drivers/usb/gadget/function/f_fs.c

   1 /*
   2  * f_fs.c -- user mode file system API for USB composite function controllers
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  * Author: Michal Nazarewicz <mina86@mina86.com>
   6  *
   7  * Based on inode.c (GadgetFS) which was:
   8  * Copyright (C) 2003-2004 David Brownell
   9  * Copyright (C) 2003 Agilent Technologies
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  */
  16
  17
  18 /* #define DEBUG */
  19 /* #define VERBOSE_DEBUG */
  20
  21 #include <linux/blkdev.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/export.h>
  24 #include <linux/hid.h>
  25 #include <linux/module.h>
  26 #include <linux/uio.h>
  27 #include <asm/unaligned.h>
  28
  29 #include <linux/usb/composite.h>
  30 #include <linux/usb/functionfs.h>
  31
  32 #include <linux/aio.h>
  33 #include <linux/mmu_context.h>
  34 #include <linux/poll.h>
  35 #include <linux/eventfd.h>
  36
  37 #include "u_fs.h"
  38 #include "u_f.h"
  39 #include "u_os_desc.h"
  40 #include "configfs.h"
  41
  42 #define FUNCTIONFS_MAGIC        0xa647361 /* Chosen by a honest dice roll ;) */
  43
  44 /* Reference counter handling */
  45 static void ffs_data_get(struct ffs_data *ffs);
  46 static void ffs_data_put(struct ffs_data *ffs);
  47 /* Creates new ffs_data object. */
  48 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
  49
  50 /* Opened counter handling. */
  51 static void ffs_data_opened(struct ffs_data *ffs);
  52 static void ffs_data_closed(struct ffs_data *ffs);
  53
  54 /* Called with ffs->mutex held; take over ownership of data. */
  55 static int __must_check
  56 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
  57 static int __must_check
  58 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
  59
  60
  61 /* The function structure ***************************************************/
  62
  63 struct ffs_ep;
  64
  65 struct ffs_function {
  66         struct usb_configuration        *conf;
  67         struct usb_gadget               *gadget;
  68         struct ffs_data                 *ffs;
  69
  70         struct ffs_ep                   *eps;
  71         u8                              eps_revmap[16];
  72         short                           *interfaces_nums;
  73
  74         struct usb_function             function;
  75 };
  76
  77
  78 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
  79 {
  80         return container_of(f, struct ffs_function, function);
  81 }
  82
  83
  84 static inline enum ffs_setup_state
  85 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
  86 {
  87         return (enum ffs_setup_state)
  88                 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
  89 }
  90
  91
  92 static void ffs_func_eps_disable(struct ffs_function *func);
  93 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
  94
  95 static int ffs_func_bind(struct usb_configuration *,
  96                          struct usb_function *);
  97 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
  98 static void ffs_func_disable(struct usb_function *);
  99 static int ffs_func_setup(struct usb_function *,
 100                           const struct usb_ctrlrequest *);
 101 static void ffs_func_suspend(struct usb_function *);
 102 static void ffs_func_resume(struct usb_function *);
 103
 104
 105 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
 106 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
 107
 108
 109 /* The endpoints structures *************************************************/
 110
 111 struct ffs_ep {
 112         struct usb_ep                   *ep;    /* P: ffs->eps_lock */
 113         struct usb_request              *req;   /* P: epfile->mutex */
 114
 115         /* [0]: full speed, [1]: high speed, [2]: super speed */
 116         struct usb_endpoint_descriptor  *descs[3];
 117
 118         u8                              num;
 119
 120         int                             status; /* P: epfile->mutex */
 121 };
 122
 123 struct ffs_epfile {
 124         /* Protects ep->ep and ep->req. */
 125         struct mutex                    mutex;
 126         wait_queue_head_t               wait;
 127
 128         struct ffs_data                 *ffs;
 129         struct ffs_ep                   *ep;    /* P: ffs->eps_lock */
 130
 131         struct dentry                   *dentry;
 132
 133         char                            name[5];
 134
 135         unsigned char                   in;     /* P: ffs->eps_lock */
 136         unsigned char                   isoc;   /* P: ffs->eps_lock */
 137
 138         unsigned char                   _pad;
 139 };
 140
 141 /*  ffs_io_data structure ***************************************************/
 142
 143 struct ffs_io_data {
 144         bool aio;
 145         bool read;
 146
 147         struct kiocb *kiocb;
 148         struct iov_iter data;
 149         const void *to_free;
 150         char *buf;
 151
 152         struct mm_struct *mm;
 153         struct work_struct work;
 154
 155         struct usb_ep *ep;
 156         struct usb_request *req;
 157
 158         struct ffs_data *ffs;
 159 };
 160
 161 struct ffs_desc_helper {
 162         struct ffs_data *ffs;
 163         unsigned interfaces_count;
 164         unsigned eps_count;
 165 };
 166
 167 static int  __must_check ffs_epfiles_create(struct ffs_data *ffs);
 168 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
 169
 170 static struct dentry *
 171 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
 172                    const struct file_operations *fops);
 173
 174 /* Devices management *******************************************************/
 175
 176 DEFINE_MUTEX(ffs_lock);
 177 EXPORT_SYMBOL_GPL(ffs_lock);
 178
 179 static struct ffs_dev *_ffs_find_dev(const char *name);
 180 static struct ffs_dev *_ffs_alloc_dev(void);
 181 static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
 182 static void _ffs_free_dev(struct ffs_dev *dev);
 183 static void *ffs_acquire_dev(const char *dev_name);
 184 static void ffs_release_dev(struct ffs_data *ffs_data);
 185 static int ffs_ready(struct ffs_data *ffs);
 186 static void ffs_closed(struct ffs_data *ffs);
 187
 188 /* Misc helper functions ****************************************************/
 189
 190 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
 191         __attribute__((warn_unused_result, nonnull));
 192 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
 193         __attribute__((warn_unused_result, nonnull));
 194
 195
 196 /* Control file aka ep0 *****************************************************/
 197
 198 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
 199 {
 200         struct ffs_data *ffs = req->context;
 201
 202         complete_all(&ffs->ep0req_completion);
 203 }
 204
 205 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 206 {
 207         struct usb_request *req = ffs->ep0req;
 208         int ret;
 209
 210         req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
 211
 212         spin_unlock_irq(&ffs->ev.waitq.lock);
 213
 214         req->buf      = data;
 215         req->length   = len;
 216
 217         /*
 218          * UDC layer requires to provide a buffer even for ZLP, but should
 219          * not use it at all. Let's provide some poisoned pointer to catch
 220          * possible bug in the driver.
 221          */
 222         if (req->buf == NULL)
 223                 req->buf = (void *)0xDEADBABE;
 224
 225         reinit_completion(&ffs->ep0req_completion);
 226
 227         ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
 228         if (unlikely(ret < 0))
 229                 return ret;
 230
 231         ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
 232         if (unlikely(ret)) {
 233                 usb_ep_dequeue(ffs->gadget->ep0, req);
 234                 return -EINTR;
 235         }
 236
 237         ffs->setup_state = FFS_NO_SETUP;
 238         return req->status ? req->status : req->actual;
 239 }
 240
 241 static int __ffs_ep0_stall(struct ffs_data *ffs)
 242 {
 243         if (ffs->ev.can_stall) {
 244                 pr_vdebug("ep0 stall\n");
 245                 usb_ep_set_halt(ffs->gadget->ep0);
 246                 ffs->setup_state = FFS_NO_SETUP;
 247                 return -EL2HLT;
 248         } else {
 249                 pr_debug("bogus ep0 stall!\n");
 250                 return -ESRCH;
 251         }
 252 }
 253
 254 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
 255                              size_t len, loff_t *ptr)
 256 {
 257         struct ffs_data *ffs = file->private_data;
 258         ssize_t ret;
 259         char *data;
 260
 261         ENTER();
 262
 263         /* Fast check if setup was canceled */
 264         if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
 265                 return -EIDRM;
 266
 267         /* Acquire mutex */
 268         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 269         if (unlikely(ret < 0))
 270                 return ret;
 271
 272         /* Check state */
 273         switch (ffs->state) {
 274         case FFS_READ_DESCRIPTORS:
 275         case FFS_READ_STRINGS:
 276                 /* Copy data */
 277                 if (unlikely(len < 16)) {
 278                         ret = -EINVAL;
 279                         break;
 280                 }
 281
 282                 data = ffs_prepare_buffer(buf, len);
 283                 if (IS_ERR(data)) {
 284                         ret = PTR_ERR(data);
 285                         break;
 286                 }
 287
 288                 /* Handle data */
 289                 if (ffs->state == FFS_READ_DESCRIPTORS) {
 290                         pr_info("read descriptors\n");
 291                         ret = __ffs_data_got_descs(ffs, data, len);
 292                         if (unlikely(ret < 0))
 293                                 break;
 294
 295                         ffs->state = FFS_READ_STRINGS;
 296                         ret = len;
 297                 } else {
 298                         pr_info("read strings\n");
 299                         ret = __ffs_data_got_strings(ffs, data, len);
 300                         if (unlikely(ret < 0))
 301                                 break;
 302
 303                         ret = ffs_epfiles_create(ffs);
 304                         if (unlikely(ret)) {
 305                                 ffs->state = FFS_CLOSING;
 306                                 break;
 307                         }
 308
 309                         ffs->state = FFS_ACTIVE;
 310                         mutex_unlock(&ffs->mutex);
 311
 312                         ret = ffs_ready(ffs);
 313                         if (unlikely(ret < 0)) {
 314                                 ffs->state = FFS_CLOSING;
 315                                 return ret;
 316                         }
 317
 318                         return len;
 319                 }
 320                 break;
 321
 322         case FFS_ACTIVE:
 323                 data = NULL;
 324                 /*
 325                  * We're called from user space, we can use _irq
 326                  * rather then _irqsave
 327                  */
 328                 spin_lock_irq(&ffs->ev.waitq.lock);
 329                 switch (ffs_setup_state_clear_cancelled(ffs)) {
 330                 case FFS_SETUP_CANCELLED:
 331                         ret = -EIDRM;
 332                         goto done_spin;
 333
 334                 case FFS_NO_SETUP:
 335                         ret = -ESRCH;
 336                         goto done_spin;
 337
 338                 case FFS_SETUP_PENDING:
 339                         break;
 340                 }
 341
 342                 /* FFS_SETUP_PENDING */
 343                 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
 344                         spin_unlock_irq(&ffs->ev.waitq.lock);
 345                         ret = __ffs_ep0_stall(ffs);
 346                         break;
 347                 }
 348
 349                 /* FFS_SETUP_PENDING and not stall */
 350                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 351
 352                 spin_unlock_irq(&ffs->ev.waitq.lock);
 353
 354                 data = ffs_prepare_buffer(buf, len);
 355                 if (IS_ERR(data)) {
 356                         ret = PTR_ERR(data);
 357                         break;
 358                 }
 359
 360                 spin_lock_irq(&ffs->ev.waitq.lock);
 361
 362                 /*
 363                  * We are guaranteed to be still in FFS_ACTIVE state
 364                  * but the state of setup could have changed from
 365                  * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
 366                  * to check for that.  If that happened we copied data
 367                  * from user space in vain but it's unlikely.
 368                  *
 369                  * For sure we are not in FFS_NO_SETUP since this is
 370                  * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
 371                  * transition can be performed and it's protected by
 372                  * mutex.
 373                  */
 374                 if (ffs_setup_state_clear_cancelled(ffs) ==
 375                     FFS_SETUP_CANCELLED) {
 376                         ret = -EIDRM;
 377 done_spin:
 378                         spin_unlock_irq(&ffs->ev.waitq.lock);
 379                 } else {
 380                         /* unlocks spinlock */
 381                         ret = __ffs_ep0_queue_wait(ffs, data, len);
 382                 }
 383                 kfree(data);
 384                 break;
 385
 386         default:
 387                 ret = -EBADFD;
 388                 break;
 389         }
 390
 391         mutex_unlock(&ffs->mutex);
 392         return ret;
 393 }
 394
 395 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
 396 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
 397                                      size_t n)
 398 {
 399         /*
 400          * n cannot be bigger than ffs->ev.count, which cannot be bigger than
 401          * size of ffs->ev.types array (which is four) so that's how much space
 402          * we reserve.
 403          */
 404         struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
 405         const size_t size = n * sizeof *events;
 406         unsigned i = 0;
 407
 408         memset(events, 0, size);
 409
 410         do {
 411                 events[i].type = ffs->ev.types[i];
 412                 if (events[i].type == FUNCTIONFS_SETUP) {
 413                         events[i].u.setup = ffs->ev.setup;
 414                         ffs->setup_state = FFS_SETUP_PENDING;
 415                 }
 416         } while (++i < n);
 417
 418         ffs->ev.count -= n;
 419         if (ffs->ev.count)
 420                 memmove(ffs->ev.types, ffs->ev.types + n,
 421                         ffs->ev.count * sizeof *ffs->ev.types);
 422
 423         spin_unlock_irq(&ffs->ev.waitq.lock);
 424         mutex_unlock(&ffs->mutex);
 425
 426         return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
 427 }
 428
 429 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
 430                             size_t len, loff_t *ptr)
 431 {
 432         struct ffs_data *ffs = file->private_data;
 433         char *data = NULL;
 434         size_t n;
 435         int ret;
 436
 437         ENTER();
 438
 439         /* Fast check if setup was canceled */
 440         if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
 441                 return -EIDRM;
 442
 443         /* Acquire mutex */
 444         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 445         if (unlikely(ret < 0))
 446                 return ret;
 447
 448         /* Check state */
 449         if (ffs->state != FFS_ACTIVE) {
 450                 ret = -EBADFD;
 451                 goto done_mutex;
 452         }
 453
 454         /*
 455          * We're called from user space, we can use _irq rather then
 456          * _irqsave
 457          */
 458         spin_lock_irq(&ffs->ev.waitq.lock);
 459
 460         switch (ffs_setup_state_clear_cancelled(ffs)) {
 461         case FFS_SETUP_CANCELLED:
 462                 ret = -EIDRM;
 463                 break;
 464
 465         case FFS_NO_SETUP:
 466                 n = len / sizeof(struct usb_functionfs_event);
 467                 if (unlikely(!n)) {
 468                         ret = -EINVAL;
 469                         break;
 470                 }
 471
 472                 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
 473                         ret = -EAGAIN;
 474                         break;
 475                 }
 476
 477                 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
 478                                                         ffs->ev.count)) {
 479                         ret = -EINTR;
 480                         break;
 481                 }
 482
 483                 return __ffs_ep0_read_events(ffs, buf,
 484                                              min(n, (size_t)ffs->ev.count));
 485
 486         case FFS_SETUP_PENDING:
 487                 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
 488                         spin_unlock_irq(&ffs->ev.waitq.lock);
 489                         ret = __ffs_ep0_stall(ffs);
 490                         goto done_mutex;
 491                 }
 492
 493                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
 494
 495                 spin_unlock_irq(&ffs->ev.waitq.lock);
 496
 497                 if (likely(len)) {
 498                         data = kmalloc(len, GFP_KERNEL);
 499                         if (unlikely(!data)) {
 500                                 ret = -ENOMEM;
 501                                 goto done_mutex;
 502                         }
 503                 }
 504
 505                 spin_lock_irq(&ffs->ev.waitq.lock);
 506
 507                 /* See ffs_ep0_write() */
 508                 if (ffs_setup_state_clear_cancelled(ffs) ==
 509                     FFS_SETUP_CANCELLED) {
 510                         ret = -EIDRM;
 511                         break;
 512                 }
 513
 514                 /* unlocks spinlock */
 515                 ret = __ffs_ep0_queue_wait(ffs, data, len);
 516                 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
 517                         ret = -EFAULT;
 518                 goto done_mutex;
 519
 520         default:
 521                 ret = -EBADFD;
 522                 break;
 523         }
 524
 525         spin_unlock_irq(&ffs->ev.waitq.lock);
 526 done_mutex:
 527         mutex_unlock(&ffs->mutex);
 528         kfree(data);
 529         return ret;
 530 }
 531
 532 static int ffs_ep0_open(struct inode *inode, struct file *file)
 533 {
 534         struct ffs_data *ffs = inode->i_private;
 535
 536         ENTER();
 537
 538         if (unlikely(ffs->state == FFS_CLOSING))
 539                 return -EBUSY;
 540
 541         file->private_data = ffs;
 542         ffs_data_opened(ffs);
 543
 544         return 0;
 545 }
 546
 547 static int ffs_ep0_release(struct inode *inode, struct file *file)
 548 {
 549         struct ffs_data *ffs = file->private_data;
 550
 551         ENTER();
 552
 553         ffs_data_closed(ffs);
 554
 555         return 0;
 556 }
 557
 558 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
 559 {
 560         struct ffs_data *ffs = file->private_data;
 561         struct usb_gadget *gadget = ffs->gadget;
 562         long ret;
 563
 564         ENTER();
 565
 566         if (code == FUNCTIONFS_INTERFACE_REVMAP) {
 567                 struct ffs_function *func = ffs->func;
 568                 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
 569         } else if (gadget && gadget->ops->ioctl) {
 570                 ret = gadget->ops->ioctl(gadget, code, value);
 571         } else {
 572                 ret = -ENOTTY;
 573         }
 574
 575         return ret;
 576 }
 577
 578 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
 579 {
 580         struct ffs_data *ffs = file->private_data;
 581         unsigned int mask = POLLWRNORM;
 582         int ret;
 583
 584         poll_wait(file, &ffs->ev.waitq, wait);
 585
 586         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
 587         if (unlikely(ret < 0))
 588                 return mask;
 589
 590         switch (ffs->state) {
 591         case FFS_READ_DESCRIPTORS:
 592         case FFS_READ_STRINGS:
 593                 mask |= POLLOUT;
 594                 break;
 595
 596         case FFS_ACTIVE:
 597                 switch (ffs->setup_state) {
 598                 case FFS_NO_SETUP:
 599                         if (ffs->ev.count)
 600                                 mask |= POLLIN;
 601                         break;
 602
 603                 case FFS_SETUP_PENDING:
 604                 case FFS_SETUP_CANCELLED:
 605                         mask |= (POLLIN | POLLOUT);
 606                         break;
 607                 }
 608         case FFS_CLOSING:
 609                 break;
 610         case FFS_DEACTIVATED:
 611                 break;
 612         }
 613
 614         mutex_unlock(&ffs->mutex);
 615
 616         return mask;
 617 }
 618
 619 static const struct file_operations ffs_ep0_operations = {
 620         .llseek =       no_llseek,
 621
 622         .open =         ffs_ep0_open,
 623         .write =        ffs_ep0_write,
 624         .read =         ffs_ep0_read,
 625         .release =      ffs_ep0_release,
 626         .unlocked_ioctl =       ffs_ep0_ioctl,
 627         .poll =         ffs_ep0_poll,
 628 };
 629
 630
 631 /* "Normal" endpoints operations ********************************************/
 632
 633 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
 634 {
 635         ENTER();
 636         if (likely(req->context)) {
 637                 struct ffs_ep *ep = _ep->driver_data;
 638                 ep->status = req->status ? req->status : req->actual;
 639                 complete(req->context);
 640         }
 641 }
 642
 643 static void ffs_user_copy_worker(struct work_struct *work)
 644 {
 645         struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
 646                                                    work);
 647         int ret = io_data->req->status ? io_data->req->status :
 648                                          io_data->req->actual;
 649         bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
 650
 651         if (io_data->read && ret > 0) {
 652                 mm_segment_t oldfs = get_fs();
 653
 654                 set_fs(USER_DS);
 655                 use_mm(io_data->mm);
 656                 ret = copy_to_iter(io_data->buf, ret, &io_data->data);
 657                 if (ret != io_data->req->actual && iov_iter_count(&io_data->data))
 658                         ret = -EFAULT;
 659                 unuse_mm(io_data->mm);
 660                 set_fs(oldfs);
 661         }
 662
 663         io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
 664
 665         if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
 666                 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
 667
 668         usb_ep_free_request(io_data->ep, io_data->req);
 669
 670         if (io_data->read)
 671                 kfree(io_data->to_free);
 672         kfree(io_data->buf);
 673         kfree(io_data);
 674 }
 675
 676 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
 677                                          struct usb_request *req)
 678 {
 679         struct ffs_io_data *io_data = req->context;
 680
 681         ENTER();
 682
 683         INIT_WORK(&io_data->work, ffs_user_copy_worker);
 684         schedule_work(&io_data->work);
 685 }
 686
 687 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
 688 {
 689         struct ffs_epfile *epfile = file->private_data;
 690         struct ffs_ep *ep;
 691         char *data = NULL;
 692         ssize_t ret, data_len = -EINVAL;
 693         int halt;
 694
 695         /* Are we still active? */
 696         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
 697                 ret = -ENODEV;
 698                 goto error;
 699         }
 700
 701         /* Wait for endpoint to be enabled */
 702         ep = epfile->ep;
 703         if (!ep) {
 704                 if (file->f_flags & O_NONBLOCK) {
 705                         ret = -EAGAIN;
 706                         goto error;
 707                 }
 708
 709                 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
 710                 if (ret) {
 711                         ret = -EINTR;
 712                         goto error;
 713                 }
 714         }
 715
 716         /* Do we halt? */
 717         halt = (!io_data->read == !epfile->in);
 718         if (halt && epfile->isoc) {
 719                 ret = -EINVAL;
 720                 goto error;
 721         }
 722
 723         /* Allocate & copy */
 724         if (!halt) {
 725                 /*
 726                  * if we _do_ wait above, the epfile->ffs->gadget might be NULL
 727                  * before the waiting completes, so do not assign to 'gadget' earlier
 728                  */
 729                 struct usb_gadget *gadget = epfile->ffs->gadget;
 730                 size_t copied;
 731
 732                 spin_lock_irq(&epfile->ffs->eps_lock);
 733                 /* In the meantime, endpoint got disabled or changed. */
 734                 if (epfile->ep != ep) {
 735                         spin_unlock_irq(&epfile->ffs->eps_lock);
 736                         return -ESHUTDOWN;
 737                 }
 738                 data_len = iov_iter_count(&io_data->data);
 739                 /*
 740                  * Controller may require buffer size to be aligned to
 741                  * maxpacketsize of an out endpoint.
 742                  */
 743                 if (io_data->read)
 744                         data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
 745                 spin_unlock_irq(&epfile->ffs->eps_lock);
 746
 747                 data = kmalloc(data_len, GFP_KERNEL);
 748                 if (unlikely(!data))
 749                         return -ENOMEM;
 750                 if (!io_data->read) {
 751                         copied = copy_from_iter(data, data_len, &io_data->data);
 752                         if (copied != data_len) {
 753                                 ret = -EFAULT;
 754                                 goto error;
 755                         }
 756                 }
 757         }
 758
 759         /* We will be using request */
 760         ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
 761         if (unlikely(ret))
 762                 goto error;
 763
 764         spin_lock_irq(&epfile->ffs->eps_lock);
 765
 766         if (epfile->ep != ep) {
 767                 /* In the meantime, endpoint got disabled or changed. */
 768                 ret = -ESHUTDOWN;
 769                 spin_unlock_irq(&epfile->ffs->eps_lock);
 770         } else if (halt) {
 771                 /* Halt */
 772                 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
 773                         usb_ep_set_halt(ep->ep);
 774                 spin_unlock_irq(&epfile->ffs->eps_lock);
 775                 ret = -EBADMSG;
 776         } else {
 777                 /* Fire the request */
 778                 struct usb_request *req;
 779
 780                 /*
 781                  * Sanity Check: even though data_len can't be used
 782                  * uninitialized at the time I write this comment, some
 783                  * compilers complain about this situation.
 784                  * In order to keep the code clean from warnings, data_len is
 785                  * being initialized to -EINVAL during its declaration, which
 786                  * means we can't rely on compiler anymore to warn no future
 787                  * changes won't result in data_len being used uninitialized.
 788                  * For such reason, we're adding this redundant sanity check
 789                  * here.
 790                  */
 791                 if (unlikely(data_len == -EINVAL)) {
 792                         WARN(1, "%s: data_len == -EINVAL\n", __func__);
 793                         ret = -EINVAL;
 794                         goto error_lock;
 795                 }
 796
 797                 if (io_data->aio) {
 798                         req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC);
 799                         if (unlikely(!req))
 800                                 goto error_lock;
 801
 802                         req->buf      = data;
 803                         req->length   = data_len;
 804
 805                         io_data->buf = data;
 806                         io_data->ep = ep->ep;
 807                         io_data->req = req;
 808                         io_data->ffs = epfile->ffs;
 809
 810                         req->context  = io_data;
 811                         req->complete = ffs_epfile_async_io_complete;
 812
 813                         ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 814                         if (unlikely(ret)) {
 815                                 io_data->req = NULL;
 816                                 usb_ep_free_request(ep->ep, req);
 817                                 goto error_lock;
 818                         }
 819                         ret = -EIOCBQUEUED;
 820
 821                         spin_unlock_irq(&epfile->ffs->eps_lock);
 822                 } else {
 823                         DECLARE_COMPLETION_ONSTACK(done);
 824
 825                         req = ep->req;
 826                         req->buf      = data;
 827                         req->length   = data_len;
 828
 829                         req->context  = &done;
 830                         req->complete = ffs_epfile_io_complete;
 831
 832                         ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
 833
 834                         spin_unlock_irq(&epfile->ffs->eps_lock);
 835
 836                         if (unlikely(ret < 0)) {
 837                                 /* nop */
 838                         } else if (unlikely(
 839                                    wait_for_completion_interruptible(&done))) {
 840                                 ret = -EINTR;
 841                                 usb_ep_dequeue(ep->ep, req);
 842                         } else {
 843                                 /*
 844                                  * XXX We may end up silently droping data
 845                                  * here.  Since data_len (i.e. req->length) may
 846                                  * be bigger than len (after being rounded up
 847                                  * to maxpacketsize), we may end up with more
 848                                  * data then user space has space for.
 849                                  */
 850                                 ret = ep->status;
 851                                 if (io_data->read && ret > 0) {
 852                                         ret = copy_to_iter(data, ret, &io_data->data);
 853                                         if (!ret)
 854                                                 ret = -EFAULT;
 855                                 }
 856                         }
 857                         kfree(data);
 858                 }
 859         }
 860
 861         mutex_unlock(&epfile->mutex);
 862         return ret;
 863
 864 error_lock:
 865         spin_unlock_irq(&epfile->ffs->eps_lock);
 866         mutex_unlock(&epfile->mutex);
 867 error:
 868         kfree(data);
 869         return ret;
 870 }
 871
 872 static int
 873 ffs_epfile_open(struct inode *inode, struct file *file)
 874 {
 875         struct ffs_epfile *epfile = inode->i_private;
 876
 877         ENTER();
 878
 879         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
 880                 return -ENODEV;
 881
 882         file->private_data = epfile;
 883         ffs_data_opened(epfile->ffs);
 884
 885         return 0;
 886 }
 887
 888 static int ffs_aio_cancel(struct kiocb *kiocb)
 889 {
 890         struct ffs_io_data *io_data = kiocb->private;
 891         struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
 892         unsigned long flags;
 893         int value;
 894
 895         ENTER();
 896
 897         spin_lock_irqsave(&epfile->ffs->eps_lock, flags);
 898
 899         if (likely(io_data && io_data->ep && io_data->req))
 900                 value = usb_ep_dequeue(io_data->ep, io_data->req);
 901         else
 902                 value = -EINVAL;
 903
 904         spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);
 905
 906         return value;
 907 }
 908
 909 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
 910 {
 911         struct ffs_io_data io_data, *p = &io_data;
 912         ssize_t res;
 913
 914         ENTER();
 915
 916         if (!is_sync_kiocb(kiocb)) {
 917                 p = kzalloc(sizeof(io_data), GFP_KERNEL);
 918                 if (unlikely(!p))
 919                         return -ENOMEM;
 920                 p->aio = true;
 921         } else {
 922                 memset(p, 0, sizeof(*p));
 923                 p->aio = false;
 924         }
 925
 926         p->read = false;
 927         p->kiocb = kiocb;
 928         p->data = *from;
 929         p->mm = current->mm;
 930
 931         kiocb->private = p;
 932
 933         if (p->aio)
 934                 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
 935
 936         res = ffs_epfile_io(kiocb->ki_filp, p);
 937         if (res == -EIOCBQUEUED)
 938                 return res;
 939         if (p->aio)
 940                 kfree(p);
 941         else
 942                 *from = p->data;
 943         return res;
 944 }
 945
 946 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
 947 {
 948         struct ffs_io_data io_data, *p = &io_data;
 949         ssize_t res;
 950
 951         ENTER();
 952
 953         if (!is_sync_kiocb(kiocb)) {
 954                 p = kzalloc(sizeof(io_data), GFP_KERNEL);
 955                 if (unlikely(!p))
 956                         return -ENOMEM;
 957                 p->aio = true;
 958         } else {
 959                 memset(p, 0, sizeof(*p));
 960                 p->aio = false;
 961         }
 962
 963         p->read = true;
 964         p->kiocb = kiocb;
 965         if (p->aio) {
 966                 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
 967                 if (!p->to_free) {
 968                         kfree(p);
 969                         return -ENOMEM;
 970                 }
 971         } else {
 972                 p->data = *to;
 973                 p->to_free = NULL;
 974         }
 975         p->mm = current->mm;
 976
 977         kiocb->private = p;
 978
 979         if (p->aio)
 980                 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
 981
 982         res = ffs_epfile_io(kiocb->ki_filp, p);
 983         if (res == -EIOCBQUEUED)
 984                 return res;
 985
 986         if (p->aio) {
 987                 kfree(p->to_free);
 988                 kfree(p);
 989         } else {
 990                 *to = p->data;
 991         }
 992         return res;
 993 }
 994
 995 static int
 996 ffs_epfile_release(struct inode *inode, struct file *file)
 997 {
 998         struct ffs_epfile *epfile = inode->i_private;
 999
1000         ENTER();
1001
1002         ffs_data_closed(epfile->ffs);
1003
1004         return 0;
1005 }
1006
1007 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1008                              unsigned long value)
1009 {
1010         struct ffs_epfile *epfile = file->private_data;
1011         int ret;
1012
1013         ENTER();
1014
1015         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1016                 return -ENODEV;
1017
1018         spin_lock_irq(&epfile->ffs->eps_lock);
1019         if (likely(epfile->ep)) {
1020                 switch (code) {
1021                 case FUNCTIONFS_FIFO_STATUS:
1022                         ret = usb_ep_fifo_status(epfile->ep->ep);
1023                         break;
1024                 case FUNCTIONFS_FIFO_FLUSH:
1025                         usb_ep_fifo_flush(epfile->ep->ep);
1026                         ret = 0;
1027                         break;
1028                 case FUNCTIONFS_CLEAR_HALT:
1029                         ret = usb_ep_clear_halt(epfile->ep->ep);
1030                         break;
1031                 case FUNCTIONFS_ENDPOINT_REVMAP:
1032                         ret = epfile->ep->num;
1033                         break;
1034                 case FUNCTIONFS_ENDPOINT_DESC:
1035                 {
1036                         int desc_idx;
1037                         struct usb_endpoint_descriptor desc1, *desc;
1038
1039                         switch (epfile->ffs->gadget->speed) {
1040                         case USB_SPEED_SUPER:
1041                                 desc_idx = 2;
1042                                 break;
1043                         case USB_SPEED_HIGH:
1044                                 desc_idx = 1;
1045                                 break;
1046                         default:
1047                                 desc_idx = 0;
1048                         }
1049
1050                         desc = epfile->ep->descs[desc_idx];
1051                         memcpy(&desc1, desc, desc->bLength);
1052
1053                         spin_unlock_irq(&epfile->ffs->eps_lock);
1054                         ret = copy_to_user((void *)value, &desc1, desc1.bLength);
1055                         if (ret)
1056                                 ret = -EFAULT;
1057                         return ret;
1058                 }
1059                 default:
1060                         ret = -ENOTTY;
1061                 }
1062         } else {
1063                 ret = -ENODEV;
1064         }
1065         spin_unlock_irq(&epfile->ffs->eps_lock);
1066
1067         return ret;
1068 }
1069
1070 static const struct file_operations ffs_epfile_operations = {
1071         .llseek =       no_llseek,
1072
1073         .open =         ffs_epfile_open,
1074         .write_iter =   ffs_epfile_write_iter,
1075         .read_iter =    ffs_epfile_read_iter,
1076         .release =      ffs_epfile_release,
1077         .unlocked_ioctl =       ffs_epfile_ioctl,
1078 };
1079
1080
1081 /* File system and super block operations ***********************************/
1082
1083 /*
1084  * Mounting the file system creates a controller file, used first for
1085  * function configuration then later for event monitoring.
1086  */
1087
1088 static struct inode *__must_check
1089 ffs_sb_make_inode(struct super_block *sb, void *data,
1090                   const struct file_operations *fops,
1091                   const struct inode_operations *iops,
1092                   struct ffs_file_perms *perms)
1093 {
1094         struct inode *inode;
1095
1096         ENTER();
1097
1098         inode = new_inode(sb);
1099
1100         if (likely(inode)) {
1101                 struct timespec current_time = CURRENT_TIME;
1102
1103                 inode->i_ino     = get_next_ino();
1104                 inode->i_mode    = perms->mode;
1105                 inode->i_uid     = perms->uid;
1106                 inode->i_gid     = perms->gid;
1107                 inode->i_atime   = current_time;
1108                 inode->i_mtime   = current_time;
1109                 inode->i_ctime   = current_time;
1110                 inode->i_private = data;
1111                 if (fops)
1112                         inode->i_fop = fops;
1113                 if (iops)
1114                         inode->i_op  = iops;
1115         }
1116
1117         return inode;
1118 }
1119
1120 /* Create "regular" file */
1121 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1122                                         const char *name, void *data,
1123                                         const struct file_operations *fops)
1124 {
1125         struct ffs_data *ffs = sb->s_fs_info;
1126         struct dentry   *dentry;
1127         struct inode    *inode;
1128
1129         ENTER();
1130
1131         dentry = d_alloc_name(sb->s_root, name);
1132         if (unlikely(!dentry))
1133                 return NULL;
1134
1135         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1136         if (unlikely(!inode)) {
1137                 dput(dentry);
1138                 return NULL;
1139         }
1140
1141         d_add(dentry, inode);
1142         return dentry;
1143 }
1144
1145 /* Super block */
1146 static const struct super_operations ffs_sb_operations = {
1147         .statfs =       simple_statfs,
1148         .drop_inode =   generic_delete_inode,
1149 };
1150
1151 struct ffs_sb_fill_data {
1152         struct ffs_file_perms perms;
1153         umode_t root_mode;
1154         const char *dev_name;
1155         bool no_disconnect;
1156         struct ffs_data *ffs_data;
1157 };
1158
1159 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1160 {
1161         struct ffs_sb_fill_data *data = _data;
1162         struct inode    *inode;
1163         struct ffs_data *ffs = data->ffs_data;
1164
1165         ENTER();
1166
1167         ffs->sb              = sb;
1168         data->ffs_data       = NULL;
1169         sb->s_fs_info        = ffs;
1170         sb->s_blocksize      = PAGE_CACHE_SIZE;
1171         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1172         sb->s_magic          = FUNCTIONFS_MAGIC;
1173         sb->s_op             = &ffs_sb_operations;
1174         sb->s_time_gran      = 1;
1175
1176         /* Root inode */
1177         data->perms.mode = data->root_mode;
1178         inode = ffs_sb_make_inode(sb, NULL,
1179                                   &simple_dir_operations,
1180                                   &simple_dir_inode_operations,
1181                                   &data->perms);
1182         sb->s_root = d_make_root(inode);
1183         if (unlikely(!sb->s_root))
1184                 return -ENOMEM;
1185
1186         /* EP0 file */
1187         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1188                                          &ffs_ep0_operations)))
1189                 return -ENOMEM;
1190
1191         return 0;
1192 }
1193
1194 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1195 {
1196         ENTER();
1197
1198         if (!opts || !*opts)
1199                 return 0;
1200
1201         for (;;) {
1202                 unsigned long value;
1203                 char *eq, *comma;
1204
1205                 /* Option limit */
1206                 comma = strchr(opts, ',');
1207                 if (comma)
1208                         *comma = 0;
1209
1210                 /* Value limit */
1211                 eq = strchr(opts, '=');
1212                 if (unlikely(!eq)) {
1213                         pr_err("'=' missing in %s\n", opts);
1214                         return -EINVAL;
1215                 }
1216                 *eq = 0;
1217
1218                 /* Parse value */
1219                 if (kstrtoul(eq + 1, 0, &value)) {
1220                         pr_err("%s: invalid value: %s\n", opts, eq + 1);
1221                         return -EINVAL;
1222                 }
1223
1224                 /* Interpret option */
1225                 switch (eq - opts) {
1226                 case 13:
1227                         if (!memcmp(opts, "no_disconnect", 13))
1228                                 data->no_disconnect = !!value;
1229                         else
1230                                 goto invalid;
1231                         break;
1232                 case 5:
1233                         if (!memcmp(opts, "rmode", 5))
1234                                 data->root_mode  = (value & 0555) | S_IFDIR;
1235                         else if (!memcmp(opts, "fmode", 5))
1236                                 data->perms.mode = (value & 0666) | S_IFREG;
1237                         else
1238                                 goto invalid;
1239                         break;
1240
1241                 case 4:
1242                         if (!memcmp(opts, "mode", 4)) {
1243                                 data->root_mode  = (value & 0555) | S_IFDIR;
1244                                 data->perms.mode = (value & 0666) | S_IFREG;
1245                         } else {
1246                                 goto invalid;
1247                         }
1248                         break;
1249
1250                 case 3:
1251                         if (!memcmp(opts, "uid", 3)) {
1252                                 data->perms.uid = make_kuid(current_user_ns(), value);
1253                                 if (!uid_valid(data->perms.uid)) {
1254                                         pr_err("%s: unmapped value: %lu\n", opts, value);
1255                                         return -EINVAL;
1256                                 }
1257                         } else if (!memcmp(opts, "gid", 3)) {
1258                                 data->perms.gid = make_kgid(current_user_ns(), value);
1259                                 if (!gid_valid(data->perms.gid)) {
1260                                         pr_err("%s: unmapped value: %lu\n", opts, value);
1261                                         return -EINVAL;
1262                                 }
1263                         } else {
1264                                 goto invalid;
1265                         }
1266                         break;
1267
1268                 default:
1269 invalid:
1270                         pr_err("%s: invalid option\n", opts);
1271                         return -EINVAL;
1272                 }
1273
1274                 /* Next iteration */
1275                 if (!comma)
1276                         break;
1277                 opts = comma + 1;
1278         }
1279
1280         return 0;
1281 }
1282
1283 /* "mount -t functionfs dev_name /dev/function" ends up here */
1284
1285 static struct dentry *
1286 ffs_fs_mount(struct file_system_type *t, int flags,
1287               const char *dev_name, void *opts)
1288 {
1289         struct ffs_sb_fill_data data = {
1290                 .perms = {
1291                         .mode = S_IFREG | 0600,
1292                         .uid = GLOBAL_ROOT_UID,
1293                         .gid = GLOBAL_ROOT_GID,
1294                 },
1295                 .root_mode = S_IFDIR | 0500,
1296                 .no_disconnect = false,
1297         };
1298         struct dentry *rv;
1299         int ret;
1300         void *ffs_dev;
1301         struct ffs_data *ffs;
1302
1303         ENTER();
1304
1305         ret = ffs_fs_parse_opts(&data, opts);
1306         if (unlikely(ret < 0))
1307                 return ERR_PTR(ret);
1308
1309         ffs = ffs_data_new();
1310         if (unlikely(!ffs))
1311                 return ERR_PTR(-ENOMEM);
1312         ffs->file_perms = data.perms;
1313         ffs->no_disconnect = data.no_disconnect;
1314
1315         ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1316         if (unlikely(!ffs->dev_name)) {
1317                 ffs_data_put(ffs);
1318                 return ERR_PTR(-ENOMEM);
1319         }
1320
1321         ffs_dev = ffs_acquire_dev(dev_name);
1322         if (IS_ERR(ffs_dev)) {
1323                 ffs_data_put(ffs);
1324                 return ERR_CAST(ffs_dev);
1325         }
1326         ffs->private_data = ffs_dev;
1327         data.ffs_data = ffs;
1328
1329         rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1330         if (IS_ERR(rv) && data.ffs_data) {
1331                 ffs_release_dev(data.ffs_data);
1332                 ffs_data_put(data.ffs_data);
1333         }
1334         return rv;
1335 }
1336
1337 static void
1338 ffs_fs_kill_sb(struct super_block *sb)
1339 {
1340         ENTER();
1341
1342         kill_litter_super(sb);
1343         if (sb->s_fs_info) {
1344                 ffs_release_dev(sb->s_fs_info);
1345                 ffs_data_closed(sb->s_fs_info);
1346         }
1347 }
1348
1349 static struct file_system_type ffs_fs_type = {
1350         .owner          = THIS_MODULE,
1351         .name           = "functionfs",
1352         .mount          = ffs_fs_mount,
1353         .kill_sb        = ffs_fs_kill_sb,
1354 };
1355 MODULE_ALIAS_FS("functionfs");
1356
1357
1358 /* Driver's main init/cleanup functions *************************************/
1359
1360 static int functionfs_init(void)
1361 {
1362         int ret;
1363
1364         ENTER();
1365
1366         ret = register_filesystem(&ffs_fs_type);
1367         if (likely(!ret))
1368                 pr_info("file system registered\n");
1369         else
1370                 pr_err("failed registering file system (%d)\n", ret);
1371
1372         return ret;
1373 }
1374
1375 static void functionfs_cleanup(void)
1376 {
1377         ENTER();
1378
1379         pr_info("unloading\n");
1380         unregister_filesystem(&ffs_fs_type);
1381 }
1382
1383
1384 /* ffs_data and ffs_function construction and destruction code **************/
1385
1386 static void ffs_data_clear(struct ffs_data *ffs);
1387 static void ffs_data_reset(struct ffs_data *ffs);
1388
1389 static void ffs_data_get(struct ffs_data *ffs)
1390 {
1391         ENTER();
1392
1393         atomic_inc(&ffs->ref);
1394 }
1395
1396 static void ffs_data_opened(struct ffs_data *ffs)
1397 {
1398         ENTER();
1399
1400         atomic_inc(&ffs->ref);
1401         if (atomic_add_return(1, &ffs->opened) == 1 &&
1402                         ffs->state == FFS_DEACTIVATED) {
1403                 ffs->state = FFS_CLOSING;
1404                 ffs_data_reset(ffs);
1405         }
1406 }
1407
1408 static void ffs_data_put(struct ffs_data *ffs)
1409 {
1410         ENTER();
1411
1412         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1413                 pr_info("%s(): freeing\n", __func__);
1414                 ffs_data_clear(ffs);
1415                 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1416                        waitqueue_active(&ffs->ep0req_completion.wait));
1417                 kfree(ffs->dev_name);
1418                 kfree(ffs);
1419         }
1420 }
1421
1422 static void ffs_data_closed(struct ffs_data *ffs)
1423 {
1424         ENTER();
1425
1426         if (atomic_dec_and_test(&ffs->opened)) {
1427                 if (ffs->no_disconnect) {
1428                         ffs->state = FFS_DEACTIVATED;
1429                         if (ffs->epfiles) {
1430                                 ffs_epfiles_destroy(ffs->epfiles,
1431                                                    ffs->eps_count);
1432                                 ffs->epfiles = NULL;
1433                         }
1434                         if (ffs->setup_state == FFS_SETUP_PENDING)
1435                                 __ffs_ep0_stall(ffs);
1436                 } else {
1437                         ffs->state = FFS_CLOSING;
1438                         ffs_data_reset(ffs);
1439                 }
1440         }
1441         if (atomic_read(&ffs->opened) < 0) {
1442                 ffs->state = FFS_CLOSING;
1443                 ffs_data_reset(ffs);
1444         }
1445
1446         ffs_data_put(ffs);
1447 }
1448
1449 static struct ffs_data *ffs_data_new(void)
1450 {
1451         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1452         if (unlikely(!ffs))
1453                 return NULL;
1454
1455         ENTER();
1456
1457         atomic_set(&ffs->ref, 1);
1458         atomic_set(&ffs->opened, 0);
1459         ffs->state = FFS_READ_DESCRIPTORS;
1460         mutex_init(&ffs->mutex);
1461         spin_lock_init(&ffs->eps_lock);
1462         init_waitqueue_head(&ffs->ev.waitq);
1463         init_completion(&ffs->ep0req_completion);
1464
1465         /* XXX REVISIT need to update it in some places, or do we? */
1466         ffs->ev.can_stall = 1;
1467
1468         return ffs;
1469 }
1470
1471 static void ffs_data_clear(struct ffs_data *ffs)
1472 {
1473         ENTER();
1474
1475         ffs_closed(ffs);
1476
1477         BUG_ON(ffs->gadget);
1478
1479         if (ffs->epfiles)
1480                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1481
1482         if (ffs->ffs_eventfd)
1483                 eventfd_ctx_put(ffs->ffs_eventfd);
1484
1485         kfree(ffs->raw_descs_data);
1486         kfree(ffs->raw_strings);
1487         kfree(ffs->stringtabs);
1488 }
1489
1490 static void ffs_data_reset(struct ffs_data *ffs)
1491 {
1492         ENTER();
1493
1494         ffs_data_clear(ffs);
1495
1496         ffs->epfiles = NULL;
1497         ffs->raw_descs_data = NULL;
1498         ffs->raw_descs = NULL;
1499         ffs->raw_strings = NULL;
1500         ffs->stringtabs = NULL;
1501
1502         ffs->raw_descs_length = 0;
1503         ffs->fs_descs_count = 0;
1504         ffs->hs_descs_count = 0;
1505         ffs->ss_descs_count = 0;
1506
1507         ffs->strings_count = 0;
1508         ffs->interfaces_count = 0;
1509         ffs->eps_count = 0;
1510
1511         ffs->ev.count = 0;
1512
1513         ffs->state = FFS_READ_DESCRIPTORS;
1514         ffs->setup_state = FFS_NO_SETUP;
1515         ffs->flags = 0;
1516
1517         ffs->ms_os_descs_ext_prop_count = 0;
1518         ffs->ms_os_descs_ext_prop_name_len = 0;
1519         ffs->ms_os_descs_ext_prop_data_len = 0;
1520 }
1521
1522
1523 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1524 {
1525         struct usb_gadget_strings **lang;
1526         int first_id;
1527
1528         ENTER();
1529
1530         if (WARN_ON(ffs->state != FFS_ACTIVE
1531                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1532                 return -EBADFD;
1533
1534         first_id = usb_string_ids_n(cdev, ffs->strings_count);
1535         if (unlikely(first_id < 0))
1536                 return first_id;
1537
1538         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1539         if (unlikely(!ffs->ep0req))
1540                 return -ENOMEM;
1541         ffs->ep0req->complete = ffs_ep0_complete;
1542         ffs->ep0req->context = ffs;
1543
1544         lang = ffs->stringtabs;
1545         if (lang) {
1546                 for (; *lang; ++lang) {
1547                         struct usb_string *str = (*lang)->strings;
1548                         int id = first_id;
1549                         for (; str->s; ++id, ++str)
1550                                 str->id = id;
1551                 }
1552         }
1553
1554         ffs->gadget = cdev->gadget;
1555         ffs_data_get(ffs);
1556         return 0;
1557 }
1558
1559 static void functionfs_unbind(struct ffs_data *ffs)
1560 {
1561         ENTER();
1562
1563         if (!WARN_ON(!ffs->gadget)) {
1564                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1565                 ffs->ep0req = NULL;
1566                 ffs->gadget = NULL;
1567                 clear_bit(FFS_FL_BOUND, &ffs->flags);
1568                 ffs_data_put(ffs);
1569         }
1570 }
1571
1572 static int ffs_epfiles_create(struct ffs_data *ffs)
1573 {
1574         struct ffs_epfile *epfile, *epfiles;
1575         unsigned i, count;
1576
1577         ENTER();
1578
1579         count = ffs->eps_count;
1580         epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1581         if (!epfiles)
1582                 return -ENOMEM;
1583
1584         epfile = epfiles;
1585         for (i = 1; i <= count; ++i, ++epfile) {
1586                 epfile->ffs = ffs;
1587                 mutex_init(&epfile->mutex);
1588                 init_waitqueue_head(&epfile->wait);
1589                 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1590                         sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1591                 else
1592                         sprintf(epfile->name, "ep%u", i);
1593                 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1594                                                  epfile,
1595                                                  &ffs_epfile_operations);
1596                 if (unlikely(!epfile->dentry)) {
1597                         ffs_epfiles_destroy(epfiles, i - 1);
1598                         return -ENOMEM;
1599                 }
1600         }
1601
1602         ffs->epfiles = epfiles;
1603         return 0;
1604 }
1605
1606 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1607 {
1608         struct ffs_epfile *epfile = epfiles;
1609
1610         ENTER();
1611
1612         for (; count; --count, ++epfile) {
1613                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1614                        waitqueue_active(&epfile->wait));
1615                 if (epfile->dentry) {
1616                         d_delete(epfile->dentry);
1617                         dput(epfile->dentry);
1618                         epfile->dentry = NULL;
1619                 }
1620         }
1621
1622         kfree(epfiles);
1623 }
1624
1625 static void ffs_func_eps_disable(struct ffs_function *func)
1626 {
1627         struct ffs_ep *ep         = func->eps;
1628         struct ffs_epfile *epfile = func->ffs->epfiles;
1629         unsigned count            = func->ffs->eps_count;
1630         unsigned long flags;
1631
1632         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1633         do {
1634                 /* pending requests get nuked */
1635                 if (likely(ep->ep))
1636                         usb_ep_disable(ep->ep);
1637                 ++ep;
1638
1639                 if (epfile) {
1640                         epfile->ep = NULL;
1641                         ++epfile;
1642                 }
1643         } while (--count);
1644         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1645 }
1646
1647 static int ffs_func_eps_enable(struct ffs_function *func)
1648 {
1649         struct ffs_data *ffs      = func->ffs;
1650         struct ffs_ep *ep         = func->eps;
1651         struct ffs_epfile *epfile = ffs->epfiles;
1652         unsigned count            = ffs->eps_count;
1653         unsigned long flags;
1654         int ret = 0;
1655
1656         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1657         do {
1658                 struct usb_endpoint_descriptor *ds;
1659                 struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
1660                 int needs_comp_desc = false;
1661                 int desc_idx;
1662
1663                 if (ffs->gadget->speed == USB_SPEED_SUPER) {
1664                         desc_idx = 2;
1665                         needs_comp_desc = true;
1666                 } else if (ffs->gadget->speed == USB_SPEED_HIGH)
1667                         desc_idx = 1;
1668                 else
1669                         desc_idx = 0;
1670
1671                 /* fall-back to lower speed if desc missing for current speed */
1672                 do {
1673                         ds = ep->descs[desc_idx];
1674                 } while (!ds && --desc_idx >= 0);
1675
1676                 if (!ds) {
1677                         ret = -EINVAL;
1678                         break;
1679                 }
1680
1681                 ep->ep->driver_data = ep;
1682                 ep->ep->desc = ds;
1683
1684                 if (needs_comp_desc) {
1685                         comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
1686                                         USB_DT_ENDPOINT_SIZE);
1687                         ep->ep->maxburst = comp_desc->bMaxBurst + 1;
1688                         ep->ep->comp_desc = comp_desc;
1689                 }
1690
1691                 ret = usb_ep_enable(ep->ep);
1692                 if (likely(!ret)) {
1693                         epfile->ep = ep;
1694                         epfile->in = usb_endpoint_dir_in(ds);
1695                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1696                 } else {
1697                         break;
1698                 }
1699
1700                 wake_up(&epfile->wait);
1701
1702                 ++ep;
1703                 ++epfile;
1704         } while (--count);
1705         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1706
1707         return ret;
1708 }
1709
1710
1711 /* Parsing and building descriptors and strings *****************************/
1712
1713 /*
1714  * This validates if data pointed by data is a valid USB descriptor as
1715  * well as record how many interfaces, endpoints and strings are
1716  * required by given configuration.  Returns address after the
1717  * descriptor or NULL if data is invalid.
1718  */
1719
1720 enum ffs_entity_type {
1721         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1722 };
1723
1724 enum ffs_os_desc_type {
1725         FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1726 };
1727
1728 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1729                                    u8 *valuep,
1730                                    struct usb_descriptor_header *desc,
1731                                    void *priv);
1732
1733 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1734                                     struct usb_os_desc_header *h, void *data,
1735                                     unsigned len, void *priv);
1736
1737 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1738                                            ffs_entity_callback entity,
1739                                            void *priv)
1740 {
1741         struct usb_descriptor_header *_ds = (void *)data;
1742         u8 length;
1743         int ret;
1744
1745         ENTER();
1746
1747         /* At least two bytes are required: length and type */
1748         if (len < 2) {
1749                 pr_vdebug("descriptor too short\n");
1750                 return -EINVAL;
1751         }
1752
1753         /* If we have at least as many bytes as the descriptor takes? */
1754         length = _ds->bLength;
1755         if (len < length) {
1756                 pr_vdebug("descriptor longer then available data\n");
1757                 return -EINVAL;
1758         }
1759
1760 #define __entity_check_INTERFACE(val)  1
1761 #define __entity_check_STRING(val)     (val)
1762 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1763 #define __entity(type, val) do {                                        \
1764                 pr_vdebug("entity " #type "(%02x)\n", (val));           \
1765                 if (unlikely(!__entity_check_ ##type(val))) {           \
1766                         pr_vdebug("invalid entity's value\n");          \
1767                         return -EINVAL;                                 \
1768                 }                                                       \
1769                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1770                 if (unlikely(ret < 0)) {                                \
1771                         pr_debug("entity " #type "(%02x); ret = %d\n",  \
1772                                  (val), ret);                           \
1773                         return ret;                                     \
1774                 }                                                       \
1775         } while (0)
1776
1777         /* Parse descriptor depending on type. */
1778         switch (_ds->bDescriptorType) {
1779         case USB_DT_DEVICE:
1780         case USB_DT_CONFIG:
1781         case USB_DT_STRING:
1782         case USB_DT_DEVICE_QUALIFIER:
1783                 /* function can't have any of those */
1784                 pr_vdebug("descriptor reserved for gadget: %d\n",
1785                       _ds->bDescriptorType);
1786                 return -EINVAL;
1787
1788         case USB_DT_INTERFACE: {
1789                 struct usb_interface_descriptor *ds = (void *)_ds;
1790                 pr_vdebug("interface descriptor\n");
1791                 if (length != sizeof *ds)
1792                         goto inv_length;
1793
1794                 __entity(INTERFACE, ds->bInterfaceNumber);
1795                 if (ds->iInterface)
1796                         __entity(STRING, ds->iInterface);
1797         }
1798                 break;
1799
1800         case USB_DT_ENDPOINT: {
1801                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1802                 pr_vdebug("endpoint descriptor\n");
1803                 if (length != USB_DT_ENDPOINT_SIZE &&
1804                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1805                         goto inv_length;
1806                 __entity(ENDPOINT, ds->bEndpointAddress);
1807         }
1808                 break;
1809
1810         case HID_DT_HID:
1811                 pr_vdebug("hid descriptor\n");
1812                 if (length != sizeof(struct hid_descriptor))
1813                         goto inv_length;
1814                 break;
1815
1816         case USB_DT_OTG:
1817                 if (length != sizeof(struct usb_otg_descriptor))
1818                         goto inv_length;
1819                 break;
1820
1821         case USB_DT_INTERFACE_ASSOCIATION: {
1822                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1823                 pr_vdebug("interface association descriptor\n");
1824                 if (length != sizeof *ds)
1825                         goto inv_length;
1826                 if (ds->iFunction)
1827                         __entity(STRING, ds->iFunction);
1828         }
1829                 break;
1830
1831         case USB_DT_SS_ENDPOINT_COMP:
1832                 pr_vdebug("EP SS companion descriptor\n");
1833                 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1834                         goto inv_length;
1835                 break;
1836
1837         case USB_DT_OTHER_SPEED_CONFIG:
1838         case USB_DT_INTERFACE_POWER:
1839         case USB_DT_DEBUG:
1840         case USB_DT_SECURITY:
1841         case USB_DT_CS_RADIO_CONTROL:
1842                 /* TODO */
1843                 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1844                 return -EINVAL;
1845
1846         default:
1847                 /* We should never be here */
1848                 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1849                 return -EINVAL;
1850
1851 inv_length:
1852                 pr_vdebug("invalid length: %d (descriptor %d)\n",
1853                           _ds->bLength, _ds->bDescriptorType);
1854                 return -EINVAL;
1855         }
1856
1857 #undef __entity
1858 #undef __entity_check_DESCRIPTOR
1859 #undef __entity_check_INTERFACE
1860 #undef __entity_check_STRING
1861 #undef __entity_check_ENDPOINT
1862
1863         return length;
1864 }
1865
1866 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1867                                      ffs_entity_callback entity, void *priv)
1868 {
1869         const unsigned _len = len;
1870         unsigned long num = 0;
1871
1872         ENTER();
1873
1874         for (;;) {
1875                 int ret;
1876
1877                 if (num == count)
1878                         data = NULL;
1879
1880                 /* Record "descriptor" entity */
1881                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1882                 if (unlikely(ret < 0)) {
1883                         pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1884                                  num, ret);
1885                         return ret;
1886                 }
1887
1888                 if (!data)
1889                         return _len - len;
1890
1891                 ret = ffs_do_single_desc(data, len, entity, priv);
1892                 if (unlikely(ret < 0)) {
1893                         pr_debug("%s returns %d\n", __func__, ret);
1894                         return ret;
1895                 }
1896
1897                 len -= ret;
1898                 data += ret;
1899                 ++num;
1900         }
1901 }
1902
1903 static int __ffs_data_do_entity(enum ffs_entity_type type,
1904                                 u8 *valuep, struct usb_descriptor_header *desc,
1905                                 void *priv)
1906 {
1907         struct ffs_desc_helper *helper = priv;
1908         struct usb_endpoint_descriptor *d;
1909
1910         ENTER();
1911
1912         switch (type) {
1913         case FFS_DESCRIPTOR:
1914                 break;
1915
1916         case FFS_INTERFACE:
1917                 /*
1918                  * Interfaces are indexed from zero so if we
1919                  * encountered interface "n" then there are at least
1920                  * "n+1" interfaces.
1921                  */
1922                 if (*valuep >= helper->interfaces_count)
1923                         helper->interfaces_count = *valuep + 1;
1924                 break;
1925
1926         case FFS_STRING:
1927                 /*
1928                  * Strings are indexed from 1 (0 is magic ;) reserved
1929                  * for languages list or some such)
1930                  */
1931                 if (*valuep > helper->ffs->strings_count)
1932                         helper->ffs->strings_count = *valuep;
1933                 break;
1934
1935         case FFS_ENDPOINT:
1936                 d = (void *)desc;
1937                 helper->eps_count++;
1938                 if (helper->eps_count >= 15)
1939                         return -EINVAL;
1940                 /* Check if descriptors for any speed were already parsed */
1941                 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
1942                         helper->ffs->eps_addrmap[helper->eps_count] =
1943                                 d->bEndpointAddress;
1944                 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
1945                                 d->bEndpointAddress)
1946                         return -EINVAL;
1947                 break;
1948         }
1949
1950         return 0;
1951 }
1952
1953 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1954                                    struct usb_os_desc_header *desc)
1955 {
1956         u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1957         u16 w_index = le16_to_cpu(desc->wIndex);
1958
1959         if (bcd_version != 1) {
1960                 pr_vdebug("unsupported os descriptors version: %d",
1961                           bcd_version);
1962                 return -EINVAL;
1963         }
1964         switch (w_index) {
1965         case 0x4:
1966                 *next_type = FFS_OS_DESC_EXT_COMPAT;
1967                 break;
1968         case 0x5:
1969                 *next_type = FFS_OS_DESC_EXT_PROP;
1970                 break;
1971         default:
1972                 pr_vdebug("unsupported os descriptor type: %d", w_index);
1973                 return -EINVAL;
1974         }
1975
1976         return sizeof(*desc);
1977 }
1978
1979 /*
1980  * Process all extended compatibility/extended property descriptors
1981  * of a feature descriptor
1982  */
1983 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1984                                               enum ffs_os_desc_type type,
1985                                               u16 feature_count,
1986                                               ffs_os_desc_callback entity,
1987                                               void *priv,
1988                                               struct usb_os_desc_header *h)
1989 {
1990         int ret;
1991         const unsigned _len = len;
1992
1993         ENTER();
1994
1995         /* loop over all ext compat/ext prop descriptors */
1996         while (feature_count--) {
1997                 ret = entity(type, h, data, len, priv);
1998                 if (unlikely(ret < 0)) {
1999                         pr_debug("bad OS descriptor, type: %d\n", type);
2000                         return ret;
2001                 }
2002                 data += ret;
2003                 len -= ret;
2004         }
2005         return _len - len;
2006 }
2007
2008 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2009 static int __must_check ffs_do_os_descs(unsigned count,
2010                                         char *data, unsigned len,
2011                                         ffs_os_desc_callback entity, void *priv)
2012 {
2013         const unsigned _len = len;
2014         unsigned long num = 0;
2015
2016         ENTER();
2017
2018         for (num = 0; num < count; ++num) {
2019                 int ret;
2020                 enum ffs_os_desc_type type;
2021                 u16 feature_count;
2022                 struct usb_os_desc_header *desc = (void *)data;
2023
2024                 if (len < sizeof(*desc))
2025                         return -EINVAL;
2026
2027                 /*
2028                  * Record "descriptor" entity.
2029                  * Process dwLength, bcdVersion, wIndex, get b/wCount.
2030                  * Move the data pointer to the beginning of extended
2031                  * compatibilities proper or extended properties proper
2032                  * portions of the data
2033                  */
2034                 if (le32_to_cpu(desc->dwLength) > len)
2035                         return -EINVAL;
2036
2037                 ret = __ffs_do_os_desc_header(&type, desc);
2038                 if (unlikely(ret < 0)) {
2039                         pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2040                                  num, ret);
2041                         return ret;
2042                 }
2043                 /*
2044                  * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2045                  */
2046                 feature_count = le16_to_cpu(desc->wCount);
2047                 if (type == FFS_OS_DESC_EXT_COMPAT &&
2048                     (feature_count > 255 || desc->Reserved))
2049                                 return -EINVAL;
2050                 len -= ret;
2051                 data += ret;
2052
2053                 /*
2054                  * Process all function/property descriptors
2055                  * of this Feature Descriptor
2056                  */
2057                 ret = ffs_do_single_os_desc(data, len, type,
2058                                             feature_count, entity, priv, desc);
2059                 if (unlikely(ret < 0)) {
2060                         pr_debug("%s returns %d\n", __func__, ret);
2061                         return ret;
2062                 }
2063
2064                 len -= ret;
2065                 data += ret;
2066         }
2067         return _len - len;
2068 }
2069
2070 /**
2071  * Validate contents of the buffer from userspace related to OS descriptors.
2072  */
2073 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2074                                  struct usb_os_desc_header *h, void *data,
2075                                  unsigned len, void *priv)
2076 {
2077         struct ffs_data *ffs = priv;
2078         u8 length;
2079
2080         ENTER();
2081
2082         switch (type) {
2083         case FFS_OS_DESC_EXT_COMPAT: {
2084                 struct usb_ext_compat_desc *d = data;
2085                 int i;
2086
2087                 if (len < sizeof(*d) ||
2088                     d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2089                     d->Reserved1)
2090                         return -EINVAL;
2091                 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2092                         if (d->Reserved2[i])
2093                                 return -EINVAL;
2094
2095                 length = sizeof(struct usb_ext_compat_desc);
2096         }
2097                 break;
2098         case FFS_OS_DESC_EXT_PROP: {
2099                 struct usb_ext_prop_desc *d = data;
2100                 u32 type, pdl;
2101                 u16 pnl;
2102
2103                 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2104                         return -EINVAL;
2105                 length = le32_to_cpu(d->dwSize);
2106                 if (len < length)
2107                         return -EINVAL;
2108                 type = le32_to_cpu(d->dwPropertyDataType);
2109                 if (type < USB_EXT_PROP_UNICODE ||
2110                     type > USB_EXT_PROP_UNICODE_MULTI) {
2111                         pr_vdebug("unsupported os descriptor property type: %d",
2112                                   type);
2113                         return -EINVAL;
2114                 }
2115                 pnl = le16_to_cpu(d->wPropertyNameLength);
2116                 if (length < 14 + pnl) {
2117                         pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2118                                   length, pnl, type);
2119                         return -EINVAL;
2120                 }
2121                 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2122                 if (length != 14 + pnl + pdl) {
2123                         pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2124                                   length, pnl, pdl, type);
2125                         return -EINVAL;
2126                 }
2127                 ++ffs->ms_os_descs_ext_prop_count;
2128                 /* property name reported to the host as "WCHAR"s */
2129                 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2130                 ffs->ms_os_descs_ext_prop_data_len += pdl;
2131         }
2132                 break;
2133         default:
2134                 pr_vdebug("unknown descriptor: %d\n", type);
2135                 return -EINVAL;
2136         }
2137         return length;
2138 }
2139
2140 static int __ffs_data_got_descs(struct ffs_data *ffs,
2141                                 char *const _data, size_t len)
2142 {
2143         char *data = _data, *raw_descs;
2144         unsigned os_descs_count = 0, counts[3], flags;
2145         int ret = -EINVAL, i;
2146         struct ffs_desc_helper helper;
2147
2148         ENTER();
2149
2150         if (get_unaligned_le32(data + 4) != len)
2151                 goto error;
2152
2153         switch (get_unaligned_le32(data)) {
2154         case FUNCTIONFS_DESCRIPTORS_MAGIC:
2155                 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2156                 data += 8;
2157                 len  -= 8;
2158                 break;
2159         case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2160                 flags = get_unaligned_le32(data + 8);
2161                 ffs->user_flags = flags;
2162                 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2163                               FUNCTIONFS_HAS_HS_DESC |
2164                               FUNCTIONFS_HAS_SS_DESC |
2165                               FUNCTIONFS_HAS_MS_OS_DESC |
2166                               FUNCTIONFS_VIRTUAL_ADDR |
2167                               FUNCTIONFS_EVENTFD)) {
2168                         ret = -ENOSYS;
2169                         goto error;
2170                 }
2171                 data += 12;
2172                 len  -= 12;
2173                 break;
2174         default:
2175                 goto error;
2176         }
2177
2178         if (flags & FUNCTIONFS_EVENTFD) {
2179                 if (len < 4)
2180                         goto error;
2181                 ffs->ffs_eventfd =
2182                         eventfd_ctx_fdget((int)get_unaligned_le32(data));
2183                 if (IS_ERR(ffs->ffs_eventfd)) {
2184                         ret = PTR_ERR(ffs->ffs_eventfd);
2185                         ffs->ffs_eventfd = NULL;
2186                         goto error;
2187                 }
2188                 data += 4;
2189                 len  -= 4;
2190         }
2191
2192         /* Read fs_count, hs_count and ss_count (if present) */
2193         for (i = 0; i < 3; ++i) {
2194                 if (!(flags & (1 << i))) {
2195                         counts[i] = 0;
2196                 } else if (len < 4) {
2197                         goto error;
2198                 } else {
2199                         counts[i] = get_unaligned_le32(data);
2200                         data += 4;
2201                         len  -= 4;
2202                 }
2203         }
2204         if (flags & (1 << i)) {
2205                 if (len < 4) {
2206                         goto error;
2207                 }
2208                 os_descs_count = get_unaligned_le32(data);
2209                 data += 4;
2210                 len -= 4;
2211         };
2212
2213         /* Read descriptors */
2214         raw_descs = data;
2215         helper.ffs = ffs;
2216         for (i = 0; i < 3; ++i) {
2217                 if (!counts[i])
2218                         continue;
2219                 helper.interfaces_count = 0;
2220                 helper.eps_count = 0;
2221                 ret = ffs_do_descs(counts[i], data, len,
2222                                    __ffs_data_do_entity, &helper);
2223                 if (ret < 0)
2224                         goto error;
2225                 if (!ffs->eps_count && !ffs->interfaces_count) {
2226                         ffs->eps_count = helper.eps_count;
2227                         ffs->interfaces_count = helper.interfaces_count;
2228                 } else {
2229                         if (ffs->eps_count != helper.eps_count) {
2230                                 ret = -EINVAL;
2231                                 goto error;
2232                         }
2233                         if (ffs->interfaces_count != helper.interfaces_count) {
2234                                 ret = -EINVAL;
2235                                 goto error;
2236                         }
2237                 }
2238                 data += ret;
2239                 len  -= ret;
2240         }
2241         if (os_descs_count) {
2242                 ret = ffs_do_os_descs(os_descs_count, data, len,
2243                                       __ffs_data_do_os_desc, ffs);
2244                 if (ret < 0)
2245                         goto error;
2246                 data += ret;
2247                 len -= ret;
2248         }
2249
2250         if (raw_descs == data || len) {
2251                 ret = -EINVAL;
2252                 goto error;
2253         }
2254
2255         ffs->raw_descs_data     = _data;
2256         ffs->raw_descs          = raw_descs;
2257         ffs->raw_descs_length   = data - raw_descs;
2258         ffs->fs_descs_count     = counts[0];
2259         ffs->hs_descs_count     = counts[1];
2260         ffs->ss_descs_count     = counts[2];
2261         ffs->ms_os_descs_count  = os_descs_count;
2262
2263         return 0;
2264
2265 error:
2266         kfree(_data);
2267         return ret;
2268 }
2269
2270 static int __ffs_data_got_strings(struct ffs_data *ffs,
2271                                   char *const _data, size_t len)
2272 {
2273         u32 str_count, needed_count, lang_count;
2274         struct usb_gadget_strings **stringtabs, *t;
2275         struct usb_string *strings, *s;
2276         const char *data = _data;
2277
2278         ENTER();
2279
2280         if (unlikely(len < 16 ||
2281                      get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2282                      get_unaligned_le32(data + 4) != len))
2283                 goto error;
2284         str_count  = get_unaligned_le32(data + 8);
2285         lang_count = get_unaligned_le32(data + 12);
2286
2287         /* if one is zero the other must be zero */
2288         if (unlikely(!str_count != !lang_count))
2289                 goto error;
2290
2291         /* Do we have at least as many strings as descriptors need? */
2292         needed_count = ffs->strings_count;
2293         if (unlikely(str_count < needed_count))
2294                 goto error;
2295
2296         /*
2297          * If we don't need any strings just return and free all
2298          * memory.
2299          */
2300         if (!needed_count) {
2301                 kfree(_data);
2302                 return 0;
2303         }
2304
2305         /* Allocate everything in one chunk so there's less maintenance. */
2306         {
2307                 unsigned i = 0;
2308                 vla_group(d);
2309                 vla_item(d, struct usb_gadget_strings *, stringtabs,
2310                         lang_count + 1);
2311                 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2312                 vla_item(d, struct usb_string, strings,
2313                         lang_count*(needed_count+1));
2314
2315                 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2316
2317                 if (unlikely(!vlabuf)) {
2318                         kfree(_data);
2319                         return -ENOMEM;
2320                 }
2321
2322                 /* Initialize the VLA pointers */
2323                 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2324                 t = vla_ptr(vlabuf, d, stringtab);
2325                 i = lang_count;
2326                 do {
2327                         *stringtabs++ = t++;
2328                 } while (--i);
2329                 *stringtabs = NULL;
2330
2331                 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2332                 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2333                 t = vla_ptr(vlabuf, d, stringtab);
2334                 s = vla_ptr(vlabuf, d, strings);
2335                 strings = s;
2336         }
2337
2338         /* For each language */
2339         data += 16;
2340         len -= 16;
2341
2342         do { /* lang_count > 0 so we can use do-while */
2343                 unsigned needed = needed_count;
2344                 u32 str_per_lang = str_count;
2345
2346                 if (unlikely(len < 3))
2347                         goto error_free;
2348                 t->language = get_unaligned_le16(data);
2349                 t->strings  = s;
2350                 ++t;
2351
2352                 data += 2;
2353                 len -= 2;
2354
2355                 /* For each string */
2356                 do { /* str_count > 0 so we can use do-while */
2357                         size_t length = strnlen(data, len);
2358
2359                         if (unlikely(length == len))
2360                                 goto error_free;
2361
2362                         /*
2363                          * User may provide more strings then we need,
2364                          * if that's the case we simply ignore the
2365                          * rest
2366                          */
2367                         if (likely(needed)) {
2368                                 /*
2369                                  * s->id will be set while adding
2370                                  * function to configuration so for
2371                                  * now just leave garbage here.
2372                                  */
2373                                 s->s = data;
2374                                 --needed;
2375                                 ++s;
2376                         }
2377
2378                         data += length + 1;
2379                         len -= length + 1;
2380                 } while (--str_per_lang);
2381
2382                 s->id = 0;   /* terminator */
2383                 s->s = NULL;
2384                 ++s;
2385
2386         } while (--lang_count);
2387
2388         /* Some garbage left? */
2389         if (unlikely(len))
2390                 goto error_free;
2391
2392         /* Done! */
2393         ffs->stringtabs = stringtabs;
2394         ffs->raw_strings = _data;
2395
2396         return 0;
2397
2398 error_free:
2399         kfree(stringtabs);
2400 error:
2401         kfree(_data);
2402         return -EINVAL;
2403 }
2404
2405
2406 /* Events handling and management *******************************************/
2407
2408 static void __ffs_event_add(struct ffs_data *ffs,
2409                             enum usb_functionfs_event_type type)
2410 {
2411         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2412         int neg = 0;
2413
2414         /*
2415          * Abort any unhandled setup
2416          *
2417          * We do not need to worry about some cmpxchg() changing value
2418          * of ffs->setup_state without holding the lock because when
2419          * state is FFS_SETUP_PENDING cmpxchg() in several places in
2420          * the source does nothing.
2421          */
2422         if (ffs->setup_state == FFS_SETUP_PENDING)
2423                 ffs->setup_state = FFS_SETUP_CANCELLED;
2424
2425         /*
2426          * Logic of this function guarantees that there are at most four pending
2427          * evens on ffs->ev.types queue.  This is important because the queue
2428          * has space for four elements only and __ffs_ep0_read_events function
2429          * depends on that limit as well.  If more event types are added, those
2430          * limits have to be revisited or guaranteed to still hold.
2431          */
2432         switch (type) {
2433         case FUNCTIONFS_RESUME:
2434                 rem_type2 = FUNCTIONFS_SUSPEND;
2435                 /* FALL THROUGH */
2436         case FUNCTIONFS_SUSPEND:
2437         case FUNCTIONFS_SETUP:
2438                 rem_type1 = type;
2439                 /* Discard all similar events */
2440                 break;
2441
2442         case FUNCTIONFS_BIND:
2443         case FUNCTIONFS_UNBIND:
2444         case FUNCTIONFS_DISABLE:
2445         case FUNCTIONFS_ENABLE:
2446                 /* Discard everything other then power management. */
2447                 rem_type1 = FUNCTIONFS_SUSPEND;
2448                 rem_type2 = FUNCTIONFS_RESUME;
2449                 neg = 1;
2450                 break;
2451
2452         default:
2453                 WARN(1, "%d: unknown event, this should not happen\n", type);
2454                 return;
2455         }
2456
2457         {
2458                 u8 *ev  = ffs->ev.types, *out = ev;
2459                 unsigned n = ffs->ev.count;
2460                 for (; n; --n, ++ev)
2461                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2462                                 *out++ = *ev;
2463                         else
2464                                 pr_vdebug("purging event %d\n", *ev);
2465                 ffs->ev.count = out - ffs->ev.types;
2466         }
2467
2468         pr_vdebug("adding event %d\n", type);
2469         ffs->ev.types[ffs->ev.count++] = type;
2470         wake_up_locked(&ffs->ev.waitq);
2471         if (ffs->ffs_eventfd)
2472                 eventfd_signal(ffs->ffs_eventfd, 1);
2473 }
2474
2475 static void ffs_event_add(struct ffs_data *ffs,
2476                           enum usb_functionfs_event_type type)
2477 {
2478         unsigned long flags;
2479         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2480         __ffs_event_add(ffs, type);
2481         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2482 }
2483
2484 /* Bind/unbind USB function hooks *******************************************/
2485
2486 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2487 {
2488         int i;
2489
2490         for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2491                 if (ffs->eps_addrmap[i] == endpoint_address)
2492                         return i;
2493         return -ENOENT;
2494 }
2495
2496 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2497                                     struct usb_descriptor_header *desc,
2498                                     void *priv)
2499 {
2500         struct usb_endpoint_descriptor *ds = (void *)desc;
2501         struct ffs_function *func = priv;
2502         struct ffs_ep *ffs_ep;
2503         unsigned ep_desc_id;
2504         int idx;
2505         static const char *speed_names[] = { "full", "high", "super" };
2506
2507         if (type != FFS_DESCRIPTOR)
2508                 return 0;
2509
2510         /*
2511          * If ss_descriptors is not NULL, we are reading super speed
2512          * descriptors; if hs_descriptors is not NULL, we are reading high
2513          * speed descriptors; otherwise, we are reading full speed
2514          * descriptors.
2515          */
2516         if (func->function.ss_descriptors) {
2517                 ep_desc_id = 2;
2518                 func->function.ss_descriptors[(long)valuep] = desc;
2519         } else if (func->function.hs_descriptors) {
2520                 ep_desc_id = 1;
2521                 func->function.hs_descriptors[(long)valuep] = desc;
2522         } else {
2523                 ep_desc_id = 0;
2524                 func->function.fs_descriptors[(long)valuep]    = desc;
2525         }
2526
2527         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2528                 return 0;
2529
2530         idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2531         if (idx < 0)
2532                 return idx;
2533
2534         ffs_ep = func->eps + idx;
2535
2536         if (unlikely(ffs_ep->descs[ep_desc_id])) {
2537                 pr_err("two %sspeed descriptors for EP %d\n",
2538                           speed_names[ep_desc_id],
2539                           ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2540                 return -EINVAL;
2541         }
2542         ffs_ep->descs[ep_desc_id] = ds;
2543
2544         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2545         if (ffs_ep->ep) {
2546                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2547                 if (!ds->wMaxPacketSize)
2548                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2549         } else {
2550                 struct usb_request *req;
2551                 struct usb_ep *ep;
2552                 u8 bEndpointAddress;
2553
2554                 /*
2555                  * We back up bEndpointAddress because autoconfig overwrites
2556                  * it with physical endpoint address.
2557                  */
2558                 bEndpointAddress = ds->bEndpointAddress;
2559                 pr_vdebug("autoconfig\n");
2560                 ep = usb_ep_autoconfig(func->gadget, ds);
2561                 if (unlikely(!ep))
2562                         return -ENOTSUPP;
2563                 ep->driver_data = func->eps + idx;
2564
2565                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2566                 if (unlikely(!req))
2567                         return -ENOMEM;
2568
2569                 ffs_ep->ep  = ep;
2570                 ffs_ep->req = req;
2571                 func->eps_revmap[ds->bEndpointAddress &
2572                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2573                 /*
2574                  * If we use virtual address mapping, we restore
2575                  * original bEndpointAddress value.
2576                  */
2577                 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2578                         ds->bEndpointAddress = bEndpointAddress;
2579         }
2580         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2581
2582         return 0;
2583 }
2584
2585 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2586                                    struct usb_descriptor_header *desc,
2587                                    void *priv)
2588 {
2589         struct ffs_function *func = priv;
2590         unsigned idx;
2591         u8 newValue;
2592
2593         switch (type) {
2594         default:
2595         case FFS_DESCRIPTOR:
2596                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2597                 return 0;
2598
2599         case FFS_INTERFACE:
2600                 idx = *valuep;
2601                 if (func->interfaces_nums[idx] < 0) {
2602                         int id = usb_interface_id(func->conf, &func->function);
2603                         if (unlikely(id < 0))
2604                                 return id;
2605                         func->interfaces_nums[idx] = id;
2606                 }
2607                 newValue = func->interfaces_nums[idx];
2608                 break;
2609
2610         case FFS_STRING:
2611                 /* String' IDs are allocated when fsf_data is bound to cdev */
2612                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2613                 break;
2614
2615         case FFS_ENDPOINT:
2616                 /*
2617                  * USB_DT_ENDPOINT are handled in
2618                  * __ffs_func_bind_do_descs().
2619                  */
2620                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2621                         return 0;
2622
2623                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2624                 if (unlikely(!func->eps[idx].ep))
2625                         return -EINVAL;
2626
2627                 {
2628                         struct usb_endpoint_descriptor **descs;
2629                         descs = func->eps[idx].descs;
2630                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2631                 }
2632                 break;
2633         }
2634
2635         pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2636         *valuep = newValue;
2637         return 0;
2638 }
2639
2640 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2641                                       struct usb_os_desc_header *h, void *data,
2642                                       unsigned len, void *priv)
2643 {
2644         struct ffs_function *func = priv;
2645         u8 length = 0;
2646
2647         switch (type) {
2648         case FFS_OS_DESC_EXT_COMPAT: {
2649                 struct usb_ext_compat_desc *desc = data;
2650                 struct usb_os_desc_table *t;
2651
2652                 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2653                 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2654                 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2655                        ARRAY_SIZE(desc->CompatibleID) +
2656                        ARRAY_SIZE(desc->SubCompatibleID));
2657                 length = sizeof(*desc);
2658         }
2659                 break;
2660         case FFS_OS_DESC_EXT_PROP: {
2661                 struct usb_ext_prop_desc *desc = data;
2662                 struct usb_os_desc_table *t;
2663                 struct usb_os_desc_ext_prop *ext_prop;
2664                 char *ext_prop_name;
2665                 char *ext_prop_data;
2666
2667                 t = &func->function.os_desc_table[h->interface];
2668                 t->if_id = func->interfaces_nums[h->interface];
2669
2670                 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2671                 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2672
2673                 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2674                 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2675                 ext_prop->data_len = le32_to_cpu(*(u32 *)
2676                         usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2677                 length = ext_prop->name_len + ext_prop->data_len + 14;
2678
2679                 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2680                 func->ffs->ms_os_descs_ext_prop_name_avail +=
2681                         ext_prop->name_len;
2682
2683                 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2684                 func->ffs->ms_os_descs_ext_prop_data_avail +=
2685                         ext_prop->data_len;
2686                 memcpy(ext_prop_data,
2687                        usb_ext_prop_data_ptr(data, ext_prop->name_len),
2688                        ext_prop->data_len);
2689                 /* unicode data reported to the host as "WCHAR"s */
2690                 switch (ext_prop->type) {
2691                 case USB_EXT_PROP_UNICODE:
2692                 case USB_EXT_PROP_UNICODE_ENV:
2693                 case USB_EXT_PROP_UNICODE_LINK:
2694                 case USB_EXT_PROP_UNICODE_MULTI:
2695                         ext_prop->data_len *= 2;
2696                         break;
2697                 }
2698                 ext_prop->data = ext_prop_data;
2699
2700                 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2701                        ext_prop->name_len);
2702                 /* property name reported to the host as "WCHAR"s */
2703                 ext_prop->name_len *= 2;
2704                 ext_prop->name = ext_prop_name;
2705
2706                 t->os_desc->ext_prop_len +=
2707                         ext_prop->name_len + ext_prop->data_len + 14;
2708                 ++t->os_desc->ext_prop_count;
2709                 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2710         }
2711                 break;
2712         default:
2713                 pr_vdebug("unknown descriptor: %d\n", type);
2714         }
2715
2716         return length;
2717 }
2718
2719 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2720                                                 struct usb_configuration *c)
2721 {
2722         struct ffs_function *func = ffs_func_from_usb(f);
2723         struct f_fs_opts *ffs_opts =
2724                 container_of(f->fi, struct f_fs_opts, func_inst);
2725         int ret;
2726
2727         ENTER();
2728
2729         /*
2730          * Legacy gadget triggers binding in functionfs_ready_callback,
2731          * which already uses locking; taking the same lock here would
2732          * cause a deadlock.
2733          *
2734          * Configfs-enabled gadgets however do need ffs_dev_lock.
2735          */
2736         if (!ffs_opts->no_configfs)
2737                 ffs_dev_lock();
2738         ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2739         func->ffs = ffs_opts->dev->ffs_data;
2740         if (!ffs_opts->no_configfs)
2741                 ffs_dev_unlock();
2742         if (ret)
2743                 return ERR_PTR(ret);
2744
2745         func->conf = c;
2746         func->gadget = c->cdev->gadget;
2747
2748         /*
2749          * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2750          * configurations are bound in sequence with list_for_each_entry,
2751          * in each configuration its functions are bound in sequence
2752          * with list_for_each_entry, so we assume no race condition
2753          * with regard to ffs_opts->bound access
2754          */
2755         if (!ffs_opts->refcnt) {
2756                 ret = functionfs_bind(func->ffs, c->cdev);
2757                 if (ret)
2758                         return ERR_PTR(ret);
2759         }
2760         ffs_opts->refcnt++;
2761         func->function.strings = func->ffs->stringtabs;
2762
2763         return ffs_opts;
2764 }
2765
2766 static int _ffs_func_bind(struct usb_configuration *c,
2767                           struct usb_function *f)
2768 {
2769         struct ffs_function *func = ffs_func_from_usb(f);
2770         struct ffs_data *ffs = func->ffs;
2771
2772         const int full = !!func->ffs->fs_descs_count;
2773         const int high = !!func->ffs->hs_descs_count;
2774         const int super = !!func->ffs->ss_descs_count;
2775
2776         int fs_len, hs_len, ss_len, ret, i;
2777         struct ffs_ep *eps_ptr;
2778
2779         /* Make it a single chunk, less management later on */
2780         vla_group(d);
2781         vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2782         vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2783                 full ? ffs->fs_descs_count + 1 : 0);
2784         vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2785                 high ? ffs->hs_descs_count + 1 : 0);
2786         vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2787                 super ? ffs->ss_descs_count + 1 : 0);
2788         vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2789         vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2790                          c->cdev->use_os_string ? ffs->interfaces_count : 0);
2791         vla_item_with_sz(d, char[16], ext_compat,
2792                          c->cdev->use_os_string ? ffs->interfaces_count : 0);
2793         vla_item_with_sz(d, struct usb_os_desc, os_desc,
2794                          c->cdev->use_os_string ? ffs->interfaces_count : 0);
2795         vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2796                          ffs->ms_os_descs_ext_prop_count);
2797         vla_item_with_sz(d, char, ext_prop_name,
2798                          ffs->ms_os_descs_ext_prop_name_len);
2799         vla_item_with_sz(d, char, ext_prop_data,
2800                          ffs->ms_os_descs_ext_prop_data_len);
2801         vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2802         char *vlabuf;
2803
2804         ENTER();
2805
2806         /* Has descriptors only for speeds gadget does not support */
2807         if (unlikely(!(full | high | super)))
2808                 return -ENOTSUPP;
2809
2810         /* Allocate a single chunk, less management later on */
2811         vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2812         if (unlikely(!vlabuf))
2813                 return -ENOMEM;
2814
2815         ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2816         ffs->ms_os_descs_ext_prop_name_avail =
2817                 vla_ptr(vlabuf, d, ext_prop_name);
2818         ffs->ms_os_descs_ext_prop_data_avail =
2819                 vla_ptr(vlabuf, d, ext_prop_data);
2820
2821         /* Copy descriptors  */
2822         memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2823                ffs->raw_descs_length);
2824
2825         memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2826         eps_ptr = vla_ptr(vlabuf, d, eps);
2827         for (i = 0; i < ffs->eps_count; i++)
2828                 eps_ptr[i].num = -1;
2829
2830         /* Save pointers
2831          * d_eps == vlabuf, func->eps used to kfree vlabuf later
2832         */
2833         func->eps             = vla_ptr(vlabuf, d, eps);
2834         func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2835
2836         /*
2837          * Go through all the endpoint descriptors and allocate
2838          * endpoints first, so that later we can rewrite the endpoint
2839          * numbers without worrying that it may be described later on.
2840          */
2841         if (likely(full)) {
2842                 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2843                 fs_len = ffs_do_descs(ffs->fs_descs_count,
2844                                       vla_ptr(vlabuf, d, raw_descs),
2845                                       d_raw_descs__sz,
2846                                       __ffs_func_bind_do_descs, func);
2847                 if (unlikely(fs_len < 0)) {
2848                         ret = fs_len;
2849                         goto error;
2850                 }
2851         } else {
2852                 fs_len = 0;
2853         }
2854
2855         if (likely(high)) {
2856                 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2857                 hs_len = ffs_do_descs(ffs->hs_descs_count,
2858                                       vla_ptr(vlabuf, d, raw_descs) + fs_len,
2859                                       d_raw_descs__sz - fs_len,
2860                                       __ffs_func_bind_do_descs, func);
2861                 if (unlikely(hs_len < 0)) {
2862                         ret = hs_len;
2863                         goto error;
2864                 }
2865         } else {
2866                 hs_len = 0;
2867         }
2868
2869         if (likely(super)) {
2870                 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2871                 ss_len = ffs_do_descs(ffs->ss_descs_count,
2872                                 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2873                                 d_raw_descs__sz - fs_len - hs_len,
2874                                 __ffs_func_bind_do_descs, func);
2875                 if (unlikely(ss_len < 0)) {
2876                         ret = ss_len;
2877                         goto error;
2878                 }
2879         } else {
2880                 ss_len = 0;
2881         }
2882
2883         /*
2884          * Now handle interface numbers allocation and interface and
2885          * endpoint numbers rewriting.  We can do that in one go
2886          * now.
2887          */
2888         ret = ffs_do_descs(ffs->fs_descs_count +
2889                            (high ? ffs->hs_descs_count : 0) +
2890                            (super ? ffs->ss_descs_count : 0),
2891                            vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2892                            __ffs_func_bind_do_nums, func);
2893         if (unlikely(ret < 0))
2894                 goto error;
2895
2896         func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2897         if (c->cdev->use_os_string)
2898                 for (i = 0; i < ffs->interfaces_count; ++i) {
2899                         struct usb_os_desc *desc;
2900
2901                         desc = func->function.os_desc_table[i].os_desc =
2902                                 vla_ptr(vlabuf, d, os_desc) +
2903                                 i * sizeof(struct usb_os_desc);
2904                         desc->ext_compat_id =
2905                                 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2906                         INIT_LIST_HEAD(&desc->ext_prop);
2907                 }
2908         ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2909                               vla_ptr(vlabuf, d, raw_descs) +
2910                               fs_len + hs_len + ss_len,
2911                               d_raw_descs__sz - fs_len - hs_len - ss_len,
2912                               __ffs_func_bind_do_os_desc, func);
2913         if (unlikely(ret < 0))
2914                 goto error;
2915         func->function.os_desc_n =
2916                 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2917
2918         /* And we're done */
2919         ffs_event_add(ffs, FUNCTIONFS_BIND);
2920         return 0;
2921
2922 error:
2923         /* XXX Do we need to release all claimed endpoints here? */
2924         return ret;
2925 }
2926
2927 static int ffs_func_bind(struct usb_configuration *c,
2928                          struct usb_function *f)
2929 {
2930         struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2931         struct ffs_function *func = ffs_func_from_usb(f);
2932         int ret;
2933
2934         if (IS_ERR(ffs_opts))
2935                 return PTR_ERR(ffs_opts);
2936
2937         ret = _ffs_func_bind(c, f);
2938         if (ret && !--ffs_opts->refcnt)
2939                 functionfs_unbind(func->ffs);
2940
2941         return ret;
2942 }
2943
2944
2945 /* Other USB function hooks *************************************************/
2946
2947 static void ffs_reset_work(struct work_struct *work)
2948 {
2949         struct ffs_data *ffs = container_of(work,
2950                 struct ffs_data, reset_work);
2951         ffs_data_reset(ffs);
2952 }
2953
2954 static int ffs_func_set_alt(struct usb_function *f,
2955                             unsigned interface, unsigned alt)
2956 {
2957         struct ffs_function *func = ffs_func_from_usb(f);
2958         struct ffs_data *ffs = func->ffs;
2959         int ret = 0, intf;
2960
2961         if (alt != (unsigned)-1) {
2962                 intf = ffs_func_revmap_intf(func, interface);
2963                 if (unlikely(intf < 0))
2964                         return intf;
2965         }
2966
2967         if (ffs->func)
2968                 ffs_func_eps_disable(ffs->func);
2969
2970         if (ffs->state == FFS_DEACTIVATED) {
2971                 ffs->state = FFS_CLOSING;
2972                 INIT_WORK(&ffs->reset_work, ffs_reset_work);
2973                 schedule_work(&ffs->reset_work);
2974                 return -ENODEV;
2975         }
2976
2977         if (ffs->state != FFS_ACTIVE)
2978                 return -ENODEV;
2979
2980         if (alt == (unsigned)-1) {
2981                 ffs->func = NULL;
2982                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2983                 return 0;
2984         }
2985
2986         ffs->func = func;
2987         ret = ffs_func_eps_enable(func);
2988         if (likely(ret >= 0))
2989                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2990         return ret;
2991 }
2992
2993 static void ffs_func_disable(struct usb_function *f)
2994 {
2995         ffs_func_set_alt(f, 0, (unsigned)-1);
2996 }
2997
2998 static int ffs_func_setup(struct usb_function *f,
2999                           const struct usb_ctrlrequest *creq)
3000 {
3001         struct ffs_function *func = ffs_func_from_usb(f);
3002         struct ffs_data *ffs = func->ffs;
3003         unsigned long flags;
3004         int ret;
3005
3006         ENTER();
3007
3008         pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3009         pr_vdebug("creq->bRequest     = %02x\n", creq->bRequest);
3010         pr_vdebug("creq->wValue       = %04x\n", le16_to_cpu(creq->wValue));
3011         pr_vdebug("creq->wIndex       = %04x\n", le16_to_cpu(creq->wIndex));
3012         pr_vdebug("creq->wLength      = %04x\n", le16_to_cpu(creq->wLength));
3013
3014         /*
3015          * Most requests directed to interface go through here
3016          * (notable exceptions are set/get interface) so we need to
3017          * handle them.  All other either handled by composite or
3018          * passed to usb_configuration->setup() (if one is set).  No
3019          * matter, we will handle requests directed to endpoint here
3020          * as well (as it's straightforward) but what to do with any
3021          * other request?
3022          */
3023         if (ffs->state != FFS_ACTIVE)
3024                 return -ENODEV;
3025
3026         switch (creq->bRequestType & USB_RECIP_MASK) {
3027         case USB_RECIP_INTERFACE:
3028                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3029                 if (unlikely(ret < 0))
3030                         return ret;
3031                 break;
3032
3033         case USB_RECIP_ENDPOINT:
3034                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3035                 if (unlikely(ret < 0))
3036                         return ret;
3037                 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3038                         ret = func->ffs->eps_addrmap[ret];
3039                 break;
3040
3041         default:
3042                 return -EOPNOTSUPP;
3043         }
3044
3045         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3046         ffs->ev.setup = *creq;
3047         ffs->ev.setup.wIndex = cpu_to_le16(ret);
3048         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3049         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3050
3051         return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
3052 }
3053
3054 static void ffs_func_suspend(struct usb_function *f)
3055 {
3056         ENTER();
3057         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3058 }
3059
3060 static void ffs_func_resume(struct usb_function *f)
3061 {
3062         ENTER();
3063         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3064 }
3065
3066
3067 /* Endpoint and interface numbers reverse mapping ***************************/
3068
3069 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3070 {
3071         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3072         return num ? num : -EDOM;
3073 }
3074
3075 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3076 {
3077         short *nums = func->interfaces_nums;
3078         unsigned count = func->ffs->interfaces_count;
3079
3080         for (; count; --count, ++nums) {
3081                 if (*nums >= 0 && *nums == intf)
3082                         return nums - func->interfaces_nums;
3083         }
3084
3085         return -EDOM;
3086 }
3087
3088
3089 /* Devices management *******************************************************/
3090
3091 static LIST_HEAD(ffs_devices);
3092
3093 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3094 {
3095         struct ffs_dev *dev;
3096
3097         list_for_each_entry(dev, &ffs_devices, entry) {
3098                 if (!dev->name || !name)
3099                         continue;
3100                 if (strcmp(dev->name, name) == 0)
3101                         return dev;
3102         }
3103
3104         return NULL;
3105 }
3106
3107 /*
3108  * ffs_lock must be taken by the caller of this function
3109  */
3110 static struct ffs_dev *_ffs_get_single_dev(void)
3111 {
3112         struct ffs_dev *dev;
3113
3114         if (list_is_singular(&ffs_devices)) {
3115                 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3116                 if (dev->single)
3117                         return dev;
3118         }
3119
3120         return NULL;
3121 }
3122
3123 /*
3124  * ffs_lock must be taken by the caller of this function
3125  */
3126 static struct ffs_dev *_ffs_find_dev(const char *name)
3127 {
3128         struct ffs_dev *dev;
3129
3130         dev = _ffs_get_single_dev();
3131         if (dev)
3132                 return dev;
3133
3134         return _ffs_do_find_dev(name);
3135 }
3136
3137 /* Configfs support *********************************************************/
3138
3139 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3140 {
3141         return container_of(to_config_group(item), struct f_fs_opts,
3142                             func_inst.group);
3143 }
3144
3145 static void ffs_attr_release(struct config_item *item)
3146 {
3147         struct f_fs_opts *opts = to_ffs_opts(item);
3148
3149         usb_put_function_instance(&opts->func_inst);
3150 }
3151
3152 static struct configfs_item_operations ffs_item_ops = {
3153         .release        = ffs_attr_release,
3154 };
3155
3156 static struct config_item_type ffs_func_type = {
3157         .ct_item_ops    = &ffs_item_ops,
3158         .ct_owner       = THIS_MODULE,
3159 };
3160
3161
3162 /* Function registration interface ******************************************/
3163
3164 static void ffs_free_inst(struct usb_function_instance *f)
3165 {
3166         struct f_fs_opts *opts;
3167
3168         opts = to_f_fs_opts(f);
3169         ffs_dev_lock();
3170         _ffs_free_dev(opts->dev);
3171         ffs_dev_unlock();
3172         kfree(opts);
3173 }
3174
3175 #define MAX_INST_NAME_LEN       40
3176
3177 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3178 {
3179         struct f_fs_opts *opts;
3180         char *ptr;
3181         const char *tmp;
3182         int name_len, ret;
3183
3184         name_len = strlen(name) + 1;
3185         if (name_len > MAX_INST_NAME_LEN)
3186                 return -ENAMETOOLONG;
3187
3188         ptr = kstrndup(name, name_len, GFP_KERNEL);
3189         if (!ptr)
3190                 return -ENOMEM;
3191
3192         opts = to_f_fs_opts(fi);
3193         tmp = NULL;
3194
3195         ffs_dev_lock();
3196
3197         tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3198         ret = _ffs_name_dev(opts->dev, ptr);
3199         if (ret) {
3200                 kfree(ptr);
3201                 ffs_dev_unlock();
3202                 return ret;
3203         }
3204         opts->dev->name_allocated = true;
3205
3206         ffs_dev_unlock();
3207
3208         kfree(tmp);
3209
3210         return 0;
3211 }
3212
3213 static struct usb_function_instance *ffs_alloc_inst(void)
3214 {
3215         struct f_fs_opts *opts;
3216         struct ffs_dev *dev;
3217
3218         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3219         if (!opts)
3220                 return ERR_PTR(-ENOMEM);
3221
3222         opts->func_inst.set_inst_name = ffs_set_inst_name;
3223         opts->func_inst.free_func_inst = ffs_free_inst;
3224         ffs_dev_lock();
3225         dev = _ffs_alloc_dev();
3226         ffs_dev_unlock();
3227         if (IS_ERR(dev)) {
3228                 kfree(opts);
3229                 return ERR_CAST(dev);
3230         }
3231         opts->dev = dev;
3232         dev->opts = opts;
3233
3234         config_group_init_type_name(&opts->func_inst.group, "",
3235                                     &ffs_func_type);
3236         return &opts->func_inst;
3237 }
3238
3239 static void ffs_free(struct usb_function *f)
3240 {
3241         kfree(ffs_func_from_usb(f));
3242 }
3243
3244 static void ffs_func_unbind(struct usb_configuration *c,
3245                             struct usb_function *f)
3246 {
3247         struct ffs_function *func = ffs_func_from_usb(f);
3248         struct ffs_data *ffs = func->ffs;
3249         struct f_fs_opts *opts =
3250                 container_of(f->fi, struct f_fs_opts, func_inst);
3251         struct ffs_ep *ep = func->eps;
3252         unsigned count = ffs->eps_count;
3253         unsigned long flags;
3254
3255         ENTER();
3256         if (ffs->func == func) {
3257                 ffs_func_eps_disable(func);
3258                 ffs->func = NULL;
3259         }
3260
3261         if (!--opts->refcnt)
3262                 functionfs_unbind(ffs);
3263
3264         /* cleanup after autoconfig */
3265         spin_lock_irqsave(&func->ffs->eps_lock, flags);
3266         do {
3267                 if (ep->ep && ep->req)
3268                         usb_ep_free_request(ep->ep, ep->req);
3269                 ep->req = NULL;
3270                 ++ep;
3271         } while (--count);
3272         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3273         kfree(func->eps);
3274         func->eps = NULL;
3275         /*
3276          * eps, descriptors and interfaces_nums are allocated in the
3277          * same chunk so only one free is required.
3278          */
3279         func->function.fs_descriptors = NULL;
3280         func->function.hs_descriptors = NULL;
3281         func->function.ss_descriptors = NULL;
3282         func->interfaces_nums = NULL;
3283
3284         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3285 }
3286
3287 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3288 {
3289         struct ffs_function *func;
3290
3291         ENTER();
3292
3293         func = kzalloc(sizeof(*func), GFP_KERNEL);
3294         if (unlikely(!func))
3295                 return ERR_PTR(-ENOMEM);
3296
3297         func->function.name    = "Function FS Gadget";
3298
3299         func->function.bind    = ffs_func_bind;
3300         func->function.unbind  = ffs_func_unbind;
3301         func->function.set_alt = ffs_func_set_alt;
3302         func->function.disable = ffs_func_disable;
3303         func->function.setup   = ffs_func_setup;
3304         func->function.suspend = ffs_func_suspend;
3305         func->function.resume  = ffs_func_resume;
3306         func->function.free_func = ffs_free;
3307
3308         return &func->function;
3309 }
3310
3311 /*
3312  * ffs_lock must be taken by the caller of this function
3313  */
3314 static struct ffs_dev *_ffs_alloc_dev(void)
3315 {
3316         struct ffs_dev *dev;
3317         int ret;
3318
3319         if (_ffs_get_single_dev())
3320                         return ERR_PTR(-EBUSY);
3321
3322         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3323         if (!dev)
3324                 return ERR_PTR(-ENOMEM);
3325
3326         if (list_empty(&ffs_devices)) {
3327                 ret = functionfs_init();
3328                 if (ret) {
3329                         kfree(dev);
3330                         return ERR_PTR(ret);
3331                 }
3332         }
3333
3334         list_add(&dev->entry, &ffs_devices);
3335
3336         return dev;
3337 }
3338
3339 /*
3340  * ffs_lock must be taken by the caller of this function
3341  * The caller is responsible for "name" being available whenever f_fs needs it
3342  */
3343 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3344 {
3345         struct ffs_dev *existing;
3346
3347         existing = _ffs_do_find_dev(name);
3348         if (existing)
3349                 return -EBUSY;
3350
3351         dev->name = name;
3352
3353         return 0;
3354 }
3355
3356 /*
3357  * The caller is responsible for "name" being available whenever f_fs needs it
3358  */
3359 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3360 {
3361         int ret;
3362
3363         ffs_dev_lock();
3364         ret = _ffs_name_dev(dev, name);
3365         ffs_dev_unlock();
3366
3367         return ret;
3368 }
3369 EXPORT_SYMBOL_GPL(ffs_name_dev);
3370
3371 int ffs_single_dev(struct ffs_dev *dev)
3372 {
3373         int ret;
3374
3375         ret = 0;
3376         ffs_dev_lock();
3377
3378         if (!list_is_singular(&ffs_devices))
3379                 ret = -EBUSY;
3380         else
3381                 dev->single = true;
3382
3383         ffs_dev_unlock();
3384         return ret;
3385 }
3386 EXPORT_SYMBOL_GPL(ffs_single_dev);
3387
3388 /*
3389  * ffs_lock must be taken by the caller of this function
3390  */
3391 static void _ffs_free_dev(struct ffs_dev *dev)
3392 {
3393         list_del(&dev->entry);
3394         if (dev->name_allocated)
3395                 kfree(dev->name);
3396         kfree(dev);
3397         if (list_empty(&ffs_devices))
3398                 functionfs_cleanup();
3399 }
3400
3401 static void *ffs_acquire_dev(const char *dev_name)
3402 {
3403         struct ffs_dev *ffs_dev;
3404
3405         ENTER();
3406         ffs_dev_lock();
3407
3408         ffs_dev = _ffs_find_dev(dev_name);
3409         if (!ffs_dev)
3410                 ffs_dev = ERR_PTR(-ENOENT);
3411         else if (ffs_dev->mounted)
3412                 ffs_dev = ERR_PTR(-EBUSY);
3413         else if (ffs_dev->ffs_acquire_dev_callback &&
3414             ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3415                 ffs_dev = ERR_PTR(-ENOENT);
3416         else
3417                 ffs_dev->mounted = true;
3418
3419         ffs_dev_unlock();
3420         return ffs_dev;
3421 }
3422
3423 static void ffs_release_dev(struct ffs_data *ffs_data)
3424 {
3425         struct ffs_dev *ffs_dev;
3426
3427         ENTER();
3428         ffs_dev_lock();
3429
3430         ffs_dev = ffs_data->private_data;
3431         if (ffs_dev) {
3432                 ffs_dev->mounted = false;
3433
3434                 if (ffs_dev->ffs_release_dev_callback)
3435                         ffs_dev->ffs_release_dev_callback(ffs_dev);
3436         }
3437
3438         ffs_dev_unlock();
3439 }
3440
3441 static int ffs_ready(struct ffs_data *ffs)
3442 {
3443         struct ffs_dev *ffs_obj;
3444         int ret = 0;
3445
3446         ENTER();
3447         ffs_dev_lock();
3448
3449         ffs_obj = ffs->private_data;
3450         if (!ffs_obj) {
3451                 ret = -EINVAL;
3452                 goto done;
3453         }
3454         if (WARN_ON(ffs_obj->desc_ready)) {
3455                 ret = -EBUSY;
3456                 goto done;
3457         }
3458
3459         ffs_obj->desc_ready = true;
3460         ffs_obj->ffs_data = ffs;
3461
3462         if (ffs_obj->ffs_ready_callback) {
3463                 ret = ffs_obj->ffs_ready_callback(ffs);
3464                 if (ret)
3465                         goto done;
3466         }
3467
3468         set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3469 done:
3470         ffs_dev_unlock();
3471         return ret;
3472 }
3473
3474 static void ffs_closed(struct ffs_data *ffs)
3475 {
3476         struct ffs_dev *ffs_obj;
3477         struct f_fs_opts *opts;
3478         struct config_item *ci;
3479
3480         ENTER();
3481         ffs_dev_lock();
3482
3483         ffs_obj = ffs->private_data;
3484         if (!ffs_obj)
3485                 goto done;
3486
3487         ffs_obj->desc_ready = false;
3488
3489         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3490             ffs_obj->ffs_closed_callback)
3491                 ffs_obj->ffs_closed_callback(ffs);
3492
3493         if (ffs_obj->opts)
3494                 opts = ffs_obj->opts;
3495         else
3496                 goto done;
3497
3498         if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3499             || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount))
3500                 goto done;
3501
3502         ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3503         ffs_dev_unlock();
3504
3505         if (test_bit(FFS_FL_BOUND, &ffs->flags))
3506                 unregister_gadget_item(ci);
3507         return;
3508 done:
3509         ffs_dev_unlock();
3510 }
3511
3512 /* Misc helper functions ****************************************************/
3513
3514 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3515 {
3516         return nonblock
3517                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3518                 : mutex_lock_interruptible(mutex);
3519 }
3520
3521 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3522 {
3523         char *data;
3524
3525         if (unlikely(!len))
3526                 return NULL;
3527
3528         data = kmalloc(len, GFP_KERNEL);
3529         if (unlikely(!data))
3530                 return ERR_PTR(-ENOMEM);
3531
3532         if (unlikely(copy_from_user(data, buf, len))) {
3533                 kfree(data);
3534                 return ERR_PTR(-EFAULT);
3535         }
3536
3537         pr_vdebug("Buffer from user space:\n");
3538         ffs_dump_mem("", data, len);
3539
3540         return data;
3541 }
3542
3543 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3544 MODULE_LICENSE("GPL");
3545 MODULE_AUTHOR("Michal Nazarewicz");