2 * f_fs.c -- user mode file system API for USB composite function controllers
4 * Copyright (C) 2010 Samsung Electronics
5 * Author: Michal Nazarewicz <mina86@mina86.com>
7 * Based on inode.c (GadgetFS) which was:
8 * Copyright (C) 2003-2004 David Brownell
9 * Copyright (C) 2003 Agilent Technologies
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.
19 /* #define VERBOSE_DEBUG */
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>
29 #include <linux/usb/composite.h>
30 #include <linux/usb/functionfs.h>
32 #include <linux/aio.h>
33 #include <linux/mmu_context.h>
34 #include <linux/poll.h>
35 #include <linux/eventfd.h>
39 #include "u_os_desc.h"
42 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
44 /* Reference counter handling */
45 static void ffs_data_get(struct ffs_data *ffs);
46 static void ffs_data_put(struct ffs_data *ffs);
47 /* Creates new ffs_data object. */
48 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
50 /* Opened counter handling. */
51 static void ffs_data_opened(struct ffs_data *ffs);
52 static void ffs_data_closed(struct ffs_data *ffs);
54 /* Called with ffs->mutex held; take over ownership of data. */
55 static int __must_check
56 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
57 static int __must_check
58 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
61 /* The function structure ***************************************************/
66 struct usb_configuration *conf;
67 struct usb_gadget *gadget;
72 short *interfaces_nums;
74 struct usb_function function;
78 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
80 return container_of(f, struct ffs_function, function);
84 static inline enum ffs_setup_state
85 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
87 return (enum ffs_setup_state)
88 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
92 static void ffs_func_eps_disable(struct ffs_function *func);
93 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
95 static int ffs_func_bind(struct usb_configuration *,
96 struct usb_function *);
97 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
98 static void ffs_func_disable(struct usb_function *);
99 static int ffs_func_setup(struct usb_function *,
100 const struct usb_ctrlrequest *);
101 static bool ffs_func_req_match(struct usb_function *,
102 const struct usb_ctrlrequest *,
104 static void ffs_func_suspend(struct usb_function *);
105 static void ffs_func_resume(struct usb_function *);
108 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
109 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
112 /* The endpoints structures *************************************************/
115 struct usb_ep *ep; /* P: ffs->eps_lock */
116 struct usb_request *req; /* P: epfile->mutex */
118 /* [0]: full speed, [1]: high speed, [2]: super speed */
119 struct usb_endpoint_descriptor *descs[3];
123 int status; /* P: epfile->mutex */
127 /* Protects ep->ep and ep->req. */
129 wait_queue_head_t wait;
131 struct ffs_data *ffs;
132 struct ffs_ep *ep; /* P: ffs->eps_lock */
134 struct dentry *dentry;
137 * Buffer for holding data from partial reads which may happen since
138 * we’re rounding user read requests to a multiple of a max packet size.
140 * The pointer is initialised with NULL value and may be set by
141 * __ffs_epfile_read_data function to point to a temporary buffer.
143 * In normal operation, calls to __ffs_epfile_read_buffered will consume
144 * data from said buffer and eventually free it. Importantly, while the
145 * function is using the buffer, it sets the pointer to NULL. This is
146 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
147 * can never run concurrently (they are synchronised by epfile->mutex)
148 * so the latter will not assign a new value to the pointer.
150 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
151 * valid) and sets the pointer to READ_BUFFER_DROP value. This special
152 * value is crux of the synchronisation between ffs_func_eps_disable and
153 * __ffs_epfile_read_data.
155 * Once __ffs_epfile_read_data is about to finish it will try to set the
156 * pointer back to its old value (as described above), but seeing as the
157 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
160 * == State transitions ==
162 * • ptr == NULL: (initial state)
163 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
164 * ◦ __ffs_epfile_read_buffered: nop
165 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
166 * ◦ reading finishes: n/a, not in ‘and reading’ state
168 * ◦ __ffs_epfile_read_buffer_free: nop
169 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL
170 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
171 * ◦ reading finishes: n/a, not in ‘and reading’ state
173 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
174 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
175 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
176 * is always called first
177 * ◦ reading finishes: n/a, not in ‘and reading’ state
178 * • ptr == NULL and reading:
179 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
180 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
181 * ◦ __ffs_epfile_read_data: n/a, mutex is held
182 * ◦ reading finishes and …
183 * … all data read: free buf, go to ptr == NULL
184 * … otherwise: go to ptr == buf and reading
185 * • ptr == DROP and reading:
186 * ◦ __ffs_epfile_read_buffer_free: nop
187 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
188 * ◦ __ffs_epfile_read_data: n/a, mutex is held
189 * ◦ reading finishes: free buf, go to ptr == DROP
191 struct ffs_buffer *read_buffer;
192 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
196 unsigned char in; /* P: ffs->eps_lock */
197 unsigned char isoc; /* P: ffs->eps_lock */
208 /* ffs_io_data structure ***************************************************/
215 struct iov_iter data;
219 struct mm_struct *mm;
220 struct work_struct work;
223 struct usb_request *req;
225 struct ffs_data *ffs;
228 struct ffs_desc_helper {
229 struct ffs_data *ffs;
230 unsigned interfaces_count;
234 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
235 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
237 static struct dentry *
238 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
239 const struct file_operations *fops);
241 /* Devices management *******************************************************/
243 DEFINE_MUTEX(ffs_lock);
244 EXPORT_SYMBOL_GPL(ffs_lock);
246 static struct ffs_dev *_ffs_find_dev(const char *name);
247 static struct ffs_dev *_ffs_alloc_dev(void);
248 static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
249 static void _ffs_free_dev(struct ffs_dev *dev);
250 static void *ffs_acquire_dev(const char *dev_name);
251 static void ffs_release_dev(struct ffs_data *ffs_data);
252 static int ffs_ready(struct ffs_data *ffs);
253 static void ffs_closed(struct ffs_data *ffs);
255 /* Misc helper functions ****************************************************/
257 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
258 __attribute__((warn_unused_result, nonnull));
259 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
260 __attribute__((warn_unused_result, nonnull));
263 /* Control file aka ep0 *****************************************************/
265 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
267 struct ffs_data *ffs = req->context;
269 complete(&ffs->ep0req_completion);
272 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
274 struct usb_request *req = ffs->ep0req;
277 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
279 spin_unlock_irq(&ffs->ev.waitq.lock);
285 * UDC layer requires to provide a buffer even for ZLP, but should
286 * not use it at all. Let's provide some poisoned pointer to catch
287 * possible bug in the driver.
289 if (req->buf == NULL)
290 req->buf = (void *)0xDEADBABE;
292 reinit_completion(&ffs->ep0req_completion);
294 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
295 if (unlikely(ret < 0))
298 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
300 usb_ep_dequeue(ffs->gadget->ep0, req);
304 ffs->setup_state = FFS_NO_SETUP;
305 return req->status ? req->status : req->actual;
308 static int __ffs_ep0_stall(struct ffs_data *ffs)
310 if (ffs->ev.can_stall) {
311 pr_vdebug("ep0 stall\n");
312 usb_ep_set_halt(ffs->gadget->ep0);
313 ffs->setup_state = FFS_NO_SETUP;
316 pr_debug("bogus ep0 stall!\n");
321 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
322 size_t len, loff_t *ptr)
324 struct ffs_data *ffs = file->private_data;
330 /* Fast check if setup was canceled */
331 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
335 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
336 if (unlikely(ret < 0))
340 switch (ffs->state) {
341 case FFS_READ_DESCRIPTORS:
342 case FFS_READ_STRINGS:
344 if (unlikely(len < 16)) {
349 data = ffs_prepare_buffer(buf, len);
356 if (ffs->state == FFS_READ_DESCRIPTORS) {
357 pr_info("read descriptors\n");
358 ret = __ffs_data_got_descs(ffs, data, len);
359 if (unlikely(ret < 0))
362 ffs->state = FFS_READ_STRINGS;
365 pr_info("read strings\n");
366 ret = __ffs_data_got_strings(ffs, data, len);
367 if (unlikely(ret < 0))
370 ret = ffs_epfiles_create(ffs);
372 ffs->state = FFS_CLOSING;
376 ffs->state = FFS_ACTIVE;
377 mutex_unlock(&ffs->mutex);
379 ret = ffs_ready(ffs);
380 if (unlikely(ret < 0)) {
381 ffs->state = FFS_CLOSING;
392 * We're called from user space, we can use _irq
393 * rather then _irqsave
395 spin_lock_irq(&ffs->ev.waitq.lock);
396 switch (ffs_setup_state_clear_cancelled(ffs)) {
397 case FFS_SETUP_CANCELLED:
405 case FFS_SETUP_PENDING:
409 /* FFS_SETUP_PENDING */
410 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
411 spin_unlock_irq(&ffs->ev.waitq.lock);
412 ret = __ffs_ep0_stall(ffs);
416 /* FFS_SETUP_PENDING and not stall */
417 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
419 spin_unlock_irq(&ffs->ev.waitq.lock);
421 data = ffs_prepare_buffer(buf, len);
427 spin_lock_irq(&ffs->ev.waitq.lock);
430 * We are guaranteed to be still in FFS_ACTIVE state
431 * but the state of setup could have changed from
432 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
433 * to check for that. If that happened we copied data
434 * from user space in vain but it's unlikely.
436 * For sure we are not in FFS_NO_SETUP since this is
437 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
438 * transition can be performed and it's protected by
441 if (ffs_setup_state_clear_cancelled(ffs) ==
442 FFS_SETUP_CANCELLED) {
445 spin_unlock_irq(&ffs->ev.waitq.lock);
447 /* unlocks spinlock */
448 ret = __ffs_ep0_queue_wait(ffs, data, len);
458 mutex_unlock(&ffs->mutex);
462 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
463 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
467 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
468 * size of ffs->ev.types array (which is four) so that's how much space
471 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
472 const size_t size = n * sizeof *events;
475 memset(events, 0, size);
478 events[i].type = ffs->ev.types[i];
479 if (events[i].type == FUNCTIONFS_SETUP) {
480 events[i].u.setup = ffs->ev.setup;
481 ffs->setup_state = FFS_SETUP_PENDING;
487 memmove(ffs->ev.types, ffs->ev.types + n,
488 ffs->ev.count * sizeof *ffs->ev.types);
490 spin_unlock_irq(&ffs->ev.waitq.lock);
491 mutex_unlock(&ffs->mutex);
493 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
496 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
497 size_t len, loff_t *ptr)
499 struct ffs_data *ffs = file->private_data;
506 /* Fast check if setup was canceled */
507 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
511 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
512 if (unlikely(ret < 0))
516 if (ffs->state != FFS_ACTIVE) {
522 * We're called from user space, we can use _irq rather then
525 spin_lock_irq(&ffs->ev.waitq.lock);
527 switch (ffs_setup_state_clear_cancelled(ffs)) {
528 case FFS_SETUP_CANCELLED:
533 n = len / sizeof(struct usb_functionfs_event);
539 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
544 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
550 return __ffs_ep0_read_events(ffs, buf,
551 min(n, (size_t)ffs->ev.count));
553 case FFS_SETUP_PENDING:
554 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
555 spin_unlock_irq(&ffs->ev.waitq.lock);
556 ret = __ffs_ep0_stall(ffs);
560 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
562 spin_unlock_irq(&ffs->ev.waitq.lock);
565 data = kmalloc(len, GFP_KERNEL);
566 if (unlikely(!data)) {
572 spin_lock_irq(&ffs->ev.waitq.lock);
574 /* See ffs_ep0_write() */
575 if (ffs_setup_state_clear_cancelled(ffs) ==
576 FFS_SETUP_CANCELLED) {
581 /* unlocks spinlock */
582 ret = __ffs_ep0_queue_wait(ffs, data, len);
583 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
592 spin_unlock_irq(&ffs->ev.waitq.lock);
594 mutex_unlock(&ffs->mutex);
599 static int ffs_ep0_open(struct inode *inode, struct file *file)
601 struct ffs_data *ffs = inode->i_private;
605 if (unlikely(ffs->state == FFS_CLOSING))
608 file->private_data = ffs;
609 ffs_data_opened(ffs);
614 static int ffs_ep0_release(struct inode *inode, struct file *file)
616 struct ffs_data *ffs = file->private_data;
620 ffs_data_closed(ffs);
625 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
627 struct ffs_data *ffs = file->private_data;
628 struct usb_gadget *gadget = ffs->gadget;
633 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
634 struct ffs_function *func = ffs->func;
635 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
636 } else if (gadget && gadget->ops->ioctl) {
637 ret = gadget->ops->ioctl(gadget, code, value);
645 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
647 struct ffs_data *ffs = file->private_data;
648 unsigned int mask = POLLWRNORM;
651 poll_wait(file, &ffs->ev.waitq, wait);
653 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
654 if (unlikely(ret < 0))
657 switch (ffs->state) {
658 case FFS_READ_DESCRIPTORS:
659 case FFS_READ_STRINGS:
664 switch (ffs->setup_state) {
670 case FFS_SETUP_PENDING:
671 case FFS_SETUP_CANCELLED:
672 mask |= (POLLIN | POLLOUT);
677 case FFS_DEACTIVATED:
681 mutex_unlock(&ffs->mutex);
686 static const struct file_operations ffs_ep0_operations = {
689 .open = ffs_ep0_open,
690 .write = ffs_ep0_write,
691 .read = ffs_ep0_read,
692 .release = ffs_ep0_release,
693 .unlocked_ioctl = ffs_ep0_ioctl,
694 .poll = ffs_ep0_poll,
698 /* "Normal" endpoints operations ********************************************/
700 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
703 if (likely(req->context)) {
704 struct ffs_ep *ep = _ep->driver_data;
705 ep->status = req->status ? req->status : req->actual;
706 complete(req->context);
710 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
712 ssize_t ret = copy_to_iter(data, data_len, iter);
713 if (likely(ret == data_len))
716 if (unlikely(iov_iter_count(iter)))
720 * Dear user space developer!
722 * TL;DR: To stop getting below error message in your kernel log, change
723 * user space code using functionfs to align read buffers to a max
726 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
727 * packet size. When unaligned buffer is passed to functionfs, it
728 * internally uses a larger, aligned buffer so that such UDCs are happy.
730 * Unfortunately, this means that host may send more data than was
731 * requested in read(2) system call. f_fs doesn’t know what to do with
732 * that excess data so it simply drops it.
734 * Was the buffer aligned in the first place, no such problem would
737 * Data may be dropped only in AIO reads. Synchronous reads are handled
738 * by splitting a request into multiple parts. This splitting may still
739 * be a problem though so it’s likely best to align the buffer
740 * regardless of it being AIO or not..
742 * This only affects OUT endpoints, i.e. reading data with a read(2),
743 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not
746 pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
747 "Align read buffer size to max packet size to avoid the problem.\n",
753 static void ffs_user_copy_worker(struct work_struct *work)
755 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
757 int ret = io_data->req->status ? io_data->req->status :
758 io_data->req->actual;
759 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
761 if (io_data->read && ret > 0) {
763 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
764 unuse_mm(io_data->mm);
767 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
769 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
770 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
772 usb_ep_free_request(io_data->ep, io_data->req);
775 kfree(io_data->to_free);
780 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
781 struct usb_request *req)
783 struct ffs_io_data *io_data = req->context;
787 INIT_WORK(&io_data->work, ffs_user_copy_worker);
788 schedule_work(&io_data->work);
791 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
794 * See comment in struct ffs_epfile for full read_buffer pointer
795 * synchronisation story.
797 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
798 if (buf && buf != READ_BUFFER_DROP)
802 /* Assumes epfile->mutex is held. */
803 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
804 struct iov_iter *iter)
807 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
808 * the buffer while we are using it. See comment in struct ffs_epfile
809 * for full read_buffer pointer synchronisation story.
811 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
813 if (!buf || buf == READ_BUFFER_DROP)
816 ret = copy_to_iter(buf->data, buf->length, iter);
817 if (buf->length == ret) {
822 if (unlikely(iov_iter_count(iter))) {
829 if (cmpxchg(&epfile->read_buffer, NULL, buf))
835 /* Assumes epfile->mutex is held. */
836 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
837 void *data, int data_len,
838 struct iov_iter *iter)
840 struct ffs_buffer *buf;
842 ssize_t ret = copy_to_iter(data, data_len, iter);
843 if (likely(data_len == ret))
846 if (unlikely(iov_iter_count(iter)))
849 /* See ffs_copy_to_iter for more context. */
850 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
854 buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL);
857 buf->length = data_len;
858 buf->data = buf->storage;
859 memcpy(buf->storage, data + ret, data_len);
862 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
863 * ffs_func_eps_disable has been called in the meanwhile). See comment
864 * in struct ffs_epfile for full read_buffer pointer synchronisation
867 if (unlikely(cmpxchg(&epfile->read_buffer, NULL, buf)))
873 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
875 struct ffs_epfile *epfile = file->private_data;
876 struct usb_request *req;
879 ssize_t ret, data_len = -EINVAL;
882 /* Are we still active? */
883 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
886 /* Wait for endpoint to be enabled */
889 if (file->f_flags & O_NONBLOCK)
892 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
898 halt = (!io_data->read == !epfile->in);
899 if (halt && epfile->isoc)
902 /* We will be using request and read_buffer */
903 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
907 /* Allocate & copy */
909 struct usb_gadget *gadget;
912 * Do we have buffered data from previous partial read? Check
913 * that for synchronous case only because we do not have
914 * facility to ‘wake up’ a pending asynchronous read and push
915 * buffered data to it which we would need to make things behave
918 if (!io_data->aio && io_data->read) {
919 ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
925 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
926 * before the waiting completes, so do not assign to 'gadget'
929 gadget = epfile->ffs->gadget;
931 spin_lock_irq(&epfile->ffs->eps_lock);
932 /* In the meantime, endpoint got disabled or changed. */
933 if (epfile->ep != ep) {
937 data_len = iov_iter_count(&io_data->data);
939 * Controller may require buffer size to be aligned to
940 * maxpacketsize of an out endpoint.
943 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
944 spin_unlock_irq(&epfile->ffs->eps_lock);
946 data = kmalloc(data_len, GFP_KERNEL);
947 if (unlikely(!data)) {
951 if (!io_data->read &&
952 !copy_from_iter_full(data, data_len, &io_data->data)) {
958 spin_lock_irq(&epfile->ffs->eps_lock);
960 if (epfile->ep != ep) {
961 /* In the meantime, endpoint got disabled or changed. */
965 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
966 usb_ep_set_halt(ep->ep);
968 } else if (unlikely(data_len == -EINVAL)) {
970 * Sanity Check: even though data_len can't be used
971 * uninitialized at the time I write this comment, some
972 * compilers complain about this situation.
973 * In order to keep the code clean from warnings, data_len is
974 * being initialized to -EINVAL during its declaration, which
975 * means we can't rely on compiler anymore to warn no future
976 * changes won't result in data_len being used uninitialized.
977 * For such reason, we're adding this redundant sanity check
980 WARN(1, "%s: data_len == -EINVAL\n", __func__);
982 } else if (!io_data->aio) {
983 DECLARE_COMPLETION_ONSTACK(done);
984 bool interrupted = false;
988 req->length = data_len;
990 req->context = &done;
991 req->complete = ffs_epfile_io_complete;
993 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
994 if (unlikely(ret < 0))
997 spin_unlock_irq(&epfile->ffs->eps_lock);
999 if (unlikely(wait_for_completion_interruptible(&done))) {
1001 * To avoid race condition with ffs_epfile_io_complete,
1002 * dequeue the request first then check
1003 * status. usb_ep_dequeue API should guarantee no race
1004 * condition with req->complete callback.
1006 usb_ep_dequeue(ep->ep, req);
1007 interrupted = ep->status < 0;
1012 else if (io_data->read && ep->status > 0)
1013 ret = __ffs_epfile_read_data(epfile, data, ep->status,
1018 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_KERNEL))) {
1022 req->length = data_len;
1024 io_data->buf = data;
1025 io_data->ep = ep->ep;
1027 io_data->ffs = epfile->ffs;
1029 req->context = io_data;
1030 req->complete = ffs_epfile_async_io_complete;
1032 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1033 if (unlikely(ret)) {
1034 usb_ep_free_request(ep->ep, req);
1040 * Do not kfree the buffer in this function. It will be freed
1041 * by ffs_user_copy_worker.
1047 spin_unlock_irq(&epfile->ffs->eps_lock);
1049 mutex_unlock(&epfile->mutex);
1056 ffs_epfile_open(struct inode *inode, struct file *file)
1058 struct ffs_epfile *epfile = inode->i_private;
1062 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1065 file->private_data = epfile;
1066 ffs_data_opened(epfile->ffs);
1071 static int ffs_aio_cancel(struct kiocb *kiocb)
1073 struct ffs_io_data *io_data = kiocb->private;
1074 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
1079 spin_lock_irq(&epfile->ffs->eps_lock);
1081 if (likely(io_data && io_data->ep && io_data->req))
1082 value = usb_ep_dequeue(io_data->ep, io_data->req);
1086 spin_unlock_irq(&epfile->ffs->eps_lock);
1091 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
1093 struct ffs_io_data io_data, *p = &io_data;
1098 if (!is_sync_kiocb(kiocb)) {
1099 p = kmalloc(sizeof(io_data), GFP_KERNEL);
1110 p->mm = current->mm;
1115 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1117 res = ffs_epfile_io(kiocb->ki_filp, p);
1118 if (res == -EIOCBQUEUED)
1127 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
1129 struct ffs_io_data io_data, *p = &io_data;
1134 if (!is_sync_kiocb(kiocb)) {
1135 p = kmalloc(sizeof(io_data), GFP_KERNEL);
1146 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
1155 p->mm = current->mm;
1160 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1162 res = ffs_epfile_io(kiocb->ki_filp, p);
1163 if (res == -EIOCBQUEUED)
1176 ffs_epfile_release(struct inode *inode, struct file *file)
1178 struct ffs_epfile *epfile = inode->i_private;
1182 __ffs_epfile_read_buffer_free(epfile);
1183 ffs_data_closed(epfile->ffs);
1188 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1189 unsigned long value)
1191 struct ffs_epfile *epfile = file->private_data;
1196 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1199 spin_lock_irq(&epfile->ffs->eps_lock);
1200 if (likely(epfile->ep)) {
1202 case FUNCTIONFS_FIFO_STATUS:
1203 ret = usb_ep_fifo_status(epfile->ep->ep);
1205 case FUNCTIONFS_FIFO_FLUSH:
1206 usb_ep_fifo_flush(epfile->ep->ep);
1209 case FUNCTIONFS_CLEAR_HALT:
1210 ret = usb_ep_clear_halt(epfile->ep->ep);
1212 case FUNCTIONFS_ENDPOINT_REVMAP:
1213 ret = epfile->ep->num;
1215 case FUNCTIONFS_ENDPOINT_DESC:
1218 struct usb_endpoint_descriptor *desc;
1220 switch (epfile->ffs->gadget->speed) {
1221 case USB_SPEED_SUPER:
1224 case USB_SPEED_HIGH:
1230 desc = epfile->ep->descs[desc_idx];
1232 spin_unlock_irq(&epfile->ffs->eps_lock);
1233 ret = copy_to_user((void *)value, desc, sizeof(*desc));
1244 spin_unlock_irq(&epfile->ffs->eps_lock);
1249 static const struct file_operations ffs_epfile_operations = {
1250 .llseek = no_llseek,
1252 .open = ffs_epfile_open,
1253 .write_iter = ffs_epfile_write_iter,
1254 .read_iter = ffs_epfile_read_iter,
1255 .release = ffs_epfile_release,
1256 .unlocked_ioctl = ffs_epfile_ioctl,
1260 /* File system and super block operations ***********************************/
1263 * Mounting the file system creates a controller file, used first for
1264 * function configuration then later for event monitoring.
1267 static struct inode *__must_check
1268 ffs_sb_make_inode(struct super_block *sb, void *data,
1269 const struct file_operations *fops,
1270 const struct inode_operations *iops,
1271 struct ffs_file_perms *perms)
1273 struct inode *inode;
1277 inode = new_inode(sb);
1279 if (likely(inode)) {
1280 struct timespec ts = current_time(inode);
1282 inode->i_ino = get_next_ino();
1283 inode->i_mode = perms->mode;
1284 inode->i_uid = perms->uid;
1285 inode->i_gid = perms->gid;
1286 inode->i_atime = ts;
1287 inode->i_mtime = ts;
1288 inode->i_ctime = ts;
1289 inode->i_private = data;
1291 inode->i_fop = fops;
1299 /* Create "regular" file */
1300 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1301 const char *name, void *data,
1302 const struct file_operations *fops)
1304 struct ffs_data *ffs = sb->s_fs_info;
1305 struct dentry *dentry;
1306 struct inode *inode;
1310 dentry = d_alloc_name(sb->s_root, name);
1311 if (unlikely(!dentry))
1314 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1315 if (unlikely(!inode)) {
1320 d_add(dentry, inode);
1325 static const struct super_operations ffs_sb_operations = {
1326 .statfs = simple_statfs,
1327 .drop_inode = generic_delete_inode,
1330 struct ffs_sb_fill_data {
1331 struct ffs_file_perms perms;
1333 const char *dev_name;
1335 struct ffs_data *ffs_data;
1338 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1340 struct ffs_sb_fill_data *data = _data;
1341 struct inode *inode;
1342 struct ffs_data *ffs = data->ffs_data;
1347 data->ffs_data = NULL;
1348 sb->s_fs_info = ffs;
1349 sb->s_blocksize = PAGE_SIZE;
1350 sb->s_blocksize_bits = PAGE_SHIFT;
1351 sb->s_magic = FUNCTIONFS_MAGIC;
1352 sb->s_op = &ffs_sb_operations;
1353 sb->s_time_gran = 1;
1356 data->perms.mode = data->root_mode;
1357 inode = ffs_sb_make_inode(sb, NULL,
1358 &simple_dir_operations,
1359 &simple_dir_inode_operations,
1361 sb->s_root = d_make_root(inode);
1362 if (unlikely(!sb->s_root))
1366 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1367 &ffs_ep0_operations)))
1373 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1377 if (!opts || !*opts)
1381 unsigned long value;
1385 comma = strchr(opts, ',');
1390 eq = strchr(opts, '=');
1391 if (unlikely(!eq)) {
1392 pr_err("'=' missing in %s\n", opts);
1398 if (kstrtoul(eq + 1, 0, &value)) {
1399 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1403 /* Interpret option */
1404 switch (eq - opts) {
1406 if (!memcmp(opts, "no_disconnect", 13))
1407 data->no_disconnect = !!value;
1412 if (!memcmp(opts, "rmode", 5))
1413 data->root_mode = (value & 0555) | S_IFDIR;
1414 else if (!memcmp(opts, "fmode", 5))
1415 data->perms.mode = (value & 0666) | S_IFREG;
1421 if (!memcmp(opts, "mode", 4)) {
1422 data->root_mode = (value & 0555) | S_IFDIR;
1423 data->perms.mode = (value & 0666) | S_IFREG;
1430 if (!memcmp(opts, "uid", 3)) {
1431 data->perms.uid = make_kuid(current_user_ns(), value);
1432 if (!uid_valid(data->perms.uid)) {
1433 pr_err("%s: unmapped value: %lu\n", opts, value);
1436 } else if (!memcmp(opts, "gid", 3)) {
1437 data->perms.gid = make_kgid(current_user_ns(), value);
1438 if (!gid_valid(data->perms.gid)) {
1439 pr_err("%s: unmapped value: %lu\n", opts, value);
1449 pr_err("%s: invalid option\n", opts);
1453 /* Next iteration */
1462 /* "mount -t functionfs dev_name /dev/function" ends up here */
1464 static struct dentry *
1465 ffs_fs_mount(struct file_system_type *t, int flags,
1466 const char *dev_name, void *opts)
1468 struct ffs_sb_fill_data data = {
1470 .mode = S_IFREG | 0600,
1471 .uid = GLOBAL_ROOT_UID,
1472 .gid = GLOBAL_ROOT_GID,
1474 .root_mode = S_IFDIR | 0500,
1475 .no_disconnect = false,
1480 struct ffs_data *ffs;
1484 ret = ffs_fs_parse_opts(&data, opts);
1485 if (unlikely(ret < 0))
1486 return ERR_PTR(ret);
1488 ffs = ffs_data_new();
1490 return ERR_PTR(-ENOMEM);
1491 ffs->file_perms = data.perms;
1492 ffs->no_disconnect = data.no_disconnect;
1494 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1495 if (unlikely(!ffs->dev_name)) {
1497 return ERR_PTR(-ENOMEM);
1500 ffs_dev = ffs_acquire_dev(dev_name);
1501 if (IS_ERR(ffs_dev)) {
1503 return ERR_CAST(ffs_dev);
1505 ffs->private_data = ffs_dev;
1506 data.ffs_data = ffs;
1508 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1509 if (IS_ERR(rv) && data.ffs_data) {
1510 ffs_release_dev(data.ffs_data);
1511 ffs_data_put(data.ffs_data);
1517 ffs_fs_kill_sb(struct super_block *sb)
1521 kill_litter_super(sb);
1522 if (sb->s_fs_info) {
1523 ffs_release_dev(sb->s_fs_info);
1524 ffs_data_closed(sb->s_fs_info);
1525 ffs_data_put(sb->s_fs_info);
1529 static struct file_system_type ffs_fs_type = {
1530 .owner = THIS_MODULE,
1531 .name = "functionfs",
1532 .mount = ffs_fs_mount,
1533 .kill_sb = ffs_fs_kill_sb,
1535 MODULE_ALIAS_FS("functionfs");
1538 /* Driver's main init/cleanup functions *************************************/
1540 static int functionfs_init(void)
1546 ret = register_filesystem(&ffs_fs_type);
1548 pr_info("file system registered\n");
1550 pr_err("failed registering file system (%d)\n", ret);
1555 static void functionfs_cleanup(void)
1559 pr_info("unloading\n");
1560 unregister_filesystem(&ffs_fs_type);
1564 /* ffs_data and ffs_function construction and destruction code **************/
1566 static void ffs_data_clear(struct ffs_data *ffs);
1567 static void ffs_data_reset(struct ffs_data *ffs);
1569 static void ffs_data_get(struct ffs_data *ffs)
1573 atomic_inc(&ffs->ref);
1576 static void ffs_data_opened(struct ffs_data *ffs)
1580 atomic_inc(&ffs->ref);
1581 if (atomic_add_return(1, &ffs->opened) == 1 &&
1582 ffs->state == FFS_DEACTIVATED) {
1583 ffs->state = FFS_CLOSING;
1584 ffs_data_reset(ffs);
1588 static void ffs_data_put(struct ffs_data *ffs)
1592 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1593 pr_info("%s(): freeing\n", __func__);
1594 ffs_data_clear(ffs);
1595 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1596 waitqueue_active(&ffs->ep0req_completion.wait));
1597 kfree(ffs->dev_name);
1602 static void ffs_data_closed(struct ffs_data *ffs)
1606 if (atomic_dec_and_test(&ffs->opened)) {
1607 if (ffs->no_disconnect) {
1608 ffs->state = FFS_DEACTIVATED;
1610 ffs_epfiles_destroy(ffs->epfiles,
1612 ffs->epfiles = NULL;
1614 if (ffs->setup_state == FFS_SETUP_PENDING)
1615 __ffs_ep0_stall(ffs);
1617 ffs->state = FFS_CLOSING;
1618 ffs_data_reset(ffs);
1621 if (atomic_read(&ffs->opened) < 0) {
1622 ffs->state = FFS_CLOSING;
1623 ffs_data_reset(ffs);
1629 static struct ffs_data *ffs_data_new(void)
1631 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1637 atomic_set(&ffs->ref, 1);
1638 atomic_set(&ffs->opened, 0);
1639 ffs->state = FFS_READ_DESCRIPTORS;
1640 mutex_init(&ffs->mutex);
1641 spin_lock_init(&ffs->eps_lock);
1642 init_waitqueue_head(&ffs->ev.waitq);
1643 init_completion(&ffs->ep0req_completion);
1645 /* XXX REVISIT need to update it in some places, or do we? */
1646 ffs->ev.can_stall = 1;
1651 static void ffs_data_clear(struct ffs_data *ffs)
1657 BUG_ON(ffs->gadget);
1660 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1662 if (ffs->ffs_eventfd)
1663 eventfd_ctx_put(ffs->ffs_eventfd);
1665 kfree(ffs->raw_descs_data);
1666 kfree(ffs->raw_strings);
1667 kfree(ffs->stringtabs);
1670 static void ffs_data_reset(struct ffs_data *ffs)
1674 ffs_data_clear(ffs);
1676 ffs->epfiles = NULL;
1677 ffs->raw_descs_data = NULL;
1678 ffs->raw_descs = NULL;
1679 ffs->raw_strings = NULL;
1680 ffs->stringtabs = NULL;
1682 ffs->raw_descs_length = 0;
1683 ffs->fs_descs_count = 0;
1684 ffs->hs_descs_count = 0;
1685 ffs->ss_descs_count = 0;
1687 ffs->strings_count = 0;
1688 ffs->interfaces_count = 0;
1693 ffs->state = FFS_READ_DESCRIPTORS;
1694 ffs->setup_state = FFS_NO_SETUP;
1699 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1701 struct usb_gadget_strings **lang;
1706 if (WARN_ON(ffs->state != FFS_ACTIVE
1707 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1710 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1711 if (unlikely(first_id < 0))
1714 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1715 if (unlikely(!ffs->ep0req))
1717 ffs->ep0req->complete = ffs_ep0_complete;
1718 ffs->ep0req->context = ffs;
1720 lang = ffs->stringtabs;
1722 for (; *lang; ++lang) {
1723 struct usb_string *str = (*lang)->strings;
1725 for (; str->s; ++id, ++str)
1730 ffs->gadget = cdev->gadget;
1735 static void functionfs_unbind(struct ffs_data *ffs)
1739 if (!WARN_ON(!ffs->gadget)) {
1740 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1743 clear_bit(FFS_FL_BOUND, &ffs->flags);
1748 static int ffs_epfiles_create(struct ffs_data *ffs)
1750 struct ffs_epfile *epfile, *epfiles;
1755 count = ffs->eps_count;
1756 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1761 for (i = 1; i <= count; ++i, ++epfile) {
1763 mutex_init(&epfile->mutex);
1764 init_waitqueue_head(&epfile->wait);
1765 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1766 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1768 sprintf(epfile->name, "ep%u", i);
1769 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1771 &ffs_epfile_operations);
1772 if (unlikely(!epfile->dentry)) {
1773 ffs_epfiles_destroy(epfiles, i - 1);
1778 ffs->epfiles = epfiles;
1782 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1784 struct ffs_epfile *epfile = epfiles;
1788 for (; count; --count, ++epfile) {
1789 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1790 waitqueue_active(&epfile->wait));
1791 if (epfile->dentry) {
1792 d_delete(epfile->dentry);
1793 dput(epfile->dentry);
1794 epfile->dentry = NULL;
1801 static void ffs_func_eps_disable(struct ffs_function *func)
1803 struct ffs_ep *ep = func->eps;
1804 struct ffs_epfile *epfile = func->ffs->epfiles;
1805 unsigned count = func->ffs->eps_count;
1806 unsigned long flags;
1808 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1810 /* pending requests get nuked */
1812 usb_ep_disable(ep->ep);
1817 __ffs_epfile_read_buffer_free(epfile);
1821 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1824 static int ffs_func_eps_enable(struct ffs_function *func)
1826 struct ffs_data *ffs = func->ffs;
1827 struct ffs_ep *ep = func->eps;
1828 struct ffs_epfile *epfile = ffs->epfiles;
1829 unsigned count = ffs->eps_count;
1830 unsigned long flags;
1833 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1835 struct usb_endpoint_descriptor *ds;
1838 if (ffs->gadget->speed == USB_SPEED_SUPER)
1840 else if (ffs->gadget->speed == USB_SPEED_HIGH)
1845 /* fall-back to lower speed if desc missing for current speed */
1847 ds = ep->descs[desc_idx];
1848 } while (!ds && --desc_idx >= 0);
1855 ep->ep->driver_data = ep;
1857 ret = usb_ep_enable(ep->ep);
1860 epfile->in = usb_endpoint_dir_in(ds);
1861 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1866 wake_up(&epfile->wait);
1871 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1877 /* Parsing and building descriptors and strings *****************************/
1880 * This validates if data pointed by data is a valid USB descriptor as
1881 * well as record how many interfaces, endpoints and strings are
1882 * required by given configuration. Returns address after the
1883 * descriptor or NULL if data is invalid.
1886 enum ffs_entity_type {
1887 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1890 enum ffs_os_desc_type {
1891 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1894 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1896 struct usb_descriptor_header *desc,
1899 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1900 struct usb_os_desc_header *h, void *data,
1901 unsigned len, void *priv);
1903 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1904 ffs_entity_callback entity,
1907 struct usb_descriptor_header *_ds = (void *)data;
1913 /* At least two bytes are required: length and type */
1915 pr_vdebug("descriptor too short\n");
1919 /* If we have at least as many bytes as the descriptor takes? */
1920 length = _ds->bLength;
1922 pr_vdebug("descriptor longer then available data\n");
1926 #define __entity_check_INTERFACE(val) 1
1927 #define __entity_check_STRING(val) (val)
1928 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1929 #define __entity(type, val) do { \
1930 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1931 if (unlikely(!__entity_check_ ##type(val))) { \
1932 pr_vdebug("invalid entity's value\n"); \
1935 ret = entity(FFS_ ##type, &val, _ds, priv); \
1936 if (unlikely(ret < 0)) { \
1937 pr_debug("entity " #type "(%02x); ret = %d\n", \
1943 /* Parse descriptor depending on type. */
1944 switch (_ds->bDescriptorType) {
1948 case USB_DT_DEVICE_QUALIFIER:
1949 /* function can't have any of those */
1950 pr_vdebug("descriptor reserved for gadget: %d\n",
1951 _ds->bDescriptorType);
1954 case USB_DT_INTERFACE: {
1955 struct usb_interface_descriptor *ds = (void *)_ds;
1956 pr_vdebug("interface descriptor\n");
1957 if (length != sizeof *ds)
1960 __entity(INTERFACE, ds->bInterfaceNumber);
1962 __entity(STRING, ds->iInterface);
1966 case USB_DT_ENDPOINT: {
1967 struct usb_endpoint_descriptor *ds = (void *)_ds;
1968 pr_vdebug("endpoint descriptor\n");
1969 if (length != USB_DT_ENDPOINT_SIZE &&
1970 length != USB_DT_ENDPOINT_AUDIO_SIZE)
1972 __entity(ENDPOINT, ds->bEndpointAddress);
1977 pr_vdebug("hid descriptor\n");
1978 if (length != sizeof(struct hid_descriptor))
1983 if (length != sizeof(struct usb_otg_descriptor))
1987 case USB_DT_INTERFACE_ASSOCIATION: {
1988 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
1989 pr_vdebug("interface association descriptor\n");
1990 if (length != sizeof *ds)
1993 __entity(STRING, ds->iFunction);
1997 case USB_DT_SS_ENDPOINT_COMP:
1998 pr_vdebug("EP SS companion descriptor\n");
1999 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2003 case USB_DT_OTHER_SPEED_CONFIG:
2004 case USB_DT_INTERFACE_POWER:
2006 case USB_DT_SECURITY:
2007 case USB_DT_CS_RADIO_CONTROL:
2009 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2013 /* We should never be here */
2014 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2018 pr_vdebug("invalid length: %d (descriptor %d)\n",
2019 _ds->bLength, _ds->bDescriptorType);
2024 #undef __entity_check_DESCRIPTOR
2025 #undef __entity_check_INTERFACE
2026 #undef __entity_check_STRING
2027 #undef __entity_check_ENDPOINT
2032 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2033 ffs_entity_callback entity, void *priv)
2035 const unsigned _len = len;
2036 unsigned long num = 0;
2046 /* Record "descriptor" entity */
2047 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2048 if (unlikely(ret < 0)) {
2049 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2057 ret = ffs_do_single_desc(data, len, entity, priv);
2058 if (unlikely(ret < 0)) {
2059 pr_debug("%s returns %d\n", __func__, ret);
2069 static int __ffs_data_do_entity(enum ffs_entity_type type,
2070 u8 *valuep, struct usb_descriptor_header *desc,
2073 struct ffs_desc_helper *helper = priv;
2074 struct usb_endpoint_descriptor *d;
2079 case FFS_DESCRIPTOR:
2084 * Interfaces are indexed from zero so if we
2085 * encountered interface "n" then there are at least
2088 if (*valuep >= helper->interfaces_count)
2089 helper->interfaces_count = *valuep + 1;
2094 * Strings are indexed from 1 (0 is reserved
2095 * for languages list)
2097 if (*valuep > helper->ffs->strings_count)
2098 helper->ffs->strings_count = *valuep;
2103 helper->eps_count++;
2104 if (helper->eps_count >= 15)
2106 /* Check if descriptors for any speed were already parsed */
2107 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2108 helper->ffs->eps_addrmap[helper->eps_count] =
2109 d->bEndpointAddress;
2110 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2111 d->bEndpointAddress)
2119 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2120 struct usb_os_desc_header *desc)
2122 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2123 u16 w_index = le16_to_cpu(desc->wIndex);
2125 if (bcd_version != 1) {
2126 pr_vdebug("unsupported os descriptors version: %d",
2132 *next_type = FFS_OS_DESC_EXT_COMPAT;
2135 *next_type = FFS_OS_DESC_EXT_PROP;
2138 pr_vdebug("unsupported os descriptor type: %d", w_index);
2142 return sizeof(*desc);
2146 * Process all extended compatibility/extended property descriptors
2147 * of a feature descriptor
2149 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2150 enum ffs_os_desc_type type,
2152 ffs_os_desc_callback entity,
2154 struct usb_os_desc_header *h)
2157 const unsigned _len = len;
2161 /* loop over all ext compat/ext prop descriptors */
2162 while (feature_count--) {
2163 ret = entity(type, h, data, len, priv);
2164 if (unlikely(ret < 0)) {
2165 pr_debug("bad OS descriptor, type: %d\n", type);
2174 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2175 static int __must_check ffs_do_os_descs(unsigned count,
2176 char *data, unsigned len,
2177 ffs_os_desc_callback entity, void *priv)
2179 const unsigned _len = len;
2180 unsigned long num = 0;
2184 for (num = 0; num < count; ++num) {
2186 enum ffs_os_desc_type type;
2188 struct usb_os_desc_header *desc = (void *)data;
2190 if (len < sizeof(*desc))
2194 * Record "descriptor" entity.
2195 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2196 * Move the data pointer to the beginning of extended
2197 * compatibilities proper or extended properties proper
2198 * portions of the data
2200 if (le32_to_cpu(desc->dwLength) > len)
2203 ret = __ffs_do_os_desc_header(&type, desc);
2204 if (unlikely(ret < 0)) {
2205 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2210 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2212 feature_count = le16_to_cpu(desc->wCount);
2213 if (type == FFS_OS_DESC_EXT_COMPAT &&
2214 (feature_count > 255 || desc->Reserved))
2220 * Process all function/property descriptors
2221 * of this Feature Descriptor
2223 ret = ffs_do_single_os_desc(data, len, type,
2224 feature_count, entity, priv, desc);
2225 if (unlikely(ret < 0)) {
2226 pr_debug("%s returns %d\n", __func__, ret);
2237 * Validate contents of the buffer from userspace related to OS descriptors.
2239 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2240 struct usb_os_desc_header *h, void *data,
2241 unsigned len, void *priv)
2243 struct ffs_data *ffs = priv;
2249 case FFS_OS_DESC_EXT_COMPAT: {
2250 struct usb_ext_compat_desc *d = data;
2253 if (len < sizeof(*d) ||
2254 d->bFirstInterfaceNumber >= ffs->interfaces_count ||
2257 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2258 if (d->Reserved2[i])
2261 length = sizeof(struct usb_ext_compat_desc);
2264 case FFS_OS_DESC_EXT_PROP: {
2265 struct usb_ext_prop_desc *d = data;
2269 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2271 length = le32_to_cpu(d->dwSize);
2274 type = le32_to_cpu(d->dwPropertyDataType);
2275 if (type < USB_EXT_PROP_UNICODE ||
2276 type > USB_EXT_PROP_UNICODE_MULTI) {
2277 pr_vdebug("unsupported os descriptor property type: %d",
2281 pnl = le16_to_cpu(d->wPropertyNameLength);
2282 if (length < 14 + pnl) {
2283 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2287 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2288 if (length != 14 + pnl + pdl) {
2289 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2290 length, pnl, pdl, type);
2293 ++ffs->ms_os_descs_ext_prop_count;
2294 /* property name reported to the host as "WCHAR"s */
2295 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2296 ffs->ms_os_descs_ext_prop_data_len += pdl;
2300 pr_vdebug("unknown descriptor: %d\n", type);
2306 static int __ffs_data_got_descs(struct ffs_data *ffs,
2307 char *const _data, size_t len)
2309 char *data = _data, *raw_descs;
2310 unsigned os_descs_count = 0, counts[3], flags;
2311 int ret = -EINVAL, i;
2312 struct ffs_desc_helper helper;
2316 if (get_unaligned_le32(data + 4) != len)
2319 switch (get_unaligned_le32(data)) {
2320 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2321 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2325 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2326 flags = get_unaligned_le32(data + 8);
2327 ffs->user_flags = flags;
2328 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2329 FUNCTIONFS_HAS_HS_DESC |
2330 FUNCTIONFS_HAS_SS_DESC |
2331 FUNCTIONFS_HAS_MS_OS_DESC |
2332 FUNCTIONFS_VIRTUAL_ADDR |
2333 FUNCTIONFS_EVENTFD |
2334 FUNCTIONFS_ALL_CTRL_RECIP |
2335 FUNCTIONFS_CONFIG0_SETUP)) {
2346 if (flags & FUNCTIONFS_EVENTFD) {
2350 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2351 if (IS_ERR(ffs->ffs_eventfd)) {
2352 ret = PTR_ERR(ffs->ffs_eventfd);
2353 ffs->ffs_eventfd = NULL;
2360 /* Read fs_count, hs_count and ss_count (if present) */
2361 for (i = 0; i < 3; ++i) {
2362 if (!(flags & (1 << i))) {
2364 } else if (len < 4) {
2367 counts[i] = get_unaligned_le32(data);
2372 if (flags & (1 << i)) {
2376 os_descs_count = get_unaligned_le32(data);
2381 /* Read descriptors */
2384 for (i = 0; i < 3; ++i) {
2387 helper.interfaces_count = 0;
2388 helper.eps_count = 0;
2389 ret = ffs_do_descs(counts[i], data, len,
2390 __ffs_data_do_entity, &helper);
2393 if (!ffs->eps_count && !ffs->interfaces_count) {
2394 ffs->eps_count = helper.eps_count;
2395 ffs->interfaces_count = helper.interfaces_count;
2397 if (ffs->eps_count != helper.eps_count) {
2401 if (ffs->interfaces_count != helper.interfaces_count) {
2409 if (os_descs_count) {
2410 ret = ffs_do_os_descs(os_descs_count, data, len,
2411 __ffs_data_do_os_desc, ffs);
2418 if (raw_descs == data || len) {
2423 ffs->raw_descs_data = _data;
2424 ffs->raw_descs = raw_descs;
2425 ffs->raw_descs_length = data - raw_descs;
2426 ffs->fs_descs_count = counts[0];
2427 ffs->hs_descs_count = counts[1];
2428 ffs->ss_descs_count = counts[2];
2429 ffs->ms_os_descs_count = os_descs_count;
2438 static int __ffs_data_got_strings(struct ffs_data *ffs,
2439 char *const _data, size_t len)
2441 u32 str_count, needed_count, lang_count;
2442 struct usb_gadget_strings **stringtabs, *t;
2443 const char *data = _data;
2444 struct usb_string *s;
2448 if (unlikely(len < 16 ||
2449 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2450 get_unaligned_le32(data + 4) != len))
2452 str_count = get_unaligned_le32(data + 8);
2453 lang_count = get_unaligned_le32(data + 12);
2455 /* if one is zero the other must be zero */
2456 if (unlikely(!str_count != !lang_count))
2459 /* Do we have at least as many strings as descriptors need? */
2460 needed_count = ffs->strings_count;
2461 if (unlikely(str_count < needed_count))
2465 * If we don't need any strings just return and free all
2468 if (!needed_count) {
2473 /* Allocate everything in one chunk so there's less maintenance. */
2477 vla_item(d, struct usb_gadget_strings *, stringtabs,
2479 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2480 vla_item(d, struct usb_string, strings,
2481 lang_count*(needed_count+1));
2483 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2485 if (unlikely(!vlabuf)) {
2490 /* Initialize the VLA pointers */
2491 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2492 t = vla_ptr(vlabuf, d, stringtab);
2495 *stringtabs++ = t++;
2499 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2500 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2501 t = vla_ptr(vlabuf, d, stringtab);
2502 s = vla_ptr(vlabuf, d, strings);
2505 /* For each language */
2509 do { /* lang_count > 0 so we can use do-while */
2510 unsigned needed = needed_count;
2512 if (unlikely(len < 3))
2514 t->language = get_unaligned_le16(data);
2521 /* For each string */
2522 do { /* str_count > 0 so we can use do-while */
2523 size_t length = strnlen(data, len);
2525 if (unlikely(length == len))
2529 * User may provide more strings then we need,
2530 * if that's the case we simply ignore the
2533 if (likely(needed)) {
2535 * s->id will be set while adding
2536 * function to configuration so for
2537 * now just leave garbage here.
2546 } while (--str_count);
2548 s->id = 0; /* terminator */
2552 } while (--lang_count);
2554 /* Some garbage left? */
2559 ffs->stringtabs = stringtabs;
2560 ffs->raw_strings = _data;
2572 /* Events handling and management *******************************************/
2574 static void __ffs_event_add(struct ffs_data *ffs,
2575 enum usb_functionfs_event_type type)
2577 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2581 * Abort any unhandled setup
2583 * We do not need to worry about some cmpxchg() changing value
2584 * of ffs->setup_state without holding the lock because when
2585 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2586 * the source does nothing.
2588 if (ffs->setup_state == FFS_SETUP_PENDING)
2589 ffs->setup_state = FFS_SETUP_CANCELLED;
2592 * Logic of this function guarantees that there are at most four pending
2593 * evens on ffs->ev.types queue. This is important because the queue
2594 * has space for four elements only and __ffs_ep0_read_events function
2595 * depends on that limit as well. If more event types are added, those
2596 * limits have to be revisited or guaranteed to still hold.
2599 case FUNCTIONFS_RESUME:
2600 rem_type2 = FUNCTIONFS_SUSPEND;
2602 case FUNCTIONFS_SUSPEND:
2603 case FUNCTIONFS_SETUP:
2605 /* Discard all similar events */
2608 case FUNCTIONFS_BIND:
2609 case FUNCTIONFS_UNBIND:
2610 case FUNCTIONFS_DISABLE:
2611 case FUNCTIONFS_ENABLE:
2612 /* Discard everything other then power management. */
2613 rem_type1 = FUNCTIONFS_SUSPEND;
2614 rem_type2 = FUNCTIONFS_RESUME;
2619 WARN(1, "%d: unknown event, this should not happen\n", type);
2624 u8 *ev = ffs->ev.types, *out = ev;
2625 unsigned n = ffs->ev.count;
2626 for (; n; --n, ++ev)
2627 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2630 pr_vdebug("purging event %d\n", *ev);
2631 ffs->ev.count = out - ffs->ev.types;
2634 pr_vdebug("adding event %d\n", type);
2635 ffs->ev.types[ffs->ev.count++] = type;
2636 wake_up_locked(&ffs->ev.waitq);
2637 if (ffs->ffs_eventfd)
2638 eventfd_signal(ffs->ffs_eventfd, 1);
2641 static void ffs_event_add(struct ffs_data *ffs,
2642 enum usb_functionfs_event_type type)
2644 unsigned long flags;
2645 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2646 __ffs_event_add(ffs, type);
2647 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2650 /* Bind/unbind USB function hooks *******************************************/
2652 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2656 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2657 if (ffs->eps_addrmap[i] == endpoint_address)
2662 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2663 struct usb_descriptor_header *desc,
2666 struct usb_endpoint_descriptor *ds = (void *)desc;
2667 struct ffs_function *func = priv;
2668 struct ffs_ep *ffs_ep;
2669 unsigned ep_desc_id;
2671 static const char *speed_names[] = { "full", "high", "super" };
2673 if (type != FFS_DESCRIPTOR)
2677 * If ss_descriptors is not NULL, we are reading super speed
2678 * descriptors; if hs_descriptors is not NULL, we are reading high
2679 * speed descriptors; otherwise, we are reading full speed
2682 if (func->function.ss_descriptors) {
2684 func->function.ss_descriptors[(long)valuep] = desc;
2685 } else if (func->function.hs_descriptors) {
2687 func->function.hs_descriptors[(long)valuep] = desc;
2690 func->function.fs_descriptors[(long)valuep] = desc;
2693 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2696 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2700 ffs_ep = func->eps + idx;
2702 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2703 pr_err("two %sspeed descriptors for EP %d\n",
2704 speed_names[ep_desc_id],
2705 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2708 ffs_ep->descs[ep_desc_id] = ds;
2710 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2712 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2713 if (!ds->wMaxPacketSize)
2714 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2716 struct usb_request *req;
2718 u8 bEndpointAddress;
2721 * We back up bEndpointAddress because autoconfig overwrites
2722 * it with physical endpoint address.
2724 bEndpointAddress = ds->bEndpointAddress;
2725 pr_vdebug("autoconfig\n");
2726 ep = usb_ep_autoconfig(func->gadget, ds);
2729 ep->driver_data = func->eps + idx;
2731 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2737 func->eps_revmap[ds->bEndpointAddress &
2738 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2740 * If we use virtual address mapping, we restore
2741 * original bEndpointAddress value.
2743 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2744 ds->bEndpointAddress = bEndpointAddress;
2746 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2751 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2752 struct usb_descriptor_header *desc,
2755 struct ffs_function *func = priv;
2761 case FFS_DESCRIPTOR:
2762 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2767 if (func->interfaces_nums[idx] < 0) {
2768 int id = usb_interface_id(func->conf, &func->function);
2769 if (unlikely(id < 0))
2771 func->interfaces_nums[idx] = id;
2773 newValue = func->interfaces_nums[idx];
2777 /* String' IDs are allocated when fsf_data is bound to cdev */
2778 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2783 * USB_DT_ENDPOINT are handled in
2784 * __ffs_func_bind_do_descs().
2786 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2789 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2790 if (unlikely(!func->eps[idx].ep))
2794 struct usb_endpoint_descriptor **descs;
2795 descs = func->eps[idx].descs;
2796 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2801 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2806 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2807 struct usb_os_desc_header *h, void *data,
2808 unsigned len, void *priv)
2810 struct ffs_function *func = priv;
2814 case FFS_OS_DESC_EXT_COMPAT: {
2815 struct usb_ext_compat_desc *desc = data;
2816 struct usb_os_desc_table *t;
2818 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2819 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2820 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2821 ARRAY_SIZE(desc->CompatibleID) +
2822 ARRAY_SIZE(desc->SubCompatibleID));
2823 length = sizeof(*desc);
2826 case FFS_OS_DESC_EXT_PROP: {
2827 struct usb_ext_prop_desc *desc = data;
2828 struct usb_os_desc_table *t;
2829 struct usb_os_desc_ext_prop *ext_prop;
2830 char *ext_prop_name;
2831 char *ext_prop_data;
2833 t = &func->function.os_desc_table[h->interface];
2834 t->if_id = func->interfaces_nums[h->interface];
2836 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2837 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2839 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2840 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2841 ext_prop->data_len = le32_to_cpu(*(u32 *)
2842 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2843 length = ext_prop->name_len + ext_prop->data_len + 14;
2845 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2846 func->ffs->ms_os_descs_ext_prop_name_avail +=
2849 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2850 func->ffs->ms_os_descs_ext_prop_data_avail +=
2852 memcpy(ext_prop_data,
2853 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2854 ext_prop->data_len);
2855 /* unicode data reported to the host as "WCHAR"s */
2856 switch (ext_prop->type) {
2857 case USB_EXT_PROP_UNICODE:
2858 case USB_EXT_PROP_UNICODE_ENV:
2859 case USB_EXT_PROP_UNICODE_LINK:
2860 case USB_EXT_PROP_UNICODE_MULTI:
2861 ext_prop->data_len *= 2;
2864 ext_prop->data = ext_prop_data;
2866 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2867 ext_prop->name_len);
2868 /* property name reported to the host as "WCHAR"s */
2869 ext_prop->name_len *= 2;
2870 ext_prop->name = ext_prop_name;
2872 t->os_desc->ext_prop_len +=
2873 ext_prop->name_len + ext_prop->data_len + 14;
2874 ++t->os_desc->ext_prop_count;
2875 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2879 pr_vdebug("unknown descriptor: %d\n", type);
2885 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2886 struct usb_configuration *c)
2888 struct ffs_function *func = ffs_func_from_usb(f);
2889 struct f_fs_opts *ffs_opts =
2890 container_of(f->fi, struct f_fs_opts, func_inst);
2896 * Legacy gadget triggers binding in functionfs_ready_callback,
2897 * which already uses locking; taking the same lock here would
2900 * Configfs-enabled gadgets however do need ffs_dev_lock.
2902 if (!ffs_opts->no_configfs)
2904 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2905 func->ffs = ffs_opts->dev->ffs_data;
2906 if (!ffs_opts->no_configfs)
2909 return ERR_PTR(ret);
2912 func->gadget = c->cdev->gadget;
2915 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2916 * configurations are bound in sequence with list_for_each_entry,
2917 * in each configuration its functions are bound in sequence
2918 * with list_for_each_entry, so we assume no race condition
2919 * with regard to ffs_opts->bound access
2921 if (!ffs_opts->refcnt) {
2922 ret = functionfs_bind(func->ffs, c->cdev);
2924 return ERR_PTR(ret);
2927 func->function.strings = func->ffs->stringtabs;
2932 static int _ffs_func_bind(struct usb_configuration *c,
2933 struct usb_function *f)
2935 struct ffs_function *func = ffs_func_from_usb(f);
2936 struct ffs_data *ffs = func->ffs;
2938 const int full = !!func->ffs->fs_descs_count;
2939 const int high = gadget_is_dualspeed(func->gadget) &&
2940 func->ffs->hs_descs_count;
2941 const int super = gadget_is_superspeed(func->gadget) &&
2942 func->ffs->ss_descs_count;
2944 int fs_len, hs_len, ss_len, ret, i;
2945 struct ffs_ep *eps_ptr;
2947 /* Make it a single chunk, less management later on */
2949 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2950 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2951 full ? ffs->fs_descs_count + 1 : 0);
2952 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2953 high ? ffs->hs_descs_count + 1 : 0);
2954 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2955 super ? ffs->ss_descs_count + 1 : 0);
2956 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2957 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2958 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2959 vla_item_with_sz(d, char[16], ext_compat,
2960 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2961 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2962 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2963 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
2964 ffs->ms_os_descs_ext_prop_count);
2965 vla_item_with_sz(d, char, ext_prop_name,
2966 ffs->ms_os_descs_ext_prop_name_len);
2967 vla_item_with_sz(d, char, ext_prop_data,
2968 ffs->ms_os_descs_ext_prop_data_len);
2969 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
2974 /* Has descriptors only for speeds gadget does not support */
2975 if (unlikely(!(full | high | super)))
2978 /* Allocate a single chunk, less management later on */
2979 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
2980 if (unlikely(!vlabuf))
2983 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
2984 ffs->ms_os_descs_ext_prop_name_avail =
2985 vla_ptr(vlabuf, d, ext_prop_name);
2986 ffs->ms_os_descs_ext_prop_data_avail =
2987 vla_ptr(vlabuf, d, ext_prop_data);
2989 /* Copy descriptors */
2990 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
2991 ffs->raw_descs_length);
2993 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
2994 eps_ptr = vla_ptr(vlabuf, d, eps);
2995 for (i = 0; i < ffs->eps_count; i++)
2996 eps_ptr[i].num = -1;
2999 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3001 func->eps = vla_ptr(vlabuf, d, eps);
3002 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3005 * Go through all the endpoint descriptors and allocate
3006 * endpoints first, so that later we can rewrite the endpoint
3007 * numbers without worrying that it may be described later on.
3010 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3011 fs_len = ffs_do_descs(ffs->fs_descs_count,
3012 vla_ptr(vlabuf, d, raw_descs),
3014 __ffs_func_bind_do_descs, func);
3015 if (unlikely(fs_len < 0)) {
3024 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3025 hs_len = ffs_do_descs(ffs->hs_descs_count,
3026 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3027 d_raw_descs__sz - fs_len,
3028 __ffs_func_bind_do_descs, func);
3029 if (unlikely(hs_len < 0)) {
3037 if (likely(super)) {
3038 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
3039 ss_len = ffs_do_descs(ffs->ss_descs_count,
3040 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3041 d_raw_descs__sz - fs_len - hs_len,
3042 __ffs_func_bind_do_descs, func);
3043 if (unlikely(ss_len < 0)) {
3052 * Now handle interface numbers allocation and interface and
3053 * endpoint numbers rewriting. We can do that in one go
3056 ret = ffs_do_descs(ffs->fs_descs_count +
3057 (high ? ffs->hs_descs_count : 0) +
3058 (super ? ffs->ss_descs_count : 0),
3059 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3060 __ffs_func_bind_do_nums, func);
3061 if (unlikely(ret < 0))
3064 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3065 if (c->cdev->use_os_string) {
3066 for (i = 0; i < ffs->interfaces_count; ++i) {
3067 struct usb_os_desc *desc;
3069 desc = func->function.os_desc_table[i].os_desc =
3070 vla_ptr(vlabuf, d, os_desc) +
3071 i * sizeof(struct usb_os_desc);
3072 desc->ext_compat_id =
3073 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3074 INIT_LIST_HEAD(&desc->ext_prop);
3076 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3077 vla_ptr(vlabuf, d, raw_descs) +
3078 fs_len + hs_len + ss_len,
3079 d_raw_descs__sz - fs_len - hs_len -
3081 __ffs_func_bind_do_os_desc, func);
3082 if (unlikely(ret < 0))
3085 func->function.os_desc_n =
3086 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3088 /* And we're done */
3089 ffs_event_add(ffs, FUNCTIONFS_BIND);
3093 /* XXX Do we need to release all claimed endpoints here? */
3097 static int ffs_func_bind(struct usb_configuration *c,
3098 struct usb_function *f)
3100 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3101 struct ffs_function *func = ffs_func_from_usb(f);
3104 if (IS_ERR(ffs_opts))
3105 return PTR_ERR(ffs_opts);
3107 ret = _ffs_func_bind(c, f);
3108 if (ret && !--ffs_opts->refcnt)
3109 functionfs_unbind(func->ffs);
3115 /* Other USB function hooks *************************************************/
3117 static void ffs_reset_work(struct work_struct *work)
3119 struct ffs_data *ffs = container_of(work,
3120 struct ffs_data, reset_work);
3121 ffs_data_reset(ffs);
3124 static int ffs_func_set_alt(struct usb_function *f,
3125 unsigned interface, unsigned alt)
3127 struct ffs_function *func = ffs_func_from_usb(f);
3128 struct ffs_data *ffs = func->ffs;
3131 if (alt != (unsigned)-1) {
3132 intf = ffs_func_revmap_intf(func, interface);
3133 if (unlikely(intf < 0))
3138 ffs_func_eps_disable(ffs->func);
3140 if (ffs->state == FFS_DEACTIVATED) {
3141 ffs->state = FFS_CLOSING;
3142 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3143 schedule_work(&ffs->reset_work);
3147 if (ffs->state != FFS_ACTIVE)
3150 if (alt == (unsigned)-1) {
3152 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3157 ret = ffs_func_eps_enable(func);
3158 if (likely(ret >= 0))
3159 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3163 static void ffs_func_disable(struct usb_function *f)
3165 ffs_func_set_alt(f, 0, (unsigned)-1);
3168 static int ffs_func_setup(struct usb_function *f,
3169 const struct usb_ctrlrequest *creq)
3171 struct ffs_function *func = ffs_func_from_usb(f);
3172 struct ffs_data *ffs = func->ffs;
3173 unsigned long flags;
3178 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3179 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3180 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3181 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3182 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3185 * Most requests directed to interface go through here
3186 * (notable exceptions are set/get interface) so we need to
3187 * handle them. All other either handled by composite or
3188 * passed to usb_configuration->setup() (if one is set). No
3189 * matter, we will handle requests directed to endpoint here
3190 * as well (as it's straightforward). Other request recipient
3191 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3194 if (ffs->state != FFS_ACTIVE)
3197 switch (creq->bRequestType & USB_RECIP_MASK) {
3198 case USB_RECIP_INTERFACE:
3199 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3200 if (unlikely(ret < 0))
3204 case USB_RECIP_ENDPOINT:
3205 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3206 if (unlikely(ret < 0))
3208 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3209 ret = func->ffs->eps_addrmap[ret];
3213 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3214 ret = le16_to_cpu(creq->wIndex);
3219 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3220 ffs->ev.setup = *creq;
3221 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3222 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3223 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3228 static bool ffs_func_req_match(struct usb_function *f,
3229 const struct usb_ctrlrequest *creq,
3232 struct ffs_function *func = ffs_func_from_usb(f);
3234 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3237 switch (creq->bRequestType & USB_RECIP_MASK) {
3238 case USB_RECIP_INTERFACE:
3239 return (ffs_func_revmap_intf(func,
3240 le16_to_cpu(creq->wIndex)) >= 0);
3241 case USB_RECIP_ENDPOINT:
3242 return (ffs_func_revmap_ep(func,
3243 le16_to_cpu(creq->wIndex)) >= 0);
3245 return (bool) (func->ffs->user_flags &
3246 FUNCTIONFS_ALL_CTRL_RECIP);
3250 static void ffs_func_suspend(struct usb_function *f)
3253 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3256 static void ffs_func_resume(struct usb_function *f)
3259 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3263 /* Endpoint and interface numbers reverse mapping ***************************/
3265 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3267 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3268 return num ? num : -EDOM;
3271 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3273 short *nums = func->interfaces_nums;
3274 unsigned count = func->ffs->interfaces_count;
3276 for (; count; --count, ++nums) {
3277 if (*nums >= 0 && *nums == intf)
3278 return nums - func->interfaces_nums;
3285 /* Devices management *******************************************************/
3287 static LIST_HEAD(ffs_devices);
3289 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3291 struct ffs_dev *dev;
3293 list_for_each_entry(dev, &ffs_devices, entry) {
3294 if (!dev->name || !name)
3296 if (strcmp(dev->name, name) == 0)
3304 * ffs_lock must be taken by the caller of this function
3306 static struct ffs_dev *_ffs_get_single_dev(void)
3308 struct ffs_dev *dev;
3310 if (list_is_singular(&ffs_devices)) {
3311 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3320 * ffs_lock must be taken by the caller of this function
3322 static struct ffs_dev *_ffs_find_dev(const char *name)
3324 struct ffs_dev *dev;
3326 dev = _ffs_get_single_dev();
3330 return _ffs_do_find_dev(name);
3333 /* Configfs support *********************************************************/
3335 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3337 return container_of(to_config_group(item), struct f_fs_opts,
3341 static void ffs_attr_release(struct config_item *item)
3343 struct f_fs_opts *opts = to_ffs_opts(item);
3345 usb_put_function_instance(&opts->func_inst);
3348 static struct configfs_item_operations ffs_item_ops = {
3349 .release = ffs_attr_release,
3352 static struct config_item_type ffs_func_type = {
3353 .ct_item_ops = &ffs_item_ops,
3354 .ct_owner = THIS_MODULE,
3358 /* Function registration interface ******************************************/
3360 static void ffs_free_inst(struct usb_function_instance *f)
3362 struct f_fs_opts *opts;
3364 opts = to_f_fs_opts(f);
3366 _ffs_free_dev(opts->dev);
3371 #define MAX_INST_NAME_LEN 40
3373 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3375 struct f_fs_opts *opts;
3380 name_len = strlen(name) + 1;
3381 if (name_len > MAX_INST_NAME_LEN)
3382 return -ENAMETOOLONG;
3384 ptr = kstrndup(name, name_len, GFP_KERNEL);
3388 opts = to_f_fs_opts(fi);
3393 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3394 ret = _ffs_name_dev(opts->dev, ptr);
3400 opts->dev->name_allocated = true;
3409 static struct usb_function_instance *ffs_alloc_inst(void)
3411 struct f_fs_opts *opts;
3412 struct ffs_dev *dev;
3414 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3416 return ERR_PTR(-ENOMEM);
3418 opts->func_inst.set_inst_name = ffs_set_inst_name;
3419 opts->func_inst.free_func_inst = ffs_free_inst;
3421 dev = _ffs_alloc_dev();
3425 return ERR_CAST(dev);
3430 config_group_init_type_name(&opts->func_inst.group, "",
3432 return &opts->func_inst;
3435 static void ffs_free(struct usb_function *f)
3437 kfree(ffs_func_from_usb(f));
3440 static void ffs_func_unbind(struct usb_configuration *c,
3441 struct usb_function *f)
3443 struct ffs_function *func = ffs_func_from_usb(f);
3444 struct ffs_data *ffs = func->ffs;
3445 struct f_fs_opts *opts =
3446 container_of(f->fi, struct f_fs_opts, func_inst);
3447 struct ffs_ep *ep = func->eps;
3448 unsigned count = ffs->eps_count;
3449 unsigned long flags;
3452 if (ffs->func == func) {
3453 ffs_func_eps_disable(func);
3457 if (!--opts->refcnt)
3458 functionfs_unbind(ffs);
3460 /* cleanup after autoconfig */
3461 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3463 if (ep->ep && ep->req)
3464 usb_ep_free_request(ep->ep, ep->req);
3468 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3472 * eps, descriptors and interfaces_nums are allocated in the
3473 * same chunk so only one free is required.
3475 func->function.fs_descriptors = NULL;
3476 func->function.hs_descriptors = NULL;
3477 func->function.ss_descriptors = NULL;
3478 func->interfaces_nums = NULL;
3480 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3483 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3485 struct ffs_function *func;
3489 func = kzalloc(sizeof(*func), GFP_KERNEL);
3490 if (unlikely(!func))
3491 return ERR_PTR(-ENOMEM);
3493 func->function.name = "Function FS Gadget";
3495 func->function.bind = ffs_func_bind;
3496 func->function.unbind = ffs_func_unbind;
3497 func->function.set_alt = ffs_func_set_alt;
3498 func->function.disable = ffs_func_disable;
3499 func->function.setup = ffs_func_setup;
3500 func->function.req_match = ffs_func_req_match;
3501 func->function.suspend = ffs_func_suspend;
3502 func->function.resume = ffs_func_resume;
3503 func->function.free_func = ffs_free;
3505 return &func->function;
3509 * ffs_lock must be taken by the caller of this function
3511 static struct ffs_dev *_ffs_alloc_dev(void)
3513 struct ffs_dev *dev;
3516 if (_ffs_get_single_dev())
3517 return ERR_PTR(-EBUSY);
3519 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3521 return ERR_PTR(-ENOMEM);
3523 if (list_empty(&ffs_devices)) {
3524 ret = functionfs_init();
3527 return ERR_PTR(ret);
3531 list_add(&dev->entry, &ffs_devices);
3537 * ffs_lock must be taken by the caller of this function
3538 * The caller is responsible for "name" being available whenever f_fs needs it
3540 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3542 struct ffs_dev *existing;
3544 existing = _ffs_do_find_dev(name);
3554 * The caller is responsible for "name" being available whenever f_fs needs it
3556 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3561 ret = _ffs_name_dev(dev, name);
3566 EXPORT_SYMBOL_GPL(ffs_name_dev);
3568 int ffs_single_dev(struct ffs_dev *dev)
3575 if (!list_is_singular(&ffs_devices))
3583 EXPORT_SYMBOL_GPL(ffs_single_dev);
3586 * ffs_lock must be taken by the caller of this function
3588 static void _ffs_free_dev(struct ffs_dev *dev)
3590 list_del(&dev->entry);
3591 if (dev->name_allocated)
3594 /* Clear the private_data pointer to stop incorrect dev access */
3596 dev->ffs_data->private_data = NULL;
3599 if (list_empty(&ffs_devices))
3600 functionfs_cleanup();
3603 static void *ffs_acquire_dev(const char *dev_name)
3605 struct ffs_dev *ffs_dev;
3610 ffs_dev = _ffs_find_dev(dev_name);
3612 ffs_dev = ERR_PTR(-ENOENT);
3613 else if (ffs_dev->mounted)
3614 ffs_dev = ERR_PTR(-EBUSY);
3615 else if (ffs_dev->ffs_acquire_dev_callback &&
3616 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3617 ffs_dev = ERR_PTR(-ENOENT);
3619 ffs_dev->mounted = true;
3625 static void ffs_release_dev(struct ffs_data *ffs_data)
3627 struct ffs_dev *ffs_dev;
3632 ffs_dev = ffs_data->private_data;
3634 ffs_dev->mounted = false;
3636 if (ffs_dev->ffs_release_dev_callback)
3637 ffs_dev->ffs_release_dev_callback(ffs_dev);
3643 static int ffs_ready(struct ffs_data *ffs)
3645 struct ffs_dev *ffs_obj;
3651 ffs_obj = ffs->private_data;
3656 if (WARN_ON(ffs_obj->desc_ready)) {
3661 ffs_obj->desc_ready = true;
3662 ffs_obj->ffs_data = ffs;
3664 if (ffs_obj->ffs_ready_callback) {
3665 ret = ffs_obj->ffs_ready_callback(ffs);
3670 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3676 static void ffs_closed(struct ffs_data *ffs)
3678 struct ffs_dev *ffs_obj;
3679 struct f_fs_opts *opts;
3680 struct config_item *ci;
3685 ffs_obj = ffs->private_data;
3689 ffs_obj->desc_ready = false;
3691 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3692 ffs_obj->ffs_closed_callback)
3693 ffs_obj->ffs_closed_callback(ffs);
3696 opts = ffs_obj->opts;
3700 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3701 || !kref_read(&opts->func_inst.group.cg_item.ci_kref))
3704 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3707 unregister_gadget_item(ci);
3713 /* Misc helper functions ****************************************************/
3715 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3718 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3719 : mutex_lock_interruptible(mutex);
3722 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3729 data = kmalloc(len, GFP_KERNEL);
3730 if (unlikely(!data))
3731 return ERR_PTR(-ENOMEM);
3733 if (unlikely(copy_from_user(data, buf, len))) {
3735 return ERR_PTR(-EFAULT);
3738 pr_vdebug("Buffer from user space:\n");
3739 ffs_dump_mem("", data, len);
3744 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3745 MODULE_LICENSE("GPL");
3746 MODULE_AUTHOR("Michal Nazarewicz");