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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_fs.c -- user mode file system API for USB composite function controllers
4 *
5 * Copyright (C) 2010 Samsung Electronics
6 * Author: Michal Nazarewicz <mina86@mina86.com>
7 *
8 * Based on inode.c (GadgetFS) which was:
9 * Copyright (C) 2003-2004 David Brownell
10 * Copyright (C) 2003 Agilent Technologies
11 */
12
13
14/* #define DEBUG */
15/* #define VERBOSE_DEBUG */
16
17#include <linux/blkdev.h>
18#include <linux/dma-buf.h>
19#include <linux/dma-fence.h>
20#include <linux/dma-resv.h>
21#include <linux/pagemap.h>
22#include <linux/export.h>
23#include <linux/fs_parser.h>
24#include <linux/hid.h>
25#include <linux/mm.h>
26#include <linux/module.h>
27#include <linux/scatterlist.h>
28#include <linux/sched/signal.h>
29#include <linux/uio.h>
30#include <linux/vmalloc.h>
31#include <asm/unaligned.h>
32
33#include <linux/usb/ccid.h>
34#include <linux/usb/composite.h>
35#include <linux/usb/functionfs.h>
36
37#include <linux/aio.h>
38#include <linux/kthread.h>
39#include <linux/poll.h>
40#include <linux/eventfd.h>
41
42#include "u_fs.h"
43#include "u_f.h"
44#include "u_os_desc.h"
45#include "configfs.h"
46
47#define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
48
49#define DMABUF_ENQUEUE_TIMEOUT_MS 5000
50
51MODULE_IMPORT_NS(DMA_BUF);
52
53/* Reference counter handling */
54static void ffs_data_get(struct ffs_data *ffs);
55static void ffs_data_put(struct ffs_data *ffs);
56/* Creates new ffs_data object. */
57static struct ffs_data *__must_check ffs_data_new(const char *dev_name)
58 __attribute__((malloc));
59
60/* Opened counter handling. */
61static void ffs_data_opened(struct ffs_data *ffs);
62static void ffs_data_closed(struct ffs_data *ffs);
63
64/* Called with ffs->mutex held; take over ownership of data. */
65static int __must_check
66__ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
67static int __must_check
68__ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
69
70
71/* The function structure ***************************************************/
72
73struct ffs_ep;
74
75struct ffs_function {
76 struct usb_configuration *conf;
77 struct usb_gadget *gadget;
78 struct ffs_data *ffs;
79
80 struct ffs_ep *eps;
81 u8 eps_revmap[16];
82 short *interfaces_nums;
83
84 struct usb_function function;
85};
86
87
88static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
89{
90 return container_of(f, struct ffs_function, function);
91}
92
93
94static inline enum ffs_setup_state
95ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
96{
97 return (enum ffs_setup_state)
98 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
99}
100
101
102static void ffs_func_eps_disable(struct ffs_function *func);
103static int __must_check ffs_func_eps_enable(struct ffs_function *func);
104
105static int ffs_func_bind(struct usb_configuration *,
106 struct usb_function *);
107static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
108static void ffs_func_disable(struct usb_function *);
109static int ffs_func_setup(struct usb_function *,
110 const struct usb_ctrlrequest *);
111static bool ffs_func_req_match(struct usb_function *,
112 const struct usb_ctrlrequest *,
113 bool config0);
114static void ffs_func_suspend(struct usb_function *);
115static void ffs_func_resume(struct usb_function *);
116
117
118static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
119static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
120
121
122/* The endpoints structures *************************************************/
123
124struct ffs_ep {
125 struct usb_ep *ep; /* P: ffs->eps_lock */
126 struct usb_request *req; /* P: epfile->mutex */
127
128 /* [0]: full speed, [1]: high speed, [2]: super speed */
129 struct usb_endpoint_descriptor *descs[3];
130
131 u8 num;
132};
133
134struct ffs_dmabuf_priv {
135 struct list_head entry;
136 struct kref ref;
137 struct ffs_data *ffs;
138 struct dma_buf_attachment *attach;
139 struct sg_table *sgt;
140 enum dma_data_direction dir;
141 spinlock_t lock;
142 u64 context;
143 struct usb_request *req; /* P: ffs->eps_lock */
144 struct usb_ep *ep; /* P: ffs->eps_lock */
145};
146
147struct ffs_dma_fence {
148 struct dma_fence base;
149 struct ffs_dmabuf_priv *priv;
150 struct work_struct work;
151};
152
153struct ffs_epfile {
154 /* Protects ep->ep and ep->req. */
155 struct mutex mutex;
156
157 struct ffs_data *ffs;
158 struct ffs_ep *ep; /* P: ffs->eps_lock */
159
160 struct dentry *dentry;
161
162 /*
163 * Buffer for holding data from partial reads which may happen since
164 * we’re rounding user read requests to a multiple of a max packet size.
165 *
166 * The pointer is initialised with NULL value and may be set by
167 * __ffs_epfile_read_data function to point to a temporary buffer.
168 *
169 * In normal operation, calls to __ffs_epfile_read_buffered will consume
170 * data from said buffer and eventually free it. Importantly, while the
171 * function is using the buffer, it sets the pointer to NULL. This is
172 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
173 * can never run concurrently (they are synchronised by epfile->mutex)
174 * so the latter will not assign a new value to the pointer.
175 *
176 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
177 * valid) and sets the pointer to READ_BUFFER_DROP value. This special
178 * value is crux of the synchronisation between ffs_func_eps_disable and
179 * __ffs_epfile_read_data.
180 *
181 * Once __ffs_epfile_read_data is about to finish it will try to set the
182 * pointer back to its old value (as described above), but seeing as the
183 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
184 * the buffer.
185 *
186 * == State transitions ==
187 *
188 * • ptr == NULL: (initial state)
189 * â—¦ __ffs_epfile_read_buffer_free: go to ptr == DROP
190 * â—¦ __ffs_epfile_read_buffered: nop
191 * â—¦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
192 * ◦ reading finishes: n/a, not in ‘and reading’ state
193 * • ptr == DROP:
194 * â—¦ __ffs_epfile_read_buffer_free: nop
195 * â—¦ __ffs_epfile_read_buffered: go to ptr == NULL
196 * â—¦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
197 * ◦ reading finishes: n/a, not in ‘and reading’ state
198 * • ptr == buf:
199 * â—¦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
200 * â—¦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
201 * â—¦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
202 * is always called first
203 * ◦ reading finishes: n/a, not in ‘and reading’ state
204 * • ptr == NULL and reading:
205 * â—¦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
206 * â—¦ __ffs_epfile_read_buffered: n/a, mutex is held
207 * â—¦ __ffs_epfile_read_data: n/a, mutex is held
208 * ◦ reading finishes and …
209 * … all data read: free buf, go to ptr == NULL
210 * … otherwise: go to ptr == buf and reading
211 * • ptr == DROP and reading:
212 * â—¦ __ffs_epfile_read_buffer_free: nop
213 * â—¦ __ffs_epfile_read_buffered: n/a, mutex is held
214 * â—¦ __ffs_epfile_read_data: n/a, mutex is held
215 * â—¦ reading finishes: free buf, go to ptr == DROP
216 */
217 struct ffs_buffer *read_buffer;
218#define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
219
220 char name[5];
221
222 unsigned char in; /* P: ffs->eps_lock */
223 unsigned char isoc; /* P: ffs->eps_lock */
224
225 unsigned char _pad;
226
227 /* Protects dmabufs */
228 struct mutex dmabufs_mutex;
229 struct list_head dmabufs; /* P: dmabufs_mutex */
230 atomic_t seqno;
231};
232
233struct ffs_buffer {
234 size_t length;
235 char *data;
236 char storage[] __counted_by(length);
237};
238
239/* ffs_io_data structure ***************************************************/
240
241struct ffs_io_data {
242 bool aio;
243 bool read;
244
245 struct kiocb *kiocb;
246 struct iov_iter data;
247 const void *to_free;
248 char *buf;
249
250 struct mm_struct *mm;
251 struct work_struct work;
252
253 struct usb_ep *ep;
254 struct usb_request *req;
255 struct sg_table sgt;
256 bool use_sg;
257
258 struct ffs_data *ffs;
259
260 int status;
261 struct completion done;
262};
263
264struct ffs_desc_helper {
265 struct ffs_data *ffs;
266 unsigned interfaces_count;
267 unsigned eps_count;
268};
269
270static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
271static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
272
273static struct dentry *
274ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
275 const struct file_operations *fops);
276
277/* Devices management *******************************************************/
278
279DEFINE_MUTEX(ffs_lock);
280EXPORT_SYMBOL_GPL(ffs_lock);
281
282static struct ffs_dev *_ffs_find_dev(const char *name);
283static struct ffs_dev *_ffs_alloc_dev(void);
284static void _ffs_free_dev(struct ffs_dev *dev);
285static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data);
286static void ffs_release_dev(struct ffs_dev *ffs_dev);
287static int ffs_ready(struct ffs_data *ffs);
288static void ffs_closed(struct ffs_data *ffs);
289
290/* Misc helper functions ****************************************************/
291
292static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
293 __attribute__((warn_unused_result, nonnull));
294static char *ffs_prepare_buffer(const char __user *buf, size_t len)
295 __attribute__((warn_unused_result, nonnull));
296
297
298/* Control file aka ep0 *****************************************************/
299
300static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
301{
302 struct ffs_data *ffs = req->context;
303
304 complete(&ffs->ep0req_completion);
305}
306
307static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
308 __releases(&ffs->ev.waitq.lock)
309{
310 struct usb_request *req = ffs->ep0req;
311 int ret;
312
313 if (!req) {
314 spin_unlock_irq(&ffs->ev.waitq.lock);
315 return -EINVAL;
316 }
317
318 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
319
320 spin_unlock_irq(&ffs->ev.waitq.lock);
321
322 req->buf = data;
323 req->length = len;
324
325 /*
326 * UDC layer requires to provide a buffer even for ZLP, but should
327 * not use it at all. Let's provide some poisoned pointer to catch
328 * possible bug in the driver.
329 */
330 if (req->buf == NULL)
331 req->buf = (void *)0xDEADBABE;
332
333 reinit_completion(&ffs->ep0req_completion);
334
335 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
336 if (ret < 0)
337 return ret;
338
339 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
340 if (ret) {
341 usb_ep_dequeue(ffs->gadget->ep0, req);
342 return -EINTR;
343 }
344
345 ffs->setup_state = FFS_NO_SETUP;
346 return req->status ? req->status : req->actual;
347}
348
349static int __ffs_ep0_stall(struct ffs_data *ffs)
350{
351 if (ffs->ev.can_stall) {
352 pr_vdebug("ep0 stall\n");
353 usb_ep_set_halt(ffs->gadget->ep0);
354 ffs->setup_state = FFS_NO_SETUP;
355 return -EL2HLT;
356 } else {
357 pr_debug("bogus ep0 stall!\n");
358 return -ESRCH;
359 }
360}
361
362static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
363 size_t len, loff_t *ptr)
364{
365 struct ffs_data *ffs = file->private_data;
366 ssize_t ret;
367 char *data;
368
369 /* Fast check if setup was canceled */
370 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
371 return -EIDRM;
372
373 /* Acquire mutex */
374 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
375 if (ret < 0)
376 return ret;
377
378 /* Check state */
379 switch (ffs->state) {
380 case FFS_READ_DESCRIPTORS:
381 case FFS_READ_STRINGS:
382 /* Copy data */
383 if (len < 16) {
384 ret = -EINVAL;
385 break;
386 }
387
388 data = ffs_prepare_buffer(buf, len);
389 if (IS_ERR(data)) {
390 ret = PTR_ERR(data);
391 break;
392 }
393
394 /* Handle data */
395 if (ffs->state == FFS_READ_DESCRIPTORS) {
396 pr_info("read descriptors\n");
397 ret = __ffs_data_got_descs(ffs, data, len);
398 if (ret < 0)
399 break;
400
401 ffs->state = FFS_READ_STRINGS;
402 ret = len;
403 } else {
404 pr_info("read strings\n");
405 ret = __ffs_data_got_strings(ffs, data, len);
406 if (ret < 0)
407 break;
408
409 ret = ffs_epfiles_create(ffs);
410 if (ret) {
411 ffs->state = FFS_CLOSING;
412 break;
413 }
414
415 ffs->state = FFS_ACTIVE;
416 mutex_unlock(&ffs->mutex);
417
418 ret = ffs_ready(ffs);
419 if (ret < 0) {
420 ffs->state = FFS_CLOSING;
421 return ret;
422 }
423
424 return len;
425 }
426 break;
427
428 case FFS_ACTIVE:
429 data = NULL;
430 /*
431 * We're called from user space, we can use _irq
432 * rather then _irqsave
433 */
434 spin_lock_irq(&ffs->ev.waitq.lock);
435 switch (ffs_setup_state_clear_cancelled(ffs)) {
436 case FFS_SETUP_CANCELLED:
437 ret = -EIDRM;
438 goto done_spin;
439
440 case FFS_NO_SETUP:
441 ret = -ESRCH;
442 goto done_spin;
443
444 case FFS_SETUP_PENDING:
445 break;
446 }
447
448 /* FFS_SETUP_PENDING */
449 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
450 spin_unlock_irq(&ffs->ev.waitq.lock);
451 ret = __ffs_ep0_stall(ffs);
452 break;
453 }
454
455 /* FFS_SETUP_PENDING and not stall */
456 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
457
458 spin_unlock_irq(&ffs->ev.waitq.lock);
459
460 data = ffs_prepare_buffer(buf, len);
461 if (IS_ERR(data)) {
462 ret = PTR_ERR(data);
463 break;
464 }
465
466 spin_lock_irq(&ffs->ev.waitq.lock);
467
468 /*
469 * We are guaranteed to be still in FFS_ACTIVE state
470 * but the state of setup could have changed from
471 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
472 * to check for that. If that happened we copied data
473 * from user space in vain but it's unlikely.
474 *
475 * For sure we are not in FFS_NO_SETUP since this is
476 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
477 * transition can be performed and it's protected by
478 * mutex.
479 */
480 if (ffs_setup_state_clear_cancelled(ffs) ==
481 FFS_SETUP_CANCELLED) {
482 ret = -EIDRM;
483done_spin:
484 spin_unlock_irq(&ffs->ev.waitq.lock);
485 } else {
486 /* unlocks spinlock */
487 ret = __ffs_ep0_queue_wait(ffs, data, len);
488 }
489 kfree(data);
490 break;
491
492 default:
493 ret = -EBADFD;
494 break;
495 }
496
497 mutex_unlock(&ffs->mutex);
498 return ret;
499}
500
501/* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
502static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
503 size_t n)
504 __releases(&ffs->ev.waitq.lock)
505{
506 /*
507 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
508 * size of ffs->ev.types array (which is four) so that's how much space
509 * we reserve.
510 */
511 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
512 const size_t size = n * sizeof *events;
513 unsigned i = 0;
514
515 memset(events, 0, size);
516
517 do {
518 events[i].type = ffs->ev.types[i];
519 if (events[i].type == FUNCTIONFS_SETUP) {
520 events[i].u.setup = ffs->ev.setup;
521 ffs->setup_state = FFS_SETUP_PENDING;
522 }
523 } while (++i < n);
524
525 ffs->ev.count -= n;
526 if (ffs->ev.count)
527 memmove(ffs->ev.types, ffs->ev.types + n,
528 ffs->ev.count * sizeof *ffs->ev.types);
529
530 spin_unlock_irq(&ffs->ev.waitq.lock);
531 mutex_unlock(&ffs->mutex);
532
533 return copy_to_user(buf, events, size) ? -EFAULT : size;
534}
535
536static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
537 size_t len, loff_t *ptr)
538{
539 struct ffs_data *ffs = file->private_data;
540 char *data = NULL;
541 size_t n;
542 int ret;
543
544 /* Fast check if setup was canceled */
545 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
546 return -EIDRM;
547
548 /* Acquire mutex */
549 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
550 if (ret < 0)
551 return ret;
552
553 /* Check state */
554 if (ffs->state != FFS_ACTIVE) {
555 ret = -EBADFD;
556 goto done_mutex;
557 }
558
559 /*
560 * We're called from user space, we can use _irq rather then
561 * _irqsave
562 */
563 spin_lock_irq(&ffs->ev.waitq.lock);
564
565 switch (ffs_setup_state_clear_cancelled(ffs)) {
566 case FFS_SETUP_CANCELLED:
567 ret = -EIDRM;
568 break;
569
570 case FFS_NO_SETUP:
571 n = len / sizeof(struct usb_functionfs_event);
572 if (!n) {
573 ret = -EINVAL;
574 break;
575 }
576
577 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
578 ret = -EAGAIN;
579 break;
580 }
581
582 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
583 ffs->ev.count)) {
584 ret = -EINTR;
585 break;
586 }
587
588 /* unlocks spinlock */
589 return __ffs_ep0_read_events(ffs, buf,
590 min(n, (size_t)ffs->ev.count));
591
592 case FFS_SETUP_PENDING:
593 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
594 spin_unlock_irq(&ffs->ev.waitq.lock);
595 ret = __ffs_ep0_stall(ffs);
596 goto done_mutex;
597 }
598
599 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
600
601 spin_unlock_irq(&ffs->ev.waitq.lock);
602
603 if (len) {
604 data = kmalloc(len, GFP_KERNEL);
605 if (!data) {
606 ret = -ENOMEM;
607 goto done_mutex;
608 }
609 }
610
611 spin_lock_irq(&ffs->ev.waitq.lock);
612
613 /* See ffs_ep0_write() */
614 if (ffs_setup_state_clear_cancelled(ffs) ==
615 FFS_SETUP_CANCELLED) {
616 ret = -EIDRM;
617 break;
618 }
619
620 /* unlocks spinlock */
621 ret = __ffs_ep0_queue_wait(ffs, data, len);
622 if ((ret > 0) && (copy_to_user(buf, data, len)))
623 ret = -EFAULT;
624 goto done_mutex;
625
626 default:
627 ret = -EBADFD;
628 break;
629 }
630
631 spin_unlock_irq(&ffs->ev.waitq.lock);
632done_mutex:
633 mutex_unlock(&ffs->mutex);
634 kfree(data);
635 return ret;
636}
637
638static int ffs_ep0_open(struct inode *inode, struct file *file)
639{
640 struct ffs_data *ffs = inode->i_private;
641
642 if (ffs->state == FFS_CLOSING)
643 return -EBUSY;
644
645 file->private_data = ffs;
646 ffs_data_opened(ffs);
647
648 return stream_open(inode, file);
649}
650
651static int ffs_ep0_release(struct inode *inode, struct file *file)
652{
653 struct ffs_data *ffs = file->private_data;
654
655 ffs_data_closed(ffs);
656
657 return 0;
658}
659
660static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
661{
662 struct ffs_data *ffs = file->private_data;
663 struct usb_gadget *gadget = ffs->gadget;
664 long ret;
665
666 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
667 struct ffs_function *func = ffs->func;
668 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
669 } else if (gadget && gadget->ops->ioctl) {
670 ret = gadget->ops->ioctl(gadget, code, value);
671 } else {
672 ret = -ENOTTY;
673 }
674
675 return ret;
676}
677
678static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait)
679{
680 struct ffs_data *ffs = file->private_data;
681 __poll_t mask = EPOLLWRNORM;
682 int ret;
683
684 poll_wait(file, &ffs->ev.waitq, wait);
685
686 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
687 if (ret < 0)
688 return mask;
689
690 switch (ffs->state) {
691 case FFS_READ_DESCRIPTORS:
692 case FFS_READ_STRINGS:
693 mask |= EPOLLOUT;
694 break;
695
696 case FFS_ACTIVE:
697 switch (ffs->setup_state) {
698 case FFS_NO_SETUP:
699 if (ffs->ev.count)
700 mask |= EPOLLIN;
701 break;
702
703 case FFS_SETUP_PENDING:
704 case FFS_SETUP_CANCELLED:
705 mask |= (EPOLLIN | EPOLLOUT);
706 break;
707 }
708 break;
709
710 case FFS_CLOSING:
711 break;
712 case FFS_DEACTIVATED:
713 break;
714 }
715
716 mutex_unlock(&ffs->mutex);
717
718 return mask;
719}
720
721static const struct file_operations ffs_ep0_operations = {
722 .llseek = no_llseek,
723
724 .open = ffs_ep0_open,
725 .write = ffs_ep0_write,
726 .read = ffs_ep0_read,
727 .release = ffs_ep0_release,
728 .unlocked_ioctl = ffs_ep0_ioctl,
729 .poll = ffs_ep0_poll,
730};
731
732
733/* "Normal" endpoints operations ********************************************/
734
735static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
736{
737 struct ffs_io_data *io_data = req->context;
738
739 if (req->status)
740 io_data->status = req->status;
741 else
742 io_data->status = req->actual;
743
744 complete(&io_data->done);
745}
746
747static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
748{
749 ssize_t ret = copy_to_iter(data, data_len, iter);
750 if (ret == data_len)
751 return ret;
752
753 if (iov_iter_count(iter))
754 return -EFAULT;
755
756 /*
757 * Dear user space developer!
758 *
759 * TL;DR: To stop getting below error message in your kernel log, change
760 * user space code using functionfs to align read buffers to a max
761 * packet size.
762 *
763 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
764 * packet size. When unaligned buffer is passed to functionfs, it
765 * internally uses a larger, aligned buffer so that such UDCs are happy.
766 *
767 * Unfortunately, this means that host may send more data than was
768 * requested in read(2) system call. f_fs doesn’t know what to do with
769 * that excess data so it simply drops it.
770 *
771 * Was the buffer aligned in the first place, no such problem would
772 * happen.
773 *
774 * Data may be dropped only in AIO reads. Synchronous reads are handled
775 * by splitting a request into multiple parts. This splitting may still
776 * be a problem though so it’s likely best to align the buffer
777 * regardless of it being AIO or not..
778 *
779 * This only affects OUT endpoints, i.e. reading data with a read(2),
780 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not
781 * affected.
782 */
783 pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
784 "Align read buffer size to max packet size to avoid the problem.\n",
785 data_len, ret);
786
787 return ret;
788}
789
790/*
791 * allocate a virtually contiguous buffer and create a scatterlist describing it
792 * @sg_table - pointer to a place to be filled with sg_table contents
793 * @size - required buffer size
794 */
795static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz)
796{
797 struct page **pages;
798 void *vaddr, *ptr;
799 unsigned int n_pages;
800 int i;
801
802 vaddr = vmalloc(sz);
803 if (!vaddr)
804 return NULL;
805
806 n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
807 pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL);
808 if (!pages) {
809 vfree(vaddr);
810
811 return NULL;
812 }
813 for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE)
814 pages[i] = vmalloc_to_page(ptr);
815
816 if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) {
817 kvfree(pages);
818 vfree(vaddr);
819
820 return NULL;
821 }
822 kvfree(pages);
823
824 return vaddr;
825}
826
827static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data,
828 size_t data_len)
829{
830 if (io_data->use_sg)
831 return ffs_build_sg_list(&io_data->sgt, data_len);
832
833 return kmalloc(data_len, GFP_KERNEL);
834}
835
836static inline void ffs_free_buffer(struct ffs_io_data *io_data)
837{
838 if (!io_data->buf)
839 return;
840
841 if (io_data->use_sg) {
842 sg_free_table(&io_data->sgt);
843 vfree(io_data->buf);
844 } else {
845 kfree(io_data->buf);
846 }
847}
848
849static void ffs_user_copy_worker(struct work_struct *work)
850{
851 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
852 work);
853 int ret = io_data->status;
854 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
855 unsigned long flags;
856
857 if (io_data->read && ret > 0) {
858 kthread_use_mm(io_data->mm);
859 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
860 kthread_unuse_mm(io_data->mm);
861 }
862
863 io_data->kiocb->ki_complete(io_data->kiocb, ret);
864
865 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
866 eventfd_signal(io_data->ffs->ffs_eventfd);
867
868 spin_lock_irqsave(&io_data->ffs->eps_lock, flags);
869 usb_ep_free_request(io_data->ep, io_data->req);
870 io_data->req = NULL;
871 spin_unlock_irqrestore(&io_data->ffs->eps_lock, flags);
872
873 if (io_data->read)
874 kfree(io_data->to_free);
875 ffs_free_buffer(io_data);
876 kfree(io_data);
877}
878
879static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
880 struct usb_request *req)
881{
882 struct ffs_io_data *io_data = req->context;
883 struct ffs_data *ffs = io_data->ffs;
884
885 io_data->status = req->status ? req->status : req->actual;
886
887 INIT_WORK(&io_data->work, ffs_user_copy_worker);
888 queue_work(ffs->io_completion_wq, &io_data->work);
889}
890
891static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
892{
893 /*
894 * See comment in struct ffs_epfile for full read_buffer pointer
895 * synchronisation story.
896 */
897 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
898 if (buf && buf != READ_BUFFER_DROP)
899 kfree(buf);
900}
901
902/* Assumes epfile->mutex is held. */
903static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
904 struct iov_iter *iter)
905{
906 /*
907 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
908 * the buffer while we are using it. See comment in struct ffs_epfile
909 * for full read_buffer pointer synchronisation story.
910 */
911 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
912 ssize_t ret;
913 if (!buf || buf == READ_BUFFER_DROP)
914 return 0;
915
916 ret = copy_to_iter(buf->data, buf->length, iter);
917 if (buf->length == ret) {
918 kfree(buf);
919 return ret;
920 }
921
922 if (iov_iter_count(iter)) {
923 ret = -EFAULT;
924 } else {
925 buf->length -= ret;
926 buf->data += ret;
927 }
928
929 if (cmpxchg(&epfile->read_buffer, NULL, buf))
930 kfree(buf);
931
932 return ret;
933}
934
935/* Assumes epfile->mutex is held. */
936static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
937 void *data, int data_len,
938 struct iov_iter *iter)
939{
940 struct ffs_buffer *buf;
941
942 ssize_t ret = copy_to_iter(data, data_len, iter);
943 if (data_len == ret)
944 return ret;
945
946 if (iov_iter_count(iter))
947 return -EFAULT;
948
949 /* See ffs_copy_to_iter for more context. */
950 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
951 data_len, ret);
952
953 data_len -= ret;
954 buf = kmalloc(struct_size(buf, storage, data_len), GFP_KERNEL);
955 if (!buf)
956 return -ENOMEM;
957 buf->length = data_len;
958 buf->data = buf->storage;
959 memcpy(buf->storage, data + ret, flex_array_size(buf, storage, data_len));
960
961 /*
962 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
963 * ffs_func_eps_disable has been called in the meanwhile). See comment
964 * in struct ffs_epfile for full read_buffer pointer synchronisation
965 * story.
966 */
967 if (cmpxchg(&epfile->read_buffer, NULL, buf))
968 kfree(buf);
969
970 return ret;
971}
972
973static struct ffs_ep *ffs_epfile_wait_ep(struct file *file)
974{
975 struct ffs_epfile *epfile = file->private_data;
976 struct ffs_ep *ep;
977 int ret;
978
979 /* Wait for endpoint to be enabled */
980 ep = epfile->ep;
981 if (!ep) {
982 if (file->f_flags & O_NONBLOCK)
983 return ERR_PTR(-EAGAIN);
984
985 ret = wait_event_interruptible(
986 epfile->ffs->wait, (ep = epfile->ep));
987 if (ret)
988 return ERR_PTR(-EINTR);
989 }
990
991 return ep;
992}
993
994static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
995{
996 struct ffs_epfile *epfile = file->private_data;
997 struct usb_request *req;
998 struct ffs_ep *ep;
999 char *data = NULL;
1000 ssize_t ret, data_len = -EINVAL;
1001 int halt;
1002
1003 /* Are we still active? */
1004 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1005 return -ENODEV;
1006
1007 ep = ffs_epfile_wait_ep(file);
1008 if (IS_ERR(ep))
1009 return PTR_ERR(ep);
1010
1011 /* Do we halt? */
1012 halt = (!io_data->read == !epfile->in);
1013 if (halt && epfile->isoc)
1014 return -EINVAL;
1015
1016 /* We will be using request and read_buffer */
1017 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
1018 if (ret)
1019 goto error;
1020
1021 /* Allocate & copy */
1022 if (!halt) {
1023 struct usb_gadget *gadget;
1024
1025 /*
1026 * Do we have buffered data from previous partial read? Check
1027 * that for synchronous case only because we do not have
1028 * facility to ‘wake up’ a pending asynchronous read and push
1029 * buffered data to it which we would need to make things behave
1030 * consistently.
1031 */
1032 if (!io_data->aio && io_data->read) {
1033 ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
1034 if (ret)
1035 goto error_mutex;
1036 }
1037
1038 /*
1039 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
1040 * before the waiting completes, so do not assign to 'gadget'
1041 * earlier
1042 */
1043 gadget = epfile->ffs->gadget;
1044
1045 spin_lock_irq(&epfile->ffs->eps_lock);
1046 /* In the meantime, endpoint got disabled or changed. */
1047 if (epfile->ep != ep) {
1048 ret = -ESHUTDOWN;
1049 goto error_lock;
1050 }
1051 data_len = iov_iter_count(&io_data->data);
1052 /*
1053 * Controller may require buffer size to be aligned to
1054 * maxpacketsize of an out endpoint.
1055 */
1056 if (io_data->read)
1057 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
1058
1059 io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE;
1060 spin_unlock_irq(&epfile->ffs->eps_lock);
1061
1062 data = ffs_alloc_buffer(io_data, data_len);
1063 if (!data) {
1064 ret = -ENOMEM;
1065 goto error_mutex;
1066 }
1067 if (!io_data->read &&
1068 !copy_from_iter_full(data, data_len, &io_data->data)) {
1069 ret = -EFAULT;
1070 goto error_mutex;
1071 }
1072 }
1073
1074 spin_lock_irq(&epfile->ffs->eps_lock);
1075
1076 if (epfile->ep != ep) {
1077 /* In the meantime, endpoint got disabled or changed. */
1078 ret = -ESHUTDOWN;
1079 } else if (halt) {
1080 ret = usb_ep_set_halt(ep->ep);
1081 if (!ret)
1082 ret = -EBADMSG;
1083 } else if (data_len == -EINVAL) {
1084 /*
1085 * Sanity Check: even though data_len can't be used
1086 * uninitialized at the time I write this comment, some
1087 * compilers complain about this situation.
1088 * In order to keep the code clean from warnings, data_len is
1089 * being initialized to -EINVAL during its declaration, which
1090 * means we can't rely on compiler anymore to warn no future
1091 * changes won't result in data_len being used uninitialized.
1092 * For such reason, we're adding this redundant sanity check
1093 * here.
1094 */
1095 WARN(1, "%s: data_len == -EINVAL\n", __func__);
1096 ret = -EINVAL;
1097 } else if (!io_data->aio) {
1098 bool interrupted = false;
1099
1100 req = ep->req;
1101 if (io_data->use_sg) {
1102 req->buf = NULL;
1103 req->sg = io_data->sgt.sgl;
1104 req->num_sgs = io_data->sgt.nents;
1105 } else {
1106 req->buf = data;
1107 req->num_sgs = 0;
1108 }
1109 req->length = data_len;
1110
1111 io_data->buf = data;
1112
1113 init_completion(&io_data->done);
1114 req->context = io_data;
1115 req->complete = ffs_epfile_io_complete;
1116
1117 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1118 if (ret < 0)
1119 goto error_lock;
1120
1121 spin_unlock_irq(&epfile->ffs->eps_lock);
1122
1123 if (wait_for_completion_interruptible(&io_data->done)) {
1124 spin_lock_irq(&epfile->ffs->eps_lock);
1125 if (epfile->ep != ep) {
1126 ret = -ESHUTDOWN;
1127 goto error_lock;
1128 }
1129 /*
1130 * To avoid race condition with ffs_epfile_io_complete,
1131 * dequeue the request first then check
1132 * status. usb_ep_dequeue API should guarantee no race
1133 * condition with req->complete callback.
1134 */
1135 usb_ep_dequeue(ep->ep, req);
1136 spin_unlock_irq(&epfile->ffs->eps_lock);
1137 wait_for_completion(&io_data->done);
1138 interrupted = io_data->status < 0;
1139 }
1140
1141 if (interrupted)
1142 ret = -EINTR;
1143 else if (io_data->read && io_data->status > 0)
1144 ret = __ffs_epfile_read_data(epfile, data, io_data->status,
1145 &io_data->data);
1146 else
1147 ret = io_data->status;
1148 goto error_mutex;
1149 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) {
1150 ret = -ENOMEM;
1151 } else {
1152 if (io_data->use_sg) {
1153 req->buf = NULL;
1154 req->sg = io_data->sgt.sgl;
1155 req->num_sgs = io_data->sgt.nents;
1156 } else {
1157 req->buf = data;
1158 req->num_sgs = 0;
1159 }
1160 req->length = data_len;
1161
1162 io_data->buf = data;
1163 io_data->ep = ep->ep;
1164 io_data->req = req;
1165 io_data->ffs = epfile->ffs;
1166
1167 req->context = io_data;
1168 req->complete = ffs_epfile_async_io_complete;
1169
1170 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1171 if (ret) {
1172 io_data->req = NULL;
1173 usb_ep_free_request(ep->ep, req);
1174 goto error_lock;
1175 }
1176
1177 ret = -EIOCBQUEUED;
1178 /*
1179 * Do not kfree the buffer in this function. It will be freed
1180 * by ffs_user_copy_worker.
1181 */
1182 data = NULL;
1183 }
1184
1185error_lock:
1186 spin_unlock_irq(&epfile->ffs->eps_lock);
1187error_mutex:
1188 mutex_unlock(&epfile->mutex);
1189error:
1190 if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */
1191 ffs_free_buffer(io_data);
1192 return ret;
1193}
1194
1195static int
1196ffs_epfile_open(struct inode *inode, struct file *file)
1197{
1198 struct ffs_epfile *epfile = inode->i_private;
1199
1200 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1201 return -ENODEV;
1202
1203 file->private_data = epfile;
1204 ffs_data_opened(epfile->ffs);
1205
1206 return stream_open(inode, file);
1207}
1208
1209static int ffs_aio_cancel(struct kiocb *kiocb)
1210{
1211 struct ffs_io_data *io_data = kiocb->private;
1212 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
1213 unsigned long flags;
1214 int value;
1215
1216 spin_lock_irqsave(&epfile->ffs->eps_lock, flags);
1217
1218 if (io_data && io_data->ep && io_data->req)
1219 value = usb_ep_dequeue(io_data->ep, io_data->req);
1220 else
1221 value = -EINVAL;
1222
1223 spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);
1224
1225 return value;
1226}
1227
1228static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
1229{
1230 struct ffs_io_data io_data, *p = &io_data;
1231 ssize_t res;
1232
1233 if (!is_sync_kiocb(kiocb)) {
1234 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1235 if (!p)
1236 return -ENOMEM;
1237 p->aio = true;
1238 } else {
1239 memset(p, 0, sizeof(*p));
1240 p->aio = false;
1241 }
1242
1243 p->read = false;
1244 p->kiocb = kiocb;
1245 p->data = *from;
1246 p->mm = current->mm;
1247
1248 kiocb->private = p;
1249
1250 if (p->aio)
1251 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1252
1253 res = ffs_epfile_io(kiocb->ki_filp, p);
1254 if (res == -EIOCBQUEUED)
1255 return res;
1256 if (p->aio)
1257 kfree(p);
1258 else
1259 *from = p->data;
1260 return res;
1261}
1262
1263static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
1264{
1265 struct ffs_io_data io_data, *p = &io_data;
1266 ssize_t res;
1267
1268 if (!is_sync_kiocb(kiocb)) {
1269 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1270 if (!p)
1271 return -ENOMEM;
1272 p->aio = true;
1273 } else {
1274 memset(p, 0, sizeof(*p));
1275 p->aio = false;
1276 }
1277
1278 p->read = true;
1279 p->kiocb = kiocb;
1280 if (p->aio) {
1281 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
1282 if (!iter_is_ubuf(&p->data) && !p->to_free) {
1283 kfree(p);
1284 return -ENOMEM;
1285 }
1286 } else {
1287 p->data = *to;
1288 p->to_free = NULL;
1289 }
1290 p->mm = current->mm;
1291
1292 kiocb->private = p;
1293
1294 if (p->aio)
1295 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1296
1297 res = ffs_epfile_io(kiocb->ki_filp, p);
1298 if (res == -EIOCBQUEUED)
1299 return res;
1300
1301 if (p->aio) {
1302 kfree(p->to_free);
1303 kfree(p);
1304 } else {
1305 *to = p->data;
1306 }
1307 return res;
1308}
1309
1310static void ffs_dmabuf_release(struct kref *ref)
1311{
1312 struct ffs_dmabuf_priv *priv = container_of(ref, struct ffs_dmabuf_priv, ref);
1313 struct dma_buf_attachment *attach = priv->attach;
1314 struct dma_buf *dmabuf = attach->dmabuf;
1315
1316 pr_vdebug("FFS DMABUF release\n");
1317 dma_resv_lock(dmabuf->resv, NULL);
1318 dma_buf_unmap_attachment(attach, priv->sgt, priv->dir);
1319 dma_resv_unlock(dmabuf->resv);
1320
1321 dma_buf_detach(attach->dmabuf, attach);
1322 dma_buf_put(dmabuf);
1323 kfree(priv);
1324}
1325
1326static void ffs_dmabuf_get(struct dma_buf_attachment *attach)
1327{
1328 struct ffs_dmabuf_priv *priv = attach->importer_priv;
1329
1330 kref_get(&priv->ref);
1331}
1332
1333static void ffs_dmabuf_put(struct dma_buf_attachment *attach)
1334{
1335 struct ffs_dmabuf_priv *priv = attach->importer_priv;
1336
1337 kref_put(&priv->ref, ffs_dmabuf_release);
1338}
1339
1340static int
1341ffs_epfile_release(struct inode *inode, struct file *file)
1342{
1343 struct ffs_epfile *epfile = inode->i_private;
1344 struct ffs_dmabuf_priv *priv, *tmp;
1345 struct ffs_data *ffs = epfile->ffs;
1346
1347 mutex_lock(&epfile->dmabufs_mutex);
1348
1349 /* Close all attached DMABUFs */
1350 list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) {
1351 /* Cancel any pending transfer */
1352 spin_lock_irq(&ffs->eps_lock);
1353 if (priv->ep && priv->req)
1354 usb_ep_dequeue(priv->ep, priv->req);
1355 spin_unlock_irq(&ffs->eps_lock);
1356
1357 list_del(&priv->entry);
1358 ffs_dmabuf_put(priv->attach);
1359 }
1360
1361 mutex_unlock(&epfile->dmabufs_mutex);
1362
1363 __ffs_epfile_read_buffer_free(epfile);
1364 ffs_data_closed(epfile->ffs);
1365
1366 return 0;
1367}
1368
1369static void ffs_dmabuf_cleanup(struct work_struct *work)
1370{
1371 struct ffs_dma_fence *dma_fence =
1372 container_of(work, struct ffs_dma_fence, work);
1373 struct ffs_dmabuf_priv *priv = dma_fence->priv;
1374 struct dma_buf_attachment *attach = priv->attach;
1375 struct dma_fence *fence = &dma_fence->base;
1376
1377 ffs_dmabuf_put(attach);
1378 dma_fence_put(fence);
1379}
1380
1381static void ffs_dmabuf_signal_done(struct ffs_dma_fence *dma_fence, int ret)
1382{
1383 struct ffs_dmabuf_priv *priv = dma_fence->priv;
1384 struct dma_fence *fence = &dma_fence->base;
1385 bool cookie = dma_fence_begin_signalling();
1386
1387 dma_fence_get(fence);
1388 fence->error = ret;
1389 dma_fence_signal(fence);
1390 dma_fence_end_signalling(cookie);
1391
1392 /*
1393 * The fence will be unref'd in ffs_dmabuf_cleanup.
1394 * It can't be done here, as the unref functions might try to lock
1395 * the resv object, which would deadlock.
1396 */
1397 INIT_WORK(&dma_fence->work, ffs_dmabuf_cleanup);
1398 queue_work(priv->ffs->io_completion_wq, &dma_fence->work);
1399}
1400
1401static void ffs_epfile_dmabuf_io_complete(struct usb_ep *ep,
1402 struct usb_request *req)
1403{
1404 pr_vdebug("FFS: DMABUF transfer complete, status=%d\n", req->status);
1405 ffs_dmabuf_signal_done(req->context, req->status);
1406 usb_ep_free_request(ep, req);
1407}
1408
1409static const char *ffs_dmabuf_get_driver_name(struct dma_fence *fence)
1410{
1411 return "functionfs";
1412}
1413
1414static const char *ffs_dmabuf_get_timeline_name(struct dma_fence *fence)
1415{
1416 return "";
1417}
1418
1419static void ffs_dmabuf_fence_release(struct dma_fence *fence)
1420{
1421 struct ffs_dma_fence *dma_fence =
1422 container_of(fence, struct ffs_dma_fence, base);
1423
1424 kfree(dma_fence);
1425}
1426
1427static const struct dma_fence_ops ffs_dmabuf_fence_ops = {
1428 .get_driver_name = ffs_dmabuf_get_driver_name,
1429 .get_timeline_name = ffs_dmabuf_get_timeline_name,
1430 .release = ffs_dmabuf_fence_release,
1431};
1432
1433static int ffs_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock)
1434{
1435 if (!nonblock)
1436 return dma_resv_lock_interruptible(dmabuf->resv, NULL);
1437
1438 if (!dma_resv_trylock(dmabuf->resv))
1439 return -EBUSY;
1440
1441 return 0;
1442}
1443
1444static struct dma_buf_attachment *
1445ffs_dmabuf_find_attachment(struct ffs_epfile *epfile, struct dma_buf *dmabuf)
1446{
1447 struct device *dev = epfile->ffs->gadget->dev.parent;
1448 struct dma_buf_attachment *attach = NULL;
1449 struct ffs_dmabuf_priv *priv;
1450
1451 mutex_lock(&epfile->dmabufs_mutex);
1452
1453 list_for_each_entry(priv, &epfile->dmabufs, entry) {
1454 if (priv->attach->dev == dev
1455 && priv->attach->dmabuf == dmabuf) {
1456 attach = priv->attach;
1457 break;
1458 }
1459 }
1460
1461 if (attach)
1462 ffs_dmabuf_get(attach);
1463
1464 mutex_unlock(&epfile->dmabufs_mutex);
1465
1466 return attach ?: ERR_PTR(-EPERM);
1467}
1468
1469static int ffs_dmabuf_attach(struct file *file, int fd)
1470{
1471 bool nonblock = file->f_flags & O_NONBLOCK;
1472 struct ffs_epfile *epfile = file->private_data;
1473 struct usb_gadget *gadget = epfile->ffs->gadget;
1474 struct dma_buf_attachment *attach;
1475 struct ffs_dmabuf_priv *priv;
1476 enum dma_data_direction dir;
1477 struct sg_table *sg_table;
1478 struct dma_buf *dmabuf;
1479 int err;
1480
1481 if (!gadget || !gadget->sg_supported)
1482 return -EPERM;
1483
1484 dmabuf = dma_buf_get(fd);
1485 if (IS_ERR(dmabuf))
1486 return PTR_ERR(dmabuf);
1487
1488 attach = dma_buf_attach(dmabuf, gadget->dev.parent);
1489 if (IS_ERR(attach)) {
1490 err = PTR_ERR(attach);
1491 goto err_dmabuf_put;
1492 }
1493
1494 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1495 if (!priv) {
1496 err = -ENOMEM;
1497 goto err_dmabuf_detach;
1498 }
1499
1500 dir = epfile->in ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1501
1502 err = ffs_dma_resv_lock(dmabuf, nonblock);
1503 if (err)
1504 goto err_free_priv;
1505
1506 sg_table = dma_buf_map_attachment(attach, dir);
1507 dma_resv_unlock(dmabuf->resv);
1508
1509 if (IS_ERR(sg_table)) {
1510 err = PTR_ERR(sg_table);
1511 goto err_free_priv;
1512 }
1513
1514 attach->importer_priv = priv;
1515
1516 priv->sgt = sg_table;
1517 priv->dir = dir;
1518 priv->ffs = epfile->ffs;
1519 priv->attach = attach;
1520 spin_lock_init(&priv->lock);
1521 kref_init(&priv->ref);
1522 priv->context = dma_fence_context_alloc(1);
1523
1524 mutex_lock(&epfile->dmabufs_mutex);
1525 list_add(&priv->entry, &epfile->dmabufs);
1526 mutex_unlock(&epfile->dmabufs_mutex);
1527
1528 return 0;
1529
1530err_free_priv:
1531 kfree(priv);
1532err_dmabuf_detach:
1533 dma_buf_detach(dmabuf, attach);
1534err_dmabuf_put:
1535 dma_buf_put(dmabuf);
1536
1537 return err;
1538}
1539
1540static int ffs_dmabuf_detach(struct file *file, int fd)
1541{
1542 struct ffs_epfile *epfile = file->private_data;
1543 struct ffs_data *ffs = epfile->ffs;
1544 struct device *dev = ffs->gadget->dev.parent;
1545 struct ffs_dmabuf_priv *priv, *tmp;
1546 struct dma_buf *dmabuf;
1547 int ret = -EPERM;
1548
1549 dmabuf = dma_buf_get(fd);
1550 if (IS_ERR(dmabuf))
1551 return PTR_ERR(dmabuf);
1552
1553 mutex_lock(&epfile->dmabufs_mutex);
1554
1555 list_for_each_entry_safe(priv, tmp, &epfile->dmabufs, entry) {
1556 if (priv->attach->dev == dev
1557 && priv->attach->dmabuf == dmabuf) {
1558 /* Cancel any pending transfer */
1559 spin_lock_irq(&ffs->eps_lock);
1560 if (priv->ep && priv->req)
1561 usb_ep_dequeue(priv->ep, priv->req);
1562 spin_unlock_irq(&ffs->eps_lock);
1563
1564 list_del(&priv->entry);
1565
1566 /* Unref the reference from ffs_dmabuf_attach() */
1567 ffs_dmabuf_put(priv->attach);
1568 ret = 0;
1569 break;
1570 }
1571 }
1572
1573 mutex_unlock(&epfile->dmabufs_mutex);
1574 dma_buf_put(dmabuf);
1575
1576 return ret;
1577}
1578
1579static int ffs_dmabuf_transfer(struct file *file,
1580 const struct usb_ffs_dmabuf_transfer_req *req)
1581{
1582 bool nonblock = file->f_flags & O_NONBLOCK;
1583 struct ffs_epfile *epfile = file->private_data;
1584 struct dma_buf_attachment *attach;
1585 struct ffs_dmabuf_priv *priv;
1586 struct ffs_dma_fence *fence;
1587 struct usb_request *usb_req;
1588 enum dma_resv_usage resv_dir;
1589 struct dma_buf *dmabuf;
1590 unsigned long timeout;
1591 struct ffs_ep *ep;
1592 bool cookie;
1593 u32 seqno;
1594 long retl;
1595 int ret;
1596
1597 if (req->flags & ~USB_FFS_DMABUF_TRANSFER_MASK)
1598 return -EINVAL;
1599
1600 dmabuf = dma_buf_get(req->fd);
1601 if (IS_ERR(dmabuf))
1602 return PTR_ERR(dmabuf);
1603
1604 if (req->length > dmabuf->size || req->length == 0) {
1605 ret = -EINVAL;
1606 goto err_dmabuf_put;
1607 }
1608
1609 attach = ffs_dmabuf_find_attachment(epfile, dmabuf);
1610 if (IS_ERR(attach)) {
1611 ret = PTR_ERR(attach);
1612 goto err_dmabuf_put;
1613 }
1614
1615 priv = attach->importer_priv;
1616
1617 ep = ffs_epfile_wait_ep(file);
1618 if (IS_ERR(ep)) {
1619 ret = PTR_ERR(ep);
1620 goto err_attachment_put;
1621 }
1622
1623 ret = ffs_dma_resv_lock(dmabuf, nonblock);
1624 if (ret)
1625 goto err_attachment_put;
1626
1627 /* Make sure we don't have writers */
1628 timeout = nonblock ? 0 : msecs_to_jiffies(DMABUF_ENQUEUE_TIMEOUT_MS);
1629 retl = dma_resv_wait_timeout(dmabuf->resv,
1630 dma_resv_usage_rw(epfile->in),
1631 true, timeout);
1632 if (retl == 0)
1633 retl = -EBUSY;
1634 if (retl < 0) {
1635 ret = (int)retl;
1636 goto err_resv_unlock;
1637 }
1638
1639 ret = dma_resv_reserve_fences(dmabuf->resv, 1);
1640 if (ret)
1641 goto err_resv_unlock;
1642
1643 fence = kmalloc(sizeof(*fence), GFP_KERNEL);
1644 if (!fence) {
1645 ret = -ENOMEM;
1646 goto err_resv_unlock;
1647 }
1648
1649 fence->priv = priv;
1650
1651 spin_lock_irq(&epfile->ffs->eps_lock);
1652
1653 /* In the meantime, endpoint got disabled or changed. */
1654 if (epfile->ep != ep) {
1655 ret = -ESHUTDOWN;
1656 goto err_fence_put;
1657 }
1658
1659 usb_req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC);
1660 if (!usb_req) {
1661 ret = -ENOMEM;
1662 goto err_fence_put;
1663 }
1664
1665 /*
1666 * usb_ep_queue() guarantees that all transfers are processed in the
1667 * order they are enqueued, so we can use a simple incrementing
1668 * sequence number for the dma_fence.
1669 */
1670 seqno = atomic_add_return(1, &epfile->seqno);
1671
1672 dma_fence_init(&fence->base, &ffs_dmabuf_fence_ops,
1673 &priv->lock, priv->context, seqno);
1674
1675 resv_dir = epfile->in ? DMA_RESV_USAGE_WRITE : DMA_RESV_USAGE_READ;
1676
1677 dma_resv_add_fence(dmabuf->resv, &fence->base, resv_dir);
1678 dma_resv_unlock(dmabuf->resv);
1679
1680 /* Now that the dma_fence is in place, queue the transfer. */
1681
1682 usb_req->length = req->length;
1683 usb_req->buf = NULL;
1684 usb_req->sg = priv->sgt->sgl;
1685 usb_req->num_sgs = sg_nents_for_len(priv->sgt->sgl, req->length);
1686 usb_req->sg_was_mapped = true;
1687 usb_req->context = fence;
1688 usb_req->complete = ffs_epfile_dmabuf_io_complete;
1689
1690 cookie = dma_fence_begin_signalling();
1691 ret = usb_ep_queue(ep->ep, usb_req, GFP_ATOMIC);
1692 dma_fence_end_signalling(cookie);
1693 if (!ret) {
1694 priv->req = usb_req;
1695 priv->ep = ep->ep;
1696 } else {
1697 pr_warn("FFS: Failed to queue DMABUF: %d\n", ret);
1698 ffs_dmabuf_signal_done(fence, ret);
1699 usb_ep_free_request(ep->ep, usb_req);
1700 }
1701
1702 spin_unlock_irq(&epfile->ffs->eps_lock);
1703 dma_buf_put(dmabuf);
1704
1705 return ret;
1706
1707err_fence_put:
1708 spin_unlock_irq(&epfile->ffs->eps_lock);
1709 dma_fence_put(&fence->base);
1710err_resv_unlock:
1711 dma_resv_unlock(dmabuf->resv);
1712err_attachment_put:
1713 ffs_dmabuf_put(attach);
1714err_dmabuf_put:
1715 dma_buf_put(dmabuf);
1716
1717 return ret;
1718}
1719
1720static long ffs_epfile_ioctl(struct file *file, unsigned code,
1721 unsigned long value)
1722{
1723 struct ffs_epfile *epfile = file->private_data;
1724 struct ffs_ep *ep;
1725 int ret;
1726
1727 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1728 return -ENODEV;
1729
1730 switch (code) {
1731 case FUNCTIONFS_DMABUF_ATTACH:
1732 {
1733 int fd;
1734
1735 if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) {
1736 ret = -EFAULT;
1737 break;
1738 }
1739
1740 return ffs_dmabuf_attach(file, fd);
1741 }
1742 case FUNCTIONFS_DMABUF_DETACH:
1743 {
1744 int fd;
1745
1746 if (copy_from_user(&fd, (void __user *)value, sizeof(fd))) {
1747 ret = -EFAULT;
1748 break;
1749 }
1750
1751 return ffs_dmabuf_detach(file, fd);
1752 }
1753 case FUNCTIONFS_DMABUF_TRANSFER:
1754 {
1755 struct usb_ffs_dmabuf_transfer_req req;
1756
1757 if (copy_from_user(&req, (void __user *)value, sizeof(req))) {
1758 ret = -EFAULT;
1759 break;
1760 }
1761
1762 return ffs_dmabuf_transfer(file, &req);
1763 }
1764 default:
1765 break;
1766 }
1767
1768 /* Wait for endpoint to be enabled */
1769 ep = ffs_epfile_wait_ep(file);
1770 if (IS_ERR(ep))
1771 return PTR_ERR(ep);
1772
1773 spin_lock_irq(&epfile->ffs->eps_lock);
1774
1775 /* In the meantime, endpoint got disabled or changed. */
1776 if (epfile->ep != ep) {
1777 spin_unlock_irq(&epfile->ffs->eps_lock);
1778 return -ESHUTDOWN;
1779 }
1780
1781 switch (code) {
1782 case FUNCTIONFS_FIFO_STATUS:
1783 ret = usb_ep_fifo_status(epfile->ep->ep);
1784 break;
1785 case FUNCTIONFS_FIFO_FLUSH:
1786 usb_ep_fifo_flush(epfile->ep->ep);
1787 ret = 0;
1788 break;
1789 case FUNCTIONFS_CLEAR_HALT:
1790 ret = usb_ep_clear_halt(epfile->ep->ep);
1791 break;
1792 case FUNCTIONFS_ENDPOINT_REVMAP:
1793 ret = epfile->ep->num;
1794 break;
1795 case FUNCTIONFS_ENDPOINT_DESC:
1796 {
1797 int desc_idx;
1798 struct usb_endpoint_descriptor desc1, *desc;
1799
1800 switch (epfile->ffs->gadget->speed) {
1801 case USB_SPEED_SUPER:
1802 case USB_SPEED_SUPER_PLUS:
1803 desc_idx = 2;
1804 break;
1805 case USB_SPEED_HIGH:
1806 desc_idx = 1;
1807 break;
1808 default:
1809 desc_idx = 0;
1810 }
1811
1812 desc = epfile->ep->descs[desc_idx];
1813 memcpy(&desc1, desc, desc->bLength);
1814
1815 spin_unlock_irq(&epfile->ffs->eps_lock);
1816 ret = copy_to_user((void __user *)value, &desc1, desc1.bLength);
1817 if (ret)
1818 ret = -EFAULT;
1819 return ret;
1820 }
1821 default:
1822 ret = -ENOTTY;
1823 }
1824 spin_unlock_irq(&epfile->ffs->eps_lock);
1825
1826 return ret;
1827}
1828
1829static const struct file_operations ffs_epfile_operations = {
1830 .llseek = no_llseek,
1831
1832 .open = ffs_epfile_open,
1833 .write_iter = ffs_epfile_write_iter,
1834 .read_iter = ffs_epfile_read_iter,
1835 .release = ffs_epfile_release,
1836 .unlocked_ioctl = ffs_epfile_ioctl,
1837 .compat_ioctl = compat_ptr_ioctl,
1838};
1839
1840
1841/* File system and super block operations ***********************************/
1842
1843/*
1844 * Mounting the file system creates a controller file, used first for
1845 * function configuration then later for event monitoring.
1846 */
1847
1848static struct inode *__must_check
1849ffs_sb_make_inode(struct super_block *sb, void *data,
1850 const struct file_operations *fops,
1851 const struct inode_operations *iops,
1852 struct ffs_file_perms *perms)
1853{
1854 struct inode *inode;
1855
1856 inode = new_inode(sb);
1857
1858 if (inode) {
1859 struct timespec64 ts = inode_set_ctime_current(inode);
1860
1861 inode->i_ino = get_next_ino();
1862 inode->i_mode = perms->mode;
1863 inode->i_uid = perms->uid;
1864 inode->i_gid = perms->gid;
1865 inode_set_atime_to_ts(inode, ts);
1866 inode_set_mtime_to_ts(inode, ts);
1867 inode->i_private = data;
1868 if (fops)
1869 inode->i_fop = fops;
1870 if (iops)
1871 inode->i_op = iops;
1872 }
1873
1874 return inode;
1875}
1876
1877/* Create "regular" file */
1878static struct dentry *ffs_sb_create_file(struct super_block *sb,
1879 const char *name, void *data,
1880 const struct file_operations *fops)
1881{
1882 struct ffs_data *ffs = sb->s_fs_info;
1883 struct dentry *dentry;
1884 struct inode *inode;
1885
1886 dentry = d_alloc_name(sb->s_root, name);
1887 if (!dentry)
1888 return NULL;
1889
1890 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1891 if (!inode) {
1892 dput(dentry);
1893 return NULL;
1894 }
1895
1896 d_add(dentry, inode);
1897 return dentry;
1898}
1899
1900/* Super block */
1901static const struct super_operations ffs_sb_operations = {
1902 .statfs = simple_statfs,
1903 .drop_inode = generic_delete_inode,
1904};
1905
1906struct ffs_sb_fill_data {
1907 struct ffs_file_perms perms;
1908 umode_t root_mode;
1909 const char *dev_name;
1910 bool no_disconnect;
1911 struct ffs_data *ffs_data;
1912};
1913
1914static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc)
1915{
1916 struct ffs_sb_fill_data *data = fc->fs_private;
1917 struct inode *inode;
1918 struct ffs_data *ffs = data->ffs_data;
1919
1920 ffs->sb = sb;
1921 data->ffs_data = NULL;
1922 sb->s_fs_info = ffs;
1923 sb->s_blocksize = PAGE_SIZE;
1924 sb->s_blocksize_bits = PAGE_SHIFT;
1925 sb->s_magic = FUNCTIONFS_MAGIC;
1926 sb->s_op = &ffs_sb_operations;
1927 sb->s_time_gran = 1;
1928
1929 /* Root inode */
1930 data->perms.mode = data->root_mode;
1931 inode = ffs_sb_make_inode(sb, NULL,
1932 &simple_dir_operations,
1933 &simple_dir_inode_operations,
1934 &data->perms);
1935 sb->s_root = d_make_root(inode);
1936 if (!sb->s_root)
1937 return -ENOMEM;
1938
1939 /* EP0 file */
1940 if (!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations))
1941 return -ENOMEM;
1942
1943 return 0;
1944}
1945
1946enum {
1947 Opt_no_disconnect,
1948 Opt_rmode,
1949 Opt_fmode,
1950 Opt_mode,
1951 Opt_uid,
1952 Opt_gid,
1953};
1954
1955static const struct fs_parameter_spec ffs_fs_fs_parameters[] = {
1956 fsparam_bool ("no_disconnect", Opt_no_disconnect),
1957 fsparam_u32 ("rmode", Opt_rmode),
1958 fsparam_u32 ("fmode", Opt_fmode),
1959 fsparam_u32 ("mode", Opt_mode),
1960 fsparam_u32 ("uid", Opt_uid),
1961 fsparam_u32 ("gid", Opt_gid),
1962 {}
1963};
1964
1965static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
1966{
1967 struct ffs_sb_fill_data *data = fc->fs_private;
1968 struct fs_parse_result result;
1969 int opt;
1970
1971 opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result);
1972 if (opt < 0)
1973 return opt;
1974
1975 switch (opt) {
1976 case Opt_no_disconnect:
1977 data->no_disconnect = result.boolean;
1978 break;
1979 case Opt_rmode:
1980 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1981 break;
1982 case Opt_fmode:
1983 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1984 break;
1985 case Opt_mode:
1986 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1987 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1988 break;
1989
1990 case Opt_uid:
1991 data->perms.uid = make_kuid(current_user_ns(), result.uint_32);
1992 if (!uid_valid(data->perms.uid))
1993 goto unmapped_value;
1994 break;
1995 case Opt_gid:
1996 data->perms.gid = make_kgid(current_user_ns(), result.uint_32);
1997 if (!gid_valid(data->perms.gid))
1998 goto unmapped_value;
1999 break;
2000
2001 default:
2002 return -ENOPARAM;
2003 }
2004
2005 return 0;
2006
2007unmapped_value:
2008 return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32);
2009}
2010
2011/*
2012 * Set up the superblock for a mount.
2013 */
2014static int ffs_fs_get_tree(struct fs_context *fc)
2015{
2016 struct ffs_sb_fill_data *ctx = fc->fs_private;
2017 struct ffs_data *ffs;
2018 int ret;
2019
2020 if (!fc->source)
2021 return invalf(fc, "No source specified");
2022
2023 ffs = ffs_data_new(fc->source);
2024 if (!ffs)
2025 return -ENOMEM;
2026 ffs->file_perms = ctx->perms;
2027 ffs->no_disconnect = ctx->no_disconnect;
2028
2029 ffs->dev_name = kstrdup(fc->source, GFP_KERNEL);
2030 if (!ffs->dev_name) {
2031 ffs_data_put(ffs);
2032 return -ENOMEM;
2033 }
2034
2035 ret = ffs_acquire_dev(ffs->dev_name, ffs);
2036 if (ret) {
2037 ffs_data_put(ffs);
2038 return ret;
2039 }
2040
2041 ctx->ffs_data = ffs;
2042 return get_tree_nodev(fc, ffs_sb_fill);
2043}
2044
2045static void ffs_fs_free_fc(struct fs_context *fc)
2046{
2047 struct ffs_sb_fill_data *ctx = fc->fs_private;
2048
2049 if (ctx) {
2050 if (ctx->ffs_data) {
2051 ffs_data_put(ctx->ffs_data);
2052 }
2053
2054 kfree(ctx);
2055 }
2056}
2057
2058static const struct fs_context_operations ffs_fs_context_ops = {
2059 .free = ffs_fs_free_fc,
2060 .parse_param = ffs_fs_parse_param,
2061 .get_tree = ffs_fs_get_tree,
2062};
2063
2064static int ffs_fs_init_fs_context(struct fs_context *fc)
2065{
2066 struct ffs_sb_fill_data *ctx;
2067
2068 ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL);
2069 if (!ctx)
2070 return -ENOMEM;
2071
2072 ctx->perms.mode = S_IFREG | 0600;
2073 ctx->perms.uid = GLOBAL_ROOT_UID;
2074 ctx->perms.gid = GLOBAL_ROOT_GID;
2075 ctx->root_mode = S_IFDIR | 0500;
2076 ctx->no_disconnect = false;
2077
2078 fc->fs_private = ctx;
2079 fc->ops = &ffs_fs_context_ops;
2080 return 0;
2081}
2082
2083static void
2084ffs_fs_kill_sb(struct super_block *sb)
2085{
2086 kill_litter_super(sb);
2087 if (sb->s_fs_info)
2088 ffs_data_closed(sb->s_fs_info);
2089}
2090
2091static struct file_system_type ffs_fs_type = {
2092 .owner = THIS_MODULE,
2093 .name = "functionfs",
2094 .init_fs_context = ffs_fs_init_fs_context,
2095 .parameters = ffs_fs_fs_parameters,
2096 .kill_sb = ffs_fs_kill_sb,
2097};
2098MODULE_ALIAS_FS("functionfs");
2099
2100
2101/* Driver's main init/cleanup functions *************************************/
2102
2103static int functionfs_init(void)
2104{
2105 int ret;
2106
2107 ret = register_filesystem(&ffs_fs_type);
2108 if (!ret)
2109 pr_info("file system registered\n");
2110 else
2111 pr_err("failed registering file system (%d)\n", ret);
2112
2113 return ret;
2114}
2115
2116static void functionfs_cleanup(void)
2117{
2118 pr_info("unloading\n");
2119 unregister_filesystem(&ffs_fs_type);
2120}
2121
2122
2123/* ffs_data and ffs_function construction and destruction code **************/
2124
2125static void ffs_data_clear(struct ffs_data *ffs);
2126static void ffs_data_reset(struct ffs_data *ffs);
2127
2128static void ffs_data_get(struct ffs_data *ffs)
2129{
2130 refcount_inc(&ffs->ref);
2131}
2132
2133static void ffs_data_opened(struct ffs_data *ffs)
2134{
2135 refcount_inc(&ffs->ref);
2136 if (atomic_add_return(1, &ffs->opened) == 1 &&
2137 ffs->state == FFS_DEACTIVATED) {
2138 ffs->state = FFS_CLOSING;
2139 ffs_data_reset(ffs);
2140 }
2141}
2142
2143static void ffs_data_put(struct ffs_data *ffs)
2144{
2145 if (refcount_dec_and_test(&ffs->ref)) {
2146 pr_info("%s(): freeing\n", __func__);
2147 ffs_data_clear(ffs);
2148 ffs_release_dev(ffs->private_data);
2149 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
2150 swait_active(&ffs->ep0req_completion.wait) ||
2151 waitqueue_active(&ffs->wait));
2152 destroy_workqueue(ffs->io_completion_wq);
2153 kfree(ffs->dev_name);
2154 kfree(ffs);
2155 }
2156}
2157
2158static void ffs_data_closed(struct ffs_data *ffs)
2159{
2160 struct ffs_epfile *epfiles;
2161 unsigned long flags;
2162
2163 if (atomic_dec_and_test(&ffs->opened)) {
2164 if (ffs->no_disconnect) {
2165 ffs->state = FFS_DEACTIVATED;
2166 spin_lock_irqsave(&ffs->eps_lock, flags);
2167 epfiles = ffs->epfiles;
2168 ffs->epfiles = NULL;
2169 spin_unlock_irqrestore(&ffs->eps_lock,
2170 flags);
2171
2172 if (epfiles)
2173 ffs_epfiles_destroy(epfiles,
2174 ffs->eps_count);
2175
2176 if (ffs->setup_state == FFS_SETUP_PENDING)
2177 __ffs_ep0_stall(ffs);
2178 } else {
2179 ffs->state = FFS_CLOSING;
2180 ffs_data_reset(ffs);
2181 }
2182 }
2183 if (atomic_read(&ffs->opened) < 0) {
2184 ffs->state = FFS_CLOSING;
2185 ffs_data_reset(ffs);
2186 }
2187
2188 ffs_data_put(ffs);
2189}
2190
2191static struct ffs_data *ffs_data_new(const char *dev_name)
2192{
2193 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
2194 if (!ffs)
2195 return NULL;
2196
2197 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name);
2198 if (!ffs->io_completion_wq) {
2199 kfree(ffs);
2200 return NULL;
2201 }
2202
2203 refcount_set(&ffs->ref, 1);
2204 atomic_set(&ffs->opened, 0);
2205 ffs->state = FFS_READ_DESCRIPTORS;
2206 mutex_init(&ffs->mutex);
2207 spin_lock_init(&ffs->eps_lock);
2208 init_waitqueue_head(&ffs->ev.waitq);
2209 init_waitqueue_head(&ffs->wait);
2210 init_completion(&ffs->ep0req_completion);
2211
2212 /* XXX REVISIT need to update it in some places, or do we? */
2213 ffs->ev.can_stall = 1;
2214
2215 return ffs;
2216}
2217
2218static void ffs_data_clear(struct ffs_data *ffs)
2219{
2220 struct ffs_epfile *epfiles;
2221 unsigned long flags;
2222
2223 ffs_closed(ffs);
2224
2225 BUG_ON(ffs->gadget);
2226
2227 spin_lock_irqsave(&ffs->eps_lock, flags);
2228 epfiles = ffs->epfiles;
2229 ffs->epfiles = NULL;
2230 spin_unlock_irqrestore(&ffs->eps_lock, flags);
2231
2232 /*
2233 * potential race possible between ffs_func_eps_disable
2234 * & ffs_epfile_release therefore maintaining a local
2235 * copy of epfile will save us from use-after-free.
2236 */
2237 if (epfiles) {
2238 ffs_epfiles_destroy(epfiles, ffs->eps_count);
2239 ffs->epfiles = NULL;
2240 }
2241
2242 if (ffs->ffs_eventfd) {
2243 eventfd_ctx_put(ffs->ffs_eventfd);
2244 ffs->ffs_eventfd = NULL;
2245 }
2246
2247 kfree(ffs->raw_descs_data);
2248 kfree(ffs->raw_strings);
2249 kfree(ffs->stringtabs);
2250}
2251
2252static void ffs_data_reset(struct ffs_data *ffs)
2253{
2254 ffs_data_clear(ffs);
2255
2256 ffs->raw_descs_data = NULL;
2257 ffs->raw_descs = NULL;
2258 ffs->raw_strings = NULL;
2259 ffs->stringtabs = NULL;
2260
2261 ffs->raw_descs_length = 0;
2262 ffs->fs_descs_count = 0;
2263 ffs->hs_descs_count = 0;
2264 ffs->ss_descs_count = 0;
2265
2266 ffs->strings_count = 0;
2267 ffs->interfaces_count = 0;
2268 ffs->eps_count = 0;
2269
2270 ffs->ev.count = 0;
2271
2272 ffs->state = FFS_READ_DESCRIPTORS;
2273 ffs->setup_state = FFS_NO_SETUP;
2274 ffs->flags = 0;
2275
2276 ffs->ms_os_descs_ext_prop_count = 0;
2277 ffs->ms_os_descs_ext_prop_name_len = 0;
2278 ffs->ms_os_descs_ext_prop_data_len = 0;
2279}
2280
2281
2282static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
2283{
2284 struct usb_gadget_strings **lang;
2285 int first_id;
2286
2287 if (WARN_ON(ffs->state != FFS_ACTIVE
2288 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
2289 return -EBADFD;
2290
2291 first_id = usb_string_ids_n(cdev, ffs->strings_count);
2292 if (first_id < 0)
2293 return first_id;
2294
2295 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
2296 if (!ffs->ep0req)
2297 return -ENOMEM;
2298 ffs->ep0req->complete = ffs_ep0_complete;
2299 ffs->ep0req->context = ffs;
2300
2301 lang = ffs->stringtabs;
2302 if (lang) {
2303 for (; *lang; ++lang) {
2304 struct usb_string *str = (*lang)->strings;
2305 int id = first_id;
2306 for (; str->s; ++id, ++str)
2307 str->id = id;
2308 }
2309 }
2310
2311 ffs->gadget = cdev->gadget;
2312 ffs_data_get(ffs);
2313 return 0;
2314}
2315
2316static void functionfs_unbind(struct ffs_data *ffs)
2317{
2318 if (!WARN_ON(!ffs->gadget)) {
2319 /* dequeue before freeing ep0req */
2320 usb_ep_dequeue(ffs->gadget->ep0, ffs->ep0req);
2321 mutex_lock(&ffs->mutex);
2322 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
2323 ffs->ep0req = NULL;
2324 ffs->gadget = NULL;
2325 clear_bit(FFS_FL_BOUND, &ffs->flags);
2326 mutex_unlock(&ffs->mutex);
2327 ffs_data_put(ffs);
2328 }
2329}
2330
2331static int ffs_epfiles_create(struct ffs_data *ffs)
2332{
2333 struct ffs_epfile *epfile, *epfiles;
2334 unsigned i, count;
2335
2336 count = ffs->eps_count;
2337 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
2338 if (!epfiles)
2339 return -ENOMEM;
2340
2341 epfile = epfiles;
2342 for (i = 1; i <= count; ++i, ++epfile) {
2343 epfile->ffs = ffs;
2344 mutex_init(&epfile->mutex);
2345 mutex_init(&epfile->dmabufs_mutex);
2346 INIT_LIST_HEAD(&epfile->dmabufs);
2347 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2348 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
2349 else
2350 sprintf(epfile->name, "ep%u", i);
2351 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
2352 epfile,
2353 &ffs_epfile_operations);
2354 if (!epfile->dentry) {
2355 ffs_epfiles_destroy(epfiles, i - 1);
2356 return -ENOMEM;
2357 }
2358 }
2359
2360 ffs->epfiles = epfiles;
2361 return 0;
2362}
2363
2364static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
2365{
2366 struct ffs_epfile *epfile = epfiles;
2367
2368 for (; count; --count, ++epfile) {
2369 BUG_ON(mutex_is_locked(&epfile->mutex));
2370 if (epfile->dentry) {
2371 d_delete(epfile->dentry);
2372 dput(epfile->dentry);
2373 epfile->dentry = NULL;
2374 }
2375 }
2376
2377 kfree(epfiles);
2378}
2379
2380static void ffs_func_eps_disable(struct ffs_function *func)
2381{
2382 struct ffs_ep *ep;
2383 struct ffs_epfile *epfile;
2384 unsigned short count;
2385 unsigned long flags;
2386
2387 spin_lock_irqsave(&func->ffs->eps_lock, flags);
2388 count = func->ffs->eps_count;
2389 epfile = func->ffs->epfiles;
2390 ep = func->eps;
2391 while (count--) {
2392 /* pending requests get nuked */
2393 if (ep->ep)
2394 usb_ep_disable(ep->ep);
2395 ++ep;
2396
2397 if (epfile) {
2398 epfile->ep = NULL;
2399 __ffs_epfile_read_buffer_free(epfile);
2400 ++epfile;
2401 }
2402 }
2403 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
2404}
2405
2406static int ffs_func_eps_enable(struct ffs_function *func)
2407{
2408 struct ffs_data *ffs;
2409 struct ffs_ep *ep;
2410 struct ffs_epfile *epfile;
2411 unsigned short count;
2412 unsigned long flags;
2413 int ret = 0;
2414
2415 spin_lock_irqsave(&func->ffs->eps_lock, flags);
2416 ffs = func->ffs;
2417 ep = func->eps;
2418 epfile = ffs->epfiles;
2419 count = ffs->eps_count;
2420 while(count--) {
2421 ep->ep->driver_data = ep;
2422
2423 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep);
2424 if (ret) {
2425 pr_err("%s: config_ep_by_speed(%s) returned %d\n",
2426 __func__, ep->ep->name, ret);
2427 break;
2428 }
2429
2430 ret = usb_ep_enable(ep->ep);
2431 if (!ret) {
2432 epfile->ep = ep;
2433 epfile->in = usb_endpoint_dir_in(ep->ep->desc);
2434 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
2435 } else {
2436 break;
2437 }
2438
2439 ++ep;
2440 ++epfile;
2441 }
2442
2443 wake_up_interruptible(&ffs->wait);
2444 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
2445
2446 return ret;
2447}
2448
2449
2450/* Parsing and building descriptors and strings *****************************/
2451
2452/*
2453 * This validates if data pointed by data is a valid USB descriptor as
2454 * well as record how many interfaces, endpoints and strings are
2455 * required by given configuration. Returns address after the
2456 * descriptor or NULL if data is invalid.
2457 */
2458
2459enum ffs_entity_type {
2460 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
2461};
2462
2463enum ffs_os_desc_type {
2464 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
2465};
2466
2467typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
2468 u8 *valuep,
2469 struct usb_descriptor_header *desc,
2470 void *priv);
2471
2472typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
2473 struct usb_os_desc_header *h, void *data,
2474 unsigned len, void *priv);
2475
2476static int __must_check ffs_do_single_desc(char *data, unsigned len,
2477 ffs_entity_callback entity,
2478 void *priv, int *current_class)
2479{
2480 struct usb_descriptor_header *_ds = (void *)data;
2481 u8 length;
2482 int ret;
2483
2484 /* At least two bytes are required: length and type */
2485 if (len < 2) {
2486 pr_vdebug("descriptor too short\n");
2487 return -EINVAL;
2488 }
2489
2490 /* If we have at least as many bytes as the descriptor takes? */
2491 length = _ds->bLength;
2492 if (len < length) {
2493 pr_vdebug("descriptor longer then available data\n");
2494 return -EINVAL;
2495 }
2496
2497#define __entity_check_INTERFACE(val) 1
2498#define __entity_check_STRING(val) (val)
2499#define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
2500#define __entity(type, val) do { \
2501 pr_vdebug("entity " #type "(%02x)\n", (val)); \
2502 if (!__entity_check_ ##type(val)) { \
2503 pr_vdebug("invalid entity's value\n"); \
2504 return -EINVAL; \
2505 } \
2506 ret = entity(FFS_ ##type, &val, _ds, priv); \
2507 if (ret < 0) { \
2508 pr_debug("entity " #type "(%02x); ret = %d\n", \
2509 (val), ret); \
2510 return ret; \
2511 } \
2512 } while (0)
2513
2514 /* Parse descriptor depending on type. */
2515 switch (_ds->bDescriptorType) {
2516 case USB_DT_DEVICE:
2517 case USB_DT_CONFIG:
2518 case USB_DT_STRING:
2519 case USB_DT_DEVICE_QUALIFIER:
2520 /* function can't have any of those */
2521 pr_vdebug("descriptor reserved for gadget: %d\n",
2522 _ds->bDescriptorType);
2523 return -EINVAL;
2524
2525 case USB_DT_INTERFACE: {
2526 struct usb_interface_descriptor *ds = (void *)_ds;
2527 pr_vdebug("interface descriptor\n");
2528 if (length != sizeof *ds)
2529 goto inv_length;
2530
2531 __entity(INTERFACE, ds->bInterfaceNumber);
2532 if (ds->iInterface)
2533 __entity(STRING, ds->iInterface);
2534 *current_class = ds->bInterfaceClass;
2535 }
2536 break;
2537
2538 case USB_DT_ENDPOINT: {
2539 struct usb_endpoint_descriptor *ds = (void *)_ds;
2540 pr_vdebug("endpoint descriptor\n");
2541 if (length != USB_DT_ENDPOINT_SIZE &&
2542 length != USB_DT_ENDPOINT_AUDIO_SIZE)
2543 goto inv_length;
2544 __entity(ENDPOINT, ds->bEndpointAddress);
2545 }
2546 break;
2547
2548 case USB_TYPE_CLASS | 0x01:
2549 if (*current_class == USB_INTERFACE_CLASS_HID) {
2550 pr_vdebug("hid descriptor\n");
2551 if (length != sizeof(struct hid_descriptor))
2552 goto inv_length;
2553 break;
2554 } else if (*current_class == USB_INTERFACE_CLASS_CCID) {
2555 pr_vdebug("ccid descriptor\n");
2556 if (length != sizeof(struct ccid_descriptor))
2557 goto inv_length;
2558 break;
2559 } else {
2560 pr_vdebug("unknown descriptor: %d for class %d\n",
2561 _ds->bDescriptorType, *current_class);
2562 return -EINVAL;
2563 }
2564
2565 case USB_DT_OTG:
2566 if (length != sizeof(struct usb_otg_descriptor))
2567 goto inv_length;
2568 break;
2569
2570 case USB_DT_INTERFACE_ASSOCIATION: {
2571 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
2572 pr_vdebug("interface association descriptor\n");
2573 if (length != sizeof *ds)
2574 goto inv_length;
2575 if (ds->iFunction)
2576 __entity(STRING, ds->iFunction);
2577 }
2578 break;
2579
2580 case USB_DT_SS_ENDPOINT_COMP:
2581 pr_vdebug("EP SS companion descriptor\n");
2582 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2583 goto inv_length;
2584 break;
2585
2586 case USB_DT_OTHER_SPEED_CONFIG:
2587 case USB_DT_INTERFACE_POWER:
2588 case USB_DT_DEBUG:
2589 case USB_DT_SECURITY:
2590 case USB_DT_CS_RADIO_CONTROL:
2591 /* TODO */
2592 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2593 return -EINVAL;
2594
2595 default:
2596 /* We should never be here */
2597 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2598 return -EINVAL;
2599
2600inv_length:
2601 pr_vdebug("invalid length: %d (descriptor %d)\n",
2602 _ds->bLength, _ds->bDescriptorType);
2603 return -EINVAL;
2604 }
2605
2606#undef __entity
2607#undef __entity_check_DESCRIPTOR
2608#undef __entity_check_INTERFACE
2609#undef __entity_check_STRING
2610#undef __entity_check_ENDPOINT
2611
2612 return length;
2613}
2614
2615static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2616 ffs_entity_callback entity, void *priv)
2617{
2618 const unsigned _len = len;
2619 unsigned long num = 0;
2620 int current_class = -1;
2621
2622 for (;;) {
2623 int ret;
2624
2625 if (num == count)
2626 data = NULL;
2627
2628 /* Record "descriptor" entity */
2629 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2630 if (ret < 0) {
2631 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2632 num, ret);
2633 return ret;
2634 }
2635
2636 if (!data)
2637 return _len - len;
2638
2639 ret = ffs_do_single_desc(data, len, entity, priv,
2640 ¤t_class);
2641 if (ret < 0) {
2642 pr_debug("%s returns %d\n", __func__, ret);
2643 return ret;
2644 }
2645
2646 len -= ret;
2647 data += ret;
2648 ++num;
2649 }
2650}
2651
2652static int __ffs_data_do_entity(enum ffs_entity_type type,
2653 u8 *valuep, struct usb_descriptor_header *desc,
2654 void *priv)
2655{
2656 struct ffs_desc_helper *helper = priv;
2657 struct usb_endpoint_descriptor *d;
2658
2659 switch (type) {
2660 case FFS_DESCRIPTOR:
2661 break;
2662
2663 case FFS_INTERFACE:
2664 /*
2665 * Interfaces are indexed from zero so if we
2666 * encountered interface "n" then there are at least
2667 * "n+1" interfaces.
2668 */
2669 if (*valuep >= helper->interfaces_count)
2670 helper->interfaces_count = *valuep + 1;
2671 break;
2672
2673 case FFS_STRING:
2674 /*
2675 * Strings are indexed from 1 (0 is reserved
2676 * for languages list)
2677 */
2678 if (*valuep > helper->ffs->strings_count)
2679 helper->ffs->strings_count = *valuep;
2680 break;
2681
2682 case FFS_ENDPOINT:
2683 d = (void *)desc;
2684 helper->eps_count++;
2685 if (helper->eps_count >= FFS_MAX_EPS_COUNT)
2686 return -EINVAL;
2687 /* Check if descriptors for any speed were already parsed */
2688 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2689 helper->ffs->eps_addrmap[helper->eps_count] =
2690 d->bEndpointAddress;
2691 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2692 d->bEndpointAddress)
2693 return -EINVAL;
2694 break;
2695 }
2696
2697 return 0;
2698}
2699
2700static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2701 struct usb_os_desc_header *desc)
2702{
2703 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2704 u16 w_index = le16_to_cpu(desc->wIndex);
2705
2706 if (bcd_version == 0x1) {
2707 pr_warn("bcdVersion must be 0x0100, stored in Little Endian order. "
2708 "Userspace driver should be fixed, accepting 0x0001 for compatibility.\n");
2709 } else if (bcd_version != 0x100) {
2710 pr_vdebug("unsupported os descriptors version: 0x%x\n",
2711 bcd_version);
2712 return -EINVAL;
2713 }
2714 switch (w_index) {
2715 case 0x4:
2716 *next_type = FFS_OS_DESC_EXT_COMPAT;
2717 break;
2718 case 0x5:
2719 *next_type = FFS_OS_DESC_EXT_PROP;
2720 break;
2721 default:
2722 pr_vdebug("unsupported os descriptor type: %d", w_index);
2723 return -EINVAL;
2724 }
2725
2726 return sizeof(*desc);
2727}
2728
2729/*
2730 * Process all extended compatibility/extended property descriptors
2731 * of a feature descriptor
2732 */
2733static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2734 enum ffs_os_desc_type type,
2735 u16 feature_count,
2736 ffs_os_desc_callback entity,
2737 void *priv,
2738 struct usb_os_desc_header *h)
2739{
2740 int ret;
2741 const unsigned _len = len;
2742
2743 /* loop over all ext compat/ext prop descriptors */
2744 while (feature_count--) {
2745 ret = entity(type, h, data, len, priv);
2746 if (ret < 0) {
2747 pr_debug("bad OS descriptor, type: %d\n", type);
2748 return ret;
2749 }
2750 data += ret;
2751 len -= ret;
2752 }
2753 return _len - len;
2754}
2755
2756/* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2757static int __must_check ffs_do_os_descs(unsigned count,
2758 char *data, unsigned len,
2759 ffs_os_desc_callback entity, void *priv)
2760{
2761 const unsigned _len = len;
2762 unsigned long num = 0;
2763
2764 for (num = 0; num < count; ++num) {
2765 int ret;
2766 enum ffs_os_desc_type type;
2767 u16 feature_count;
2768 struct usb_os_desc_header *desc = (void *)data;
2769
2770 if (len < sizeof(*desc))
2771 return -EINVAL;
2772
2773 /*
2774 * Record "descriptor" entity.
2775 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2776 * Move the data pointer to the beginning of extended
2777 * compatibilities proper or extended properties proper
2778 * portions of the data
2779 */
2780 if (le32_to_cpu(desc->dwLength) > len)
2781 return -EINVAL;
2782
2783 ret = __ffs_do_os_desc_header(&type, desc);
2784 if (ret < 0) {
2785 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2786 num, ret);
2787 return ret;
2788 }
2789 /*
2790 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2791 */
2792 feature_count = le16_to_cpu(desc->wCount);
2793 if (type == FFS_OS_DESC_EXT_COMPAT &&
2794 (feature_count > 255 || desc->Reserved))
2795 return -EINVAL;
2796 len -= ret;
2797 data += ret;
2798
2799 /*
2800 * Process all function/property descriptors
2801 * of this Feature Descriptor
2802 */
2803 ret = ffs_do_single_os_desc(data, len, type,
2804 feature_count, entity, priv, desc);
2805 if (ret < 0) {
2806 pr_debug("%s returns %d\n", __func__, ret);
2807 return ret;
2808 }
2809
2810 len -= ret;
2811 data += ret;
2812 }
2813 return _len - len;
2814}
2815
2816/*
2817 * Validate contents of the buffer from userspace related to OS descriptors.
2818 */
2819static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2820 struct usb_os_desc_header *h, void *data,
2821 unsigned len, void *priv)
2822{
2823 struct ffs_data *ffs = priv;
2824 u8 length;
2825
2826 switch (type) {
2827 case FFS_OS_DESC_EXT_COMPAT: {
2828 struct usb_ext_compat_desc *d = data;
2829 int i;
2830
2831 if (len < sizeof(*d) ||
2832 d->bFirstInterfaceNumber >= ffs->interfaces_count)
2833 return -EINVAL;
2834 if (d->Reserved1 != 1) {
2835 /*
2836 * According to the spec, Reserved1 must be set to 1
2837 * but older kernels incorrectly rejected non-zero
2838 * values. We fix it here to avoid returning EINVAL
2839 * in response to values we used to accept.
2840 */
2841 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
2842 d->Reserved1 = 1;
2843 }
2844 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2845 if (d->Reserved2[i])
2846 return -EINVAL;
2847
2848 length = sizeof(struct usb_ext_compat_desc);
2849 }
2850 break;
2851 case FFS_OS_DESC_EXT_PROP: {
2852 struct usb_ext_prop_desc *d = data;
2853 u32 type, pdl;
2854 u16 pnl;
2855
2856 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2857 return -EINVAL;
2858 length = le32_to_cpu(d->dwSize);
2859 if (len < length)
2860 return -EINVAL;
2861 type = le32_to_cpu(d->dwPropertyDataType);
2862 if (type < USB_EXT_PROP_UNICODE ||
2863 type > USB_EXT_PROP_UNICODE_MULTI) {
2864 pr_vdebug("unsupported os descriptor property type: %d",
2865 type);
2866 return -EINVAL;
2867 }
2868 pnl = le16_to_cpu(d->wPropertyNameLength);
2869 if (length < 14 + pnl) {
2870 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2871 length, pnl, type);
2872 return -EINVAL;
2873 }
2874 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl));
2875 if (length != 14 + pnl + pdl) {
2876 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2877 length, pnl, pdl, type);
2878 return -EINVAL;
2879 }
2880 ++ffs->ms_os_descs_ext_prop_count;
2881 /* property name reported to the host as "WCHAR"s */
2882 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2883 ffs->ms_os_descs_ext_prop_data_len += pdl;
2884 }
2885 break;
2886 default:
2887 pr_vdebug("unknown descriptor: %d\n", type);
2888 return -EINVAL;
2889 }
2890 return length;
2891}
2892
2893static int __ffs_data_got_descs(struct ffs_data *ffs,
2894 char *const _data, size_t len)
2895{
2896 char *data = _data, *raw_descs;
2897 unsigned os_descs_count = 0, counts[3], flags;
2898 int ret = -EINVAL, i;
2899 struct ffs_desc_helper helper;
2900
2901 if (get_unaligned_le32(data + 4) != len)
2902 goto error;
2903
2904 switch (get_unaligned_le32(data)) {
2905 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2906 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2907 data += 8;
2908 len -= 8;
2909 break;
2910 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2911 flags = get_unaligned_le32(data + 8);
2912 ffs->user_flags = flags;
2913 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2914 FUNCTIONFS_HAS_HS_DESC |
2915 FUNCTIONFS_HAS_SS_DESC |
2916 FUNCTIONFS_HAS_MS_OS_DESC |
2917 FUNCTIONFS_VIRTUAL_ADDR |
2918 FUNCTIONFS_EVENTFD |
2919 FUNCTIONFS_ALL_CTRL_RECIP |
2920 FUNCTIONFS_CONFIG0_SETUP)) {
2921 ret = -ENOSYS;
2922 goto error;
2923 }
2924 data += 12;
2925 len -= 12;
2926 break;
2927 default:
2928 goto error;
2929 }
2930
2931 if (flags & FUNCTIONFS_EVENTFD) {
2932 if (len < 4)
2933 goto error;
2934 ffs->ffs_eventfd =
2935 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2936 if (IS_ERR(ffs->ffs_eventfd)) {
2937 ret = PTR_ERR(ffs->ffs_eventfd);
2938 ffs->ffs_eventfd = NULL;
2939 goto error;
2940 }
2941 data += 4;
2942 len -= 4;
2943 }
2944
2945 /* Read fs_count, hs_count and ss_count (if present) */
2946 for (i = 0; i < 3; ++i) {
2947 if (!(flags & (1 << i))) {
2948 counts[i] = 0;
2949 } else if (len < 4) {
2950 goto error;
2951 } else {
2952 counts[i] = get_unaligned_le32(data);
2953 data += 4;
2954 len -= 4;
2955 }
2956 }
2957 if (flags & (1 << i)) {
2958 if (len < 4) {
2959 goto error;
2960 }
2961 os_descs_count = get_unaligned_le32(data);
2962 data += 4;
2963 len -= 4;
2964 }
2965
2966 /* Read descriptors */
2967 raw_descs = data;
2968 helper.ffs = ffs;
2969 for (i = 0; i < 3; ++i) {
2970 if (!counts[i])
2971 continue;
2972 helper.interfaces_count = 0;
2973 helper.eps_count = 0;
2974 ret = ffs_do_descs(counts[i], data, len,
2975 __ffs_data_do_entity, &helper);
2976 if (ret < 0)
2977 goto error;
2978 if (!ffs->eps_count && !ffs->interfaces_count) {
2979 ffs->eps_count = helper.eps_count;
2980 ffs->interfaces_count = helper.interfaces_count;
2981 } else {
2982 if (ffs->eps_count != helper.eps_count) {
2983 ret = -EINVAL;
2984 goto error;
2985 }
2986 if (ffs->interfaces_count != helper.interfaces_count) {
2987 ret = -EINVAL;
2988 goto error;
2989 }
2990 }
2991 data += ret;
2992 len -= ret;
2993 }
2994 if (os_descs_count) {
2995 ret = ffs_do_os_descs(os_descs_count, data, len,
2996 __ffs_data_do_os_desc, ffs);
2997 if (ret < 0)
2998 goto error;
2999 data += ret;
3000 len -= ret;
3001 }
3002
3003 if (raw_descs == data || len) {
3004 ret = -EINVAL;
3005 goto error;
3006 }
3007
3008 ffs->raw_descs_data = _data;
3009 ffs->raw_descs = raw_descs;
3010 ffs->raw_descs_length = data - raw_descs;
3011 ffs->fs_descs_count = counts[0];
3012 ffs->hs_descs_count = counts[1];
3013 ffs->ss_descs_count = counts[2];
3014 ffs->ms_os_descs_count = os_descs_count;
3015
3016 return 0;
3017
3018error:
3019 kfree(_data);
3020 return ret;
3021}
3022
3023static int __ffs_data_got_strings(struct ffs_data *ffs,
3024 char *const _data, size_t len)
3025{
3026 u32 str_count, needed_count, lang_count;
3027 struct usb_gadget_strings **stringtabs, *t;
3028 const char *data = _data;
3029 struct usb_string *s;
3030
3031 if (len < 16 ||
3032 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
3033 get_unaligned_le32(data + 4) != len)
3034 goto error;
3035 str_count = get_unaligned_le32(data + 8);
3036 lang_count = get_unaligned_le32(data + 12);
3037
3038 /* if one is zero the other must be zero */
3039 if (!str_count != !lang_count)
3040 goto error;
3041
3042 /* Do we have at least as many strings as descriptors need? */
3043 needed_count = ffs->strings_count;
3044 if (str_count < needed_count)
3045 goto error;
3046
3047 /*
3048 * If we don't need any strings just return and free all
3049 * memory.
3050 */
3051 if (!needed_count) {
3052 kfree(_data);
3053 return 0;
3054 }
3055
3056 /* Allocate everything in one chunk so there's less maintenance. */
3057 {
3058 unsigned i = 0;
3059 vla_group(d);
3060 vla_item(d, struct usb_gadget_strings *, stringtabs,
3061 size_add(lang_count, 1));
3062 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
3063 vla_item(d, struct usb_string, strings,
3064 size_mul(lang_count, (needed_count + 1)));
3065
3066 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
3067
3068 if (!vlabuf) {
3069 kfree(_data);
3070 return -ENOMEM;
3071 }
3072
3073 /* Initialize the VLA pointers */
3074 stringtabs = vla_ptr(vlabuf, d, stringtabs);
3075 t = vla_ptr(vlabuf, d, stringtab);
3076 i = lang_count;
3077 do {
3078 *stringtabs++ = t++;
3079 } while (--i);
3080 *stringtabs = NULL;
3081
3082 /* stringtabs = vlabuf = d_stringtabs for later kfree */
3083 stringtabs = vla_ptr(vlabuf, d, stringtabs);
3084 t = vla_ptr(vlabuf, d, stringtab);
3085 s = vla_ptr(vlabuf, d, strings);
3086 }
3087
3088 /* For each language */
3089 data += 16;
3090 len -= 16;
3091
3092 do { /* lang_count > 0 so we can use do-while */
3093 unsigned needed = needed_count;
3094 u32 str_per_lang = str_count;
3095
3096 if (len < 3)
3097 goto error_free;
3098 t->language = get_unaligned_le16(data);
3099 t->strings = s;
3100 ++t;
3101
3102 data += 2;
3103 len -= 2;
3104
3105 /* For each string */
3106 do { /* str_count > 0 so we can use do-while */
3107 size_t length = strnlen(data, len);
3108
3109 if (length == len)
3110 goto error_free;
3111
3112 /*
3113 * User may provide more strings then we need,
3114 * if that's the case we simply ignore the
3115 * rest
3116 */
3117 if (needed) {
3118 /*
3119 * s->id will be set while adding
3120 * function to configuration so for
3121 * now just leave garbage here.
3122 */
3123 s->s = data;
3124 --needed;
3125 ++s;
3126 }
3127
3128 data += length + 1;
3129 len -= length + 1;
3130 } while (--str_per_lang);
3131
3132 s->id = 0; /* terminator */
3133 s->s = NULL;
3134 ++s;
3135
3136 } while (--lang_count);
3137
3138 /* Some garbage left? */
3139 if (len)
3140 goto error_free;
3141
3142 /* Done! */
3143 ffs->stringtabs = stringtabs;
3144 ffs->raw_strings = _data;
3145
3146 return 0;
3147
3148error_free:
3149 kfree(stringtabs);
3150error:
3151 kfree(_data);
3152 return -EINVAL;
3153}
3154
3155
3156/* Events handling and management *******************************************/
3157
3158static void __ffs_event_add(struct ffs_data *ffs,
3159 enum usb_functionfs_event_type type)
3160{
3161 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
3162 int neg = 0;
3163
3164 /*
3165 * Abort any unhandled setup
3166 *
3167 * We do not need to worry about some cmpxchg() changing value
3168 * of ffs->setup_state without holding the lock because when
3169 * state is FFS_SETUP_PENDING cmpxchg() in several places in
3170 * the source does nothing.
3171 */
3172 if (ffs->setup_state == FFS_SETUP_PENDING)
3173 ffs->setup_state = FFS_SETUP_CANCELLED;
3174
3175 /*
3176 * Logic of this function guarantees that there are at most four pending
3177 * evens on ffs->ev.types queue. This is important because the queue
3178 * has space for four elements only and __ffs_ep0_read_events function
3179 * depends on that limit as well. If more event types are added, those
3180 * limits have to be revisited or guaranteed to still hold.
3181 */
3182 switch (type) {
3183 case FUNCTIONFS_RESUME:
3184 rem_type2 = FUNCTIONFS_SUSPEND;
3185 fallthrough;
3186 case FUNCTIONFS_SUSPEND:
3187 case FUNCTIONFS_SETUP:
3188 rem_type1 = type;
3189 /* Discard all similar events */
3190 break;
3191
3192 case FUNCTIONFS_BIND:
3193 case FUNCTIONFS_UNBIND:
3194 case FUNCTIONFS_DISABLE:
3195 case FUNCTIONFS_ENABLE:
3196 /* Discard everything other then power management. */
3197 rem_type1 = FUNCTIONFS_SUSPEND;
3198 rem_type2 = FUNCTIONFS_RESUME;
3199 neg = 1;
3200 break;
3201
3202 default:
3203 WARN(1, "%d: unknown event, this should not happen\n", type);
3204 return;
3205 }
3206
3207 {
3208 u8 *ev = ffs->ev.types, *out = ev;
3209 unsigned n = ffs->ev.count;
3210 for (; n; --n, ++ev)
3211 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
3212 *out++ = *ev;
3213 else
3214 pr_vdebug("purging event %d\n", *ev);
3215 ffs->ev.count = out - ffs->ev.types;
3216 }
3217
3218 pr_vdebug("adding event %d\n", type);
3219 ffs->ev.types[ffs->ev.count++] = type;
3220 wake_up_locked(&ffs->ev.waitq);
3221 if (ffs->ffs_eventfd)
3222 eventfd_signal(ffs->ffs_eventfd);
3223}
3224
3225static void ffs_event_add(struct ffs_data *ffs,
3226 enum usb_functionfs_event_type type)
3227{
3228 unsigned long flags;
3229 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3230 __ffs_event_add(ffs, type);
3231 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3232}
3233
3234/* Bind/unbind USB function hooks *******************************************/
3235
3236static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
3237{
3238 int i;
3239
3240 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
3241 if (ffs->eps_addrmap[i] == endpoint_address)
3242 return i;
3243 return -ENOENT;
3244}
3245
3246static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
3247 struct usb_descriptor_header *desc,
3248 void *priv)
3249{
3250 struct usb_endpoint_descriptor *ds = (void *)desc;
3251 struct ffs_function *func = priv;
3252 struct ffs_ep *ffs_ep;
3253 unsigned ep_desc_id;
3254 int idx;
3255 static const char *speed_names[] = { "full", "high", "super" };
3256
3257 if (type != FFS_DESCRIPTOR)
3258 return 0;
3259
3260 /*
3261 * If ss_descriptors is not NULL, we are reading super speed
3262 * descriptors; if hs_descriptors is not NULL, we are reading high
3263 * speed descriptors; otherwise, we are reading full speed
3264 * descriptors.
3265 */
3266 if (func->function.ss_descriptors) {
3267 ep_desc_id = 2;
3268 func->function.ss_descriptors[(long)valuep] = desc;
3269 } else if (func->function.hs_descriptors) {
3270 ep_desc_id = 1;
3271 func->function.hs_descriptors[(long)valuep] = desc;
3272 } else {
3273 ep_desc_id = 0;
3274 func->function.fs_descriptors[(long)valuep] = desc;
3275 }
3276
3277 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
3278 return 0;
3279
3280 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
3281 if (idx < 0)
3282 return idx;
3283
3284 ffs_ep = func->eps + idx;
3285
3286 if (ffs_ep->descs[ep_desc_id]) {
3287 pr_err("two %sspeed descriptors for EP %d\n",
3288 speed_names[ep_desc_id],
3289 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
3290 return -EINVAL;
3291 }
3292 ffs_ep->descs[ep_desc_id] = ds;
3293
3294 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
3295 if (ffs_ep->ep) {
3296 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
3297 if (!ds->wMaxPacketSize)
3298 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
3299 } else {
3300 struct usb_request *req;
3301 struct usb_ep *ep;
3302 u8 bEndpointAddress;
3303 u16 wMaxPacketSize;
3304
3305 /*
3306 * We back up bEndpointAddress because autoconfig overwrites
3307 * it with physical endpoint address.
3308 */
3309 bEndpointAddress = ds->bEndpointAddress;
3310 /*
3311 * We back up wMaxPacketSize because autoconfig treats
3312 * endpoint descriptors as if they were full speed.
3313 */
3314 wMaxPacketSize = ds->wMaxPacketSize;
3315 pr_vdebug("autoconfig\n");
3316 ep = usb_ep_autoconfig(func->gadget, ds);
3317 if (!ep)
3318 return -ENOTSUPP;
3319 ep->driver_data = func->eps + idx;
3320
3321 req = usb_ep_alloc_request(ep, GFP_KERNEL);
3322 if (!req)
3323 return -ENOMEM;
3324
3325 ffs_ep->ep = ep;
3326 ffs_ep->req = req;
3327 func->eps_revmap[ds->bEndpointAddress &
3328 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
3329 /*
3330 * If we use virtual address mapping, we restore
3331 * original bEndpointAddress value.
3332 */
3333 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3334 ds->bEndpointAddress = bEndpointAddress;
3335 /*
3336 * Restore wMaxPacketSize which was potentially
3337 * overwritten by autoconfig.
3338 */
3339 ds->wMaxPacketSize = wMaxPacketSize;
3340 }
3341 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
3342
3343 return 0;
3344}
3345
3346static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
3347 struct usb_descriptor_header *desc,
3348 void *priv)
3349{
3350 struct ffs_function *func = priv;
3351 unsigned idx;
3352 u8 newValue;
3353
3354 switch (type) {
3355 default:
3356 case FFS_DESCRIPTOR:
3357 /* Handled in previous pass by __ffs_func_bind_do_descs() */
3358 return 0;
3359
3360 case FFS_INTERFACE:
3361 idx = *valuep;
3362 if (func->interfaces_nums[idx] < 0) {
3363 int id = usb_interface_id(func->conf, &func->function);
3364 if (id < 0)
3365 return id;
3366 func->interfaces_nums[idx] = id;
3367 }
3368 newValue = func->interfaces_nums[idx];
3369 break;
3370
3371 case FFS_STRING:
3372 /* String' IDs are allocated when fsf_data is bound to cdev */
3373 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
3374 break;
3375
3376 case FFS_ENDPOINT:
3377 /*
3378 * USB_DT_ENDPOINT are handled in
3379 * __ffs_func_bind_do_descs().
3380 */
3381 if (desc->bDescriptorType == USB_DT_ENDPOINT)
3382 return 0;
3383
3384 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
3385 if (!func->eps[idx].ep)
3386 return -EINVAL;
3387
3388 {
3389 struct usb_endpoint_descriptor **descs;
3390 descs = func->eps[idx].descs;
3391 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
3392 }
3393 break;
3394 }
3395
3396 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
3397 *valuep = newValue;
3398 return 0;
3399}
3400
3401static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
3402 struct usb_os_desc_header *h, void *data,
3403 unsigned len, void *priv)
3404{
3405 struct ffs_function *func = priv;
3406 u8 length = 0;
3407
3408 switch (type) {
3409 case FFS_OS_DESC_EXT_COMPAT: {
3410 struct usb_ext_compat_desc *desc = data;
3411 struct usb_os_desc_table *t;
3412
3413 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
3414 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
3415 memcpy(t->os_desc->ext_compat_id, &desc->IDs,
3416 sizeof_field(struct usb_ext_compat_desc, IDs));
3417 length = sizeof(*desc);
3418 }
3419 break;
3420 case FFS_OS_DESC_EXT_PROP: {
3421 struct usb_ext_prop_desc *desc = data;
3422 struct usb_os_desc_table *t;
3423 struct usb_os_desc_ext_prop *ext_prop;
3424 char *ext_prop_name;
3425 char *ext_prop_data;
3426
3427 t = &func->function.os_desc_table[h->interface];
3428 t->if_id = func->interfaces_nums[h->interface];
3429
3430 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
3431 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
3432
3433 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
3434 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
3435 ext_prop->data_len = le32_to_cpu(*(__le32 *)
3436 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
3437 length = ext_prop->name_len + ext_prop->data_len + 14;
3438
3439 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
3440 func->ffs->ms_os_descs_ext_prop_name_avail +=
3441 ext_prop->name_len;
3442
3443 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
3444 func->ffs->ms_os_descs_ext_prop_data_avail +=
3445 ext_prop->data_len;
3446 memcpy(ext_prop_data,
3447 usb_ext_prop_data_ptr(data, ext_prop->name_len),
3448 ext_prop->data_len);
3449 /* unicode data reported to the host as "WCHAR"s */
3450 switch (ext_prop->type) {
3451 case USB_EXT_PROP_UNICODE:
3452 case USB_EXT_PROP_UNICODE_ENV:
3453 case USB_EXT_PROP_UNICODE_LINK:
3454 case USB_EXT_PROP_UNICODE_MULTI:
3455 ext_prop->data_len *= 2;
3456 break;
3457 }
3458 ext_prop->data = ext_prop_data;
3459
3460 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
3461 ext_prop->name_len);
3462 /* property name reported to the host as "WCHAR"s */
3463 ext_prop->name_len *= 2;
3464 ext_prop->name = ext_prop_name;
3465
3466 t->os_desc->ext_prop_len +=
3467 ext_prop->name_len + ext_prop->data_len + 14;
3468 ++t->os_desc->ext_prop_count;
3469 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
3470 }
3471 break;
3472 default:
3473 pr_vdebug("unknown descriptor: %d\n", type);
3474 }
3475
3476 return length;
3477}
3478
3479static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
3480 struct usb_configuration *c)
3481{
3482 struct ffs_function *func = ffs_func_from_usb(f);
3483 struct f_fs_opts *ffs_opts =
3484 container_of(f->fi, struct f_fs_opts, func_inst);
3485 struct ffs_data *ffs_data;
3486 int ret;
3487
3488 /*
3489 * Legacy gadget triggers binding in functionfs_ready_callback,
3490 * which already uses locking; taking the same lock here would
3491 * cause a deadlock.
3492 *
3493 * Configfs-enabled gadgets however do need ffs_dev_lock.
3494 */
3495 if (!ffs_opts->no_configfs)
3496 ffs_dev_lock();
3497 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
3498 ffs_data = ffs_opts->dev->ffs_data;
3499 if (!ffs_opts->no_configfs)
3500 ffs_dev_unlock();
3501 if (ret)
3502 return ERR_PTR(ret);
3503
3504 func->ffs = ffs_data;
3505 func->conf = c;
3506 func->gadget = c->cdev->gadget;
3507
3508 /*
3509 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
3510 * configurations are bound in sequence with list_for_each_entry,
3511 * in each configuration its functions are bound in sequence
3512 * with list_for_each_entry, so we assume no race condition
3513 * with regard to ffs_opts->bound access
3514 */
3515 if (!ffs_opts->refcnt) {
3516 ret = functionfs_bind(func->ffs, c->cdev);
3517 if (ret)
3518 return ERR_PTR(ret);
3519 }
3520 ffs_opts->refcnt++;
3521 func->function.strings = func->ffs->stringtabs;
3522
3523 return ffs_opts;
3524}
3525
3526static int _ffs_func_bind(struct usb_configuration *c,
3527 struct usb_function *f)
3528{
3529 struct ffs_function *func = ffs_func_from_usb(f);
3530 struct ffs_data *ffs = func->ffs;
3531
3532 const int full = !!func->ffs->fs_descs_count;
3533 const int high = !!func->ffs->hs_descs_count;
3534 const int super = !!func->ffs->ss_descs_count;
3535
3536 int fs_len, hs_len, ss_len, ret, i;
3537 struct ffs_ep *eps_ptr;
3538
3539 /* Make it a single chunk, less management later on */
3540 vla_group(d);
3541 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
3542 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
3543 full ? ffs->fs_descs_count + 1 : 0);
3544 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
3545 high ? ffs->hs_descs_count + 1 : 0);
3546 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
3547 super ? ffs->ss_descs_count + 1 : 0);
3548 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
3549 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
3550 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3551 vla_item_with_sz(d, char[16], ext_compat,
3552 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3553 vla_item_with_sz(d, struct usb_os_desc, os_desc,
3554 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3555 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
3556 ffs->ms_os_descs_ext_prop_count);
3557 vla_item_with_sz(d, char, ext_prop_name,
3558 ffs->ms_os_descs_ext_prop_name_len);
3559 vla_item_with_sz(d, char, ext_prop_data,
3560 ffs->ms_os_descs_ext_prop_data_len);
3561 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
3562 char *vlabuf;
3563
3564 /* Has descriptors only for speeds gadget does not support */
3565 if (!(full | high | super))
3566 return -ENOTSUPP;
3567
3568 /* Allocate a single chunk, less management later on */
3569 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
3570 if (!vlabuf)
3571 return -ENOMEM;
3572
3573 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
3574 ffs->ms_os_descs_ext_prop_name_avail =
3575 vla_ptr(vlabuf, d, ext_prop_name);
3576 ffs->ms_os_descs_ext_prop_data_avail =
3577 vla_ptr(vlabuf, d, ext_prop_data);
3578
3579 /* Copy descriptors */
3580 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
3581 ffs->raw_descs_length);
3582
3583 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
3584 eps_ptr = vla_ptr(vlabuf, d, eps);
3585 for (i = 0; i < ffs->eps_count; i++)
3586 eps_ptr[i].num = -1;
3587
3588 /* Save pointers
3589 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3590 */
3591 func->eps = vla_ptr(vlabuf, d, eps);
3592 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3593
3594 /*
3595 * Go through all the endpoint descriptors and allocate
3596 * endpoints first, so that later we can rewrite the endpoint
3597 * numbers without worrying that it may be described later on.
3598 */
3599 if (full) {
3600 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3601 fs_len = ffs_do_descs(ffs->fs_descs_count,
3602 vla_ptr(vlabuf, d, raw_descs),
3603 d_raw_descs__sz,
3604 __ffs_func_bind_do_descs, func);
3605 if (fs_len < 0) {
3606 ret = fs_len;
3607 goto error;
3608 }
3609 } else {
3610 fs_len = 0;
3611 }
3612
3613 if (high) {
3614 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3615 hs_len = ffs_do_descs(ffs->hs_descs_count,
3616 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3617 d_raw_descs__sz - fs_len,
3618 __ffs_func_bind_do_descs, func);
3619 if (hs_len < 0) {
3620 ret = hs_len;
3621 goto error;
3622 }
3623 } else {
3624 hs_len = 0;
3625 }
3626
3627 if (super) {
3628 func->function.ss_descriptors = func->function.ssp_descriptors =
3629 vla_ptr(vlabuf, d, ss_descs);
3630 ss_len = ffs_do_descs(ffs->ss_descs_count,
3631 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3632 d_raw_descs__sz - fs_len - hs_len,
3633 __ffs_func_bind_do_descs, func);
3634 if (ss_len < 0) {
3635 ret = ss_len;
3636 goto error;
3637 }
3638 } else {
3639 ss_len = 0;
3640 }
3641
3642 /*
3643 * Now handle interface numbers allocation and interface and
3644 * endpoint numbers rewriting. We can do that in one go
3645 * now.
3646 */
3647 ret = ffs_do_descs(ffs->fs_descs_count +
3648 (high ? ffs->hs_descs_count : 0) +
3649 (super ? ffs->ss_descs_count : 0),
3650 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3651 __ffs_func_bind_do_nums, func);
3652 if (ret < 0)
3653 goto error;
3654
3655 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3656 if (c->cdev->use_os_string) {
3657 for (i = 0; i < ffs->interfaces_count; ++i) {
3658 struct usb_os_desc *desc;
3659
3660 desc = func->function.os_desc_table[i].os_desc =
3661 vla_ptr(vlabuf, d, os_desc) +
3662 i * sizeof(struct usb_os_desc);
3663 desc->ext_compat_id =
3664 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3665 INIT_LIST_HEAD(&desc->ext_prop);
3666 }
3667 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3668 vla_ptr(vlabuf, d, raw_descs) +
3669 fs_len + hs_len + ss_len,
3670 d_raw_descs__sz - fs_len - hs_len -
3671 ss_len,
3672 __ffs_func_bind_do_os_desc, func);
3673 if (ret < 0)
3674 goto error;
3675 }
3676 func->function.os_desc_n =
3677 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3678
3679 /* And we're done */
3680 ffs_event_add(ffs, FUNCTIONFS_BIND);
3681 return 0;
3682
3683error:
3684 /* XXX Do we need to release all claimed endpoints here? */
3685 return ret;
3686}
3687
3688static int ffs_func_bind(struct usb_configuration *c,
3689 struct usb_function *f)
3690{
3691 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3692 struct ffs_function *func = ffs_func_from_usb(f);
3693 int ret;
3694
3695 if (IS_ERR(ffs_opts))
3696 return PTR_ERR(ffs_opts);
3697
3698 ret = _ffs_func_bind(c, f);
3699 if (ret && !--ffs_opts->refcnt)
3700 functionfs_unbind(func->ffs);
3701
3702 return ret;
3703}
3704
3705
3706/* Other USB function hooks *************************************************/
3707
3708static void ffs_reset_work(struct work_struct *work)
3709{
3710 struct ffs_data *ffs = container_of(work,
3711 struct ffs_data, reset_work);
3712 ffs_data_reset(ffs);
3713}
3714
3715static int ffs_func_set_alt(struct usb_function *f,
3716 unsigned interface, unsigned alt)
3717{
3718 struct ffs_function *func = ffs_func_from_usb(f);
3719 struct ffs_data *ffs = func->ffs;
3720 int ret = 0, intf;
3721
3722 if (alt != (unsigned)-1) {
3723 intf = ffs_func_revmap_intf(func, interface);
3724 if (intf < 0)
3725 return intf;
3726 }
3727
3728 if (ffs->func)
3729 ffs_func_eps_disable(ffs->func);
3730
3731 if (ffs->state == FFS_DEACTIVATED) {
3732 ffs->state = FFS_CLOSING;
3733 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3734 schedule_work(&ffs->reset_work);
3735 return -ENODEV;
3736 }
3737
3738 if (ffs->state != FFS_ACTIVE)
3739 return -ENODEV;
3740
3741 if (alt == (unsigned)-1) {
3742 ffs->func = NULL;
3743 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3744 return 0;
3745 }
3746
3747 ffs->func = func;
3748 ret = ffs_func_eps_enable(func);
3749 if (ret >= 0)
3750 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3751 return ret;
3752}
3753
3754static void ffs_func_disable(struct usb_function *f)
3755{
3756 ffs_func_set_alt(f, 0, (unsigned)-1);
3757}
3758
3759static int ffs_func_setup(struct usb_function *f,
3760 const struct usb_ctrlrequest *creq)
3761{
3762 struct ffs_function *func = ffs_func_from_usb(f);
3763 struct ffs_data *ffs = func->ffs;
3764 unsigned long flags;
3765 int ret;
3766
3767 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3768 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3769 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3770 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3771 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3772
3773 /*
3774 * Most requests directed to interface go through here
3775 * (notable exceptions are set/get interface) so we need to
3776 * handle them. All other either handled by composite or
3777 * passed to usb_configuration->setup() (if one is set). No
3778 * matter, we will handle requests directed to endpoint here
3779 * as well (as it's straightforward). Other request recipient
3780 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3781 * is being used.
3782 */
3783 if (ffs->state != FFS_ACTIVE)
3784 return -ENODEV;
3785
3786 switch (creq->bRequestType & USB_RECIP_MASK) {
3787 case USB_RECIP_INTERFACE:
3788 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3789 if (ret < 0)
3790 return ret;
3791 break;
3792
3793 case USB_RECIP_ENDPOINT:
3794 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3795 if (ret < 0)
3796 return ret;
3797 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3798 ret = func->ffs->eps_addrmap[ret];
3799 break;
3800
3801 default:
3802 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3803 ret = le16_to_cpu(creq->wIndex);
3804 else
3805 return -EOPNOTSUPP;
3806 }
3807
3808 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3809 ffs->ev.setup = *creq;
3810 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3811 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3812 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3813
3814 return ffs->ev.setup.wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
3815}
3816
3817static bool ffs_func_req_match(struct usb_function *f,
3818 const struct usb_ctrlrequest *creq,
3819 bool config0)
3820{
3821 struct ffs_function *func = ffs_func_from_usb(f);
3822
3823 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3824 return false;
3825
3826 switch (creq->bRequestType & USB_RECIP_MASK) {
3827 case USB_RECIP_INTERFACE:
3828 return (ffs_func_revmap_intf(func,
3829 le16_to_cpu(creq->wIndex)) >= 0);
3830 case USB_RECIP_ENDPOINT:
3831 return (ffs_func_revmap_ep(func,
3832 le16_to_cpu(creq->wIndex)) >= 0);
3833 default:
3834 return (bool) (func->ffs->user_flags &
3835 FUNCTIONFS_ALL_CTRL_RECIP);
3836 }
3837}
3838
3839static void ffs_func_suspend(struct usb_function *f)
3840{
3841 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3842}
3843
3844static void ffs_func_resume(struct usb_function *f)
3845{
3846 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3847}
3848
3849
3850/* Endpoint and interface numbers reverse mapping ***************************/
3851
3852static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3853{
3854 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3855 return num ? num : -EDOM;
3856}
3857
3858static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3859{
3860 short *nums = func->interfaces_nums;
3861 unsigned count = func->ffs->interfaces_count;
3862
3863 for (; count; --count, ++nums) {
3864 if (*nums >= 0 && *nums == intf)
3865 return nums - func->interfaces_nums;
3866 }
3867
3868 return -EDOM;
3869}
3870
3871
3872/* Devices management *******************************************************/
3873
3874static LIST_HEAD(ffs_devices);
3875
3876static struct ffs_dev *_ffs_do_find_dev(const char *name)
3877{
3878 struct ffs_dev *dev;
3879
3880 if (!name)
3881 return NULL;
3882
3883 list_for_each_entry(dev, &ffs_devices, entry) {
3884 if (strcmp(dev->name, name) == 0)
3885 return dev;
3886 }
3887
3888 return NULL;
3889}
3890
3891/*
3892 * ffs_lock must be taken by the caller of this function
3893 */
3894static struct ffs_dev *_ffs_get_single_dev(void)
3895{
3896 struct ffs_dev *dev;
3897
3898 if (list_is_singular(&ffs_devices)) {
3899 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3900 if (dev->single)
3901 return dev;
3902 }
3903
3904 return NULL;
3905}
3906
3907/*
3908 * ffs_lock must be taken by the caller of this function
3909 */
3910static struct ffs_dev *_ffs_find_dev(const char *name)
3911{
3912 struct ffs_dev *dev;
3913
3914 dev = _ffs_get_single_dev();
3915 if (dev)
3916 return dev;
3917
3918 return _ffs_do_find_dev(name);
3919}
3920
3921/* Configfs support *********************************************************/
3922
3923static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3924{
3925 return container_of(to_config_group(item), struct f_fs_opts,
3926 func_inst.group);
3927}
3928
3929static ssize_t f_fs_opts_ready_show(struct config_item *item, char *page)
3930{
3931 struct f_fs_opts *opts = to_ffs_opts(item);
3932 int ready;
3933
3934 ffs_dev_lock();
3935 ready = opts->dev->desc_ready;
3936 ffs_dev_unlock();
3937
3938 return sprintf(page, "%d\n", ready);
3939}
3940
3941CONFIGFS_ATTR_RO(f_fs_opts_, ready);
3942
3943static struct configfs_attribute *ffs_attrs[] = {
3944 &f_fs_opts_attr_ready,
3945 NULL,
3946};
3947
3948static void ffs_attr_release(struct config_item *item)
3949{
3950 struct f_fs_opts *opts = to_ffs_opts(item);
3951
3952 usb_put_function_instance(&opts->func_inst);
3953}
3954
3955static struct configfs_item_operations ffs_item_ops = {
3956 .release = ffs_attr_release,
3957};
3958
3959static const struct config_item_type ffs_func_type = {
3960 .ct_item_ops = &ffs_item_ops,
3961 .ct_attrs = ffs_attrs,
3962 .ct_owner = THIS_MODULE,
3963};
3964
3965
3966/* Function registration interface ******************************************/
3967
3968static void ffs_free_inst(struct usb_function_instance *f)
3969{
3970 struct f_fs_opts *opts;
3971
3972 opts = to_f_fs_opts(f);
3973 ffs_release_dev(opts->dev);
3974 ffs_dev_lock();
3975 _ffs_free_dev(opts->dev);
3976 ffs_dev_unlock();
3977 kfree(opts);
3978}
3979
3980static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3981{
3982 if (strlen(name) >= sizeof_field(struct ffs_dev, name))
3983 return -ENAMETOOLONG;
3984 return ffs_name_dev(to_f_fs_opts(fi)->dev, name);
3985}
3986
3987static struct usb_function_instance *ffs_alloc_inst(void)
3988{
3989 struct f_fs_opts *opts;
3990 struct ffs_dev *dev;
3991
3992 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3993 if (!opts)
3994 return ERR_PTR(-ENOMEM);
3995
3996 opts->func_inst.set_inst_name = ffs_set_inst_name;
3997 opts->func_inst.free_func_inst = ffs_free_inst;
3998 ffs_dev_lock();
3999 dev = _ffs_alloc_dev();
4000 ffs_dev_unlock();
4001 if (IS_ERR(dev)) {
4002 kfree(opts);
4003 return ERR_CAST(dev);
4004 }
4005 opts->dev = dev;
4006 dev->opts = opts;
4007
4008 config_group_init_type_name(&opts->func_inst.group, "",
4009 &ffs_func_type);
4010 return &opts->func_inst;
4011}
4012
4013static void ffs_free(struct usb_function *f)
4014{
4015 kfree(ffs_func_from_usb(f));
4016}
4017
4018static void ffs_func_unbind(struct usb_configuration *c,
4019 struct usb_function *f)
4020{
4021 struct ffs_function *func = ffs_func_from_usb(f);
4022 struct ffs_data *ffs = func->ffs;
4023 struct f_fs_opts *opts =
4024 container_of(f->fi, struct f_fs_opts, func_inst);
4025 struct ffs_ep *ep = func->eps;
4026 unsigned count = ffs->eps_count;
4027 unsigned long flags;
4028
4029 if (ffs->func == func) {
4030 ffs_func_eps_disable(func);
4031 ffs->func = NULL;
4032 }
4033
4034 /* Drain any pending AIO completions */
4035 drain_workqueue(ffs->io_completion_wq);
4036
4037 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
4038 if (!--opts->refcnt)
4039 functionfs_unbind(ffs);
4040
4041 /* cleanup after autoconfig */
4042 spin_lock_irqsave(&func->ffs->eps_lock, flags);
4043 while (count--) {
4044 if (ep->ep && ep->req)
4045 usb_ep_free_request(ep->ep, ep->req);
4046 ep->req = NULL;
4047 ++ep;
4048 }
4049 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
4050 kfree(func->eps);
4051 func->eps = NULL;
4052 /*
4053 * eps, descriptors and interfaces_nums are allocated in the
4054 * same chunk so only one free is required.
4055 */
4056 func->function.fs_descriptors = NULL;
4057 func->function.hs_descriptors = NULL;
4058 func->function.ss_descriptors = NULL;
4059 func->function.ssp_descriptors = NULL;
4060 func->interfaces_nums = NULL;
4061
4062}
4063
4064static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
4065{
4066 struct ffs_function *func;
4067
4068 func = kzalloc(sizeof(*func), GFP_KERNEL);
4069 if (!func)
4070 return ERR_PTR(-ENOMEM);
4071
4072 func->function.name = "Function FS Gadget";
4073
4074 func->function.bind = ffs_func_bind;
4075 func->function.unbind = ffs_func_unbind;
4076 func->function.set_alt = ffs_func_set_alt;
4077 func->function.disable = ffs_func_disable;
4078 func->function.setup = ffs_func_setup;
4079 func->function.req_match = ffs_func_req_match;
4080 func->function.suspend = ffs_func_suspend;
4081 func->function.resume = ffs_func_resume;
4082 func->function.free_func = ffs_free;
4083
4084 return &func->function;
4085}
4086
4087/*
4088 * ffs_lock must be taken by the caller of this function
4089 */
4090static struct ffs_dev *_ffs_alloc_dev(void)
4091{
4092 struct ffs_dev *dev;
4093 int ret;
4094
4095 if (_ffs_get_single_dev())
4096 return ERR_PTR(-EBUSY);
4097
4098 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
4099 if (!dev)
4100 return ERR_PTR(-ENOMEM);
4101
4102 if (list_empty(&ffs_devices)) {
4103 ret = functionfs_init();
4104 if (ret) {
4105 kfree(dev);
4106 return ERR_PTR(ret);
4107 }
4108 }
4109
4110 list_add(&dev->entry, &ffs_devices);
4111
4112 return dev;
4113}
4114
4115int ffs_name_dev(struct ffs_dev *dev, const char *name)
4116{
4117 struct ffs_dev *existing;
4118 int ret = 0;
4119
4120 ffs_dev_lock();
4121
4122 existing = _ffs_do_find_dev(name);
4123 if (!existing)
4124 strscpy(dev->name, name, ARRAY_SIZE(dev->name));
4125 else if (existing != dev)
4126 ret = -EBUSY;
4127
4128 ffs_dev_unlock();
4129
4130 return ret;
4131}
4132EXPORT_SYMBOL_GPL(ffs_name_dev);
4133
4134int ffs_single_dev(struct ffs_dev *dev)
4135{
4136 int ret;
4137
4138 ret = 0;
4139 ffs_dev_lock();
4140
4141 if (!list_is_singular(&ffs_devices))
4142 ret = -EBUSY;
4143 else
4144 dev->single = true;
4145
4146 ffs_dev_unlock();
4147 return ret;
4148}
4149EXPORT_SYMBOL_GPL(ffs_single_dev);
4150
4151/*
4152 * ffs_lock must be taken by the caller of this function
4153 */
4154static void _ffs_free_dev(struct ffs_dev *dev)
4155{
4156 list_del(&dev->entry);
4157
4158 kfree(dev);
4159 if (list_empty(&ffs_devices))
4160 functionfs_cleanup();
4161}
4162
4163static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data)
4164{
4165 int ret = 0;
4166 struct ffs_dev *ffs_dev;
4167
4168 ffs_dev_lock();
4169
4170 ffs_dev = _ffs_find_dev(dev_name);
4171 if (!ffs_dev) {
4172 ret = -ENOENT;
4173 } else if (ffs_dev->mounted) {
4174 ret = -EBUSY;
4175 } else if (ffs_dev->ffs_acquire_dev_callback &&
4176 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) {
4177 ret = -ENOENT;
4178 } else {
4179 ffs_dev->mounted = true;
4180 ffs_dev->ffs_data = ffs_data;
4181 ffs_data->private_data = ffs_dev;
4182 }
4183
4184 ffs_dev_unlock();
4185 return ret;
4186}
4187
4188static void ffs_release_dev(struct ffs_dev *ffs_dev)
4189{
4190 ffs_dev_lock();
4191
4192 if (ffs_dev && ffs_dev->mounted) {
4193 ffs_dev->mounted = false;
4194 if (ffs_dev->ffs_data) {
4195 ffs_dev->ffs_data->private_data = NULL;
4196 ffs_dev->ffs_data = NULL;
4197 }
4198
4199 if (ffs_dev->ffs_release_dev_callback)
4200 ffs_dev->ffs_release_dev_callback(ffs_dev);
4201 }
4202
4203 ffs_dev_unlock();
4204}
4205
4206static int ffs_ready(struct ffs_data *ffs)
4207{
4208 struct ffs_dev *ffs_obj;
4209 int ret = 0;
4210
4211 ffs_dev_lock();
4212
4213 ffs_obj = ffs->private_data;
4214 if (!ffs_obj) {
4215 ret = -EINVAL;
4216 goto done;
4217 }
4218 if (WARN_ON(ffs_obj->desc_ready)) {
4219 ret = -EBUSY;
4220 goto done;
4221 }
4222
4223 ffs_obj->desc_ready = true;
4224
4225 if (ffs_obj->ffs_ready_callback) {
4226 ret = ffs_obj->ffs_ready_callback(ffs);
4227 if (ret)
4228 goto done;
4229 }
4230
4231 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
4232done:
4233 ffs_dev_unlock();
4234 return ret;
4235}
4236
4237static void ffs_closed(struct ffs_data *ffs)
4238{
4239 struct ffs_dev *ffs_obj;
4240 struct f_fs_opts *opts;
4241 struct config_item *ci;
4242
4243 ffs_dev_lock();
4244
4245 ffs_obj = ffs->private_data;
4246 if (!ffs_obj)
4247 goto done;
4248
4249 ffs_obj->desc_ready = false;
4250
4251 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
4252 ffs_obj->ffs_closed_callback)
4253 ffs_obj->ffs_closed_callback(ffs);
4254
4255 if (ffs_obj->opts)
4256 opts = ffs_obj->opts;
4257 else
4258 goto done;
4259
4260 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
4261 || !kref_read(&opts->func_inst.group.cg_item.ci_kref))
4262 goto done;
4263
4264 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
4265 ffs_dev_unlock();
4266
4267 if (test_bit(FFS_FL_BOUND, &ffs->flags))
4268 unregister_gadget_item(ci);
4269 return;
4270done:
4271 ffs_dev_unlock();
4272}
4273
4274/* Misc helper functions ****************************************************/
4275
4276static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
4277{
4278 return nonblock
4279 ? mutex_trylock(mutex) ? 0 : -EAGAIN
4280 : mutex_lock_interruptible(mutex);
4281}
4282
4283static char *ffs_prepare_buffer(const char __user *buf, size_t len)
4284{
4285 char *data;
4286
4287 if (!len)
4288 return NULL;
4289
4290 data = memdup_user(buf, len);
4291 if (IS_ERR(data))
4292 return data;
4293
4294 pr_vdebug("Buffer from user space:\n");
4295 ffs_dump_mem("", data, len);
4296
4297 return data;
4298}
4299
4300DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
4301MODULE_LICENSE("GPL");
4302MODULE_AUTHOR("Michal Nazarewicz");
1/*
2 * f_fs.c -- user mode file system API for USB composite function controllers
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 * Author: Michal Nazarewicz <mina86@mina86.com>
6 *
7 * Based on inode.c (GadgetFS) which was:
8 * Copyright (C) 2003-2004 David Brownell
9 * Copyright (C) 2003 Agilent Technologies
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 */
16
17
18/* #define DEBUG */
19/* #define VERBOSE_DEBUG */
20
21#include <linux/blkdev.h>
22#include <linux/pagemap.h>
23#include <linux/export.h>
24#include <linux/hid.h>
25#include <linux/module.h>
26#include <linux/uio.h>
27#include <asm/unaligned.h>
28
29#include <linux/usb/composite.h>
30#include <linux/usb/functionfs.h>
31
32#include <linux/aio.h>
33#include <linux/mmu_context.h>
34#include <linux/poll.h>
35#include <linux/eventfd.h>
36
37#include "u_fs.h"
38#include "u_f.h"
39#include "u_os_desc.h"
40#include "configfs.h"
41
42#define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
43
44/* Reference counter handling */
45static void ffs_data_get(struct ffs_data *ffs);
46static void ffs_data_put(struct ffs_data *ffs);
47/* Creates new ffs_data object. */
48static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
49
50/* Opened counter handling. */
51static void ffs_data_opened(struct ffs_data *ffs);
52static void ffs_data_closed(struct ffs_data *ffs);
53
54/* Called with ffs->mutex held; take over ownership of data. */
55static int __must_check
56__ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
57static int __must_check
58__ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
59
60
61/* The function structure ***************************************************/
62
63struct ffs_ep;
64
65struct ffs_function {
66 struct usb_configuration *conf;
67 struct usb_gadget *gadget;
68 struct ffs_data *ffs;
69
70 struct ffs_ep *eps;
71 u8 eps_revmap[16];
72 short *interfaces_nums;
73
74 struct usb_function function;
75};
76
77
78static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
79{
80 return container_of(f, struct ffs_function, function);
81}
82
83
84static inline enum ffs_setup_state
85ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
86{
87 return (enum ffs_setup_state)
88 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
89}
90
91
92static void ffs_func_eps_disable(struct ffs_function *func);
93static int __must_check ffs_func_eps_enable(struct ffs_function *func);
94
95static int ffs_func_bind(struct usb_configuration *,
96 struct usb_function *);
97static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
98static void ffs_func_disable(struct usb_function *);
99static int ffs_func_setup(struct usb_function *,
100 const struct usb_ctrlrequest *);
101static void ffs_func_suspend(struct usb_function *);
102static void ffs_func_resume(struct usb_function *);
103
104
105static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
106static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
107
108
109/* The endpoints structures *************************************************/
110
111struct ffs_ep {
112 struct usb_ep *ep; /* P: ffs->eps_lock */
113 struct usb_request *req; /* P: epfile->mutex */
114
115 /* [0]: full speed, [1]: high speed, [2]: super speed */
116 struct usb_endpoint_descriptor *descs[3];
117
118 u8 num;
119
120 int status; /* P: epfile->mutex */
121};
122
123struct ffs_epfile {
124 /* Protects ep->ep and ep->req. */
125 struct mutex mutex;
126 wait_queue_head_t wait;
127
128 struct ffs_data *ffs;
129 struct ffs_ep *ep; /* P: ffs->eps_lock */
130
131 struct dentry *dentry;
132
133 char name[5];
134
135 unsigned char in; /* P: ffs->eps_lock */
136 unsigned char isoc; /* P: ffs->eps_lock */
137
138 unsigned char _pad;
139};
140
141/* ffs_io_data structure ***************************************************/
142
143struct ffs_io_data {
144 bool aio;
145 bool read;
146
147 struct kiocb *kiocb;
148 struct iov_iter data;
149 const void *to_free;
150 char *buf;
151
152 struct mm_struct *mm;
153 struct work_struct work;
154
155 struct usb_ep *ep;
156 struct usb_request *req;
157
158 struct ffs_data *ffs;
159};
160
161struct ffs_desc_helper {
162 struct ffs_data *ffs;
163 unsigned interfaces_count;
164 unsigned eps_count;
165};
166
167static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
168static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
169
170static struct dentry *
171ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
172 const struct file_operations *fops);
173
174/* Devices management *******************************************************/
175
176DEFINE_MUTEX(ffs_lock);
177EXPORT_SYMBOL_GPL(ffs_lock);
178
179static struct ffs_dev *_ffs_find_dev(const char *name);
180static struct ffs_dev *_ffs_alloc_dev(void);
181static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
182static void _ffs_free_dev(struct ffs_dev *dev);
183static void *ffs_acquire_dev(const char *dev_name);
184static void ffs_release_dev(struct ffs_data *ffs_data);
185static int ffs_ready(struct ffs_data *ffs);
186static void ffs_closed(struct ffs_data *ffs);
187
188/* Misc helper functions ****************************************************/
189
190static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
191 __attribute__((warn_unused_result, nonnull));
192static char *ffs_prepare_buffer(const char __user *buf, size_t len)
193 __attribute__((warn_unused_result, nonnull));
194
195
196/* Control file aka ep0 *****************************************************/
197
198static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
199{
200 struct ffs_data *ffs = req->context;
201
202 complete_all(&ffs->ep0req_completion);
203}
204
205static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
206{
207 struct usb_request *req = ffs->ep0req;
208 int ret;
209
210 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
211
212 spin_unlock_irq(&ffs->ev.waitq.lock);
213
214 req->buf = data;
215 req->length = len;
216
217 /*
218 * UDC layer requires to provide a buffer even for ZLP, but should
219 * not use it at all. Let's provide some poisoned pointer to catch
220 * possible bug in the driver.
221 */
222 if (req->buf == NULL)
223 req->buf = (void *)0xDEADBABE;
224
225 reinit_completion(&ffs->ep0req_completion);
226
227 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
228 if (unlikely(ret < 0))
229 return ret;
230
231 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
232 if (unlikely(ret)) {
233 usb_ep_dequeue(ffs->gadget->ep0, req);
234 return -EINTR;
235 }
236
237 ffs->setup_state = FFS_NO_SETUP;
238 return req->status ? req->status : req->actual;
239}
240
241static int __ffs_ep0_stall(struct ffs_data *ffs)
242{
243 if (ffs->ev.can_stall) {
244 pr_vdebug("ep0 stall\n");
245 usb_ep_set_halt(ffs->gadget->ep0);
246 ffs->setup_state = FFS_NO_SETUP;
247 return -EL2HLT;
248 } else {
249 pr_debug("bogus ep0 stall!\n");
250 return -ESRCH;
251 }
252}
253
254static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
255 size_t len, loff_t *ptr)
256{
257 struct ffs_data *ffs = file->private_data;
258 ssize_t ret;
259 char *data;
260
261 ENTER();
262
263 /* Fast check if setup was canceled */
264 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
265 return -EIDRM;
266
267 /* Acquire mutex */
268 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
269 if (unlikely(ret < 0))
270 return ret;
271
272 /* Check state */
273 switch (ffs->state) {
274 case FFS_READ_DESCRIPTORS:
275 case FFS_READ_STRINGS:
276 /* Copy data */
277 if (unlikely(len < 16)) {
278 ret = -EINVAL;
279 break;
280 }
281
282 data = ffs_prepare_buffer(buf, len);
283 if (IS_ERR(data)) {
284 ret = PTR_ERR(data);
285 break;
286 }
287
288 /* Handle data */
289 if (ffs->state == FFS_READ_DESCRIPTORS) {
290 pr_info("read descriptors\n");
291 ret = __ffs_data_got_descs(ffs, data, len);
292 if (unlikely(ret < 0))
293 break;
294
295 ffs->state = FFS_READ_STRINGS;
296 ret = len;
297 } else {
298 pr_info("read strings\n");
299 ret = __ffs_data_got_strings(ffs, data, len);
300 if (unlikely(ret < 0))
301 break;
302
303 ret = ffs_epfiles_create(ffs);
304 if (unlikely(ret)) {
305 ffs->state = FFS_CLOSING;
306 break;
307 }
308
309 ffs->state = FFS_ACTIVE;
310 mutex_unlock(&ffs->mutex);
311
312 ret = ffs_ready(ffs);
313 if (unlikely(ret < 0)) {
314 ffs->state = FFS_CLOSING;
315 return ret;
316 }
317
318 return len;
319 }
320 break;
321
322 case FFS_ACTIVE:
323 data = NULL;
324 /*
325 * We're called from user space, we can use _irq
326 * rather then _irqsave
327 */
328 spin_lock_irq(&ffs->ev.waitq.lock);
329 switch (ffs_setup_state_clear_cancelled(ffs)) {
330 case FFS_SETUP_CANCELLED:
331 ret = -EIDRM;
332 goto done_spin;
333
334 case FFS_NO_SETUP:
335 ret = -ESRCH;
336 goto done_spin;
337
338 case FFS_SETUP_PENDING:
339 break;
340 }
341
342 /* FFS_SETUP_PENDING */
343 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
344 spin_unlock_irq(&ffs->ev.waitq.lock);
345 ret = __ffs_ep0_stall(ffs);
346 break;
347 }
348
349 /* FFS_SETUP_PENDING and not stall */
350 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
351
352 spin_unlock_irq(&ffs->ev.waitq.lock);
353
354 data = ffs_prepare_buffer(buf, len);
355 if (IS_ERR(data)) {
356 ret = PTR_ERR(data);
357 break;
358 }
359
360 spin_lock_irq(&ffs->ev.waitq.lock);
361
362 /*
363 * We are guaranteed to be still in FFS_ACTIVE state
364 * but the state of setup could have changed from
365 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
366 * to check for that. If that happened we copied data
367 * from user space in vain but it's unlikely.
368 *
369 * For sure we are not in FFS_NO_SETUP since this is
370 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
371 * transition can be performed and it's protected by
372 * mutex.
373 */
374 if (ffs_setup_state_clear_cancelled(ffs) ==
375 FFS_SETUP_CANCELLED) {
376 ret = -EIDRM;
377done_spin:
378 spin_unlock_irq(&ffs->ev.waitq.lock);
379 } else {
380 /* unlocks spinlock */
381 ret = __ffs_ep0_queue_wait(ffs, data, len);
382 }
383 kfree(data);
384 break;
385
386 default:
387 ret = -EBADFD;
388 break;
389 }
390
391 mutex_unlock(&ffs->mutex);
392 return ret;
393}
394
395/* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
396static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
397 size_t n)
398{
399 /*
400 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
401 * size of ffs->ev.types array (which is four) so that's how much space
402 * we reserve.
403 */
404 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
405 const size_t size = n * sizeof *events;
406 unsigned i = 0;
407
408 memset(events, 0, size);
409
410 do {
411 events[i].type = ffs->ev.types[i];
412 if (events[i].type == FUNCTIONFS_SETUP) {
413 events[i].u.setup = ffs->ev.setup;
414 ffs->setup_state = FFS_SETUP_PENDING;
415 }
416 } while (++i < n);
417
418 ffs->ev.count -= n;
419 if (ffs->ev.count)
420 memmove(ffs->ev.types, ffs->ev.types + n,
421 ffs->ev.count * sizeof *ffs->ev.types);
422
423 spin_unlock_irq(&ffs->ev.waitq.lock);
424 mutex_unlock(&ffs->mutex);
425
426 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
427}
428
429static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
430 size_t len, loff_t *ptr)
431{
432 struct ffs_data *ffs = file->private_data;
433 char *data = NULL;
434 size_t n;
435 int ret;
436
437 ENTER();
438
439 /* Fast check if setup was canceled */
440 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
441 return -EIDRM;
442
443 /* Acquire mutex */
444 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
445 if (unlikely(ret < 0))
446 return ret;
447
448 /* Check state */
449 if (ffs->state != FFS_ACTIVE) {
450 ret = -EBADFD;
451 goto done_mutex;
452 }
453
454 /*
455 * We're called from user space, we can use _irq rather then
456 * _irqsave
457 */
458 spin_lock_irq(&ffs->ev.waitq.lock);
459
460 switch (ffs_setup_state_clear_cancelled(ffs)) {
461 case FFS_SETUP_CANCELLED:
462 ret = -EIDRM;
463 break;
464
465 case FFS_NO_SETUP:
466 n = len / sizeof(struct usb_functionfs_event);
467 if (unlikely(!n)) {
468 ret = -EINVAL;
469 break;
470 }
471
472 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
473 ret = -EAGAIN;
474 break;
475 }
476
477 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
478 ffs->ev.count)) {
479 ret = -EINTR;
480 break;
481 }
482
483 return __ffs_ep0_read_events(ffs, buf,
484 min(n, (size_t)ffs->ev.count));
485
486 case FFS_SETUP_PENDING:
487 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
488 spin_unlock_irq(&ffs->ev.waitq.lock);
489 ret = __ffs_ep0_stall(ffs);
490 goto done_mutex;
491 }
492
493 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
494
495 spin_unlock_irq(&ffs->ev.waitq.lock);
496
497 if (likely(len)) {
498 data = kmalloc(len, GFP_KERNEL);
499 if (unlikely(!data)) {
500 ret = -ENOMEM;
501 goto done_mutex;
502 }
503 }
504
505 spin_lock_irq(&ffs->ev.waitq.lock);
506
507 /* See ffs_ep0_write() */
508 if (ffs_setup_state_clear_cancelled(ffs) ==
509 FFS_SETUP_CANCELLED) {
510 ret = -EIDRM;
511 break;
512 }
513
514 /* unlocks spinlock */
515 ret = __ffs_ep0_queue_wait(ffs, data, len);
516 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
517 ret = -EFAULT;
518 goto done_mutex;
519
520 default:
521 ret = -EBADFD;
522 break;
523 }
524
525 spin_unlock_irq(&ffs->ev.waitq.lock);
526done_mutex:
527 mutex_unlock(&ffs->mutex);
528 kfree(data);
529 return ret;
530}
531
532static int ffs_ep0_open(struct inode *inode, struct file *file)
533{
534 struct ffs_data *ffs = inode->i_private;
535
536 ENTER();
537
538 if (unlikely(ffs->state == FFS_CLOSING))
539 return -EBUSY;
540
541 file->private_data = ffs;
542 ffs_data_opened(ffs);
543
544 return 0;
545}
546
547static int ffs_ep0_release(struct inode *inode, struct file *file)
548{
549 struct ffs_data *ffs = file->private_data;
550
551 ENTER();
552
553 ffs_data_closed(ffs);
554
555 return 0;
556}
557
558static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
559{
560 struct ffs_data *ffs = file->private_data;
561 struct usb_gadget *gadget = ffs->gadget;
562 long ret;
563
564 ENTER();
565
566 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
567 struct ffs_function *func = ffs->func;
568 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
569 } else if (gadget && gadget->ops->ioctl) {
570 ret = gadget->ops->ioctl(gadget, code, value);
571 } else {
572 ret = -ENOTTY;
573 }
574
575 return ret;
576}
577
578static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
579{
580 struct ffs_data *ffs = file->private_data;
581 unsigned int mask = POLLWRNORM;
582 int ret;
583
584 poll_wait(file, &ffs->ev.waitq, wait);
585
586 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
587 if (unlikely(ret < 0))
588 return mask;
589
590 switch (ffs->state) {
591 case FFS_READ_DESCRIPTORS:
592 case FFS_READ_STRINGS:
593 mask |= POLLOUT;
594 break;
595
596 case FFS_ACTIVE:
597 switch (ffs->setup_state) {
598 case FFS_NO_SETUP:
599 if (ffs->ev.count)
600 mask |= POLLIN;
601 break;
602
603 case FFS_SETUP_PENDING:
604 case FFS_SETUP_CANCELLED:
605 mask |= (POLLIN | POLLOUT);
606 break;
607 }
608 case FFS_CLOSING:
609 break;
610 case FFS_DEACTIVATED:
611 break;
612 }
613
614 mutex_unlock(&ffs->mutex);
615
616 return mask;
617}
618
619static const struct file_operations ffs_ep0_operations = {
620 .llseek = no_llseek,
621
622 .open = ffs_ep0_open,
623 .write = ffs_ep0_write,
624 .read = ffs_ep0_read,
625 .release = ffs_ep0_release,
626 .unlocked_ioctl = ffs_ep0_ioctl,
627 .poll = ffs_ep0_poll,
628};
629
630
631/* "Normal" endpoints operations ********************************************/
632
633static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
634{
635 ENTER();
636 if (likely(req->context)) {
637 struct ffs_ep *ep = _ep->driver_data;
638 ep->status = req->status ? req->status : req->actual;
639 complete(req->context);
640 }
641}
642
643static void ffs_user_copy_worker(struct work_struct *work)
644{
645 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
646 work);
647 int ret = io_data->req->status ? io_data->req->status :
648 io_data->req->actual;
649 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
650
651 if (io_data->read && ret > 0) {
652 use_mm(io_data->mm);
653 ret = copy_to_iter(io_data->buf, ret, &io_data->data);
654 if (iov_iter_count(&io_data->data))
655 ret = -EFAULT;
656 unuse_mm(io_data->mm);
657 }
658
659 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
660
661 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
662 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
663
664 usb_ep_free_request(io_data->ep, io_data->req);
665
666 if (io_data->read)
667 kfree(io_data->to_free);
668 kfree(io_data->buf);
669 kfree(io_data);
670}
671
672static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
673 struct usb_request *req)
674{
675 struct ffs_io_data *io_data = req->context;
676
677 ENTER();
678
679 INIT_WORK(&io_data->work, ffs_user_copy_worker);
680 schedule_work(&io_data->work);
681}
682
683static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
684{
685 struct ffs_epfile *epfile = file->private_data;
686 struct usb_request *req;
687 struct ffs_ep *ep;
688 char *data = NULL;
689 ssize_t ret, data_len = -EINVAL;
690 int halt;
691
692 /* Are we still active? */
693 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
694 return -ENODEV;
695
696 /* Wait for endpoint to be enabled */
697 ep = epfile->ep;
698 if (!ep) {
699 if (file->f_flags & O_NONBLOCK)
700 return -EAGAIN;
701
702 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
703 if (ret)
704 return -EINTR;
705 }
706
707 /* Do we halt? */
708 halt = (!io_data->read == !epfile->in);
709 if (halt && epfile->isoc)
710 return -EINVAL;
711
712 /* Allocate & copy */
713 if (!halt) {
714 /*
715 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
716 * before the waiting completes, so do not assign to 'gadget'
717 * earlier
718 */
719 struct usb_gadget *gadget = epfile->ffs->gadget;
720 size_t copied;
721
722 spin_lock_irq(&epfile->ffs->eps_lock);
723 /* In the meantime, endpoint got disabled or changed. */
724 if (epfile->ep != ep) {
725 spin_unlock_irq(&epfile->ffs->eps_lock);
726 return -ESHUTDOWN;
727 }
728 data_len = iov_iter_count(&io_data->data);
729 /*
730 * Controller may require buffer size to be aligned to
731 * maxpacketsize of an out endpoint.
732 */
733 if (io_data->read)
734 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
735 spin_unlock_irq(&epfile->ffs->eps_lock);
736
737 data = kmalloc(data_len, GFP_KERNEL);
738 if (unlikely(!data))
739 return -ENOMEM;
740 if (!io_data->read) {
741 copied = copy_from_iter(data, data_len, &io_data->data);
742 if (copied != data_len) {
743 ret = -EFAULT;
744 goto error;
745 }
746 }
747 }
748
749 /* We will be using request */
750 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
751 if (unlikely(ret))
752 goto error;
753
754 spin_lock_irq(&epfile->ffs->eps_lock);
755
756 if (epfile->ep != ep) {
757 /* In the meantime, endpoint got disabled or changed. */
758 ret = -ESHUTDOWN;
759 } else if (halt) {
760 /* Halt */
761 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
762 usb_ep_set_halt(ep->ep);
763 ret = -EBADMSG;
764 } else if (unlikely(data_len == -EINVAL)) {
765 /*
766 * Sanity Check: even though data_len can't be used
767 * uninitialized at the time I write this comment, some
768 * compilers complain about this situation.
769 * In order to keep the code clean from warnings, data_len is
770 * being initialized to -EINVAL during its declaration, which
771 * means we can't rely on compiler anymore to warn no future
772 * changes won't result in data_len being used uninitialized.
773 * For such reason, we're adding this redundant sanity check
774 * here.
775 */
776 WARN(1, "%s: data_len == -EINVAL\n", __func__);
777 ret = -EINVAL;
778 } else if (!io_data->aio) {
779 DECLARE_COMPLETION_ONSTACK(done);
780 bool interrupted = false;
781
782 req = ep->req;
783 req->buf = data;
784 req->length = data_len;
785
786 req->context = &done;
787 req->complete = ffs_epfile_io_complete;
788
789 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
790 if (unlikely(ret < 0))
791 goto error_lock;
792
793 spin_unlock_irq(&epfile->ffs->eps_lock);
794
795 if (unlikely(wait_for_completion_interruptible(&done))) {
796 /*
797 * To avoid race condition with ffs_epfile_io_complete,
798 * dequeue the request first then check
799 * status. usb_ep_dequeue API should guarantee no race
800 * condition with req->complete callback.
801 */
802 usb_ep_dequeue(ep->ep, req);
803 interrupted = ep->status < 0;
804 }
805
806 /*
807 * XXX We may end up silently droping data here. Since data_len
808 * (i.e. req->length) may be bigger than len (after being
809 * rounded up to maxpacketsize), we may end up with more data
810 * then user space has space for.
811 */
812 ret = interrupted ? -EINTR : ep->status;
813 if (io_data->read && ret > 0) {
814 ret = copy_to_iter(data, ret, &io_data->data);
815 if (!ret)
816 ret = -EFAULT;
817 }
818 goto error_mutex;
819 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_KERNEL))) {
820 ret = -ENOMEM;
821 } else {
822 req->buf = data;
823 req->length = data_len;
824
825 io_data->buf = data;
826 io_data->ep = ep->ep;
827 io_data->req = req;
828 io_data->ffs = epfile->ffs;
829
830 req->context = io_data;
831 req->complete = ffs_epfile_async_io_complete;
832
833 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
834 if (unlikely(ret)) {
835 usb_ep_free_request(ep->ep, req);
836 goto error_lock;
837 }
838
839 ret = -EIOCBQUEUED;
840 /*
841 * Do not kfree the buffer in this function. It will be freed
842 * by ffs_user_copy_worker.
843 */
844 data = NULL;
845 }
846
847error_lock:
848 spin_unlock_irq(&epfile->ffs->eps_lock);
849error_mutex:
850 mutex_unlock(&epfile->mutex);
851error:
852 kfree(data);
853 return ret;
854}
855
856static int
857ffs_epfile_open(struct inode *inode, struct file *file)
858{
859 struct ffs_epfile *epfile = inode->i_private;
860
861 ENTER();
862
863 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
864 return -ENODEV;
865
866 file->private_data = epfile;
867 ffs_data_opened(epfile->ffs);
868
869 return 0;
870}
871
872static int ffs_aio_cancel(struct kiocb *kiocb)
873{
874 struct ffs_io_data *io_data = kiocb->private;
875 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
876 int value;
877
878 ENTER();
879
880 spin_lock_irq(&epfile->ffs->eps_lock);
881
882 if (likely(io_data && io_data->ep && io_data->req))
883 value = usb_ep_dequeue(io_data->ep, io_data->req);
884 else
885 value = -EINVAL;
886
887 spin_unlock_irq(&epfile->ffs->eps_lock);
888
889 return value;
890}
891
892static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
893{
894 struct ffs_io_data io_data, *p = &io_data;
895 ssize_t res;
896
897 ENTER();
898
899 if (!is_sync_kiocb(kiocb)) {
900 p = kmalloc(sizeof(io_data), GFP_KERNEL);
901 if (unlikely(!p))
902 return -ENOMEM;
903 p->aio = true;
904 } else {
905 p->aio = false;
906 }
907
908 p->read = false;
909 p->kiocb = kiocb;
910 p->data = *from;
911 p->mm = current->mm;
912
913 kiocb->private = p;
914
915 if (p->aio)
916 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
917
918 res = ffs_epfile_io(kiocb->ki_filp, p);
919 if (res == -EIOCBQUEUED)
920 return res;
921 if (p->aio)
922 kfree(p);
923 else
924 *from = p->data;
925 return res;
926}
927
928static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
929{
930 struct ffs_io_data io_data, *p = &io_data;
931 ssize_t res;
932
933 ENTER();
934
935 if (!is_sync_kiocb(kiocb)) {
936 p = kmalloc(sizeof(io_data), GFP_KERNEL);
937 if (unlikely(!p))
938 return -ENOMEM;
939 p->aio = true;
940 } else {
941 p->aio = false;
942 }
943
944 p->read = true;
945 p->kiocb = kiocb;
946 if (p->aio) {
947 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
948 if (!p->to_free) {
949 kfree(p);
950 return -ENOMEM;
951 }
952 } else {
953 p->data = *to;
954 p->to_free = NULL;
955 }
956 p->mm = current->mm;
957
958 kiocb->private = p;
959
960 if (p->aio)
961 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
962
963 res = ffs_epfile_io(kiocb->ki_filp, p);
964 if (res == -EIOCBQUEUED)
965 return res;
966
967 if (p->aio) {
968 kfree(p->to_free);
969 kfree(p);
970 } else {
971 *to = p->data;
972 }
973 return res;
974}
975
976static int
977ffs_epfile_release(struct inode *inode, struct file *file)
978{
979 struct ffs_epfile *epfile = inode->i_private;
980
981 ENTER();
982
983 ffs_data_closed(epfile->ffs);
984
985 return 0;
986}
987
988static long ffs_epfile_ioctl(struct file *file, unsigned code,
989 unsigned long value)
990{
991 struct ffs_epfile *epfile = file->private_data;
992 int ret;
993
994 ENTER();
995
996 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
997 return -ENODEV;
998
999 spin_lock_irq(&epfile->ffs->eps_lock);
1000 if (likely(epfile->ep)) {
1001 switch (code) {
1002 case FUNCTIONFS_FIFO_STATUS:
1003 ret = usb_ep_fifo_status(epfile->ep->ep);
1004 break;
1005 case FUNCTIONFS_FIFO_FLUSH:
1006 usb_ep_fifo_flush(epfile->ep->ep);
1007 ret = 0;
1008 break;
1009 case FUNCTIONFS_CLEAR_HALT:
1010 ret = usb_ep_clear_halt(epfile->ep->ep);
1011 break;
1012 case FUNCTIONFS_ENDPOINT_REVMAP:
1013 ret = epfile->ep->num;
1014 break;
1015 case FUNCTIONFS_ENDPOINT_DESC:
1016 {
1017 int desc_idx;
1018 struct usb_endpoint_descriptor *desc;
1019
1020 switch (epfile->ffs->gadget->speed) {
1021 case USB_SPEED_SUPER:
1022 desc_idx = 2;
1023 break;
1024 case USB_SPEED_HIGH:
1025 desc_idx = 1;
1026 break;
1027 default:
1028 desc_idx = 0;
1029 }
1030 desc = epfile->ep->descs[desc_idx];
1031
1032 spin_unlock_irq(&epfile->ffs->eps_lock);
1033 ret = copy_to_user((void *)value, desc, sizeof(*desc));
1034 if (ret)
1035 ret = -EFAULT;
1036 return ret;
1037 }
1038 default:
1039 ret = -ENOTTY;
1040 }
1041 } else {
1042 ret = -ENODEV;
1043 }
1044 spin_unlock_irq(&epfile->ffs->eps_lock);
1045
1046 return ret;
1047}
1048
1049static const struct file_operations ffs_epfile_operations = {
1050 .llseek = no_llseek,
1051
1052 .open = ffs_epfile_open,
1053 .write_iter = ffs_epfile_write_iter,
1054 .read_iter = ffs_epfile_read_iter,
1055 .release = ffs_epfile_release,
1056 .unlocked_ioctl = ffs_epfile_ioctl,
1057};
1058
1059
1060/* File system and super block operations ***********************************/
1061
1062/*
1063 * Mounting the file system creates a controller file, used first for
1064 * function configuration then later for event monitoring.
1065 */
1066
1067static struct inode *__must_check
1068ffs_sb_make_inode(struct super_block *sb, void *data,
1069 const struct file_operations *fops,
1070 const struct inode_operations *iops,
1071 struct ffs_file_perms *perms)
1072{
1073 struct inode *inode;
1074
1075 ENTER();
1076
1077 inode = new_inode(sb);
1078
1079 if (likely(inode)) {
1080 struct timespec current_time = CURRENT_TIME;
1081
1082 inode->i_ino = get_next_ino();
1083 inode->i_mode = perms->mode;
1084 inode->i_uid = perms->uid;
1085 inode->i_gid = perms->gid;
1086 inode->i_atime = current_time;
1087 inode->i_mtime = current_time;
1088 inode->i_ctime = current_time;
1089 inode->i_private = data;
1090 if (fops)
1091 inode->i_fop = fops;
1092 if (iops)
1093 inode->i_op = iops;
1094 }
1095
1096 return inode;
1097}
1098
1099/* Create "regular" file */
1100static struct dentry *ffs_sb_create_file(struct super_block *sb,
1101 const char *name, void *data,
1102 const struct file_operations *fops)
1103{
1104 struct ffs_data *ffs = sb->s_fs_info;
1105 struct dentry *dentry;
1106 struct inode *inode;
1107
1108 ENTER();
1109
1110 dentry = d_alloc_name(sb->s_root, name);
1111 if (unlikely(!dentry))
1112 return NULL;
1113
1114 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1115 if (unlikely(!inode)) {
1116 dput(dentry);
1117 return NULL;
1118 }
1119
1120 d_add(dentry, inode);
1121 return dentry;
1122}
1123
1124/* Super block */
1125static const struct super_operations ffs_sb_operations = {
1126 .statfs = simple_statfs,
1127 .drop_inode = generic_delete_inode,
1128};
1129
1130struct ffs_sb_fill_data {
1131 struct ffs_file_perms perms;
1132 umode_t root_mode;
1133 const char *dev_name;
1134 bool no_disconnect;
1135 struct ffs_data *ffs_data;
1136};
1137
1138static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1139{
1140 struct ffs_sb_fill_data *data = _data;
1141 struct inode *inode;
1142 struct ffs_data *ffs = data->ffs_data;
1143
1144 ENTER();
1145
1146 ffs->sb = sb;
1147 data->ffs_data = NULL;
1148 sb->s_fs_info = ffs;
1149 sb->s_blocksize = PAGE_SIZE;
1150 sb->s_blocksize_bits = PAGE_SHIFT;
1151 sb->s_magic = FUNCTIONFS_MAGIC;
1152 sb->s_op = &ffs_sb_operations;
1153 sb->s_time_gran = 1;
1154
1155 /* Root inode */
1156 data->perms.mode = data->root_mode;
1157 inode = ffs_sb_make_inode(sb, NULL,
1158 &simple_dir_operations,
1159 &simple_dir_inode_operations,
1160 &data->perms);
1161 sb->s_root = d_make_root(inode);
1162 if (unlikely(!sb->s_root))
1163 return -ENOMEM;
1164
1165 /* EP0 file */
1166 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1167 &ffs_ep0_operations)))
1168 return -ENOMEM;
1169
1170 return 0;
1171}
1172
1173static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1174{
1175 ENTER();
1176
1177 if (!opts || !*opts)
1178 return 0;
1179
1180 for (;;) {
1181 unsigned long value;
1182 char *eq, *comma;
1183
1184 /* Option limit */
1185 comma = strchr(opts, ',');
1186 if (comma)
1187 *comma = 0;
1188
1189 /* Value limit */
1190 eq = strchr(opts, '=');
1191 if (unlikely(!eq)) {
1192 pr_err("'=' missing in %s\n", opts);
1193 return -EINVAL;
1194 }
1195 *eq = 0;
1196
1197 /* Parse value */
1198 if (kstrtoul(eq + 1, 0, &value)) {
1199 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1200 return -EINVAL;
1201 }
1202
1203 /* Interpret option */
1204 switch (eq - opts) {
1205 case 13:
1206 if (!memcmp(opts, "no_disconnect", 13))
1207 data->no_disconnect = !!value;
1208 else
1209 goto invalid;
1210 break;
1211 case 5:
1212 if (!memcmp(opts, "rmode", 5))
1213 data->root_mode = (value & 0555) | S_IFDIR;
1214 else if (!memcmp(opts, "fmode", 5))
1215 data->perms.mode = (value & 0666) | S_IFREG;
1216 else
1217 goto invalid;
1218 break;
1219
1220 case 4:
1221 if (!memcmp(opts, "mode", 4)) {
1222 data->root_mode = (value & 0555) | S_IFDIR;
1223 data->perms.mode = (value & 0666) | S_IFREG;
1224 } else {
1225 goto invalid;
1226 }
1227 break;
1228
1229 case 3:
1230 if (!memcmp(opts, "uid", 3)) {
1231 data->perms.uid = make_kuid(current_user_ns(), value);
1232 if (!uid_valid(data->perms.uid)) {
1233 pr_err("%s: unmapped value: %lu\n", opts, value);
1234 return -EINVAL;
1235 }
1236 } else if (!memcmp(opts, "gid", 3)) {
1237 data->perms.gid = make_kgid(current_user_ns(), value);
1238 if (!gid_valid(data->perms.gid)) {
1239 pr_err("%s: unmapped value: %lu\n", opts, value);
1240 return -EINVAL;
1241 }
1242 } else {
1243 goto invalid;
1244 }
1245 break;
1246
1247 default:
1248invalid:
1249 pr_err("%s: invalid option\n", opts);
1250 return -EINVAL;
1251 }
1252
1253 /* Next iteration */
1254 if (!comma)
1255 break;
1256 opts = comma + 1;
1257 }
1258
1259 return 0;
1260}
1261
1262/* "mount -t functionfs dev_name /dev/function" ends up here */
1263
1264static struct dentry *
1265ffs_fs_mount(struct file_system_type *t, int flags,
1266 const char *dev_name, void *opts)
1267{
1268 struct ffs_sb_fill_data data = {
1269 .perms = {
1270 .mode = S_IFREG | 0600,
1271 .uid = GLOBAL_ROOT_UID,
1272 .gid = GLOBAL_ROOT_GID,
1273 },
1274 .root_mode = S_IFDIR | 0500,
1275 .no_disconnect = false,
1276 };
1277 struct dentry *rv;
1278 int ret;
1279 void *ffs_dev;
1280 struct ffs_data *ffs;
1281
1282 ENTER();
1283
1284 ret = ffs_fs_parse_opts(&data, opts);
1285 if (unlikely(ret < 0))
1286 return ERR_PTR(ret);
1287
1288 ffs = ffs_data_new();
1289 if (unlikely(!ffs))
1290 return ERR_PTR(-ENOMEM);
1291 ffs->file_perms = data.perms;
1292 ffs->no_disconnect = data.no_disconnect;
1293
1294 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1295 if (unlikely(!ffs->dev_name)) {
1296 ffs_data_put(ffs);
1297 return ERR_PTR(-ENOMEM);
1298 }
1299
1300 ffs_dev = ffs_acquire_dev(dev_name);
1301 if (IS_ERR(ffs_dev)) {
1302 ffs_data_put(ffs);
1303 return ERR_CAST(ffs_dev);
1304 }
1305 ffs->private_data = ffs_dev;
1306 data.ffs_data = ffs;
1307
1308 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1309 if (IS_ERR(rv) && data.ffs_data) {
1310 ffs_release_dev(data.ffs_data);
1311 ffs_data_put(data.ffs_data);
1312 }
1313 return rv;
1314}
1315
1316static void
1317ffs_fs_kill_sb(struct super_block *sb)
1318{
1319 ENTER();
1320
1321 kill_litter_super(sb);
1322 if (sb->s_fs_info) {
1323 ffs_release_dev(sb->s_fs_info);
1324 ffs_data_closed(sb->s_fs_info);
1325 ffs_data_put(sb->s_fs_info);
1326 }
1327}
1328
1329static struct file_system_type ffs_fs_type = {
1330 .owner = THIS_MODULE,
1331 .name = "functionfs",
1332 .mount = ffs_fs_mount,
1333 .kill_sb = ffs_fs_kill_sb,
1334};
1335MODULE_ALIAS_FS("functionfs");
1336
1337
1338/* Driver's main init/cleanup functions *************************************/
1339
1340static int functionfs_init(void)
1341{
1342 int ret;
1343
1344 ENTER();
1345
1346 ret = register_filesystem(&ffs_fs_type);
1347 if (likely(!ret))
1348 pr_info("file system registered\n");
1349 else
1350 pr_err("failed registering file system (%d)\n", ret);
1351
1352 return ret;
1353}
1354
1355static void functionfs_cleanup(void)
1356{
1357 ENTER();
1358
1359 pr_info("unloading\n");
1360 unregister_filesystem(&ffs_fs_type);
1361}
1362
1363
1364/* ffs_data and ffs_function construction and destruction code **************/
1365
1366static void ffs_data_clear(struct ffs_data *ffs);
1367static void ffs_data_reset(struct ffs_data *ffs);
1368
1369static void ffs_data_get(struct ffs_data *ffs)
1370{
1371 ENTER();
1372
1373 atomic_inc(&ffs->ref);
1374}
1375
1376static void ffs_data_opened(struct ffs_data *ffs)
1377{
1378 ENTER();
1379
1380 atomic_inc(&ffs->ref);
1381 if (atomic_add_return(1, &ffs->opened) == 1 &&
1382 ffs->state == FFS_DEACTIVATED) {
1383 ffs->state = FFS_CLOSING;
1384 ffs_data_reset(ffs);
1385 }
1386}
1387
1388static void ffs_data_put(struct ffs_data *ffs)
1389{
1390 ENTER();
1391
1392 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1393 pr_info("%s(): freeing\n", __func__);
1394 ffs_data_clear(ffs);
1395 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1396 waitqueue_active(&ffs->ep0req_completion.wait));
1397 kfree(ffs->dev_name);
1398 kfree(ffs);
1399 }
1400}
1401
1402static void ffs_data_closed(struct ffs_data *ffs)
1403{
1404 ENTER();
1405
1406 if (atomic_dec_and_test(&ffs->opened)) {
1407 if (ffs->no_disconnect) {
1408 ffs->state = FFS_DEACTIVATED;
1409 if (ffs->epfiles) {
1410 ffs_epfiles_destroy(ffs->epfiles,
1411 ffs->eps_count);
1412 ffs->epfiles = NULL;
1413 }
1414 if (ffs->setup_state == FFS_SETUP_PENDING)
1415 __ffs_ep0_stall(ffs);
1416 } else {
1417 ffs->state = FFS_CLOSING;
1418 ffs_data_reset(ffs);
1419 }
1420 }
1421 if (atomic_read(&ffs->opened) < 0) {
1422 ffs->state = FFS_CLOSING;
1423 ffs_data_reset(ffs);
1424 }
1425
1426 ffs_data_put(ffs);
1427}
1428
1429static struct ffs_data *ffs_data_new(void)
1430{
1431 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1432 if (unlikely(!ffs))
1433 return NULL;
1434
1435 ENTER();
1436
1437 atomic_set(&ffs->ref, 1);
1438 atomic_set(&ffs->opened, 0);
1439 ffs->state = FFS_READ_DESCRIPTORS;
1440 mutex_init(&ffs->mutex);
1441 spin_lock_init(&ffs->eps_lock);
1442 init_waitqueue_head(&ffs->ev.waitq);
1443 init_completion(&ffs->ep0req_completion);
1444
1445 /* XXX REVISIT need to update it in some places, or do we? */
1446 ffs->ev.can_stall = 1;
1447
1448 return ffs;
1449}
1450
1451static void ffs_data_clear(struct ffs_data *ffs)
1452{
1453 ENTER();
1454
1455 ffs_closed(ffs);
1456
1457 BUG_ON(ffs->gadget);
1458
1459 if (ffs->epfiles)
1460 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1461
1462 if (ffs->ffs_eventfd)
1463 eventfd_ctx_put(ffs->ffs_eventfd);
1464
1465 kfree(ffs->raw_descs_data);
1466 kfree(ffs->raw_strings);
1467 kfree(ffs->stringtabs);
1468}
1469
1470static void ffs_data_reset(struct ffs_data *ffs)
1471{
1472 ENTER();
1473
1474 ffs_data_clear(ffs);
1475
1476 ffs->epfiles = NULL;
1477 ffs->raw_descs_data = NULL;
1478 ffs->raw_descs = NULL;
1479 ffs->raw_strings = NULL;
1480 ffs->stringtabs = NULL;
1481
1482 ffs->raw_descs_length = 0;
1483 ffs->fs_descs_count = 0;
1484 ffs->hs_descs_count = 0;
1485 ffs->ss_descs_count = 0;
1486
1487 ffs->strings_count = 0;
1488 ffs->interfaces_count = 0;
1489 ffs->eps_count = 0;
1490
1491 ffs->ev.count = 0;
1492
1493 ffs->state = FFS_READ_DESCRIPTORS;
1494 ffs->setup_state = FFS_NO_SETUP;
1495 ffs->flags = 0;
1496}
1497
1498
1499static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1500{
1501 struct usb_gadget_strings **lang;
1502 int first_id;
1503
1504 ENTER();
1505
1506 if (WARN_ON(ffs->state != FFS_ACTIVE
1507 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1508 return -EBADFD;
1509
1510 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1511 if (unlikely(first_id < 0))
1512 return first_id;
1513
1514 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1515 if (unlikely(!ffs->ep0req))
1516 return -ENOMEM;
1517 ffs->ep0req->complete = ffs_ep0_complete;
1518 ffs->ep0req->context = ffs;
1519
1520 lang = ffs->stringtabs;
1521 if (lang) {
1522 for (; *lang; ++lang) {
1523 struct usb_string *str = (*lang)->strings;
1524 int id = first_id;
1525 for (; str->s; ++id, ++str)
1526 str->id = id;
1527 }
1528 }
1529
1530 ffs->gadget = cdev->gadget;
1531 ffs_data_get(ffs);
1532 return 0;
1533}
1534
1535static void functionfs_unbind(struct ffs_data *ffs)
1536{
1537 ENTER();
1538
1539 if (!WARN_ON(!ffs->gadget)) {
1540 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1541 ffs->ep0req = NULL;
1542 ffs->gadget = NULL;
1543 clear_bit(FFS_FL_BOUND, &ffs->flags);
1544 ffs_data_put(ffs);
1545 }
1546}
1547
1548static int ffs_epfiles_create(struct ffs_data *ffs)
1549{
1550 struct ffs_epfile *epfile, *epfiles;
1551 unsigned i, count;
1552
1553 ENTER();
1554
1555 count = ffs->eps_count;
1556 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1557 if (!epfiles)
1558 return -ENOMEM;
1559
1560 epfile = epfiles;
1561 for (i = 1; i <= count; ++i, ++epfile) {
1562 epfile->ffs = ffs;
1563 mutex_init(&epfile->mutex);
1564 init_waitqueue_head(&epfile->wait);
1565 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1566 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1567 else
1568 sprintf(epfile->name, "ep%u", i);
1569 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1570 epfile,
1571 &ffs_epfile_operations);
1572 if (unlikely(!epfile->dentry)) {
1573 ffs_epfiles_destroy(epfiles, i - 1);
1574 return -ENOMEM;
1575 }
1576 }
1577
1578 ffs->epfiles = epfiles;
1579 return 0;
1580}
1581
1582static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1583{
1584 struct ffs_epfile *epfile = epfiles;
1585
1586 ENTER();
1587
1588 for (; count; --count, ++epfile) {
1589 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1590 waitqueue_active(&epfile->wait));
1591 if (epfile->dentry) {
1592 d_delete(epfile->dentry);
1593 dput(epfile->dentry);
1594 epfile->dentry = NULL;
1595 }
1596 }
1597
1598 kfree(epfiles);
1599}
1600
1601static void ffs_func_eps_disable(struct ffs_function *func)
1602{
1603 struct ffs_ep *ep = func->eps;
1604 struct ffs_epfile *epfile = func->ffs->epfiles;
1605 unsigned count = func->ffs->eps_count;
1606 unsigned long flags;
1607
1608 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1609 do {
1610 /* pending requests get nuked */
1611 if (likely(ep->ep))
1612 usb_ep_disable(ep->ep);
1613 ++ep;
1614
1615 if (epfile) {
1616 epfile->ep = NULL;
1617 ++epfile;
1618 }
1619 } while (--count);
1620 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1621}
1622
1623static int ffs_func_eps_enable(struct ffs_function *func)
1624{
1625 struct ffs_data *ffs = func->ffs;
1626 struct ffs_ep *ep = func->eps;
1627 struct ffs_epfile *epfile = ffs->epfiles;
1628 unsigned count = ffs->eps_count;
1629 unsigned long flags;
1630 int ret = 0;
1631
1632 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1633 do {
1634 struct usb_endpoint_descriptor *ds;
1635 int desc_idx;
1636
1637 if (ffs->gadget->speed == USB_SPEED_SUPER)
1638 desc_idx = 2;
1639 else if (ffs->gadget->speed == USB_SPEED_HIGH)
1640 desc_idx = 1;
1641 else
1642 desc_idx = 0;
1643
1644 /* fall-back to lower speed if desc missing for current speed */
1645 do {
1646 ds = ep->descs[desc_idx];
1647 } while (!ds && --desc_idx >= 0);
1648
1649 if (!ds) {
1650 ret = -EINVAL;
1651 break;
1652 }
1653
1654 ep->ep->driver_data = ep;
1655 ep->ep->desc = ds;
1656 ret = usb_ep_enable(ep->ep);
1657 if (likely(!ret)) {
1658 epfile->ep = ep;
1659 epfile->in = usb_endpoint_dir_in(ds);
1660 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1661 } else {
1662 break;
1663 }
1664
1665 wake_up(&epfile->wait);
1666
1667 ++ep;
1668 ++epfile;
1669 } while (--count);
1670 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1671
1672 return ret;
1673}
1674
1675
1676/* Parsing and building descriptors and strings *****************************/
1677
1678/*
1679 * This validates if data pointed by data is a valid USB descriptor as
1680 * well as record how many interfaces, endpoints and strings are
1681 * required by given configuration. Returns address after the
1682 * descriptor or NULL if data is invalid.
1683 */
1684
1685enum ffs_entity_type {
1686 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1687};
1688
1689enum ffs_os_desc_type {
1690 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1691};
1692
1693typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1694 u8 *valuep,
1695 struct usb_descriptor_header *desc,
1696 void *priv);
1697
1698typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1699 struct usb_os_desc_header *h, void *data,
1700 unsigned len, void *priv);
1701
1702static int __must_check ffs_do_single_desc(char *data, unsigned len,
1703 ffs_entity_callback entity,
1704 void *priv)
1705{
1706 struct usb_descriptor_header *_ds = (void *)data;
1707 u8 length;
1708 int ret;
1709
1710 ENTER();
1711
1712 /* At least two bytes are required: length and type */
1713 if (len < 2) {
1714 pr_vdebug("descriptor too short\n");
1715 return -EINVAL;
1716 }
1717
1718 /* If we have at least as many bytes as the descriptor takes? */
1719 length = _ds->bLength;
1720 if (len < length) {
1721 pr_vdebug("descriptor longer then available data\n");
1722 return -EINVAL;
1723 }
1724
1725#define __entity_check_INTERFACE(val) 1
1726#define __entity_check_STRING(val) (val)
1727#define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1728#define __entity(type, val) do { \
1729 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1730 if (unlikely(!__entity_check_ ##type(val))) { \
1731 pr_vdebug("invalid entity's value\n"); \
1732 return -EINVAL; \
1733 } \
1734 ret = entity(FFS_ ##type, &val, _ds, priv); \
1735 if (unlikely(ret < 0)) { \
1736 pr_debug("entity " #type "(%02x); ret = %d\n", \
1737 (val), ret); \
1738 return ret; \
1739 } \
1740 } while (0)
1741
1742 /* Parse descriptor depending on type. */
1743 switch (_ds->bDescriptorType) {
1744 case USB_DT_DEVICE:
1745 case USB_DT_CONFIG:
1746 case USB_DT_STRING:
1747 case USB_DT_DEVICE_QUALIFIER:
1748 /* function can't have any of those */
1749 pr_vdebug("descriptor reserved for gadget: %d\n",
1750 _ds->bDescriptorType);
1751 return -EINVAL;
1752
1753 case USB_DT_INTERFACE: {
1754 struct usb_interface_descriptor *ds = (void *)_ds;
1755 pr_vdebug("interface descriptor\n");
1756 if (length != sizeof *ds)
1757 goto inv_length;
1758
1759 __entity(INTERFACE, ds->bInterfaceNumber);
1760 if (ds->iInterface)
1761 __entity(STRING, ds->iInterface);
1762 }
1763 break;
1764
1765 case USB_DT_ENDPOINT: {
1766 struct usb_endpoint_descriptor *ds = (void *)_ds;
1767 pr_vdebug("endpoint descriptor\n");
1768 if (length != USB_DT_ENDPOINT_SIZE &&
1769 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1770 goto inv_length;
1771 __entity(ENDPOINT, ds->bEndpointAddress);
1772 }
1773 break;
1774
1775 case HID_DT_HID:
1776 pr_vdebug("hid descriptor\n");
1777 if (length != sizeof(struct hid_descriptor))
1778 goto inv_length;
1779 break;
1780
1781 case USB_DT_OTG:
1782 if (length != sizeof(struct usb_otg_descriptor))
1783 goto inv_length;
1784 break;
1785
1786 case USB_DT_INTERFACE_ASSOCIATION: {
1787 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1788 pr_vdebug("interface association descriptor\n");
1789 if (length != sizeof *ds)
1790 goto inv_length;
1791 if (ds->iFunction)
1792 __entity(STRING, ds->iFunction);
1793 }
1794 break;
1795
1796 case USB_DT_SS_ENDPOINT_COMP:
1797 pr_vdebug("EP SS companion descriptor\n");
1798 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
1799 goto inv_length;
1800 break;
1801
1802 case USB_DT_OTHER_SPEED_CONFIG:
1803 case USB_DT_INTERFACE_POWER:
1804 case USB_DT_DEBUG:
1805 case USB_DT_SECURITY:
1806 case USB_DT_CS_RADIO_CONTROL:
1807 /* TODO */
1808 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
1809 return -EINVAL;
1810
1811 default:
1812 /* We should never be here */
1813 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
1814 return -EINVAL;
1815
1816inv_length:
1817 pr_vdebug("invalid length: %d (descriptor %d)\n",
1818 _ds->bLength, _ds->bDescriptorType);
1819 return -EINVAL;
1820 }
1821
1822#undef __entity
1823#undef __entity_check_DESCRIPTOR
1824#undef __entity_check_INTERFACE
1825#undef __entity_check_STRING
1826#undef __entity_check_ENDPOINT
1827
1828 return length;
1829}
1830
1831static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
1832 ffs_entity_callback entity, void *priv)
1833{
1834 const unsigned _len = len;
1835 unsigned long num = 0;
1836
1837 ENTER();
1838
1839 for (;;) {
1840 int ret;
1841
1842 if (num == count)
1843 data = NULL;
1844
1845 /* Record "descriptor" entity */
1846 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
1847 if (unlikely(ret < 0)) {
1848 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
1849 num, ret);
1850 return ret;
1851 }
1852
1853 if (!data)
1854 return _len - len;
1855
1856 ret = ffs_do_single_desc(data, len, entity, priv);
1857 if (unlikely(ret < 0)) {
1858 pr_debug("%s returns %d\n", __func__, ret);
1859 return ret;
1860 }
1861
1862 len -= ret;
1863 data += ret;
1864 ++num;
1865 }
1866}
1867
1868static int __ffs_data_do_entity(enum ffs_entity_type type,
1869 u8 *valuep, struct usb_descriptor_header *desc,
1870 void *priv)
1871{
1872 struct ffs_desc_helper *helper = priv;
1873 struct usb_endpoint_descriptor *d;
1874
1875 ENTER();
1876
1877 switch (type) {
1878 case FFS_DESCRIPTOR:
1879 break;
1880
1881 case FFS_INTERFACE:
1882 /*
1883 * Interfaces are indexed from zero so if we
1884 * encountered interface "n" then there are at least
1885 * "n+1" interfaces.
1886 */
1887 if (*valuep >= helper->interfaces_count)
1888 helper->interfaces_count = *valuep + 1;
1889 break;
1890
1891 case FFS_STRING:
1892 /*
1893 * Strings are indexed from 1 (0 is magic ;) reserved
1894 * for languages list or some such)
1895 */
1896 if (*valuep > helper->ffs->strings_count)
1897 helper->ffs->strings_count = *valuep;
1898 break;
1899
1900 case FFS_ENDPOINT:
1901 d = (void *)desc;
1902 helper->eps_count++;
1903 if (helper->eps_count >= 15)
1904 return -EINVAL;
1905 /* Check if descriptors for any speed were already parsed */
1906 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
1907 helper->ffs->eps_addrmap[helper->eps_count] =
1908 d->bEndpointAddress;
1909 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
1910 d->bEndpointAddress)
1911 return -EINVAL;
1912 break;
1913 }
1914
1915 return 0;
1916}
1917
1918static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
1919 struct usb_os_desc_header *desc)
1920{
1921 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
1922 u16 w_index = le16_to_cpu(desc->wIndex);
1923
1924 if (bcd_version != 1) {
1925 pr_vdebug("unsupported os descriptors version: %d",
1926 bcd_version);
1927 return -EINVAL;
1928 }
1929 switch (w_index) {
1930 case 0x4:
1931 *next_type = FFS_OS_DESC_EXT_COMPAT;
1932 break;
1933 case 0x5:
1934 *next_type = FFS_OS_DESC_EXT_PROP;
1935 break;
1936 default:
1937 pr_vdebug("unsupported os descriptor type: %d", w_index);
1938 return -EINVAL;
1939 }
1940
1941 return sizeof(*desc);
1942}
1943
1944/*
1945 * Process all extended compatibility/extended property descriptors
1946 * of a feature descriptor
1947 */
1948static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
1949 enum ffs_os_desc_type type,
1950 u16 feature_count,
1951 ffs_os_desc_callback entity,
1952 void *priv,
1953 struct usb_os_desc_header *h)
1954{
1955 int ret;
1956 const unsigned _len = len;
1957
1958 ENTER();
1959
1960 /* loop over all ext compat/ext prop descriptors */
1961 while (feature_count--) {
1962 ret = entity(type, h, data, len, priv);
1963 if (unlikely(ret < 0)) {
1964 pr_debug("bad OS descriptor, type: %d\n", type);
1965 return ret;
1966 }
1967 data += ret;
1968 len -= ret;
1969 }
1970 return _len - len;
1971}
1972
1973/* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
1974static int __must_check ffs_do_os_descs(unsigned count,
1975 char *data, unsigned len,
1976 ffs_os_desc_callback entity, void *priv)
1977{
1978 const unsigned _len = len;
1979 unsigned long num = 0;
1980
1981 ENTER();
1982
1983 for (num = 0; num < count; ++num) {
1984 int ret;
1985 enum ffs_os_desc_type type;
1986 u16 feature_count;
1987 struct usb_os_desc_header *desc = (void *)data;
1988
1989 if (len < sizeof(*desc))
1990 return -EINVAL;
1991
1992 /*
1993 * Record "descriptor" entity.
1994 * Process dwLength, bcdVersion, wIndex, get b/wCount.
1995 * Move the data pointer to the beginning of extended
1996 * compatibilities proper or extended properties proper
1997 * portions of the data
1998 */
1999 if (le32_to_cpu(desc->dwLength) > len)
2000 return -EINVAL;
2001
2002 ret = __ffs_do_os_desc_header(&type, desc);
2003 if (unlikely(ret < 0)) {
2004 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2005 num, ret);
2006 return ret;
2007 }
2008 /*
2009 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2010 */
2011 feature_count = le16_to_cpu(desc->wCount);
2012 if (type == FFS_OS_DESC_EXT_COMPAT &&
2013 (feature_count > 255 || desc->Reserved))
2014 return -EINVAL;
2015 len -= ret;
2016 data += ret;
2017
2018 /*
2019 * Process all function/property descriptors
2020 * of this Feature Descriptor
2021 */
2022 ret = ffs_do_single_os_desc(data, len, type,
2023 feature_count, entity, priv, desc);
2024 if (unlikely(ret < 0)) {
2025 pr_debug("%s returns %d\n", __func__, ret);
2026 return ret;
2027 }
2028
2029 len -= ret;
2030 data += ret;
2031 }
2032 return _len - len;
2033}
2034
2035/**
2036 * Validate contents of the buffer from userspace related to OS descriptors.
2037 */
2038static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2039 struct usb_os_desc_header *h, void *data,
2040 unsigned len, void *priv)
2041{
2042 struct ffs_data *ffs = priv;
2043 u8 length;
2044
2045 ENTER();
2046
2047 switch (type) {
2048 case FFS_OS_DESC_EXT_COMPAT: {
2049 struct usb_ext_compat_desc *d = data;
2050 int i;
2051
2052 if (len < sizeof(*d) ||
2053 d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2054 d->Reserved1)
2055 return -EINVAL;
2056 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2057 if (d->Reserved2[i])
2058 return -EINVAL;
2059
2060 length = sizeof(struct usb_ext_compat_desc);
2061 }
2062 break;
2063 case FFS_OS_DESC_EXT_PROP: {
2064 struct usb_ext_prop_desc *d = data;
2065 u32 type, pdl;
2066 u16 pnl;
2067
2068 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2069 return -EINVAL;
2070 length = le32_to_cpu(d->dwSize);
2071 type = le32_to_cpu(d->dwPropertyDataType);
2072 if (type < USB_EXT_PROP_UNICODE ||
2073 type > USB_EXT_PROP_UNICODE_MULTI) {
2074 pr_vdebug("unsupported os descriptor property type: %d",
2075 type);
2076 return -EINVAL;
2077 }
2078 pnl = le16_to_cpu(d->wPropertyNameLength);
2079 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2080 if (length != 14 + pnl + pdl) {
2081 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2082 length, pnl, pdl, type);
2083 return -EINVAL;
2084 }
2085 ++ffs->ms_os_descs_ext_prop_count;
2086 /* property name reported to the host as "WCHAR"s */
2087 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2088 ffs->ms_os_descs_ext_prop_data_len += pdl;
2089 }
2090 break;
2091 default:
2092 pr_vdebug("unknown descriptor: %d\n", type);
2093 return -EINVAL;
2094 }
2095 return length;
2096}
2097
2098static int __ffs_data_got_descs(struct ffs_data *ffs,
2099 char *const _data, size_t len)
2100{
2101 char *data = _data, *raw_descs;
2102 unsigned os_descs_count = 0, counts[3], flags;
2103 int ret = -EINVAL, i;
2104 struct ffs_desc_helper helper;
2105
2106 ENTER();
2107
2108 if (get_unaligned_le32(data + 4) != len)
2109 goto error;
2110
2111 switch (get_unaligned_le32(data)) {
2112 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2113 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2114 data += 8;
2115 len -= 8;
2116 break;
2117 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2118 flags = get_unaligned_le32(data + 8);
2119 ffs->user_flags = flags;
2120 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2121 FUNCTIONFS_HAS_HS_DESC |
2122 FUNCTIONFS_HAS_SS_DESC |
2123 FUNCTIONFS_HAS_MS_OS_DESC |
2124 FUNCTIONFS_VIRTUAL_ADDR |
2125 FUNCTIONFS_EVENTFD)) {
2126 ret = -ENOSYS;
2127 goto error;
2128 }
2129 data += 12;
2130 len -= 12;
2131 break;
2132 default:
2133 goto error;
2134 }
2135
2136 if (flags & FUNCTIONFS_EVENTFD) {
2137 if (len < 4)
2138 goto error;
2139 ffs->ffs_eventfd =
2140 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2141 if (IS_ERR(ffs->ffs_eventfd)) {
2142 ret = PTR_ERR(ffs->ffs_eventfd);
2143 ffs->ffs_eventfd = NULL;
2144 goto error;
2145 }
2146 data += 4;
2147 len -= 4;
2148 }
2149
2150 /* Read fs_count, hs_count and ss_count (if present) */
2151 for (i = 0; i < 3; ++i) {
2152 if (!(flags & (1 << i))) {
2153 counts[i] = 0;
2154 } else if (len < 4) {
2155 goto error;
2156 } else {
2157 counts[i] = get_unaligned_le32(data);
2158 data += 4;
2159 len -= 4;
2160 }
2161 }
2162 if (flags & (1 << i)) {
2163 os_descs_count = get_unaligned_le32(data);
2164 data += 4;
2165 len -= 4;
2166 };
2167
2168 /* Read descriptors */
2169 raw_descs = data;
2170 helper.ffs = ffs;
2171 for (i = 0; i < 3; ++i) {
2172 if (!counts[i])
2173 continue;
2174 helper.interfaces_count = 0;
2175 helper.eps_count = 0;
2176 ret = ffs_do_descs(counts[i], data, len,
2177 __ffs_data_do_entity, &helper);
2178 if (ret < 0)
2179 goto error;
2180 if (!ffs->eps_count && !ffs->interfaces_count) {
2181 ffs->eps_count = helper.eps_count;
2182 ffs->interfaces_count = helper.interfaces_count;
2183 } else {
2184 if (ffs->eps_count != helper.eps_count) {
2185 ret = -EINVAL;
2186 goto error;
2187 }
2188 if (ffs->interfaces_count != helper.interfaces_count) {
2189 ret = -EINVAL;
2190 goto error;
2191 }
2192 }
2193 data += ret;
2194 len -= ret;
2195 }
2196 if (os_descs_count) {
2197 ret = ffs_do_os_descs(os_descs_count, data, len,
2198 __ffs_data_do_os_desc, ffs);
2199 if (ret < 0)
2200 goto error;
2201 data += ret;
2202 len -= ret;
2203 }
2204
2205 if (raw_descs == data || len) {
2206 ret = -EINVAL;
2207 goto error;
2208 }
2209
2210 ffs->raw_descs_data = _data;
2211 ffs->raw_descs = raw_descs;
2212 ffs->raw_descs_length = data - raw_descs;
2213 ffs->fs_descs_count = counts[0];
2214 ffs->hs_descs_count = counts[1];
2215 ffs->ss_descs_count = counts[2];
2216 ffs->ms_os_descs_count = os_descs_count;
2217
2218 return 0;
2219
2220error:
2221 kfree(_data);
2222 return ret;
2223}
2224
2225static int __ffs_data_got_strings(struct ffs_data *ffs,
2226 char *const _data, size_t len)
2227{
2228 u32 str_count, needed_count, lang_count;
2229 struct usb_gadget_strings **stringtabs, *t;
2230 struct usb_string *strings, *s;
2231 const char *data = _data;
2232
2233 ENTER();
2234
2235 if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2236 get_unaligned_le32(data + 4) != len))
2237 goto error;
2238 str_count = get_unaligned_le32(data + 8);
2239 lang_count = get_unaligned_le32(data + 12);
2240
2241 /* if one is zero the other must be zero */
2242 if (unlikely(!str_count != !lang_count))
2243 goto error;
2244
2245 /* Do we have at least as many strings as descriptors need? */
2246 needed_count = ffs->strings_count;
2247 if (unlikely(str_count < needed_count))
2248 goto error;
2249
2250 /*
2251 * If we don't need any strings just return and free all
2252 * memory.
2253 */
2254 if (!needed_count) {
2255 kfree(_data);
2256 return 0;
2257 }
2258
2259 /* Allocate everything in one chunk so there's less maintenance. */
2260 {
2261 unsigned i = 0;
2262 vla_group(d);
2263 vla_item(d, struct usb_gadget_strings *, stringtabs,
2264 lang_count + 1);
2265 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2266 vla_item(d, struct usb_string, strings,
2267 lang_count*(needed_count+1));
2268
2269 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2270
2271 if (unlikely(!vlabuf)) {
2272 kfree(_data);
2273 return -ENOMEM;
2274 }
2275
2276 /* Initialize the VLA pointers */
2277 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2278 t = vla_ptr(vlabuf, d, stringtab);
2279 i = lang_count;
2280 do {
2281 *stringtabs++ = t++;
2282 } while (--i);
2283 *stringtabs = NULL;
2284
2285 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2286 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2287 t = vla_ptr(vlabuf, d, stringtab);
2288 s = vla_ptr(vlabuf, d, strings);
2289 strings = s;
2290 }
2291
2292 /* For each language */
2293 data += 16;
2294 len -= 16;
2295
2296 do { /* lang_count > 0 so we can use do-while */
2297 unsigned needed = needed_count;
2298
2299 if (unlikely(len < 3))
2300 goto error_free;
2301 t->language = get_unaligned_le16(data);
2302 t->strings = s;
2303 ++t;
2304
2305 data += 2;
2306 len -= 2;
2307
2308 /* For each string */
2309 do { /* str_count > 0 so we can use do-while */
2310 size_t length = strnlen(data, len);
2311
2312 if (unlikely(length == len))
2313 goto error_free;
2314
2315 /*
2316 * User may provide more strings then we need,
2317 * if that's the case we simply ignore the
2318 * rest
2319 */
2320 if (likely(needed)) {
2321 /*
2322 * s->id will be set while adding
2323 * function to configuration so for
2324 * now just leave garbage here.
2325 */
2326 s->s = data;
2327 --needed;
2328 ++s;
2329 }
2330
2331 data += length + 1;
2332 len -= length + 1;
2333 } while (--str_count);
2334
2335 s->id = 0; /* terminator */
2336 s->s = NULL;
2337 ++s;
2338
2339 } while (--lang_count);
2340
2341 /* Some garbage left? */
2342 if (unlikely(len))
2343 goto error_free;
2344
2345 /* Done! */
2346 ffs->stringtabs = stringtabs;
2347 ffs->raw_strings = _data;
2348
2349 return 0;
2350
2351error_free:
2352 kfree(stringtabs);
2353error:
2354 kfree(_data);
2355 return -EINVAL;
2356}
2357
2358
2359/* Events handling and management *******************************************/
2360
2361static void __ffs_event_add(struct ffs_data *ffs,
2362 enum usb_functionfs_event_type type)
2363{
2364 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2365 int neg = 0;
2366
2367 /*
2368 * Abort any unhandled setup
2369 *
2370 * We do not need to worry about some cmpxchg() changing value
2371 * of ffs->setup_state without holding the lock because when
2372 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2373 * the source does nothing.
2374 */
2375 if (ffs->setup_state == FFS_SETUP_PENDING)
2376 ffs->setup_state = FFS_SETUP_CANCELLED;
2377
2378 /*
2379 * Logic of this function guarantees that there are at most four pending
2380 * evens on ffs->ev.types queue. This is important because the queue
2381 * has space for four elements only and __ffs_ep0_read_events function
2382 * depends on that limit as well. If more event types are added, those
2383 * limits have to be revisited or guaranteed to still hold.
2384 */
2385 switch (type) {
2386 case FUNCTIONFS_RESUME:
2387 rem_type2 = FUNCTIONFS_SUSPEND;
2388 /* FALL THROUGH */
2389 case FUNCTIONFS_SUSPEND:
2390 case FUNCTIONFS_SETUP:
2391 rem_type1 = type;
2392 /* Discard all similar events */
2393 break;
2394
2395 case FUNCTIONFS_BIND:
2396 case FUNCTIONFS_UNBIND:
2397 case FUNCTIONFS_DISABLE:
2398 case FUNCTIONFS_ENABLE:
2399 /* Discard everything other then power management. */
2400 rem_type1 = FUNCTIONFS_SUSPEND;
2401 rem_type2 = FUNCTIONFS_RESUME;
2402 neg = 1;
2403 break;
2404
2405 default:
2406 WARN(1, "%d: unknown event, this should not happen\n", type);
2407 return;
2408 }
2409
2410 {
2411 u8 *ev = ffs->ev.types, *out = ev;
2412 unsigned n = ffs->ev.count;
2413 for (; n; --n, ++ev)
2414 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2415 *out++ = *ev;
2416 else
2417 pr_vdebug("purging event %d\n", *ev);
2418 ffs->ev.count = out - ffs->ev.types;
2419 }
2420
2421 pr_vdebug("adding event %d\n", type);
2422 ffs->ev.types[ffs->ev.count++] = type;
2423 wake_up_locked(&ffs->ev.waitq);
2424 if (ffs->ffs_eventfd)
2425 eventfd_signal(ffs->ffs_eventfd, 1);
2426}
2427
2428static void ffs_event_add(struct ffs_data *ffs,
2429 enum usb_functionfs_event_type type)
2430{
2431 unsigned long flags;
2432 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2433 __ffs_event_add(ffs, type);
2434 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2435}
2436
2437/* Bind/unbind USB function hooks *******************************************/
2438
2439static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2440{
2441 int i;
2442
2443 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2444 if (ffs->eps_addrmap[i] == endpoint_address)
2445 return i;
2446 return -ENOENT;
2447}
2448
2449static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2450 struct usb_descriptor_header *desc,
2451 void *priv)
2452{
2453 struct usb_endpoint_descriptor *ds = (void *)desc;
2454 struct ffs_function *func = priv;
2455 struct ffs_ep *ffs_ep;
2456 unsigned ep_desc_id;
2457 int idx;
2458 static const char *speed_names[] = { "full", "high", "super" };
2459
2460 if (type != FFS_DESCRIPTOR)
2461 return 0;
2462
2463 /*
2464 * If ss_descriptors is not NULL, we are reading super speed
2465 * descriptors; if hs_descriptors is not NULL, we are reading high
2466 * speed descriptors; otherwise, we are reading full speed
2467 * descriptors.
2468 */
2469 if (func->function.ss_descriptors) {
2470 ep_desc_id = 2;
2471 func->function.ss_descriptors[(long)valuep] = desc;
2472 } else if (func->function.hs_descriptors) {
2473 ep_desc_id = 1;
2474 func->function.hs_descriptors[(long)valuep] = desc;
2475 } else {
2476 ep_desc_id = 0;
2477 func->function.fs_descriptors[(long)valuep] = desc;
2478 }
2479
2480 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2481 return 0;
2482
2483 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2484 if (idx < 0)
2485 return idx;
2486
2487 ffs_ep = func->eps + idx;
2488
2489 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2490 pr_err("two %sspeed descriptors for EP %d\n",
2491 speed_names[ep_desc_id],
2492 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2493 return -EINVAL;
2494 }
2495 ffs_ep->descs[ep_desc_id] = ds;
2496
2497 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2498 if (ffs_ep->ep) {
2499 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2500 if (!ds->wMaxPacketSize)
2501 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2502 } else {
2503 struct usb_request *req;
2504 struct usb_ep *ep;
2505 u8 bEndpointAddress;
2506
2507 /*
2508 * We back up bEndpointAddress because autoconfig overwrites
2509 * it with physical endpoint address.
2510 */
2511 bEndpointAddress = ds->bEndpointAddress;
2512 pr_vdebug("autoconfig\n");
2513 ep = usb_ep_autoconfig(func->gadget, ds);
2514 if (unlikely(!ep))
2515 return -ENOTSUPP;
2516 ep->driver_data = func->eps + idx;
2517
2518 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2519 if (unlikely(!req))
2520 return -ENOMEM;
2521
2522 ffs_ep->ep = ep;
2523 ffs_ep->req = req;
2524 func->eps_revmap[ds->bEndpointAddress &
2525 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2526 /*
2527 * If we use virtual address mapping, we restore
2528 * original bEndpointAddress value.
2529 */
2530 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2531 ds->bEndpointAddress = bEndpointAddress;
2532 }
2533 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2534
2535 return 0;
2536}
2537
2538static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2539 struct usb_descriptor_header *desc,
2540 void *priv)
2541{
2542 struct ffs_function *func = priv;
2543 unsigned idx;
2544 u8 newValue;
2545
2546 switch (type) {
2547 default:
2548 case FFS_DESCRIPTOR:
2549 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2550 return 0;
2551
2552 case FFS_INTERFACE:
2553 idx = *valuep;
2554 if (func->interfaces_nums[idx] < 0) {
2555 int id = usb_interface_id(func->conf, &func->function);
2556 if (unlikely(id < 0))
2557 return id;
2558 func->interfaces_nums[idx] = id;
2559 }
2560 newValue = func->interfaces_nums[idx];
2561 break;
2562
2563 case FFS_STRING:
2564 /* String' IDs are allocated when fsf_data is bound to cdev */
2565 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2566 break;
2567
2568 case FFS_ENDPOINT:
2569 /*
2570 * USB_DT_ENDPOINT are handled in
2571 * __ffs_func_bind_do_descs().
2572 */
2573 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2574 return 0;
2575
2576 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2577 if (unlikely(!func->eps[idx].ep))
2578 return -EINVAL;
2579
2580 {
2581 struct usb_endpoint_descriptor **descs;
2582 descs = func->eps[idx].descs;
2583 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2584 }
2585 break;
2586 }
2587
2588 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2589 *valuep = newValue;
2590 return 0;
2591}
2592
2593static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2594 struct usb_os_desc_header *h, void *data,
2595 unsigned len, void *priv)
2596{
2597 struct ffs_function *func = priv;
2598 u8 length = 0;
2599
2600 switch (type) {
2601 case FFS_OS_DESC_EXT_COMPAT: {
2602 struct usb_ext_compat_desc *desc = data;
2603 struct usb_os_desc_table *t;
2604
2605 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2606 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2607 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2608 ARRAY_SIZE(desc->CompatibleID) +
2609 ARRAY_SIZE(desc->SubCompatibleID));
2610 length = sizeof(*desc);
2611 }
2612 break;
2613 case FFS_OS_DESC_EXT_PROP: {
2614 struct usb_ext_prop_desc *desc = data;
2615 struct usb_os_desc_table *t;
2616 struct usb_os_desc_ext_prop *ext_prop;
2617 char *ext_prop_name;
2618 char *ext_prop_data;
2619
2620 t = &func->function.os_desc_table[h->interface];
2621 t->if_id = func->interfaces_nums[h->interface];
2622
2623 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2624 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2625
2626 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2627 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2628 ext_prop->data_len = le32_to_cpu(*(u32 *)
2629 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2630 length = ext_prop->name_len + ext_prop->data_len + 14;
2631
2632 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2633 func->ffs->ms_os_descs_ext_prop_name_avail +=
2634 ext_prop->name_len;
2635
2636 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2637 func->ffs->ms_os_descs_ext_prop_data_avail +=
2638 ext_prop->data_len;
2639 memcpy(ext_prop_data,
2640 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2641 ext_prop->data_len);
2642 /* unicode data reported to the host as "WCHAR"s */
2643 switch (ext_prop->type) {
2644 case USB_EXT_PROP_UNICODE:
2645 case USB_EXT_PROP_UNICODE_ENV:
2646 case USB_EXT_PROP_UNICODE_LINK:
2647 case USB_EXT_PROP_UNICODE_MULTI:
2648 ext_prop->data_len *= 2;
2649 break;
2650 }
2651 ext_prop->data = ext_prop_data;
2652
2653 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2654 ext_prop->name_len);
2655 /* property name reported to the host as "WCHAR"s */
2656 ext_prop->name_len *= 2;
2657 ext_prop->name = ext_prop_name;
2658
2659 t->os_desc->ext_prop_len +=
2660 ext_prop->name_len + ext_prop->data_len + 14;
2661 ++t->os_desc->ext_prop_count;
2662 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2663 }
2664 break;
2665 default:
2666 pr_vdebug("unknown descriptor: %d\n", type);
2667 }
2668
2669 return length;
2670}
2671
2672static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2673 struct usb_configuration *c)
2674{
2675 struct ffs_function *func = ffs_func_from_usb(f);
2676 struct f_fs_opts *ffs_opts =
2677 container_of(f->fi, struct f_fs_opts, func_inst);
2678 int ret;
2679
2680 ENTER();
2681
2682 /*
2683 * Legacy gadget triggers binding in functionfs_ready_callback,
2684 * which already uses locking; taking the same lock here would
2685 * cause a deadlock.
2686 *
2687 * Configfs-enabled gadgets however do need ffs_dev_lock.
2688 */
2689 if (!ffs_opts->no_configfs)
2690 ffs_dev_lock();
2691 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2692 func->ffs = ffs_opts->dev->ffs_data;
2693 if (!ffs_opts->no_configfs)
2694 ffs_dev_unlock();
2695 if (ret)
2696 return ERR_PTR(ret);
2697
2698 func->conf = c;
2699 func->gadget = c->cdev->gadget;
2700
2701 /*
2702 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2703 * configurations are bound in sequence with list_for_each_entry,
2704 * in each configuration its functions are bound in sequence
2705 * with list_for_each_entry, so we assume no race condition
2706 * with regard to ffs_opts->bound access
2707 */
2708 if (!ffs_opts->refcnt) {
2709 ret = functionfs_bind(func->ffs, c->cdev);
2710 if (ret)
2711 return ERR_PTR(ret);
2712 }
2713 ffs_opts->refcnt++;
2714 func->function.strings = func->ffs->stringtabs;
2715
2716 return ffs_opts;
2717}
2718
2719static int _ffs_func_bind(struct usb_configuration *c,
2720 struct usb_function *f)
2721{
2722 struct ffs_function *func = ffs_func_from_usb(f);
2723 struct ffs_data *ffs = func->ffs;
2724
2725 const int full = !!func->ffs->fs_descs_count;
2726 const int high = gadget_is_dualspeed(func->gadget) &&
2727 func->ffs->hs_descs_count;
2728 const int super = gadget_is_superspeed(func->gadget) &&
2729 func->ffs->ss_descs_count;
2730
2731 int fs_len, hs_len, ss_len, ret, i;
2732
2733 /* Make it a single chunk, less management later on */
2734 vla_group(d);
2735 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2736 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2737 full ? ffs->fs_descs_count + 1 : 0);
2738 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2739 high ? ffs->hs_descs_count + 1 : 0);
2740 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2741 super ? ffs->ss_descs_count + 1 : 0);
2742 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2743 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2744 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2745 vla_item_with_sz(d, char[16], ext_compat,
2746 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2747 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2748 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2749 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2750 ffs->ms_os_descs_ext_prop_count);
2751 vla_item_with_sz(d, char, ext_prop_name,
2752 ffs->ms_os_descs_ext_prop_name_len);
2753 vla_item_with_sz(d, char, ext_prop_data,
2754 ffs->ms_os_descs_ext_prop_data_len);
2755 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2756 char *vlabuf;
2757
2758 ENTER();
2759
2760 /* Has descriptors only for speeds gadget does not support */
2761 if (unlikely(!(full | high | super)))
2762 return -ENOTSUPP;
2763
2764 /* Allocate a single chunk, less management later on */
2765 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2766 if (unlikely(!vlabuf))
2767 return -ENOMEM;
2768
2769 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2770 ffs->ms_os_descs_ext_prop_name_avail =
2771 vla_ptr(vlabuf, d, ext_prop_name);
2772 ffs->ms_os_descs_ext_prop_data_avail =
2773 vla_ptr(vlabuf, d, ext_prop_data);
2774
2775 /* Copy descriptors */
2776 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2777 ffs->raw_descs_length);
2778
2779 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2780 for (ret = ffs->eps_count; ret; --ret) {
2781 struct ffs_ep *ptr;
2782
2783 ptr = vla_ptr(vlabuf, d, eps);
2784 ptr[ret].num = -1;
2785 }
2786
2787 /* Save pointers
2788 * d_eps == vlabuf, func->eps used to kfree vlabuf later
2789 */
2790 func->eps = vla_ptr(vlabuf, d, eps);
2791 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
2792
2793 /*
2794 * Go through all the endpoint descriptors and allocate
2795 * endpoints first, so that later we can rewrite the endpoint
2796 * numbers without worrying that it may be described later on.
2797 */
2798 if (likely(full)) {
2799 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
2800 fs_len = ffs_do_descs(ffs->fs_descs_count,
2801 vla_ptr(vlabuf, d, raw_descs),
2802 d_raw_descs__sz,
2803 __ffs_func_bind_do_descs, func);
2804 if (unlikely(fs_len < 0)) {
2805 ret = fs_len;
2806 goto error;
2807 }
2808 } else {
2809 fs_len = 0;
2810 }
2811
2812 if (likely(high)) {
2813 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
2814 hs_len = ffs_do_descs(ffs->hs_descs_count,
2815 vla_ptr(vlabuf, d, raw_descs) + fs_len,
2816 d_raw_descs__sz - fs_len,
2817 __ffs_func_bind_do_descs, func);
2818 if (unlikely(hs_len < 0)) {
2819 ret = hs_len;
2820 goto error;
2821 }
2822 } else {
2823 hs_len = 0;
2824 }
2825
2826 if (likely(super)) {
2827 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
2828 ss_len = ffs_do_descs(ffs->ss_descs_count,
2829 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
2830 d_raw_descs__sz - fs_len - hs_len,
2831 __ffs_func_bind_do_descs, func);
2832 if (unlikely(ss_len < 0)) {
2833 ret = ss_len;
2834 goto error;
2835 }
2836 } else {
2837 ss_len = 0;
2838 }
2839
2840 /*
2841 * Now handle interface numbers allocation and interface and
2842 * endpoint numbers rewriting. We can do that in one go
2843 * now.
2844 */
2845 ret = ffs_do_descs(ffs->fs_descs_count +
2846 (high ? ffs->hs_descs_count : 0) +
2847 (super ? ffs->ss_descs_count : 0),
2848 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
2849 __ffs_func_bind_do_nums, func);
2850 if (unlikely(ret < 0))
2851 goto error;
2852
2853 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
2854 if (c->cdev->use_os_string)
2855 for (i = 0; i < ffs->interfaces_count; ++i) {
2856 struct usb_os_desc *desc;
2857
2858 desc = func->function.os_desc_table[i].os_desc =
2859 vla_ptr(vlabuf, d, os_desc) +
2860 i * sizeof(struct usb_os_desc);
2861 desc->ext_compat_id =
2862 vla_ptr(vlabuf, d, ext_compat) + i * 16;
2863 INIT_LIST_HEAD(&desc->ext_prop);
2864 }
2865 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
2866 vla_ptr(vlabuf, d, raw_descs) +
2867 fs_len + hs_len + ss_len,
2868 d_raw_descs__sz - fs_len - hs_len - ss_len,
2869 __ffs_func_bind_do_os_desc, func);
2870 if (unlikely(ret < 0))
2871 goto error;
2872 func->function.os_desc_n =
2873 c->cdev->use_os_string ? ffs->interfaces_count : 0;
2874
2875 /* And we're done */
2876 ffs_event_add(ffs, FUNCTIONFS_BIND);
2877 return 0;
2878
2879error:
2880 /* XXX Do we need to release all claimed endpoints here? */
2881 return ret;
2882}
2883
2884static int ffs_func_bind(struct usb_configuration *c,
2885 struct usb_function *f)
2886{
2887 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
2888 struct ffs_function *func = ffs_func_from_usb(f);
2889 int ret;
2890
2891 if (IS_ERR(ffs_opts))
2892 return PTR_ERR(ffs_opts);
2893
2894 ret = _ffs_func_bind(c, f);
2895 if (ret && !--ffs_opts->refcnt)
2896 functionfs_unbind(func->ffs);
2897
2898 return ret;
2899}
2900
2901
2902/* Other USB function hooks *************************************************/
2903
2904static void ffs_reset_work(struct work_struct *work)
2905{
2906 struct ffs_data *ffs = container_of(work,
2907 struct ffs_data, reset_work);
2908 ffs_data_reset(ffs);
2909}
2910
2911static int ffs_func_set_alt(struct usb_function *f,
2912 unsigned interface, unsigned alt)
2913{
2914 struct ffs_function *func = ffs_func_from_usb(f);
2915 struct ffs_data *ffs = func->ffs;
2916 int ret = 0, intf;
2917
2918 if (alt != (unsigned)-1) {
2919 intf = ffs_func_revmap_intf(func, interface);
2920 if (unlikely(intf < 0))
2921 return intf;
2922 }
2923
2924 if (ffs->func)
2925 ffs_func_eps_disable(ffs->func);
2926
2927 if (ffs->state == FFS_DEACTIVATED) {
2928 ffs->state = FFS_CLOSING;
2929 INIT_WORK(&ffs->reset_work, ffs_reset_work);
2930 schedule_work(&ffs->reset_work);
2931 return -ENODEV;
2932 }
2933
2934 if (ffs->state != FFS_ACTIVE)
2935 return -ENODEV;
2936
2937 if (alt == (unsigned)-1) {
2938 ffs->func = NULL;
2939 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
2940 return 0;
2941 }
2942
2943 ffs->func = func;
2944 ret = ffs_func_eps_enable(func);
2945 if (likely(ret >= 0))
2946 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
2947 return ret;
2948}
2949
2950static void ffs_func_disable(struct usb_function *f)
2951{
2952 ffs_func_set_alt(f, 0, (unsigned)-1);
2953}
2954
2955static int ffs_func_setup(struct usb_function *f,
2956 const struct usb_ctrlrequest *creq)
2957{
2958 struct ffs_function *func = ffs_func_from_usb(f);
2959 struct ffs_data *ffs = func->ffs;
2960 unsigned long flags;
2961 int ret;
2962
2963 ENTER();
2964
2965 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
2966 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
2967 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
2968 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
2969 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
2970
2971 /*
2972 * Most requests directed to interface go through here
2973 * (notable exceptions are set/get interface) so we need to
2974 * handle them. All other either handled by composite or
2975 * passed to usb_configuration->setup() (if one is set). No
2976 * matter, we will handle requests directed to endpoint here
2977 * as well (as it's straightforward) but what to do with any
2978 * other request?
2979 */
2980 if (ffs->state != FFS_ACTIVE)
2981 return -ENODEV;
2982
2983 switch (creq->bRequestType & USB_RECIP_MASK) {
2984 case USB_RECIP_INTERFACE:
2985 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
2986 if (unlikely(ret < 0))
2987 return ret;
2988 break;
2989
2990 case USB_RECIP_ENDPOINT:
2991 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
2992 if (unlikely(ret < 0))
2993 return ret;
2994 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2995 ret = func->ffs->eps_addrmap[ret];
2996 break;
2997
2998 default:
2999 return -EOPNOTSUPP;
3000 }
3001
3002 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3003 ffs->ev.setup = *creq;
3004 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3005 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3006 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3007
3008 return 0;
3009}
3010
3011static void ffs_func_suspend(struct usb_function *f)
3012{
3013 ENTER();
3014 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3015}
3016
3017static void ffs_func_resume(struct usb_function *f)
3018{
3019 ENTER();
3020 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3021}
3022
3023
3024/* Endpoint and interface numbers reverse mapping ***************************/
3025
3026static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3027{
3028 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3029 return num ? num : -EDOM;
3030}
3031
3032static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3033{
3034 short *nums = func->interfaces_nums;
3035 unsigned count = func->ffs->interfaces_count;
3036
3037 for (; count; --count, ++nums) {
3038 if (*nums >= 0 && *nums == intf)
3039 return nums - func->interfaces_nums;
3040 }
3041
3042 return -EDOM;
3043}
3044
3045
3046/* Devices management *******************************************************/
3047
3048static LIST_HEAD(ffs_devices);
3049
3050static struct ffs_dev *_ffs_do_find_dev(const char *name)
3051{
3052 struct ffs_dev *dev;
3053
3054 list_for_each_entry(dev, &ffs_devices, entry) {
3055 if (!dev->name || !name)
3056 continue;
3057 if (strcmp(dev->name, name) == 0)
3058 return dev;
3059 }
3060
3061 return NULL;
3062}
3063
3064/*
3065 * ffs_lock must be taken by the caller of this function
3066 */
3067static struct ffs_dev *_ffs_get_single_dev(void)
3068{
3069 struct ffs_dev *dev;
3070
3071 if (list_is_singular(&ffs_devices)) {
3072 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3073 if (dev->single)
3074 return dev;
3075 }
3076
3077 return NULL;
3078}
3079
3080/*
3081 * ffs_lock must be taken by the caller of this function
3082 */
3083static struct ffs_dev *_ffs_find_dev(const char *name)
3084{
3085 struct ffs_dev *dev;
3086
3087 dev = _ffs_get_single_dev();
3088 if (dev)
3089 return dev;
3090
3091 return _ffs_do_find_dev(name);
3092}
3093
3094/* Configfs support *********************************************************/
3095
3096static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3097{
3098 return container_of(to_config_group(item), struct f_fs_opts,
3099 func_inst.group);
3100}
3101
3102static void ffs_attr_release(struct config_item *item)
3103{
3104 struct f_fs_opts *opts = to_ffs_opts(item);
3105
3106 usb_put_function_instance(&opts->func_inst);
3107}
3108
3109static struct configfs_item_operations ffs_item_ops = {
3110 .release = ffs_attr_release,
3111};
3112
3113static struct config_item_type ffs_func_type = {
3114 .ct_item_ops = &ffs_item_ops,
3115 .ct_owner = THIS_MODULE,
3116};
3117
3118
3119/* Function registration interface ******************************************/
3120
3121static void ffs_free_inst(struct usb_function_instance *f)
3122{
3123 struct f_fs_opts *opts;
3124
3125 opts = to_f_fs_opts(f);
3126 ffs_dev_lock();
3127 _ffs_free_dev(opts->dev);
3128 ffs_dev_unlock();
3129 kfree(opts);
3130}
3131
3132#define MAX_INST_NAME_LEN 40
3133
3134static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3135{
3136 struct f_fs_opts *opts;
3137 char *ptr;
3138 const char *tmp;
3139 int name_len, ret;
3140
3141 name_len = strlen(name) + 1;
3142 if (name_len > MAX_INST_NAME_LEN)
3143 return -ENAMETOOLONG;
3144
3145 ptr = kstrndup(name, name_len, GFP_KERNEL);
3146 if (!ptr)
3147 return -ENOMEM;
3148
3149 opts = to_f_fs_opts(fi);
3150 tmp = NULL;
3151
3152 ffs_dev_lock();
3153
3154 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3155 ret = _ffs_name_dev(opts->dev, ptr);
3156 if (ret) {
3157 kfree(ptr);
3158 ffs_dev_unlock();
3159 return ret;
3160 }
3161 opts->dev->name_allocated = true;
3162
3163 ffs_dev_unlock();
3164
3165 kfree(tmp);
3166
3167 return 0;
3168}
3169
3170static struct usb_function_instance *ffs_alloc_inst(void)
3171{
3172 struct f_fs_opts *opts;
3173 struct ffs_dev *dev;
3174
3175 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3176 if (!opts)
3177 return ERR_PTR(-ENOMEM);
3178
3179 opts->func_inst.set_inst_name = ffs_set_inst_name;
3180 opts->func_inst.free_func_inst = ffs_free_inst;
3181 ffs_dev_lock();
3182 dev = _ffs_alloc_dev();
3183 ffs_dev_unlock();
3184 if (IS_ERR(dev)) {
3185 kfree(opts);
3186 return ERR_CAST(dev);
3187 }
3188 opts->dev = dev;
3189 dev->opts = opts;
3190
3191 config_group_init_type_name(&opts->func_inst.group, "",
3192 &ffs_func_type);
3193 return &opts->func_inst;
3194}
3195
3196static void ffs_free(struct usb_function *f)
3197{
3198 kfree(ffs_func_from_usb(f));
3199}
3200
3201static void ffs_func_unbind(struct usb_configuration *c,
3202 struct usb_function *f)
3203{
3204 struct ffs_function *func = ffs_func_from_usb(f);
3205 struct ffs_data *ffs = func->ffs;
3206 struct f_fs_opts *opts =
3207 container_of(f->fi, struct f_fs_opts, func_inst);
3208 struct ffs_ep *ep = func->eps;
3209 unsigned count = ffs->eps_count;
3210 unsigned long flags;
3211
3212 ENTER();
3213 if (ffs->func == func) {
3214 ffs_func_eps_disable(func);
3215 ffs->func = NULL;
3216 }
3217
3218 if (!--opts->refcnt)
3219 functionfs_unbind(ffs);
3220
3221 /* cleanup after autoconfig */
3222 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3223 do {
3224 if (ep->ep && ep->req)
3225 usb_ep_free_request(ep->ep, ep->req);
3226 ep->req = NULL;
3227 ++ep;
3228 } while (--count);
3229 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3230 kfree(func->eps);
3231 func->eps = NULL;
3232 /*
3233 * eps, descriptors and interfaces_nums are allocated in the
3234 * same chunk so only one free is required.
3235 */
3236 func->function.fs_descriptors = NULL;
3237 func->function.hs_descriptors = NULL;
3238 func->function.ss_descriptors = NULL;
3239 func->interfaces_nums = NULL;
3240
3241 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3242}
3243
3244static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3245{
3246 struct ffs_function *func;
3247
3248 ENTER();
3249
3250 func = kzalloc(sizeof(*func), GFP_KERNEL);
3251 if (unlikely(!func))
3252 return ERR_PTR(-ENOMEM);
3253
3254 func->function.name = "Function FS Gadget";
3255
3256 func->function.bind = ffs_func_bind;
3257 func->function.unbind = ffs_func_unbind;
3258 func->function.set_alt = ffs_func_set_alt;
3259 func->function.disable = ffs_func_disable;
3260 func->function.setup = ffs_func_setup;
3261 func->function.suspend = ffs_func_suspend;
3262 func->function.resume = ffs_func_resume;
3263 func->function.free_func = ffs_free;
3264
3265 return &func->function;
3266}
3267
3268/*
3269 * ffs_lock must be taken by the caller of this function
3270 */
3271static struct ffs_dev *_ffs_alloc_dev(void)
3272{
3273 struct ffs_dev *dev;
3274 int ret;
3275
3276 if (_ffs_get_single_dev())
3277 return ERR_PTR(-EBUSY);
3278
3279 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3280 if (!dev)
3281 return ERR_PTR(-ENOMEM);
3282
3283 if (list_empty(&ffs_devices)) {
3284 ret = functionfs_init();
3285 if (ret) {
3286 kfree(dev);
3287 return ERR_PTR(ret);
3288 }
3289 }
3290
3291 list_add(&dev->entry, &ffs_devices);
3292
3293 return dev;
3294}
3295
3296/*
3297 * ffs_lock must be taken by the caller of this function
3298 * The caller is responsible for "name" being available whenever f_fs needs it
3299 */
3300static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3301{
3302 struct ffs_dev *existing;
3303
3304 existing = _ffs_do_find_dev(name);
3305 if (existing)
3306 return -EBUSY;
3307
3308 dev->name = name;
3309
3310 return 0;
3311}
3312
3313/*
3314 * The caller is responsible for "name" being available whenever f_fs needs it
3315 */
3316int ffs_name_dev(struct ffs_dev *dev, const char *name)
3317{
3318 int ret;
3319
3320 ffs_dev_lock();
3321 ret = _ffs_name_dev(dev, name);
3322 ffs_dev_unlock();
3323
3324 return ret;
3325}
3326EXPORT_SYMBOL_GPL(ffs_name_dev);
3327
3328int ffs_single_dev(struct ffs_dev *dev)
3329{
3330 int ret;
3331
3332 ret = 0;
3333 ffs_dev_lock();
3334
3335 if (!list_is_singular(&ffs_devices))
3336 ret = -EBUSY;
3337 else
3338 dev->single = true;
3339
3340 ffs_dev_unlock();
3341 return ret;
3342}
3343EXPORT_SYMBOL_GPL(ffs_single_dev);
3344
3345/*
3346 * ffs_lock must be taken by the caller of this function
3347 */
3348static void _ffs_free_dev(struct ffs_dev *dev)
3349{
3350 list_del(&dev->entry);
3351 if (dev->name_allocated)
3352 kfree(dev->name);
3353 kfree(dev);
3354 if (list_empty(&ffs_devices))
3355 functionfs_cleanup();
3356}
3357
3358static void *ffs_acquire_dev(const char *dev_name)
3359{
3360 struct ffs_dev *ffs_dev;
3361
3362 ENTER();
3363 ffs_dev_lock();
3364
3365 ffs_dev = _ffs_find_dev(dev_name);
3366 if (!ffs_dev)
3367 ffs_dev = ERR_PTR(-ENOENT);
3368 else if (ffs_dev->mounted)
3369 ffs_dev = ERR_PTR(-EBUSY);
3370 else if (ffs_dev->ffs_acquire_dev_callback &&
3371 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3372 ffs_dev = ERR_PTR(-ENOENT);
3373 else
3374 ffs_dev->mounted = true;
3375
3376 ffs_dev_unlock();
3377 return ffs_dev;
3378}
3379
3380static void ffs_release_dev(struct ffs_data *ffs_data)
3381{
3382 struct ffs_dev *ffs_dev;
3383
3384 ENTER();
3385 ffs_dev_lock();
3386
3387 ffs_dev = ffs_data->private_data;
3388 if (ffs_dev) {
3389 ffs_dev->mounted = false;
3390
3391 if (ffs_dev->ffs_release_dev_callback)
3392 ffs_dev->ffs_release_dev_callback(ffs_dev);
3393 }
3394
3395 ffs_dev_unlock();
3396}
3397
3398static int ffs_ready(struct ffs_data *ffs)
3399{
3400 struct ffs_dev *ffs_obj;
3401 int ret = 0;
3402
3403 ENTER();
3404 ffs_dev_lock();
3405
3406 ffs_obj = ffs->private_data;
3407 if (!ffs_obj) {
3408 ret = -EINVAL;
3409 goto done;
3410 }
3411 if (WARN_ON(ffs_obj->desc_ready)) {
3412 ret = -EBUSY;
3413 goto done;
3414 }
3415
3416 ffs_obj->desc_ready = true;
3417 ffs_obj->ffs_data = ffs;
3418
3419 if (ffs_obj->ffs_ready_callback) {
3420 ret = ffs_obj->ffs_ready_callback(ffs);
3421 if (ret)
3422 goto done;
3423 }
3424
3425 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3426done:
3427 ffs_dev_unlock();
3428 return ret;
3429}
3430
3431static void ffs_closed(struct ffs_data *ffs)
3432{
3433 struct ffs_dev *ffs_obj;
3434 struct f_fs_opts *opts;
3435
3436 ENTER();
3437 ffs_dev_lock();
3438
3439 ffs_obj = ffs->private_data;
3440 if (!ffs_obj)
3441 goto done;
3442
3443 ffs_obj->desc_ready = false;
3444
3445 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3446 ffs_obj->ffs_closed_callback)
3447 ffs_obj->ffs_closed_callback(ffs);
3448
3449 if (ffs_obj->opts)
3450 opts = ffs_obj->opts;
3451 else
3452 goto done;
3453
3454 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3455 || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount))
3456 goto done;
3457
3458 unregister_gadget_item(ffs_obj->opts->
3459 func_inst.group.cg_item.ci_parent->ci_parent);
3460done:
3461 ffs_dev_unlock();
3462}
3463
3464/* Misc helper functions ****************************************************/
3465
3466static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3467{
3468 return nonblock
3469 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3470 : mutex_lock_interruptible(mutex);
3471}
3472
3473static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3474{
3475 char *data;
3476
3477 if (unlikely(!len))
3478 return NULL;
3479
3480 data = kmalloc(len, GFP_KERNEL);
3481 if (unlikely(!data))
3482 return ERR_PTR(-ENOMEM);
3483
3484 if (unlikely(copy_from_user(data, buf, len))) {
3485 kfree(data);
3486 return ERR_PTR(-EFAULT);
3487 }
3488
3489 pr_vdebug("Buffer from user space:\n");
3490 ffs_dump_mem("", data, len);
3491
3492 return data;
3493}
3494
3495DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3496MODULE_LICENSE("GPL");
3497MODULE_AUTHOR("Michal Nazarewicz");