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_mode    = perms->mode;
 984                 inode->i_uid     = perms->uid;
 985                 inode->i_gid     = perms->gid;
 986                 inode->i_atime   = current_time;
 987                 inode->i_mtime   = current_time;
 988                 inode->i_ctime   = current_time;
 989                 inode->i_private = data;
 990                 if (fops)
 991                         inode->i_fop = fops;
 992                 if (iops)
 993                         inode->i_op  = iops;
 994         }
 995
 996         return inode;
 997 }
 998
 999
1000 /* Create "regular" file */
1001
1002 static struct inode *ffs_sb_create_file(struct super_block *sb,
1003                                         const char *name, void *data,
1004                                         const struct file_operations *fops,
1005                                         struct dentry **dentry_p)
1006 {
1007         struct ffs_data *ffs = sb->s_fs_info;
1008         struct dentry   *dentry;
1009         struct inode    *inode;
1010
1011         ENTER();
1012
1013         dentry = d_alloc_name(sb->s_root, name);
1014         if (unlikely(!dentry))
1015                 return NULL;
1016
1017         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1018         if (unlikely(!inode)) {
1019                 dput(dentry);
1020                 return NULL;
1021         }
1022
1023         d_add(dentry, inode);
1024         if (dentry_p)
1025                 *dentry_p = dentry;
1026
1027         return inode;
1028 }
1029
1030
1031 /* Super block */
1032
1033 static const struct super_operations ffs_sb_operations = {
1034         .statfs =       simple_statfs,
1035         .drop_inode =   generic_delete_inode,
1036 };
1037
1038 struct ffs_sb_fill_data {
1039         struct ffs_file_perms perms;
1040         umode_t root_mode;
1041         const char *dev_name;
1042 };
1043
1044 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1045 {
1046         struct ffs_sb_fill_data *data = _data;
1047         struct inode    *inode;
1048         struct dentry   *d;
1049         struct ffs_data *ffs;
1050
1051         ENTER();
1052
1053         /* Initialize data */
1054         ffs = ffs_data_new();
1055         if (unlikely(!ffs))
1056                 goto enomem0;
1057
1058         ffs->sb              = sb;
1059         ffs->dev_name        = data->dev_name;
1060         ffs->file_perms      = data->perms;
1061
1062         sb->s_fs_info        = ffs;
1063         sb->s_blocksize      = PAGE_CACHE_SIZE;
1064         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1065         sb->s_magic          = FUNCTIONFS_MAGIC;
1066         sb->s_op             = &ffs_sb_operations;
1067         sb->s_time_gran      = 1;
1068
1069         /* Root inode */
1070         data->perms.mode = data->root_mode;
1071         inode = ffs_sb_make_inode(sb, NULL,
1072                                   &simple_dir_operations,
1073                                   &simple_dir_inode_operations,
1074                                   &data->perms);
1075         if (unlikely(!inode))
1076                 goto enomem1;
1077         d = d_alloc_root(inode);
1078         if (unlikely(!d))
1079                 goto enomem2;
1080         sb->s_root = d;
1081
1082         /* EP0 file */
1083         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1084                                          &ffs_ep0_operations, NULL)))
1085                 goto enomem3;
1086
1087         return 0;
1088
1089 enomem3:
1090         dput(d);
1091 enomem2:
1092         iput(inode);
1093 enomem1:
1094         ffs_data_put(ffs);
1095 enomem0:
1096         return -ENOMEM;
1097 }
1098
1099
1100 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1101 {
1102         ENTER();
1103
1104         if (!opts || !*opts)
1105                 return 0;
1106
1107         for (;;) {
1108                 char *end, *eq, *comma;
1109                 unsigned long value;
1110
1111                 /* Option limit */
1112                 comma = strchr(opts, ',');
1113                 if (comma)
1114                         *comma = 0;
1115
1116                 /* Value limit */
1117                 eq = strchr(opts, '=');
1118                 if (unlikely(!eq)) {
1119                         FERR("'=' missing in %s", opts);
1120                         return -EINVAL;
1121                 }
1122                 *eq = 0;
1123
1124                 /* Parse value */
1125                 value = simple_strtoul(eq + 1, &end, 0);
1126                 if (unlikely(*end != ',' && *end != 0)) {
1127                         FERR("%s: invalid value: %s", opts, eq + 1);
1128                         return -EINVAL;
1129                 }
1130
1131                 /* Interpret option */
1132                 switch (eq - opts) {
1133                 case 5:
1134                         if (!memcmp(opts, "rmode", 5))
1135                                 data->root_mode  = (value & 0555) | S_IFDIR;
1136                         else if (!memcmp(opts, "fmode", 5))
1137                                 data->perms.mode = (value & 0666) | S_IFREG;
1138                         else
1139                                 goto invalid;
1140                         break;
1141
1142                 case 4:
1143                         if (!memcmp(opts, "mode", 4)) {
1144                                 data->root_mode  = (value & 0555) | S_IFDIR;
1145                                 data->perms.mode = (value & 0666) | S_IFREG;
1146                         } else {
1147                                 goto invalid;
1148                         }
1149                         break;
1150
1151                 case 3:
1152                         if (!memcmp(opts, "uid", 3))
1153                                 data->perms.uid = value;
1154                         else if (!memcmp(opts, "gid", 3))
1155                                 data->perms.gid = value;
1156                         else
1157                                 goto invalid;
1158                         break;
1159
1160                 default:
1161 invalid:
1162                         FERR("%s: invalid option", opts);
1163                         return -EINVAL;
1164                 }
1165
1166                 /* Next iteration */
1167                 if (!comma)
1168                         break;
1169                 opts = comma + 1;
1170         }
1171
1172         return 0;
1173 }
1174
1175
1176 /* "mount -t functionfs dev_name /dev/function" ends up here */
1177
1178 static int
1179 ffs_fs_get_sb(struct file_system_type *t, int flags,
1180               const char *dev_name, void *opts, struct vfsmount *mnt)
1181 {
1182         struct ffs_sb_fill_data data = {
1183                 .perms = {
1184                         .mode = S_IFREG | 0600,
1185                         .uid = 0,
1186                         .gid = 0
1187                 },
1188                 .root_mode = S_IFDIR | 0500,
1189         };
1190         int ret;
1191
1192         ENTER();
1193
1194         ret = functionfs_check_dev_callback(dev_name);
1195         if (unlikely(ret < 0))
1196                 return ret;
1197
1198         ret = ffs_fs_parse_opts(&data, opts);
1199         if (unlikely(ret < 0))
1200                 return ret;
1201
1202         data.dev_name = dev_name;
1203         return get_sb_single(t, flags, &data, ffs_sb_fill, mnt);
1204 }
1205
1206 static void
1207 ffs_fs_kill_sb(struct super_block *sb)
1208 {
1209         void *ptr;
1210
1211         ENTER();
1212
1213         kill_litter_super(sb);
1214         ptr = xchg(&sb->s_fs_info, NULL);
1215         if (ptr)
1216                 ffs_data_put(ptr);
1217 }
1218
1219 static struct file_system_type ffs_fs_type = {
1220         .owner          = THIS_MODULE,
1221         .name           = "functionfs",
1222         .get_sb         = ffs_fs_get_sb,
1223         .kill_sb        = ffs_fs_kill_sb,
1224 };
1225
1226
1227
1228 /* Driver's main init/cleanup functions *************************************/
1229
1230
1231 static int functionfs_init(void)
1232 {
1233         int ret;
1234
1235         ENTER();
1236
1237         ret = register_filesystem(&ffs_fs_type);
1238         if (likely(!ret))
1239                 FINFO("file system registered");
1240         else
1241                 FERR("failed registering file system (%d)", ret);
1242
1243         return ret;
1244 }
1245
1246 static void functionfs_cleanup(void)
1247 {
1248         ENTER();
1249
1250         FINFO("unloading");
1251         unregister_filesystem(&ffs_fs_type);
1252 }
1253
1254
1255
1256 /* ffs_data and ffs_function construction and destruction code **************/
1257
1258 static void ffs_data_clear(struct ffs_data *ffs);
1259 static void ffs_data_reset(struct ffs_data *ffs);
1260
1261
1262 static void ffs_data_get(struct ffs_data *ffs)
1263 {
1264         ENTER();
1265
1266         atomic_inc(&ffs->ref);
1267 }
1268
1269 static void ffs_data_opened(struct ffs_data *ffs)
1270 {
1271         ENTER();
1272
1273         atomic_inc(&ffs->ref);
1274         atomic_inc(&ffs->opened);
1275 }
1276
1277 static void ffs_data_put(struct ffs_data *ffs)
1278 {
1279         ENTER();
1280
1281         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1282                 FINFO("%s(): freeing", __func__);
1283                 ffs_data_clear(ffs);
1284                 BUG_ON(mutex_is_locked(&ffs->mutex) ||
1285                        spin_is_locked(&ffs->ev.waitq.lock) ||
1286                        waitqueue_active(&ffs->ev.waitq) ||
1287                        waitqueue_active(&ffs->ep0req_completion.wait));
1288                 kfree(ffs);
1289         }
1290 }
1291
1292
1293
1294 static void ffs_data_closed(struct ffs_data *ffs)
1295 {
1296         ENTER();
1297
1298         if (atomic_dec_and_test(&ffs->opened)) {
1299                 ffs->state = FFS_CLOSING;
1300                 ffs_data_reset(ffs);
1301         }
1302
1303         ffs_data_put(ffs);
1304 }
1305
1306
1307 static struct ffs_data *ffs_data_new(void)
1308 {
1309         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1310         if (unlikely(!ffs))
1311                 return 0;
1312
1313         ENTER();
1314
1315         atomic_set(&ffs->ref, 1);
1316         atomic_set(&ffs->opened, 0);
1317         ffs->state = FFS_READ_DESCRIPTORS;
1318         mutex_init(&ffs->mutex);
1319         spin_lock_init(&ffs->eps_lock);
1320         init_waitqueue_head(&ffs->ev.waitq);
1321         init_completion(&ffs->ep0req_completion);
1322
1323         /* XXX REVISIT need to update it in some places, or do we? */
1324         ffs->ev.can_stall = 1;
1325
1326         return ffs;
1327 }
1328
1329
1330 static void ffs_data_clear(struct ffs_data *ffs)
1331 {
1332         ENTER();
1333
1334         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1335                 functionfs_closed_callback(ffs);
1336
1337         BUG_ON(ffs->gadget);
1338
1339         if (ffs->epfiles)
1340                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1341
1342         kfree(ffs->raw_descs);
1343         kfree(ffs->raw_strings);
1344         kfree(ffs->stringtabs);
1345 }
1346
1347
1348 static void ffs_data_reset(struct ffs_data *ffs)
1349 {
1350         ENTER();
1351
1352         ffs_data_clear(ffs);
1353
1354         ffs->epfiles = NULL;
1355         ffs->raw_descs = NULL;
1356         ffs->raw_strings = NULL;
1357         ffs->stringtabs = NULL;
1358
1359         ffs->raw_descs_length = 0;
1360         ffs->raw_fs_descs_length = 0;
1361         ffs->fs_descs_count = 0;
1362         ffs->hs_descs_count = 0;
1363
1364         ffs->strings_count = 0;
1365         ffs->interfaces_count = 0;
1366         ffs->eps_count = 0;
1367
1368         ffs->ev.count = 0;
1369
1370         ffs->state = FFS_READ_DESCRIPTORS;
1371         ffs->setup_state = FFS_NO_SETUP;
1372         ffs->flags = 0;
1373 }
1374
1375
1376 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1377 {
1378         struct usb_gadget_strings **lang;
1379         int first_id;
1380
1381         ENTER();
1382
1383         if (WARN_ON(ffs->state != FFS_ACTIVE
1384                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1385                 return -EBADFD;
1386
1387         first_id = usb_string_ids_n(cdev, ffs->strings_count);
1388         if (unlikely(first_id < 0))
1389                 return first_id;
1390
1391         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1392         if (unlikely(!ffs->ep0req))
1393                 return -ENOMEM;
1394         ffs->ep0req->complete = ffs_ep0_complete;
1395         ffs->ep0req->context = ffs;
1396
1397         lang = ffs->stringtabs;
1398         for (lang = ffs->stringtabs; *lang; ++lang) {
1399                 struct usb_string *str = (*lang)->strings;
1400                 int id = first_id;
1401                 for (; str->s; ++id, ++str)
1402                         str->id = id;
1403         }
1404
1405         ffs->gadget = cdev->gadget;
1406         ffs_data_get(ffs);
1407         return 0;
1408 }
1409
1410
1411 static void functionfs_unbind(struct ffs_data *ffs)
1412 {
1413         ENTER();
1414
1415         if (!WARN_ON(!ffs->gadget)) {
1416                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1417                 ffs->ep0req = NULL;
1418                 ffs->gadget = NULL;
1419                 ffs_data_put(ffs);
1420         }
1421 }
1422
1423
1424 static int ffs_epfiles_create(struct ffs_data *ffs)
1425 {
1426         struct ffs_epfile *epfile, *epfiles;
1427         unsigned i, count;
1428
1429         ENTER();
1430
1431         count = ffs->eps_count;
1432         epfiles = kzalloc(count * sizeof *epfiles, GFP_KERNEL);
1433         if (!epfiles)
1434                 return -ENOMEM;
1435
1436         epfile = epfiles;
1437         for (i = 1; i <= count; ++i, ++epfile) {
1438                 epfile->ffs = ffs;
1439                 mutex_init(&epfile->mutex);
1440                 init_waitqueue_head(&epfile->wait);
1441                 sprintf(epfiles->name, "ep%u",  i);
1442                 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1443                                                  &ffs_epfile_operations,
1444                                                  &epfile->dentry))) {
1445                         ffs_epfiles_destroy(epfiles, i - 1);
1446                         return -ENOMEM;
1447                 }
1448         }
1449
1450         ffs->epfiles = epfiles;
1451         return 0;
1452 }
1453
1454
1455 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1456 {
1457         struct ffs_epfile *epfile = epfiles;
1458
1459         ENTER();
1460
1461         for (; count; --count, ++epfile) {
1462                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1463                        waitqueue_active(&epfile->wait));
1464                 if (epfile->dentry) {
1465                         d_delete(epfile->dentry);
1466                         dput(epfile->dentry);
1467                         epfile->dentry = NULL;
1468                 }
1469         }
1470
1471         kfree(epfiles);
1472 }
1473
1474
1475 static int functionfs_bind_config(struct usb_composite_dev *cdev,
1476                                   struct usb_configuration *c,
1477                                   struct ffs_data *ffs)
1478 {
1479         struct ffs_function *func;
1480         int ret;
1481
1482         ENTER();
1483
1484         func = kzalloc(sizeof *func, GFP_KERNEL);
1485         if (unlikely(!func))
1486                 return -ENOMEM;
1487
1488         func->function.name    = "Function FS Gadget";
1489         func->function.strings = ffs->stringtabs;
1490
1491         func->function.bind    = ffs_func_bind;
1492         func->function.unbind  = ffs_func_unbind;
1493         func->function.set_alt = ffs_func_set_alt;
1494         /*func->function.get_alt = ffs_func_get_alt;*/
1495         func->function.disable = ffs_func_disable;
1496         func->function.setup   = ffs_func_setup;
1497         func->function.suspend = ffs_func_suspend;
1498         func->function.resume  = ffs_func_resume;
1499
1500         func->conf   = c;
1501         func->gadget = cdev->gadget;
1502         func->ffs = ffs;
1503         ffs_data_get(ffs);
1504
1505         ret = usb_add_function(c, &func->function);
1506         if (unlikely(ret))
1507                 ffs_func_free(func);
1508
1509         return ret;
1510 }
1511
1512 static void ffs_func_free(struct ffs_function *func)
1513 {
1514         ENTER();
1515
1516         ffs_data_put(func->ffs);
1517
1518         kfree(func->eps);
1519         /* eps and interfaces_nums are allocated in the same chunk so
1520          * only one free is required.  Descriptors are also allocated
1521          * in the same chunk. */
1522
1523         kfree(func);
1524 }
1525
1526
1527 static void ffs_func_eps_disable(struct ffs_function *func)
1528 {
1529         struct ffs_ep *ep         = func->eps;
1530         struct ffs_epfile *epfile = func->ffs->epfiles;
1531         unsigned count            = func->ffs->eps_count;
1532         unsigned long flags;
1533
1534         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1535         do {
1536                 /* pending requests get nuked */
1537                 if (likely(ep->ep))
1538                         usb_ep_disable(ep->ep);
1539                 epfile->ep = NULL;
1540
1541                 ++ep;
1542                 ++epfile;
1543         } while (--count);
1544         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1545 }
1546
1547 static int ffs_func_eps_enable(struct ffs_function *func)
1548 {
1549         struct ffs_data *ffs      = func->ffs;
1550         struct ffs_ep *ep         = func->eps;
1551         struct ffs_epfile *epfile = ffs->epfiles;
1552         unsigned count            = ffs->eps_count;
1553         unsigned long flags;
1554         int ret = 0;
1555
1556         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1557         do {
1558                 struct usb_endpoint_descriptor *ds;
1559                 ds = ep->descs[ep->descs[1] ? 1 : 0];
1560
1561                 ep->ep->driver_data = ep;
1562                 ret = usb_ep_enable(ep->ep, ds);
1563                 if (likely(!ret)) {
1564                         epfile->ep = ep;
1565                         epfile->in = usb_endpoint_dir_in(ds);
1566                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1567                 } else {
1568                         break;
1569                 }
1570
1571                 wake_up(&epfile->wait);
1572
1573                 ++ep;
1574                 ++epfile;
1575         } while (--count);
1576         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1577
1578         return ret;
1579 }
1580
1581
1582 /* Parsing and building descriptors and strings *****************************/
1583
1584
1585 /* This validates if data pointed by data is a valid USB descriptor as
1586  * well as record how many interfaces, endpoints and strings are
1587  * required by given configuration.  Returns address afther the
1588  * descriptor or NULL if data is invalid. */
1589
1590 enum ffs_entity_type {
1591         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1592 };
1593
1594 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1595                                    u8 *valuep,
1596                                    struct usb_descriptor_header *desc,
1597                                    void *priv);
1598
1599 static int __must_check ffs_do_desc(char *data, unsigned len,
1600                                     ffs_entity_callback entity, void *priv)
1601 {
1602         struct usb_descriptor_header *_ds = (void *)data;
1603         u8 length;
1604         int ret;
1605
1606         ENTER();
1607
1608         /* At least two bytes are required: length and type */
1609         if (len < 2) {
1610                 FVDBG("descriptor too short");
1611                 return -EINVAL;
1612         }
1613
1614         /* If we have at least as many bytes as the descriptor takes? */
1615         length = _ds->bLength;
1616         if (len < length) {
1617                 FVDBG("descriptor longer then available data");
1618                 return -EINVAL;
1619         }
1620
1621 #define __entity_check_INTERFACE(val)  1
1622 #define __entity_check_STRING(val)     (val)
1623 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1624 #define __entity(type, val) do {                                        \
1625                 FVDBG("entity " #type "(%02x)", (val));                 \
1626                 if (unlikely(!__entity_check_ ##type(val))) {           \
1627                         FVDBG("invalid entity's value");                \
1628                         return -EINVAL;                                 \
1629                 }                                                       \
1630                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1631                 if (unlikely(ret < 0)) {                                \
1632                         FDBG("entity " #type "(%02x); ret = %d",        \
1633                              (val), ret);                               \
1634                         return ret;                                     \
1635                 }                                                       \
1636         } while (0)
1637
1638         /* Parse descriptor depending on type. */
1639         switch (_ds->bDescriptorType) {
1640         case USB_DT_DEVICE:
1641         case USB_DT_CONFIG:
1642         case USB_DT_STRING:
1643         case USB_DT_DEVICE_QUALIFIER:
1644                 /* function can't have any of those */
1645                 FVDBG("descriptor reserved for gadget: %d", _ds->bDescriptorType);
1646                 return -EINVAL;
1647
1648         case USB_DT_INTERFACE: {
1649                 struct usb_interface_descriptor *ds = (void *)_ds;
1650                 FVDBG("interface descriptor");
1651                 if (length != sizeof *ds)
1652                         goto inv_length;
1653
1654                 __entity(INTERFACE, ds->bInterfaceNumber);
1655                 if (ds->iInterface)
1656                         __entity(STRING, ds->iInterface);
1657         }
1658                 break;
1659
1660         case USB_DT_ENDPOINT: {
1661                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1662                 FVDBG("endpoint descriptor");
1663                 if (length != USB_DT_ENDPOINT_SIZE &&
1664                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1665                         goto inv_length;
1666                 __entity(ENDPOINT, ds->bEndpointAddress);
1667         }
1668                 break;
1669
1670         case USB_DT_OTG:
1671                 if (length != sizeof(struct usb_otg_descriptor))
1672                         goto inv_length;
1673                 break;
1674
1675         case USB_DT_INTERFACE_ASSOCIATION: {
1676                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1677                 FVDBG("interface association descriptor");
1678                 if (length != sizeof *ds)
1679                         goto inv_length;
1680                 if (ds->iFunction)
1681                         __entity(STRING, ds->iFunction);
1682         }
1683                 break;
1684
1685         case USB_DT_OTHER_SPEED_CONFIG:
1686         case USB_DT_INTERFACE_POWER:
1687         case USB_DT_DEBUG:
1688         case USB_DT_SECURITY:
1689         case USB_DT_CS_RADIO_CONTROL:
1690                 /* TODO */
1691                 FVDBG("unimplemented descriptor: %d", _ds->bDescriptorType);
1692                 return -EINVAL;
1693
1694         default:
1695                 /* We should never be here */
1696                 FVDBG("unknown descriptor: %d", _ds->bDescriptorType);
1697                 return -EINVAL;
1698
1699         inv_length:
1700                 FVDBG("invalid length: %d (descriptor %d)",
1701                       _ds->bLength, _ds->bDescriptorType);
1702                 return -EINVAL;
1703         }
1704
1705 #undef __entity
1706 #undef __entity_check_DESCRIPTOR
1707 #undef __entity_check_INTERFACE
1708 #undef __entity_check_STRING
1709 #undef __entity_check_ENDPOINT
1710
1711         return length;
1712 }
1713
1714
1715 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1716                                      ffs_entity_callback entity, void *priv)
1717 {
1718         const unsigned _len = len;
1719         unsigned long num = 0;
1720
1721         ENTER();
1722
1723         for (;;) {
1724                 int ret;
1725
1726                 if (num == count)
1727                         data = NULL;
1728
1729                 /* Record "descriptor" entitny */
1730                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1731                 if (unlikely(ret < 0)) {
1732                         FDBG("entity DESCRIPTOR(%02lx); ret = %d", num, ret);
1733                         return ret;
1734                 }
1735
1736                 if (!data)
1737                         return _len - len;
1738
1739                 ret = ffs_do_desc(data, len, entity, priv);
1740                 if (unlikely(ret < 0)) {
1741                         FDBG("%s returns %d", __func__, ret);
1742                         return ret;
1743                 }
1744
1745                 len -= ret;
1746                 data += ret;
1747                 ++num;
1748         }
1749 }
1750
1751
1752 static int __ffs_data_do_entity(enum ffs_entity_type type,
1753                                 u8 *valuep, struct usb_descriptor_header *desc,
1754                                 void *priv)
1755 {
1756         struct ffs_data *ffs = priv;
1757
1758         ENTER();
1759
1760         switch (type) {
1761         case FFS_DESCRIPTOR:
1762                 break;
1763
1764         case FFS_INTERFACE:
1765                 /* Interfaces are indexed from zero so if we
1766                  * encountered interface "n" then there are at least
1767                  * "n+1" interfaces. */
1768                 if (*valuep >= ffs->interfaces_count)
1769                         ffs->interfaces_count = *valuep + 1;
1770                 break;
1771
1772         case FFS_STRING:
1773                 /* Strings are indexed from 1 (0 is magic ;) reserved
1774                  * for languages list or some such) */
1775                 if (*valuep > ffs->strings_count)
1776                         ffs->strings_count = *valuep;
1777                 break;
1778
1779         case FFS_ENDPOINT:
1780                 /* Endpoints are indexed from 1 as well. */
1781                 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1782                         ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1783                 break;
1784         }
1785
1786         return 0;
1787 }
1788
1789
1790 static int __ffs_data_got_descs(struct ffs_data *ffs,
1791                                 char *const _data, size_t len)
1792 {
1793         unsigned fs_count, hs_count;
1794         int fs_len, ret = -EINVAL;
1795         char *data = _data;
1796
1797         ENTER();
1798
1799         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1800                      get_unaligned_le32(data + 4) != len))
1801                 goto error;
1802         fs_count = get_unaligned_le32(data +  8);
1803         hs_count = get_unaligned_le32(data + 12);
1804
1805         if (!fs_count && !hs_count)
1806                 goto einval;
1807
1808         data += 16;
1809         len  -= 16;
1810
1811         if (likely(fs_count)) {
1812                 fs_len = ffs_do_descs(fs_count, data, len,
1813                                       __ffs_data_do_entity, ffs);
1814                 if (unlikely(fs_len < 0)) {
1815                         ret = fs_len;
1816                         goto error;
1817                 }
1818
1819                 data += fs_len;
1820                 len  -= fs_len;
1821         } else {
1822                 fs_len = 0;
1823         }
1824
1825         if (likely(hs_count)) {
1826                 ret = ffs_do_descs(hs_count, data, len,
1827                                    __ffs_data_do_entity, ffs);
1828                 if (unlikely(ret < 0))
1829                         goto error;
1830         } else {
1831                 ret = 0;
1832         }
1833
1834         if (unlikely(len != ret))
1835                 goto einval;
1836
1837         ffs->raw_fs_descs_length = fs_len;
1838         ffs->raw_descs_length    = fs_len + ret;
1839         ffs->raw_descs           = _data;
1840         ffs->fs_descs_count      = fs_count;
1841         ffs->hs_descs_count      = hs_count;
1842
1843         return 0;
1844
1845 einval:
1846         ret = -EINVAL;
1847 error:
1848         kfree(_data);
1849         return ret;
1850 }
1851
1852
1853
1854 static int __ffs_data_got_strings(struct ffs_data *ffs,
1855                                   char *const _data, size_t len)
1856 {
1857         u32 str_count, needed_count, lang_count;
1858         struct usb_gadget_strings **stringtabs, *t;
1859         struct usb_string *strings, *s;
1860         const char *data = _data;
1861
1862         ENTER();
1863
1864         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1865                      get_unaligned_le32(data + 4) != len))
1866                 goto error;
1867         str_count  = get_unaligned_le32(data + 8);
1868         lang_count = get_unaligned_le32(data + 12);
1869
1870         /* if one is zero the other must be zero */
1871         if (unlikely(!str_count != !lang_count))
1872                 goto error;
1873
1874         /* Do we have at least as many strings as descriptors need? */
1875         needed_count = ffs->strings_count;
1876         if (unlikely(str_count < needed_count))
1877                 goto error;
1878
1879         /* If we don't need any strings just return and free all
1880          * memory */
1881         if (!needed_count) {
1882                 kfree(_data);
1883                 return 0;
1884         }
1885
1886         /* Allocate */
1887         {
1888                 /* Allocate everything in one chunk so there's less
1889                  * maintanance. */
1890                 struct {
1891                         struct usb_gadget_strings *stringtabs[lang_count + 1];
1892                         struct usb_gadget_strings stringtab[lang_count];
1893                         struct usb_string strings[lang_count*(needed_count+1)];
1894                 } *d;
1895                 unsigned i = 0;
1896
1897                 d = kmalloc(sizeof *d, GFP_KERNEL);
1898                 if (unlikely(!d)) {
1899                         kfree(_data);
1900                         return -ENOMEM;
1901                 }
1902
1903                 stringtabs = d->stringtabs;
1904                 t = d->stringtab;
1905                 i = lang_count;
1906                 do {
1907                         *stringtabs++ = t++;
1908                 } while (--i);
1909                 *stringtabs = NULL;
1910
1911                 stringtabs = d->stringtabs;
1912                 t = d->stringtab;
1913                 s = d->strings;
1914                 strings = s;
1915         }
1916
1917         /* For each language */
1918         data += 16;
1919         len -= 16;
1920
1921         do { /* lang_count > 0 so we can use do-while */
1922                 unsigned needed = needed_count;
1923
1924                 if (unlikely(len < 3))
1925                         goto error_free;
1926                 t->language = get_unaligned_le16(data);
1927                 t->strings  = s;
1928                 ++t;
1929
1930                 data += 2;
1931                 len -= 2;
1932
1933                 /* For each string */
1934                 do { /* str_count > 0 so we can use do-while */
1935                         size_t length = strnlen(data, len);
1936
1937                         if (unlikely(length == len))
1938                                 goto error_free;
1939
1940                         /* user may provide more strings then we need,
1941                          * if that's the case we simply ingore the
1942                          * rest */
1943                         if (likely(needed)) {
1944                                 /* s->id will be set while adding
1945                                  * function to configuration so for
1946                                  * now just leave garbage here. */
1947                                 s->s = data;
1948                                 --needed;
1949                                 ++s;
1950                         }
1951
1952                         data += length + 1;
1953                         len -= length + 1;
1954                 } while (--str_count);
1955
1956                 s->id = 0;   /* terminator */
1957                 s->s = NULL;
1958                 ++s;
1959
1960         } while (--lang_count);
1961
1962         /* Some garbage left? */
1963         if (unlikely(len))
1964                 goto error_free;
1965
1966         /* Done! */
1967         ffs->stringtabs = stringtabs;
1968         ffs->raw_strings = _data;
1969
1970         return 0;
1971
1972 error_free:
1973         kfree(stringtabs);
1974 error:
1975         kfree(_data);
1976         return -EINVAL;
1977 }
1978
1979
1980
1981
1982 /* Events handling and management *******************************************/
1983
1984 static void __ffs_event_add(struct ffs_data *ffs,
1985                             enum usb_functionfs_event_type type)
1986 {
1987         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
1988         int neg = 0;
1989
1990         /* Abort any unhandled setup */
1991         /* We do not need to worry about some cmpxchg() changing value
1992          * of ffs->setup_state without holding the lock because when
1993          * state is FFS_SETUP_PENDING cmpxchg() in several places in
1994          * the source does nothing. */
1995         if (ffs->setup_state == FFS_SETUP_PENDING)
1996                 ffs->setup_state = FFS_SETUP_CANCELED;
1997
1998         switch (type) {
1999         case FUNCTIONFS_RESUME:
2000                 rem_type2 = FUNCTIONFS_SUSPEND;
2001                 /* FALL THGOUTH */
2002         case FUNCTIONFS_SUSPEND:
2003         case FUNCTIONFS_SETUP:
2004                 rem_type1 = type;
2005                 /* discard all similar events */
2006                 break;
2007
2008         case FUNCTIONFS_BIND:
2009         case FUNCTIONFS_UNBIND:
2010         case FUNCTIONFS_DISABLE:
2011         case FUNCTIONFS_ENABLE:
2012                 /* discard everything other then power management. */
2013                 rem_type1 = FUNCTIONFS_SUSPEND;
2014                 rem_type2 = FUNCTIONFS_RESUME;
2015                 neg = 1;
2016                 break;
2017
2018         default:
2019                 BUG();
2020         }
2021
2022         {
2023                 u8 *ev  = ffs->ev.types, *out = ev;
2024                 unsigned n = ffs->ev.count;
2025                 for (; n; --n, ++ev)
2026                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2027                                 *out++ = *ev;
2028                         else
2029                                 FVDBG("purging event %d", *ev);
2030                 ffs->ev.count = out - ffs->ev.types;
2031         }
2032
2033         FVDBG("adding event %d", type);
2034         ffs->ev.types[ffs->ev.count++] = type;
2035         wake_up_locked(&ffs->ev.waitq);
2036 }
2037
2038 static void ffs_event_add(struct ffs_data *ffs,
2039                           enum usb_functionfs_event_type type)
2040 {
2041         unsigned long flags;
2042         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2043         __ffs_event_add(ffs, type);
2044         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2045 }
2046
2047
2048 /* Bind/unbind USB function hooks *******************************************/
2049
2050 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2051                                     struct usb_descriptor_header *desc,
2052                                     void *priv)
2053 {
2054         struct usb_endpoint_descriptor *ds = (void *)desc;
2055         struct ffs_function *func = priv;
2056         struct ffs_ep *ffs_ep;
2057
2058         /* If hs_descriptors is not NULL then we are reading hs
2059          * descriptors now */
2060         const int isHS = func->function.hs_descriptors != NULL;
2061         unsigned idx;
2062
2063         if (type != FFS_DESCRIPTOR)
2064                 return 0;
2065
2066         if (isHS)
2067                 func->function.hs_descriptors[(long)valuep] = desc;
2068         else
2069                 func->function.descriptors[(long)valuep]    = desc;
2070
2071         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2072                 return 0;
2073
2074         idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2075         ffs_ep = func->eps + idx;
2076
2077         if (unlikely(ffs_ep->descs[isHS])) {
2078                 FVDBG("two %sspeed descriptors for EP %d",
2079                       isHS ? "high" : "full",
2080                       ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2081                 return -EINVAL;
2082         }
2083         ffs_ep->descs[isHS] = ds;
2084
2085         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2086         if (ffs_ep->ep) {
2087                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2088                 if (!ds->wMaxPacketSize)
2089                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2090         } else {
2091                 struct usb_request *req;
2092                 struct usb_ep *ep;
2093
2094                 FVDBG("autoconfig");
2095                 ep = usb_ep_autoconfig(func->gadget, ds);
2096                 if (unlikely(!ep))
2097                         return -ENOTSUPP;
2098                 ep->driver_data = func->eps + idx;;
2099
2100                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2101                 if (unlikely(!req))
2102                         return -ENOMEM;
2103
2104                 ffs_ep->ep  = ep;
2105                 ffs_ep->req = req;
2106                 func->eps_revmap[ds->bEndpointAddress &
2107                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2108         }
2109         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2110
2111         return 0;
2112 }
2113
2114
2115 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2116                                    struct usb_descriptor_header *desc,
2117                                    void *priv)
2118 {
2119         struct ffs_function *func = priv;
2120         unsigned idx;
2121         u8 newValue;
2122
2123         switch (type) {
2124         default:
2125         case FFS_DESCRIPTOR:
2126                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2127                 return 0;
2128
2129         case FFS_INTERFACE:
2130                 idx = *valuep;
2131                 if (func->interfaces_nums[idx] < 0) {
2132                         int id = usb_interface_id(func->conf, &func->function);
2133                         if (unlikely(id < 0))
2134                                 return id;
2135                         func->interfaces_nums[idx] = id;
2136                 }
2137                 newValue = func->interfaces_nums[idx];
2138                 break;
2139
2140         case FFS_STRING:
2141                 /* String' IDs are allocated when fsf_data is bound to cdev */
2142                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2143                 break;
2144
2145         case FFS_ENDPOINT:
2146                 /* USB_DT_ENDPOINT are handled in
2147                  * __ffs_func_bind_do_descs(). */
2148                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2149                         return 0;
2150
2151                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2152                 if (unlikely(!func->eps[idx].ep))
2153                         return -EINVAL;
2154
2155                 {
2156                         struct usb_endpoint_descriptor **descs;
2157                         descs = func->eps[idx].descs;
2158                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2159                 }
2160                 break;
2161         }
2162
2163         FVDBG("%02x -> %02x", *valuep, newValue);
2164         *valuep = newValue;
2165         return 0;
2166 }
2167
2168 static int ffs_func_bind(struct usb_configuration *c,
2169                          struct usb_function *f)
2170 {
2171         struct ffs_function *func = ffs_func_from_usb(f);
2172         struct ffs_data *ffs = func->ffs;
2173
2174         const int full = !!func->ffs->fs_descs_count;
2175         const int high = gadget_is_dualspeed(func->gadget) &&
2176                 func->ffs->hs_descs_count;
2177
2178         int ret;
2179
2180         /* Make it a single chunk, less management later on */
2181         struct {
2182                 struct ffs_ep eps[ffs->eps_count];
2183                 struct usb_descriptor_header
2184                         *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2185                 struct usb_descriptor_header
2186                         *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2187                 short inums[ffs->interfaces_count];
2188                 char raw_descs[high ? ffs->raw_descs_length
2189                                     : ffs->raw_fs_descs_length];
2190         } *data;
2191
2192         ENTER();
2193
2194         /* Only high speed but not supported by gadget? */
2195         if (unlikely(!(full | high)))
2196                 return -ENOTSUPP;
2197
2198         /* Allocate */
2199         data = kmalloc(sizeof *data, GFP_KERNEL);
2200         if (unlikely(!data))
2201                 return -ENOMEM;
2202
2203         /* Zero */
2204         memset(data->eps, 0, sizeof data->eps);
2205         memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2206         memset(data->inums, 0xff, sizeof data->inums);
2207         for (ret = ffs->eps_count; ret; --ret)
2208                 data->eps[ret].num = -1;
2209
2210         /* Save pointers */
2211         func->eps             = data->eps;
2212         func->interfaces_nums = data->inums;
2213
2214         /* Go throught all the endpoint descriptors and allocate
2215          * endpoints first, so that later we can rewrite the endpoint
2216          * numbers without worying that it may be described later on. */
2217         if (likely(full)) {
2218                 func->function.descriptors = data->fs_descs;
2219                 ret = ffs_do_descs(ffs->fs_descs_count,
2220                                    data->raw_descs,
2221                                    sizeof data->raw_descs,
2222                                    __ffs_func_bind_do_descs, func);
2223                 if (unlikely(ret < 0))
2224                         goto error;
2225         } else {
2226                 ret = 0;
2227         }
2228
2229         if (likely(high)) {
2230                 func->function.hs_descriptors = data->hs_descs;
2231                 ret = ffs_do_descs(ffs->hs_descs_count,
2232                                    data->raw_descs + ret,
2233                                    (sizeof data->raw_descs) - ret,
2234                                    __ffs_func_bind_do_descs, func);
2235         }
2236
2237         /* Now handle interface numbers allocation and interface and
2238          * enpoint numbers rewritting.  We can do that in one go
2239          * now. */
2240         ret = ffs_do_descs(ffs->fs_descs_count +
2241                            (high ? ffs->hs_descs_count : 0),
2242                            data->raw_descs, sizeof data->raw_descs,
2243                            __ffs_func_bind_do_nums, func);
2244         if (unlikely(ret < 0))
2245                 goto error;
2246
2247         /* And we're done */
2248         ffs_event_add(ffs, FUNCTIONFS_BIND);
2249         return 0;
2250
2251 error:
2252         /* XXX Do we need to release all claimed endpoints here? */
2253         return ret;
2254 }
2255
2256
2257 /* Other USB function hooks *************************************************/
2258
2259 static void ffs_func_unbind(struct usb_configuration *c,
2260                             struct usb_function *f)
2261 {
2262         struct ffs_function *func = ffs_func_from_usb(f);
2263         struct ffs_data *ffs = func->ffs;
2264
2265         ENTER();
2266
2267         if (ffs->func == func) {
2268                 ffs_func_eps_disable(func);
2269                 ffs->func = NULL;
2270         }
2271
2272         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2273
2274         ffs_func_free(func);
2275 }
2276
2277
2278 static int ffs_func_set_alt(struct usb_function *f,
2279                             unsigned interface, unsigned alt)
2280 {
2281         struct ffs_function *func = ffs_func_from_usb(f);
2282         struct ffs_data *ffs = func->ffs;
2283         int ret = 0, intf;
2284
2285         if (alt != (unsigned)-1) {
2286                 intf = ffs_func_revmap_intf(func, interface);
2287                 if (unlikely(intf < 0))
2288                         return intf;
2289         }
2290
2291         if (ffs->func)
2292                 ffs_func_eps_disable(ffs->func);
2293
2294         if (ffs->state != FFS_ACTIVE)
2295                 return -ENODEV;
2296
2297         if (alt == (unsigned)-1) {
2298                 ffs->func = NULL;
2299                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2300                 return 0;
2301         }
2302
2303         ffs->func = func;
2304         ret = ffs_func_eps_enable(func);
2305         if (likely(ret >= 0))
2306                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2307         return ret;
2308 }
2309
2310 static void ffs_func_disable(struct usb_function *f)
2311 {
2312         ffs_func_set_alt(f, 0, (unsigned)-1);
2313 }
2314
2315 static int ffs_func_setup(struct usb_function *f,
2316                           const struct usb_ctrlrequest *creq)
2317 {
2318         struct ffs_function *func = ffs_func_from_usb(f);
2319         struct ffs_data *ffs = func->ffs;
2320         unsigned long flags;
2321         int ret;
2322
2323         ENTER();
2324
2325         FVDBG("creq->bRequestType = %02x", creq->bRequestType);
2326         FVDBG("creq->bRequest     = %02x", creq->bRequest);
2327         FVDBG("creq->wValue       = %04x", le16_to_cpu(creq->wValue));
2328         FVDBG("creq->wIndex       = %04x", le16_to_cpu(creq->wIndex));
2329         FVDBG("creq->wLength      = %04x", le16_to_cpu(creq->wLength));
2330
2331         /* Most requests directed to interface go throught here
2332          * (notable exceptions are set/get interface) so we need to
2333          * handle them.  All other either handled by composite or
2334          * passed to usb_configuration->setup() (if one is set).  No
2335          * matter, we will handle requests directed to endpoint here
2336          * as well (as it's straightforward) but what to do with any
2337          * other request? */
2338
2339         if (ffs->state != FFS_ACTIVE)
2340                 return -ENODEV;
2341
2342         switch (creq->bRequestType & USB_RECIP_MASK) {
2343         case USB_RECIP_INTERFACE:
2344                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2345                 if (unlikely(ret < 0))
2346                         return ret;
2347                 break;
2348
2349         case USB_RECIP_ENDPOINT:
2350                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2351                 if (unlikely(ret < 0))
2352                         return ret;
2353                 break;
2354
2355         default:
2356                 return -EOPNOTSUPP;
2357         }
2358
2359         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2360         ffs->ev.setup = *creq;
2361         ffs->ev.setup.wIndex = cpu_to_le16(ret);
2362         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2363         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2364
2365         return 0;
2366 }
2367
2368 static void ffs_func_suspend(struct usb_function *f)
2369 {
2370         ENTER();
2371         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2372 }
2373
2374 static void ffs_func_resume(struct usb_function *f)
2375 {
2376         ENTER();
2377         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2378 }
2379
2380
2381
2382 /* Enpoint and interface numbers reverse mapping ****************************/
2383
2384 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2385 {
2386         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2387         return num ? num : -EDOM;
2388 }
2389
2390 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2391 {
2392         short *nums = func->interfaces_nums;
2393         unsigned count = func->ffs->interfaces_count;
2394
2395         for (; count; --count, ++nums) {
2396                 if (*nums >= 0 && *nums == intf)
2397                         return nums - func->interfaces_nums;
2398         }
2399
2400         return -EDOM;
2401 }
2402
2403
2404 /* Misc helper functions ****************************************************/
2405
2406 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2407 {
2408         return nonblock
2409                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2410                 : mutex_lock_interruptible(mutex);
2411 }
2412
2413
2414 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
2415 {
2416         char *data;
2417
2418         if (unlikely(!len))
2419                 return NULL;
2420
2421         data = kmalloc(len, GFP_KERNEL);
2422         if (unlikely(!data))
2423                 return ERR_PTR(-ENOMEM);
2424
2425         if (unlikely(__copy_from_user(data, buf, len))) {
2426                 kfree(data);
2427                 return ERR_PTR(-EFAULT);
2428         }
2429
2430         FVDBG("Buffer from user space:");
2431         ffs_dump_mem("", data, len);
2432
2433         return data;
2434 }