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