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/fs_parser.h>
21 #include <linux/hid.h>
23 #include <linux/module.h>
24 #include <linux/scatterlist.h>
25 #include <linux/sched/signal.h>
26 #include <linux/uio.h>
27 #include <linux/vmalloc.h>
28 #include <asm/unaligned.h>
30 #include <linux/usb/ccid.h>
31 #include <linux/usb/composite.h>
32 #include <linux/usb/functionfs.h>
34 #include <linux/aio.h>
35 #include <linux/kthread.h>
36 #include <linux/poll.h>
37 #include <linux/eventfd.h>
41 #include "u_os_desc.h"
44 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
46 /* Reference counter handling */
47 static void ffs_data_get(struct ffs_data *ffs);
48 static void ffs_data_put(struct ffs_data *ffs);
49 /* Creates new ffs_data object. */
50 static struct ffs_data *__must_check ffs_data_new(const char *dev_name)
51 __attribute__((malloc));
53 /* Opened counter handling. */
54 static void ffs_data_opened(struct ffs_data *ffs);
55 static void ffs_data_closed(struct ffs_data *ffs);
57 /* Called with ffs->mutex held; take over ownership of data. */
58 static int __must_check
59 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
60 static int __must_check
61 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
64 /* The function structure ***************************************************/
69 struct usb_configuration *conf;
70 struct usb_gadget *gadget;
75 short *interfaces_nums;
77 struct usb_function function;
81 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
83 return container_of(f, struct ffs_function, function);
87 static inline enum ffs_setup_state
88 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
90 return (enum ffs_setup_state)
91 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
95 static void ffs_func_eps_disable(struct ffs_function *func);
96 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
98 static int ffs_func_bind(struct usb_configuration *,
99 struct usb_function *);
100 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
101 static void ffs_func_disable(struct usb_function *);
102 static int ffs_func_setup(struct usb_function *,
103 const struct usb_ctrlrequest *);
104 static bool ffs_func_req_match(struct usb_function *,
105 const struct usb_ctrlrequest *,
107 static void ffs_func_suspend(struct usb_function *);
108 static void ffs_func_resume(struct usb_function *);
111 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
112 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
115 /* The endpoints structures *************************************************/
118 struct usb_ep *ep; /* P: ffs->eps_lock */
119 struct usb_request *req; /* P: epfile->mutex */
121 /* [0]: full speed, [1]: high speed, [2]: super speed */
122 struct usb_endpoint_descriptor *descs[3];
126 int status; /* P: epfile->mutex */
130 /* Protects ep->ep and ep->req. */
133 struct ffs_data *ffs;
134 struct ffs_ep *ep; /* P: ffs->eps_lock */
136 struct dentry *dentry;
139 * Buffer for holding data from partial reads which may happen since
140 * we’re rounding user read requests to a multiple of a max packet size.
142 * The pointer is initialised with NULL value and may be set by
143 * __ffs_epfile_read_data function to point to a temporary buffer.
145 * In normal operation, calls to __ffs_epfile_read_buffered will consume
146 * data from said buffer and eventually free it. Importantly, while the
147 * function is using the buffer, it sets the pointer to NULL. This is
148 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
149 * can never run concurrently (they are synchronised by epfile->mutex)
150 * so the latter will not assign a new value to the pointer.
152 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
153 * valid) and sets the pointer to READ_BUFFER_DROP value. This special
154 * value is crux of the synchronisation between ffs_func_eps_disable and
155 * __ffs_epfile_read_data.
157 * Once __ffs_epfile_read_data is about to finish it will try to set the
158 * pointer back to its old value (as described above), but seeing as the
159 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
162 * == State transitions ==
164 * • ptr == NULL: (initial state)
165 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
166 * ◦ __ffs_epfile_read_buffered: nop
167 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
168 * ◦ reading finishes: n/a, not in ‘and reading’ state
170 * ◦ __ffs_epfile_read_buffer_free: nop
171 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL
172 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
173 * ◦ reading finishes: n/a, not in ‘and reading’ state
175 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
176 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
177 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
178 * is always called first
179 * ◦ reading finishes: n/a, not in ‘and reading’ state
180 * • ptr == NULL and reading:
181 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
182 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
183 * ◦ __ffs_epfile_read_data: n/a, mutex is held
184 * ◦ reading finishes and …
185 * … all data read: free buf, go to ptr == NULL
186 * … otherwise: go to ptr == buf and reading
187 * • ptr == DROP and reading:
188 * ◦ __ffs_epfile_read_buffer_free: nop
189 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
190 * ◦ __ffs_epfile_read_data: n/a, mutex is held
191 * ◦ reading finishes: free buf, go to ptr == DROP
193 struct ffs_buffer *read_buffer;
194 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
198 unsigned char in; /* P: ffs->eps_lock */
199 unsigned char isoc; /* P: ffs->eps_lock */
210 /* ffs_io_data structure ***************************************************/
217 struct iov_iter data;
221 struct mm_struct *mm;
222 struct work_struct work;
225 struct usb_request *req;
229 struct ffs_data *ffs;
232 struct ffs_desc_helper {
233 struct ffs_data *ffs;
234 unsigned interfaces_count;
238 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
239 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
241 static struct dentry *
242 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
243 const struct file_operations *fops);
245 /* Devices management *******************************************************/
247 DEFINE_MUTEX(ffs_lock);
248 EXPORT_SYMBOL_GPL(ffs_lock);
250 static struct ffs_dev *_ffs_find_dev(const char *name);
251 static struct ffs_dev *_ffs_alloc_dev(void);
252 static void _ffs_free_dev(struct ffs_dev *dev);
253 static void *ffs_acquire_dev(const char *dev_name);
254 static void ffs_release_dev(struct ffs_data *ffs_data);
255 static int ffs_ready(struct ffs_data *ffs);
256 static void ffs_closed(struct ffs_data *ffs);
258 /* Misc helper functions ****************************************************/
260 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
261 __attribute__((warn_unused_result, nonnull));
262 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
263 __attribute__((warn_unused_result, nonnull));
266 /* Control file aka ep0 *****************************************************/
268 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
270 struct ffs_data *ffs = req->context;
272 complete(&ffs->ep0req_completion);
275 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
276 __releases(&ffs->ev.waitq.lock)
278 struct usb_request *req = ffs->ep0req;
281 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
283 spin_unlock_irq(&ffs->ev.waitq.lock);
289 * UDC layer requires to provide a buffer even for ZLP, but should
290 * not use it at all. Let's provide some poisoned pointer to catch
291 * possible bug in the driver.
293 if (req->buf == NULL)
294 req->buf = (void *)0xDEADBABE;
296 reinit_completion(&ffs->ep0req_completion);
298 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
302 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
304 usb_ep_dequeue(ffs->gadget->ep0, req);
308 ffs->setup_state = FFS_NO_SETUP;
309 return req->status ? req->status : req->actual;
312 static int __ffs_ep0_stall(struct ffs_data *ffs)
314 if (ffs->ev.can_stall) {
315 pr_vdebug("ep0 stall\n");
316 usb_ep_set_halt(ffs->gadget->ep0);
317 ffs->setup_state = FFS_NO_SETUP;
320 pr_debug("bogus ep0 stall!\n");
325 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
326 size_t len, loff_t *ptr)
328 struct ffs_data *ffs = file->private_data;
334 /* Fast check if setup was canceled */
335 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
339 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
344 switch (ffs->state) {
345 case FFS_READ_DESCRIPTORS:
346 case FFS_READ_STRINGS:
353 data = ffs_prepare_buffer(buf, len);
360 if (ffs->state == FFS_READ_DESCRIPTORS) {
361 pr_info("read descriptors\n");
362 ret = __ffs_data_got_descs(ffs, data, len);
366 ffs->state = FFS_READ_STRINGS;
369 pr_info("read strings\n");
370 ret = __ffs_data_got_strings(ffs, data, len);
374 ret = ffs_epfiles_create(ffs);
376 ffs->state = FFS_CLOSING;
380 ffs->state = FFS_ACTIVE;
381 mutex_unlock(&ffs->mutex);
383 ret = ffs_ready(ffs);
385 ffs->state = FFS_CLOSING;
396 * We're called from user space, we can use _irq
397 * rather then _irqsave
399 spin_lock_irq(&ffs->ev.waitq.lock);
400 switch (ffs_setup_state_clear_cancelled(ffs)) {
401 case FFS_SETUP_CANCELLED:
409 case FFS_SETUP_PENDING:
413 /* FFS_SETUP_PENDING */
414 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
415 spin_unlock_irq(&ffs->ev.waitq.lock);
416 ret = __ffs_ep0_stall(ffs);
420 /* FFS_SETUP_PENDING and not stall */
421 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
423 spin_unlock_irq(&ffs->ev.waitq.lock);
425 data = ffs_prepare_buffer(buf, len);
431 spin_lock_irq(&ffs->ev.waitq.lock);
434 * We are guaranteed to be still in FFS_ACTIVE state
435 * but the state of setup could have changed from
436 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
437 * to check for that. If that happened we copied data
438 * from user space in vain but it's unlikely.
440 * For sure we are not in FFS_NO_SETUP since this is
441 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
442 * transition can be performed and it's protected by
445 if (ffs_setup_state_clear_cancelled(ffs) ==
446 FFS_SETUP_CANCELLED) {
449 spin_unlock_irq(&ffs->ev.waitq.lock);
451 /* unlocks spinlock */
452 ret = __ffs_ep0_queue_wait(ffs, data, len);
462 mutex_unlock(&ffs->mutex);
466 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
467 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
469 __releases(&ffs->ev.waitq.lock)
472 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
473 * size of ffs->ev.types array (which is four) so that's how much space
476 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
477 const size_t size = n * sizeof *events;
480 memset(events, 0, size);
483 events[i].type = ffs->ev.types[i];
484 if (events[i].type == FUNCTIONFS_SETUP) {
485 events[i].u.setup = ffs->ev.setup;
486 ffs->setup_state = FFS_SETUP_PENDING;
492 memmove(ffs->ev.types, ffs->ev.types + n,
493 ffs->ev.count * sizeof *ffs->ev.types);
495 spin_unlock_irq(&ffs->ev.waitq.lock);
496 mutex_unlock(&ffs->mutex);
498 return copy_to_user(buf, events, size) ? -EFAULT : size;
501 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
502 size_t len, loff_t *ptr)
504 struct ffs_data *ffs = file->private_data;
511 /* Fast check if setup was canceled */
512 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
516 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
521 if (ffs->state != FFS_ACTIVE) {
527 * We're called from user space, we can use _irq rather then
530 spin_lock_irq(&ffs->ev.waitq.lock);
532 switch (ffs_setup_state_clear_cancelled(ffs)) {
533 case FFS_SETUP_CANCELLED:
538 n = len / sizeof(struct usb_functionfs_event);
544 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
549 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
555 /* unlocks spinlock */
556 return __ffs_ep0_read_events(ffs, buf,
557 min(n, (size_t)ffs->ev.count));
559 case FFS_SETUP_PENDING:
560 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
561 spin_unlock_irq(&ffs->ev.waitq.lock);
562 ret = __ffs_ep0_stall(ffs);
566 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
568 spin_unlock_irq(&ffs->ev.waitq.lock);
571 data = kmalloc(len, GFP_KERNEL);
578 spin_lock_irq(&ffs->ev.waitq.lock);
580 /* See ffs_ep0_write() */
581 if (ffs_setup_state_clear_cancelled(ffs) ==
582 FFS_SETUP_CANCELLED) {
587 /* unlocks spinlock */
588 ret = __ffs_ep0_queue_wait(ffs, data, len);
589 if ((ret > 0) && (copy_to_user(buf, data, len)))
598 spin_unlock_irq(&ffs->ev.waitq.lock);
600 mutex_unlock(&ffs->mutex);
605 static int ffs_ep0_open(struct inode *inode, struct file *file)
607 struct ffs_data *ffs = inode->i_private;
611 if (ffs->state == FFS_CLOSING)
614 file->private_data = ffs;
615 ffs_data_opened(ffs);
620 static int ffs_ep0_release(struct inode *inode, struct file *file)
622 struct ffs_data *ffs = file->private_data;
626 ffs_data_closed(ffs);
631 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
633 struct ffs_data *ffs = file->private_data;
634 struct usb_gadget *gadget = ffs->gadget;
639 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
640 struct ffs_function *func = ffs->func;
641 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
642 } else if (gadget && gadget->ops->ioctl) {
643 ret = gadget->ops->ioctl(gadget, code, value);
651 static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait)
653 struct ffs_data *ffs = file->private_data;
654 __poll_t mask = EPOLLWRNORM;
657 poll_wait(file, &ffs->ev.waitq, wait);
659 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
663 switch (ffs->state) {
664 case FFS_READ_DESCRIPTORS:
665 case FFS_READ_STRINGS:
670 switch (ffs->setup_state) {
676 case FFS_SETUP_PENDING:
677 case FFS_SETUP_CANCELLED:
678 mask |= (EPOLLIN | EPOLLOUT);
685 case FFS_DEACTIVATED:
689 mutex_unlock(&ffs->mutex);
694 static const struct file_operations ffs_ep0_operations = {
697 .open = ffs_ep0_open,
698 .write = ffs_ep0_write,
699 .read = ffs_ep0_read,
700 .release = ffs_ep0_release,
701 .unlocked_ioctl = ffs_ep0_ioctl,
702 .poll = ffs_ep0_poll,
706 /* "Normal" endpoints operations ********************************************/
708 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
712 struct ffs_ep *ep = _ep->driver_data;
713 ep->status = req->status ? req->status : req->actual;
714 complete(req->context);
718 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
720 ssize_t ret = copy_to_iter(data, data_len, iter);
724 if (iov_iter_count(iter))
728 * Dear user space developer!
730 * TL;DR: To stop getting below error message in your kernel log, change
731 * user space code using functionfs to align read buffers to a max
734 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
735 * packet size. When unaligned buffer is passed to functionfs, it
736 * internally uses a larger, aligned buffer so that such UDCs are happy.
738 * Unfortunately, this means that host may send more data than was
739 * requested in read(2) system call. f_fs doesn’t know what to do with
740 * that excess data so it simply drops it.
742 * Was the buffer aligned in the first place, no such problem would
745 * Data may be dropped only in AIO reads. Synchronous reads are handled
746 * by splitting a request into multiple parts. This splitting may still
747 * be a problem though so it’s likely best to align the buffer
748 * regardless of it being AIO or not..
750 * This only affects OUT endpoints, i.e. reading data with a read(2),
751 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not
754 pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
755 "Align read buffer size to max packet size to avoid the problem.\n",
762 * allocate a virtually contiguous buffer and create a scatterlist describing it
763 * @sg_table - pointer to a place to be filled with sg_table contents
764 * @size - required buffer size
766 static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz)
770 unsigned int n_pages;
777 n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
778 pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL);
784 for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE)
785 pages[i] = vmalloc_to_page(ptr);
787 if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) {
798 static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data,
802 return ffs_build_sg_list(&io_data->sgt, data_len);
804 return kmalloc(data_len, GFP_KERNEL);
807 static inline void ffs_free_buffer(struct ffs_io_data *io_data)
812 if (io_data->use_sg) {
813 sg_free_table(&io_data->sgt);
820 static void ffs_user_copy_worker(struct work_struct *work)
822 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
824 int ret = io_data->req->status ? io_data->req->status :
825 io_data->req->actual;
826 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
828 if (io_data->read && ret > 0) {
829 kthread_use_mm(io_data->mm);
830 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
831 kthread_unuse_mm(io_data->mm);
834 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
836 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
837 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
839 usb_ep_free_request(io_data->ep, io_data->req);
842 kfree(io_data->to_free);
843 ffs_free_buffer(io_data);
847 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
848 struct usb_request *req)
850 struct ffs_io_data *io_data = req->context;
851 struct ffs_data *ffs = io_data->ffs;
855 INIT_WORK(&io_data->work, ffs_user_copy_worker);
856 queue_work(ffs->io_completion_wq, &io_data->work);
859 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
862 * See comment in struct ffs_epfile for full read_buffer pointer
863 * synchronisation story.
865 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
866 if (buf && buf != READ_BUFFER_DROP)
870 /* Assumes epfile->mutex is held. */
871 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
872 struct iov_iter *iter)
875 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
876 * the buffer while we are using it. See comment in struct ffs_epfile
877 * for full read_buffer pointer synchronisation story.
879 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
881 if (!buf || buf == READ_BUFFER_DROP)
884 ret = copy_to_iter(buf->data, buf->length, iter);
885 if (buf->length == ret) {
890 if (iov_iter_count(iter)) {
897 if (cmpxchg(&epfile->read_buffer, NULL, buf))
903 /* Assumes epfile->mutex is held. */
904 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
905 void *data, int data_len,
906 struct iov_iter *iter)
908 struct ffs_buffer *buf;
910 ssize_t ret = copy_to_iter(data, data_len, iter);
914 if (iov_iter_count(iter))
917 /* See ffs_copy_to_iter for more context. */
918 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
922 buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL);
925 buf->length = data_len;
926 buf->data = buf->storage;
927 memcpy(buf->storage, data + ret, data_len);
930 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
931 * ffs_func_eps_disable has been called in the meanwhile). See comment
932 * in struct ffs_epfile for full read_buffer pointer synchronisation
935 if (cmpxchg(&epfile->read_buffer, NULL, buf))
941 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
943 struct ffs_epfile *epfile = file->private_data;
944 struct usb_request *req;
947 ssize_t ret, data_len = -EINVAL;
950 /* Are we still active? */
951 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
954 /* Wait for endpoint to be enabled */
957 if (file->f_flags & O_NONBLOCK)
960 ret = wait_event_interruptible(
961 epfile->ffs->wait, (ep = epfile->ep));
967 halt = (!io_data->read == !epfile->in);
968 if (halt && epfile->isoc)
971 /* We will be using request and read_buffer */
972 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
976 /* Allocate & copy */
978 struct usb_gadget *gadget;
981 * Do we have buffered data from previous partial read? Check
982 * that for synchronous case only because we do not have
983 * facility to ‘wake up’ a pending asynchronous read and push
984 * buffered data to it which we would need to make things behave
987 if (!io_data->aio && io_data->read) {
988 ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
994 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
995 * before the waiting completes, so do not assign to 'gadget'
998 gadget = epfile->ffs->gadget;
1000 spin_lock_irq(&epfile->ffs->eps_lock);
1001 /* In the meantime, endpoint got disabled or changed. */
1002 if (epfile->ep != ep) {
1006 data_len = iov_iter_count(&io_data->data);
1008 * Controller may require buffer size to be aligned to
1009 * maxpacketsize of an out endpoint.
1012 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
1014 io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE;
1015 spin_unlock_irq(&epfile->ffs->eps_lock);
1017 data = ffs_alloc_buffer(io_data, data_len);
1022 if (!io_data->read &&
1023 !copy_from_iter_full(data, data_len, &io_data->data)) {
1029 spin_lock_irq(&epfile->ffs->eps_lock);
1031 if (epfile->ep != ep) {
1032 /* In the meantime, endpoint got disabled or changed. */
1035 ret = usb_ep_set_halt(ep->ep);
1038 } else if (data_len == -EINVAL) {
1040 * Sanity Check: even though data_len can't be used
1041 * uninitialized at the time I write this comment, some
1042 * compilers complain about this situation.
1043 * In order to keep the code clean from warnings, data_len is
1044 * being initialized to -EINVAL during its declaration, which
1045 * means we can't rely on compiler anymore to warn no future
1046 * changes won't result in data_len being used uninitialized.
1047 * For such reason, we're adding this redundant sanity check
1050 WARN(1, "%s: data_len == -EINVAL\n", __func__);
1052 } else if (!io_data->aio) {
1053 DECLARE_COMPLETION_ONSTACK(done);
1054 bool interrupted = false;
1057 if (io_data->use_sg) {
1059 req->sg = io_data->sgt.sgl;
1060 req->num_sgs = io_data->sgt.nents;
1065 req->length = data_len;
1067 io_data->buf = data;
1069 req->context = &done;
1070 req->complete = ffs_epfile_io_complete;
1072 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1076 spin_unlock_irq(&epfile->ffs->eps_lock);
1078 if (wait_for_completion_interruptible(&done)) {
1080 * To avoid race condition with ffs_epfile_io_complete,
1081 * dequeue the request first then check
1082 * status. usb_ep_dequeue API should guarantee no race
1083 * condition with req->complete callback.
1085 usb_ep_dequeue(ep->ep, req);
1086 wait_for_completion(&done);
1087 interrupted = ep->status < 0;
1092 else if (io_data->read && ep->status > 0)
1093 ret = __ffs_epfile_read_data(epfile, data, ep->status,
1098 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) {
1101 if (io_data->use_sg) {
1103 req->sg = io_data->sgt.sgl;
1104 req->num_sgs = io_data->sgt.nents;
1109 req->length = data_len;
1111 io_data->buf = data;
1112 io_data->ep = ep->ep;
1114 io_data->ffs = epfile->ffs;
1116 req->context = io_data;
1117 req->complete = ffs_epfile_async_io_complete;
1119 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1121 io_data->req = NULL;
1122 usb_ep_free_request(ep->ep, req);
1128 * Do not kfree the buffer in this function. It will be freed
1129 * by ffs_user_copy_worker.
1135 spin_unlock_irq(&epfile->ffs->eps_lock);
1137 mutex_unlock(&epfile->mutex);
1139 if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */
1140 ffs_free_buffer(io_data);
1145 ffs_epfile_open(struct inode *inode, struct file *file)
1147 struct ffs_epfile *epfile = inode->i_private;
1151 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1154 file->private_data = epfile;
1155 ffs_data_opened(epfile->ffs);
1160 static int ffs_aio_cancel(struct kiocb *kiocb)
1162 struct ffs_io_data *io_data = kiocb->private;
1163 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
1164 unsigned long flags;
1169 spin_lock_irqsave(&epfile->ffs->eps_lock, flags);
1171 if (io_data && io_data->ep && io_data->req)
1172 value = usb_ep_dequeue(io_data->ep, io_data->req);
1176 spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);
1181 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
1183 struct ffs_io_data io_data, *p = &io_data;
1188 if (!is_sync_kiocb(kiocb)) {
1189 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1194 memset(p, 0, sizeof(*p));
1201 p->mm = current->mm;
1206 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1208 res = ffs_epfile_io(kiocb->ki_filp, p);
1209 if (res == -EIOCBQUEUED)
1218 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
1220 struct ffs_io_data io_data, *p = &io_data;
1225 if (!is_sync_kiocb(kiocb)) {
1226 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1231 memset(p, 0, sizeof(*p));
1238 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
1247 p->mm = current->mm;
1252 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1254 res = ffs_epfile_io(kiocb->ki_filp, p);
1255 if (res == -EIOCBQUEUED)
1268 ffs_epfile_release(struct inode *inode, struct file *file)
1270 struct ffs_epfile *epfile = inode->i_private;
1274 __ffs_epfile_read_buffer_free(epfile);
1275 ffs_data_closed(epfile->ffs);
1280 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1281 unsigned long value)
1283 struct ffs_epfile *epfile = file->private_data;
1289 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1292 /* Wait for endpoint to be enabled */
1295 if (file->f_flags & O_NONBLOCK)
1298 ret = wait_event_interruptible(
1299 epfile->ffs->wait, (ep = epfile->ep));
1304 spin_lock_irq(&epfile->ffs->eps_lock);
1306 /* In the meantime, endpoint got disabled or changed. */
1307 if (epfile->ep != ep) {
1308 spin_unlock_irq(&epfile->ffs->eps_lock);
1313 case FUNCTIONFS_FIFO_STATUS:
1314 ret = usb_ep_fifo_status(epfile->ep->ep);
1316 case FUNCTIONFS_FIFO_FLUSH:
1317 usb_ep_fifo_flush(epfile->ep->ep);
1320 case FUNCTIONFS_CLEAR_HALT:
1321 ret = usb_ep_clear_halt(epfile->ep->ep);
1323 case FUNCTIONFS_ENDPOINT_REVMAP:
1324 ret = epfile->ep->num;
1326 case FUNCTIONFS_ENDPOINT_DESC:
1329 struct usb_endpoint_descriptor desc1, *desc;
1331 switch (epfile->ffs->gadget->speed) {
1332 case USB_SPEED_SUPER:
1333 case USB_SPEED_SUPER_PLUS:
1336 case USB_SPEED_HIGH:
1343 desc = epfile->ep->descs[desc_idx];
1344 memcpy(&desc1, desc, desc->bLength);
1346 spin_unlock_irq(&epfile->ffs->eps_lock);
1347 ret = copy_to_user((void __user *)value, &desc1, desc1.bLength);
1355 spin_unlock_irq(&epfile->ffs->eps_lock);
1360 static const struct file_operations ffs_epfile_operations = {
1361 .llseek = no_llseek,
1363 .open = ffs_epfile_open,
1364 .write_iter = ffs_epfile_write_iter,
1365 .read_iter = ffs_epfile_read_iter,
1366 .release = ffs_epfile_release,
1367 .unlocked_ioctl = ffs_epfile_ioctl,
1368 .compat_ioctl = compat_ptr_ioctl,
1372 /* File system and super block operations ***********************************/
1375 * Mounting the file system creates a controller file, used first for
1376 * function configuration then later for event monitoring.
1379 static struct inode *__must_check
1380 ffs_sb_make_inode(struct super_block *sb, void *data,
1381 const struct file_operations *fops,
1382 const struct inode_operations *iops,
1383 struct ffs_file_perms *perms)
1385 struct inode *inode;
1389 inode = new_inode(sb);
1392 struct timespec64 ts = current_time(inode);
1394 inode->i_ino = get_next_ino();
1395 inode->i_mode = perms->mode;
1396 inode->i_uid = perms->uid;
1397 inode->i_gid = perms->gid;
1398 inode->i_atime = ts;
1399 inode->i_mtime = ts;
1400 inode->i_ctime = ts;
1401 inode->i_private = data;
1403 inode->i_fop = fops;
1411 /* Create "regular" file */
1412 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1413 const char *name, void *data,
1414 const struct file_operations *fops)
1416 struct ffs_data *ffs = sb->s_fs_info;
1417 struct dentry *dentry;
1418 struct inode *inode;
1422 dentry = d_alloc_name(sb->s_root, name);
1426 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1432 d_add(dentry, inode);
1437 static const struct super_operations ffs_sb_operations = {
1438 .statfs = simple_statfs,
1439 .drop_inode = generic_delete_inode,
1442 struct ffs_sb_fill_data {
1443 struct ffs_file_perms perms;
1445 const char *dev_name;
1447 struct ffs_data *ffs_data;
1450 static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc)
1452 struct ffs_sb_fill_data *data = fc->fs_private;
1453 struct inode *inode;
1454 struct ffs_data *ffs = data->ffs_data;
1459 data->ffs_data = NULL;
1460 sb->s_fs_info = ffs;
1461 sb->s_blocksize = PAGE_SIZE;
1462 sb->s_blocksize_bits = PAGE_SHIFT;
1463 sb->s_magic = FUNCTIONFS_MAGIC;
1464 sb->s_op = &ffs_sb_operations;
1465 sb->s_time_gran = 1;
1468 data->perms.mode = data->root_mode;
1469 inode = ffs_sb_make_inode(sb, NULL,
1470 &simple_dir_operations,
1471 &simple_dir_inode_operations,
1473 sb->s_root = d_make_root(inode);
1478 if (!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations))
1493 static const struct fs_parameter_spec ffs_fs_fs_parameters[] = {
1494 fsparam_bool ("no_disconnect", Opt_no_disconnect),
1495 fsparam_u32 ("rmode", Opt_rmode),
1496 fsparam_u32 ("fmode", Opt_fmode),
1497 fsparam_u32 ("mode", Opt_mode),
1498 fsparam_u32 ("uid", Opt_uid),
1499 fsparam_u32 ("gid", Opt_gid),
1503 static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
1505 struct ffs_sb_fill_data *data = fc->fs_private;
1506 struct fs_parse_result result;
1511 opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result);
1516 case Opt_no_disconnect:
1517 data->no_disconnect = result.boolean;
1520 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1523 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1526 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1527 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1531 data->perms.uid = make_kuid(current_user_ns(), result.uint_32);
1532 if (!uid_valid(data->perms.uid))
1533 goto unmapped_value;
1536 data->perms.gid = make_kgid(current_user_ns(), result.uint_32);
1537 if (!gid_valid(data->perms.gid))
1538 goto unmapped_value;
1548 return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32);
1552 * Set up the superblock for a mount.
1554 static int ffs_fs_get_tree(struct fs_context *fc)
1556 struct ffs_sb_fill_data *ctx = fc->fs_private;
1558 struct ffs_data *ffs;
1563 return invalf(fc, "No source specified");
1565 ffs = ffs_data_new(fc->source);
1568 ffs->file_perms = ctx->perms;
1569 ffs->no_disconnect = ctx->no_disconnect;
1571 ffs->dev_name = kstrdup(fc->source, GFP_KERNEL);
1572 if (!ffs->dev_name) {
1577 ffs_dev = ffs_acquire_dev(ffs->dev_name);
1578 if (IS_ERR(ffs_dev)) {
1580 return PTR_ERR(ffs_dev);
1583 ffs->private_data = ffs_dev;
1584 ctx->ffs_data = ffs;
1585 return get_tree_nodev(fc, ffs_sb_fill);
1588 static void ffs_fs_free_fc(struct fs_context *fc)
1590 struct ffs_sb_fill_data *ctx = fc->fs_private;
1593 if (ctx->ffs_data) {
1594 ffs_release_dev(ctx->ffs_data);
1595 ffs_data_put(ctx->ffs_data);
1602 static const struct fs_context_operations ffs_fs_context_ops = {
1603 .free = ffs_fs_free_fc,
1604 .parse_param = ffs_fs_parse_param,
1605 .get_tree = ffs_fs_get_tree,
1608 static int ffs_fs_init_fs_context(struct fs_context *fc)
1610 struct ffs_sb_fill_data *ctx;
1612 ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL);
1616 ctx->perms.mode = S_IFREG | 0600;
1617 ctx->perms.uid = GLOBAL_ROOT_UID;
1618 ctx->perms.gid = GLOBAL_ROOT_GID;
1619 ctx->root_mode = S_IFDIR | 0500;
1620 ctx->no_disconnect = false;
1622 fc->fs_private = ctx;
1623 fc->ops = &ffs_fs_context_ops;
1628 ffs_fs_kill_sb(struct super_block *sb)
1632 kill_litter_super(sb);
1633 if (sb->s_fs_info) {
1634 ffs_release_dev(sb->s_fs_info);
1635 ffs_data_closed(sb->s_fs_info);
1639 static struct file_system_type ffs_fs_type = {
1640 .owner = THIS_MODULE,
1641 .name = "functionfs",
1642 .init_fs_context = ffs_fs_init_fs_context,
1643 .parameters = ffs_fs_fs_parameters,
1644 .kill_sb = ffs_fs_kill_sb,
1646 MODULE_ALIAS_FS("functionfs");
1649 /* Driver's main init/cleanup functions *************************************/
1651 static int functionfs_init(void)
1657 ret = register_filesystem(&ffs_fs_type);
1659 pr_info("file system registered\n");
1661 pr_err("failed registering file system (%d)\n", ret);
1666 static void functionfs_cleanup(void)
1670 pr_info("unloading\n");
1671 unregister_filesystem(&ffs_fs_type);
1675 /* ffs_data and ffs_function construction and destruction code **************/
1677 static void ffs_data_clear(struct ffs_data *ffs);
1678 static void ffs_data_reset(struct ffs_data *ffs);
1680 static void ffs_data_get(struct ffs_data *ffs)
1684 refcount_inc(&ffs->ref);
1687 static void ffs_data_opened(struct ffs_data *ffs)
1691 refcount_inc(&ffs->ref);
1692 if (atomic_add_return(1, &ffs->opened) == 1 &&
1693 ffs->state == FFS_DEACTIVATED) {
1694 ffs->state = FFS_CLOSING;
1695 ffs_data_reset(ffs);
1699 static void ffs_data_put(struct ffs_data *ffs)
1703 if (refcount_dec_and_test(&ffs->ref)) {
1704 pr_info("%s(): freeing\n", __func__);
1705 ffs_data_clear(ffs);
1706 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1707 swait_active(&ffs->ep0req_completion.wait) ||
1708 waitqueue_active(&ffs->wait));
1709 destroy_workqueue(ffs->io_completion_wq);
1710 kfree(ffs->dev_name);
1715 static void ffs_data_closed(struct ffs_data *ffs)
1719 if (atomic_dec_and_test(&ffs->opened)) {
1720 if (ffs->no_disconnect) {
1721 ffs->state = FFS_DEACTIVATED;
1723 ffs_epfiles_destroy(ffs->epfiles,
1725 ffs->epfiles = NULL;
1727 if (ffs->setup_state == FFS_SETUP_PENDING)
1728 __ffs_ep0_stall(ffs);
1730 ffs->state = FFS_CLOSING;
1731 ffs_data_reset(ffs);
1734 if (atomic_read(&ffs->opened) < 0) {
1735 ffs->state = FFS_CLOSING;
1736 ffs_data_reset(ffs);
1742 static struct ffs_data *ffs_data_new(const char *dev_name)
1744 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1750 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name);
1751 if (!ffs->io_completion_wq) {
1756 refcount_set(&ffs->ref, 1);
1757 atomic_set(&ffs->opened, 0);
1758 ffs->state = FFS_READ_DESCRIPTORS;
1759 mutex_init(&ffs->mutex);
1760 spin_lock_init(&ffs->eps_lock);
1761 init_waitqueue_head(&ffs->ev.waitq);
1762 init_waitqueue_head(&ffs->wait);
1763 init_completion(&ffs->ep0req_completion);
1765 /* XXX REVISIT need to update it in some places, or do we? */
1766 ffs->ev.can_stall = 1;
1771 static void ffs_data_clear(struct ffs_data *ffs)
1777 BUG_ON(ffs->gadget);
1780 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1782 if (ffs->ffs_eventfd)
1783 eventfd_ctx_put(ffs->ffs_eventfd);
1785 kfree(ffs->raw_descs_data);
1786 kfree(ffs->raw_strings);
1787 kfree(ffs->stringtabs);
1790 static void ffs_data_reset(struct ffs_data *ffs)
1794 ffs_data_clear(ffs);
1796 ffs->epfiles = NULL;
1797 ffs->raw_descs_data = NULL;
1798 ffs->raw_descs = NULL;
1799 ffs->raw_strings = NULL;
1800 ffs->stringtabs = NULL;
1802 ffs->raw_descs_length = 0;
1803 ffs->fs_descs_count = 0;
1804 ffs->hs_descs_count = 0;
1805 ffs->ss_descs_count = 0;
1807 ffs->strings_count = 0;
1808 ffs->interfaces_count = 0;
1813 ffs->state = FFS_READ_DESCRIPTORS;
1814 ffs->setup_state = FFS_NO_SETUP;
1817 ffs->ms_os_descs_ext_prop_count = 0;
1818 ffs->ms_os_descs_ext_prop_name_len = 0;
1819 ffs->ms_os_descs_ext_prop_data_len = 0;
1823 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1825 struct usb_gadget_strings **lang;
1830 if (WARN_ON(ffs->state != FFS_ACTIVE
1831 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1834 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1838 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1841 ffs->ep0req->complete = ffs_ep0_complete;
1842 ffs->ep0req->context = ffs;
1844 lang = ffs->stringtabs;
1846 for (; *lang; ++lang) {
1847 struct usb_string *str = (*lang)->strings;
1849 for (; str->s; ++id, ++str)
1854 ffs->gadget = cdev->gadget;
1859 static void functionfs_unbind(struct ffs_data *ffs)
1863 if (!WARN_ON(!ffs->gadget)) {
1864 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1867 clear_bit(FFS_FL_BOUND, &ffs->flags);
1872 static int ffs_epfiles_create(struct ffs_data *ffs)
1874 struct ffs_epfile *epfile, *epfiles;
1879 count = ffs->eps_count;
1880 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1885 for (i = 1; i <= count; ++i, ++epfile) {
1887 mutex_init(&epfile->mutex);
1888 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1889 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1891 sprintf(epfile->name, "ep%u", i);
1892 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1894 &ffs_epfile_operations);
1895 if (!epfile->dentry) {
1896 ffs_epfiles_destroy(epfiles, i - 1);
1901 ffs->epfiles = epfiles;
1905 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1907 struct ffs_epfile *epfile = epfiles;
1911 for (; count; --count, ++epfile) {
1912 BUG_ON(mutex_is_locked(&epfile->mutex));
1913 if (epfile->dentry) {
1914 d_delete(epfile->dentry);
1915 dput(epfile->dentry);
1916 epfile->dentry = NULL;
1923 static void ffs_func_eps_disable(struct ffs_function *func)
1925 struct ffs_ep *ep = func->eps;
1926 struct ffs_epfile *epfile = func->ffs->epfiles;
1927 unsigned count = func->ffs->eps_count;
1928 unsigned long flags;
1930 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1932 /* pending requests get nuked */
1934 usb_ep_disable(ep->ep);
1939 __ffs_epfile_read_buffer_free(epfile);
1943 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1946 static int ffs_func_eps_enable(struct ffs_function *func)
1948 struct ffs_data *ffs = func->ffs;
1949 struct ffs_ep *ep = func->eps;
1950 struct ffs_epfile *epfile = ffs->epfiles;
1951 unsigned count = ffs->eps_count;
1952 unsigned long flags;
1955 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1957 ep->ep->driver_data = ep;
1959 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep);
1961 pr_err("%s: config_ep_by_speed(%s) returned %d\n",
1962 __func__, ep->ep->name, ret);
1966 ret = usb_ep_enable(ep->ep);
1969 epfile->in = usb_endpoint_dir_in(ep->ep->desc);
1970 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
1979 wake_up_interruptible(&ffs->wait);
1980 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1986 /* Parsing and building descriptors and strings *****************************/
1989 * This validates if data pointed by data is a valid USB descriptor as
1990 * well as record how many interfaces, endpoints and strings are
1991 * required by given configuration. Returns address after the
1992 * descriptor or NULL if data is invalid.
1995 enum ffs_entity_type {
1996 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1999 enum ffs_os_desc_type {
2000 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
2003 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
2005 struct usb_descriptor_header *desc,
2008 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
2009 struct usb_os_desc_header *h, void *data,
2010 unsigned len, void *priv);
2012 static int __must_check ffs_do_single_desc(char *data, unsigned len,
2013 ffs_entity_callback entity,
2014 void *priv, int *current_class)
2016 struct usb_descriptor_header *_ds = (void *)data;
2022 /* At least two bytes are required: length and type */
2024 pr_vdebug("descriptor too short\n");
2028 /* If we have at least as many bytes as the descriptor takes? */
2029 length = _ds->bLength;
2031 pr_vdebug("descriptor longer then available data\n");
2035 #define __entity_check_INTERFACE(val) 1
2036 #define __entity_check_STRING(val) (val)
2037 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
2038 #define __entity(type, val) do { \
2039 pr_vdebug("entity " #type "(%02x)\n", (val)); \
2040 if (!__entity_check_ ##type(val)) { \
2041 pr_vdebug("invalid entity's value\n"); \
2044 ret = entity(FFS_ ##type, &val, _ds, priv); \
2046 pr_debug("entity " #type "(%02x); ret = %d\n", \
2052 /* Parse descriptor depending on type. */
2053 switch (_ds->bDescriptorType) {
2057 case USB_DT_DEVICE_QUALIFIER:
2058 /* function can't have any of those */
2059 pr_vdebug("descriptor reserved for gadget: %d\n",
2060 _ds->bDescriptorType);
2063 case USB_DT_INTERFACE: {
2064 struct usb_interface_descriptor *ds = (void *)_ds;
2065 pr_vdebug("interface descriptor\n");
2066 if (length != sizeof *ds)
2069 __entity(INTERFACE, ds->bInterfaceNumber);
2071 __entity(STRING, ds->iInterface);
2072 *current_class = ds->bInterfaceClass;
2076 case USB_DT_ENDPOINT: {
2077 struct usb_endpoint_descriptor *ds = (void *)_ds;
2078 pr_vdebug("endpoint descriptor\n");
2079 if (length != USB_DT_ENDPOINT_SIZE &&
2080 length != USB_DT_ENDPOINT_AUDIO_SIZE)
2082 __entity(ENDPOINT, ds->bEndpointAddress);
2086 case USB_TYPE_CLASS | 0x01:
2087 if (*current_class == USB_INTERFACE_CLASS_HID) {
2088 pr_vdebug("hid descriptor\n");
2089 if (length != sizeof(struct hid_descriptor))
2092 } else if (*current_class == USB_INTERFACE_CLASS_CCID) {
2093 pr_vdebug("ccid descriptor\n");
2094 if (length != sizeof(struct ccid_descriptor))
2098 pr_vdebug("unknown descriptor: %d for class %d\n",
2099 _ds->bDescriptorType, *current_class);
2104 if (length != sizeof(struct usb_otg_descriptor))
2108 case USB_DT_INTERFACE_ASSOCIATION: {
2109 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
2110 pr_vdebug("interface association descriptor\n");
2111 if (length != sizeof *ds)
2114 __entity(STRING, ds->iFunction);
2118 case USB_DT_SS_ENDPOINT_COMP:
2119 pr_vdebug("EP SS companion descriptor\n");
2120 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2124 case USB_DT_OTHER_SPEED_CONFIG:
2125 case USB_DT_INTERFACE_POWER:
2127 case USB_DT_SECURITY:
2128 case USB_DT_CS_RADIO_CONTROL:
2130 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2134 /* We should never be here */
2135 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2139 pr_vdebug("invalid length: %d (descriptor %d)\n",
2140 _ds->bLength, _ds->bDescriptorType);
2145 #undef __entity_check_DESCRIPTOR
2146 #undef __entity_check_INTERFACE
2147 #undef __entity_check_STRING
2148 #undef __entity_check_ENDPOINT
2153 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2154 ffs_entity_callback entity, void *priv)
2156 const unsigned _len = len;
2157 unsigned long num = 0;
2158 int current_class = -1;
2168 /* Record "descriptor" entity */
2169 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2171 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2179 ret = ffs_do_single_desc(data, len, entity, priv,
2182 pr_debug("%s returns %d\n", __func__, ret);
2192 static int __ffs_data_do_entity(enum ffs_entity_type type,
2193 u8 *valuep, struct usb_descriptor_header *desc,
2196 struct ffs_desc_helper *helper = priv;
2197 struct usb_endpoint_descriptor *d;
2202 case FFS_DESCRIPTOR:
2207 * Interfaces are indexed from zero so if we
2208 * encountered interface "n" then there are at least
2211 if (*valuep >= helper->interfaces_count)
2212 helper->interfaces_count = *valuep + 1;
2217 * Strings are indexed from 1 (0 is reserved
2218 * for languages list)
2220 if (*valuep > helper->ffs->strings_count)
2221 helper->ffs->strings_count = *valuep;
2226 helper->eps_count++;
2227 if (helper->eps_count >= FFS_MAX_EPS_COUNT)
2229 /* Check if descriptors for any speed were already parsed */
2230 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2231 helper->ffs->eps_addrmap[helper->eps_count] =
2232 d->bEndpointAddress;
2233 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2234 d->bEndpointAddress)
2242 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2243 struct usb_os_desc_header *desc)
2245 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2246 u16 w_index = le16_to_cpu(desc->wIndex);
2248 if (bcd_version != 1) {
2249 pr_vdebug("unsupported os descriptors version: %d",
2255 *next_type = FFS_OS_DESC_EXT_COMPAT;
2258 *next_type = FFS_OS_DESC_EXT_PROP;
2261 pr_vdebug("unsupported os descriptor type: %d", w_index);
2265 return sizeof(*desc);
2269 * Process all extended compatibility/extended property descriptors
2270 * of a feature descriptor
2272 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2273 enum ffs_os_desc_type type,
2275 ffs_os_desc_callback entity,
2277 struct usb_os_desc_header *h)
2280 const unsigned _len = len;
2284 /* loop over all ext compat/ext prop descriptors */
2285 while (feature_count--) {
2286 ret = entity(type, h, data, len, priv);
2288 pr_debug("bad OS descriptor, type: %d\n", type);
2297 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2298 static int __must_check ffs_do_os_descs(unsigned count,
2299 char *data, unsigned len,
2300 ffs_os_desc_callback entity, void *priv)
2302 const unsigned _len = len;
2303 unsigned long num = 0;
2307 for (num = 0; num < count; ++num) {
2309 enum ffs_os_desc_type type;
2311 struct usb_os_desc_header *desc = (void *)data;
2313 if (len < sizeof(*desc))
2317 * Record "descriptor" entity.
2318 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2319 * Move the data pointer to the beginning of extended
2320 * compatibilities proper or extended properties proper
2321 * portions of the data
2323 if (le32_to_cpu(desc->dwLength) > len)
2326 ret = __ffs_do_os_desc_header(&type, desc);
2328 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2333 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2335 feature_count = le16_to_cpu(desc->wCount);
2336 if (type == FFS_OS_DESC_EXT_COMPAT &&
2337 (feature_count > 255 || desc->Reserved))
2343 * Process all function/property descriptors
2344 * of this Feature Descriptor
2346 ret = ffs_do_single_os_desc(data, len, type,
2347 feature_count, entity, priv, desc);
2349 pr_debug("%s returns %d\n", __func__, ret);
2360 * Validate contents of the buffer from userspace related to OS descriptors.
2362 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2363 struct usb_os_desc_header *h, void *data,
2364 unsigned len, void *priv)
2366 struct ffs_data *ffs = priv;
2372 case FFS_OS_DESC_EXT_COMPAT: {
2373 struct usb_ext_compat_desc *d = data;
2376 if (len < sizeof(*d) ||
2377 d->bFirstInterfaceNumber >= ffs->interfaces_count)
2379 if (d->Reserved1 != 1) {
2381 * According to the spec, Reserved1 must be set to 1
2382 * but older kernels incorrectly rejected non-zero
2383 * values. We fix it here to avoid returning EINVAL
2384 * in response to values we used to accept.
2386 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
2389 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2390 if (d->Reserved2[i])
2393 length = sizeof(struct usb_ext_compat_desc);
2396 case FFS_OS_DESC_EXT_PROP: {
2397 struct usb_ext_prop_desc *d = data;
2401 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2403 length = le32_to_cpu(d->dwSize);
2406 type = le32_to_cpu(d->dwPropertyDataType);
2407 if (type < USB_EXT_PROP_UNICODE ||
2408 type > USB_EXT_PROP_UNICODE_MULTI) {
2409 pr_vdebug("unsupported os descriptor property type: %d",
2413 pnl = le16_to_cpu(d->wPropertyNameLength);
2414 if (length < 14 + pnl) {
2415 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2419 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl));
2420 if (length != 14 + pnl + pdl) {
2421 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2422 length, pnl, pdl, type);
2425 ++ffs->ms_os_descs_ext_prop_count;
2426 /* property name reported to the host as "WCHAR"s */
2427 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2428 ffs->ms_os_descs_ext_prop_data_len += pdl;
2432 pr_vdebug("unknown descriptor: %d\n", type);
2438 static int __ffs_data_got_descs(struct ffs_data *ffs,
2439 char *const _data, size_t len)
2441 char *data = _data, *raw_descs;
2442 unsigned os_descs_count = 0, counts[3], flags;
2443 int ret = -EINVAL, i;
2444 struct ffs_desc_helper helper;
2448 if (get_unaligned_le32(data + 4) != len)
2451 switch (get_unaligned_le32(data)) {
2452 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2453 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2457 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2458 flags = get_unaligned_le32(data + 8);
2459 ffs->user_flags = flags;
2460 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2461 FUNCTIONFS_HAS_HS_DESC |
2462 FUNCTIONFS_HAS_SS_DESC |
2463 FUNCTIONFS_HAS_MS_OS_DESC |
2464 FUNCTIONFS_VIRTUAL_ADDR |
2465 FUNCTIONFS_EVENTFD |
2466 FUNCTIONFS_ALL_CTRL_RECIP |
2467 FUNCTIONFS_CONFIG0_SETUP)) {
2478 if (flags & FUNCTIONFS_EVENTFD) {
2482 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2483 if (IS_ERR(ffs->ffs_eventfd)) {
2484 ret = PTR_ERR(ffs->ffs_eventfd);
2485 ffs->ffs_eventfd = NULL;
2492 /* Read fs_count, hs_count and ss_count (if present) */
2493 for (i = 0; i < 3; ++i) {
2494 if (!(flags & (1 << i))) {
2496 } else if (len < 4) {
2499 counts[i] = get_unaligned_le32(data);
2504 if (flags & (1 << i)) {
2508 os_descs_count = get_unaligned_le32(data);
2513 /* Read descriptors */
2516 for (i = 0; i < 3; ++i) {
2519 helper.interfaces_count = 0;
2520 helper.eps_count = 0;
2521 ret = ffs_do_descs(counts[i], data, len,
2522 __ffs_data_do_entity, &helper);
2525 if (!ffs->eps_count && !ffs->interfaces_count) {
2526 ffs->eps_count = helper.eps_count;
2527 ffs->interfaces_count = helper.interfaces_count;
2529 if (ffs->eps_count != helper.eps_count) {
2533 if (ffs->interfaces_count != helper.interfaces_count) {
2541 if (os_descs_count) {
2542 ret = ffs_do_os_descs(os_descs_count, data, len,
2543 __ffs_data_do_os_desc, ffs);
2550 if (raw_descs == data || len) {
2555 ffs->raw_descs_data = _data;
2556 ffs->raw_descs = raw_descs;
2557 ffs->raw_descs_length = data - raw_descs;
2558 ffs->fs_descs_count = counts[0];
2559 ffs->hs_descs_count = counts[1];
2560 ffs->ss_descs_count = counts[2];
2561 ffs->ms_os_descs_count = os_descs_count;
2570 static int __ffs_data_got_strings(struct ffs_data *ffs,
2571 char *const _data, size_t len)
2573 u32 str_count, needed_count, lang_count;
2574 struct usb_gadget_strings **stringtabs, *t;
2575 const char *data = _data;
2576 struct usb_string *s;
2581 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2582 get_unaligned_le32(data + 4) != len)
2584 str_count = get_unaligned_le32(data + 8);
2585 lang_count = get_unaligned_le32(data + 12);
2587 /* if one is zero the other must be zero */
2588 if (!str_count != !lang_count)
2591 /* Do we have at least as many strings as descriptors need? */
2592 needed_count = ffs->strings_count;
2593 if (str_count < needed_count)
2597 * If we don't need any strings just return and free all
2600 if (!needed_count) {
2605 /* Allocate everything in one chunk so there's less maintenance. */
2609 vla_item(d, struct usb_gadget_strings *, stringtabs,
2611 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2612 vla_item(d, struct usb_string, strings,
2613 lang_count*(needed_count+1));
2615 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2622 /* Initialize the VLA pointers */
2623 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2624 t = vla_ptr(vlabuf, d, stringtab);
2627 *stringtabs++ = t++;
2631 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2632 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2633 t = vla_ptr(vlabuf, d, stringtab);
2634 s = vla_ptr(vlabuf, d, strings);
2637 /* For each language */
2641 do { /* lang_count > 0 so we can use do-while */
2642 unsigned needed = needed_count;
2646 t->language = get_unaligned_le16(data);
2653 /* For each string */
2654 do { /* str_count > 0 so we can use do-while */
2655 size_t length = strnlen(data, len);
2661 * User may provide more strings then we need,
2662 * if that's the case we simply ignore the
2667 * s->id will be set while adding
2668 * function to configuration so for
2669 * now just leave garbage here.
2678 } while (--str_count);
2680 s->id = 0; /* terminator */
2684 } while (--lang_count);
2686 /* Some garbage left? */
2691 ffs->stringtabs = stringtabs;
2692 ffs->raw_strings = _data;
2704 /* Events handling and management *******************************************/
2706 static void __ffs_event_add(struct ffs_data *ffs,
2707 enum usb_functionfs_event_type type)
2709 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2713 * Abort any unhandled setup
2715 * We do not need to worry about some cmpxchg() changing value
2716 * of ffs->setup_state without holding the lock because when
2717 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2718 * the source does nothing.
2720 if (ffs->setup_state == FFS_SETUP_PENDING)
2721 ffs->setup_state = FFS_SETUP_CANCELLED;
2724 * Logic of this function guarantees that there are at most four pending
2725 * evens on ffs->ev.types queue. This is important because the queue
2726 * has space for four elements only and __ffs_ep0_read_events function
2727 * depends on that limit as well. If more event types are added, those
2728 * limits have to be revisited or guaranteed to still hold.
2731 case FUNCTIONFS_RESUME:
2732 rem_type2 = FUNCTIONFS_SUSPEND;
2734 case FUNCTIONFS_SUSPEND:
2735 case FUNCTIONFS_SETUP:
2737 /* Discard all similar events */
2740 case FUNCTIONFS_BIND:
2741 case FUNCTIONFS_UNBIND:
2742 case FUNCTIONFS_DISABLE:
2743 case FUNCTIONFS_ENABLE:
2744 /* Discard everything other then power management. */
2745 rem_type1 = FUNCTIONFS_SUSPEND;
2746 rem_type2 = FUNCTIONFS_RESUME;
2751 WARN(1, "%d: unknown event, this should not happen\n", type);
2756 u8 *ev = ffs->ev.types, *out = ev;
2757 unsigned n = ffs->ev.count;
2758 for (; n; --n, ++ev)
2759 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2762 pr_vdebug("purging event %d\n", *ev);
2763 ffs->ev.count = out - ffs->ev.types;
2766 pr_vdebug("adding event %d\n", type);
2767 ffs->ev.types[ffs->ev.count++] = type;
2768 wake_up_locked(&ffs->ev.waitq);
2769 if (ffs->ffs_eventfd)
2770 eventfd_signal(ffs->ffs_eventfd, 1);
2773 static void ffs_event_add(struct ffs_data *ffs,
2774 enum usb_functionfs_event_type type)
2776 unsigned long flags;
2777 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2778 __ffs_event_add(ffs, type);
2779 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2782 /* Bind/unbind USB function hooks *******************************************/
2784 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2788 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2789 if (ffs->eps_addrmap[i] == endpoint_address)
2794 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2795 struct usb_descriptor_header *desc,
2798 struct usb_endpoint_descriptor *ds = (void *)desc;
2799 struct ffs_function *func = priv;
2800 struct ffs_ep *ffs_ep;
2801 unsigned ep_desc_id;
2803 static const char *speed_names[] = { "full", "high", "super" };
2805 if (type != FFS_DESCRIPTOR)
2809 * If ss_descriptors is not NULL, we are reading super speed
2810 * descriptors; if hs_descriptors is not NULL, we are reading high
2811 * speed descriptors; otherwise, we are reading full speed
2814 if (func->function.ss_descriptors) {
2816 func->function.ss_descriptors[(long)valuep] = desc;
2817 } else if (func->function.hs_descriptors) {
2819 func->function.hs_descriptors[(long)valuep] = desc;
2822 func->function.fs_descriptors[(long)valuep] = desc;
2825 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2828 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2832 ffs_ep = func->eps + idx;
2834 if (ffs_ep->descs[ep_desc_id]) {
2835 pr_err("two %sspeed descriptors for EP %d\n",
2836 speed_names[ep_desc_id],
2837 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2840 ffs_ep->descs[ep_desc_id] = ds;
2842 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2844 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2845 if (!ds->wMaxPacketSize)
2846 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2848 struct usb_request *req;
2850 u8 bEndpointAddress;
2854 * We back up bEndpointAddress because autoconfig overwrites
2855 * it with physical endpoint address.
2857 bEndpointAddress = ds->bEndpointAddress;
2859 * We back up wMaxPacketSize because autoconfig treats
2860 * endpoint descriptors as if they were full speed.
2862 wMaxPacketSize = ds->wMaxPacketSize;
2863 pr_vdebug("autoconfig\n");
2864 ep = usb_ep_autoconfig(func->gadget, ds);
2867 ep->driver_data = func->eps + idx;
2869 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2875 func->eps_revmap[ds->bEndpointAddress &
2876 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2878 * If we use virtual address mapping, we restore
2879 * original bEndpointAddress value.
2881 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2882 ds->bEndpointAddress = bEndpointAddress;
2884 * Restore wMaxPacketSize which was potentially
2885 * overwritten by autoconfig.
2887 ds->wMaxPacketSize = wMaxPacketSize;
2889 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2894 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2895 struct usb_descriptor_header *desc,
2898 struct ffs_function *func = priv;
2904 case FFS_DESCRIPTOR:
2905 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2910 if (func->interfaces_nums[idx] < 0) {
2911 int id = usb_interface_id(func->conf, &func->function);
2914 func->interfaces_nums[idx] = id;
2916 newValue = func->interfaces_nums[idx];
2920 /* String' IDs are allocated when fsf_data is bound to cdev */
2921 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2926 * USB_DT_ENDPOINT are handled in
2927 * __ffs_func_bind_do_descs().
2929 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2932 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2933 if (!func->eps[idx].ep)
2937 struct usb_endpoint_descriptor **descs;
2938 descs = func->eps[idx].descs;
2939 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2944 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2949 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2950 struct usb_os_desc_header *h, void *data,
2951 unsigned len, void *priv)
2953 struct ffs_function *func = priv;
2957 case FFS_OS_DESC_EXT_COMPAT: {
2958 struct usb_ext_compat_desc *desc = data;
2959 struct usb_os_desc_table *t;
2961 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2962 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2963 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2964 ARRAY_SIZE(desc->CompatibleID) +
2965 ARRAY_SIZE(desc->SubCompatibleID));
2966 length = sizeof(*desc);
2969 case FFS_OS_DESC_EXT_PROP: {
2970 struct usb_ext_prop_desc *desc = data;
2971 struct usb_os_desc_table *t;
2972 struct usb_os_desc_ext_prop *ext_prop;
2973 char *ext_prop_name;
2974 char *ext_prop_data;
2976 t = &func->function.os_desc_table[h->interface];
2977 t->if_id = func->interfaces_nums[h->interface];
2979 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2980 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2982 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2983 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2984 ext_prop->data_len = le32_to_cpu(*(__le32 *)
2985 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2986 length = ext_prop->name_len + ext_prop->data_len + 14;
2988 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2989 func->ffs->ms_os_descs_ext_prop_name_avail +=
2992 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2993 func->ffs->ms_os_descs_ext_prop_data_avail +=
2995 memcpy(ext_prop_data,
2996 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2997 ext_prop->data_len);
2998 /* unicode data reported to the host as "WCHAR"s */
2999 switch (ext_prop->type) {
3000 case USB_EXT_PROP_UNICODE:
3001 case USB_EXT_PROP_UNICODE_ENV:
3002 case USB_EXT_PROP_UNICODE_LINK:
3003 case USB_EXT_PROP_UNICODE_MULTI:
3004 ext_prop->data_len *= 2;
3007 ext_prop->data = ext_prop_data;
3009 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
3010 ext_prop->name_len);
3011 /* property name reported to the host as "WCHAR"s */
3012 ext_prop->name_len *= 2;
3013 ext_prop->name = ext_prop_name;
3015 t->os_desc->ext_prop_len +=
3016 ext_prop->name_len + ext_prop->data_len + 14;
3017 ++t->os_desc->ext_prop_count;
3018 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
3022 pr_vdebug("unknown descriptor: %d\n", type);
3028 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
3029 struct usb_configuration *c)
3031 struct ffs_function *func = ffs_func_from_usb(f);
3032 struct f_fs_opts *ffs_opts =
3033 container_of(f->fi, struct f_fs_opts, func_inst);
3039 * Legacy gadget triggers binding in functionfs_ready_callback,
3040 * which already uses locking; taking the same lock here would
3043 * Configfs-enabled gadgets however do need ffs_dev_lock.
3045 if (!ffs_opts->no_configfs)
3047 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
3048 func->ffs = ffs_opts->dev->ffs_data;
3049 if (!ffs_opts->no_configfs)
3052 return ERR_PTR(ret);
3055 func->gadget = c->cdev->gadget;
3058 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
3059 * configurations are bound in sequence with list_for_each_entry,
3060 * in each configuration its functions are bound in sequence
3061 * with list_for_each_entry, so we assume no race condition
3062 * with regard to ffs_opts->bound access
3064 if (!ffs_opts->refcnt) {
3065 ret = functionfs_bind(func->ffs, c->cdev);
3067 return ERR_PTR(ret);
3070 func->function.strings = func->ffs->stringtabs;
3075 static int _ffs_func_bind(struct usb_configuration *c,
3076 struct usb_function *f)
3078 struct ffs_function *func = ffs_func_from_usb(f);
3079 struct ffs_data *ffs = func->ffs;
3081 const int full = !!func->ffs->fs_descs_count;
3082 const int high = !!func->ffs->hs_descs_count;
3083 const int super = !!func->ffs->ss_descs_count;
3085 int fs_len, hs_len, ss_len, ret, i;
3086 struct ffs_ep *eps_ptr;
3088 /* Make it a single chunk, less management later on */
3090 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
3091 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
3092 full ? ffs->fs_descs_count + 1 : 0);
3093 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
3094 high ? ffs->hs_descs_count + 1 : 0);
3095 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
3096 super ? ffs->ss_descs_count + 1 : 0);
3097 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
3098 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
3099 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3100 vla_item_with_sz(d, char[16], ext_compat,
3101 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3102 vla_item_with_sz(d, struct usb_os_desc, os_desc,
3103 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3104 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
3105 ffs->ms_os_descs_ext_prop_count);
3106 vla_item_with_sz(d, char, ext_prop_name,
3107 ffs->ms_os_descs_ext_prop_name_len);
3108 vla_item_with_sz(d, char, ext_prop_data,
3109 ffs->ms_os_descs_ext_prop_data_len);
3110 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
3115 /* Has descriptors only for speeds gadget does not support */
3116 if (!(full | high | super))
3119 /* Allocate a single chunk, less management later on */
3120 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
3124 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
3125 ffs->ms_os_descs_ext_prop_name_avail =
3126 vla_ptr(vlabuf, d, ext_prop_name);
3127 ffs->ms_os_descs_ext_prop_data_avail =
3128 vla_ptr(vlabuf, d, ext_prop_data);
3130 /* Copy descriptors */
3131 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
3132 ffs->raw_descs_length);
3134 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
3135 eps_ptr = vla_ptr(vlabuf, d, eps);
3136 for (i = 0; i < ffs->eps_count; i++)
3137 eps_ptr[i].num = -1;
3140 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3142 func->eps = vla_ptr(vlabuf, d, eps);
3143 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3146 * Go through all the endpoint descriptors and allocate
3147 * endpoints first, so that later we can rewrite the endpoint
3148 * numbers without worrying that it may be described later on.
3151 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3152 fs_len = ffs_do_descs(ffs->fs_descs_count,
3153 vla_ptr(vlabuf, d, raw_descs),
3155 __ffs_func_bind_do_descs, func);
3165 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3166 hs_len = ffs_do_descs(ffs->hs_descs_count,
3167 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3168 d_raw_descs__sz - fs_len,
3169 __ffs_func_bind_do_descs, func);
3179 func->function.ss_descriptors = func->function.ssp_descriptors =
3180 vla_ptr(vlabuf, d, ss_descs);
3181 ss_len = ffs_do_descs(ffs->ss_descs_count,
3182 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3183 d_raw_descs__sz - fs_len - hs_len,
3184 __ffs_func_bind_do_descs, func);
3194 * Now handle interface numbers allocation and interface and
3195 * endpoint numbers rewriting. We can do that in one go
3198 ret = ffs_do_descs(ffs->fs_descs_count +
3199 (high ? ffs->hs_descs_count : 0) +
3200 (super ? ffs->ss_descs_count : 0),
3201 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3202 __ffs_func_bind_do_nums, func);
3206 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3207 if (c->cdev->use_os_string) {
3208 for (i = 0; i < ffs->interfaces_count; ++i) {
3209 struct usb_os_desc *desc;
3211 desc = func->function.os_desc_table[i].os_desc =
3212 vla_ptr(vlabuf, d, os_desc) +
3213 i * sizeof(struct usb_os_desc);
3214 desc->ext_compat_id =
3215 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3216 INIT_LIST_HEAD(&desc->ext_prop);
3218 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3219 vla_ptr(vlabuf, d, raw_descs) +
3220 fs_len + hs_len + ss_len,
3221 d_raw_descs__sz - fs_len - hs_len -
3223 __ffs_func_bind_do_os_desc, func);
3227 func->function.os_desc_n =
3228 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3230 /* And we're done */
3231 ffs_event_add(ffs, FUNCTIONFS_BIND);
3235 /* XXX Do we need to release all claimed endpoints here? */
3239 static int ffs_func_bind(struct usb_configuration *c,
3240 struct usb_function *f)
3242 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3243 struct ffs_function *func = ffs_func_from_usb(f);
3246 if (IS_ERR(ffs_opts))
3247 return PTR_ERR(ffs_opts);
3249 ret = _ffs_func_bind(c, f);
3250 if (ret && !--ffs_opts->refcnt)
3251 functionfs_unbind(func->ffs);
3257 /* Other USB function hooks *************************************************/
3259 static void ffs_reset_work(struct work_struct *work)
3261 struct ffs_data *ffs = container_of(work,
3262 struct ffs_data, reset_work);
3263 ffs_data_reset(ffs);
3266 static int ffs_func_set_alt(struct usb_function *f,
3267 unsigned interface, unsigned alt)
3269 struct ffs_function *func = ffs_func_from_usb(f);
3270 struct ffs_data *ffs = func->ffs;
3273 if (alt != (unsigned)-1) {
3274 intf = ffs_func_revmap_intf(func, interface);
3280 ffs_func_eps_disable(ffs->func);
3282 if (ffs->state == FFS_DEACTIVATED) {
3283 ffs->state = FFS_CLOSING;
3284 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3285 schedule_work(&ffs->reset_work);
3289 if (ffs->state != FFS_ACTIVE)
3292 if (alt == (unsigned)-1) {
3294 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3299 ret = ffs_func_eps_enable(func);
3301 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3305 static void ffs_func_disable(struct usb_function *f)
3307 ffs_func_set_alt(f, 0, (unsigned)-1);
3310 static int ffs_func_setup(struct usb_function *f,
3311 const struct usb_ctrlrequest *creq)
3313 struct ffs_function *func = ffs_func_from_usb(f);
3314 struct ffs_data *ffs = func->ffs;
3315 unsigned long flags;
3320 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3321 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3322 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3323 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3324 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3327 * Most requests directed to interface go through here
3328 * (notable exceptions are set/get interface) so we need to
3329 * handle them. All other either handled by composite or
3330 * passed to usb_configuration->setup() (if one is set). No
3331 * matter, we will handle requests directed to endpoint here
3332 * as well (as it's straightforward). Other request recipient
3333 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3336 if (ffs->state != FFS_ACTIVE)
3339 switch (creq->bRequestType & USB_RECIP_MASK) {
3340 case USB_RECIP_INTERFACE:
3341 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3346 case USB_RECIP_ENDPOINT:
3347 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3350 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3351 ret = func->ffs->eps_addrmap[ret];
3355 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3356 ret = le16_to_cpu(creq->wIndex);
3361 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3362 ffs->ev.setup = *creq;
3363 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3364 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3365 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3367 return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
3370 static bool ffs_func_req_match(struct usb_function *f,
3371 const struct usb_ctrlrequest *creq,
3374 struct ffs_function *func = ffs_func_from_usb(f);
3376 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3379 switch (creq->bRequestType & USB_RECIP_MASK) {
3380 case USB_RECIP_INTERFACE:
3381 return (ffs_func_revmap_intf(func,
3382 le16_to_cpu(creq->wIndex)) >= 0);
3383 case USB_RECIP_ENDPOINT:
3384 return (ffs_func_revmap_ep(func,
3385 le16_to_cpu(creq->wIndex)) >= 0);
3387 return (bool) (func->ffs->user_flags &
3388 FUNCTIONFS_ALL_CTRL_RECIP);
3392 static void ffs_func_suspend(struct usb_function *f)
3395 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3398 static void ffs_func_resume(struct usb_function *f)
3401 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3405 /* Endpoint and interface numbers reverse mapping ***************************/
3407 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3409 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3410 return num ? num : -EDOM;
3413 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3415 short *nums = func->interfaces_nums;
3416 unsigned count = func->ffs->interfaces_count;
3418 for (; count; --count, ++nums) {
3419 if (*nums >= 0 && *nums == intf)
3420 return nums - func->interfaces_nums;
3427 /* Devices management *******************************************************/
3429 static LIST_HEAD(ffs_devices);
3431 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3433 struct ffs_dev *dev;
3438 list_for_each_entry(dev, &ffs_devices, entry) {
3439 if (strcmp(dev->name, name) == 0)
3447 * ffs_lock must be taken by the caller of this function
3449 static struct ffs_dev *_ffs_get_single_dev(void)
3451 struct ffs_dev *dev;
3453 if (list_is_singular(&ffs_devices)) {
3454 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3463 * ffs_lock must be taken by the caller of this function
3465 static struct ffs_dev *_ffs_find_dev(const char *name)
3467 struct ffs_dev *dev;
3469 dev = _ffs_get_single_dev();
3473 return _ffs_do_find_dev(name);
3476 /* Configfs support *********************************************************/
3478 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3480 return container_of(to_config_group(item), struct f_fs_opts,
3484 static void ffs_attr_release(struct config_item *item)
3486 struct f_fs_opts *opts = to_ffs_opts(item);
3488 usb_put_function_instance(&opts->func_inst);
3491 static struct configfs_item_operations ffs_item_ops = {
3492 .release = ffs_attr_release,
3495 static const struct config_item_type ffs_func_type = {
3496 .ct_item_ops = &ffs_item_ops,
3497 .ct_owner = THIS_MODULE,
3501 /* Function registration interface ******************************************/
3503 static void ffs_free_inst(struct usb_function_instance *f)
3505 struct f_fs_opts *opts;
3507 opts = to_f_fs_opts(f);
3509 _ffs_free_dev(opts->dev);
3514 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3516 if (strlen(name) >= sizeof_field(struct ffs_dev, name))
3517 return -ENAMETOOLONG;
3518 return ffs_name_dev(to_f_fs_opts(fi)->dev, name);
3521 static struct usb_function_instance *ffs_alloc_inst(void)
3523 struct f_fs_opts *opts;
3524 struct ffs_dev *dev;
3526 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3528 return ERR_PTR(-ENOMEM);
3530 opts->func_inst.set_inst_name = ffs_set_inst_name;
3531 opts->func_inst.free_func_inst = ffs_free_inst;
3533 dev = _ffs_alloc_dev();
3537 return ERR_CAST(dev);
3542 config_group_init_type_name(&opts->func_inst.group, "",
3544 return &opts->func_inst;
3547 static void ffs_free(struct usb_function *f)
3549 kfree(ffs_func_from_usb(f));
3552 static void ffs_func_unbind(struct usb_configuration *c,
3553 struct usb_function *f)
3555 struct ffs_function *func = ffs_func_from_usb(f);
3556 struct ffs_data *ffs = func->ffs;
3557 struct f_fs_opts *opts =
3558 container_of(f->fi, struct f_fs_opts, func_inst);
3559 struct ffs_ep *ep = func->eps;
3560 unsigned count = ffs->eps_count;
3561 unsigned long flags;
3564 if (ffs->func == func) {
3565 ffs_func_eps_disable(func);
3569 if (!--opts->refcnt)
3570 functionfs_unbind(ffs);
3572 /* cleanup after autoconfig */
3573 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3575 if (ep->ep && ep->req)
3576 usb_ep_free_request(ep->ep, ep->req);
3580 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3584 * eps, descriptors and interfaces_nums are allocated in the
3585 * same chunk so only one free is required.
3587 func->function.fs_descriptors = NULL;
3588 func->function.hs_descriptors = NULL;
3589 func->function.ss_descriptors = NULL;
3590 func->function.ssp_descriptors = NULL;
3591 func->interfaces_nums = NULL;
3593 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3596 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3598 struct ffs_function *func;
3602 func = kzalloc(sizeof(*func), GFP_KERNEL);
3604 return ERR_PTR(-ENOMEM);
3606 func->function.name = "Function FS Gadget";
3608 func->function.bind = ffs_func_bind;
3609 func->function.unbind = ffs_func_unbind;
3610 func->function.set_alt = ffs_func_set_alt;
3611 func->function.disable = ffs_func_disable;
3612 func->function.setup = ffs_func_setup;
3613 func->function.req_match = ffs_func_req_match;
3614 func->function.suspend = ffs_func_suspend;
3615 func->function.resume = ffs_func_resume;
3616 func->function.free_func = ffs_free;
3618 return &func->function;
3622 * ffs_lock must be taken by the caller of this function
3624 static struct ffs_dev *_ffs_alloc_dev(void)
3626 struct ffs_dev *dev;
3629 if (_ffs_get_single_dev())
3630 return ERR_PTR(-EBUSY);
3632 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3634 return ERR_PTR(-ENOMEM);
3636 if (list_empty(&ffs_devices)) {
3637 ret = functionfs_init();
3640 return ERR_PTR(ret);
3644 list_add(&dev->entry, &ffs_devices);
3649 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3651 struct ffs_dev *existing;
3656 existing = _ffs_do_find_dev(name);
3658 strlcpy(dev->name, name, ARRAY_SIZE(dev->name));
3659 else if (existing != dev)
3666 EXPORT_SYMBOL_GPL(ffs_name_dev);
3668 int ffs_single_dev(struct ffs_dev *dev)
3675 if (!list_is_singular(&ffs_devices))
3683 EXPORT_SYMBOL_GPL(ffs_single_dev);
3686 * ffs_lock must be taken by the caller of this function
3688 static void _ffs_free_dev(struct ffs_dev *dev)
3690 list_del(&dev->entry);
3692 /* Clear the private_data pointer to stop incorrect dev access */
3694 dev->ffs_data->private_data = NULL;
3697 if (list_empty(&ffs_devices))
3698 functionfs_cleanup();
3701 static void *ffs_acquire_dev(const char *dev_name)
3703 struct ffs_dev *ffs_dev;
3708 ffs_dev = _ffs_find_dev(dev_name);
3710 ffs_dev = ERR_PTR(-ENOENT);
3711 else if (ffs_dev->mounted)
3712 ffs_dev = ERR_PTR(-EBUSY);
3713 else if (ffs_dev->ffs_acquire_dev_callback &&
3714 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3715 ffs_dev = ERR_PTR(-ENOENT);
3717 ffs_dev->mounted = true;
3723 static void ffs_release_dev(struct ffs_data *ffs_data)
3725 struct ffs_dev *ffs_dev;
3730 ffs_dev = ffs_data->private_data;
3732 ffs_dev->mounted = false;
3734 if (ffs_dev->ffs_release_dev_callback)
3735 ffs_dev->ffs_release_dev_callback(ffs_dev);
3741 static int ffs_ready(struct ffs_data *ffs)
3743 struct ffs_dev *ffs_obj;
3749 ffs_obj = ffs->private_data;
3754 if (WARN_ON(ffs_obj->desc_ready)) {
3759 ffs_obj->desc_ready = true;
3760 ffs_obj->ffs_data = ffs;
3762 if (ffs_obj->ffs_ready_callback) {
3763 ret = ffs_obj->ffs_ready_callback(ffs);
3768 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3774 static void ffs_closed(struct ffs_data *ffs)
3776 struct ffs_dev *ffs_obj;
3777 struct f_fs_opts *opts;
3778 struct config_item *ci;
3783 ffs_obj = ffs->private_data;
3787 ffs_obj->desc_ready = false;
3788 ffs_obj->ffs_data = NULL;
3790 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3791 ffs_obj->ffs_closed_callback)
3792 ffs_obj->ffs_closed_callback(ffs);
3795 opts = ffs_obj->opts;
3799 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3800 || !kref_read(&opts->func_inst.group.cg_item.ci_kref))
3803 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3806 if (test_bit(FFS_FL_BOUND, &ffs->flags))
3807 unregister_gadget_item(ci);
3813 /* Misc helper functions ****************************************************/
3815 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3818 ? mutex_trylock(mutex) ? 0 : -EAGAIN
3819 : mutex_lock_interruptible(mutex);
3822 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3829 data = kmalloc(len, GFP_KERNEL);
3831 return ERR_PTR(-ENOMEM);
3833 if (copy_from_user(data, buf, len)) {
3835 return ERR_PTR(-EFAULT);
3838 pr_vdebug("Buffer from user space:\n");
3839 ffs_dump_mem("", data, len);
3844 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3845 MODULE_LICENSE("GPL");
3846 MODULE_AUTHOR("Michal Nazarewicz");