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