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dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / drivers / usb / gadget / function / f_fs.c
blob4800bb22cdd61c14258d557644e526acbba4b933
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 mm_segment_t oldfs = get_fs();
653
654 set_fs(USER_DS);
655 use_mm(io_data->mm);
656 ret = copy_to_iter(io_data->buf, ret, &io_data->data);
657 if (ret != io_data->req->actual && iov_iter_count(&io_data->data))
658 ret = -EFAULT;
659 unuse_mm(io_data->mm);
660 set_fs(oldfs);
661 }
662
663 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
664
665 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
666 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
667
668 usb_ep_free_request(io_data->ep, io_data->req);
669
670 if (io_data->read)
671 kfree(io_data->to_free);
672 kfree(io_data->buf);
673 kfree(io_data);
674 }
675
676 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
677 struct usb_request *req)
678 {
679 struct ffs_io_data *io_data = req->context;
680
681 ENTER();
682
683 INIT_WORK(&io_data->work, ffs_user_copy_worker);
684 schedule_work(&io_data->work);
685 }
686
687 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
688 {
689 struct ffs_epfile *epfile = file->private_data;
690 struct ffs_ep *ep;
691 char *data = NULL;
692 ssize_t ret, data_len = -EINVAL;
693 int halt;
694
695 /* Are we still active? */
696 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
697 ret = -ENODEV;
698 goto error;
699 }
700
701 /* Wait for endpoint to be enabled */
702 ep = epfile->ep;
703 if (!ep) {
704 if (file->f_flags & O_NONBLOCK) {
705 ret = -EAGAIN;
706 goto error;
707 }
708
709 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
710 if (ret) {
711 ret = -EINTR;
712 goto error;
713 }
714 }
715
716 /* Do we halt? */
717 halt = (!io_data->read == !epfile->in);
718 if (halt && epfile->isoc) {
719 ret = -EINVAL;
720 goto error;
721 }
722
723 /* Allocate & copy */
724 if (!halt) {
725 /*
726 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
727 * before the waiting completes, so do not assign to 'gadget' earlier
728 */
729 struct usb_gadget *gadget = epfile->ffs->gadget;
730 size_t copied;
731
732 spin_lock_irq(&epfile->ffs->eps_lock);
733 /* In the meantime, endpoint got disabled or changed. */
734 if (epfile->ep != ep) {
735 spin_unlock_irq(&epfile->ffs->eps_lock);
736 return -ESHUTDOWN;
737 }
738 data_len = iov_iter_count(&io_data->data);
739 /*
740 * Controller may require buffer size to be aligned to
741 * maxpacketsize of an out endpoint.
742 */
743 if (io_data->read)
744 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
745 spin_unlock_irq(&epfile->ffs->eps_lock);
746
747 data = kmalloc(data_len, GFP_KERNEL);
748 if (unlikely(!data))
749 return -ENOMEM;
750 if (!io_data->read) {
751 copied = copy_from_iter(data, data_len, &io_data->data);
752 if (copied != data_len) {
753 ret = -EFAULT;
754 goto error;
755 }
756 }
757 }
758
759 /* We will be using request */
760 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
761 if (unlikely(ret))
762 goto error;
763
764 spin_lock_irq(&epfile->ffs->eps_lock);
765
766 if (epfile->ep != ep) {
767 /* In the meantime, endpoint got disabled or changed. */
768 ret = -ESHUTDOWN;
769 spin_unlock_irq(&epfile->ffs->eps_lock);
770 } else if (halt) {
771 /* Halt */
772 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
773 usb_ep_set_halt(ep->ep);
774 spin_unlock_irq(&epfile->ffs->eps_lock);
775 ret = -EBADMSG;
776 } else {
777 /* Fire the request */
778 struct usb_request *req;
779
780 /*
781 * Sanity Check: even though data_len can't be used
782 * uninitialized at the time I write this comment, some
783 * compilers complain about this situation.
784 * In order to keep the code clean from warnings, data_len is
785 * being initialized to -EINVAL during its declaration, which
786 * means we can't rely on compiler anymore to warn no future
787 * changes won't result in data_len being used uninitialized.
788 * For such reason, we're adding this redundant sanity check
789 * here.
790 */
791 if (unlikely(data_len == -EINVAL)) {
792 WARN(1, "%s: data_len == -EINVAL\n", __func__);
793 ret = -EINVAL;
794 goto error_lock;
795 }
796
797 if (io_data->aio) {
798 req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC);
799 if (unlikely(!req))
800 goto error_lock;
801
802 req->buf = data;
803 req->length = data_len;
804
805 io_data->buf = data;
806 io_data->ep = ep->ep;
807 io_data->req = req;
808 io_data->ffs = epfile->ffs;
809
810 req->context = io_data;
811 req->complete = ffs_epfile_async_io_complete;
812
813 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
814 if (unlikely(ret)) {
815 usb_ep_free_request(ep->ep, req);
816 goto error_lock;
817 }
818 ret = -EIOCBQUEUED;
819
820 spin_unlock_irq(&epfile->ffs->eps_lock);
821 } else {
822 DECLARE_COMPLETION_ONSTACK(done);
823
824 req = ep->req;
825 req->buf = data;
826 req->length = data_len;
827
828 req->context = &done;
829 req->complete = ffs_epfile_io_complete;
830
831 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
832
833 spin_unlock_irq(&epfile->ffs->eps_lock);
834
835 if (unlikely(ret < 0)) {
836 /* nop */
837 } else if (unlikely(
838 wait_for_completion_interruptible(&done))) {
839 ret = -EINTR;
840 usb_ep_dequeue(ep->ep, req);
841 } else {
842 /*
843 * XXX We may end up silently droping data
844 * here. Since data_len (i.e. req->length) may
845 * be bigger than len (after being rounded up
846 * to maxpacketsize), we may end up with more
847 * data then user space has space for.
848 */
849 ret = ep->status;
850 if (io_data->read && ret > 0) {
851 ret = copy_to_iter(data, ret, &io_data->data);
852 if (!ret)
853 ret = -EFAULT;
854 }
855 }
856 kfree(data);
857 }
858 }
859
860 mutex_unlock(&epfile->mutex);
861 return ret;
862
863 error_lock:
864 spin_unlock_irq(&epfile->ffs->eps_lock);
865 mutex_unlock(&epfile->mutex);
866 error:
867 kfree(data);
868 return ret;
869 }
870
871 static int
872 ffs_epfile_open(struct inode *inode, struct file *file)
873 {
874 struct ffs_epfile *epfile = inode->i_private;
875
876 ENTER();
877
878 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
879 return -ENODEV;
880
881 file->private_data = epfile;
882 ffs_data_opened(epfile->ffs);
883
884 return 0;
885 }
886
887 static int ffs_aio_cancel(struct kiocb *kiocb)
888 {
889 struct ffs_io_data *io_data = kiocb->private;
890 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
891 int value;
892
893 ENTER();
894
895 spin_lock_irq(&epfile->ffs->eps_lock);
896
897 if (likely(io_data && io_data->ep && io_data->req))
898 value = usb_ep_dequeue(io_data->ep, io_data->req);
899 else
900 value = -EINVAL;
901
902 spin_unlock_irq(&epfile->ffs->eps_lock);
903
904 return value;
905 }
906
907 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
908 {
909 struct ffs_io_data io_data, *p = &io_data;
910 ssize_t res;
911
912 ENTER();
913
914 if (!is_sync_kiocb(kiocb)) {
915 p = kmalloc(sizeof(io_data), GFP_KERNEL);
916 if (unlikely(!p))
917 return -ENOMEM;
918 p->aio = true;
919 } else {
920 p->aio = false;
921 }
922
923 p->read = false;
924 p->kiocb = kiocb;
925 p->data = *from;
926 p->mm = current->mm;
927
928 kiocb->private = p;
929
930 if (p->aio)
931 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
932
933 res = ffs_epfile_io(kiocb->ki_filp, p);
934 if (res == -EIOCBQUEUED)
935 return res;
936 if (p->aio)
937 kfree(p);
938 else
939 *from = p->data;
940 return res;
941 }
942
943 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
944 {
945 struct ffs_io_data io_data, *p = &io_data;
946 ssize_t res;
947
948 ENTER();
949
950 if (!is_sync_kiocb(kiocb)) {
951 p = kmalloc(sizeof(io_data), GFP_KERNEL);
952 if (unlikely(!p))
953 return -ENOMEM;
954 p->aio = true;
955 } else {
956 p->aio = false;
957 }
958
959 p->read = true;
960 p->kiocb = kiocb;
961 if (p->aio) {
962 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
963 if (!p->to_free) {
964 kfree(p);
965 return -ENOMEM;
966 }
967 } else {
968 p->data = *to;
969 p->to_free = NULL;
970 }
971 p->mm = current->mm;
972
973 kiocb->private = p;
974
975 if (p->aio)
976 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
977
978 res = ffs_epfile_io(kiocb->ki_filp, p);
979 if (res == -EIOCBQUEUED)
980 return res;
981
982 if (p->aio) {
983 kfree(p->to_free);
984 kfree(p);
985 } else {
986 *to = p->data;
987 }
988 return res;
989 }
990
991 static int
992 ffs_epfile_release(struct inode *inode, struct file *file)
993 {
994 struct ffs_epfile *epfile = inode->i_private;
995
996 ENTER();
997
998 ffs_data_closed(epfile->ffs);
999
1000 return 0;
1001 }
1002
1003 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1004 unsigned long value)
1005 {
1006 struct ffs_epfile *epfile = file->private_data;
1007 int ret;
1008
1009 ENTER();
1010
1011 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1012 return -ENODEV;
1013
1014 spin_lock_irq(&epfile->ffs->eps_lock);
1015 if (likely(epfile->ep)) {
1016 switch (code) {
1017 case FUNCTIONFS_FIFO_STATUS:
1018 ret = usb_ep_fifo_status(epfile->ep->ep);
1019 break;
1020 case FUNCTIONFS_FIFO_FLUSH:
1021 usb_ep_fifo_flush(epfile->ep->ep);
1022 ret = 0;
1023 break;
1024 case FUNCTIONFS_CLEAR_HALT:
1025 ret = usb_ep_clear_halt(epfile->ep->ep);
1026 break;
1027 case FUNCTIONFS_ENDPOINT_REVMAP:
1028 ret = epfile->ep->num;
1029 break;
1030 case FUNCTIONFS_ENDPOINT_DESC:
1031 {
1032 int desc_idx;
1033 struct usb_endpoint_descriptor *desc;
1034
1035 switch (epfile->ffs->gadget->speed) {
1036 case USB_SPEED_SUPER:
1037 desc_idx = 2;
1038 break;
1039 case USB_SPEED_HIGH:
1040 desc_idx = 1;
1041 break;
1042 default:
1043 desc_idx = 0;
1044 }
1045 desc = epfile->ep->descs[desc_idx];
1046
1047 spin_unlock_irq(&epfile->ffs->eps_lock);
1048 ret = copy_to_user((void *)value, desc, sizeof(*desc));
1049 if (ret)
1050 ret = -EFAULT;
1051 return ret;
1052 }
1053 default:
1054 ret = -ENOTTY;
1055 }
1056 } else {
1057 ret = -ENODEV;
1058 }
1059 spin_unlock_irq(&epfile->ffs->eps_lock);
1060
1061 return ret;
1062 }
1063
1064 static const struct file_operations ffs_epfile_operations = {
1065 .llseek = no_llseek,
1066
1067 .open = ffs_epfile_open,
1068 .write_iter = ffs_epfile_write_iter,
1069 .read_iter = ffs_epfile_read_iter,
1070 .release = ffs_epfile_release,
1071 .unlocked_ioctl = ffs_epfile_ioctl,
1072 };
1073
1074
1075 /* File system and super block operations ***********************************/
1076
1077 /*
1078 * Mounting the file system creates a controller file, used first for
1079 * function configuration then later for event monitoring.
1080 */
1081
1082 static struct inode *__must_check
1083 ffs_sb_make_inode(struct super_block *sb, void *data,
1084 const struct file_operations *fops,
1085 const struct inode_operations *iops,
1086 struct ffs_file_perms *perms)
1087 {
1088 struct inode *inode;
1089
1090 ENTER();
1091
1092 inode = new_inode(sb);
1093
1094 if (likely(inode)) {
1095 struct timespec current_time = CURRENT_TIME;
1096
1097 inode->i_ino = get_next_ino();
1098 inode->i_mode = perms->mode;
1099 inode->i_uid = perms->uid;
1100 inode->i_gid = perms->gid;
1101 inode->i_atime = current_time;
1102 inode->i_mtime = current_time;
1103 inode->i_ctime = current_time;
1104 inode->i_private = data;
1105 if (fops)
1106 inode->i_fop = fops;
1107 if (iops)
1108 inode->i_op = iops;
1109 }
1110
1111 return inode;
1112 }
1113
1114 /* Create "regular" file */
1115 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1116 const char *name, void *data,
1117 const struct file_operations *fops)
1118 {
1119 struct ffs_data *ffs = sb->s_fs_info;
1120 struct dentry *dentry;
1121 struct inode *inode;
1122
1123 ENTER();
1124
1125 dentry = d_alloc_name(sb->s_root, name);
1126 if (unlikely(!dentry))
1127 return NULL;
1128
1129 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1130 if (unlikely(!inode)) {
1131 dput(dentry);
1132 return NULL;
1133 }
1134
1135 d_add(dentry, inode);
1136 return dentry;
1137 }
1138
1139 /* Super block */
1140 static const struct super_operations ffs_sb_operations = {
1141 .statfs = simple_statfs,
1142 .drop_inode = generic_delete_inode,
1143 };
1144
1145 struct ffs_sb_fill_data {
1146 struct ffs_file_perms perms;
1147 umode_t root_mode;
1148 const char *dev_name;
1149 bool no_disconnect;
1150 struct ffs_data *ffs_data;
1151 };
1152
1153 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1154 {
1155 struct ffs_sb_fill_data *data = _data;
1156 struct inode *inode;
1157 struct ffs_data *ffs = data->ffs_data;
1158
1159 ENTER();
1160
1161 ffs->sb = sb;
1162 data->ffs_data = NULL;
1163 sb->s_fs_info = ffs;
1164 sb->s_blocksize = PAGE_CACHE_SIZE;
1165 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1166 sb->s_magic = FUNCTIONFS_MAGIC;
1167 sb->s_op = &ffs_sb_operations;
1168 sb->s_time_gran = 1;
1169
1170 /* Root inode */
1171 data->perms.mode = data->root_mode;
1172 inode = ffs_sb_make_inode(sb, NULL,
1173 &simple_dir_operations,
1174 &simple_dir_inode_operations,
1175 &data->perms);
1176 sb->s_root = d_make_root(inode);
1177 if (unlikely(!sb->s_root))
1178 return -ENOMEM;
1179
1180 /* EP0 file */
1181 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1182 &ffs_ep0_operations)))
1183 return -ENOMEM;
1184
1185 return 0;
1186 }
1187
1188 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1189 {
1190 ENTER();
1191
1192 if (!opts || !*opts)
1193 return 0;
1194
1195 for (;;) {
1196 unsigned long value;
1197 char *eq, *comma;
1198
1199 /* Option limit */
1200 comma = strchr(opts, ',');
1201 if (comma)
1202 *comma = 0;
1203
1204 /* Value limit */
1205 eq = strchr(opts, '=');
1206 if (unlikely(!eq)) {
1207 pr_err("'=' missing in %s\n", opts);
1208 return -EINVAL;
1209 }
1210 *eq = 0;
1211
1212 /* Parse value */
1213 if (kstrtoul(eq + 1, 0, &value)) {
1214 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1215 return -EINVAL;
1216 }
1217
1218 /* Interpret option */
1219 switch (eq - opts) {
1220 case 13:
1221 if (!memcmp(opts, "no_disconnect", 13))
1222 data->no_disconnect = !!value;
1223 else
1224 goto invalid;
1225 break;
1226 case 5:
1227 if (!memcmp(opts, "rmode", 5))
1228 data->root_mode = (value & 0555) | S_IFDIR;
1229 else if (!memcmp(opts, "fmode", 5))
1230 data->perms.mode = (value & 0666) | S_IFREG;
1231 else
1232 goto invalid;
1233 break;
1234
1235 case 4:
1236 if (!memcmp(opts, "mode", 4)) {
1237 data->root_mode = (value & 0555) | S_IFDIR;
1238 data->perms.mode = (value & 0666) | S_IFREG;
1239 } else {
1240 goto invalid;
1241 }
1242 break;
1243
1244 case 3:
1245 if (!memcmp(opts, "uid", 3)) {
1246 data->perms.uid = make_kuid(current_user_ns(), value);
1247 if (!uid_valid(data->perms.uid)) {
1248 pr_err("%s: unmapped value: %lu\n", opts, value);
1249 return -EINVAL;
1250 }
1251 } else if (!memcmp(opts, "gid", 3)) {
1252 data->perms.gid = make_kgid(current_user_ns(), value);
1253 if (!gid_valid(data->perms.gid)) {
1254 pr_err("%s: unmapped value: %lu\n", opts, value);
1255 return -EINVAL;
1256 }
1257 } else {
1258 goto invalid;
1259 }
1260 break;
1261
1262 default:
1263 invalid:
1264 pr_err("%s: invalid option\n", opts);
1265 return -EINVAL;
1266 }
1267
1268 /* Next iteration */
1269 if (!comma)
1270 break;
1271 opts = comma + 1;
1272 }
1273
1274 return 0;
1275 }
1276
1277 /* "mount -t functionfs dev_name /dev/function" ends up here */
1278
1279 static struct dentry *
1280 ffs_fs_mount(struct file_system_type *t, int flags,
1281 const char *dev_name, void *opts)
1282 {
1283 struct ffs_sb_fill_data data = {
1284 .perms = {
1285 .mode = S_IFREG | 0600,
1286 .uid = GLOBAL_ROOT_UID,
1287 .gid = GLOBAL_ROOT_GID,
1288 },
1289 .root_mode = S_IFDIR | 0500,
1290 .no_disconnect = false,
1291 };
1292 struct dentry *rv;
1293 int ret;
1294 void *ffs_dev;
1295 struct ffs_data *ffs;
1296
1297 ENTER();
1298
1299 ret = ffs_fs_parse_opts(&data, opts);
1300 if (unlikely(ret < 0))
1301 return ERR_PTR(ret);
1302
1303 ffs = ffs_data_new();
1304 if (unlikely(!ffs))
1305 return ERR_PTR(-ENOMEM);
1306 ffs->file_perms = data.perms;
1307 ffs->no_disconnect = data.no_disconnect;
1308
1309 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1310 if (unlikely(!ffs->dev_name)) {
1311 ffs_data_put(ffs);
1312 return ERR_PTR(-ENOMEM);
1313 }
1314
1315 ffs_dev = ffs_acquire_dev(dev_name);
1316 if (IS_ERR(ffs_dev)) {
1317 ffs_data_put(ffs);
1318 return ERR_CAST(ffs_dev);
1319 }
1320 ffs->private_data = ffs_dev;
1321 data.ffs_data = ffs;
1322
1323 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1324 if (IS_ERR(rv) && data.ffs_data) {
1325 ffs_release_dev(data.ffs_data);
1326 ffs_data_put(data.ffs_data);
1327 }
1328 return rv;
1329 }
1330
1331 static void
1332 ffs_fs_kill_sb(struct super_block *sb)
1333 {
1334 ENTER();
1335
1336 kill_litter_super(sb);
1337 if (sb->s_fs_info) {
1338 ffs_release_dev(sb->s_fs_info);
1339 ffs_data_closed(sb->s_fs_info);
1340 }
1341 }
1342
1343 static struct file_system_type ffs_fs_type = {
1344 .owner = THIS_MODULE,
1345 .name = "functionfs",
1346 .mount = ffs_fs_mount,
1347 .kill_sb = ffs_fs_kill_sb,
1348 };
1349 MODULE_ALIAS_FS("functionfs");
1350
1351
1352 /* Driver's main init/cleanup functions *************************************/
1353
1354 static int functionfs_init(void)
1355 {
1356 int ret;
1357
1358 ENTER();
1359
1360 ret = register_filesystem(&ffs_fs_type);
1361 if (likely(!ret))
1362 pr_info("file system registered\n");
1363 else
1364 pr_err("failed registering file system (%d)\n", ret);
1365
1366 return ret;
1367 }
1368
1369 static void functionfs_cleanup(void)
1370 {
1371 ENTER();
1372
1373 pr_info("unloading\n");
1374 unregister_filesystem(&ffs_fs_type);
1375 }
1376
1377
1378 /* ffs_data and ffs_function construction and destruction code **************/
1379
1380 static void ffs_data_clear(struct ffs_data *ffs);
1381 static void ffs_data_reset(struct ffs_data *ffs);
1382
1383 static void ffs_data_get(struct ffs_data *ffs)
1384 {
1385 ENTER();
1386
1387 atomic_inc(&ffs->ref);
1388 }
1389
1390 static void ffs_data_opened(struct ffs_data *ffs)
1391 {
1392 ENTER();
1393
1394 atomic_inc(&ffs->ref);
1395 if (atomic_add_return(1, &ffs->opened) == 1 &&
1396 ffs->state == FFS_DEACTIVATED) {
1397 ffs->state = FFS_CLOSING;
1398 ffs_data_reset(ffs);
1399 }
1400 }
1401
1402 static void ffs_data_put(struct ffs_data *ffs)
1403 {
1404 ENTER();
1405
1406 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1407 pr_info("%s(): freeing\n", __func__);
1408 ffs_data_clear(ffs);
1409 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1410 waitqueue_active(&ffs->ep0req_completion.wait));
1411 kfree(ffs->dev_name);
1412 kfree(ffs);
1413 }
1414 }
1415
1416 static void ffs_data_closed(struct ffs_data *ffs)
1417 {
1418 ENTER();
1419
1420 if (atomic_dec_and_test(&ffs->opened)) {
1421 if (ffs->no_disconnect) {
1422 ffs->state = FFS_DEACTIVATED;
1423 if (ffs->epfiles) {
1424 ffs_epfiles_destroy(ffs->epfiles,
1425 ffs->eps_count);
1426 ffs->epfiles = NULL;
1427 }
1428 if (ffs->setup_state == FFS_SETUP_PENDING)
1429 __ffs_ep0_stall(ffs);
1430 } else {
1431 ffs->state = FFS_CLOSING;
1432 ffs_data_reset(ffs);
1433 }
1434 }
1435 if (atomic_read(&ffs->opened) < 0) {
1436 ffs->state = FFS_CLOSING;
1437 ffs_data_reset(ffs);
1438 }
1439
1440 ffs_data_put(ffs);
1441 }
1442
1443 static struct ffs_data *ffs_data_new(void)
1444 {
1445 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1446 if (unlikely(!ffs))
1447 return NULL;
1448
1449 ENTER();
1450
1451 atomic_set(&ffs->ref, 1);
1452 atomic_set(&ffs->opened, 0);
1453 ffs->state = FFS_READ_DESCRIPTORS;
1454 mutex_init(&ffs->mutex);
1455 spin_lock_init(&ffs->eps_lock);
1456 init_waitqueue_head(&ffs->ev.waitq);
1457 init_completion(&ffs->ep0req_completion);
1458
1459 /* XXX REVISIT need to update it in some places, or do we? */
1460 ffs->ev.can_stall = 1;
1461
1462 return ffs;
1463 }
1464
1465 static void ffs_data_clear(struct ffs_data *ffs)
1466 {
1467 ENTER();
1468
1469 ffs_closed(ffs);
1470
1471 BUG_ON(ffs->gadget);
1472
1473 if (ffs->epfiles)
1474 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1475
1476 if (ffs->ffs_eventfd)
1477 eventfd_ctx_put(ffs->ffs_eventfd);
1478
1479 kfree(ffs->raw_descs_data);
1480 kfree(ffs->raw_strings);
1481 kfree(ffs->stringtabs);
1482 }
1483
1484 static void ffs_data_reset(struct ffs_data *ffs)
1485 {
1486 ENTER();
1487
1488 ffs_data_clear(ffs);
1489
1490 ffs->epfiles = NULL;
1491 ffs->raw_descs_data = NULL;
1492 ffs->raw_descs = NULL;
1493 ffs->raw_strings = NULL;
1494 ffs->stringtabs = NULL;
1495
1496 ffs->raw_descs_length = 0;
1497 ffs->fs_descs_count = 0;
1498 ffs->hs_descs_count = 0;
1499 ffs->ss_descs_count = 0;
1500
1501 ffs->strings_count = 0;
1502 ffs->interfaces_count = 0;
1503 ffs->eps_count = 0;
1504
1505 ffs->ev.count = 0;
1506
1507 ffs->state = FFS_READ_DESCRIPTORS;
1508 ffs->setup_state = FFS_NO_SETUP;
1509 ffs->flags = 0;
1510 }
1511
1512
1513 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1514 {
1515 struct usb_gadget_strings **lang;
1516 int first_id;
1517
1518 ENTER();
1519
1520 if (WARN_ON(ffs->state != FFS_ACTIVE
1521 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1522 return -EBADFD;
1523
1524 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1525 if (unlikely(first_id < 0))
1526 return first_id;
1527
1528 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1529 if (unlikely(!ffs->ep0req))
1530 return -ENOMEM;
1531 ffs->ep0req->complete = ffs_ep0_complete;
1532 ffs->ep0req->context = ffs;
1533
1534 lang = ffs->stringtabs;
1535 if (lang) {
1536 for (; *lang; ++lang) {
1537 struct usb_string *str = (*lang)->strings;
1538 int id = first_id;
1539 for (; str->s; ++id, ++str)
1540 str->id = id;
1541 }
1542 }
1543
1544 ffs->gadget = cdev->gadget;
1545 ffs_data_get(ffs);
1546 return 0;
1547 }
1548
1549 static void functionfs_unbind(struct ffs_data *ffs)
1550 {
1551 ENTER();
1552
1553 if (!WARN_ON(!ffs->gadget)) {
1554 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1555 ffs->ep0req = NULL;
1556 ffs->gadget = NULL;
1557 clear_bit(FFS_FL_BOUND, &ffs->flags);
1558 ffs_data_put(ffs);
1559 }
1560 }
1561
1562 static int ffs_epfiles_create(struct ffs_data *ffs)
1563 {
1564 struct ffs_epfile *epfile, *epfiles;
1565 unsigned i, count;
1566
1567 ENTER();
1568
1569 count = ffs->eps_count;
1570 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1571 if (!epfiles)
1572 return -ENOMEM;
1573
1574 epfile = epfiles;
1575 for (i = 1; i <= count; ++i, ++epfile) {
1576 epfile->ffs = ffs;
1577 mutex_init(&epfile->mutex);
1578 init_waitqueue_head(&epfile->wait);
1579 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1580 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1581 else
1582 sprintf(epfile->name, "ep%u", i);
1583 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1584 epfile,
1585 &ffs_epfile_operations);
1586 if (unlikely(!epfile->dentry)) {
1587 ffs_epfiles_destroy(epfiles, i - 1);
1588 return -ENOMEM;
1589 }
1590 }
1591
1592 ffs->epfiles = epfiles;
1593 return 0;
1594 }
1595
1596 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1597 {
1598 struct ffs_epfile *epfile = epfiles;
1599
1600 ENTER();
1601
1602 for (; count; --count, ++epfile) {
1603 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1604 waitqueue_active(&epfile->wait));
1605 if (epfile->dentry) {
1606 d_delete(epfile->dentry);
1607 dput(epfile->dentry);
1608 epfile->dentry = NULL;
1609 }
1610 }
1611
1612 kfree(epfiles);
1613 }
1614
1615 static void ffs_func_eps_disable(struct ffs_function *func)
1616 {
1617 struct ffs_ep *ep = func->eps;
1618 struct ffs_epfile *epfile = func->ffs->epfiles;
1619 unsigned count = func->ffs->eps_count;
1620 unsigned long flags;
1621
1622 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1623 do {
1624 /* pending requests get nuked */
1625 if (likely(ep->ep))
1626 usb_ep_disable(ep->ep);
1627 ++ep;
1628
1629 if (epfile) {
1630 epfile->ep = NULL;
1631 ++epfile;
1632 }
1633 } while (--count);
1634 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1635 }
1636
1637 static int ffs_func_eps_enable(struct ffs_function *func)
1638 {
1639 struct ffs_data *ffs = func->ffs;
1640 struct ffs_ep *ep = func->eps;
1641 struct ffs_epfile *epfile = ffs->epfiles;
1642 unsigned count = ffs->eps_count;
1643 unsigned long flags;
1644 int ret = 0;
1645
1646 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1647 do {
1648 struct usb_endpoint_descriptor *ds;
1649 struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
1650 int needs_comp_desc = false;
1651 int desc_idx;
1652
1653 if (ffs->gadget->speed == USB_SPEED_SUPER) {
1654 desc_idx = 2;
1655 needs_comp_desc = true;
1656 } else if (ffs->gadget->speed == USB_SPEED_HIGH)
1657 desc_idx = 1;
1658 else
1659 desc_idx = 0;
1660
1661 /* fall-back to lower speed if desc missing for current speed */
1662 do {
1663 ds = ep->descs[desc_idx];
1664 } while (!ds && --desc_idx >= 0);
1665
1666 if (!ds) {
1667 ret = -EINVAL;
1668 break;
1669 }
1670
1671 ep->ep->driver_data = ep;
1672 ep->ep->desc = ds;
1673
1674 if (needs_comp_desc) {
1675 comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
1676 USB_DT_ENDPOINT_SIZE);
1677 ep->ep->maxburst = comp_desc->bMaxBurst + 1;
1678 ep->ep->comp_desc = comp_desc;
1679 }
1680
1681 ret = usb_ep_enable(ep->ep);
1682 if (likely(!ret)) {
1683 epfile->ep = ep;
1684 epfile->in = usb_endpoint_dir_in(ds);
1685 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1686 } else {
1687 break;
1688 }
1689
1690 wake_up(&epfile->wait);
1691
1692 ++ep;
1693 ++epfile;
1694 } while (--count);
1695 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1696
1697 return ret;
1698 }
1699
1700
1701 /* Parsing and building descriptors and strings *****************************/
1702
1703 /*
1704 * This validates if data pointed by data is a valid USB descriptor as
1705 * well as record how many interfaces, endpoints and strings are
1706 * required by given configuration. Returns address after the
1707 * descriptor or NULL if data is invalid.
1708 */
1709
1710 enum ffs_entity_type {
1711 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1712 };
1713
1714 enum ffs_os_desc_type {
1715 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1716 };
1717
1718 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1719 u8 *valuep,
1720 struct usb_descriptor_header *desc,
1721 void *priv);
1722
1723 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1724 struct usb_os_desc_header *h, void *data,
1725 unsigned len, void *priv);
1726
1727 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1728 ffs_entity_callback entity,
1729 void *priv)
1730 {
1731 struct usb_descriptor_header *_ds = (void *)data;
1732 u8 length;
1733 int ret;
1734
1735 ENTER();
1736
1737 /* At least two bytes are required: length and type */
1738 if (len < 2) {
1739 pr_vdebug("descriptor too short\n");
1740 return -EINVAL;
1741 }
1742
1743 /* If we have at least as many bytes as the descriptor takes? */
1744 length = _ds->bLength;
1745 if (len < length) {
1746 pr_vdebug("descriptor longer then available data\n");
1747 return -EINVAL;
1748 }
1749
1750 #define __entity_check_INTERFACE(val) 1
1751 #define __entity_check_STRING(val) (val)
1752 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1753 #define __entity(type, val) do { \
1754 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1755 if (unlikely(!__entity_check_ ##type(val))) { \
1756 pr_vdebug("invalid entity's value\n"); \
1757 return -EINVAL; \
1758 } \
1759 ret = entity(FFS_ ##type, &val, _ds, priv); \
1760 if (unlikely(ret < 0)) { \
1761 pr_debug("entity " #type "(%02x); ret = %d\n", \
1762 (val), ret); \
1763 return ret; \
1764 } \
1765 } while (0)
1766
1767 /* Parse descriptor depending on type. */
1768 switch (_ds->bDescriptorType) {
1769 case USB_DT_DEVICE:
1770 case USB_DT_CONFIG:
1771 case USB_DT_STRING:
1772 case USB_DT_DEVICE_QUALIFIER:
1773 /* function can't have any of those */
1774 pr_vdebug("descriptor reserved for gadget: %d\n",
1775 _ds->bDescriptorType);
1776 return -EINVAL;
1777
1778 case USB_DT_INTERFACE: {
1779 struct usb_interface_descriptor *ds = (void *)_ds;
1780 pr_vdebug("interface descriptor\n");
1781 if (length != sizeof *ds)
1782 goto inv_length;
1783
1784 __entity(INTERFACE, ds->bInterfaceNumber);
1785 if (ds->iInterface)
1786 __entity(STRING, ds->iInterface);
1787 }
1788 break;
1789
1790 case USB_DT_ENDPOINT: {
1791 struct usb_endpoint_descriptor *ds = (void *)_ds;
1792 pr_vdebug("endpoint descriptor\n");
1793 if (length != USB_DT_ENDPOINT_SIZE &&
1794 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1795 goto inv_length;
1796 __entity(ENDPOINT, ds->bEndpointAddress);
1797 }
1798 break;
1799
1800 case HID_DT_HID:
1801 pr_vdebug("hid descriptor\n");
1802 if (length != sizeof(struct hid_descriptor))
1803 goto inv_length;
1804 break;
1805
1806 case USB_DT_OTG:
1807 if (length != sizeof(struct usb_otg_descriptor))
1808 goto inv_length;
1809 break;
1810
1811 case USB_DT_INTERFACE_ASSOCIATION: {
1812 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1813 pr_vdebug("interface association descriptor\n");
1814 if (length != sizeof *ds)
1815 goto inv_length;
1816 if (ds->iFunction)
1817 __entity(STRING, ds->iFunction);
1818 }
1819 break;
1820
1821 case USB_DT_SS_ENDPOINT_COMP:
1822 pr_vdebug("EP SS companion descriptor\n");
1823 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1824 goto inv_length;
1825 break;
1826
1827 case USB_DT_OTHER_SPEED_CONFIG:
1828 case USB_DT_INTERFACE_POWER:
1829 case USB_DT_DEBUG:
1830 case USB_DT_SECURITY:
1831 case USB_DT_CS_RADIO_CONTROL:
1832 /* TODO */
1833 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1834 return -EINVAL;
1835
1836 default:
1837 /* We should never be here */
1838 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1839 return -EINVAL;
1840
1841 inv_length:
1842 pr_vdebug("invalid length: %d (descriptor %d)\n",
1843 _ds->bLength, _ds->bDescriptorType);
1844 return -EINVAL;
1845 }
1846
1847 #undef __entity
1848 #undef __entity_check_DESCRIPTOR
1849 #undef __entity_check_INTERFACE
1850 #undef __entity_check_STRING
1851 #undef __entity_check_ENDPOINT
1852
1853 return length;
1854 }
1855
1856 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1857 ffs_entity_callback entity, void *priv)
1858 {
1859 const unsigned _len = len;
1860 unsigned long num = 0;
1861
1862 ENTER();
1863
1864 for (;;) {
1865 int ret;
1866
1867 if (num == count)
1868 data = NULL;
1869
1870 /* Record "descriptor" entity */
1871 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1872 if (unlikely(ret < 0)) {
1873 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1874 num, ret);
1875 return ret;
1876 }
1877
1878 if (!data)
1879 return _len - len;
1880
1881 ret = ffs_do_single_desc(data, len, entity, priv);
1882 if (unlikely(ret < 0)) {
1883 pr_debug("%s returns %d\n", __func__, ret);
1884 return ret;
1885 }
1886
1887 len -= ret;
1888 data += ret;
1889 ++num;
1890 }
1891 }
1892
1893 static int __ffs_data_do_entity(enum ffs_entity_type type,
1894 u8 *valuep, struct usb_descriptor_header *desc,
1895 void *priv)
1896 {
1897 struct ffs_desc_helper *helper = priv;
1898 struct usb_endpoint_descriptor *d;
1899
1900 ENTER();
1901
1902 switch (type) {
1903 case FFS_DESCRIPTOR:
1904 break;
1905
1906 case FFS_INTERFACE:
1907 /*
1908 * Interfaces are indexed from zero so if we
1909 * encountered interface "n" then there are at least
1910 * "n+1" interfaces.
1911 */
1912 if (*valuep >= helper->interfaces_count)
1913 helper->interfaces_count = *valuep + 1;
1914 break;
1915
1916 case FFS_STRING:
1917 /*
1918 * Strings are indexed from 1 (0 is magic ;) reserved
1919 * for languages list or some such)
1920 */
1921 if (*valuep > helper->ffs->strings_count)
1922 helper->ffs->strings_count = *valuep;
1923 break;
1924
1925 case FFS_ENDPOINT:
1926 d = (void *)desc;
1927 helper->eps_count++;
1928 if (helper->eps_count >= 15)
1929 return -EINVAL;
1930 /* Check if descriptors for any speed were already parsed */
1931 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
1932 helper->ffs->eps_addrmap[helper->eps_count] =
1933 d->bEndpointAddress;
1934 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
1935 d->bEndpointAddress)
1936 return -EINVAL;
1937 break;
1938 }
1939
1940 return 0;
1941 }
1942
1943 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1944 struct usb_os_desc_header *desc)
1945 {
1946 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1947 u16 w_index = le16_to_cpu(desc->wIndex);
1948
1949 if (bcd_version != 1) {
1950 pr_vdebug("unsupported os descriptors version: %d",
1951 bcd_version);
1952 return -EINVAL;
1953 }
1954 switch (w_index) {
1955 case 0x4:
1956 *next_type = FFS_OS_DESC_EXT_COMPAT;
1957 break;
1958 case 0x5:
1959 *next_type = FFS_OS_DESC_EXT_PROP;
1960 break;
1961 default:
1962 pr_vdebug("unsupported os descriptor type: %d", w_index);
1963 return -EINVAL;
1964 }
1965
1966 return sizeof(*desc);
1967 }
1968
1969 /*
1970 * Process all extended compatibility/extended property descriptors
1971 * of a feature descriptor
1972 */
1973 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1974 enum ffs_os_desc_type type,
1975 u16 feature_count,
1976 ffs_os_desc_callback entity,
1977 void *priv,
1978 struct usb_os_desc_header *h)
1979 {
1980 int ret;
1981 const unsigned _len = len;
1982
1983 ENTER();
1984
1985 /* loop over all ext compat/ext prop descriptors */
1986 while (feature_count--) {
1987 ret = entity(type, h, data, len, priv);
1988 if (unlikely(ret < 0)) {
1989 pr_debug("bad OS descriptor, type: %d\n", type);
1990 return ret;
1991 }
1992 data += ret;
1993 len -= ret;
1994 }
1995 return _len - len;
1996 }
1997
1998 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
1999 static int __must_check ffs_do_os_descs(unsigned count,
2000 char *data, unsigned len,
2001 ffs_os_desc_callback entity, void *priv)
2002 {
2003 const unsigned _len = len;
2004 unsigned long num = 0;
2005
2006 ENTER();
2007
2008 for (num = 0; num < count; ++num) {
2009 int ret;
2010 enum ffs_os_desc_type type;
2011 u16 feature_count;
2012 struct usb_os_desc_header *desc = (void *)data;
2013
2014 if (len < sizeof(*desc))
2015 return -EINVAL;
2016
2017 /*
2018 * Record "descriptor" entity.
2019 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2020 * Move the data pointer to the beginning of extended
2021 * compatibilities proper or extended properties proper
2022 * portions of the data
2023 */
2024 if (le32_to_cpu(desc->dwLength) > len)
2025 return -EINVAL;
2026
2027 ret = __ffs_do_os_desc_header(&type, desc);
2028 if (unlikely(ret < 0)) {
2029 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2030 num, ret);
2031 return ret;
2032 }
2033 /*
2034 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2035 */
2036 feature_count = le16_to_cpu(desc->wCount);
2037 if (type == FFS_OS_DESC_EXT_COMPAT &&
2038 (feature_count > 255 || desc->Reserved))
2039 return -EINVAL;
2040 len -= ret;
2041 data += ret;
2042
2043 /*
2044 * Process all function/property descriptors
2045 * of this Feature Descriptor
2046 */
2047 ret = ffs_do_single_os_desc(data, len, type,
2048 feature_count, entity, priv, desc);
2049 if (unlikely(ret < 0)) {
2050 pr_debug("%s returns %d\n", __func__, ret);
2051 return ret;
2052 }
2053
2054 len -= ret;
2055 data += ret;
2056 }
2057 return _len - len;
2058 }
2059
2060 /**
2061 * Validate contents of the buffer from userspace related to OS descriptors.
2062 */
2063 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2064 struct usb_os_desc_header *h, void *data,
2065 unsigned len, void *priv)
2066 {
2067 struct ffs_data *ffs = priv;
2068 u8 length;
2069
2070 ENTER();
2071
2072 switch (type) {
2073 case FFS_OS_DESC_EXT_COMPAT: {
2074 struct usb_ext_compat_desc *d = data;
2075 int i;
2076
2077 if (len < sizeof(*d) ||
2078 d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2079 d->Reserved1)
2080 return -EINVAL;
2081 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2082 if (d->Reserved2[i])
2083 return -EINVAL;
2084
2085 length = sizeof(struct usb_ext_compat_desc);
2086 }
2087 break;
2088 case FFS_OS_DESC_EXT_PROP: {
2089 struct usb_ext_prop_desc *d = data;
2090 u32 type, pdl;
2091 u16 pnl;
2092
2093 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2094 return -EINVAL;
2095 length = le32_to_cpu(d->dwSize);
2096 if (len < length)
2097 return -EINVAL;
2098 type = le32_to_cpu(d->dwPropertyDataType);
2099 if (type < USB_EXT_PROP_UNICODE ||
2100 type > USB_EXT_PROP_UNICODE_MULTI) {
2101 pr_vdebug("unsupported os descriptor property type: %d",
2102 type);
2103 return -EINVAL;
2104 }
2105 pnl = le16_to_cpu(d->wPropertyNameLength);
2106 if (length < 14 + pnl) {
2107 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2108 length, pnl, type);
2109 return -EINVAL;
2110 }
2111 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2112 if (length != 14 + pnl + pdl) {
2113 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2114 length, pnl, pdl, type);
2115 return -EINVAL;
2116 }
2117 ++ffs->ms_os_descs_ext_prop_count;
2118 /* property name reported to the host as "WCHAR"s */
2119 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2120 ffs->ms_os_descs_ext_prop_data_len += pdl;
2121 }
2122 break;
2123 default:
2124 pr_vdebug("unknown descriptor: %d\n", type);
2125 return -EINVAL;
2126 }
2127 return length;
2128 }
2129
2130 static int __ffs_data_got_descs(struct ffs_data *ffs,
2131 char *const _data, size_t len)
2132 {
2133 char *data = _data, *raw_descs;
2134 unsigned os_descs_count = 0, counts[3], flags;
2135 int ret = -EINVAL, i;
2136 struct ffs_desc_helper helper;
2137
2138 ENTER();
2139
2140 if (get_unaligned_le32(data + 4) != len)
2141 goto error;
2142
2143 switch (get_unaligned_le32(data)) {
2144 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2145 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2146 data += 8;
2147 len -= 8;
2148 break;
2149 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2150 flags = get_unaligned_le32(data + 8);
2151 ffs->user_flags = flags;
2152 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2153 FUNCTIONFS_HAS_HS_DESC |
2154 FUNCTIONFS_HAS_SS_DESC |
2155 FUNCTIONFS_HAS_MS_OS_DESC |
2156 FUNCTIONFS_VIRTUAL_ADDR |
2157 FUNCTIONFS_EVENTFD)) {
2158 ret = -ENOSYS;
2159 goto error;
2160 }
2161 data += 12;
2162 len -= 12;
2163 break;
2164 default:
2165 goto error;
2166 }
2167
2168 if (flags & FUNCTIONFS_EVENTFD) {
2169 if (len < 4)
2170 goto error;
2171 ffs->ffs_eventfd =
2172 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2173 if (IS_ERR(ffs->ffs_eventfd)) {
2174 ret = PTR_ERR(ffs->ffs_eventfd);
2175 ffs->ffs_eventfd = NULL;
2176 goto error;
2177 }
2178 data += 4;
2179 len -= 4;
2180 }
2181
2182 /* Read fs_count, hs_count and ss_count (if present) */
2183 for (i = 0; i < 3; ++i) {
2184 if (!(flags & (1 << i))) {
2185 counts[i] = 0;
2186 } else if (len < 4) {
2187 goto error;
2188 } else {
2189 counts[i] = get_unaligned_le32(data);
2190 data += 4;
2191 len -= 4;
2192 }
2193 }
2194 if (flags & (1 << i)) {
2195 if (len < 4) {
2196 goto error;
2197 }
2198 os_descs_count = get_unaligned_le32(data);
2199 data += 4;
2200 len -= 4;
2201 };
2202
2203 /* Read descriptors */
2204 raw_descs = data;
2205 helper.ffs = ffs;
2206 for (i = 0; i < 3; ++i) {
2207 if (!counts[i])
2208 continue;
2209 helper.interfaces_count = 0;
2210 helper.eps_count = 0;
2211 ret = ffs_do_descs(counts[i], data, len,
2212 __ffs_data_do_entity, &helper);
2213 if (ret < 0)
2214 goto error;
2215 if (!ffs->eps_count && !ffs->interfaces_count) {
2216 ffs->eps_count = helper.eps_count;
2217 ffs->interfaces_count = helper.interfaces_count;
2218 } else {
2219 if (ffs->eps_count != helper.eps_count) {
2220 ret = -EINVAL;
2221 goto error;
2222 }
2223 if (ffs->interfaces_count != helper.interfaces_count) {
2224 ret = -EINVAL;
2225 goto error;
2226 }
2227 }
2228 data += ret;
2229 len -= ret;
2230 }
2231 if (os_descs_count) {
2232 ret = ffs_do_os_descs(os_descs_count, data, len,
2233 __ffs_data_do_os_desc, ffs);
2234 if (ret < 0)
2235 goto error;
2236 data += ret;
2237 len -= ret;
2238 }
2239
2240 if (raw_descs == data || len) {
2241 ret = -EINVAL;
2242 goto error;
2243 }
2244
2245 ffs->raw_descs_data = _data;
2246 ffs->raw_descs = raw_descs;
2247 ffs->raw_descs_length = data - raw_descs;
2248 ffs->fs_descs_count = counts[0];
2249 ffs->hs_descs_count = counts[1];
2250 ffs->ss_descs_count = counts[2];
2251 ffs->ms_os_descs_count = os_descs_count;
2252
2253 return 0;
2254
2255 error:
2256 kfree(_data);
2257 return ret;
2258 }
2259
2260 static int __ffs_data_got_strings(struct ffs_data *ffs,
2261 char *const _data, size_t len)
2262 {
2263 u32 str_count, needed_count, lang_count;
2264 struct usb_gadget_strings **stringtabs, *t;
2265 struct usb_string *strings, *s;
2266 const char *data = _data;
2267
2268 ENTER();
2269
2270 if (unlikely(len < 16 ||
2271 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2272 get_unaligned_le32(data + 4) != len))
2273 goto error;
2274 str_count = get_unaligned_le32(data + 8);
2275 lang_count = get_unaligned_le32(data + 12);
2276
2277 /* if one is zero the other must be zero */
2278 if (unlikely(!str_count != !lang_count))
2279 goto error;
2280
2281 /* Do we have at least as many strings as descriptors need? */
2282 needed_count = ffs->strings_count;
2283 if (unlikely(str_count < needed_count))
2284 goto error;
2285
2286 /*
2287 * If we don't need any strings just return and free all
2288 * memory.
2289 */
2290 if (!needed_count) {
2291 kfree(_data);
2292 return 0;
2293 }
2294
2295 /* Allocate everything in one chunk so there's less maintenance. */
2296 {
2297 unsigned i = 0;
2298 vla_group(d);
2299 vla_item(d, struct usb_gadget_strings *, stringtabs,
2300 lang_count + 1);
2301 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2302 vla_item(d, struct usb_string, strings,
2303 lang_count*(needed_count+1));
2304
2305 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2306
2307 if (unlikely(!vlabuf)) {
2308 kfree(_data);
2309 return -ENOMEM;
2310 }
2311
2312 /* Initialize the VLA pointers */
2313 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2314 t = vla_ptr(vlabuf, d, stringtab);
2315 i = lang_count;
2316 do {
2317 *stringtabs++ = t++;
2318 } while (--i);
2319 *stringtabs = NULL;
2320
2321 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2322 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2323 t = vla_ptr(vlabuf, d, stringtab);
2324 s = vla_ptr(vlabuf, d, strings);
2325 strings = s;
2326 }
2327
2328 /* For each language */
2329 data += 16;
2330 len -= 16;
2331
2332 do { /* lang_count > 0 so we can use do-while */
2333 unsigned needed = needed_count;
2334
2335 if (unlikely(len < 3))
2336 goto error_free;
2337 t->language = get_unaligned_le16(data);
2338 t->strings = s;
2339 ++t;
2340
2341 data += 2;
2342 len -= 2;
2343
2344 /* For each string */
2345 do { /* str_count > 0 so we can use do-while */
2346 size_t length = strnlen(data, len);
2347
2348 if (unlikely(length == len))
2349 goto error_free;
2350
2351 /*
2352 * User may provide more strings then we need,
2353 * if that's the case we simply ignore the
2354 * rest
2355 */
2356 if (likely(needed)) {
2357 /*
2358 * s->id will be set while adding
2359 * function to configuration so for
2360 * now just leave garbage here.
2361 */
2362 s->s = data;
2363 --needed;
2364 ++s;
2365 }
2366
2367 data += length + 1;
2368 len -= length + 1;
2369 } while (--str_count);
2370
2371 s->id = 0; /* terminator */
2372 s->s = NULL;
2373 ++s;
2374
2375 } while (--lang_count);
2376
2377 /* Some garbage left? */
2378 if (unlikely(len))
2379 goto error_free;
2380
2381 /* Done! */
2382 ffs->stringtabs = stringtabs;
2383 ffs->raw_strings = _data;
2384
2385 return 0;
2386
2387 error_free:
2388 kfree(stringtabs);
2389 error:
2390 kfree(_data);
2391 return -EINVAL;
2392 }
2393
2394
2395 /* Events handling and management *******************************************/
2396
2397 static void __ffs_event_add(struct ffs_data *ffs,
2398 enum usb_functionfs_event_type type)
2399 {
2400 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2401 int neg = 0;
2402
2403 /*
2404 * Abort any unhandled setup
2405 *
2406 * We do not need to worry about some cmpxchg() changing value
2407 * of ffs->setup_state without holding the lock because when
2408 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2409 * the source does nothing.
2410 */
2411 if (ffs->setup_state == FFS_SETUP_PENDING)
2412 ffs->setup_state = FFS_SETUP_CANCELLED;
2413
2414 /*
2415 * Logic of this function guarantees that there are at most four pending
2416 * evens on ffs->ev.types queue. This is important because the queue
2417 * has space for four elements only and __ffs_ep0_read_events function
2418 * depends on that limit as well. If more event types are added, those
2419 * limits have to be revisited or guaranteed to still hold.
2420 */
2421 switch (type) {
2422 case FUNCTIONFS_RESUME:
2423 rem_type2 = FUNCTIONFS_SUSPEND;
2424 /* FALL THROUGH */
2425 case FUNCTIONFS_SUSPEND:
2426 case FUNCTIONFS_SETUP:
2427 rem_type1 = type;
2428 /* Discard all similar events */
2429 break;
2430
2431 case FUNCTIONFS_BIND:
2432 case FUNCTIONFS_UNBIND:
2433 case FUNCTIONFS_DISABLE:
2434 case FUNCTIONFS_ENABLE:
2435 /* Discard everything other then power management. */
2436 rem_type1 = FUNCTIONFS_SUSPEND;
2437 rem_type2 = FUNCTIONFS_RESUME;
2438 neg = 1;
2439 break;
2440
2441 default:
2442 WARN(1, "%d: unknown event, this should not happen\n", type);
2443 return;
2444 }
2445
2446 {
2447 u8 *ev = ffs->ev.types, *out = ev;
2448 unsigned n = ffs->ev.count;
2449 for (; n; --n, ++ev)
2450 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2451 *out++ = *ev;
2452 else
2453 pr_vdebug("purging event %d\n", *ev);
2454 ffs->ev.count = out - ffs->ev.types;
2455 }
2456
2457 pr_vdebug("adding event %d\n", type);
2458 ffs->ev.types[ffs->ev.count++] = type;
2459 wake_up_locked(&ffs->ev.waitq);
2460 if (ffs->ffs_eventfd)
2461 eventfd_signal(ffs->ffs_eventfd, 1);
2462 }
2463
2464 static void ffs_event_add(struct ffs_data *ffs,
2465 enum usb_functionfs_event_type type)
2466 {
2467 unsigned long flags;
2468 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2469 __ffs_event_add(ffs, type);
2470 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2471 }
2472
2473 /* Bind/unbind USB function hooks *******************************************/
2474
2475 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2476 {
2477 int i;
2478
2479 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2480 if (ffs->eps_addrmap[i] == endpoint_address)
2481 return i;
2482 return -ENOENT;
2483 }
2484
2485 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2486 struct usb_descriptor_header *desc,
2487 void *priv)
2488 {
2489 struct usb_endpoint_descriptor *ds = (void *)desc;
2490 struct ffs_function *func = priv;
2491 struct ffs_ep *ffs_ep;
2492 unsigned ep_desc_id;
2493 int idx;
2494 static const char *speed_names[] = { "full", "high", "super" };
2495
2496 if (type != FFS_DESCRIPTOR)
2497 return 0;
2498
2499 /*
2500 * If ss_descriptors is not NULL, we are reading super speed
2501 * descriptors; if hs_descriptors is not NULL, we are reading high
2502 * speed descriptors; otherwise, we are reading full speed
2503 * descriptors.
2504 */
2505 if (func->function.ss_descriptors) {
2506 ep_desc_id = 2;
2507 func->function.ss_descriptors[(long)valuep] = desc;
2508 } else if (func->function.hs_descriptors) {
2509 ep_desc_id = 1;
2510 func->function.hs_descriptors[(long)valuep] = desc;
2511 } else {
2512 ep_desc_id = 0;
2513 func->function.fs_descriptors[(long)valuep] = desc;
2514 }
2515
2516 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2517 return 0;
2518
2519 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2520 if (idx < 0)
2521 return idx;
2522
2523 ffs_ep = func->eps + idx;
2524
2525 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2526 pr_err("two %sspeed descriptors for EP %d\n",
2527 speed_names[ep_desc_id],
2528 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2529 return -EINVAL;
2530 }
2531 ffs_ep->descs[ep_desc_id] = ds;
2532
2533 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2534 if (ffs_ep->ep) {
2535 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2536 if (!ds->wMaxPacketSize)
2537 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2538 } else {
2539 struct usb_request *req;
2540 struct usb_ep *ep;
2541 u8 bEndpointAddress;
2542
2543 /*
2544 * We back up bEndpointAddress because autoconfig overwrites
2545 * it with physical endpoint address.
2546 */
2547 bEndpointAddress = ds->bEndpointAddress;
2548 pr_vdebug("autoconfig\n");
2549 ep = usb_ep_autoconfig(func->gadget, ds);
2550 if (unlikely(!ep))
2551 return -ENOTSUPP;
2552 ep->driver_data = func->eps + idx;
2553
2554 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2555 if (unlikely(!req))
2556 return -ENOMEM;
2557
2558 ffs_ep->ep = ep;
2559 ffs_ep->req = req;
2560 func->eps_revmap[ds->bEndpointAddress &
2561 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2562 /*
2563 * If we use virtual address mapping, we restore
2564 * original bEndpointAddress value.
2565 */
2566 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2567 ds->bEndpointAddress = bEndpointAddress;
2568 }
2569 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2570
2571 return 0;
2572 }
2573
2574 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2575 struct usb_descriptor_header *desc,
2576 void *priv)
2577 {
2578 struct ffs_function *func = priv;
2579 unsigned idx;
2580 u8 newValue;
2581
2582 switch (type) {
2583 default:
2584 case FFS_DESCRIPTOR:
2585 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2586 return 0;
2587
2588 case FFS_INTERFACE:
2589 idx = *valuep;
2590 if (func->interfaces_nums[idx] < 0) {
2591 int id = usb_interface_id(func->conf, &func->function);
2592 if (unlikely(id < 0))
2593 return id;
2594 func->interfaces_nums[idx] = id;
2595 }
2596 newValue = func->interfaces_nums[idx];
2597 break;
2598
2599 case FFS_STRING:
2600 /* String' IDs are allocated when fsf_data is bound to cdev */
2601 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2602 break;
2603
2604 case FFS_ENDPOINT:
2605 /*
2606 * USB_DT_ENDPOINT are handled in
2607 * __ffs_func_bind_do_descs().
2608 */
2609 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2610 return 0;
2611
2612 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2613 if (unlikely(!func->eps[idx].ep))
2614 return -EINVAL;
2615
2616 {
2617 struct usb_endpoint_descriptor **descs;
2618 descs = func->eps[idx].descs;
2619 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2620 }
2621 break;
2622 }
2623
2624 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2625 *valuep = newValue;
2626 return 0;
2627 }
2628
2629 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2630 struct usb_os_desc_header *h, void *data,
2631 unsigned len, void *priv)
2632 {
2633 struct ffs_function *func = priv;
2634 u8 length = 0;
2635
2636 switch (type) {
2637 case FFS_OS_DESC_EXT_COMPAT: {
2638 struct usb_ext_compat_desc *desc = data;
2639 struct usb_os_desc_table *t;
2640
2641 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2642 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2643 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2644 ARRAY_SIZE(desc->CompatibleID) +
2645 ARRAY_SIZE(desc->SubCompatibleID));
2646 length = sizeof(*desc);
2647 }
2648 break;
2649 case FFS_OS_DESC_EXT_PROP: {
2650 struct usb_ext_prop_desc *desc = data;
2651 struct usb_os_desc_table *t;
2652 struct usb_os_desc_ext_prop *ext_prop;
2653 char *ext_prop_name;
2654 char *ext_prop_data;
2655
2656 t = &func->function.os_desc_table[h->interface];
2657 t->if_id = func->interfaces_nums[h->interface];
2658
2659 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2660 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2661
2662 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2663 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2664 ext_prop->data_len = le32_to_cpu(*(u32 *)
2665 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2666 length = ext_prop->name_len + ext_prop->data_len + 14;
2667
2668 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2669 func->ffs->ms_os_descs_ext_prop_name_avail +=
2670 ext_prop->name_len;
2671
2672 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2673 func->ffs->ms_os_descs_ext_prop_data_avail +=
2674 ext_prop->data_len;
2675 memcpy(ext_prop_data,
2676 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2677 ext_prop->data_len);
2678 /* unicode data reported to the host as "WCHAR"s */
2679 switch (ext_prop->type) {
2680 case USB_EXT_PROP_UNICODE:
2681 case USB_EXT_PROP_UNICODE_ENV:
2682 case USB_EXT_PROP_UNICODE_LINK:
2683 case USB_EXT_PROP_UNICODE_MULTI:
2684 ext_prop->data_len *= 2;
2685 break;
2686 }
2687 ext_prop->data = ext_prop_data;
2688
2689 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2690 ext_prop->name_len);
2691 /* property name reported to the host as "WCHAR"s */
2692 ext_prop->name_len *= 2;
2693 ext_prop->name = ext_prop_name;
2694
2695 t->os_desc->ext_prop_len +=
2696 ext_prop->name_len + ext_prop->data_len + 14;
2697 ++t->os_desc->ext_prop_count;
2698 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2699 }
2700 break;
2701 default:
2702 pr_vdebug("unknown descriptor: %d\n", type);
2703 }
2704
2705 return length;
2706 }
2707
2708 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2709 struct usb_configuration *c)
2710 {
2711 struct ffs_function *func = ffs_func_from_usb(f);
2712 struct f_fs_opts *ffs_opts =
2713 container_of(f->fi, struct f_fs_opts, func_inst);
2714 int ret;
2715
2716 ENTER();
2717
2718 /*
2719 * Legacy gadget triggers binding in functionfs_ready_callback,
2720 * which already uses locking; taking the same lock here would
2721 * cause a deadlock.
2722 *
2723 * Configfs-enabled gadgets however do need ffs_dev_lock.
2724 */
2725 if (!ffs_opts->no_configfs)
2726 ffs_dev_lock();
2727 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2728 func->ffs = ffs_opts->dev->ffs_data;
2729 if (!ffs_opts->no_configfs)
2730 ffs_dev_unlock();
2731 if (ret)
2732 return ERR_PTR(ret);
2733
2734 func->conf = c;
2735 func->gadget = c->cdev->gadget;
2736
2737 /*
2738 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2739 * configurations are bound in sequence with list_for_each_entry,
2740 * in each configuration its functions are bound in sequence
2741 * with list_for_each_entry, so we assume no race condition
2742 * with regard to ffs_opts->bound access
2743 */
2744 if (!ffs_opts->refcnt) {
2745 ret = functionfs_bind(func->ffs, c->cdev);
2746 if (ret)
2747 return ERR_PTR(ret);
2748 }
2749 ffs_opts->refcnt++;
2750 func->function.strings = func->ffs->stringtabs;
2751
2752 return ffs_opts;
2753 }
2754
2755 static int _ffs_func_bind(struct usb_configuration *c,
2756 struct usb_function *f)
2757 {
2758 struct ffs_function *func = ffs_func_from_usb(f);
2759 struct ffs_data *ffs = func->ffs;
2760
2761 const int full = !!func->ffs->fs_descs_count;
2762 const int high = !!func->ffs->hs_descs_count;
2763 const int super = !!func->ffs->ss_descs_count;
2764
2765 int fs_len, hs_len, ss_len, ret, i;
2766 struct ffs_ep *eps_ptr;
2767
2768 /* Make it a single chunk, less management later on */
2769 vla_group(d);
2770 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2771 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2772 full ? ffs->fs_descs_count + 1 : 0);
2773 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2774 high ? ffs->hs_descs_count + 1 : 0);
2775 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2776 super ? ffs->ss_descs_count + 1 : 0);
2777 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2778 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2779 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2780 vla_item_with_sz(d, char[16], ext_compat,
2781 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2782 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2783 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2784 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2785 ffs->ms_os_descs_ext_prop_count);
2786 vla_item_with_sz(d, char, ext_prop_name,
2787 ffs->ms_os_descs_ext_prop_name_len);
2788 vla_item_with_sz(d, char, ext_prop_data,
2789 ffs->ms_os_descs_ext_prop_data_len);
2790 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2791 char *vlabuf;
2792
2793 ENTER();
2794
2795 /* Has descriptors only for speeds gadget does not support */
2796 if (unlikely(!(full | high | super)))
2797 return -ENOTSUPP;
2798
2799 /* Allocate a single chunk, less management later on */
2800 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2801 if (unlikely(!vlabuf))
2802 return -ENOMEM;
2803
2804 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2805 ffs->ms_os_descs_ext_prop_name_avail =
2806 vla_ptr(vlabuf, d, ext_prop_name);
2807 ffs->ms_os_descs_ext_prop_data_avail =
2808 vla_ptr(vlabuf, d, ext_prop_data);
2809
2810 /* Copy descriptors */
2811 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2812 ffs->raw_descs_length);
2813
2814 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2815 eps_ptr = vla_ptr(vlabuf, d, eps);
2816 for (i = 0; i < ffs->eps_count; i++)
2817 eps_ptr[i].num = -1;
2818
2819 /* Save pointers
2820 * d_eps == vlabuf, func->eps used to kfree vlabuf later
2821 */
2822 func->eps = vla_ptr(vlabuf, d, eps);
2823 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2824
2825 /*
2826 * Go through all the endpoint descriptors and allocate
2827 * endpoints first, so that later we can rewrite the endpoint
2828 * numbers without worrying that it may be described later on.
2829 */
2830 if (likely(full)) {
2831 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2832 fs_len = ffs_do_descs(ffs->fs_descs_count,
2833 vla_ptr(vlabuf, d, raw_descs),
2834 d_raw_descs__sz,
2835 __ffs_func_bind_do_descs, func);
2836 if (unlikely(fs_len < 0)) {
2837 ret = fs_len;
2838 goto error;
2839 }
2840 } else {
2841 fs_len = 0;
2842 }
2843
2844 if (likely(high)) {
2845 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2846 hs_len = ffs_do_descs(ffs->hs_descs_count,
2847 vla_ptr(vlabuf, d, raw_descs) + fs_len,
2848 d_raw_descs__sz - fs_len,
2849 __ffs_func_bind_do_descs, func);
2850 if (unlikely(hs_len < 0)) {
2851 ret = hs_len;
2852 goto error;
2853 }
2854 } else {
2855 hs_len = 0;
2856 }
2857
2858 if (likely(super)) {
2859 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2860 ss_len = ffs_do_descs(ffs->ss_descs_count,
2861 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2862 d_raw_descs__sz - fs_len - hs_len,
2863 __ffs_func_bind_do_descs, func);
2864 if (unlikely(ss_len < 0)) {
2865 ret = ss_len;
2866 goto error;
2867 }
2868 } else {
2869 ss_len = 0;
2870 }
2871
2872 /*
2873 * Now handle interface numbers allocation and interface and
2874 * endpoint numbers rewriting. We can do that in one go
2875 * now.
2876 */
2877 ret = ffs_do_descs(ffs->fs_descs_count +
2878 (high ? ffs->hs_descs_count : 0) +
2879 (super ? ffs->ss_descs_count : 0),
2880 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2881 __ffs_func_bind_do_nums, func);
2882 if (unlikely(ret < 0))
2883 goto error;
2884
2885 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2886 if (c->cdev->use_os_string)
2887 for (i = 0; i < ffs->interfaces_count; ++i) {
2888 struct usb_os_desc *desc;
2889
2890 desc = func->function.os_desc_table[i].os_desc =
2891 vla_ptr(vlabuf, d, os_desc) +
2892 i * sizeof(struct usb_os_desc);
2893 desc->ext_compat_id =
2894 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2895 INIT_LIST_HEAD(&desc->ext_prop);
2896 }
2897 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2898 vla_ptr(vlabuf, d, raw_descs) +
2899 fs_len + hs_len + ss_len,
2900 d_raw_descs__sz - fs_len - hs_len - ss_len,
2901 __ffs_func_bind_do_os_desc, func);
2902 if (unlikely(ret < 0))
2903 goto error;
2904 func->function.os_desc_n =
2905 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2906
2907 /* And we're done */
2908 ffs_event_add(ffs, FUNCTIONFS_BIND);
2909 return 0;
2910
2911 error:
2912 /* XXX Do we need to release all claimed endpoints here? */
2913 return ret;
2914 }
2915
2916 static int ffs_func_bind(struct usb_configuration *c,
2917 struct usb_function *f)
2918 {
2919 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2920 struct ffs_function *func = ffs_func_from_usb(f);
2921 int ret;
2922
2923 if (IS_ERR(ffs_opts))
2924 return PTR_ERR(ffs_opts);
2925
2926 ret = _ffs_func_bind(c, f);
2927 if (ret && !--ffs_opts->refcnt)
2928 functionfs_unbind(func->ffs);
2929
2930 return ret;
2931 }
2932
2933
2934 /* Other USB function hooks *************************************************/
2935
2936 static void ffs_reset_work(struct work_struct *work)
2937 {
2938 struct ffs_data *ffs = container_of(work,
2939 struct ffs_data, reset_work);
2940 ffs_data_reset(ffs);
2941 }
2942
2943 static int ffs_func_set_alt(struct usb_function *f,
2944 unsigned interface, unsigned alt)
2945 {
2946 struct ffs_function *func = ffs_func_from_usb(f);
2947 struct ffs_data *ffs = func->ffs;
2948 int ret = 0, intf;
2949
2950 if (alt != (unsigned)-1) {
2951 intf = ffs_func_revmap_intf(func, interface);
2952 if (unlikely(intf < 0))
2953 return intf;
2954 }
2955
2956 if (ffs->func)
2957 ffs_func_eps_disable(ffs->func);
2958
2959 if (ffs->state == FFS_DEACTIVATED) {
2960 ffs->state = FFS_CLOSING;
2961 INIT_WORK(&ffs->reset_work, ffs_reset_work);
2962 schedule_work(&ffs->reset_work);
2963 return -ENODEV;
2964 }
2965
2966 if (ffs->state != FFS_ACTIVE)
2967 return -ENODEV;
2968
2969 if (alt == (unsigned)-1) {
2970 ffs->func = NULL;
2971 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2972 return 0;
2973 }
2974
2975 ffs->func = func;
2976 ret = ffs_func_eps_enable(func);
2977 if (likely(ret >= 0))
2978 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2979 return ret;
2980 }
2981
2982 static void ffs_func_disable(struct usb_function *f)
2983 {
2984 ffs_func_set_alt(f, 0, (unsigned)-1);
2985 }
2986
2987 static int ffs_func_setup(struct usb_function *f,
2988 const struct usb_ctrlrequest *creq)
2989 {
2990 struct ffs_function *func = ffs_func_from_usb(f);
2991 struct ffs_data *ffs = func->ffs;
2992 unsigned long flags;
2993 int ret;
2994
2995 ENTER();
2996
2997 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2998 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2999 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3000 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3001 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3002
3003 /*
3004 * Most requests directed to interface go through here
3005 * (notable exceptions are set/get interface) so we need to
3006 * handle them. All other either handled by composite or
3007 * passed to usb_configuration->setup() (if one is set). No
3008 * matter, we will handle requests directed to endpoint here
3009 * as well (as it's straightforward) but what to do with any
3010 * other request?
3011 */
3012 if (ffs->state != FFS_ACTIVE)
3013 return -ENODEV;
3014
3015 switch (creq->bRequestType & USB_RECIP_MASK) {
3016 case USB_RECIP_INTERFACE:
3017 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3018 if (unlikely(ret < 0))
3019 return ret;
3020 break;
3021
3022 case USB_RECIP_ENDPOINT:
3023 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3024 if (unlikely(ret < 0))
3025 return ret;
3026 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3027 ret = func->ffs->eps_addrmap[ret];
3028 break;
3029
3030 default:
3031 return -EOPNOTSUPP;
3032 }
3033
3034 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3035 ffs->ev.setup = *creq;
3036 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3037 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3038 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3039
3040 return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
3041 }
3042
3043 static void ffs_func_suspend(struct usb_function *f)
3044 {
3045 ENTER();
3046 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3047 }
3048
3049 static void ffs_func_resume(struct usb_function *f)
3050 {
3051 ENTER();
3052 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3053 }
3054
3055
3056 /* Endpoint and interface numbers reverse mapping ***************************/
3057
3058 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3059 {
3060 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3061 return num ? num : -EDOM;
3062 }
3063
3064 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3065 {
3066 short *nums = func->interfaces_nums;
3067 unsigned count = func->ffs->interfaces_count;
3068
3069 for (; count; --count, ++nums) {
3070 if (*nums >= 0 && *nums == intf)
3071 return nums - func->interfaces_nums;
3072 }
3073
3074 return -EDOM;
3075 }
3076
3077
3078 /* Devices management *******************************************************/
3079
3080 static LIST_HEAD(ffs_devices);
3081
3082 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3083 {
3084 struct ffs_dev *dev;
3085
3086 list_for_each_entry(dev, &ffs_devices, entry) {
3087 if (!dev->name || !name)
3088 continue;
3089 if (strcmp(dev->name, name) == 0)
3090 return dev;
3091 }
3092
3093 return NULL;
3094 }
3095
3096 /*
3097 * ffs_lock must be taken by the caller of this function
3098 */
3099 static struct ffs_dev *_ffs_get_single_dev(void)
3100 {
3101 struct ffs_dev *dev;
3102
3103 if (list_is_singular(&ffs_devices)) {
3104 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3105 if (dev->single)
3106 return dev;
3107 }
3108
3109 return NULL;
3110 }
3111
3112 /*
3113 * ffs_lock must be taken by the caller of this function
3114 */
3115 static struct ffs_dev *_ffs_find_dev(const char *name)
3116 {
3117 struct ffs_dev *dev;
3118
3119 dev = _ffs_get_single_dev();
3120 if (dev)
3121 return dev;
3122
3123 return _ffs_do_find_dev(name);
3124 }
3125
3126 /* Configfs support *********************************************************/
3127
3128 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3129 {
3130 return container_of(to_config_group(item), struct f_fs_opts,
3131 func_inst.group);
3132 }
3133
3134 static void ffs_attr_release(struct config_item *item)
3135 {
3136 struct f_fs_opts *opts = to_ffs_opts(item);
3137
3138 usb_put_function_instance(&opts->func_inst);
3139 }
3140
3141 static struct configfs_item_operations ffs_item_ops = {
3142 .release = ffs_attr_release,
3143 };
3144
3145 static struct config_item_type ffs_func_type = {
3146 .ct_item_ops = &ffs_item_ops,
3147 .ct_owner = THIS_MODULE,
3148 };
3149
3150
3151 /* Function registration interface ******************************************/
3152
3153 static void ffs_free_inst(struct usb_function_instance *f)
3154 {
3155 struct f_fs_opts *opts;
3156
3157 opts = to_f_fs_opts(f);
3158 ffs_dev_lock();
3159 _ffs_free_dev(opts->dev);
3160 ffs_dev_unlock();
3161 kfree(opts);
3162 }
3163
3164 #define MAX_INST_NAME_LEN 40
3165
3166 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3167 {
3168 struct f_fs_opts *opts;
3169 char *ptr;
3170 const char *tmp;
3171 int name_len, ret;
3172
3173 name_len = strlen(name) + 1;
3174 if (name_len > MAX_INST_NAME_LEN)
3175 return -ENAMETOOLONG;
3176
3177 ptr = kstrndup(name, name_len, GFP_KERNEL);
3178 if (!ptr)
3179 return -ENOMEM;
3180
3181 opts = to_f_fs_opts(fi);
3182 tmp = NULL;
3183
3184 ffs_dev_lock();
3185
3186 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3187 ret = _ffs_name_dev(opts->dev, ptr);
3188 if (ret) {
3189 kfree(ptr);
3190 ffs_dev_unlock();
3191 return ret;
3192 }
3193 opts->dev->name_allocated = true;
3194
3195 ffs_dev_unlock();
3196
3197 kfree(tmp);
3198
3199 return 0;
3200 }
3201
3202 static struct usb_function_instance *ffs_alloc_inst(void)
3203 {
3204 struct f_fs_opts *opts;
3205 struct ffs_dev *dev;
3206
3207 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3208 if (!opts)
3209 return ERR_PTR(-ENOMEM);
3210
3211 opts->func_inst.set_inst_name = ffs_set_inst_name;
3212 opts->func_inst.free_func_inst = ffs_free_inst;
3213 ffs_dev_lock();
3214 dev = _ffs_alloc_dev();
3215 ffs_dev_unlock();
3216 if (IS_ERR(dev)) {
3217 kfree(opts);
3218 return ERR_CAST(dev);
3219 }
3220 opts->dev = dev;
3221 dev->opts = opts;
3222
3223 config_group_init_type_name(&opts->func_inst.group, "",
3224 &ffs_func_type);
3225 return &opts->func_inst;
3226 }
3227
3228 static void ffs_free(struct usb_function *f)
3229 {
3230 kfree(ffs_func_from_usb(f));
3231 }
3232
3233 static void ffs_func_unbind(struct usb_configuration *c,
3234 struct usb_function *f)
3235 {
3236 struct ffs_function *func = ffs_func_from_usb(f);
3237 struct ffs_data *ffs = func->ffs;
3238 struct f_fs_opts *opts =
3239 container_of(f->fi, struct f_fs_opts, func_inst);
3240 struct ffs_ep *ep = func->eps;
3241 unsigned count = ffs->eps_count;
3242 unsigned long flags;
3243
3244 ENTER();
3245 if (ffs->func == func) {
3246 ffs_func_eps_disable(func);
3247 ffs->func = NULL;
3248 }
3249
3250 if (!--opts->refcnt)
3251 functionfs_unbind(ffs);
3252
3253 /* cleanup after autoconfig */
3254 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3255 do {
3256 if (ep->ep && ep->req)
3257 usb_ep_free_request(ep->ep, ep->req);
3258 ep->req = NULL;
3259 ++ep;
3260 } while (--count);
3261 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3262 kfree(func->eps);
3263 func->eps = NULL;
3264 /*
3265 * eps, descriptors and interfaces_nums are allocated in the
3266 * same chunk so only one free is required.
3267 */
3268 func->function.fs_descriptors = NULL;
3269 func->function.hs_descriptors = NULL;
3270 func->function.ss_descriptors = NULL;
3271 func->interfaces_nums = NULL;
3272
3273 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3274 }
3275
3276 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3277 {
3278 struct ffs_function *func;
3279
3280 ENTER();
3281
3282 func = kzalloc(sizeof(*func), GFP_KERNEL);
3283 if (unlikely(!func))
3284 return ERR_PTR(-ENOMEM);
3285
3286 func->function.name = "Function FS Gadget";
3287
3288 func->function.bind = ffs_func_bind;
3289 func->function.unbind = ffs_func_unbind;
3290 func->function.set_alt = ffs_func_set_alt;
3291 func->function.disable = ffs_func_disable;
3292 func->function.setup = ffs_func_setup;
3293 func->function.suspend = ffs_func_suspend;
3294 func->function.resume = ffs_func_resume;
3295 func->function.free_func = ffs_free;
3296
3297 return &func->function;
3298 }
3299
3300 /*
3301 * ffs_lock must be taken by the caller of this function
3302 */
3303 static struct ffs_dev *_ffs_alloc_dev(void)
3304 {
3305 struct ffs_dev *dev;
3306 int ret;
3307
3308 if (_ffs_get_single_dev())
3309 return ERR_PTR(-EBUSY);
3310
3311 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3312 if (!dev)
3313 return ERR_PTR(-ENOMEM);
3314
3315 if (list_empty(&ffs_devices)) {
3316 ret = functionfs_init();
3317 if (ret) {
3318 kfree(dev);
3319 return ERR_PTR(ret);
3320 }
3321 }
3322
3323 list_add(&dev->entry, &ffs_devices);
3324
3325 return dev;
3326 }
3327
3328 /*
3329 * ffs_lock must be taken by the caller of this function
3330 * The caller is responsible for "name" being available whenever f_fs needs it
3331 */
3332 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3333 {
3334 struct ffs_dev *existing;
3335
3336 existing = _ffs_do_find_dev(name);
3337 if (existing)
3338 return -EBUSY;
3339
3340 dev->name = name;
3341
3342 return 0;
3343 }
3344
3345 /*
3346 * The caller is responsible for "name" being available whenever f_fs needs it
3347 */
3348 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3349 {
3350 int ret;
3351
3352 ffs_dev_lock();
3353 ret = _ffs_name_dev(dev, name);
3354 ffs_dev_unlock();
3355
3356 return ret;
3357 }
3358 EXPORT_SYMBOL_GPL(ffs_name_dev);
3359
3360 int ffs_single_dev(struct ffs_dev *dev)
3361 {
3362 int ret;
3363
3364 ret = 0;
3365 ffs_dev_lock();
3366
3367 if (!list_is_singular(&ffs_devices))
3368 ret = -EBUSY;
3369 else
3370 dev->single = true;
3371
3372 ffs_dev_unlock();
3373 return ret;
3374 }
3375 EXPORT_SYMBOL_GPL(ffs_single_dev);
3376
3377 /*
3378 * ffs_lock must be taken by the caller of this function
3379 */
3380 static void _ffs_free_dev(struct ffs_dev *dev)
3381 {
3382 list_del(&dev->entry);
3383 if (dev->name_allocated)
3384 kfree(dev->name);
3385 kfree(dev);
3386 if (list_empty(&ffs_devices))
3387 functionfs_cleanup();
3388 }
3389
3390 static void *ffs_acquire_dev(const char *dev_name)
3391 {
3392 struct ffs_dev *ffs_dev;
3393
3394 ENTER();
3395 ffs_dev_lock();
3396
3397 ffs_dev = _ffs_find_dev(dev_name);
3398 if (!ffs_dev)
3399 ffs_dev = ERR_PTR(-ENOENT);
3400 else if (ffs_dev->mounted)
3401 ffs_dev = ERR_PTR(-EBUSY);
3402 else if (ffs_dev->ffs_acquire_dev_callback &&
3403 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3404 ffs_dev = ERR_PTR(-ENOENT);
3405 else
3406 ffs_dev->mounted = true;
3407
3408 ffs_dev_unlock();
3409 return ffs_dev;
3410 }
3411
3412 static void ffs_release_dev(struct ffs_data *ffs_data)
3413 {
3414 struct ffs_dev *ffs_dev;
3415
3416 ENTER();
3417 ffs_dev_lock();
3418
3419 ffs_dev = ffs_data->private_data;
3420 if (ffs_dev) {
3421 ffs_dev->mounted = false;
3422
3423 if (ffs_dev->ffs_release_dev_callback)
3424 ffs_dev->ffs_release_dev_callback(ffs_dev);
3425 }
3426
3427 ffs_dev_unlock();
3428 }
3429
3430 static int ffs_ready(struct ffs_data *ffs)
3431 {
3432 struct ffs_dev *ffs_obj;
3433 int ret = 0;
3434
3435 ENTER();
3436 ffs_dev_lock();
3437
3438 ffs_obj = ffs->private_data;
3439 if (!ffs_obj) {
3440 ret = -EINVAL;
3441 goto done;
3442 }
3443 if (WARN_ON(ffs_obj->desc_ready)) {
3444 ret = -EBUSY;
3445 goto done;
3446 }
3447
3448 ffs_obj->desc_ready = true;
3449 ffs_obj->ffs_data = ffs;
3450
3451 if (ffs_obj->ffs_ready_callback) {
3452 ret = ffs_obj->ffs_ready_callback(ffs);
3453 if (ret)
3454 goto done;
3455 }
3456
3457 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3458 done:
3459 ffs_dev_unlock();
3460 return ret;
3461 }
3462
3463 static void ffs_closed(struct ffs_data *ffs)
3464 {
3465 struct ffs_dev *ffs_obj;
3466 struct f_fs_opts *opts;
3467 struct config_item *ci;
3468
3469 ENTER();
3470 ffs_dev_lock();
3471
3472 ffs_obj = ffs->private_data;
3473 if (!ffs_obj)
3474 goto done;
3475
3476 ffs_obj->desc_ready = false;
3477
3478 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3479 ffs_obj->ffs_closed_callback)
3480 ffs_obj->ffs_closed_callback(ffs);
3481
3482 if (ffs_obj->opts)
3483 opts = ffs_obj->opts;
3484 else
3485 goto done;
3486
3487 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3488 || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount))
3489 goto done;
3490
3491 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3492 ffs_dev_unlock();
3493
3494 if (test_bit(FFS_FL_BOUND, &ffs->flags))
3495 unregister_gadget_item(ci);
3496 return;
3497 done:
3498 ffs_dev_unlock();
3499 }
3500
3501 /* Misc helper functions ****************************************************/
3502
3503 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3504 {
3505 return nonblock
3506 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3507 : mutex_lock_interruptible(mutex);
3508 }
3509
3510 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3511 {
3512 char *data;
3513
3514 if (unlikely(!len))
3515 return NULL;
3516
3517 data = kmalloc(len, GFP_KERNEL);
3518 if (unlikely(!data))
3519 return ERR_PTR(-ENOMEM);
3520
3521 if (unlikely(copy_from_user(data, buf, len))) {
3522 kfree(data);
3523 return ERR_PTR(-EFAULT);
3524 }
3525
3526 pr_vdebug("Buffer from user space:\n");
3527 ffs_dump_mem("", data, len);
3528
3529 return data;
3530 }
3531
3532 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3533 MODULE_LICENSE("GPL");
3534 MODULE_AUTHOR("Michal Nazarewicz");
Linux with added FPC-III support