drivers/usb/gadget/f_fs.c

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