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 */
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, 1);
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 = current_time(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->i_atime = ts;
1387 inode->i_mtime = ts;
1388 inode->i_ctime = ts;
1389 inode->i_private = data;
1391 inode->i_fop = fops;
1399 /* Create "regular" file */
1400 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1401 const char *name, void *data,
1402 const struct file_operations *fops)
1404 struct ffs_data *ffs = sb->s_fs_info;
1405 struct dentry *dentry;
1406 struct inode *inode;
1408 dentry = d_alloc_name(sb->s_root, name);
1412 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1418 d_add(dentry, inode);
1423 static const struct super_operations ffs_sb_operations = {
1424 .statfs = simple_statfs,
1425 .drop_inode = generic_delete_inode,
1428 struct ffs_sb_fill_data {
1429 struct ffs_file_perms perms;
1431 const char *dev_name;
1433 struct ffs_data *ffs_data;
1436 static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc)
1438 struct ffs_sb_fill_data *data = fc->fs_private;
1439 struct inode *inode;
1440 struct ffs_data *ffs = data->ffs_data;
1443 data->ffs_data = NULL;
1444 sb->s_fs_info = ffs;
1445 sb->s_blocksize = PAGE_SIZE;
1446 sb->s_blocksize_bits = PAGE_SHIFT;
1447 sb->s_magic = FUNCTIONFS_MAGIC;
1448 sb->s_op = &ffs_sb_operations;
1449 sb->s_time_gran = 1;
1452 data->perms.mode = data->root_mode;
1453 inode = ffs_sb_make_inode(sb, NULL,
1454 &simple_dir_operations,
1455 &simple_dir_inode_operations,
1457 sb->s_root = d_make_root(inode);
1462 if (!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations))
1477 static const struct fs_parameter_spec ffs_fs_fs_parameters[] = {
1478 fsparam_bool ("no_disconnect", Opt_no_disconnect),
1479 fsparam_u32 ("rmode", Opt_rmode),
1480 fsparam_u32 ("fmode", Opt_fmode),
1481 fsparam_u32 ("mode", Opt_mode),
1482 fsparam_u32 ("uid", Opt_uid),
1483 fsparam_u32 ("gid", Opt_gid),
1487 static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
1489 struct ffs_sb_fill_data *data = fc->fs_private;
1490 struct fs_parse_result result;
1493 opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result);
1498 case Opt_no_disconnect:
1499 data->no_disconnect = result.boolean;
1502 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1505 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1508 data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
1509 data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
1513 data->perms.uid = make_kuid(current_user_ns(), result.uint_32);
1514 if (!uid_valid(data->perms.uid))
1515 goto unmapped_value;
1518 data->perms.gid = make_kgid(current_user_ns(), result.uint_32);
1519 if (!gid_valid(data->perms.gid))
1520 goto unmapped_value;
1530 return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32);
1534 * Set up the superblock for a mount.
1536 static int ffs_fs_get_tree(struct fs_context *fc)
1538 struct ffs_sb_fill_data *ctx = fc->fs_private;
1539 struct ffs_data *ffs;
1543 return invalf(fc, "No source specified");
1545 ffs = ffs_data_new(fc->source);
1548 ffs->file_perms = ctx->perms;
1549 ffs->no_disconnect = ctx->no_disconnect;
1551 ffs->dev_name = kstrdup(fc->source, GFP_KERNEL);
1552 if (!ffs->dev_name) {
1557 ret = ffs_acquire_dev(ffs->dev_name, ffs);
1563 ctx->ffs_data = ffs;
1564 return get_tree_nodev(fc, ffs_sb_fill);
1567 static void ffs_fs_free_fc(struct fs_context *fc)
1569 struct ffs_sb_fill_data *ctx = fc->fs_private;
1572 if (ctx->ffs_data) {
1573 ffs_data_put(ctx->ffs_data);
1580 static const struct fs_context_operations ffs_fs_context_ops = {
1581 .free = ffs_fs_free_fc,
1582 .parse_param = ffs_fs_parse_param,
1583 .get_tree = ffs_fs_get_tree,
1586 static int ffs_fs_init_fs_context(struct fs_context *fc)
1588 struct ffs_sb_fill_data *ctx;
1590 ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL);
1594 ctx->perms.mode = S_IFREG | 0600;
1595 ctx->perms.uid = GLOBAL_ROOT_UID;
1596 ctx->perms.gid = GLOBAL_ROOT_GID;
1597 ctx->root_mode = S_IFDIR | 0500;
1598 ctx->no_disconnect = false;
1600 fc->fs_private = ctx;
1601 fc->ops = &ffs_fs_context_ops;
1606 ffs_fs_kill_sb(struct super_block *sb)
1608 kill_litter_super(sb);
1610 ffs_data_closed(sb->s_fs_info);
1613 static struct file_system_type ffs_fs_type = {
1614 .owner = THIS_MODULE,
1615 .name = "functionfs",
1616 .init_fs_context = ffs_fs_init_fs_context,
1617 .parameters = ffs_fs_fs_parameters,
1618 .kill_sb = ffs_fs_kill_sb,
1620 MODULE_ALIAS_FS("functionfs");
1623 /* Driver's main init/cleanup functions *************************************/
1625 static int functionfs_init(void)
1629 ret = register_filesystem(&ffs_fs_type);
1631 pr_info("file system registered\n");
1633 pr_err("failed registering file system (%d)\n", ret);
1638 static void functionfs_cleanup(void)
1640 pr_info("unloading\n");
1641 unregister_filesystem(&ffs_fs_type);
1645 /* ffs_data and ffs_function construction and destruction code **************/
1647 static void ffs_data_clear(struct ffs_data *ffs);
1648 static void ffs_data_reset(struct ffs_data *ffs);
1650 static void ffs_data_get(struct ffs_data *ffs)
1652 refcount_inc(&ffs->ref);
1655 static void ffs_data_opened(struct ffs_data *ffs)
1657 refcount_inc(&ffs->ref);
1658 if (atomic_add_return(1, &ffs->opened) == 1 &&
1659 ffs->state == FFS_DEACTIVATED) {
1660 ffs->state = FFS_CLOSING;
1661 ffs_data_reset(ffs);
1665 static void ffs_data_put(struct ffs_data *ffs)
1667 if (refcount_dec_and_test(&ffs->ref)) {
1668 pr_info("%s(): freeing\n", __func__);
1669 ffs_data_clear(ffs);
1670 ffs_release_dev(ffs->private_data);
1671 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1672 swait_active(&ffs->ep0req_completion.wait) ||
1673 waitqueue_active(&ffs->wait));
1674 destroy_workqueue(ffs->io_completion_wq);
1675 kfree(ffs->dev_name);
1680 static void ffs_data_closed(struct ffs_data *ffs)
1682 struct ffs_epfile *epfiles;
1683 unsigned long flags;
1685 if (atomic_dec_and_test(&ffs->opened)) {
1686 if (ffs->no_disconnect) {
1687 ffs->state = FFS_DEACTIVATED;
1688 spin_lock_irqsave(&ffs->eps_lock, flags);
1689 epfiles = ffs->epfiles;
1690 ffs->epfiles = NULL;
1691 spin_unlock_irqrestore(&ffs->eps_lock,
1695 ffs_epfiles_destroy(epfiles,
1698 if (ffs->setup_state == FFS_SETUP_PENDING)
1699 __ffs_ep0_stall(ffs);
1701 ffs->state = FFS_CLOSING;
1702 ffs_data_reset(ffs);
1705 if (atomic_read(&ffs->opened) < 0) {
1706 ffs->state = FFS_CLOSING;
1707 ffs_data_reset(ffs);
1713 static struct ffs_data *ffs_data_new(const char *dev_name)
1715 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1719 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name);
1720 if (!ffs->io_completion_wq) {
1725 refcount_set(&ffs->ref, 1);
1726 atomic_set(&ffs->opened, 0);
1727 ffs->state = FFS_READ_DESCRIPTORS;
1728 mutex_init(&ffs->mutex);
1729 spin_lock_init(&ffs->eps_lock);
1730 init_waitqueue_head(&ffs->ev.waitq);
1731 init_waitqueue_head(&ffs->wait);
1732 init_completion(&ffs->ep0req_completion);
1734 /* XXX REVISIT need to update it in some places, or do we? */
1735 ffs->ev.can_stall = 1;
1740 static void ffs_data_clear(struct ffs_data *ffs)
1742 struct ffs_epfile *epfiles;
1743 unsigned long flags;
1747 BUG_ON(ffs->gadget);
1749 spin_lock_irqsave(&ffs->eps_lock, flags);
1750 epfiles = ffs->epfiles;
1751 ffs->epfiles = NULL;
1752 spin_unlock_irqrestore(&ffs->eps_lock, flags);
1755 * potential race possible between ffs_func_eps_disable
1756 * & ffs_epfile_release therefore maintaining a local
1757 * copy of epfile will save us from use-after-free.
1760 ffs_epfiles_destroy(epfiles, ffs->eps_count);
1761 ffs->epfiles = NULL;
1764 if (ffs->ffs_eventfd) {
1765 eventfd_ctx_put(ffs->ffs_eventfd);
1766 ffs->ffs_eventfd = NULL;
1769 kfree(ffs->raw_descs_data);
1770 kfree(ffs->raw_strings);
1771 kfree(ffs->stringtabs);
1774 static void ffs_data_reset(struct ffs_data *ffs)
1776 ffs_data_clear(ffs);
1778 ffs->raw_descs_data = NULL;
1779 ffs->raw_descs = NULL;
1780 ffs->raw_strings = NULL;
1781 ffs->stringtabs = NULL;
1783 ffs->raw_descs_length = 0;
1784 ffs->fs_descs_count = 0;
1785 ffs->hs_descs_count = 0;
1786 ffs->ss_descs_count = 0;
1788 ffs->strings_count = 0;
1789 ffs->interfaces_count = 0;
1794 ffs->state = FFS_READ_DESCRIPTORS;
1795 ffs->setup_state = FFS_NO_SETUP;
1798 ffs->ms_os_descs_ext_prop_count = 0;
1799 ffs->ms_os_descs_ext_prop_name_len = 0;
1800 ffs->ms_os_descs_ext_prop_data_len = 0;
1804 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1806 struct usb_gadget_strings **lang;
1809 if (WARN_ON(ffs->state != FFS_ACTIVE
1810 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1813 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1817 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1820 ffs->ep0req->complete = ffs_ep0_complete;
1821 ffs->ep0req->context = ffs;
1823 lang = ffs->stringtabs;
1825 for (; *lang; ++lang) {
1826 struct usb_string *str = (*lang)->strings;
1828 for (; str->s; ++id, ++str)
1833 ffs->gadget = cdev->gadget;
1838 static void functionfs_unbind(struct ffs_data *ffs)
1840 if (!WARN_ON(!ffs->gadget)) {
1841 /* dequeue before freeing ep0req */
1842 usb_ep_dequeue(ffs->gadget->ep0, ffs->ep0req);
1843 mutex_lock(&ffs->mutex);
1844 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1847 clear_bit(FFS_FL_BOUND, &ffs->flags);
1848 mutex_unlock(&ffs->mutex);
1853 static int ffs_epfiles_create(struct ffs_data *ffs)
1855 struct ffs_epfile *epfile, *epfiles;
1858 count = ffs->eps_count;
1859 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1864 for (i = 1; i <= count; ++i, ++epfile) {
1866 mutex_init(&epfile->mutex);
1867 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1868 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1870 sprintf(epfile->name, "ep%u", i);
1871 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1873 &ffs_epfile_operations);
1874 if (!epfile->dentry) {
1875 ffs_epfiles_destroy(epfiles, i - 1);
1880 ffs->epfiles = epfiles;
1884 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1886 struct ffs_epfile *epfile = epfiles;
1888 for (; count; --count, ++epfile) {
1889 BUG_ON(mutex_is_locked(&epfile->mutex));
1890 if (epfile->dentry) {
1891 d_delete(epfile->dentry);
1892 dput(epfile->dentry);
1893 epfile->dentry = NULL;
1900 static void ffs_func_eps_disable(struct ffs_function *func)
1903 struct ffs_epfile *epfile;
1904 unsigned short count;
1905 unsigned long flags;
1907 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1908 count = func->ffs->eps_count;
1909 epfile = func->ffs->epfiles;
1912 /* pending requests get nuked */
1914 usb_ep_disable(ep->ep);
1919 __ffs_epfile_read_buffer_free(epfile);
1923 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1926 static int ffs_func_eps_enable(struct ffs_function *func)
1928 struct ffs_data *ffs;
1930 struct ffs_epfile *epfile;
1931 unsigned short count;
1932 unsigned long flags;
1935 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1938 epfile = ffs->epfiles;
1939 count = ffs->eps_count;
1941 ep->ep->driver_data = ep;
1943 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep);
1945 pr_err("%s: config_ep_by_speed(%s) returned %d\n",
1946 __func__, ep->ep->name, ret);
1950 ret = usb_ep_enable(ep->ep);
1953 epfile->in = usb_endpoint_dir_in(ep->ep->desc);
1954 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
1963 wake_up_interruptible(&ffs->wait);
1964 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1970 /* Parsing and building descriptors and strings *****************************/
1973 * This validates if data pointed by data is a valid USB descriptor as
1974 * well as record how many interfaces, endpoints and strings are
1975 * required by given configuration. Returns address after the
1976 * descriptor or NULL if data is invalid.
1979 enum ffs_entity_type {
1980 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1983 enum ffs_os_desc_type {
1984 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1987 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1989 struct usb_descriptor_header *desc,
1992 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1993 struct usb_os_desc_header *h, void *data,
1994 unsigned len, void *priv);
1996 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1997 ffs_entity_callback entity,
1998 void *priv, int *current_class)
2000 struct usb_descriptor_header *_ds = (void *)data;
2004 /* At least two bytes are required: length and type */
2006 pr_vdebug("descriptor too short\n");
2010 /* If we have at least as many bytes as the descriptor takes? */
2011 length = _ds->bLength;
2013 pr_vdebug("descriptor longer then available data\n");
2017 #define __entity_check_INTERFACE(val) 1
2018 #define __entity_check_STRING(val) (val)
2019 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
2020 #define __entity(type, val) do { \
2021 pr_vdebug("entity " #type "(%02x)\n", (val)); \
2022 if (!__entity_check_ ##type(val)) { \
2023 pr_vdebug("invalid entity's value\n"); \
2026 ret = entity(FFS_ ##type, &val, _ds, priv); \
2028 pr_debug("entity " #type "(%02x); ret = %d\n", \
2034 /* Parse descriptor depending on type. */
2035 switch (_ds->bDescriptorType) {
2039 case USB_DT_DEVICE_QUALIFIER:
2040 /* function can't have any of those */
2041 pr_vdebug("descriptor reserved for gadget: %d\n",
2042 _ds->bDescriptorType);
2045 case USB_DT_INTERFACE: {
2046 struct usb_interface_descriptor *ds = (void *)_ds;
2047 pr_vdebug("interface descriptor\n");
2048 if (length != sizeof *ds)
2051 __entity(INTERFACE, ds->bInterfaceNumber);
2053 __entity(STRING, ds->iInterface);
2054 *current_class = ds->bInterfaceClass;
2058 case USB_DT_ENDPOINT: {
2059 struct usb_endpoint_descriptor *ds = (void *)_ds;
2060 pr_vdebug("endpoint descriptor\n");
2061 if (length != USB_DT_ENDPOINT_SIZE &&
2062 length != USB_DT_ENDPOINT_AUDIO_SIZE)
2064 __entity(ENDPOINT, ds->bEndpointAddress);
2068 case USB_TYPE_CLASS | 0x01:
2069 if (*current_class == USB_INTERFACE_CLASS_HID) {
2070 pr_vdebug("hid descriptor\n");
2071 if (length != sizeof(struct hid_descriptor))
2074 } else if (*current_class == USB_INTERFACE_CLASS_CCID) {
2075 pr_vdebug("ccid descriptor\n");
2076 if (length != sizeof(struct ccid_descriptor))
2080 pr_vdebug("unknown descriptor: %d for class %d\n",
2081 _ds->bDescriptorType, *current_class);
2086 if (length != sizeof(struct usb_otg_descriptor))
2090 case USB_DT_INTERFACE_ASSOCIATION: {
2091 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
2092 pr_vdebug("interface association descriptor\n");
2093 if (length != sizeof *ds)
2096 __entity(STRING, ds->iFunction);
2100 case USB_DT_SS_ENDPOINT_COMP:
2101 pr_vdebug("EP SS companion descriptor\n");
2102 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2106 case USB_DT_OTHER_SPEED_CONFIG:
2107 case USB_DT_INTERFACE_POWER:
2109 case USB_DT_SECURITY:
2110 case USB_DT_CS_RADIO_CONTROL:
2112 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2116 /* We should never be here */
2117 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2121 pr_vdebug("invalid length: %d (descriptor %d)\n",
2122 _ds->bLength, _ds->bDescriptorType);
2127 #undef __entity_check_DESCRIPTOR
2128 #undef __entity_check_INTERFACE
2129 #undef __entity_check_STRING
2130 #undef __entity_check_ENDPOINT
2135 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2136 ffs_entity_callback entity, void *priv)
2138 const unsigned _len = len;
2139 unsigned long num = 0;
2140 int current_class = -1;
2148 /* Record "descriptor" entity */
2149 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2151 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2159 ret = ffs_do_single_desc(data, len, entity, priv,
2162 pr_debug("%s returns %d\n", __func__, ret);
2172 static int __ffs_data_do_entity(enum ffs_entity_type type,
2173 u8 *valuep, struct usb_descriptor_header *desc,
2176 struct ffs_desc_helper *helper = priv;
2177 struct usb_endpoint_descriptor *d;
2180 case FFS_DESCRIPTOR:
2185 * Interfaces are indexed from zero so if we
2186 * encountered interface "n" then there are at least
2189 if (*valuep >= helper->interfaces_count)
2190 helper->interfaces_count = *valuep + 1;
2195 * Strings are indexed from 1 (0 is reserved
2196 * for languages list)
2198 if (*valuep > helper->ffs->strings_count)
2199 helper->ffs->strings_count = *valuep;
2204 helper->eps_count++;
2205 if (helper->eps_count >= FFS_MAX_EPS_COUNT)
2207 /* Check if descriptors for any speed were already parsed */
2208 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2209 helper->ffs->eps_addrmap[helper->eps_count] =
2210 d->bEndpointAddress;
2211 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2212 d->bEndpointAddress)
2220 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2221 struct usb_os_desc_header *desc)
2223 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2224 u16 w_index = le16_to_cpu(desc->wIndex);
2226 if (bcd_version == 0x1) {
2227 pr_warn("bcdVersion must be 0x0100, stored in Little Endian order. "
2228 "Userspace driver should be fixed, accepting 0x0001 for compatibility.\n");
2229 } else if (bcd_version != 0x100) {
2230 pr_vdebug("unsupported os descriptors version: 0x%x\n",
2236 *next_type = FFS_OS_DESC_EXT_COMPAT;
2239 *next_type = FFS_OS_DESC_EXT_PROP;
2242 pr_vdebug("unsupported os descriptor type: %d", w_index);
2246 return sizeof(*desc);
2250 * Process all extended compatibility/extended property descriptors
2251 * of a feature descriptor
2253 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2254 enum ffs_os_desc_type type,
2256 ffs_os_desc_callback entity,
2258 struct usb_os_desc_header *h)
2261 const unsigned _len = len;
2263 /* loop over all ext compat/ext prop descriptors */
2264 while (feature_count--) {
2265 ret = entity(type, h, data, len, priv);
2267 pr_debug("bad OS descriptor, type: %d\n", type);
2276 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2277 static int __must_check ffs_do_os_descs(unsigned count,
2278 char *data, unsigned len,
2279 ffs_os_desc_callback entity, void *priv)
2281 const unsigned _len = len;
2282 unsigned long num = 0;
2284 for (num = 0; num < count; ++num) {
2286 enum ffs_os_desc_type type;
2288 struct usb_os_desc_header *desc = (void *)data;
2290 if (len < sizeof(*desc))
2294 * Record "descriptor" entity.
2295 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2296 * Move the data pointer to the beginning of extended
2297 * compatibilities proper or extended properties proper
2298 * portions of the data
2300 if (le32_to_cpu(desc->dwLength) > len)
2303 ret = __ffs_do_os_desc_header(&type, desc);
2305 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2310 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2312 feature_count = le16_to_cpu(desc->wCount);
2313 if (type == FFS_OS_DESC_EXT_COMPAT &&
2314 (feature_count > 255 || desc->Reserved))
2320 * Process all function/property descriptors
2321 * of this Feature Descriptor
2323 ret = ffs_do_single_os_desc(data, len, type,
2324 feature_count, entity, priv, desc);
2326 pr_debug("%s returns %d\n", __func__, ret);
2337 * Validate contents of the buffer from userspace related to OS descriptors.
2339 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2340 struct usb_os_desc_header *h, void *data,
2341 unsigned len, void *priv)
2343 struct ffs_data *ffs = priv;
2347 case FFS_OS_DESC_EXT_COMPAT: {
2348 struct usb_ext_compat_desc *d = data;
2351 if (len < sizeof(*d) ||
2352 d->bFirstInterfaceNumber >= ffs->interfaces_count)
2354 if (d->Reserved1 != 1) {
2356 * According to the spec, Reserved1 must be set to 1
2357 * but older kernels incorrectly rejected non-zero
2358 * values. We fix it here to avoid returning EINVAL
2359 * in response to values we used to accept.
2361 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
2364 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2365 if (d->Reserved2[i])
2368 length = sizeof(struct usb_ext_compat_desc);
2371 case FFS_OS_DESC_EXT_PROP: {
2372 struct usb_ext_prop_desc *d = data;
2376 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2378 length = le32_to_cpu(d->dwSize);
2381 type = le32_to_cpu(d->dwPropertyDataType);
2382 if (type < USB_EXT_PROP_UNICODE ||
2383 type > USB_EXT_PROP_UNICODE_MULTI) {
2384 pr_vdebug("unsupported os descriptor property type: %d",
2388 pnl = le16_to_cpu(d->wPropertyNameLength);
2389 if (length < 14 + pnl) {
2390 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2394 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl));
2395 if (length != 14 + pnl + pdl) {
2396 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2397 length, pnl, pdl, type);
2400 ++ffs->ms_os_descs_ext_prop_count;
2401 /* property name reported to the host as "WCHAR"s */
2402 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2403 ffs->ms_os_descs_ext_prop_data_len += pdl;
2407 pr_vdebug("unknown descriptor: %d\n", type);
2413 static int __ffs_data_got_descs(struct ffs_data *ffs,
2414 char *const _data, size_t len)
2416 char *data = _data, *raw_descs;
2417 unsigned os_descs_count = 0, counts[3], flags;
2418 int ret = -EINVAL, i;
2419 struct ffs_desc_helper helper;
2421 if (get_unaligned_le32(data + 4) != len)
2424 switch (get_unaligned_le32(data)) {
2425 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2426 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2430 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2431 flags = get_unaligned_le32(data + 8);
2432 ffs->user_flags = flags;
2433 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2434 FUNCTIONFS_HAS_HS_DESC |
2435 FUNCTIONFS_HAS_SS_DESC |
2436 FUNCTIONFS_HAS_MS_OS_DESC |
2437 FUNCTIONFS_VIRTUAL_ADDR |
2438 FUNCTIONFS_EVENTFD |
2439 FUNCTIONFS_ALL_CTRL_RECIP |
2440 FUNCTIONFS_CONFIG0_SETUP)) {
2451 if (flags & FUNCTIONFS_EVENTFD) {
2455 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2456 if (IS_ERR(ffs->ffs_eventfd)) {
2457 ret = PTR_ERR(ffs->ffs_eventfd);
2458 ffs->ffs_eventfd = NULL;
2465 /* Read fs_count, hs_count and ss_count (if present) */
2466 for (i = 0; i < 3; ++i) {
2467 if (!(flags & (1 << i))) {
2469 } else if (len < 4) {
2472 counts[i] = get_unaligned_le32(data);
2477 if (flags & (1 << i)) {
2481 os_descs_count = get_unaligned_le32(data);
2486 /* Read descriptors */
2489 for (i = 0; i < 3; ++i) {
2492 helper.interfaces_count = 0;
2493 helper.eps_count = 0;
2494 ret = ffs_do_descs(counts[i], data, len,
2495 __ffs_data_do_entity, &helper);
2498 if (!ffs->eps_count && !ffs->interfaces_count) {
2499 ffs->eps_count = helper.eps_count;
2500 ffs->interfaces_count = helper.interfaces_count;
2502 if (ffs->eps_count != helper.eps_count) {
2506 if (ffs->interfaces_count != helper.interfaces_count) {
2514 if (os_descs_count) {
2515 ret = ffs_do_os_descs(os_descs_count, data, len,
2516 __ffs_data_do_os_desc, ffs);
2523 if (raw_descs == data || len) {
2528 ffs->raw_descs_data = _data;
2529 ffs->raw_descs = raw_descs;
2530 ffs->raw_descs_length = data - raw_descs;
2531 ffs->fs_descs_count = counts[0];
2532 ffs->hs_descs_count = counts[1];
2533 ffs->ss_descs_count = counts[2];
2534 ffs->ms_os_descs_count = os_descs_count;
2543 static int __ffs_data_got_strings(struct ffs_data *ffs,
2544 char *const _data, size_t len)
2546 u32 str_count, needed_count, lang_count;
2547 struct usb_gadget_strings **stringtabs, *t;
2548 const char *data = _data;
2549 struct usb_string *s;
2552 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2553 get_unaligned_le32(data + 4) != len)
2555 str_count = get_unaligned_le32(data + 8);
2556 lang_count = get_unaligned_le32(data + 12);
2558 /* if one is zero the other must be zero */
2559 if (!str_count != !lang_count)
2562 /* Do we have at least as many strings as descriptors need? */
2563 needed_count = ffs->strings_count;
2564 if (str_count < needed_count)
2568 * If we don't need any strings just return and free all
2571 if (!needed_count) {
2576 /* Allocate everything in one chunk so there's less maintenance. */
2580 vla_item(d, struct usb_gadget_strings *, stringtabs,
2581 size_add(lang_count, 1));
2582 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2583 vla_item(d, struct usb_string, strings,
2584 size_mul(lang_count, (needed_count + 1)));
2586 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2593 /* Initialize the VLA pointers */
2594 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2595 t = vla_ptr(vlabuf, d, stringtab);
2598 *stringtabs++ = t++;
2602 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2603 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2604 t = vla_ptr(vlabuf, d, stringtab);
2605 s = vla_ptr(vlabuf, d, strings);
2608 /* For each language */
2612 do { /* lang_count > 0 so we can use do-while */
2613 unsigned needed = needed_count;
2614 u32 str_per_lang = str_count;
2618 t->language = get_unaligned_le16(data);
2625 /* For each string */
2626 do { /* str_count > 0 so we can use do-while */
2627 size_t length = strnlen(data, len);
2633 * User may provide more strings then we need,
2634 * if that's the case we simply ignore the
2639 * s->id will be set while adding
2640 * function to configuration so for
2641 * now just leave garbage here.
2650 } while (--str_per_lang);
2652 s->id = 0; /* terminator */
2656 } while (--lang_count);
2658 /* Some garbage left? */
2663 ffs->stringtabs = stringtabs;
2664 ffs->raw_strings = _data;
2676 /* Events handling and management *******************************************/
2678 static void __ffs_event_add(struct ffs_data *ffs,
2679 enum usb_functionfs_event_type type)
2681 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2685 * Abort any unhandled setup
2687 * We do not need to worry about some cmpxchg() changing value
2688 * of ffs->setup_state without holding the lock because when
2689 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2690 * the source does nothing.
2692 if (ffs->setup_state == FFS_SETUP_PENDING)
2693 ffs->setup_state = FFS_SETUP_CANCELLED;
2696 * Logic of this function guarantees that there are at most four pending
2697 * evens on ffs->ev.types queue. This is important because the queue
2698 * has space for four elements only and __ffs_ep0_read_events function
2699 * depends on that limit as well. If more event types are added, those
2700 * limits have to be revisited or guaranteed to still hold.
2703 case FUNCTIONFS_RESUME:
2704 rem_type2 = FUNCTIONFS_SUSPEND;
2706 case FUNCTIONFS_SUSPEND:
2707 case FUNCTIONFS_SETUP:
2709 /* Discard all similar events */
2712 case FUNCTIONFS_BIND:
2713 case FUNCTIONFS_UNBIND:
2714 case FUNCTIONFS_DISABLE:
2715 case FUNCTIONFS_ENABLE:
2716 /* Discard everything other then power management. */
2717 rem_type1 = FUNCTIONFS_SUSPEND;
2718 rem_type2 = FUNCTIONFS_RESUME;
2723 WARN(1, "%d: unknown event, this should not happen\n", type);
2728 u8 *ev = ffs->ev.types, *out = ev;
2729 unsigned n = ffs->ev.count;
2730 for (; n; --n, ++ev)
2731 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2734 pr_vdebug("purging event %d\n", *ev);
2735 ffs->ev.count = out - ffs->ev.types;
2738 pr_vdebug("adding event %d\n", type);
2739 ffs->ev.types[ffs->ev.count++] = type;
2740 wake_up_locked(&ffs->ev.waitq);
2741 if (ffs->ffs_eventfd)
2742 eventfd_signal(ffs->ffs_eventfd, 1);
2745 static void ffs_event_add(struct ffs_data *ffs,
2746 enum usb_functionfs_event_type type)
2748 unsigned long flags;
2749 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2750 __ffs_event_add(ffs, type);
2751 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2754 /* Bind/unbind USB function hooks *******************************************/
2756 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2760 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2761 if (ffs->eps_addrmap[i] == endpoint_address)
2766 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2767 struct usb_descriptor_header *desc,
2770 struct usb_endpoint_descriptor *ds = (void *)desc;
2771 struct ffs_function *func = priv;
2772 struct ffs_ep *ffs_ep;
2773 unsigned ep_desc_id;
2775 static const char *speed_names[] = { "full", "high", "super" };
2777 if (type != FFS_DESCRIPTOR)
2781 * If ss_descriptors is not NULL, we are reading super speed
2782 * descriptors; if hs_descriptors is not NULL, we are reading high
2783 * speed descriptors; otherwise, we are reading full speed
2786 if (func->function.ss_descriptors) {
2788 func->function.ss_descriptors[(long)valuep] = desc;
2789 } else if (func->function.hs_descriptors) {
2791 func->function.hs_descriptors[(long)valuep] = desc;
2794 func->function.fs_descriptors[(long)valuep] = desc;
2797 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2800 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2804 ffs_ep = func->eps + idx;
2806 if (ffs_ep->descs[ep_desc_id]) {
2807 pr_err("two %sspeed descriptors for EP %d\n",
2808 speed_names[ep_desc_id],
2809 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2812 ffs_ep->descs[ep_desc_id] = ds;
2814 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2816 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2817 if (!ds->wMaxPacketSize)
2818 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2820 struct usb_request *req;
2822 u8 bEndpointAddress;
2826 * We back up bEndpointAddress because autoconfig overwrites
2827 * it with physical endpoint address.
2829 bEndpointAddress = ds->bEndpointAddress;
2831 * We back up wMaxPacketSize because autoconfig treats
2832 * endpoint descriptors as if they were full speed.
2834 wMaxPacketSize = ds->wMaxPacketSize;
2835 pr_vdebug("autoconfig\n");
2836 ep = usb_ep_autoconfig(func->gadget, ds);
2839 ep->driver_data = func->eps + idx;
2841 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2847 func->eps_revmap[ds->bEndpointAddress &
2848 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2850 * If we use virtual address mapping, we restore
2851 * original bEndpointAddress value.
2853 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2854 ds->bEndpointAddress = bEndpointAddress;
2856 * Restore wMaxPacketSize which was potentially
2857 * overwritten by autoconfig.
2859 ds->wMaxPacketSize = wMaxPacketSize;
2861 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2866 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2867 struct usb_descriptor_header *desc,
2870 struct ffs_function *func = priv;
2876 case FFS_DESCRIPTOR:
2877 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2882 if (func->interfaces_nums[idx] < 0) {
2883 int id = usb_interface_id(func->conf, &func->function);
2886 func->interfaces_nums[idx] = id;
2888 newValue = func->interfaces_nums[idx];
2892 /* String' IDs are allocated when fsf_data is bound to cdev */
2893 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2898 * USB_DT_ENDPOINT are handled in
2899 * __ffs_func_bind_do_descs().
2901 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2904 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2905 if (!func->eps[idx].ep)
2909 struct usb_endpoint_descriptor **descs;
2910 descs = func->eps[idx].descs;
2911 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2916 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2921 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2922 struct usb_os_desc_header *h, void *data,
2923 unsigned len, void *priv)
2925 struct ffs_function *func = priv;
2929 case FFS_OS_DESC_EXT_COMPAT: {
2930 struct usb_ext_compat_desc *desc = data;
2931 struct usb_os_desc_table *t;
2933 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2934 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2935 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2936 ARRAY_SIZE(desc->CompatibleID) +
2937 ARRAY_SIZE(desc->SubCompatibleID));
2938 length = sizeof(*desc);
2941 case FFS_OS_DESC_EXT_PROP: {
2942 struct usb_ext_prop_desc *desc = data;
2943 struct usb_os_desc_table *t;
2944 struct usb_os_desc_ext_prop *ext_prop;
2945 char *ext_prop_name;
2946 char *ext_prop_data;
2948 t = &func->function.os_desc_table[h->interface];
2949 t->if_id = func->interfaces_nums[h->interface];
2951 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2952 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2954 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2955 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2956 ext_prop->data_len = le32_to_cpu(*(__le32 *)
2957 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2958 length = ext_prop->name_len + ext_prop->data_len + 14;
2960 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2961 func->ffs->ms_os_descs_ext_prop_name_avail +=
2964 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2965 func->ffs->ms_os_descs_ext_prop_data_avail +=
2967 memcpy(ext_prop_data,
2968 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2969 ext_prop->data_len);
2970 /* unicode data reported to the host as "WCHAR"s */
2971 switch (ext_prop->type) {
2972 case USB_EXT_PROP_UNICODE:
2973 case USB_EXT_PROP_UNICODE_ENV:
2974 case USB_EXT_PROP_UNICODE_LINK:
2975 case USB_EXT_PROP_UNICODE_MULTI:
2976 ext_prop->data_len *= 2;
2979 ext_prop->data = ext_prop_data;
2981 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2982 ext_prop->name_len);
2983 /* property name reported to the host as "WCHAR"s */
2984 ext_prop->name_len *= 2;
2985 ext_prop->name = ext_prop_name;
2987 t->os_desc->ext_prop_len +=
2988 ext_prop->name_len + ext_prop->data_len + 14;
2989 ++t->os_desc->ext_prop_count;
2990 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2994 pr_vdebug("unknown descriptor: %d\n", type);
3000 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
3001 struct usb_configuration *c)
3003 struct ffs_function *func = ffs_func_from_usb(f);
3004 struct f_fs_opts *ffs_opts =
3005 container_of(f->fi, struct f_fs_opts, func_inst);
3006 struct ffs_data *ffs_data;
3010 * Legacy gadget triggers binding in functionfs_ready_callback,
3011 * which already uses locking; taking the same lock here would
3014 * Configfs-enabled gadgets however do need ffs_dev_lock.
3016 if (!ffs_opts->no_configfs)
3018 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
3019 ffs_data = ffs_opts->dev->ffs_data;
3020 if (!ffs_opts->no_configfs)
3023 return ERR_PTR(ret);
3025 func->ffs = ffs_data;
3027 func->gadget = c->cdev->gadget;
3030 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
3031 * configurations are bound in sequence with list_for_each_entry,
3032 * in each configuration its functions are bound in sequence
3033 * with list_for_each_entry, so we assume no race condition
3034 * with regard to ffs_opts->bound access
3036 if (!ffs_opts->refcnt) {
3037 ret = functionfs_bind(func->ffs, c->cdev);
3039 return ERR_PTR(ret);
3042 func->function.strings = func->ffs->stringtabs;
3047 static int _ffs_func_bind(struct usb_configuration *c,
3048 struct usb_function *f)
3050 struct ffs_function *func = ffs_func_from_usb(f);
3051 struct ffs_data *ffs = func->ffs;
3053 const int full = !!func->ffs->fs_descs_count;
3054 const int high = !!func->ffs->hs_descs_count;
3055 const int super = !!func->ffs->ss_descs_count;
3057 int fs_len, hs_len, ss_len, ret, i;
3058 struct ffs_ep *eps_ptr;
3060 /* Make it a single chunk, less management later on */
3062 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
3063 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
3064 full ? ffs->fs_descs_count + 1 : 0);
3065 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
3066 high ? ffs->hs_descs_count + 1 : 0);
3067 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
3068 super ? ffs->ss_descs_count + 1 : 0);
3069 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
3070 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
3071 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3072 vla_item_with_sz(d, char[16], ext_compat,
3073 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3074 vla_item_with_sz(d, struct usb_os_desc, os_desc,
3075 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3076 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
3077 ffs->ms_os_descs_ext_prop_count);
3078 vla_item_with_sz(d, char, ext_prop_name,
3079 ffs->ms_os_descs_ext_prop_name_len);
3080 vla_item_with_sz(d, char, ext_prop_data,
3081 ffs->ms_os_descs_ext_prop_data_len);
3082 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
3085 /* Has descriptors only for speeds gadget does not support */
3086 if (!(full | high | super))
3089 /* Allocate a single chunk, less management later on */
3090 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
3094 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
3095 ffs->ms_os_descs_ext_prop_name_avail =
3096 vla_ptr(vlabuf, d, ext_prop_name);
3097 ffs->ms_os_descs_ext_prop_data_avail =
3098 vla_ptr(vlabuf, d, ext_prop_data);
3100 /* Copy descriptors */
3101 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
3102 ffs->raw_descs_length);
3104 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
3105 eps_ptr = vla_ptr(vlabuf, d, eps);
3106 for (i = 0; i < ffs->eps_count; i++)
3107 eps_ptr[i].num = -1;
3110 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3112 func->eps = vla_ptr(vlabuf, d, eps);
3113 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3116 * Go through all the endpoint descriptors and allocate
3117 * endpoints first, so that later we can rewrite the endpoint
3118 * numbers without worrying that it may be described later on.
3121 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3122 fs_len = ffs_do_descs(ffs->fs_descs_count,
3123 vla_ptr(vlabuf, d, raw_descs),
3125 __ffs_func_bind_do_descs, func);
3135 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3136 hs_len = ffs_do_descs(ffs->hs_descs_count,
3137 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3138 d_raw_descs__sz - fs_len,
3139 __ffs_func_bind_do_descs, func);
3149 func->function.ss_descriptors = func->function.ssp_descriptors =
3150 vla_ptr(vlabuf, d, ss_descs);
3151 ss_len = ffs_do_descs(ffs->ss_descs_count,
3152 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3153 d_raw_descs__sz - fs_len - hs_len,
3154 __ffs_func_bind_do_descs, func);
3164 * Now handle interface numbers allocation and interface and
3165 * endpoint numbers rewriting. We can do that in one go
3168 ret = ffs_do_descs(ffs->fs_descs_count +
3169 (high ? ffs->hs_descs_count : 0) +
3170 (super ? ffs->ss_descs_count : 0),
3171 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3172 __ffs_func_bind_do_nums, func);
3176 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3177 if (c->cdev->use_os_string) {
3178 for (i = 0; i < ffs->interfaces_count; ++i) {
3179 struct usb_os_desc *desc;
3181 desc = func->function.os_desc_table[i].os_desc =
3182 vla_ptr(vlabuf, d, os_desc) +
3183 i * sizeof(struct usb_os_desc);
3184 desc->ext_compat_id =
3185 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3186 INIT_LIST_HEAD(&desc->ext_prop);
3188 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3189 vla_ptr(vlabuf, d, raw_descs) +
3190 fs_len + hs_len + ss_len,
3191 d_raw_descs__sz - fs_len - hs_len -
3193 __ffs_func_bind_do_os_desc, func);
3197 func->function.os_desc_n =
3198 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3200 /* And we're done */
3201 ffs_event_add(ffs, FUNCTIONFS_BIND);
3205 /* XXX Do we need to release all claimed endpoints here? */
3209 static int ffs_func_bind(struct usb_configuration *c,
3210 struct usb_function *f)
3212 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3213 struct ffs_function *func = ffs_func_from_usb(f);
3216 if (IS_ERR(ffs_opts))
3217 return PTR_ERR(ffs_opts);
3219 ret = _ffs_func_bind(c, f);
3220 if (ret && !--ffs_opts->refcnt)
3221 functionfs_unbind(func->ffs);
3227 /* Other USB function hooks *************************************************/
3229 static void ffs_reset_work(struct work_struct *work)
3231 struct ffs_data *ffs = container_of(work,
3232 struct ffs_data, reset_work);
3233 ffs_data_reset(ffs);
3236 static int ffs_func_set_alt(struct usb_function *f,
3237 unsigned interface, unsigned alt)
3239 struct ffs_function *func = ffs_func_from_usb(f);
3240 struct ffs_data *ffs = func->ffs;
3243 if (alt != (unsigned)-1) {
3244 intf = ffs_func_revmap_intf(func, interface);
3250 ffs_func_eps_disable(ffs->func);
3252 if (ffs->state == FFS_DEACTIVATED) {
3253 ffs->state = FFS_CLOSING;
3254 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3255 schedule_work(&ffs->reset_work);
3259 if (ffs->state != FFS_ACTIVE)
3262 if (alt == (unsigned)-1) {
3264 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3269 ret = ffs_func_eps_enable(func);
3271 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3275 static void ffs_func_disable(struct usb_function *f)
3277 ffs_func_set_alt(f, 0, (unsigned)-1);
3280 static int ffs_func_setup(struct usb_function *f,
3281 const struct usb_ctrlrequest *creq)
3283 struct ffs_function *func = ffs_func_from_usb(f);
3284 struct ffs_data *ffs = func->ffs;
3285 unsigned long flags;
3288 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3289 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3290 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3291 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3292 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3295 * Most requests directed to interface go through here
3296 * (notable exceptions are set/get interface) so we need to
3297 * handle them. All other either handled by composite or
3298 * passed to usb_configuration->setup() (if one is set). No
3299 * matter, we will handle requests directed to endpoint here
3300 * as well (as it's straightforward). Other request recipient
3301 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3304 if (ffs->state != FFS_ACTIVE)
3307 switch (creq->bRequestType & USB_RECIP_MASK) {
3308 case USB_RECIP_INTERFACE:
3309 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3314 case USB_RECIP_ENDPOINT:
3315 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3318 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3319 ret = func->ffs->eps_addrmap[ret];
3323 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3324 ret = le16_to_cpu(creq->wIndex);
3329 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3330 ffs->ev.setup = *creq;
3331 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3332 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3333 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3335 return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
3338 static bool ffs_func_req_match(struct usb_function *f,
3339 const struct usb_ctrlrequest *creq,
3342 struct ffs_function *func = ffs_func_from_usb(f);
3344 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3347 switch (creq->bRequestType & USB_RECIP_MASK) {
3348 case USB_RECIP_INTERFACE:
3349 return (ffs_func_revmap_intf(func,
3350 le16_to_cpu(creq->wIndex)) >= 0);
3351 case USB_RECIP_ENDPOINT:
3352 return (ffs_func_revmap_ep(func,
3353 le16_to_cpu(creq->wIndex)) >= 0);
3355 return (bool) (func->ffs->user_flags &
3356 FUNCTIONFS_ALL_CTRL_RECIP);
3360 static void ffs_func_suspend(struct usb_function *f)
3362 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3365 static void ffs_func_resume(struct usb_function *f)
3367 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3371 /* Endpoint and interface numbers reverse mapping ***************************/
3373 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3375 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3376 return num ? num : -EDOM;
3379 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3381 short *nums = func->interfaces_nums;
3382 unsigned count = func->ffs->interfaces_count;
3384 for (; count; --count, ++nums) {
3385 if (*nums >= 0 && *nums == intf)
3386 return nums - func->interfaces_nums;
3393 /* Devices management *******************************************************/
3395 static LIST_HEAD(ffs_devices);
3397 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3399 struct ffs_dev *dev;
3404 list_for_each_entry(dev, &ffs_devices, entry) {
3405 if (strcmp(dev->name, name) == 0)
3413 * ffs_lock must be taken by the caller of this function
3415 static struct ffs_dev *_ffs_get_single_dev(void)
3417 struct ffs_dev *dev;
3419 if (list_is_singular(&ffs_devices)) {
3420 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3429 * ffs_lock must be taken by the caller of this function
3431 static struct ffs_dev *_ffs_find_dev(const char *name)
3433 struct ffs_dev *dev;
3435 dev = _ffs_get_single_dev();
3439 return _ffs_do_find_dev(name);
3442 /* Configfs support *********************************************************/
3444 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3446 return container_of(to_config_group(item), struct f_fs_opts,
3450 static void ffs_attr_release(struct config_item *item)
3452 struct f_fs_opts *opts = to_ffs_opts(item);
3454 usb_put_function_instance(&opts->func_inst);
3457 static struct configfs_item_operations ffs_item_ops = {
3458 .release = ffs_attr_release,
3461 static const struct config_item_type ffs_func_type = {
3462 .ct_item_ops = &ffs_item_ops,
3463 .ct_owner = THIS_MODULE,
3467 /* Function registration interface ******************************************/
3469 static void ffs_free_inst(struct usb_function_instance *f)
3471 struct f_fs_opts *opts;
3473 opts = to_f_fs_opts(f);
3474 ffs_release_dev(opts->dev);
3476 _ffs_free_dev(opts->dev);
3481 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3483 if (strlen(name) >= sizeof_field(struct ffs_dev, name))
3484 return -ENAMETOOLONG;
3485 return ffs_name_dev(to_f_fs_opts(fi)->dev, name);
3488 static struct usb_function_instance *ffs_alloc_inst(void)
3490 struct f_fs_opts *opts;
3491 struct ffs_dev *dev;
3493 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3495 return ERR_PTR(-ENOMEM);
3497 opts->func_inst.set_inst_name = ffs_set_inst_name;
3498 opts->func_inst.free_func_inst = ffs_free_inst;
3500 dev = _ffs_alloc_dev();
3504 return ERR_CAST(dev);
3509 config_group_init_type_name(&opts->func_inst.group, "",
3511 return &opts->func_inst;
3514 static void ffs_free(struct usb_function *f)
3516 kfree(ffs_func_from_usb(f));
3519 static void ffs_func_unbind(struct usb_configuration *c,
3520 struct usb_function *f)
3522 struct ffs_function *func = ffs_func_from_usb(f);
3523 struct ffs_data *ffs = func->ffs;
3524 struct f_fs_opts *opts =
3525 container_of(f->fi, struct f_fs_opts, func_inst);
3526 struct ffs_ep *ep = func->eps;
3527 unsigned count = ffs->eps_count;
3528 unsigned long flags;
3530 if (ffs->func == func) {
3531 ffs_func_eps_disable(func);
3535 /* Drain any pending AIO completions */
3536 drain_workqueue(ffs->io_completion_wq);
3538 if (!--opts->refcnt)
3539 functionfs_unbind(ffs);
3541 /* cleanup after autoconfig */
3542 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3544 if (ep->ep && ep->req)
3545 usb_ep_free_request(ep->ep, ep->req);
3549 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3553 * eps, descriptors and interfaces_nums are allocated in the
3554 * same chunk so only one free is required.
3556 func->function.fs_descriptors = NULL;
3557 func->function.hs_descriptors = NULL;
3558 func->function.ss_descriptors = NULL;
3559 func->function.ssp_descriptors = NULL;
3560 func->interfaces_nums = NULL;
3562 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3565 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3567 struct ffs_function *func;
3569 func = kzalloc(sizeof(*func), GFP_KERNEL);
3571 return ERR_PTR(-ENOMEM);
3573 func->function.name = "Function FS Gadget";
3575 func->function.bind = ffs_func_bind;
3576 func->function.unbind = ffs_func_unbind;
3577 func->function.set_alt = ffs_func_set_alt;
3578 func->function.disable = ffs_func_disable;
3579 func->function.setup = ffs_func_setup;
3580 func->function.req_match = ffs_func_req_match;
3581 func->function.suspend = ffs_func_suspend;
3582 func->function.resume = ffs_func_resume;
3583 func->function.free_func = ffs_free;
3585 return &func->function;
3589 * ffs_lock must be taken by the caller of this function
3591 static struct ffs_dev *_ffs_alloc_dev(void)
3593 struct ffs_dev *dev;
3596 if (_ffs_get_single_dev())
3597 return ERR_PTR(-EBUSY);
3599 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3601 return ERR_PTR(-ENOMEM);
3603 if (list_empty(&ffs_devices)) {
3604 ret = functionfs_init();
3607 return ERR_PTR(ret);
3611 list_add(&dev->entry, &ffs_devices);
3616 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3618 struct ffs_dev *existing;
3623 existing = _ffs_do_find_dev(name);
3625 strscpy(dev->name, name, ARRAY_SIZE(dev->name));
3626 else if (existing != dev)
3633 EXPORT_SYMBOL_GPL(ffs_name_dev);
3635 int ffs_single_dev(struct ffs_dev *dev)
3642 if (!list_is_singular(&ffs_devices))
3650 EXPORT_SYMBOL_GPL(ffs_single_dev);
3653 * ffs_lock must be taken by the caller of this function
3655 static void _ffs_free_dev(struct ffs_dev *dev)
3657 list_del(&dev->entry);
3660 if (list_empty(&ffs_devices))
3661 functionfs_cleanup();
3664 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data)
3667 struct ffs_dev *ffs_dev;
3671 ffs_dev = _ffs_find_dev(dev_name);
3674 } else if (ffs_dev->mounted) {
3676 } else if (ffs_dev->ffs_acquire_dev_callback &&
3677 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) {
3680 ffs_dev->mounted = true;
3681 ffs_dev->ffs_data = ffs_data;
3682 ffs_data->private_data = ffs_dev;
3689 static void ffs_release_dev(struct ffs_dev *ffs_dev)
3693 if (ffs_dev && ffs_dev->mounted) {
3694 ffs_dev->mounted = false;
3695 if (ffs_dev->ffs_data) {
3696 ffs_dev->ffs_data->private_data = NULL;
3697 ffs_dev->ffs_data = NULL;
3700 if (ffs_dev->ffs_release_dev_callback)
3701 ffs_dev->ffs_release_dev_callback(ffs_dev);
3707 static int ffs_ready(struct ffs_data *ffs)
3709 struct ffs_dev *ffs_obj;
3714 ffs_obj = ffs->private_data;
3719 if (WARN_ON(ffs_obj->desc_ready)) {
3724 ffs_obj->desc_ready = true;
3726 if (ffs_obj->ffs_ready_callback) {
3727 ret = ffs_obj->ffs_ready_callback(ffs);
3732 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3738 static void ffs_closed(struct ffs_data *ffs)
3740 struct ffs_dev *ffs_obj;
3741 struct f_fs_opts *opts;
3742 struct config_item *ci;
3746 ffs_obj = ffs->private_data;
3750 ffs_obj->desc_ready = false;
3752 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3753 ffs_obj->ffs_closed_callback)
3754 ffs_obj->ffs_closed_callback(ffs);
3757 opts = ffs_obj->opts;
3761 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3762 || !kref_read(&opts->func_inst.group.cg_item.ci_kref))
3765 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3768 if (test_bit(FFS_FL_BOUND, &ffs->flags))
3769 unregister_gadget_item(ci);
3775 /* Misc helper functions ****************************************************/
3777 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3780 ? mutex_trylock(mutex) ? 0 : -EAGAIN
3781 : mutex_lock_interruptible(mutex);
3784 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3791 data = memdup_user(buf, len);
3795 pr_vdebug("Buffer from user space:\n");
3796 ffs_dump_mem("", data, len);
3801 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3802 MODULE_LICENSE("GPL");
3803 MODULE_AUTHOR("Michal Nazarewicz");