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[mirror_ubuntu-eoan-kernel.git] / drivers / usb / gadget / function / f_fs.c
1 /*
2 * f_fs.c -- user mode file system API for USB composite function controllers
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 * Author: Michal Nazarewicz <mina86@mina86.com>
6 *
7 * Based on inode.c (GadgetFS) which was:
8 * Copyright (C) 2003-2004 David Brownell
9 * Copyright (C) 2003 Agilent Technologies
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 */
16
17
18 /* #define DEBUG */
19 /* #define VERBOSE_DEBUG */
20
21 #include <linux/blkdev.h>
22 #include <linux/pagemap.h>
23 #include <linux/export.h>
24 #include <linux/hid.h>
25 #include <linux/module.h>
26 #include <asm/unaligned.h>
27
28 #include <linux/usb/composite.h>
29 #include <linux/usb/functionfs.h>
30
31 #include <linux/aio.h>
32 #include <linux/mmu_context.h>
33 #include <linux/poll.h>
34
35 #include "u_fs.h"
36 #include "u_f.h"
37 #include "u_os_desc.h"
38 #include "configfs.h"
39
40 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
41
42 /* Reference counter handling */
43 static void ffs_data_get(struct ffs_data *ffs);
44 static void ffs_data_put(struct ffs_data *ffs);
45 /* Creates new ffs_data object. */
46 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
47
48 /* Opened counter handling. */
49 static void ffs_data_opened(struct ffs_data *ffs);
50 static void ffs_data_closed(struct ffs_data *ffs);
51
52 /* Called with ffs->mutex held; take over ownership of data. */
53 static int __must_check
54 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
55 static int __must_check
56 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
57
58
59 /* The function structure ***************************************************/
60
61 struct ffs_ep;
62
63 struct ffs_function {
64 struct usb_configuration *conf;
65 struct usb_gadget *gadget;
66 struct ffs_data *ffs;
67
68 struct ffs_ep *eps;
69 u8 eps_revmap[16];
70 short *interfaces_nums;
71
72 struct usb_function function;
73 };
74
75
76 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
77 {
78 return container_of(f, struct ffs_function, function);
79 }
80
81
82 static inline enum ffs_setup_state
83 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
84 {
85 return (enum ffs_setup_state)
86 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
87 }
88
89
90 static void ffs_func_eps_disable(struct ffs_function *func);
91 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
92
93 static int ffs_func_bind(struct usb_configuration *,
94 struct usb_function *);
95 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
96 static void ffs_func_disable(struct usb_function *);
97 static int ffs_func_setup(struct usb_function *,
98 const struct usb_ctrlrequest *);
99 static void ffs_func_suspend(struct usb_function *);
100 static void ffs_func_resume(struct usb_function *);
101
102
103 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
104 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
105
106
107 /* The endpoints structures *************************************************/
108
109 struct ffs_ep {
110 struct usb_ep *ep; /* P: ffs->eps_lock */
111 struct usb_request *req; /* P: epfile->mutex */
112
113 /* [0]: full speed, [1]: high speed, [2]: super speed */
114 struct usb_endpoint_descriptor *descs[3];
115
116 u8 num;
117
118 int status; /* P: epfile->mutex */
119 };
120
121 struct ffs_epfile {
122 /* Protects ep->ep and ep->req. */
123 struct mutex mutex;
124 wait_queue_head_t wait;
125
126 struct ffs_data *ffs;
127 struct ffs_ep *ep; /* P: ffs->eps_lock */
128
129 struct dentry *dentry;
130
131 char name[5];
132
133 unsigned char in; /* P: ffs->eps_lock */
134 unsigned char isoc; /* P: ffs->eps_lock */
135
136 unsigned char _pad;
137 };
138
139 /* ffs_io_data structure ***************************************************/
140
141 struct ffs_io_data {
142 bool aio;
143 bool read;
144
145 struct kiocb *kiocb;
146 const struct iovec *iovec;
147 unsigned long nr_segs;
148 char __user *buf;
149 size_t len;
150
151 struct mm_struct *mm;
152 struct work_struct work;
153
154 struct usb_ep *ep;
155 struct usb_request *req;
156 };
157
158 struct ffs_desc_helper {
159 struct ffs_data *ffs;
160 unsigned interfaces_count;
161 unsigned eps_count;
162 };
163
164 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
165 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
166
167 static struct dentry *
168 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
169 const struct file_operations *fops);
170
171 /* Devices management *******************************************************/
172
173 DEFINE_MUTEX(ffs_lock);
174 EXPORT_SYMBOL_GPL(ffs_lock);
175
176 static struct ffs_dev *_ffs_find_dev(const char *name);
177 static struct ffs_dev *_ffs_alloc_dev(void);
178 static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
179 static void _ffs_free_dev(struct ffs_dev *dev);
180 static void *ffs_acquire_dev(const char *dev_name);
181 static void ffs_release_dev(struct ffs_data *ffs_data);
182 static int ffs_ready(struct ffs_data *ffs);
183 static void ffs_closed(struct ffs_data *ffs);
184
185 /* Misc helper functions ****************************************************/
186
187 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
188 __attribute__((warn_unused_result, nonnull));
189 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
190 __attribute__((warn_unused_result, nonnull));
191
192
193 /* Control file aka ep0 *****************************************************/
194
195 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
196 {
197 struct ffs_data *ffs = req->context;
198
199 complete_all(&ffs->ep0req_completion);
200 }
201
202 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
203 {
204 struct usb_request *req = ffs->ep0req;
205 int ret;
206
207 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
208
209 spin_unlock_irq(&ffs->ev.waitq.lock);
210
211 req->buf = data;
212 req->length = len;
213
214 /*
215 * UDC layer requires to provide a buffer even for ZLP, but should
216 * not use it at all. Let's provide some poisoned pointer to catch
217 * possible bug in the driver.
218 */
219 if (req->buf == NULL)
220 req->buf = (void *)0xDEADBABE;
221
222 reinit_completion(&ffs->ep0req_completion);
223
224 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
225 if (unlikely(ret < 0))
226 return ret;
227
228 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
229 if (unlikely(ret)) {
230 usb_ep_dequeue(ffs->gadget->ep0, req);
231 return -EINTR;
232 }
233
234 ffs->setup_state = FFS_NO_SETUP;
235 return req->status ? req->status : req->actual;
236 }
237
238 static int __ffs_ep0_stall(struct ffs_data *ffs)
239 {
240 if (ffs->ev.can_stall) {
241 pr_vdebug("ep0 stall\n");
242 usb_ep_set_halt(ffs->gadget->ep0);
243 ffs->setup_state = FFS_NO_SETUP;
244 return -EL2HLT;
245 } else {
246 pr_debug("bogus ep0 stall!\n");
247 return -ESRCH;
248 }
249 }
250
251 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
252 size_t len, loff_t *ptr)
253 {
254 struct ffs_data *ffs = file->private_data;
255 ssize_t ret;
256 char *data;
257
258 ENTER();
259
260 /* Fast check if setup was canceled */
261 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
262 return -EIDRM;
263
264 /* Acquire mutex */
265 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
266 if (unlikely(ret < 0))
267 return ret;
268
269 /* Check state */
270 switch (ffs->state) {
271 case FFS_READ_DESCRIPTORS:
272 case FFS_READ_STRINGS:
273 /* Copy data */
274 if (unlikely(len < 16)) {
275 ret = -EINVAL;
276 break;
277 }
278
279 data = ffs_prepare_buffer(buf, len);
280 if (IS_ERR(data)) {
281 ret = PTR_ERR(data);
282 break;
283 }
284
285 /* Handle data */
286 if (ffs->state == FFS_READ_DESCRIPTORS) {
287 pr_info("read descriptors\n");
288 ret = __ffs_data_got_descs(ffs, data, len);
289 if (unlikely(ret < 0))
290 break;
291
292 ffs->state = FFS_READ_STRINGS;
293 ret = len;
294 } else {
295 pr_info("read strings\n");
296 ret = __ffs_data_got_strings(ffs, data, len);
297 if (unlikely(ret < 0))
298 break;
299
300 ret = ffs_epfiles_create(ffs);
301 if (unlikely(ret)) {
302 ffs->state = FFS_CLOSING;
303 break;
304 }
305
306 ffs->state = FFS_ACTIVE;
307 mutex_unlock(&ffs->mutex);
308
309 ret = ffs_ready(ffs);
310 if (unlikely(ret < 0)) {
311 ffs->state = FFS_CLOSING;
312 return ret;
313 }
314
315 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
316 return len;
317 }
318 break;
319
320 case FFS_ACTIVE:
321 data = NULL;
322 /*
323 * We're called from user space, we can use _irq
324 * rather then _irqsave
325 */
326 spin_lock_irq(&ffs->ev.waitq.lock);
327 switch (ffs_setup_state_clear_cancelled(ffs)) {
328 case FFS_SETUP_CANCELLED:
329 ret = -EIDRM;
330 goto done_spin;
331
332 case FFS_NO_SETUP:
333 ret = -ESRCH;
334 goto done_spin;
335
336 case FFS_SETUP_PENDING:
337 break;
338 }
339
340 /* FFS_SETUP_PENDING */
341 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
342 spin_unlock_irq(&ffs->ev.waitq.lock);
343 ret = __ffs_ep0_stall(ffs);
344 break;
345 }
346
347 /* FFS_SETUP_PENDING and not stall */
348 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
349
350 spin_unlock_irq(&ffs->ev.waitq.lock);
351
352 data = ffs_prepare_buffer(buf, len);
353 if (IS_ERR(data)) {
354 ret = PTR_ERR(data);
355 break;
356 }
357
358 spin_lock_irq(&ffs->ev.waitq.lock);
359
360 /*
361 * We are guaranteed to be still in FFS_ACTIVE state
362 * but the state of setup could have changed from
363 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
364 * to check for that. If that happened we copied data
365 * from user space in vain but it's unlikely.
366 *
367 * For sure we are not in FFS_NO_SETUP since this is
368 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
369 * transition can be performed and it's protected by
370 * mutex.
371 */
372 if (ffs_setup_state_clear_cancelled(ffs) ==
373 FFS_SETUP_CANCELLED) {
374 ret = -EIDRM;
375 done_spin:
376 spin_unlock_irq(&ffs->ev.waitq.lock);
377 } else {
378 /* unlocks spinlock */
379 ret = __ffs_ep0_queue_wait(ffs, data, len);
380 }
381 kfree(data);
382 break;
383
384 default:
385 ret = -EBADFD;
386 break;
387 }
388
389 mutex_unlock(&ffs->mutex);
390 return ret;
391 }
392
393 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
394 size_t n)
395 {
396 /*
397 * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
398 * to release them.
399 */
400 struct usb_functionfs_event events[n];
401 unsigned i = 0;
402
403 memset(events, 0, sizeof events);
404
405 do {
406 events[i].type = ffs->ev.types[i];
407 if (events[i].type == FUNCTIONFS_SETUP) {
408 events[i].u.setup = ffs->ev.setup;
409 ffs->setup_state = FFS_SETUP_PENDING;
410 }
411 } while (++i < n);
412
413 if (n < ffs->ev.count) {
414 ffs->ev.count -= n;
415 memmove(ffs->ev.types, ffs->ev.types + n,
416 ffs->ev.count * sizeof *ffs->ev.types);
417 } else {
418 ffs->ev.count = 0;
419 }
420
421 spin_unlock_irq(&ffs->ev.waitq.lock);
422 mutex_unlock(&ffs->mutex);
423
424 return unlikely(__copy_to_user(buf, events, sizeof events))
425 ? -EFAULT : sizeof events;
426 }
427
428 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
429 size_t len, loff_t *ptr)
430 {
431 struct ffs_data *ffs = file->private_data;
432 char *data = NULL;
433 size_t n;
434 int ret;
435
436 ENTER();
437
438 /* Fast check if setup was canceled */
439 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
440 return -EIDRM;
441
442 /* Acquire mutex */
443 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
444 if (unlikely(ret < 0))
445 return ret;
446
447 /* Check state */
448 if (ffs->state != FFS_ACTIVE) {
449 ret = -EBADFD;
450 goto done_mutex;
451 }
452
453 /*
454 * We're called from user space, we can use _irq rather then
455 * _irqsave
456 */
457 spin_lock_irq(&ffs->ev.waitq.lock);
458
459 switch (ffs_setup_state_clear_cancelled(ffs)) {
460 case FFS_SETUP_CANCELLED:
461 ret = -EIDRM;
462 break;
463
464 case FFS_NO_SETUP:
465 n = len / sizeof(struct usb_functionfs_event);
466 if (unlikely(!n)) {
467 ret = -EINVAL;
468 break;
469 }
470
471 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
472 ret = -EAGAIN;
473 break;
474 }
475
476 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
477 ffs->ev.count)) {
478 ret = -EINTR;
479 break;
480 }
481
482 return __ffs_ep0_read_events(ffs, buf,
483 min(n, (size_t)ffs->ev.count));
484
485 case FFS_SETUP_PENDING:
486 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
487 spin_unlock_irq(&ffs->ev.waitq.lock);
488 ret = __ffs_ep0_stall(ffs);
489 goto done_mutex;
490 }
491
492 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
493
494 spin_unlock_irq(&ffs->ev.waitq.lock);
495
496 if (likely(len)) {
497 data = kmalloc(len, GFP_KERNEL);
498 if (unlikely(!data)) {
499 ret = -ENOMEM;
500 goto done_mutex;
501 }
502 }
503
504 spin_lock_irq(&ffs->ev.waitq.lock);
505
506 /* See ffs_ep0_write() */
507 if (ffs_setup_state_clear_cancelled(ffs) ==
508 FFS_SETUP_CANCELLED) {
509 ret = -EIDRM;
510 break;
511 }
512
513 /* unlocks spinlock */
514 ret = __ffs_ep0_queue_wait(ffs, data, len);
515 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
516 ret = -EFAULT;
517 goto done_mutex;
518
519 default:
520 ret = -EBADFD;
521 break;
522 }
523
524 spin_unlock_irq(&ffs->ev.waitq.lock);
525 done_mutex:
526 mutex_unlock(&ffs->mutex);
527 kfree(data);
528 return ret;
529 }
530
531 static int ffs_ep0_open(struct inode *inode, struct file *file)
532 {
533 struct ffs_data *ffs = inode->i_private;
534
535 ENTER();
536
537 if (unlikely(ffs->state == FFS_CLOSING))
538 return -EBUSY;
539
540 file->private_data = ffs;
541 ffs_data_opened(ffs);
542
543 return 0;
544 }
545
546 static int ffs_ep0_release(struct inode *inode, struct file *file)
547 {
548 struct ffs_data *ffs = file->private_data;
549
550 ENTER();
551
552 ffs_data_closed(ffs);
553
554 return 0;
555 }
556
557 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
558 {
559 struct ffs_data *ffs = file->private_data;
560 struct usb_gadget *gadget = ffs->gadget;
561 long ret;
562
563 ENTER();
564
565 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
566 struct ffs_function *func = ffs->func;
567 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
568 } else if (gadget && gadget->ops->ioctl) {
569 ret = gadget->ops->ioctl(gadget, code, value);
570 } else {
571 ret = -ENOTTY;
572 }
573
574 return ret;
575 }
576
577 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
578 {
579 struct ffs_data *ffs = file->private_data;
580 unsigned int mask = POLLWRNORM;
581 int ret;
582
583 poll_wait(file, &ffs->ev.waitq, wait);
584
585 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
586 if (unlikely(ret < 0))
587 return mask;
588
589 switch (ffs->state) {
590 case FFS_READ_DESCRIPTORS:
591 case FFS_READ_STRINGS:
592 mask |= POLLOUT;
593 break;
594
595 case FFS_ACTIVE:
596 switch (ffs->setup_state) {
597 case FFS_NO_SETUP:
598 if (ffs->ev.count)
599 mask |= POLLIN;
600 break;
601
602 case FFS_SETUP_PENDING:
603 case FFS_SETUP_CANCELLED:
604 mask |= (POLLIN | POLLOUT);
605 break;
606 }
607 case FFS_CLOSING:
608 break;
609 }
610
611 mutex_unlock(&ffs->mutex);
612
613 return mask;
614 }
615
616 static const struct file_operations ffs_ep0_operations = {
617 .llseek = no_llseek,
618
619 .open = ffs_ep0_open,
620 .write = ffs_ep0_write,
621 .read = ffs_ep0_read,
622 .release = ffs_ep0_release,
623 .unlocked_ioctl = ffs_ep0_ioctl,
624 .poll = ffs_ep0_poll,
625 };
626
627
628 /* "Normal" endpoints operations ********************************************/
629
630 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
631 {
632 ENTER();
633 if (likely(req->context)) {
634 struct ffs_ep *ep = _ep->driver_data;
635 ep->status = req->status ? req->status : req->actual;
636 complete(req->context);
637 }
638 }
639
640 static void ffs_user_copy_worker(struct work_struct *work)
641 {
642 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
643 work);
644 int ret = io_data->req->status ? io_data->req->status :
645 io_data->req->actual;
646
647 if (io_data->read && ret > 0) {
648 int i;
649 size_t pos = 0;
650
651 /*
652 * Since req->length may be bigger than io_data->len (after
653 * being rounded up to maxpacketsize), we may end up with more
654 * data then user space has space for.
655 */
656 ret = min_t(int, ret, io_data->len);
657
658 use_mm(io_data->mm);
659 for (i = 0; i < io_data->nr_segs; i++) {
660 size_t len = min_t(size_t, ret - pos,
661 io_data->iovec[i].iov_len);
662 if (!len)
663 break;
664 if (unlikely(copy_to_user(io_data->iovec[i].iov_base,
665 &io_data->buf[pos], len))) {
666 ret = -EFAULT;
667 break;
668 }
669 pos += len;
670 }
671 unuse_mm(io_data->mm);
672 }
673
674 aio_complete(io_data->kiocb, ret, ret);
675
676 usb_ep_free_request(io_data->ep, io_data->req);
677
678 io_data->kiocb->private = NULL;
679 if (io_data->read)
680 kfree(io_data->iovec);
681 kfree(io_data->buf);
682 kfree(io_data);
683 }
684
685 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
686 struct usb_request *req)
687 {
688 struct ffs_io_data *io_data = req->context;
689
690 ENTER();
691
692 INIT_WORK(&io_data->work, ffs_user_copy_worker);
693 schedule_work(&io_data->work);
694 }
695
696 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
697 {
698 struct ffs_epfile *epfile = file->private_data;
699 struct ffs_ep *ep;
700 char *data = NULL;
701 ssize_t ret, data_len = -EINVAL;
702 int halt;
703
704 /* Are we still active? */
705 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
706 ret = -ENODEV;
707 goto error;
708 }
709
710 /* Wait for endpoint to be enabled */
711 ep = epfile->ep;
712 if (!ep) {
713 if (file->f_flags & O_NONBLOCK) {
714 ret = -EAGAIN;
715 goto error;
716 }
717
718 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
719 if (ret) {
720 ret = -EINTR;
721 goto error;
722 }
723 }
724
725 /* Do we halt? */
726 halt = (!io_data->read == !epfile->in);
727 if (halt && epfile->isoc) {
728 ret = -EINVAL;
729 goto error;
730 }
731
732 /* Allocate & copy */
733 if (!halt) {
734 /*
735 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
736 * before the waiting completes, so do not assign to 'gadget' earlier
737 */
738 struct usb_gadget *gadget = epfile->ffs->gadget;
739
740 spin_lock_irq(&epfile->ffs->eps_lock);
741 /* In the meantime, endpoint got disabled or changed. */
742 if (epfile->ep != ep) {
743 spin_unlock_irq(&epfile->ffs->eps_lock);
744 return -ESHUTDOWN;
745 }
746 /*
747 * Controller may require buffer size to be aligned to
748 * maxpacketsize of an out endpoint.
749 */
750 data_len = io_data->read ?
751 usb_ep_align_maybe(gadget, ep->ep, io_data->len) :
752 io_data->len;
753 spin_unlock_irq(&epfile->ffs->eps_lock);
754
755 data = kmalloc(data_len, GFP_KERNEL);
756 if (unlikely(!data))
757 return -ENOMEM;
758 if (io_data->aio && !io_data->read) {
759 int i;
760 size_t pos = 0;
761 for (i = 0; i < io_data->nr_segs; i++) {
762 if (unlikely(copy_from_user(&data[pos],
763 io_data->iovec[i].iov_base,
764 io_data->iovec[i].iov_len))) {
765 ret = -EFAULT;
766 goto error;
767 }
768 pos += io_data->iovec[i].iov_len;
769 }
770 } else {
771 if (!io_data->read &&
772 unlikely(__copy_from_user(data, io_data->buf,
773 io_data->len))) {
774 ret = -EFAULT;
775 goto error;
776 }
777 }
778 }
779
780 /* We will be using request */
781 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
782 if (unlikely(ret))
783 goto error;
784
785 spin_lock_irq(&epfile->ffs->eps_lock);
786
787 if (epfile->ep != ep) {
788 /* In the meantime, endpoint got disabled or changed. */
789 ret = -ESHUTDOWN;
790 spin_unlock_irq(&epfile->ffs->eps_lock);
791 } else if (halt) {
792 /* Halt */
793 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
794 usb_ep_set_halt(ep->ep);
795 spin_unlock_irq(&epfile->ffs->eps_lock);
796 ret = -EBADMSG;
797 } else {
798 /* Fire the request */
799 struct usb_request *req;
800
801 /*
802 * Sanity Check: even though data_len can't be used
803 * uninitialized at the time I write this comment, some
804 * compilers complain about this situation.
805 * In order to keep the code clean from warnings, data_len is
806 * being initialized to -EINVAL during its declaration, which
807 * means we can't rely on compiler anymore to warn no future
808 * changes won't result in data_len being used uninitialized.
809 * For such reason, we're adding this redundant sanity check
810 * here.
811 */
812 if (unlikely(data_len == -EINVAL)) {
813 WARN(1, "%s: data_len == -EINVAL\n", __func__);
814 ret = -EINVAL;
815 goto error_lock;
816 }
817
818 if (io_data->aio) {
819 req = usb_ep_alloc_request(ep->ep, GFP_KERNEL);
820 if (unlikely(!req))
821 goto error_lock;
822
823 req->buf = data;
824 req->length = data_len;
825
826 io_data->buf = data;
827 io_data->ep = ep->ep;
828 io_data->req = req;
829
830 req->context = io_data;
831 req->complete = ffs_epfile_async_io_complete;
832
833 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
834 if (unlikely(ret)) {
835 usb_ep_free_request(ep->ep, req);
836 goto error_lock;
837 }
838 ret = -EIOCBQUEUED;
839
840 spin_unlock_irq(&epfile->ffs->eps_lock);
841 } else {
842 DECLARE_COMPLETION_ONSTACK(done);
843
844 req = ep->req;
845 req->buf = data;
846 req->length = data_len;
847
848 req->context = &done;
849 req->complete = ffs_epfile_io_complete;
850
851 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
852
853 spin_unlock_irq(&epfile->ffs->eps_lock);
854
855 if (unlikely(ret < 0)) {
856 /* nop */
857 } else if (unlikely(
858 wait_for_completion_interruptible(&done))) {
859 ret = -EINTR;
860 usb_ep_dequeue(ep->ep, req);
861 } else {
862 /*
863 * XXX We may end up silently droping data
864 * here. Since data_len (i.e. req->length) may
865 * be bigger than len (after being rounded up
866 * to maxpacketsize), we may end up with more
867 * data then user space has space for.
868 */
869 ret = ep->status;
870 if (io_data->read && ret > 0) {
871 ret = min_t(size_t, ret, io_data->len);
872
873 if (unlikely(copy_to_user(io_data->buf,
874 data, ret)))
875 ret = -EFAULT;
876 }
877 }
878 kfree(data);
879 }
880 }
881
882 mutex_unlock(&epfile->mutex);
883 return ret;
884
885 error_lock:
886 spin_unlock_irq(&epfile->ffs->eps_lock);
887 mutex_unlock(&epfile->mutex);
888 error:
889 kfree(data);
890 return ret;
891 }
892
893 static ssize_t
894 ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
895 loff_t *ptr)
896 {
897 struct ffs_io_data io_data;
898
899 ENTER();
900
901 io_data.aio = false;
902 io_data.read = false;
903 io_data.buf = (char * __user)buf;
904 io_data.len = len;
905
906 return ffs_epfile_io(file, &io_data);
907 }
908
909 static ssize_t
910 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
911 {
912 struct ffs_io_data io_data;
913
914 ENTER();
915
916 io_data.aio = false;
917 io_data.read = true;
918 io_data.buf = buf;
919 io_data.len = len;
920
921 return ffs_epfile_io(file, &io_data);
922 }
923
924 static int
925 ffs_epfile_open(struct inode *inode, struct file *file)
926 {
927 struct ffs_epfile *epfile = inode->i_private;
928
929 ENTER();
930
931 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
932 return -ENODEV;
933
934 file->private_data = epfile;
935 ffs_data_opened(epfile->ffs);
936
937 return 0;
938 }
939
940 static int ffs_aio_cancel(struct kiocb *kiocb)
941 {
942 struct ffs_io_data *io_data = kiocb->private;
943 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
944 int value;
945
946 ENTER();
947
948 spin_lock_irq(&epfile->ffs->eps_lock);
949
950 if (likely(io_data && io_data->ep && io_data->req))
951 value = usb_ep_dequeue(io_data->ep, io_data->req);
952 else
953 value = -EINVAL;
954
955 spin_unlock_irq(&epfile->ffs->eps_lock);
956
957 return value;
958 }
959
960 static ssize_t ffs_epfile_aio_write(struct kiocb *kiocb,
961 const struct iovec *iovec,
962 unsigned long nr_segs, loff_t loff)
963 {
964 struct ffs_io_data *io_data;
965
966 ENTER();
967
968 io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
969 if (unlikely(!io_data))
970 return -ENOMEM;
971
972 io_data->aio = true;
973 io_data->read = false;
974 io_data->kiocb = kiocb;
975 io_data->iovec = iovec;
976 io_data->nr_segs = nr_segs;
977 io_data->len = kiocb->ki_nbytes;
978 io_data->mm = current->mm;
979
980 kiocb->private = io_data;
981
982 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
983
984 return ffs_epfile_io(kiocb->ki_filp, io_data);
985 }
986
987 static ssize_t ffs_epfile_aio_read(struct kiocb *kiocb,
988 const struct iovec *iovec,
989 unsigned long nr_segs, loff_t loff)
990 {
991 struct ffs_io_data *io_data;
992 struct iovec *iovec_copy;
993
994 ENTER();
995
996 iovec_copy = kmalloc_array(nr_segs, sizeof(*iovec_copy), GFP_KERNEL);
997 if (unlikely(!iovec_copy))
998 return -ENOMEM;
999
1000 memcpy(iovec_copy, iovec, sizeof(struct iovec)*nr_segs);
1001
1002 io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
1003 if (unlikely(!io_data)) {
1004 kfree(iovec_copy);
1005 return -ENOMEM;
1006 }
1007
1008 io_data->aio = true;
1009 io_data->read = true;
1010 io_data->kiocb = kiocb;
1011 io_data->iovec = iovec_copy;
1012 io_data->nr_segs = nr_segs;
1013 io_data->len = kiocb->ki_nbytes;
1014 io_data->mm = current->mm;
1015
1016 kiocb->private = io_data;
1017
1018 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1019
1020 return ffs_epfile_io(kiocb->ki_filp, io_data);
1021 }
1022
1023 static int
1024 ffs_epfile_release(struct inode *inode, struct file *file)
1025 {
1026 struct ffs_epfile *epfile = inode->i_private;
1027
1028 ENTER();
1029
1030 ffs_data_closed(epfile->ffs);
1031
1032 return 0;
1033 }
1034
1035 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1036 unsigned long value)
1037 {
1038 struct ffs_epfile *epfile = file->private_data;
1039 int ret;
1040
1041 ENTER();
1042
1043 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1044 return -ENODEV;
1045
1046 spin_lock_irq(&epfile->ffs->eps_lock);
1047 if (likely(epfile->ep)) {
1048 switch (code) {
1049 case FUNCTIONFS_FIFO_STATUS:
1050 ret = usb_ep_fifo_status(epfile->ep->ep);
1051 break;
1052 case FUNCTIONFS_FIFO_FLUSH:
1053 usb_ep_fifo_flush(epfile->ep->ep);
1054 ret = 0;
1055 break;
1056 case FUNCTIONFS_CLEAR_HALT:
1057 ret = usb_ep_clear_halt(epfile->ep->ep);
1058 break;
1059 case FUNCTIONFS_ENDPOINT_REVMAP:
1060 ret = epfile->ep->num;
1061 break;
1062 case FUNCTIONFS_ENDPOINT_DESC:
1063 {
1064 int desc_idx;
1065 struct usb_endpoint_descriptor *desc;
1066
1067 switch (epfile->ffs->gadget->speed) {
1068 case USB_SPEED_SUPER:
1069 desc_idx = 2;
1070 break;
1071 case USB_SPEED_HIGH:
1072 desc_idx = 1;
1073 break;
1074 default:
1075 desc_idx = 0;
1076 }
1077 desc = epfile->ep->descs[desc_idx];
1078
1079 spin_unlock_irq(&epfile->ffs->eps_lock);
1080 ret = copy_to_user((void *)value, desc, sizeof(*desc));
1081 if (ret)
1082 ret = -EFAULT;
1083 return ret;
1084 }
1085 default:
1086 ret = -ENOTTY;
1087 }
1088 } else {
1089 ret = -ENODEV;
1090 }
1091 spin_unlock_irq(&epfile->ffs->eps_lock);
1092
1093 return ret;
1094 }
1095
1096 static const struct file_operations ffs_epfile_operations = {
1097 .llseek = no_llseek,
1098
1099 .open = ffs_epfile_open,
1100 .write = ffs_epfile_write,
1101 .read = ffs_epfile_read,
1102 .aio_write = ffs_epfile_aio_write,
1103 .aio_read = ffs_epfile_aio_read,
1104 .release = ffs_epfile_release,
1105 .unlocked_ioctl = ffs_epfile_ioctl,
1106 };
1107
1108
1109 /* File system and super block operations ***********************************/
1110
1111 /*
1112 * Mounting the file system creates a controller file, used first for
1113 * function configuration then later for event monitoring.
1114 */
1115
1116 static struct inode *__must_check
1117 ffs_sb_make_inode(struct super_block *sb, void *data,
1118 const struct file_operations *fops,
1119 const struct inode_operations *iops,
1120 struct ffs_file_perms *perms)
1121 {
1122 struct inode *inode;
1123
1124 ENTER();
1125
1126 inode = new_inode(sb);
1127
1128 if (likely(inode)) {
1129 struct timespec current_time = CURRENT_TIME;
1130
1131 inode->i_ino = get_next_ino();
1132 inode->i_mode = perms->mode;
1133 inode->i_uid = perms->uid;
1134 inode->i_gid = perms->gid;
1135 inode->i_atime = current_time;
1136 inode->i_mtime = current_time;
1137 inode->i_ctime = current_time;
1138 inode->i_private = data;
1139 if (fops)
1140 inode->i_fop = fops;
1141 if (iops)
1142 inode->i_op = iops;
1143 }
1144
1145 return inode;
1146 }
1147
1148 /* Create "regular" file */
1149 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1150 const char *name, void *data,
1151 const struct file_operations *fops)
1152 {
1153 struct ffs_data *ffs = sb->s_fs_info;
1154 struct dentry *dentry;
1155 struct inode *inode;
1156
1157 ENTER();
1158
1159 dentry = d_alloc_name(sb->s_root, name);
1160 if (unlikely(!dentry))
1161 return NULL;
1162
1163 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1164 if (unlikely(!inode)) {
1165 dput(dentry);
1166 return NULL;
1167 }
1168
1169 d_add(dentry, inode);
1170 return dentry;
1171 }
1172
1173 /* Super block */
1174 static const struct super_operations ffs_sb_operations = {
1175 .statfs = simple_statfs,
1176 .drop_inode = generic_delete_inode,
1177 };
1178
1179 struct ffs_sb_fill_data {
1180 struct ffs_file_perms perms;
1181 umode_t root_mode;
1182 const char *dev_name;
1183 struct ffs_data *ffs_data;
1184 };
1185
1186 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1187 {
1188 struct ffs_sb_fill_data *data = _data;
1189 struct inode *inode;
1190 struct ffs_data *ffs = data->ffs_data;
1191
1192 ENTER();
1193
1194 ffs->sb = sb;
1195 data->ffs_data = NULL;
1196 sb->s_fs_info = ffs;
1197 sb->s_blocksize = PAGE_CACHE_SIZE;
1198 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1199 sb->s_magic = FUNCTIONFS_MAGIC;
1200 sb->s_op = &ffs_sb_operations;
1201 sb->s_time_gran = 1;
1202
1203 /* Root inode */
1204 data->perms.mode = data->root_mode;
1205 inode = ffs_sb_make_inode(sb, NULL,
1206 &simple_dir_operations,
1207 &simple_dir_inode_operations,
1208 &data->perms);
1209 sb->s_root = d_make_root(inode);
1210 if (unlikely(!sb->s_root))
1211 return -ENOMEM;
1212
1213 /* EP0 file */
1214 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1215 &ffs_ep0_operations)))
1216 return -ENOMEM;
1217
1218 return 0;
1219 }
1220
1221 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1222 {
1223 ENTER();
1224
1225 if (!opts || !*opts)
1226 return 0;
1227
1228 for (;;) {
1229 unsigned long value;
1230 char *eq, *comma;
1231
1232 /* Option limit */
1233 comma = strchr(opts, ',');
1234 if (comma)
1235 *comma = 0;
1236
1237 /* Value limit */
1238 eq = strchr(opts, '=');
1239 if (unlikely(!eq)) {
1240 pr_err("'=' missing in %s\n", opts);
1241 return -EINVAL;
1242 }
1243 *eq = 0;
1244
1245 /* Parse value */
1246 if (kstrtoul(eq + 1, 0, &value)) {
1247 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1248 return -EINVAL;
1249 }
1250
1251 /* Interpret option */
1252 switch (eq - opts) {
1253 case 5:
1254 if (!memcmp(opts, "rmode", 5))
1255 data->root_mode = (value & 0555) | S_IFDIR;
1256 else if (!memcmp(opts, "fmode", 5))
1257 data->perms.mode = (value & 0666) | S_IFREG;
1258 else
1259 goto invalid;
1260 break;
1261
1262 case 4:
1263 if (!memcmp(opts, "mode", 4)) {
1264 data->root_mode = (value & 0555) | S_IFDIR;
1265 data->perms.mode = (value & 0666) | S_IFREG;
1266 } else {
1267 goto invalid;
1268 }
1269 break;
1270
1271 case 3:
1272 if (!memcmp(opts, "uid", 3)) {
1273 data->perms.uid = make_kuid(current_user_ns(), value);
1274 if (!uid_valid(data->perms.uid)) {
1275 pr_err("%s: unmapped value: %lu\n", opts, value);
1276 return -EINVAL;
1277 }
1278 } else if (!memcmp(opts, "gid", 3)) {
1279 data->perms.gid = make_kgid(current_user_ns(), value);
1280 if (!gid_valid(data->perms.gid)) {
1281 pr_err("%s: unmapped value: %lu\n", opts, value);
1282 return -EINVAL;
1283 }
1284 } else {
1285 goto invalid;
1286 }
1287 break;
1288
1289 default:
1290 invalid:
1291 pr_err("%s: invalid option\n", opts);
1292 return -EINVAL;
1293 }
1294
1295 /* Next iteration */
1296 if (!comma)
1297 break;
1298 opts = comma + 1;
1299 }
1300
1301 return 0;
1302 }
1303
1304 /* "mount -t functionfs dev_name /dev/function" ends up here */
1305
1306 static struct dentry *
1307 ffs_fs_mount(struct file_system_type *t, int flags,
1308 const char *dev_name, void *opts)
1309 {
1310 struct ffs_sb_fill_data data = {
1311 .perms = {
1312 .mode = S_IFREG | 0600,
1313 .uid = GLOBAL_ROOT_UID,
1314 .gid = GLOBAL_ROOT_GID,
1315 },
1316 .root_mode = S_IFDIR | 0500,
1317 };
1318 struct dentry *rv;
1319 int ret;
1320 void *ffs_dev;
1321 struct ffs_data *ffs;
1322
1323 ENTER();
1324
1325 ret = ffs_fs_parse_opts(&data, opts);
1326 if (unlikely(ret < 0))
1327 return ERR_PTR(ret);
1328
1329 ffs = ffs_data_new();
1330 if (unlikely(!ffs))
1331 return ERR_PTR(-ENOMEM);
1332 ffs->file_perms = data.perms;
1333
1334 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1335 if (unlikely(!ffs->dev_name)) {
1336 ffs_data_put(ffs);
1337 return ERR_PTR(-ENOMEM);
1338 }
1339
1340 ffs_dev = ffs_acquire_dev(dev_name);
1341 if (IS_ERR(ffs_dev)) {
1342 ffs_data_put(ffs);
1343 return ERR_CAST(ffs_dev);
1344 }
1345 ffs->private_data = ffs_dev;
1346 data.ffs_data = ffs;
1347
1348 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1349 if (IS_ERR(rv) && data.ffs_data) {
1350 ffs_release_dev(data.ffs_data);
1351 ffs_data_put(data.ffs_data);
1352 }
1353 return rv;
1354 }
1355
1356 static void
1357 ffs_fs_kill_sb(struct super_block *sb)
1358 {
1359 ENTER();
1360
1361 kill_litter_super(sb);
1362 if (sb->s_fs_info) {
1363 ffs_release_dev(sb->s_fs_info);
1364 ffs_data_put(sb->s_fs_info);
1365 }
1366 }
1367
1368 static struct file_system_type ffs_fs_type = {
1369 .owner = THIS_MODULE,
1370 .name = "functionfs",
1371 .mount = ffs_fs_mount,
1372 .kill_sb = ffs_fs_kill_sb,
1373 };
1374 MODULE_ALIAS_FS("functionfs");
1375
1376
1377 /* Driver's main init/cleanup functions *************************************/
1378
1379 static int functionfs_init(void)
1380 {
1381 int ret;
1382
1383 ENTER();
1384
1385 ret = register_filesystem(&ffs_fs_type);
1386 if (likely(!ret))
1387 pr_info("file system registered\n");
1388 else
1389 pr_err("failed registering file system (%d)\n", ret);
1390
1391 return ret;
1392 }
1393
1394 static void functionfs_cleanup(void)
1395 {
1396 ENTER();
1397
1398 pr_info("unloading\n");
1399 unregister_filesystem(&ffs_fs_type);
1400 }
1401
1402
1403 /* ffs_data and ffs_function construction and destruction code **************/
1404
1405 static void ffs_data_clear(struct ffs_data *ffs);
1406 static void ffs_data_reset(struct ffs_data *ffs);
1407
1408 static void ffs_data_get(struct ffs_data *ffs)
1409 {
1410 ENTER();
1411
1412 atomic_inc(&ffs->ref);
1413 }
1414
1415 static void ffs_data_opened(struct ffs_data *ffs)
1416 {
1417 ENTER();
1418
1419 atomic_inc(&ffs->ref);
1420 atomic_inc(&ffs->opened);
1421 }
1422
1423 static void ffs_data_put(struct ffs_data *ffs)
1424 {
1425 ENTER();
1426
1427 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1428 pr_info("%s(): freeing\n", __func__);
1429 ffs_data_clear(ffs);
1430 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1431 waitqueue_active(&ffs->ep0req_completion.wait));
1432 kfree(ffs->dev_name);
1433 kfree(ffs);
1434 }
1435 }
1436
1437 static void ffs_data_closed(struct ffs_data *ffs)
1438 {
1439 ENTER();
1440
1441 if (atomic_dec_and_test(&ffs->opened)) {
1442 ffs->state = FFS_CLOSING;
1443 ffs_data_reset(ffs);
1444 }
1445
1446 ffs_data_put(ffs);
1447 }
1448
1449 static struct ffs_data *ffs_data_new(void)
1450 {
1451 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1452 if (unlikely(!ffs))
1453 return NULL;
1454
1455 ENTER();
1456
1457 atomic_set(&ffs->ref, 1);
1458 atomic_set(&ffs->opened, 0);
1459 ffs->state = FFS_READ_DESCRIPTORS;
1460 mutex_init(&ffs->mutex);
1461 spin_lock_init(&ffs->eps_lock);
1462 init_waitqueue_head(&ffs->ev.waitq);
1463 init_completion(&ffs->ep0req_completion);
1464
1465 /* XXX REVISIT need to update it in some places, or do we? */
1466 ffs->ev.can_stall = 1;
1467
1468 return ffs;
1469 }
1470
1471 static void ffs_data_clear(struct ffs_data *ffs)
1472 {
1473 ENTER();
1474
1475 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1476 ffs_closed(ffs);
1477
1478 BUG_ON(ffs->gadget);
1479
1480 if (ffs->epfiles)
1481 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1482
1483 kfree(ffs->raw_descs_data);
1484 kfree(ffs->raw_strings);
1485 kfree(ffs->stringtabs);
1486 }
1487
1488 static void ffs_data_reset(struct ffs_data *ffs)
1489 {
1490 ENTER();
1491
1492 ffs_data_clear(ffs);
1493
1494 ffs->epfiles = NULL;
1495 ffs->raw_descs_data = NULL;
1496 ffs->raw_descs = NULL;
1497 ffs->raw_strings = NULL;
1498 ffs->stringtabs = NULL;
1499
1500 ffs->raw_descs_length = 0;
1501 ffs->fs_descs_count = 0;
1502 ffs->hs_descs_count = 0;
1503 ffs->ss_descs_count = 0;
1504
1505 ffs->strings_count = 0;
1506 ffs->interfaces_count = 0;
1507 ffs->eps_count = 0;
1508
1509 ffs->ev.count = 0;
1510
1511 ffs->state = FFS_READ_DESCRIPTORS;
1512 ffs->setup_state = FFS_NO_SETUP;
1513 ffs->flags = 0;
1514 }
1515
1516
1517 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1518 {
1519 struct usb_gadget_strings **lang;
1520 int first_id;
1521
1522 ENTER();
1523
1524 if (WARN_ON(ffs->state != FFS_ACTIVE
1525 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1526 return -EBADFD;
1527
1528 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1529 if (unlikely(first_id < 0))
1530 return first_id;
1531
1532 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1533 if (unlikely(!ffs->ep0req))
1534 return -ENOMEM;
1535 ffs->ep0req->complete = ffs_ep0_complete;
1536 ffs->ep0req->context = ffs;
1537
1538 lang = ffs->stringtabs;
1539 if (lang) {
1540 for (; *lang; ++lang) {
1541 struct usb_string *str = (*lang)->strings;
1542 int id = first_id;
1543 for (; str->s; ++id, ++str)
1544 str->id = id;
1545 }
1546 }
1547
1548 ffs->gadget = cdev->gadget;
1549 ffs_data_get(ffs);
1550 return 0;
1551 }
1552
1553 static void functionfs_unbind(struct ffs_data *ffs)
1554 {
1555 ENTER();
1556
1557 if (!WARN_ON(!ffs->gadget)) {
1558 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1559 ffs->ep0req = NULL;
1560 ffs->gadget = NULL;
1561 clear_bit(FFS_FL_BOUND, &ffs->flags);
1562 ffs_data_put(ffs);
1563 }
1564 }
1565
1566 static int ffs_epfiles_create(struct ffs_data *ffs)
1567 {
1568 struct ffs_epfile *epfile, *epfiles;
1569 unsigned i, count;
1570
1571 ENTER();
1572
1573 count = ffs->eps_count;
1574 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1575 if (!epfiles)
1576 return -ENOMEM;
1577
1578 epfile = epfiles;
1579 for (i = 1; i <= count; ++i, ++epfile) {
1580 epfile->ffs = ffs;
1581 mutex_init(&epfile->mutex);
1582 init_waitqueue_head(&epfile->wait);
1583 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1584 sprintf(epfiles->name, "ep%02x", ffs->eps_addrmap[i]);
1585 else
1586 sprintf(epfiles->name, "ep%u", i);
1587 epfile->dentry = ffs_sb_create_file(ffs->sb, epfiles->name,
1588 epfile,
1589 &ffs_epfile_operations);
1590 if (unlikely(!epfile->dentry)) {
1591 ffs_epfiles_destroy(epfiles, i - 1);
1592 return -ENOMEM;
1593 }
1594 }
1595
1596 ffs->epfiles = epfiles;
1597 return 0;
1598 }
1599
1600 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1601 {
1602 struct ffs_epfile *epfile = epfiles;
1603
1604 ENTER();
1605
1606 for (; count; --count, ++epfile) {
1607 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1608 waitqueue_active(&epfile->wait));
1609 if (epfile->dentry) {
1610 d_delete(epfile->dentry);
1611 dput(epfile->dentry);
1612 epfile->dentry = NULL;
1613 }
1614 }
1615
1616 kfree(epfiles);
1617 }
1618
1619
1620 static void ffs_func_eps_disable(struct ffs_function *func)
1621 {
1622 struct ffs_ep *ep = func->eps;
1623 struct ffs_epfile *epfile = func->ffs->epfiles;
1624 unsigned count = func->ffs->eps_count;
1625 unsigned long flags;
1626
1627 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1628 do {
1629 /* pending requests get nuked */
1630 if (likely(ep->ep))
1631 usb_ep_disable(ep->ep);
1632 epfile->ep = NULL;
1633
1634 ++ep;
1635 ++epfile;
1636 } while (--count);
1637 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1638 }
1639
1640 static int ffs_func_eps_enable(struct ffs_function *func)
1641 {
1642 struct ffs_data *ffs = func->ffs;
1643 struct ffs_ep *ep = func->eps;
1644 struct ffs_epfile *epfile = ffs->epfiles;
1645 unsigned count = ffs->eps_count;
1646 unsigned long flags;
1647 int ret = 0;
1648
1649 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1650 do {
1651 struct usb_endpoint_descriptor *ds;
1652 int desc_idx;
1653
1654 if (ffs->gadget->speed == USB_SPEED_SUPER)
1655 desc_idx = 2;
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 ret = usb_ep_enable(ep->ep);
1674 if (likely(!ret)) {
1675 epfile->ep = ep;
1676 epfile->in = usb_endpoint_dir_in(ds);
1677 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1678 } else {
1679 break;
1680 }
1681
1682 wake_up(&epfile->wait);
1683
1684 ++ep;
1685 ++epfile;
1686 } while (--count);
1687 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1688
1689 return ret;
1690 }
1691
1692
1693 /* Parsing and building descriptors and strings *****************************/
1694
1695 /*
1696 * This validates if data pointed by data is a valid USB descriptor as
1697 * well as record how many interfaces, endpoints and strings are
1698 * required by given configuration. Returns address after the
1699 * descriptor or NULL if data is invalid.
1700 */
1701
1702 enum ffs_entity_type {
1703 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1704 };
1705
1706 enum ffs_os_desc_type {
1707 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1708 };
1709
1710 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1711 u8 *valuep,
1712 struct usb_descriptor_header *desc,
1713 void *priv);
1714
1715 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1716 struct usb_os_desc_header *h, void *data,
1717 unsigned len, void *priv);
1718
1719 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1720 ffs_entity_callback entity,
1721 void *priv)
1722 {
1723 struct usb_descriptor_header *_ds = (void *)data;
1724 u8 length;
1725 int ret;
1726
1727 ENTER();
1728
1729 /* At least two bytes are required: length and type */
1730 if (len < 2) {
1731 pr_vdebug("descriptor too short\n");
1732 return -EINVAL;
1733 }
1734
1735 /* If we have at least as many bytes as the descriptor takes? */
1736 length = _ds->bLength;
1737 if (len < length) {
1738 pr_vdebug("descriptor longer then available data\n");
1739 return -EINVAL;
1740 }
1741
1742 #define __entity_check_INTERFACE(val) 1
1743 #define __entity_check_STRING(val) (val)
1744 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1745 #define __entity(type, val) do { \
1746 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1747 if (unlikely(!__entity_check_ ##type(val))) { \
1748 pr_vdebug("invalid entity's value\n"); \
1749 return -EINVAL; \
1750 } \
1751 ret = entity(FFS_ ##type, &val, _ds, priv); \
1752 if (unlikely(ret < 0)) { \
1753 pr_debug("entity " #type "(%02x); ret = %d\n", \
1754 (val), ret); \
1755 return ret; \
1756 } \
1757 } while (0)
1758
1759 /* Parse descriptor depending on type. */
1760 switch (_ds->bDescriptorType) {
1761 case USB_DT_DEVICE:
1762 case USB_DT_CONFIG:
1763 case USB_DT_STRING:
1764 case USB_DT_DEVICE_QUALIFIER:
1765 /* function can't have any of those */
1766 pr_vdebug("descriptor reserved for gadget: %d\n",
1767 _ds->bDescriptorType);
1768 return -EINVAL;
1769
1770 case USB_DT_INTERFACE: {
1771 struct usb_interface_descriptor *ds = (void *)_ds;
1772 pr_vdebug("interface descriptor\n");
1773 if (length != sizeof *ds)
1774 goto inv_length;
1775
1776 __entity(INTERFACE, ds->bInterfaceNumber);
1777 if (ds->iInterface)
1778 __entity(STRING, ds->iInterface);
1779 }
1780 break;
1781
1782 case USB_DT_ENDPOINT: {
1783 struct usb_endpoint_descriptor *ds = (void *)_ds;
1784 pr_vdebug("endpoint descriptor\n");
1785 if (length != USB_DT_ENDPOINT_SIZE &&
1786 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1787 goto inv_length;
1788 __entity(ENDPOINT, ds->bEndpointAddress);
1789 }
1790 break;
1791
1792 case HID_DT_HID:
1793 pr_vdebug("hid descriptor\n");
1794 if (length != sizeof(struct hid_descriptor))
1795 goto inv_length;
1796 break;
1797
1798 case USB_DT_OTG:
1799 if (length != sizeof(struct usb_otg_descriptor))
1800 goto inv_length;
1801 break;
1802
1803 case USB_DT_INTERFACE_ASSOCIATION: {
1804 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1805 pr_vdebug("interface association descriptor\n");
1806 if (length != sizeof *ds)
1807 goto inv_length;
1808 if (ds->iFunction)
1809 __entity(STRING, ds->iFunction);
1810 }
1811 break;
1812
1813 case USB_DT_SS_ENDPOINT_COMP:
1814 pr_vdebug("EP SS companion descriptor\n");
1815 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1816 goto inv_length;
1817 break;
1818
1819 case USB_DT_OTHER_SPEED_CONFIG:
1820 case USB_DT_INTERFACE_POWER:
1821 case USB_DT_DEBUG:
1822 case USB_DT_SECURITY:
1823 case USB_DT_CS_RADIO_CONTROL:
1824 /* TODO */
1825 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1826 return -EINVAL;
1827
1828 default:
1829 /* We should never be here */
1830 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1831 return -EINVAL;
1832
1833 inv_length:
1834 pr_vdebug("invalid length: %d (descriptor %d)\n",
1835 _ds->bLength, _ds->bDescriptorType);
1836 return -EINVAL;
1837 }
1838
1839 #undef __entity
1840 #undef __entity_check_DESCRIPTOR
1841 #undef __entity_check_INTERFACE
1842 #undef __entity_check_STRING
1843 #undef __entity_check_ENDPOINT
1844
1845 return length;
1846 }
1847
1848 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1849 ffs_entity_callback entity, void *priv)
1850 {
1851 const unsigned _len = len;
1852 unsigned long num = 0;
1853
1854 ENTER();
1855
1856 for (;;) {
1857 int ret;
1858
1859 if (num == count)
1860 data = NULL;
1861
1862 /* Record "descriptor" entity */
1863 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1864 if (unlikely(ret < 0)) {
1865 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1866 num, ret);
1867 return ret;
1868 }
1869
1870 if (!data)
1871 return _len - len;
1872
1873 ret = ffs_do_single_desc(data, len, entity, priv);
1874 if (unlikely(ret < 0)) {
1875 pr_debug("%s returns %d\n", __func__, ret);
1876 return ret;
1877 }
1878
1879 len -= ret;
1880 data += ret;
1881 ++num;
1882 }
1883 }
1884
1885 static int __ffs_data_do_entity(enum ffs_entity_type type,
1886 u8 *valuep, struct usb_descriptor_header *desc,
1887 void *priv)
1888 {
1889 struct ffs_desc_helper *helper = priv;
1890 struct usb_endpoint_descriptor *d;
1891
1892 ENTER();
1893
1894 switch (type) {
1895 case FFS_DESCRIPTOR:
1896 break;
1897
1898 case FFS_INTERFACE:
1899 /*
1900 * Interfaces are indexed from zero so if we
1901 * encountered interface "n" then there are at least
1902 * "n+1" interfaces.
1903 */
1904 if (*valuep >= helper->interfaces_count)
1905 helper->interfaces_count = *valuep + 1;
1906 break;
1907
1908 case FFS_STRING:
1909 /*
1910 * Strings are indexed from 1 (0 is magic ;) reserved
1911 * for languages list or some such)
1912 */
1913 if (*valuep > helper->ffs->strings_count)
1914 helper->ffs->strings_count = *valuep;
1915 break;
1916
1917 case FFS_ENDPOINT:
1918 d = (void *)desc;
1919 helper->eps_count++;
1920 if (helper->eps_count >= 15)
1921 return -EINVAL;
1922 /* Check if descriptors for any speed were already parsed */
1923 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
1924 helper->ffs->eps_addrmap[helper->eps_count] =
1925 d->bEndpointAddress;
1926 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
1927 d->bEndpointAddress)
1928 return -EINVAL;
1929 break;
1930 }
1931
1932 return 0;
1933 }
1934
1935 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1936 struct usb_os_desc_header *desc)
1937 {
1938 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1939 u16 w_index = le16_to_cpu(desc->wIndex);
1940
1941 if (bcd_version != 1) {
1942 pr_vdebug("unsupported os descriptors version: %d",
1943 bcd_version);
1944 return -EINVAL;
1945 }
1946 switch (w_index) {
1947 case 0x4:
1948 *next_type = FFS_OS_DESC_EXT_COMPAT;
1949 break;
1950 case 0x5:
1951 *next_type = FFS_OS_DESC_EXT_PROP;
1952 break;
1953 default:
1954 pr_vdebug("unsupported os descriptor type: %d", w_index);
1955 return -EINVAL;
1956 }
1957
1958 return sizeof(*desc);
1959 }
1960
1961 /*
1962 * Process all extended compatibility/extended property descriptors
1963 * of a feature descriptor
1964 */
1965 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1966 enum ffs_os_desc_type type,
1967 u16 feature_count,
1968 ffs_os_desc_callback entity,
1969 void *priv,
1970 struct usb_os_desc_header *h)
1971 {
1972 int ret;
1973 const unsigned _len = len;
1974
1975 ENTER();
1976
1977 /* loop over all ext compat/ext prop descriptors */
1978 while (feature_count--) {
1979 ret = entity(type, h, data, len, priv);
1980 if (unlikely(ret < 0)) {
1981 pr_debug("bad OS descriptor, type: %d\n", type);
1982 return ret;
1983 }
1984 data += ret;
1985 len -= ret;
1986 }
1987 return _len - len;
1988 }
1989
1990 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
1991 static int __must_check ffs_do_os_descs(unsigned count,
1992 char *data, unsigned len,
1993 ffs_os_desc_callback entity, void *priv)
1994 {
1995 const unsigned _len = len;
1996 unsigned long num = 0;
1997
1998 ENTER();
1999
2000 for (num = 0; num < count; ++num) {
2001 int ret;
2002 enum ffs_os_desc_type type;
2003 u16 feature_count;
2004 struct usb_os_desc_header *desc = (void *)data;
2005
2006 if (len < sizeof(*desc))
2007 return -EINVAL;
2008
2009 /*
2010 * Record "descriptor" entity.
2011 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2012 * Move the data pointer to the beginning of extended
2013 * compatibilities proper or extended properties proper
2014 * portions of the data
2015 */
2016 if (le32_to_cpu(desc->dwLength) > len)
2017 return -EINVAL;
2018
2019 ret = __ffs_do_os_desc_header(&type, desc);
2020 if (unlikely(ret < 0)) {
2021 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2022 num, ret);
2023 return ret;
2024 }
2025 /*
2026 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2027 */
2028 feature_count = le16_to_cpu(desc->wCount);
2029 if (type == FFS_OS_DESC_EXT_COMPAT &&
2030 (feature_count > 255 || desc->Reserved))
2031 return -EINVAL;
2032 len -= ret;
2033 data += ret;
2034
2035 /*
2036 * Process all function/property descriptors
2037 * of this Feature Descriptor
2038 */
2039 ret = ffs_do_single_os_desc(data, len, type,
2040 feature_count, entity, priv, desc);
2041 if (unlikely(ret < 0)) {
2042 pr_debug("%s returns %d\n", __func__, ret);
2043 return ret;
2044 }
2045
2046 len -= ret;
2047 data += ret;
2048 }
2049 return _len - len;
2050 }
2051
2052 /**
2053 * Validate contents of the buffer from userspace related to OS descriptors.
2054 */
2055 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2056 struct usb_os_desc_header *h, void *data,
2057 unsigned len, void *priv)
2058 {
2059 struct ffs_data *ffs = priv;
2060 u8 length;
2061
2062 ENTER();
2063
2064 switch (type) {
2065 case FFS_OS_DESC_EXT_COMPAT: {
2066 struct usb_ext_compat_desc *d = data;
2067 int i;
2068
2069 if (len < sizeof(*d) ||
2070 d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2071 d->Reserved1)
2072 return -EINVAL;
2073 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2074 if (d->Reserved2[i])
2075 return -EINVAL;
2076
2077 length = sizeof(struct usb_ext_compat_desc);
2078 }
2079 break;
2080 case FFS_OS_DESC_EXT_PROP: {
2081 struct usb_ext_prop_desc *d = data;
2082 u32 type, pdl;
2083 u16 pnl;
2084
2085 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2086 return -EINVAL;
2087 length = le32_to_cpu(d->dwSize);
2088 type = le32_to_cpu(d->dwPropertyDataType);
2089 if (type < USB_EXT_PROP_UNICODE ||
2090 type > USB_EXT_PROP_UNICODE_MULTI) {
2091 pr_vdebug("unsupported os descriptor property type: %d",
2092 type);
2093 return -EINVAL;
2094 }
2095 pnl = le16_to_cpu(d->wPropertyNameLength);
2096 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2097 if (length != 14 + pnl + pdl) {
2098 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2099 length, pnl, pdl, type);
2100 return -EINVAL;
2101 }
2102 ++ffs->ms_os_descs_ext_prop_count;
2103 /* property name reported to the host as "WCHAR"s */
2104 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2105 ffs->ms_os_descs_ext_prop_data_len += pdl;
2106 }
2107 break;
2108 default:
2109 pr_vdebug("unknown descriptor: %d\n", type);
2110 return -EINVAL;
2111 }
2112 return length;
2113 }
2114
2115 static int __ffs_data_got_descs(struct ffs_data *ffs,
2116 char *const _data, size_t len)
2117 {
2118 char *data = _data, *raw_descs;
2119 unsigned os_descs_count = 0, counts[3], flags;
2120 int ret = -EINVAL, i;
2121 struct ffs_desc_helper helper;
2122
2123 ENTER();
2124
2125 if (get_unaligned_le32(data + 4) != len)
2126 goto error;
2127
2128 switch (get_unaligned_le32(data)) {
2129 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2130 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2131 data += 8;
2132 len -= 8;
2133 break;
2134 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2135 flags = get_unaligned_le32(data + 8);
2136 ffs->user_flags = flags;
2137 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2138 FUNCTIONFS_HAS_HS_DESC |
2139 FUNCTIONFS_HAS_SS_DESC |
2140 FUNCTIONFS_HAS_MS_OS_DESC |
2141 FUNCTIONFS_VIRTUAL_ADDR)) {
2142 ret = -ENOSYS;
2143 goto error;
2144 }
2145 data += 12;
2146 len -= 12;
2147 break;
2148 default:
2149 goto error;
2150 }
2151
2152 /* Read fs_count, hs_count and ss_count (if present) */
2153 for (i = 0; i < 3; ++i) {
2154 if (!(flags & (1 << i))) {
2155 counts[i] = 0;
2156 } else if (len < 4) {
2157 goto error;
2158 } else {
2159 counts[i] = get_unaligned_le32(data);
2160 data += 4;
2161 len -= 4;
2162 }
2163 }
2164 if (flags & (1 << i)) {
2165 os_descs_count = get_unaligned_le32(data);
2166 data += 4;
2167 len -= 4;
2168 };
2169
2170 /* Read descriptors */
2171 raw_descs = data;
2172 helper.ffs = ffs;
2173 for (i = 0; i < 3; ++i) {
2174 if (!counts[i])
2175 continue;
2176 helper.interfaces_count = 0;
2177 helper.eps_count = 0;
2178 ret = ffs_do_descs(counts[i], data, len,
2179 __ffs_data_do_entity, &helper);
2180 if (ret < 0)
2181 goto error;
2182 if (!ffs->eps_count && !ffs->interfaces_count) {
2183 ffs->eps_count = helper.eps_count;
2184 ffs->interfaces_count = helper.interfaces_count;
2185 } else {
2186 if (ffs->eps_count != helper.eps_count) {
2187 ret = -EINVAL;
2188 goto error;
2189 }
2190 if (ffs->interfaces_count != helper.interfaces_count) {
2191 ret = -EINVAL;
2192 goto error;
2193 }
2194 }
2195 data += ret;
2196 len -= ret;
2197 }
2198 if (os_descs_count) {
2199 ret = ffs_do_os_descs(os_descs_count, data, len,
2200 __ffs_data_do_os_desc, ffs);
2201 if (ret < 0)
2202 goto error;
2203 data += ret;
2204 len -= ret;
2205 }
2206
2207 if (raw_descs == data || len) {
2208 ret = -EINVAL;
2209 goto error;
2210 }
2211
2212 ffs->raw_descs_data = _data;
2213 ffs->raw_descs = raw_descs;
2214 ffs->raw_descs_length = data - raw_descs;
2215 ffs->fs_descs_count = counts[0];
2216 ffs->hs_descs_count = counts[1];
2217 ffs->ss_descs_count = counts[2];
2218 ffs->ms_os_descs_count = os_descs_count;
2219
2220 return 0;
2221
2222 error:
2223 kfree(_data);
2224 return ret;
2225 }
2226
2227 static int __ffs_data_got_strings(struct ffs_data *ffs,
2228 char *const _data, size_t len)
2229 {
2230 u32 str_count, needed_count, lang_count;
2231 struct usb_gadget_strings **stringtabs, *t;
2232 struct usb_string *strings, *s;
2233 const char *data = _data;
2234
2235 ENTER();
2236
2237 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2238 get_unaligned_le32(data + 4) != len))
2239 goto error;
2240 str_count = get_unaligned_le32(data + 8);
2241 lang_count = get_unaligned_le32(data + 12);
2242
2243 /* if one is zero the other must be zero */
2244 if (unlikely(!str_count != !lang_count))
2245 goto error;
2246
2247 /* Do we have at least as many strings as descriptors need? */
2248 needed_count = ffs->strings_count;
2249 if (unlikely(str_count < needed_count))
2250 goto error;
2251
2252 /*
2253 * If we don't need any strings just return and free all
2254 * memory.
2255 */
2256 if (!needed_count) {
2257 kfree(_data);
2258 return 0;
2259 }
2260
2261 /* Allocate everything in one chunk so there's less maintenance. */
2262 {
2263 unsigned i = 0;
2264 vla_group(d);
2265 vla_item(d, struct usb_gadget_strings *, stringtabs,
2266 lang_count + 1);
2267 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2268 vla_item(d, struct usb_string, strings,
2269 lang_count*(needed_count+1));
2270
2271 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2272
2273 if (unlikely(!vlabuf)) {
2274 kfree(_data);
2275 return -ENOMEM;
2276 }
2277
2278 /* Initialize the VLA pointers */
2279 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2280 t = vla_ptr(vlabuf, d, stringtab);
2281 i = lang_count;
2282 do {
2283 *stringtabs++ = t++;
2284 } while (--i);
2285 *stringtabs = NULL;
2286
2287 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2288 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2289 t = vla_ptr(vlabuf, d, stringtab);
2290 s = vla_ptr(vlabuf, d, strings);
2291 strings = s;
2292 }
2293
2294 /* For each language */
2295 data += 16;
2296 len -= 16;
2297
2298 do { /* lang_count > 0 so we can use do-while */
2299 unsigned needed = needed_count;
2300
2301 if (unlikely(len < 3))
2302 goto error_free;
2303 t->language = get_unaligned_le16(data);
2304 t->strings = s;
2305 ++t;
2306
2307 data += 2;
2308 len -= 2;
2309
2310 /* For each string */
2311 do { /* str_count > 0 so we can use do-while */
2312 size_t length = strnlen(data, len);
2313
2314 if (unlikely(length == len))
2315 goto error_free;
2316
2317 /*
2318 * User may provide more strings then we need,
2319 * if that's the case we simply ignore the
2320 * rest
2321 */
2322 if (likely(needed)) {
2323 /*
2324 * s->id will be set while adding
2325 * function to configuration so for
2326 * now just leave garbage here.
2327 */
2328 s->s = data;
2329 --needed;
2330 ++s;
2331 }
2332
2333 data += length + 1;
2334 len -= length + 1;
2335 } while (--str_count);
2336
2337 s->id = 0; /* terminator */
2338 s->s = NULL;
2339 ++s;
2340
2341 } while (--lang_count);
2342
2343 /* Some garbage left? */
2344 if (unlikely(len))
2345 goto error_free;
2346
2347 /* Done! */
2348 ffs->stringtabs = stringtabs;
2349 ffs->raw_strings = _data;
2350
2351 return 0;
2352
2353 error_free:
2354 kfree(stringtabs);
2355 error:
2356 kfree(_data);
2357 return -EINVAL;
2358 }
2359
2360
2361 /* Events handling and management *******************************************/
2362
2363 static void __ffs_event_add(struct ffs_data *ffs,
2364 enum usb_functionfs_event_type type)
2365 {
2366 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2367 int neg = 0;
2368
2369 /*
2370 * Abort any unhandled setup
2371 *
2372 * We do not need to worry about some cmpxchg() changing value
2373 * of ffs->setup_state without holding the lock because when
2374 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2375 * the source does nothing.
2376 */
2377 if (ffs->setup_state == FFS_SETUP_PENDING)
2378 ffs->setup_state = FFS_SETUP_CANCELLED;
2379
2380 switch (type) {
2381 case FUNCTIONFS_RESUME:
2382 rem_type2 = FUNCTIONFS_SUSPEND;
2383 /* FALL THROUGH */
2384 case FUNCTIONFS_SUSPEND:
2385 case FUNCTIONFS_SETUP:
2386 rem_type1 = type;
2387 /* Discard all similar events */
2388 break;
2389
2390 case FUNCTIONFS_BIND:
2391 case FUNCTIONFS_UNBIND:
2392 case FUNCTIONFS_DISABLE:
2393 case FUNCTIONFS_ENABLE:
2394 /* Discard everything other then power management. */
2395 rem_type1 = FUNCTIONFS_SUSPEND;
2396 rem_type2 = FUNCTIONFS_RESUME;
2397 neg = 1;
2398 break;
2399
2400 default:
2401 WARN(1, "%d: unknown event, this should not happen\n", type);
2402 return;
2403 }
2404
2405 {
2406 u8 *ev = ffs->ev.types, *out = ev;
2407 unsigned n = ffs->ev.count;
2408 for (; n; --n, ++ev)
2409 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2410 *out++ = *ev;
2411 else
2412 pr_vdebug("purging event %d\n", *ev);
2413 ffs->ev.count = out - ffs->ev.types;
2414 }
2415
2416 pr_vdebug("adding event %d\n", type);
2417 ffs->ev.types[ffs->ev.count++] = type;
2418 wake_up_locked(&ffs->ev.waitq);
2419 }
2420
2421 static void ffs_event_add(struct ffs_data *ffs,
2422 enum usb_functionfs_event_type type)
2423 {
2424 unsigned long flags;
2425 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2426 __ffs_event_add(ffs, type);
2427 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2428 }
2429
2430 /* Bind/unbind USB function hooks *******************************************/
2431
2432 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2433 {
2434 int i;
2435
2436 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2437 if (ffs->eps_addrmap[i] == endpoint_address)
2438 return i;
2439 return -ENOENT;
2440 }
2441
2442 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2443 struct usb_descriptor_header *desc,
2444 void *priv)
2445 {
2446 struct usb_endpoint_descriptor *ds = (void *)desc;
2447 struct ffs_function *func = priv;
2448 struct ffs_ep *ffs_ep;
2449 unsigned ep_desc_id;
2450 int idx;
2451 static const char *speed_names[] = { "full", "high", "super" };
2452
2453 if (type != FFS_DESCRIPTOR)
2454 return 0;
2455
2456 /*
2457 * If ss_descriptors is not NULL, we are reading super speed
2458 * descriptors; if hs_descriptors is not NULL, we are reading high
2459 * speed descriptors; otherwise, we are reading full speed
2460 * descriptors.
2461 */
2462 if (func->function.ss_descriptors) {
2463 ep_desc_id = 2;
2464 func->function.ss_descriptors[(long)valuep] = desc;
2465 } else if (func->function.hs_descriptors) {
2466 ep_desc_id = 1;
2467 func->function.hs_descriptors[(long)valuep] = desc;
2468 } else {
2469 ep_desc_id = 0;
2470 func->function.fs_descriptors[(long)valuep] = desc;
2471 }
2472
2473 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2474 return 0;
2475
2476 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2477 if (idx < 0)
2478 return idx;
2479
2480 ffs_ep = func->eps + idx;
2481
2482 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2483 pr_err("two %sspeed descriptors for EP %d\n",
2484 speed_names[ep_desc_id],
2485 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2486 return -EINVAL;
2487 }
2488 ffs_ep->descs[ep_desc_id] = ds;
2489
2490 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2491 if (ffs_ep->ep) {
2492 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2493 if (!ds->wMaxPacketSize)
2494 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2495 } else {
2496 struct usb_request *req;
2497 struct usb_ep *ep;
2498 u8 bEndpointAddress;
2499
2500 /*
2501 * We back up bEndpointAddress because autoconfig overwrites
2502 * it with physical endpoint address.
2503 */
2504 bEndpointAddress = ds->bEndpointAddress;
2505 pr_vdebug("autoconfig\n");
2506 ep = usb_ep_autoconfig(func->gadget, ds);
2507 if (unlikely(!ep))
2508 return -ENOTSUPP;
2509 ep->driver_data = func->eps + idx;
2510
2511 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2512 if (unlikely(!req))
2513 return -ENOMEM;
2514
2515 ffs_ep->ep = ep;
2516 ffs_ep->req = req;
2517 func->eps_revmap[ds->bEndpointAddress &
2518 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2519 /*
2520 * If we use virtual address mapping, we restore
2521 * original bEndpointAddress value.
2522 */
2523 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2524 ds->bEndpointAddress = bEndpointAddress;
2525 }
2526 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2527
2528 return 0;
2529 }
2530
2531 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2532 struct usb_descriptor_header *desc,
2533 void *priv)
2534 {
2535 struct ffs_function *func = priv;
2536 unsigned idx;
2537 u8 newValue;
2538
2539 switch (type) {
2540 default:
2541 case FFS_DESCRIPTOR:
2542 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2543 return 0;
2544
2545 case FFS_INTERFACE:
2546 idx = *valuep;
2547 if (func->interfaces_nums[idx] < 0) {
2548 int id = usb_interface_id(func->conf, &func->function);
2549 if (unlikely(id < 0))
2550 return id;
2551 func->interfaces_nums[idx] = id;
2552 }
2553 newValue = func->interfaces_nums[idx];
2554 break;
2555
2556 case FFS_STRING:
2557 /* String' IDs are allocated when fsf_data is bound to cdev */
2558 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2559 break;
2560
2561 case FFS_ENDPOINT:
2562 /*
2563 * USB_DT_ENDPOINT are handled in
2564 * __ffs_func_bind_do_descs().
2565 */
2566 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2567 return 0;
2568
2569 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2570 if (unlikely(!func->eps[idx].ep))
2571 return -EINVAL;
2572
2573 {
2574 struct usb_endpoint_descriptor **descs;
2575 descs = func->eps[idx].descs;
2576 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2577 }
2578 break;
2579 }
2580
2581 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2582 *valuep = newValue;
2583 return 0;
2584 }
2585
2586 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2587 struct usb_os_desc_header *h, void *data,
2588 unsigned len, void *priv)
2589 {
2590 struct ffs_function *func = priv;
2591 u8 length = 0;
2592
2593 switch (type) {
2594 case FFS_OS_DESC_EXT_COMPAT: {
2595 struct usb_ext_compat_desc *desc = data;
2596 struct usb_os_desc_table *t;
2597
2598 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2599 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2600 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2601 ARRAY_SIZE(desc->CompatibleID) +
2602 ARRAY_SIZE(desc->SubCompatibleID));
2603 length = sizeof(*desc);
2604 }
2605 break;
2606 case FFS_OS_DESC_EXT_PROP: {
2607 struct usb_ext_prop_desc *desc = data;
2608 struct usb_os_desc_table *t;
2609 struct usb_os_desc_ext_prop *ext_prop;
2610 char *ext_prop_name;
2611 char *ext_prop_data;
2612
2613 t = &func->function.os_desc_table[h->interface];
2614 t->if_id = func->interfaces_nums[h->interface];
2615
2616 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2617 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2618
2619 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2620 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2621 ext_prop->data_len = le32_to_cpu(*(u32 *)
2622 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2623 length = ext_prop->name_len + ext_prop->data_len + 14;
2624
2625 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2626 func->ffs->ms_os_descs_ext_prop_name_avail +=
2627 ext_prop->name_len;
2628
2629 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2630 func->ffs->ms_os_descs_ext_prop_data_avail +=
2631 ext_prop->data_len;
2632 memcpy(ext_prop_data,
2633 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2634 ext_prop->data_len);
2635 /* unicode data reported to the host as "WCHAR"s */
2636 switch (ext_prop->type) {
2637 case USB_EXT_PROP_UNICODE:
2638 case USB_EXT_PROP_UNICODE_ENV:
2639 case USB_EXT_PROP_UNICODE_LINK:
2640 case USB_EXT_PROP_UNICODE_MULTI:
2641 ext_prop->data_len *= 2;
2642 break;
2643 }
2644 ext_prop->data = ext_prop_data;
2645
2646 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2647 ext_prop->name_len);
2648 /* property name reported to the host as "WCHAR"s */
2649 ext_prop->name_len *= 2;
2650 ext_prop->name = ext_prop_name;
2651
2652 t->os_desc->ext_prop_len +=
2653 ext_prop->name_len + ext_prop->data_len + 14;
2654 ++t->os_desc->ext_prop_count;
2655 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2656 }
2657 break;
2658 default:
2659 pr_vdebug("unknown descriptor: %d\n", type);
2660 }
2661
2662 return length;
2663 }
2664
2665 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2666 struct usb_configuration *c)
2667 {
2668 struct ffs_function *func = ffs_func_from_usb(f);
2669 struct f_fs_opts *ffs_opts =
2670 container_of(f->fi, struct f_fs_opts, func_inst);
2671 int ret;
2672
2673 ENTER();
2674
2675 /*
2676 * Legacy gadget triggers binding in functionfs_ready_callback,
2677 * which already uses locking; taking the same lock here would
2678 * cause a deadlock.
2679 *
2680 * Configfs-enabled gadgets however do need ffs_dev_lock.
2681 */
2682 if (!ffs_opts->no_configfs)
2683 ffs_dev_lock();
2684 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2685 func->ffs = ffs_opts->dev->ffs_data;
2686 if (!ffs_opts->no_configfs)
2687 ffs_dev_unlock();
2688 if (ret)
2689 return ERR_PTR(ret);
2690
2691 func->conf = c;
2692 func->gadget = c->cdev->gadget;
2693
2694 /*
2695 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2696 * configurations are bound in sequence with list_for_each_entry,
2697 * in each configuration its functions are bound in sequence
2698 * with list_for_each_entry, so we assume no race condition
2699 * with regard to ffs_opts->bound access
2700 */
2701 if (!ffs_opts->refcnt) {
2702 ret = functionfs_bind(func->ffs, c->cdev);
2703 if (ret)
2704 return ERR_PTR(ret);
2705 }
2706 ffs_opts->refcnt++;
2707 func->function.strings = func->ffs->stringtabs;
2708
2709 return ffs_opts;
2710 }
2711
2712 static int _ffs_func_bind(struct usb_configuration *c,
2713 struct usb_function *f)
2714 {
2715 struct ffs_function *func = ffs_func_from_usb(f);
2716 struct ffs_data *ffs = func->ffs;
2717
2718 const int full = !!func->ffs->fs_descs_count;
2719 const int high = gadget_is_dualspeed(func->gadget) &&
2720 func->ffs->hs_descs_count;
2721 const int super = gadget_is_superspeed(func->gadget) &&
2722 func->ffs->ss_descs_count;
2723
2724 int fs_len, hs_len, ss_len, ret, i;
2725
2726 /* Make it a single chunk, less management later on */
2727 vla_group(d);
2728 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2729 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2730 full ? ffs->fs_descs_count + 1 : 0);
2731 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2732 high ? ffs->hs_descs_count + 1 : 0);
2733 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2734 super ? ffs->ss_descs_count + 1 : 0);
2735 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2736 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2737 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2738 vla_item_with_sz(d, char[16], ext_compat,
2739 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2740 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2741 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2742 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2743 ffs->ms_os_descs_ext_prop_count);
2744 vla_item_with_sz(d, char, ext_prop_name,
2745 ffs->ms_os_descs_ext_prop_name_len);
2746 vla_item_with_sz(d, char, ext_prop_data,
2747 ffs->ms_os_descs_ext_prop_data_len);
2748 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2749 char *vlabuf;
2750
2751 ENTER();
2752
2753 /* Has descriptors only for speeds gadget does not support */
2754 if (unlikely(!(full | high | super)))
2755 return -ENOTSUPP;
2756
2757 /* Allocate a single chunk, less management later on */
2758 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2759 if (unlikely(!vlabuf))
2760 return -ENOMEM;
2761
2762 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2763 ffs->ms_os_descs_ext_prop_name_avail =
2764 vla_ptr(vlabuf, d, ext_prop_name);
2765 ffs->ms_os_descs_ext_prop_data_avail =
2766 vla_ptr(vlabuf, d, ext_prop_data);
2767
2768 /* Copy descriptors */
2769 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2770 ffs->raw_descs_length);
2771
2772 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2773 for (ret = ffs->eps_count; ret; --ret) {
2774 struct ffs_ep *ptr;
2775
2776 ptr = vla_ptr(vlabuf, d, eps);
2777 ptr[ret].num = -1;
2778 }
2779
2780 /* Save pointers
2781 * d_eps == vlabuf, func->eps used to kfree vlabuf later
2782 */
2783 func->eps = vla_ptr(vlabuf, d, eps);
2784 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2785
2786 /*
2787 * Go through all the endpoint descriptors and allocate
2788 * endpoints first, so that later we can rewrite the endpoint
2789 * numbers without worrying that it may be described later on.
2790 */
2791 if (likely(full)) {
2792 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2793 fs_len = ffs_do_descs(ffs->fs_descs_count,
2794 vla_ptr(vlabuf, d, raw_descs),
2795 d_raw_descs__sz,
2796 __ffs_func_bind_do_descs, func);
2797 if (unlikely(fs_len < 0)) {
2798 ret = fs_len;
2799 goto error;
2800 }
2801 } else {
2802 fs_len = 0;
2803 }
2804
2805 if (likely(high)) {
2806 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2807 hs_len = ffs_do_descs(ffs->hs_descs_count,
2808 vla_ptr(vlabuf, d, raw_descs) + fs_len,
2809 d_raw_descs__sz - fs_len,
2810 __ffs_func_bind_do_descs, func);
2811 if (unlikely(hs_len < 0)) {
2812 ret = hs_len;
2813 goto error;
2814 }
2815 } else {
2816 hs_len = 0;
2817 }
2818
2819 if (likely(super)) {
2820 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2821 ss_len = ffs_do_descs(ffs->ss_descs_count,
2822 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2823 d_raw_descs__sz - fs_len - hs_len,
2824 __ffs_func_bind_do_descs, func);
2825 if (unlikely(ss_len < 0)) {
2826 ret = ss_len;
2827 goto error;
2828 }
2829 } else {
2830 ss_len = 0;
2831 }
2832
2833 /*
2834 * Now handle interface numbers allocation and interface and
2835 * endpoint numbers rewriting. We can do that in one go
2836 * now.
2837 */
2838 ret = ffs_do_descs(ffs->fs_descs_count +
2839 (high ? ffs->hs_descs_count : 0) +
2840 (super ? ffs->ss_descs_count : 0),
2841 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2842 __ffs_func_bind_do_nums, func);
2843 if (unlikely(ret < 0))
2844 goto error;
2845
2846 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2847 if (c->cdev->use_os_string)
2848 for (i = 0; i < ffs->interfaces_count; ++i) {
2849 struct usb_os_desc *desc;
2850
2851 desc = func->function.os_desc_table[i].os_desc =
2852 vla_ptr(vlabuf, d, os_desc) +
2853 i * sizeof(struct usb_os_desc);
2854 desc->ext_compat_id =
2855 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2856 INIT_LIST_HEAD(&desc->ext_prop);
2857 }
2858 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2859 vla_ptr(vlabuf, d, raw_descs) +
2860 fs_len + hs_len + ss_len,
2861 d_raw_descs__sz - fs_len - hs_len - ss_len,
2862 __ffs_func_bind_do_os_desc, func);
2863 if (unlikely(ret < 0))
2864 goto error;
2865 func->function.os_desc_n =
2866 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2867
2868 /* And we're done */
2869 ffs_event_add(ffs, FUNCTIONFS_BIND);
2870 return 0;
2871
2872 error:
2873 /* XXX Do we need to release all claimed endpoints here? */
2874 return ret;
2875 }
2876
2877 static int ffs_func_bind(struct usb_configuration *c,
2878 struct usb_function *f)
2879 {
2880 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2881
2882 if (IS_ERR(ffs_opts))
2883 return PTR_ERR(ffs_opts);
2884
2885 return _ffs_func_bind(c, f);
2886 }
2887
2888
2889 /* Other USB function hooks *************************************************/
2890
2891 static int ffs_func_set_alt(struct usb_function *f,
2892 unsigned interface, unsigned alt)
2893 {
2894 struct ffs_function *func = ffs_func_from_usb(f);
2895 struct ffs_data *ffs = func->ffs;
2896 int ret = 0, intf;
2897
2898 if (alt != (unsigned)-1) {
2899 intf = ffs_func_revmap_intf(func, interface);
2900 if (unlikely(intf < 0))
2901 return intf;
2902 }
2903
2904 if (ffs->func)
2905 ffs_func_eps_disable(ffs->func);
2906
2907 if (ffs->state != FFS_ACTIVE)
2908 return -ENODEV;
2909
2910 if (alt == (unsigned)-1) {
2911 ffs->func = NULL;
2912 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2913 return 0;
2914 }
2915
2916 ffs->func = func;
2917 ret = ffs_func_eps_enable(func);
2918 if (likely(ret >= 0))
2919 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2920 return ret;
2921 }
2922
2923 static void ffs_func_disable(struct usb_function *f)
2924 {
2925 ffs_func_set_alt(f, 0, (unsigned)-1);
2926 }
2927
2928 static int ffs_func_setup(struct usb_function *f,
2929 const struct usb_ctrlrequest *creq)
2930 {
2931 struct ffs_function *func = ffs_func_from_usb(f);
2932 struct ffs_data *ffs = func->ffs;
2933 unsigned long flags;
2934 int ret;
2935
2936 ENTER();
2937
2938 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2939 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2940 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
2941 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
2942 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
2943
2944 /*
2945 * Most requests directed to interface go through here
2946 * (notable exceptions are set/get interface) so we need to
2947 * handle them. All other either handled by composite or
2948 * passed to usb_configuration->setup() (if one is set). No
2949 * matter, we will handle requests directed to endpoint here
2950 * as well (as it's straightforward) but what to do with any
2951 * other request?
2952 */
2953 if (ffs->state != FFS_ACTIVE)
2954 return -ENODEV;
2955
2956 switch (creq->bRequestType & USB_RECIP_MASK) {
2957 case USB_RECIP_INTERFACE:
2958 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2959 if (unlikely(ret < 0))
2960 return ret;
2961 break;
2962
2963 case USB_RECIP_ENDPOINT:
2964 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2965 if (unlikely(ret < 0))
2966 return ret;
2967 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2968 ret = func->ffs->eps_addrmap[ret];
2969 break;
2970
2971 default:
2972 return -EOPNOTSUPP;
2973 }
2974
2975 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2976 ffs->ev.setup = *creq;
2977 ffs->ev.setup.wIndex = cpu_to_le16(ret);
2978 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2979 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2980
2981 return 0;
2982 }
2983
2984 static void ffs_func_suspend(struct usb_function *f)
2985 {
2986 ENTER();
2987 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2988 }
2989
2990 static void ffs_func_resume(struct usb_function *f)
2991 {
2992 ENTER();
2993 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2994 }
2995
2996
2997 /* Endpoint and interface numbers reverse mapping ***************************/
2998
2999 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3000 {
3001 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3002 return num ? num : -EDOM;
3003 }
3004
3005 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3006 {
3007 short *nums = func->interfaces_nums;
3008 unsigned count = func->ffs->interfaces_count;
3009
3010 for (; count; --count, ++nums) {
3011 if (*nums >= 0 && *nums == intf)
3012 return nums - func->interfaces_nums;
3013 }
3014
3015 return -EDOM;
3016 }
3017
3018
3019 /* Devices management *******************************************************/
3020
3021 static LIST_HEAD(ffs_devices);
3022
3023 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3024 {
3025 struct ffs_dev *dev;
3026
3027 list_for_each_entry(dev, &ffs_devices, entry) {
3028 if (!dev->name || !name)
3029 continue;
3030 if (strcmp(dev->name, name) == 0)
3031 return dev;
3032 }
3033
3034 return NULL;
3035 }
3036
3037 /*
3038 * ffs_lock must be taken by the caller of this function
3039 */
3040 static struct ffs_dev *_ffs_get_single_dev(void)
3041 {
3042 struct ffs_dev *dev;
3043
3044 if (list_is_singular(&ffs_devices)) {
3045 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3046 if (dev->single)
3047 return dev;
3048 }
3049
3050 return NULL;
3051 }
3052
3053 /*
3054 * ffs_lock must be taken by the caller of this function
3055 */
3056 static struct ffs_dev *_ffs_find_dev(const char *name)
3057 {
3058 struct ffs_dev *dev;
3059
3060 dev = _ffs_get_single_dev();
3061 if (dev)
3062 return dev;
3063
3064 return _ffs_do_find_dev(name);
3065 }
3066
3067 /* Configfs support *********************************************************/
3068
3069 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3070 {
3071 return container_of(to_config_group(item), struct f_fs_opts,
3072 func_inst.group);
3073 }
3074
3075 static void ffs_attr_release(struct config_item *item)
3076 {
3077 struct f_fs_opts *opts = to_ffs_opts(item);
3078
3079 usb_put_function_instance(&opts->func_inst);
3080 }
3081
3082 static struct configfs_item_operations ffs_item_ops = {
3083 .release = ffs_attr_release,
3084 };
3085
3086 static struct config_item_type ffs_func_type = {
3087 .ct_item_ops = &ffs_item_ops,
3088 .ct_owner = THIS_MODULE,
3089 };
3090
3091
3092 /* Function registration interface ******************************************/
3093
3094 static void ffs_free_inst(struct usb_function_instance *f)
3095 {
3096 struct f_fs_opts *opts;
3097
3098 opts = to_f_fs_opts(f);
3099 ffs_dev_lock();
3100 _ffs_free_dev(opts->dev);
3101 ffs_dev_unlock();
3102 kfree(opts);
3103 }
3104
3105 #define MAX_INST_NAME_LEN 40
3106
3107 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3108 {
3109 struct f_fs_opts *opts;
3110 char *ptr;
3111 const char *tmp;
3112 int name_len, ret;
3113
3114 name_len = strlen(name) + 1;
3115 if (name_len > MAX_INST_NAME_LEN)
3116 return -ENAMETOOLONG;
3117
3118 ptr = kstrndup(name, name_len, GFP_KERNEL);
3119 if (!ptr)
3120 return -ENOMEM;
3121
3122 opts = to_f_fs_opts(fi);
3123 tmp = NULL;
3124
3125 ffs_dev_lock();
3126
3127 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3128 ret = _ffs_name_dev(opts->dev, ptr);
3129 if (ret) {
3130 kfree(ptr);
3131 ffs_dev_unlock();
3132 return ret;
3133 }
3134 opts->dev->name_allocated = true;
3135
3136 ffs_dev_unlock();
3137
3138 kfree(tmp);
3139
3140 return 0;
3141 }
3142
3143 static struct usb_function_instance *ffs_alloc_inst(void)
3144 {
3145 struct f_fs_opts *opts;
3146 struct ffs_dev *dev;
3147
3148 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3149 if (!opts)
3150 return ERR_PTR(-ENOMEM);
3151
3152 opts->func_inst.set_inst_name = ffs_set_inst_name;
3153 opts->func_inst.free_func_inst = ffs_free_inst;
3154 ffs_dev_lock();
3155 dev = _ffs_alloc_dev();
3156 ffs_dev_unlock();
3157 if (IS_ERR(dev)) {
3158 kfree(opts);
3159 return ERR_CAST(dev);
3160 }
3161 opts->dev = dev;
3162 dev->opts = opts;
3163
3164 config_group_init_type_name(&opts->func_inst.group, "",
3165 &ffs_func_type);
3166 return &opts->func_inst;
3167 }
3168
3169 static void ffs_free(struct usb_function *f)
3170 {
3171 kfree(ffs_func_from_usb(f));
3172 }
3173
3174 static void ffs_func_unbind(struct usb_configuration *c,
3175 struct usb_function *f)
3176 {
3177 struct ffs_function *func = ffs_func_from_usb(f);
3178 struct ffs_data *ffs = func->ffs;
3179 struct f_fs_opts *opts =
3180 container_of(f->fi, struct f_fs_opts, func_inst);
3181 struct ffs_ep *ep = func->eps;
3182 unsigned count = ffs->eps_count;
3183 unsigned long flags;
3184
3185 ENTER();
3186 if (ffs->func == func) {
3187 ffs_func_eps_disable(func);
3188 ffs->func = NULL;
3189 }
3190
3191 if (!--opts->refcnt)
3192 functionfs_unbind(ffs);
3193
3194 /* cleanup after autoconfig */
3195 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3196 do {
3197 if (ep->ep && ep->req)
3198 usb_ep_free_request(ep->ep, ep->req);
3199 ep->req = NULL;
3200 ++ep;
3201 } while (--count);
3202 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3203 kfree(func->eps);
3204 func->eps = NULL;
3205 /*
3206 * eps, descriptors and interfaces_nums are allocated in the
3207 * same chunk so only one free is required.
3208 */
3209 func->function.fs_descriptors = NULL;
3210 func->function.hs_descriptors = NULL;
3211 func->function.ss_descriptors = NULL;
3212 func->interfaces_nums = NULL;
3213
3214 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3215 }
3216
3217 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3218 {
3219 struct ffs_function *func;
3220
3221 ENTER();
3222
3223 func = kzalloc(sizeof(*func), GFP_KERNEL);
3224 if (unlikely(!func))
3225 return ERR_PTR(-ENOMEM);
3226
3227 func->function.name = "Function FS Gadget";
3228
3229 func->function.bind = ffs_func_bind;
3230 func->function.unbind = ffs_func_unbind;
3231 func->function.set_alt = ffs_func_set_alt;
3232 func->function.disable = ffs_func_disable;
3233 func->function.setup = ffs_func_setup;
3234 func->function.suspend = ffs_func_suspend;
3235 func->function.resume = ffs_func_resume;
3236 func->function.free_func = ffs_free;
3237
3238 return &func->function;
3239 }
3240
3241 /*
3242 * ffs_lock must be taken by the caller of this function
3243 */
3244 static struct ffs_dev *_ffs_alloc_dev(void)
3245 {
3246 struct ffs_dev *dev;
3247 int ret;
3248
3249 if (_ffs_get_single_dev())
3250 return ERR_PTR(-EBUSY);
3251
3252 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3253 if (!dev)
3254 return ERR_PTR(-ENOMEM);
3255
3256 if (list_empty(&ffs_devices)) {
3257 ret = functionfs_init();
3258 if (ret) {
3259 kfree(dev);
3260 return ERR_PTR(ret);
3261 }
3262 }
3263
3264 list_add(&dev->entry, &ffs_devices);
3265
3266 return dev;
3267 }
3268
3269 /*
3270 * ffs_lock must be taken by the caller of this function
3271 * The caller is responsible for "name" being available whenever f_fs needs it
3272 */
3273 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3274 {
3275 struct ffs_dev *existing;
3276
3277 existing = _ffs_do_find_dev(name);
3278 if (existing)
3279 return -EBUSY;
3280
3281 dev->name = name;
3282
3283 return 0;
3284 }
3285
3286 /*
3287 * The caller is responsible for "name" being available whenever f_fs needs it
3288 */
3289 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3290 {
3291 int ret;
3292
3293 ffs_dev_lock();
3294 ret = _ffs_name_dev(dev, name);
3295 ffs_dev_unlock();
3296
3297 return ret;
3298 }
3299 EXPORT_SYMBOL_GPL(ffs_name_dev);
3300
3301 int ffs_single_dev(struct ffs_dev *dev)
3302 {
3303 int ret;
3304
3305 ret = 0;
3306 ffs_dev_lock();
3307
3308 if (!list_is_singular(&ffs_devices))
3309 ret = -EBUSY;
3310 else
3311 dev->single = true;
3312
3313 ffs_dev_unlock();
3314 return ret;
3315 }
3316 EXPORT_SYMBOL_GPL(ffs_single_dev);
3317
3318 /*
3319 * ffs_lock must be taken by the caller of this function
3320 */
3321 static void _ffs_free_dev(struct ffs_dev *dev)
3322 {
3323 list_del(&dev->entry);
3324 if (dev->name_allocated)
3325 kfree(dev->name);
3326 kfree(dev);
3327 if (list_empty(&ffs_devices))
3328 functionfs_cleanup();
3329 }
3330
3331 static void *ffs_acquire_dev(const char *dev_name)
3332 {
3333 struct ffs_dev *ffs_dev;
3334
3335 ENTER();
3336 ffs_dev_lock();
3337
3338 ffs_dev = _ffs_find_dev(dev_name);
3339 if (!ffs_dev)
3340 ffs_dev = ERR_PTR(-ENOENT);
3341 else if (ffs_dev->mounted)
3342 ffs_dev = ERR_PTR(-EBUSY);
3343 else if (ffs_dev->ffs_acquire_dev_callback &&
3344 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3345 ffs_dev = ERR_PTR(-ENOENT);
3346 else
3347 ffs_dev->mounted = true;
3348
3349 ffs_dev_unlock();
3350 return ffs_dev;
3351 }
3352
3353 static void ffs_release_dev(struct ffs_data *ffs_data)
3354 {
3355 struct ffs_dev *ffs_dev;
3356
3357 ENTER();
3358 ffs_dev_lock();
3359
3360 ffs_dev = ffs_data->private_data;
3361 if (ffs_dev) {
3362 ffs_dev->mounted = false;
3363
3364 if (ffs_dev->ffs_release_dev_callback)
3365 ffs_dev->ffs_release_dev_callback(ffs_dev);
3366 }
3367
3368 ffs_dev_unlock();
3369 }
3370
3371 static int ffs_ready(struct ffs_data *ffs)
3372 {
3373 struct ffs_dev *ffs_obj;
3374 int ret = 0;
3375
3376 ENTER();
3377 ffs_dev_lock();
3378
3379 ffs_obj = ffs->private_data;
3380 if (!ffs_obj) {
3381 ret = -EINVAL;
3382 goto done;
3383 }
3384 if (WARN_ON(ffs_obj->desc_ready)) {
3385 ret = -EBUSY;
3386 goto done;
3387 }
3388
3389 ffs_obj->desc_ready = true;
3390 ffs_obj->ffs_data = ffs;
3391
3392 if (ffs_obj->ffs_ready_callback)
3393 ret = ffs_obj->ffs_ready_callback(ffs);
3394
3395 done:
3396 ffs_dev_unlock();
3397 return ret;
3398 }
3399
3400 static void ffs_closed(struct ffs_data *ffs)
3401 {
3402 struct ffs_dev *ffs_obj;
3403
3404 ENTER();
3405 ffs_dev_lock();
3406
3407 ffs_obj = ffs->private_data;
3408 if (!ffs_obj)
3409 goto done;
3410
3411 ffs_obj->desc_ready = false;
3412
3413 if (ffs_obj->ffs_closed_callback)
3414 ffs_obj->ffs_closed_callback(ffs);
3415
3416 if (!ffs_obj->opts || ffs_obj->opts->no_configfs
3417 || !ffs_obj->opts->func_inst.group.cg_item.ci_parent)
3418 goto done;
3419
3420 unregister_gadget_item(ffs_obj->opts->
3421 func_inst.group.cg_item.ci_parent->ci_parent);
3422 done:
3423 ffs_dev_unlock();
3424 }
3425
3426 /* Misc helper functions ****************************************************/
3427
3428 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3429 {
3430 return nonblock
3431 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3432 : mutex_lock_interruptible(mutex);
3433 }
3434
3435 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3436 {
3437 char *data;
3438
3439 if (unlikely(!len))
3440 return NULL;
3441
3442 data = kmalloc(len, GFP_KERNEL);
3443 if (unlikely(!data))
3444 return ERR_PTR(-ENOMEM);
3445
3446 if (unlikely(__copy_from_user(data, buf, len))) {
3447 kfree(data);
3448 return ERR_PTR(-EFAULT);
3449 }
3450
3451 pr_vdebug("Buffer from user space:\n");
3452 ffs_dump_mem("", data, len);
3453
3454 return data;
3455 }
3456
3457 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3458 MODULE_LICENSE("GPL");
3459 MODULE_AUTHOR("Michal Nazarewicz");
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