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                 case FUNCTIONFS_ENDPOINT_DESC:
1035                 {
1036                         int desc_idx;
1037                         struct usb_endpoint_descriptor *desc;
1038
1039                         switch (epfile->ffs->gadget->speed) {
1040                         case USB_SPEED_SUPER:
1041                                 desc_idx = 2;
1042                                 break;
1043                         case USB_SPEED_HIGH:
1044                                 desc_idx = 1;
1045                                 break;
1046                         default:
1047                                 desc_idx = 0;
1048                         }
1049                         desc = epfile->ep->descs[desc_idx];
1050
1051                         spin_unlock_irq(&epfile->ffs->eps_lock);
1052                         ret = copy_to_user((void *)value, desc, sizeof(*desc));
1053                         if (ret)
1054                                 ret = -EFAULT;
1055                         return ret;
1056                 }
1057                 default:
1058                         ret = -ENOTTY;
1059                 }
1060         } else {
1061                 ret = -ENODEV;
1062         }
1063         spin_unlock_irq(&epfile->ffs->eps_lock);
1064
1065         return ret;
1066 }
1067
1068 static const struct file_operations ffs_epfile_operations = {
1069         .llseek =       no_llseek,
1070
1071         .open =         ffs_epfile_open,
1072         .write =        ffs_epfile_write,
1073         .read =         ffs_epfile_read,
1074         .aio_write =    ffs_epfile_aio_write,
1075         .aio_read =     ffs_epfile_aio_read,
1076         .release =      ffs_epfile_release,
1077         .unlocked_ioctl =       ffs_epfile_ioctl,
1078 };
1079
1080
1081 /* File system and super block operations ***********************************/
1082
1083 /*
1084  * Mounting the file system creates a controller file, used first for
1085  * function configuration then later for event monitoring.
1086  */
1087
1088 static struct inode *__must_check
1089 ffs_sb_make_inode(struct super_block *sb, void *data,
1090                   const struct file_operations *fops,
1091                   const struct inode_operations *iops,
1092                   struct ffs_file_perms *perms)
1093 {
1094         struct inode *inode;
1095
1096         ENTER();
1097
1098         inode = new_inode(sb);
1099
1100         if (likely(inode)) {
1101                 struct timespec current_time = CURRENT_TIME;
1102
1103                 inode->i_ino     = get_next_ino();
1104                 inode->i_mode    = perms->mode;
1105                 inode->i_uid     = perms->uid;
1106                 inode->i_gid     = perms->gid;
1107                 inode->i_atime   = current_time;
1108                 inode->i_mtime   = current_time;
1109                 inode->i_ctime   = current_time;
1110                 inode->i_private = data;
1111                 if (fops)
1112                         inode->i_fop = fops;
1113                 if (iops)
1114                         inode->i_op  = iops;
1115         }
1116
1117         return inode;
1118 }
1119
1120 /* Create "regular" file */
1121 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1122                                         const char *name, void *data,
1123                                         const struct file_operations *fops)
1124 {
1125         struct ffs_data *ffs = sb->s_fs_info;
1126         struct dentry   *dentry;
1127         struct inode    *inode;
1128
1129         ENTER();
1130
1131         dentry = d_alloc_name(sb->s_root, name);
1132         if (unlikely(!dentry))
1133                 return NULL;
1134
1135         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1136         if (unlikely(!inode)) {
1137                 dput(dentry);
1138                 return NULL;
1139         }
1140
1141         d_add(dentry, inode);
1142         return dentry;
1143 }
1144
1145 /* Super block */
1146 static const struct super_operations ffs_sb_operations = {
1147         .statfs =       simple_statfs,
1148         .drop_inode =   generic_delete_inode,
1149 };
1150
1151 struct ffs_sb_fill_data {
1152         struct ffs_file_perms perms;
1153         umode_t root_mode;
1154         const char *dev_name;
1155         struct ffs_data *ffs_data;
1156 };
1157
1158 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1159 {
1160         struct ffs_sb_fill_data *data = _data;
1161         struct inode    *inode;
1162         struct ffs_data *ffs = data->ffs_data;
1163
1164         ENTER();
1165
1166         ffs->sb              = sb;
1167         data->ffs_data       = NULL;
1168         sb->s_fs_info        = ffs;
1169         sb->s_blocksize      = PAGE_CACHE_SIZE;
1170         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1171         sb->s_magic          = FUNCTIONFS_MAGIC;
1172         sb->s_op             = &ffs_sb_operations;
1173         sb->s_time_gran      = 1;
1174
1175         /* Root inode */
1176         data->perms.mode = data->root_mode;
1177         inode = ffs_sb_make_inode(sb, NULL,
1178                                   &simple_dir_operations,
1179                                   &simple_dir_inode_operations,
1180                                   &data->perms);
1181         sb->s_root = d_make_root(inode);
1182         if (unlikely(!sb->s_root))
1183                 return -ENOMEM;
1184
1185         /* EP0 file */
1186         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1187                                          &ffs_ep0_operations)))
1188                 return -ENOMEM;
1189
1190         return 0;
1191 }
1192
1193 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1194 {
1195         ENTER();
1196
1197         if (!opts || !*opts)
1198                 return 0;
1199
1200         for (;;) {
1201                 unsigned long value;
1202                 char *eq, *comma;
1203
1204                 /* Option limit */
1205                 comma = strchr(opts, ',');
1206                 if (comma)
1207                         *comma = 0;
1208
1209                 /* Value limit */
1210                 eq = strchr(opts, '=');
1211                 if (unlikely(!eq)) {
1212                         pr_err("'=' missing in %s\n", opts);
1213                         return -EINVAL;
1214                 }
1215                 *eq = 0;
1216
1217                 /* Parse value */
1218                 if (kstrtoul(eq + 1, 0, &value)) {
1219                         pr_err("%s: invalid value: %s\n", opts, eq + 1);
1220                         return -EINVAL;
1221                 }
1222
1223                 /* Interpret option */
1224                 switch (eq - opts) {
1225                 case 5:
1226                         if (!memcmp(opts, "rmode", 5))
1227                                 data->root_mode  = (value & 0555) | S_IFDIR;
1228                         else if (!memcmp(opts, "fmode", 5))
1229                                 data->perms.mode = (value & 0666) | S_IFREG;
1230                         else
1231                                 goto invalid;
1232                         break;
1233
1234                 case 4:
1235                         if (!memcmp(opts, "mode", 4)) {
1236                                 data->root_mode  = (value & 0555) | S_IFDIR;
1237                                 data->perms.mode = (value & 0666) | S_IFREG;
1238                         } else {
1239                                 goto invalid;
1240                         }
1241                         break;
1242
1243                 case 3:
1244                         if (!memcmp(opts, "uid", 3)) {
1245                                 data->perms.uid = make_kuid(current_user_ns(), value);
1246                                 if (!uid_valid(data->perms.uid)) {
1247                                         pr_err("%s: unmapped value: %lu\n", opts, value);
1248                                         return -EINVAL;
1249                                 }
1250                         } else if (!memcmp(opts, "gid", 3)) {
1251                                 data->perms.gid = make_kgid(current_user_ns(), value);
1252                                 if (!gid_valid(data->perms.gid)) {
1253                                         pr_err("%s: unmapped value: %lu\n", opts, value);
1254                                         return -EINVAL;
1255                                 }
1256                         } else {
1257                                 goto invalid;
1258                         }
1259                         break;
1260
1261                 default:
1262 invalid:
1263                         pr_err("%s: invalid option\n", opts);
1264                         return -EINVAL;
1265                 }
1266
1267                 /* Next iteration */
1268                 if (!comma)
1269                         break;
1270                 opts = comma + 1;
1271         }
1272
1273         return 0;
1274 }
1275
1276 /* "mount -t functionfs dev_name /dev/function" ends up here */
1277
1278 static struct dentry *
1279 ffs_fs_mount(struct file_system_type *t, int flags,
1280               const char *dev_name, void *opts)
1281 {
1282         struct ffs_sb_fill_data data = {
1283                 .perms = {
1284                         .mode = S_IFREG | 0600,
1285                         .uid = GLOBAL_ROOT_UID,
1286                         .gid = GLOBAL_ROOT_GID,
1287                 },
1288                 .root_mode = S_IFDIR | 0500,
1289         };
1290         struct dentry *rv;
1291         int ret;
1292         void *ffs_dev;
1293         struct ffs_data *ffs;
1294
1295         ENTER();
1296
1297         ret = ffs_fs_parse_opts(&data, opts);
1298         if (unlikely(ret < 0))
1299                 return ERR_PTR(ret);
1300
1301         ffs = ffs_data_new();
1302         if (unlikely(!ffs))
1303                 return ERR_PTR(-ENOMEM);
1304         ffs->file_perms = data.perms;
1305
1306         ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1307         if (unlikely(!ffs->dev_name)) {
1308                 ffs_data_put(ffs);
1309                 return ERR_PTR(-ENOMEM);
1310         }
1311
1312         ffs_dev = ffs_acquire_dev(dev_name);
1313         if (IS_ERR(ffs_dev)) {
1314                 ffs_data_put(ffs);
1315                 return ERR_CAST(ffs_dev);
1316         }
1317         ffs->private_data = ffs_dev;
1318         data.ffs_data = ffs;
1319
1320         rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1321         if (IS_ERR(rv) && data.ffs_data) {
1322                 ffs_release_dev(data.ffs_data);
1323                 ffs_data_put(data.ffs_data);
1324         }
1325         return rv;
1326 }
1327
1328 static void
1329 ffs_fs_kill_sb(struct super_block *sb)
1330 {
1331         ENTER();
1332
1333         kill_litter_super(sb);
1334         if (sb->s_fs_info) {
1335                 ffs_release_dev(sb->s_fs_info);
1336                 ffs_data_put(sb->s_fs_info);
1337         }
1338 }
1339
1340 static struct file_system_type ffs_fs_type = {
1341         .owner          = THIS_MODULE,
1342         .name           = "functionfs",
1343         .mount          = ffs_fs_mount,
1344         .kill_sb        = ffs_fs_kill_sb,
1345 };
1346 MODULE_ALIAS_FS("functionfs");
1347
1348
1349 /* Driver's main init/cleanup functions *************************************/
1350
1351 static int functionfs_init(void)
1352 {
1353         int ret;
1354
1355         ENTER();
1356
1357         ret = register_filesystem(&ffs_fs_type);
1358         if (likely(!ret))
1359                 pr_info("file system registered\n");
1360         else
1361                 pr_err("failed registering file system (%d)\n", ret);
1362
1363         return ret;
1364 }
1365
1366 static void functionfs_cleanup(void)
1367 {
1368         ENTER();
1369
1370         pr_info("unloading\n");
1371         unregister_filesystem(&ffs_fs_type);
1372 }
1373
1374
1375 /* ffs_data and ffs_function construction and destruction code **************/
1376
1377 static void ffs_data_clear(struct ffs_data *ffs);
1378 static void ffs_data_reset(struct ffs_data *ffs);
1379
1380 static void ffs_data_get(struct ffs_data *ffs)
1381 {
1382         ENTER();
1383
1384         atomic_inc(&ffs->ref);
1385 }
1386
1387 static void ffs_data_opened(struct ffs_data *ffs)
1388 {
1389         ENTER();
1390
1391         atomic_inc(&ffs->ref);
1392         atomic_inc(&ffs->opened);
1393 }
1394
1395 static void ffs_data_put(struct ffs_data *ffs)
1396 {
1397         ENTER();
1398
1399         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1400                 pr_info("%s(): freeing\n", __func__);
1401                 ffs_data_clear(ffs);
1402                 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1403                        waitqueue_active(&ffs->ep0req_completion.wait));
1404                 kfree(ffs->dev_name);
1405                 kfree(ffs);
1406         }
1407 }
1408
1409 static void ffs_data_closed(struct ffs_data *ffs)
1410 {
1411         ENTER();
1412
1413         if (atomic_dec_and_test(&ffs->opened)) {
1414                 ffs->state = FFS_CLOSING;
1415                 ffs_data_reset(ffs);
1416         }
1417
1418         ffs_data_put(ffs);
1419 }
1420
1421 static struct ffs_data *ffs_data_new(void)
1422 {
1423         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1424         if (unlikely(!ffs))
1425                 return NULL;
1426
1427         ENTER();
1428
1429         atomic_set(&ffs->ref, 1);
1430         atomic_set(&ffs->opened, 0);
1431         ffs->state = FFS_READ_DESCRIPTORS;
1432         mutex_init(&ffs->mutex);
1433         spin_lock_init(&ffs->eps_lock);
1434         init_waitqueue_head(&ffs->ev.waitq);
1435         init_completion(&ffs->ep0req_completion);
1436
1437         /* XXX REVISIT need to update it in some places, or do we? */
1438         ffs->ev.can_stall = 1;
1439
1440         return ffs;
1441 }
1442
1443 static void ffs_data_clear(struct ffs_data *ffs)
1444 {
1445         ENTER();
1446
1447         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1448                 ffs_closed(ffs);
1449
1450         BUG_ON(ffs->gadget);
1451
1452         if (ffs->epfiles)
1453                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1454
1455         kfree(ffs->raw_descs_data);
1456         kfree(ffs->raw_strings);
1457         kfree(ffs->stringtabs);
1458 }
1459
1460 static void ffs_data_reset(struct ffs_data *ffs)
1461 {
1462         ENTER();
1463
1464         ffs_data_clear(ffs);
1465
1466         ffs->epfiles = NULL;
1467         ffs->raw_descs_data = NULL;
1468         ffs->raw_descs = NULL;
1469         ffs->raw_strings = NULL;
1470         ffs->stringtabs = NULL;
1471
1472         ffs->raw_descs_length = 0;
1473         ffs->fs_descs_count = 0;
1474         ffs->hs_descs_count = 0;
1475         ffs->ss_descs_count = 0;
1476
1477         ffs->strings_count = 0;
1478         ffs->interfaces_count = 0;
1479         ffs->eps_count = 0;
1480
1481         ffs->ev.count = 0;
1482
1483         ffs->state = FFS_READ_DESCRIPTORS;
1484         ffs->setup_state = FFS_NO_SETUP;
1485         ffs->flags = 0;
1486 }
1487
1488
1489 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1490 {
1491         struct usb_gadget_strings **lang;
1492         int first_id;
1493
1494         ENTER();
1495
1496         if (WARN_ON(ffs->state != FFS_ACTIVE
1497                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1498                 return -EBADFD;
1499
1500         first_id = usb_string_ids_n(cdev, ffs->strings_count);
1501         if (unlikely(first_id < 0))
1502                 return first_id;
1503
1504         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1505         if (unlikely(!ffs->ep0req))
1506                 return -ENOMEM;
1507         ffs->ep0req->complete = ffs_ep0_complete;
1508         ffs->ep0req->context = ffs;
1509
1510         lang = ffs->stringtabs;
1511         if (lang) {
1512                 for (; *lang; ++lang) {
1513                         struct usb_string *str = (*lang)->strings;
1514                         int id = first_id;
1515                         for (; str->s; ++id, ++str)
1516                                 str->id = id;
1517                 }
1518         }
1519
1520         ffs->gadget = cdev->gadget;
1521         ffs_data_get(ffs);
1522         return 0;
1523 }
1524
1525 static void functionfs_unbind(struct ffs_data *ffs)
1526 {
1527         ENTER();
1528
1529         if (!WARN_ON(!ffs->gadget)) {
1530                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1531                 ffs->ep0req = NULL;
1532                 ffs->gadget = NULL;
1533                 clear_bit(FFS_FL_BOUND, &ffs->flags);
1534                 ffs_data_put(ffs);
1535         }
1536 }
1537
1538 static int ffs_epfiles_create(struct ffs_data *ffs)
1539 {
1540         struct ffs_epfile *epfile, *epfiles;
1541         unsigned i, count;
1542
1543         ENTER();
1544
1545         count = ffs->eps_count;
1546         epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1547         if (!epfiles)
1548                 return -ENOMEM;
1549
1550         epfile = epfiles;
1551         for (i = 1; i <= count; ++i, ++epfile) {
1552                 epfile->ffs = ffs;
1553                 mutex_init(&epfile->mutex);
1554                 init_waitqueue_head(&epfile->wait);
1555                 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1556                         sprintf(epfiles->name, "ep%02x", ffs->eps_addrmap[i]);
1557                 else
1558                         sprintf(epfiles->name, "ep%u", i);
1559                 epfile->dentry = ffs_sb_create_file(ffs->sb, epfiles->name,
1560                                                  epfile,
1561                                                  &ffs_epfile_operations);
1562                 if (unlikely(!epfile->dentry)) {
1563                         ffs_epfiles_destroy(epfiles, i - 1);
1564                         return -ENOMEM;
1565                 }
1566         }
1567
1568         ffs->epfiles = epfiles;
1569         return 0;
1570 }
1571
1572 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1573 {
1574         struct ffs_epfile *epfile = epfiles;
1575
1576         ENTER();
1577
1578         for (; count; --count, ++epfile) {
1579                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1580                        waitqueue_active(&epfile->wait));
1581                 if (epfile->dentry) {
1582                         d_delete(epfile->dentry);
1583                         dput(epfile->dentry);
1584                         epfile->dentry = NULL;
1585                 }
1586         }
1587
1588         kfree(epfiles);
1589 }
1590
1591
1592 static void ffs_func_eps_disable(struct ffs_function *func)
1593 {
1594         struct ffs_ep *ep         = func->eps;
1595         struct ffs_epfile *epfile = func->ffs->epfiles;
1596         unsigned count            = func->ffs->eps_count;
1597         unsigned long flags;
1598
1599         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1600         do {
1601                 /* pending requests get nuked */
1602                 if (likely(ep->ep))
1603                         usb_ep_disable(ep->ep);
1604                 epfile->ep = NULL;
1605
1606                 ++ep;
1607                 ++epfile;
1608         } while (--count);
1609         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1610 }
1611
1612 static int ffs_func_eps_enable(struct ffs_function *func)
1613 {
1614         struct ffs_data *ffs      = func->ffs;
1615         struct ffs_ep *ep         = func->eps;
1616         struct ffs_epfile *epfile = ffs->epfiles;
1617         unsigned count            = ffs->eps_count;
1618         unsigned long flags;
1619         int ret = 0;
1620
1621         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1622         do {
1623                 struct usb_endpoint_descriptor *ds;
1624                 int desc_idx;
1625
1626                 if (ffs->gadget->speed == USB_SPEED_SUPER)
1627                         desc_idx = 2;
1628                 else if (ffs->gadget->speed == USB_SPEED_HIGH)
1629                         desc_idx = 1;
1630                 else
1631                         desc_idx = 0;
1632
1633                 /* fall-back to lower speed if desc missing for current speed */
1634                 do {
1635                         ds = ep->descs[desc_idx];
1636                 } while (!ds && --desc_idx >= 0);
1637
1638                 if (!ds) {
1639                         ret = -EINVAL;
1640                         break;
1641                 }
1642
1643                 ep->ep->driver_data = ep;
1644                 ep->ep->desc = ds;
1645                 ret = usb_ep_enable(ep->ep);
1646                 if (likely(!ret)) {
1647                         epfile->ep = ep;
1648                         epfile->in = usb_endpoint_dir_in(ds);
1649                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1650                 } else {
1651                         break;
1652                 }
1653
1654                 wake_up(&epfile->wait);
1655
1656                 ++ep;
1657                 ++epfile;
1658         } while (--count);
1659         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1660
1661         return ret;
1662 }
1663
1664
1665 /* Parsing and building descriptors and strings *****************************/
1666
1667 /*
1668  * This validates if data pointed by data is a valid USB descriptor as
1669  * well as record how many interfaces, endpoints and strings are
1670  * required by given configuration.  Returns address after the
1671  * descriptor or NULL if data is invalid.
1672  */
1673
1674 enum ffs_entity_type {
1675         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1676 };
1677
1678 enum ffs_os_desc_type {
1679         FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1680 };
1681
1682 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1683                                    u8 *valuep,
1684                                    struct usb_descriptor_header *desc,
1685                                    void *priv);
1686
1687 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1688                                     struct usb_os_desc_header *h, void *data,
1689                                     unsigned len, void *priv);
1690
1691 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1692                                            ffs_entity_callback entity,
1693                                            void *priv)
1694 {
1695         struct usb_descriptor_header *_ds = (void *)data;
1696         u8 length;
1697         int ret;
1698
1699         ENTER();
1700
1701         /* At least two bytes are required: length and type */
1702         if (len < 2) {
1703                 pr_vdebug("descriptor too short\n");
1704                 return -EINVAL;
1705         }
1706
1707         /* If we have at least as many bytes as the descriptor takes? */
1708         length = _ds->bLength;
1709         if (len < length) {
1710                 pr_vdebug("descriptor longer then available data\n");
1711                 return -EINVAL;
1712         }
1713
1714 #define __entity_check_INTERFACE(val)  1
1715 #define __entity_check_STRING(val)     (val)
1716 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1717 #define __entity(type, val) do {                                        \
1718                 pr_vdebug("entity " #type "(%02x)\n", (val));           \
1719                 if (unlikely(!__entity_check_ ##type(val))) {           \
1720                         pr_vdebug("invalid entity's value\n");          \
1721                         return -EINVAL;                                 \
1722                 }                                                       \
1723                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1724                 if (unlikely(ret < 0)) {                                \
1725                         pr_debug("entity " #type "(%02x); ret = %d\n",  \
1726                                  (val), ret);                           \
1727                         return ret;                                     \
1728                 }                                                       \
1729         } while (0)
1730
1731         /* Parse descriptor depending on type. */
1732         switch (_ds->bDescriptorType) {
1733         case USB_DT_DEVICE:
1734         case USB_DT_CONFIG:
1735         case USB_DT_STRING:
1736         case USB_DT_DEVICE_QUALIFIER:
1737                 /* function can't have any of those */
1738                 pr_vdebug("descriptor reserved for gadget: %d\n",
1739                       _ds->bDescriptorType);
1740                 return -EINVAL;
1741
1742         case USB_DT_INTERFACE: {
1743                 struct usb_interface_descriptor *ds = (void *)_ds;
1744                 pr_vdebug("interface descriptor\n");
1745                 if (length != sizeof *ds)
1746                         goto inv_length;
1747
1748                 __entity(INTERFACE, ds->bInterfaceNumber);
1749                 if (ds->iInterface)
1750                         __entity(STRING, ds->iInterface);
1751         }
1752                 break;
1753
1754         case USB_DT_ENDPOINT: {
1755                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1756                 pr_vdebug("endpoint descriptor\n");
1757                 if (length != USB_DT_ENDPOINT_SIZE &&
1758                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1759                         goto inv_length;
1760                 __entity(ENDPOINT, ds->bEndpointAddress);
1761         }
1762                 break;
1763
1764         case HID_DT_HID:
1765                 pr_vdebug("hid descriptor\n");
1766                 if (length != sizeof(struct hid_descriptor))
1767                         goto inv_length;
1768                 break;
1769
1770         case USB_DT_OTG:
1771                 if (length != sizeof(struct usb_otg_descriptor))
1772                         goto inv_length;
1773                 break;
1774
1775         case USB_DT_INTERFACE_ASSOCIATION: {
1776                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1777                 pr_vdebug("interface association descriptor\n");
1778                 if (length != sizeof *ds)
1779                         goto inv_length;
1780                 if (ds->iFunction)
1781                         __entity(STRING, ds->iFunction);
1782         }
1783                 break;
1784
1785         case USB_DT_SS_ENDPOINT_COMP:
1786                 pr_vdebug("EP SS companion descriptor\n");
1787                 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1788                         goto inv_length;
1789                 break;
1790
1791         case USB_DT_OTHER_SPEED_CONFIG:
1792         case USB_DT_INTERFACE_POWER:
1793         case USB_DT_DEBUG:
1794         case USB_DT_SECURITY:
1795         case USB_DT_CS_RADIO_CONTROL:
1796                 /* TODO */
1797                 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1798                 return -EINVAL;
1799
1800         default:
1801                 /* We should never be here */
1802                 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1803                 return -EINVAL;
1804
1805 inv_length:
1806                 pr_vdebug("invalid length: %d (descriptor %d)\n",
1807                           _ds->bLength, _ds->bDescriptorType);
1808                 return -EINVAL;
1809         }
1810
1811 #undef __entity
1812 #undef __entity_check_DESCRIPTOR
1813 #undef __entity_check_INTERFACE
1814 #undef __entity_check_STRING
1815 #undef __entity_check_ENDPOINT
1816
1817         return length;
1818 }
1819
1820 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1821                                      ffs_entity_callback entity, void *priv)
1822 {
1823         const unsigned _len = len;
1824         unsigned long num = 0;
1825
1826         ENTER();
1827
1828         for (;;) {
1829                 int ret;
1830
1831                 if (num == count)
1832                         data = NULL;
1833
1834                 /* Record "descriptor" entity */
1835                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1836                 if (unlikely(ret < 0)) {
1837                         pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1838                                  num, ret);
1839                         return ret;
1840                 }
1841
1842                 if (!data)
1843                         return _len - len;
1844
1845                 ret = ffs_do_single_desc(data, len, entity, priv);
1846                 if (unlikely(ret < 0)) {
1847                         pr_debug("%s returns %d\n", __func__, ret);
1848                         return ret;
1849                 }
1850
1851                 len -= ret;
1852                 data += ret;
1853                 ++num;
1854         }
1855 }
1856
1857 static int __ffs_data_do_entity(enum ffs_entity_type type,
1858                                 u8 *valuep, struct usb_descriptor_header *desc,
1859                                 void *priv)
1860 {
1861         struct ffs_desc_helper *helper = priv;
1862         struct usb_endpoint_descriptor *d;
1863
1864         ENTER();
1865
1866         switch (type) {
1867         case FFS_DESCRIPTOR:
1868                 break;
1869
1870         case FFS_INTERFACE:
1871                 /*
1872                  * Interfaces are indexed from zero so if we
1873                  * encountered interface "n" then there are at least
1874                  * "n+1" interfaces.
1875                  */
1876                 if (*valuep >= helper->interfaces_count)
1877                         helper->interfaces_count = *valuep + 1;
1878                 break;
1879
1880         case FFS_STRING:
1881                 /*
1882                  * Strings are indexed from 1 (0 is magic ;) reserved
1883                  * for languages list or some such)
1884                  */
1885                 if (*valuep > helper->ffs->strings_count)
1886                         helper->ffs->strings_count = *valuep;
1887                 break;
1888
1889         case FFS_ENDPOINT:
1890                 d = (void *)desc;
1891                 helper->eps_count++;
1892                 if (helper->eps_count >= 15)
1893                         return -EINVAL;
1894                 /* Check if descriptors for any speed were already parsed */
1895                 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
1896                         helper->ffs->eps_addrmap[helper->eps_count] =
1897                                 d->bEndpointAddress;
1898                 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
1899                                 d->bEndpointAddress)
1900                         return -EINVAL;
1901                 break;
1902         }
1903
1904         return 0;
1905 }
1906
1907 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1908                                    struct usb_os_desc_header *desc)
1909 {
1910         u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1911         u16 w_index = le16_to_cpu(desc->wIndex);
1912
1913         if (bcd_version != 1) {
1914                 pr_vdebug("unsupported os descriptors version: %d",
1915                           bcd_version);
1916                 return -EINVAL;
1917         }
1918         switch (w_index) {
1919         case 0x4:
1920                 *next_type = FFS_OS_DESC_EXT_COMPAT;
1921                 break;
1922         case 0x5:
1923                 *next_type = FFS_OS_DESC_EXT_PROP;
1924                 break;
1925         default:
1926                 pr_vdebug("unsupported os descriptor type: %d", w_index);
1927                 return -EINVAL;
1928         }
1929
1930         return sizeof(*desc);
1931 }
1932
1933 /*
1934  * Process all extended compatibility/extended property descriptors
1935  * of a feature descriptor
1936  */
1937 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1938                                               enum ffs_os_desc_type type,
1939                                               u16 feature_count,
1940                                               ffs_os_desc_callback entity,
1941                                               void *priv,
1942                                               struct usb_os_desc_header *h)
1943 {
1944         int ret;
1945         const unsigned _len = len;
1946
1947         ENTER();
1948
1949         /* loop over all ext compat/ext prop descriptors */
1950         while (feature_count--) {
1951                 ret = entity(type, h, data, len, priv);
1952                 if (unlikely(ret < 0)) {
1953                         pr_debug("bad OS descriptor, type: %d\n", type);
1954                         return ret;
1955                 }
1956                 data += ret;
1957                 len -= ret;
1958         }
1959         return _len - len;
1960 }
1961
1962 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
1963 static int __must_check ffs_do_os_descs(unsigned count,
1964                                         char *data, unsigned len,
1965                                         ffs_os_desc_callback entity, void *priv)
1966 {
1967         const unsigned _len = len;
1968         unsigned long num = 0;
1969
1970         ENTER();
1971
1972         for (num = 0; num < count; ++num) {
1973                 int ret;
1974                 enum ffs_os_desc_type type;
1975                 u16 feature_count;
1976                 struct usb_os_desc_header *desc = (void *)data;
1977
1978                 if (len < sizeof(*desc))
1979                         return -EINVAL;
1980
1981                 /*
1982                  * Record "descriptor" entity.
1983                  * Process dwLength, bcdVersion, wIndex, get b/wCount.
1984                  * Move the data pointer to the beginning of extended
1985                  * compatibilities proper or extended properties proper
1986                  * portions of the data
1987                  */
1988                 if (le32_to_cpu(desc->dwLength) > len)
1989                         return -EINVAL;
1990
1991                 ret = __ffs_do_os_desc_header(&type, desc);
1992                 if (unlikely(ret < 0)) {
1993                         pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
1994                                  num, ret);
1995                         return ret;
1996                 }
1997                 /*
1998                  * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
1999                  */
2000                 feature_count = le16_to_cpu(desc->wCount);
2001                 if (type == FFS_OS_DESC_EXT_COMPAT &&
2002                     (feature_count > 255 || desc->Reserved))
2003                                 return -EINVAL;
2004                 len -= ret;
2005                 data += ret;
2006
2007                 /*
2008                  * Process all function/property descriptors
2009                  * of this Feature Descriptor
2010                  */
2011                 ret = ffs_do_single_os_desc(data, len, type,
2012                                             feature_count, entity, priv, desc);
2013                 if (unlikely(ret < 0)) {
2014                         pr_debug("%s returns %d\n", __func__, ret);
2015                         return ret;
2016                 }
2017
2018                 len -= ret;
2019                 data += ret;
2020         }
2021         return _len - len;
2022 }
2023
2024 /**
2025  * Validate contents of the buffer from userspace related to OS descriptors.
2026  */
2027 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2028                                  struct usb_os_desc_header *h, void *data,
2029                                  unsigned len, void *priv)
2030 {
2031         struct ffs_data *ffs = priv;
2032         u8 length;
2033
2034         ENTER();
2035
2036         switch (type) {
2037         case FFS_OS_DESC_EXT_COMPAT: {
2038                 struct usb_ext_compat_desc *d = data;
2039                 int i;
2040
2041                 if (len < sizeof(*d) ||
2042                     d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2043                     d->Reserved1)
2044                         return -EINVAL;
2045                 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2046                         if (d->Reserved2[i])
2047                                 return -EINVAL;
2048
2049                 length = sizeof(struct usb_ext_compat_desc);
2050         }
2051                 break;
2052         case FFS_OS_DESC_EXT_PROP: {
2053                 struct usb_ext_prop_desc *d = data;
2054                 u32 type, pdl;
2055                 u16 pnl;
2056
2057                 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2058                         return -EINVAL;
2059                 length = le32_to_cpu(d->dwSize);
2060                 type = le32_to_cpu(d->dwPropertyDataType);
2061                 if (type < USB_EXT_PROP_UNICODE ||
2062                     type > USB_EXT_PROP_UNICODE_MULTI) {
2063                         pr_vdebug("unsupported os descriptor property type: %d",
2064                                   type);
2065                         return -EINVAL;
2066                 }
2067                 pnl = le16_to_cpu(d->wPropertyNameLength);
2068                 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2069                 if (length != 14 + pnl + pdl) {
2070                         pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2071                                   length, pnl, pdl, type);
2072                         return -EINVAL;
2073                 }
2074                 ++ffs->ms_os_descs_ext_prop_count;
2075                 /* property name reported to the host as "WCHAR"s */
2076                 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2077                 ffs->ms_os_descs_ext_prop_data_len += pdl;
2078         }
2079                 break;
2080         default:
2081                 pr_vdebug("unknown descriptor: %d\n", type);
2082                 return -EINVAL;
2083         }
2084         return length;
2085 }
2086
2087 static int __ffs_data_got_descs(struct ffs_data *ffs,
2088                                 char *const _data, size_t len)
2089 {
2090         char *data = _data, *raw_descs;
2091         unsigned os_descs_count = 0, counts[3], flags;
2092         int ret = -EINVAL, i;
2093         struct ffs_desc_helper helper;
2094
2095         ENTER();
2096
2097         if (get_unaligned_le32(data + 4) != len)
2098                 goto error;
2099
2100         switch (get_unaligned_le32(data)) {
2101         case FUNCTIONFS_DESCRIPTORS_MAGIC:
2102                 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2103                 data += 8;
2104                 len  -= 8;
2105                 break;
2106         case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2107                 flags = get_unaligned_le32(data + 8);
2108                 ffs->user_flags = flags;
2109                 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2110                               FUNCTIONFS_HAS_HS_DESC |
2111                               FUNCTIONFS_HAS_SS_DESC |
2112                               FUNCTIONFS_HAS_MS_OS_DESC |
2113                               FUNCTIONFS_VIRTUAL_ADDR)) {
2114                         ret = -ENOSYS;
2115                         goto error;
2116                 }
2117                 data += 12;
2118                 len  -= 12;
2119                 break;
2120         default:
2121                 goto error;
2122         }
2123
2124         /* Read fs_count, hs_count and ss_count (if present) */
2125         for (i = 0; i < 3; ++i) {
2126                 if (!(flags & (1 << i))) {
2127                         counts[i] = 0;
2128                 } else if (len < 4) {
2129                         goto error;
2130                 } else {
2131                         counts[i] = get_unaligned_le32(data);
2132                         data += 4;
2133                         len  -= 4;
2134                 }
2135         }
2136         if (flags & (1 << i)) {
2137                 os_descs_count = get_unaligned_le32(data);
2138                 data += 4;
2139                 len -= 4;
2140         };
2141
2142         /* Read descriptors */
2143         raw_descs = data;
2144         helper.ffs = ffs;
2145         for (i = 0; i < 3; ++i) {
2146                 if (!counts[i])
2147                         continue;
2148                 helper.interfaces_count = 0;
2149                 helper.eps_count = 0;
2150                 ret = ffs_do_descs(counts[i], data, len,
2151                                    __ffs_data_do_entity, &helper);
2152                 if (ret < 0)
2153                         goto error;
2154                 if (!ffs->eps_count && !ffs->interfaces_count) {
2155                         ffs->eps_count = helper.eps_count;
2156                         ffs->interfaces_count = helper.interfaces_count;
2157                 } else {
2158                         if (ffs->eps_count != helper.eps_count) {
2159                                 ret = -EINVAL;
2160                                 goto error;
2161                         }
2162                         if (ffs->interfaces_count != helper.interfaces_count) {
2163                                 ret = -EINVAL;
2164                                 goto error;
2165                         }
2166                 }
2167                 data += ret;
2168                 len  -= ret;
2169         }
2170         if (os_descs_count) {
2171                 ret = ffs_do_os_descs(os_descs_count, data, len,
2172                                       __ffs_data_do_os_desc, ffs);
2173                 if (ret < 0)
2174                         goto error;
2175                 data += ret;
2176                 len -= ret;
2177         }
2178
2179         if (raw_descs == data || len) {
2180                 ret = -EINVAL;
2181                 goto error;
2182         }
2183
2184         ffs->raw_descs_data     = _data;
2185         ffs->raw_descs          = raw_descs;
2186         ffs->raw_descs_length   = data - raw_descs;
2187         ffs->fs_descs_count     = counts[0];
2188         ffs->hs_descs_count     = counts[1];
2189         ffs->ss_descs_count     = counts[2];
2190         ffs->ms_os_descs_count  = os_descs_count;
2191
2192         return 0;
2193
2194 error:
2195         kfree(_data);
2196         return ret;
2197 }
2198
2199 static int __ffs_data_got_strings(struct ffs_data *ffs,
2200                                   char *const _data, size_t len)
2201 {
2202         u32 str_count, needed_count, lang_count;
2203         struct usb_gadget_strings **stringtabs, *t;
2204         struct usb_string *strings, *s;
2205         const char *data = _data;
2206
2207         ENTER();
2208
2209         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2210                      get_unaligned_le32(data + 4) != len))
2211                 goto error;
2212         str_count  = get_unaligned_le32(data + 8);
2213         lang_count = get_unaligned_le32(data + 12);
2214
2215         /* if one is zero the other must be zero */
2216         if (unlikely(!str_count != !lang_count))
2217                 goto error;
2218
2219         /* Do we have at least as many strings as descriptors need? */
2220         needed_count = ffs->strings_count;
2221         if (unlikely(str_count < needed_count))
2222                 goto error;
2223
2224         /*
2225          * If we don't need any strings just return and free all
2226          * memory.
2227          */
2228         if (!needed_count) {
2229                 kfree(_data);
2230                 return 0;
2231         }
2232
2233         /* Allocate everything in one chunk so there's less maintenance. */
2234         {
2235                 unsigned i = 0;
2236                 vla_group(d);
2237                 vla_item(d, struct usb_gadget_strings *, stringtabs,
2238                         lang_count + 1);
2239                 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2240                 vla_item(d, struct usb_string, strings,
2241                         lang_count*(needed_count+1));
2242
2243                 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2244
2245                 if (unlikely(!vlabuf)) {
2246                         kfree(_data);
2247                         return -ENOMEM;
2248                 }
2249
2250                 /* Initialize the VLA pointers */
2251                 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2252                 t = vla_ptr(vlabuf, d, stringtab);
2253                 i = lang_count;
2254                 do {
2255                         *stringtabs++ = t++;
2256                 } while (--i);
2257                 *stringtabs = NULL;
2258
2259                 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2260                 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2261                 t = vla_ptr(vlabuf, d, stringtab);
2262                 s = vla_ptr(vlabuf, d, strings);
2263                 strings = s;
2264         }
2265
2266         /* For each language */
2267         data += 16;
2268         len -= 16;
2269
2270         do { /* lang_count > 0 so we can use do-while */
2271                 unsigned needed = needed_count;
2272
2273                 if (unlikely(len < 3))
2274                         goto error_free;
2275                 t->language = get_unaligned_le16(data);
2276                 t->strings  = s;
2277                 ++t;
2278
2279                 data += 2;
2280                 len -= 2;
2281
2282                 /* For each string */
2283                 do { /* str_count > 0 so we can use do-while */
2284                         size_t length = strnlen(data, len);
2285
2286                         if (unlikely(length == len))
2287                                 goto error_free;
2288
2289                         /*
2290                          * User may provide more strings then we need,
2291                          * if that's the case we simply ignore the
2292                          * rest
2293                          */
2294                         if (likely(needed)) {
2295                                 /*
2296                                  * s->id will be set while adding
2297                                  * function to configuration so for
2298                                  * now just leave garbage here.
2299                                  */
2300                                 s->s = data;
2301                                 --needed;
2302                                 ++s;
2303                         }
2304
2305                         data += length + 1;
2306                         len -= length + 1;
2307                 } while (--str_count);
2308
2309                 s->id = 0;   /* terminator */
2310                 s->s = NULL;
2311                 ++s;
2312
2313         } while (--lang_count);
2314
2315         /* Some garbage left? */
2316         if (unlikely(len))
2317                 goto error_free;
2318
2319         /* Done! */
2320         ffs->stringtabs = stringtabs;
2321         ffs->raw_strings = _data;
2322
2323         return 0;
2324
2325 error_free:
2326         kfree(stringtabs);
2327 error:
2328         kfree(_data);
2329         return -EINVAL;
2330 }
2331
2332
2333 /* Events handling and management *******************************************/
2334
2335 static void __ffs_event_add(struct ffs_data *ffs,
2336                             enum usb_functionfs_event_type type)
2337 {
2338         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2339         int neg = 0;
2340
2341         /*
2342          * Abort any unhandled setup
2343          *
2344          * We do not need to worry about some cmpxchg() changing value
2345          * of ffs->setup_state without holding the lock because when
2346          * state is FFS_SETUP_PENDING cmpxchg() in several places in
2347          * the source does nothing.
2348          */
2349         if (ffs->setup_state == FFS_SETUP_PENDING)
2350                 ffs->setup_state = FFS_SETUP_CANCELLED;
2351
2352         switch (type) {
2353         case FUNCTIONFS_RESUME:
2354                 rem_type2 = FUNCTIONFS_SUSPEND;
2355                 /* FALL THROUGH */
2356         case FUNCTIONFS_SUSPEND:
2357         case FUNCTIONFS_SETUP:
2358                 rem_type1 = type;
2359                 /* Discard all similar events */
2360                 break;
2361
2362         case FUNCTIONFS_BIND:
2363         case FUNCTIONFS_UNBIND:
2364         case FUNCTIONFS_DISABLE:
2365         case FUNCTIONFS_ENABLE:
2366                 /* Discard everything other then power management. */
2367                 rem_type1 = FUNCTIONFS_SUSPEND;
2368                 rem_type2 = FUNCTIONFS_RESUME;
2369                 neg = 1;
2370                 break;
2371
2372         default:
2373                 WARN(1, "%d: unknown event, this should not happen\n", type);
2374                 return;
2375         }
2376
2377         {
2378                 u8 *ev  = ffs->ev.types, *out = ev;
2379                 unsigned n = ffs->ev.count;
2380                 for (; n; --n, ++ev)
2381                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2382                                 *out++ = *ev;
2383                         else
2384                                 pr_vdebug("purging event %d\n", *ev);
2385                 ffs->ev.count = out - ffs->ev.types;
2386         }
2387
2388         pr_vdebug("adding event %d\n", type);
2389         ffs->ev.types[ffs->ev.count++] = type;
2390         wake_up_locked(&ffs->ev.waitq);
2391 }
2392
2393 static void ffs_event_add(struct ffs_data *ffs,
2394                           enum usb_functionfs_event_type type)
2395 {
2396         unsigned long flags;
2397         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2398         __ffs_event_add(ffs, type);
2399         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2400 }
2401
2402 /* Bind/unbind USB function hooks *******************************************/
2403
2404 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2405 {
2406         int i;
2407
2408         for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2409                 if (ffs->eps_addrmap[i] == endpoint_address)
2410                         return i;
2411         return -ENOENT;
2412 }
2413
2414 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2415                                     struct usb_descriptor_header *desc,
2416                                     void *priv)
2417 {
2418         struct usb_endpoint_descriptor *ds = (void *)desc;
2419         struct ffs_function *func = priv;
2420         struct ffs_ep *ffs_ep;
2421         unsigned ep_desc_id;
2422         int idx;
2423         static const char *speed_names[] = { "full", "high", "super" };
2424
2425         if (type != FFS_DESCRIPTOR)
2426                 return 0;
2427
2428         /*
2429          * If ss_descriptors is not NULL, we are reading super speed
2430          * descriptors; if hs_descriptors is not NULL, we are reading high
2431          * speed descriptors; otherwise, we are reading full speed
2432          * descriptors.
2433          */
2434         if (func->function.ss_descriptors) {
2435                 ep_desc_id = 2;
2436                 func->function.ss_descriptors[(long)valuep] = desc;
2437         } else if (func->function.hs_descriptors) {
2438                 ep_desc_id = 1;
2439                 func->function.hs_descriptors[(long)valuep] = desc;
2440         } else {
2441                 ep_desc_id = 0;
2442                 func->function.fs_descriptors[(long)valuep]    = desc;
2443         }
2444
2445         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2446                 return 0;
2447
2448         idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2449         if (idx < 0)
2450                 return idx;
2451
2452         ffs_ep = func->eps + idx;
2453
2454         if (unlikely(ffs_ep->descs[ep_desc_id])) {
2455                 pr_err("two %sspeed descriptors for EP %d\n",
2456                           speed_names[ep_desc_id],
2457                           ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2458                 return -EINVAL;
2459         }
2460         ffs_ep->descs[ep_desc_id] = ds;
2461
2462         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2463         if (ffs_ep->ep) {
2464                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2465                 if (!ds->wMaxPacketSize)
2466                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2467         } else {
2468                 struct usb_request *req;
2469                 struct usb_ep *ep;
2470                 u8 bEndpointAddress;
2471
2472                 /*
2473                  * We back up bEndpointAddress because autoconfig overwrites
2474                  * it with physical endpoint address.
2475                  */
2476                 bEndpointAddress = ds->bEndpointAddress;
2477                 pr_vdebug("autoconfig\n");
2478                 ep = usb_ep_autoconfig(func->gadget, ds);
2479                 if (unlikely(!ep))
2480                         return -ENOTSUPP;
2481                 ep->driver_data = func->eps + idx;
2482
2483                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2484                 if (unlikely(!req))
2485                         return -ENOMEM;
2486
2487                 ffs_ep->ep  = ep;
2488                 ffs_ep->req = req;
2489                 func->eps_revmap[ds->bEndpointAddress &
2490                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2491                 /*
2492                  * If we use virtual address mapping, we restore
2493                  * original bEndpointAddress value.
2494                  */
2495                 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2496                         ds->bEndpointAddress = bEndpointAddress;
2497         }
2498         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2499
2500         return 0;
2501 }
2502
2503 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2504                                    struct usb_descriptor_header *desc,
2505                                    void *priv)
2506 {
2507         struct ffs_function *func = priv;
2508         unsigned idx;
2509         u8 newValue;
2510
2511         switch (type) {
2512         default:
2513         case FFS_DESCRIPTOR:
2514                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2515                 return 0;
2516
2517         case FFS_INTERFACE:
2518                 idx = *valuep;
2519                 if (func->interfaces_nums[idx] < 0) {
2520                         int id = usb_interface_id(func->conf, &func->function);
2521                         if (unlikely(id < 0))
2522                                 return id;
2523                         func->interfaces_nums[idx] = id;
2524                 }
2525                 newValue = func->interfaces_nums[idx];
2526                 break;
2527
2528         case FFS_STRING:
2529                 /* String' IDs are allocated when fsf_data is bound to cdev */
2530                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2531                 break;
2532
2533         case FFS_ENDPOINT:
2534                 /*
2535                  * USB_DT_ENDPOINT are handled in
2536                  * __ffs_func_bind_do_descs().
2537                  */
2538                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2539                         return 0;
2540
2541                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2542                 if (unlikely(!func->eps[idx].ep))
2543                         return -EINVAL;
2544
2545                 {
2546                         struct usb_endpoint_descriptor **descs;
2547                         descs = func->eps[idx].descs;
2548                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2549                 }
2550                 break;
2551         }
2552
2553         pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2554         *valuep = newValue;
2555         return 0;
2556 }
2557
2558 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2559                                       struct usb_os_desc_header *h, void *data,
2560                                       unsigned len, void *priv)
2561 {
2562         struct ffs_function *func = priv;
2563         u8 length = 0;
2564
2565         switch (type) {
2566         case FFS_OS_DESC_EXT_COMPAT: {
2567                 struct usb_ext_compat_desc *desc = data;
2568                 struct usb_os_desc_table *t;
2569
2570                 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2571                 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2572                 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2573                        ARRAY_SIZE(desc->CompatibleID) +
2574                        ARRAY_SIZE(desc->SubCompatibleID));
2575                 length = sizeof(*desc);
2576         }
2577                 break;
2578         case FFS_OS_DESC_EXT_PROP: {
2579                 struct usb_ext_prop_desc *desc = data;
2580                 struct usb_os_desc_table *t;
2581                 struct usb_os_desc_ext_prop *ext_prop;
2582                 char *ext_prop_name;
2583                 char *ext_prop_data;
2584
2585                 t = &func->function.os_desc_table[h->interface];
2586                 t->if_id = func->interfaces_nums[h->interface];
2587
2588                 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2589                 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2590
2591                 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2592                 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2593                 ext_prop->data_len = le32_to_cpu(*(u32 *)
2594                         usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2595                 length = ext_prop->name_len + ext_prop->data_len + 14;
2596
2597                 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2598                 func->ffs->ms_os_descs_ext_prop_name_avail +=
2599                         ext_prop->name_len;
2600
2601                 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2602                 func->ffs->ms_os_descs_ext_prop_data_avail +=
2603                         ext_prop->data_len;
2604                 memcpy(ext_prop_data,
2605                        usb_ext_prop_data_ptr(data, ext_prop->name_len),
2606                        ext_prop->data_len);
2607                 /* unicode data reported to the host as "WCHAR"s */
2608                 switch (ext_prop->type) {
2609                 case USB_EXT_PROP_UNICODE:
2610                 case USB_EXT_PROP_UNICODE_ENV:
2611                 case USB_EXT_PROP_UNICODE_LINK:
2612                 case USB_EXT_PROP_UNICODE_MULTI:
2613                         ext_prop->data_len *= 2;
2614                         break;
2615                 }
2616                 ext_prop->data = ext_prop_data;
2617
2618                 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2619                        ext_prop->name_len);
2620                 /* property name reported to the host as "WCHAR"s */
2621                 ext_prop->name_len *= 2;
2622                 ext_prop->name = ext_prop_name;
2623
2624                 t->os_desc->ext_prop_len +=
2625                         ext_prop->name_len + ext_prop->data_len + 14;
2626                 ++t->os_desc->ext_prop_count;
2627                 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2628         }
2629                 break;
2630         default:
2631                 pr_vdebug("unknown descriptor: %d\n", type);
2632         }
2633
2634         return length;
2635 }
2636
2637 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2638                                                 struct usb_configuration *c)
2639 {
2640         struct ffs_function *func = ffs_func_from_usb(f);
2641         struct f_fs_opts *ffs_opts =
2642                 container_of(f->fi, struct f_fs_opts, func_inst);
2643         int ret;
2644
2645         ENTER();
2646
2647         /*
2648          * Legacy gadget triggers binding in functionfs_ready_callback,
2649          * which already uses locking; taking the same lock here would
2650          * cause a deadlock.
2651          *
2652          * Configfs-enabled gadgets however do need ffs_dev_lock.
2653          */
2654         if (!ffs_opts->no_configfs)
2655                 ffs_dev_lock();
2656         ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2657         func->ffs = ffs_opts->dev->ffs_data;
2658         if (!ffs_opts->no_configfs)
2659                 ffs_dev_unlock();
2660         if (ret)
2661                 return ERR_PTR(ret);
2662
2663         func->conf = c;
2664         func->gadget = c->cdev->gadget;
2665
2666         ffs_data_get(func->ffs);
2667
2668         /*
2669          * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2670          * configurations are bound in sequence with list_for_each_entry,
2671          * in each configuration its functions are bound in sequence
2672          * with list_for_each_entry, so we assume no race condition
2673          * with regard to ffs_opts->bound access
2674          */
2675         if (!ffs_opts->refcnt) {
2676                 ret = functionfs_bind(func->ffs, c->cdev);
2677                 if (ret)
2678                         return ERR_PTR(ret);
2679         }
2680         ffs_opts->refcnt++;
2681         func->function.strings = func->ffs->stringtabs;
2682
2683         return ffs_opts;
2684 }
2685
2686 static int _ffs_func_bind(struct usb_configuration *c,
2687                           struct usb_function *f)
2688 {
2689         struct ffs_function *func = ffs_func_from_usb(f);
2690         struct ffs_data *ffs = func->ffs;
2691
2692         const int full = !!func->ffs->fs_descs_count;
2693         const int high = gadget_is_dualspeed(func->gadget) &&
2694                 func->ffs->hs_descs_count;
2695         const int super = gadget_is_superspeed(func->gadget) &&
2696                 func->ffs->ss_descs_count;
2697
2698         int fs_len, hs_len, ss_len, ret, i;
2699
2700         /* Make it a single chunk, less management later on */
2701         vla_group(d);
2702         vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2703         vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2704                 full ? ffs->fs_descs_count + 1 : 0);
2705         vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2706                 high ? ffs->hs_descs_count + 1 : 0);
2707         vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2708                 super ? ffs->ss_descs_count + 1 : 0);
2709         vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2710         vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2711                          c->cdev->use_os_string ? ffs->interfaces_count : 0);
2712         vla_item_with_sz(d, char[16], ext_compat,
2713                          c->cdev->use_os_string ? ffs->interfaces_count : 0);
2714         vla_item_with_sz(d, struct usb_os_desc, os_desc,
2715                          c->cdev->use_os_string ? ffs->interfaces_count : 0);
2716         vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2717                          ffs->ms_os_descs_ext_prop_count);
2718         vla_item_with_sz(d, char, ext_prop_name,
2719                          ffs->ms_os_descs_ext_prop_name_len);
2720         vla_item_with_sz(d, char, ext_prop_data,
2721                          ffs->ms_os_descs_ext_prop_data_len);
2722         vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2723         char *vlabuf;
2724
2725         ENTER();
2726
2727         /* Has descriptors only for speeds gadget does not support */
2728         if (unlikely(!(full | high | super)))
2729                 return -ENOTSUPP;
2730
2731         /* Allocate a single chunk, less management later on */
2732         vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2733         if (unlikely(!vlabuf))
2734                 return -ENOMEM;
2735
2736         ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2737         ffs->ms_os_descs_ext_prop_name_avail =
2738                 vla_ptr(vlabuf, d, ext_prop_name);
2739         ffs->ms_os_descs_ext_prop_data_avail =
2740                 vla_ptr(vlabuf, d, ext_prop_data);
2741
2742         /* Copy descriptors  */
2743         memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2744                ffs->raw_descs_length);
2745
2746         memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2747         for (ret = ffs->eps_count; ret; --ret) {
2748                 struct ffs_ep *ptr;
2749
2750                 ptr = vla_ptr(vlabuf, d, eps);
2751                 ptr[ret].num = -1;
2752         }
2753
2754         /* Save pointers
2755          * d_eps == vlabuf, func->eps used to kfree vlabuf later
2756         */
2757         func->eps             = vla_ptr(vlabuf, d, eps);
2758         func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2759
2760         /*
2761          * Go through all the endpoint descriptors and allocate
2762          * endpoints first, so that later we can rewrite the endpoint
2763          * numbers without worrying that it may be described later on.
2764          */
2765         if (likely(full)) {
2766                 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2767                 fs_len = ffs_do_descs(ffs->fs_descs_count,
2768                                       vla_ptr(vlabuf, d, raw_descs),
2769                                       d_raw_descs__sz,
2770                                       __ffs_func_bind_do_descs, func);
2771                 if (unlikely(fs_len < 0)) {
2772                         ret = fs_len;
2773                         goto error;
2774                 }
2775         } else {
2776                 fs_len = 0;
2777         }
2778
2779         if (likely(high)) {
2780                 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2781                 hs_len = ffs_do_descs(ffs->hs_descs_count,
2782                                       vla_ptr(vlabuf, d, raw_descs) + fs_len,
2783                                       d_raw_descs__sz - fs_len,
2784                                       __ffs_func_bind_do_descs, func);
2785                 if (unlikely(hs_len < 0)) {
2786                         ret = hs_len;
2787                         goto error;
2788                 }
2789         } else {
2790                 hs_len = 0;
2791         }
2792
2793         if (likely(super)) {
2794                 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2795                 ss_len = ffs_do_descs(ffs->ss_descs_count,
2796                                 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2797                                 d_raw_descs__sz - fs_len - hs_len,
2798                                 __ffs_func_bind_do_descs, func);
2799                 if (unlikely(ss_len < 0)) {
2800                         ret = ss_len;
2801                         goto error;
2802                 }
2803         } else {
2804                 ss_len = 0;
2805         }
2806
2807         /*
2808          * Now handle interface numbers allocation and interface and
2809          * endpoint numbers rewriting.  We can do that in one go
2810          * now.
2811          */
2812         ret = ffs_do_descs(ffs->fs_descs_count +
2813                            (high ? ffs->hs_descs_count : 0) +
2814                            (super ? ffs->ss_descs_count : 0),
2815                            vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2816                            __ffs_func_bind_do_nums, func);
2817         if (unlikely(ret < 0))
2818                 goto error;
2819
2820         func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2821         if (c->cdev->use_os_string)
2822                 for (i = 0; i < ffs->interfaces_count; ++i) {
2823                         struct usb_os_desc *desc;
2824
2825                         desc = func->function.os_desc_table[i].os_desc =
2826                                 vla_ptr(vlabuf, d, os_desc) +
2827                                 i * sizeof(struct usb_os_desc);
2828                         desc->ext_compat_id =
2829                                 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2830                         INIT_LIST_HEAD(&desc->ext_prop);
2831                 }
2832         ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2833                               vla_ptr(vlabuf, d, raw_descs) +
2834                               fs_len + hs_len + ss_len,
2835                               d_raw_descs__sz - fs_len - hs_len - ss_len,
2836                               __ffs_func_bind_do_os_desc, func);
2837         if (unlikely(ret < 0))
2838                 goto error;
2839         func->function.os_desc_n =
2840                 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2841
2842         /* And we're done */
2843         ffs_event_add(ffs, FUNCTIONFS_BIND);
2844         return 0;
2845
2846 error:
2847         /* XXX Do we need to release all claimed endpoints here? */
2848         return ret;
2849 }
2850
2851 static int ffs_func_bind(struct usb_configuration *c,
2852                          struct usb_function *f)
2853 {
2854         struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2855
2856         if (IS_ERR(ffs_opts))
2857                 return PTR_ERR(ffs_opts);
2858
2859         return _ffs_func_bind(c, f);
2860 }
2861
2862
2863 /* Other USB function hooks *************************************************/
2864
2865 static int ffs_func_set_alt(struct usb_function *f,
2866                             unsigned interface, unsigned alt)
2867 {
2868         struct ffs_function *func = ffs_func_from_usb(f);
2869         struct ffs_data *ffs = func->ffs;
2870         int ret = 0, intf;
2871
2872         if (alt != (unsigned)-1) {
2873                 intf = ffs_func_revmap_intf(func, interface);
2874                 if (unlikely(intf < 0))
2875                         return intf;
2876         }
2877
2878         if (ffs->func)
2879                 ffs_func_eps_disable(ffs->func);
2880
2881         if (ffs->state != FFS_ACTIVE)
2882                 return -ENODEV;
2883
2884         if (alt == (unsigned)-1) {
2885                 ffs->func = NULL;
2886                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2887                 return 0;
2888         }
2889
2890         ffs->func = func;
2891         ret = ffs_func_eps_enable(func);
2892         if (likely(ret >= 0))
2893                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2894         return ret;
2895 }
2896
2897 static void ffs_func_disable(struct usb_function *f)
2898 {
2899         ffs_func_set_alt(f, 0, (unsigned)-1);
2900 }
2901
2902 static int ffs_func_setup(struct usb_function *f,
2903                           const struct usb_ctrlrequest *creq)
2904 {
2905         struct ffs_function *func = ffs_func_from_usb(f);
2906         struct ffs_data *ffs = func->ffs;
2907         unsigned long flags;
2908         int ret;
2909
2910         ENTER();
2911
2912         pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2913         pr_vdebug("creq->bRequest     = %02x\n", creq->bRequest);
2914         pr_vdebug("creq->wValue       = %04x\n", le16_to_cpu(creq->wValue));
2915         pr_vdebug("creq->wIndex       = %04x\n", le16_to_cpu(creq->wIndex));
2916         pr_vdebug("creq->wLength      = %04x\n", le16_to_cpu(creq->wLength));
2917
2918         /*
2919          * Most requests directed to interface go through here
2920          * (notable exceptions are set/get interface) so we need to
2921          * handle them.  All other either handled by composite or
2922          * passed to usb_configuration->setup() (if one is set).  No
2923          * matter, we will handle requests directed to endpoint here
2924          * as well (as it's straightforward) but what to do with any
2925          * other request?
2926          */
2927         if (ffs->state != FFS_ACTIVE)
2928                 return -ENODEV;
2929
2930         switch (creq->bRequestType & USB_RECIP_MASK) {
2931         case USB_RECIP_INTERFACE:
2932                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2933                 if (unlikely(ret < 0))
2934                         return ret;
2935                 break;
2936
2937         case USB_RECIP_ENDPOINT:
2938                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2939                 if (unlikely(ret < 0))
2940                         return ret;
2941                 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2942                         ret = func->ffs->eps_addrmap[ret];
2943                 break;
2944
2945         default:
2946                 return -EOPNOTSUPP;
2947         }
2948
2949         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2950         ffs->ev.setup = *creq;
2951         ffs->ev.setup.wIndex = cpu_to_le16(ret);
2952         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2953         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2954
2955         return 0;
2956 }
2957
2958 static void ffs_func_suspend(struct usb_function *f)
2959 {
2960         ENTER();
2961         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2962 }
2963
2964 static void ffs_func_resume(struct usb_function *f)
2965 {
2966         ENTER();
2967         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2968 }
2969
2970
2971 /* Endpoint and interface numbers reverse mapping ***************************/
2972
2973 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2974 {
2975         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2976         return num ? num : -EDOM;
2977 }
2978
2979 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2980 {
2981         short *nums = func->interfaces_nums;
2982         unsigned count = func->ffs->interfaces_count;
2983
2984         for (; count; --count, ++nums) {
2985                 if (*nums >= 0 && *nums == intf)
2986                         return nums - func->interfaces_nums;
2987         }
2988
2989         return -EDOM;
2990 }
2991
2992
2993 /* Devices management *******************************************************/
2994
2995 static LIST_HEAD(ffs_devices);
2996
2997 static struct ffs_dev *_ffs_do_find_dev(const char *name)
2998 {
2999         struct ffs_dev *dev;
3000
3001         list_for_each_entry(dev, &ffs_devices, entry) {
3002                 if (!dev->name || !name)
3003                         continue;
3004                 if (strcmp(dev->name, name) == 0)
3005                         return dev;
3006         }
3007
3008         return NULL;
3009 }
3010
3011 /*
3012  * ffs_lock must be taken by the caller of this function
3013  */
3014 static struct ffs_dev *_ffs_get_single_dev(void)
3015 {
3016         struct ffs_dev *dev;
3017
3018         if (list_is_singular(&ffs_devices)) {
3019                 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3020                 if (dev->single)
3021                         return dev;
3022         }
3023
3024         return NULL;
3025 }
3026
3027 /*
3028  * ffs_lock must be taken by the caller of this function
3029  */
3030 static struct ffs_dev *_ffs_find_dev(const char *name)
3031 {
3032         struct ffs_dev *dev;
3033
3034         dev = _ffs_get_single_dev();
3035         if (dev)
3036                 return dev;
3037
3038         return _ffs_do_find_dev(name);
3039 }
3040
3041 /* Configfs support *********************************************************/
3042
3043 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3044 {
3045         return container_of(to_config_group(item), struct f_fs_opts,
3046                             func_inst.group);
3047 }
3048
3049 static void ffs_attr_release(struct config_item *item)
3050 {
3051         struct f_fs_opts *opts = to_ffs_opts(item);
3052
3053         usb_put_function_instance(&opts->func_inst);
3054 }
3055
3056 static struct configfs_item_operations ffs_item_ops = {
3057         .release        = ffs_attr_release,
3058 };
3059
3060 static struct config_item_type ffs_func_type = {
3061         .ct_item_ops    = &ffs_item_ops,
3062         .ct_owner       = THIS_MODULE,
3063 };
3064
3065
3066 /* Function registration interface ******************************************/
3067
3068 static void ffs_free_inst(struct usb_function_instance *f)
3069 {
3070         struct f_fs_opts *opts;
3071
3072         opts = to_f_fs_opts(f);
3073         ffs_dev_lock();
3074         _ffs_free_dev(opts->dev);
3075         ffs_dev_unlock();
3076         kfree(opts);
3077 }
3078
3079 #define MAX_INST_NAME_LEN       40
3080
3081 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3082 {
3083         struct f_fs_opts *opts;
3084         char *ptr;
3085         const char *tmp;
3086         int name_len, ret;
3087
3088         name_len = strlen(name) + 1;
3089         if (name_len > MAX_INST_NAME_LEN)
3090                 return -ENAMETOOLONG;
3091
3092         ptr = kstrndup(name, name_len, GFP_KERNEL);
3093         if (!ptr)
3094                 return -ENOMEM;
3095
3096         opts = to_f_fs_opts(fi);
3097         tmp = NULL;
3098
3099         ffs_dev_lock();
3100
3101         tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3102         ret = _ffs_name_dev(opts->dev, ptr);
3103         if (ret) {
3104                 kfree(ptr);
3105                 ffs_dev_unlock();
3106                 return ret;
3107         }
3108         opts->dev->name_allocated = true;
3109
3110         ffs_dev_unlock();
3111
3112         kfree(tmp);
3113
3114         return 0;
3115 }
3116
3117 static struct usb_function_instance *ffs_alloc_inst(void)
3118 {
3119         struct f_fs_opts *opts;
3120         struct ffs_dev *dev;
3121
3122         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3123         if (!opts)
3124                 return ERR_PTR(-ENOMEM);
3125
3126         opts->func_inst.set_inst_name = ffs_set_inst_name;
3127         opts->func_inst.free_func_inst = ffs_free_inst;
3128         ffs_dev_lock();
3129         dev = _ffs_alloc_dev();
3130         ffs_dev_unlock();
3131         if (IS_ERR(dev)) {
3132                 kfree(opts);
3133                 return ERR_CAST(dev);
3134         }
3135         opts->dev = dev;
3136         dev->opts = opts;
3137
3138         config_group_init_type_name(&opts->func_inst.group, "",
3139                                     &ffs_func_type);
3140         return &opts->func_inst;
3141 }
3142
3143 static void ffs_free(struct usb_function *f)
3144 {
3145         kfree(ffs_func_from_usb(f));
3146 }
3147
3148 static void ffs_func_unbind(struct usb_configuration *c,
3149                             struct usb_function *f)
3150 {
3151         struct ffs_function *func = ffs_func_from_usb(f);
3152         struct ffs_data *ffs = func->ffs;
3153         struct f_fs_opts *opts =
3154                 container_of(f->fi, struct f_fs_opts, func_inst);
3155         struct ffs_ep *ep = func->eps;
3156         unsigned count = ffs->eps_count;
3157         unsigned long flags;
3158
3159         ENTER();
3160         if (ffs->func == func) {
3161                 ffs_func_eps_disable(func);
3162                 ffs->func = NULL;
3163         }
3164
3165         if (!--opts->refcnt)
3166                 functionfs_unbind(ffs);
3167
3168         /* cleanup after autoconfig */
3169         spin_lock_irqsave(&func->ffs->eps_lock, flags);
3170         do {
3171                 if (ep->ep && ep->req)
3172                         usb_ep_free_request(ep->ep, ep->req);
3173                 ep->req = NULL;
3174                 ++ep;
3175         } while (--count);
3176         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3177         kfree(func->eps);
3178         func->eps = NULL;
3179         /*
3180          * eps, descriptors and interfaces_nums are allocated in the
3181          * same chunk so only one free is required.
3182          */
3183         func->function.fs_descriptors = NULL;
3184         func->function.hs_descriptors = NULL;
3185         func->function.ss_descriptors = NULL;
3186         func->interfaces_nums = NULL;
3187
3188         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3189 }
3190
3191 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3192 {
3193         struct ffs_function *func;
3194
3195         ENTER();
3196
3197         func = kzalloc(sizeof(*func), GFP_KERNEL);
3198         if (unlikely(!func))
3199                 return ERR_PTR(-ENOMEM);
3200
3201         func->function.name    = "Function FS Gadget";
3202
3203         func->function.bind    = ffs_func_bind;
3204         func->function.unbind  = ffs_func_unbind;
3205         func->function.set_alt = ffs_func_set_alt;
3206         func->function.disable = ffs_func_disable;
3207         func->function.setup   = ffs_func_setup;
3208         func->function.suspend = ffs_func_suspend;
3209         func->function.resume  = ffs_func_resume;
3210         func->function.free_func = ffs_free;
3211
3212         return &func->function;
3213 }
3214
3215 /*
3216  * ffs_lock must be taken by the caller of this function
3217  */
3218 static struct ffs_dev *_ffs_alloc_dev(void)
3219 {
3220         struct ffs_dev *dev;
3221         int ret;
3222
3223         if (_ffs_get_single_dev())
3224                         return ERR_PTR(-EBUSY);
3225
3226         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3227         if (!dev)
3228                 return ERR_PTR(-ENOMEM);
3229
3230         if (list_empty(&ffs_devices)) {
3231                 ret = functionfs_init();
3232                 if (ret) {
3233                         kfree(dev);
3234                         return ERR_PTR(ret);
3235                 }
3236         }
3237
3238         list_add(&dev->entry, &ffs_devices);
3239
3240         return dev;
3241 }
3242
3243 /*
3244  * ffs_lock must be taken by the caller of this function
3245  * The caller is responsible for "name" being available whenever f_fs needs it
3246  */
3247 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3248 {
3249         struct ffs_dev *existing;
3250
3251         existing = _ffs_do_find_dev(name);
3252         if (existing)
3253                 return -EBUSY;
3254
3255         dev->name = name;
3256
3257         return 0;
3258 }
3259
3260 /*
3261  * The caller is responsible for "name" being available whenever f_fs needs it
3262  */
3263 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3264 {
3265         int ret;
3266
3267         ffs_dev_lock();
3268         ret = _ffs_name_dev(dev, name);
3269         ffs_dev_unlock();
3270
3271         return ret;
3272 }
3273 EXPORT_SYMBOL_GPL(ffs_name_dev);
3274
3275 int ffs_single_dev(struct ffs_dev *dev)
3276 {
3277         int ret;
3278
3279         ret = 0;
3280         ffs_dev_lock();
3281
3282         if (!list_is_singular(&ffs_devices))
3283                 ret = -EBUSY;
3284         else
3285                 dev->single = true;
3286
3287         ffs_dev_unlock();
3288         return ret;
3289 }
3290 EXPORT_SYMBOL_GPL(ffs_single_dev);
3291
3292 /*
3293  * ffs_lock must be taken by the caller of this function
3294  */
3295 static void _ffs_free_dev(struct ffs_dev *dev)
3296 {
3297         list_del(&dev->entry);
3298         if (dev->name_allocated)
3299                 kfree(dev->name);
3300         kfree(dev);
3301         if (list_empty(&ffs_devices))
3302                 functionfs_cleanup();
3303 }
3304
3305 static void *ffs_acquire_dev(const char *dev_name)
3306 {
3307         struct ffs_dev *ffs_dev;
3308
3309         ENTER();
3310         ffs_dev_lock();
3311
3312         ffs_dev = _ffs_find_dev(dev_name);
3313         if (!ffs_dev)
3314                 ffs_dev = ERR_PTR(-ENOENT);
3315         else if (ffs_dev->mounted)
3316                 ffs_dev = ERR_PTR(-EBUSY);
3317         else if (ffs_dev->ffs_acquire_dev_callback &&
3318             ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3319                 ffs_dev = ERR_PTR(-ENOENT);
3320         else
3321                 ffs_dev->mounted = true;
3322
3323         ffs_dev_unlock();
3324         return ffs_dev;
3325 }
3326
3327 static void ffs_release_dev(struct ffs_data *ffs_data)
3328 {
3329         struct ffs_dev *ffs_dev;
3330
3331         ENTER();
3332         ffs_dev_lock();
3333
3334         ffs_dev = ffs_data->private_data;
3335         if (ffs_dev) {
3336                 ffs_dev->mounted = false;
3337
3338                 if (ffs_dev->ffs_release_dev_callback)
3339                         ffs_dev->ffs_release_dev_callback(ffs_dev);
3340         }
3341
3342         ffs_dev_unlock();
3343 }
3344
3345 static int ffs_ready(struct ffs_data *ffs)
3346 {
3347         struct ffs_dev *ffs_obj;
3348         int ret = 0;
3349
3350         ENTER();
3351         ffs_dev_lock();
3352
3353         ffs_obj = ffs->private_data;
3354         if (!ffs_obj) {
3355                 ret = -EINVAL;
3356                 goto done;
3357         }
3358         if (WARN_ON(ffs_obj->desc_ready)) {
3359                 ret = -EBUSY;
3360                 goto done;
3361         }
3362
3363         ffs_obj->desc_ready = true;
3364         ffs_obj->ffs_data = ffs;
3365
3366         if (ffs_obj->ffs_ready_callback)
3367                 ret = ffs_obj->ffs_ready_callback(ffs);
3368
3369 done:
3370         ffs_dev_unlock();
3371         return ret;
3372 }
3373
3374 static void ffs_closed(struct ffs_data *ffs)
3375 {
3376         struct ffs_dev *ffs_obj;
3377
3378         ENTER();
3379         ffs_dev_lock();
3380
3381         ffs_obj = ffs->private_data;
3382         if (!ffs_obj)
3383                 goto done;
3384
3385         ffs_obj->desc_ready = false;
3386
3387         if (ffs_obj->ffs_closed_callback)
3388                 ffs_obj->ffs_closed_callback(ffs);
3389
3390         if (!ffs_obj->opts || ffs_obj->opts->no_configfs
3391             || !ffs_obj->opts->func_inst.group.cg_item.ci_parent)
3392                 goto done;
3393
3394         unregister_gadget_item(ffs_obj->opts->
3395                                func_inst.group.cg_item.ci_parent->ci_parent);
3396 done:
3397         ffs_dev_unlock();
3398 }
3399
3400 /* Misc helper functions ****************************************************/
3401
3402 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3403 {
3404         return nonblock
3405                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3406                 : mutex_lock_interruptible(mutex);
3407 }
3408
3409 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3410 {
3411         char *data;
3412
3413         if (unlikely(!len))
3414                 return NULL;
3415
3416         data = kmalloc(len, GFP_KERNEL);
3417         if (unlikely(!data))
3418                 return ERR_PTR(-ENOMEM);
3419
3420         if (unlikely(__copy_from_user(data, buf, len))) {
3421                 kfree(data);
3422                 return ERR_PTR(-EFAULT);
3423         }
3424
3425         pr_vdebug("Buffer from user space:\n");
3426         ffs_dump_mem("", data, len);
3427
3428         return data;
3429 }
3430
3431 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3432 MODULE_LICENSE("GPL");
3433 MODULE_AUTHOR("Michal Nazarewicz");