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Merge tag 'range-macro' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...
[deliverable/linux.git] / drivers / usb / gadget / 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 <asm/unaligned.h>
26
27 #include <linux/usb/composite.h>
28 #include <linux/usb/functionfs.h>
29
30
31 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
32
33
34 /* Debugging ****************************************************************/
35
36 #ifdef VERBOSE_DEBUG
37 #ifndef pr_vdebug
38 # define pr_vdebug pr_debug
39 #endif /* pr_vdebug */
40 # define ffs_dump_mem(prefix, ptr, len) \
41 print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
42 #else
43 #ifndef pr_vdebug
44 # define pr_vdebug(...) do { } while (0)
45 #endif /* pr_vdebug */
46 # define ffs_dump_mem(prefix, ptr, len) do { } while (0)
47 #endif /* VERBOSE_DEBUG */
48
49 #define ENTER() pr_vdebug("%s()\n", __func__)
50
51
52 /* The data structure and setup file ****************************************/
53
54 enum ffs_state {
55 /*
56 * Waiting for descriptors and strings.
57 *
58 * In this state no open(2), read(2) or write(2) on epfiles
59 * may succeed (which should not be the problem as there
60 * should be no such files opened in the first place).
61 */
62 FFS_READ_DESCRIPTORS,
63 FFS_READ_STRINGS,
64
65 /*
66 * We've got descriptors and strings. We are or have called
67 * functionfs_ready_callback(). functionfs_bind() may have
68 * been called but we don't know.
69 *
70 * This is the only state in which operations on epfiles may
71 * succeed.
72 */
73 FFS_ACTIVE,
74
75 /*
76 * All endpoints have been closed. This state is also set if
77 * we encounter an unrecoverable error. The only
78 * unrecoverable error is situation when after reading strings
79 * from user space we fail to initialise epfiles or
80 * functionfs_ready_callback() returns with error (<0).
81 *
82 * In this state no open(2), read(2) or write(2) (both on ep0
83 * as well as epfile) may succeed (at this point epfiles are
84 * unlinked and all closed so this is not a problem; ep0 is
85 * also closed but ep0 file exists and so open(2) on ep0 must
86 * fail).
87 */
88 FFS_CLOSING
89 };
90
91
92 enum ffs_setup_state {
93 /* There is no setup request pending. */
94 FFS_NO_SETUP,
95 /*
96 * User has read events and there was a setup request event
97 * there. The next read/write on ep0 will handle the
98 * request.
99 */
100 FFS_SETUP_PENDING,
101 /*
102 * There was event pending but before user space handled it
103 * some other event was introduced which canceled existing
104 * setup. If this state is set read/write on ep0 return
105 * -EIDRM. This state is only set when adding event.
106 */
107 FFS_SETUP_CANCELED
108 };
109
110
111
112 struct ffs_epfile;
113 struct ffs_function;
114
115 struct ffs_data {
116 struct usb_gadget *gadget;
117
118 /*
119 * Protect access read/write operations, only one read/write
120 * at a time. As a consequence protects ep0req and company.
121 * While setup request is being processed (queued) this is
122 * held.
123 */
124 struct mutex mutex;
125
126 /*
127 * Protect access to endpoint related structures (basically
128 * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
129 * endpoint zero.
130 */
131 spinlock_t eps_lock;
132
133 /*
134 * XXX REVISIT do we need our own request? Since we are not
135 * handling setup requests immediately user space may be so
136 * slow that another setup will be sent to the gadget but this
137 * time not to us but another function and then there could be
138 * a race. Is that the case? Or maybe we can use cdev->req
139 * after all, maybe we just need some spinlock for that?
140 */
141 struct usb_request *ep0req; /* P: mutex */
142 struct completion ep0req_completion; /* P: mutex */
143 int ep0req_status; /* P: mutex */
144
145 /* reference counter */
146 atomic_t ref;
147 /* how many files are opened (EP0 and others) */
148 atomic_t opened;
149
150 /* EP0 state */
151 enum ffs_state state;
152
153 /*
154 * Possible transitions:
155 * + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
156 * happens only in ep0 read which is P: mutex
157 * + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
158 * happens only in ep0 i/o which is P: mutex
159 * + FFS_SETUP_PENDING -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
160 * + FFS_SETUP_CANCELED -> FFS_NO_SETUP -- cmpxchg
161 */
162 enum ffs_setup_state setup_state;
163
164 #define FFS_SETUP_STATE(ffs) \
165 ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state, \
166 FFS_SETUP_CANCELED, FFS_NO_SETUP))
167
168 /* Events & such. */
169 struct {
170 u8 types[4];
171 unsigned short count;
172 /* XXX REVISIT need to update it in some places, or do we? */
173 unsigned short can_stall;
174 struct usb_ctrlrequest setup;
175
176 wait_queue_head_t waitq;
177 } ev; /* the whole structure, P: ev.waitq.lock */
178
179 /* Flags */
180 unsigned long flags;
181 #define FFS_FL_CALL_CLOSED_CALLBACK 0
182 #define FFS_FL_BOUND 1
183
184 /* Active function */
185 struct ffs_function *func;
186
187 /*
188 * Device name, write once when file system is mounted.
189 * Intended for user to read if she wants.
190 */
191 const char *dev_name;
192 /* Private data for our user (ie. gadget). Managed by user. */
193 void *private_data;
194
195 /* filled by __ffs_data_got_descs() */
196 /*
197 * Real descriptors are 16 bytes after raw_descs (so you need
198 * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
199 * first full speed descriptor). raw_descs_length and
200 * raw_fs_descs_length do not have those 16 bytes added.
201 */
202 const void *raw_descs;
203 unsigned raw_descs_length;
204 unsigned raw_fs_descs_length;
205 unsigned fs_descs_count;
206 unsigned hs_descs_count;
207
208 unsigned short strings_count;
209 unsigned short interfaces_count;
210 unsigned short eps_count;
211 unsigned short _pad1;
212
213 /* filled by __ffs_data_got_strings() */
214 /* ids in stringtabs are set in functionfs_bind() */
215 const void *raw_strings;
216 struct usb_gadget_strings **stringtabs;
217
218 /*
219 * File system's super block, write once when file system is
220 * mounted.
221 */
222 struct super_block *sb;
223
224 /* File permissions, written once when fs is mounted */
225 struct ffs_file_perms {
226 umode_t mode;
227 kuid_t uid;
228 kgid_t gid;
229 } file_perms;
230
231 /*
232 * The endpoint files, filled by ffs_epfiles_create(),
233 * destroyed by ffs_epfiles_destroy().
234 */
235 struct ffs_epfile *epfiles;
236 };
237
238 /* Reference counter handling */
239 static void ffs_data_get(struct ffs_data *ffs);
240 static void ffs_data_put(struct ffs_data *ffs);
241 /* Creates new ffs_data object. */
242 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
243
244 /* Opened counter handling. */
245 static void ffs_data_opened(struct ffs_data *ffs);
246 static void ffs_data_closed(struct ffs_data *ffs);
247
248 /* Called with ffs->mutex held; take over ownership of data. */
249 static int __must_check
250 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
251 static int __must_check
252 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
253
254
255 /* The function structure ***************************************************/
256
257 struct ffs_ep;
258
259 struct ffs_function {
260 struct usb_configuration *conf;
261 struct usb_gadget *gadget;
262 struct ffs_data *ffs;
263
264 struct ffs_ep *eps;
265 u8 eps_revmap[16];
266 short *interfaces_nums;
267
268 struct usb_function function;
269 };
270
271
272 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
273 {
274 return container_of(f, struct ffs_function, function);
275 }
276
277 static void ffs_func_free(struct ffs_function *func);
278
279 static void ffs_func_eps_disable(struct ffs_function *func);
280 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
281
282 static int ffs_func_bind(struct usb_configuration *,
283 struct usb_function *);
284 static void ffs_func_unbind(struct usb_configuration *,
285 struct usb_function *);
286 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
287 static void ffs_func_disable(struct usb_function *);
288 static int ffs_func_setup(struct usb_function *,
289 const struct usb_ctrlrequest *);
290 static void ffs_func_suspend(struct usb_function *);
291 static void ffs_func_resume(struct usb_function *);
292
293
294 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
295 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
296
297
298 /* The endpoints structures *************************************************/
299
300 struct ffs_ep {
301 struct usb_ep *ep; /* P: ffs->eps_lock */
302 struct usb_request *req; /* P: epfile->mutex */
303
304 /* [0]: full speed, [1]: high speed */
305 struct usb_endpoint_descriptor *descs[2];
306
307 u8 num;
308
309 int status; /* P: epfile->mutex */
310 };
311
312 struct ffs_epfile {
313 /* Protects ep->ep and ep->req. */
314 struct mutex mutex;
315 wait_queue_head_t wait;
316
317 struct ffs_data *ffs;
318 struct ffs_ep *ep; /* P: ffs->eps_lock */
319
320 struct dentry *dentry;
321
322 char name[5];
323
324 unsigned char in; /* P: ffs->eps_lock */
325 unsigned char isoc; /* P: ffs->eps_lock */
326
327 unsigned char _pad;
328 };
329
330 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
331 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
332
333 static struct inode *__must_check
334 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
335 const struct file_operations *fops,
336 struct dentry **dentry_p);
337
338
339 /* Misc helper functions ****************************************************/
340
341 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
342 __attribute__((warn_unused_result, nonnull));
343 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
344 __attribute__((warn_unused_result, nonnull));
345
346
347 /* Control file aka ep0 *****************************************************/
348
349 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
350 {
351 struct ffs_data *ffs = req->context;
352
353 complete_all(&ffs->ep0req_completion);
354 }
355
356 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
357 {
358 struct usb_request *req = ffs->ep0req;
359 int ret;
360
361 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
362
363 spin_unlock_irq(&ffs->ev.waitq.lock);
364
365 req->buf = data;
366 req->length = len;
367
368 /*
369 * UDC layer requires to provide a buffer even for ZLP, but should
370 * not use it at all. Let's provide some poisoned pointer to catch
371 * possible bug in the driver.
372 */
373 if (req->buf == NULL)
374 req->buf = (void *)0xDEADBABE;
375
376 INIT_COMPLETION(ffs->ep0req_completion);
377
378 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
379 if (unlikely(ret < 0))
380 return ret;
381
382 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
383 if (unlikely(ret)) {
384 usb_ep_dequeue(ffs->gadget->ep0, req);
385 return -EINTR;
386 }
387
388 ffs->setup_state = FFS_NO_SETUP;
389 return ffs->ep0req_status;
390 }
391
392 static int __ffs_ep0_stall(struct ffs_data *ffs)
393 {
394 if (ffs->ev.can_stall) {
395 pr_vdebug("ep0 stall\n");
396 usb_ep_set_halt(ffs->gadget->ep0);
397 ffs->setup_state = FFS_NO_SETUP;
398 return -EL2HLT;
399 } else {
400 pr_debug("bogus ep0 stall!\n");
401 return -ESRCH;
402 }
403 }
404
405 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
406 size_t len, loff_t *ptr)
407 {
408 struct ffs_data *ffs = file->private_data;
409 ssize_t ret;
410 char *data;
411
412 ENTER();
413
414 /* Fast check if setup was canceled */
415 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
416 return -EIDRM;
417
418 /* Acquire mutex */
419 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
420 if (unlikely(ret < 0))
421 return ret;
422
423 /* Check state */
424 switch (ffs->state) {
425 case FFS_READ_DESCRIPTORS:
426 case FFS_READ_STRINGS:
427 /* Copy data */
428 if (unlikely(len < 16)) {
429 ret = -EINVAL;
430 break;
431 }
432
433 data = ffs_prepare_buffer(buf, len);
434 if (IS_ERR(data)) {
435 ret = PTR_ERR(data);
436 break;
437 }
438
439 /* Handle data */
440 if (ffs->state == FFS_READ_DESCRIPTORS) {
441 pr_info("read descriptors\n");
442 ret = __ffs_data_got_descs(ffs, data, len);
443 if (unlikely(ret < 0))
444 break;
445
446 ffs->state = FFS_READ_STRINGS;
447 ret = len;
448 } else {
449 pr_info("read strings\n");
450 ret = __ffs_data_got_strings(ffs, data, len);
451 if (unlikely(ret < 0))
452 break;
453
454 ret = ffs_epfiles_create(ffs);
455 if (unlikely(ret)) {
456 ffs->state = FFS_CLOSING;
457 break;
458 }
459
460 ffs->state = FFS_ACTIVE;
461 mutex_unlock(&ffs->mutex);
462
463 ret = functionfs_ready_callback(ffs);
464 if (unlikely(ret < 0)) {
465 ffs->state = FFS_CLOSING;
466 return ret;
467 }
468
469 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
470 return len;
471 }
472 break;
473
474 case FFS_ACTIVE:
475 data = NULL;
476 /*
477 * We're called from user space, we can use _irq
478 * rather then _irqsave
479 */
480 spin_lock_irq(&ffs->ev.waitq.lock);
481 switch (FFS_SETUP_STATE(ffs)) {
482 case FFS_SETUP_CANCELED:
483 ret = -EIDRM;
484 goto done_spin;
485
486 case FFS_NO_SETUP:
487 ret = -ESRCH;
488 goto done_spin;
489
490 case FFS_SETUP_PENDING:
491 break;
492 }
493
494 /* FFS_SETUP_PENDING */
495 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
496 spin_unlock_irq(&ffs->ev.waitq.lock);
497 ret = __ffs_ep0_stall(ffs);
498 break;
499 }
500
501 /* FFS_SETUP_PENDING and not stall */
502 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
503
504 spin_unlock_irq(&ffs->ev.waitq.lock);
505
506 data = ffs_prepare_buffer(buf, len);
507 if (IS_ERR(data)) {
508 ret = PTR_ERR(data);
509 break;
510 }
511
512 spin_lock_irq(&ffs->ev.waitq.lock);
513
514 /*
515 * We are guaranteed to be still in FFS_ACTIVE state
516 * but the state of setup could have changed from
517 * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need
518 * to check for that. If that happened we copied data
519 * from user space in vain but it's unlikely.
520 *
521 * For sure we are not in FFS_NO_SETUP since this is
522 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
523 * transition can be performed and it's protected by
524 * mutex.
525 */
526 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
527 ret = -EIDRM;
528 done_spin:
529 spin_unlock_irq(&ffs->ev.waitq.lock);
530 } else {
531 /* unlocks spinlock */
532 ret = __ffs_ep0_queue_wait(ffs, data, len);
533 }
534 kfree(data);
535 break;
536
537 default:
538 ret = -EBADFD;
539 break;
540 }
541
542 mutex_unlock(&ffs->mutex);
543 return ret;
544 }
545
546 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
547 size_t n)
548 {
549 /*
550 * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
551 * to release them.
552 */
553 struct usb_functionfs_event events[n];
554 unsigned i = 0;
555
556 memset(events, 0, sizeof events);
557
558 do {
559 events[i].type = ffs->ev.types[i];
560 if (events[i].type == FUNCTIONFS_SETUP) {
561 events[i].u.setup = ffs->ev.setup;
562 ffs->setup_state = FFS_SETUP_PENDING;
563 }
564 } while (++i < n);
565
566 if (n < ffs->ev.count) {
567 ffs->ev.count -= n;
568 memmove(ffs->ev.types, ffs->ev.types + n,
569 ffs->ev.count * sizeof *ffs->ev.types);
570 } else {
571 ffs->ev.count = 0;
572 }
573
574 spin_unlock_irq(&ffs->ev.waitq.lock);
575 mutex_unlock(&ffs->mutex);
576
577 return unlikely(__copy_to_user(buf, events, sizeof events))
578 ? -EFAULT : sizeof events;
579 }
580
581 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
582 size_t len, loff_t *ptr)
583 {
584 struct ffs_data *ffs = file->private_data;
585 char *data = NULL;
586 size_t n;
587 int ret;
588
589 ENTER();
590
591 /* Fast check if setup was canceled */
592 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
593 return -EIDRM;
594
595 /* Acquire mutex */
596 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
597 if (unlikely(ret < 0))
598 return ret;
599
600 /* Check state */
601 if (ffs->state != FFS_ACTIVE) {
602 ret = -EBADFD;
603 goto done_mutex;
604 }
605
606 /*
607 * We're called from user space, we can use _irq rather then
608 * _irqsave
609 */
610 spin_lock_irq(&ffs->ev.waitq.lock);
611
612 switch (FFS_SETUP_STATE(ffs)) {
613 case FFS_SETUP_CANCELED:
614 ret = -EIDRM;
615 break;
616
617 case FFS_NO_SETUP:
618 n = len / sizeof(struct usb_functionfs_event);
619 if (unlikely(!n)) {
620 ret = -EINVAL;
621 break;
622 }
623
624 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
625 ret = -EAGAIN;
626 break;
627 }
628
629 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
630 ffs->ev.count)) {
631 ret = -EINTR;
632 break;
633 }
634
635 return __ffs_ep0_read_events(ffs, buf,
636 min(n, (size_t)ffs->ev.count));
637
638 case FFS_SETUP_PENDING:
639 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
640 spin_unlock_irq(&ffs->ev.waitq.lock);
641 ret = __ffs_ep0_stall(ffs);
642 goto done_mutex;
643 }
644
645 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
646
647 spin_unlock_irq(&ffs->ev.waitq.lock);
648
649 if (likely(len)) {
650 data = kmalloc(len, GFP_KERNEL);
651 if (unlikely(!data)) {
652 ret = -ENOMEM;
653 goto done_mutex;
654 }
655 }
656
657 spin_lock_irq(&ffs->ev.waitq.lock);
658
659 /* See ffs_ep0_write() */
660 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
661 ret = -EIDRM;
662 break;
663 }
664
665 /* unlocks spinlock */
666 ret = __ffs_ep0_queue_wait(ffs, data, len);
667 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
668 ret = -EFAULT;
669 goto done_mutex;
670
671 default:
672 ret = -EBADFD;
673 break;
674 }
675
676 spin_unlock_irq(&ffs->ev.waitq.lock);
677 done_mutex:
678 mutex_unlock(&ffs->mutex);
679 kfree(data);
680 return ret;
681 }
682
683 static int ffs_ep0_open(struct inode *inode, struct file *file)
684 {
685 struct ffs_data *ffs = inode->i_private;
686
687 ENTER();
688
689 if (unlikely(ffs->state == FFS_CLOSING))
690 return -EBUSY;
691
692 file->private_data = ffs;
693 ffs_data_opened(ffs);
694
695 return 0;
696 }
697
698 static int ffs_ep0_release(struct inode *inode, struct file *file)
699 {
700 struct ffs_data *ffs = file->private_data;
701
702 ENTER();
703
704 ffs_data_closed(ffs);
705
706 return 0;
707 }
708
709 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
710 {
711 struct ffs_data *ffs = file->private_data;
712 struct usb_gadget *gadget = ffs->gadget;
713 long ret;
714
715 ENTER();
716
717 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
718 struct ffs_function *func = ffs->func;
719 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
720 } else if (gadget && gadget->ops->ioctl) {
721 ret = gadget->ops->ioctl(gadget, code, value);
722 } else {
723 ret = -ENOTTY;
724 }
725
726 return ret;
727 }
728
729 static const struct file_operations ffs_ep0_operations = {
730 .llseek = no_llseek,
731
732 .open = ffs_ep0_open,
733 .write = ffs_ep0_write,
734 .read = ffs_ep0_read,
735 .release = ffs_ep0_release,
736 .unlocked_ioctl = ffs_ep0_ioctl,
737 };
738
739
740 /* "Normal" endpoints operations ********************************************/
741
742 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
743 {
744 ENTER();
745 if (likely(req->context)) {
746 struct ffs_ep *ep = _ep->driver_data;
747 ep->status = req->status ? req->status : req->actual;
748 complete(req->context);
749 }
750 }
751
752 static ssize_t ffs_epfile_io(struct file *file,
753 char __user *buf, size_t len, int read)
754 {
755 struct ffs_epfile *epfile = file->private_data;
756 struct ffs_ep *ep;
757 char *data = NULL;
758 ssize_t ret;
759 int halt;
760
761 goto first_try;
762 do {
763 spin_unlock_irq(&epfile->ffs->eps_lock);
764 mutex_unlock(&epfile->mutex);
765
766 first_try:
767 /* Are we still active? */
768 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
769 ret = -ENODEV;
770 goto error;
771 }
772
773 /* Wait for endpoint to be enabled */
774 ep = epfile->ep;
775 if (!ep) {
776 if (file->f_flags & O_NONBLOCK) {
777 ret = -EAGAIN;
778 goto error;
779 }
780
781 if (wait_event_interruptible(epfile->wait,
782 (ep = epfile->ep))) {
783 ret = -EINTR;
784 goto error;
785 }
786 }
787
788 /* Do we halt? */
789 halt = !read == !epfile->in;
790 if (halt && epfile->isoc) {
791 ret = -EINVAL;
792 goto error;
793 }
794
795 /* Allocate & copy */
796 if (!halt && !data) {
797 data = kzalloc(len, GFP_KERNEL);
798 if (unlikely(!data))
799 return -ENOMEM;
800
801 if (!read &&
802 unlikely(__copy_from_user(data, buf, len))) {
803 ret = -EFAULT;
804 goto error;
805 }
806 }
807
808 /* We will be using request */
809 ret = ffs_mutex_lock(&epfile->mutex,
810 file->f_flags & O_NONBLOCK);
811 if (unlikely(ret))
812 goto error;
813
814 /*
815 * We're called from user space, we can use _irq rather then
816 * _irqsave
817 */
818 spin_lock_irq(&epfile->ffs->eps_lock);
819
820 /*
821 * While we were acquiring mutex endpoint got disabled
822 * or changed?
823 */
824 } while (unlikely(epfile->ep != ep));
825
826 /* Halt */
827 if (unlikely(halt)) {
828 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
829 usb_ep_set_halt(ep->ep);
830 spin_unlock_irq(&epfile->ffs->eps_lock);
831 ret = -EBADMSG;
832 } else {
833 /* Fire the request */
834 DECLARE_COMPLETION_ONSTACK(done);
835
836 struct usb_request *req = ep->req;
837 req->context = &done;
838 req->complete = ffs_epfile_io_complete;
839 req->buf = data;
840 req->length = len;
841
842 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
843
844 spin_unlock_irq(&epfile->ffs->eps_lock);
845
846 if (unlikely(ret < 0)) {
847 /* nop */
848 } else if (unlikely(wait_for_completion_interruptible(&done))) {
849 ret = -EINTR;
850 usb_ep_dequeue(ep->ep, req);
851 } else {
852 ret = ep->status;
853 if (read && ret > 0 &&
854 unlikely(copy_to_user(buf, data, ret)))
855 ret = -EFAULT;
856 }
857 }
858
859 mutex_unlock(&epfile->mutex);
860 error:
861 kfree(data);
862 return ret;
863 }
864
865 static ssize_t
866 ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
867 loff_t *ptr)
868 {
869 ENTER();
870
871 return ffs_epfile_io(file, (char __user *)buf, len, 0);
872 }
873
874 static ssize_t
875 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
876 {
877 ENTER();
878
879 return ffs_epfile_io(file, buf, len, 1);
880 }
881
882 static int
883 ffs_epfile_open(struct inode *inode, struct file *file)
884 {
885 struct ffs_epfile *epfile = inode->i_private;
886
887 ENTER();
888
889 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
890 return -ENODEV;
891
892 file->private_data = epfile;
893 ffs_data_opened(epfile->ffs);
894
895 return 0;
896 }
897
898 static int
899 ffs_epfile_release(struct inode *inode, struct file *file)
900 {
901 struct ffs_epfile *epfile = inode->i_private;
902
903 ENTER();
904
905 ffs_data_closed(epfile->ffs);
906
907 return 0;
908 }
909
910 static long ffs_epfile_ioctl(struct file *file, unsigned code,
911 unsigned long value)
912 {
913 struct ffs_epfile *epfile = file->private_data;
914 int ret;
915
916 ENTER();
917
918 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
919 return -ENODEV;
920
921 spin_lock_irq(&epfile->ffs->eps_lock);
922 if (likely(epfile->ep)) {
923 switch (code) {
924 case FUNCTIONFS_FIFO_STATUS:
925 ret = usb_ep_fifo_status(epfile->ep->ep);
926 break;
927 case FUNCTIONFS_FIFO_FLUSH:
928 usb_ep_fifo_flush(epfile->ep->ep);
929 ret = 0;
930 break;
931 case FUNCTIONFS_CLEAR_HALT:
932 ret = usb_ep_clear_halt(epfile->ep->ep);
933 break;
934 case FUNCTIONFS_ENDPOINT_REVMAP:
935 ret = epfile->ep->num;
936 break;
937 default:
938 ret = -ENOTTY;
939 }
940 } else {
941 ret = -ENODEV;
942 }
943 spin_unlock_irq(&epfile->ffs->eps_lock);
944
945 return ret;
946 }
947
948 static const struct file_operations ffs_epfile_operations = {
949 .llseek = no_llseek,
950
951 .open = ffs_epfile_open,
952 .write = ffs_epfile_write,
953 .read = ffs_epfile_read,
954 .release = ffs_epfile_release,
955 .unlocked_ioctl = ffs_epfile_ioctl,
956 };
957
958
959 /* File system and super block operations ***********************************/
960
961 /*
962 * Mounting the file system creates a controller file, used first for
963 * function configuration then later for event monitoring.
964 */
965
966 static struct inode *__must_check
967 ffs_sb_make_inode(struct super_block *sb, void *data,
968 const struct file_operations *fops,
969 const struct inode_operations *iops,
970 struct ffs_file_perms *perms)
971 {
972 struct inode *inode;
973
974 ENTER();
975
976 inode = new_inode(sb);
977
978 if (likely(inode)) {
979 struct timespec current_time = CURRENT_TIME;
980
981 inode->i_ino = get_next_ino();
982 inode->i_mode = perms->mode;
983 inode->i_uid = perms->uid;
984 inode->i_gid = perms->gid;
985 inode->i_atime = current_time;
986 inode->i_mtime = current_time;
987 inode->i_ctime = current_time;
988 inode->i_private = data;
989 if (fops)
990 inode->i_fop = fops;
991 if (iops)
992 inode->i_op = iops;
993 }
994
995 return inode;
996 }
997
998 /* Create "regular" file */
999 static struct inode *ffs_sb_create_file(struct super_block *sb,
1000 const char *name, void *data,
1001 const struct file_operations *fops,
1002 struct dentry **dentry_p)
1003 {
1004 struct ffs_data *ffs = sb->s_fs_info;
1005 struct dentry *dentry;
1006 struct inode *inode;
1007
1008 ENTER();
1009
1010 dentry = d_alloc_name(sb->s_root, name);
1011 if (unlikely(!dentry))
1012 return NULL;
1013
1014 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1015 if (unlikely(!inode)) {
1016 dput(dentry);
1017 return NULL;
1018 }
1019
1020 d_add(dentry, inode);
1021 if (dentry_p)
1022 *dentry_p = dentry;
1023
1024 return inode;
1025 }
1026
1027 /* Super block */
1028 static const struct super_operations ffs_sb_operations = {
1029 .statfs = simple_statfs,
1030 .drop_inode = generic_delete_inode,
1031 };
1032
1033 struct ffs_sb_fill_data {
1034 struct ffs_file_perms perms;
1035 umode_t root_mode;
1036 const char *dev_name;
1037 struct ffs_data *ffs_data;
1038 };
1039
1040 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1041 {
1042 struct ffs_sb_fill_data *data = _data;
1043 struct inode *inode;
1044 struct ffs_data *ffs = data->ffs_data;
1045
1046 ENTER();
1047
1048 ffs->sb = sb;
1049 data->ffs_data = NULL;
1050 sb->s_fs_info = ffs;
1051 sb->s_blocksize = PAGE_CACHE_SIZE;
1052 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1053 sb->s_magic = FUNCTIONFS_MAGIC;
1054 sb->s_op = &ffs_sb_operations;
1055 sb->s_time_gran = 1;
1056
1057 /* Root inode */
1058 data->perms.mode = data->root_mode;
1059 inode = ffs_sb_make_inode(sb, NULL,
1060 &simple_dir_operations,
1061 &simple_dir_inode_operations,
1062 &data->perms);
1063 sb->s_root = d_make_root(inode);
1064 if (unlikely(!sb->s_root))
1065 return -ENOMEM;
1066
1067 /* EP0 file */
1068 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1069 &ffs_ep0_operations, NULL)))
1070 return -ENOMEM;
1071
1072 return 0;
1073 }
1074
1075 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1076 {
1077 ENTER();
1078
1079 if (!opts || !*opts)
1080 return 0;
1081
1082 for (;;) {
1083 unsigned long value;
1084 char *eq, *comma;
1085
1086 /* Option limit */
1087 comma = strchr(opts, ',');
1088 if (comma)
1089 *comma = 0;
1090
1091 /* Value limit */
1092 eq = strchr(opts, '=');
1093 if (unlikely(!eq)) {
1094 pr_err("'=' missing in %s\n", opts);
1095 return -EINVAL;
1096 }
1097 *eq = 0;
1098
1099 /* Parse value */
1100 if (kstrtoul(eq + 1, 0, &value)) {
1101 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1102 return -EINVAL;
1103 }
1104
1105 /* Interpret option */
1106 switch (eq - opts) {
1107 case 5:
1108 if (!memcmp(opts, "rmode", 5))
1109 data->root_mode = (value & 0555) | S_IFDIR;
1110 else if (!memcmp(opts, "fmode", 5))
1111 data->perms.mode = (value & 0666) | S_IFREG;
1112 else
1113 goto invalid;
1114 break;
1115
1116 case 4:
1117 if (!memcmp(opts, "mode", 4)) {
1118 data->root_mode = (value & 0555) | S_IFDIR;
1119 data->perms.mode = (value & 0666) | S_IFREG;
1120 } else {
1121 goto invalid;
1122 }
1123 break;
1124
1125 case 3:
1126 if (!memcmp(opts, "uid", 3)) {
1127 data->perms.uid = make_kuid(current_user_ns(), value);
1128 if (!uid_valid(data->perms.uid)) {
1129 pr_err("%s: unmapped value: %lu\n", opts, value);
1130 return -EINVAL;
1131 }
1132 } else if (!memcmp(opts, "gid", 3)) {
1133 data->perms.gid = make_kgid(current_user_ns(), value);
1134 if (!gid_valid(data->perms.gid)) {
1135 pr_err("%s: unmapped value: %lu\n", opts, value);
1136 return -EINVAL;
1137 }
1138 } else {
1139 goto invalid;
1140 }
1141 break;
1142
1143 default:
1144 invalid:
1145 pr_err("%s: invalid option\n", opts);
1146 return -EINVAL;
1147 }
1148
1149 /* Next iteration */
1150 if (!comma)
1151 break;
1152 opts = comma + 1;
1153 }
1154
1155 return 0;
1156 }
1157
1158 /* "mount -t functionfs dev_name /dev/function" ends up here */
1159
1160 static struct dentry *
1161 ffs_fs_mount(struct file_system_type *t, int flags,
1162 const char *dev_name, void *opts)
1163 {
1164 struct ffs_sb_fill_data data = {
1165 .perms = {
1166 .mode = S_IFREG | 0600,
1167 .uid = GLOBAL_ROOT_UID,
1168 .gid = GLOBAL_ROOT_GID,
1169 },
1170 .root_mode = S_IFDIR | 0500,
1171 };
1172 struct dentry *rv;
1173 int ret;
1174 void *ffs_dev;
1175 struct ffs_data *ffs;
1176
1177 ENTER();
1178
1179 ret = ffs_fs_parse_opts(&data, opts);
1180 if (unlikely(ret < 0))
1181 return ERR_PTR(ret);
1182
1183 ffs = ffs_data_new();
1184 if (unlikely(!ffs))
1185 return ERR_PTR(-ENOMEM);
1186 ffs->file_perms = data.perms;
1187
1188 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1189 if (unlikely(!ffs->dev_name)) {
1190 ffs_data_put(ffs);
1191 return ERR_PTR(-ENOMEM);
1192 }
1193
1194 ffs_dev = functionfs_acquire_dev_callback(dev_name);
1195 if (IS_ERR(ffs_dev)) {
1196 ffs_data_put(ffs);
1197 return ERR_CAST(ffs_dev);
1198 }
1199 ffs->private_data = ffs_dev;
1200 data.ffs_data = ffs;
1201
1202 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1203 if (IS_ERR(rv) && data.ffs_data) {
1204 functionfs_release_dev_callback(data.ffs_data);
1205 ffs_data_put(data.ffs_data);
1206 }
1207 return rv;
1208 }
1209
1210 static void
1211 ffs_fs_kill_sb(struct super_block *sb)
1212 {
1213 ENTER();
1214
1215 kill_litter_super(sb);
1216 if (sb->s_fs_info) {
1217 functionfs_release_dev_callback(sb->s_fs_info);
1218 ffs_data_put(sb->s_fs_info);
1219 }
1220 }
1221
1222 static struct file_system_type ffs_fs_type = {
1223 .owner = THIS_MODULE,
1224 .name = "functionfs",
1225 .mount = ffs_fs_mount,
1226 .kill_sb = ffs_fs_kill_sb,
1227 };
1228 MODULE_ALIAS_FS("functionfs");
1229
1230
1231 /* Driver's main init/cleanup functions *************************************/
1232
1233 static int functionfs_init(void)
1234 {
1235 int ret;
1236
1237 ENTER();
1238
1239 ret = register_filesystem(&ffs_fs_type);
1240 if (likely(!ret))
1241 pr_info("file system registered\n");
1242 else
1243 pr_err("failed registering file system (%d)\n", ret);
1244
1245 return ret;
1246 }
1247
1248 static void functionfs_cleanup(void)
1249 {
1250 ENTER();
1251
1252 pr_info("unloading\n");
1253 unregister_filesystem(&ffs_fs_type);
1254 }
1255
1256
1257 /* ffs_data and ffs_function construction and destruction code **************/
1258
1259 static void ffs_data_clear(struct ffs_data *ffs);
1260 static void ffs_data_reset(struct ffs_data *ffs);
1261
1262 static void ffs_data_get(struct ffs_data *ffs)
1263 {
1264 ENTER();
1265
1266 atomic_inc(&ffs->ref);
1267 }
1268
1269 static void ffs_data_opened(struct ffs_data *ffs)
1270 {
1271 ENTER();
1272
1273 atomic_inc(&ffs->ref);
1274 atomic_inc(&ffs->opened);
1275 }
1276
1277 static void ffs_data_put(struct ffs_data *ffs)
1278 {
1279 ENTER();
1280
1281 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1282 pr_info("%s(): freeing\n", __func__);
1283 ffs_data_clear(ffs);
1284 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1285 waitqueue_active(&ffs->ep0req_completion.wait));
1286 kfree(ffs->dev_name);
1287 kfree(ffs);
1288 }
1289 }
1290
1291 static void ffs_data_closed(struct ffs_data *ffs)
1292 {
1293 ENTER();
1294
1295 if (atomic_dec_and_test(&ffs->opened)) {
1296 ffs->state = FFS_CLOSING;
1297 ffs_data_reset(ffs);
1298 }
1299
1300 ffs_data_put(ffs);
1301 }
1302
1303 static struct ffs_data *ffs_data_new(void)
1304 {
1305 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1306 if (unlikely(!ffs))
1307 return 0;
1308
1309 ENTER();
1310
1311 atomic_set(&ffs->ref, 1);
1312 atomic_set(&ffs->opened, 0);
1313 ffs->state = FFS_READ_DESCRIPTORS;
1314 mutex_init(&ffs->mutex);
1315 spin_lock_init(&ffs->eps_lock);
1316 init_waitqueue_head(&ffs->ev.waitq);
1317 init_completion(&ffs->ep0req_completion);
1318
1319 /* XXX REVISIT need to update it in some places, or do we? */
1320 ffs->ev.can_stall = 1;
1321
1322 return ffs;
1323 }
1324
1325 static void ffs_data_clear(struct ffs_data *ffs)
1326 {
1327 ENTER();
1328
1329 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1330 functionfs_closed_callback(ffs);
1331
1332 BUG_ON(ffs->gadget);
1333
1334 if (ffs->epfiles)
1335 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1336
1337 kfree(ffs->raw_descs);
1338 kfree(ffs->raw_strings);
1339 kfree(ffs->stringtabs);
1340 }
1341
1342 static void ffs_data_reset(struct ffs_data *ffs)
1343 {
1344 ENTER();
1345
1346 ffs_data_clear(ffs);
1347
1348 ffs->epfiles = NULL;
1349 ffs->raw_descs = NULL;
1350 ffs->raw_strings = NULL;
1351 ffs->stringtabs = NULL;
1352
1353 ffs->raw_descs_length = 0;
1354 ffs->raw_fs_descs_length = 0;
1355 ffs->fs_descs_count = 0;
1356 ffs->hs_descs_count = 0;
1357
1358 ffs->strings_count = 0;
1359 ffs->interfaces_count = 0;
1360 ffs->eps_count = 0;
1361
1362 ffs->ev.count = 0;
1363
1364 ffs->state = FFS_READ_DESCRIPTORS;
1365 ffs->setup_state = FFS_NO_SETUP;
1366 ffs->flags = 0;
1367 }
1368
1369
1370 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1371 {
1372 struct usb_gadget_strings **lang;
1373 int first_id;
1374
1375 ENTER();
1376
1377 if (WARN_ON(ffs->state != FFS_ACTIVE
1378 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1379 return -EBADFD;
1380
1381 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1382 if (unlikely(first_id < 0))
1383 return first_id;
1384
1385 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1386 if (unlikely(!ffs->ep0req))
1387 return -ENOMEM;
1388 ffs->ep0req->complete = ffs_ep0_complete;
1389 ffs->ep0req->context = ffs;
1390
1391 lang = ffs->stringtabs;
1392 for (lang = ffs->stringtabs; *lang; ++lang) {
1393 struct usb_string *str = (*lang)->strings;
1394 int id = first_id;
1395 for (; str->s; ++id, ++str)
1396 str->id = id;
1397 }
1398
1399 ffs->gadget = cdev->gadget;
1400 ffs_data_get(ffs);
1401 return 0;
1402 }
1403
1404 static void functionfs_unbind(struct ffs_data *ffs)
1405 {
1406 ENTER();
1407
1408 if (!WARN_ON(!ffs->gadget)) {
1409 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1410 ffs->ep0req = NULL;
1411 ffs->gadget = NULL;
1412 clear_bit(FFS_FL_BOUND, &ffs->flags);
1413 ffs_data_put(ffs);
1414 }
1415 }
1416
1417 static int ffs_epfiles_create(struct ffs_data *ffs)
1418 {
1419 struct ffs_epfile *epfile, *epfiles;
1420 unsigned i, count;
1421
1422 ENTER();
1423
1424 count = ffs->eps_count;
1425 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1426 if (!epfiles)
1427 return -ENOMEM;
1428
1429 epfile = epfiles;
1430 for (i = 1; i <= count; ++i, ++epfile) {
1431 epfile->ffs = ffs;
1432 mutex_init(&epfile->mutex);
1433 init_waitqueue_head(&epfile->wait);
1434 sprintf(epfiles->name, "ep%u", i);
1435 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1436 &ffs_epfile_operations,
1437 &epfile->dentry))) {
1438 ffs_epfiles_destroy(epfiles, i - 1);
1439 return -ENOMEM;
1440 }
1441 }
1442
1443 ffs->epfiles = epfiles;
1444 return 0;
1445 }
1446
1447 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1448 {
1449 struct ffs_epfile *epfile = epfiles;
1450
1451 ENTER();
1452
1453 for (; count; --count, ++epfile) {
1454 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1455 waitqueue_active(&epfile->wait));
1456 if (epfile->dentry) {
1457 d_delete(epfile->dentry);
1458 dput(epfile->dentry);
1459 epfile->dentry = NULL;
1460 }
1461 }
1462
1463 kfree(epfiles);
1464 }
1465
1466 static int functionfs_bind_config(struct usb_composite_dev *cdev,
1467 struct usb_configuration *c,
1468 struct ffs_data *ffs)
1469 {
1470 struct ffs_function *func;
1471 int ret;
1472
1473 ENTER();
1474
1475 func = kzalloc(sizeof *func, GFP_KERNEL);
1476 if (unlikely(!func))
1477 return -ENOMEM;
1478
1479 func->function.name = "Function FS Gadget";
1480 func->function.strings = ffs->stringtabs;
1481
1482 func->function.bind = ffs_func_bind;
1483 func->function.unbind = ffs_func_unbind;
1484 func->function.set_alt = ffs_func_set_alt;
1485 func->function.disable = ffs_func_disable;
1486 func->function.setup = ffs_func_setup;
1487 func->function.suspend = ffs_func_suspend;
1488 func->function.resume = ffs_func_resume;
1489
1490 func->conf = c;
1491 func->gadget = cdev->gadget;
1492 func->ffs = ffs;
1493 ffs_data_get(ffs);
1494
1495 ret = usb_add_function(c, &func->function);
1496 if (unlikely(ret))
1497 ffs_func_free(func);
1498
1499 return ret;
1500 }
1501
1502 static void ffs_func_free(struct ffs_function *func)
1503 {
1504 struct ffs_ep *ep = func->eps;
1505 unsigned count = func->ffs->eps_count;
1506 unsigned long flags;
1507
1508 ENTER();
1509
1510 /* cleanup after autoconfig */
1511 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1512 do {
1513 if (ep->ep && ep->req)
1514 usb_ep_free_request(ep->ep, ep->req);
1515 ep->req = NULL;
1516 ++ep;
1517 } while (--count);
1518 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1519
1520 ffs_data_put(func->ffs);
1521
1522 kfree(func->eps);
1523 /*
1524 * eps and interfaces_nums are allocated in the same chunk so
1525 * only one free is required. Descriptors are also allocated
1526 * in the same chunk.
1527 */
1528
1529 kfree(func);
1530 }
1531
1532 static void ffs_func_eps_disable(struct ffs_function *func)
1533 {
1534 struct ffs_ep *ep = func->eps;
1535 struct ffs_epfile *epfile = func->ffs->epfiles;
1536 unsigned count = func->ffs->eps_count;
1537 unsigned long flags;
1538
1539 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1540 do {
1541 /* pending requests get nuked */
1542 if (likely(ep->ep))
1543 usb_ep_disable(ep->ep);
1544 epfile->ep = NULL;
1545
1546 ++ep;
1547 ++epfile;
1548 } while (--count);
1549 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1550 }
1551
1552 static int ffs_func_eps_enable(struct ffs_function *func)
1553 {
1554 struct ffs_data *ffs = func->ffs;
1555 struct ffs_ep *ep = func->eps;
1556 struct ffs_epfile *epfile = ffs->epfiles;
1557 unsigned count = ffs->eps_count;
1558 unsigned long flags;
1559 int ret = 0;
1560
1561 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1562 do {
1563 struct usb_endpoint_descriptor *ds;
1564 ds = ep->descs[ep->descs[1] ? 1 : 0];
1565
1566 ep->ep->driver_data = ep;
1567 ep->ep->desc = ds;
1568 ret = usb_ep_enable(ep->ep);
1569 if (likely(!ret)) {
1570 epfile->ep = ep;
1571 epfile->in = usb_endpoint_dir_in(ds);
1572 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1573 } else {
1574 break;
1575 }
1576
1577 wake_up(&epfile->wait);
1578
1579 ++ep;
1580 ++epfile;
1581 } while (--count);
1582 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1583
1584 return ret;
1585 }
1586
1587
1588 /* Parsing and building descriptors and strings *****************************/
1589
1590 /*
1591 * This validates if data pointed by data is a valid USB descriptor as
1592 * well as record how many interfaces, endpoints and strings are
1593 * required by given configuration. Returns address after the
1594 * descriptor or NULL if data is invalid.
1595 */
1596
1597 enum ffs_entity_type {
1598 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1599 };
1600
1601 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1602 u8 *valuep,
1603 struct usb_descriptor_header *desc,
1604 void *priv);
1605
1606 static int __must_check ffs_do_desc(char *data, unsigned len,
1607 ffs_entity_callback entity, void *priv)
1608 {
1609 struct usb_descriptor_header *_ds = (void *)data;
1610 u8 length;
1611 int ret;
1612
1613 ENTER();
1614
1615 /* At least two bytes are required: length and type */
1616 if (len < 2) {
1617 pr_vdebug("descriptor too short\n");
1618 return -EINVAL;
1619 }
1620
1621 /* If we have at least as many bytes as the descriptor takes? */
1622 length = _ds->bLength;
1623 if (len < length) {
1624 pr_vdebug("descriptor longer then available data\n");
1625 return -EINVAL;
1626 }
1627
1628 #define __entity_check_INTERFACE(val) 1
1629 #define __entity_check_STRING(val) (val)
1630 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1631 #define __entity(type, val) do { \
1632 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1633 if (unlikely(!__entity_check_ ##type(val))) { \
1634 pr_vdebug("invalid entity's value\n"); \
1635 return -EINVAL; \
1636 } \
1637 ret = entity(FFS_ ##type, &val, _ds, priv); \
1638 if (unlikely(ret < 0)) { \
1639 pr_debug("entity " #type "(%02x); ret = %d\n", \
1640 (val), ret); \
1641 return ret; \
1642 } \
1643 } while (0)
1644
1645 /* Parse descriptor depending on type. */
1646 switch (_ds->bDescriptorType) {
1647 case USB_DT_DEVICE:
1648 case USB_DT_CONFIG:
1649 case USB_DT_STRING:
1650 case USB_DT_DEVICE_QUALIFIER:
1651 /* function can't have any of those */
1652 pr_vdebug("descriptor reserved for gadget: %d\n",
1653 _ds->bDescriptorType);
1654 return -EINVAL;
1655
1656 case USB_DT_INTERFACE: {
1657 struct usb_interface_descriptor *ds = (void *)_ds;
1658 pr_vdebug("interface descriptor\n");
1659 if (length != sizeof *ds)
1660 goto inv_length;
1661
1662 __entity(INTERFACE, ds->bInterfaceNumber);
1663 if (ds->iInterface)
1664 __entity(STRING, ds->iInterface);
1665 }
1666 break;
1667
1668 case USB_DT_ENDPOINT: {
1669 struct usb_endpoint_descriptor *ds = (void *)_ds;
1670 pr_vdebug("endpoint descriptor\n");
1671 if (length != USB_DT_ENDPOINT_SIZE &&
1672 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1673 goto inv_length;
1674 __entity(ENDPOINT, ds->bEndpointAddress);
1675 }
1676 break;
1677
1678 case HID_DT_HID:
1679 pr_vdebug("hid descriptor\n");
1680 if (length != sizeof(struct hid_descriptor))
1681 goto inv_length;
1682 break;
1683
1684 case USB_DT_OTG:
1685 if (length != sizeof(struct usb_otg_descriptor))
1686 goto inv_length;
1687 break;
1688
1689 case USB_DT_INTERFACE_ASSOCIATION: {
1690 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1691 pr_vdebug("interface association descriptor\n");
1692 if (length != sizeof *ds)
1693 goto inv_length;
1694 if (ds->iFunction)
1695 __entity(STRING, ds->iFunction);
1696 }
1697 break;
1698
1699 case USB_DT_OTHER_SPEED_CONFIG:
1700 case USB_DT_INTERFACE_POWER:
1701 case USB_DT_DEBUG:
1702 case USB_DT_SECURITY:
1703 case USB_DT_CS_RADIO_CONTROL:
1704 /* TODO */
1705 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1706 return -EINVAL;
1707
1708 default:
1709 /* We should never be here */
1710 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1711 return -EINVAL;
1712
1713 inv_length:
1714 pr_vdebug("invalid length: %d (descriptor %d)\n",
1715 _ds->bLength, _ds->bDescriptorType);
1716 return -EINVAL;
1717 }
1718
1719 #undef __entity
1720 #undef __entity_check_DESCRIPTOR
1721 #undef __entity_check_INTERFACE
1722 #undef __entity_check_STRING
1723 #undef __entity_check_ENDPOINT
1724
1725 return length;
1726 }
1727
1728 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1729 ffs_entity_callback entity, void *priv)
1730 {
1731 const unsigned _len = len;
1732 unsigned long num = 0;
1733
1734 ENTER();
1735
1736 for (;;) {
1737 int ret;
1738
1739 if (num == count)
1740 data = NULL;
1741
1742 /* Record "descriptor" entity */
1743 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1744 if (unlikely(ret < 0)) {
1745 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1746 num, ret);
1747 return ret;
1748 }
1749
1750 if (!data)
1751 return _len - len;
1752
1753 ret = ffs_do_desc(data, len, entity, priv);
1754 if (unlikely(ret < 0)) {
1755 pr_debug("%s returns %d\n", __func__, ret);
1756 return ret;
1757 }
1758
1759 len -= ret;
1760 data += ret;
1761 ++num;
1762 }
1763 }
1764
1765 static int __ffs_data_do_entity(enum ffs_entity_type type,
1766 u8 *valuep, struct usb_descriptor_header *desc,
1767 void *priv)
1768 {
1769 struct ffs_data *ffs = priv;
1770
1771 ENTER();
1772
1773 switch (type) {
1774 case FFS_DESCRIPTOR:
1775 break;
1776
1777 case FFS_INTERFACE:
1778 /*
1779 * Interfaces are indexed from zero so if we
1780 * encountered interface "n" then there are at least
1781 * "n+1" interfaces.
1782 */
1783 if (*valuep >= ffs->interfaces_count)
1784 ffs->interfaces_count = *valuep + 1;
1785 break;
1786
1787 case FFS_STRING:
1788 /*
1789 * Strings are indexed from 1 (0 is magic ;) reserved
1790 * for languages list or some such)
1791 */
1792 if (*valuep > ffs->strings_count)
1793 ffs->strings_count = *valuep;
1794 break;
1795
1796 case FFS_ENDPOINT:
1797 /* Endpoints are indexed from 1 as well. */
1798 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1799 ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1800 break;
1801 }
1802
1803 return 0;
1804 }
1805
1806 static int __ffs_data_got_descs(struct ffs_data *ffs,
1807 char *const _data, size_t len)
1808 {
1809 unsigned fs_count, hs_count;
1810 int fs_len, ret = -EINVAL;
1811 char *data = _data;
1812
1813 ENTER();
1814
1815 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1816 get_unaligned_le32(data + 4) != len))
1817 goto error;
1818 fs_count = get_unaligned_le32(data + 8);
1819 hs_count = get_unaligned_le32(data + 12);
1820
1821 if (!fs_count && !hs_count)
1822 goto einval;
1823
1824 data += 16;
1825 len -= 16;
1826
1827 if (likely(fs_count)) {
1828 fs_len = ffs_do_descs(fs_count, data, len,
1829 __ffs_data_do_entity, ffs);
1830 if (unlikely(fs_len < 0)) {
1831 ret = fs_len;
1832 goto error;
1833 }
1834
1835 data += fs_len;
1836 len -= fs_len;
1837 } else {
1838 fs_len = 0;
1839 }
1840
1841 if (likely(hs_count)) {
1842 ret = ffs_do_descs(hs_count, data, len,
1843 __ffs_data_do_entity, ffs);
1844 if (unlikely(ret < 0))
1845 goto error;
1846 } else {
1847 ret = 0;
1848 }
1849
1850 if (unlikely(len != ret))
1851 goto einval;
1852
1853 ffs->raw_fs_descs_length = fs_len;
1854 ffs->raw_descs_length = fs_len + ret;
1855 ffs->raw_descs = _data;
1856 ffs->fs_descs_count = fs_count;
1857 ffs->hs_descs_count = hs_count;
1858
1859 return 0;
1860
1861 einval:
1862 ret = -EINVAL;
1863 error:
1864 kfree(_data);
1865 return ret;
1866 }
1867
1868 static int __ffs_data_got_strings(struct ffs_data *ffs,
1869 char *const _data, size_t len)
1870 {
1871 u32 str_count, needed_count, lang_count;
1872 struct usb_gadget_strings **stringtabs, *t;
1873 struct usb_string *strings, *s;
1874 const char *data = _data;
1875
1876 ENTER();
1877
1878 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1879 get_unaligned_le32(data + 4) != len))
1880 goto error;
1881 str_count = get_unaligned_le32(data + 8);
1882 lang_count = get_unaligned_le32(data + 12);
1883
1884 /* if one is zero the other must be zero */
1885 if (unlikely(!str_count != !lang_count))
1886 goto error;
1887
1888 /* Do we have at least as many strings as descriptors need? */
1889 needed_count = ffs->strings_count;
1890 if (unlikely(str_count < needed_count))
1891 goto error;
1892
1893 /*
1894 * If we don't need any strings just return and free all
1895 * memory.
1896 */
1897 if (!needed_count) {
1898 kfree(_data);
1899 return 0;
1900 }
1901
1902 /* Allocate everything in one chunk so there's less maintenance. */
1903 {
1904 struct {
1905 struct usb_gadget_strings *stringtabs[lang_count + 1];
1906 struct usb_gadget_strings stringtab[lang_count];
1907 struct usb_string strings[lang_count*(needed_count+1)];
1908 } *d;
1909 unsigned i = 0;
1910
1911 d = kmalloc(sizeof *d, GFP_KERNEL);
1912 if (unlikely(!d)) {
1913 kfree(_data);
1914 return -ENOMEM;
1915 }
1916
1917 stringtabs = d->stringtabs;
1918 t = d->stringtab;
1919 i = lang_count;
1920 do {
1921 *stringtabs++ = t++;
1922 } while (--i);
1923 *stringtabs = NULL;
1924
1925 stringtabs = d->stringtabs;
1926 t = d->stringtab;
1927 s = d->strings;
1928 strings = s;
1929 }
1930
1931 /* For each language */
1932 data += 16;
1933 len -= 16;
1934
1935 do { /* lang_count > 0 so we can use do-while */
1936 unsigned needed = needed_count;
1937
1938 if (unlikely(len < 3))
1939 goto error_free;
1940 t->language = get_unaligned_le16(data);
1941 t->strings = s;
1942 ++t;
1943
1944 data += 2;
1945 len -= 2;
1946
1947 /* For each string */
1948 do { /* str_count > 0 so we can use do-while */
1949 size_t length = strnlen(data, len);
1950
1951 if (unlikely(length == len))
1952 goto error_free;
1953
1954 /*
1955 * User may provide more strings then we need,
1956 * if that's the case we simply ignore the
1957 * rest
1958 */
1959 if (likely(needed)) {
1960 /*
1961 * s->id will be set while adding
1962 * function to configuration so for
1963 * now just leave garbage here.
1964 */
1965 s->s = data;
1966 --needed;
1967 ++s;
1968 }
1969
1970 data += length + 1;
1971 len -= length + 1;
1972 } while (--str_count);
1973
1974 s->id = 0; /* terminator */
1975 s->s = NULL;
1976 ++s;
1977
1978 } while (--lang_count);
1979
1980 /* Some garbage left? */
1981 if (unlikely(len))
1982 goto error_free;
1983
1984 /* Done! */
1985 ffs->stringtabs = stringtabs;
1986 ffs->raw_strings = _data;
1987
1988 return 0;
1989
1990 error_free:
1991 kfree(stringtabs);
1992 error:
1993 kfree(_data);
1994 return -EINVAL;
1995 }
1996
1997
1998 /* Events handling and management *******************************************/
1999
2000 static void __ffs_event_add(struct ffs_data *ffs,
2001 enum usb_functionfs_event_type type)
2002 {
2003 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2004 int neg = 0;
2005
2006 /*
2007 * Abort any unhandled setup
2008 *
2009 * We do not need to worry about some cmpxchg() changing value
2010 * of ffs->setup_state without holding the lock because when
2011 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2012 * the source does nothing.
2013 */
2014 if (ffs->setup_state == FFS_SETUP_PENDING)
2015 ffs->setup_state = FFS_SETUP_CANCELED;
2016
2017 switch (type) {
2018 case FUNCTIONFS_RESUME:
2019 rem_type2 = FUNCTIONFS_SUSPEND;
2020 /* FALL THROUGH */
2021 case FUNCTIONFS_SUSPEND:
2022 case FUNCTIONFS_SETUP:
2023 rem_type1 = type;
2024 /* Discard all similar events */
2025 break;
2026
2027 case FUNCTIONFS_BIND:
2028 case FUNCTIONFS_UNBIND:
2029 case FUNCTIONFS_DISABLE:
2030 case FUNCTIONFS_ENABLE:
2031 /* Discard everything other then power management. */
2032 rem_type1 = FUNCTIONFS_SUSPEND;
2033 rem_type2 = FUNCTIONFS_RESUME;
2034 neg = 1;
2035 break;
2036
2037 default:
2038 BUG();
2039 }
2040
2041 {
2042 u8 *ev = ffs->ev.types, *out = ev;
2043 unsigned n = ffs->ev.count;
2044 for (; n; --n, ++ev)
2045 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2046 *out++ = *ev;
2047 else
2048 pr_vdebug("purging event %d\n", *ev);
2049 ffs->ev.count = out - ffs->ev.types;
2050 }
2051
2052 pr_vdebug("adding event %d\n", type);
2053 ffs->ev.types[ffs->ev.count++] = type;
2054 wake_up_locked(&ffs->ev.waitq);
2055 }
2056
2057 static void ffs_event_add(struct ffs_data *ffs,
2058 enum usb_functionfs_event_type type)
2059 {
2060 unsigned long flags;
2061 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2062 __ffs_event_add(ffs, type);
2063 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2064 }
2065
2066
2067 /* Bind/unbind USB function hooks *******************************************/
2068
2069 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2070 struct usb_descriptor_header *desc,
2071 void *priv)
2072 {
2073 struct usb_endpoint_descriptor *ds = (void *)desc;
2074 struct ffs_function *func = priv;
2075 struct ffs_ep *ffs_ep;
2076
2077 /*
2078 * If hs_descriptors is not NULL then we are reading hs
2079 * descriptors now
2080 */
2081 const int isHS = func->function.hs_descriptors != NULL;
2082 unsigned idx;
2083
2084 if (type != FFS_DESCRIPTOR)
2085 return 0;
2086
2087 if (isHS)
2088 func->function.hs_descriptors[(long)valuep] = desc;
2089 else
2090 func->function.fs_descriptors[(long)valuep] = desc;
2091
2092 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2093 return 0;
2094
2095 idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2096 ffs_ep = func->eps + idx;
2097
2098 if (unlikely(ffs_ep->descs[isHS])) {
2099 pr_vdebug("two %sspeed descriptors for EP %d\n",
2100 isHS ? "high" : "full",
2101 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2102 return -EINVAL;
2103 }
2104 ffs_ep->descs[isHS] = ds;
2105
2106 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2107 if (ffs_ep->ep) {
2108 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2109 if (!ds->wMaxPacketSize)
2110 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2111 } else {
2112 struct usb_request *req;
2113 struct usb_ep *ep;
2114
2115 pr_vdebug("autoconfig\n");
2116 ep = usb_ep_autoconfig(func->gadget, ds);
2117 if (unlikely(!ep))
2118 return -ENOTSUPP;
2119 ep->driver_data = func->eps + idx;
2120
2121 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2122 if (unlikely(!req))
2123 return -ENOMEM;
2124
2125 ffs_ep->ep = ep;
2126 ffs_ep->req = req;
2127 func->eps_revmap[ds->bEndpointAddress &
2128 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2129 }
2130 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2131
2132 return 0;
2133 }
2134
2135 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2136 struct usb_descriptor_header *desc,
2137 void *priv)
2138 {
2139 struct ffs_function *func = priv;
2140 unsigned idx;
2141 u8 newValue;
2142
2143 switch (type) {
2144 default:
2145 case FFS_DESCRIPTOR:
2146 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2147 return 0;
2148
2149 case FFS_INTERFACE:
2150 idx = *valuep;
2151 if (func->interfaces_nums[idx] < 0) {
2152 int id = usb_interface_id(func->conf, &func->function);
2153 if (unlikely(id < 0))
2154 return id;
2155 func->interfaces_nums[idx] = id;
2156 }
2157 newValue = func->interfaces_nums[idx];
2158 break;
2159
2160 case FFS_STRING:
2161 /* String' IDs are allocated when fsf_data is bound to cdev */
2162 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2163 break;
2164
2165 case FFS_ENDPOINT:
2166 /*
2167 * USB_DT_ENDPOINT are handled in
2168 * __ffs_func_bind_do_descs().
2169 */
2170 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2171 return 0;
2172
2173 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2174 if (unlikely(!func->eps[idx].ep))
2175 return -EINVAL;
2176
2177 {
2178 struct usb_endpoint_descriptor **descs;
2179 descs = func->eps[idx].descs;
2180 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2181 }
2182 break;
2183 }
2184
2185 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2186 *valuep = newValue;
2187 return 0;
2188 }
2189
2190 static int ffs_func_bind(struct usb_configuration *c,
2191 struct usb_function *f)
2192 {
2193 struct ffs_function *func = ffs_func_from_usb(f);
2194 struct ffs_data *ffs = func->ffs;
2195
2196 const int full = !!func->ffs->fs_descs_count;
2197 const int high = gadget_is_dualspeed(func->gadget) &&
2198 func->ffs->hs_descs_count;
2199
2200 int ret;
2201
2202 /* Make it a single chunk, less management later on */
2203 struct {
2204 struct ffs_ep eps[ffs->eps_count];
2205 struct usb_descriptor_header
2206 *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2207 struct usb_descriptor_header
2208 *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2209 short inums[ffs->interfaces_count];
2210 char raw_descs[high ? ffs->raw_descs_length
2211 : ffs->raw_fs_descs_length];
2212 } *data;
2213
2214 ENTER();
2215
2216 /* Only high speed but not supported by gadget? */
2217 if (unlikely(!(full | high)))
2218 return -ENOTSUPP;
2219
2220 /* Allocate */
2221 data = kmalloc(sizeof *data, GFP_KERNEL);
2222 if (unlikely(!data))
2223 return -ENOMEM;
2224
2225 /* Zero */
2226 memset(data->eps, 0, sizeof data->eps);
2227 memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2228 memset(data->inums, 0xff, sizeof data->inums);
2229 for (ret = ffs->eps_count; ret; --ret)
2230 data->eps[ret].num = -1;
2231
2232 /* Save pointers */
2233 func->eps = data->eps;
2234 func->interfaces_nums = data->inums;
2235
2236 /*
2237 * Go through all the endpoint descriptors and allocate
2238 * endpoints first, so that later we can rewrite the endpoint
2239 * numbers without worrying that it may be described later on.
2240 */
2241 if (likely(full)) {
2242 func->function.fs_descriptors = data->fs_descs;
2243 ret = ffs_do_descs(ffs->fs_descs_count,
2244 data->raw_descs,
2245 sizeof data->raw_descs,
2246 __ffs_func_bind_do_descs, func);
2247 if (unlikely(ret < 0))
2248 goto error;
2249 } else {
2250 ret = 0;
2251 }
2252
2253 if (likely(high)) {
2254 func->function.hs_descriptors = data->hs_descs;
2255 ret = ffs_do_descs(ffs->hs_descs_count,
2256 data->raw_descs + ret,
2257 (sizeof data->raw_descs) - ret,
2258 __ffs_func_bind_do_descs, func);
2259 if (unlikely(ret < 0))
2260 goto error;
2261 }
2262
2263 /*
2264 * Now handle interface numbers allocation and interface and
2265 * endpoint numbers rewriting. We can do that in one go
2266 * now.
2267 */
2268 ret = ffs_do_descs(ffs->fs_descs_count +
2269 (high ? ffs->hs_descs_count : 0),
2270 data->raw_descs, sizeof data->raw_descs,
2271 __ffs_func_bind_do_nums, func);
2272 if (unlikely(ret < 0))
2273 goto error;
2274
2275 /* And we're done */
2276 ffs_event_add(ffs, FUNCTIONFS_BIND);
2277 return 0;
2278
2279 error:
2280 /* XXX Do we need to release all claimed endpoints here? */
2281 return ret;
2282 }
2283
2284
2285 /* Other USB function hooks *************************************************/
2286
2287 static void ffs_func_unbind(struct usb_configuration *c,
2288 struct usb_function *f)
2289 {
2290 struct ffs_function *func = ffs_func_from_usb(f);
2291 struct ffs_data *ffs = func->ffs;
2292
2293 ENTER();
2294
2295 if (ffs->func == func) {
2296 ffs_func_eps_disable(func);
2297 ffs->func = NULL;
2298 }
2299
2300 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2301
2302 ffs_func_free(func);
2303 }
2304
2305 static int ffs_func_set_alt(struct usb_function *f,
2306 unsigned interface, unsigned alt)
2307 {
2308 struct ffs_function *func = ffs_func_from_usb(f);
2309 struct ffs_data *ffs = func->ffs;
2310 int ret = 0, intf;
2311
2312 if (alt != (unsigned)-1) {
2313 intf = ffs_func_revmap_intf(func, interface);
2314 if (unlikely(intf < 0))
2315 return intf;
2316 }
2317
2318 if (ffs->func)
2319 ffs_func_eps_disable(ffs->func);
2320
2321 if (ffs->state != FFS_ACTIVE)
2322 return -ENODEV;
2323
2324 if (alt == (unsigned)-1) {
2325 ffs->func = NULL;
2326 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2327 return 0;
2328 }
2329
2330 ffs->func = func;
2331 ret = ffs_func_eps_enable(func);
2332 if (likely(ret >= 0))
2333 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2334 return ret;
2335 }
2336
2337 static void ffs_func_disable(struct usb_function *f)
2338 {
2339 ffs_func_set_alt(f, 0, (unsigned)-1);
2340 }
2341
2342 static int ffs_func_setup(struct usb_function *f,
2343 const struct usb_ctrlrequest *creq)
2344 {
2345 struct ffs_function *func = ffs_func_from_usb(f);
2346 struct ffs_data *ffs = func->ffs;
2347 unsigned long flags;
2348 int ret;
2349
2350 ENTER();
2351
2352 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2353 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2354 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
2355 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
2356 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
2357
2358 /*
2359 * Most requests directed to interface go through here
2360 * (notable exceptions are set/get interface) so we need to
2361 * handle them. All other either handled by composite or
2362 * passed to usb_configuration->setup() (if one is set). No
2363 * matter, we will handle requests directed to endpoint here
2364 * as well (as it's straightforward) but what to do with any
2365 * other request?
2366 */
2367 if (ffs->state != FFS_ACTIVE)
2368 return -ENODEV;
2369
2370 switch (creq->bRequestType & USB_RECIP_MASK) {
2371 case USB_RECIP_INTERFACE:
2372 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2373 if (unlikely(ret < 0))
2374 return ret;
2375 break;
2376
2377 case USB_RECIP_ENDPOINT:
2378 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2379 if (unlikely(ret < 0))
2380 return ret;
2381 break;
2382
2383 default:
2384 return -EOPNOTSUPP;
2385 }
2386
2387 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2388 ffs->ev.setup = *creq;
2389 ffs->ev.setup.wIndex = cpu_to_le16(ret);
2390 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2391 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2392
2393 return 0;
2394 }
2395
2396 static void ffs_func_suspend(struct usb_function *f)
2397 {
2398 ENTER();
2399 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2400 }
2401
2402 static void ffs_func_resume(struct usb_function *f)
2403 {
2404 ENTER();
2405 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2406 }
2407
2408
2409 /* Endpoint and interface numbers reverse mapping ***************************/
2410
2411 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2412 {
2413 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2414 return num ? num : -EDOM;
2415 }
2416
2417 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2418 {
2419 short *nums = func->interfaces_nums;
2420 unsigned count = func->ffs->interfaces_count;
2421
2422 for (; count; --count, ++nums) {
2423 if (*nums >= 0 && *nums == intf)
2424 return nums - func->interfaces_nums;
2425 }
2426
2427 return -EDOM;
2428 }
2429
2430
2431 /* Misc helper functions ****************************************************/
2432
2433 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2434 {
2435 return nonblock
2436 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2437 : mutex_lock_interruptible(mutex);
2438 }
2439
2440 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
2441 {
2442 char *data;
2443
2444 if (unlikely(!len))
2445 return NULL;
2446
2447 data = kmalloc(len, GFP_KERNEL);
2448 if (unlikely(!data))
2449 return ERR_PTR(-ENOMEM);
2450
2451 if (unlikely(__copy_from_user(data, buf, len))) {
2452 kfree(data);
2453 return ERR_PTR(-EFAULT);
2454 }
2455
2456 pr_vdebug("Buffer from user space:\n");
2457 ffs_dump_mem("", data, len);
2458
2459 return data;
2460 }
Linux kernel - Deliverables
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