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