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];
128 /* Protects ep->ep and ep->req. */
131 struct ffs_data *ffs;
132 struct ffs_ep *ep; /* P: ffs->eps_lock */
134 struct dentry *dentry;
137 * Buffer for holding data from partial reads which may happen since
138 * we’re rounding user read requests to a multiple of a max packet size.
140 * The pointer is initialised with NULL value and may be set by
141 * __ffs_epfile_read_data function to point to a temporary buffer.
143 * In normal operation, calls to __ffs_epfile_read_buffered will consume
144 * data from said buffer and eventually free it. Importantly, while the
145 * function is using the buffer, it sets the pointer to NULL. This is
146 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
147 * can never run concurrently (they are synchronised by epfile->mutex)
148 * so the latter will not assign a new value to the pointer.
150 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
151 * valid) and sets the pointer to READ_BUFFER_DROP value. This special
152 * value is crux of the synchronisation between ffs_func_eps_disable and
153 * __ffs_epfile_read_data.
155 * Once __ffs_epfile_read_data is about to finish it will try to set the
156 * pointer back to its old value (as described above), but seeing as the
157 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
160 * == State transitions ==
162 * • ptr == NULL: (initial state)
163 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
164 * ◦ __ffs_epfile_read_buffered: nop
165 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
166 * ◦ reading finishes: n/a, not in ‘and reading’ state
168 * ◦ __ffs_epfile_read_buffer_free: nop
169 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL
170 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
171 * ◦ reading finishes: n/a, not in ‘and reading’ state
173 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
174 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
175 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
176 * is always called first
177 * ◦ reading finishes: n/a, not in ‘and reading’ state
178 * • ptr == NULL and reading:
179 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
180 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
181 * ◦ __ffs_epfile_read_data: n/a, mutex is held
182 * ◦ reading finishes and …
183 * … all data read: free buf, go to ptr == NULL
184 * … otherwise: go to ptr == buf and reading
185 * • ptr == DROP and reading:
186 * ◦ __ffs_epfile_read_buffer_free: nop
187 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
188 * ◦ __ffs_epfile_read_data: n/a, mutex is held
189 * ◦ reading finishes: free buf, go to ptr == DROP
191 struct ffs_buffer *read_buffer;
192 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
196 unsigned char in; /* P: ffs->eps_lock */
197 unsigned char isoc; /* P: ffs->eps_lock */
205 char storage[] __counted_by(length);
208 /* ffs_io_data structure ***************************************************/
215 struct iov_iter data;
219 struct mm_struct *mm;
220 struct work_struct work;
223 struct usb_request *req;
227 struct ffs_data *ffs;
230 struct completion done;
233 struct ffs_desc_helper {
234 struct ffs_data *ffs;
235 unsigned interfaces_count;
239 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
240 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
242 static struct dentry *
243 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
244 const struct file_operations *fops);
246 /* Devices management *******************************************************/
248 DEFINE_MUTEX(ffs_lock);
249 EXPORT_SYMBOL_GPL(ffs_lock);
251 static struct ffs_dev *_ffs_find_dev(const char *name);
252 static struct ffs_dev *_ffs_alloc_dev(void);
253 static void _ffs_free_dev(struct ffs_dev *dev);
254 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data);
255 static void ffs_release_dev(struct ffs_dev *ffs_dev);
256 static int ffs_ready(struct ffs_data *ffs);
257 static void ffs_closed(struct ffs_data *ffs);
259 /* Misc helper functions ****************************************************/
261 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
262 __attribute__((warn_unused_result, nonnull));
263 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
264 __attribute__((warn_unused_result, nonnull));
267 /* Control file aka ep0 *****************************************************/
269 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
271 struct ffs_data *ffs = req->context;
273 complete(&ffs->ep0req_completion);
276 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
277 __releases(&ffs->ev.waitq.lock)
279 struct usb_request *req = ffs->ep0req;
283 spin_unlock_irq(&ffs->ev.waitq.lock);
287 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
289 spin_unlock_irq(&ffs->ev.waitq.lock);
295 * UDC layer requires to provide a buffer even for ZLP, but should
296 * not use it at all. Let's provide some poisoned pointer to catch
297 * possible bug in the driver.
299 if (req->buf == NULL)
300 req->buf = (void *)0xDEADBABE;
302 reinit_completion(&ffs->ep0req_completion);
304 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
308 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
310 usb_ep_dequeue(ffs->gadget->ep0, req);
314 ffs->setup_state = FFS_NO_SETUP;
315 return req->status ? req->status : req->actual;
318 static int __ffs_ep0_stall(struct ffs_data *ffs)
320 if (ffs->ev.can_stall) {
321 pr_vdebug("ep0 stall\n");
322 usb_ep_set_halt(ffs->gadget->ep0);
323 ffs->setup_state = FFS_NO_SETUP;
326 pr_debug("bogus ep0 stall!\n");
331 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
332 size_t len, loff_t *ptr)
334 struct ffs_data *ffs = file->private_data;
338 /* Fast check if setup was canceled */
339 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
343 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
348 switch (ffs->state) {
349 case FFS_READ_DESCRIPTORS:
350 case FFS_READ_STRINGS:
357 data = ffs_prepare_buffer(buf, len);
364 if (ffs->state == FFS_READ_DESCRIPTORS) {
365 pr_info("read descriptors\n");
366 ret = __ffs_data_got_descs(ffs, data, len);
370 ffs->state = FFS_READ_STRINGS;
373 pr_info("read strings\n");
374 ret = __ffs_data_got_strings(ffs, data, len);
378 ret = ffs_epfiles_create(ffs);
380 ffs->state = FFS_CLOSING;
384 ffs->state = FFS_ACTIVE;
385 mutex_unlock(&ffs->mutex);
387 ret = ffs_ready(ffs);
389 ffs->state = FFS_CLOSING;
400 * We're called from user space, we can use _irq
401 * rather then _irqsave
403 spin_lock_irq(&ffs->ev.waitq.lock);
404 switch (ffs_setup_state_clear_cancelled(ffs)) {
405 case FFS_SETUP_CANCELLED:
413 case FFS_SETUP_PENDING:
417 /* FFS_SETUP_PENDING */
418 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
419 spin_unlock_irq(&ffs->ev.waitq.lock);
420 ret = __ffs_ep0_stall(ffs);
424 /* FFS_SETUP_PENDING and not stall */
425 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
427 spin_unlock_irq(&ffs->ev.waitq.lock);
429 data = ffs_prepare_buffer(buf, len);
435 spin_lock_irq(&ffs->ev.waitq.lock);
438 * We are guaranteed to be still in FFS_ACTIVE state
439 * but the state of setup could have changed from
440 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
441 * to check for that. If that happened we copied data
442 * from user space in vain but it's unlikely.
444 * For sure we are not in FFS_NO_SETUP since this is
445 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
446 * transition can be performed and it's protected by
449 if (ffs_setup_state_clear_cancelled(ffs) ==
450 FFS_SETUP_CANCELLED) {
453 spin_unlock_irq(&ffs->ev.waitq.lock);
455 /* unlocks spinlock */
456 ret = __ffs_ep0_queue_wait(ffs, data, len);
466 mutex_unlock(&ffs->mutex);
470 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
471 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
473 __releases(&ffs->ev.waitq.lock)
476 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
477 * size of ffs->ev.types array (which is four) so that's how much space
480 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
481 const size_t size = n * sizeof *events;
484 memset(events, 0, size);
487 events[i].type = ffs->ev.types[i];
488 if (events[i].type == FUNCTIONFS_SETUP) {
489 events[i].u.setup = ffs->ev.setup;
490 ffs->setup_state = FFS_SETUP_PENDING;
496 memmove(ffs->ev.types, ffs->ev.types + n,
497 ffs->ev.count * sizeof *ffs->ev.types);
499 spin_unlock_irq(&ffs->ev.waitq.lock);
500 mutex_unlock(&ffs->mutex);
502 return copy_to_user(buf, events, size) ? -EFAULT : size;
505 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
506 size_t len, loff_t *ptr)
508 struct ffs_data *ffs = file->private_data;
513 /* Fast check if setup was canceled */
514 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
518 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
523 if (ffs->state != FFS_ACTIVE) {
529 * We're called from user space, we can use _irq rather then
532 spin_lock_irq(&ffs->ev.waitq.lock);
534 switch (ffs_setup_state_clear_cancelled(ffs)) {
535 case FFS_SETUP_CANCELLED:
540 n = len / sizeof(struct usb_functionfs_event);
546 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
551 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
557 /* unlocks spinlock */
558 return __ffs_ep0_read_events(ffs, buf,
559 min(n, (size_t)ffs->ev.count));
561 case FFS_SETUP_PENDING:
562 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
563 spin_unlock_irq(&ffs->ev.waitq.lock);
564 ret = __ffs_ep0_stall(ffs);
568 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
570 spin_unlock_irq(&ffs->ev.waitq.lock);
573 data = kmalloc(len, GFP_KERNEL);
580 spin_lock_irq(&ffs->ev.waitq.lock);
582 /* See ffs_ep0_write() */
583 if (ffs_setup_state_clear_cancelled(ffs) ==
584 FFS_SETUP_CANCELLED) {
589 /* unlocks spinlock */
590 ret = __ffs_ep0_queue_wait(ffs, data, len);
591 if ((ret > 0) && (copy_to_user(buf, data, len)))
600 spin_unlock_irq(&ffs->ev.waitq.lock);
602 mutex_unlock(&ffs->mutex);
607 static int ffs_ep0_open(struct inode *inode, struct file *file)
609 struct ffs_data *ffs = inode->i_private;
611 if (ffs->state == FFS_CLOSING)
614 file->private_data = ffs;
615 ffs_data_opened(ffs);
617 return stream_open(inode, file);
620 static int ffs_ep0_release(struct inode *inode, struct file *file)
622 struct ffs_data *ffs = file->private_data;
624 ffs_data_closed(ffs);
629 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
631 struct ffs_data *ffs = file->private_data;
632 struct usb_gadget *gadget = ffs->gadget;
635 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
636 struct ffs_function *func = ffs->func;
637 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
638 } else if (gadget && gadget->ops->ioctl) {
639 ret = gadget->ops->ioctl(gadget, code, value);
647 static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait)
649 struct ffs_data *ffs = file->private_data;
650 __poll_t mask = EPOLLWRNORM;
653 poll_wait(file, &ffs->ev.waitq, wait);
655 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
659 switch (ffs->state) {
660 case FFS_READ_DESCRIPTORS:
661 case FFS_READ_STRINGS:
666 switch (ffs->setup_state) {
672 case FFS_SETUP_PENDING:
673 case FFS_SETUP_CANCELLED:
674 mask |= (EPOLLIN | EPOLLOUT);
681 case FFS_DEACTIVATED:
685 mutex_unlock(&ffs->mutex);
690 static const struct file_operations ffs_ep0_operations = {
693 .open = ffs_ep0_open,
694 .write = ffs_ep0_write,
695 .read = ffs_ep0_read,
696 .release = ffs_ep0_release,
697 .unlocked_ioctl = ffs_ep0_ioctl,
698 .poll = ffs_ep0_poll,
702 /* "Normal" endpoints operations ********************************************/
704 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
706 struct ffs_io_data *io_data = req->context;
709 io_data->status = req->status;
711 io_data->status = req->actual;
713 complete(&io_data->done);
716 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
718 ssize_t ret = copy_to_iter(data, data_len, iter);
722 if (iov_iter_count(iter))
726 * Dear user space developer!
728 * TL;DR: To stop getting below error message in your kernel log, change
729 * user space code using functionfs to align read buffers to a max
732 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
733 * packet size. When unaligned buffer is passed to functionfs, it
734 * internally uses a larger, aligned buffer so that such UDCs are happy.
736 * Unfortunately, this means that host may send more data than was
737 * requested in read(2) system call. f_fs doesn’t know what to do with
738 * that excess data so it simply drops it.
740 * Was the buffer aligned in the first place, no such problem would
743 * Data may be dropped only in AIO reads. Synchronous reads are handled
744 * by splitting a request into multiple parts. This splitting may still
745 * be a problem though so it’s likely best to align the buffer
746 * regardless of it being AIO or not..
748 * This only affects OUT endpoints, i.e. reading data with a read(2),
749 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not
752 pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
753 "Align read buffer size to max packet size to avoid the problem.\n",
760 * allocate a virtually contiguous buffer and create a scatterlist describing it
761 * @sg_table - pointer to a place to be filled with sg_table contents
762 * @size - required buffer size
764 static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz)
768 unsigned int n_pages;
775 n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
776 pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL);
782 for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE)
783 pages[i] = vmalloc_to_page(ptr);
785 if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) {
796 static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data,
800 return ffs_build_sg_list(&io_data->sgt, data_len);
802 return kmalloc(data_len, GFP_KERNEL);
805 static inline void ffs_free_buffer(struct ffs_io_data *io_data)
810 if (io_data->use_sg) {
811 sg_free_table(&io_data->sgt);
818 static void ffs_user_copy_worker(struct work_struct *work)
820 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
822 int ret = io_data->status;
823 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
825 if (io_data->read && ret > 0) {
826 kthread_use_mm(io_data->mm);
827 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
828 kthread_unuse_mm(io_data->mm);
831 io_data->kiocb->ki_complete(io_data->kiocb, ret);
833 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
834 eventfd_signal(io_data->ffs->ffs_eventfd);
837 kfree(io_data->to_free);
838 ffs_free_buffer(io_data);
842 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
843 struct usb_request *req)
845 struct ffs_io_data *io_data = req->context;
846 struct ffs_data *ffs = io_data->ffs;
848 io_data->status = req->status ? req->status : req->actual;
849 usb_ep_free_request(_ep, req);
851 INIT_WORK(&io_data->work, ffs_user_copy_worker);
852 queue_work(ffs->io_completion_wq, &io_data->work);
855 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
858 * See comment in struct ffs_epfile for full read_buffer pointer
859 * synchronisation story.
861 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
862 if (buf && buf != READ_BUFFER_DROP)
866 /* Assumes epfile->mutex is held. */
867 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
868 struct iov_iter *iter)
871 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
872 * the buffer while we are using it. See comment in struct ffs_epfile
873 * for full read_buffer pointer synchronisation story.
875 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
877 if (!buf || buf == READ_BUFFER_DROP)
880 ret = copy_to_iter(buf->data, buf->length, iter);
881 if (buf->length == ret) {
886 if (iov_iter_count(iter)) {
893 if (cmpxchg(&epfile->read_buffer, NULL, buf))
899 /* Assumes epfile->mutex is held. */
900 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
901 void *data, int data_len,
902 struct iov_iter *iter)
904 struct ffs_buffer *buf;
906 ssize_t ret = copy_to_iter(data, data_len, iter);
910 if (iov_iter_count(iter))
913 /* See ffs_copy_to_iter for more context. */
914 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
918 buf = kmalloc(struct_size(buf, storage, data_len), GFP_KERNEL);
921 buf->length = data_len;
922 buf->data = buf->storage;
923 memcpy(buf->storage, data + ret, flex_array_size(buf, storage, data_len));
926 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
927 * ffs_func_eps_disable has been called in the meanwhile). See comment
928 * in struct ffs_epfile for full read_buffer pointer synchronisation
931 if (cmpxchg(&epfile->read_buffer, NULL, buf))
937 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
939 struct ffs_epfile *epfile = file->private_data;
940 struct usb_request *req;
943 ssize_t ret, data_len = -EINVAL;
946 /* Are we still active? */
947 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
950 /* Wait for endpoint to be enabled */
953 if (file->f_flags & O_NONBLOCK)
956 ret = wait_event_interruptible(
957 epfile->ffs->wait, (ep = epfile->ep));
963 halt = (!io_data->read == !epfile->in);
964 if (halt && epfile->isoc)
967 /* We will be using request and read_buffer */
968 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
972 /* Allocate & copy */
974 struct usb_gadget *gadget;
977 * Do we have buffered data from previous partial read? Check
978 * that for synchronous case only because we do not have
979 * facility to ‘wake up’ a pending asynchronous read and push
980 * buffered data to it which we would need to make things behave
983 if (!io_data->aio && io_data->read) {
984 ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
990 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
991 * before the waiting completes, so do not assign to 'gadget'
994 gadget = epfile->ffs->gadget;
996 spin_lock_irq(&epfile->ffs->eps_lock);
997 /* In the meantime, endpoint got disabled or changed. */
998 if (epfile->ep != ep) {
1002 data_len = iov_iter_count(&io_data->data);
1004 * Controller may require buffer size to be aligned to
1005 * maxpacketsize of an out endpoint.
1008 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
1010 io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE;
1011 spin_unlock_irq(&epfile->ffs->eps_lock);
1013 data = ffs_alloc_buffer(io_data, data_len);
1018 if (!io_data->read &&
1019 !copy_from_iter_full(data, data_len, &io_data->data)) {
1025 spin_lock_irq(&epfile->ffs->eps_lock);
1027 if (epfile->ep != ep) {
1028 /* In the meantime, endpoint got disabled or changed. */
1031 ret = usb_ep_set_halt(ep->ep);
1034 } else if (data_len == -EINVAL) {
1036 * Sanity Check: even though data_len can't be used
1037 * uninitialized at the time I write this comment, some
1038 * compilers complain about this situation.
1039 * In order to keep the code clean from warnings, data_len is
1040 * being initialized to -EINVAL during its declaration, which
1041 * means we can't rely on compiler anymore to warn no future
1042 * changes won't result in data_len being used uninitialized.
1043 * For such reason, we're adding this redundant sanity check
1046 WARN(1, "%s: data_len == -EINVAL\n", __func__);
1048 } else if (!io_data->aio) {
1049 bool interrupted = false;
1052 if (io_data->use_sg) {
1054 req->sg = io_data->sgt.sgl;
1055 req->num_sgs = io_data->sgt.nents;
1060 req->length = data_len;
1062 io_data->buf = data;
1064 init_completion(&io_data->done);
1065 req->context = io_data;
1066 req->complete = ffs_epfile_io_complete;
1068 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1072 spin_unlock_irq(&epfile->ffs->eps_lock);
1074 if (wait_for_completion_interruptible(&io_data->done)) {
1075 spin_lock_irq(&epfile->ffs->eps_lock);
1076 if (epfile->ep != ep) {
1081 * To avoid race condition with ffs_epfile_io_complete,
1082 * dequeue the request first then check
1083 * status. usb_ep_dequeue API should guarantee no race
1084 * condition with req->complete callback.
1086 usb_ep_dequeue(ep->ep, req);
1087 spin_unlock_irq(&epfile->ffs->eps_lock);
1088 wait_for_completion(&io_data->done);
1089 interrupted = io_data->status < 0;
1094 else if (io_data->read && io_data->status > 0)
1095 ret = __ffs_epfile_read_data(epfile, data, io_data->status,
1098 ret = io_data->status;
1100 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) {
1103 if (io_data->use_sg) {
1105 req->sg = io_data->sgt.sgl;
1106 req->num_sgs = io_data->sgt.nents;
1111 req->length = data_len;
1113 io_data->buf = data;
1114 io_data->ep = ep->ep;
1116 io_data->ffs = epfile->ffs;
1118 req->context = io_data;
1119 req->complete = ffs_epfile_async_io_complete;
1121 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1123 io_data->req = NULL;
1124 usb_ep_free_request(ep->ep, req);
1130 * Do not kfree the buffer in this function. It will be freed
1131 * by ffs_user_copy_worker.
1137 spin_unlock_irq(&epfile->ffs->eps_lock);
1139 mutex_unlock(&epfile->mutex);
1141 if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */
1142 ffs_free_buffer(io_data);
1147 ffs_epfile_open(struct inode *inode, struct file *file)
1149 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);
1157 return stream_open(inode, file);
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;
1167 spin_lock_irqsave(&epfile->ffs->eps_lock, flags);
1169 if (io_data && io_data->ep && io_data->req)
1170 value = usb_ep_dequeue(io_data->ep, io_data->req);
1174 spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);
1179 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
1181 struct ffs_io_data io_data, *p = &io_data;
1184 if (!is_sync_kiocb(kiocb)) {
1185 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1190 memset(p, 0, sizeof(*p));
1197 p->mm = current->mm;
1202 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1204 res = ffs_epfile_io(kiocb->ki_filp, p);
1205 if (res == -EIOCBQUEUED)
1214 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
1216 struct ffs_io_data io_data, *p = &io_data;
1219 if (!is_sync_kiocb(kiocb)) {
1220 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1225 memset(p, 0, sizeof(*p));
1232 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
1233 if (!iter_is_ubuf(&p->data) && !p->to_free) {
1241 p->mm = current->mm;
1246 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1248 res = ffs_epfile_io(kiocb->ki_filp, p);
1249 if (res == -EIOCBQUEUED)
1262 ffs_epfile_release(struct inode *inode, struct file *file)
1264 struct ffs_epfile *epfile = inode->i_private;
1266 __ffs_epfile_read_buffer_free(epfile);
1267 ffs_data_closed(epfile->ffs);
1272 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1273 unsigned long value)
1275 struct ffs_epfile *epfile = file->private_data;
1279 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1282 /* Wait for endpoint to be enabled */
1285 if (file->f_flags & O_NONBLOCK)
1288 ret = wait_event_interruptible(
1289 epfile->ffs->wait, (ep = epfile->ep));
1294 spin_lock_irq(&epfile->ffs->eps_lock);
1296 /* In the meantime, endpoint got disabled or changed. */
1297 if (epfile->ep != ep) {
1298 spin_unlock_irq(&epfile->ffs->eps_lock);
1303 case FUNCTIONFS_FIFO_STATUS:
1304 ret = usb_ep_fifo_status(epfile->ep->ep);
1306 case FUNCTIONFS_FIFO_FLUSH:
1307 usb_ep_fifo_flush(epfile->ep->ep);
1310 case FUNCTIONFS_CLEAR_HALT:
1311 ret = usb_ep_clear_halt(epfile->ep->ep);
1313 case FUNCTIONFS_ENDPOINT_REVMAP:
1314 ret = epfile->ep->num;
1316 case FUNCTIONFS_ENDPOINT_DESC:
1319 struct usb_endpoint_descriptor desc1, *desc;
1321 switch (epfile->ffs->gadget->speed) {
1322 case USB_SPEED_SUPER:
1323 case USB_SPEED_SUPER_PLUS:
1326 case USB_SPEED_HIGH:
1333 desc = epfile->ep->descs[desc_idx];
1334 memcpy(&desc1, desc, desc->bLength);
1336 spin_unlock_irq(&epfile->ffs->eps_lock);
1337 ret = copy_to_user((void __user *)value, &desc1, desc1.bLength);
1345 spin_unlock_irq(&epfile->ffs->eps_lock);
1350 static const struct file_operations ffs_epfile_operations = {
1351 .llseek = no_llseek,
1353 .open = ffs_epfile_open,
1354 .write_iter = ffs_epfile_write_iter,
1355 .read_iter = ffs_epfile_read_iter,
1356 .release = ffs_epfile_release,
1357 .unlocked_ioctl = ffs_epfile_ioctl,
1358 .compat_ioctl = compat_ptr_ioctl,
1362 /* File system and super block operations ***********************************/
1365 * Mounting the file system creates a controller file, used first for
1366 * function configuration then later for event monitoring.
1369 static struct inode *__must_check
1370 ffs_sb_make_inode(struct super_block *sb, void *data,
1371 const struct file_operations *fops,
1372 const struct inode_operations *iops,
1373 struct ffs_file_perms *perms)
1375 struct inode *inode;
1377 inode = new_inode(sb);
1380 struct timespec64 ts = inode_set_ctime_current(inode);
1382 inode->i_ino = get_next_ino();
1383 inode->i_mode = perms->mode;
1384 inode->i_uid = perms->uid;
1385 inode->i_gid = perms->gid;
1386 inode_set_atime_to_ts(inode, ts);
1387 inode_set_mtime_to_ts(inode, ts);
1388 inode->i_private = data;
1390 inode->i_fop = fops;
1398 /* Create "regular" file */
1399 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1400 const char *name, void *data,
1401 const struct file_operations *fops)
1403 struct ffs_data *ffs = sb->s_fs_info;
1404 struct dentry *dentry;
1405 struct inode *inode;
1407 dentry = d_alloc_name(sb->s_root, name);
1411 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1417 d_add(dentry, inode);
1422 static const struct super_operations ffs_sb_operations = {
1423 .statfs = simple_statfs,
1424 .drop_inode = generic_delete_inode,
1427 struct ffs_sb_fill_data {
1428 struct ffs_file_perms perms;
1430 const char *dev_name;
1432 struct ffs_data *ffs_data;
1435 static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc)
1437 struct ffs_sb_fill_data *data = fc->fs_private;
1438 struct inode *inode;
1439 struct ffs_data *ffs = data->ffs_data;
1442 data->ffs_data = NULL;
1443 sb->s_fs_info = ffs;
1444 sb->s_blocksize = PAGE_SIZE;
1445 sb->s_blocksize_bits = PAGE_SHIFT;
1446 sb->s_magic = FUNCTIONFS_MAGIC;
1447 sb->s_op = &ffs_sb_operations;
1448 sb->s_time_gran = 1;
1451 data->perms.mode = data->root_mode;
1452 inode = ffs_sb_make_inode(sb, NULL,
1453 &simple_dir_operations,
1454 &simple_dir_inode_operations,
1456 sb->s_root = d_make_root(inode);
1461 if (!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations))
1476 static const struct fs_parameter_spec ffs_fs_fs_parameters[] = {
1477 fsparam_bool ("no_disconnect", Opt_no_disconnect),
1478 fsparam_u32 ("rmode", Opt_rmode),
1479 fsparam_u32 ("fmode", Opt_fmode),
1480 fsparam_u32 ("mode", Opt_mode),
1481 fsparam_u32 ("uid", Opt_uid),
1482 fsparam_u32 ("gid", Opt_gid),
1486 static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
1488 struct ffs_sb_fill_data *data = fc->fs_private;
1489 struct fs_parse_result result;
1492 opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result);
1497 case Opt_no_disconnect:
1498 data->no_disconnect = result.boolean;
1501 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1504 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1507 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1508 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1512 data->perms.uid = make_kuid(current_user_ns(), result.uint_32);
1513 if (!uid_valid(data->perms.uid))
1514 goto unmapped_value;
1517 data->perms.gid = make_kgid(current_user_ns(), result.uint_32);
1518 if (!gid_valid(data->perms.gid))
1519 goto unmapped_value;
1529 return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32);
1533 * Set up the superblock for a mount.
1535 static int ffs_fs_get_tree(struct fs_context *fc)
1537 struct ffs_sb_fill_data *ctx = fc->fs_private;
1538 struct ffs_data *ffs;
1542 return invalf(fc, "No source specified");
1544 ffs = ffs_data_new(fc->source);
1547 ffs->file_perms = ctx->perms;
1548 ffs->no_disconnect = ctx->no_disconnect;
1550 ffs->dev_name = kstrdup(fc->source, GFP_KERNEL);
1551 if (!ffs->dev_name) {
1556 ret = ffs_acquire_dev(ffs->dev_name, ffs);
1562 ctx->ffs_data = ffs;
1563 return get_tree_nodev(fc, ffs_sb_fill);
1566 static void ffs_fs_free_fc(struct fs_context *fc)
1568 struct ffs_sb_fill_data *ctx = fc->fs_private;
1571 if (ctx->ffs_data) {
1572 ffs_data_put(ctx->ffs_data);
1579 static const struct fs_context_operations ffs_fs_context_ops = {
1580 .free = ffs_fs_free_fc,
1581 .parse_param = ffs_fs_parse_param,
1582 .get_tree = ffs_fs_get_tree,
1585 static int ffs_fs_init_fs_context(struct fs_context *fc)
1587 struct ffs_sb_fill_data *ctx;
1589 ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL);
1593 ctx->perms.mode = S_IFREG | 0600;
1594 ctx->perms.uid = GLOBAL_ROOT_UID;
1595 ctx->perms.gid = GLOBAL_ROOT_GID;
1596 ctx->root_mode = S_IFDIR | 0500;
1597 ctx->no_disconnect = false;
1599 fc->fs_private = ctx;
1600 fc->ops = &ffs_fs_context_ops;
1605 ffs_fs_kill_sb(struct super_block *sb)
1607 kill_litter_super(sb);
1609 ffs_data_closed(sb->s_fs_info);
1612 static struct file_system_type ffs_fs_type = {
1613 .owner = THIS_MODULE,
1614 .name = "functionfs",
1615 .init_fs_context = ffs_fs_init_fs_context,
1616 .parameters = ffs_fs_fs_parameters,
1617 .kill_sb = ffs_fs_kill_sb,
1619 MODULE_ALIAS_FS("functionfs");
1622 /* Driver's main init/cleanup functions *************************************/
1624 static int functionfs_init(void)
1628 ret = register_filesystem(&ffs_fs_type);
1630 pr_info("file system registered\n");
1632 pr_err("failed registering file system (%d)\n", ret);
1637 static void functionfs_cleanup(void)
1639 pr_info("unloading\n");
1640 unregister_filesystem(&ffs_fs_type);
1644 /* ffs_data and ffs_function construction and destruction code **************/
1646 static void ffs_data_clear(struct ffs_data *ffs);
1647 static void ffs_data_reset(struct ffs_data *ffs);
1649 static void ffs_data_get(struct ffs_data *ffs)
1651 refcount_inc(&ffs->ref);
1654 static void ffs_data_opened(struct ffs_data *ffs)
1656 refcount_inc(&ffs->ref);
1657 if (atomic_add_return(1, &ffs->opened) == 1 &&
1658 ffs->state == FFS_DEACTIVATED) {
1659 ffs->state = FFS_CLOSING;
1660 ffs_data_reset(ffs);
1664 static void ffs_data_put(struct ffs_data *ffs)
1666 if (refcount_dec_and_test(&ffs->ref)) {
1667 pr_info("%s(): freeing\n", __func__);
1668 ffs_data_clear(ffs);
1669 ffs_release_dev(ffs->private_data);
1670 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1671 swait_active(&ffs->ep0req_completion.wait) ||
1672 waitqueue_active(&ffs->wait));
1673 destroy_workqueue(ffs->io_completion_wq);
1674 kfree(ffs->dev_name);
1679 static void ffs_data_closed(struct ffs_data *ffs)
1681 struct ffs_epfile *epfiles;
1682 unsigned long flags;
1684 if (atomic_dec_and_test(&ffs->opened)) {
1685 if (ffs->no_disconnect) {
1686 ffs->state = FFS_DEACTIVATED;
1687 spin_lock_irqsave(&ffs->eps_lock, flags);
1688 epfiles = ffs->epfiles;
1689 ffs->epfiles = NULL;
1690 spin_unlock_irqrestore(&ffs->eps_lock,
1694 ffs_epfiles_destroy(epfiles,
1697 if (ffs->setup_state == FFS_SETUP_PENDING)
1698 __ffs_ep0_stall(ffs);
1700 ffs->state = FFS_CLOSING;
1701 ffs_data_reset(ffs);
1704 if (atomic_read(&ffs->opened) < 0) {
1705 ffs->state = FFS_CLOSING;
1706 ffs_data_reset(ffs);
1712 static struct ffs_data *ffs_data_new(const char *dev_name)
1714 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1718 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name);
1719 if (!ffs->io_completion_wq) {
1724 refcount_set(&ffs->ref, 1);
1725 atomic_set(&ffs->opened, 0);
1726 ffs->state = FFS_READ_DESCRIPTORS;
1727 mutex_init(&ffs->mutex);
1728 spin_lock_init(&ffs->eps_lock);
1729 init_waitqueue_head(&ffs->ev.waitq);
1730 init_waitqueue_head(&ffs->wait);
1731 init_completion(&ffs->ep0req_completion);
1733 /* XXX REVISIT need to update it in some places, or do we? */
1734 ffs->ev.can_stall = 1;
1739 static void ffs_data_clear(struct ffs_data *ffs)
1741 struct ffs_epfile *epfiles;
1742 unsigned long flags;
1746 BUG_ON(ffs->gadget);
1748 spin_lock_irqsave(&ffs->eps_lock, flags);
1749 epfiles = ffs->epfiles;
1750 ffs->epfiles = NULL;
1751 spin_unlock_irqrestore(&ffs->eps_lock, flags);
1754 * potential race possible between ffs_func_eps_disable
1755 * & ffs_epfile_release therefore maintaining a local
1756 * copy of epfile will save us from use-after-free.
1759 ffs_epfiles_destroy(epfiles, ffs->eps_count);
1760 ffs->epfiles = NULL;
1763 if (ffs->ffs_eventfd) {
1764 eventfd_ctx_put(ffs->ffs_eventfd);
1765 ffs->ffs_eventfd = NULL;
1768 kfree(ffs->raw_descs_data);
1769 kfree(ffs->raw_strings);
1770 kfree(ffs->stringtabs);
1773 static void ffs_data_reset(struct ffs_data *ffs)
1775 ffs_data_clear(ffs);
1777 ffs->raw_descs_data = NULL;
1778 ffs->raw_descs = NULL;
1779 ffs->raw_strings = NULL;
1780 ffs->stringtabs = NULL;
1782 ffs->raw_descs_length = 0;
1783 ffs->fs_descs_count = 0;
1784 ffs->hs_descs_count = 0;
1785 ffs->ss_descs_count = 0;
1787 ffs->strings_count = 0;
1788 ffs->interfaces_count = 0;
1793 ffs->state = FFS_READ_DESCRIPTORS;
1794 ffs->setup_state = FFS_NO_SETUP;
1797 ffs->ms_os_descs_ext_prop_count = 0;
1798 ffs->ms_os_descs_ext_prop_name_len = 0;
1799 ffs->ms_os_descs_ext_prop_data_len = 0;
1803 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1805 struct usb_gadget_strings **lang;
1808 if (WARN_ON(ffs->state != FFS_ACTIVE
1809 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1812 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1816 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1819 ffs->ep0req->complete = ffs_ep0_complete;
1820 ffs->ep0req->context = ffs;
1822 lang = ffs->stringtabs;
1824 for (; *lang; ++lang) {
1825 struct usb_string *str = (*lang)->strings;
1827 for (; str->s; ++id, ++str)
1832 ffs->gadget = cdev->gadget;
1837 static void functionfs_unbind(struct ffs_data *ffs)
1839 if (!WARN_ON(!ffs->gadget)) {
1840 /* dequeue before freeing ep0req */
1841 usb_ep_dequeue(ffs->gadget->ep0, ffs->ep0req);
1842 mutex_lock(&ffs->mutex);
1843 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1846 clear_bit(FFS_FL_BOUND, &ffs->flags);
1847 mutex_unlock(&ffs->mutex);
1852 static int ffs_epfiles_create(struct ffs_data *ffs)
1854 struct ffs_epfile *epfile, *epfiles;
1857 count = ffs->eps_count;
1858 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1863 for (i = 1; i <= count; ++i, ++epfile) {
1865 mutex_init(&epfile->mutex);
1866 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1867 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1869 sprintf(epfile->name, "ep%u", i);
1870 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1872 &ffs_epfile_operations);
1873 if (!epfile->dentry) {
1874 ffs_epfiles_destroy(epfiles, i - 1);
1879 ffs->epfiles = epfiles;
1883 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1885 struct ffs_epfile *epfile = epfiles;
1887 for (; count; --count, ++epfile) {
1888 BUG_ON(mutex_is_locked(&epfile->mutex));
1889 if (epfile->dentry) {
1890 d_delete(epfile->dentry);
1891 dput(epfile->dentry);
1892 epfile->dentry = NULL;
1899 static void ffs_func_eps_disable(struct ffs_function *func)
1902 struct ffs_epfile *epfile;
1903 unsigned short count;
1904 unsigned long flags;
1906 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1907 count = func->ffs->eps_count;
1908 epfile = func->ffs->epfiles;
1911 /* pending requests get nuked */
1913 usb_ep_disable(ep->ep);
1918 __ffs_epfile_read_buffer_free(epfile);
1922 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1925 static int ffs_func_eps_enable(struct ffs_function *func)
1927 struct ffs_data *ffs;
1929 struct ffs_epfile *epfile;
1930 unsigned short count;
1931 unsigned long flags;
1934 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1937 epfile = ffs->epfiles;
1938 count = ffs->eps_count;
1940 ep->ep->driver_data = ep;
1942 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep);
1944 pr_err("%s: config_ep_by_speed(%s) returned %d\n",
1945 __func__, ep->ep->name, ret);
1949 ret = usb_ep_enable(ep->ep);
1952 epfile->in = usb_endpoint_dir_in(ep->ep->desc);
1953 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
1962 wake_up_interruptible(&ffs->wait);
1963 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1969 /* Parsing and building descriptors and strings *****************************/
1972 * This validates if data pointed by data is a valid USB descriptor as
1973 * well as record how many interfaces, endpoints and strings are
1974 * required by given configuration. Returns address after the
1975 * descriptor or NULL if data is invalid.
1978 enum ffs_entity_type {
1979 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1982 enum ffs_os_desc_type {
1983 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1986 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1988 struct usb_descriptor_header *desc,
1991 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1992 struct usb_os_desc_header *h, void *data,
1993 unsigned len, void *priv);
1995 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1996 ffs_entity_callback entity,
1997 void *priv, int *current_class)
1999 struct usb_descriptor_header *_ds = (void *)data;
2003 /* At least two bytes are required: length and type */
2005 pr_vdebug("descriptor too short\n");
2009 /* If we have at least as many bytes as the descriptor takes? */
2010 length = _ds->bLength;
2012 pr_vdebug("descriptor longer then available data\n");
2016 #define __entity_check_INTERFACE(val) 1
2017 #define __entity_check_STRING(val) (val)
2018 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
2019 #define __entity(type, val) do { \
2020 pr_vdebug("entity " #type "(%02x)\n", (val)); \
2021 if (!__entity_check_ ##type(val)) { \
2022 pr_vdebug("invalid entity's value\n"); \
2025 ret = entity(FFS_ ##type, &val, _ds, priv); \
2027 pr_debug("entity " #type "(%02x); ret = %d\n", \
2033 /* Parse descriptor depending on type. */
2034 switch (_ds->bDescriptorType) {
2038 case USB_DT_DEVICE_QUALIFIER:
2039 /* function can't have any of those */
2040 pr_vdebug("descriptor reserved for gadget: %d\n",
2041 _ds->bDescriptorType);
2044 case USB_DT_INTERFACE: {
2045 struct usb_interface_descriptor *ds = (void *)_ds;
2046 pr_vdebug("interface descriptor\n");
2047 if (length != sizeof *ds)
2050 __entity(INTERFACE, ds->bInterfaceNumber);
2052 __entity(STRING, ds->iInterface);
2053 *current_class = ds->bInterfaceClass;
2057 case USB_DT_ENDPOINT: {
2058 struct usb_endpoint_descriptor *ds = (void *)_ds;
2059 pr_vdebug("endpoint descriptor\n");
2060 if (length != USB_DT_ENDPOINT_SIZE &&
2061 length != USB_DT_ENDPOINT_AUDIO_SIZE)
2063 __entity(ENDPOINT, ds->bEndpointAddress);
2067 case USB_TYPE_CLASS | 0x01:
2068 if (*current_class == USB_INTERFACE_CLASS_HID) {
2069 pr_vdebug("hid descriptor\n");
2070 if (length != sizeof(struct hid_descriptor))
2073 } else if (*current_class == USB_INTERFACE_CLASS_CCID) {
2074 pr_vdebug("ccid descriptor\n");
2075 if (length != sizeof(struct ccid_descriptor))
2079 pr_vdebug("unknown descriptor: %d for class %d\n",
2080 _ds->bDescriptorType, *current_class);
2085 if (length != sizeof(struct usb_otg_descriptor))
2089 case USB_DT_INTERFACE_ASSOCIATION: {
2090 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
2091 pr_vdebug("interface association descriptor\n");
2092 if (length != sizeof *ds)
2095 __entity(STRING, ds->iFunction);
2099 case USB_DT_SS_ENDPOINT_COMP:
2100 pr_vdebug("EP SS companion descriptor\n");
2101 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2105 case USB_DT_OTHER_SPEED_CONFIG:
2106 case USB_DT_INTERFACE_POWER:
2108 case USB_DT_SECURITY:
2109 case USB_DT_CS_RADIO_CONTROL:
2111 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2115 /* We should never be here */
2116 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2120 pr_vdebug("invalid length: %d (descriptor %d)\n",
2121 _ds->bLength, _ds->bDescriptorType);
2126 #undef __entity_check_DESCRIPTOR
2127 #undef __entity_check_INTERFACE
2128 #undef __entity_check_STRING
2129 #undef __entity_check_ENDPOINT
2134 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2135 ffs_entity_callback entity, void *priv)
2137 const unsigned _len = len;
2138 unsigned long num = 0;
2139 int current_class = -1;
2147 /* Record "descriptor" entity */
2148 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2150 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2158 ret = ffs_do_single_desc(data, len, entity, priv,
2161 pr_debug("%s returns %d\n", __func__, ret);
2171 static int __ffs_data_do_entity(enum ffs_entity_type type,
2172 u8 *valuep, struct usb_descriptor_header *desc,
2175 struct ffs_desc_helper *helper = priv;
2176 struct usb_endpoint_descriptor *d;
2179 case FFS_DESCRIPTOR:
2184 * Interfaces are indexed from zero so if we
2185 * encountered interface "n" then there are at least
2188 if (*valuep >= helper->interfaces_count)
2189 helper->interfaces_count = *valuep + 1;
2194 * Strings are indexed from 1 (0 is reserved
2195 * for languages list)
2197 if (*valuep > helper->ffs->strings_count)
2198 helper->ffs->strings_count = *valuep;
2203 helper->eps_count++;
2204 if (helper->eps_count >= FFS_MAX_EPS_COUNT)
2206 /* Check if descriptors for any speed were already parsed */
2207 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2208 helper->ffs->eps_addrmap[helper->eps_count] =
2209 d->bEndpointAddress;
2210 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2211 d->bEndpointAddress)
2219 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2220 struct usb_os_desc_header *desc)
2222 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2223 u16 w_index = le16_to_cpu(desc->wIndex);
2225 if (bcd_version == 0x1) {
2226 pr_warn("bcdVersion must be 0x0100, stored in Little Endian order. "
2227 "Userspace driver should be fixed, accepting 0x0001 for compatibility.\n");
2228 } else if (bcd_version != 0x100) {
2229 pr_vdebug("unsupported os descriptors version: 0x%x\n",
2235 *next_type = FFS_OS_DESC_EXT_COMPAT;
2238 *next_type = FFS_OS_DESC_EXT_PROP;
2241 pr_vdebug("unsupported os descriptor type: %d", w_index);
2245 return sizeof(*desc);
2249 * Process all extended compatibility/extended property descriptors
2250 * of a feature descriptor
2252 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2253 enum ffs_os_desc_type type,
2255 ffs_os_desc_callback entity,
2257 struct usb_os_desc_header *h)
2260 const unsigned _len = len;
2262 /* loop over all ext compat/ext prop descriptors */
2263 while (feature_count--) {
2264 ret = entity(type, h, data, len, priv);
2266 pr_debug("bad OS descriptor, type: %d\n", type);
2275 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2276 static int __must_check ffs_do_os_descs(unsigned count,
2277 char *data, unsigned len,
2278 ffs_os_desc_callback entity, void *priv)
2280 const unsigned _len = len;
2281 unsigned long num = 0;
2283 for (num = 0; num < count; ++num) {
2285 enum ffs_os_desc_type type;
2287 struct usb_os_desc_header *desc = (void *)data;
2289 if (len < sizeof(*desc))
2293 * Record "descriptor" entity.
2294 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2295 * Move the data pointer to the beginning of extended
2296 * compatibilities proper or extended properties proper
2297 * portions of the data
2299 if (le32_to_cpu(desc->dwLength) > len)
2302 ret = __ffs_do_os_desc_header(&type, desc);
2304 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2309 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2311 feature_count = le16_to_cpu(desc->wCount);
2312 if (type == FFS_OS_DESC_EXT_COMPAT &&
2313 (feature_count > 255 || desc->Reserved))
2319 * Process all function/property descriptors
2320 * of this Feature Descriptor
2322 ret = ffs_do_single_os_desc(data, len, type,
2323 feature_count, entity, priv, desc);
2325 pr_debug("%s returns %d\n", __func__, ret);
2336 * Validate contents of the buffer from userspace related to OS descriptors.
2338 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2339 struct usb_os_desc_header *h, void *data,
2340 unsigned len, void *priv)
2342 struct ffs_data *ffs = priv;
2346 case FFS_OS_DESC_EXT_COMPAT: {
2347 struct usb_ext_compat_desc *d = data;
2350 if (len < sizeof(*d) ||
2351 d->bFirstInterfaceNumber >= ffs->interfaces_count)
2353 if (d->Reserved1 != 1) {
2355 * According to the spec, Reserved1 must be set to 1
2356 * but older kernels incorrectly rejected non-zero
2357 * values. We fix it here to avoid returning EINVAL
2358 * in response to values we used to accept.
2360 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
2363 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2364 if (d->Reserved2[i])
2367 length = sizeof(struct usb_ext_compat_desc);
2370 case FFS_OS_DESC_EXT_PROP: {
2371 struct usb_ext_prop_desc *d = data;
2375 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2377 length = le32_to_cpu(d->dwSize);
2380 type = le32_to_cpu(d->dwPropertyDataType);
2381 if (type < USB_EXT_PROP_UNICODE ||
2382 type > USB_EXT_PROP_UNICODE_MULTI) {
2383 pr_vdebug("unsupported os descriptor property type: %d",
2387 pnl = le16_to_cpu(d->wPropertyNameLength);
2388 if (length < 14 + pnl) {
2389 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2393 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl));
2394 if (length != 14 + pnl + pdl) {
2395 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2396 length, pnl, pdl, type);
2399 ++ffs->ms_os_descs_ext_prop_count;
2400 /* property name reported to the host as "WCHAR"s */
2401 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2402 ffs->ms_os_descs_ext_prop_data_len += pdl;
2406 pr_vdebug("unknown descriptor: %d\n", type);
2412 static int __ffs_data_got_descs(struct ffs_data *ffs,
2413 char *const _data, size_t len)
2415 char *data = _data, *raw_descs;
2416 unsigned os_descs_count = 0, counts[3], flags;
2417 int ret = -EINVAL, i;
2418 struct ffs_desc_helper helper;
2420 if (get_unaligned_le32(data + 4) != len)
2423 switch (get_unaligned_le32(data)) {
2424 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2425 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2429 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2430 flags = get_unaligned_le32(data + 8);
2431 ffs->user_flags = flags;
2432 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2433 FUNCTIONFS_HAS_HS_DESC |
2434 FUNCTIONFS_HAS_SS_DESC |
2435 FUNCTIONFS_HAS_MS_OS_DESC |
2436 FUNCTIONFS_VIRTUAL_ADDR |
2437 FUNCTIONFS_EVENTFD |
2438 FUNCTIONFS_ALL_CTRL_RECIP |
2439 FUNCTIONFS_CONFIG0_SETUP)) {
2450 if (flags & FUNCTIONFS_EVENTFD) {
2454 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2455 if (IS_ERR(ffs->ffs_eventfd)) {
2456 ret = PTR_ERR(ffs->ffs_eventfd);
2457 ffs->ffs_eventfd = NULL;
2464 /* Read fs_count, hs_count and ss_count (if present) */
2465 for (i = 0; i < 3; ++i) {
2466 if (!(flags & (1 << i))) {
2468 } else if (len < 4) {
2471 counts[i] = get_unaligned_le32(data);
2476 if (flags & (1 << i)) {
2480 os_descs_count = get_unaligned_le32(data);
2485 /* Read descriptors */
2488 for (i = 0; i < 3; ++i) {
2491 helper.interfaces_count = 0;
2492 helper.eps_count = 0;
2493 ret = ffs_do_descs(counts[i], data, len,
2494 __ffs_data_do_entity, &helper);
2497 if (!ffs->eps_count && !ffs->interfaces_count) {
2498 ffs->eps_count = helper.eps_count;
2499 ffs->interfaces_count = helper.interfaces_count;
2501 if (ffs->eps_count != helper.eps_count) {
2505 if (ffs->interfaces_count != helper.interfaces_count) {
2513 if (os_descs_count) {
2514 ret = ffs_do_os_descs(os_descs_count, data, len,
2515 __ffs_data_do_os_desc, ffs);
2522 if (raw_descs == data || len) {
2527 ffs->raw_descs_data = _data;
2528 ffs->raw_descs = raw_descs;
2529 ffs->raw_descs_length = data - raw_descs;
2530 ffs->fs_descs_count = counts[0];
2531 ffs->hs_descs_count = counts[1];
2532 ffs->ss_descs_count = counts[2];
2533 ffs->ms_os_descs_count = os_descs_count;
2542 static int __ffs_data_got_strings(struct ffs_data *ffs,
2543 char *const _data, size_t len)
2545 u32 str_count, needed_count, lang_count;
2546 struct usb_gadget_strings **stringtabs, *t;
2547 const char *data = _data;
2548 struct usb_string *s;
2551 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2552 get_unaligned_le32(data + 4) != len)
2554 str_count = get_unaligned_le32(data + 8);
2555 lang_count = get_unaligned_le32(data + 12);
2557 /* if one is zero the other must be zero */
2558 if (!str_count != !lang_count)
2561 /* Do we have at least as many strings as descriptors need? */
2562 needed_count = ffs->strings_count;
2563 if (str_count < needed_count)
2567 * If we don't need any strings just return and free all
2570 if (!needed_count) {
2575 /* Allocate everything in one chunk so there's less maintenance. */
2579 vla_item(d, struct usb_gadget_strings *, stringtabs,
2580 size_add(lang_count, 1));
2581 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2582 vla_item(d, struct usb_string, strings,
2583 size_mul(lang_count, (needed_count + 1)));
2585 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2592 /* Initialize the VLA pointers */
2593 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2594 t = vla_ptr(vlabuf, d, stringtab);
2597 *stringtabs++ = t++;
2601 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2602 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2603 t = vla_ptr(vlabuf, d, stringtab);
2604 s = vla_ptr(vlabuf, d, strings);
2607 /* For each language */
2611 do { /* lang_count > 0 so we can use do-while */
2612 unsigned needed = needed_count;
2613 u32 str_per_lang = str_count;
2617 t->language = get_unaligned_le16(data);
2624 /* For each string */
2625 do { /* str_count > 0 so we can use do-while */
2626 size_t length = strnlen(data, len);
2632 * User may provide more strings then we need,
2633 * if that's the case we simply ignore the
2638 * s->id will be set while adding
2639 * function to configuration so for
2640 * now just leave garbage here.
2649 } while (--str_per_lang);
2651 s->id = 0; /* terminator */
2655 } while (--lang_count);
2657 /* Some garbage left? */
2662 ffs->stringtabs = stringtabs;
2663 ffs->raw_strings = _data;
2675 /* Events handling and management *******************************************/
2677 static void __ffs_event_add(struct ffs_data *ffs,
2678 enum usb_functionfs_event_type type)
2680 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2684 * Abort any unhandled setup
2686 * We do not need to worry about some cmpxchg() changing value
2687 * of ffs->setup_state without holding the lock because when
2688 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2689 * the source does nothing.
2691 if (ffs->setup_state == FFS_SETUP_PENDING)
2692 ffs->setup_state = FFS_SETUP_CANCELLED;
2695 * Logic of this function guarantees that there are at most four pending
2696 * evens on ffs->ev.types queue. This is important because the queue
2697 * has space for four elements only and __ffs_ep0_read_events function
2698 * depends on that limit as well. If more event types are added, those
2699 * limits have to be revisited or guaranteed to still hold.
2702 case FUNCTIONFS_RESUME:
2703 rem_type2 = FUNCTIONFS_SUSPEND;
2705 case FUNCTIONFS_SUSPEND:
2706 case FUNCTIONFS_SETUP:
2708 /* Discard all similar events */
2711 case FUNCTIONFS_BIND:
2712 case FUNCTIONFS_UNBIND:
2713 case FUNCTIONFS_DISABLE:
2714 case FUNCTIONFS_ENABLE:
2715 /* Discard everything other then power management. */
2716 rem_type1 = FUNCTIONFS_SUSPEND;
2717 rem_type2 = FUNCTIONFS_RESUME;
2722 WARN(1, "%d: unknown event, this should not happen\n", type);
2727 u8 *ev = ffs->ev.types, *out = ev;
2728 unsigned n = ffs->ev.count;
2729 for (; n; --n, ++ev)
2730 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2733 pr_vdebug("purging event %d\n", *ev);
2734 ffs->ev.count = out - ffs->ev.types;
2737 pr_vdebug("adding event %d\n", type);
2738 ffs->ev.types[ffs->ev.count++] = type;
2739 wake_up_locked(&ffs->ev.waitq);
2740 if (ffs->ffs_eventfd)
2741 eventfd_signal(ffs->ffs_eventfd);
2744 static void ffs_event_add(struct ffs_data *ffs,
2745 enum usb_functionfs_event_type type)
2747 unsigned long flags;
2748 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2749 __ffs_event_add(ffs, type);
2750 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2753 /* Bind/unbind USB function hooks *******************************************/
2755 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2759 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2760 if (ffs->eps_addrmap[i] == endpoint_address)
2765 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2766 struct usb_descriptor_header *desc,
2769 struct usb_endpoint_descriptor *ds = (void *)desc;
2770 struct ffs_function *func = priv;
2771 struct ffs_ep *ffs_ep;
2772 unsigned ep_desc_id;
2774 static const char *speed_names[] = { "full", "high", "super" };
2776 if (type != FFS_DESCRIPTOR)
2780 * If ss_descriptors is not NULL, we are reading super speed
2781 * descriptors; if hs_descriptors is not NULL, we are reading high
2782 * speed descriptors; otherwise, we are reading full speed
2785 if (func->function.ss_descriptors) {
2787 func->function.ss_descriptors[(long)valuep] = desc;
2788 } else if (func->function.hs_descriptors) {
2790 func->function.hs_descriptors[(long)valuep] = desc;
2793 func->function.fs_descriptors[(long)valuep] = desc;
2796 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2799 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2803 ffs_ep = func->eps + idx;
2805 if (ffs_ep->descs[ep_desc_id]) {
2806 pr_err("two %sspeed descriptors for EP %d\n",
2807 speed_names[ep_desc_id],
2808 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2811 ffs_ep->descs[ep_desc_id] = ds;
2813 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2815 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2816 if (!ds->wMaxPacketSize)
2817 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2819 struct usb_request *req;
2821 u8 bEndpointAddress;
2825 * We back up bEndpointAddress because autoconfig overwrites
2826 * it with physical endpoint address.
2828 bEndpointAddress = ds->bEndpointAddress;
2830 * We back up wMaxPacketSize because autoconfig treats
2831 * endpoint descriptors as if they were full speed.
2833 wMaxPacketSize = ds->wMaxPacketSize;
2834 pr_vdebug("autoconfig\n");
2835 ep = usb_ep_autoconfig(func->gadget, ds);
2838 ep->driver_data = func->eps + idx;
2840 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2846 func->eps_revmap[ds->bEndpointAddress &
2847 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2849 * If we use virtual address mapping, we restore
2850 * original bEndpointAddress value.
2852 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2853 ds->bEndpointAddress = bEndpointAddress;
2855 * Restore wMaxPacketSize which was potentially
2856 * overwritten by autoconfig.
2858 ds->wMaxPacketSize = wMaxPacketSize;
2860 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2865 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2866 struct usb_descriptor_header *desc,
2869 struct ffs_function *func = priv;
2875 case FFS_DESCRIPTOR:
2876 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2881 if (func->interfaces_nums[idx] < 0) {
2882 int id = usb_interface_id(func->conf, &func->function);
2885 func->interfaces_nums[idx] = id;
2887 newValue = func->interfaces_nums[idx];
2891 /* String' IDs are allocated when fsf_data is bound to cdev */
2892 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2897 * USB_DT_ENDPOINT are handled in
2898 * __ffs_func_bind_do_descs().
2900 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2903 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2904 if (!func->eps[idx].ep)
2908 struct usb_endpoint_descriptor **descs;
2909 descs = func->eps[idx].descs;
2910 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2915 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2920 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2921 struct usb_os_desc_header *h, void *data,
2922 unsigned len, void *priv)
2924 struct ffs_function *func = priv;
2928 case FFS_OS_DESC_EXT_COMPAT: {
2929 struct usb_ext_compat_desc *desc = data;
2930 struct usb_os_desc_table *t;
2932 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2933 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2934 memcpy(t->os_desc->ext_compat_id, &desc->IDs,
2935 sizeof_field(struct usb_ext_compat_desc, IDs));
2936 length = sizeof(*desc);
2939 case FFS_OS_DESC_EXT_PROP: {
2940 struct usb_ext_prop_desc *desc = data;
2941 struct usb_os_desc_table *t;
2942 struct usb_os_desc_ext_prop *ext_prop;
2943 char *ext_prop_name;
2944 char *ext_prop_data;
2946 t = &func->function.os_desc_table[h->interface];
2947 t->if_id = func->interfaces_nums[h->interface];
2949 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2950 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2952 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2953 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2954 ext_prop->data_len = le32_to_cpu(*(__le32 *)
2955 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2956 length = ext_prop->name_len + ext_prop->data_len + 14;
2958 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2959 func->ffs->ms_os_descs_ext_prop_name_avail +=
2962 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2963 func->ffs->ms_os_descs_ext_prop_data_avail +=
2965 memcpy(ext_prop_data,
2966 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2967 ext_prop->data_len);
2968 /* unicode data reported to the host as "WCHAR"s */
2969 switch (ext_prop->type) {
2970 case USB_EXT_PROP_UNICODE:
2971 case USB_EXT_PROP_UNICODE_ENV:
2972 case USB_EXT_PROP_UNICODE_LINK:
2973 case USB_EXT_PROP_UNICODE_MULTI:
2974 ext_prop->data_len *= 2;
2977 ext_prop->data = ext_prop_data;
2979 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2980 ext_prop->name_len);
2981 /* property name reported to the host as "WCHAR"s */
2982 ext_prop->name_len *= 2;
2983 ext_prop->name = ext_prop_name;
2985 t->os_desc->ext_prop_len +=
2986 ext_prop->name_len + ext_prop->data_len + 14;
2987 ++t->os_desc->ext_prop_count;
2988 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2992 pr_vdebug("unknown descriptor: %d\n", type);
2998 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2999 struct usb_configuration *c)
3001 struct ffs_function *func = ffs_func_from_usb(f);
3002 struct f_fs_opts *ffs_opts =
3003 container_of(f->fi, struct f_fs_opts, func_inst);
3004 struct ffs_data *ffs_data;
3008 * Legacy gadget triggers binding in functionfs_ready_callback,
3009 * which already uses locking; taking the same lock here would
3012 * Configfs-enabled gadgets however do need ffs_dev_lock.
3014 if (!ffs_opts->no_configfs)
3016 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
3017 ffs_data = ffs_opts->dev->ffs_data;
3018 if (!ffs_opts->no_configfs)
3021 return ERR_PTR(ret);
3023 func->ffs = ffs_data;
3025 func->gadget = c->cdev->gadget;
3028 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
3029 * configurations are bound in sequence with list_for_each_entry,
3030 * in each configuration its functions are bound in sequence
3031 * with list_for_each_entry, so we assume no race condition
3032 * with regard to ffs_opts->bound access
3034 if (!ffs_opts->refcnt) {
3035 ret = functionfs_bind(func->ffs, c->cdev);
3037 return ERR_PTR(ret);
3040 func->function.strings = func->ffs->stringtabs;
3045 static int _ffs_func_bind(struct usb_configuration *c,
3046 struct usb_function *f)
3048 struct ffs_function *func = ffs_func_from_usb(f);
3049 struct ffs_data *ffs = func->ffs;
3051 const int full = !!func->ffs->fs_descs_count;
3052 const int high = !!func->ffs->hs_descs_count;
3053 const int super = !!func->ffs->ss_descs_count;
3055 int fs_len, hs_len, ss_len, ret, i;
3056 struct ffs_ep *eps_ptr;
3058 /* Make it a single chunk, less management later on */
3060 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
3061 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
3062 full ? ffs->fs_descs_count + 1 : 0);
3063 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
3064 high ? ffs->hs_descs_count + 1 : 0);
3065 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
3066 super ? ffs->ss_descs_count + 1 : 0);
3067 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
3068 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
3069 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3070 vla_item_with_sz(d, char[16], ext_compat,
3071 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3072 vla_item_with_sz(d, struct usb_os_desc, os_desc,
3073 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3074 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
3075 ffs->ms_os_descs_ext_prop_count);
3076 vla_item_with_sz(d, char, ext_prop_name,
3077 ffs->ms_os_descs_ext_prop_name_len);
3078 vla_item_with_sz(d, char, ext_prop_data,
3079 ffs->ms_os_descs_ext_prop_data_len);
3080 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
3083 /* Has descriptors only for speeds gadget does not support */
3084 if (!(full | high | super))
3087 /* Allocate a single chunk, less management later on */
3088 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
3092 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
3093 ffs->ms_os_descs_ext_prop_name_avail =
3094 vla_ptr(vlabuf, d, ext_prop_name);
3095 ffs->ms_os_descs_ext_prop_data_avail =
3096 vla_ptr(vlabuf, d, ext_prop_data);
3098 /* Copy descriptors */
3099 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
3100 ffs->raw_descs_length);
3102 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
3103 eps_ptr = vla_ptr(vlabuf, d, eps);
3104 for (i = 0; i < ffs->eps_count; i++)
3105 eps_ptr[i].num = -1;
3108 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3110 func->eps = vla_ptr(vlabuf, d, eps);
3111 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3114 * Go through all the endpoint descriptors and allocate
3115 * endpoints first, so that later we can rewrite the endpoint
3116 * numbers without worrying that it may be described later on.
3119 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3120 fs_len = ffs_do_descs(ffs->fs_descs_count,
3121 vla_ptr(vlabuf, d, raw_descs),
3123 __ffs_func_bind_do_descs, func);
3133 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3134 hs_len = ffs_do_descs(ffs->hs_descs_count,
3135 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3136 d_raw_descs__sz - fs_len,
3137 __ffs_func_bind_do_descs, func);
3147 func->function.ss_descriptors = func->function.ssp_descriptors =
3148 vla_ptr(vlabuf, d, ss_descs);
3149 ss_len = ffs_do_descs(ffs->ss_descs_count,
3150 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3151 d_raw_descs__sz - fs_len - hs_len,
3152 __ffs_func_bind_do_descs, func);
3162 * Now handle interface numbers allocation and interface and
3163 * endpoint numbers rewriting. We can do that in one go
3166 ret = ffs_do_descs(ffs->fs_descs_count +
3167 (high ? ffs->hs_descs_count : 0) +
3168 (super ? ffs->ss_descs_count : 0),
3169 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3170 __ffs_func_bind_do_nums, func);
3174 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3175 if (c->cdev->use_os_string) {
3176 for (i = 0; i < ffs->interfaces_count; ++i) {
3177 struct usb_os_desc *desc;
3179 desc = func->function.os_desc_table[i].os_desc =
3180 vla_ptr(vlabuf, d, os_desc) +
3181 i * sizeof(struct usb_os_desc);
3182 desc->ext_compat_id =
3183 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3184 INIT_LIST_HEAD(&desc->ext_prop);
3186 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3187 vla_ptr(vlabuf, d, raw_descs) +
3188 fs_len + hs_len + ss_len,
3189 d_raw_descs__sz - fs_len - hs_len -
3191 __ffs_func_bind_do_os_desc, func);
3195 func->function.os_desc_n =
3196 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3198 /* And we're done */
3199 ffs_event_add(ffs, FUNCTIONFS_BIND);
3203 /* XXX Do we need to release all claimed endpoints here? */
3207 static int ffs_func_bind(struct usb_configuration *c,
3208 struct usb_function *f)
3210 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3211 struct ffs_function *func = ffs_func_from_usb(f);
3214 if (IS_ERR(ffs_opts))
3215 return PTR_ERR(ffs_opts);
3217 ret = _ffs_func_bind(c, f);
3218 if (ret && !--ffs_opts->refcnt)
3219 functionfs_unbind(func->ffs);
3225 /* Other USB function hooks *************************************************/
3227 static void ffs_reset_work(struct work_struct *work)
3229 struct ffs_data *ffs = container_of(work,
3230 struct ffs_data, reset_work);
3231 ffs_data_reset(ffs);
3234 static int ffs_func_set_alt(struct usb_function *f,
3235 unsigned interface, unsigned alt)
3237 struct ffs_function *func = ffs_func_from_usb(f);
3238 struct ffs_data *ffs = func->ffs;
3241 if (alt != (unsigned)-1) {
3242 intf = ffs_func_revmap_intf(func, interface);
3248 ffs_func_eps_disable(ffs->func);
3250 if (ffs->state == FFS_DEACTIVATED) {
3251 ffs->state = FFS_CLOSING;
3252 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3253 schedule_work(&ffs->reset_work);
3257 if (ffs->state != FFS_ACTIVE)
3260 if (alt == (unsigned)-1) {
3262 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3267 ret = ffs_func_eps_enable(func);
3269 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3273 static void ffs_func_disable(struct usb_function *f)
3275 ffs_func_set_alt(f, 0, (unsigned)-1);
3278 static int ffs_func_setup(struct usb_function *f,
3279 const struct usb_ctrlrequest *creq)
3281 struct ffs_function *func = ffs_func_from_usb(f);
3282 struct ffs_data *ffs = func->ffs;
3283 unsigned long flags;
3286 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3287 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3288 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3289 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3290 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3293 * Most requests directed to interface go through here
3294 * (notable exceptions are set/get interface) so we need to
3295 * handle them. All other either handled by composite or
3296 * passed to usb_configuration->setup() (if one is set). No
3297 * matter, we will handle requests directed to endpoint here
3298 * as well (as it's straightforward). Other request recipient
3299 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3302 if (ffs->state != FFS_ACTIVE)
3305 switch (creq->bRequestType & USB_RECIP_MASK) {
3306 case USB_RECIP_INTERFACE:
3307 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3312 case USB_RECIP_ENDPOINT:
3313 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3316 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3317 ret = func->ffs->eps_addrmap[ret];
3321 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3322 ret = le16_to_cpu(creq->wIndex);
3327 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3328 ffs->ev.setup = *creq;
3329 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3330 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3331 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3333 return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
3336 static bool ffs_func_req_match(struct usb_function *f,
3337 const struct usb_ctrlrequest *creq,
3340 struct ffs_function *func = ffs_func_from_usb(f);
3342 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3345 switch (creq->bRequestType & USB_RECIP_MASK) {
3346 case USB_RECIP_INTERFACE:
3347 return (ffs_func_revmap_intf(func,
3348 le16_to_cpu(creq->wIndex)) >= 0);
3349 case USB_RECIP_ENDPOINT:
3350 return (ffs_func_revmap_ep(func,
3351 le16_to_cpu(creq->wIndex)) >= 0);
3353 return (bool) (func->ffs->user_flags &
3354 FUNCTIONFS_ALL_CTRL_RECIP);
3358 static void ffs_func_suspend(struct usb_function *f)
3360 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3363 static void ffs_func_resume(struct usb_function *f)
3365 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3369 /* Endpoint and interface numbers reverse mapping ***************************/
3371 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3373 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3374 return num ? num : -EDOM;
3377 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3379 short *nums = func->interfaces_nums;
3380 unsigned count = func->ffs->interfaces_count;
3382 for (; count; --count, ++nums) {
3383 if (*nums >= 0 && *nums == intf)
3384 return nums - func->interfaces_nums;
3391 /* Devices management *******************************************************/
3393 static LIST_HEAD(ffs_devices);
3395 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3397 struct ffs_dev *dev;
3402 list_for_each_entry(dev, &ffs_devices, entry) {
3403 if (strcmp(dev->name, name) == 0)
3411 * ffs_lock must be taken by the caller of this function
3413 static struct ffs_dev *_ffs_get_single_dev(void)
3415 struct ffs_dev *dev;
3417 if (list_is_singular(&ffs_devices)) {
3418 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3427 * ffs_lock must be taken by the caller of this function
3429 static struct ffs_dev *_ffs_find_dev(const char *name)
3431 struct ffs_dev *dev;
3433 dev = _ffs_get_single_dev();
3437 return _ffs_do_find_dev(name);
3440 /* Configfs support *********************************************************/
3442 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3444 return container_of(to_config_group(item), struct f_fs_opts,
3448 static void ffs_attr_release(struct config_item *item)
3450 struct f_fs_opts *opts = to_ffs_opts(item);
3452 usb_put_function_instance(&opts->func_inst);
3455 static struct configfs_item_operations ffs_item_ops = {
3456 .release = ffs_attr_release,
3459 static const struct config_item_type ffs_func_type = {
3460 .ct_item_ops = &ffs_item_ops,
3461 .ct_owner = THIS_MODULE,
3465 /* Function registration interface ******************************************/
3467 static void ffs_free_inst(struct usb_function_instance *f)
3469 struct f_fs_opts *opts;
3471 opts = to_f_fs_opts(f);
3472 ffs_release_dev(opts->dev);
3474 _ffs_free_dev(opts->dev);
3479 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3481 if (strlen(name) >= sizeof_field(struct ffs_dev, name))
3482 return -ENAMETOOLONG;
3483 return ffs_name_dev(to_f_fs_opts(fi)->dev, name);
3486 static struct usb_function_instance *ffs_alloc_inst(void)
3488 struct f_fs_opts *opts;
3489 struct ffs_dev *dev;
3491 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3493 return ERR_PTR(-ENOMEM);
3495 opts->func_inst.set_inst_name = ffs_set_inst_name;
3496 opts->func_inst.free_func_inst = ffs_free_inst;
3498 dev = _ffs_alloc_dev();
3502 return ERR_CAST(dev);
3507 config_group_init_type_name(&opts->func_inst.group, "",
3509 return &opts->func_inst;
3512 static void ffs_free(struct usb_function *f)
3514 kfree(ffs_func_from_usb(f));
3517 static void ffs_func_unbind(struct usb_configuration *c,
3518 struct usb_function *f)
3520 struct ffs_function *func = ffs_func_from_usb(f);
3521 struct ffs_data *ffs = func->ffs;
3522 struct f_fs_opts *opts =
3523 container_of(f->fi, struct f_fs_opts, func_inst);
3524 struct ffs_ep *ep = func->eps;
3525 unsigned count = ffs->eps_count;
3526 unsigned long flags;
3528 if (ffs->func == func) {
3529 ffs_func_eps_disable(func);
3533 /* Drain any pending AIO completions */
3534 drain_workqueue(ffs->io_completion_wq);
3536 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3537 if (!--opts->refcnt)
3538 functionfs_unbind(ffs);
3540 /* cleanup after autoconfig */
3541 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3543 if (ep->ep && ep->req)
3544 usb_ep_free_request(ep->ep, ep->req);
3548 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3552 * eps, descriptors and interfaces_nums are allocated in the
3553 * same chunk so only one free is required.
3555 func->function.fs_descriptors = NULL;
3556 func->function.hs_descriptors = NULL;
3557 func->function.ss_descriptors = NULL;
3558 func->function.ssp_descriptors = NULL;
3559 func->interfaces_nums = NULL;
3563 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3565 struct ffs_function *func;
3567 func = kzalloc(sizeof(*func), GFP_KERNEL);
3569 return ERR_PTR(-ENOMEM);
3571 func->function.name = "Function FS Gadget";
3573 func->function.bind = ffs_func_bind;
3574 func->function.unbind = ffs_func_unbind;
3575 func->function.set_alt = ffs_func_set_alt;
3576 func->function.disable = ffs_func_disable;
3577 func->function.setup = ffs_func_setup;
3578 func->function.req_match = ffs_func_req_match;
3579 func->function.suspend = ffs_func_suspend;
3580 func->function.resume = ffs_func_resume;
3581 func->function.free_func = ffs_free;
3583 return &func->function;
3587 * ffs_lock must be taken by the caller of this function
3589 static struct ffs_dev *_ffs_alloc_dev(void)
3591 struct ffs_dev *dev;
3594 if (_ffs_get_single_dev())
3595 return ERR_PTR(-EBUSY);
3597 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3599 return ERR_PTR(-ENOMEM);
3601 if (list_empty(&ffs_devices)) {
3602 ret = functionfs_init();
3605 return ERR_PTR(ret);
3609 list_add(&dev->entry, &ffs_devices);
3614 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3616 struct ffs_dev *existing;
3621 existing = _ffs_do_find_dev(name);
3623 strscpy(dev->name, name, ARRAY_SIZE(dev->name));
3624 else if (existing != dev)
3631 EXPORT_SYMBOL_GPL(ffs_name_dev);
3633 int ffs_single_dev(struct ffs_dev *dev)
3640 if (!list_is_singular(&ffs_devices))
3648 EXPORT_SYMBOL_GPL(ffs_single_dev);
3651 * ffs_lock must be taken by the caller of this function
3653 static void _ffs_free_dev(struct ffs_dev *dev)
3655 list_del(&dev->entry);
3658 if (list_empty(&ffs_devices))
3659 functionfs_cleanup();
3662 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data)
3665 struct ffs_dev *ffs_dev;
3669 ffs_dev = _ffs_find_dev(dev_name);
3672 } else if (ffs_dev->mounted) {
3674 } else if (ffs_dev->ffs_acquire_dev_callback &&
3675 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) {
3678 ffs_dev->mounted = true;
3679 ffs_dev->ffs_data = ffs_data;
3680 ffs_data->private_data = ffs_dev;
3687 static void ffs_release_dev(struct ffs_dev *ffs_dev)
3691 if (ffs_dev && ffs_dev->mounted) {
3692 ffs_dev->mounted = false;
3693 if (ffs_dev->ffs_data) {
3694 ffs_dev->ffs_data->private_data = NULL;
3695 ffs_dev->ffs_data = NULL;
3698 if (ffs_dev->ffs_release_dev_callback)
3699 ffs_dev->ffs_release_dev_callback(ffs_dev);
3705 static int ffs_ready(struct ffs_data *ffs)
3707 struct ffs_dev *ffs_obj;
3712 ffs_obj = ffs->private_data;
3717 if (WARN_ON(ffs_obj->desc_ready)) {
3722 ffs_obj->desc_ready = true;
3724 if (ffs_obj->ffs_ready_callback) {
3725 ret = ffs_obj->ffs_ready_callback(ffs);
3730 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3736 static void ffs_closed(struct ffs_data *ffs)
3738 struct ffs_dev *ffs_obj;
3739 struct f_fs_opts *opts;
3740 struct config_item *ci;
3744 ffs_obj = ffs->private_data;
3748 ffs_obj->desc_ready = false;
3750 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3751 ffs_obj->ffs_closed_callback)
3752 ffs_obj->ffs_closed_callback(ffs);
3755 opts = ffs_obj->opts;
3759 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3760 || !kref_read(&opts->func_inst.group.cg_item.ci_kref))
3763 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3766 if (test_bit(FFS_FL_BOUND, &ffs->flags))
3767 unregister_gadget_item(ci);
3773 /* Misc helper functions ****************************************************/
3775 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3778 ? mutex_trylock(mutex) ? 0 : -EAGAIN
3779 : mutex_lock_interruptible(mutex);
3782 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3789 data = memdup_user(buf, len);
3793 pr_vdebug("Buffer from user space:\n");
3794 ffs_dump_mem("", data, len);
3799 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3800 MODULE_LICENSE("GPL");
3801 MODULE_AUTHOR("Michal Nazarewicz");