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Merge tag 'staging-4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[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 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
650
651 if (io_data->read && ret > 0) {
652 use_mm(io_data->mm);
653 ret = copy_to_iter(io_data->buf, ret, &io_data->data);
654 if (iov_iter_count(&io_data->data))
655 ret = -EFAULT;
656 unuse_mm(io_data->mm);
657 }
658
659 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
660
661 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
662 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
663
664 usb_ep_free_request(io_data->ep, io_data->req);
665
666 if (io_data->read)
667 kfree(io_data->to_free);
668 kfree(io_data->buf);
669 kfree(io_data);
670 }
671
672 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
673 struct usb_request *req)
674 {
675 struct ffs_io_data *io_data = req->context;
676
677 ENTER();
678
679 INIT_WORK(&io_data->work, ffs_user_copy_worker);
680 schedule_work(&io_data->work);
681 }
682
683 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
684 {
685 struct ffs_epfile *epfile = file->private_data;
686 struct usb_request *req;
687 struct ffs_ep *ep;
688 char *data = NULL;
689 ssize_t ret, data_len = -EINVAL;
690 int halt;
691
692 /* Are we still active? */
693 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
694 return -ENODEV;
695
696 /* Wait for endpoint to be enabled */
697 ep = epfile->ep;
698 if (!ep) {
699 if (file->f_flags & O_NONBLOCK)
700 return -EAGAIN;
701
702 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
703 if (ret)
704 return -EINTR;
705 }
706
707 /* Do we halt? */
708 halt = (!io_data->read == !epfile->in);
709 if (halt && epfile->isoc)
710 return -EINVAL;
711
712 /* Allocate & copy */
713 if (!halt) {
714 /*
715 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
716 * before the waiting completes, so do not assign to 'gadget'
717 * earlier
718 */
719 struct usb_gadget *gadget = epfile->ffs->gadget;
720 size_t copied;
721
722 spin_lock_irq(&epfile->ffs->eps_lock);
723 /* In the meantime, endpoint got disabled or changed. */
724 if (epfile->ep != ep) {
725 spin_unlock_irq(&epfile->ffs->eps_lock);
726 return -ESHUTDOWN;
727 }
728 data_len = iov_iter_count(&io_data->data);
729 /*
730 * Controller may require buffer size to be aligned to
731 * maxpacketsize of an out endpoint.
732 */
733 if (io_data->read)
734 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
735 spin_unlock_irq(&epfile->ffs->eps_lock);
736
737 data = kmalloc(data_len, GFP_KERNEL);
738 if (unlikely(!data))
739 return -ENOMEM;
740 if (!io_data->read) {
741 copied = copy_from_iter(data, data_len, &io_data->data);
742 if (copied != data_len) {
743 ret = -EFAULT;
744 goto error;
745 }
746 }
747 }
748
749 /* We will be using request */
750 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
751 if (unlikely(ret))
752 goto error;
753
754 spin_lock_irq(&epfile->ffs->eps_lock);
755
756 if (epfile->ep != ep) {
757 /* In the meantime, endpoint got disabled or changed. */
758 ret = -ESHUTDOWN;
759 } else if (halt) {
760 /* Halt */
761 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
762 usb_ep_set_halt(ep->ep);
763 ret = -EBADMSG;
764 } else if (unlikely(data_len == -EINVAL)) {
765 /*
766 * Sanity Check: even though data_len can't be used
767 * uninitialized at the time I write this comment, some
768 * compilers complain about this situation.
769 * In order to keep the code clean from warnings, data_len is
770 * being initialized to -EINVAL during its declaration, which
771 * means we can't rely on compiler anymore to warn no future
772 * changes won't result in data_len being used uninitialized.
773 * For such reason, we're adding this redundant sanity check
774 * here.
775 */
776 WARN(1, "%s: data_len == -EINVAL\n", __func__);
777 ret = -EINVAL;
778 } else if (!io_data->aio) {
779 DECLARE_COMPLETION_ONSTACK(done);
780 bool interrupted = false;
781
782 req = ep->req;
783 req->buf = data;
784 req->length = data_len;
785
786 req->context = &done;
787 req->complete = ffs_epfile_io_complete;
788
789 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
790 if (unlikely(ret < 0))
791 goto error_lock;
792
793 spin_unlock_irq(&epfile->ffs->eps_lock);
794
795 if (unlikely(wait_for_completion_interruptible(&done))) {
796 /*
797 * To avoid race condition with ffs_epfile_io_complete,
798 * dequeue the request first then check
799 * status. usb_ep_dequeue API should guarantee no race
800 * condition with req->complete callback.
801 */
802 usb_ep_dequeue(ep->ep, req);
803 interrupted = ep->status < 0;
804 }
805
806 /*
807 * XXX We may end up silently droping data here. Since data_len
808 * (i.e. req->length) may be bigger than len (after being
809 * rounded up to maxpacketsize), we may end up with more data
810 * then user space has space for.
811 */
812 ret = interrupted ? -EINTR : ep->status;
813 if (io_data->read && ret > 0) {
814 ret = copy_to_iter(data, ret, &io_data->data);
815 if (!ret)
816 ret = -EFAULT;
817 }
818 goto error_mutex;
819 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_KERNEL))) {
820 ret = -ENOMEM;
821 } else {
822 req->buf = data;
823 req->length = data_len;
824
825 io_data->buf = data;
826 io_data->ep = ep->ep;
827 io_data->req = req;
828 io_data->ffs = epfile->ffs;
829
830 req->context = io_data;
831 req->complete = ffs_epfile_async_io_complete;
832
833 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
834 if (unlikely(ret)) {
835 usb_ep_free_request(ep->ep, req);
836 goto error_lock;
837 }
838
839 ret = -EIOCBQUEUED;
840 /*
841 * Do not kfree the buffer in this function. It will be freed
842 * by ffs_user_copy_worker.
843 */
844 data = NULL;
845 }
846
847 error_lock:
848 spin_unlock_irq(&epfile->ffs->eps_lock);
849 error_mutex:
850 mutex_unlock(&epfile->mutex);
851 error:
852 kfree(data);
853 return ret;
854 }
855
856 static int
857 ffs_epfile_open(struct inode *inode, struct file *file)
858 {
859 struct ffs_epfile *epfile = inode->i_private;
860
861 ENTER();
862
863 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
864 return -ENODEV;
865
866 file->private_data = epfile;
867 ffs_data_opened(epfile->ffs);
868
869 return 0;
870 }
871
872 static int ffs_aio_cancel(struct kiocb *kiocb)
873 {
874 struct ffs_io_data *io_data = kiocb->private;
875 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
876 int value;
877
878 ENTER();
879
880 spin_lock_irq(&epfile->ffs->eps_lock);
881
882 if (likely(io_data && io_data->ep && io_data->req))
883 value = usb_ep_dequeue(io_data->ep, io_data->req);
884 else
885 value = -EINVAL;
886
887 spin_unlock_irq(&epfile->ffs->eps_lock);
888
889 return value;
890 }
891
892 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
893 {
894 struct ffs_io_data io_data, *p = &io_data;
895 ssize_t res;
896
897 ENTER();
898
899 if (!is_sync_kiocb(kiocb)) {
900 p = kmalloc(sizeof(io_data), GFP_KERNEL);
901 if (unlikely(!p))
902 return -ENOMEM;
903 p->aio = true;
904 } else {
905 p->aio = false;
906 }
907
908 p->read = false;
909 p->kiocb = kiocb;
910 p->data = *from;
911 p->mm = current->mm;
912
913 kiocb->private = p;
914
915 if (p->aio)
916 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
917
918 res = ffs_epfile_io(kiocb->ki_filp, p);
919 if (res == -EIOCBQUEUED)
920 return res;
921 if (p->aio)
922 kfree(p);
923 else
924 *from = p->data;
925 return res;
926 }
927
928 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
929 {
930 struct ffs_io_data io_data, *p = &io_data;
931 ssize_t res;
932
933 ENTER();
934
935 if (!is_sync_kiocb(kiocb)) {
936 p = kmalloc(sizeof(io_data), GFP_KERNEL);
937 if (unlikely(!p))
938 return -ENOMEM;
939 p->aio = true;
940 } else {
941 p->aio = false;
942 }
943
944 p->read = true;
945 p->kiocb = kiocb;
946 if (p->aio) {
947 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
948 if (!p->to_free) {
949 kfree(p);
950 return -ENOMEM;
951 }
952 } else {
953 p->data = *to;
954 p->to_free = NULL;
955 }
956 p->mm = current->mm;
957
958 kiocb->private = p;
959
960 if (p->aio)
961 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
962
963 res = ffs_epfile_io(kiocb->ki_filp, p);
964 if (res == -EIOCBQUEUED)
965 return res;
966
967 if (p->aio) {
968 kfree(p->to_free);
969 kfree(p);
970 } else {
971 *to = p->data;
972 }
973 return res;
974 }
975
976 static int
977 ffs_epfile_release(struct inode *inode, struct file *file)
978 {
979 struct ffs_epfile *epfile = inode->i_private;
980
981 ENTER();
982
983 ffs_data_closed(epfile->ffs);
984
985 return 0;
986 }
987
988 static long ffs_epfile_ioctl(struct file *file, unsigned code,
989 unsigned long value)
990 {
991 struct ffs_epfile *epfile = file->private_data;
992 int ret;
993
994 ENTER();
995
996 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
997 return -ENODEV;
998
999 spin_lock_irq(&epfile->ffs->eps_lock);
1000 if (likely(epfile->ep)) {
1001 switch (code) {
1002 case FUNCTIONFS_FIFO_STATUS:
1003 ret = usb_ep_fifo_status(epfile->ep->ep);
1004 break;
1005 case FUNCTIONFS_FIFO_FLUSH:
1006 usb_ep_fifo_flush(epfile->ep->ep);
1007 ret = 0;
1008 break;
1009 case FUNCTIONFS_CLEAR_HALT:
1010 ret = usb_ep_clear_halt(epfile->ep->ep);
1011 break;
1012 case FUNCTIONFS_ENDPOINT_REVMAP:
1013 ret = epfile->ep->num;
1014 break;
1015 case FUNCTIONFS_ENDPOINT_DESC:
1016 {
1017 int desc_idx;
1018 struct usb_endpoint_descriptor *desc;
1019
1020 switch (epfile->ffs->gadget->speed) {
1021 case USB_SPEED_SUPER:
1022 desc_idx = 2;
1023 break;
1024 case USB_SPEED_HIGH:
1025 desc_idx = 1;
1026 break;
1027 default:
1028 desc_idx = 0;
1029 }
1030 desc = epfile->ep->descs[desc_idx];
1031
1032 spin_unlock_irq(&epfile->ffs->eps_lock);
1033 ret = copy_to_user((void *)value, desc, sizeof(*desc));
1034 if (ret)
1035 ret = -EFAULT;
1036 return ret;
1037 }
1038 default:
1039 ret = -ENOTTY;
1040 }
1041 } else {
1042 ret = -ENODEV;
1043 }
1044 spin_unlock_irq(&epfile->ffs->eps_lock);
1045
1046 return ret;
1047 }
1048
1049 static const struct file_operations ffs_epfile_operations = {
1050 .llseek = no_llseek,
1051
1052 .open = ffs_epfile_open,
1053 .write_iter = ffs_epfile_write_iter,
1054 .read_iter = ffs_epfile_read_iter,
1055 .release = ffs_epfile_release,
1056 .unlocked_ioctl = ffs_epfile_ioctl,
1057 };
1058
1059
1060 /* File system and super block operations ***********************************/
1061
1062 /*
1063 * Mounting the file system creates a controller file, used first for
1064 * function configuration then later for event monitoring.
1065 */
1066
1067 static struct inode *__must_check
1068 ffs_sb_make_inode(struct super_block *sb, void *data,
1069 const struct file_operations *fops,
1070 const struct inode_operations *iops,
1071 struct ffs_file_perms *perms)
1072 {
1073 struct inode *inode;
1074
1075 ENTER();
1076
1077 inode = new_inode(sb);
1078
1079 if (likely(inode)) {
1080 struct timespec current_time = CURRENT_TIME;
1081
1082 inode->i_ino = get_next_ino();
1083 inode->i_mode = perms->mode;
1084 inode->i_uid = perms->uid;
1085 inode->i_gid = perms->gid;
1086 inode->i_atime = current_time;
1087 inode->i_mtime = current_time;
1088 inode->i_ctime = current_time;
1089 inode->i_private = data;
1090 if (fops)
1091 inode->i_fop = fops;
1092 if (iops)
1093 inode->i_op = iops;
1094 }
1095
1096 return inode;
1097 }
1098
1099 /* Create "regular" file */
1100 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1101 const char *name, void *data,
1102 const struct file_operations *fops)
1103 {
1104 struct ffs_data *ffs = sb->s_fs_info;
1105 struct dentry *dentry;
1106 struct inode *inode;
1107
1108 ENTER();
1109
1110 dentry = d_alloc_name(sb->s_root, name);
1111 if (unlikely(!dentry))
1112 return NULL;
1113
1114 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1115 if (unlikely(!inode)) {
1116 dput(dentry);
1117 return NULL;
1118 }
1119
1120 d_add(dentry, inode);
1121 return dentry;
1122 }
1123
1124 /* Super block */
1125 static const struct super_operations ffs_sb_operations = {
1126 .statfs = simple_statfs,
1127 .drop_inode = generic_delete_inode,
1128 };
1129
1130 struct ffs_sb_fill_data {
1131 struct ffs_file_perms perms;
1132 umode_t root_mode;
1133 const char *dev_name;
1134 bool no_disconnect;
1135 struct ffs_data *ffs_data;
1136 };
1137
1138 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1139 {
1140 struct ffs_sb_fill_data *data = _data;
1141 struct inode *inode;
1142 struct ffs_data *ffs = data->ffs_data;
1143
1144 ENTER();
1145
1146 ffs->sb = sb;
1147 data->ffs_data = NULL;
1148 sb->s_fs_info = ffs;
1149 sb->s_blocksize = PAGE_SIZE;
1150 sb->s_blocksize_bits = PAGE_SHIFT;
1151 sb->s_magic = FUNCTIONFS_MAGIC;
1152 sb->s_op = &ffs_sb_operations;
1153 sb->s_time_gran = 1;
1154
1155 /* Root inode */
1156 data->perms.mode = data->root_mode;
1157 inode = ffs_sb_make_inode(sb, NULL,
1158 &simple_dir_operations,
1159 &simple_dir_inode_operations,
1160 &data->perms);
1161 sb->s_root = d_make_root(inode);
1162 if (unlikely(!sb->s_root))
1163 return -ENOMEM;
1164
1165 /* EP0 file */
1166 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1167 &ffs_ep0_operations)))
1168 return -ENOMEM;
1169
1170 return 0;
1171 }
1172
1173 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1174 {
1175 ENTER();
1176
1177 if (!opts || !*opts)
1178 return 0;
1179
1180 for (;;) {
1181 unsigned long value;
1182 char *eq, *comma;
1183
1184 /* Option limit */
1185 comma = strchr(opts, ',');
1186 if (comma)
1187 *comma = 0;
1188
1189 /* Value limit */
1190 eq = strchr(opts, '=');
1191 if (unlikely(!eq)) {
1192 pr_err("'=' missing in %s\n", opts);
1193 return -EINVAL;
1194 }
1195 *eq = 0;
1196
1197 /* Parse value */
1198 if (kstrtoul(eq + 1, 0, &value)) {
1199 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1200 return -EINVAL;
1201 }
1202
1203 /* Interpret option */
1204 switch (eq - opts) {
1205 case 13:
1206 if (!memcmp(opts, "no_disconnect", 13))
1207 data->no_disconnect = !!value;
1208 else
1209 goto invalid;
1210 break;
1211 case 5:
1212 if (!memcmp(opts, "rmode", 5))
1213 data->root_mode = (value & 0555) | S_IFDIR;
1214 else if (!memcmp(opts, "fmode", 5))
1215 data->perms.mode = (value & 0666) | S_IFREG;
1216 else
1217 goto invalid;
1218 break;
1219
1220 case 4:
1221 if (!memcmp(opts, "mode", 4)) {
1222 data->root_mode = (value & 0555) | S_IFDIR;
1223 data->perms.mode = (value & 0666) | S_IFREG;
1224 } else {
1225 goto invalid;
1226 }
1227 break;
1228
1229 case 3:
1230 if (!memcmp(opts, "uid", 3)) {
1231 data->perms.uid = make_kuid(current_user_ns(), value);
1232 if (!uid_valid(data->perms.uid)) {
1233 pr_err("%s: unmapped value: %lu\n", opts, value);
1234 return -EINVAL;
1235 }
1236 } else if (!memcmp(opts, "gid", 3)) {
1237 data->perms.gid = make_kgid(current_user_ns(), value);
1238 if (!gid_valid(data->perms.gid)) {
1239 pr_err("%s: unmapped value: %lu\n", opts, value);
1240 return -EINVAL;
1241 }
1242 } else {
1243 goto invalid;
1244 }
1245 break;
1246
1247 default:
1248 invalid:
1249 pr_err("%s: invalid option\n", opts);
1250 return -EINVAL;
1251 }
1252
1253 /* Next iteration */
1254 if (!comma)
1255 break;
1256 opts = comma + 1;
1257 }
1258
1259 return 0;
1260 }
1261
1262 /* "mount -t functionfs dev_name /dev/function" ends up here */
1263
1264 static struct dentry *
1265 ffs_fs_mount(struct file_system_type *t, int flags,
1266 const char *dev_name, void *opts)
1267 {
1268 struct ffs_sb_fill_data data = {
1269 .perms = {
1270 .mode = S_IFREG | 0600,
1271 .uid = GLOBAL_ROOT_UID,
1272 .gid = GLOBAL_ROOT_GID,
1273 },
1274 .root_mode = S_IFDIR | 0500,
1275 .no_disconnect = false,
1276 };
1277 struct dentry *rv;
1278 int ret;
1279 void *ffs_dev;
1280 struct ffs_data *ffs;
1281
1282 ENTER();
1283
1284 ret = ffs_fs_parse_opts(&data, opts);
1285 if (unlikely(ret < 0))
1286 return ERR_PTR(ret);
1287
1288 ffs = ffs_data_new();
1289 if (unlikely(!ffs))
1290 return ERR_PTR(-ENOMEM);
1291 ffs->file_perms = data.perms;
1292 ffs->no_disconnect = data.no_disconnect;
1293
1294 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1295 if (unlikely(!ffs->dev_name)) {
1296 ffs_data_put(ffs);
1297 return ERR_PTR(-ENOMEM);
1298 }
1299
1300 ffs_dev = ffs_acquire_dev(dev_name);
1301 if (IS_ERR(ffs_dev)) {
1302 ffs_data_put(ffs);
1303 return ERR_CAST(ffs_dev);
1304 }
1305 ffs->private_data = ffs_dev;
1306 data.ffs_data = ffs;
1307
1308 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1309 if (IS_ERR(rv) && data.ffs_data) {
1310 ffs_release_dev(data.ffs_data);
1311 ffs_data_put(data.ffs_data);
1312 }
1313 return rv;
1314 }
1315
1316 static void
1317 ffs_fs_kill_sb(struct super_block *sb)
1318 {
1319 ENTER();
1320
1321 kill_litter_super(sb);
1322 if (sb->s_fs_info) {
1323 ffs_release_dev(sb->s_fs_info);
1324 ffs_data_closed(sb->s_fs_info);
1325 ffs_data_put(sb->s_fs_info);
1326 }
1327 }
1328
1329 static struct file_system_type ffs_fs_type = {
1330 .owner = THIS_MODULE,
1331 .name = "functionfs",
1332 .mount = ffs_fs_mount,
1333 .kill_sb = ffs_fs_kill_sb,
1334 };
1335 MODULE_ALIAS_FS("functionfs");
1336
1337
1338 /* Driver's main init/cleanup functions *************************************/
1339
1340 static int functionfs_init(void)
1341 {
1342 int ret;
1343
1344 ENTER();
1345
1346 ret = register_filesystem(&ffs_fs_type);
1347 if (likely(!ret))
1348 pr_info("file system registered\n");
1349 else
1350 pr_err("failed registering file system (%d)\n", ret);
1351
1352 return ret;
1353 }
1354
1355 static void functionfs_cleanup(void)
1356 {
1357 ENTER();
1358
1359 pr_info("unloading\n");
1360 unregister_filesystem(&ffs_fs_type);
1361 }
1362
1363
1364 /* ffs_data and ffs_function construction and destruction code **************/
1365
1366 static void ffs_data_clear(struct ffs_data *ffs);
1367 static void ffs_data_reset(struct ffs_data *ffs);
1368
1369 static void ffs_data_get(struct ffs_data *ffs)
1370 {
1371 ENTER();
1372
1373 atomic_inc(&ffs->ref);
1374 }
1375
1376 static void ffs_data_opened(struct ffs_data *ffs)
1377 {
1378 ENTER();
1379
1380 atomic_inc(&ffs->ref);
1381 if (atomic_add_return(1, &ffs->opened) == 1 &&
1382 ffs->state == FFS_DEACTIVATED) {
1383 ffs->state = FFS_CLOSING;
1384 ffs_data_reset(ffs);
1385 }
1386 }
1387
1388 static void ffs_data_put(struct ffs_data *ffs)
1389 {
1390 ENTER();
1391
1392 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1393 pr_info("%s(): freeing\n", __func__);
1394 ffs_data_clear(ffs);
1395 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1396 waitqueue_active(&ffs->ep0req_completion.wait));
1397 kfree(ffs->dev_name);
1398 kfree(ffs);
1399 }
1400 }
1401
1402 static void ffs_data_closed(struct ffs_data *ffs)
1403 {
1404 ENTER();
1405
1406 if (atomic_dec_and_test(&ffs->opened)) {
1407 if (ffs->no_disconnect) {
1408 ffs->state = FFS_DEACTIVATED;
1409 if (ffs->epfiles) {
1410 ffs_epfiles_destroy(ffs->epfiles,
1411 ffs->eps_count);
1412 ffs->epfiles = NULL;
1413 }
1414 if (ffs->setup_state == FFS_SETUP_PENDING)
1415 __ffs_ep0_stall(ffs);
1416 } else {
1417 ffs->state = FFS_CLOSING;
1418 ffs_data_reset(ffs);
1419 }
1420 }
1421 if (atomic_read(&ffs->opened) < 0) {
1422 ffs->state = FFS_CLOSING;
1423 ffs_data_reset(ffs);
1424 }
1425
1426 ffs_data_put(ffs);
1427 }
1428
1429 static struct ffs_data *ffs_data_new(void)
1430 {
1431 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1432 if (unlikely(!ffs))
1433 return NULL;
1434
1435 ENTER();
1436
1437 atomic_set(&ffs->ref, 1);
1438 atomic_set(&ffs->opened, 0);
1439 ffs->state = FFS_READ_DESCRIPTORS;
1440 mutex_init(&ffs->mutex);
1441 spin_lock_init(&ffs->eps_lock);
1442 init_waitqueue_head(&ffs->ev.waitq);
1443 init_completion(&ffs->ep0req_completion);
1444
1445 /* XXX REVISIT need to update it in some places, or do we? */
1446 ffs->ev.can_stall = 1;
1447
1448 return ffs;
1449 }
1450
1451 static void ffs_data_clear(struct ffs_data *ffs)
1452 {
1453 ENTER();
1454
1455 ffs_closed(ffs);
1456
1457 BUG_ON(ffs->gadget);
1458
1459 if (ffs->epfiles)
1460 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1461
1462 if (ffs->ffs_eventfd)
1463 eventfd_ctx_put(ffs->ffs_eventfd);
1464
1465 kfree(ffs->raw_descs_data);
1466 kfree(ffs->raw_strings);
1467 kfree(ffs->stringtabs);
1468 }
1469
1470 static void ffs_data_reset(struct ffs_data *ffs)
1471 {
1472 ENTER();
1473
1474 ffs_data_clear(ffs);
1475
1476 ffs->epfiles = NULL;
1477 ffs->raw_descs_data = NULL;
1478 ffs->raw_descs = NULL;
1479 ffs->raw_strings = NULL;
1480 ffs->stringtabs = NULL;
1481
1482 ffs->raw_descs_length = 0;
1483 ffs->fs_descs_count = 0;
1484 ffs->hs_descs_count = 0;
1485 ffs->ss_descs_count = 0;
1486
1487 ffs->strings_count = 0;
1488 ffs->interfaces_count = 0;
1489 ffs->eps_count = 0;
1490
1491 ffs->ev.count = 0;
1492
1493 ffs->state = FFS_READ_DESCRIPTORS;
1494 ffs->setup_state = FFS_NO_SETUP;
1495 ffs->flags = 0;
1496 }
1497
1498
1499 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1500 {
1501 struct usb_gadget_strings **lang;
1502 int first_id;
1503
1504 ENTER();
1505
1506 if (WARN_ON(ffs->state != FFS_ACTIVE
1507 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1508 return -EBADFD;
1509
1510 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1511 if (unlikely(first_id < 0))
1512 return first_id;
1513
1514 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1515 if (unlikely(!ffs->ep0req))
1516 return -ENOMEM;
1517 ffs->ep0req->complete = ffs_ep0_complete;
1518 ffs->ep0req->context = ffs;
1519
1520 lang = ffs->stringtabs;
1521 if (lang) {
1522 for (; *lang; ++lang) {
1523 struct usb_string *str = (*lang)->strings;
1524 int id = first_id;
1525 for (; str->s; ++id, ++str)
1526 str->id = id;
1527 }
1528 }
1529
1530 ffs->gadget = cdev->gadget;
1531 ffs_data_get(ffs);
1532 return 0;
1533 }
1534
1535 static void functionfs_unbind(struct ffs_data *ffs)
1536 {
1537 ENTER();
1538
1539 if (!WARN_ON(!ffs->gadget)) {
1540 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1541 ffs->ep0req = NULL;
1542 ffs->gadget = NULL;
1543 clear_bit(FFS_FL_BOUND, &ffs->flags);
1544 ffs_data_put(ffs);
1545 }
1546 }
1547
1548 static int ffs_epfiles_create(struct ffs_data *ffs)
1549 {
1550 struct ffs_epfile *epfile, *epfiles;
1551 unsigned i, count;
1552
1553 ENTER();
1554
1555 count = ffs->eps_count;
1556 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1557 if (!epfiles)
1558 return -ENOMEM;
1559
1560 epfile = epfiles;
1561 for (i = 1; i <= count; ++i, ++epfile) {
1562 epfile->ffs = ffs;
1563 mutex_init(&epfile->mutex);
1564 init_waitqueue_head(&epfile->wait);
1565 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1566 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1567 else
1568 sprintf(epfile->name, "ep%u", i);
1569 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1570 epfile,
1571 &ffs_epfile_operations);
1572 if (unlikely(!epfile->dentry)) {
1573 ffs_epfiles_destroy(epfiles, i - 1);
1574 return -ENOMEM;
1575 }
1576 }
1577
1578 ffs->epfiles = epfiles;
1579 return 0;
1580 }
1581
1582 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1583 {
1584 struct ffs_epfile *epfile = epfiles;
1585
1586 ENTER();
1587
1588 for (; count; --count, ++epfile) {
1589 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1590 waitqueue_active(&epfile->wait));
1591 if (epfile->dentry) {
1592 d_delete(epfile->dentry);
1593 dput(epfile->dentry);
1594 epfile->dentry = NULL;
1595 }
1596 }
1597
1598 kfree(epfiles);
1599 }
1600
1601 static void ffs_func_eps_disable(struct ffs_function *func)
1602 {
1603 struct ffs_ep *ep = func->eps;
1604 struct ffs_epfile *epfile = func->ffs->epfiles;
1605 unsigned count = func->ffs->eps_count;
1606 unsigned long flags;
1607
1608 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1609 do {
1610 /* pending requests get nuked */
1611 if (likely(ep->ep))
1612 usb_ep_disable(ep->ep);
1613 ++ep;
1614
1615 if (epfile) {
1616 epfile->ep = NULL;
1617 ++epfile;
1618 }
1619 } while (--count);
1620 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1621 }
1622
1623 static int ffs_func_eps_enable(struct ffs_function *func)
1624 {
1625 struct ffs_data *ffs = func->ffs;
1626 struct ffs_ep *ep = func->eps;
1627 struct ffs_epfile *epfile = ffs->epfiles;
1628 unsigned count = ffs->eps_count;
1629 unsigned long flags;
1630 int ret = 0;
1631
1632 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1633 do {
1634 struct usb_endpoint_descriptor *ds;
1635 int desc_idx;
1636
1637 if (ffs->gadget->speed == USB_SPEED_SUPER)
1638 desc_idx = 2;
1639 else if (ffs->gadget->speed == USB_SPEED_HIGH)
1640 desc_idx = 1;
1641 else
1642 desc_idx = 0;
1643
1644 /* fall-back to lower speed if desc missing for current speed */
1645 do {
1646 ds = ep->descs[desc_idx];
1647 } while (!ds && --desc_idx >= 0);
1648
1649 if (!ds) {
1650 ret = -EINVAL;
1651 break;
1652 }
1653
1654 ep->ep->driver_data = ep;
1655 ep->ep->desc = ds;
1656 ret = usb_ep_enable(ep->ep);
1657 if (likely(!ret)) {
1658 epfile->ep = ep;
1659 epfile->in = usb_endpoint_dir_in(ds);
1660 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1661 } else {
1662 break;
1663 }
1664
1665 wake_up(&epfile->wait);
1666
1667 ++ep;
1668 ++epfile;
1669 } while (--count);
1670 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1671
1672 return ret;
1673 }
1674
1675
1676 /* Parsing and building descriptors and strings *****************************/
1677
1678 /*
1679 * This validates if data pointed by data is a valid USB descriptor as
1680 * well as record how many interfaces, endpoints and strings are
1681 * required by given configuration. Returns address after the
1682 * descriptor or NULL if data is invalid.
1683 */
1684
1685 enum ffs_entity_type {
1686 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1687 };
1688
1689 enum ffs_os_desc_type {
1690 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1691 };
1692
1693 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1694 u8 *valuep,
1695 struct usb_descriptor_header *desc,
1696 void *priv);
1697
1698 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1699 struct usb_os_desc_header *h, void *data,
1700 unsigned len, void *priv);
1701
1702 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1703 ffs_entity_callback entity,
1704 void *priv)
1705 {
1706 struct usb_descriptor_header *_ds = (void *)data;
1707 u8 length;
1708 int ret;
1709
1710 ENTER();
1711
1712 /* At least two bytes are required: length and type */
1713 if (len < 2) {
1714 pr_vdebug("descriptor too short\n");
1715 return -EINVAL;
1716 }
1717
1718 /* If we have at least as many bytes as the descriptor takes? */
1719 length = _ds->bLength;
1720 if (len < length) {
1721 pr_vdebug("descriptor longer then available data\n");
1722 return -EINVAL;
1723 }
1724
1725 #define __entity_check_INTERFACE(val) 1
1726 #define __entity_check_STRING(val) (val)
1727 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1728 #define __entity(type, val) do { \
1729 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1730 if (unlikely(!__entity_check_ ##type(val))) { \
1731 pr_vdebug("invalid entity's value\n"); \
1732 return -EINVAL; \
1733 } \
1734 ret = entity(FFS_ ##type, &val, _ds, priv); \
1735 if (unlikely(ret < 0)) { \
1736 pr_debug("entity " #type "(%02x); ret = %d\n", \
1737 (val), ret); \
1738 return ret; \
1739 } \
1740 } while (0)
1741
1742 /* Parse descriptor depending on type. */
1743 switch (_ds->bDescriptorType) {
1744 case USB_DT_DEVICE:
1745 case USB_DT_CONFIG:
1746 case USB_DT_STRING:
1747 case USB_DT_DEVICE_QUALIFIER:
1748 /* function can't have any of those */
1749 pr_vdebug("descriptor reserved for gadget: %d\n",
1750 _ds->bDescriptorType);
1751 return -EINVAL;
1752
1753 case USB_DT_INTERFACE: {
1754 struct usb_interface_descriptor *ds = (void *)_ds;
1755 pr_vdebug("interface descriptor\n");
1756 if (length != sizeof *ds)
1757 goto inv_length;
1758
1759 __entity(INTERFACE, ds->bInterfaceNumber);
1760 if (ds->iInterface)
1761 __entity(STRING, ds->iInterface);
1762 }
1763 break;
1764
1765 case USB_DT_ENDPOINT: {
1766 struct usb_endpoint_descriptor *ds = (void *)_ds;
1767 pr_vdebug("endpoint descriptor\n");
1768 if (length != USB_DT_ENDPOINT_SIZE &&
1769 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1770 goto inv_length;
1771 __entity(ENDPOINT, ds->bEndpointAddress);
1772 }
1773 break;
1774
1775 case HID_DT_HID:
1776 pr_vdebug("hid descriptor\n");
1777 if (length != sizeof(struct hid_descriptor))
1778 goto inv_length;
1779 break;
1780
1781 case USB_DT_OTG:
1782 if (length != sizeof(struct usb_otg_descriptor))
1783 goto inv_length;
1784 break;
1785
1786 case USB_DT_INTERFACE_ASSOCIATION: {
1787 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1788 pr_vdebug("interface association descriptor\n");
1789 if (length != sizeof *ds)
1790 goto inv_length;
1791 if (ds->iFunction)
1792 __entity(STRING, ds->iFunction);
1793 }
1794 break;
1795
1796 case USB_DT_SS_ENDPOINT_COMP:
1797 pr_vdebug("EP SS companion descriptor\n");
1798 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1799 goto inv_length;
1800 break;
1801
1802 case USB_DT_OTHER_SPEED_CONFIG:
1803 case USB_DT_INTERFACE_POWER:
1804 case USB_DT_DEBUG:
1805 case USB_DT_SECURITY:
1806 case USB_DT_CS_RADIO_CONTROL:
1807 /* TODO */
1808 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1809 return -EINVAL;
1810
1811 default:
1812 /* We should never be here */
1813 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1814 return -EINVAL;
1815
1816 inv_length:
1817 pr_vdebug("invalid length: %d (descriptor %d)\n",
1818 _ds->bLength, _ds->bDescriptorType);
1819 return -EINVAL;
1820 }
1821
1822 #undef __entity
1823 #undef __entity_check_DESCRIPTOR
1824 #undef __entity_check_INTERFACE
1825 #undef __entity_check_STRING
1826 #undef __entity_check_ENDPOINT
1827
1828 return length;
1829 }
1830
1831 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1832 ffs_entity_callback entity, void *priv)
1833 {
1834 const unsigned _len = len;
1835 unsigned long num = 0;
1836
1837 ENTER();
1838
1839 for (;;) {
1840 int ret;
1841
1842 if (num == count)
1843 data = NULL;
1844
1845 /* Record "descriptor" entity */
1846 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1847 if (unlikely(ret < 0)) {
1848 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1849 num, ret);
1850 return ret;
1851 }
1852
1853 if (!data)
1854 return _len - len;
1855
1856 ret = ffs_do_single_desc(data, len, entity, priv);
1857 if (unlikely(ret < 0)) {
1858 pr_debug("%s returns %d\n", __func__, ret);
1859 return ret;
1860 }
1861
1862 len -= ret;
1863 data += ret;
1864 ++num;
1865 }
1866 }
1867
1868 static int __ffs_data_do_entity(enum ffs_entity_type type,
1869 u8 *valuep, struct usb_descriptor_header *desc,
1870 void *priv)
1871 {
1872 struct ffs_desc_helper *helper = priv;
1873 struct usb_endpoint_descriptor *d;
1874
1875 ENTER();
1876
1877 switch (type) {
1878 case FFS_DESCRIPTOR:
1879 break;
1880
1881 case FFS_INTERFACE:
1882 /*
1883 * Interfaces are indexed from zero so if we
1884 * encountered interface "n" then there are at least
1885 * "n+1" interfaces.
1886 */
1887 if (*valuep >= helper->interfaces_count)
1888 helper->interfaces_count = *valuep + 1;
1889 break;
1890
1891 case FFS_STRING:
1892 /*
1893 * Strings are indexed from 1 (0 is magic ;) reserved
1894 * for languages list or some such)
1895 */
1896 if (*valuep > helper->ffs->strings_count)
1897 helper->ffs->strings_count = *valuep;
1898 break;
1899
1900 case FFS_ENDPOINT:
1901 d = (void *)desc;
1902 helper->eps_count++;
1903 if (helper->eps_count >= 15)
1904 return -EINVAL;
1905 /* Check if descriptors for any speed were already parsed */
1906 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
1907 helper->ffs->eps_addrmap[helper->eps_count] =
1908 d->bEndpointAddress;
1909 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
1910 d->bEndpointAddress)
1911 return -EINVAL;
1912 break;
1913 }
1914
1915 return 0;
1916 }
1917
1918 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1919 struct usb_os_desc_header *desc)
1920 {
1921 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1922 u16 w_index = le16_to_cpu(desc->wIndex);
1923
1924 if (bcd_version != 1) {
1925 pr_vdebug("unsupported os descriptors version: %d",
1926 bcd_version);
1927 return -EINVAL;
1928 }
1929 switch (w_index) {
1930 case 0x4:
1931 *next_type = FFS_OS_DESC_EXT_COMPAT;
1932 break;
1933 case 0x5:
1934 *next_type = FFS_OS_DESC_EXT_PROP;
1935 break;
1936 default:
1937 pr_vdebug("unsupported os descriptor type: %d", w_index);
1938 return -EINVAL;
1939 }
1940
1941 return sizeof(*desc);
1942 }
1943
1944 /*
1945 * Process all extended compatibility/extended property descriptors
1946 * of a feature descriptor
1947 */
1948 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1949 enum ffs_os_desc_type type,
1950 u16 feature_count,
1951 ffs_os_desc_callback entity,
1952 void *priv,
1953 struct usb_os_desc_header *h)
1954 {
1955 int ret;
1956 const unsigned _len = len;
1957
1958 ENTER();
1959
1960 /* loop over all ext compat/ext prop descriptors */
1961 while (feature_count--) {
1962 ret = entity(type, h, data, len, priv);
1963 if (unlikely(ret < 0)) {
1964 pr_debug("bad OS descriptor, type: %d\n", type);
1965 return ret;
1966 }
1967 data += ret;
1968 len -= ret;
1969 }
1970 return _len - len;
1971 }
1972
1973 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
1974 static int __must_check ffs_do_os_descs(unsigned count,
1975 char *data, unsigned len,
1976 ffs_os_desc_callback entity, void *priv)
1977 {
1978 const unsigned _len = len;
1979 unsigned long num = 0;
1980
1981 ENTER();
1982
1983 for (num = 0; num < count; ++num) {
1984 int ret;
1985 enum ffs_os_desc_type type;
1986 u16 feature_count;
1987 struct usb_os_desc_header *desc = (void *)data;
1988
1989 if (len < sizeof(*desc))
1990 return -EINVAL;
1991
1992 /*
1993 * Record "descriptor" entity.
1994 * Process dwLength, bcdVersion, wIndex, get b/wCount.
1995 * Move the data pointer to the beginning of extended
1996 * compatibilities proper or extended properties proper
1997 * portions of the data
1998 */
1999 if (le32_to_cpu(desc->dwLength) > len)
2000 return -EINVAL;
2001
2002 ret = __ffs_do_os_desc_header(&type, desc);
2003 if (unlikely(ret < 0)) {
2004 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2005 num, ret);
2006 return ret;
2007 }
2008 /*
2009 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2010 */
2011 feature_count = le16_to_cpu(desc->wCount);
2012 if (type == FFS_OS_DESC_EXT_COMPAT &&
2013 (feature_count > 255 || desc->Reserved))
2014 return -EINVAL;
2015 len -= ret;
2016 data += ret;
2017
2018 /*
2019 * Process all function/property descriptors
2020 * of this Feature Descriptor
2021 */
2022 ret = ffs_do_single_os_desc(data, len, type,
2023 feature_count, entity, priv, desc);
2024 if (unlikely(ret < 0)) {
2025 pr_debug("%s returns %d\n", __func__, ret);
2026 return ret;
2027 }
2028
2029 len -= ret;
2030 data += ret;
2031 }
2032 return _len - len;
2033 }
2034
2035 /**
2036 * Validate contents of the buffer from userspace related to OS descriptors.
2037 */
2038 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2039 struct usb_os_desc_header *h, void *data,
2040 unsigned len, void *priv)
2041 {
2042 struct ffs_data *ffs = priv;
2043 u8 length;
2044
2045 ENTER();
2046
2047 switch (type) {
2048 case FFS_OS_DESC_EXT_COMPAT: {
2049 struct usb_ext_compat_desc *d = data;
2050 int i;
2051
2052 if (len < sizeof(*d) ||
2053 d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2054 d->Reserved1)
2055 return -EINVAL;
2056 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2057 if (d->Reserved2[i])
2058 return -EINVAL;
2059
2060 length = sizeof(struct usb_ext_compat_desc);
2061 }
2062 break;
2063 case FFS_OS_DESC_EXT_PROP: {
2064 struct usb_ext_prop_desc *d = data;
2065 u32 type, pdl;
2066 u16 pnl;
2067
2068 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2069 return -EINVAL;
2070 length = le32_to_cpu(d->dwSize);
2071 type = le32_to_cpu(d->dwPropertyDataType);
2072 if (type < USB_EXT_PROP_UNICODE ||
2073 type > USB_EXT_PROP_UNICODE_MULTI) {
2074 pr_vdebug("unsupported os descriptor property type: %d",
2075 type);
2076 return -EINVAL;
2077 }
2078 pnl = le16_to_cpu(d->wPropertyNameLength);
2079 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2080 if (length != 14 + pnl + pdl) {
2081 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2082 length, pnl, pdl, type);
2083 return -EINVAL;
2084 }
2085 ++ffs->ms_os_descs_ext_prop_count;
2086 /* property name reported to the host as "WCHAR"s */
2087 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2088 ffs->ms_os_descs_ext_prop_data_len += pdl;
2089 }
2090 break;
2091 default:
2092 pr_vdebug("unknown descriptor: %d\n", type);
2093 return -EINVAL;
2094 }
2095 return length;
2096 }
2097
2098 static int __ffs_data_got_descs(struct ffs_data *ffs,
2099 char *const _data, size_t len)
2100 {
2101 char *data = _data, *raw_descs;
2102 unsigned os_descs_count = 0, counts[3], flags;
2103 int ret = -EINVAL, i;
2104 struct ffs_desc_helper helper;
2105
2106 ENTER();
2107
2108 if (get_unaligned_le32(data + 4) != len)
2109 goto error;
2110
2111 switch (get_unaligned_le32(data)) {
2112 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2113 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2114 data += 8;
2115 len -= 8;
2116 break;
2117 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2118 flags = get_unaligned_le32(data + 8);
2119 ffs->user_flags = flags;
2120 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2121 FUNCTIONFS_HAS_HS_DESC |
2122 FUNCTIONFS_HAS_SS_DESC |
2123 FUNCTIONFS_HAS_MS_OS_DESC |
2124 FUNCTIONFS_VIRTUAL_ADDR |
2125 FUNCTIONFS_EVENTFD)) {
2126 ret = -ENOSYS;
2127 goto error;
2128 }
2129 data += 12;
2130 len -= 12;
2131 break;
2132 default:
2133 goto error;
2134 }
2135
2136 if (flags & FUNCTIONFS_EVENTFD) {
2137 if (len < 4)
2138 goto error;
2139 ffs->ffs_eventfd =
2140 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2141 if (IS_ERR(ffs->ffs_eventfd)) {
2142 ret = PTR_ERR(ffs->ffs_eventfd);
2143 ffs->ffs_eventfd = NULL;
2144 goto error;
2145 }
2146 data += 4;
2147 len -= 4;
2148 }
2149
2150 /* Read fs_count, hs_count and ss_count (if present) */
2151 for (i = 0; i < 3; ++i) {
2152 if (!(flags & (1 << i))) {
2153 counts[i] = 0;
2154 } else if (len < 4) {
2155 goto error;
2156 } else {
2157 counts[i] = get_unaligned_le32(data);
2158 data += 4;
2159 len -= 4;
2160 }
2161 }
2162 if (flags & (1 << i)) {
2163 os_descs_count = get_unaligned_le32(data);
2164 data += 4;
2165 len -= 4;
2166 };
2167
2168 /* Read descriptors */
2169 raw_descs = data;
2170 helper.ffs = ffs;
2171 for (i = 0; i < 3; ++i) {
2172 if (!counts[i])
2173 continue;
2174 helper.interfaces_count = 0;
2175 helper.eps_count = 0;
2176 ret = ffs_do_descs(counts[i], data, len,
2177 __ffs_data_do_entity, &helper);
2178 if (ret < 0)
2179 goto error;
2180 if (!ffs->eps_count && !ffs->interfaces_count) {
2181 ffs->eps_count = helper.eps_count;
2182 ffs->interfaces_count = helper.interfaces_count;
2183 } else {
2184 if (ffs->eps_count != helper.eps_count) {
2185 ret = -EINVAL;
2186 goto error;
2187 }
2188 if (ffs->interfaces_count != helper.interfaces_count) {
2189 ret = -EINVAL;
2190 goto error;
2191 }
2192 }
2193 data += ret;
2194 len -= ret;
2195 }
2196 if (os_descs_count) {
2197 ret = ffs_do_os_descs(os_descs_count, data, len,
2198 __ffs_data_do_os_desc, ffs);
2199 if (ret < 0)
2200 goto error;
2201 data += ret;
2202 len -= ret;
2203 }
2204
2205 if (raw_descs == data || len) {
2206 ret = -EINVAL;
2207 goto error;
2208 }
2209
2210 ffs->raw_descs_data = _data;
2211 ffs->raw_descs = raw_descs;
2212 ffs->raw_descs_length = data - raw_descs;
2213 ffs->fs_descs_count = counts[0];
2214 ffs->hs_descs_count = counts[1];
2215 ffs->ss_descs_count = counts[2];
2216 ffs->ms_os_descs_count = os_descs_count;
2217
2218 return 0;
2219
2220 error:
2221 kfree(_data);
2222 return ret;
2223 }
2224
2225 static int __ffs_data_got_strings(struct ffs_data *ffs,
2226 char *const _data, size_t len)
2227 {
2228 u32 str_count, needed_count, lang_count;
2229 struct usb_gadget_strings **stringtabs, *t;
2230 struct usb_string *strings, *s;
2231 const char *data = _data;
2232
2233 ENTER();
2234
2235 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2236 get_unaligned_le32(data + 4) != len))
2237 goto error;
2238 str_count = get_unaligned_le32(data + 8);
2239 lang_count = get_unaligned_le32(data + 12);
2240
2241 /* if one is zero the other must be zero */
2242 if (unlikely(!str_count != !lang_count))
2243 goto error;
2244
2245 /* Do we have at least as many strings as descriptors need? */
2246 needed_count = ffs->strings_count;
2247 if (unlikely(str_count < needed_count))
2248 goto error;
2249
2250 /*
2251 * If we don't need any strings just return and free all
2252 * memory.
2253 */
2254 if (!needed_count) {
2255 kfree(_data);
2256 return 0;
2257 }
2258
2259 /* Allocate everything in one chunk so there's less maintenance. */
2260 {
2261 unsigned i = 0;
2262 vla_group(d);
2263 vla_item(d, struct usb_gadget_strings *, stringtabs,
2264 lang_count + 1);
2265 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2266 vla_item(d, struct usb_string, strings,
2267 lang_count*(needed_count+1));
2268
2269 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2270
2271 if (unlikely(!vlabuf)) {
2272 kfree(_data);
2273 return -ENOMEM;
2274 }
2275
2276 /* Initialize the VLA pointers */
2277 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2278 t = vla_ptr(vlabuf, d, stringtab);
2279 i = lang_count;
2280 do {
2281 *stringtabs++ = t++;
2282 } while (--i);
2283 *stringtabs = NULL;
2284
2285 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2286 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2287 t = vla_ptr(vlabuf, d, stringtab);
2288 s = vla_ptr(vlabuf, d, strings);
2289 strings = s;
2290 }
2291
2292 /* For each language */
2293 data += 16;
2294 len -= 16;
2295
2296 do { /* lang_count > 0 so we can use do-while */
2297 unsigned needed = needed_count;
2298
2299 if (unlikely(len < 3))
2300 goto error_free;
2301 t->language = get_unaligned_le16(data);
2302 t->strings = s;
2303 ++t;
2304
2305 data += 2;
2306 len -= 2;
2307
2308 /* For each string */
2309 do { /* str_count > 0 so we can use do-while */
2310 size_t length = strnlen(data, len);
2311
2312 if (unlikely(length == len))
2313 goto error_free;
2314
2315 /*
2316 * User may provide more strings then we need,
2317 * if that's the case we simply ignore the
2318 * rest
2319 */
2320 if (likely(needed)) {
2321 /*
2322 * s->id will be set while adding
2323 * function to configuration so for
2324 * now just leave garbage here.
2325 */
2326 s->s = data;
2327 --needed;
2328 ++s;
2329 }
2330
2331 data += length + 1;
2332 len -= length + 1;
2333 } while (--str_count);
2334
2335 s->id = 0; /* terminator */
2336 s->s = NULL;
2337 ++s;
2338
2339 } while (--lang_count);
2340
2341 /* Some garbage left? */
2342 if (unlikely(len))
2343 goto error_free;
2344
2345 /* Done! */
2346 ffs->stringtabs = stringtabs;
2347 ffs->raw_strings = _data;
2348
2349 return 0;
2350
2351 error_free:
2352 kfree(stringtabs);
2353 error:
2354 kfree(_data);
2355 return -EINVAL;
2356 }
2357
2358
2359 /* Events handling and management *******************************************/
2360
2361 static void __ffs_event_add(struct ffs_data *ffs,
2362 enum usb_functionfs_event_type type)
2363 {
2364 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2365 int neg = 0;
2366
2367 /*
2368 * Abort any unhandled setup
2369 *
2370 * We do not need to worry about some cmpxchg() changing value
2371 * of ffs->setup_state without holding the lock because when
2372 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2373 * the source does nothing.
2374 */
2375 if (ffs->setup_state == FFS_SETUP_PENDING)
2376 ffs->setup_state = FFS_SETUP_CANCELLED;
2377
2378 /*
2379 * Logic of this function guarantees that there are at most four pending
2380 * evens on ffs->ev.types queue. This is important because the queue
2381 * has space for four elements only and __ffs_ep0_read_events function
2382 * depends on that limit as well. If more event types are added, those
2383 * limits have to be revisited or guaranteed to still hold.
2384 */
2385 switch (type) {
2386 case FUNCTIONFS_RESUME:
2387 rem_type2 = FUNCTIONFS_SUSPEND;
2388 /* FALL THROUGH */
2389 case FUNCTIONFS_SUSPEND:
2390 case FUNCTIONFS_SETUP:
2391 rem_type1 = type;
2392 /* Discard all similar events */
2393 break;
2394
2395 case FUNCTIONFS_BIND:
2396 case FUNCTIONFS_UNBIND:
2397 case FUNCTIONFS_DISABLE:
2398 case FUNCTIONFS_ENABLE:
2399 /* Discard everything other then power management. */
2400 rem_type1 = FUNCTIONFS_SUSPEND;
2401 rem_type2 = FUNCTIONFS_RESUME;
2402 neg = 1;
2403 break;
2404
2405 default:
2406 WARN(1, "%d: unknown event, this should not happen\n", type);
2407 return;
2408 }
2409
2410 {
2411 u8 *ev = ffs->ev.types, *out = ev;
2412 unsigned n = ffs->ev.count;
2413 for (; n; --n, ++ev)
2414 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2415 *out++ = *ev;
2416 else
2417 pr_vdebug("purging event %d\n", *ev);
2418 ffs->ev.count = out - ffs->ev.types;
2419 }
2420
2421 pr_vdebug("adding event %d\n", type);
2422 ffs->ev.types[ffs->ev.count++] = type;
2423 wake_up_locked(&ffs->ev.waitq);
2424 if (ffs->ffs_eventfd)
2425 eventfd_signal(ffs->ffs_eventfd, 1);
2426 }
2427
2428 static void ffs_event_add(struct ffs_data *ffs,
2429 enum usb_functionfs_event_type type)
2430 {
2431 unsigned long flags;
2432 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2433 __ffs_event_add(ffs, type);
2434 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2435 }
2436
2437 /* Bind/unbind USB function hooks *******************************************/
2438
2439 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2440 {
2441 int i;
2442
2443 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2444 if (ffs->eps_addrmap[i] == endpoint_address)
2445 return i;
2446 return -ENOENT;
2447 }
2448
2449 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2450 struct usb_descriptor_header *desc,
2451 void *priv)
2452 {
2453 struct usb_endpoint_descriptor *ds = (void *)desc;
2454 struct ffs_function *func = priv;
2455 struct ffs_ep *ffs_ep;
2456 unsigned ep_desc_id;
2457 int idx;
2458 static const char *speed_names[] = { "full", "high", "super" };
2459
2460 if (type != FFS_DESCRIPTOR)
2461 return 0;
2462
2463 /*
2464 * If ss_descriptors is not NULL, we are reading super speed
2465 * descriptors; if hs_descriptors is not NULL, we are reading high
2466 * speed descriptors; otherwise, we are reading full speed
2467 * descriptors.
2468 */
2469 if (func->function.ss_descriptors) {
2470 ep_desc_id = 2;
2471 func->function.ss_descriptors[(long)valuep] = desc;
2472 } else if (func->function.hs_descriptors) {
2473 ep_desc_id = 1;
2474 func->function.hs_descriptors[(long)valuep] = desc;
2475 } else {
2476 ep_desc_id = 0;
2477 func->function.fs_descriptors[(long)valuep] = desc;
2478 }
2479
2480 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2481 return 0;
2482
2483 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2484 if (idx < 0)
2485 return idx;
2486
2487 ffs_ep = func->eps + idx;
2488
2489 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2490 pr_err("two %sspeed descriptors for EP %d\n",
2491 speed_names[ep_desc_id],
2492 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2493 return -EINVAL;
2494 }
2495 ffs_ep->descs[ep_desc_id] = ds;
2496
2497 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2498 if (ffs_ep->ep) {
2499 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2500 if (!ds->wMaxPacketSize)
2501 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2502 } else {
2503 struct usb_request *req;
2504 struct usb_ep *ep;
2505 u8 bEndpointAddress;
2506
2507 /*
2508 * We back up bEndpointAddress because autoconfig overwrites
2509 * it with physical endpoint address.
2510 */
2511 bEndpointAddress = ds->bEndpointAddress;
2512 pr_vdebug("autoconfig\n");
2513 ep = usb_ep_autoconfig(func->gadget, ds);
2514 if (unlikely(!ep))
2515 return -ENOTSUPP;
2516 ep->driver_data = func->eps + idx;
2517
2518 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2519 if (unlikely(!req))
2520 return -ENOMEM;
2521
2522 ffs_ep->ep = ep;
2523 ffs_ep->req = req;
2524 func->eps_revmap[ds->bEndpointAddress &
2525 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2526 /*
2527 * If we use virtual address mapping, we restore
2528 * original bEndpointAddress value.
2529 */
2530 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2531 ds->bEndpointAddress = bEndpointAddress;
2532 }
2533 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2534
2535 return 0;
2536 }
2537
2538 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2539 struct usb_descriptor_header *desc,
2540 void *priv)
2541 {
2542 struct ffs_function *func = priv;
2543 unsigned idx;
2544 u8 newValue;
2545
2546 switch (type) {
2547 default:
2548 case FFS_DESCRIPTOR:
2549 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2550 return 0;
2551
2552 case FFS_INTERFACE:
2553 idx = *valuep;
2554 if (func->interfaces_nums[idx] < 0) {
2555 int id = usb_interface_id(func->conf, &func->function);
2556 if (unlikely(id < 0))
2557 return id;
2558 func->interfaces_nums[idx] = id;
2559 }
2560 newValue = func->interfaces_nums[idx];
2561 break;
2562
2563 case FFS_STRING:
2564 /* String' IDs are allocated when fsf_data is bound to cdev */
2565 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2566 break;
2567
2568 case FFS_ENDPOINT:
2569 /*
2570 * USB_DT_ENDPOINT are handled in
2571 * __ffs_func_bind_do_descs().
2572 */
2573 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2574 return 0;
2575
2576 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2577 if (unlikely(!func->eps[idx].ep))
2578 return -EINVAL;
2579
2580 {
2581 struct usb_endpoint_descriptor **descs;
2582 descs = func->eps[idx].descs;
2583 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2584 }
2585 break;
2586 }
2587
2588 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2589 *valuep = newValue;
2590 return 0;
2591 }
2592
2593 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2594 struct usb_os_desc_header *h, void *data,
2595 unsigned len, void *priv)
2596 {
2597 struct ffs_function *func = priv;
2598 u8 length = 0;
2599
2600 switch (type) {
2601 case FFS_OS_DESC_EXT_COMPAT: {
2602 struct usb_ext_compat_desc *desc = data;
2603 struct usb_os_desc_table *t;
2604
2605 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2606 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2607 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2608 ARRAY_SIZE(desc->CompatibleID) +
2609 ARRAY_SIZE(desc->SubCompatibleID));
2610 length = sizeof(*desc);
2611 }
2612 break;
2613 case FFS_OS_DESC_EXT_PROP: {
2614 struct usb_ext_prop_desc *desc = data;
2615 struct usb_os_desc_table *t;
2616 struct usb_os_desc_ext_prop *ext_prop;
2617 char *ext_prop_name;
2618 char *ext_prop_data;
2619
2620 t = &func->function.os_desc_table[h->interface];
2621 t->if_id = func->interfaces_nums[h->interface];
2622
2623 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2624 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2625
2626 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2627 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2628 ext_prop->data_len = le32_to_cpu(*(u32 *)
2629 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2630 length = ext_prop->name_len + ext_prop->data_len + 14;
2631
2632 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2633 func->ffs->ms_os_descs_ext_prop_name_avail +=
2634 ext_prop->name_len;
2635
2636 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2637 func->ffs->ms_os_descs_ext_prop_data_avail +=
2638 ext_prop->data_len;
2639 memcpy(ext_prop_data,
2640 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2641 ext_prop->data_len);
2642 /* unicode data reported to the host as "WCHAR"s */
2643 switch (ext_prop->type) {
2644 case USB_EXT_PROP_UNICODE:
2645 case USB_EXT_PROP_UNICODE_ENV:
2646 case USB_EXT_PROP_UNICODE_LINK:
2647 case USB_EXT_PROP_UNICODE_MULTI:
2648 ext_prop->data_len *= 2;
2649 break;
2650 }
2651 ext_prop->data = ext_prop_data;
2652
2653 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2654 ext_prop->name_len);
2655 /* property name reported to the host as "WCHAR"s */
2656 ext_prop->name_len *= 2;
2657 ext_prop->name = ext_prop_name;
2658
2659 t->os_desc->ext_prop_len +=
2660 ext_prop->name_len + ext_prop->data_len + 14;
2661 ++t->os_desc->ext_prop_count;
2662 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2663 }
2664 break;
2665 default:
2666 pr_vdebug("unknown descriptor: %d\n", type);
2667 }
2668
2669 return length;
2670 }
2671
2672 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2673 struct usb_configuration *c)
2674 {
2675 struct ffs_function *func = ffs_func_from_usb(f);
2676 struct f_fs_opts *ffs_opts =
2677 container_of(f->fi, struct f_fs_opts, func_inst);
2678 int ret;
2679
2680 ENTER();
2681
2682 /*
2683 * Legacy gadget triggers binding in functionfs_ready_callback,
2684 * which already uses locking; taking the same lock here would
2685 * cause a deadlock.
2686 *
2687 * Configfs-enabled gadgets however do need ffs_dev_lock.
2688 */
2689 if (!ffs_opts->no_configfs)
2690 ffs_dev_lock();
2691 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2692 func->ffs = ffs_opts->dev->ffs_data;
2693 if (!ffs_opts->no_configfs)
2694 ffs_dev_unlock();
2695 if (ret)
2696 return ERR_PTR(ret);
2697
2698 func->conf = c;
2699 func->gadget = c->cdev->gadget;
2700
2701 /*
2702 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2703 * configurations are bound in sequence with list_for_each_entry,
2704 * in each configuration its functions are bound in sequence
2705 * with list_for_each_entry, so we assume no race condition
2706 * with regard to ffs_opts->bound access
2707 */
2708 if (!ffs_opts->refcnt) {
2709 ret = functionfs_bind(func->ffs, c->cdev);
2710 if (ret)
2711 return ERR_PTR(ret);
2712 }
2713 ffs_opts->refcnt++;
2714 func->function.strings = func->ffs->stringtabs;
2715
2716 return ffs_opts;
2717 }
2718
2719 static int _ffs_func_bind(struct usb_configuration *c,
2720 struct usb_function *f)
2721 {
2722 struct ffs_function *func = ffs_func_from_usb(f);
2723 struct ffs_data *ffs = func->ffs;
2724
2725 const int full = !!func->ffs->fs_descs_count;
2726 const int high = gadget_is_dualspeed(func->gadget) &&
2727 func->ffs->hs_descs_count;
2728 const int super = gadget_is_superspeed(func->gadget) &&
2729 func->ffs->ss_descs_count;
2730
2731 int fs_len, hs_len, ss_len, ret, i;
2732
2733 /* Make it a single chunk, less management later on */
2734 vla_group(d);
2735 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2736 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2737 full ? ffs->fs_descs_count + 1 : 0);
2738 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2739 high ? ffs->hs_descs_count + 1 : 0);
2740 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2741 super ? ffs->ss_descs_count + 1 : 0);
2742 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2743 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2744 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2745 vla_item_with_sz(d, char[16], ext_compat,
2746 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2747 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2748 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2749 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2750 ffs->ms_os_descs_ext_prop_count);
2751 vla_item_with_sz(d, char, ext_prop_name,
2752 ffs->ms_os_descs_ext_prop_name_len);
2753 vla_item_with_sz(d, char, ext_prop_data,
2754 ffs->ms_os_descs_ext_prop_data_len);
2755 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2756 char *vlabuf;
2757
2758 ENTER();
2759
2760 /* Has descriptors only for speeds gadget does not support */
2761 if (unlikely(!(full | high | super)))
2762 return -ENOTSUPP;
2763
2764 /* Allocate a single chunk, less management later on */
2765 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2766 if (unlikely(!vlabuf))
2767 return -ENOMEM;
2768
2769 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2770 ffs->ms_os_descs_ext_prop_name_avail =
2771 vla_ptr(vlabuf, d, ext_prop_name);
2772 ffs->ms_os_descs_ext_prop_data_avail =
2773 vla_ptr(vlabuf, d, ext_prop_data);
2774
2775 /* Copy descriptors */
2776 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2777 ffs->raw_descs_length);
2778
2779 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2780 for (ret = ffs->eps_count; ret; --ret) {
2781 struct ffs_ep *ptr;
2782
2783 ptr = vla_ptr(vlabuf, d, eps);
2784 ptr[ret].num = -1;
2785 }
2786
2787 /* Save pointers
2788 * d_eps == vlabuf, func->eps used to kfree vlabuf later
2789 */
2790 func->eps = vla_ptr(vlabuf, d, eps);
2791 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2792
2793 /*
2794 * Go through all the endpoint descriptors and allocate
2795 * endpoints first, so that later we can rewrite the endpoint
2796 * numbers without worrying that it may be described later on.
2797 */
2798 if (likely(full)) {
2799 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2800 fs_len = ffs_do_descs(ffs->fs_descs_count,
2801 vla_ptr(vlabuf, d, raw_descs),
2802 d_raw_descs__sz,
2803 __ffs_func_bind_do_descs, func);
2804 if (unlikely(fs_len < 0)) {
2805 ret = fs_len;
2806 goto error;
2807 }
2808 } else {
2809 fs_len = 0;
2810 }
2811
2812 if (likely(high)) {
2813 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2814 hs_len = ffs_do_descs(ffs->hs_descs_count,
2815 vla_ptr(vlabuf, d, raw_descs) + fs_len,
2816 d_raw_descs__sz - fs_len,
2817 __ffs_func_bind_do_descs, func);
2818 if (unlikely(hs_len < 0)) {
2819 ret = hs_len;
2820 goto error;
2821 }
2822 } else {
2823 hs_len = 0;
2824 }
2825
2826 if (likely(super)) {
2827 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2828 ss_len = ffs_do_descs(ffs->ss_descs_count,
2829 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2830 d_raw_descs__sz - fs_len - hs_len,
2831 __ffs_func_bind_do_descs, func);
2832 if (unlikely(ss_len < 0)) {
2833 ret = ss_len;
2834 goto error;
2835 }
2836 } else {
2837 ss_len = 0;
2838 }
2839
2840 /*
2841 * Now handle interface numbers allocation and interface and
2842 * endpoint numbers rewriting. We can do that in one go
2843 * now.
2844 */
2845 ret = ffs_do_descs(ffs->fs_descs_count +
2846 (high ? ffs->hs_descs_count : 0) +
2847 (super ? ffs->ss_descs_count : 0),
2848 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2849 __ffs_func_bind_do_nums, func);
2850 if (unlikely(ret < 0))
2851 goto error;
2852
2853 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2854 if (c->cdev->use_os_string)
2855 for (i = 0; i < ffs->interfaces_count; ++i) {
2856 struct usb_os_desc *desc;
2857
2858 desc = func->function.os_desc_table[i].os_desc =
2859 vla_ptr(vlabuf, d, os_desc) +
2860 i * sizeof(struct usb_os_desc);
2861 desc->ext_compat_id =
2862 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2863 INIT_LIST_HEAD(&desc->ext_prop);
2864 }
2865 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2866 vla_ptr(vlabuf, d, raw_descs) +
2867 fs_len + hs_len + ss_len,
2868 d_raw_descs__sz - fs_len - hs_len - ss_len,
2869 __ffs_func_bind_do_os_desc, func);
2870 if (unlikely(ret < 0))
2871 goto error;
2872 func->function.os_desc_n =
2873 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2874
2875 /* And we're done */
2876 ffs_event_add(ffs, FUNCTIONFS_BIND);
2877 return 0;
2878
2879 error:
2880 /* XXX Do we need to release all claimed endpoints here? */
2881 return ret;
2882 }
2883
2884 static int ffs_func_bind(struct usb_configuration *c,
2885 struct usb_function *f)
2886 {
2887 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2888 struct ffs_function *func = ffs_func_from_usb(f);
2889 int ret;
2890
2891 if (IS_ERR(ffs_opts))
2892 return PTR_ERR(ffs_opts);
2893
2894 ret = _ffs_func_bind(c, f);
2895 if (ret && !--ffs_opts->refcnt)
2896 functionfs_unbind(func->ffs);
2897
2898 return ret;
2899 }
2900
2901
2902 /* Other USB function hooks *************************************************/
2903
2904 static void ffs_reset_work(struct work_struct *work)
2905 {
2906 struct ffs_data *ffs = container_of(work,
2907 struct ffs_data, reset_work);
2908 ffs_data_reset(ffs);
2909 }
2910
2911 static int ffs_func_set_alt(struct usb_function *f,
2912 unsigned interface, unsigned alt)
2913 {
2914 struct ffs_function *func = ffs_func_from_usb(f);
2915 struct ffs_data *ffs = func->ffs;
2916 int ret = 0, intf;
2917
2918 if (alt != (unsigned)-1) {
2919 intf = ffs_func_revmap_intf(func, interface);
2920 if (unlikely(intf < 0))
2921 return intf;
2922 }
2923
2924 if (ffs->func)
2925 ffs_func_eps_disable(ffs->func);
2926
2927 if (ffs->state == FFS_DEACTIVATED) {
2928 ffs->state = FFS_CLOSING;
2929 INIT_WORK(&ffs->reset_work, ffs_reset_work);
2930 schedule_work(&ffs->reset_work);
2931 return -ENODEV;
2932 }
2933
2934 if (ffs->state != FFS_ACTIVE)
2935 return -ENODEV;
2936
2937 if (alt == (unsigned)-1) {
2938 ffs->func = NULL;
2939 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2940 return 0;
2941 }
2942
2943 ffs->func = func;
2944 ret = ffs_func_eps_enable(func);
2945 if (likely(ret >= 0))
2946 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2947 return ret;
2948 }
2949
2950 static void ffs_func_disable(struct usb_function *f)
2951 {
2952 ffs_func_set_alt(f, 0, (unsigned)-1);
2953 }
2954
2955 static int ffs_func_setup(struct usb_function *f,
2956 const struct usb_ctrlrequest *creq)
2957 {
2958 struct ffs_function *func = ffs_func_from_usb(f);
2959 struct ffs_data *ffs = func->ffs;
2960 unsigned long flags;
2961 int ret;
2962
2963 ENTER();
2964
2965 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2966 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2967 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
2968 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
2969 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
2970
2971 /*
2972 * Most requests directed to interface go through here
2973 * (notable exceptions are set/get interface) so we need to
2974 * handle them. All other either handled by composite or
2975 * passed to usb_configuration->setup() (if one is set). No
2976 * matter, we will handle requests directed to endpoint here
2977 * as well (as it's straightforward) but what to do with any
2978 * other request?
2979 */
2980 if (ffs->state != FFS_ACTIVE)
2981 return -ENODEV;
2982
2983 switch (creq->bRequestType & USB_RECIP_MASK) {
2984 case USB_RECIP_INTERFACE:
2985 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2986 if (unlikely(ret < 0))
2987 return ret;
2988 break;
2989
2990 case USB_RECIP_ENDPOINT:
2991 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2992 if (unlikely(ret < 0))
2993 return ret;
2994 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2995 ret = func->ffs->eps_addrmap[ret];
2996 break;
2997
2998 default:
2999 return -EOPNOTSUPP;
3000 }
3001
3002 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3003 ffs->ev.setup = *creq;
3004 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3005 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3006 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3007
3008 return 0;
3009 }
3010
3011 static void ffs_func_suspend(struct usb_function *f)
3012 {
3013 ENTER();
3014 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3015 }
3016
3017 static void ffs_func_resume(struct usb_function *f)
3018 {
3019 ENTER();
3020 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3021 }
3022
3023
3024 /* Endpoint and interface numbers reverse mapping ***************************/
3025
3026 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3027 {
3028 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3029 return num ? num : -EDOM;
3030 }
3031
3032 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3033 {
3034 short *nums = func->interfaces_nums;
3035 unsigned count = func->ffs->interfaces_count;
3036
3037 for (; count; --count, ++nums) {
3038 if (*nums >= 0 && *nums == intf)
3039 return nums - func->interfaces_nums;
3040 }
3041
3042 return -EDOM;
3043 }
3044
3045
3046 /* Devices management *******************************************************/
3047
3048 static LIST_HEAD(ffs_devices);
3049
3050 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3051 {
3052 struct ffs_dev *dev;
3053
3054 list_for_each_entry(dev, &ffs_devices, entry) {
3055 if (!dev->name || !name)
3056 continue;
3057 if (strcmp(dev->name, name) == 0)
3058 return dev;
3059 }
3060
3061 return NULL;
3062 }
3063
3064 /*
3065 * ffs_lock must be taken by the caller of this function
3066 */
3067 static struct ffs_dev *_ffs_get_single_dev(void)
3068 {
3069 struct ffs_dev *dev;
3070
3071 if (list_is_singular(&ffs_devices)) {
3072 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3073 if (dev->single)
3074 return dev;
3075 }
3076
3077 return NULL;
3078 }
3079
3080 /*
3081 * ffs_lock must be taken by the caller of this function
3082 */
3083 static struct ffs_dev *_ffs_find_dev(const char *name)
3084 {
3085 struct ffs_dev *dev;
3086
3087 dev = _ffs_get_single_dev();
3088 if (dev)
3089 return dev;
3090
3091 return _ffs_do_find_dev(name);
3092 }
3093
3094 /* Configfs support *********************************************************/
3095
3096 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3097 {
3098 return container_of(to_config_group(item), struct f_fs_opts,
3099 func_inst.group);
3100 }
3101
3102 static void ffs_attr_release(struct config_item *item)
3103 {
3104 struct f_fs_opts *opts = to_ffs_opts(item);
3105
3106 usb_put_function_instance(&opts->func_inst);
3107 }
3108
3109 static struct configfs_item_operations ffs_item_ops = {
3110 .release = ffs_attr_release,
3111 };
3112
3113 static struct config_item_type ffs_func_type = {
3114 .ct_item_ops = &ffs_item_ops,
3115 .ct_owner = THIS_MODULE,
3116 };
3117
3118
3119 /* Function registration interface ******************************************/
3120
3121 static void ffs_free_inst(struct usb_function_instance *f)
3122 {
3123 struct f_fs_opts *opts;
3124
3125 opts = to_f_fs_opts(f);
3126 ffs_dev_lock();
3127 _ffs_free_dev(opts->dev);
3128 ffs_dev_unlock();
3129 kfree(opts);
3130 }
3131
3132 #define MAX_INST_NAME_LEN 40
3133
3134 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3135 {
3136 struct f_fs_opts *opts;
3137 char *ptr;
3138 const char *tmp;
3139 int name_len, ret;
3140
3141 name_len = strlen(name) + 1;
3142 if (name_len > MAX_INST_NAME_LEN)
3143 return -ENAMETOOLONG;
3144
3145 ptr = kstrndup(name, name_len, GFP_KERNEL);
3146 if (!ptr)
3147 return -ENOMEM;
3148
3149 opts = to_f_fs_opts(fi);
3150 tmp = NULL;
3151
3152 ffs_dev_lock();
3153
3154 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3155 ret = _ffs_name_dev(opts->dev, ptr);
3156 if (ret) {
3157 kfree(ptr);
3158 ffs_dev_unlock();
3159 return ret;
3160 }
3161 opts->dev->name_allocated = true;
3162
3163 ffs_dev_unlock();
3164
3165 kfree(tmp);
3166
3167 return 0;
3168 }
3169
3170 static struct usb_function_instance *ffs_alloc_inst(void)
3171 {
3172 struct f_fs_opts *opts;
3173 struct ffs_dev *dev;
3174
3175 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3176 if (!opts)
3177 return ERR_PTR(-ENOMEM);
3178
3179 opts->func_inst.set_inst_name = ffs_set_inst_name;
3180 opts->func_inst.free_func_inst = ffs_free_inst;
3181 ffs_dev_lock();
3182 dev = _ffs_alloc_dev();
3183 ffs_dev_unlock();
3184 if (IS_ERR(dev)) {
3185 kfree(opts);
3186 return ERR_CAST(dev);
3187 }
3188 opts->dev = dev;
3189 dev->opts = opts;
3190
3191 config_group_init_type_name(&opts->func_inst.group, "",
3192 &ffs_func_type);
3193 return &opts->func_inst;
3194 }
3195
3196 static void ffs_free(struct usb_function *f)
3197 {
3198 kfree(ffs_func_from_usb(f));
3199 }
3200
3201 static void ffs_func_unbind(struct usb_configuration *c,
3202 struct usb_function *f)
3203 {
3204 struct ffs_function *func = ffs_func_from_usb(f);
3205 struct ffs_data *ffs = func->ffs;
3206 struct f_fs_opts *opts =
3207 container_of(f->fi, struct f_fs_opts, func_inst);
3208 struct ffs_ep *ep = func->eps;
3209 unsigned count = ffs->eps_count;
3210 unsigned long flags;
3211
3212 ENTER();
3213 if (ffs->func == func) {
3214 ffs_func_eps_disable(func);
3215 ffs->func = NULL;
3216 }
3217
3218 if (!--opts->refcnt)
3219 functionfs_unbind(ffs);
3220
3221 /* cleanup after autoconfig */
3222 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3223 do {
3224 if (ep->ep && ep->req)
3225 usb_ep_free_request(ep->ep, ep->req);
3226 ep->req = NULL;
3227 ++ep;
3228 } while (--count);
3229 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3230 kfree(func->eps);
3231 func->eps = NULL;
3232 /*
3233 * eps, descriptors and interfaces_nums are allocated in the
3234 * same chunk so only one free is required.
3235 */
3236 func->function.fs_descriptors = NULL;
3237 func->function.hs_descriptors = NULL;
3238 func->function.ss_descriptors = NULL;
3239 func->interfaces_nums = NULL;
3240
3241 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3242 }
3243
3244 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3245 {
3246 struct ffs_function *func;
3247
3248 ENTER();
3249
3250 func = kzalloc(sizeof(*func), GFP_KERNEL);
3251 if (unlikely(!func))
3252 return ERR_PTR(-ENOMEM);
3253
3254 func->function.name = "Function FS Gadget";
3255
3256 func->function.bind = ffs_func_bind;
3257 func->function.unbind = ffs_func_unbind;
3258 func->function.set_alt = ffs_func_set_alt;
3259 func->function.disable = ffs_func_disable;
3260 func->function.setup = ffs_func_setup;
3261 func->function.suspend = ffs_func_suspend;
3262 func->function.resume = ffs_func_resume;
3263 func->function.free_func = ffs_free;
3264
3265 return &func->function;
3266 }
3267
3268 /*
3269 * ffs_lock must be taken by the caller of this function
3270 */
3271 static struct ffs_dev *_ffs_alloc_dev(void)
3272 {
3273 struct ffs_dev *dev;
3274 int ret;
3275
3276 if (_ffs_get_single_dev())
3277 return ERR_PTR(-EBUSY);
3278
3279 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3280 if (!dev)
3281 return ERR_PTR(-ENOMEM);
3282
3283 if (list_empty(&ffs_devices)) {
3284 ret = functionfs_init();
3285 if (ret) {
3286 kfree(dev);
3287 return ERR_PTR(ret);
3288 }
3289 }
3290
3291 list_add(&dev->entry, &ffs_devices);
3292
3293 return dev;
3294 }
3295
3296 /*
3297 * ffs_lock must be taken by the caller of this function
3298 * The caller is responsible for "name" being available whenever f_fs needs it
3299 */
3300 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3301 {
3302 struct ffs_dev *existing;
3303
3304 existing = _ffs_do_find_dev(name);
3305 if (existing)
3306 return -EBUSY;
3307
3308 dev->name = name;
3309
3310 return 0;
3311 }
3312
3313 /*
3314 * The caller is responsible for "name" being available whenever f_fs needs it
3315 */
3316 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3317 {
3318 int ret;
3319
3320 ffs_dev_lock();
3321 ret = _ffs_name_dev(dev, name);
3322 ffs_dev_unlock();
3323
3324 return ret;
3325 }
3326 EXPORT_SYMBOL_GPL(ffs_name_dev);
3327
3328 int ffs_single_dev(struct ffs_dev *dev)
3329 {
3330 int ret;
3331
3332 ret = 0;
3333 ffs_dev_lock();
3334
3335 if (!list_is_singular(&ffs_devices))
3336 ret = -EBUSY;
3337 else
3338 dev->single = true;
3339
3340 ffs_dev_unlock();
3341 return ret;
3342 }
3343 EXPORT_SYMBOL_GPL(ffs_single_dev);
3344
3345 /*
3346 * ffs_lock must be taken by the caller of this function
3347 */
3348 static void _ffs_free_dev(struct ffs_dev *dev)
3349 {
3350 list_del(&dev->entry);
3351 if (dev->name_allocated)
3352 kfree(dev->name);
3353 kfree(dev);
3354 if (list_empty(&ffs_devices))
3355 functionfs_cleanup();
3356 }
3357
3358 static void *ffs_acquire_dev(const char *dev_name)
3359 {
3360 struct ffs_dev *ffs_dev;
3361
3362 ENTER();
3363 ffs_dev_lock();
3364
3365 ffs_dev = _ffs_find_dev(dev_name);
3366 if (!ffs_dev)
3367 ffs_dev = ERR_PTR(-ENOENT);
3368 else if (ffs_dev->mounted)
3369 ffs_dev = ERR_PTR(-EBUSY);
3370 else if (ffs_dev->ffs_acquire_dev_callback &&
3371 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3372 ffs_dev = ERR_PTR(-ENOENT);
3373 else
3374 ffs_dev->mounted = true;
3375
3376 ffs_dev_unlock();
3377 return ffs_dev;
3378 }
3379
3380 static void ffs_release_dev(struct ffs_data *ffs_data)
3381 {
3382 struct ffs_dev *ffs_dev;
3383
3384 ENTER();
3385 ffs_dev_lock();
3386
3387 ffs_dev = ffs_data->private_data;
3388 if (ffs_dev) {
3389 ffs_dev->mounted = false;
3390
3391 if (ffs_dev->ffs_release_dev_callback)
3392 ffs_dev->ffs_release_dev_callback(ffs_dev);
3393 }
3394
3395 ffs_dev_unlock();
3396 }
3397
3398 static int ffs_ready(struct ffs_data *ffs)
3399 {
3400 struct ffs_dev *ffs_obj;
3401 int ret = 0;
3402
3403 ENTER();
3404 ffs_dev_lock();
3405
3406 ffs_obj = ffs->private_data;
3407 if (!ffs_obj) {
3408 ret = -EINVAL;
3409 goto done;
3410 }
3411 if (WARN_ON(ffs_obj->desc_ready)) {
3412 ret = -EBUSY;
3413 goto done;
3414 }
3415
3416 ffs_obj->desc_ready = true;
3417 ffs_obj->ffs_data = ffs;
3418
3419 if (ffs_obj->ffs_ready_callback) {
3420 ret = ffs_obj->ffs_ready_callback(ffs);
3421 if (ret)
3422 goto done;
3423 }
3424
3425 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3426 done:
3427 ffs_dev_unlock();
3428 return ret;
3429 }
3430
3431 static void ffs_closed(struct ffs_data *ffs)
3432 {
3433 struct ffs_dev *ffs_obj;
3434 struct f_fs_opts *opts;
3435
3436 ENTER();
3437 ffs_dev_lock();
3438
3439 ffs_obj = ffs->private_data;
3440 if (!ffs_obj)
3441 goto done;
3442
3443 ffs_obj->desc_ready = false;
3444
3445 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3446 ffs_obj->ffs_closed_callback)
3447 ffs_obj->ffs_closed_callback(ffs);
3448
3449 if (ffs_obj->opts)
3450 opts = ffs_obj->opts;
3451 else
3452 goto done;
3453
3454 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3455 || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount))
3456 goto done;
3457
3458 unregister_gadget_item(ffs_obj->opts->
3459 func_inst.group.cg_item.ci_parent->ci_parent);
3460 done:
3461 ffs_dev_unlock();
3462 }
3463
3464 /* Misc helper functions ****************************************************/
3465
3466 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3467 {
3468 return nonblock
3469 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3470 : mutex_lock_interruptible(mutex);
3471 }
3472
3473 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3474 {
3475 char *data;
3476
3477 if (unlikely(!len))
3478 return NULL;
3479
3480 data = kmalloc(len, GFP_KERNEL);
3481 if (unlikely(!data))
3482 return ERR_PTR(-ENOMEM);
3483
3484 if (unlikely(copy_from_user(data, buf, len))) {
3485 kfree(data);
3486 return ERR_PTR(-EFAULT);
3487 }
3488
3489 pr_vdebug("Buffer from user space:\n");
3490 ffs_dump_mem("", data, len);
3491
3492 return data;
3493 }
3494
3495 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3496 MODULE_LICENSE("GPL");
3497 MODULE_AUTHOR("Michal Nazarewicz");
Linux kernel - Deliverables
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