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Merge tag 'imx-clk-fixes-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/shawng...
[deliverable/linux.git] / 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 <linux/uio.h>
27 #include <asm/unaligned.h>
28
29 #include <linux/usb/composite.h>
30 #include <linux/usb/functionfs.h>
31
32 #include <linux/aio.h>
33 #include <linux/mmu_context.h>
34 #include <linux/poll.h>
35 #include <linux/eventfd.h>
36
37 #include "u_fs.h"
38 #include "u_f.h"
39 #include "u_os_desc.h"
40 #include "configfs.h"
41
42 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
43
44 /* Reference counter handling */
45 static void ffs_data_get(struct ffs_data *ffs);
46 static void ffs_data_put(struct ffs_data *ffs);
47 /* Creates new ffs_data object. */
48 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
49
50 /* Opened counter handling. */
51 static void ffs_data_opened(struct ffs_data *ffs);
52 static void ffs_data_closed(struct ffs_data *ffs);
53
54 /* Called with ffs->mutex held; take over ownership of data. */
55 static int __must_check
56 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
57 static int __must_check
58 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
59
60
61 /* The function structure ***************************************************/
62
63 struct ffs_ep;
64
65 struct ffs_function {
66 struct usb_configuration *conf;
67 struct usb_gadget *gadget;
68 struct ffs_data *ffs;
69
70 struct ffs_ep *eps;
71 u8 eps_revmap[16];
72 short *interfaces_nums;
73
74 struct usb_function function;
75 };
76
77
78 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
79 {
80 return container_of(f, struct ffs_function, function);
81 }
82
83
84 static inline enum ffs_setup_state
85 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
86 {
87 return (enum ffs_setup_state)
88 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
89 }
90
91
92 static void ffs_func_eps_disable(struct ffs_function *func);
93 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
94
95 static int ffs_func_bind(struct usb_configuration *,
96 struct usb_function *);
97 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
98 static void ffs_func_disable(struct usb_function *);
99 static int ffs_func_setup(struct usb_function *,
100 const struct usb_ctrlrequest *);
101 static void ffs_func_suspend(struct usb_function *);
102 static void ffs_func_resume(struct usb_function *);
103
104
105 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
106 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
107
108
109 /* The endpoints structures *************************************************/
110
111 struct ffs_ep {
112 struct usb_ep *ep; /* P: ffs->eps_lock */
113 struct usb_request *req; /* P: epfile->mutex */
114
115 /* [0]: full speed, [1]: high speed, [2]: super speed */
116 struct usb_endpoint_descriptor *descs[3];
117
118 u8 num;
119
120 int status; /* P: epfile->mutex */
121 };
122
123 struct ffs_epfile {
124 /* Protects ep->ep and ep->req. */
125 struct mutex mutex;
126 wait_queue_head_t wait;
127
128 struct ffs_data *ffs;
129 struct ffs_ep *ep; /* P: ffs->eps_lock */
130
131 struct dentry *dentry;
132
133 char name[5];
134
135 unsigned char in; /* P: ffs->eps_lock */
136 unsigned char isoc; /* P: ffs->eps_lock */
137
138 unsigned char _pad;
139 };
140
141 /* ffs_io_data structure ***************************************************/
142
143 struct ffs_io_data {
144 bool aio;
145 bool read;
146
147 struct kiocb *kiocb;
148 struct iov_iter data;
149 const void *to_free;
150 char *buf;
151
152 struct mm_struct *mm;
153 struct work_struct work;
154
155 struct usb_ep *ep;
156 struct usb_request *req;
157
158 struct ffs_data *ffs;
159 };
160
161 struct ffs_desc_helper {
162 struct ffs_data *ffs;
163 unsigned interfaces_count;
164 unsigned eps_count;
165 };
166
167 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
168 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
169
170 static struct dentry *
171 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
172 const struct file_operations *fops);
173
174 /* Devices management *******************************************************/
175
176 DEFINE_MUTEX(ffs_lock);
177 EXPORT_SYMBOL_GPL(ffs_lock);
178
179 static struct ffs_dev *_ffs_find_dev(const char *name);
180 static struct ffs_dev *_ffs_alloc_dev(void);
181 static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
182 static void _ffs_free_dev(struct ffs_dev *dev);
183 static void *ffs_acquire_dev(const char *dev_name);
184 static void ffs_release_dev(struct ffs_data *ffs_data);
185 static int ffs_ready(struct ffs_data *ffs);
186 static void ffs_closed(struct ffs_data *ffs);
187
188 /* Misc helper functions ****************************************************/
189
190 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
191 __attribute__((warn_unused_result, nonnull));
192 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
193 __attribute__((warn_unused_result, nonnull));
194
195
196 /* Control file aka ep0 *****************************************************/
197
198 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
199 {
200 struct ffs_data *ffs = req->context;
201
202 complete_all(&ffs->ep0req_completion);
203 }
204
205 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
206 {
207 struct usb_request *req = ffs->ep0req;
208 int ret;
209
210 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
211
212 spin_unlock_irq(&ffs->ev.waitq.lock);
213
214 req->buf = data;
215 req->length = len;
216
217 /*
218 * UDC layer requires to provide a buffer even for ZLP, but should
219 * not use it at all. Let's provide some poisoned pointer to catch
220 * possible bug in the driver.
221 */
222 if (req->buf == NULL)
223 req->buf = (void *)0xDEADBABE;
224
225 reinit_completion(&ffs->ep0req_completion);
226
227 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
228 if (unlikely(ret < 0))
229 return ret;
230
231 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
232 if (unlikely(ret)) {
233 usb_ep_dequeue(ffs->gadget->ep0, req);
234 return -EINTR;
235 }
236
237 ffs->setup_state = FFS_NO_SETUP;
238 return req->status ? req->status : req->actual;
239 }
240
241 static int __ffs_ep0_stall(struct ffs_data *ffs)
242 {
243 if (ffs->ev.can_stall) {
244 pr_vdebug("ep0 stall\n");
245 usb_ep_set_halt(ffs->gadget->ep0);
246 ffs->setup_state = FFS_NO_SETUP;
247 return -EL2HLT;
248 } else {
249 pr_debug("bogus ep0 stall!\n");
250 return -ESRCH;
251 }
252 }
253
254 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
255 size_t len, loff_t *ptr)
256 {
257 struct ffs_data *ffs = file->private_data;
258 ssize_t ret;
259 char *data;
260
261 ENTER();
262
263 /* Fast check if setup was canceled */
264 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
265 return -EIDRM;
266
267 /* Acquire mutex */
268 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
269 if (unlikely(ret < 0))
270 return ret;
271
272 /* Check state */
273 switch (ffs->state) {
274 case FFS_READ_DESCRIPTORS:
275 case FFS_READ_STRINGS:
276 /* Copy data */
277 if (unlikely(len < 16)) {
278 ret = -EINVAL;
279 break;
280 }
281
282 data = ffs_prepare_buffer(buf, len);
283 if (IS_ERR(data)) {
284 ret = PTR_ERR(data);
285 break;
286 }
287
288 /* Handle data */
289 if (ffs->state == FFS_READ_DESCRIPTORS) {
290 pr_info("read descriptors\n");
291 ret = __ffs_data_got_descs(ffs, data, len);
292 if (unlikely(ret < 0))
293 break;
294
295 ffs->state = FFS_READ_STRINGS;
296 ret = len;
297 } else {
298 pr_info("read strings\n");
299 ret = __ffs_data_got_strings(ffs, data, len);
300 if (unlikely(ret < 0))
301 break;
302
303 ret = ffs_epfiles_create(ffs);
304 if (unlikely(ret)) {
305 ffs->state = FFS_CLOSING;
306 break;
307 }
308
309 ffs->state = FFS_ACTIVE;
310 mutex_unlock(&ffs->mutex);
311
312 ret = ffs_ready(ffs);
313 if (unlikely(ret < 0)) {
314 ffs->state = FFS_CLOSING;
315 return ret;
316 }
317
318 return len;
319 }
320 break;
321
322 case FFS_ACTIVE:
323 data = NULL;
324 /*
325 * We're called from user space, we can use _irq
326 * rather then _irqsave
327 */
328 spin_lock_irq(&ffs->ev.waitq.lock);
329 switch (ffs_setup_state_clear_cancelled(ffs)) {
330 case FFS_SETUP_CANCELLED:
331 ret = -EIDRM;
332 goto done_spin;
333
334 case FFS_NO_SETUP:
335 ret = -ESRCH;
336 goto done_spin;
337
338 case FFS_SETUP_PENDING:
339 break;
340 }
341
342 /* FFS_SETUP_PENDING */
343 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
344 spin_unlock_irq(&ffs->ev.waitq.lock);
345 ret = __ffs_ep0_stall(ffs);
346 break;
347 }
348
349 /* FFS_SETUP_PENDING and not stall */
350 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
351
352 spin_unlock_irq(&ffs->ev.waitq.lock);
353
354 data = ffs_prepare_buffer(buf, len);
355 if (IS_ERR(data)) {
356 ret = PTR_ERR(data);
357 break;
358 }
359
360 spin_lock_irq(&ffs->ev.waitq.lock);
361
362 /*
363 * We are guaranteed to be still in FFS_ACTIVE state
364 * but the state of setup could have changed from
365 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
366 * to check for that. If that happened we copied data
367 * from user space in vain but it's unlikely.
368 *
369 * For sure we are not in FFS_NO_SETUP since this is
370 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
371 * transition can be performed and it's protected by
372 * mutex.
373 */
374 if (ffs_setup_state_clear_cancelled(ffs) ==
375 FFS_SETUP_CANCELLED) {
376 ret = -EIDRM;
377 done_spin:
378 spin_unlock_irq(&ffs->ev.waitq.lock);
379 } else {
380 /* unlocks spinlock */
381 ret = __ffs_ep0_queue_wait(ffs, data, len);
382 }
383 kfree(data);
384 break;
385
386 default:
387 ret = -EBADFD;
388 break;
389 }
390
391 mutex_unlock(&ffs->mutex);
392 return ret;
393 }
394
395 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
396 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
397 size_t n)
398 {
399 /*
400 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
401 * size of ffs->ev.types array (which is four) so that's how much space
402 * we reserve.
403 */
404 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
405 const size_t size = n * sizeof *events;
406 unsigned i = 0;
407
408 memset(events, 0, size);
409
410 do {
411 events[i].type = ffs->ev.types[i];
412 if (events[i].type == FUNCTIONFS_SETUP) {
413 events[i].u.setup = ffs->ev.setup;
414 ffs->setup_state = FFS_SETUP_PENDING;
415 }
416 } while (++i < n);
417
418 ffs->ev.count -= n;
419 if (ffs->ev.count)
420 memmove(ffs->ev.types, ffs->ev.types + n,
421 ffs->ev.count * sizeof *ffs->ev.types);
422
423 spin_unlock_irq(&ffs->ev.waitq.lock);
424 mutex_unlock(&ffs->mutex);
425
426 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
427 }
428
429 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
430 size_t len, loff_t *ptr)
431 {
432 struct ffs_data *ffs = file->private_data;
433 char *data = NULL;
434 size_t n;
435 int ret;
436
437 ENTER();
438
439 /* Fast check if setup was canceled */
440 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
441 return -EIDRM;
442
443 /* Acquire mutex */
444 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
445 if (unlikely(ret < 0))
446 return ret;
447
448 /* Check state */
449 if (ffs->state != FFS_ACTIVE) {
450 ret = -EBADFD;
451 goto done_mutex;
452 }
453
454 /*
455 * We're called from user space, we can use _irq rather then
456 * _irqsave
457 */
458 spin_lock_irq(&ffs->ev.waitq.lock);
459
460 switch (ffs_setup_state_clear_cancelled(ffs)) {
461 case FFS_SETUP_CANCELLED:
462 ret = -EIDRM;
463 break;
464
465 case FFS_NO_SETUP:
466 n = len / sizeof(struct usb_functionfs_event);
467 if (unlikely(!n)) {
468 ret = -EINVAL;
469 break;
470 }
471
472 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
473 ret = -EAGAIN;
474 break;
475 }
476
477 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
478 ffs->ev.count)) {
479 ret = -EINTR;
480 break;
481 }
482
483 return __ffs_ep0_read_events(ffs, buf,
484 min(n, (size_t)ffs->ev.count));
485
486 case FFS_SETUP_PENDING:
487 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
488 spin_unlock_irq(&ffs->ev.waitq.lock);
489 ret = __ffs_ep0_stall(ffs);
490 goto done_mutex;
491 }
492
493 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
494
495 spin_unlock_irq(&ffs->ev.waitq.lock);
496
497 if (likely(len)) {
498 data = kmalloc(len, GFP_KERNEL);
499 if (unlikely(!data)) {
500 ret = -ENOMEM;
501 goto done_mutex;
502 }
503 }
504
505 spin_lock_irq(&ffs->ev.waitq.lock);
506
507 /* See ffs_ep0_write() */
508 if (ffs_setup_state_clear_cancelled(ffs) ==
509 FFS_SETUP_CANCELLED) {
510 ret = -EIDRM;
511 break;
512 }
513
514 /* unlocks spinlock */
515 ret = __ffs_ep0_queue_wait(ffs, data, len);
516 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
517 ret = -EFAULT;
518 goto done_mutex;
519
520 default:
521 ret = -EBADFD;
522 break;
523 }
524
525 spin_unlock_irq(&ffs->ev.waitq.lock);
526 done_mutex:
527 mutex_unlock(&ffs->mutex);
528 kfree(data);
529 return ret;
530 }
531
532 static int ffs_ep0_open(struct inode *inode, struct file *file)
533 {
534 struct ffs_data *ffs = inode->i_private;
535
536 ENTER();
537
538 if (unlikely(ffs->state == FFS_CLOSING))
539 return -EBUSY;
540
541 file->private_data = ffs;
542 ffs_data_opened(ffs);
543
544 return 0;
545 }
546
547 static int ffs_ep0_release(struct inode *inode, struct file *file)
548 {
549 struct ffs_data *ffs = file->private_data;
550
551 ENTER();
552
553 ffs_data_closed(ffs);
554
555 return 0;
556 }
557
558 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
559 {
560 struct ffs_data *ffs = file->private_data;
561 struct usb_gadget *gadget = ffs->gadget;
562 long ret;
563
564 ENTER();
565
566 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
567 struct ffs_function *func = ffs->func;
568 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
569 } else if (gadget && gadget->ops->ioctl) {
570 ret = gadget->ops->ioctl(gadget, code, value);
571 } else {
572 ret = -ENOTTY;
573 }
574
575 return ret;
576 }
577
578 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
579 {
580 struct ffs_data *ffs = file->private_data;
581 unsigned int mask = POLLWRNORM;
582 int ret;
583
584 poll_wait(file, &ffs->ev.waitq, wait);
585
586 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
587 if (unlikely(ret < 0))
588 return mask;
589
590 switch (ffs->state) {
591 case FFS_READ_DESCRIPTORS:
592 case FFS_READ_STRINGS:
593 mask |= POLLOUT;
594 break;
595
596 case FFS_ACTIVE:
597 switch (ffs->setup_state) {
598 case FFS_NO_SETUP:
599 if (ffs->ev.count)
600 mask |= POLLIN;
601 break;
602
603 case FFS_SETUP_PENDING:
604 case FFS_SETUP_CANCELLED:
605 mask |= (POLLIN | POLLOUT);
606 break;
607 }
608 case FFS_CLOSING:
609 break;
610 case FFS_DEACTIVATED:
611 break;
612 }
613
614 mutex_unlock(&ffs->mutex);
615
616 return mask;
617 }
618
619 static const struct file_operations ffs_ep0_operations = {
620 .llseek = no_llseek,
621
622 .open = ffs_ep0_open,
623 .write = ffs_ep0_write,
624 .read = ffs_ep0_read,
625 .release = ffs_ep0_release,
626 .unlocked_ioctl = ffs_ep0_ioctl,
627 .poll = ffs_ep0_poll,
628 };
629
630
631 /* "Normal" endpoints operations ********************************************/
632
633 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
634 {
635 ENTER();
636 if (likely(req->context)) {
637 struct ffs_ep *ep = _ep->driver_data;
638 ep->status = req->status ? req->status : req->actual;
639 complete(req->context);
640 }
641 }
642
643 static void ffs_user_copy_worker(struct work_struct *work)
644 {
645 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
646 work);
647 int ret = io_data->req->status ? io_data->req->status :
648 io_data->req->actual;
649
650 if (io_data->read && ret > 0) {
651 use_mm(io_data->mm);
652 ret = copy_to_iter(io_data->buf, ret, &io_data->data);
653 if (iov_iter_count(&io_data->data))
654 ret = -EFAULT;
655 unuse_mm(io_data->mm);
656 }
657
658 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
659
660 if (io_data->ffs->ffs_eventfd &&
661 !(io_data->kiocb->ki_flags & IOCB_EVENTFD))
662 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
663
664 usb_ep_free_request(io_data->ep, io_data->req);
665
666 io_data->kiocb->private = NULL;
667 if (io_data->read)
668 kfree(io_data->to_free);
669 kfree(io_data->buf);
670 kfree(io_data);
671 }
672
673 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
674 struct usb_request *req)
675 {
676 struct ffs_io_data *io_data = req->context;
677
678 ENTER();
679
680 INIT_WORK(&io_data->work, ffs_user_copy_worker);
681 schedule_work(&io_data->work);
682 }
683
684 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
685 {
686 struct ffs_epfile *epfile = file->private_data;
687 struct usb_request *req;
688 struct ffs_ep *ep;
689 char *data = NULL;
690 ssize_t ret, data_len = -EINVAL;
691 int halt;
692
693 /* Are we still active? */
694 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
695 return -ENODEV;
696
697 /* Wait for endpoint to be enabled */
698 ep = epfile->ep;
699 if (!ep) {
700 if (file->f_flags & O_NONBLOCK)
701 return -EAGAIN;
702
703 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
704 if (ret)
705 return -EINTR;
706 }
707
708 /* Do we halt? */
709 halt = (!io_data->read == !epfile->in);
710 if (halt && epfile->isoc)
711 return -EINVAL;
712
713 /* Allocate & copy */
714 if (!halt) {
715 /*
716 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
717 * before the waiting completes, so do not assign to 'gadget'
718 * earlier
719 */
720 struct usb_gadget *gadget = epfile->ffs->gadget;
721 size_t copied;
722
723 spin_lock_irq(&epfile->ffs->eps_lock);
724 /* In the meantime, endpoint got disabled or changed. */
725 if (epfile->ep != ep) {
726 spin_unlock_irq(&epfile->ffs->eps_lock);
727 return -ESHUTDOWN;
728 }
729 data_len = iov_iter_count(&io_data->data);
730 /*
731 * Controller may require buffer size to be aligned to
732 * maxpacketsize of an out endpoint.
733 */
734 if (io_data->read)
735 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
736 spin_unlock_irq(&epfile->ffs->eps_lock);
737
738 data = kmalloc(data_len, GFP_KERNEL);
739 if (unlikely(!data))
740 return -ENOMEM;
741 if (!io_data->read) {
742 copied = copy_from_iter(data, data_len, &io_data->data);
743 if (copied != data_len) {
744 ret = -EFAULT;
745 goto error;
746 }
747 }
748 }
749
750 /* We will be using request */
751 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
752 if (unlikely(ret))
753 goto error;
754
755 spin_lock_irq(&epfile->ffs->eps_lock);
756
757 if (epfile->ep != ep) {
758 /* In the meantime, endpoint got disabled or changed. */
759 ret = -ESHUTDOWN;
760 } else if (halt) {
761 /* Halt */
762 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
763 usb_ep_set_halt(ep->ep);
764 ret = -EBADMSG;
765 } else if (unlikely(data_len == -EINVAL)) {
766 /*
767 * Sanity Check: even though data_len can't be used
768 * uninitialized at the time I write this comment, some
769 * compilers complain about this situation.
770 * In order to keep the code clean from warnings, data_len is
771 * being initialized to -EINVAL during its declaration, which
772 * means we can't rely on compiler anymore to warn no future
773 * changes won't result in data_len being used uninitialized.
774 * For such reason, we're adding this redundant sanity check
775 * here.
776 */
777 WARN(1, "%s: data_len == -EINVAL\n", __func__);
778 ret = -EINVAL;
779 } else if (!io_data->aio) {
780 DECLARE_COMPLETION_ONSTACK(done);
781 bool interrupted = false;
782
783 req = ep->req;
784 req->buf = data;
785 req->length = data_len;
786
787 req->context = &done;
788 req->complete = ffs_epfile_io_complete;
789
790 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
791 if (unlikely(ret < 0))
792 goto error_lock;
793
794 spin_unlock_irq(&epfile->ffs->eps_lock);
795
796 if (unlikely(wait_for_completion_interruptible(&done))) {
797 /*
798 * To avoid race condition with ffs_epfile_io_complete,
799 * dequeue the request first then check
800 * status. usb_ep_dequeue API should guarantee no race
801 * condition with req->complete callback.
802 */
803 usb_ep_dequeue(ep->ep, req);
804 interrupted = ep->status < 0;
805 }
806
807 /*
808 * XXX We may end up silently droping data here. Since data_len
809 * (i.e. req->length) may be bigger than len (after being
810 * rounded up to maxpacketsize), we may end up with more data
811 * then user space has space for.
812 */
813 ret = interrupted ? -EINTR : ep->status;
814 if (io_data->read && ret > 0) {
815 ret = copy_to_iter(data, ret, &io_data->data);
816 if (!ret)
817 ret = -EFAULT;
818 }
819 goto error_mutex;
820 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_KERNEL))) {
821 ret = -ENOMEM;
822 } else {
823 req->buf = data;
824 req->length = data_len;
825
826 io_data->buf = data;
827 io_data->ep = ep->ep;
828 io_data->req = req;
829 io_data->ffs = epfile->ffs;
830
831 req->context = io_data;
832 req->complete = ffs_epfile_async_io_complete;
833
834 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
835 if (unlikely(ret)) {
836 usb_ep_free_request(ep->ep, req);
837 goto error_lock;
838 }
839
840 ret = -EIOCBQUEUED;
841 /*
842 * Do not kfree the buffer in this function. It will be freed
843 * by ffs_user_copy_worker.
844 */
845 data = NULL;
846 }
847
848 error_lock:
849 spin_unlock_irq(&epfile->ffs->eps_lock);
850 error_mutex:
851 mutex_unlock(&epfile->mutex);
852 error:
853 kfree(data);
854 return ret;
855 }
856
857 static int
858 ffs_epfile_open(struct inode *inode, struct file *file)
859 {
860 struct ffs_epfile *epfile = inode->i_private;
861
862 ENTER();
863
864 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
865 return -ENODEV;
866
867 file->private_data = epfile;
868 ffs_data_opened(epfile->ffs);
869
870 return 0;
871 }
872
873 static int ffs_aio_cancel(struct kiocb *kiocb)
874 {
875 struct ffs_io_data *io_data = kiocb->private;
876 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
877 int value;
878
879 ENTER();
880
881 spin_lock_irq(&epfile->ffs->eps_lock);
882
883 if (likely(io_data && io_data->ep && io_data->req))
884 value = usb_ep_dequeue(io_data->ep, io_data->req);
885 else
886 value = -EINVAL;
887
888 spin_unlock_irq(&epfile->ffs->eps_lock);
889
890 return value;
891 }
892
893 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
894 {
895 struct ffs_io_data io_data, *p = &io_data;
896 ssize_t res;
897
898 ENTER();
899
900 if (!is_sync_kiocb(kiocb)) {
901 p = kmalloc(sizeof(io_data), GFP_KERNEL);
902 if (unlikely(!p))
903 return -ENOMEM;
904 p->aio = true;
905 } else {
906 p->aio = false;
907 }
908
909 p->read = false;
910 p->kiocb = kiocb;
911 p->data = *from;
912 p->mm = current->mm;
913
914 kiocb->private = p;
915
916 if (p->aio)
917 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
918
919 res = ffs_epfile_io(kiocb->ki_filp, p);
920 if (res == -EIOCBQUEUED)
921 return res;
922 if (p->aio)
923 kfree(p);
924 else
925 *from = p->data;
926 return res;
927 }
928
929 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
930 {
931 struct ffs_io_data io_data, *p = &io_data;
932 ssize_t res;
933
934 ENTER();
935
936 if (!is_sync_kiocb(kiocb)) {
937 p = kmalloc(sizeof(io_data), GFP_KERNEL);
938 if (unlikely(!p))
939 return -ENOMEM;
940 p->aio = true;
941 } else {
942 p->aio = false;
943 }
944
945 p->read = true;
946 p->kiocb = kiocb;
947 if (p->aio) {
948 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
949 if (!p->to_free) {
950 kfree(p);
951 return -ENOMEM;
952 }
953 } else {
954 p->data = *to;
955 p->to_free = NULL;
956 }
957 p->mm = current->mm;
958
959 kiocb->private = p;
960
961 if (p->aio)
962 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
963
964 res = ffs_epfile_io(kiocb->ki_filp, p);
965 if (res == -EIOCBQUEUED)
966 return res;
967
968 if (p->aio) {
969 kfree(p->to_free);
970 kfree(p);
971 } else {
972 *to = p->data;
973 }
974 return res;
975 }
976
977 static int
978 ffs_epfile_release(struct inode *inode, struct file *file)
979 {
980 struct ffs_epfile *epfile = inode->i_private;
981
982 ENTER();
983
984 ffs_data_closed(epfile->ffs);
985
986 return 0;
987 }
988
989 static long ffs_epfile_ioctl(struct file *file, unsigned code,
990 unsigned long value)
991 {
992 struct ffs_epfile *epfile = file->private_data;
993 int ret;
994
995 ENTER();
996
997 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
998 return -ENODEV;
999
1000 spin_lock_irq(&epfile->ffs->eps_lock);
1001 if (likely(epfile->ep)) {
1002 switch (code) {
1003 case FUNCTIONFS_FIFO_STATUS:
1004 ret = usb_ep_fifo_status(epfile->ep->ep);
1005 break;
1006 case FUNCTIONFS_FIFO_FLUSH:
1007 usb_ep_fifo_flush(epfile->ep->ep);
1008 ret = 0;
1009 break;
1010 case FUNCTIONFS_CLEAR_HALT:
1011 ret = usb_ep_clear_halt(epfile->ep->ep);
1012 break;
1013 case FUNCTIONFS_ENDPOINT_REVMAP:
1014 ret = epfile->ep->num;
1015 break;
1016 case FUNCTIONFS_ENDPOINT_DESC:
1017 {
1018 int desc_idx;
1019 struct usb_endpoint_descriptor *desc;
1020
1021 switch (epfile->ffs->gadget->speed) {
1022 case USB_SPEED_SUPER:
1023 desc_idx = 2;
1024 break;
1025 case USB_SPEED_HIGH:
1026 desc_idx = 1;
1027 break;
1028 default:
1029 desc_idx = 0;
1030 }
1031 desc = epfile->ep->descs[desc_idx];
1032
1033 spin_unlock_irq(&epfile->ffs->eps_lock);
1034 ret = copy_to_user((void *)value, desc, sizeof(*desc));
1035 if (ret)
1036 ret = -EFAULT;
1037 return ret;
1038 }
1039 default:
1040 ret = -ENOTTY;
1041 }
1042 } else {
1043 ret = -ENODEV;
1044 }
1045 spin_unlock_irq(&epfile->ffs->eps_lock);
1046
1047 return ret;
1048 }
1049
1050 static const struct file_operations ffs_epfile_operations = {
1051 .llseek = no_llseek,
1052
1053 .open = ffs_epfile_open,
1054 .write_iter = ffs_epfile_write_iter,
1055 .read_iter = ffs_epfile_read_iter,
1056 .release = ffs_epfile_release,
1057 .unlocked_ioctl = ffs_epfile_ioctl,
1058 };
1059
1060
1061 /* File system and super block operations ***********************************/
1062
1063 /*
1064 * Mounting the file system creates a controller file, used first for
1065 * function configuration then later for event monitoring.
1066 */
1067
1068 static struct inode *__must_check
1069 ffs_sb_make_inode(struct super_block *sb, void *data,
1070 const struct file_operations *fops,
1071 const struct inode_operations *iops,
1072 struct ffs_file_perms *perms)
1073 {
1074 struct inode *inode;
1075
1076 ENTER();
1077
1078 inode = new_inode(sb);
1079
1080 if (likely(inode)) {
1081 struct timespec current_time = CURRENT_TIME;
1082
1083 inode->i_ino = get_next_ino();
1084 inode->i_mode = perms->mode;
1085 inode->i_uid = perms->uid;
1086 inode->i_gid = perms->gid;
1087 inode->i_atime = current_time;
1088 inode->i_mtime = current_time;
1089 inode->i_ctime = current_time;
1090 inode->i_private = data;
1091 if (fops)
1092 inode->i_fop = fops;
1093 if (iops)
1094 inode->i_op = iops;
1095 }
1096
1097 return inode;
1098 }
1099
1100 /* Create "regular" file */
1101 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1102 const char *name, void *data,
1103 const struct file_operations *fops)
1104 {
1105 struct ffs_data *ffs = sb->s_fs_info;
1106 struct dentry *dentry;
1107 struct inode *inode;
1108
1109 ENTER();
1110
1111 dentry = d_alloc_name(sb->s_root, name);
1112 if (unlikely(!dentry))
1113 return NULL;
1114
1115 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1116 if (unlikely(!inode)) {
1117 dput(dentry);
1118 return NULL;
1119 }
1120
1121 d_add(dentry, inode);
1122 return dentry;
1123 }
1124
1125 /* Super block */
1126 static const struct super_operations ffs_sb_operations = {
1127 .statfs = simple_statfs,
1128 .drop_inode = generic_delete_inode,
1129 };
1130
1131 struct ffs_sb_fill_data {
1132 struct ffs_file_perms perms;
1133 umode_t root_mode;
1134 const char *dev_name;
1135 bool no_disconnect;
1136 struct ffs_data *ffs_data;
1137 };
1138
1139 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1140 {
1141 struct ffs_sb_fill_data *data = _data;
1142 struct inode *inode;
1143 struct ffs_data *ffs = data->ffs_data;
1144
1145 ENTER();
1146
1147 ffs->sb = sb;
1148 data->ffs_data = NULL;
1149 sb->s_fs_info = ffs;
1150 sb->s_blocksize = PAGE_CACHE_SIZE;
1151 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1152 sb->s_magic = FUNCTIONFS_MAGIC;
1153 sb->s_op = &ffs_sb_operations;
1154 sb->s_time_gran = 1;
1155
1156 /* Root inode */
1157 data->perms.mode = data->root_mode;
1158 inode = ffs_sb_make_inode(sb, NULL,
1159 &simple_dir_operations,
1160 &simple_dir_inode_operations,
1161 &data->perms);
1162 sb->s_root = d_make_root(inode);
1163 if (unlikely(!sb->s_root))
1164 return -ENOMEM;
1165
1166 /* EP0 file */
1167 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1168 &ffs_ep0_operations)))
1169 return -ENOMEM;
1170
1171 return 0;
1172 }
1173
1174 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1175 {
1176 ENTER();
1177
1178 if (!opts || !*opts)
1179 return 0;
1180
1181 for (;;) {
1182 unsigned long value;
1183 char *eq, *comma;
1184
1185 /* Option limit */
1186 comma = strchr(opts, ',');
1187 if (comma)
1188 *comma = 0;
1189
1190 /* Value limit */
1191 eq = strchr(opts, '=');
1192 if (unlikely(!eq)) {
1193 pr_err("'=' missing in %s\n", opts);
1194 return -EINVAL;
1195 }
1196 *eq = 0;
1197
1198 /* Parse value */
1199 if (kstrtoul(eq + 1, 0, &value)) {
1200 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1201 return -EINVAL;
1202 }
1203
1204 /* Interpret option */
1205 switch (eq - opts) {
1206 case 13:
1207 if (!memcmp(opts, "no_disconnect", 13))
1208 data->no_disconnect = !!value;
1209 else
1210 goto invalid;
1211 break;
1212 case 5:
1213 if (!memcmp(opts, "rmode", 5))
1214 data->root_mode = (value & 0555) | S_IFDIR;
1215 else if (!memcmp(opts, "fmode", 5))
1216 data->perms.mode = (value & 0666) | S_IFREG;
1217 else
1218 goto invalid;
1219 break;
1220
1221 case 4:
1222 if (!memcmp(opts, "mode", 4)) {
1223 data->root_mode = (value & 0555) | S_IFDIR;
1224 data->perms.mode = (value & 0666) | S_IFREG;
1225 } else {
1226 goto invalid;
1227 }
1228 break;
1229
1230 case 3:
1231 if (!memcmp(opts, "uid", 3)) {
1232 data->perms.uid = make_kuid(current_user_ns(), value);
1233 if (!uid_valid(data->perms.uid)) {
1234 pr_err("%s: unmapped value: %lu\n", opts, value);
1235 return -EINVAL;
1236 }
1237 } else if (!memcmp(opts, "gid", 3)) {
1238 data->perms.gid = make_kgid(current_user_ns(), value);
1239 if (!gid_valid(data->perms.gid)) {
1240 pr_err("%s: unmapped value: %lu\n", opts, value);
1241 return -EINVAL;
1242 }
1243 } else {
1244 goto invalid;
1245 }
1246 break;
1247
1248 default:
1249 invalid:
1250 pr_err("%s: invalid option\n", opts);
1251 return -EINVAL;
1252 }
1253
1254 /* Next iteration */
1255 if (!comma)
1256 break;
1257 opts = comma + 1;
1258 }
1259
1260 return 0;
1261 }
1262
1263 /* "mount -t functionfs dev_name /dev/function" ends up here */
1264
1265 static struct dentry *
1266 ffs_fs_mount(struct file_system_type *t, int flags,
1267 const char *dev_name, void *opts)
1268 {
1269 struct ffs_sb_fill_data data = {
1270 .perms = {
1271 .mode = S_IFREG | 0600,
1272 .uid = GLOBAL_ROOT_UID,
1273 .gid = GLOBAL_ROOT_GID,
1274 },
1275 .root_mode = S_IFDIR | 0500,
1276 .no_disconnect = false,
1277 };
1278 struct dentry *rv;
1279 int ret;
1280 void *ffs_dev;
1281 struct ffs_data *ffs;
1282
1283 ENTER();
1284
1285 ret = ffs_fs_parse_opts(&data, opts);
1286 if (unlikely(ret < 0))
1287 return ERR_PTR(ret);
1288
1289 ffs = ffs_data_new();
1290 if (unlikely(!ffs))
1291 return ERR_PTR(-ENOMEM);
1292 ffs->file_perms = data.perms;
1293 ffs->no_disconnect = data.no_disconnect;
1294
1295 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1296 if (unlikely(!ffs->dev_name)) {
1297 ffs_data_put(ffs);
1298 return ERR_PTR(-ENOMEM);
1299 }
1300
1301 ffs_dev = ffs_acquire_dev(dev_name);
1302 if (IS_ERR(ffs_dev)) {
1303 ffs_data_put(ffs);
1304 return ERR_CAST(ffs_dev);
1305 }
1306 ffs->private_data = ffs_dev;
1307 data.ffs_data = ffs;
1308
1309 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1310 if (IS_ERR(rv) && data.ffs_data) {
1311 ffs_release_dev(data.ffs_data);
1312 ffs_data_put(data.ffs_data);
1313 }
1314 return rv;
1315 }
1316
1317 static void
1318 ffs_fs_kill_sb(struct super_block *sb)
1319 {
1320 ENTER();
1321
1322 kill_litter_super(sb);
1323 if (sb->s_fs_info) {
1324 ffs_release_dev(sb->s_fs_info);
1325 ffs_data_closed(sb->s_fs_info);
1326 ffs_data_put(sb->s_fs_info);
1327 }
1328 }
1329
1330 static struct file_system_type ffs_fs_type = {
1331 .owner = THIS_MODULE,
1332 .name = "functionfs",
1333 .mount = ffs_fs_mount,
1334 .kill_sb = ffs_fs_kill_sb,
1335 };
1336 MODULE_ALIAS_FS("functionfs");
1337
1338
1339 /* Driver's main init/cleanup functions *************************************/
1340
1341 static int functionfs_init(void)
1342 {
1343 int ret;
1344
1345 ENTER();
1346
1347 ret = register_filesystem(&ffs_fs_type);
1348 if (likely(!ret))
1349 pr_info("file system registered\n");
1350 else
1351 pr_err("failed registering file system (%d)\n", ret);
1352
1353 return ret;
1354 }
1355
1356 static void functionfs_cleanup(void)
1357 {
1358 ENTER();
1359
1360 pr_info("unloading\n");
1361 unregister_filesystem(&ffs_fs_type);
1362 }
1363
1364
1365 /* ffs_data and ffs_function construction and destruction code **************/
1366
1367 static void ffs_data_clear(struct ffs_data *ffs);
1368 static void ffs_data_reset(struct ffs_data *ffs);
1369
1370 static void ffs_data_get(struct ffs_data *ffs)
1371 {
1372 ENTER();
1373
1374 atomic_inc(&ffs->ref);
1375 }
1376
1377 static void ffs_data_opened(struct ffs_data *ffs)
1378 {
1379 ENTER();
1380
1381 atomic_inc(&ffs->ref);
1382 if (atomic_add_return(1, &ffs->opened) == 1 &&
1383 ffs->state == FFS_DEACTIVATED) {
1384 ffs->state = FFS_CLOSING;
1385 ffs_data_reset(ffs);
1386 }
1387 }
1388
1389 static void ffs_data_put(struct ffs_data *ffs)
1390 {
1391 ENTER();
1392
1393 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1394 pr_info("%s(): freeing\n", __func__);
1395 ffs_data_clear(ffs);
1396 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1397 waitqueue_active(&ffs->ep0req_completion.wait));
1398 kfree(ffs->dev_name);
1399 kfree(ffs);
1400 }
1401 }
1402
1403 static void ffs_data_closed(struct ffs_data *ffs)
1404 {
1405 ENTER();
1406
1407 if (atomic_dec_and_test(&ffs->opened)) {
1408 if (ffs->no_disconnect) {
1409 ffs->state = FFS_DEACTIVATED;
1410 if (ffs->epfiles) {
1411 ffs_epfiles_destroy(ffs->epfiles,
1412 ffs->eps_count);
1413 ffs->epfiles = NULL;
1414 }
1415 if (ffs->setup_state == FFS_SETUP_PENDING)
1416 __ffs_ep0_stall(ffs);
1417 } else {
1418 ffs->state = FFS_CLOSING;
1419 ffs_data_reset(ffs);
1420 }
1421 }
1422 if (atomic_read(&ffs->opened) < 0) {
1423 ffs->state = FFS_CLOSING;
1424 ffs_data_reset(ffs);
1425 }
1426
1427 ffs_data_put(ffs);
1428 }
1429
1430 static struct ffs_data *ffs_data_new(void)
1431 {
1432 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1433 if (unlikely(!ffs))
1434 return NULL;
1435
1436 ENTER();
1437
1438 atomic_set(&ffs->ref, 1);
1439 atomic_set(&ffs->opened, 0);
1440 ffs->state = FFS_READ_DESCRIPTORS;
1441 mutex_init(&ffs->mutex);
1442 spin_lock_init(&ffs->eps_lock);
1443 init_waitqueue_head(&ffs->ev.waitq);
1444 init_completion(&ffs->ep0req_completion);
1445
1446 /* XXX REVISIT need to update it in some places, or do we? */
1447 ffs->ev.can_stall = 1;
1448
1449 return ffs;
1450 }
1451
1452 static void ffs_data_clear(struct ffs_data *ffs)
1453 {
1454 ENTER();
1455
1456 ffs_closed(ffs);
1457
1458 BUG_ON(ffs->gadget);
1459
1460 if (ffs->epfiles)
1461 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1462
1463 if (ffs->ffs_eventfd)
1464 eventfd_ctx_put(ffs->ffs_eventfd);
1465
1466 kfree(ffs->raw_descs_data);
1467 kfree(ffs->raw_strings);
1468 kfree(ffs->stringtabs);
1469 }
1470
1471 static void ffs_data_reset(struct ffs_data *ffs)
1472 {
1473 ENTER();
1474
1475 ffs_data_clear(ffs);
1476
1477 ffs->epfiles = NULL;
1478 ffs->raw_descs_data = NULL;
1479 ffs->raw_descs = NULL;
1480 ffs->raw_strings = NULL;
1481 ffs->stringtabs = NULL;
1482
1483 ffs->raw_descs_length = 0;
1484 ffs->fs_descs_count = 0;
1485 ffs->hs_descs_count = 0;
1486 ffs->ss_descs_count = 0;
1487
1488 ffs->strings_count = 0;
1489 ffs->interfaces_count = 0;
1490 ffs->eps_count = 0;
1491
1492 ffs->ev.count = 0;
1493
1494 ffs->state = FFS_READ_DESCRIPTORS;
1495 ffs->setup_state = FFS_NO_SETUP;
1496 ffs->flags = 0;
1497 }
1498
1499
1500 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1501 {
1502 struct usb_gadget_strings **lang;
1503 int first_id;
1504
1505 ENTER();
1506
1507 if (WARN_ON(ffs->state != FFS_ACTIVE
1508 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1509 return -EBADFD;
1510
1511 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1512 if (unlikely(first_id < 0))
1513 return first_id;
1514
1515 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1516 if (unlikely(!ffs->ep0req))
1517 return -ENOMEM;
1518 ffs->ep0req->complete = ffs_ep0_complete;
1519 ffs->ep0req->context = ffs;
1520
1521 lang = ffs->stringtabs;
1522 if (lang) {
1523 for (; *lang; ++lang) {
1524 struct usb_string *str = (*lang)->strings;
1525 int id = first_id;
1526 for (; str->s; ++id, ++str)
1527 str->id = id;
1528 }
1529 }
1530
1531 ffs->gadget = cdev->gadget;
1532 ffs_data_get(ffs);
1533 return 0;
1534 }
1535
1536 static void functionfs_unbind(struct ffs_data *ffs)
1537 {
1538 ENTER();
1539
1540 if (!WARN_ON(!ffs->gadget)) {
1541 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1542 ffs->ep0req = NULL;
1543 ffs->gadget = NULL;
1544 clear_bit(FFS_FL_BOUND, &ffs->flags);
1545 ffs_data_put(ffs);
1546 }
1547 }
1548
1549 static int ffs_epfiles_create(struct ffs_data *ffs)
1550 {
1551 struct ffs_epfile *epfile, *epfiles;
1552 unsigned i, count;
1553
1554 ENTER();
1555
1556 count = ffs->eps_count;
1557 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1558 if (!epfiles)
1559 return -ENOMEM;
1560
1561 epfile = epfiles;
1562 for (i = 1; i <= count; ++i, ++epfile) {
1563 epfile->ffs = ffs;
1564 mutex_init(&epfile->mutex);
1565 init_waitqueue_head(&epfile->wait);
1566 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1567 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1568 else
1569 sprintf(epfile->name, "ep%u", i);
1570 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1571 epfile,
1572 &ffs_epfile_operations);
1573 if (unlikely(!epfile->dentry)) {
1574 ffs_epfiles_destroy(epfiles, i - 1);
1575 return -ENOMEM;
1576 }
1577 }
1578
1579 ffs->epfiles = epfiles;
1580 return 0;
1581 }
1582
1583 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1584 {
1585 struct ffs_epfile *epfile = epfiles;
1586
1587 ENTER();
1588
1589 for (; count; --count, ++epfile) {
1590 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1591 waitqueue_active(&epfile->wait));
1592 if (epfile->dentry) {
1593 d_delete(epfile->dentry);
1594 dput(epfile->dentry);
1595 epfile->dentry = NULL;
1596 }
1597 }
1598
1599 kfree(epfiles);
1600 }
1601
1602 static void ffs_func_eps_disable(struct ffs_function *func)
1603 {
1604 struct ffs_ep *ep = func->eps;
1605 struct ffs_epfile *epfile = func->ffs->epfiles;
1606 unsigned count = func->ffs->eps_count;
1607 unsigned long flags;
1608
1609 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1610 do {
1611 /* pending requests get nuked */
1612 if (likely(ep->ep))
1613 usb_ep_disable(ep->ep);
1614 ++ep;
1615
1616 if (epfile) {
1617 epfile->ep = NULL;
1618 ++epfile;
1619 }
1620 } while (--count);
1621 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1622 }
1623
1624 static int ffs_func_eps_enable(struct ffs_function *func)
1625 {
1626 struct ffs_data *ffs = func->ffs;
1627 struct ffs_ep *ep = func->eps;
1628 struct ffs_epfile *epfile = ffs->epfiles;
1629 unsigned count = ffs->eps_count;
1630 unsigned long flags;
1631 int ret = 0;
1632
1633 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1634 do {
1635 struct usb_endpoint_descriptor *ds;
1636 int desc_idx;
1637
1638 if (ffs->gadget->speed == USB_SPEED_SUPER)
1639 desc_idx = 2;
1640 else if (ffs->gadget->speed == USB_SPEED_HIGH)
1641 desc_idx = 1;
1642 else
1643 desc_idx = 0;
1644
1645 /* fall-back to lower speed if desc missing for current speed */
1646 do {
1647 ds = ep->descs[desc_idx];
1648 } while (!ds && --desc_idx >= 0);
1649
1650 if (!ds) {
1651 ret = -EINVAL;
1652 break;
1653 }
1654
1655 ep->ep->driver_data = ep;
1656 ep->ep->desc = ds;
1657 ret = usb_ep_enable(ep->ep);
1658 if (likely(!ret)) {
1659 epfile->ep = ep;
1660 epfile->in = usb_endpoint_dir_in(ds);
1661 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1662 } else {
1663 break;
1664 }
1665
1666 wake_up(&epfile->wait);
1667
1668 ++ep;
1669 ++epfile;
1670 } while (--count);
1671 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1672
1673 return ret;
1674 }
1675
1676
1677 /* Parsing and building descriptors and strings *****************************/
1678
1679 /*
1680 * This validates if data pointed by data is a valid USB descriptor as
1681 * well as record how many interfaces, endpoints and strings are
1682 * required by given configuration. Returns address after the
1683 * descriptor or NULL if data is invalid.
1684 */
1685
1686 enum ffs_entity_type {
1687 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1688 };
1689
1690 enum ffs_os_desc_type {
1691 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1692 };
1693
1694 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1695 u8 *valuep,
1696 struct usb_descriptor_header *desc,
1697 void *priv);
1698
1699 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1700 struct usb_os_desc_header *h, void *data,
1701 unsigned len, void *priv);
1702
1703 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1704 ffs_entity_callback entity,
1705 void *priv)
1706 {
1707 struct usb_descriptor_header *_ds = (void *)data;
1708 u8 length;
1709 int ret;
1710
1711 ENTER();
1712
1713 /* At least two bytes are required: length and type */
1714 if (len < 2) {
1715 pr_vdebug("descriptor too short\n");
1716 return -EINVAL;
1717 }
1718
1719 /* If we have at least as many bytes as the descriptor takes? */
1720 length = _ds->bLength;
1721 if (len < length) {
1722 pr_vdebug("descriptor longer then available data\n");
1723 return -EINVAL;
1724 }
1725
1726 #define __entity_check_INTERFACE(val) 1
1727 #define __entity_check_STRING(val) (val)
1728 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1729 #define __entity(type, val) do { \
1730 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1731 if (unlikely(!__entity_check_ ##type(val))) { \
1732 pr_vdebug("invalid entity's value\n"); \
1733 return -EINVAL; \
1734 } \
1735 ret = entity(FFS_ ##type, &val, _ds, priv); \
1736 if (unlikely(ret < 0)) { \
1737 pr_debug("entity " #type "(%02x); ret = %d\n", \
1738 (val), ret); \
1739 return ret; \
1740 } \
1741 } while (0)
1742
1743 /* Parse descriptor depending on type. */
1744 switch (_ds->bDescriptorType) {
1745 case USB_DT_DEVICE:
1746 case USB_DT_CONFIG:
1747 case USB_DT_STRING:
1748 case USB_DT_DEVICE_QUALIFIER:
1749 /* function can't have any of those */
1750 pr_vdebug("descriptor reserved for gadget: %d\n",
1751 _ds->bDescriptorType);
1752 return -EINVAL;
1753
1754 case USB_DT_INTERFACE: {
1755 struct usb_interface_descriptor *ds = (void *)_ds;
1756 pr_vdebug("interface descriptor\n");
1757 if (length != sizeof *ds)
1758 goto inv_length;
1759
1760 __entity(INTERFACE, ds->bInterfaceNumber);
1761 if (ds->iInterface)
1762 __entity(STRING, ds->iInterface);
1763 }
1764 break;
1765
1766 case USB_DT_ENDPOINT: {
1767 struct usb_endpoint_descriptor *ds = (void *)_ds;
1768 pr_vdebug("endpoint descriptor\n");
1769 if (length != USB_DT_ENDPOINT_SIZE &&
1770 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1771 goto inv_length;
1772 __entity(ENDPOINT, ds->bEndpointAddress);
1773 }
1774 break;
1775
1776 case HID_DT_HID:
1777 pr_vdebug("hid descriptor\n");
1778 if (length != sizeof(struct hid_descriptor))
1779 goto inv_length;
1780 break;
1781
1782 case USB_DT_OTG:
1783 if (length != sizeof(struct usb_otg_descriptor))
1784 goto inv_length;
1785 break;
1786
1787 case USB_DT_INTERFACE_ASSOCIATION: {
1788 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1789 pr_vdebug("interface association descriptor\n");
1790 if (length != sizeof *ds)
1791 goto inv_length;
1792 if (ds->iFunction)
1793 __entity(STRING, ds->iFunction);
1794 }
1795 break;
1796
1797 case USB_DT_SS_ENDPOINT_COMP:
1798 pr_vdebug("EP SS companion descriptor\n");
1799 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1800 goto inv_length;
1801 break;
1802
1803 case USB_DT_OTHER_SPEED_CONFIG:
1804 case USB_DT_INTERFACE_POWER:
1805 case USB_DT_DEBUG:
1806 case USB_DT_SECURITY:
1807 case USB_DT_CS_RADIO_CONTROL:
1808 /* TODO */
1809 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1810 return -EINVAL;
1811
1812 default:
1813 /* We should never be here */
1814 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1815 return -EINVAL;
1816
1817 inv_length:
1818 pr_vdebug("invalid length: %d (descriptor %d)\n",
1819 _ds->bLength, _ds->bDescriptorType);
1820 return -EINVAL;
1821 }
1822
1823 #undef __entity
1824 #undef __entity_check_DESCRIPTOR
1825 #undef __entity_check_INTERFACE
1826 #undef __entity_check_STRING
1827 #undef __entity_check_ENDPOINT
1828
1829 return length;
1830 }
1831
1832 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1833 ffs_entity_callback entity, void *priv)
1834 {
1835 const unsigned _len = len;
1836 unsigned long num = 0;
1837
1838 ENTER();
1839
1840 for (;;) {
1841 int ret;
1842
1843 if (num == count)
1844 data = NULL;
1845
1846 /* Record "descriptor" entity */
1847 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1848 if (unlikely(ret < 0)) {
1849 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1850 num, ret);
1851 return ret;
1852 }
1853
1854 if (!data)
1855 return _len - len;
1856
1857 ret = ffs_do_single_desc(data, len, entity, priv);
1858 if (unlikely(ret < 0)) {
1859 pr_debug("%s returns %d\n", __func__, ret);
1860 return ret;
1861 }
1862
1863 len -= ret;
1864 data += ret;
1865 ++num;
1866 }
1867 }
1868
1869 static int __ffs_data_do_entity(enum ffs_entity_type type,
1870 u8 *valuep, struct usb_descriptor_header *desc,
1871 void *priv)
1872 {
1873 struct ffs_desc_helper *helper = priv;
1874 struct usb_endpoint_descriptor *d;
1875
1876 ENTER();
1877
1878 switch (type) {
1879 case FFS_DESCRIPTOR:
1880 break;
1881
1882 case FFS_INTERFACE:
1883 /*
1884 * Interfaces are indexed from zero so if we
1885 * encountered interface "n" then there are at least
1886 * "n+1" interfaces.
1887 */
1888 if (*valuep >= helper->interfaces_count)
1889 helper->interfaces_count = *valuep + 1;
1890 break;
1891
1892 case FFS_STRING:
1893 /*
1894 * Strings are indexed from 1 (0 is magic ;) reserved
1895 * for languages list or some such)
1896 */
1897 if (*valuep > helper->ffs->strings_count)
1898 helper->ffs->strings_count = *valuep;
1899 break;
1900
1901 case FFS_ENDPOINT:
1902 d = (void *)desc;
1903 helper->eps_count++;
1904 if (helper->eps_count >= 15)
1905 return -EINVAL;
1906 /* Check if descriptors for any speed were already parsed */
1907 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
1908 helper->ffs->eps_addrmap[helper->eps_count] =
1909 d->bEndpointAddress;
1910 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
1911 d->bEndpointAddress)
1912 return -EINVAL;
1913 break;
1914 }
1915
1916 return 0;
1917 }
1918
1919 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1920 struct usb_os_desc_header *desc)
1921 {
1922 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1923 u16 w_index = le16_to_cpu(desc->wIndex);
1924
1925 if (bcd_version != 1) {
1926 pr_vdebug("unsupported os descriptors version: %d",
1927 bcd_version);
1928 return -EINVAL;
1929 }
1930 switch (w_index) {
1931 case 0x4:
1932 *next_type = FFS_OS_DESC_EXT_COMPAT;
1933 break;
1934 case 0x5:
1935 *next_type = FFS_OS_DESC_EXT_PROP;
1936 break;
1937 default:
1938 pr_vdebug("unsupported os descriptor type: %d", w_index);
1939 return -EINVAL;
1940 }
1941
1942 return sizeof(*desc);
1943 }
1944
1945 /*
1946 * Process all extended compatibility/extended property descriptors
1947 * of a feature descriptor
1948 */
1949 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1950 enum ffs_os_desc_type type,
1951 u16 feature_count,
1952 ffs_os_desc_callback entity,
1953 void *priv,
1954 struct usb_os_desc_header *h)
1955 {
1956 int ret;
1957 const unsigned _len = len;
1958
1959 ENTER();
1960
1961 /* loop over all ext compat/ext prop descriptors */
1962 while (feature_count--) {
1963 ret = entity(type, h, data, len, priv);
1964 if (unlikely(ret < 0)) {
1965 pr_debug("bad OS descriptor, type: %d\n", type);
1966 return ret;
1967 }
1968 data += ret;
1969 len -= ret;
1970 }
1971 return _len - len;
1972 }
1973
1974 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
1975 static int __must_check ffs_do_os_descs(unsigned count,
1976 char *data, unsigned len,
1977 ffs_os_desc_callback entity, void *priv)
1978 {
1979 const unsigned _len = len;
1980 unsigned long num = 0;
1981
1982 ENTER();
1983
1984 for (num = 0; num < count; ++num) {
1985 int ret;
1986 enum ffs_os_desc_type type;
1987 u16 feature_count;
1988 struct usb_os_desc_header *desc = (void *)data;
1989
1990 if (len < sizeof(*desc))
1991 return -EINVAL;
1992
1993 /*
1994 * Record "descriptor" entity.
1995 * Process dwLength, bcdVersion, wIndex, get b/wCount.
1996 * Move the data pointer to the beginning of extended
1997 * compatibilities proper or extended properties proper
1998 * portions of the data
1999 */
2000 if (le32_to_cpu(desc->dwLength) > len)
2001 return -EINVAL;
2002
2003 ret = __ffs_do_os_desc_header(&type, desc);
2004 if (unlikely(ret < 0)) {
2005 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2006 num, ret);
2007 return ret;
2008 }
2009 /*
2010 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2011 */
2012 feature_count = le16_to_cpu(desc->wCount);
2013 if (type == FFS_OS_DESC_EXT_COMPAT &&
2014 (feature_count > 255 || desc->Reserved))
2015 return -EINVAL;
2016 len -= ret;
2017 data += ret;
2018
2019 /*
2020 * Process all function/property descriptors
2021 * of this Feature Descriptor
2022 */
2023 ret = ffs_do_single_os_desc(data, len, type,
2024 feature_count, entity, priv, desc);
2025 if (unlikely(ret < 0)) {
2026 pr_debug("%s returns %d\n", __func__, ret);
2027 return ret;
2028 }
2029
2030 len -= ret;
2031 data += ret;
2032 }
2033 return _len - len;
2034 }
2035
2036 /**
2037 * Validate contents of the buffer from userspace related to OS descriptors.
2038 */
2039 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2040 struct usb_os_desc_header *h, void *data,
2041 unsigned len, void *priv)
2042 {
2043 struct ffs_data *ffs = priv;
2044 u8 length;
2045
2046 ENTER();
2047
2048 switch (type) {
2049 case FFS_OS_DESC_EXT_COMPAT: {
2050 struct usb_ext_compat_desc *d = data;
2051 int i;
2052
2053 if (len < sizeof(*d) ||
2054 d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2055 d->Reserved1)
2056 return -EINVAL;
2057 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2058 if (d->Reserved2[i])
2059 return -EINVAL;
2060
2061 length = sizeof(struct usb_ext_compat_desc);
2062 }
2063 break;
2064 case FFS_OS_DESC_EXT_PROP: {
2065 struct usb_ext_prop_desc *d = data;
2066 u32 type, pdl;
2067 u16 pnl;
2068
2069 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2070 return -EINVAL;
2071 length = le32_to_cpu(d->dwSize);
2072 type = le32_to_cpu(d->dwPropertyDataType);
2073 if (type < USB_EXT_PROP_UNICODE ||
2074 type > USB_EXT_PROP_UNICODE_MULTI) {
2075 pr_vdebug("unsupported os descriptor property type: %d",
2076 type);
2077 return -EINVAL;
2078 }
2079 pnl = le16_to_cpu(d->wPropertyNameLength);
2080 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2081 if (length != 14 + pnl + pdl) {
2082 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2083 length, pnl, pdl, type);
2084 return -EINVAL;
2085 }
2086 ++ffs->ms_os_descs_ext_prop_count;
2087 /* property name reported to the host as "WCHAR"s */
2088 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2089 ffs->ms_os_descs_ext_prop_data_len += pdl;
2090 }
2091 break;
2092 default:
2093 pr_vdebug("unknown descriptor: %d\n", type);
2094 return -EINVAL;
2095 }
2096 return length;
2097 }
2098
2099 static int __ffs_data_got_descs(struct ffs_data *ffs,
2100 char *const _data, size_t len)
2101 {
2102 char *data = _data, *raw_descs;
2103 unsigned os_descs_count = 0, counts[3], flags;
2104 int ret = -EINVAL, i;
2105 struct ffs_desc_helper helper;
2106
2107 ENTER();
2108
2109 if (get_unaligned_le32(data + 4) != len)
2110 goto error;
2111
2112 switch (get_unaligned_le32(data)) {
2113 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2114 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2115 data += 8;
2116 len -= 8;
2117 break;
2118 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2119 flags = get_unaligned_le32(data + 8);
2120 ffs->user_flags = flags;
2121 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2122 FUNCTIONFS_HAS_HS_DESC |
2123 FUNCTIONFS_HAS_SS_DESC |
2124 FUNCTIONFS_HAS_MS_OS_DESC |
2125 FUNCTIONFS_VIRTUAL_ADDR |
2126 FUNCTIONFS_EVENTFD)) {
2127 ret = -ENOSYS;
2128 goto error;
2129 }
2130 data += 12;
2131 len -= 12;
2132 break;
2133 default:
2134 goto error;
2135 }
2136
2137 if (flags & FUNCTIONFS_EVENTFD) {
2138 if (len < 4)
2139 goto error;
2140 ffs->ffs_eventfd =
2141 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2142 if (IS_ERR(ffs->ffs_eventfd)) {
2143 ret = PTR_ERR(ffs->ffs_eventfd);
2144 ffs->ffs_eventfd = NULL;
2145 goto error;
2146 }
2147 data += 4;
2148 len -= 4;
2149 }
2150
2151 /* Read fs_count, hs_count and ss_count (if present) */
2152 for (i = 0; i < 3; ++i) {
2153 if (!(flags & (1 << i))) {
2154 counts[i] = 0;
2155 } else if (len < 4) {
2156 goto error;
2157 } else {
2158 counts[i] = get_unaligned_le32(data);
2159 data += 4;
2160 len -= 4;
2161 }
2162 }
2163 if (flags & (1 << i)) {
2164 os_descs_count = get_unaligned_le32(data);
2165 data += 4;
2166 len -= 4;
2167 };
2168
2169 /* Read descriptors */
2170 raw_descs = data;
2171 helper.ffs = ffs;
2172 for (i = 0; i < 3; ++i) {
2173 if (!counts[i])
2174 continue;
2175 helper.interfaces_count = 0;
2176 helper.eps_count = 0;
2177 ret = ffs_do_descs(counts[i], data, len,
2178 __ffs_data_do_entity, &helper);
2179 if (ret < 0)
2180 goto error;
2181 if (!ffs->eps_count && !ffs->interfaces_count) {
2182 ffs->eps_count = helper.eps_count;
2183 ffs->interfaces_count = helper.interfaces_count;
2184 } else {
2185 if (ffs->eps_count != helper.eps_count) {
2186 ret = -EINVAL;
2187 goto error;
2188 }
2189 if (ffs->interfaces_count != helper.interfaces_count) {
2190 ret = -EINVAL;
2191 goto error;
2192 }
2193 }
2194 data += ret;
2195 len -= ret;
2196 }
2197 if (os_descs_count) {
2198 ret = ffs_do_os_descs(os_descs_count, data, len,
2199 __ffs_data_do_os_desc, ffs);
2200 if (ret < 0)
2201 goto error;
2202 data += ret;
2203 len -= ret;
2204 }
2205
2206 if (raw_descs == data || len) {
2207 ret = -EINVAL;
2208 goto error;
2209 }
2210
2211 ffs->raw_descs_data = _data;
2212 ffs->raw_descs = raw_descs;
2213 ffs->raw_descs_length = data - raw_descs;
2214 ffs->fs_descs_count = counts[0];
2215 ffs->hs_descs_count = counts[1];
2216 ffs->ss_descs_count = counts[2];
2217 ffs->ms_os_descs_count = os_descs_count;
2218
2219 return 0;
2220
2221 error:
2222 kfree(_data);
2223 return ret;
2224 }
2225
2226 static int __ffs_data_got_strings(struct ffs_data *ffs,
2227 char *const _data, size_t len)
2228 {
2229 u32 str_count, needed_count, lang_count;
2230 struct usb_gadget_strings **stringtabs, *t;
2231 struct usb_string *strings, *s;
2232 const char *data = _data;
2233
2234 ENTER();
2235
2236 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2237 get_unaligned_le32(data + 4) != len))
2238 goto error;
2239 str_count = get_unaligned_le32(data + 8);
2240 lang_count = get_unaligned_le32(data + 12);
2241
2242 /* if one is zero the other must be zero */
2243 if (unlikely(!str_count != !lang_count))
2244 goto error;
2245
2246 /* Do we have at least as many strings as descriptors need? */
2247 needed_count = ffs->strings_count;
2248 if (unlikely(str_count < needed_count))
2249 goto error;
2250
2251 /*
2252 * If we don't need any strings just return and free all
2253 * memory.
2254 */
2255 if (!needed_count) {
2256 kfree(_data);
2257 return 0;
2258 }
2259
2260 /* Allocate everything in one chunk so there's less maintenance. */
2261 {
2262 unsigned i = 0;
2263 vla_group(d);
2264 vla_item(d, struct usb_gadget_strings *, stringtabs,
2265 lang_count + 1);
2266 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2267 vla_item(d, struct usb_string, strings,
2268 lang_count*(needed_count+1));
2269
2270 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2271
2272 if (unlikely(!vlabuf)) {
2273 kfree(_data);
2274 return -ENOMEM;
2275 }
2276
2277 /* Initialize the VLA pointers */
2278 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2279 t = vla_ptr(vlabuf, d, stringtab);
2280 i = lang_count;
2281 do {
2282 *stringtabs++ = t++;
2283 } while (--i);
2284 *stringtabs = NULL;
2285
2286 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2287 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2288 t = vla_ptr(vlabuf, d, stringtab);
2289 s = vla_ptr(vlabuf, d, strings);
2290 strings = s;
2291 }
2292
2293 /* For each language */
2294 data += 16;
2295 len -= 16;
2296
2297 do { /* lang_count > 0 so we can use do-while */
2298 unsigned needed = needed_count;
2299
2300 if (unlikely(len < 3))
2301 goto error_free;
2302 t->language = get_unaligned_le16(data);
2303 t->strings = s;
2304 ++t;
2305
2306 data += 2;
2307 len -= 2;
2308
2309 /* For each string */
2310 do { /* str_count > 0 so we can use do-while */
2311 size_t length = strnlen(data, len);
2312
2313 if (unlikely(length == len))
2314 goto error_free;
2315
2316 /*
2317 * User may provide more strings then we need,
2318 * if that's the case we simply ignore the
2319 * rest
2320 */
2321 if (likely(needed)) {
2322 /*
2323 * s->id will be set while adding
2324 * function to configuration so for
2325 * now just leave garbage here.
2326 */
2327 s->s = data;
2328 --needed;
2329 ++s;
2330 }
2331
2332 data += length + 1;
2333 len -= length + 1;
2334 } while (--str_count);
2335
2336 s->id = 0; /* terminator */
2337 s->s = NULL;
2338 ++s;
2339
2340 } while (--lang_count);
2341
2342 /* Some garbage left? */
2343 if (unlikely(len))
2344 goto error_free;
2345
2346 /* Done! */
2347 ffs->stringtabs = stringtabs;
2348 ffs->raw_strings = _data;
2349
2350 return 0;
2351
2352 error_free:
2353 kfree(stringtabs);
2354 error:
2355 kfree(_data);
2356 return -EINVAL;
2357 }
2358
2359
2360 /* Events handling and management *******************************************/
2361
2362 static void __ffs_event_add(struct ffs_data *ffs,
2363 enum usb_functionfs_event_type type)
2364 {
2365 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2366 int neg = 0;
2367
2368 /*
2369 * Abort any unhandled setup
2370 *
2371 * We do not need to worry about some cmpxchg() changing value
2372 * of ffs->setup_state without holding the lock because when
2373 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2374 * the source does nothing.
2375 */
2376 if (ffs->setup_state == FFS_SETUP_PENDING)
2377 ffs->setup_state = FFS_SETUP_CANCELLED;
2378
2379 /*
2380 * Logic of this function guarantees that there are at most four pending
2381 * evens on ffs->ev.types queue. This is important because the queue
2382 * has space for four elements only and __ffs_ep0_read_events function
2383 * depends on that limit as well. If more event types are added, those
2384 * limits have to be revisited or guaranteed to still hold.
2385 */
2386 switch (type) {
2387 case FUNCTIONFS_RESUME:
2388 rem_type2 = FUNCTIONFS_SUSPEND;
2389 /* FALL THROUGH */
2390 case FUNCTIONFS_SUSPEND:
2391 case FUNCTIONFS_SETUP:
2392 rem_type1 = type;
2393 /* Discard all similar events */
2394 break;
2395
2396 case FUNCTIONFS_BIND:
2397 case FUNCTIONFS_UNBIND:
2398 case FUNCTIONFS_DISABLE:
2399 case FUNCTIONFS_ENABLE:
2400 /* Discard everything other then power management. */
2401 rem_type1 = FUNCTIONFS_SUSPEND;
2402 rem_type2 = FUNCTIONFS_RESUME;
2403 neg = 1;
2404 break;
2405
2406 default:
2407 WARN(1, "%d: unknown event, this should not happen\n", type);
2408 return;
2409 }
2410
2411 {
2412 u8 *ev = ffs->ev.types, *out = ev;
2413 unsigned n = ffs->ev.count;
2414 for (; n; --n, ++ev)
2415 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2416 *out++ = *ev;
2417 else
2418 pr_vdebug("purging event %d\n", *ev);
2419 ffs->ev.count = out - ffs->ev.types;
2420 }
2421
2422 pr_vdebug("adding event %d\n", type);
2423 ffs->ev.types[ffs->ev.count++] = type;
2424 wake_up_locked(&ffs->ev.waitq);
2425 if (ffs->ffs_eventfd)
2426 eventfd_signal(ffs->ffs_eventfd, 1);
2427 }
2428
2429 static void ffs_event_add(struct ffs_data *ffs,
2430 enum usb_functionfs_event_type type)
2431 {
2432 unsigned long flags;
2433 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2434 __ffs_event_add(ffs, type);
2435 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2436 }
2437
2438 /* Bind/unbind USB function hooks *******************************************/
2439
2440 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2441 {
2442 int i;
2443
2444 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2445 if (ffs->eps_addrmap[i] == endpoint_address)
2446 return i;
2447 return -ENOENT;
2448 }
2449
2450 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2451 struct usb_descriptor_header *desc,
2452 void *priv)
2453 {
2454 struct usb_endpoint_descriptor *ds = (void *)desc;
2455 struct ffs_function *func = priv;
2456 struct ffs_ep *ffs_ep;
2457 unsigned ep_desc_id;
2458 int idx;
2459 static const char *speed_names[] = { "full", "high", "super" };
2460
2461 if (type != FFS_DESCRIPTOR)
2462 return 0;
2463
2464 /*
2465 * If ss_descriptors is not NULL, we are reading super speed
2466 * descriptors; if hs_descriptors is not NULL, we are reading high
2467 * speed descriptors; otherwise, we are reading full speed
2468 * descriptors.
2469 */
2470 if (func->function.ss_descriptors) {
2471 ep_desc_id = 2;
2472 func->function.ss_descriptors[(long)valuep] = desc;
2473 } else if (func->function.hs_descriptors) {
2474 ep_desc_id = 1;
2475 func->function.hs_descriptors[(long)valuep] = desc;
2476 } else {
2477 ep_desc_id = 0;
2478 func->function.fs_descriptors[(long)valuep] = desc;
2479 }
2480
2481 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2482 return 0;
2483
2484 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2485 if (idx < 0)
2486 return idx;
2487
2488 ffs_ep = func->eps + idx;
2489
2490 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2491 pr_err("two %sspeed descriptors for EP %d\n",
2492 speed_names[ep_desc_id],
2493 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2494 return -EINVAL;
2495 }
2496 ffs_ep->descs[ep_desc_id] = ds;
2497
2498 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2499 if (ffs_ep->ep) {
2500 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2501 if (!ds->wMaxPacketSize)
2502 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2503 } else {
2504 struct usb_request *req;
2505 struct usb_ep *ep;
2506 u8 bEndpointAddress;
2507
2508 /*
2509 * We back up bEndpointAddress because autoconfig overwrites
2510 * it with physical endpoint address.
2511 */
2512 bEndpointAddress = ds->bEndpointAddress;
2513 pr_vdebug("autoconfig\n");
2514 ep = usb_ep_autoconfig(func->gadget, ds);
2515 if (unlikely(!ep))
2516 return -ENOTSUPP;
2517 ep->driver_data = func->eps + idx;
2518
2519 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2520 if (unlikely(!req))
2521 return -ENOMEM;
2522
2523 ffs_ep->ep = ep;
2524 ffs_ep->req = req;
2525 func->eps_revmap[ds->bEndpointAddress &
2526 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2527 /*
2528 * If we use virtual address mapping, we restore
2529 * original bEndpointAddress value.
2530 */
2531 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2532 ds->bEndpointAddress = bEndpointAddress;
2533 }
2534 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2535
2536 return 0;
2537 }
2538
2539 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2540 struct usb_descriptor_header *desc,
2541 void *priv)
2542 {
2543 struct ffs_function *func = priv;
2544 unsigned idx;
2545 u8 newValue;
2546
2547 switch (type) {
2548 default:
2549 case FFS_DESCRIPTOR:
2550 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2551 return 0;
2552
2553 case FFS_INTERFACE:
2554 idx = *valuep;
2555 if (func->interfaces_nums[idx] < 0) {
2556 int id = usb_interface_id(func->conf, &func->function);
2557 if (unlikely(id < 0))
2558 return id;
2559 func->interfaces_nums[idx] = id;
2560 }
2561 newValue = func->interfaces_nums[idx];
2562 break;
2563
2564 case FFS_STRING:
2565 /* String' IDs are allocated when fsf_data is bound to cdev */
2566 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2567 break;
2568
2569 case FFS_ENDPOINT:
2570 /*
2571 * USB_DT_ENDPOINT are handled in
2572 * __ffs_func_bind_do_descs().
2573 */
2574 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2575 return 0;
2576
2577 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2578 if (unlikely(!func->eps[idx].ep))
2579 return -EINVAL;
2580
2581 {
2582 struct usb_endpoint_descriptor **descs;
2583 descs = func->eps[idx].descs;
2584 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2585 }
2586 break;
2587 }
2588
2589 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2590 *valuep = newValue;
2591 return 0;
2592 }
2593
2594 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2595 struct usb_os_desc_header *h, void *data,
2596 unsigned len, void *priv)
2597 {
2598 struct ffs_function *func = priv;
2599 u8 length = 0;
2600
2601 switch (type) {
2602 case FFS_OS_DESC_EXT_COMPAT: {
2603 struct usb_ext_compat_desc *desc = data;
2604 struct usb_os_desc_table *t;
2605
2606 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2607 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2608 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2609 ARRAY_SIZE(desc->CompatibleID) +
2610 ARRAY_SIZE(desc->SubCompatibleID));
2611 length = sizeof(*desc);
2612 }
2613 break;
2614 case FFS_OS_DESC_EXT_PROP: {
2615 struct usb_ext_prop_desc *desc = data;
2616 struct usb_os_desc_table *t;
2617 struct usb_os_desc_ext_prop *ext_prop;
2618 char *ext_prop_name;
2619 char *ext_prop_data;
2620
2621 t = &func->function.os_desc_table[h->interface];
2622 t->if_id = func->interfaces_nums[h->interface];
2623
2624 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2625 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2626
2627 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2628 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2629 ext_prop->data_len = le32_to_cpu(*(u32 *)
2630 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2631 length = ext_prop->name_len + ext_prop->data_len + 14;
2632
2633 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2634 func->ffs->ms_os_descs_ext_prop_name_avail +=
2635 ext_prop->name_len;
2636
2637 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2638 func->ffs->ms_os_descs_ext_prop_data_avail +=
2639 ext_prop->data_len;
2640 memcpy(ext_prop_data,
2641 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2642 ext_prop->data_len);
2643 /* unicode data reported to the host as "WCHAR"s */
2644 switch (ext_prop->type) {
2645 case USB_EXT_PROP_UNICODE:
2646 case USB_EXT_PROP_UNICODE_ENV:
2647 case USB_EXT_PROP_UNICODE_LINK:
2648 case USB_EXT_PROP_UNICODE_MULTI:
2649 ext_prop->data_len *= 2;
2650 break;
2651 }
2652 ext_prop->data = ext_prop_data;
2653
2654 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2655 ext_prop->name_len);
2656 /* property name reported to the host as "WCHAR"s */
2657 ext_prop->name_len *= 2;
2658 ext_prop->name = ext_prop_name;
2659
2660 t->os_desc->ext_prop_len +=
2661 ext_prop->name_len + ext_prop->data_len + 14;
2662 ++t->os_desc->ext_prop_count;
2663 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2664 }
2665 break;
2666 default:
2667 pr_vdebug("unknown descriptor: %d\n", type);
2668 }
2669
2670 return length;
2671 }
2672
2673 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2674 struct usb_configuration *c)
2675 {
2676 struct ffs_function *func = ffs_func_from_usb(f);
2677 struct f_fs_opts *ffs_opts =
2678 container_of(f->fi, struct f_fs_opts, func_inst);
2679 int ret;
2680
2681 ENTER();
2682
2683 /*
2684 * Legacy gadget triggers binding in functionfs_ready_callback,
2685 * which already uses locking; taking the same lock here would
2686 * cause a deadlock.
2687 *
2688 * Configfs-enabled gadgets however do need ffs_dev_lock.
2689 */
2690 if (!ffs_opts->no_configfs)
2691 ffs_dev_lock();
2692 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2693 func->ffs = ffs_opts->dev->ffs_data;
2694 if (!ffs_opts->no_configfs)
2695 ffs_dev_unlock();
2696 if (ret)
2697 return ERR_PTR(ret);
2698
2699 func->conf = c;
2700 func->gadget = c->cdev->gadget;
2701
2702 /*
2703 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2704 * configurations are bound in sequence with list_for_each_entry,
2705 * in each configuration its functions are bound in sequence
2706 * with list_for_each_entry, so we assume no race condition
2707 * with regard to ffs_opts->bound access
2708 */
2709 if (!ffs_opts->refcnt) {
2710 ret = functionfs_bind(func->ffs, c->cdev);
2711 if (ret)
2712 return ERR_PTR(ret);
2713 }
2714 ffs_opts->refcnt++;
2715 func->function.strings = func->ffs->stringtabs;
2716
2717 return ffs_opts;
2718 }
2719
2720 static int _ffs_func_bind(struct usb_configuration *c,
2721 struct usb_function *f)
2722 {
2723 struct ffs_function *func = ffs_func_from_usb(f);
2724 struct ffs_data *ffs = func->ffs;
2725
2726 const int full = !!func->ffs->fs_descs_count;
2727 const int high = gadget_is_dualspeed(func->gadget) &&
2728 func->ffs->hs_descs_count;
2729 const int super = gadget_is_superspeed(func->gadget) &&
2730 func->ffs->ss_descs_count;
2731
2732 int fs_len, hs_len, ss_len, ret, i;
2733
2734 /* Make it a single chunk, less management later on */
2735 vla_group(d);
2736 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2737 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2738 full ? ffs->fs_descs_count + 1 : 0);
2739 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2740 high ? ffs->hs_descs_count + 1 : 0);
2741 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2742 super ? ffs->ss_descs_count + 1 : 0);
2743 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2744 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2745 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2746 vla_item_with_sz(d, char[16], ext_compat,
2747 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2748 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2749 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2750 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2751 ffs->ms_os_descs_ext_prop_count);
2752 vla_item_with_sz(d, char, ext_prop_name,
2753 ffs->ms_os_descs_ext_prop_name_len);
2754 vla_item_with_sz(d, char, ext_prop_data,
2755 ffs->ms_os_descs_ext_prop_data_len);
2756 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2757 char *vlabuf;
2758
2759 ENTER();
2760
2761 /* Has descriptors only for speeds gadget does not support */
2762 if (unlikely(!(full | high | super)))
2763 return -ENOTSUPP;
2764
2765 /* Allocate a single chunk, less management later on */
2766 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2767 if (unlikely(!vlabuf))
2768 return -ENOMEM;
2769
2770 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2771 ffs->ms_os_descs_ext_prop_name_avail =
2772 vla_ptr(vlabuf, d, ext_prop_name);
2773 ffs->ms_os_descs_ext_prop_data_avail =
2774 vla_ptr(vlabuf, d, ext_prop_data);
2775
2776 /* Copy descriptors */
2777 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2778 ffs->raw_descs_length);
2779
2780 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2781 for (ret = ffs->eps_count; ret; --ret) {
2782 struct ffs_ep *ptr;
2783
2784 ptr = vla_ptr(vlabuf, d, eps);
2785 ptr[ret].num = -1;
2786 }
2787
2788 /* Save pointers
2789 * d_eps == vlabuf, func->eps used to kfree vlabuf later
2790 */
2791 func->eps = vla_ptr(vlabuf, d, eps);
2792 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2793
2794 /*
2795 * Go through all the endpoint descriptors and allocate
2796 * endpoints first, so that later we can rewrite the endpoint
2797 * numbers without worrying that it may be described later on.
2798 */
2799 if (likely(full)) {
2800 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2801 fs_len = ffs_do_descs(ffs->fs_descs_count,
2802 vla_ptr(vlabuf, d, raw_descs),
2803 d_raw_descs__sz,
2804 __ffs_func_bind_do_descs, func);
2805 if (unlikely(fs_len < 0)) {
2806 ret = fs_len;
2807 goto error;
2808 }
2809 } else {
2810 fs_len = 0;
2811 }
2812
2813 if (likely(high)) {
2814 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2815 hs_len = ffs_do_descs(ffs->hs_descs_count,
2816 vla_ptr(vlabuf, d, raw_descs) + fs_len,
2817 d_raw_descs__sz - fs_len,
2818 __ffs_func_bind_do_descs, func);
2819 if (unlikely(hs_len < 0)) {
2820 ret = hs_len;
2821 goto error;
2822 }
2823 } else {
2824 hs_len = 0;
2825 }
2826
2827 if (likely(super)) {
2828 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2829 ss_len = ffs_do_descs(ffs->ss_descs_count,
2830 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2831 d_raw_descs__sz - fs_len - hs_len,
2832 __ffs_func_bind_do_descs, func);
2833 if (unlikely(ss_len < 0)) {
2834 ret = ss_len;
2835 goto error;
2836 }
2837 } else {
2838 ss_len = 0;
2839 }
2840
2841 /*
2842 * Now handle interface numbers allocation and interface and
2843 * endpoint numbers rewriting. We can do that in one go
2844 * now.
2845 */
2846 ret = ffs_do_descs(ffs->fs_descs_count +
2847 (high ? ffs->hs_descs_count : 0) +
2848 (super ? ffs->ss_descs_count : 0),
2849 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2850 __ffs_func_bind_do_nums, func);
2851 if (unlikely(ret < 0))
2852 goto error;
2853
2854 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2855 if (c->cdev->use_os_string)
2856 for (i = 0; i < ffs->interfaces_count; ++i) {
2857 struct usb_os_desc *desc;
2858
2859 desc = func->function.os_desc_table[i].os_desc =
2860 vla_ptr(vlabuf, d, os_desc) +
2861 i * sizeof(struct usb_os_desc);
2862 desc->ext_compat_id =
2863 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2864 INIT_LIST_HEAD(&desc->ext_prop);
2865 }
2866 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2867 vla_ptr(vlabuf, d, raw_descs) +
2868 fs_len + hs_len + ss_len,
2869 d_raw_descs__sz - fs_len - hs_len - ss_len,
2870 __ffs_func_bind_do_os_desc, func);
2871 if (unlikely(ret < 0))
2872 goto error;
2873 func->function.os_desc_n =
2874 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2875
2876 /* And we're done */
2877 ffs_event_add(ffs, FUNCTIONFS_BIND);
2878 return 0;
2879
2880 error:
2881 /* XXX Do we need to release all claimed endpoints here? */
2882 return ret;
2883 }
2884
2885 static int ffs_func_bind(struct usb_configuration *c,
2886 struct usb_function *f)
2887 {
2888 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2889 struct ffs_function *func = ffs_func_from_usb(f);
2890 int ret;
2891
2892 if (IS_ERR(ffs_opts))
2893 return PTR_ERR(ffs_opts);
2894
2895 ret = _ffs_func_bind(c, f);
2896 if (ret && !--ffs_opts->refcnt)
2897 functionfs_unbind(func->ffs);
2898
2899 return ret;
2900 }
2901
2902
2903 /* Other USB function hooks *************************************************/
2904
2905 static void ffs_reset_work(struct work_struct *work)
2906 {
2907 struct ffs_data *ffs = container_of(work,
2908 struct ffs_data, reset_work);
2909 ffs_data_reset(ffs);
2910 }
2911
2912 static int ffs_func_set_alt(struct usb_function *f,
2913 unsigned interface, unsigned alt)
2914 {
2915 struct ffs_function *func = ffs_func_from_usb(f);
2916 struct ffs_data *ffs = func->ffs;
2917 int ret = 0, intf;
2918
2919 if (alt != (unsigned)-1) {
2920 intf = ffs_func_revmap_intf(func, interface);
2921 if (unlikely(intf < 0))
2922 return intf;
2923 }
2924
2925 if (ffs->func)
2926 ffs_func_eps_disable(ffs->func);
2927
2928 if (ffs->state == FFS_DEACTIVATED) {
2929 ffs->state = FFS_CLOSING;
2930 INIT_WORK(&ffs->reset_work, ffs_reset_work);
2931 schedule_work(&ffs->reset_work);
2932 return -ENODEV;
2933 }
2934
2935 if (ffs->state != FFS_ACTIVE)
2936 return -ENODEV;
2937
2938 if (alt == (unsigned)-1) {
2939 ffs->func = NULL;
2940 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2941 return 0;
2942 }
2943
2944 ffs->func = func;
2945 ret = ffs_func_eps_enable(func);
2946 if (likely(ret >= 0))
2947 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2948 return ret;
2949 }
2950
2951 static void ffs_func_disable(struct usb_function *f)
2952 {
2953 ffs_func_set_alt(f, 0, (unsigned)-1);
2954 }
2955
2956 static int ffs_func_setup(struct usb_function *f,
2957 const struct usb_ctrlrequest *creq)
2958 {
2959 struct ffs_function *func = ffs_func_from_usb(f);
2960 struct ffs_data *ffs = func->ffs;
2961 unsigned long flags;
2962 int ret;
2963
2964 ENTER();
2965
2966 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2967 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2968 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
2969 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
2970 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
2971
2972 /*
2973 * Most requests directed to interface go through here
2974 * (notable exceptions are set/get interface) so we need to
2975 * handle them. All other either handled by composite or
2976 * passed to usb_configuration->setup() (if one is set). No
2977 * matter, we will handle requests directed to endpoint here
2978 * as well (as it's straightforward) but what to do with any
2979 * other request?
2980 */
2981 if (ffs->state != FFS_ACTIVE)
2982 return -ENODEV;
2983
2984 switch (creq->bRequestType & USB_RECIP_MASK) {
2985 case USB_RECIP_INTERFACE:
2986 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2987 if (unlikely(ret < 0))
2988 return ret;
2989 break;
2990
2991 case USB_RECIP_ENDPOINT:
2992 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2993 if (unlikely(ret < 0))
2994 return ret;
2995 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2996 ret = func->ffs->eps_addrmap[ret];
2997 break;
2998
2999 default:
3000 return -EOPNOTSUPP;
3001 }
3002
3003 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3004 ffs->ev.setup = *creq;
3005 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3006 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3007 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3008
3009 return 0;
3010 }
3011
3012 static void ffs_func_suspend(struct usb_function *f)
3013 {
3014 ENTER();
3015 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3016 }
3017
3018 static void ffs_func_resume(struct usb_function *f)
3019 {
3020 ENTER();
3021 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3022 }
3023
3024
3025 /* Endpoint and interface numbers reverse mapping ***************************/
3026
3027 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3028 {
3029 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3030 return num ? num : -EDOM;
3031 }
3032
3033 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3034 {
3035 short *nums = func->interfaces_nums;
3036 unsigned count = func->ffs->interfaces_count;
3037
3038 for (; count; --count, ++nums) {
3039 if (*nums >= 0 && *nums == intf)
3040 return nums - func->interfaces_nums;
3041 }
3042
3043 return -EDOM;
3044 }
3045
3046
3047 /* Devices management *******************************************************/
3048
3049 static LIST_HEAD(ffs_devices);
3050
3051 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3052 {
3053 struct ffs_dev *dev;
3054
3055 list_for_each_entry(dev, &ffs_devices, entry) {
3056 if (!dev->name || !name)
3057 continue;
3058 if (strcmp(dev->name, name) == 0)
3059 return dev;
3060 }
3061
3062 return NULL;
3063 }
3064
3065 /*
3066 * ffs_lock must be taken by the caller of this function
3067 */
3068 static struct ffs_dev *_ffs_get_single_dev(void)
3069 {
3070 struct ffs_dev *dev;
3071
3072 if (list_is_singular(&ffs_devices)) {
3073 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3074 if (dev->single)
3075 return dev;
3076 }
3077
3078 return NULL;
3079 }
3080
3081 /*
3082 * ffs_lock must be taken by the caller of this function
3083 */
3084 static struct ffs_dev *_ffs_find_dev(const char *name)
3085 {
3086 struct ffs_dev *dev;
3087
3088 dev = _ffs_get_single_dev();
3089 if (dev)
3090 return dev;
3091
3092 return _ffs_do_find_dev(name);
3093 }
3094
3095 /* Configfs support *********************************************************/
3096
3097 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3098 {
3099 return container_of(to_config_group(item), struct f_fs_opts,
3100 func_inst.group);
3101 }
3102
3103 static void ffs_attr_release(struct config_item *item)
3104 {
3105 struct f_fs_opts *opts = to_ffs_opts(item);
3106
3107 usb_put_function_instance(&opts->func_inst);
3108 }
3109
3110 static struct configfs_item_operations ffs_item_ops = {
3111 .release = ffs_attr_release,
3112 };
3113
3114 static struct config_item_type ffs_func_type = {
3115 .ct_item_ops = &ffs_item_ops,
3116 .ct_owner = THIS_MODULE,
3117 };
3118
3119
3120 /* Function registration interface ******************************************/
3121
3122 static void ffs_free_inst(struct usb_function_instance *f)
3123 {
3124 struct f_fs_opts *opts;
3125
3126 opts = to_f_fs_opts(f);
3127 ffs_dev_lock();
3128 _ffs_free_dev(opts->dev);
3129 ffs_dev_unlock();
3130 kfree(opts);
3131 }
3132
3133 #define MAX_INST_NAME_LEN 40
3134
3135 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3136 {
3137 struct f_fs_opts *opts;
3138 char *ptr;
3139 const char *tmp;
3140 int name_len, ret;
3141
3142 name_len = strlen(name) + 1;
3143 if (name_len > MAX_INST_NAME_LEN)
3144 return -ENAMETOOLONG;
3145
3146 ptr = kstrndup(name, name_len, GFP_KERNEL);
3147 if (!ptr)
3148 return -ENOMEM;
3149
3150 opts = to_f_fs_opts(fi);
3151 tmp = NULL;
3152
3153 ffs_dev_lock();
3154
3155 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3156 ret = _ffs_name_dev(opts->dev, ptr);
3157 if (ret) {
3158 kfree(ptr);
3159 ffs_dev_unlock();
3160 return ret;
3161 }
3162 opts->dev->name_allocated = true;
3163
3164 ffs_dev_unlock();
3165
3166 kfree(tmp);
3167
3168 return 0;
3169 }
3170
3171 static struct usb_function_instance *ffs_alloc_inst(void)
3172 {
3173 struct f_fs_opts *opts;
3174 struct ffs_dev *dev;
3175
3176 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3177 if (!opts)
3178 return ERR_PTR(-ENOMEM);
3179
3180 opts->func_inst.set_inst_name = ffs_set_inst_name;
3181 opts->func_inst.free_func_inst = ffs_free_inst;
3182 ffs_dev_lock();
3183 dev = _ffs_alloc_dev();
3184 ffs_dev_unlock();
3185 if (IS_ERR(dev)) {
3186 kfree(opts);
3187 return ERR_CAST(dev);
3188 }
3189 opts->dev = dev;
3190 dev->opts = opts;
3191
3192 config_group_init_type_name(&opts->func_inst.group, "",
3193 &ffs_func_type);
3194 return &opts->func_inst;
3195 }
3196
3197 static void ffs_free(struct usb_function *f)
3198 {
3199 kfree(ffs_func_from_usb(f));
3200 }
3201
3202 static void ffs_func_unbind(struct usb_configuration *c,
3203 struct usb_function *f)
3204 {
3205 struct ffs_function *func = ffs_func_from_usb(f);
3206 struct ffs_data *ffs = func->ffs;
3207 struct f_fs_opts *opts =
3208 container_of(f->fi, struct f_fs_opts, func_inst);
3209 struct ffs_ep *ep = func->eps;
3210 unsigned count = ffs->eps_count;
3211 unsigned long flags;
3212
3213 ENTER();
3214 if (ffs->func == func) {
3215 ffs_func_eps_disable(func);
3216 ffs->func = NULL;
3217 }
3218
3219 if (!--opts->refcnt)
3220 functionfs_unbind(ffs);
3221
3222 /* cleanup after autoconfig */
3223 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3224 do {
3225 if (ep->ep && ep->req)
3226 usb_ep_free_request(ep->ep, ep->req);
3227 ep->req = NULL;
3228 ++ep;
3229 } while (--count);
3230 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3231 kfree(func->eps);
3232 func->eps = NULL;
3233 /*
3234 * eps, descriptors and interfaces_nums are allocated in the
3235 * same chunk so only one free is required.
3236 */
3237 func->function.fs_descriptors = NULL;
3238 func->function.hs_descriptors = NULL;
3239 func->function.ss_descriptors = NULL;
3240 func->interfaces_nums = NULL;
3241
3242 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3243 }
3244
3245 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3246 {
3247 struct ffs_function *func;
3248
3249 ENTER();
3250
3251 func = kzalloc(sizeof(*func), GFP_KERNEL);
3252 if (unlikely(!func))
3253 return ERR_PTR(-ENOMEM);
3254
3255 func->function.name = "Function FS Gadget";
3256
3257 func->function.bind = ffs_func_bind;
3258 func->function.unbind = ffs_func_unbind;
3259 func->function.set_alt = ffs_func_set_alt;
3260 func->function.disable = ffs_func_disable;
3261 func->function.setup = ffs_func_setup;
3262 func->function.suspend = ffs_func_suspend;
3263 func->function.resume = ffs_func_resume;
3264 func->function.free_func = ffs_free;
3265
3266 return &func->function;
3267 }
3268
3269 /*
3270 * ffs_lock must be taken by the caller of this function
3271 */
3272 static struct ffs_dev *_ffs_alloc_dev(void)
3273 {
3274 struct ffs_dev *dev;
3275 int ret;
3276
3277 if (_ffs_get_single_dev())
3278 return ERR_PTR(-EBUSY);
3279
3280 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3281 if (!dev)
3282 return ERR_PTR(-ENOMEM);
3283
3284 if (list_empty(&ffs_devices)) {
3285 ret = functionfs_init();
3286 if (ret) {
3287 kfree(dev);
3288 return ERR_PTR(ret);
3289 }
3290 }
3291
3292 list_add(&dev->entry, &ffs_devices);
3293
3294 return dev;
3295 }
3296
3297 /*
3298 * ffs_lock must be taken by the caller of this function
3299 * The caller is responsible for "name" being available whenever f_fs needs it
3300 */
3301 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3302 {
3303 struct ffs_dev *existing;
3304
3305 existing = _ffs_do_find_dev(name);
3306 if (existing)
3307 return -EBUSY;
3308
3309 dev->name = name;
3310
3311 return 0;
3312 }
3313
3314 /*
3315 * The caller is responsible for "name" being available whenever f_fs needs it
3316 */
3317 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3318 {
3319 int ret;
3320
3321 ffs_dev_lock();
3322 ret = _ffs_name_dev(dev, name);
3323 ffs_dev_unlock();
3324
3325 return ret;
3326 }
3327 EXPORT_SYMBOL_GPL(ffs_name_dev);
3328
3329 int ffs_single_dev(struct ffs_dev *dev)
3330 {
3331 int ret;
3332
3333 ret = 0;
3334 ffs_dev_lock();
3335
3336 if (!list_is_singular(&ffs_devices))
3337 ret = -EBUSY;
3338 else
3339 dev->single = true;
3340
3341 ffs_dev_unlock();
3342 return ret;
3343 }
3344 EXPORT_SYMBOL_GPL(ffs_single_dev);
3345
3346 /*
3347 * ffs_lock must be taken by the caller of this function
3348 */
3349 static void _ffs_free_dev(struct ffs_dev *dev)
3350 {
3351 list_del(&dev->entry);
3352 if (dev->name_allocated)
3353 kfree(dev->name);
3354 kfree(dev);
3355 if (list_empty(&ffs_devices))
3356 functionfs_cleanup();
3357 }
3358
3359 static void *ffs_acquire_dev(const char *dev_name)
3360 {
3361 struct ffs_dev *ffs_dev;
3362
3363 ENTER();
3364 ffs_dev_lock();
3365
3366 ffs_dev = _ffs_find_dev(dev_name);
3367 if (!ffs_dev)
3368 ffs_dev = ERR_PTR(-ENOENT);
3369 else if (ffs_dev->mounted)
3370 ffs_dev = ERR_PTR(-EBUSY);
3371 else if (ffs_dev->ffs_acquire_dev_callback &&
3372 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3373 ffs_dev = ERR_PTR(-ENOENT);
3374 else
3375 ffs_dev->mounted = true;
3376
3377 ffs_dev_unlock();
3378 return ffs_dev;
3379 }
3380
3381 static void ffs_release_dev(struct ffs_data *ffs_data)
3382 {
3383 struct ffs_dev *ffs_dev;
3384
3385 ENTER();
3386 ffs_dev_lock();
3387
3388 ffs_dev = ffs_data->private_data;
3389 if (ffs_dev) {
3390 ffs_dev->mounted = false;
3391
3392 if (ffs_dev->ffs_release_dev_callback)
3393 ffs_dev->ffs_release_dev_callback(ffs_dev);
3394 }
3395
3396 ffs_dev_unlock();
3397 }
3398
3399 static int ffs_ready(struct ffs_data *ffs)
3400 {
3401 struct ffs_dev *ffs_obj;
3402 int ret = 0;
3403
3404 ENTER();
3405 ffs_dev_lock();
3406
3407 ffs_obj = ffs->private_data;
3408 if (!ffs_obj) {
3409 ret = -EINVAL;
3410 goto done;
3411 }
3412 if (WARN_ON(ffs_obj->desc_ready)) {
3413 ret = -EBUSY;
3414 goto done;
3415 }
3416
3417 ffs_obj->desc_ready = true;
3418 ffs_obj->ffs_data = ffs;
3419
3420 if (ffs_obj->ffs_ready_callback) {
3421 ret = ffs_obj->ffs_ready_callback(ffs);
3422 if (ret)
3423 goto done;
3424 }
3425
3426 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3427 done:
3428 ffs_dev_unlock();
3429 return ret;
3430 }
3431
3432 static void ffs_closed(struct ffs_data *ffs)
3433 {
3434 struct ffs_dev *ffs_obj;
3435 struct f_fs_opts *opts;
3436
3437 ENTER();
3438 ffs_dev_lock();
3439
3440 ffs_obj = ffs->private_data;
3441 if (!ffs_obj)
3442 goto done;
3443
3444 ffs_obj->desc_ready = false;
3445
3446 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3447 ffs_obj->ffs_closed_callback)
3448 ffs_obj->ffs_closed_callback(ffs);
3449
3450 if (ffs_obj->opts)
3451 opts = ffs_obj->opts;
3452 else
3453 goto done;
3454
3455 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3456 || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount))
3457 goto done;
3458
3459 unregister_gadget_item(ffs_obj->opts->
3460 func_inst.group.cg_item.ci_parent->ci_parent);
3461 done:
3462 ffs_dev_unlock();
3463 }
3464
3465 /* Misc helper functions ****************************************************/
3466
3467 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3468 {
3469 return nonblock
3470 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3471 : mutex_lock_interruptible(mutex);
3472 }
3473
3474 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3475 {
3476 char *data;
3477
3478 if (unlikely(!len))
3479 return NULL;
3480
3481 data = kmalloc(len, GFP_KERNEL);
3482 if (unlikely(!data))
3483 return ERR_PTR(-ENOMEM);
3484
3485 if (unlikely(copy_from_user(data, buf, len))) {
3486 kfree(data);
3487 return ERR_PTR(-EFAULT);
3488 }
3489
3490 pr_vdebug("Buffer from user space:\n");
3491 ffs_dump_mem("", data, len);
3492
3493 return data;
3494 }
3495
3496 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3497 MODULE_LICENSE("GPL");
3498 MODULE_AUTHOR("Michal Nazarewicz");
Linux kernel - Deliverables
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