
1286                        spin_is_locked(&ffs->ev.waitq.lock) ||
1287                        waitqueue_active(&ffs->ev.waitq) ||
1288                        waitqueue_active(&ffs->ep0req_completion.wait));
1289                 kfree(ffs);
1290         }
1291 }
1292
1293
1294
1295 static void ffs_data_closed(struct ffs_data *ffs)
1296 {
1297         ENTER();
1298
1299         if (atomic_dec_and_test(&ffs->opened)) {
1300                 ffs->state = FFS_CLOSING;
1301                 ffs_data_reset(ffs);
1302         }
1303
1304         ffs_data_put(ffs);
1305 }
1306
1307
1308 static struct ffs_data *ffs_data_new(void)
1309 {
1310         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1311         if (unlikely(!ffs))
1312                 return 0;
1313
1314         ENTER();
1315
1316         atomic_set(&ffs->ref, 1);
1317         atomic_set(&ffs->opened, 0);
1318         ffs->state = FFS_READ_DESCRIPTORS;
1319         mutex_init(&ffs->mutex);
1320         spin_lock_init(&ffs->eps_lock);
1321         init_waitqueue_head(&ffs->ev.waitq);
1322         init_completion(&ffs->ep0req_completion);
1323
1324         /* XXX REVISIT need to update it in some places, or do we? */
1325         ffs->ev.can_stall = 1;
1326
1327         return ffs;
1328 }
1329
1330
1331 static void ffs_data_clear(struct ffs_data *ffs)
1332 {
1333         ENTER();
1334
1335         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1336                 functionfs_closed_callback(ffs);
1337
1338         BUG_ON(ffs->gadget);
1339
1340         if (ffs->epfiles)
1341                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1342
1343         kfree(ffs->raw_descs);
1344         kfree(ffs->raw_strings);
1345         kfree(ffs->stringtabs);
1346 }
1347
1348
1349 static void ffs_data_reset(struct ffs_data *ffs)
1350 {
1351         ENTER();
1352
1353         ffs_data_clear(ffs);
1354
1355         ffs->epfiles = NULL;
1356         ffs->raw_descs = NULL;
1357         ffs->raw_strings = NULL;
1358         ffs->stringtabs = NULL;
1359
1360         ffs->raw_descs_length = 0;
1361         ffs->raw_fs_descs_length = 0;
1362         ffs->fs_descs_count = 0;
1363         ffs->hs_descs_count = 0;
1364
1365         ffs->strings_count = 0;
1366         ffs->interfaces_count = 0;
1367         ffs->eps_count = 0;
1368
1369         ffs->ev.count = 0;
1370
1371         ffs->state = FFS_READ_DESCRIPTORS;
1372         ffs->setup_state = FFS_NO_SETUP;
1373         ffs->flags = 0;
1374 }
1375
1376
1377 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1378 {
1379         struct usb_gadget_strings **lang;
1380         int first_id;
1381
1382         ENTER();
1383
1384         if (WARN_ON(ffs->state != FFS_ACTIVE
1385                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1386                 return -EBADFD;
1387
1388         first_id = usb_string_ids_n(cdev, ffs->strings_count);
1389         if (unlikely(first_id < 0))
1390                 return first_id;
1391
1392         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1393         if (unlikely(!ffs->ep0req))
1394                 return -ENOMEM;
1395         ffs->ep0req->complete = ffs_ep0_complete;
1396         ffs->ep0req->context = ffs;
1397
1398         lang = ffs->stringtabs;
1399         for (lang = ffs->stringtabs; *lang; ++lang) {
1400                 struct usb_string *str = (*lang)->strings;
1401                 int id = first_id;
1402                 for (; str->s; ++id, ++str)
1403                         str->id = id;
1404         }
1405
1406         ffs->gadget = cdev->gadget;
1407         ffs_data_get(ffs);
1408         return 0;
1409 }
1410
1411
1412 static void functionfs_unbind(struct ffs_data *ffs)
1413 {
1414         ENTER();
1415
1416         if (!WARN_ON(!ffs->gadget)) {
1417                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1418                 ffs->ep0req = NULL;
1419                 ffs->gadget = NULL;
1420                 ffs_data_put(ffs);
1421         }
1422 }
1423
1424
1425 static int ffs_epfiles_create(struct ffs_data *ffs)
1426 {
1427         struct ffs_epfile *epfile, *epfiles;
1428         unsigned i, count;
1429
1430         ENTER();
1431
1432         count = ffs->eps_count;
1433         epfiles = kzalloc(count * sizeof *epfiles, GFP_KERNEL);
1434         if (!epfiles)
1435                 return -ENOMEM;
1436
1437         epfile = epfiles;
1438         for (i = 1; i <= count; ++i, ++epfile) {
1439                 epfile->ffs = ffs;
1440                 mutex_init(&epfile->mutex);
1441                 init_waitqueue_head(&epfile->wait);
1442                 sprintf(epfiles->name, "ep%u",  i);
1443                 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1444                                                  &ffs_epfile_operations,
1445                                                  &epfile->dentry))) {
1446                         ffs_epfiles_destroy(epfiles, i - 1);
1447                         return -ENOMEM;
1448                 }
1449         }
1450
1451         ffs->epfiles = epfiles;
1452         return 0;
1453 }
1454
1455
1456 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1457 {
1458         struct ffs_epfile *epfile = epfiles;
1459
1460         ENTER();
1461
1462         for (; count; --count, ++epfile) {
1463                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1464                        waitqueue_active(&epfile->wait));
1465                 if (epfile->dentry) {
1466                         d_delete(epfile->dentry);
1467                         dput(epfile->dentry);
1468                         epfile->dentry = NULL;
1469                 }
1470         }
1471
1472         kfree(epfiles);
1473 }
1474
1475
1476 static int functionfs_bind_config(struct usb_composite_dev *cdev,
1477                                   struct usb_configuration *c,
1478                                   struct ffs_data *ffs)
1479 {
1480         struct ffs_function *func;
1481         int ret;
1482
1483         ENTER();
1484
1485         func = kzalloc(sizeof *func, GFP_KERNEL);
1486         if (unlikely(!func))
1487                 return -ENOMEM;
1488
1489         func->function.name    = "Function FS Gadget";
1490         func->function.strings = ffs->stringtabs;
1491
1492         func->function.bind    = ffs_func_bind;
1493         func->function.unbind  = ffs_func_unbind;
1494         func->function.set_alt = ffs_func_set_alt;
1495         /*func->function.get_alt = ffs_func_get_alt;*/
1496         func->function.disable = ffs_func_disable;
1497         func->function.setup   = ffs_func_setup;
1498         func->function.suspend = ffs_func_suspend;
1499         func->function.resume  = ffs_func_resume;
1500
1501         func->conf   = c;
1502         func->gadget = cdev->gadget;
1503         func->ffs = ffs;
1504         ffs_data_get(ffs);
1505
1506         ret = usb_add_function(c, &func->function);
1507         if (unlikely(ret))
1508                 ffs_func_free(func);
1509
1510         return ret;
1511 }
1512
1513 static void ffs_func_free(struct ffs_function *func)
1514 {
1515         ENTER();
1516
1517         ffs_data_put(func->ffs);
1518
1519         kfree(func->eps);
1520         /* eps and interfaces_nums are allocated in the same chunk so
1521          * only one free is required.  Descriptors are also allocated
1522          * in the same chunk. */
1523
1524         kfree(func);
1525 }
1526
1527
1528 static void ffs_func_eps_disable(struct ffs_function *func)
1529 {
1530         struct ffs_ep *ep         = func->eps;
1531         struct ffs_epfile *epfile = func->ffs->epfiles;
1532         unsigned count            = func->ffs->eps_count;
1533         unsigned long flags;
1534
1535         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1536         do {
1537                 /* pending requests get nuked */
1538                 if (likely(ep->ep))
1539                         usb_ep_disable(ep->ep);
1540                 epfile->ep = NULL;
1541
1542                 ++ep;
1543                 ++epfile;
1544         } while (--count);
1545         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1546 }
1547
1548 static int ffs_func_eps_enable(struct ffs_function *func)
1549 {
1550         struct ffs_data *ffs      = func->ffs;
1551         struct ffs_ep *ep         = func->eps;
1552         struct ffs_epfile *epfile = ffs->epfiles;
1553         unsigned count            = ffs->eps_count;
1554         unsigned long flags;
1555         int ret = 0;
1556
1557         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1558         do {
1559                 struct usb_endpoint_descriptor *ds;
1560                 ds = ep->descs[ep->descs[1] ? 1 : 0];
1561
1562                 ep->ep->driver_data = ep;
1563                 ret = usb_ep_enable(ep->ep, ds);
1564                 if (likely(!ret)) {
1565                         epfile->ep = ep;
1566                         epfile->in = usb_endpoint_dir_in(ds);
1567                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1568                 } else {
1569                         break;
1570                 }
1571
1572                 wake_up(&epfile->wait);
1573
1574                 ++ep;
1575                 ++epfile;
1576         } while (--count);
1577         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1578
1579         return ret;
1580 }
1581
1582
1583 /* Parsing and building descriptors and strings *****************************/
1584
1585
1586 /* This validates if data pointed by data is a valid USB descriptor as
1587  * well as record how many interfaces, endpoints and strings are
1588  * required by given configuration.  Returns address afther the
1589  * descriptor or NULL if data is invalid. */
1590
1591 enum ffs_entity_type {
1592         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1593 };
1594
1595 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1596                                    u8 *valuep,
1597                                    struct usb_descriptor_header *desc,
1598                                    void *priv);
1599
1600 static int __must_check ffs_do_desc(char *data, unsigned len,
1601                                     ffs_entity_callback entity, void *priv)
1602 {
1603         struct usb_descriptor_header *_ds = (void *)data;
1604         u8 length;
1605         int ret;
1606
1607         ENTER();
1608
1609         /* At least two bytes are required: length and type */
1610         if (len < 2) {
1611                 FVDBG("descriptor too short");
1612                 return -EINVAL;
1613         }
1614
1615         /* If we have at least as many bytes as the descriptor takes? */
1616         length = _ds->bLength;
1617         if (len < length) {
1618                 FVDBG("descriptor longer then available data");
1619                 return -EINVAL;
1620         }
1621
1622 #define __entity_check_INTERFACE(val)  1
1623 #define __entity_check_STRING(val)     (val)
1624 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1625 #define __entity(type, val) do {                                        \
1626                 FVDBG("entity " #type "(%02x)", (val));                 \
1627                 if (unlikely(!__entity_check_ ##type(val))) {           \
1628                         FVDBG("invalid entity's value");                \
1629                         return -EINVAL;                                 \
1630                 }                                                       \
1631                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1632                 if (unlikely(ret < 0)) {                                \
1633                         FDBG("entity " #type "(%02x); ret = %d",        \
1634                              (val), ret);                               \
1635                         return ret;                                     \
1636                 }                                                       \
1637         } while (0)
1638
1639         /* Parse descriptor depending on type. */
1640         switch (_ds->bDescriptorType) {
1641         case USB_DT_DEVICE:
1642         case USB_DT_CONFIG:
1643         case USB_DT_STRING:
1644         case USB_DT_DEVICE_QUALIFIER:
1645                 /* function can't have any of those */
1646                 FVDBG("descriptor reserved for gadget: %d", _ds->bDescriptorType);
1647                 return -EINVAL;
1648
1649         case USB_DT_INTERFACE: {
1650                 struct usb_interface_descriptor *ds = (void *)_ds;
1651                 FVDBG("interface descriptor");
1652                 if (length != sizeof *ds)
1653                         goto inv_length;
1654
1655                 __entity(INTERFACE, ds->bInterfaceNumber);
1656                 if (ds->iInterface)
1657                         __entity(STRING, ds->iInterface);
1658         }
1659                 break;
1660
1661         case USB_DT_ENDPOINT: {
1662                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1663                 FVDBG("endpoint descriptor");
1664                 if (length != USB_DT_ENDPOINT_SIZE &&
1665                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1666                         goto inv_length;
1667                 __entity(ENDPOINT, ds->bEndpointAddress);
1668         }
1669                 break;
1670
1671         case USB_DT_OTG:
1672                 if (length != sizeof(struct usb_otg_descriptor))
1673                         goto inv_length;
1674                 break;
1675
1676         case USB_DT_INTERFACE_ASSOCIATION: {
1677                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1678                 FVDBG("interface association descriptor");
1679                 if (length != sizeof *ds)
1680                         goto inv_length;
1681                 if (ds->iFunction)
1682                         __entity(STRING, ds->iFunction);
1683         }
1684                 break;
1685
1686         case USB_DT_OTHER_SPEED_CONFIG:
1687         case USB_DT_INTERFACE_POWER:
1688         case USB_DT_DEBUG:
1689         case USB_DT_SECURITY:
1690         case USB_DT_CS_RADIO_CONTROL:
1691                 /* TODO */
1692                 FVDBG("unimplemented descriptor: %d", _ds->bDescriptorType);
1693                 return -EINVAL;
1694
1695         default:
1696                 /* We should never be here */
1697                 FVDBG("unknown descriptor: %d", _ds->bDescriptorType);
1698                 return -EINVAL;
1699
1700         inv_length:
1701                 FVDBG("invalid length: %d (descriptor %d)",
1702                       _ds->bLength, _ds->bDescriptorType);
1703                 return -EINVAL;
1704         }
1705
1706 #undef __entity
1707 #undef __entity_check_DESCRIPTOR
1708 #undef __entity_check_INTERFACE
1709 #undef __entity_check_STRING
1710 #undef __entity_check_ENDPOINT
1711
1712         return length;
1713 }
1714
1715
1716 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1717                                      ffs_entity_callback entity, void *priv)
1718 {
1719         const unsigned _len = len;
1720         unsigned long num = 0;
1721
1722         ENTER();
1723
1724         for (;;) {
1725                 int ret;
1726
1727                 if (num == count)
1728                         data = NULL;
1729
1730                 /* Record "descriptor" entitny */
1731                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1732                 if (unlikely(ret < 0)) {
1733                         FDBG("entity DESCRIPTOR(%02lx); ret = %d", num, ret);
1734                         return ret;
1735                 }
1736
1737                 if (!data)
1738                         return _len - len;
1739
1740                 ret = ffs_do_desc(data, len, entity, priv);
1741                 if (unlikely(ret < 0)) {
1742                         FDBG("%s returns %d", __func__, ret);
1743                         return ret;
1744                 }
1745
1746                 len -= ret;
1747                 data += ret;
1748                 ++num;
1749         }
1750 }
1751
1752
1753 static int __ffs_data_do_entity(enum ffs_entity_type type,
1754                                 u8 *valuep, struct usb_descriptor_header *desc,
1755                                 void *priv)
1756 {
1757         struct ffs_data *ffs = priv;
1758
1759         ENTER();
1760
1761         switch (type) {
1762         case FFS_DESCRIPTOR:
1763                 break;
1764
1765         case FFS_INTERFACE:
1766                 /* Interfaces are indexed from zero so if we
1767                  * encountered interface "n" then there are at least
1768                  * "n+1" interfaces. */
1769                 if (*valuep >= ffs->interfaces_count)
1770                         ffs->interfaces_count = *valuep + 1;
1771                 break;
1772
1773         case FFS_STRING:
1774                 /* Strings are indexed from 1 (0 is magic ;) reserved
1775                  * for languages list or some such) */
1776                 if (*valuep > ffs->strings_count)
1777                         ffs->strings_count = *valuep;
1778                 break;
1779
1780         case FFS_ENDPOINT:
1781                 /* Endpoints are indexed from 1 as well. */
1782                 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1783                         ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1784                 break;
1785         }
1786
1787         return 0;
1788 }
1789
1790
1791 static int __ffs_data_got_descs(struct ffs_data *ffs,
1792                                 char *const _data, size_t len)
1793 {
1794         unsigned fs_count, hs_count;
1795         int fs_len, ret = -EINVAL;
1796         char *data = _data;
1797
1798         ENTER();
1799
1800         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1801                      get_unaligned_le32(data + 4) != len))
1802                 goto error;
1803         fs_count = get_unaligned_le32(data +  8);
1804         hs_count = get_unaligned_le32(data + 12);
1805
1806         if (!fs_count && !hs_count)
1807                 goto einval;
1808
1809         data += 16;
1810         len  -= 16;
1811
1812         if (likely(fs_count)) {
1813                 fs_len = ffs_do_descs(fs_count, data, len,
1814                                       __ffs_data_do_entity, ffs);
1815                 if (unlikely(fs_len < 0)) {
1816                         ret = fs_len;
1817                         goto error;
1818                 }
1819
1820                 data += fs_len;
1821                 len  -= fs_len;
1822         } else {
1823                 fs_len = 0;
1824         }
1825
1826         if (likely(hs_count)) {
1827                 ret = ffs_do_descs(hs_count, data, len,
1828                                    __ffs_data_do_entity, ffs);
1829                 if (unlikely(ret < 0))
1830                         goto error;
1831         } else {
1832                 ret = 0;
1833         }
1834
1835         if (unlikely(len != ret))
1836                 goto einval;
1837
1838         ffs->raw_fs_descs_length = fs_len;
1839         ffs->raw_descs_length    = fs_len + ret;
1840         ffs->raw_descs           = _data;
1841         ffs->fs_descs_count      = fs_count;
1842         ffs->hs_descs_count      = hs_count;
1843
1844         return 0;
1845
1846 einval:
1847         ret = -EINVAL;
1848 error:
1849         kfree(_data);
1850         return ret;
1851 }
1852
1853
1854
1855 static int __ffs_data_got_strings(struct ffs_data *ffs,
1856                                   char *const _data, size_t len)
1857 {
1858         u32 str_count, needed_count, lang_count;
1859         struct usb_gadget_strings **stringtabs, *t;
1860         struct usb_string *strings, *s;
1861         const char *data = _data;
1862
1863         ENTER();
1864
1865         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1866                      get_unaligned_le32(data + 4) != len))
1867                 goto error;
1868         str_count  = get_unaligned_le32(data + 8);
1869         lang_count = get_unaligned_le32(data + 12);
1870
1871         /* if one is zero the other must be zero */
1872         if (unlikely(!str_count != !lang_count))
1873                 goto error;
1874
1875         /* Do we have at least as many strings as descriptors need? */
1876         needed_count = ffs->strings_count;
1877         if (unlikely(str_count < needed_count))
1878                 goto error;
1879
1880         /* If we don't need any strings just return and free all
1881          * memory */
1882         if (!needed_count) {
1883                 kfree(_data);
1884                 return 0;
1885         }
1886
1887         /* Allocate */
1888         {
1889                 /* Allocate everything in one chunk so there's less
1890                  * maintanance. */
1891                 struct {
1892                         struct usb_gadget_strings *stringtabs[lang_count + 1];
1893                         struct usb_gadget_strings stringtab[lang_count];
1894                         struct usb_string strings[lang_count*(needed_count+1)];
1895                 } *d;
1896                 unsigned i = 0;
1897
1898                 d = kmalloc(sizeof *d, GFP_KERNEL);
1899                 if (unlikely(!d)) {
1900                         kfree(_data);
1901                         return -ENOMEM;
1902                 }
1903
1904                 stringtabs = d->stringtabs;
1905                 t = d->stringtab;
1906                 i = lang_count;
1907                 do {
1908                         *stringtabs++ = t++;
1909                 } while (--i);
1910                 *stringtabs = NULL;
1911
1912                 stringtabs = d->stringtabs;
1913                 t = d->stringtab;
1914                 s = d->strings;
1915                 strings = s;
1916         }
1917
1918         /* For each language */
1919         data += 16;
1920         len -= 16;
1921
1922         do { /* lang_count > 0 so we can use do-while */
1923                 unsigned needed = needed_count;
1924
1925                 if (unlikely(len < 3))
1926                         goto error_free;
1927                 t->language = get_unaligned_le16(data);
1928                 t->strings  = s;
1929                 ++t;
1930
1931                 data += 2;
1932                 len -= 2;
1933
1934                 /* For each string */
1935                 do { /* str_count > 0 so we can use do-while */
1936                         size_t length = strnlen(data, len);
1937
1938                         if (unlikely(length == len))
1939                                 goto error_free;
1940
1941                         /* user may provide more strings then we need,
1942                          * if that's the case we simply ingore the
1943                          * rest */
1944                         if (likely(needed)) {
1945                                 /* s->id will be set while adding
1946                                  * function to configuration so for
1947                                  * now just leave garbage here. */
1948                                 s->s = data;
1949                                 --needed;
1950                                 ++s;
1951                         }
1952
1953                         data += length + 1;
1954                         len -= length + 1;
1955                 } while (--str_count);
1956
1957                 s->id = 0;   /* terminator */
1958                 s->s = NULL;
1959                 ++s;
1960
1961         } while (--lang_count);
1962
1963         /* Some garbage left? */
1964         if (unlikely(len))
1965                 goto error_free;
1966
1967         /* Done! */
1968         ffs->stringtabs = stringtabs;
1969         ffs->raw_strings = _data;
1970
1971         return 0;
1972
1973 error_free:
1974         kfree(stringtabs);
1975 error:
1976         kfree(_data);
1977         return -EINVAL;
1978 }
1979
1980
1981
1982
1983 /* Events handling and management *******************************************/
1984
1985 static void __ffs_event_add(struct ffs_data *ffs,
1986                             enum usb_functionfs_event_type type)
1987 {
1988         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
1989         int neg = 0;
1990
1991         /* Abort any unhandled setup */
1992         /* We do not need to worry about some cmpxchg() changing value
1993          * of ffs->setup_state without holding the lock because when
1994          * state is FFS_SETUP_PENDING cmpxchg() in several places in
1995          * the source does nothing. */
1996         if (ffs->setup_state == FFS_SETUP_PENDING)
1997                 ffs->setup_state = FFS_SETUP_CANCELED;
1998
1999         switch (type) {
2000         case FUNCTIONFS_RESUME:
2001                 rem_type2 = FUNCTIONFS_SUSPEND;
2002                 /* FALL THGOUTH */
2003         case FUNCTIONFS_SUSPEND:
2004         case FUNCTIONFS_SETUP:
2005                 rem_type1 = type;
2006                 /* discard all similar events */
2007                 break;
2008
2009         case FUNCTIONFS_BIND:
2010         case FUNCTIONFS_UNBIND:
2011         case FUNCTIONFS_DISABLE:
2012         case FUNCTIONFS_ENABLE:
2013                 /* discard everything other then power management. */
2014                 rem_type1 = FUNCTIONFS_SUSPEND;
2015                 rem_type2 = FUNCTIONFS_RESUME;
2016                 neg = 1;
2017                 break;
2018
2019         default:
2020                 BUG();
2021         }
2022
2023         {
2024                 u8 *ev  = ffs->ev.types, *out = ev;
2025                 unsigned n = ffs->ev.count;
2026                 for (; n; --n, ++ev)
2027                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2028                                 *out++ = *ev;
2029                         else
2030                                 FVDBG("purging event %d", *ev);
2031                 ffs->ev.count = out - ffs->ev.types;
2032         }
2033
2034         FVDBG("adding event %d", type);
2035         ffs->ev.types[ffs->ev.count++] = type;
2036         wake_up_locked(&ffs->ev.waitq);
2037 }
2038
2039 static void ffs_event_add(struct ffs_data *ffs,
2040                           enum usb_functionfs_event_type type)
2041 {
2042         unsigned long flags;
2043         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2044         __ffs_event_add(ffs, type);
2045         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2046 }
2047
2048
2049 /* Bind/unbind USB function hooks *******************************************/
2050
2051 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2052                                     struct usb_descriptor_header *desc,
2053                                     void *priv)
2054 {
2055         struct usb_endpoint_descriptor *ds = (void *)desc;
2056         struct ffs_function *func = priv;
2057         struct ffs_ep *ffs_ep;
2058
2059         /* If hs_descriptors is not NULL then we are reading hs
2060          * descriptors now */
2061         const int isHS = func->function.hs_descriptors != NULL;
2062         unsigned idx;
2063
2064         if (type != FFS_DESCRIPTOR)
2065                 return 0;
2066
2067         if (isHS)
2068                 func->function.hs_descriptors[(long)valuep] = desc;
2069         else
2070                 func->function.descriptors[(long)valuep]    = desc;
2071
2072         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2073                 return 0;
2074
2075         idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2076         ffs_ep = func->eps + idx;
2077
2078         if (unlikely(ffs_ep->descs[isHS])) {
2079                 FVDBG("two %sspeed descriptors for EP %d",
2080                       isHS ? "high" : "full",
2081                       ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2082                 return -EINVAL;
2083         }
2084         ffs_ep->descs[isHS] = ds;
2085
2086         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2087         if (ffs_ep->ep) {
2088                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2089                 if (!ds->wMaxPacketSize)
2090                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2091         } else {
2092                 struct usb_request *req;
2093                 struct usb_ep *ep;
2094
2095                 FVDBG("autoconfig");
2096                 ep = usb_ep_autoconfig(func->gadget, ds);
2097                 if (unlikely(!ep))
2098                         return -ENOTSUPP;
2099                 ep->driver_data = func->eps + idx;;
2100
2101                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2102                 if (unlikely(!req))
2103                         return -ENOMEM;
2104
2105                 ffs_ep->ep  = ep;
2106                 ffs_ep->req = req;
2107                 func->eps_revmap[ds->bEndpointAddress &
2108                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2109         }
2110         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2111
2112         return 0;
2113 }
2114
2115
2116 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2117                                    struct usb_descriptor_header *desc,
2118                                    void *priv)
2119 {
2120         struct ffs_function *func = priv;
2121         unsigned idx;
2122         u8 newValue;
2123
2124         switch (type) {
2125         default:
2126         case FFS_DESCRIPTOR:
2127                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2128                 return 0;
2129
2130         case FFS_INTERFACE:
2131                 idx = *valuep;
2132                 if (func->interfaces_nums[idx] < 0) {
2133                         int id = usb_interface_id(func->conf, &func->function);
2134                         if (unlikely(id < 0))
2135                                 return id;
2136                         func->interfaces_nums[idx] = id;
2137                 }
2138                 newValue = func->interfaces_nums[idx];
2139                 break;
2140
2141         case FFS_STRING:
2142                 /* String' IDs are allocated when fsf_data is bound to cdev */
2143                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2144                 break;
2145
2146         case FFS_ENDPOINT:
2147                 /* USB_DT_ENDPOINT are handled in
2148                  * __ffs_func_bind_do_descs(). */
2149                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2150                         return 0;
2151
2152                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2153                 if (unlikely(!func->eps[idx].ep))
2154                         return -EINVAL;
2155
2156                 {
2157                         struct usb_endpoint_descriptor **descs;
2158                         descs = func->eps[idx].descs;
2159                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2160                 }
2161                 break;
2162         }
2163
2164         FVDBG("%02x -> %02x", *valuep, newValue);
2165         *valuep = newValue;
2166         return 0;
2167 }
2168
2169 static int ffs_func_bind(struct usb_configuration *c,
2170                          struct usb_function *f)
2171 {
2172         struct ffs_function *func = ffs_func_from_usb(f);
2173         struct ffs_data *ffs = func->ffs;
2174
2175         const int full = !!func->ffs->fs_descs_count;
2176         const int high = gadget_is_dualspeed(func->gadget) &&
2177                 func->ffs->hs_descs_count;
2178
2179         int ret;
2180
2181         /* Make it a single chunk, less management later on */
2182         struct {
2183                 struct ffs_ep eps[ffs->eps_count];
2184                 struct usb_descriptor_header
2185                         *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2186                 struct usb_descriptor_header
2187                         *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2188                 short inums[ffs->interfaces_count];
2189                 char raw_descs[high ? ffs->raw_descs_length
2190                                     : ffs->raw_fs_descs_length];
2191         } *data;
2192
2193         ENTER();
2194
2195         /* Only high speed but not supported by gadget? */
2196         if (unlikely(!(full | high)))
2197                 return -ENOTSUPP;
2198
2199         /* Allocate */
2200         data = kmalloc(sizeof *data, GFP_KERNEL);
2201         if (unlikely(!data))
2202                 return -ENOMEM;
2203
2204         /* Zero */
2205         memset(data->eps, 0, sizeof data->eps);
2206         memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2207         memset(data->inums, 0xff, sizeof data->inums);
2208         for (ret = ffs->eps_count; ret; --ret)
2209                 data->eps[ret].num = -1;
2210
2211         /* Save pointers */
2212         func->eps             = data->eps;
2213         func->interfaces_nums = data->inums;
2214
2215         /* Go throught all the endpoint descriptors and allocate
2216          * endpoints first, so that later we can rewrite the endpoint
2217          * numbers without worying that it may be described later on. */
2218         if (likely(full)) {
2219                 func->function.descriptors = data->fs_descs;
2220                 ret = ffs_do_descs(ffs->fs_descs_count,
2221                                    data->raw_descs,
2222                                    sizeof data->raw_descs,
2223                                    __ffs_func_bind_do_descs, func);
2224                 if (unlikely(ret < 0))
2225                         goto error;
2226         } else {
2227                 ret = 0;
2228         }
2229
2230         if (likely(high)) {
2231                 func->function.hs_descriptors = data->hs_descs;
2232                 ret = ffs_do_descs(ffs->hs_descs_count,
2233                                    data->raw_descs + ret,
2234                                    (sizeof data->raw_descs) - ret,
2235                                    __ffs_func_bind_do_descs, func);
2236         }
2237
2238         /* Now handle interface numbers allocation and interface and
2239          * enpoint numbers rewritting.  We can do that in one go
2240          * now. */
2241         ret = ffs_do_descs(ffs->fs_descs_count +
2242                            (high ? ffs->hs_descs_count : 0),
2243                            data->raw_descs, sizeof data->raw_descs,
2244                            __ffs_func_bind_do_nums, func);
2245         if (unlikely(ret < 0))
2246                 goto error;
2247
2248         /* And we're done */
2249         ffs_event_add(ffs, FUNCTIONFS_BIND);
2250         return 0;
2251
2252 error:
2253         /* XXX Do we need to release all claimed endpoints here? */
2254         return ret;
2255 }
2256
2257
2258 /* Other USB function hooks *************************************************/
2259
2260 static void ffs_func_unbind(struct usb_configuration *c,
2261                             struct usb_function *f)
2262 {
2263         struct ffs_function *func = ffs_func_from_usb(f);
2264         struct ffs_data *ffs = func->ffs;
2265
2266         ENTER();
2267
2268         if (ffs->func == func) {
2269                 ffs_func_eps_disable(func);
2270                 ffs->func = NULL;
2271         }
2272
2273         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2274
2275         ffs_func_free(func);
2276 }
2277
2278
2279 static int ffs_func_set_alt(struct usb_function *f,
2280                             unsigned interface, unsigned alt)
2281 {
2282         struct ffs_function *func = ffs_func_from_usb(f);
2283         struct ffs_data *ffs = func->ffs;
2284         int ret = 0, intf;
2285
2286         if (alt != (unsigned)-1) {
2287                 intf = ffs_func_revmap_intf(func, interface);
2288                 if (unlikely(intf < 0))
2289                         return intf;
2290         }
2291
2292         if (ffs->func)
2293                 ffs_func_eps_disable(ffs->func);
2294
2295         if (ffs->state != FFS_ACTIVE)
2296                 return -ENODEV;
2297
2298         if (alt == (unsigned)-1) {
2299                 ffs->func = NULL;
2300                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2301                 return 0;
2302         }
2303
2304         ffs->func = func;
2305         ret = ffs_func_eps_enable(func);
2306         if (likely(ret >= 0))
2307                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2308         return ret;
2309 }
2310
2311 static void ffs_func_disable(struct usb_function *f)
2312 {
2313         ffs_func_set_alt(f, 0, (unsigned)-1);
2314 }
2315
2316 static int ffs_func_setup(struct usb_function *f,
2317                           const struct usb_ctrlrequest *creq)
2318 {
2319         struct ffs_function *func = ffs_func_from_usb(f);
2320         struct ffs_data *ffs = func->ffs;
2321         unsigned long flags;
2322         int ret;
2323
2324         ENTER();
2325
2326         FVDBG("creq->bRequestType = %02x", creq->bRequestType);
2327         FVDBG("creq->bRequest     = %02x", creq->bRequest);
2328         FVDBG("creq->wValue       = %04x", le16_to_cpu(creq->wValue));
2329         FVDBG("creq->wIndex       = %04x", le16_to_cpu(creq->wIndex));
2330         FVDBG("creq->wLength      = %04x", le16_to_cpu(creq->wLength));
2331
2332         /* Most requests directed to interface go throught here
2333          * (notable exceptions are set/get interface) so we need to
2334          * handle them.  All other either handled by composite or
2335          * passed to usb_configuration->setup() (if one is set).  No
2336          * matter, we will handle requests directed to endpoint here
2337          * as well (as it's straightforward) but what to do with any
2338          * other request? */
2339
2340         if (ffs->state != FFS_ACTIVE)
2341                 return -ENODEV;
2342
2343         switch (creq->bRequestType & USB_RECIP_MASK) {
2344         case USB_RECIP_INTERFACE:
2345                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2346                 if (unlikely(ret < 0))
2347                         return ret;
2348                 break;
2349
2350         case USB_RECIP_ENDPOINT:
2351                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2352                 if (unlikely(ret < 0))
2353                         return ret;
2354                 break;
2355
2356         default:
2357                 return -EOPNOTSUPP;
2358         }
2359
2360         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2361         ffs->ev.setup = *creq;
2362         ffs->ev.setup.wIndex = cpu_to_le16(ret);
2363         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2364         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2365
2366         return 0;
2367 }
2368
2369 static void ffs_func_suspend(struct usb_function *f)
2370 {
2371         ENTER();
2372         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2373 }
2374
2375 static void ffs_func_resume(struct usb_function *f)
2376 {
2377         ENTER();
2378         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2379 }
2380
2381
2382
2383 /* Enpoint and interface numbers reverse mapping ****************************/
2384
2385 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2386 {
2387         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2388         return num ? num : -EDOM;
2389 }
2390
2391 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2392 {
2393         short *nums = func->interfaces_nums;
2394         unsigned count = func->ffs->interfaces_count;
2395
2396         for (; count; --count, ++nums) {
2397                 if (*nums >= 0 && *nums == intf)
2398                         return nums - func->interfaces_nums;
2399         }
2400
2401         return -EDOM;
2402 }
2403
2404
2405 /* Misc helper functions ****************************************************/
2406
2407 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2408 {
2409         return nonblock
2410                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2411                 : mutex_lock_interruptible(mutex);
2412 }
2413
2414
2415 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
2416 {
2417         char *data;
2418
2419         if (unlikely(!len))
2420                 return NULL;
2421
2422         data = kmalloc(len, GFP_KERNEL);
2423         if (unlikely(!data))
2424                 return ERR_PTR(-ENOMEM);
2425
2426         if (unlikely(__copy_from_user(data, buf, len))) {
2427                 kfree(data);
2428                 return ERR_PTR(-EFAULT);
2429         }
2430
2431         FVDBG("Buffer from user space:");
2432         ffs_dump_mem("", data, len);
2433
2434         return data;
2435 }