1 // SPDX-License-Identifier: GPL-2.0+
3 * f_fs.c -- user mode file system API for USB composite function controllers
5 * Copyright (C) 2010 Samsung Electronics
6 * Author: Michal Nazarewicz <mina86@mina86.com>
8 * Based on inode.c (GadgetFS) which was:
9 * Copyright (C) 2003-2004 David Brownell
10 * Copyright (C) 2003 Agilent Technologies
15 /* #define VERBOSE_DEBUG */
17 #include <linux/blkdev.h>
18 #include <linux/pagemap.h>
19 #include <linux/export.h>
20 #include <linux/hid.h>
21 #include <linux/module.h>
22 #include <linux/sched/signal.h>
23 #include <linux/uio.h>
24 #include <asm/unaligned.h>
26 #include <linux/usb/composite.h>
27 #include <linux/usb/functionfs.h>
29 #include <linux/aio.h>
30 #include <linux/mmu_context.h>
31 #include <linux/poll.h>
32 #include <linux/eventfd.h>
36 #include "u_os_desc.h"
39 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
41 /* Reference counter handling */
42 static void ffs_data_get(struct ffs_data *ffs);
43 static void ffs_data_put(struct ffs_data *ffs);
44 /* Creates new ffs_data object. */
45 static struct ffs_data *__must_check ffs_data_new(const char *dev_name)
46 __attribute__((malloc));
48 /* Opened counter handling. */
49 static void ffs_data_opened(struct ffs_data *ffs);
50 static void ffs_data_closed(struct ffs_data *ffs);
52 /* Called with ffs->mutex held; take over ownership of data. */
53 static int __must_check
54 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
55 static int __must_check
56 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
59 /* The function structure ***************************************************/
64 struct usb_configuration *conf;
65 struct usb_gadget *gadget;
70 short *interfaces_nums;
72 struct usb_function function;
76 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
78 return container_of(f, struct ffs_function, function);
82 static inline enum ffs_setup_state
83 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
85 return (enum ffs_setup_state)
86 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
90 static void ffs_func_eps_disable(struct ffs_function *func);
91 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
93 static int ffs_func_bind(struct usb_configuration *,
94 struct usb_function *);
95 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
96 static void ffs_func_disable(struct usb_function *);
97 static int ffs_func_setup(struct usb_function *,
98 const struct usb_ctrlrequest *);
99 static bool ffs_func_req_match(struct usb_function *,
100 const struct usb_ctrlrequest *,
102 static void ffs_func_suspend(struct usb_function *);
103 static void ffs_func_resume(struct usb_function *);
106 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
107 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
110 /* The endpoints structures *************************************************/
113 struct usb_ep *ep; /* P: ffs->eps_lock */
114 struct usb_request *req; /* P: epfile->mutex */
116 /* [0]: full speed, [1]: high speed, [2]: super speed */
117 struct usb_endpoint_descriptor *descs[3];
121 int status; /* P: epfile->mutex */
125 /* Protects ep->ep and ep->req. */
128 struct ffs_data *ffs;
129 struct ffs_ep *ep; /* P: ffs->eps_lock */
131 struct dentry *dentry;
134 * Buffer for holding data from partial reads which may happen since
135 * we’re rounding user read requests to a multiple of a max packet size.
137 * The pointer is initialised with NULL value and may be set by
138 * __ffs_epfile_read_data function to point to a temporary buffer.
140 * In normal operation, calls to __ffs_epfile_read_buffered will consume
141 * data from said buffer and eventually free it. Importantly, while the
142 * function is using the buffer, it sets the pointer to NULL. This is
143 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
144 * can never run concurrently (they are synchronised by epfile->mutex)
145 * so the latter will not assign a new value to the pointer.
147 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
148 * valid) and sets the pointer to READ_BUFFER_DROP value. This special
149 * value is crux of the synchronisation between ffs_func_eps_disable and
150 * __ffs_epfile_read_data.
152 * Once __ffs_epfile_read_data is about to finish it will try to set the
153 * pointer back to its old value (as described above), but seeing as the
154 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
157 * == State transitions ==
159 * • ptr == NULL: (initial state)
160 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
161 * ◦ __ffs_epfile_read_buffered: nop
162 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
163 * ◦ reading finishes: n/a, not in ‘and reading’ state
165 * ◦ __ffs_epfile_read_buffer_free: nop
166 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL
167 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
168 * ◦ reading finishes: n/a, not in ‘and reading’ state
170 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
171 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
172 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
173 * is always called first
174 * ◦ reading finishes: n/a, not in ‘and reading’ state
175 * • ptr == NULL and reading:
176 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
177 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
178 * ◦ __ffs_epfile_read_data: n/a, mutex is held
179 * ◦ reading finishes and …
180 * … all data read: free buf, go to ptr == NULL
181 * … otherwise: go to ptr == buf and reading
182 * • ptr == DROP and reading:
183 * ◦ __ffs_epfile_read_buffer_free: nop
184 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
185 * ◦ __ffs_epfile_read_data: n/a, mutex is held
186 * ◦ reading finishes: free buf, go to ptr == DROP
188 struct ffs_buffer *read_buffer;
189 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
193 unsigned char in; /* P: ffs->eps_lock */
194 unsigned char isoc; /* P: ffs->eps_lock */
205 /* ffs_io_data structure ***************************************************/
212 struct iov_iter data;
216 struct mm_struct *mm;
217 struct work_struct work;
220 struct usb_request *req;
222 struct ffs_data *ffs;
225 struct ffs_desc_helper {
226 struct ffs_data *ffs;
227 unsigned interfaces_count;
231 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
232 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
234 static struct dentry *
235 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
236 const struct file_operations *fops);
238 /* Devices management *******************************************************/
240 DEFINE_MUTEX(ffs_lock);
241 EXPORT_SYMBOL_GPL(ffs_lock);
243 static struct ffs_dev *_ffs_find_dev(const char *name);
244 static struct ffs_dev *_ffs_alloc_dev(void);
245 static void _ffs_free_dev(struct ffs_dev *dev);
246 static void *ffs_acquire_dev(const char *dev_name);
247 static void ffs_release_dev(struct ffs_data *ffs_data);
248 static int ffs_ready(struct ffs_data *ffs);
249 static void ffs_closed(struct ffs_data *ffs);
251 /* Misc helper functions ****************************************************/
253 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
254 __attribute__((warn_unused_result, nonnull));
255 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
256 __attribute__((warn_unused_result, nonnull));
259 /* Control file aka ep0 *****************************************************/
261 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
263 struct ffs_data *ffs = req->context;
265 complete(&ffs->ep0req_completion);
268 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
270 struct usb_request *req = ffs->ep0req;
273 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
275 spin_unlock_irq(&ffs->ev.waitq.lock);
281 * UDC layer requires to provide a buffer even for ZLP, but should
282 * not use it at all. Let's provide some poisoned pointer to catch
283 * possible bug in the driver.
285 if (req->buf == NULL)
286 req->buf = (void *)0xDEADBABE;
288 reinit_completion(&ffs->ep0req_completion);
290 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
291 if (unlikely(ret < 0))
294 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
296 usb_ep_dequeue(ffs->gadget->ep0, req);
300 ffs->setup_state = FFS_NO_SETUP;
301 return req->status ? req->status : req->actual;
304 static int __ffs_ep0_stall(struct ffs_data *ffs)
306 if (ffs->ev.can_stall) {
307 pr_vdebug("ep0 stall\n");
308 usb_ep_set_halt(ffs->gadget->ep0);
309 ffs->setup_state = FFS_NO_SETUP;
312 pr_debug("bogus ep0 stall!\n");
317 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
318 size_t len, loff_t *ptr)
320 struct ffs_data *ffs = file->private_data;
326 /* Fast check if setup was canceled */
327 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
331 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
332 if (unlikely(ret < 0))
336 switch (ffs->state) {
337 case FFS_READ_DESCRIPTORS:
338 case FFS_READ_STRINGS:
340 if (unlikely(len < 16)) {
345 data = ffs_prepare_buffer(buf, len);
352 if (ffs->state == FFS_READ_DESCRIPTORS) {
353 pr_info("read descriptors\n");
354 ret = __ffs_data_got_descs(ffs, data, len);
355 if (unlikely(ret < 0))
358 ffs->state = FFS_READ_STRINGS;
361 pr_info("read strings\n");
362 ret = __ffs_data_got_strings(ffs, data, len);
363 if (unlikely(ret < 0))
366 ret = ffs_epfiles_create(ffs);
368 ffs->state = FFS_CLOSING;
372 ffs->state = FFS_ACTIVE;
373 mutex_unlock(&ffs->mutex);
375 ret = ffs_ready(ffs);
376 if (unlikely(ret < 0)) {
377 ffs->state = FFS_CLOSING;
388 * We're called from user space, we can use _irq
389 * rather then _irqsave
391 spin_lock_irq(&ffs->ev.waitq.lock);
392 switch (ffs_setup_state_clear_cancelled(ffs)) {
393 case FFS_SETUP_CANCELLED:
401 case FFS_SETUP_PENDING:
405 /* FFS_SETUP_PENDING */
406 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
407 spin_unlock_irq(&ffs->ev.waitq.lock);
408 ret = __ffs_ep0_stall(ffs);
412 /* FFS_SETUP_PENDING and not stall */
413 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
415 spin_unlock_irq(&ffs->ev.waitq.lock);
417 data = ffs_prepare_buffer(buf, len);
423 spin_lock_irq(&ffs->ev.waitq.lock);
426 * We are guaranteed to be still in FFS_ACTIVE state
427 * but the state of setup could have changed from
428 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
429 * to check for that. If that happened we copied data
430 * from user space in vain but it's unlikely.
432 * For sure we are not in FFS_NO_SETUP since this is
433 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
434 * transition can be performed and it's protected by
437 if (ffs_setup_state_clear_cancelled(ffs) ==
438 FFS_SETUP_CANCELLED) {
441 spin_unlock_irq(&ffs->ev.waitq.lock);
443 /* unlocks spinlock */
444 ret = __ffs_ep0_queue_wait(ffs, data, len);
454 mutex_unlock(&ffs->mutex);
458 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
459 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
463 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
464 * size of ffs->ev.types array (which is four) so that's how much space
467 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
468 const size_t size = n * sizeof *events;
471 memset(events, 0, size);
474 events[i].type = ffs->ev.types[i];
475 if (events[i].type == FUNCTIONFS_SETUP) {
476 events[i].u.setup = ffs->ev.setup;
477 ffs->setup_state = FFS_SETUP_PENDING;
483 memmove(ffs->ev.types, ffs->ev.types + n,
484 ffs->ev.count * sizeof *ffs->ev.types);
486 spin_unlock_irq(&ffs->ev.waitq.lock);
487 mutex_unlock(&ffs->mutex);
489 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
492 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
493 size_t len, loff_t *ptr)
495 struct ffs_data *ffs = file->private_data;
502 /* Fast check if setup was canceled */
503 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
507 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
508 if (unlikely(ret < 0))
512 if (ffs->state != FFS_ACTIVE) {
518 * We're called from user space, we can use _irq rather then
521 spin_lock_irq(&ffs->ev.waitq.lock);
523 switch (ffs_setup_state_clear_cancelled(ffs)) {
524 case FFS_SETUP_CANCELLED:
529 n = len / sizeof(struct usb_functionfs_event);
535 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
540 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
546 return __ffs_ep0_read_events(ffs, buf,
547 min(n, (size_t)ffs->ev.count));
549 case FFS_SETUP_PENDING:
550 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
551 spin_unlock_irq(&ffs->ev.waitq.lock);
552 ret = __ffs_ep0_stall(ffs);
556 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
558 spin_unlock_irq(&ffs->ev.waitq.lock);
561 data = kmalloc(len, GFP_KERNEL);
562 if (unlikely(!data)) {
568 spin_lock_irq(&ffs->ev.waitq.lock);
570 /* See ffs_ep0_write() */
571 if (ffs_setup_state_clear_cancelled(ffs) ==
572 FFS_SETUP_CANCELLED) {
577 /* unlocks spinlock */
578 ret = __ffs_ep0_queue_wait(ffs, data, len);
579 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
588 spin_unlock_irq(&ffs->ev.waitq.lock);
590 mutex_unlock(&ffs->mutex);
595 static int ffs_ep0_open(struct inode *inode, struct file *file)
597 struct ffs_data *ffs = inode->i_private;
601 if (unlikely(ffs->state == FFS_CLOSING))
604 file->private_data = ffs;
605 ffs_data_opened(ffs);
610 static int ffs_ep0_release(struct inode *inode, struct file *file)
612 struct ffs_data *ffs = file->private_data;
616 ffs_data_closed(ffs);
621 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
623 struct ffs_data *ffs = file->private_data;
624 struct usb_gadget *gadget = ffs->gadget;
629 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
630 struct ffs_function *func = ffs->func;
631 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
632 } else if (gadget && gadget->ops->ioctl) {
633 ret = gadget->ops->ioctl(gadget, code, value);
641 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
643 struct ffs_data *ffs = file->private_data;
644 unsigned int mask = POLLWRNORM;
647 poll_wait(file, &ffs->ev.waitq, wait);
649 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
650 if (unlikely(ret < 0))
653 switch (ffs->state) {
654 case FFS_READ_DESCRIPTORS:
655 case FFS_READ_STRINGS:
660 switch (ffs->setup_state) {
666 case FFS_SETUP_PENDING:
667 case FFS_SETUP_CANCELLED:
668 mask |= (POLLIN | POLLOUT);
673 case FFS_DEACTIVATED:
677 mutex_unlock(&ffs->mutex);
682 static const struct file_operations ffs_ep0_operations = {
685 .open = ffs_ep0_open,
686 .write = ffs_ep0_write,
687 .read = ffs_ep0_read,
688 .release = ffs_ep0_release,
689 .unlocked_ioctl = ffs_ep0_ioctl,
690 .poll = ffs_ep0_poll,
694 /* "Normal" endpoints operations ********************************************/
696 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
699 if (likely(req->context)) {
700 struct ffs_ep *ep = _ep->driver_data;
701 ep->status = req->status ? req->status : req->actual;
702 complete(req->context);
706 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
708 ssize_t ret = copy_to_iter(data, data_len, iter);
709 if (likely(ret == data_len))
712 if (unlikely(iov_iter_count(iter)))
716 * Dear user space developer!
718 * TL;DR: To stop getting below error message in your kernel log, change
719 * user space code using functionfs to align read buffers to a max
722 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
723 * packet size. When unaligned buffer is passed to functionfs, it
724 * internally uses a larger, aligned buffer so that such UDCs are happy.
726 * Unfortunately, this means that host may send more data than was
727 * requested in read(2) system call. f_fs doesn’t know what to do with
728 * that excess data so it simply drops it.
730 * Was the buffer aligned in the first place, no such problem would
733 * Data may be dropped only in AIO reads. Synchronous reads are handled
734 * by splitting a request into multiple parts. This splitting may still
735 * be a problem though so it’s likely best to align the buffer
736 * regardless of it being AIO or not..
738 * This only affects OUT endpoints, i.e. reading data with a read(2),
739 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not
742 pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
743 "Align read buffer size to max packet size to avoid the problem.\n",
749 static void ffs_user_copy_worker(struct work_struct *work)
751 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
753 int ret = io_data->req->status ? io_data->req->status :
754 io_data->req->actual;
755 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
757 if (io_data->read && ret > 0) {
759 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
760 unuse_mm(io_data->mm);
763 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
765 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
766 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
768 usb_ep_free_request(io_data->ep, io_data->req);
771 kfree(io_data->to_free);
776 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
777 struct usb_request *req)
779 struct ffs_io_data *io_data = req->context;
780 struct ffs_data *ffs = io_data->ffs;
784 INIT_WORK(&io_data->work, ffs_user_copy_worker);
785 queue_work(ffs->io_completion_wq, &io_data->work);
788 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
791 * See comment in struct ffs_epfile for full read_buffer pointer
792 * synchronisation story.
794 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
795 if (buf && buf != READ_BUFFER_DROP)
799 /* Assumes epfile->mutex is held. */
800 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
801 struct iov_iter *iter)
804 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
805 * the buffer while we are using it. See comment in struct ffs_epfile
806 * for full read_buffer pointer synchronisation story.
808 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
810 if (!buf || buf == READ_BUFFER_DROP)
813 ret = copy_to_iter(buf->data, buf->length, iter);
814 if (buf->length == ret) {
819 if (unlikely(iov_iter_count(iter))) {
826 if (cmpxchg(&epfile->read_buffer, NULL, buf))
832 /* Assumes epfile->mutex is held. */
833 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
834 void *data, int data_len,
835 struct iov_iter *iter)
837 struct ffs_buffer *buf;
839 ssize_t ret = copy_to_iter(data, data_len, iter);
840 if (likely(data_len == ret))
843 if (unlikely(iov_iter_count(iter)))
846 /* See ffs_copy_to_iter for more context. */
847 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
851 buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL);
854 buf->length = data_len;
855 buf->data = buf->storage;
856 memcpy(buf->storage, data + ret, data_len);
859 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
860 * ffs_func_eps_disable has been called in the meanwhile). See comment
861 * in struct ffs_epfile for full read_buffer pointer synchronisation
864 if (unlikely(cmpxchg(&epfile->read_buffer, NULL, buf)))
870 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
872 struct ffs_epfile *epfile = file->private_data;
873 struct usb_request *req;
876 ssize_t ret, data_len = -EINVAL;
879 /* Are we still active? */
880 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
883 /* Wait for endpoint to be enabled */
886 if (file->f_flags & O_NONBLOCK)
889 ret = wait_event_interruptible(
890 epfile->ffs->wait, (ep = epfile->ep));
896 halt = (!io_data->read == !epfile->in);
897 if (halt && epfile->isoc)
900 /* We will be using request and read_buffer */
901 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
905 /* Allocate & copy */
907 struct usb_gadget *gadget;
910 * Do we have buffered data from previous partial read? Check
911 * that for synchronous case only because we do not have
912 * facility to ‘wake up’ a pending asynchronous read and push
913 * buffered data to it which we would need to make things behave
916 if (!io_data->aio && io_data->read) {
917 ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
923 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
924 * before the waiting completes, so do not assign to 'gadget'
927 gadget = epfile->ffs->gadget;
929 spin_lock_irq(&epfile->ffs->eps_lock);
930 /* In the meantime, endpoint got disabled or changed. */
931 if (epfile->ep != ep) {
935 data_len = iov_iter_count(&io_data->data);
937 * Controller may require buffer size to be aligned to
938 * maxpacketsize of an out endpoint.
941 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
942 spin_unlock_irq(&epfile->ffs->eps_lock);
944 data = kmalloc(data_len, GFP_KERNEL);
945 if (unlikely(!data)) {
949 if (!io_data->read &&
950 !copy_from_iter_full(data, data_len, &io_data->data)) {
956 spin_lock_irq(&epfile->ffs->eps_lock);
958 if (epfile->ep != ep) {
959 /* In the meantime, endpoint got disabled or changed. */
962 ret = usb_ep_set_halt(ep->ep);
965 } else if (unlikely(data_len == -EINVAL)) {
967 * Sanity Check: even though data_len can't be used
968 * uninitialized at the time I write this comment, some
969 * compilers complain about this situation.
970 * In order to keep the code clean from warnings, data_len is
971 * being initialized to -EINVAL during its declaration, which
972 * means we can't rely on compiler anymore to warn no future
973 * changes won't result in data_len being used uninitialized.
974 * For such reason, we're adding this redundant sanity check
977 WARN(1, "%s: data_len == -EINVAL\n", __func__);
979 } else if (!io_data->aio) {
980 DECLARE_COMPLETION_ONSTACK(done);
981 bool interrupted = false;
985 req->length = data_len;
987 req->context = &done;
988 req->complete = ffs_epfile_io_complete;
990 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
991 if (unlikely(ret < 0))
994 spin_unlock_irq(&epfile->ffs->eps_lock);
996 if (unlikely(wait_for_completion_interruptible(&done))) {
998 * To avoid race condition with ffs_epfile_io_complete,
999 * dequeue the request first then check
1000 * status. usb_ep_dequeue API should guarantee no race
1001 * condition with req->complete callback.
1003 usb_ep_dequeue(ep->ep, req);
1004 interrupted = ep->status < 0;
1009 else if (io_data->read && ep->status > 0)
1010 ret = __ffs_epfile_read_data(epfile, data, ep->status,
1015 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) {
1019 req->length = data_len;
1021 io_data->buf = data;
1022 io_data->ep = ep->ep;
1024 io_data->ffs = epfile->ffs;
1026 req->context = io_data;
1027 req->complete = ffs_epfile_async_io_complete;
1029 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1030 if (unlikely(ret)) {
1031 usb_ep_free_request(ep->ep, req);
1037 * Do not kfree the buffer in this function. It will be freed
1038 * by ffs_user_copy_worker.
1044 spin_unlock_irq(&epfile->ffs->eps_lock);
1046 mutex_unlock(&epfile->mutex);
1053 ffs_epfile_open(struct inode *inode, struct file *file)
1055 struct ffs_epfile *epfile = inode->i_private;
1059 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1062 file->private_data = epfile;
1063 ffs_data_opened(epfile->ffs);
1068 static int ffs_aio_cancel(struct kiocb *kiocb)
1070 struct ffs_io_data *io_data = kiocb->private;
1071 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
1076 spin_lock_irq(&epfile->ffs->eps_lock);
1078 if (likely(io_data && io_data->ep && io_data->req))
1079 value = usb_ep_dequeue(io_data->ep, io_data->req);
1083 spin_unlock_irq(&epfile->ffs->eps_lock);
1088 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
1090 struct ffs_io_data io_data, *p = &io_data;
1095 if (!is_sync_kiocb(kiocb)) {
1096 p = kmalloc(sizeof(io_data), GFP_KERNEL);
1107 p->mm = current->mm;
1112 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1114 res = ffs_epfile_io(kiocb->ki_filp, p);
1115 if (res == -EIOCBQUEUED)
1124 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
1126 struct ffs_io_data io_data, *p = &io_data;
1131 if (!is_sync_kiocb(kiocb)) {
1132 p = kmalloc(sizeof(io_data), GFP_KERNEL);
1143 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
1152 p->mm = current->mm;
1157 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1159 res = ffs_epfile_io(kiocb->ki_filp, p);
1160 if (res == -EIOCBQUEUED)
1173 ffs_epfile_release(struct inode *inode, struct file *file)
1175 struct ffs_epfile *epfile = inode->i_private;
1179 __ffs_epfile_read_buffer_free(epfile);
1180 ffs_data_closed(epfile->ffs);
1185 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1186 unsigned long value)
1188 struct ffs_epfile *epfile = file->private_data;
1194 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1197 /* Wait for endpoint to be enabled */
1200 if (file->f_flags & O_NONBLOCK)
1203 ret = wait_event_interruptible(
1204 epfile->ffs->wait, (ep = epfile->ep));
1209 spin_lock_irq(&epfile->ffs->eps_lock);
1211 /* In the meantime, endpoint got disabled or changed. */
1212 if (epfile->ep != ep) {
1213 spin_unlock_irq(&epfile->ffs->eps_lock);
1218 case FUNCTIONFS_FIFO_STATUS:
1219 ret = usb_ep_fifo_status(epfile->ep->ep);
1221 case FUNCTIONFS_FIFO_FLUSH:
1222 usb_ep_fifo_flush(epfile->ep->ep);
1225 case FUNCTIONFS_CLEAR_HALT:
1226 ret = usb_ep_clear_halt(epfile->ep->ep);
1228 case FUNCTIONFS_ENDPOINT_REVMAP:
1229 ret = epfile->ep->num;
1231 case FUNCTIONFS_ENDPOINT_DESC:
1234 struct usb_endpoint_descriptor *desc;
1236 switch (epfile->ffs->gadget->speed) {
1237 case USB_SPEED_SUPER:
1240 case USB_SPEED_HIGH:
1246 desc = epfile->ep->descs[desc_idx];
1248 spin_unlock_irq(&epfile->ffs->eps_lock);
1249 ret = copy_to_user((void *)value, desc, desc->bLength);
1257 spin_unlock_irq(&epfile->ffs->eps_lock);
1262 static const struct file_operations ffs_epfile_operations = {
1263 .llseek = no_llseek,
1265 .open = ffs_epfile_open,
1266 .write_iter = ffs_epfile_write_iter,
1267 .read_iter = ffs_epfile_read_iter,
1268 .release = ffs_epfile_release,
1269 .unlocked_ioctl = ffs_epfile_ioctl,
1273 /* File system and super block operations ***********************************/
1276 * Mounting the file system creates a controller file, used first for
1277 * function configuration then later for event monitoring.
1280 static struct inode *__must_check
1281 ffs_sb_make_inode(struct super_block *sb, void *data,
1282 const struct file_operations *fops,
1283 const struct inode_operations *iops,
1284 struct ffs_file_perms *perms)
1286 struct inode *inode;
1290 inode = new_inode(sb);
1292 if (likely(inode)) {
1293 struct timespec ts = current_time(inode);
1295 inode->i_ino = get_next_ino();
1296 inode->i_mode = perms->mode;
1297 inode->i_uid = perms->uid;
1298 inode->i_gid = perms->gid;
1299 inode->i_atime = ts;
1300 inode->i_mtime = ts;
1301 inode->i_ctime = ts;
1302 inode->i_private = data;
1304 inode->i_fop = fops;
1312 /* Create "regular" file */
1313 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1314 const char *name, void *data,
1315 const struct file_operations *fops)
1317 struct ffs_data *ffs = sb->s_fs_info;
1318 struct dentry *dentry;
1319 struct inode *inode;
1323 dentry = d_alloc_name(sb->s_root, name);
1324 if (unlikely(!dentry))
1327 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1328 if (unlikely(!inode)) {
1333 d_add(dentry, inode);
1338 static const struct super_operations ffs_sb_operations = {
1339 .statfs = simple_statfs,
1340 .drop_inode = generic_delete_inode,
1343 struct ffs_sb_fill_data {
1344 struct ffs_file_perms perms;
1346 const char *dev_name;
1348 struct ffs_data *ffs_data;
1351 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1353 struct ffs_sb_fill_data *data = _data;
1354 struct inode *inode;
1355 struct ffs_data *ffs = data->ffs_data;
1360 data->ffs_data = NULL;
1361 sb->s_fs_info = ffs;
1362 sb->s_blocksize = PAGE_SIZE;
1363 sb->s_blocksize_bits = PAGE_SHIFT;
1364 sb->s_magic = FUNCTIONFS_MAGIC;
1365 sb->s_op = &ffs_sb_operations;
1366 sb->s_time_gran = 1;
1369 data->perms.mode = data->root_mode;
1370 inode = ffs_sb_make_inode(sb, NULL,
1371 &simple_dir_operations,
1372 &simple_dir_inode_operations,
1374 sb->s_root = d_make_root(inode);
1375 if (unlikely(!sb->s_root))
1379 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1380 &ffs_ep0_operations)))
1386 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1390 if (!opts || !*opts)
1394 unsigned long value;
1398 comma = strchr(opts, ',');
1403 eq = strchr(opts, '=');
1404 if (unlikely(!eq)) {
1405 pr_err("'=' missing in %s\n", opts);
1411 if (kstrtoul(eq + 1, 0, &value)) {
1412 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1416 /* Interpret option */
1417 switch (eq - opts) {
1419 if (!memcmp(opts, "no_disconnect", 13))
1420 data->no_disconnect = !!value;
1425 if (!memcmp(opts, "rmode", 5))
1426 data->root_mode = (value & 0555) | S_IFDIR;
1427 else if (!memcmp(opts, "fmode", 5))
1428 data->perms.mode = (value & 0666) | S_IFREG;
1434 if (!memcmp(opts, "mode", 4)) {
1435 data->root_mode = (value & 0555) | S_IFDIR;
1436 data->perms.mode = (value & 0666) | S_IFREG;
1443 if (!memcmp(opts, "uid", 3)) {
1444 data->perms.uid = make_kuid(current_user_ns(), value);
1445 if (!uid_valid(data->perms.uid)) {
1446 pr_err("%s: unmapped value: %lu\n", opts, value);
1449 } else if (!memcmp(opts, "gid", 3)) {
1450 data->perms.gid = make_kgid(current_user_ns(), value);
1451 if (!gid_valid(data->perms.gid)) {
1452 pr_err("%s: unmapped value: %lu\n", opts, value);
1462 pr_err("%s: invalid option\n", opts);
1466 /* Next iteration */
1475 /* "mount -t functionfs dev_name /dev/function" ends up here */
1477 static struct dentry *
1478 ffs_fs_mount(struct file_system_type *t, int flags,
1479 const char *dev_name, void *opts)
1481 struct ffs_sb_fill_data data = {
1483 .mode = S_IFREG | 0600,
1484 .uid = GLOBAL_ROOT_UID,
1485 .gid = GLOBAL_ROOT_GID,
1487 .root_mode = S_IFDIR | 0500,
1488 .no_disconnect = false,
1493 struct ffs_data *ffs;
1497 ret = ffs_fs_parse_opts(&data, opts);
1498 if (unlikely(ret < 0))
1499 return ERR_PTR(ret);
1501 ffs = ffs_data_new(dev_name);
1503 return ERR_PTR(-ENOMEM);
1504 ffs->file_perms = data.perms;
1505 ffs->no_disconnect = data.no_disconnect;
1507 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1508 if (unlikely(!ffs->dev_name)) {
1510 return ERR_PTR(-ENOMEM);
1513 ffs_dev = ffs_acquire_dev(dev_name);
1514 if (IS_ERR(ffs_dev)) {
1516 return ERR_CAST(ffs_dev);
1518 ffs->private_data = ffs_dev;
1519 data.ffs_data = ffs;
1521 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1522 if (IS_ERR(rv) && data.ffs_data) {
1523 ffs_release_dev(data.ffs_data);
1524 ffs_data_put(data.ffs_data);
1530 ffs_fs_kill_sb(struct super_block *sb)
1534 kill_litter_super(sb);
1535 if (sb->s_fs_info) {
1536 ffs_release_dev(sb->s_fs_info);
1537 ffs_data_closed(sb->s_fs_info);
1538 ffs_data_put(sb->s_fs_info);
1542 static struct file_system_type ffs_fs_type = {
1543 .owner = THIS_MODULE,
1544 .name = "functionfs",
1545 .mount = ffs_fs_mount,
1546 .kill_sb = ffs_fs_kill_sb,
1548 MODULE_ALIAS_FS("functionfs");
1551 /* Driver's main init/cleanup functions *************************************/
1553 static int functionfs_init(void)
1559 ret = register_filesystem(&ffs_fs_type);
1561 pr_info("file system registered\n");
1563 pr_err("failed registering file system (%d)\n", ret);
1568 static void functionfs_cleanup(void)
1572 pr_info("unloading\n");
1573 unregister_filesystem(&ffs_fs_type);
1577 /* ffs_data and ffs_function construction and destruction code **************/
1579 static void ffs_data_clear(struct ffs_data *ffs);
1580 static void ffs_data_reset(struct ffs_data *ffs);
1582 static void ffs_data_get(struct ffs_data *ffs)
1586 refcount_inc(&ffs->ref);
1589 static void ffs_data_opened(struct ffs_data *ffs)
1593 refcount_inc(&ffs->ref);
1594 if (atomic_add_return(1, &ffs->opened) == 1 &&
1595 ffs->state == FFS_DEACTIVATED) {
1596 ffs->state = FFS_CLOSING;
1597 ffs_data_reset(ffs);
1601 static void ffs_data_put(struct ffs_data *ffs)
1605 if (unlikely(refcount_dec_and_test(&ffs->ref))) {
1606 pr_info("%s(): freeing\n", __func__);
1607 ffs_data_clear(ffs);
1608 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1609 waitqueue_active(&ffs->ep0req_completion.wait) ||
1610 waitqueue_active(&ffs->wait));
1611 destroy_workqueue(ffs->io_completion_wq);
1612 kfree(ffs->dev_name);
1617 static void ffs_data_closed(struct ffs_data *ffs)
1621 if (atomic_dec_and_test(&ffs->opened)) {
1622 if (ffs->no_disconnect) {
1623 ffs->state = FFS_DEACTIVATED;
1625 ffs_epfiles_destroy(ffs->epfiles,
1627 ffs->epfiles = NULL;
1629 if (ffs->setup_state == FFS_SETUP_PENDING)
1630 __ffs_ep0_stall(ffs);
1632 ffs->state = FFS_CLOSING;
1633 ffs_data_reset(ffs);
1636 if (atomic_read(&ffs->opened) < 0) {
1637 ffs->state = FFS_CLOSING;
1638 ffs_data_reset(ffs);
1644 static struct ffs_data *ffs_data_new(const char *dev_name)
1646 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1652 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name);
1653 if (!ffs->io_completion_wq) {
1658 refcount_set(&ffs->ref, 1);
1659 atomic_set(&ffs->opened, 0);
1660 ffs->state = FFS_READ_DESCRIPTORS;
1661 mutex_init(&ffs->mutex);
1662 spin_lock_init(&ffs->eps_lock);
1663 init_waitqueue_head(&ffs->ev.waitq);
1664 init_waitqueue_head(&ffs->wait);
1665 init_completion(&ffs->ep0req_completion);
1667 /* XXX REVISIT need to update it in some places, or do we? */
1668 ffs->ev.can_stall = 1;
1673 static void ffs_data_clear(struct ffs_data *ffs)
1679 BUG_ON(ffs->gadget);
1682 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1684 if (ffs->ffs_eventfd)
1685 eventfd_ctx_put(ffs->ffs_eventfd);
1687 kfree(ffs->raw_descs_data);
1688 kfree(ffs->raw_strings);
1689 kfree(ffs->stringtabs);
1692 static void ffs_data_reset(struct ffs_data *ffs)
1696 ffs_data_clear(ffs);
1698 ffs->epfiles = NULL;
1699 ffs->raw_descs_data = NULL;
1700 ffs->raw_descs = NULL;
1701 ffs->raw_strings = NULL;
1702 ffs->stringtabs = NULL;
1704 ffs->raw_descs_length = 0;
1705 ffs->fs_descs_count = 0;
1706 ffs->hs_descs_count = 0;
1707 ffs->ss_descs_count = 0;
1709 ffs->strings_count = 0;
1710 ffs->interfaces_count = 0;
1715 ffs->state = FFS_READ_DESCRIPTORS;
1716 ffs->setup_state = FFS_NO_SETUP;
1721 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1723 struct usb_gadget_strings **lang;
1728 if (WARN_ON(ffs->state != FFS_ACTIVE
1729 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1732 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1733 if (unlikely(first_id < 0))
1736 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1737 if (unlikely(!ffs->ep0req))
1739 ffs->ep0req->complete = ffs_ep0_complete;
1740 ffs->ep0req->context = ffs;
1742 lang = ffs->stringtabs;
1744 for (; *lang; ++lang) {
1745 struct usb_string *str = (*lang)->strings;
1747 for (; str->s; ++id, ++str)
1752 ffs->gadget = cdev->gadget;
1757 static void functionfs_unbind(struct ffs_data *ffs)
1761 if (!WARN_ON(!ffs->gadget)) {
1762 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1765 clear_bit(FFS_FL_BOUND, &ffs->flags);
1770 static int ffs_epfiles_create(struct ffs_data *ffs)
1772 struct ffs_epfile *epfile, *epfiles;
1777 count = ffs->eps_count;
1778 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1783 for (i = 1; i <= count; ++i, ++epfile) {
1785 mutex_init(&epfile->mutex);
1786 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1787 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1789 sprintf(epfile->name, "ep%u", i);
1790 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1792 &ffs_epfile_operations);
1793 if (unlikely(!epfile->dentry)) {
1794 ffs_epfiles_destroy(epfiles, i - 1);
1799 ffs->epfiles = epfiles;
1803 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1805 struct ffs_epfile *epfile = epfiles;
1809 for (; count; --count, ++epfile) {
1810 BUG_ON(mutex_is_locked(&epfile->mutex));
1811 if (epfile->dentry) {
1812 d_delete(epfile->dentry);
1813 dput(epfile->dentry);
1814 epfile->dentry = NULL;
1821 static void ffs_func_eps_disable(struct ffs_function *func)
1823 struct ffs_ep *ep = func->eps;
1824 struct ffs_epfile *epfile = func->ffs->epfiles;
1825 unsigned count = func->ffs->eps_count;
1826 unsigned long flags;
1828 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1830 /* pending requests get nuked */
1832 usb_ep_disable(ep->ep);
1837 __ffs_epfile_read_buffer_free(epfile);
1841 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1844 static int ffs_func_eps_enable(struct ffs_function *func)
1846 struct ffs_data *ffs = func->ffs;
1847 struct ffs_ep *ep = func->eps;
1848 struct ffs_epfile *epfile = ffs->epfiles;
1849 unsigned count = ffs->eps_count;
1850 unsigned long flags;
1853 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1855 struct usb_endpoint_descriptor *ds;
1856 struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
1857 int needs_comp_desc = false;
1860 if (ffs->gadget->speed == USB_SPEED_SUPER) {
1862 needs_comp_desc = true;
1863 } else if (ffs->gadget->speed == USB_SPEED_HIGH)
1868 /* fall-back to lower speed if desc missing for current speed */
1870 ds = ep->descs[desc_idx];
1871 } while (!ds && --desc_idx >= 0);
1878 ep->ep->driver_data = ep;
1881 if (needs_comp_desc) {
1882 comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
1883 USB_DT_ENDPOINT_SIZE);
1884 ep->ep->maxburst = comp_desc->bMaxBurst + 1;
1885 ep->ep->comp_desc = comp_desc;
1888 ret = usb_ep_enable(ep->ep);
1891 epfile->in = usb_endpoint_dir_in(ds);
1892 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1901 wake_up_interruptible(&ffs->wait);
1902 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1908 /* Parsing and building descriptors and strings *****************************/
1911 * This validates if data pointed by data is a valid USB descriptor as
1912 * well as record how many interfaces, endpoints and strings are
1913 * required by given configuration. Returns address after the
1914 * descriptor or NULL if data is invalid.
1917 enum ffs_entity_type {
1918 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1921 enum ffs_os_desc_type {
1922 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1925 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1927 struct usb_descriptor_header *desc,
1930 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1931 struct usb_os_desc_header *h, void *data,
1932 unsigned len, void *priv);
1934 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1935 ffs_entity_callback entity,
1938 struct usb_descriptor_header *_ds = (void *)data;
1944 /* At least two bytes are required: length and type */
1946 pr_vdebug("descriptor too short\n");
1950 /* If we have at least as many bytes as the descriptor takes? */
1951 length = _ds->bLength;
1953 pr_vdebug("descriptor longer then available data\n");
1957 #define __entity_check_INTERFACE(val) 1
1958 #define __entity_check_STRING(val) (val)
1959 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1960 #define __entity(type, val) do { \
1961 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1962 if (unlikely(!__entity_check_ ##type(val))) { \
1963 pr_vdebug("invalid entity's value\n"); \
1966 ret = entity(FFS_ ##type, &val, _ds, priv); \
1967 if (unlikely(ret < 0)) { \
1968 pr_debug("entity " #type "(%02x); ret = %d\n", \
1974 /* Parse descriptor depending on type. */
1975 switch (_ds->bDescriptorType) {
1979 case USB_DT_DEVICE_QUALIFIER:
1980 /* function can't have any of those */
1981 pr_vdebug("descriptor reserved for gadget: %d\n",
1982 _ds->bDescriptorType);
1985 case USB_DT_INTERFACE: {
1986 struct usb_interface_descriptor *ds = (void *)_ds;
1987 pr_vdebug("interface descriptor\n");
1988 if (length != sizeof *ds)
1991 __entity(INTERFACE, ds->bInterfaceNumber);
1993 __entity(STRING, ds->iInterface);
1997 case USB_DT_ENDPOINT: {
1998 struct usb_endpoint_descriptor *ds = (void *)_ds;
1999 pr_vdebug("endpoint descriptor\n");
2000 if (length != USB_DT_ENDPOINT_SIZE &&
2001 length != USB_DT_ENDPOINT_AUDIO_SIZE)
2003 __entity(ENDPOINT, ds->bEndpointAddress);
2008 pr_vdebug("hid descriptor\n");
2009 if (length != sizeof(struct hid_descriptor))
2014 if (length != sizeof(struct usb_otg_descriptor))
2018 case USB_DT_INTERFACE_ASSOCIATION: {
2019 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
2020 pr_vdebug("interface association descriptor\n");
2021 if (length != sizeof *ds)
2024 __entity(STRING, ds->iFunction);
2028 case USB_DT_SS_ENDPOINT_COMP:
2029 pr_vdebug("EP SS companion descriptor\n");
2030 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2034 case USB_DT_OTHER_SPEED_CONFIG:
2035 case USB_DT_INTERFACE_POWER:
2037 case USB_DT_SECURITY:
2038 case USB_DT_CS_RADIO_CONTROL:
2040 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2044 /* We should never be here */
2045 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2049 pr_vdebug("invalid length: %d (descriptor %d)\n",
2050 _ds->bLength, _ds->bDescriptorType);
2055 #undef __entity_check_DESCRIPTOR
2056 #undef __entity_check_INTERFACE
2057 #undef __entity_check_STRING
2058 #undef __entity_check_ENDPOINT
2063 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2064 ffs_entity_callback entity, void *priv)
2066 const unsigned _len = len;
2067 unsigned long num = 0;
2077 /* Record "descriptor" entity */
2078 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2079 if (unlikely(ret < 0)) {
2080 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2088 ret = ffs_do_single_desc(data, len, entity, priv);
2089 if (unlikely(ret < 0)) {
2090 pr_debug("%s returns %d\n", __func__, ret);
2100 static int __ffs_data_do_entity(enum ffs_entity_type type,
2101 u8 *valuep, struct usb_descriptor_header *desc,
2104 struct ffs_desc_helper *helper = priv;
2105 struct usb_endpoint_descriptor *d;
2110 case FFS_DESCRIPTOR:
2115 * Interfaces are indexed from zero so if we
2116 * encountered interface "n" then there are at least
2119 if (*valuep >= helper->interfaces_count)
2120 helper->interfaces_count = *valuep + 1;
2125 * Strings are indexed from 1 (0 is reserved
2126 * for languages list)
2128 if (*valuep > helper->ffs->strings_count)
2129 helper->ffs->strings_count = *valuep;
2134 helper->eps_count++;
2135 if (helper->eps_count >= FFS_MAX_EPS_COUNT)
2137 /* Check if descriptors for any speed were already parsed */
2138 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2139 helper->ffs->eps_addrmap[helper->eps_count] =
2140 d->bEndpointAddress;
2141 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2142 d->bEndpointAddress)
2150 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2151 struct usb_os_desc_header *desc)
2153 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2154 u16 w_index = le16_to_cpu(desc->wIndex);
2156 if (bcd_version != 1) {
2157 pr_vdebug("unsupported os descriptors version: %d",
2163 *next_type = FFS_OS_DESC_EXT_COMPAT;
2166 *next_type = FFS_OS_DESC_EXT_PROP;
2169 pr_vdebug("unsupported os descriptor type: %d", w_index);
2173 return sizeof(*desc);
2177 * Process all extended compatibility/extended property descriptors
2178 * of a feature descriptor
2180 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2181 enum ffs_os_desc_type type,
2183 ffs_os_desc_callback entity,
2185 struct usb_os_desc_header *h)
2188 const unsigned _len = len;
2192 /* loop over all ext compat/ext prop descriptors */
2193 while (feature_count--) {
2194 ret = entity(type, h, data, len, priv);
2195 if (unlikely(ret < 0)) {
2196 pr_debug("bad OS descriptor, type: %d\n", type);
2205 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2206 static int __must_check ffs_do_os_descs(unsigned count,
2207 char *data, unsigned len,
2208 ffs_os_desc_callback entity, void *priv)
2210 const unsigned _len = len;
2211 unsigned long num = 0;
2215 for (num = 0; num < count; ++num) {
2217 enum ffs_os_desc_type type;
2219 struct usb_os_desc_header *desc = (void *)data;
2221 if (len < sizeof(*desc))
2225 * Record "descriptor" entity.
2226 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2227 * Move the data pointer to the beginning of extended
2228 * compatibilities proper or extended properties proper
2229 * portions of the data
2231 if (le32_to_cpu(desc->dwLength) > len)
2234 ret = __ffs_do_os_desc_header(&type, desc);
2235 if (unlikely(ret < 0)) {
2236 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2241 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2243 feature_count = le16_to_cpu(desc->wCount);
2244 if (type == FFS_OS_DESC_EXT_COMPAT &&
2245 (feature_count > 255 || desc->Reserved))
2251 * Process all function/property descriptors
2252 * of this Feature Descriptor
2254 ret = ffs_do_single_os_desc(data, len, type,
2255 feature_count, entity, priv, desc);
2256 if (unlikely(ret < 0)) {
2257 pr_debug("%s returns %d\n", __func__, ret);
2268 * Validate contents of the buffer from userspace related to OS descriptors.
2270 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2271 struct usb_os_desc_header *h, void *data,
2272 unsigned len, void *priv)
2274 struct ffs_data *ffs = priv;
2280 case FFS_OS_DESC_EXT_COMPAT: {
2281 struct usb_ext_compat_desc *d = data;
2284 if (len < sizeof(*d) ||
2285 d->bFirstInterfaceNumber >= ffs->interfaces_count)
2287 if (d->Reserved1 != 1) {
2289 * According to the spec, Reserved1 must be set to 1
2290 * but older kernels incorrectly rejected non-zero
2291 * values. We fix it here to avoid returning EINVAL
2292 * in response to values we used to accept.
2294 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
2297 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2298 if (d->Reserved2[i])
2301 length = sizeof(struct usb_ext_compat_desc);
2304 case FFS_OS_DESC_EXT_PROP: {
2305 struct usb_ext_prop_desc *d = data;
2309 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2311 length = le32_to_cpu(d->dwSize);
2314 type = le32_to_cpu(d->dwPropertyDataType);
2315 if (type < USB_EXT_PROP_UNICODE ||
2316 type > USB_EXT_PROP_UNICODE_MULTI) {
2317 pr_vdebug("unsupported os descriptor property type: %d",
2321 pnl = le16_to_cpu(d->wPropertyNameLength);
2322 if (length < 14 + pnl) {
2323 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2327 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2328 if (length != 14 + pnl + pdl) {
2329 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2330 length, pnl, pdl, type);
2333 ++ffs->ms_os_descs_ext_prop_count;
2334 /* property name reported to the host as "WCHAR"s */
2335 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2336 ffs->ms_os_descs_ext_prop_data_len += pdl;
2340 pr_vdebug("unknown descriptor: %d\n", type);
2346 static int __ffs_data_got_descs(struct ffs_data *ffs,
2347 char *const _data, size_t len)
2349 char *data = _data, *raw_descs;
2350 unsigned os_descs_count = 0, counts[3], flags;
2351 int ret = -EINVAL, i;
2352 struct ffs_desc_helper helper;
2356 if (get_unaligned_le32(data + 4) != len)
2359 switch (get_unaligned_le32(data)) {
2360 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2361 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2365 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2366 flags = get_unaligned_le32(data + 8);
2367 ffs->user_flags = flags;
2368 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2369 FUNCTIONFS_HAS_HS_DESC |
2370 FUNCTIONFS_HAS_SS_DESC |
2371 FUNCTIONFS_HAS_MS_OS_DESC |
2372 FUNCTIONFS_VIRTUAL_ADDR |
2373 FUNCTIONFS_EVENTFD |
2374 FUNCTIONFS_ALL_CTRL_RECIP |
2375 FUNCTIONFS_CONFIG0_SETUP)) {
2386 if (flags & FUNCTIONFS_EVENTFD) {
2390 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2391 if (IS_ERR(ffs->ffs_eventfd)) {
2392 ret = PTR_ERR(ffs->ffs_eventfd);
2393 ffs->ffs_eventfd = NULL;
2400 /* Read fs_count, hs_count and ss_count (if present) */
2401 for (i = 0; i < 3; ++i) {
2402 if (!(flags & (1 << i))) {
2404 } else if (len < 4) {
2407 counts[i] = get_unaligned_le32(data);
2412 if (flags & (1 << i)) {
2416 os_descs_count = get_unaligned_le32(data);
2421 /* Read descriptors */
2424 for (i = 0; i < 3; ++i) {
2427 helper.interfaces_count = 0;
2428 helper.eps_count = 0;
2429 ret = ffs_do_descs(counts[i], data, len,
2430 __ffs_data_do_entity, &helper);
2433 if (!ffs->eps_count && !ffs->interfaces_count) {
2434 ffs->eps_count = helper.eps_count;
2435 ffs->interfaces_count = helper.interfaces_count;
2437 if (ffs->eps_count != helper.eps_count) {
2441 if (ffs->interfaces_count != helper.interfaces_count) {
2449 if (os_descs_count) {
2450 ret = ffs_do_os_descs(os_descs_count, data, len,
2451 __ffs_data_do_os_desc, ffs);
2458 if (raw_descs == data || len) {
2463 ffs->raw_descs_data = _data;
2464 ffs->raw_descs = raw_descs;
2465 ffs->raw_descs_length = data - raw_descs;
2466 ffs->fs_descs_count = counts[0];
2467 ffs->hs_descs_count = counts[1];
2468 ffs->ss_descs_count = counts[2];
2469 ffs->ms_os_descs_count = os_descs_count;
2478 static int __ffs_data_got_strings(struct ffs_data *ffs,
2479 char *const _data, size_t len)
2481 u32 str_count, needed_count, lang_count;
2482 struct usb_gadget_strings **stringtabs, *t;
2483 const char *data = _data;
2484 struct usb_string *s;
2488 if (unlikely(len < 16 ||
2489 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2490 get_unaligned_le32(data + 4) != len))
2492 str_count = get_unaligned_le32(data + 8);
2493 lang_count = get_unaligned_le32(data + 12);
2495 /* if one is zero the other must be zero */
2496 if (unlikely(!str_count != !lang_count))
2499 /* Do we have at least as many strings as descriptors need? */
2500 needed_count = ffs->strings_count;
2501 if (unlikely(str_count < needed_count))
2505 * If we don't need any strings just return and free all
2508 if (!needed_count) {
2513 /* Allocate everything in one chunk so there's less maintenance. */
2517 vla_item(d, struct usb_gadget_strings *, stringtabs,
2519 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2520 vla_item(d, struct usb_string, strings,
2521 lang_count*(needed_count+1));
2523 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2525 if (unlikely(!vlabuf)) {
2530 /* Initialize the VLA pointers */
2531 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2532 t = vla_ptr(vlabuf, d, stringtab);
2535 *stringtabs++ = t++;
2539 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2540 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2541 t = vla_ptr(vlabuf, d, stringtab);
2542 s = vla_ptr(vlabuf, d, strings);
2545 /* For each language */
2549 do { /* lang_count > 0 so we can use do-while */
2550 unsigned needed = needed_count;
2552 if (unlikely(len < 3))
2554 t->language = get_unaligned_le16(data);
2561 /* For each string */
2562 do { /* str_count > 0 so we can use do-while */
2563 size_t length = strnlen(data, len);
2565 if (unlikely(length == len))
2569 * User may provide more strings then we need,
2570 * if that's the case we simply ignore the
2573 if (likely(needed)) {
2575 * s->id will be set while adding
2576 * function to configuration so for
2577 * now just leave garbage here.
2586 } while (--str_count);
2588 s->id = 0; /* terminator */
2592 } while (--lang_count);
2594 /* Some garbage left? */
2599 ffs->stringtabs = stringtabs;
2600 ffs->raw_strings = _data;
2612 /* Events handling and management *******************************************/
2614 static void __ffs_event_add(struct ffs_data *ffs,
2615 enum usb_functionfs_event_type type)
2617 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2621 * Abort any unhandled setup
2623 * We do not need to worry about some cmpxchg() changing value
2624 * of ffs->setup_state without holding the lock because when
2625 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2626 * the source does nothing.
2628 if (ffs->setup_state == FFS_SETUP_PENDING)
2629 ffs->setup_state = FFS_SETUP_CANCELLED;
2632 * Logic of this function guarantees that there are at most four pending
2633 * evens on ffs->ev.types queue. This is important because the queue
2634 * has space for four elements only and __ffs_ep0_read_events function
2635 * depends on that limit as well. If more event types are added, those
2636 * limits have to be revisited or guaranteed to still hold.
2639 case FUNCTIONFS_RESUME:
2640 rem_type2 = FUNCTIONFS_SUSPEND;
2642 case FUNCTIONFS_SUSPEND:
2643 case FUNCTIONFS_SETUP:
2645 /* Discard all similar events */
2648 case FUNCTIONFS_BIND:
2649 case FUNCTIONFS_UNBIND:
2650 case FUNCTIONFS_DISABLE:
2651 case FUNCTIONFS_ENABLE:
2652 /* Discard everything other then power management. */
2653 rem_type1 = FUNCTIONFS_SUSPEND;
2654 rem_type2 = FUNCTIONFS_RESUME;
2659 WARN(1, "%d: unknown event, this should not happen\n", type);
2664 u8 *ev = ffs->ev.types, *out = ev;
2665 unsigned n = ffs->ev.count;
2666 for (; n; --n, ++ev)
2667 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2670 pr_vdebug("purging event %d\n", *ev);
2671 ffs->ev.count = out - ffs->ev.types;
2674 pr_vdebug("adding event %d\n", type);
2675 ffs->ev.types[ffs->ev.count++] = type;
2676 wake_up_locked(&ffs->ev.waitq);
2677 if (ffs->ffs_eventfd)
2678 eventfd_signal(ffs->ffs_eventfd, 1);
2681 static void ffs_event_add(struct ffs_data *ffs,
2682 enum usb_functionfs_event_type type)
2684 unsigned long flags;
2685 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2686 __ffs_event_add(ffs, type);
2687 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2690 /* Bind/unbind USB function hooks *******************************************/
2692 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2696 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2697 if (ffs->eps_addrmap[i] == endpoint_address)
2702 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2703 struct usb_descriptor_header *desc,
2706 struct usb_endpoint_descriptor *ds = (void *)desc;
2707 struct ffs_function *func = priv;
2708 struct ffs_ep *ffs_ep;
2709 unsigned ep_desc_id;
2711 static const char *speed_names[] = { "full", "high", "super" };
2713 if (type != FFS_DESCRIPTOR)
2717 * If ss_descriptors is not NULL, we are reading super speed
2718 * descriptors; if hs_descriptors is not NULL, we are reading high
2719 * speed descriptors; otherwise, we are reading full speed
2722 if (func->function.ss_descriptors) {
2724 func->function.ss_descriptors[(long)valuep] = desc;
2725 } else if (func->function.hs_descriptors) {
2727 func->function.hs_descriptors[(long)valuep] = desc;
2730 func->function.fs_descriptors[(long)valuep] = desc;
2733 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2736 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2740 ffs_ep = func->eps + idx;
2742 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2743 pr_err("two %sspeed descriptors for EP %d\n",
2744 speed_names[ep_desc_id],
2745 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2748 ffs_ep->descs[ep_desc_id] = ds;
2750 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2752 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2753 if (!ds->wMaxPacketSize)
2754 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2756 struct usb_request *req;
2758 u8 bEndpointAddress;
2761 * We back up bEndpointAddress because autoconfig overwrites
2762 * it with physical endpoint address.
2764 bEndpointAddress = ds->bEndpointAddress;
2765 pr_vdebug("autoconfig\n");
2766 ep = usb_ep_autoconfig(func->gadget, ds);
2769 ep->driver_data = func->eps + idx;
2771 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2777 func->eps_revmap[ds->bEndpointAddress &
2778 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2780 * If we use virtual address mapping, we restore
2781 * original bEndpointAddress value.
2783 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2784 ds->bEndpointAddress = bEndpointAddress;
2786 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2791 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2792 struct usb_descriptor_header *desc,
2795 struct ffs_function *func = priv;
2801 case FFS_DESCRIPTOR:
2802 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2807 if (func->interfaces_nums[idx] < 0) {
2808 int id = usb_interface_id(func->conf, &func->function);
2809 if (unlikely(id < 0))
2811 func->interfaces_nums[idx] = id;
2813 newValue = func->interfaces_nums[idx];
2817 /* String' IDs are allocated when fsf_data is bound to cdev */
2818 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2823 * USB_DT_ENDPOINT are handled in
2824 * __ffs_func_bind_do_descs().
2826 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2829 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2830 if (unlikely(!func->eps[idx].ep))
2834 struct usb_endpoint_descriptor **descs;
2835 descs = func->eps[idx].descs;
2836 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2841 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2846 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2847 struct usb_os_desc_header *h, void *data,
2848 unsigned len, void *priv)
2850 struct ffs_function *func = priv;
2854 case FFS_OS_DESC_EXT_COMPAT: {
2855 struct usb_ext_compat_desc *desc = data;
2856 struct usb_os_desc_table *t;
2858 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2859 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2860 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2861 ARRAY_SIZE(desc->CompatibleID) +
2862 ARRAY_SIZE(desc->SubCompatibleID));
2863 length = sizeof(*desc);
2866 case FFS_OS_DESC_EXT_PROP: {
2867 struct usb_ext_prop_desc *desc = data;
2868 struct usb_os_desc_table *t;
2869 struct usb_os_desc_ext_prop *ext_prop;
2870 char *ext_prop_name;
2871 char *ext_prop_data;
2873 t = &func->function.os_desc_table[h->interface];
2874 t->if_id = func->interfaces_nums[h->interface];
2876 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2877 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2879 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2880 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2881 ext_prop->data_len = le32_to_cpu(*(u32 *)
2882 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2883 length = ext_prop->name_len + ext_prop->data_len + 14;
2885 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2886 func->ffs->ms_os_descs_ext_prop_name_avail +=
2889 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2890 func->ffs->ms_os_descs_ext_prop_data_avail +=
2892 memcpy(ext_prop_data,
2893 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2894 ext_prop->data_len);
2895 /* unicode data reported to the host as "WCHAR"s */
2896 switch (ext_prop->type) {
2897 case USB_EXT_PROP_UNICODE:
2898 case USB_EXT_PROP_UNICODE_ENV:
2899 case USB_EXT_PROP_UNICODE_LINK:
2900 case USB_EXT_PROP_UNICODE_MULTI:
2901 ext_prop->data_len *= 2;
2904 ext_prop->data = ext_prop_data;
2906 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2907 ext_prop->name_len);
2908 /* property name reported to the host as "WCHAR"s */
2909 ext_prop->name_len *= 2;
2910 ext_prop->name = ext_prop_name;
2912 t->os_desc->ext_prop_len +=
2913 ext_prop->name_len + ext_prop->data_len + 14;
2914 ++t->os_desc->ext_prop_count;
2915 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2919 pr_vdebug("unknown descriptor: %d\n", type);
2925 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2926 struct usb_configuration *c)
2928 struct ffs_function *func = ffs_func_from_usb(f);
2929 struct f_fs_opts *ffs_opts =
2930 container_of(f->fi, struct f_fs_opts, func_inst);
2936 * Legacy gadget triggers binding in functionfs_ready_callback,
2937 * which already uses locking; taking the same lock here would
2940 * Configfs-enabled gadgets however do need ffs_dev_lock.
2942 if (!ffs_opts->no_configfs)
2944 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2945 func->ffs = ffs_opts->dev->ffs_data;
2946 if (!ffs_opts->no_configfs)
2949 return ERR_PTR(ret);
2952 func->gadget = c->cdev->gadget;
2955 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2956 * configurations are bound in sequence with list_for_each_entry,
2957 * in each configuration its functions are bound in sequence
2958 * with list_for_each_entry, so we assume no race condition
2959 * with regard to ffs_opts->bound access
2961 if (!ffs_opts->refcnt) {
2962 ret = functionfs_bind(func->ffs, c->cdev);
2964 return ERR_PTR(ret);
2967 func->function.strings = func->ffs->stringtabs;
2972 static int _ffs_func_bind(struct usb_configuration *c,
2973 struct usb_function *f)
2975 struct ffs_function *func = ffs_func_from_usb(f);
2976 struct ffs_data *ffs = func->ffs;
2978 const int full = !!func->ffs->fs_descs_count;
2979 const int high = gadget_is_dualspeed(func->gadget) &&
2980 func->ffs->hs_descs_count;
2981 const int super = gadget_is_superspeed(func->gadget) &&
2982 func->ffs->ss_descs_count;
2984 int fs_len, hs_len, ss_len, ret, i;
2985 struct ffs_ep *eps_ptr;
2987 /* Make it a single chunk, less management later on */
2989 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2990 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2991 full ? ffs->fs_descs_count + 1 : 0);
2992 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2993 high ? ffs->hs_descs_count + 1 : 0);
2994 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2995 super ? ffs->ss_descs_count + 1 : 0);
2996 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2997 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2998 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2999 vla_item_with_sz(d, char[16], ext_compat,
3000 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3001 vla_item_with_sz(d, struct usb_os_desc, os_desc,
3002 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3003 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
3004 ffs->ms_os_descs_ext_prop_count);
3005 vla_item_with_sz(d, char, ext_prop_name,
3006 ffs->ms_os_descs_ext_prop_name_len);
3007 vla_item_with_sz(d, char, ext_prop_data,
3008 ffs->ms_os_descs_ext_prop_data_len);
3009 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
3014 /* Has descriptors only for speeds gadget does not support */
3015 if (unlikely(!(full | high | super)))
3018 /* Allocate a single chunk, less management later on */
3019 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
3020 if (unlikely(!vlabuf))
3023 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
3024 ffs->ms_os_descs_ext_prop_name_avail =
3025 vla_ptr(vlabuf, d, ext_prop_name);
3026 ffs->ms_os_descs_ext_prop_data_avail =
3027 vla_ptr(vlabuf, d, ext_prop_data);
3029 /* Copy descriptors */
3030 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
3031 ffs->raw_descs_length);
3033 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
3034 eps_ptr = vla_ptr(vlabuf, d, eps);
3035 for (i = 0; i < ffs->eps_count; i++)
3036 eps_ptr[i].num = -1;
3039 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3041 func->eps = vla_ptr(vlabuf, d, eps);
3042 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3045 * Go through all the endpoint descriptors and allocate
3046 * endpoints first, so that later we can rewrite the endpoint
3047 * numbers without worrying that it may be described later on.
3050 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3051 fs_len = ffs_do_descs(ffs->fs_descs_count,
3052 vla_ptr(vlabuf, d, raw_descs),
3054 __ffs_func_bind_do_descs, func);
3055 if (unlikely(fs_len < 0)) {
3064 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3065 hs_len = ffs_do_descs(ffs->hs_descs_count,
3066 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3067 d_raw_descs__sz - fs_len,
3068 __ffs_func_bind_do_descs, func);
3069 if (unlikely(hs_len < 0)) {
3077 if (likely(super)) {
3078 func->function.ss_descriptors = vla_ptr(vlabuf, d, ss_descs);
3079 ss_len = ffs_do_descs(ffs->ss_descs_count,
3080 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3081 d_raw_descs__sz - fs_len - hs_len,
3082 __ffs_func_bind_do_descs, func);
3083 if (unlikely(ss_len < 0)) {
3092 * Now handle interface numbers allocation and interface and
3093 * endpoint numbers rewriting. We can do that in one go
3096 ret = ffs_do_descs(ffs->fs_descs_count +
3097 (high ? ffs->hs_descs_count : 0) +
3098 (super ? ffs->ss_descs_count : 0),
3099 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3100 __ffs_func_bind_do_nums, func);
3101 if (unlikely(ret < 0))
3104 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3105 if (c->cdev->use_os_string) {
3106 for (i = 0; i < ffs->interfaces_count; ++i) {
3107 struct usb_os_desc *desc;
3109 desc = func->function.os_desc_table[i].os_desc =
3110 vla_ptr(vlabuf, d, os_desc) +
3111 i * sizeof(struct usb_os_desc);
3112 desc->ext_compat_id =
3113 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3114 INIT_LIST_HEAD(&desc->ext_prop);
3116 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3117 vla_ptr(vlabuf, d, raw_descs) +
3118 fs_len + hs_len + ss_len,
3119 d_raw_descs__sz - fs_len - hs_len -
3121 __ffs_func_bind_do_os_desc, func);
3122 if (unlikely(ret < 0))
3125 func->function.os_desc_n =
3126 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3128 /* And we're done */
3129 ffs_event_add(ffs, FUNCTIONFS_BIND);
3133 /* XXX Do we need to release all claimed endpoints here? */
3137 static int ffs_func_bind(struct usb_configuration *c,
3138 struct usb_function *f)
3140 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3141 struct ffs_function *func = ffs_func_from_usb(f);
3144 if (IS_ERR(ffs_opts))
3145 return PTR_ERR(ffs_opts);
3147 ret = _ffs_func_bind(c, f);
3148 if (ret && !--ffs_opts->refcnt)
3149 functionfs_unbind(func->ffs);
3155 /* Other USB function hooks *************************************************/
3157 static void ffs_reset_work(struct work_struct *work)
3159 struct ffs_data *ffs = container_of(work,
3160 struct ffs_data, reset_work);
3161 ffs_data_reset(ffs);
3164 static int ffs_func_set_alt(struct usb_function *f,
3165 unsigned interface, unsigned alt)
3167 struct ffs_function *func = ffs_func_from_usb(f);
3168 struct ffs_data *ffs = func->ffs;
3171 if (alt != (unsigned)-1) {
3172 intf = ffs_func_revmap_intf(func, interface);
3173 if (unlikely(intf < 0))
3178 ffs_func_eps_disable(ffs->func);
3180 if (ffs->state == FFS_DEACTIVATED) {
3181 ffs->state = FFS_CLOSING;
3182 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3183 schedule_work(&ffs->reset_work);
3187 if (ffs->state != FFS_ACTIVE)
3190 if (alt == (unsigned)-1) {
3192 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3197 ret = ffs_func_eps_enable(func);
3198 if (likely(ret >= 0))
3199 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3203 static void ffs_func_disable(struct usb_function *f)
3205 ffs_func_set_alt(f, 0, (unsigned)-1);
3208 static int ffs_func_setup(struct usb_function *f,
3209 const struct usb_ctrlrequest *creq)
3211 struct ffs_function *func = ffs_func_from_usb(f);
3212 struct ffs_data *ffs = func->ffs;
3213 unsigned long flags;
3218 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3219 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3220 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3221 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3222 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3225 * Most requests directed to interface go through here
3226 * (notable exceptions are set/get interface) so we need to
3227 * handle them. All other either handled by composite or
3228 * passed to usb_configuration->setup() (if one is set). No
3229 * matter, we will handle requests directed to endpoint here
3230 * as well (as it's straightforward). Other request recipient
3231 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3234 if (ffs->state != FFS_ACTIVE)
3237 switch (creq->bRequestType & USB_RECIP_MASK) {
3238 case USB_RECIP_INTERFACE:
3239 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3240 if (unlikely(ret < 0))
3244 case USB_RECIP_ENDPOINT:
3245 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3246 if (unlikely(ret < 0))
3248 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3249 ret = func->ffs->eps_addrmap[ret];
3253 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3254 ret = le16_to_cpu(creq->wIndex);
3259 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3260 ffs->ev.setup = *creq;
3261 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3262 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3263 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3268 static bool ffs_func_req_match(struct usb_function *f,
3269 const struct usb_ctrlrequest *creq,
3272 struct ffs_function *func = ffs_func_from_usb(f);
3274 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3277 switch (creq->bRequestType & USB_RECIP_MASK) {
3278 case USB_RECIP_INTERFACE:
3279 return (ffs_func_revmap_intf(func,
3280 le16_to_cpu(creq->wIndex)) >= 0);
3281 case USB_RECIP_ENDPOINT:
3282 return (ffs_func_revmap_ep(func,
3283 le16_to_cpu(creq->wIndex)) >= 0);
3285 return (bool) (func->ffs->user_flags &
3286 FUNCTIONFS_ALL_CTRL_RECIP);
3290 static void ffs_func_suspend(struct usb_function *f)
3293 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3296 static void ffs_func_resume(struct usb_function *f)
3299 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3303 /* Endpoint and interface numbers reverse mapping ***************************/
3305 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3307 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3308 return num ? num : -EDOM;
3311 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3313 short *nums = func->interfaces_nums;
3314 unsigned count = func->ffs->interfaces_count;
3316 for (; count; --count, ++nums) {
3317 if (*nums >= 0 && *nums == intf)
3318 return nums - func->interfaces_nums;
3325 /* Devices management *******************************************************/
3327 static LIST_HEAD(ffs_devices);
3329 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3331 struct ffs_dev *dev;
3336 list_for_each_entry(dev, &ffs_devices, entry) {
3337 if (strcmp(dev->name, name) == 0)
3345 * ffs_lock must be taken by the caller of this function
3347 static struct ffs_dev *_ffs_get_single_dev(void)
3349 struct ffs_dev *dev;
3351 if (list_is_singular(&ffs_devices)) {
3352 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3361 * ffs_lock must be taken by the caller of this function
3363 static struct ffs_dev *_ffs_find_dev(const char *name)
3365 struct ffs_dev *dev;
3367 dev = _ffs_get_single_dev();
3371 return _ffs_do_find_dev(name);
3374 /* Configfs support *********************************************************/
3376 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3378 return container_of(to_config_group(item), struct f_fs_opts,
3382 static void ffs_attr_release(struct config_item *item)
3384 struct f_fs_opts *opts = to_ffs_opts(item);
3386 usb_put_function_instance(&opts->func_inst);
3389 static struct configfs_item_operations ffs_item_ops = {
3390 .release = ffs_attr_release,
3393 static const struct config_item_type ffs_func_type = {
3394 .ct_item_ops = &ffs_item_ops,
3395 .ct_owner = THIS_MODULE,
3399 /* Function registration interface ******************************************/
3401 static void ffs_free_inst(struct usb_function_instance *f)
3403 struct f_fs_opts *opts;
3405 opts = to_f_fs_opts(f);
3407 _ffs_free_dev(opts->dev);
3412 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3414 if (strlen(name) >= FIELD_SIZEOF(struct ffs_dev, name))
3415 return -ENAMETOOLONG;
3416 return ffs_name_dev(to_f_fs_opts(fi)->dev, name);
3419 static struct usb_function_instance *ffs_alloc_inst(void)
3421 struct f_fs_opts *opts;
3422 struct ffs_dev *dev;
3424 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3426 return ERR_PTR(-ENOMEM);
3428 opts->func_inst.set_inst_name = ffs_set_inst_name;
3429 opts->func_inst.free_func_inst = ffs_free_inst;
3431 dev = _ffs_alloc_dev();
3435 return ERR_CAST(dev);
3440 config_group_init_type_name(&opts->func_inst.group, "",
3442 return &opts->func_inst;
3445 static void ffs_free(struct usb_function *f)
3447 kfree(ffs_func_from_usb(f));
3450 static void ffs_func_unbind(struct usb_configuration *c,
3451 struct usb_function *f)
3453 struct ffs_function *func = ffs_func_from_usb(f);
3454 struct ffs_data *ffs = func->ffs;
3455 struct f_fs_opts *opts =
3456 container_of(f->fi, struct f_fs_opts, func_inst);
3457 struct ffs_ep *ep = func->eps;
3458 unsigned count = ffs->eps_count;
3459 unsigned long flags;
3462 if (ffs->func == func) {
3463 ffs_func_eps_disable(func);
3467 if (!--opts->refcnt)
3468 functionfs_unbind(ffs);
3470 /* cleanup after autoconfig */
3471 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3473 if (ep->ep && ep->req)
3474 usb_ep_free_request(ep->ep, ep->req);
3478 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3482 * eps, descriptors and interfaces_nums are allocated in the
3483 * same chunk so only one free is required.
3485 func->function.fs_descriptors = NULL;
3486 func->function.hs_descriptors = NULL;
3487 func->function.ss_descriptors = NULL;
3488 func->interfaces_nums = NULL;
3490 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3493 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3495 struct ffs_function *func;
3499 func = kzalloc(sizeof(*func), GFP_KERNEL);
3500 if (unlikely(!func))
3501 return ERR_PTR(-ENOMEM);
3503 func->function.name = "Function FS Gadget";
3505 func->function.bind = ffs_func_bind;
3506 func->function.unbind = ffs_func_unbind;
3507 func->function.set_alt = ffs_func_set_alt;
3508 func->function.disable = ffs_func_disable;
3509 func->function.setup = ffs_func_setup;
3510 func->function.req_match = ffs_func_req_match;
3511 func->function.suspend = ffs_func_suspend;
3512 func->function.resume = ffs_func_resume;
3513 func->function.free_func = ffs_free;
3515 return &func->function;
3519 * ffs_lock must be taken by the caller of this function
3521 static struct ffs_dev *_ffs_alloc_dev(void)
3523 struct ffs_dev *dev;
3526 if (_ffs_get_single_dev())
3527 return ERR_PTR(-EBUSY);
3529 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3531 return ERR_PTR(-ENOMEM);
3533 if (list_empty(&ffs_devices)) {
3534 ret = functionfs_init();
3537 return ERR_PTR(ret);
3541 list_add(&dev->entry, &ffs_devices);
3546 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3548 struct ffs_dev *existing;
3553 existing = _ffs_do_find_dev(name);
3555 strlcpy(dev->name, name, ARRAY_SIZE(dev->name));
3556 else if (existing != dev)
3563 EXPORT_SYMBOL_GPL(ffs_name_dev);
3565 int ffs_single_dev(struct ffs_dev *dev)
3572 if (!list_is_singular(&ffs_devices))
3580 EXPORT_SYMBOL_GPL(ffs_single_dev);
3583 * ffs_lock must be taken by the caller of this function
3585 static void _ffs_free_dev(struct ffs_dev *dev)
3587 list_del(&dev->entry);
3589 /* Clear the private_data pointer to stop incorrect dev access */
3591 dev->ffs_data->private_data = NULL;
3594 if (list_empty(&ffs_devices))
3595 functionfs_cleanup();
3598 static void *ffs_acquire_dev(const char *dev_name)
3600 struct ffs_dev *ffs_dev;
3605 ffs_dev = _ffs_find_dev(dev_name);
3607 ffs_dev = ERR_PTR(-ENOENT);
3608 else if (ffs_dev->mounted)
3609 ffs_dev = ERR_PTR(-EBUSY);
3610 else if (ffs_dev->ffs_acquire_dev_callback &&
3611 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3612 ffs_dev = ERR_PTR(-ENOENT);
3614 ffs_dev->mounted = true;
3620 static void ffs_release_dev(struct ffs_data *ffs_data)
3622 struct ffs_dev *ffs_dev;
3627 ffs_dev = ffs_data->private_data;
3629 ffs_dev->mounted = false;
3631 if (ffs_dev->ffs_release_dev_callback)
3632 ffs_dev->ffs_release_dev_callback(ffs_dev);
3638 static int ffs_ready(struct ffs_data *ffs)
3640 struct ffs_dev *ffs_obj;
3646 ffs_obj = ffs->private_data;
3651 if (WARN_ON(ffs_obj->desc_ready)) {
3656 ffs_obj->desc_ready = true;
3657 ffs_obj->ffs_data = ffs;
3659 if (ffs_obj->ffs_ready_callback) {
3660 ret = ffs_obj->ffs_ready_callback(ffs);
3665 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3671 static void ffs_closed(struct ffs_data *ffs)
3673 struct ffs_dev *ffs_obj;
3674 struct f_fs_opts *opts;
3675 struct config_item *ci;
3680 ffs_obj = ffs->private_data;
3684 ffs_obj->desc_ready = false;
3685 ffs_obj->ffs_data = NULL;
3687 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3688 ffs_obj->ffs_closed_callback)
3689 ffs_obj->ffs_closed_callback(ffs);
3692 opts = ffs_obj->opts;
3696 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3697 || !kref_read(&opts->func_inst.group.cg_item.ci_kref))
3700 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3703 unregister_gadget_item(ci);
3709 /* Misc helper functions ****************************************************/
3711 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3714 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3715 : mutex_lock_interruptible(mutex);
3718 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3725 data = kmalloc(len, GFP_KERNEL);
3726 if (unlikely(!data))
3727 return ERR_PTR(-ENOMEM);
3729 if (unlikely(copy_from_user(data, buf, len))) {
3731 return ERR_PTR(-EFAULT);
3734 pr_vdebug("Buffer from user space:\n");
3735 ffs_dump_mem("", data, len);
3740 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3741 MODULE_LICENSE("GPL");
3742 MODULE_AUTHOR("Michal Nazarewicz");