switch open-coded instances of d_make_root() to new helper
[linux-2.6.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 <m.nazarewicz@samsung.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 <asm/unaligned.h>
25
26 #include <linux/usb/composite.h>
27 #include <linux/usb/functionfs.h>
28
29
30 #define FUNCTIONFS_MAGIC        0xa647361 /* Chosen by a honest dice roll ;) */
31
32
33 /* Debugging ****************************************************************/
34
35 #ifdef VERBOSE_DEBUG
36 #  define pr_vdebug pr_debug
37 #  define ffs_dump_mem(prefix, ptr, len) \
38         print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
39 #else
40 #  define pr_vdebug(...)                 do { } while (0)
41 #  define ffs_dump_mem(prefix, ptr, len) do { } while (0)
42 #endif /* VERBOSE_DEBUG */
43
44 #define ENTER()    pr_vdebug("%s()\n", __func__)
45
46
47 /* The data structure and setup file ****************************************/
48
49 enum ffs_state {
50         /*
51          * Waiting for descriptors and strings.
52          *
53          * In this state no open(2), read(2) or write(2) on epfiles
54          * may succeed (which should not be the problem as there
55          * should be no such files opened in the first place).
56          */
57         FFS_READ_DESCRIPTORS,
58         FFS_READ_STRINGS,
59
60         /*
61          * We've got descriptors and strings.  We are or have called
62          * functionfs_ready_callback().  functionfs_bind() may have
63          * been called but we don't know.
64          *
65          * This is the only state in which operations on epfiles may
66          * succeed.
67          */
68         FFS_ACTIVE,
69
70         /*
71          * All endpoints have been closed.  This state is also set if
72          * we encounter an unrecoverable error.  The only
73          * unrecoverable error is situation when after reading strings
74          * from user space we fail to initialise epfiles or
75          * functionfs_ready_callback() returns with error (<0).
76          *
77          * In this state no open(2), read(2) or write(2) (both on ep0
78          * as well as epfile) may succeed (at this point epfiles are
79          * unlinked and all closed so this is not a problem; ep0 is
80          * also closed but ep0 file exists and so open(2) on ep0 must
81          * fail).
82          */
83         FFS_CLOSING
84 };
85
86
87 enum ffs_setup_state {
88         /* There is no setup request pending. */
89         FFS_NO_SETUP,
90         /*
91          * User has read events and there was a setup request event
92          * there.  The next read/write on ep0 will handle the
93          * request.
94          */
95         FFS_SETUP_PENDING,
96         /*
97          * There was event pending but before user space handled it
98          * some other event was introduced which canceled existing
99          * setup.  If this state is set read/write on ep0 return
100          * -EIDRM.  This state is only set when adding event.
101          */
102         FFS_SETUP_CANCELED
103 };
104
105
106
107 struct ffs_epfile;
108 struct ffs_function;
109
110 struct ffs_data {
111         struct usb_gadget               *gadget;
112
113         /*
114          * Protect access read/write operations, only one read/write
115          * at a time.  As a consequence protects ep0req and company.
116          * While setup request is being processed (queued) this is
117          * held.
118          */
119         struct mutex                    mutex;
120
121         /*
122          * Protect access to endpoint related structures (basically
123          * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
124          * endpoint zero.
125          */
126         spinlock_t                      eps_lock;
127
128         /*
129          * XXX REVISIT do we need our own request? Since we are not
130          * handling setup requests immediately user space may be so
131          * slow that another setup will be sent to the gadget but this
132          * time not to us but another function and then there could be
133          * a race.  Is that the case? Or maybe we can use cdev->req
134          * after all, maybe we just need some spinlock for that?
135          */
136         struct usb_request              *ep0req;                /* P: mutex */
137         struct completion               ep0req_completion;      /* P: mutex */
138         int                             ep0req_status;          /* P: mutex */
139
140         /* reference counter */
141         atomic_t                        ref;
142         /* how many files are opened (EP0 and others) */
143         atomic_t                        opened;
144
145         /* EP0 state */
146         enum ffs_state                  state;
147
148         /*
149          * Possible transitions:
150          * + FFS_NO_SETUP       -> FFS_SETUP_PENDING  -- P: ev.waitq.lock
151          *               happens only in ep0 read which is P: mutex
152          * + FFS_SETUP_PENDING  -> FFS_NO_SETUP       -- P: ev.waitq.lock
153          *               happens only in ep0 i/o  which is P: mutex
154          * + FFS_SETUP_PENDING  -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
155          * + FFS_SETUP_CANCELED -> FFS_NO_SETUP       -- cmpxchg
156          */
157         enum ffs_setup_state            setup_state;
158
159 #define FFS_SETUP_STATE(ffs)                                    \
160         ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state,     \
161                                        FFS_SETUP_CANCELED, FFS_NO_SETUP))
162
163         /* Events & such. */
164         struct {
165                 u8                              types[4];
166                 unsigned short                  count;
167                 /* XXX REVISIT need to update it in some places, or do we? */
168                 unsigned short                  can_stall;
169                 struct usb_ctrlrequest          setup;
170
171                 wait_queue_head_t               waitq;
172         } ev; /* the whole structure, P: ev.waitq.lock */
173
174         /* Flags */
175         unsigned long                   flags;
176 #define FFS_FL_CALL_CLOSED_CALLBACK 0
177 #define FFS_FL_BOUND                1
178
179         /* Active function */
180         struct ffs_function             *func;
181
182         /*
183          * Device name, write once when file system is mounted.
184          * Intended for user to read if she wants.
185          */
186         const char                      *dev_name;
187         /* Private data for our user (ie. gadget).  Managed by user. */
188         void                            *private_data;
189
190         /* filled by __ffs_data_got_descs() */
191         /*
192          * Real descriptors are 16 bytes after raw_descs (so you need
193          * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
194          * first full speed descriptor).  raw_descs_length and
195          * raw_fs_descs_length do not have those 16 bytes added.
196          */
197         const void                      *raw_descs;
198         unsigned                        raw_descs_length;
199         unsigned                        raw_fs_descs_length;
200         unsigned                        fs_descs_count;
201         unsigned                        hs_descs_count;
202
203         unsigned short                  strings_count;
204         unsigned short                  interfaces_count;
205         unsigned short                  eps_count;
206         unsigned short                  _pad1;
207
208         /* filled by __ffs_data_got_strings() */
209         /* ids in stringtabs are set in functionfs_bind() */
210         const void                      *raw_strings;
211         struct usb_gadget_strings       **stringtabs;
212
213         /*
214          * File system's super block, write once when file system is
215          * mounted.
216          */
217         struct super_block              *sb;
218
219         /* File permissions, written once when fs is mounted */
220         struct ffs_file_perms {
221                 umode_t                         mode;
222                 uid_t                           uid;
223                 gid_t                           gid;
224         }                               file_perms;
225
226         /*
227          * The endpoint files, filled by ffs_epfiles_create(),
228          * destroyed by ffs_epfiles_destroy().
229          */
230         struct ffs_epfile               *epfiles;
231 };
232
233 /* Reference counter handling */
234 static void ffs_data_get(struct ffs_data *ffs);
235 static void ffs_data_put(struct ffs_data *ffs);
236 /* Creates new ffs_data object. */
237 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
238
239 /* Opened counter handling. */
240 static void ffs_data_opened(struct ffs_data *ffs);
241 static void ffs_data_closed(struct ffs_data *ffs);
242
243 /* Called with ffs->mutex held; take over ownership of data. */
244 static int __must_check
245 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
246 static int __must_check
247 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
248
249
250 /* The function structure ***************************************************/
251
252 struct ffs_ep;
253
254 struct ffs_function {
255         struct usb_configuration        *conf;
256         struct usb_gadget               *gadget;
257         struct ffs_data                 *ffs;
258
259         struct ffs_ep                   *eps;
260         u8                              eps_revmap[16];
261         short                           *interfaces_nums;
262
263         struct usb_function             function;
264 };
265
266
267 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
268 {
269         return container_of(f, struct ffs_function, function);
270 }
271
272 static void ffs_func_free(struct ffs_function *func);
273
274 static void ffs_func_eps_disable(struct ffs_function *func);
275 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
276
277 static int ffs_func_bind(struct usb_configuration *,
278                          struct usb_function *);
279 static void ffs_func_unbind(struct usb_configuration *,
280                             struct usb_function *);
281 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
282 static void ffs_func_disable(struct usb_function *);
283 static int ffs_func_setup(struct usb_function *,
284                           const struct usb_ctrlrequest *);
285 static void ffs_func_suspend(struct usb_function *);
286 static void ffs_func_resume(struct usb_function *);
287
288
289 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
290 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
291
292
293 /* The endpoints structures *************************************************/
294
295 struct ffs_ep {
296         struct usb_ep                   *ep;    /* P: ffs->eps_lock */
297         struct usb_request              *req;   /* P: epfile->mutex */
298
299         /* [0]: full speed, [1]: high speed */
300         struct usb_endpoint_descriptor  *descs[2];
301
302         u8                              num;
303
304         int                             status; /* P: epfile->mutex */
305 };
306
307 struct ffs_epfile {
308         /* Protects ep->ep and ep->req. */
309         struct mutex                    mutex;
310         wait_queue_head_t               wait;
311
312         struct ffs_data                 *ffs;
313         struct ffs_ep                   *ep;    /* P: ffs->eps_lock */
314
315         struct dentry                   *dentry;
316
317         char                            name[5];
318
319         unsigned char                   in;     /* P: ffs->eps_lock */
320         unsigned char                   isoc;   /* P: ffs->eps_lock */
321
322         unsigned char                   _pad;
323 };
324
325 static int  __must_check ffs_epfiles_create(struct ffs_data *ffs);
326 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
327
328 static struct inode *__must_check
329 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
330                    const struct file_operations *fops,
331                    struct dentry **dentry_p);
332
333
334 /* Misc helper functions ****************************************************/
335
336 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
337         __attribute__((warn_unused_result, nonnull));
338 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
339         __attribute__((warn_unused_result, nonnull));
340
341
342 /* Control file aka ep0 *****************************************************/
343
344 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
345 {
346         struct ffs_data *ffs = req->context;
347
348         complete_all(&ffs->ep0req_completion);
349 }
350
351 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
352 {
353         struct usb_request *req = ffs->ep0req;
354         int ret;
355
356         req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);
357
358         spin_unlock_irq(&ffs->ev.waitq.lock);
359
360         req->buf      = data;
361         req->length   = len;
362
363         /*
364          * UDC layer requires to provide a buffer even for ZLP, but should
365          * not use it at all. Let's provide some poisoned pointer to catch
366          * possible bug in the driver.
367          */
368         if (req->buf == NULL)
369                 req->buf = (void *)0xDEADBABE;
370
371         INIT_COMPLETION(ffs->ep0req_completion);
372
373         ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
374         if (unlikely(ret < 0))
375                 return ret;
376
377         ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
378         if (unlikely(ret)) {
379                 usb_ep_dequeue(ffs->gadget->ep0, req);
380                 return -EINTR;
381         }
382
383         ffs->setup_state = FFS_NO_SETUP;
384         return ffs->ep0req_status;
385 }
386
387 static int __ffs_ep0_stall(struct ffs_data *ffs)
388 {
389         if (ffs->ev.can_stall) {
390                 pr_vdebug("ep0 stall\n");
391                 usb_ep_set_halt(ffs->gadget->ep0);
392                 ffs->setup_state = FFS_NO_SETUP;
393                 return -EL2HLT;
394         } else {
395                 pr_debug("bogus ep0 stall!\n");
396                 return -ESRCH;
397         }
398 }
399
400 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
401                              size_t len, loff_t *ptr)
402 {
403         struct ffs_data *ffs = file->private_data;
404         ssize_t ret;
405         char *data;
406
407         ENTER();
408
409         /* Fast check if setup was canceled */
410         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
411                 return -EIDRM;
412
413         /* Acquire mutex */
414         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
415         if (unlikely(ret < 0))
416                 return ret;
417
418         /* Check state */
419         switch (ffs->state) {
420         case FFS_READ_DESCRIPTORS:
421         case FFS_READ_STRINGS:
422                 /* Copy data */
423                 if (unlikely(len < 16)) {
424                         ret = -EINVAL;
425                         break;
426                 }
427
428                 data = ffs_prepare_buffer(buf, len);
429                 if (IS_ERR(data)) {
430                         ret = PTR_ERR(data);
431                         break;
432                 }
433
434                 /* Handle data */
435                 if (ffs->state == FFS_READ_DESCRIPTORS) {
436                         pr_info("read descriptors\n");
437                         ret = __ffs_data_got_descs(ffs, data, len);
438                         if (unlikely(ret < 0))
439                                 break;
440
441                         ffs->state = FFS_READ_STRINGS;
442                         ret = len;
443                 } else {
444                         pr_info("read strings\n");
445                         ret = __ffs_data_got_strings(ffs, data, len);
446                         if (unlikely(ret < 0))
447                                 break;
448
449                         ret = ffs_epfiles_create(ffs);
450                         if (unlikely(ret)) {
451                                 ffs->state = FFS_CLOSING;
452                                 break;
453                         }
454
455                         ffs->state = FFS_ACTIVE;
456                         mutex_unlock(&ffs->mutex);
457
458                         ret = functionfs_ready_callback(ffs);
459                         if (unlikely(ret < 0)) {
460                                 ffs->state = FFS_CLOSING;
461                                 return ret;
462                         }
463
464                         set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
465                         return len;
466                 }
467                 break;
468
469         case FFS_ACTIVE:
470                 data = NULL;
471                 /*
472                  * We're called from user space, we can use _irq
473                  * rather then _irqsave
474                  */
475                 spin_lock_irq(&ffs->ev.waitq.lock);
476                 switch (FFS_SETUP_STATE(ffs)) {
477                 case FFS_SETUP_CANCELED:
478                         ret = -EIDRM;
479                         goto done_spin;
480
481                 case FFS_NO_SETUP:
482                         ret = -ESRCH;
483                         goto done_spin;
484
485                 case FFS_SETUP_PENDING:
486                         break;
487                 }
488
489                 /* FFS_SETUP_PENDING */
490                 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
491                         spin_unlock_irq(&ffs->ev.waitq.lock);
492                         ret = __ffs_ep0_stall(ffs);
493                         break;
494                 }
495
496                 /* FFS_SETUP_PENDING and not stall */
497                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
498
499                 spin_unlock_irq(&ffs->ev.waitq.lock);
500
501                 data = ffs_prepare_buffer(buf, len);
502                 if (IS_ERR(data)) {
503                         ret = PTR_ERR(data);
504                         break;
505                 }
506
507                 spin_lock_irq(&ffs->ev.waitq.lock);
508
509                 /*
510                  * We are guaranteed to be still in FFS_ACTIVE state
511                  * but the state of setup could have changed from
512                  * FFS_SETUP_PENDING to FFS_SETUP_CANCELED so we need
513                  * to check for that.  If that happened we copied data
514                  * from user space in vain but it's unlikely.
515                  *
516                  * For sure we are not in FFS_NO_SETUP since this is
517                  * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
518                  * transition can be performed and it's protected by
519                  * mutex.
520                  */
521                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
522                         ret = -EIDRM;
523 done_spin:
524                         spin_unlock_irq(&ffs->ev.waitq.lock);
525                 } else {
526                         /* unlocks spinlock */
527                         ret = __ffs_ep0_queue_wait(ffs, data, len);
528                 }
529                 kfree(data);
530                 break;
531
532         default:
533                 ret = -EBADFD;
534                 break;
535         }
536
537         mutex_unlock(&ffs->mutex);
538         return ret;
539 }
540
541 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
542                                      size_t n)
543 {
544         /*
545          * We are holding ffs->ev.waitq.lock and ffs->mutex and we need
546          * to release them.
547          */
548         struct usb_functionfs_event events[n];
549         unsigned i = 0;
550
551         memset(events, 0, sizeof events);
552
553         do {
554                 events[i].type = ffs->ev.types[i];
555                 if (events[i].type == FUNCTIONFS_SETUP) {
556                         events[i].u.setup = ffs->ev.setup;
557                         ffs->setup_state = FFS_SETUP_PENDING;
558                 }
559         } while (++i < n);
560
561         if (n < ffs->ev.count) {
562                 ffs->ev.count -= n;
563                 memmove(ffs->ev.types, ffs->ev.types + n,
564                         ffs->ev.count * sizeof *ffs->ev.types);
565         } else {
566                 ffs->ev.count = 0;
567         }
568
569         spin_unlock_irq(&ffs->ev.waitq.lock);
570         mutex_unlock(&ffs->mutex);
571
572         return unlikely(__copy_to_user(buf, events, sizeof events))
573                 ? -EFAULT : sizeof events;
574 }
575
576 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
577                             size_t len, loff_t *ptr)
578 {
579         struct ffs_data *ffs = file->private_data;
580         char *data = NULL;
581         size_t n;
582         int ret;
583
584         ENTER();
585
586         /* Fast check if setup was canceled */
587         if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED)
588                 return -EIDRM;
589
590         /* Acquire mutex */
591         ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
592         if (unlikely(ret < 0))
593                 return ret;
594
595         /* Check state */
596         if (ffs->state != FFS_ACTIVE) {
597                 ret = -EBADFD;
598                 goto done_mutex;
599         }
600
601         /*
602          * We're called from user space, we can use _irq rather then
603          * _irqsave
604          */
605         spin_lock_irq(&ffs->ev.waitq.lock);
606
607         switch (FFS_SETUP_STATE(ffs)) {
608         case FFS_SETUP_CANCELED:
609                 ret = -EIDRM;
610                 break;
611
612         case FFS_NO_SETUP:
613                 n = len / sizeof(struct usb_functionfs_event);
614                 if (unlikely(!n)) {
615                         ret = -EINVAL;
616                         break;
617                 }
618
619                 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
620                         ret = -EAGAIN;
621                         break;
622                 }
623
624                 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
625                                                         ffs->ev.count)) {
626                         ret = -EINTR;
627                         break;
628                 }
629
630                 return __ffs_ep0_read_events(ffs, buf,
631                                              min(n, (size_t)ffs->ev.count));
632
633         case FFS_SETUP_PENDING:
634                 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
635                         spin_unlock_irq(&ffs->ev.waitq.lock);
636                         ret = __ffs_ep0_stall(ffs);
637                         goto done_mutex;
638                 }
639
640                 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
641
642                 spin_unlock_irq(&ffs->ev.waitq.lock);
643
644                 if (likely(len)) {
645                         data = kmalloc(len, GFP_KERNEL);
646                         if (unlikely(!data)) {
647                                 ret = -ENOMEM;
648                                 goto done_mutex;
649                         }
650                 }
651
652                 spin_lock_irq(&ffs->ev.waitq.lock);
653
654                 /* See ffs_ep0_write() */
655                 if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
656                         ret = -EIDRM;
657                         break;
658                 }
659
660                 /* unlocks spinlock */
661                 ret = __ffs_ep0_queue_wait(ffs, data, len);
662                 if (likely(ret > 0) && unlikely(__copy_to_user(buf, data, len)))
663                         ret = -EFAULT;
664                 goto done_mutex;
665
666         default:
667                 ret = -EBADFD;
668                 break;
669         }
670
671         spin_unlock_irq(&ffs->ev.waitq.lock);
672 done_mutex:
673         mutex_unlock(&ffs->mutex);
674         kfree(data);
675         return ret;
676 }
677
678 static int ffs_ep0_open(struct inode *inode, struct file *file)
679 {
680         struct ffs_data *ffs = inode->i_private;
681
682         ENTER();
683
684         if (unlikely(ffs->state == FFS_CLOSING))
685                 return -EBUSY;
686
687         file->private_data = ffs;
688         ffs_data_opened(ffs);
689
690         return 0;
691 }
692
693 static int ffs_ep0_release(struct inode *inode, struct file *file)
694 {
695         struct ffs_data *ffs = file->private_data;
696
697         ENTER();
698
699         ffs_data_closed(ffs);
700
701         return 0;
702 }
703
704 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
705 {
706         struct ffs_data *ffs = file->private_data;
707         struct usb_gadget *gadget = ffs->gadget;
708         long ret;
709
710         ENTER();
711
712         if (code == FUNCTIONFS_INTERFACE_REVMAP) {
713                 struct ffs_function *func = ffs->func;
714                 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
715         } else if (gadget->ops->ioctl) {
716                 ret = gadget->ops->ioctl(gadget, code, value);
717         } else {
718                 ret = -ENOTTY;
719         }
720
721         return ret;
722 }
723
724 static const struct file_operations ffs_ep0_operations = {
725         .owner =        THIS_MODULE,
726         .llseek =       no_llseek,
727
728         .open =         ffs_ep0_open,
729         .write =        ffs_ep0_write,
730         .read =         ffs_ep0_read,
731         .release =      ffs_ep0_release,
732         .unlocked_ioctl =       ffs_ep0_ioctl,
733 };
734
735
736 /* "Normal" endpoints operations ********************************************/
737
738 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
739 {
740         ENTER();
741         if (likely(req->context)) {
742                 struct ffs_ep *ep = _ep->driver_data;
743                 ep->status = req->status ? req->status : req->actual;
744                 complete(req->context);
745         }
746 }
747
748 static ssize_t ffs_epfile_io(struct file *file,
749                              char __user *buf, size_t len, int read)
750 {
751         struct ffs_epfile *epfile = file->private_data;
752         struct ffs_ep *ep;
753         char *data = NULL;
754         ssize_t ret;
755         int halt;
756
757         goto first_try;
758         do {
759                 spin_unlock_irq(&epfile->ffs->eps_lock);
760                 mutex_unlock(&epfile->mutex);
761
762 first_try:
763                 /* Are we still active? */
764                 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
765                         ret = -ENODEV;
766                         goto error;
767                 }
768
769                 /* Wait for endpoint to be enabled */
770                 ep = epfile->ep;
771                 if (!ep) {
772                         if (file->f_flags & O_NONBLOCK) {
773                                 ret = -EAGAIN;
774                                 goto error;
775                         }
776
777                         if (wait_event_interruptible(epfile->wait,
778                                                      (ep = epfile->ep))) {
779                                 ret = -EINTR;
780                                 goto error;
781                         }
782                 }
783
784                 /* Do we halt? */
785                 halt = !read == !epfile->in;
786                 if (halt && epfile->isoc) {
787                         ret = -EINVAL;
788                         goto error;
789                 }
790
791                 /* Allocate & copy */
792                 if (!halt && !data) {
793                         data = kzalloc(len, GFP_KERNEL);
794                         if (unlikely(!data))
795                                 return -ENOMEM;
796
797                         if (!read &&
798                             unlikely(__copy_from_user(data, buf, len))) {
799                                 ret = -EFAULT;
800                                 goto error;
801                         }
802                 }
803
804                 /* We will be using request */
805                 ret = ffs_mutex_lock(&epfile->mutex,
806                                      file->f_flags & O_NONBLOCK);
807                 if (unlikely(ret))
808                         goto error;
809
810                 /*
811                  * We're called from user space, we can use _irq rather then
812                  * _irqsave
813                  */
814                 spin_lock_irq(&epfile->ffs->eps_lock);
815
816                 /*
817                  * While we were acquiring mutex endpoint got disabled
818                  * or changed?
819                  */
820         } while (unlikely(epfile->ep != ep));
821
822         /* Halt */
823         if (unlikely(halt)) {
824                 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
825                         usb_ep_set_halt(ep->ep);
826                 spin_unlock_irq(&epfile->ffs->eps_lock);
827                 ret = -EBADMSG;
828         } else {
829                 /* Fire the request */
830                 DECLARE_COMPLETION_ONSTACK(done);
831
832                 struct usb_request *req = ep->req;
833                 req->context  = &done;
834                 req->complete = ffs_epfile_io_complete;
835                 req->buf      = data;
836                 req->length   = len;
837
838                 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
839
840                 spin_unlock_irq(&epfile->ffs->eps_lock);
841
842                 if (unlikely(ret < 0)) {
843                         /* nop */
844                 } else if (unlikely(wait_for_completion_interruptible(&done))) {
845                         ret = -EINTR;
846                         usb_ep_dequeue(ep->ep, req);
847                 } else {
848                         ret = ep->status;
849                         if (read && ret > 0 &&
850                             unlikely(copy_to_user(buf, data, ret)))
851                                 ret = -EFAULT;
852                 }
853         }
854
855         mutex_unlock(&epfile->mutex);
856 error:
857         kfree(data);
858         return ret;
859 }
860
861 static ssize_t
862 ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
863                  loff_t *ptr)
864 {
865         ENTER();
866
867         return ffs_epfile_io(file, (char __user *)buf, len, 0);
868 }
869
870 static ssize_t
871 ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
872 {
873         ENTER();
874
875         return ffs_epfile_io(file, buf, len, 1);
876 }
877
878 static int
879 ffs_epfile_open(struct inode *inode, struct file *file)
880 {
881         struct ffs_epfile *epfile = inode->i_private;
882
883         ENTER();
884
885         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
886                 return -ENODEV;
887
888         file->private_data = epfile;
889         ffs_data_opened(epfile->ffs);
890
891         return 0;
892 }
893
894 static int
895 ffs_epfile_release(struct inode *inode, struct file *file)
896 {
897         struct ffs_epfile *epfile = inode->i_private;
898
899         ENTER();
900
901         ffs_data_closed(epfile->ffs);
902
903         return 0;
904 }
905
906 static long ffs_epfile_ioctl(struct file *file, unsigned code,
907                              unsigned long value)
908 {
909         struct ffs_epfile *epfile = file->private_data;
910         int ret;
911
912         ENTER();
913
914         if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
915                 return -ENODEV;
916
917         spin_lock_irq(&epfile->ffs->eps_lock);
918         if (likely(epfile->ep)) {
919                 switch (code) {
920                 case FUNCTIONFS_FIFO_STATUS:
921                         ret = usb_ep_fifo_status(epfile->ep->ep);
922                         break;
923                 case FUNCTIONFS_FIFO_FLUSH:
924                         usb_ep_fifo_flush(epfile->ep->ep);
925                         ret = 0;
926                         break;
927                 case FUNCTIONFS_CLEAR_HALT:
928                         ret = usb_ep_clear_halt(epfile->ep->ep);
929                         break;
930                 case FUNCTIONFS_ENDPOINT_REVMAP:
931                         ret = epfile->ep->num;
932                         break;
933                 default:
934                         ret = -ENOTTY;
935                 }
936         } else {
937                 ret = -ENODEV;
938         }
939         spin_unlock_irq(&epfile->ffs->eps_lock);
940
941         return ret;
942 }
943
944 static const struct file_operations ffs_epfile_operations = {
945         .owner =        THIS_MODULE,
946         .llseek =       no_llseek,
947
948         .open =         ffs_epfile_open,
949         .write =        ffs_epfile_write,
950         .read =         ffs_epfile_read,
951         .release =      ffs_epfile_release,
952         .unlocked_ioctl =       ffs_epfile_ioctl,
953 };
954
955
956 /* File system and super block operations ***********************************/
957
958 /*
959  * Mounting the file system creates a controller file, used first for
960  * function configuration then later for event monitoring.
961  */
962
963 static struct inode *__must_check
964 ffs_sb_make_inode(struct super_block *sb, void *data,
965                   const struct file_operations *fops,
966                   const struct inode_operations *iops,
967                   struct ffs_file_perms *perms)
968 {
969         struct inode *inode;
970
971         ENTER();
972
973         inode = new_inode(sb);
974
975         if (likely(inode)) {
976                 struct timespec current_time = CURRENT_TIME;
977
978                 inode->i_ino     = get_next_ino();
979                 inode->i_mode    = perms->mode;
980                 inode->i_uid     = perms->uid;
981                 inode->i_gid     = perms->gid;
982                 inode->i_atime   = current_time;
983                 inode->i_mtime   = current_time;
984                 inode->i_ctime   = current_time;
985                 inode->i_private = data;
986                 if (fops)
987                         inode->i_fop = fops;
988                 if (iops)
989                         inode->i_op  = iops;
990         }
991
992         return inode;
993 }
994
995 /* Create "regular" file */
996 static struct inode *ffs_sb_create_file(struct super_block *sb,
997                                         const char *name, void *data,
998                                         const struct file_operations *fops,
999                                         struct dentry **dentry_p)
1000 {
1001         struct ffs_data *ffs = sb->s_fs_info;
1002         struct dentry   *dentry;
1003         struct inode    *inode;
1004
1005         ENTER();
1006
1007         dentry = d_alloc_name(sb->s_root, name);
1008         if (unlikely(!dentry))
1009                 return NULL;
1010
1011         inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1012         if (unlikely(!inode)) {
1013                 dput(dentry);
1014                 return NULL;
1015         }
1016
1017         d_add(dentry, inode);
1018         if (dentry_p)
1019                 *dentry_p = dentry;
1020
1021         return inode;
1022 }
1023
1024 /* Super block */
1025 static const struct super_operations ffs_sb_operations = {
1026         .statfs =       simple_statfs,
1027         .drop_inode =   generic_delete_inode,
1028 };
1029
1030 struct ffs_sb_fill_data {
1031         struct ffs_file_perms perms;
1032         umode_t root_mode;
1033         const char *dev_name;
1034 };
1035
1036 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1037 {
1038         struct ffs_sb_fill_data *data = _data;
1039         struct inode    *inode;
1040         struct ffs_data *ffs;
1041
1042         ENTER();
1043
1044         /* Initialise data */
1045         ffs = ffs_data_new();
1046         if (unlikely(!ffs))
1047                 goto Enomem;
1048
1049         ffs->sb              = sb;
1050         ffs->dev_name        = data->dev_name;
1051         ffs->file_perms      = data->perms;
1052
1053         sb->s_fs_info        = ffs;
1054         sb->s_blocksize      = PAGE_CACHE_SIZE;
1055         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1056         sb->s_magic          = FUNCTIONFS_MAGIC;
1057         sb->s_op             = &ffs_sb_operations;
1058         sb->s_time_gran      = 1;
1059
1060         /* Root inode */
1061         data->perms.mode = data->root_mode;
1062         inode = ffs_sb_make_inode(sb, NULL,
1063                                   &simple_dir_operations,
1064                                   &simple_dir_inode_operations,
1065                                   &data->perms);
1066         sb->s_root = d_make_root(inode);
1067         if (unlikely(!sb->s_root))
1068                 goto Enomem;
1069
1070         /* EP0 file */
1071         if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1072                                          &ffs_ep0_operations, NULL)))
1073                 goto Enomem;
1074
1075         return 0;
1076
1077 Enomem:
1078         return -ENOMEM;
1079 }
1080
1081 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1082 {
1083         ENTER();
1084
1085         if (!opts || !*opts)
1086                 return 0;
1087
1088         for (;;) {
1089                 char *end, *eq, *comma;
1090                 unsigned long value;
1091
1092                 /* Option limit */
1093                 comma = strchr(opts, ',');
1094                 if (comma)
1095                         *comma = 0;
1096
1097                 /* Value limit */
1098                 eq = strchr(opts, '=');
1099                 if (unlikely(!eq)) {
1100                         pr_err("'=' missing in %s\n", opts);
1101                         return -EINVAL;
1102                 }
1103                 *eq = 0;
1104
1105                 /* Parse value */
1106                 value = simple_strtoul(eq + 1, &end, 0);
1107                 if (unlikely(*end != ',' && *end != 0)) {
1108                         pr_err("%s: invalid value: %s\n", opts, eq + 1);
1109                         return -EINVAL;
1110                 }
1111
1112                 /* Interpret option */
1113                 switch (eq - opts) {
1114                 case 5:
1115                         if (!memcmp(opts, "rmode", 5))
1116                                 data->root_mode  = (value & 0555) | S_IFDIR;
1117                         else if (!memcmp(opts, "fmode", 5))
1118                                 data->perms.mode = (value & 0666) | S_IFREG;
1119                         else
1120                                 goto invalid;
1121                         break;
1122
1123                 case 4:
1124                         if (!memcmp(opts, "mode", 4)) {
1125                                 data->root_mode  = (value & 0555) | S_IFDIR;
1126                                 data->perms.mode = (value & 0666) | S_IFREG;
1127                         } else {
1128                                 goto invalid;
1129                         }
1130                         break;
1131
1132                 case 3:
1133                         if (!memcmp(opts, "uid", 3))
1134                                 data->perms.uid = value;
1135                         else if (!memcmp(opts, "gid", 3))
1136                                 data->perms.gid = value;
1137                         else
1138                                 goto invalid;
1139                         break;
1140
1141                 default:
1142 invalid:
1143                         pr_err("%s: invalid option\n", opts);
1144                         return -EINVAL;
1145                 }
1146
1147                 /* Next iteration */
1148                 if (!comma)
1149                         break;
1150                 opts = comma + 1;
1151         }
1152
1153         return 0;
1154 }
1155
1156 /* "mount -t functionfs dev_name /dev/function" ends up here */
1157
1158 static struct dentry *
1159 ffs_fs_mount(struct file_system_type *t, int flags,
1160               const char *dev_name, void *opts)
1161 {
1162         struct ffs_sb_fill_data data = {
1163                 .perms = {
1164                         .mode = S_IFREG | 0600,
1165                         .uid = 0,
1166                         .gid = 0
1167                 },
1168                 .root_mode = S_IFDIR | 0500,
1169         };
1170         int ret;
1171
1172         ENTER();
1173
1174         ret = functionfs_check_dev_callback(dev_name);
1175         if (unlikely(ret < 0))
1176                 return ERR_PTR(ret);
1177
1178         ret = ffs_fs_parse_opts(&data, opts);
1179         if (unlikely(ret < 0))
1180                 return ERR_PTR(ret);
1181
1182         data.dev_name = dev_name;
1183         return mount_single(t, flags, &data, ffs_sb_fill);
1184 }
1185
1186 static void
1187 ffs_fs_kill_sb(struct super_block *sb)
1188 {
1189         ENTER();
1190
1191         kill_litter_super(sb);
1192         if (sb->s_fs_info)
1193                 ffs_data_put(sb->s_fs_info);
1194 }
1195
1196 static struct file_system_type ffs_fs_type = {
1197         .owner          = THIS_MODULE,
1198         .name           = "functionfs",
1199         .mount          = ffs_fs_mount,
1200         .kill_sb        = ffs_fs_kill_sb,
1201 };
1202
1203
1204 /* Driver's main init/cleanup functions *************************************/
1205
1206 static int functionfs_init(void)
1207 {
1208         int ret;
1209
1210         ENTER();
1211
1212         ret = register_filesystem(&ffs_fs_type);
1213         if (likely(!ret))
1214                 pr_info("file system registered\n");
1215         else
1216                 pr_err("failed registering file system (%d)\n", ret);
1217
1218         return ret;
1219 }
1220
1221 static void functionfs_cleanup(void)
1222 {
1223         ENTER();
1224
1225         pr_info("unloading\n");
1226         unregister_filesystem(&ffs_fs_type);
1227 }
1228
1229
1230 /* ffs_data and ffs_function construction and destruction code **************/
1231
1232 static void ffs_data_clear(struct ffs_data *ffs);
1233 static void ffs_data_reset(struct ffs_data *ffs);
1234
1235 static void ffs_data_get(struct ffs_data *ffs)
1236 {
1237         ENTER();
1238
1239         atomic_inc(&ffs->ref);
1240 }
1241
1242 static void ffs_data_opened(struct ffs_data *ffs)
1243 {
1244         ENTER();
1245
1246         atomic_inc(&ffs->ref);
1247         atomic_inc(&ffs->opened);
1248 }
1249
1250 static void ffs_data_put(struct ffs_data *ffs)
1251 {
1252         ENTER();
1253
1254         if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1255                 pr_info("%s(): freeing\n", __func__);
1256                 ffs_data_clear(ffs);
1257                 BUG_ON(mutex_is_locked(&ffs->mutex) ||
1258                        spin_is_locked(&ffs->ev.waitq.lock) ||
1259                        waitqueue_active(&ffs->ev.waitq) ||
1260                        waitqueue_active(&ffs->ep0req_completion.wait));
1261                 kfree(ffs);
1262         }
1263 }
1264
1265 static void ffs_data_closed(struct ffs_data *ffs)
1266 {
1267         ENTER();
1268
1269         if (atomic_dec_and_test(&ffs->opened)) {
1270                 ffs->state = FFS_CLOSING;
1271                 ffs_data_reset(ffs);
1272         }
1273
1274         ffs_data_put(ffs);
1275 }
1276
1277 static struct ffs_data *ffs_data_new(void)
1278 {
1279         struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1280         if (unlikely(!ffs))
1281                 return 0;
1282
1283         ENTER();
1284
1285         atomic_set(&ffs->ref, 1);
1286         atomic_set(&ffs->opened, 0);
1287         ffs->state = FFS_READ_DESCRIPTORS;
1288         mutex_init(&ffs->mutex);
1289         spin_lock_init(&ffs->eps_lock);
1290         init_waitqueue_head(&ffs->ev.waitq);
1291         init_completion(&ffs->ep0req_completion);
1292
1293         /* XXX REVISIT need to update it in some places, or do we? */
1294         ffs->ev.can_stall = 1;
1295
1296         return ffs;
1297 }
1298
1299 static void ffs_data_clear(struct ffs_data *ffs)
1300 {
1301         ENTER();
1302
1303         if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
1304                 functionfs_closed_callback(ffs);
1305
1306         BUG_ON(ffs->gadget);
1307
1308         if (ffs->epfiles)
1309                 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1310
1311         kfree(ffs->raw_descs);
1312         kfree(ffs->raw_strings);
1313         kfree(ffs->stringtabs);
1314 }
1315
1316 static void ffs_data_reset(struct ffs_data *ffs)
1317 {
1318         ENTER();
1319
1320         ffs_data_clear(ffs);
1321
1322         ffs->epfiles = NULL;
1323         ffs->raw_descs = NULL;
1324         ffs->raw_strings = NULL;
1325         ffs->stringtabs = NULL;
1326
1327         ffs->raw_descs_length = 0;
1328         ffs->raw_fs_descs_length = 0;
1329         ffs->fs_descs_count = 0;
1330         ffs->hs_descs_count = 0;
1331
1332         ffs->strings_count = 0;
1333         ffs->interfaces_count = 0;
1334         ffs->eps_count = 0;
1335
1336         ffs->ev.count = 0;
1337
1338         ffs->state = FFS_READ_DESCRIPTORS;
1339         ffs->setup_state = FFS_NO_SETUP;
1340         ffs->flags = 0;
1341 }
1342
1343
1344 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1345 {
1346         struct usb_gadget_strings **lang;
1347         int first_id;
1348
1349         ENTER();
1350
1351         if (WARN_ON(ffs->state != FFS_ACTIVE
1352                  || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1353                 return -EBADFD;
1354
1355         first_id = usb_string_ids_n(cdev, ffs->strings_count);
1356         if (unlikely(first_id < 0))
1357                 return first_id;
1358
1359         ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1360         if (unlikely(!ffs->ep0req))
1361                 return -ENOMEM;
1362         ffs->ep0req->complete = ffs_ep0_complete;
1363         ffs->ep0req->context = ffs;
1364
1365         lang = ffs->stringtabs;
1366         for (lang = ffs->stringtabs; *lang; ++lang) {
1367                 struct usb_string *str = (*lang)->strings;
1368                 int id = first_id;
1369                 for (; str->s; ++id, ++str)
1370                         str->id = id;
1371         }
1372
1373         ffs->gadget = cdev->gadget;
1374         ffs_data_get(ffs);
1375         return 0;
1376 }
1377
1378 static void functionfs_unbind(struct ffs_data *ffs)
1379 {
1380         ENTER();
1381
1382         if (!WARN_ON(!ffs->gadget)) {
1383                 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1384                 ffs->ep0req = NULL;
1385                 ffs->gadget = NULL;
1386                 ffs_data_put(ffs);
1387         }
1388 }
1389
1390 static int ffs_epfiles_create(struct ffs_data *ffs)
1391 {
1392         struct ffs_epfile *epfile, *epfiles;
1393         unsigned i, count;
1394
1395         ENTER();
1396
1397         count = ffs->eps_count;
1398         epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1399         if (!epfiles)
1400                 return -ENOMEM;
1401
1402         epfile = epfiles;
1403         for (i = 1; i <= count; ++i, ++epfile) {
1404                 epfile->ffs = ffs;
1405                 mutex_init(&epfile->mutex);
1406                 init_waitqueue_head(&epfile->wait);
1407                 sprintf(epfiles->name, "ep%u",  i);
1408                 if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
1409                                                  &ffs_epfile_operations,
1410                                                  &epfile->dentry))) {
1411                         ffs_epfiles_destroy(epfiles, i - 1);
1412                         return -ENOMEM;
1413                 }
1414         }
1415
1416         ffs->epfiles = epfiles;
1417         return 0;
1418 }
1419
1420 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1421 {
1422         struct ffs_epfile *epfile = epfiles;
1423
1424         ENTER();
1425
1426         for (; count; --count, ++epfile) {
1427                 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1428                        waitqueue_active(&epfile->wait));
1429                 if (epfile->dentry) {
1430                         d_delete(epfile->dentry);
1431                         dput(epfile->dentry);
1432                         epfile->dentry = NULL;
1433                 }
1434         }
1435
1436         kfree(epfiles);
1437 }
1438
1439 static int functionfs_bind_config(struct usb_composite_dev *cdev,
1440                                   struct usb_configuration *c,
1441                                   struct ffs_data *ffs)
1442 {
1443         struct ffs_function *func;
1444         int ret;
1445
1446         ENTER();
1447
1448         func = kzalloc(sizeof *func, GFP_KERNEL);
1449         if (unlikely(!func))
1450                 return -ENOMEM;
1451
1452         func->function.name    = "Function FS Gadget";
1453         func->function.strings = ffs->stringtabs;
1454
1455         func->function.bind    = ffs_func_bind;
1456         func->function.unbind  = ffs_func_unbind;
1457         func->function.set_alt = ffs_func_set_alt;
1458         func->function.disable = ffs_func_disable;
1459         func->function.setup   = ffs_func_setup;
1460         func->function.suspend = ffs_func_suspend;
1461         func->function.resume  = ffs_func_resume;
1462
1463         func->conf   = c;
1464         func->gadget = cdev->gadget;
1465         func->ffs = ffs;
1466         ffs_data_get(ffs);
1467
1468         ret = usb_add_function(c, &func->function);
1469         if (unlikely(ret))
1470                 ffs_func_free(func);
1471
1472         return ret;
1473 }
1474
1475 static void ffs_func_free(struct ffs_function *func)
1476 {
1477         ENTER();
1478
1479         ffs_data_put(func->ffs);
1480
1481         kfree(func->eps);
1482         /*
1483          * eps and interfaces_nums are allocated in the same chunk so
1484          * only one free is required.  Descriptors are also allocated
1485          * in the same chunk.
1486          */
1487
1488         kfree(func);
1489 }
1490
1491 static void ffs_func_eps_disable(struct ffs_function *func)
1492 {
1493         struct ffs_ep *ep         = func->eps;
1494         struct ffs_epfile *epfile = func->ffs->epfiles;
1495         unsigned count            = func->ffs->eps_count;
1496         unsigned long flags;
1497
1498         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1499         do {
1500                 /* pending requests get nuked */
1501                 if (likely(ep->ep))
1502                         usb_ep_disable(ep->ep);
1503                 epfile->ep = NULL;
1504
1505                 ++ep;
1506                 ++epfile;
1507         } while (--count);
1508         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1509 }
1510
1511 static int ffs_func_eps_enable(struct ffs_function *func)
1512 {
1513         struct ffs_data *ffs      = func->ffs;
1514         struct ffs_ep *ep         = func->eps;
1515         struct ffs_epfile *epfile = ffs->epfiles;
1516         unsigned count            = ffs->eps_count;
1517         unsigned long flags;
1518         int ret = 0;
1519
1520         spin_lock_irqsave(&func->ffs->eps_lock, flags);
1521         do {
1522                 struct usb_endpoint_descriptor *ds;
1523                 ds = ep->descs[ep->descs[1] ? 1 : 0];
1524
1525                 ep->ep->driver_data = ep;
1526                 ep->ep->desc = ds;
1527                 ret = usb_ep_enable(ep->ep);
1528                 if (likely(!ret)) {
1529                         epfile->ep = ep;
1530                         epfile->in = usb_endpoint_dir_in(ds);
1531                         epfile->isoc = usb_endpoint_xfer_isoc(ds);
1532                 } else {
1533                         break;
1534                 }
1535
1536                 wake_up(&epfile->wait);
1537
1538                 ++ep;
1539                 ++epfile;
1540         } while (--count);
1541         spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1542
1543         return ret;
1544 }
1545
1546
1547 /* Parsing and building descriptors and strings *****************************/
1548
1549 /*
1550  * This validates if data pointed by data is a valid USB descriptor as
1551  * well as record how many interfaces, endpoints and strings are
1552  * required by given configuration.  Returns address after the
1553  * descriptor or NULL if data is invalid.
1554  */
1555
1556 enum ffs_entity_type {
1557         FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1558 };
1559
1560 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1561                                    u8 *valuep,
1562                                    struct usb_descriptor_header *desc,
1563                                    void *priv);
1564
1565 static int __must_check ffs_do_desc(char *data, unsigned len,
1566                                     ffs_entity_callback entity, void *priv)
1567 {
1568         struct usb_descriptor_header *_ds = (void *)data;
1569         u8 length;
1570         int ret;
1571
1572         ENTER();
1573
1574         /* At least two bytes are required: length and type */
1575         if (len < 2) {
1576                 pr_vdebug("descriptor too short\n");
1577                 return -EINVAL;
1578         }
1579
1580         /* If we have at least as many bytes as the descriptor takes? */
1581         length = _ds->bLength;
1582         if (len < length) {
1583                 pr_vdebug("descriptor longer then available data\n");
1584                 return -EINVAL;
1585         }
1586
1587 #define __entity_check_INTERFACE(val)  1
1588 #define __entity_check_STRING(val)     (val)
1589 #define __entity_check_ENDPOINT(val)   ((val) & USB_ENDPOINT_NUMBER_MASK)
1590 #define __entity(type, val) do {                                        \
1591                 pr_vdebug("entity " #type "(%02x)\n", (val));           \
1592                 if (unlikely(!__entity_check_ ##type(val))) {           \
1593                         pr_vdebug("invalid entity's value\n");          \
1594                         return -EINVAL;                                 \
1595                 }                                                       \
1596                 ret = entity(FFS_ ##type, &val, _ds, priv);             \
1597                 if (unlikely(ret < 0)) {                                \
1598                         pr_debug("entity " #type "(%02x); ret = %d\n",  \
1599                                  (val), ret);                           \
1600                         return ret;                                     \
1601                 }                                                       \
1602         } while (0)
1603
1604         /* Parse descriptor depending on type. */
1605         switch (_ds->bDescriptorType) {
1606         case USB_DT_DEVICE:
1607         case USB_DT_CONFIG:
1608         case USB_DT_STRING:
1609         case USB_DT_DEVICE_QUALIFIER:
1610                 /* function can't have any of those */
1611                 pr_vdebug("descriptor reserved for gadget: %d\n",
1612                       _ds->bDescriptorType);
1613                 return -EINVAL;
1614
1615         case USB_DT_INTERFACE: {
1616                 struct usb_interface_descriptor *ds = (void *)_ds;
1617                 pr_vdebug("interface descriptor\n");
1618                 if (length != sizeof *ds)
1619                         goto inv_length;
1620
1621                 __entity(INTERFACE, ds->bInterfaceNumber);
1622                 if (ds->iInterface)
1623                         __entity(STRING, ds->iInterface);
1624         }
1625                 break;
1626
1627         case USB_DT_ENDPOINT: {
1628                 struct usb_endpoint_descriptor *ds = (void *)_ds;
1629                 pr_vdebug("endpoint descriptor\n");
1630                 if (length != USB_DT_ENDPOINT_SIZE &&
1631                     length != USB_DT_ENDPOINT_AUDIO_SIZE)
1632                         goto inv_length;
1633                 __entity(ENDPOINT, ds->bEndpointAddress);
1634         }
1635                 break;
1636
1637         case USB_DT_OTG:
1638                 if (length != sizeof(struct usb_otg_descriptor))
1639                         goto inv_length;
1640                 break;
1641
1642         case USB_DT_INTERFACE_ASSOCIATION: {
1643                 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1644                 pr_vdebug("interface association descriptor\n");
1645                 if (length != sizeof *ds)
1646                         goto inv_length;
1647                 if (ds->iFunction)
1648                         __entity(STRING, ds->iFunction);
1649         }
1650                 break;
1651
1652         case USB_DT_OTHER_SPEED_CONFIG:
1653         case USB_DT_INTERFACE_POWER:
1654         case USB_DT_DEBUG:
1655         case USB_DT_SECURITY:
1656         case USB_DT_CS_RADIO_CONTROL:
1657                 /* TODO */
1658                 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1659                 return -EINVAL;
1660
1661         default:
1662                 /* We should never be here */
1663                 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1664                 return -EINVAL;
1665
1666 inv_length:
1667                 pr_vdebug("invalid length: %d (descriptor %d)\n",
1668                           _ds->bLength, _ds->bDescriptorType);
1669                 return -EINVAL;
1670         }
1671
1672 #undef __entity
1673 #undef __entity_check_DESCRIPTOR
1674 #undef __entity_check_INTERFACE
1675 #undef __entity_check_STRING
1676 #undef __entity_check_ENDPOINT
1677
1678         return length;
1679 }
1680
1681 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1682                                      ffs_entity_callback entity, void *priv)
1683 {
1684         const unsigned _len = len;
1685         unsigned long num = 0;
1686
1687         ENTER();
1688
1689         for (;;) {
1690                 int ret;
1691
1692                 if (num == count)
1693                         data = NULL;
1694
1695                 /* Record "descriptor" entity */
1696                 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1697                 if (unlikely(ret < 0)) {
1698                         pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1699                                  num, ret);
1700                         return ret;
1701                 }
1702
1703                 if (!data)
1704                         return _len - len;
1705
1706                 ret = ffs_do_desc(data, len, entity, priv);
1707                 if (unlikely(ret < 0)) {
1708                         pr_debug("%s returns %d\n", __func__, ret);
1709                         return ret;
1710                 }
1711
1712                 len -= ret;
1713                 data += ret;
1714                 ++num;
1715         }
1716 }
1717
1718 static int __ffs_data_do_entity(enum ffs_entity_type type,
1719                                 u8 *valuep, struct usb_descriptor_header *desc,
1720                                 void *priv)
1721 {
1722         struct ffs_data *ffs = priv;
1723
1724         ENTER();
1725
1726         switch (type) {
1727         case FFS_DESCRIPTOR:
1728                 break;
1729
1730         case FFS_INTERFACE:
1731                 /*
1732                  * Interfaces are indexed from zero so if we
1733                  * encountered interface "n" then there are at least
1734                  * "n+1" interfaces.
1735                  */
1736                 if (*valuep >= ffs->interfaces_count)
1737                         ffs->interfaces_count = *valuep + 1;
1738                 break;
1739
1740         case FFS_STRING:
1741                 /*
1742                  * Strings are indexed from 1 (0 is magic ;) reserved
1743                  * for languages list or some such)
1744                  */
1745                 if (*valuep > ffs->strings_count)
1746                         ffs->strings_count = *valuep;
1747                 break;
1748
1749         case FFS_ENDPOINT:
1750                 /* Endpoints are indexed from 1 as well. */
1751                 if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
1752                         ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
1753                 break;
1754         }
1755
1756         return 0;
1757 }
1758
1759 static int __ffs_data_got_descs(struct ffs_data *ffs,
1760                                 char *const _data, size_t len)
1761 {
1762         unsigned fs_count, hs_count;
1763         int fs_len, ret = -EINVAL;
1764         char *data = _data;
1765
1766         ENTER();
1767
1768         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
1769                      get_unaligned_le32(data + 4) != len))
1770                 goto error;
1771         fs_count = get_unaligned_le32(data +  8);
1772         hs_count = get_unaligned_le32(data + 12);
1773
1774         if (!fs_count && !hs_count)
1775                 goto einval;
1776
1777         data += 16;
1778         len  -= 16;
1779
1780         if (likely(fs_count)) {
1781                 fs_len = ffs_do_descs(fs_count, data, len,
1782                                       __ffs_data_do_entity, ffs);
1783                 if (unlikely(fs_len < 0)) {
1784                         ret = fs_len;
1785                         goto error;
1786                 }
1787
1788                 data += fs_len;
1789                 len  -= fs_len;
1790         } else {
1791                 fs_len = 0;
1792         }
1793
1794         if (likely(hs_count)) {
1795                 ret = ffs_do_descs(hs_count, data, len,
1796                                    __ffs_data_do_entity, ffs);
1797                 if (unlikely(ret < 0))
1798                         goto error;
1799         } else {
1800                 ret = 0;
1801         }
1802
1803         if (unlikely(len != ret))
1804                 goto einval;
1805
1806         ffs->raw_fs_descs_length = fs_len;
1807         ffs->raw_descs_length    = fs_len + ret;
1808         ffs->raw_descs           = _data;
1809         ffs->fs_descs_count      = fs_count;
1810         ffs->hs_descs_count      = hs_count;
1811
1812         return 0;
1813
1814 einval:
1815         ret = -EINVAL;
1816 error:
1817         kfree(_data);
1818         return ret;
1819 }
1820
1821 static int __ffs_data_got_strings(struct ffs_data *ffs,
1822                                   char *const _data, size_t len)
1823 {
1824         u32 str_count, needed_count, lang_count;
1825         struct usb_gadget_strings **stringtabs, *t;
1826         struct usb_string *strings, *s;
1827         const char *data = _data;
1828
1829         ENTER();
1830
1831         if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
1832                      get_unaligned_le32(data + 4) != len))
1833                 goto error;
1834         str_count  = get_unaligned_le32(data + 8);
1835         lang_count = get_unaligned_le32(data + 12);
1836
1837         /* if one is zero the other must be zero */
1838         if (unlikely(!str_count != !lang_count))
1839                 goto error;
1840
1841         /* Do we have at least as many strings as descriptors need? */
1842         needed_count = ffs->strings_count;
1843         if (unlikely(str_count < needed_count))
1844                 goto error;
1845
1846         /*
1847          * If we don't need any strings just return and free all
1848          * memory.
1849          */
1850         if (!needed_count) {
1851                 kfree(_data);
1852                 return 0;
1853         }
1854
1855         /* Allocate everything in one chunk so there's less maintenance. */
1856         {
1857                 struct {
1858                         struct usb_gadget_strings *stringtabs[lang_count + 1];
1859                         struct usb_gadget_strings stringtab[lang_count];
1860                         struct usb_string strings[lang_count*(needed_count+1)];
1861                 } *d;
1862                 unsigned i = 0;
1863
1864                 d = kmalloc(sizeof *d, GFP_KERNEL);
1865                 if (unlikely(!d)) {
1866                         kfree(_data);
1867                         return -ENOMEM;
1868                 }
1869
1870                 stringtabs = d->stringtabs;
1871                 t = d->stringtab;
1872                 i = lang_count;
1873                 do {
1874                         *stringtabs++ = t++;
1875                 } while (--i);
1876                 *stringtabs = NULL;
1877
1878                 stringtabs = d->stringtabs;
1879                 t = d->stringtab;
1880                 s = d->strings;
1881                 strings = s;
1882         }
1883
1884         /* For each language */
1885         data += 16;
1886         len -= 16;
1887
1888         do { /* lang_count > 0 so we can use do-while */
1889                 unsigned needed = needed_count;
1890
1891                 if (unlikely(len < 3))
1892                         goto error_free;
1893                 t->language = get_unaligned_le16(data);
1894                 t->strings  = s;
1895                 ++t;
1896
1897                 data += 2;
1898                 len -= 2;
1899
1900                 /* For each string */
1901                 do { /* str_count > 0 so we can use do-while */
1902                         size_t length = strnlen(data, len);
1903
1904                         if (unlikely(length == len))
1905                                 goto error_free;
1906
1907                         /*
1908                          * User may provide more strings then we need,
1909                          * if that's the case we simply ignore the
1910                          * rest
1911                          */
1912                         if (likely(needed)) {
1913                                 /*
1914                                  * s->id will be set while adding
1915                                  * function to configuration so for
1916                                  * now just leave garbage here.
1917                                  */
1918                                 s->s = data;
1919                                 --needed;
1920                                 ++s;
1921                         }
1922
1923                         data += length + 1;
1924                         len -= length + 1;
1925                 } while (--str_count);
1926
1927                 s->id = 0;   /* terminator */
1928                 s->s = NULL;
1929                 ++s;
1930
1931         } while (--lang_count);
1932
1933         /* Some garbage left? */
1934         if (unlikely(len))
1935                 goto error_free;
1936
1937         /* Done! */
1938         ffs->stringtabs = stringtabs;
1939         ffs->raw_strings = _data;
1940
1941         return 0;
1942
1943 error_free:
1944         kfree(stringtabs);
1945 error:
1946         kfree(_data);
1947         return -EINVAL;
1948 }
1949
1950
1951 /* Events handling and management *******************************************/
1952
1953 static void __ffs_event_add(struct ffs_data *ffs,
1954                             enum usb_functionfs_event_type type)
1955 {
1956         enum usb_functionfs_event_type rem_type1, rem_type2 = type;
1957         int neg = 0;
1958
1959         /*
1960          * Abort any unhandled setup
1961          *
1962          * We do not need to worry about some cmpxchg() changing value
1963          * of ffs->setup_state without holding the lock because when
1964          * state is FFS_SETUP_PENDING cmpxchg() in several places in
1965          * the source does nothing.
1966          */
1967         if (ffs->setup_state == FFS_SETUP_PENDING)
1968                 ffs->setup_state = FFS_SETUP_CANCELED;
1969
1970         switch (type) {
1971         case FUNCTIONFS_RESUME:
1972                 rem_type2 = FUNCTIONFS_SUSPEND;
1973                 /* FALL THROUGH */
1974         case FUNCTIONFS_SUSPEND:
1975         case FUNCTIONFS_SETUP:
1976                 rem_type1 = type;
1977                 /* Discard all similar events */
1978                 break;
1979
1980         case FUNCTIONFS_BIND:
1981         case FUNCTIONFS_UNBIND:
1982         case FUNCTIONFS_DISABLE:
1983         case FUNCTIONFS_ENABLE:
1984                 /* Discard everything other then power management. */
1985                 rem_type1 = FUNCTIONFS_SUSPEND;
1986                 rem_type2 = FUNCTIONFS_RESUME;
1987                 neg = 1;
1988                 break;
1989
1990         default:
1991                 BUG();
1992         }
1993
1994         {
1995                 u8 *ev  = ffs->ev.types, *out = ev;
1996                 unsigned n = ffs->ev.count;
1997                 for (; n; --n, ++ev)
1998                         if ((*ev == rem_type1 || *ev == rem_type2) == neg)
1999                                 *out++ = *ev;
2000                         else
2001                                 pr_vdebug("purging event %d\n", *ev);
2002                 ffs->ev.count = out - ffs->ev.types;
2003         }
2004
2005         pr_vdebug("adding event %d\n", type);
2006         ffs->ev.types[ffs->ev.count++] = type;
2007         wake_up_locked(&ffs->ev.waitq);
2008 }
2009
2010 static void ffs_event_add(struct ffs_data *ffs,
2011                           enum usb_functionfs_event_type type)
2012 {
2013         unsigned long flags;
2014         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2015         __ffs_event_add(ffs, type);
2016         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2017 }
2018
2019
2020 /* Bind/unbind USB function hooks *******************************************/
2021
2022 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2023                                     struct usb_descriptor_header *desc,
2024                                     void *priv)
2025 {
2026         struct usb_endpoint_descriptor *ds = (void *)desc;
2027         struct ffs_function *func = priv;
2028         struct ffs_ep *ffs_ep;
2029
2030         /*
2031          * If hs_descriptors is not NULL then we are reading hs
2032          * descriptors now
2033          */
2034         const int isHS = func->function.hs_descriptors != NULL;
2035         unsigned idx;
2036
2037         if (type != FFS_DESCRIPTOR)
2038                 return 0;
2039
2040         if (isHS)
2041                 func->function.hs_descriptors[(long)valuep] = desc;
2042         else
2043                 func->function.descriptors[(long)valuep]    = desc;
2044
2045         if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2046                 return 0;
2047
2048         idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
2049         ffs_ep = func->eps + idx;
2050
2051         if (unlikely(ffs_ep->descs[isHS])) {
2052                 pr_vdebug("two %sspeed descriptors for EP %d\n",
2053                           isHS ? "high" : "full",
2054                           ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2055                 return -EINVAL;
2056         }
2057         ffs_ep->descs[isHS] = ds;
2058
2059         ffs_dump_mem(": Original  ep desc", ds, ds->bLength);
2060         if (ffs_ep->ep) {
2061                 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2062                 if (!ds->wMaxPacketSize)
2063                         ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2064         } else {
2065                 struct usb_request *req;
2066                 struct usb_ep *ep;
2067
2068                 pr_vdebug("autoconfig\n");
2069                 ep = usb_ep_autoconfig(func->gadget, ds);
2070                 if (unlikely(!ep))
2071                         return -ENOTSUPP;
2072                 ep->driver_data = func->eps + idx;
2073
2074                 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2075                 if (unlikely(!req))
2076                         return -ENOMEM;
2077
2078                 ffs_ep->ep  = ep;
2079                 ffs_ep->req = req;
2080                 func->eps_revmap[ds->bEndpointAddress &
2081                                  USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2082         }
2083         ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2084
2085         return 0;
2086 }
2087
2088 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2089                                    struct usb_descriptor_header *desc,
2090                                    void *priv)
2091 {
2092         struct ffs_function *func = priv;
2093         unsigned idx;
2094         u8 newValue;
2095
2096         switch (type) {
2097         default:
2098         case FFS_DESCRIPTOR:
2099                 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2100                 return 0;
2101
2102         case FFS_INTERFACE:
2103                 idx = *valuep;
2104                 if (func->interfaces_nums[idx] < 0) {
2105                         int id = usb_interface_id(func->conf, &func->function);
2106                         if (unlikely(id < 0))
2107                                 return id;
2108                         func->interfaces_nums[idx] = id;
2109                 }
2110                 newValue = func->interfaces_nums[idx];
2111                 break;
2112
2113         case FFS_STRING:
2114                 /* String' IDs are allocated when fsf_data is bound to cdev */
2115                 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2116                 break;
2117
2118         case FFS_ENDPOINT:
2119                 /*
2120                  * USB_DT_ENDPOINT are handled in
2121                  * __ffs_func_bind_do_descs().
2122                  */
2123                 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2124                         return 0;
2125
2126                 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2127                 if (unlikely(!func->eps[idx].ep))
2128                         return -EINVAL;
2129
2130                 {
2131                         struct usb_endpoint_descriptor **descs;
2132                         descs = func->eps[idx].descs;
2133                         newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2134                 }
2135                 break;
2136         }
2137
2138         pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2139         *valuep = newValue;
2140         return 0;
2141 }
2142
2143 static int ffs_func_bind(struct usb_configuration *c,
2144                          struct usb_function *f)
2145 {
2146         struct ffs_function *func = ffs_func_from_usb(f);
2147         struct ffs_data *ffs = func->ffs;
2148
2149         const int full = !!func->ffs->fs_descs_count;
2150         const int high = gadget_is_dualspeed(func->gadget) &&
2151                 func->ffs->hs_descs_count;
2152
2153         int ret;
2154
2155         /* Make it a single chunk, less management later on */
2156         struct {
2157                 struct ffs_ep eps[ffs->eps_count];
2158                 struct usb_descriptor_header
2159                         *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
2160                 struct usb_descriptor_header
2161                         *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
2162                 short inums[ffs->interfaces_count];
2163                 char raw_descs[high ? ffs->raw_descs_length
2164                                     : ffs->raw_fs_descs_length];
2165         } *data;
2166
2167         ENTER();
2168
2169         /* Only high speed but not supported by gadget? */
2170         if (unlikely(!(full | high)))
2171                 return -ENOTSUPP;
2172
2173         /* Allocate */
2174         data = kmalloc(sizeof *data, GFP_KERNEL);
2175         if (unlikely(!data))
2176                 return -ENOMEM;
2177
2178         /* Zero */
2179         memset(data->eps, 0, sizeof data->eps);
2180         memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
2181         memset(data->inums, 0xff, sizeof data->inums);
2182         for (ret = ffs->eps_count; ret; --ret)
2183                 data->eps[ret].num = -1;
2184
2185         /* Save pointers */
2186         func->eps             = data->eps;
2187         func->interfaces_nums = data->inums;
2188
2189         /*
2190          * Go through all the endpoint descriptors and allocate
2191          * endpoints first, so that later we can rewrite the endpoint
2192          * numbers without worrying that it may be described later on.
2193          */
2194         if (likely(full)) {
2195                 func->function.descriptors = data->fs_descs;
2196                 ret = ffs_do_descs(ffs->fs_descs_count,
2197                                    data->raw_descs,
2198                                    sizeof data->raw_descs,
2199                                    __ffs_func_bind_do_descs, func);
2200                 if (unlikely(ret < 0))
2201                         goto error;
2202         } else {
2203                 ret = 0;
2204         }
2205
2206         if (likely(high)) {
2207                 func->function.hs_descriptors = data->hs_descs;
2208                 ret = ffs_do_descs(ffs->hs_descs_count,
2209                                    data->raw_descs + ret,
2210                                    (sizeof data->raw_descs) - ret,
2211                                    __ffs_func_bind_do_descs, func);
2212         }
2213
2214         /*
2215          * Now handle interface numbers allocation and interface and
2216          * endpoint numbers rewriting.  We can do that in one go
2217          * now.
2218          */
2219         ret = ffs_do_descs(ffs->fs_descs_count +
2220                            (high ? ffs->hs_descs_count : 0),
2221                            data->raw_descs, sizeof data->raw_descs,
2222                            __ffs_func_bind_do_nums, func);
2223         if (unlikely(ret < 0))
2224                 goto error;
2225
2226         /* And we're done */
2227         ffs_event_add(ffs, FUNCTIONFS_BIND);
2228         return 0;
2229
2230 error:
2231         /* XXX Do we need to release all claimed endpoints here? */
2232         return ret;
2233 }
2234
2235
2236 /* Other USB function hooks *************************************************/
2237
2238 static void ffs_func_unbind(struct usb_configuration *c,
2239                             struct usb_function *f)
2240 {
2241         struct ffs_function *func = ffs_func_from_usb(f);
2242         struct ffs_data *ffs = func->ffs;
2243
2244         ENTER();
2245
2246         if (ffs->func == func) {
2247                 ffs_func_eps_disable(func);
2248                 ffs->func = NULL;
2249         }
2250
2251         ffs_event_add(ffs, FUNCTIONFS_UNBIND);
2252
2253         ffs_func_free(func);
2254 }
2255
2256 static int ffs_func_set_alt(struct usb_function *f,
2257                             unsigned interface, unsigned alt)
2258 {
2259         struct ffs_function *func = ffs_func_from_usb(f);
2260         struct ffs_data *ffs = func->ffs;
2261         int ret = 0, intf;
2262
2263         if (alt != (unsigned)-1) {
2264                 intf = ffs_func_revmap_intf(func, interface);
2265                 if (unlikely(intf < 0))
2266                         return intf;
2267         }
2268
2269         if (ffs->func)
2270                 ffs_func_eps_disable(ffs->func);
2271
2272         if (ffs->state != FFS_ACTIVE)
2273                 return -ENODEV;
2274
2275         if (alt == (unsigned)-1) {
2276                 ffs->func = NULL;
2277                 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2278                 return 0;
2279         }
2280
2281         ffs->func = func;
2282         ret = ffs_func_eps_enable(func);
2283         if (likely(ret >= 0))
2284                 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2285         return ret;
2286 }
2287
2288 static void ffs_func_disable(struct usb_function *f)
2289 {
2290         ffs_func_set_alt(f, 0, (unsigned)-1);
2291 }
2292
2293 static int ffs_func_setup(struct usb_function *f,
2294                           const struct usb_ctrlrequest *creq)
2295 {
2296         struct ffs_function *func = ffs_func_from_usb(f);
2297         struct ffs_data *ffs = func->ffs;
2298         unsigned long flags;
2299         int ret;
2300
2301         ENTER();
2302
2303         pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2304         pr_vdebug("creq->bRequest     = %02x\n", creq->bRequest);
2305         pr_vdebug("creq->wValue       = %04x\n", le16_to_cpu(creq->wValue));
2306         pr_vdebug("creq->wIndex       = %04x\n", le16_to_cpu(creq->wIndex));
2307         pr_vdebug("creq->wLength      = %04x\n", le16_to_cpu(creq->wLength));
2308
2309         /*
2310          * Most requests directed to interface go through here
2311          * (notable exceptions are set/get interface) so we need to
2312          * handle them.  All other either handled by composite or
2313          * passed to usb_configuration->setup() (if one is set).  No
2314          * matter, we will handle requests directed to endpoint here
2315          * as well (as it's straightforward) but what to do with any
2316          * other request?
2317          */
2318         if (ffs->state != FFS_ACTIVE)
2319                 return -ENODEV;
2320
2321         switch (creq->bRequestType & USB_RECIP_MASK) {
2322         case USB_RECIP_INTERFACE:
2323                 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2324                 if (unlikely(ret < 0))
2325                         return ret;
2326                 break;
2327
2328         case USB_RECIP_ENDPOINT:
2329                 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2330                 if (unlikely(ret < 0))
2331                         return ret;
2332                 break;
2333
2334         default:
2335                 return -EOPNOTSUPP;
2336         }
2337
2338         spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2339         ffs->ev.setup = *creq;
2340         ffs->ev.setup.wIndex = cpu_to_le16(ret);
2341         __ffs_event_add(ffs, FUNCTIONFS_SETUP);
2342         spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2343
2344         return 0;
2345 }
2346
2347 static void ffs_func_suspend(struct usb_function *f)
2348 {
2349         ENTER();
2350         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
2351 }
2352
2353 static void ffs_func_resume(struct usb_function *f)
2354 {
2355         ENTER();
2356         ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
2357 }
2358
2359
2360 /* Endpoint and interface numbers reverse mapping ***************************/
2361
2362 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
2363 {
2364         num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
2365         return num ? num : -EDOM;
2366 }
2367
2368 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
2369 {
2370         short *nums = func->interfaces_nums;
2371         unsigned count = func->ffs->interfaces_count;
2372
2373         for (; count; --count, ++nums) {
2374                 if (*nums >= 0 && *nums == intf)
2375                         return nums - func->interfaces_nums;
2376         }
2377
2378         return -EDOM;
2379 }
2380
2381
2382 /* Misc helper functions ****************************************************/
2383
2384 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
2385 {
2386         return nonblock
2387                 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
2388                 : mutex_lock_interruptible(mutex);
2389 }
2390
2391 static char *ffs_prepare_buffer(const char * __user buf, size_t len)
2392 {
2393         char *data;
2394
2395         if (unlikely(!len))
2396                 return NULL;
2397
2398         data = kmalloc(len, GFP_KERNEL);
2399         if (unlikely(!data))
2400                 return ERR_PTR(-ENOMEM);
2401
2402         if (unlikely(__copy_from_user(data, buf, len))) {
2403                 kfree(data);
2404                 return ERR_PTR(-EFAULT);
2405         }
2406
2407         pr_vdebug("Buffer from user space:\n");
2408         ffs_dump_mem("", data, len);
2409
2410         return data;
2411 }