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