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path: root/drivers/usb/gadget/function/f_fs.c
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Diffstat (limited to 'drivers/usb/gadget/function/f_fs.c')
-rw-r--r--drivers/usb/gadget/function/f_fs.c3349
1 files changed, 3349 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
new file mode 100644
index 000000000000..dc30adf15a01
--- /dev/null
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -0,0 +1,3349 @@
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 */
43static void ffs_data_get(struct ffs_data *ffs);
44static void ffs_data_put(struct ffs_data *ffs);
45/* Creates new ffs_data object. */
46static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
47
48/* Opened counter handling. */
49static void ffs_data_opened(struct ffs_data *ffs);
50static void ffs_data_closed(struct ffs_data *ffs);
51
52/* Called with ffs->mutex held; take over ownership of data. */
53static int __must_check
54__ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
55static int __must_check
56__ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
57
58
59/* The function structure ***************************************************/
60
61struct ffs_ep;
62
63struct 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
76static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
77{
78 return container_of(f, struct ffs_function, function);
79}
80
81
82static inline enum ffs_setup_state
83ffs_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
90static void ffs_func_eps_disable(struct ffs_function *func);
91static int __must_check ffs_func_eps_enable(struct ffs_function *func);
92
93static int ffs_func_bind(struct usb_configuration *,
94 struct usb_function *);
95static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
96static void ffs_func_disable(struct usb_function *);
97static int ffs_func_setup(struct usb_function *,
98 const struct usb_ctrlrequest *);
99static void ffs_func_suspend(struct usb_function *);
100static void ffs_func_resume(struct usb_function *);
101
102
103static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
104static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
105
106
107/* The endpoints structures *************************************************/
108
109struct 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
121struct 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
141struct 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
158static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
159static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
160
161static struct inode *__must_check
162ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
163 const struct file_operations *fops,
164 struct dentry **dentry_p);
165
166/* Devices management *******************************************************/
167
168DEFINE_MUTEX(ffs_lock);
169EXPORT_SYMBOL_GPL(ffs_lock);
170
171static struct ffs_dev *_ffs_find_dev(const char *name);
172static struct ffs_dev *_ffs_alloc_dev(void);
173static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
174static void _ffs_free_dev(struct ffs_dev *dev);
175static void *ffs_acquire_dev(const char *dev_name);
176static void ffs_release_dev(struct ffs_data *ffs_data);
177static int ffs_ready(struct ffs_data *ffs);
178static void ffs_closed(struct ffs_data *ffs);
179
180/* Misc helper functions ****************************************************/
181
182static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
183 __attribute__((warn_unused_result, nonnull));
184static char *ffs_prepare_buffer(const char __user *buf, size_t len)
185 __attribute__((warn_unused_result, nonnull));
186
187
188/* Control file aka ep0 *****************************************************/
189
190static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
191{
192 struct ffs_data *ffs = req->context;
193
194 complete_all(&ffs->ep0req_completion);
195}
196
197static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
198{
199 struct usb_request *req = ffs->ep0req;
200 int ret;
201
202 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
203
204 spin_unlock_irq(&ffs->ev.waitq.lock);
205
206 req->buf = data;
207 req->length = len;
208
209 /*
210 * UDC layer requires to provide a buffer even for ZLP, but should
211 * not use it at all. Let's provide some poisoned pointer to catch
212 * possible bug in the driver.
213 */
214 if (req->buf == NULL)
215 req->buf = (void *)0xDEADBABE;
216
217 reinit_completion(&ffs->ep0req_completion);
218
219 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
220 if (unlikely(ret < 0))
221 return ret;
222
223 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
224 if (unlikely(ret)) {
225 usb_ep_dequeue(ffs->gadget->ep0, req);
226 return -EINTR;
227 }
228
229 ffs->setup_state = FFS_NO_SETUP;
230 return req->status ? req->status : req->actual;
231}
232
233static int __ffs_ep0_stall(struct ffs_data *ffs)
234{
235 if (ffs->ev.can_stall) {
236 pr_vdebug("ep0 stall\n");
237 usb_ep_set_halt(ffs->gadget->ep0);
238 ffs->setup_state = FFS_NO_SETUP;
239 return -EL2HLT;
240 } else {
241 pr_debug("bogus ep0 stall!\n");
242 return -ESRCH;
243 }
244}
245
246static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
247 size_t len, loff_t *ptr)
248{
249 struct ffs_data *ffs = file->private_data;
250 ssize_t ret;
251 char *data;
252
253 ENTER();
254
255 /* Fast check if setup was canceled */
256 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
257 return -EIDRM;
258
259 /* Acquire mutex */
260 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
261 if (unlikely(ret < 0))
262 return ret;
263
264 /* Check state */
265 switch (ffs->state) {
266 case FFS_READ_DESCRIPTORS:
267 case FFS_READ_STRINGS:
268 /* Copy data */
269 if (unlikely(len < 16)) {
270 ret = -EINVAL;
271 break;
272 }
273
274 data = ffs_prepare_buffer(buf, len);
275 if (IS_ERR(data)) {
276 ret = PTR_ERR(data);
277 break;
278 }
279
280 /* Handle data */
281 if (ffs->state == FFS_READ_DESCRIPTORS) {
282 pr_info("read descriptors\n");
283 ret = __ffs_data_got_descs(ffs, data, len);
284 if (unlikely(ret < 0))
285 break;
286
287 ffs->state = FFS_READ_STRINGS;
288 ret = len;
289 } else {
290 pr_info("read strings\n");
291 ret = __ffs_data_got_strings(ffs, data, len);
292 if (unlikely(ret < 0))
293 break;
294
295 ret = ffs_epfiles_create(ffs);
296 if (unlikely(ret)) {
297 ffs->state = FFS_CLOSING;
298 break;
299 }
300
301 ffs->state = FFS_ACTIVE;
302 mutex_unlock(&ffs->mutex);
303
304 ret = ffs_ready(ffs);
305 if (unlikely(ret < 0)) {
306 ffs->state = FFS_CLOSING;
307 return ret;
308 }
309
310 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
311 return len;
312 }
313 break;
314
315 case FFS_ACTIVE:
316 data = NULL;
317 /*
318 * We're called from user space, we can use _irq
319 * rather then _irqsave
320 */
321 spin_lock_irq(&ffs->ev.waitq.lock);
322 switch (ffs_setup_state_clear_cancelled(ffs)) {
323 case FFS_SETUP_CANCELLED:
324 ret = -EIDRM;
325 goto done_spin;
326
327 case FFS_NO_SETUP:
328 ret = -ESRCH;
329 goto done_spin;
330
331 case FFS_SETUP_PENDING:
332 break;
333 }
334
335 /* FFS_SETUP_PENDING */
336 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
337 spin_unlock_irq(&ffs->ev.waitq.lock);
338 ret = __ffs_ep0_stall(ffs);
339 break;
340 }
341
342 /* FFS_SETUP_PENDING and not stall */
343 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
344
345 spin_unlock_irq(&ffs->ev.waitq.lock);
346
347 data = ffs_prepare_buffer(buf, len);
348 if (IS_ERR(data)) {
349 ret = PTR_ERR(data);
350 break;
351 }
352
353 spin_lock_irq(&ffs->ev.waitq.lock);
354
355 /*
356 * We are guaranteed to be still in FFS_ACTIVE state
357 * but the state of setup could have changed from
358 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
359 * to check for that. If that happened we copied data
360 * from user space in vain but it's unlikely.
361 *
362 * For sure we are not in FFS_NO_SETUP since this is
363 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
364 * transition can be performed and it's protected by
365 * mutex.
366 */
367 if (ffs_setup_state_clear_cancelled(ffs) ==
368 FFS_SETUP_CANCELLED) {
369 ret = -EIDRM;
370done_spin:
371 spin_unlock_irq(&ffs->ev.waitq.lock);
372 } else {
373 /* unlocks spinlock */
374 ret = __ffs_ep0_queue_wait(ffs, data, len);
375 }
376 kfree(data);
377 break;
378
379 default:
380 ret = -EBADFD;
381 break;
382 }
383
384 mutex_unlock(&ffs->mutex);
385 return ret;
386}
387
388static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
389 size_t n)
390{
391 /*
392 * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
393 * to release them.
394 */
395 struct usb_functionfs_event events[n];
396 unsigned i = 0;
397
398 memset(events, 0, sizeof events);
399
400 do {
401 events[i].type = ffs->ev.types[i];
402 if (events[i].type == FUNCTIONFS_SETUP) {
403 events[i].u.setup = ffs->ev.setup;
404 ffs->setup_state = FFS_SETUP_PENDING;
405 }
406 } while (++i < n);
407
408 if (n < ffs->ev.count) {
409 ffs->ev.count -= n;
410 memmove(ffs->ev.types, ffs->ev.types + n,
411 ffs->ev.count * sizeof *ffs->ev.types);
412 } else {
413 ffs->ev.count = 0;
414 }
415
416 spin_unlock_irq(&ffs->ev.waitq.lock);
417 mutex_unlock(&ffs->mutex);
418
419 return unlikely(__copy_to_user(buf, events, sizeof events))
420 ? -EFAULT : sizeof events;
421}
422
423static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
424 size_t len, loff_t *ptr)
425{
426 struct ffs_data *ffs = file->private_data;
427 char *data = NULL;
428 size_t n;
429 int ret;
430
431 ENTER();
432
433 /* Fast check if setup was canceled */
434 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
435 return -EIDRM;
436
437 /* Acquire mutex */
438 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
439 if (unlikely(ret < 0))
440 return ret;
441
442 /* Check state */
443 if (ffs->state != FFS_ACTIVE) {
444 ret = -EBADFD;
445 goto done_mutex;
446 }
447
448 /*
449 * We're called from user space, we can use _irq rather then
450 * _irqsave
451 */
452 spin_lock_irq(&ffs->ev.waitq.lock);
453
454 switch (ffs_setup_state_clear_cancelled(ffs)) {
455 case FFS_SETUP_CANCELLED:
456 ret = -EIDRM;
457 break;
458
459 case FFS_NO_SETUP:
460 n = len / sizeof(struct usb_functionfs_event);
461 if (unlikely(!n)) {
462 ret = -EINVAL;
463 break;
464 }
465
466 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
467 ret = -EAGAIN;
468 break;
469 }
470
471 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
472 ffs->ev.count)) {
473 ret = -EINTR;
474 break;
475 }
476
477 return __ffs_ep0_read_events(ffs, buf,
478 min(n, (size_t)ffs->ev.count));
479
480 case FFS_SETUP_PENDING:
481 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
482 spin_unlock_irq(&ffs->ev.waitq.lock);
483 ret = __ffs_ep0_stall(ffs);
484 goto done_mutex;
485 }
486
487 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
488
489 spin_unlock_irq(&ffs->ev.waitq.lock);
490
491 if (likely(len)) {
492 data = kmalloc(len, GFP_KERNEL);
493 if (unlikely(!data)) {
494 ret = -ENOMEM;
495 goto done_mutex;
496 }
497 }
498
499 spin_lock_irq(&ffs->ev.waitq.lock);
500
501 /* See ffs_ep0_write() */
502 if (ffs_setup_state_clear_cancelled(ffs) ==
503 FFS_SETUP_CANCELLED) {
504 ret = -EIDRM;
505 break;
506 }
507
508 /* unlocks spinlock */
509 ret = __ffs_ep0_queue_wait(ffs, data, len);
510 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
511 ret = -EFAULT;
512 goto done_mutex;
513
514 default:
515 ret = -EBADFD;
516 break;
517 }
518
519 spin_unlock_irq(&ffs->ev.waitq.lock);
520done_mutex:
521 mutex_unlock(&ffs->mutex);
522 kfree(data);
523 return ret;
524}
525
526static int ffs_ep0_open(struct inode *inode, struct file *file)
527{
528 struct ffs_data *ffs = inode->i_private;
529
530 ENTER();
531
532 if (unlikely(ffs->state == FFS_CLOSING))
533 return -EBUSY;
534
535 file->private_data = ffs;
536 ffs_data_opened(ffs);
537
538 return 0;
539}
540
541static int ffs_ep0_release(struct inode *inode, struct file *file)
542{
543 struct ffs_data *ffs = file->private_data;
544
545 ENTER();
546
547 ffs_data_closed(ffs);
548
549 return 0;
550}
551
552static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
553{
554 struct ffs_data *ffs = file->private_data;
555 struct usb_gadget *gadget = ffs->gadget;
556 long ret;
557
558 ENTER();
559
560 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
561 struct ffs_function *func = ffs->func;
562 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
563 } else if (gadget && gadget->ops->ioctl) {
564 ret = gadget->ops->ioctl(gadget, code, value);
565 } else {
566 ret = -ENOTTY;
567 }
568
569 return ret;
570}
571
572static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
573{
574 struct ffs_data *ffs = file->private_data;
575 unsigned int mask = POLLWRNORM;
576 int ret;
577
578 poll_wait(file, &ffs->ev.waitq, wait);
579
580 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
581 if (unlikely(ret < 0))
582 return mask;
583
584 switch (ffs->state) {
585 case FFS_READ_DESCRIPTORS:
586 case FFS_READ_STRINGS:
587 mask |= POLLOUT;
588 break;
589
590 case FFS_ACTIVE:
591 switch (ffs->setup_state) {
592 case FFS_NO_SETUP:
593 if (ffs->ev.count)
594 mask |= POLLIN;
595 break;
596
597 case FFS_SETUP_PENDING:
598 case FFS_SETUP_CANCELLED:
599 mask |= (POLLIN | POLLOUT);
600 break;
601 }
602 case FFS_CLOSING:
603 break;
604 }
605
606 mutex_unlock(&ffs->mutex);
607
608 return mask;
609}
610
611static const struct file_operations ffs_ep0_operations = {
612 .llseek = no_llseek,
613
614 .open = ffs_ep0_open,
615 .write = ffs_ep0_write,
616 .read = ffs_ep0_read,
617 .release = ffs_ep0_release,
618 .unlocked_ioctl = ffs_ep0_ioctl,
619 .poll = ffs_ep0_poll,
620};
621
622
623/* "Normal" endpoints operations ********************************************/
624
625static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
626{
627 ENTER();
628 if (likely(req->context)) {
629 struct ffs_ep *ep = _ep->driver_data;
630 ep->status = req->status ? req->status : req->actual;
631 complete(req->context);
632 }
633}
634
635static void ffs_user_copy_worker(struct work_struct *work)
636{
637 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
638 work);
639 int ret = io_data->req->status ? io_data->req->status :
640 io_data->req->actual;
641
642 if (io_data->read && ret > 0) {
643 int i;
644 size_t pos = 0;
645 use_mm(io_data->mm);
646 for (i = 0; i < io_data->nr_segs; i++) {
647 if (unlikely(copy_to_user(io_data->iovec[i].iov_base,
648 &io_data->buf[pos],
649 io_data->iovec[i].iov_len))) {
650 ret = -EFAULT;
651 break;
652 }
653 pos += io_data->iovec[i].iov_len;
654 }
655 unuse_mm(io_data->mm);
656 }
657
658 aio_complete(io_data->kiocb, ret, ret);
659
660 usb_ep_free_request(io_data->ep, io_data->req);
661
662 io_data->kiocb->private = NULL;
663 if (io_data->read)
664 kfree(io_data->iovec);
665 kfree(io_data->buf);
666 kfree(io_data);
667}
668
669static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
670 struct usb_request *req)
671{
672 struct ffs_io_data *io_data = req->context;
673
674 ENTER();
675
676 INIT_WORK(&io_data->work, ffs_user_copy_worker);
677 schedule_work(&io_data->work);
678}
679
680static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
681{
682 struct ffs_epfile *epfile = file->private_data;
683 struct ffs_ep *ep;
684 char *data = NULL;
685 ssize_t ret, data_len;
686 int halt;
687
688 /* Are we still active? */
689 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
690 ret = -ENODEV;
691 goto error;
692 }
693
694 /* Wait for endpoint to be enabled */
695 ep = epfile->ep;
696 if (!ep) {
697 if (file->f_flags & O_NONBLOCK) {
698 ret = -EAGAIN;
699 goto error;
700 }
701
702 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
703 if (ret) {
704 ret = -EINTR;
705 goto error;
706 }
707 }
708
709 /* Do we halt? */
710 halt = (!io_data->read == !epfile->in);
711 if (halt && epfile->isoc) {
712 ret = -EINVAL;
713 goto error;
714 }
715
716 /* Allocate & copy */
717 if (!halt) {
718 /*
719 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
720 * before the waiting completes, so do not assign to 'gadget' earlier
721 */
722 struct usb_gadget *gadget = epfile->ffs->gadget;
723
724 spin_lock_irq(&epfile->ffs->eps_lock);
725 /* In the meantime, endpoint got disabled or changed. */
726 if (epfile->ep != ep) {
727 spin_unlock_irq(&epfile->ffs->eps_lock);
728 return -ESHUTDOWN;
729 }
730 /*
731 * Controller may require buffer size to be aligned to
732 * maxpacketsize of an out endpoint.
733 */
734 data_len = io_data->read ?
735 usb_ep_align_maybe(gadget, ep->ep, io_data->len) :
736 io_data->len;
737 spin_unlock_irq(&epfile->ffs->eps_lock);
738
739 data = kmalloc(data_len, GFP_KERNEL);
740 if (unlikely(!data))
741 return -ENOMEM;
742 if (io_data->aio && !io_data->read) {
743 int i;
744 size_t pos = 0;
745 for (i = 0; i < io_data->nr_segs; i++) {
746 if (unlikely(copy_from_user(&data[pos],
747 io_data->iovec[i].iov_base,
748 io_data->iovec[i].iov_len))) {
749 ret = -EFAULT;
750 goto error;
751 }
752 pos += io_data->iovec[i].iov_len;
753 }
754 } else {
755 if (!io_data->read &&
756 unlikely(__copy_from_user(data, io_data->buf,
757 io_data->len))) {
758 ret = -EFAULT;
759 goto error;
760 }
761 }
762 }
763
764 /* We will be using request */
765 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
766 if (unlikely(ret))
767 goto error;
768
769 spin_lock_irq(&epfile->ffs->eps_lock);
770
771 if (epfile->ep != ep) {
772 /* In the meantime, endpoint got disabled or changed. */
773 ret = -ESHUTDOWN;
774 spin_unlock_irq(&epfile->ffs->eps_lock);
775 } else if (halt) {
776 /* Halt */
777 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
778 usb_ep_set_halt(ep->ep);
779 spin_unlock_irq(&epfile->ffs->eps_lock);
780 ret = -EBADMSG;
781 } else {
782 /* Fire the request */
783 struct usb_request *req;
784
785 if (io_data->aio) {
786 req = usb_ep_alloc_request(ep->ep, GFP_KERNEL);
787 if (unlikely(!req))
788 goto error_lock;
789
790 req->buf = data;
791 req->length = io_data->len;
792
793 io_data->buf = data;
794 io_data->ep = ep->ep;
795 io_data->req = req;
796
797 req->context = io_data;
798 req->complete = ffs_epfile_async_io_complete;
799
800 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
801 if (unlikely(ret)) {
802 usb_ep_free_request(ep->ep, req);
803 goto error_lock;
804 }
805 ret = -EIOCBQUEUED;
806
807 spin_unlock_irq(&epfile->ffs->eps_lock);
808 } else {
809 DECLARE_COMPLETION_ONSTACK(done);
810
811 req = ep->req;
812 req->buf = data;
813 req->length = io_data->len;
814
815 req->context = &done;
816 req->complete = ffs_epfile_io_complete;
817
818 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
819
820 spin_unlock_irq(&epfile->ffs->eps_lock);
821
822 if (unlikely(ret < 0)) {
823 /* nop */
824 } else if (unlikely(
825 wait_for_completion_interruptible(&done))) {
826 ret = -EINTR;
827 usb_ep_dequeue(ep->ep, req);
828 } else {
829 /*
830 * XXX We may end up silently droping data
831 * here. Since data_len (i.e. req->length) may
832 * be bigger than len (after being rounded up
833 * to maxpacketsize), we may end up with more
834 * data then user space has space for.
835 */
836 ret = ep->status;
837 if (io_data->read && ret > 0) {
838 ret = min_t(size_t, ret, io_data->len);
839
840 if (unlikely(copy_to_user(io_data->buf,
841 data, ret)))
842 ret = -EFAULT;
843 }
844 }
845 kfree(data);
846 }
847 }
848
849 mutex_unlock(&epfile->mutex);
850 return ret;
851
852error_lock:
853 spin_unlock_irq(&epfile->ffs->eps_lock);
854 mutex_unlock(&epfile->mutex);
855error:
856 kfree(data);
857 return ret;
858}
859
860static ssize_t
861ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
862 loff_t *ptr)
863{
864 struct ffs_io_data io_data;
865
866 ENTER();
867
868 io_data.aio = false;
869 io_data.read = false;
870 io_data.buf = (char * __user)buf;
871 io_data.len = len;
872
873 return ffs_epfile_io(file, &io_data);
874}
875
876static ssize_t
877ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
878{
879 struct ffs_io_data io_data;
880
881 ENTER();
882
883 io_data.aio = false;
884 io_data.read = true;
885 io_data.buf = buf;
886 io_data.len = len;
887
888 return ffs_epfile_io(file, &io_data);
889}
890
891static int
892ffs_epfile_open(struct inode *inode, struct file *file)
893{
894 struct ffs_epfile *epfile = inode->i_private;
895
896 ENTER();
897
898 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
899 return -ENODEV;
900
901 file->private_data = epfile;
902 ffs_data_opened(epfile->ffs);
903
904 return 0;
905}
906
907static int ffs_aio_cancel(struct kiocb *kiocb)
908{
909 struct ffs_io_data *io_data = kiocb->private;
910 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
911 int value;
912
913 ENTER();
914
915 spin_lock_irq(&epfile->ffs->eps_lock);
916
917 if (likely(io_data && io_data->ep && io_data->req))
918 value = usb_ep_dequeue(io_data->ep, io_data->req);
919 else
920 value = -EINVAL;
921
922 spin_unlock_irq(&epfile->ffs->eps_lock);
923
924 return value;
925}
926
927static ssize_t ffs_epfile_aio_write(struct kiocb *kiocb,
928 const struct iovec *iovec,
929 unsigned long nr_segs, loff_t loff)
930{
931 struct ffs_io_data *io_data;
932
933 ENTER();
934
935 io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
936 if (unlikely(!io_data))
937 return -ENOMEM;
938
939 io_data->aio = true;
940 io_data->read = false;
941 io_data->kiocb = kiocb;
942 io_data->iovec = iovec;
943 io_data->nr_segs = nr_segs;
944 io_data->len = kiocb->ki_nbytes;
945 io_data->mm = current->mm;
946
947 kiocb->private = io_data;
948
949 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
950
951 return ffs_epfile_io(kiocb->ki_filp, io_data);
952}
953
954static ssize_t ffs_epfile_aio_read(struct kiocb *kiocb,
955 const struct iovec *iovec,
956 unsigned long nr_segs, loff_t loff)
957{
958 struct ffs_io_data *io_data;
959 struct iovec *iovec_copy;
960
961 ENTER();
962
963 iovec_copy = kmalloc_array(nr_segs, sizeof(*iovec_copy), GFP_KERNEL);
964 if (unlikely(!iovec_copy))
965 return -ENOMEM;
966
967 memcpy(iovec_copy, iovec, sizeof(struct iovec)*nr_segs);
968
969 io_data = kmalloc(sizeof(*io_data), GFP_KERNEL);
970 if (unlikely(!io_data)) {
971 kfree(iovec_copy);
972 return -ENOMEM;
973 }
974
975 io_data->aio = true;
976 io_data->read = true;
977 io_data->kiocb = kiocb;
978 io_data->iovec = iovec_copy;
979 io_data->nr_segs = nr_segs;
980 io_data->len = kiocb->ki_nbytes;
981 io_data->mm = current->mm;
982
983 kiocb->private = io_data;
984
985 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
986
987 return ffs_epfile_io(kiocb->ki_filp, io_data);
988}
989
990static int
991ffs_epfile_release(struct inode *inode, struct file *file)
992{
993 struct ffs_epfile *epfile = inode->i_private;
994
995 ENTER();
996
997 ffs_data_closed(epfile->ffs);
998
999 return 0;
1000}
1001
1002static long ffs_epfile_ioctl(struct file *file, unsigned code,
1003 unsigned long value)
1004{
1005 struct ffs_epfile *epfile = file->private_data;
1006 int ret;
1007
1008 ENTER();
1009
1010 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1011 return -ENODEV;
1012
1013 spin_lock_irq(&epfile->ffs->eps_lock);
1014 if (likely(epfile->ep)) {
1015 switch (code) {
1016 case FUNCTIONFS_FIFO_STATUS:
1017 ret = usb_ep_fifo_status(epfile->ep->ep);
1018 break;
1019 case FUNCTIONFS_FIFO_FLUSH:
1020 usb_ep_fifo_flush(epfile->ep->ep);
1021 ret = 0;
1022 break;
1023 case FUNCTIONFS_CLEAR_HALT:
1024 ret = usb_ep_clear_halt(epfile->ep->ep);
1025 break;
1026 case FUNCTIONFS_ENDPOINT_REVMAP:
1027 ret = epfile->ep->num;
1028 break;
1029 default:
1030 ret = -ENOTTY;
1031 }
1032 } else {
1033 ret = -ENODEV;
1034 }
1035 spin_unlock_irq(&epfile->ffs->eps_lock);
1036
1037 return ret;
1038}
1039
1040static const struct file_operations ffs_epfile_operations = {
1041 .llseek = no_llseek,
1042
1043 .open = ffs_epfile_open,
1044 .write = ffs_epfile_write,
1045 .read = ffs_epfile_read,
1046 .aio_write = ffs_epfile_aio_write,
1047 .aio_read = ffs_epfile_aio_read,
1048 .release = ffs_epfile_release,
1049 .unlocked_ioctl = ffs_epfile_ioctl,
1050};
1051
1052
1053/* File system and super block operations ***********************************/
1054
1055/*
1056 * Mounting the file system creates a controller file, used first for
1057 * function configuration then later for event monitoring.
1058 */
1059
1060static struct inode *__must_check
1061ffs_sb_make_inode(struct super_block *sb, void *data,
1062 const struct file_operations *fops,
1063 const struct inode_operations *iops,
1064 struct ffs_file_perms *perms)
1065{
1066 struct inode *inode;
1067
1068 ENTER();
1069
1070 inode = new_inode(sb);
1071
1072 if (likely(inode)) {
1073 struct timespec current_time = CURRENT_TIME;
1074
1075 inode->i_ino = get_next_ino();
1076 inode->i_mode = perms->mode;
1077 inode->i_uid = perms->uid;
1078 inode->i_gid = perms->gid;
1079 inode->i_atime = current_time;
1080 inode->i_mtime = current_time;
1081 inode->i_ctime = current_time;
1082 inode->i_private = data;
1083 if (fops)
1084 inode->i_fop = fops;
1085 if (iops)
1086 inode->i_op = iops;
1087 }
1088
1089 return inode;
1090}
1091
1092/* Create "regular" file */
1093static struct inode *ffs_sb_create_file(struct super_block *sb,
1094 const char *name, void *data,
1095 const struct file_operations *fops,
1096 struct dentry **dentry_p)
1097{
1098 struct ffs_data *ffs = sb->s_fs_info;
1099 struct dentry *dentry;
1100 struct inode *inode;
1101
1102 ENTER();
1103
1104 dentry = d_alloc_name(sb->s_root, name);
1105 if (unlikely(!dentry))
1106 return NULL;
1107
1108 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1109 if (unlikely(!inode)) {
1110 dput(dentry);
1111 return NULL;
1112 }
1113
1114 d_add(dentry, inode);
1115 if (dentry_p)
1116 *dentry_p = dentry;
1117
1118 return inode;
1119}
1120
1121/* Super block */
1122static const struct super_operations ffs_sb_operations = {
1123 .statfs = simple_statfs,
1124 .drop_inode = generic_delete_inode,
1125};
1126
1127struct ffs_sb_fill_data {
1128 struct ffs_file_perms perms;
1129 umode_t root_mode;
1130 const char *dev_name;
1131 struct ffs_data *ffs_data;
1132};
1133
1134static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1135{
1136 struct ffs_sb_fill_data *data = _data;
1137 struct inode *inode;
1138 struct ffs_data *ffs = data->ffs_data;
1139
1140 ENTER();
1141
1142 ffs->sb = sb;
1143 data->ffs_data = NULL;
1144 sb->s_fs_info = ffs;
1145 sb->s_blocksize = PAGE_CACHE_SIZE;
1146 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1147 sb->s_magic = FUNCTIONFS_MAGIC;
1148 sb->s_op = &ffs_sb_operations;
1149 sb->s_time_gran = 1;
1150
1151 /* Root inode */
1152 data->perms.mode = data->root_mode;
1153 inode = ffs_sb_make_inode(sb, NULL,
1154 &simple_dir_operations,
1155 &simple_dir_inode_operations,
1156 &data->perms);
1157 sb->s_root = d_make_root(inode);
1158 if (unlikely(!sb->s_root))
1159 return -ENOMEM;
1160
1161 /* EP0 file */
1162 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1163 &ffs_ep0_operations, NULL)))
1164 return -ENOMEM;
1165
1166 return 0;
1167}
1168
1169static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1170{
1171 ENTER();
1172
1173 if (!opts || !*opts)
1174 return 0;
1175
1176 for (;;) {
1177 unsigned long value;
1178 char *eq, *comma;
1179
1180 /* Option limit */
1181 comma = strchr(opts, ',');
1182 if (comma)
1183 *comma = 0;
1184
1185 /* Value limit */
1186 eq = strchr(opts, '=');
1187 if (unlikely(!eq)) {
1188 pr_err("'=' missing in %s\n", opts);
1189 return -EINVAL;
1190 }
1191 *eq = 0;
1192
1193 /* Parse value */
1194 if (kstrtoul(eq + 1, 0, &value)) {
1195 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1196 return -EINVAL;
1197 }
1198
1199 /* Interpret option */
1200 switch (eq - opts) {
1201 case 5:
1202 if (!memcmp(opts, "rmode", 5))
1203 data->root_mode = (value & 0555) | S_IFDIR;
1204 else if (!memcmp(opts, "fmode", 5))
1205 data->perms.mode = (value & 0666) | S_IFREG;
1206 else
1207 goto invalid;
1208 break;
1209
1210 case 4:
1211 if (!memcmp(opts, "mode", 4)) {
1212 data->root_mode = (value & 0555) | S_IFDIR;
1213 data->perms.mode = (value & 0666) | S_IFREG;
1214 } else {
1215 goto invalid;
1216 }
1217 break;
1218
1219 case 3:
1220 if (!memcmp(opts, "uid", 3)) {
1221 data->perms.uid = make_kuid(current_user_ns(), value);
1222 if (!uid_valid(data->perms.uid)) {
1223 pr_err("%s: unmapped value: %lu\n", opts, value);
1224 return -EINVAL;
1225 }
1226 } else if (!memcmp(opts, "gid", 3)) {
1227 data->perms.gid = make_kgid(current_user_ns(), value);
1228 if (!gid_valid(data->perms.gid)) {
1229 pr_err("%s: unmapped value: %lu\n", opts, value);
1230 return -EINVAL;
1231 }
1232 } else {
1233 goto invalid;
1234 }
1235 break;
1236
1237 default:
1238invalid:
1239 pr_err("%s: invalid option\n", opts);
1240 return -EINVAL;
1241 }
1242
1243 /* Next iteration */
1244 if (!comma)
1245 break;
1246 opts = comma + 1;
1247 }
1248
1249 return 0;
1250}
1251
1252/* "mount -t functionfs dev_name /dev/function" ends up here */
1253
1254static struct dentry *
1255ffs_fs_mount(struct file_system_type *t, int flags,
1256 const char *dev_name, void *opts)
1257{
1258 struct ffs_sb_fill_data data = {
1259 .perms = {
1260 .mode = S_IFREG | 0600,
1261 .uid = GLOBAL_ROOT_UID,
1262 .gid = GLOBAL_ROOT_GID,
1263 },
1264 .root_mode = S_IFDIR | 0500,
1265 };
1266 struct dentry *rv;
1267 int ret;
1268 void *ffs_dev;
1269 struct ffs_data *ffs;
1270
1271 ENTER();
1272
1273 ret = ffs_fs_parse_opts(&data, opts);
1274 if (unlikely(ret < 0))
1275 return ERR_PTR(ret);
1276
1277 ffs = ffs_data_new();
1278 if (unlikely(!ffs))
1279 return ERR_PTR(-ENOMEM);
1280 ffs->file_perms = data.perms;
1281
1282 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1283 if (unlikely(!ffs->dev_name)) {
1284 ffs_data_put(ffs);
1285 return ERR_PTR(-ENOMEM);
1286 }
1287
1288 ffs_dev = ffs_acquire_dev(dev_name);
1289 if (IS_ERR(ffs_dev)) {
1290 ffs_data_put(ffs);
1291 return ERR_CAST(ffs_dev);
1292 }
1293 ffs->private_data = ffs_dev;
1294 data.ffs_data = ffs;
1295
1296 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1297 if (IS_ERR(rv) && data.ffs_data) {
1298 ffs_release_dev(data.ffs_data);
1299 ffs_data_put(data.ffs_data);
1300 }
1301 return rv;
1302}
1303
1304static void
1305ffs_fs_kill_sb(struct super_block *sb)
1306{
1307 ENTER();
1308
1309 kill_litter_super(sb);
1310 if (sb->s_fs_info) {
1311 ffs_release_dev(sb->s_fs_info);
1312 ffs_data_put(sb->s_fs_info);
1313 }
1314}
1315
1316static struct file_system_type ffs_fs_type = {
1317 .owner = THIS_MODULE,
1318 .name = "functionfs",
1319 .mount = ffs_fs_mount,
1320 .kill_sb = ffs_fs_kill_sb,
1321};
1322MODULE_ALIAS_FS("functionfs");
1323
1324
1325/* Driver's main init/cleanup functions *************************************/
1326
1327static int functionfs_init(void)
1328{
1329 int ret;
1330
1331 ENTER();
1332
1333 ret = register_filesystem(&ffs_fs_type);
1334 if (likely(!ret))
1335 pr_info("file system registered\n");
1336 else
1337 pr_err("failed registering file system (%d)\n", ret);
1338
1339 return ret;
1340}
1341
1342static void functionfs_cleanup(void)
1343{
1344 ENTER();
1345
1346 pr_info("unloading\n");
1347 unregister_filesystem(&ffs_fs_type);
1348}
1349
1350
1351/* ffs_data and ffs_function construction and destruction code **************/
1352
1353static void ffs_data_clear(struct ffs_data *ffs);
1354static void ffs_data_reset(struct ffs_data *ffs);
1355
1356static void ffs_data_get(struct ffs_data *ffs)
1357{
1358 ENTER();
1359
1360 atomic_inc(&ffs->ref);
1361}
1362
1363static void ffs_data_opened(struct ffs_data *ffs)
1364{
1365 ENTER();
1366
1367 atomic_inc(&ffs->ref);
1368 atomic_inc(&ffs->opened);
1369}
1370
1371static void ffs_data_put(struct ffs_data *ffs)
1372{
1373 ENTER();
1374
1375 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1376 pr_info("%s(): freeing\n", __func__);
1377 ffs_data_clear(ffs);
1378 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1379 waitqueue_active(&ffs->ep0req_completion.wait));
1380 kfree(ffs->dev_name);
1381 kfree(ffs);
1382 }
1383}
1384
1385static void ffs_data_closed(struct ffs_data *ffs)
1386{
1387 ENTER();
1388
1389 if (atomic_dec_and_test(&ffs->opened)) {
1390 ffs->state = FFS_CLOSING;
1391 ffs_data_reset(ffs);
1392 }
1393
1394 ffs_data_put(ffs);
1395}
1396
1397static struct ffs_data *ffs_data_new(void)
1398{
1399 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1400 if (unlikely(!ffs))
1401 return NULL;
1402
1403 ENTER();
1404
1405 atomic_set(&ffs->ref, 1);
1406 atomic_set(&ffs->opened, 0);
1407 ffs->state = FFS_READ_DESCRIPTORS;
1408 mutex_init(&ffs->mutex);
1409 spin_lock_init(&ffs->eps_lock);
1410 init_waitqueue_head(&ffs->ev.waitq);
1411 init_completion(&ffs->ep0req_completion);
1412
1413 /* XXX REVISIT need to update it in some places, or do we? */
1414 ffs->ev.can_stall = 1;
1415
1416 return ffs;
1417}
1418
1419static void ffs_data_clear(struct ffs_data *ffs)
1420{
1421 ENTER();
1422
1423 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1424 ffs_closed(ffs);
1425
1426 BUG_ON(ffs->gadget);
1427
1428 if (ffs->epfiles)
1429 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1430
1431 kfree(ffs->raw_descs_data);
1432 kfree(ffs->raw_strings);
1433 kfree(ffs->stringtabs);
1434}
1435
1436static void ffs_data_reset(struct ffs_data *ffs)
1437{
1438 ENTER();
1439
1440 ffs_data_clear(ffs);
1441
1442 ffs->epfiles = NULL;
1443 ffs->raw_descs_data = NULL;
1444 ffs->raw_descs = NULL;
1445 ffs->raw_strings = NULL;
1446 ffs->stringtabs = NULL;
1447
1448 ffs->raw_descs_length = 0;
1449 ffs->fs_descs_count = 0;
1450 ffs->hs_descs_count = 0;
1451 ffs->ss_descs_count = 0;
1452
1453 ffs->strings_count = 0;
1454 ffs->interfaces_count = 0;
1455 ffs->eps_count = 0;
1456
1457 ffs->ev.count = 0;
1458
1459 ffs->state = FFS_READ_DESCRIPTORS;
1460 ffs->setup_state = FFS_NO_SETUP;
1461 ffs->flags = 0;
1462}
1463
1464
1465static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1466{
1467 struct usb_gadget_strings **lang;
1468 int first_id;
1469
1470 ENTER();
1471
1472 if (WARN_ON(ffs->state != FFS_ACTIVE
1473 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1474 return -EBADFD;
1475
1476 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1477 if (unlikely(first_id < 0))
1478 return first_id;
1479
1480 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1481 if (unlikely(!ffs->ep0req))
1482 return -ENOMEM;
1483 ffs->ep0req->complete = ffs_ep0_complete;
1484 ffs->ep0req->context = ffs;
1485
1486 lang = ffs->stringtabs;
1487 if (lang) {
1488 for (; *lang; ++lang) {
1489 struct usb_string *str = (*lang)->strings;
1490 int id = first_id;
1491 for (; str->s; ++id, ++str)
1492 str->id = id;
1493 }
1494 }
1495
1496 ffs->gadget = cdev->gadget;
1497 ffs_data_get(ffs);
1498 return 0;
1499}
1500
1501static void functionfs_unbind(struct ffs_data *ffs)
1502{
1503 ENTER();
1504
1505 if (!WARN_ON(!ffs->gadget)) {
1506 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1507 ffs->ep0req = NULL;
1508 ffs->gadget = NULL;
1509 clear_bit(FFS_FL_BOUND, &ffs->flags);
1510 ffs_data_put(ffs);
1511 }
1512}
1513
1514static int ffs_epfiles_create(struct ffs_data *ffs)
1515{
1516 struct ffs_epfile *epfile, *epfiles;
1517 unsigned i, count;
1518
1519 ENTER();
1520
1521 count = ffs->eps_count;
1522 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1523 if (!epfiles)
1524 return -ENOMEM;
1525
1526 epfile = epfiles;
1527 for (i = 1; i <= count; ++i, ++epfile) {
1528 epfile->ffs = ffs;
1529 mutex_init(&epfile->mutex);
1530 init_waitqueue_head(&epfile->wait);
1531 sprintf(epfiles->name, "ep%u", i);
1532 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1533 &ffs_epfile_operations,
1534 &epfile->dentry))) {
1535 ffs_epfiles_destroy(epfiles, i - 1);
1536 return -ENOMEM;
1537 }
1538 }
1539
1540 ffs->epfiles = epfiles;
1541 return 0;
1542}
1543
1544static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1545{
1546 struct ffs_epfile *epfile = epfiles;
1547
1548 ENTER();
1549
1550 for (; count; --count, ++epfile) {
1551 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1552 waitqueue_active(&epfile->wait));
1553 if (epfile->dentry) {
1554 d_delete(epfile->dentry);
1555 dput(epfile->dentry);
1556 epfile->dentry = NULL;
1557 }
1558 }
1559
1560 kfree(epfiles);
1561}
1562
1563
1564static void ffs_func_eps_disable(struct ffs_function *func)
1565{
1566 struct ffs_ep *ep = func->eps;
1567 struct ffs_epfile *epfile = func->ffs->epfiles;
1568 unsigned count = func->ffs->eps_count;
1569 unsigned long flags;
1570
1571 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1572 do {
1573 /* pending requests get nuked */
1574 if (likely(ep->ep))
1575 usb_ep_disable(ep->ep);
1576 epfile->ep = NULL;
1577
1578 ++ep;
1579 ++epfile;
1580 } while (--count);
1581 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1582}
1583
1584static int ffs_func_eps_enable(struct ffs_function *func)
1585{
1586 struct ffs_data *ffs = func->ffs;
1587 struct ffs_ep *ep = func->eps;
1588 struct ffs_epfile *epfile = ffs->epfiles;
1589 unsigned count = ffs->eps_count;
1590 unsigned long flags;
1591 int ret = 0;
1592
1593 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1594 do {
1595 struct usb_endpoint_descriptor *ds;
1596 int desc_idx;
1597
1598 if (ffs->gadget->speed == USB_SPEED_SUPER)
1599 desc_idx = 2;
1600 else if (ffs->gadget->speed == USB_SPEED_HIGH)
1601 desc_idx = 1;
1602 else
1603 desc_idx = 0;
1604
1605 /* fall-back to lower speed if desc missing for current speed */
1606 do {
1607 ds = ep->descs[desc_idx];
1608 } while (!ds && --desc_idx >= 0);
1609
1610 if (!ds) {
1611 ret = -EINVAL;
1612 break;
1613 }
1614
1615 ep->ep->driver_data = ep;
1616 ep->ep->desc = ds;
1617 ret = usb_ep_enable(ep->ep);
1618 if (likely(!ret)) {
1619 epfile->ep = ep;
1620 epfile->in = usb_endpoint_dir_in(ds);
1621 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1622 } else {
1623 break;
1624 }
1625
1626 wake_up(&epfile->wait);
1627
1628 ++ep;
1629 ++epfile;
1630 } while (--count);
1631 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1632
1633 return ret;
1634}
1635
1636
1637/* Parsing and building descriptors and strings *****************************/
1638
1639/*
1640 * This validates if data pointed by data is a valid USB descriptor as
1641 * well as record how many interfaces, endpoints and strings are
1642 * required by given configuration. Returns address after the
1643 * descriptor or NULL if data is invalid.
1644 */
1645
1646enum ffs_entity_type {
1647 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1648};
1649
1650enum ffs_os_desc_type {
1651 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1652};
1653
1654typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1655 u8 *valuep,
1656 struct usb_descriptor_header *desc,
1657 void *priv);
1658
1659typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1660 struct usb_os_desc_header *h, void *data,
1661 unsigned len, void *priv);
1662
1663static int __must_check ffs_do_single_desc(char *data, unsigned len,
1664 ffs_entity_callback entity,
1665 void *priv)
1666{
1667 struct usb_descriptor_header *_ds = (void *)data;
1668 u8 length;
1669 int ret;
1670
1671 ENTER();
1672
1673 /* At least two bytes are required: length and type */
1674 if (len < 2) {
1675 pr_vdebug("descriptor too short\n");
1676 return -EINVAL;
1677 }
1678
1679 /* If we have at least as many bytes as the descriptor takes? */
1680 length = _ds->bLength;
1681 if (len < length) {
1682 pr_vdebug("descriptor longer then available data\n");
1683 return -EINVAL;
1684 }
1685
1686#define __entity_check_INTERFACE(val) 1
1687#define __entity_check_STRING(val) (val)
1688#define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1689#define __entity(type, val) do { \
1690 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1691 if (unlikely(!__entity_check_ ##type(val))) { \
1692 pr_vdebug("invalid entity's value\n"); \
1693 return -EINVAL; \
1694 } \
1695 ret = entity(FFS_ ##type, &val, _ds, priv); \
1696 if (unlikely(ret < 0)) { \
1697 pr_debug("entity " #type "(%02x); ret = %d\n", \
1698 (val), ret); \
1699 return ret; \
1700 } \
1701 } while (0)
1702
1703 /* Parse descriptor depending on type. */
1704 switch (_ds->bDescriptorType) {
1705 case USB_DT_DEVICE:
1706 case USB_DT_CONFIG:
1707 case USB_DT_STRING:
1708 case USB_DT_DEVICE_QUALIFIER:
1709 /* function can't have any of those */
1710 pr_vdebug("descriptor reserved for gadget: %d\n",
1711 _ds->bDescriptorType);
1712 return -EINVAL;
1713
1714 case USB_DT_INTERFACE: {
1715 struct usb_interface_descriptor *ds = (void *)_ds;
1716 pr_vdebug("interface descriptor\n");
1717 if (length != sizeof *ds)
1718 goto inv_length;
1719
1720 __entity(INTERFACE, ds->bInterfaceNumber);
1721 if (ds->iInterface)
1722 __entity(STRING, ds->iInterface);
1723 }
1724 break;
1725
1726 case USB_DT_ENDPOINT: {
1727 struct usb_endpoint_descriptor *ds = (void *)_ds;
1728 pr_vdebug("endpoint descriptor\n");
1729 if (length != USB_DT_ENDPOINT_SIZE &&
1730 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1731 goto inv_length;
1732 __entity(ENDPOINT, ds->bEndpointAddress);
1733 }
1734 break;
1735
1736 case HID_DT_HID:
1737 pr_vdebug("hid descriptor\n");
1738 if (length != sizeof(struct hid_descriptor))
1739 goto inv_length;
1740 break;
1741
1742 case USB_DT_OTG:
1743 if (length != sizeof(struct usb_otg_descriptor))
1744 goto inv_length;
1745 break;
1746
1747 case USB_DT_INTERFACE_ASSOCIATION: {
1748 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1749 pr_vdebug("interface association descriptor\n");
1750 if (length != sizeof *ds)
1751 goto inv_length;
1752 if (ds->iFunction)
1753 __entity(STRING, ds->iFunction);
1754 }
1755 break;
1756
1757 case USB_DT_SS_ENDPOINT_COMP:
1758 pr_vdebug("EP SS companion descriptor\n");
1759 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1760 goto inv_length;
1761 break;
1762
1763 case USB_DT_OTHER_SPEED_CONFIG:
1764 case USB_DT_INTERFACE_POWER:
1765 case USB_DT_DEBUG:
1766 case USB_DT_SECURITY:
1767 case USB_DT_CS_RADIO_CONTROL:
1768 /* TODO */
1769 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1770 return -EINVAL;
1771
1772 default:
1773 /* We should never be here */
1774 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1775 return -EINVAL;
1776
1777inv_length:
1778 pr_vdebug("invalid length: %d (descriptor %d)\n",
1779 _ds->bLength, _ds->bDescriptorType);
1780 return -EINVAL;
1781 }
1782
1783#undef __entity
1784#undef __entity_check_DESCRIPTOR
1785#undef __entity_check_INTERFACE
1786#undef __entity_check_STRING
1787#undef __entity_check_ENDPOINT
1788
1789 return length;
1790}
1791
1792static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1793 ffs_entity_callback entity, void *priv)
1794{
1795 const unsigned _len = len;
1796 unsigned long num = 0;
1797
1798 ENTER();
1799
1800 for (;;) {
1801 int ret;
1802
1803 if (num == count)
1804 data = NULL;
1805
1806 /* Record "descriptor" entity */
1807 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1808 if (unlikely(ret < 0)) {
1809 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1810 num, ret);
1811 return ret;
1812 }
1813
1814 if (!data)
1815 return _len - len;
1816
1817 ret = ffs_do_single_desc(data, len, entity, priv);
1818 if (unlikely(ret < 0)) {
1819 pr_debug("%s returns %d\n", __func__, ret);
1820 return ret;
1821 }
1822
1823 len -= ret;
1824 data += ret;
1825 ++num;
1826 }
1827}
1828
1829static int __ffs_data_do_entity(enum ffs_entity_type type,
1830 u8 *valuep, struct usb_descriptor_header *desc,
1831 void *priv)
1832{
1833 struct ffs_data *ffs = priv;
1834
1835 ENTER();
1836
1837 switch (type) {
1838 case FFS_DESCRIPTOR:
1839 break;
1840
1841 case FFS_INTERFACE:
1842 /*
1843 * Interfaces are indexed from zero so if we
1844 * encountered interface "n" then there are at least
1845 * "n+1" interfaces.
1846 */
1847 if (*valuep >= ffs->interfaces_count)
1848 ffs->interfaces_count = *valuep + 1;
1849 break;
1850
1851 case FFS_STRING:
1852 /*
1853 * Strings are indexed from 1 (0 is magic ;) reserved
1854 * for languages list or some such)
1855 */
1856 if (*valuep > ffs->strings_count)
1857 ffs->strings_count = *valuep;
1858 break;
1859
1860 case FFS_ENDPOINT:
1861 /* Endpoints are indexed from 1 as well. */
1862 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1863 ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1864 break;
1865 }
1866
1867 return 0;
1868}
1869
1870static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1871 struct usb_os_desc_header *desc)
1872{
1873 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1874 u16 w_index = le16_to_cpu(desc->wIndex);
1875
1876 if (bcd_version != 1) {
1877 pr_vdebug("unsupported os descriptors version: %d",
1878 bcd_version);
1879 return -EINVAL;
1880 }
1881 switch (w_index) {
1882 case 0x4:
1883 *next_type = FFS_OS_DESC_EXT_COMPAT;
1884 break;
1885 case 0x5:
1886 *next_type = FFS_OS_DESC_EXT_PROP;
1887 break;
1888 default:
1889 pr_vdebug("unsupported os descriptor type: %d", w_index);
1890 return -EINVAL;
1891 }
1892
1893 return sizeof(*desc);
1894}
1895
1896/*
1897 * Process all extended compatibility/extended property descriptors
1898 * of a feature descriptor
1899 */
1900static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1901 enum ffs_os_desc_type type,
1902 u16 feature_count,
1903 ffs_os_desc_callback entity,
1904 void *priv,
1905 struct usb_os_desc_header *h)
1906{
1907 int ret;
1908 const unsigned _len = len;
1909
1910 ENTER();
1911
1912 /* loop over all ext compat/ext prop descriptors */
1913 while (feature_count--) {
1914 ret = entity(type, h, data, len, priv);
1915 if (unlikely(ret < 0)) {
1916 pr_debug("bad OS descriptor, type: %d\n", type);
1917 return ret;
1918 }
1919 data += ret;
1920 len -= ret;
1921 }
1922 return _len - len;
1923}
1924
1925/* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
1926static int __must_check ffs_do_os_descs(unsigned count,
1927 char *data, unsigned len,
1928 ffs_os_desc_callback entity, void *priv)
1929{
1930 const unsigned _len = len;
1931 unsigned long num = 0;
1932
1933 ENTER();
1934
1935 for (num = 0; num < count; ++num) {
1936 int ret;
1937 enum ffs_os_desc_type type;
1938 u16 feature_count;
1939 struct usb_os_desc_header *desc = (void *)data;
1940
1941 if (len < sizeof(*desc))
1942 return -EINVAL;
1943
1944 /*
1945 * Record "descriptor" entity.
1946 * Process dwLength, bcdVersion, wIndex, get b/wCount.
1947 * Move the data pointer to the beginning of extended
1948 * compatibilities proper or extended properties proper
1949 * portions of the data
1950 */
1951 if (le32_to_cpu(desc->dwLength) > len)
1952 return -EINVAL;
1953
1954 ret = __ffs_do_os_desc_header(&type, desc);
1955 if (unlikely(ret < 0)) {
1956 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
1957 num, ret);
1958 return ret;
1959 }
1960 /*
1961 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
1962 */
1963 feature_count = le16_to_cpu(desc->wCount);
1964 if (type == FFS_OS_DESC_EXT_COMPAT &&
1965 (feature_count > 255 || desc->Reserved))
1966 return -EINVAL;
1967 len -= ret;
1968 data += ret;
1969
1970 /*
1971 * Process all function/property descriptors
1972 * of this Feature Descriptor
1973 */
1974 ret = ffs_do_single_os_desc(data, len, type,
1975 feature_count, entity, priv, desc);
1976 if (unlikely(ret < 0)) {
1977 pr_debug("%s returns %d\n", __func__, ret);
1978 return ret;
1979 }
1980
1981 len -= ret;
1982 data += ret;
1983 }
1984 return _len - len;
1985}
1986
1987/**
1988 * Validate contents of the buffer from userspace related to OS descriptors.
1989 */
1990static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
1991 struct usb_os_desc_header *h, void *data,
1992 unsigned len, void *priv)
1993{
1994 struct ffs_data *ffs = priv;
1995 u8 length;
1996
1997 ENTER();
1998
1999 switch (type) {
2000 case FFS_OS_DESC_EXT_COMPAT: {
2001 struct usb_ext_compat_desc *d = data;
2002 int i;
2003
2004 if (len < sizeof(*d) ||
2005 d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2006 d->Reserved1)
2007 return -EINVAL;
2008 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2009 if (d->Reserved2[i])
2010 return -EINVAL;
2011
2012 length = sizeof(struct usb_ext_compat_desc);
2013 }
2014 break;
2015 case FFS_OS_DESC_EXT_PROP: {
2016 struct usb_ext_prop_desc *d = data;
2017 u32 type, pdl;
2018 u16 pnl;
2019
2020 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2021 return -EINVAL;
2022 length = le32_to_cpu(d->dwSize);
2023 type = le32_to_cpu(d->dwPropertyDataType);
2024 if (type < USB_EXT_PROP_UNICODE ||
2025 type > USB_EXT_PROP_UNICODE_MULTI) {
2026 pr_vdebug("unsupported os descriptor property type: %d",
2027 type);
2028 return -EINVAL;
2029 }
2030 pnl = le16_to_cpu(d->wPropertyNameLength);
2031 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2032 if (length != 14 + pnl + pdl) {
2033 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2034 length, pnl, pdl, type);
2035 return -EINVAL;
2036 }
2037 ++ffs->ms_os_descs_ext_prop_count;
2038 /* property name reported to the host as "WCHAR"s */
2039 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2040 ffs->ms_os_descs_ext_prop_data_len += pdl;
2041 }
2042 break;
2043 default:
2044 pr_vdebug("unknown descriptor: %d\n", type);
2045 return -EINVAL;
2046 }
2047 return length;
2048}
2049
2050static int __ffs_data_got_descs(struct ffs_data *ffs,
2051 char *const _data, size_t len)
2052{
2053 char *data = _data, *raw_descs;
2054 unsigned os_descs_count = 0, counts[3], flags;
2055 int ret = -EINVAL, i;
2056
2057 ENTER();
2058
2059 if (get_unaligned_le32(data + 4) != len)
2060 goto error;
2061
2062 switch (get_unaligned_le32(data)) {
2063 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2064 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2065 data += 8;
2066 len -= 8;
2067 break;
2068 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2069 flags = get_unaligned_le32(data + 8);
2070 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2071 FUNCTIONFS_HAS_HS_DESC |
2072 FUNCTIONFS_HAS_SS_DESC |
2073 FUNCTIONFS_HAS_MS_OS_DESC)) {
2074 ret = -ENOSYS;
2075 goto error;
2076 }
2077 data += 12;
2078 len -= 12;
2079 break;
2080 default:
2081 goto error;
2082 }
2083
2084 /* Read fs_count, hs_count and ss_count (if present) */
2085 for (i = 0; i < 3; ++i) {
2086 if (!(flags & (1 << i))) {
2087 counts[i] = 0;
2088 } else if (len < 4) {
2089 goto error;
2090 } else {
2091 counts[i] = get_unaligned_le32(data);
2092 data += 4;
2093 len -= 4;
2094 }
2095 }
2096 if (flags & (1 << i)) {
2097 os_descs_count = get_unaligned_le32(data);
2098 data += 4;
2099 len -= 4;
2100 };
2101
2102 /* Read descriptors */
2103 raw_descs = data;
2104 for (i = 0; i < 3; ++i) {
2105 if (!counts[i])
2106 continue;
2107 ret = ffs_do_descs(counts[i], data, len,
2108 __ffs_data_do_entity, ffs);
2109 if (ret < 0)
2110 goto error;
2111 data += ret;
2112 len -= ret;
2113 }
2114 if (os_descs_count) {
2115 ret = ffs_do_os_descs(os_descs_count, data, len,
2116 __ffs_data_do_os_desc, ffs);
2117 if (ret < 0)
2118 goto error;
2119 data += ret;
2120 len -= ret;
2121 }
2122
2123 if (raw_descs == data || len) {
2124 ret = -EINVAL;
2125 goto error;
2126 }
2127
2128 ffs->raw_descs_data = _data;
2129 ffs->raw_descs = raw_descs;
2130 ffs->raw_descs_length = data - raw_descs;
2131 ffs->fs_descs_count = counts[0];
2132 ffs->hs_descs_count = counts[1];
2133 ffs->ss_descs_count = counts[2];
2134 ffs->ms_os_descs_count = os_descs_count;
2135
2136 return 0;
2137
2138error:
2139 kfree(_data);
2140 return ret;
2141}
2142
2143static int __ffs_data_got_strings(struct ffs_data *ffs,
2144 char *const _data, size_t len)
2145{
2146 u32 str_count, needed_count, lang_count;
2147 struct usb_gadget_strings **stringtabs, *t;
2148 struct usb_string *strings, *s;
2149 const char *data = _data;
2150
2151 ENTER();
2152
2153 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2154 get_unaligned_le32(data + 4) != len))
2155 goto error;
2156 str_count = get_unaligned_le32(data + 8);
2157 lang_count = get_unaligned_le32(data + 12);
2158
2159 /* if one is zero the other must be zero */
2160 if (unlikely(!str_count != !lang_count))
2161 goto error;
2162
2163 /* Do we have at least as many strings as descriptors need? */
2164 needed_count = ffs->strings_count;
2165 if (unlikely(str_count < needed_count))
2166 goto error;
2167
2168 /*
2169 * If we don't need any strings just return and free all
2170 * memory.
2171 */
2172 if (!needed_count) {
2173 kfree(_data);
2174 return 0;
2175 }
2176
2177 /* Allocate everything in one chunk so there's less maintenance. */
2178 {
2179 unsigned i = 0;
2180 vla_group(d);
2181 vla_item(d, struct usb_gadget_strings *, stringtabs,
2182 lang_count + 1);
2183 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2184 vla_item(d, struct usb_string, strings,
2185 lang_count*(needed_count+1));
2186
2187 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2188
2189 if (unlikely(!vlabuf)) {
2190 kfree(_data);
2191 return -ENOMEM;
2192 }
2193
2194 /* Initialize the VLA pointers */
2195 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2196 t = vla_ptr(vlabuf, d, stringtab);
2197 i = lang_count;
2198 do {
2199 *stringtabs++ = t++;
2200 } while (--i);
2201 *stringtabs = NULL;
2202
2203 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2204 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2205 t = vla_ptr(vlabuf, d, stringtab);
2206 s = vla_ptr(vlabuf, d, strings);
2207 strings = s;
2208 }
2209
2210 /* For each language */
2211 data += 16;
2212 len -= 16;
2213
2214 do { /* lang_count > 0 so we can use do-while */
2215 unsigned needed = needed_count;
2216
2217 if (unlikely(len < 3))
2218 goto error_free;
2219 t->language = get_unaligned_le16(data);
2220 t->strings = s;
2221 ++t;
2222
2223 data += 2;
2224 len -= 2;
2225
2226 /* For each string */
2227 do { /* str_count > 0 so we can use do-while */
2228 size_t length = strnlen(data, len);
2229
2230 if (unlikely(length == len))
2231 goto error_free;
2232
2233 /*
2234 * User may provide more strings then we need,
2235 * if that's the case we simply ignore the
2236 * rest
2237 */
2238 if (likely(needed)) {
2239 /*
2240 * s->id will be set while adding
2241 * function to configuration so for
2242 * now just leave garbage here.
2243 */
2244 s->s = data;
2245 --needed;
2246 ++s;
2247 }
2248
2249 data += length + 1;
2250 len -= length + 1;
2251 } while (--str_count);
2252
2253 s->id = 0; /* terminator */
2254 s->s = NULL;
2255 ++s;
2256
2257 } while (--lang_count);
2258
2259 /* Some garbage left? */
2260 if (unlikely(len))
2261 goto error_free;
2262
2263 /* Done! */
2264 ffs->stringtabs = stringtabs;
2265 ffs->raw_strings = _data;
2266
2267 return 0;
2268
2269error_free:
2270 kfree(stringtabs);
2271error:
2272 kfree(_data);
2273 return -EINVAL;
2274}
2275
2276
2277/* Events handling and management *******************************************/
2278
2279static void __ffs_event_add(struct ffs_data *ffs,
2280 enum usb_functionfs_event_type type)
2281{
2282 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2283 int neg = 0;
2284
2285 /*
2286 * Abort any unhandled setup
2287 *
2288 * We do not need to worry about some cmpxchg() changing value
2289 * of ffs->setup_state without holding the lock because when
2290 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2291 * the source does nothing.
2292 */
2293 if (ffs->setup_state == FFS_SETUP_PENDING)
2294 ffs->setup_state = FFS_SETUP_CANCELLED;
2295
2296 switch (type) {
2297 case FUNCTIONFS_RESUME:
2298 rem_type2 = FUNCTIONFS_SUSPEND;
2299 /* FALL THROUGH */
2300 case FUNCTIONFS_SUSPEND:
2301 case FUNCTIONFS_SETUP:
2302 rem_type1 = type;
2303 /* Discard all similar events */
2304 break;
2305
2306 case FUNCTIONFS_BIND:
2307 case FUNCTIONFS_UNBIND:
2308 case FUNCTIONFS_DISABLE:
2309 case FUNCTIONFS_ENABLE:
2310 /* Discard everything other then power management. */
2311 rem_type1 = FUNCTIONFS_SUSPEND;
2312 rem_type2 = FUNCTIONFS_RESUME;
2313 neg = 1;
2314 break;
2315
2316 default:
2317 BUG();
2318 }
2319
2320 {
2321 u8 *ev = ffs->ev.types, *out = ev;
2322 unsigned n = ffs->ev.count;
2323 for (; n; --n, ++ev)
2324 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2325 *out++ = *ev;
2326 else
2327 pr_vdebug("purging event %d\n", *ev);
2328 ffs->ev.count = out - ffs->ev.types;
2329 }
2330
2331 pr_vdebug("adding event %d\n", type);
2332 ffs->ev.types[ffs->ev.count++] = type;
2333 wake_up_locked(&ffs->ev.waitq);
2334}
2335
2336static void ffs_event_add(struct ffs_data *ffs,
2337 enum usb_functionfs_event_type type)
2338{
2339 unsigned long flags;
2340 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2341 __ffs_event_add(ffs, type);
2342 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2343}
2344
2345
2346/* Bind/unbind USB function hooks *******************************************/
2347
2348static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2349 struct usb_descriptor_header *desc,
2350 void *priv)
2351{
2352 struct usb_endpoint_descriptor *ds = (void *)desc;
2353 struct ffs_function *func = priv;
2354 struct ffs_ep *ffs_ep;
2355 unsigned ep_desc_id, idx;
2356 static const char *speed_names[] = { "full", "high", "super" };
2357
2358 if (type != FFS_DESCRIPTOR)
2359 return 0;
2360
2361 /*
2362 * If ss_descriptors is not NULL, we are reading super speed
2363 * descriptors; if hs_descriptors is not NULL, we are reading high
2364 * speed descriptors; otherwise, we are reading full speed
2365 * descriptors.
2366 */
2367 if (func->function.ss_descriptors) {
2368 ep_desc_id = 2;
2369 func->function.ss_descriptors[(long)valuep] = desc;
2370 } else if (func->function.hs_descriptors) {
2371 ep_desc_id = 1;
2372 func->function.hs_descriptors[(long)valuep] = desc;
2373 } else {
2374 ep_desc_id = 0;
2375 func->function.fs_descriptors[(long)valuep] = desc;
2376 }
2377
2378 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2379 return 0;
2380
2381 idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2382 ffs_ep = func->eps + idx;
2383
2384 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2385 pr_err("two %sspeed descriptors for EP %d\n",
2386 speed_names[ep_desc_id],
2387 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2388 return -EINVAL;
2389 }
2390 ffs_ep->descs[ep_desc_id] = ds;
2391
2392 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2393 if (ffs_ep->ep) {
2394 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2395 if (!ds->wMaxPacketSize)
2396 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2397 } else {
2398 struct usb_request *req;
2399 struct usb_ep *ep;
2400
2401 pr_vdebug("autoconfig\n");
2402 ep = usb_ep_autoconfig(func->gadget, ds);
2403 if (unlikely(!ep))
2404 return -ENOTSUPP;
2405 ep->driver_data = func->eps + idx;
2406
2407 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2408 if (unlikely(!req))
2409 return -ENOMEM;
2410
2411 ffs_ep->ep = ep;
2412 ffs_ep->req = req;
2413 func->eps_revmap[ds->bEndpointAddress &
2414 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2415 }
2416 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2417
2418 return 0;
2419}
2420
2421static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2422 struct usb_descriptor_header *desc,
2423 void *priv)
2424{
2425 struct ffs_function *func = priv;
2426 unsigned idx;
2427 u8 newValue;
2428
2429 switch (type) {
2430 default:
2431 case FFS_DESCRIPTOR:
2432 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2433 return 0;
2434
2435 case FFS_INTERFACE:
2436 idx = *valuep;
2437 if (func->interfaces_nums[idx] < 0) {
2438 int id = usb_interface_id(func->conf, &func->function);
2439 if (unlikely(id < 0))
2440 return id;
2441 func->interfaces_nums[idx] = id;
2442 }
2443 newValue = func->interfaces_nums[idx];
2444 break;
2445
2446 case FFS_STRING:
2447 /* String' IDs are allocated when fsf_data is bound to cdev */
2448 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2449 break;
2450
2451 case FFS_ENDPOINT:
2452 /*
2453 * USB_DT_ENDPOINT are handled in
2454 * __ffs_func_bind_do_descs().
2455 */
2456 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2457 return 0;
2458
2459 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2460 if (unlikely(!func->eps[idx].ep))
2461 return -EINVAL;
2462
2463 {
2464 struct usb_endpoint_descriptor **descs;
2465 descs = func->eps[idx].descs;
2466 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2467 }
2468 break;
2469 }
2470
2471 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2472 *valuep = newValue;
2473 return 0;
2474}
2475
2476static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2477 struct usb_os_desc_header *h, void *data,
2478 unsigned len, void *priv)
2479{
2480 struct ffs_function *func = priv;
2481 u8 length = 0;
2482
2483 switch (type) {
2484 case FFS_OS_DESC_EXT_COMPAT: {
2485 struct usb_ext_compat_desc *desc = data;
2486 struct usb_os_desc_table *t;
2487
2488 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2489 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2490 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2491 ARRAY_SIZE(desc->CompatibleID) +
2492 ARRAY_SIZE(desc->SubCompatibleID));
2493 length = sizeof(*desc);
2494 }
2495 break;
2496 case FFS_OS_DESC_EXT_PROP: {
2497 struct usb_ext_prop_desc *desc = data;
2498 struct usb_os_desc_table *t;
2499 struct usb_os_desc_ext_prop *ext_prop;
2500 char *ext_prop_name;
2501 char *ext_prop_data;
2502
2503 t = &func->function.os_desc_table[h->interface];
2504 t->if_id = func->interfaces_nums[h->interface];
2505
2506 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2507 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2508
2509 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2510 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2511 ext_prop->data_len = le32_to_cpu(*(u32 *)
2512 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2513 length = ext_prop->name_len + ext_prop->data_len + 14;
2514
2515 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2516 func->ffs->ms_os_descs_ext_prop_name_avail +=
2517 ext_prop->name_len;
2518
2519 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2520 func->ffs->ms_os_descs_ext_prop_data_avail +=
2521 ext_prop->data_len;
2522 memcpy(ext_prop_data,
2523 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2524 ext_prop->data_len);
2525 /* unicode data reported to the host as "WCHAR"s */
2526 switch (ext_prop->type) {
2527 case USB_EXT_PROP_UNICODE:
2528 case USB_EXT_PROP_UNICODE_ENV:
2529 case USB_EXT_PROP_UNICODE_LINK:
2530 case USB_EXT_PROP_UNICODE_MULTI:
2531 ext_prop->data_len *= 2;
2532 break;
2533 }
2534 ext_prop->data = ext_prop_data;
2535
2536 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2537 ext_prop->name_len);
2538 /* property name reported to the host as "WCHAR"s */
2539 ext_prop->name_len *= 2;
2540 ext_prop->name = ext_prop_name;
2541
2542 t->os_desc->ext_prop_len +=
2543 ext_prop->name_len + ext_prop->data_len + 14;
2544 ++t->os_desc->ext_prop_count;
2545 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2546 }
2547 break;
2548 default:
2549 pr_vdebug("unknown descriptor: %d\n", type);
2550 }
2551
2552 return length;
2553}
2554
2555static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2556 struct usb_configuration *c)
2557{
2558 struct ffs_function *func = ffs_func_from_usb(f);
2559 struct f_fs_opts *ffs_opts =
2560 container_of(f->fi, struct f_fs_opts, func_inst);
2561 int ret;
2562
2563 ENTER();
2564
2565 /*
2566 * Legacy gadget triggers binding in functionfs_ready_callback,
2567 * which already uses locking; taking the same lock here would
2568 * cause a deadlock.
2569 *
2570 * Configfs-enabled gadgets however do need ffs_dev_lock.
2571 */
2572 if (!ffs_opts->no_configfs)
2573 ffs_dev_lock();
2574 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2575 func->ffs = ffs_opts->dev->ffs_data;
2576 if (!ffs_opts->no_configfs)
2577 ffs_dev_unlock();
2578 if (ret)
2579 return ERR_PTR(ret);
2580
2581 func->conf = c;
2582 func->gadget = c->cdev->gadget;
2583
2584 ffs_data_get(func->ffs);
2585
2586 /*
2587 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2588 * configurations are bound in sequence with list_for_each_entry,
2589 * in each configuration its functions are bound in sequence
2590 * with list_for_each_entry, so we assume no race condition
2591 * with regard to ffs_opts->bound access
2592 */
2593 if (!ffs_opts->refcnt) {
2594 ret = functionfs_bind(func->ffs, c->cdev);
2595 if (ret)
2596 return ERR_PTR(ret);
2597 }
2598 ffs_opts->refcnt++;
2599 func->function.strings = func->ffs->stringtabs;
2600
2601 return ffs_opts;
2602}
2603
2604static int _ffs_func_bind(struct usb_configuration *c,
2605 struct usb_function *f)
2606{
2607 struct ffs_function *func = ffs_func_from_usb(f);
2608 struct ffs_data *ffs = func->ffs;
2609
2610 const int full = !!func->ffs->fs_descs_count;
2611 const int high = gadget_is_dualspeed(func->gadget) &&
2612 func->ffs->hs_descs_count;
2613 const int super = gadget_is_superspeed(func->gadget) &&
2614 func->ffs->ss_descs_count;
2615
2616 int fs_len, hs_len, ss_len, ret, i;
2617
2618 /* Make it a single chunk, less management later on */
2619 vla_group(d);
2620 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2621 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2622 full ? ffs->fs_descs_count + 1 : 0);
2623 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2624 high ? ffs->hs_descs_count + 1 : 0);
2625 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2626 super ? ffs->ss_descs_count + 1 : 0);
2627 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2628 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2629 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2630 vla_item_with_sz(d, char[16], ext_compat,
2631 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2632 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2633 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2634 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2635 ffs->ms_os_descs_ext_prop_count);
2636 vla_item_with_sz(d, char, ext_prop_name,
2637 ffs->ms_os_descs_ext_prop_name_len);
2638 vla_item_with_sz(d, char, ext_prop_data,
2639 ffs->ms_os_descs_ext_prop_data_len);
2640 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2641 char *vlabuf;
2642
2643 ENTER();
2644
2645 /* Has descriptors only for speeds gadget does not support */
2646 if (unlikely(!(full | high | super)))
2647 return -ENOTSUPP;
2648
2649 /* Allocate a single chunk, less management later on */
2650 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2651 if (unlikely(!vlabuf))
2652 return -ENOMEM;
2653
2654 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2655 ffs->ms_os_descs_ext_prop_name_avail =
2656 vla_ptr(vlabuf, d, ext_prop_name);
2657 ffs->ms_os_descs_ext_prop_data_avail =
2658 vla_ptr(vlabuf, d, ext_prop_data);
2659
2660 /* Copy descriptors */
2661 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2662 ffs->raw_descs_length);
2663
2664 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2665 for (ret = ffs->eps_count; ret; --ret) {
2666 struct ffs_ep *ptr;
2667
2668 ptr = vla_ptr(vlabuf, d, eps);
2669 ptr[ret].num = -1;
2670 }
2671
2672 /* Save pointers
2673 * d_eps == vlabuf, func->eps used to kfree vlabuf later
2674 */
2675 func->eps = vla_ptr(vlabuf, d, eps);
2676 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2677
2678 /*
2679 * Go through all the endpoint descriptors and allocate
2680 * endpoints first, so that later we can rewrite the endpoint
2681 * numbers without worrying that it may be described later on.
2682 */
2683 if (likely(full)) {
2684 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2685 fs_len = ffs_do_descs(ffs->fs_descs_count,
2686 vla_ptr(vlabuf, d, raw_descs),
2687 d_raw_descs__sz,
2688 __ffs_func_bind_do_descs, func);
2689 if (unlikely(fs_len < 0)) {
2690 ret = fs_len;
2691 goto error;
2692 }
2693 } else {
2694 fs_len = 0;
2695 }
2696
2697 if (likely(high)) {
2698 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2699 hs_len = ffs_do_descs(ffs->hs_descs_count,
2700 vla_ptr(vlabuf, d, raw_descs) + fs_len,
2701 d_raw_descs__sz - fs_len,
2702 __ffs_func_bind_do_descs, func);
2703 if (unlikely(hs_len < 0)) {
2704 ret = hs_len;
2705 goto error;
2706 }
2707 } else {
2708 hs_len = 0;
2709 }
2710
2711 if (likely(super)) {
2712 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2713 ss_len = ffs_do_descs(ffs->ss_descs_count,
2714 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2715 d_raw_descs__sz - fs_len - hs_len,
2716 __ffs_func_bind_do_descs, func);
2717 if (unlikely(ss_len < 0)) {
2718 ret = ss_len;
2719 goto error;
2720 }
2721 } else {
2722 ss_len = 0;
2723 }
2724
2725 /*
2726 * Now handle interface numbers allocation and interface and
2727 * endpoint numbers rewriting. We can do that in one go
2728 * now.
2729 */
2730 ret = ffs_do_descs(ffs->fs_descs_count +
2731 (high ? ffs->hs_descs_count : 0) +
2732 (super ? ffs->ss_descs_count : 0),
2733 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2734 __ffs_func_bind_do_nums, func);
2735 if (unlikely(ret < 0))
2736 goto error;
2737
2738 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2739 if (c->cdev->use_os_string)
2740 for (i = 0; i < ffs->interfaces_count; ++i) {
2741 struct usb_os_desc *desc;
2742
2743 desc = func->function.os_desc_table[i].os_desc =
2744 vla_ptr(vlabuf, d, os_desc) +
2745 i * sizeof(struct usb_os_desc);
2746 desc->ext_compat_id =
2747 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2748 INIT_LIST_HEAD(&desc->ext_prop);
2749 }
2750 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2751 vla_ptr(vlabuf, d, raw_descs) +
2752 fs_len + hs_len + ss_len,
2753 d_raw_descs__sz - fs_len - hs_len - ss_len,
2754 __ffs_func_bind_do_os_desc, func);
2755 if (unlikely(ret < 0))
2756 goto error;
2757 func->function.os_desc_n =
2758 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2759
2760 /* And we're done */
2761 ffs_event_add(ffs, FUNCTIONFS_BIND);
2762 return 0;
2763
2764error:
2765 /* XXX Do we need to release all claimed endpoints here? */
2766 return ret;
2767}
2768
2769static int ffs_func_bind(struct usb_configuration *c,
2770 struct usb_function *f)
2771{
2772 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2773
2774 if (IS_ERR(ffs_opts))
2775 return PTR_ERR(ffs_opts);
2776
2777 return _ffs_func_bind(c, f);
2778}
2779
2780
2781/* Other USB function hooks *************************************************/
2782
2783static int ffs_func_set_alt(struct usb_function *f,
2784 unsigned interface, unsigned alt)
2785{
2786 struct ffs_function *func = ffs_func_from_usb(f);
2787 struct ffs_data *ffs = func->ffs;
2788 int ret = 0, intf;
2789
2790 if (alt != (unsigned)-1) {
2791 intf = ffs_func_revmap_intf(func, interface);
2792 if (unlikely(intf < 0))
2793 return intf;
2794 }
2795
2796 if (ffs->func)
2797 ffs_func_eps_disable(ffs->func);
2798
2799 if (ffs->state != FFS_ACTIVE)
2800 return -ENODEV;
2801
2802 if (alt == (unsigned)-1) {
2803 ffs->func = NULL;
2804 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2805 return 0;
2806 }
2807
2808 ffs->func = func;
2809 ret = ffs_func_eps_enable(func);
2810 if (likely(ret >= 0))
2811 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2812 return ret;
2813}
2814
2815static void ffs_func_disable(struct usb_function *f)
2816{
2817 ffs_func_set_alt(f, 0, (unsigned)-1);
2818}
2819
2820static int ffs_func_setup(struct usb_function *f,
2821 const struct usb_ctrlrequest *creq)
2822{
2823 struct ffs_function *func = ffs_func_from_usb(f);
2824 struct ffs_data *ffs = func->ffs;
2825 unsigned long flags;
2826 int ret;
2827
2828 ENTER();
2829
2830 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2831 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2832 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
2833 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
2834 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
2835
2836 /*
2837 * Most requests directed to interface go through here
2838 * (notable exceptions are set/get interface) so we need to
2839 * handle them. All other either handled by composite or
2840 * passed to usb_configuration->setup() (if one is set). No
2841 * matter, we will handle requests directed to endpoint here
2842 * as well (as it's straightforward) but what to do with any
2843 * other request?
2844 */
2845 if (ffs->state != FFS_ACTIVE)
2846 return -ENODEV;
2847
2848 switch (creq->bRequestType & USB_RECIP_MASK) {
2849 case USB_RECIP_INTERFACE:
2850 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2851 if (unlikely(ret < 0))
2852 return ret;
2853 break;
2854
2855 case USB_RECIP_ENDPOINT:
2856 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2857 if (unlikely(ret < 0))
2858 return ret;
2859 break;
2860
2861 default:
2862 return -EOPNOTSUPP;
2863 }
2864
2865 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2866 ffs->ev.setup = *creq;
2867 ffs->ev.setup.wIndex = cpu_to_le16(ret);
2868 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2869 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2870
2871 return 0;
2872}
2873
2874static void ffs_func_suspend(struct usb_function *f)
2875{
2876 ENTER();
2877 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2878}
2879
2880static void ffs_func_resume(struct usb_function *f)
2881{
2882 ENTER();
2883 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2884}
2885
2886
2887/* Endpoint and interface numbers reverse mapping ***************************/
2888
2889static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2890{
2891 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2892 return num ? num : -EDOM;
2893}
2894
2895static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2896{
2897 short *nums = func->interfaces_nums;
2898 unsigned count = func->ffs->interfaces_count;
2899
2900 for (; count; --count, ++nums) {
2901 if (*nums >= 0 && *nums == intf)
2902 return nums - func->interfaces_nums;
2903 }
2904
2905 return -EDOM;
2906}
2907
2908
2909/* Devices management *******************************************************/
2910
2911static LIST_HEAD(ffs_devices);
2912
2913static struct ffs_dev *_ffs_do_find_dev(const char *name)
2914{
2915 struct ffs_dev *dev;
2916
2917 list_for_each_entry(dev, &ffs_devices, entry) {
2918 if (!dev->name || !name)
2919 continue;
2920 if (strcmp(dev->name, name) == 0)
2921 return dev;
2922 }
2923
2924 return NULL;
2925}
2926
2927/*
2928 * ffs_lock must be taken by the caller of this function
2929 */
2930static struct ffs_dev *_ffs_get_single_dev(void)
2931{
2932 struct ffs_dev *dev;
2933
2934 if (list_is_singular(&ffs_devices)) {
2935 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
2936 if (dev->single)
2937 return dev;
2938 }
2939
2940 return NULL;
2941}
2942
2943/*
2944 * ffs_lock must be taken by the caller of this function
2945 */
2946static struct ffs_dev *_ffs_find_dev(const char *name)
2947{
2948 struct ffs_dev *dev;
2949
2950 dev = _ffs_get_single_dev();
2951 if (dev)
2952 return dev;
2953
2954 return _ffs_do_find_dev(name);
2955}
2956
2957/* Configfs support *********************************************************/
2958
2959static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
2960{
2961 return container_of(to_config_group(item), struct f_fs_opts,
2962 func_inst.group);
2963}
2964
2965static void ffs_attr_release(struct config_item *item)
2966{
2967 struct f_fs_opts *opts = to_ffs_opts(item);
2968
2969 usb_put_function_instance(&opts->func_inst);
2970}
2971
2972static struct configfs_item_operations ffs_item_ops = {
2973 .release = ffs_attr_release,
2974};
2975
2976static struct config_item_type ffs_func_type = {
2977 .ct_item_ops = &ffs_item_ops,
2978 .ct_owner = THIS_MODULE,
2979};
2980
2981
2982/* Function registration interface ******************************************/
2983
2984static void ffs_free_inst(struct usb_function_instance *f)
2985{
2986 struct f_fs_opts *opts;
2987
2988 opts = to_f_fs_opts(f);
2989 ffs_dev_lock();
2990 _ffs_free_dev(opts->dev);
2991 ffs_dev_unlock();
2992 kfree(opts);
2993}
2994
2995#define MAX_INST_NAME_LEN 40
2996
2997static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
2998{
2999 struct f_fs_opts *opts;
3000 char *ptr;
3001 const char *tmp;
3002 int name_len, ret;
3003
3004 name_len = strlen(name) + 1;
3005 if (name_len > MAX_INST_NAME_LEN)
3006 return -ENAMETOOLONG;
3007
3008 ptr = kstrndup(name, name_len, GFP_KERNEL);
3009 if (!ptr)
3010 return -ENOMEM;
3011
3012 opts = to_f_fs_opts(fi);
3013 tmp = NULL;
3014
3015 ffs_dev_lock();
3016
3017 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3018 ret = _ffs_name_dev(opts->dev, ptr);
3019 if (ret) {
3020 kfree(ptr);
3021 ffs_dev_unlock();
3022 return ret;
3023 }
3024 opts->dev->name_allocated = true;
3025
3026 ffs_dev_unlock();
3027
3028 kfree(tmp);
3029
3030 return 0;
3031}
3032
3033static struct usb_function_instance *ffs_alloc_inst(void)
3034{
3035 struct f_fs_opts *opts;
3036 struct ffs_dev *dev;
3037
3038 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3039 if (!opts)
3040 return ERR_PTR(-ENOMEM);
3041
3042 opts->func_inst.set_inst_name = ffs_set_inst_name;
3043 opts->func_inst.free_func_inst = ffs_free_inst;
3044 ffs_dev_lock();
3045 dev = _ffs_alloc_dev();
3046 ffs_dev_unlock();
3047 if (IS_ERR(dev)) {
3048 kfree(opts);
3049 return ERR_CAST(dev);
3050 }
3051 opts->dev = dev;
3052 dev->opts = opts;
3053
3054 config_group_init_type_name(&opts->func_inst.group, "",
3055 &ffs_func_type);
3056 return &opts->func_inst;
3057}
3058
3059static void ffs_free(struct usb_function *f)
3060{
3061 kfree(ffs_func_from_usb(f));
3062}
3063
3064static void ffs_func_unbind(struct usb_configuration *c,
3065 struct usb_function *f)
3066{
3067 struct ffs_function *func = ffs_func_from_usb(f);
3068 struct ffs_data *ffs = func->ffs;
3069 struct f_fs_opts *opts =
3070 container_of(f->fi, struct f_fs_opts, func_inst);
3071 struct ffs_ep *ep = func->eps;
3072 unsigned count = ffs->eps_count;
3073 unsigned long flags;
3074
3075 ENTER();
3076 if (ffs->func == func) {
3077 ffs_func_eps_disable(func);
3078 ffs->func = NULL;
3079 }
3080
3081 if (!--opts->refcnt)
3082 functionfs_unbind(ffs);
3083
3084 /* cleanup after autoconfig */
3085 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3086 do {
3087 if (ep->ep && ep->req)
3088 usb_ep_free_request(ep->ep, ep->req);
3089 ep->req = NULL;
3090 ++ep;
3091 } while (--count);
3092 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3093 kfree(func->eps);
3094 func->eps = NULL;
3095 /*
3096 * eps, descriptors and interfaces_nums are allocated in the
3097 * same chunk so only one free is required.
3098 */
3099 func->function.fs_descriptors = NULL;
3100 func->function.hs_descriptors = NULL;
3101 func->function.ss_descriptors = NULL;
3102 func->interfaces_nums = NULL;
3103
3104 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3105}
3106
3107static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3108{
3109 struct ffs_function *func;
3110
3111 ENTER();
3112
3113 func = kzalloc(sizeof(*func), GFP_KERNEL);
3114 if (unlikely(!func))
3115 return ERR_PTR(-ENOMEM);
3116
3117 func->function.name = "Function FS Gadget";
3118
3119 func->function.bind = ffs_func_bind;
3120 func->function.unbind = ffs_func_unbind;
3121 func->function.set_alt = ffs_func_set_alt;
3122 func->function.disable = ffs_func_disable;
3123 func->function.setup = ffs_func_setup;
3124 func->function.suspend = ffs_func_suspend;
3125 func->function.resume = ffs_func_resume;
3126 func->function.free_func = ffs_free;
3127
3128 return &func->function;
3129}
3130
3131/*
3132 * ffs_lock must be taken by the caller of this function
3133 */
3134static struct ffs_dev *_ffs_alloc_dev(void)
3135{
3136 struct ffs_dev *dev;
3137 int ret;
3138
3139 if (_ffs_get_single_dev())
3140 return ERR_PTR(-EBUSY);
3141
3142 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3143 if (!dev)
3144 return ERR_PTR(-ENOMEM);
3145
3146 if (list_empty(&ffs_devices)) {
3147 ret = functionfs_init();
3148 if (ret) {
3149 kfree(dev);
3150 return ERR_PTR(ret);
3151 }
3152 }
3153
3154 list_add(&dev->entry, &ffs_devices);
3155
3156 return dev;
3157}
3158
3159/*
3160 * ffs_lock must be taken by the caller of this function
3161 * The caller is responsible for "name" being available whenever f_fs needs it
3162 */
3163static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3164{
3165 struct ffs_dev *existing;
3166
3167 existing = _ffs_do_find_dev(name);
3168 if (existing)
3169 return -EBUSY;
3170
3171 dev->name = name;
3172
3173 return 0;
3174}
3175
3176/*
3177 * The caller is responsible for "name" being available whenever f_fs needs it
3178 */
3179int ffs_name_dev(struct ffs_dev *dev, const char *name)
3180{
3181 int ret;
3182
3183 ffs_dev_lock();
3184 ret = _ffs_name_dev(dev, name);
3185 ffs_dev_unlock();
3186
3187 return ret;
3188}
3189EXPORT_SYMBOL_GPL(ffs_name_dev);
3190
3191int ffs_single_dev(struct ffs_dev *dev)
3192{
3193 int ret;
3194
3195 ret = 0;
3196 ffs_dev_lock();
3197
3198 if (!list_is_singular(&ffs_devices))
3199 ret = -EBUSY;
3200 else
3201 dev->single = true;
3202
3203 ffs_dev_unlock();
3204 return ret;
3205}
3206EXPORT_SYMBOL_GPL(ffs_single_dev);
3207
3208/*
3209 * ffs_lock must be taken by the caller of this function
3210 */
3211static void _ffs_free_dev(struct ffs_dev *dev)
3212{
3213 list_del(&dev->entry);
3214 if (dev->name_allocated)
3215 kfree(dev->name);
3216 kfree(dev);
3217 if (list_empty(&ffs_devices))
3218 functionfs_cleanup();
3219}
3220
3221static void *ffs_acquire_dev(const char *dev_name)
3222{
3223 struct ffs_dev *ffs_dev;
3224
3225 ENTER();
3226 ffs_dev_lock();
3227
3228 ffs_dev = _ffs_find_dev(dev_name);
3229 if (!ffs_dev)
3230 ffs_dev = ERR_PTR(-ENOENT);
3231 else if (ffs_dev->mounted)
3232 ffs_dev = ERR_PTR(-EBUSY);
3233 else if (ffs_dev->ffs_acquire_dev_callback &&
3234 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3235 ffs_dev = ERR_PTR(-ENOENT);
3236 else
3237 ffs_dev->mounted = true;
3238
3239 ffs_dev_unlock();
3240 return ffs_dev;
3241}
3242
3243static void ffs_release_dev(struct ffs_data *ffs_data)
3244{
3245 struct ffs_dev *ffs_dev;
3246
3247 ENTER();
3248 ffs_dev_lock();
3249
3250 ffs_dev = ffs_data->private_data;
3251 if (ffs_dev) {
3252 ffs_dev->mounted = false;
3253
3254 if (ffs_dev->ffs_release_dev_callback)
3255 ffs_dev->ffs_release_dev_callback(ffs_dev);
3256 }
3257
3258 ffs_dev_unlock();
3259}
3260
3261static int ffs_ready(struct ffs_data *ffs)
3262{
3263 struct ffs_dev *ffs_obj;
3264 int ret = 0;
3265
3266 ENTER();
3267 ffs_dev_lock();
3268
3269 ffs_obj = ffs->private_data;
3270 if (!ffs_obj) {
3271 ret = -EINVAL;
3272 goto done;
3273 }
3274 if (WARN_ON(ffs_obj->desc_ready)) {
3275 ret = -EBUSY;
3276 goto done;
3277 }
3278
3279 ffs_obj->desc_ready = true;
3280 ffs_obj->ffs_data = ffs;
3281
3282 if (ffs_obj->ffs_ready_callback)
3283 ret = ffs_obj->ffs_ready_callback(ffs);
3284
3285done:
3286 ffs_dev_unlock();
3287 return ret;
3288}
3289
3290static void ffs_closed(struct ffs_data *ffs)
3291{
3292 struct ffs_dev *ffs_obj;
3293
3294 ENTER();
3295 ffs_dev_lock();
3296
3297 ffs_obj = ffs->private_data;
3298 if (!ffs_obj)
3299 goto done;
3300
3301 ffs_obj->desc_ready = false;
3302
3303 if (ffs_obj->ffs_closed_callback)
3304 ffs_obj->ffs_closed_callback(ffs);
3305
3306 if (!ffs_obj->opts || ffs_obj->opts->no_configfs
3307 || !ffs_obj->opts->func_inst.group.cg_item.ci_parent)
3308 goto done;
3309
3310 unregister_gadget_item(ffs_obj->opts->
3311 func_inst.group.cg_item.ci_parent->ci_parent);
3312done:
3313 ffs_dev_unlock();
3314}
3315
3316/* Misc helper functions ****************************************************/
3317
3318static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3319{
3320 return nonblock
3321 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3322 : mutex_lock_interruptible(mutex);
3323}
3324
3325static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3326{
3327 char *data;
3328
3329 if (unlikely(!len))
3330 return NULL;
3331
3332 data = kmalloc(len, GFP_KERNEL);
3333 if (unlikely(!data))
3334 return ERR_PTR(-ENOMEM);
3335
3336 if (unlikely(__copy_from_user(data, buf, len))) {
3337 kfree(data);
3338 return ERR_PTR(-EFAULT);
3339 }
3340
3341 pr_vdebug("Buffer from user space:\n");
3342 ffs_dump_mem("", data, len);
3343
3344 return data;
3345}
3346
3347DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3348MODULE_LICENSE("GPL");
3349MODULE_AUTHOR("Michal Nazarewicz");
generated by cgit v1.2.2 (git 2.25.0) at 2026-05-29 12:32:27 -0400