2 * f_fs.c -- user mode file system API for USB composite function controllers
4 * Copyright (C) 2010 Samsung Electronics
5 * Author: Michal Nazarewicz <mina86@mina86.com>
7 * Based on inode.c (GadgetFS) which was:
8 * Copyright (C) 2003-2004 David Brownell
9 * Copyright (C) 2003 Agilent Technologies
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
19 /* #define VERBOSE_DEBUG */
21 #include <linux/blkdev.h>
22 #include <linux/pagemap.h>
23 #include <linux/export.h>
24 #include <linux/hid.h>
25 #include <linux/module.h>
26 #include <linux/uio.h>
27 #include <asm/unaligned.h>
29 #include <linux/usb/composite.h>
30 #include <linux/usb/functionfs.h>
32 #include <linux/aio.h>
33 #include <linux/mmu_context.h>
34 #include <linux/poll.h>
35 #include <linux/eventfd.h>
39 #include "u_os_desc.h"
42 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
44 /* Reference counter handling */
45 static void ffs_data_get(struct ffs_data *ffs);
46 static void ffs_data_put(struct ffs_data *ffs);
47 /* Creates new ffs_data object. */
48 static struct ffs_data *__must_check ffs_data_new(void) __attribute__((malloc));
50 /* Opened counter handling. */
51 static void ffs_data_opened(struct ffs_data *ffs);
52 static void ffs_data_closed(struct ffs_data *ffs);
54 /* Called with ffs->mutex held; take over ownership of data. */
55 static int __must_check
56 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
57 static int __must_check
58 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
61 /* The function structure ***************************************************/
66 struct usb_configuration *conf;
67 struct usb_gadget *gadget;
72 short *interfaces_nums;
74 struct usb_function function;
78 static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
80 return container_of(f, struct ffs_function, function);
84 static inline enum ffs_setup_state
85 ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
87 return (enum ffs_setup_state)
88 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
92 static void ffs_func_eps_disable(struct ffs_function *func);
93 static int __must_check ffs_func_eps_enable(struct ffs_function *func);
95 static int ffs_func_bind(struct usb_configuration *,
96 struct usb_function *);
97 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
98 static void ffs_func_disable(struct usb_function *);
99 static int ffs_func_setup(struct usb_function *,
100 const struct usb_ctrlrequest *);
101 static bool ffs_func_req_match(struct usb_function *,
102 const struct usb_ctrlrequest *,
104 static void ffs_func_suspend(struct usb_function *);
105 static void ffs_func_resume(struct usb_function *);
108 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
109 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
112 /* The endpoints structures *************************************************/
115 struct usb_ep *ep; /* P: ffs->eps_lock */
116 struct usb_request *req; /* P: epfile->mutex */
118 /* [0]: full speed, [1]: high speed, [2]: super speed */
119 struct usb_endpoint_descriptor *descs[3];
123 int status; /* P: epfile->mutex */
127 /* Protects ep->ep and ep->req. */
129 wait_queue_head_t wait;
131 struct ffs_data *ffs;
132 struct ffs_ep *ep; /* P: ffs->eps_lock */
134 struct dentry *dentry;
137 * Buffer for holding data from partial reads which may happen since
138 * we’re rounding user read requests to a multiple of a max packet size.
140 * The pointer is initialised with NULL value and may be set by
141 * __ffs_epfile_read_data function to point to a temporary buffer.
143 * In normal operation, calls to __ffs_epfile_read_buffered will consume
144 * data from said buffer and eventually free it. Importantly, while the
145 * function is using the buffer, it sets the pointer to NULL. This is
146 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
147 * can never run concurrently (they are synchronised by epfile->mutex)
148 * so the latter will not assign a new value to the pointer.
150 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
151 * valid) and sets the pointer to READ_BUFFER_DROP value. This special
152 * value is crux of the synchronisation between ffs_func_eps_disable and
153 * __ffs_epfile_read_data.
155 * Once __ffs_epfile_read_data is about to finish it will try to set the
156 * pointer back to its old value (as described above), but seeing as the
157 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
160 * == State transitions ==
162 * • ptr == NULL: (initial state)
163 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
164 * ◦ __ffs_epfile_read_buffered: nop
165 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
166 * ◦ reading finishes: n/a, not in ‘and reading’ state
168 * ◦ __ffs_epfile_read_buffer_free: nop
169 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL
170 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
171 * ◦ reading finishes: n/a, not in ‘and reading’ state
173 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
174 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
175 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
176 * is always called first
177 * ◦ reading finishes: n/a, not in ‘and reading’ state
178 * • ptr == NULL and reading:
179 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
180 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
181 * ◦ __ffs_epfile_read_data: n/a, mutex is held
182 * ◦ reading finishes and …
183 * … all data read: free buf, go to ptr == NULL
184 * … otherwise: go to ptr == buf and reading
185 * • ptr == DROP and reading:
186 * ◦ __ffs_epfile_read_buffer_free: nop
187 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held
188 * ◦ __ffs_epfile_read_data: n/a, mutex is held
189 * ◦ reading finishes: free buf, go to ptr == DROP
191 struct ffs_buffer *read_buffer;
192 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
196 unsigned char in; /* P: ffs->eps_lock */
197 unsigned char isoc; /* P: ffs->eps_lock */
208 /* ffs_io_data structure ***************************************************/
215 struct iov_iter data;
219 struct mm_struct *mm;
220 struct work_struct work;
223 struct usb_request *req;
225 struct ffs_data *ffs;
228 struct ffs_desc_helper {
229 struct ffs_data *ffs;
230 unsigned interfaces_count;
234 static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
235 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
237 static struct dentry *
238 ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
239 const struct file_operations *fops);
241 /* Devices management *******************************************************/
243 DEFINE_MUTEX(ffs_lock);
244 EXPORT_SYMBOL_GPL(ffs_lock);
246 static struct ffs_dev *_ffs_find_dev(const char *name);
247 static struct ffs_dev *_ffs_alloc_dev(void);
248 static int _ffs_name_dev(struct ffs_dev *dev, const char *name);
249 static void _ffs_free_dev(struct ffs_dev *dev);
250 static void *ffs_acquire_dev(const char *dev_name);
251 static void ffs_release_dev(struct ffs_data *ffs_data);
252 static int ffs_ready(struct ffs_data *ffs);
253 static void ffs_closed(struct ffs_data *ffs);
255 /* Misc helper functions ****************************************************/
257 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
258 __attribute__((warn_unused_result, nonnull));
259 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
260 __attribute__((warn_unused_result, nonnull));
263 /* Control file aka ep0 *****************************************************/
265 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
267 struct ffs_data *ffs = req->context;
269 complete_all(&ffs->ep0req_completion);
272 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
274 struct usb_request *req = ffs->ep0req;
277 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
279 spin_unlock_irq(&ffs->ev.waitq.lock);
285 * UDC layer requires to provide a buffer even for ZLP, but should
286 * not use it at all. Let's provide some poisoned pointer to catch
287 * possible bug in the driver.
289 if (req->buf == NULL)
290 req->buf = (void *)0xDEADBABE;
292 reinit_completion(&ffs->ep0req_completion);
294 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
295 if (unlikely(ret < 0))
298 ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
300 usb_ep_dequeue(ffs->gadget->ep0, req);
304 ffs->setup_state = FFS_NO_SETUP;
305 return req->status ? req->status : req->actual;
308 static int __ffs_ep0_stall(struct ffs_data *ffs)
310 if (ffs->ev.can_stall) {
311 pr_vdebug("ep0 stall\n");
312 usb_ep_set_halt(ffs->gadget->ep0);
313 ffs->setup_state = FFS_NO_SETUP;
316 pr_debug("bogus ep0 stall!\n");
321 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
322 size_t len, loff_t *ptr)
324 struct ffs_data *ffs = file->private_data;
330 /* Fast check if setup was canceled */
331 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
335 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
336 if (unlikely(ret < 0))
340 switch (ffs->state) {
341 case FFS_READ_DESCRIPTORS:
342 case FFS_READ_STRINGS:
344 if (unlikely(len < 16)) {
349 data = ffs_prepare_buffer(buf, len);
356 if (ffs->state == FFS_READ_DESCRIPTORS) {
357 pr_info("read descriptors\n");
358 ret = __ffs_data_got_descs(ffs, data, len);
359 if (unlikely(ret < 0))
362 ffs->state = FFS_READ_STRINGS;
365 pr_info("read strings\n");
366 ret = __ffs_data_got_strings(ffs, data, len);
367 if (unlikely(ret < 0))
370 ret = ffs_epfiles_create(ffs);
372 ffs->state = FFS_CLOSING;
376 ffs->state = FFS_ACTIVE;
377 mutex_unlock(&ffs->mutex);
379 ret = ffs_ready(ffs);
380 if (unlikely(ret < 0)) {
381 ffs->state = FFS_CLOSING;
392 * We're called from user space, we can use _irq
393 * rather then _irqsave
395 spin_lock_irq(&ffs->ev.waitq.lock);
396 switch (ffs_setup_state_clear_cancelled(ffs)) {
397 case FFS_SETUP_CANCELLED:
405 case FFS_SETUP_PENDING:
409 /* FFS_SETUP_PENDING */
410 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
411 spin_unlock_irq(&ffs->ev.waitq.lock);
412 ret = __ffs_ep0_stall(ffs);
416 /* FFS_SETUP_PENDING and not stall */
417 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
419 spin_unlock_irq(&ffs->ev.waitq.lock);
421 data = ffs_prepare_buffer(buf, len);
427 spin_lock_irq(&ffs->ev.waitq.lock);
430 * We are guaranteed to be still in FFS_ACTIVE state
431 * but the state of setup could have changed from
432 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
433 * to check for that. If that happened we copied data
434 * from user space in vain but it's unlikely.
436 * For sure we are not in FFS_NO_SETUP since this is
437 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
438 * transition can be performed and it's protected by
441 if (ffs_setup_state_clear_cancelled(ffs) ==
442 FFS_SETUP_CANCELLED) {
445 spin_unlock_irq(&ffs->ev.waitq.lock);
447 /* unlocks spinlock */
448 ret = __ffs_ep0_queue_wait(ffs, data, len);
458 mutex_unlock(&ffs->mutex);
462 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
463 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
467 * n cannot be bigger than ffs->ev.count, which cannot be bigger than
468 * size of ffs->ev.types array (which is four) so that's how much space
471 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
472 const size_t size = n * sizeof *events;
475 memset(events, 0, size);
478 events[i].type = ffs->ev.types[i];
479 if (events[i].type == FUNCTIONFS_SETUP) {
480 events[i].u.setup = ffs->ev.setup;
481 ffs->setup_state = FFS_SETUP_PENDING;
487 memmove(ffs->ev.types, ffs->ev.types + n,
488 ffs->ev.count * sizeof *ffs->ev.types);
490 spin_unlock_irq(&ffs->ev.waitq.lock);
491 mutex_unlock(&ffs->mutex);
493 return unlikely(copy_to_user(buf, events, size)) ? -EFAULT : size;
496 static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
497 size_t len, loff_t *ptr)
499 struct ffs_data *ffs = file->private_data;
506 /* Fast check if setup was canceled */
507 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
511 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
512 if (unlikely(ret < 0))
516 if (ffs->state != FFS_ACTIVE) {
522 * We're called from user space, we can use _irq rather then
525 spin_lock_irq(&ffs->ev.waitq.lock);
527 switch (ffs_setup_state_clear_cancelled(ffs)) {
528 case FFS_SETUP_CANCELLED:
533 n = len / sizeof(struct usb_functionfs_event);
539 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
544 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
550 return __ffs_ep0_read_events(ffs, buf,
551 min(n, (size_t)ffs->ev.count));
553 case FFS_SETUP_PENDING:
554 if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
555 spin_unlock_irq(&ffs->ev.waitq.lock);
556 ret = __ffs_ep0_stall(ffs);
560 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
562 spin_unlock_irq(&ffs->ev.waitq.lock);
565 data = kmalloc(len, GFP_KERNEL);
566 if (unlikely(!data)) {
572 spin_lock_irq(&ffs->ev.waitq.lock);
574 /* See ffs_ep0_write() */
575 if (ffs_setup_state_clear_cancelled(ffs) ==
576 FFS_SETUP_CANCELLED) {
581 /* unlocks spinlock */
582 ret = __ffs_ep0_queue_wait(ffs, data, len);
583 if (likely(ret > 0) && unlikely(copy_to_user(buf, data, len)))
592 spin_unlock_irq(&ffs->ev.waitq.lock);
594 mutex_unlock(&ffs->mutex);
599 static int ffs_ep0_open(struct inode *inode, struct file *file)
601 struct ffs_data *ffs = inode->i_private;
605 if (unlikely(ffs->state == FFS_CLOSING))
608 file->private_data = ffs;
609 ffs_data_opened(ffs);
611 return stream_open(inode, file);
614 static int ffs_ep0_release(struct inode *inode, struct file *file)
616 struct ffs_data *ffs = file->private_data;
620 ffs_data_closed(ffs);
625 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
627 struct ffs_data *ffs = file->private_data;
628 struct usb_gadget *gadget = ffs->gadget;
633 if (code == FUNCTIONFS_INTERFACE_REVMAP) {
634 struct ffs_function *func = ffs->func;
635 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
636 } else if (gadget && gadget->ops->ioctl) {
637 ret = gadget->ops->ioctl(gadget, code, value);
645 static unsigned int ffs_ep0_poll(struct file *file, poll_table *wait)
647 struct ffs_data *ffs = file->private_data;
648 unsigned int mask = POLLWRNORM;
651 poll_wait(file, &ffs->ev.waitq, wait);
653 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
654 if (unlikely(ret < 0))
657 switch (ffs->state) {
658 case FFS_READ_DESCRIPTORS:
659 case FFS_READ_STRINGS:
664 switch (ffs->setup_state) {
670 case FFS_SETUP_PENDING:
671 case FFS_SETUP_CANCELLED:
672 mask |= (POLLIN | POLLOUT);
677 case FFS_DEACTIVATED:
681 mutex_unlock(&ffs->mutex);
686 static const struct file_operations ffs_ep0_operations = {
689 .open = ffs_ep0_open,
690 .write = ffs_ep0_write,
691 .read = ffs_ep0_read,
692 .release = ffs_ep0_release,
693 .unlocked_ioctl = ffs_ep0_ioctl,
694 .poll = ffs_ep0_poll,
698 /* "Normal" endpoints operations ********************************************/
700 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
703 if (likely(req->context)) {
704 struct ffs_ep *ep = _ep->driver_data;
705 ep->status = req->status ? req->status : req->actual;
706 complete(req->context);
710 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
712 ssize_t ret = copy_to_iter(data, data_len, iter);
713 if (likely(ret == data_len))
716 if (unlikely(iov_iter_count(iter)))
720 * Dear user space developer!
722 * TL;DR: To stop getting below error message in your kernel log, change
723 * user space code using functionfs to align read buffers to a max
726 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
727 * packet size. When unaligned buffer is passed to functionfs, it
728 * internally uses a larger, aligned buffer so that such UDCs are happy.
730 * Unfortunately, this means that host may send more data than was
731 * requested in read(2) system call. f_fs doesn’t know what to do with
732 * that excess data so it simply drops it.
734 * Was the buffer aligned in the first place, no such problem would
737 * Data may be dropped only in AIO reads. Synchronous reads are handled
738 * by splitting a request into multiple parts. This splitting may still
739 * be a problem though so it’s likely best to align the buffer
740 * regardless of it being AIO or not..
742 * This only affects OUT endpoints, i.e. reading data with a read(2),
743 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not
746 pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
747 "Align read buffer size to max packet size to avoid the problem.\n",
753 static void ffs_user_copy_worker(struct work_struct *work)
755 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
757 int ret = io_data->req->status ? io_data->req->status :
758 io_data->req->actual;
759 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
761 if (io_data->read && ret > 0) {
762 mm_segment_t oldfs = get_fs();
766 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
767 unuse_mm(io_data->mm);
771 io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
773 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
774 eventfd_signal(io_data->ffs->ffs_eventfd, 1);
776 usb_ep_free_request(io_data->ep, io_data->req);
779 kfree(io_data->to_free);
784 static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
785 struct usb_request *req)
787 struct ffs_io_data *io_data = req->context;
791 INIT_WORK(&io_data->work, ffs_user_copy_worker);
792 schedule_work(&io_data->work);
795 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
798 * See comment in struct ffs_epfile for full read_buffer pointer
799 * synchronisation story.
801 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
802 if (buf && buf != READ_BUFFER_DROP)
806 /* Assumes epfile->mutex is held. */
807 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
808 struct iov_iter *iter)
811 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
812 * the buffer while we are using it. See comment in struct ffs_epfile
813 * for full read_buffer pointer synchronisation story.
815 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
817 if (!buf || buf == READ_BUFFER_DROP)
820 ret = copy_to_iter(buf->data, buf->length, iter);
821 if (buf->length == ret) {
826 if (unlikely(iov_iter_count(iter))) {
833 if (cmpxchg(&epfile->read_buffer, NULL, buf))
839 /* Assumes epfile->mutex is held. */
840 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
841 void *data, int data_len,
842 struct iov_iter *iter)
844 struct ffs_buffer *buf;
846 ssize_t ret = copy_to_iter(data, data_len, iter);
847 if (likely(data_len == ret))
850 if (unlikely(iov_iter_count(iter)))
853 /* See ffs_copy_to_iter for more context. */
854 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
858 buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL);
861 buf->length = data_len;
862 buf->data = buf->storage;
863 memcpy(buf->storage, data + ret, data_len);
866 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
867 * ffs_func_eps_disable has been called in the meanwhile). See comment
868 * in struct ffs_epfile for full read_buffer pointer synchronisation
871 if (unlikely(cmpxchg(&epfile->read_buffer, NULL, buf)))
877 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
879 struct ffs_epfile *epfile = file->private_data;
880 struct usb_request *req;
883 ssize_t ret, data_len = -EINVAL;
886 /* Are we still active? */
887 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
890 /* Wait for endpoint to be enabled */
893 if (file->f_flags & O_NONBLOCK)
896 ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
902 halt = (!io_data->read == !epfile->in);
903 if (halt && epfile->isoc)
906 /* We will be using request and read_buffer */
907 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
911 /* Allocate & copy */
913 struct usb_gadget *gadget;
916 * Do we have buffered data from previous partial read? Check
917 * that for synchronous case only because we do not have
918 * facility to ‘wake up’ a pending asynchronous read and push
919 * buffered data to it which we would need to make things behave
922 if (!io_data->aio && io_data->read) {
923 ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
929 * if we _do_ wait above, the epfile->ffs->gadget might be NULL
930 * before the waiting completes, so do not assign to 'gadget'
933 gadget = epfile->ffs->gadget;
935 spin_lock_irq(&epfile->ffs->eps_lock);
936 /* In the meantime, endpoint got disabled or changed. */
937 if (epfile->ep != ep) {
941 data_len = iov_iter_count(&io_data->data);
943 * Controller may require buffer size to be aligned to
944 * maxpacketsize of an out endpoint.
947 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
948 spin_unlock_irq(&epfile->ffs->eps_lock);
950 data = kmalloc(data_len, GFP_KERNEL);
951 if (unlikely(!data)) {
955 if (!io_data->read &&
956 copy_from_iter(data, data_len, &io_data->data) != data_len) {
962 spin_lock_irq(&epfile->ffs->eps_lock);
964 if (epfile->ep != ep) {
965 /* In the meantime, endpoint got disabled or changed. */
969 if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
970 usb_ep_set_halt(ep->ep);
972 } else if (unlikely(data_len == -EINVAL)) {
974 * Sanity Check: even though data_len can't be used
975 * uninitialized at the time I write this comment, some
976 * compilers complain about this situation.
977 * In order to keep the code clean from warnings, data_len is
978 * being initialized to -EINVAL during its declaration, which
979 * means we can't rely on compiler anymore to warn no future
980 * changes won't result in data_len being used uninitialized.
981 * For such reason, we're adding this redundant sanity check
984 WARN(1, "%s: data_len == -EINVAL\n", __func__);
986 } else if (!io_data->aio) {
987 DECLARE_COMPLETION_ONSTACK(done);
988 bool interrupted = false;
992 req->length = data_len;
994 req->context = &done;
995 req->complete = ffs_epfile_io_complete;
997 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
998 if (unlikely(ret < 0))
1001 spin_unlock_irq(&epfile->ffs->eps_lock);
1003 if (unlikely(wait_for_completion_interruptible(&done))) {
1005 * To avoid race condition with ffs_epfile_io_complete,
1006 * dequeue the request first then check
1007 * status. usb_ep_dequeue API should guarantee no race
1008 * condition with req->complete callback.
1010 usb_ep_dequeue(ep->ep, req);
1011 wait_for_completion(&done);
1012 interrupted = ep->status < 0;
1017 else if (io_data->read && ep->status > 0)
1018 ret = __ffs_epfile_read_data(epfile, data, ep->status,
1023 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) {
1027 req->length = data_len;
1029 io_data->buf = data;
1030 io_data->ep = ep->ep;
1032 io_data->ffs = epfile->ffs;
1034 req->context = io_data;
1035 req->complete = ffs_epfile_async_io_complete;
1037 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
1038 if (unlikely(ret)) {
1039 io_data->req = NULL;
1040 usb_ep_free_request(ep->ep, req);
1046 * Do not kfree the buffer in this function. It will be freed
1047 * by ffs_user_copy_worker.
1053 spin_unlock_irq(&epfile->ffs->eps_lock);
1055 mutex_unlock(&epfile->mutex);
1062 ffs_epfile_open(struct inode *inode, struct file *file)
1064 struct ffs_epfile *epfile = inode->i_private;
1068 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1071 file->private_data = epfile;
1072 ffs_data_opened(epfile->ffs);
1074 return stream_open(inode, file);
1077 static int ffs_aio_cancel(struct kiocb *kiocb)
1079 struct ffs_io_data *io_data = kiocb->private;
1080 struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
1081 unsigned long flags;
1086 spin_lock_irqsave(&epfile->ffs->eps_lock, flags);
1088 if (likely(io_data && io_data->ep && io_data->req))
1089 value = usb_ep_dequeue(io_data->ep, io_data->req);
1093 spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);
1098 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
1100 struct ffs_io_data io_data, *p = &io_data;
1105 if (!is_sync_kiocb(kiocb)) {
1106 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1111 memset(p, 0, sizeof(*p));
1118 p->mm = current->mm;
1123 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1125 res = ffs_epfile_io(kiocb->ki_filp, p);
1126 if (res == -EIOCBQUEUED)
1135 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
1137 struct ffs_io_data io_data, *p = &io_data;
1142 if (!is_sync_kiocb(kiocb)) {
1143 p = kzalloc(sizeof(io_data), GFP_KERNEL);
1148 memset(p, 0, sizeof(*p));
1155 p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
1164 p->mm = current->mm;
1169 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
1171 res = ffs_epfile_io(kiocb->ki_filp, p);
1172 if (res == -EIOCBQUEUED)
1185 ffs_epfile_release(struct inode *inode, struct file *file)
1187 struct ffs_epfile *epfile = inode->i_private;
1191 __ffs_epfile_read_buffer_free(epfile);
1192 ffs_data_closed(epfile->ffs);
1197 static long ffs_epfile_ioctl(struct file *file, unsigned code,
1198 unsigned long value)
1200 struct ffs_epfile *epfile = file->private_data;
1205 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
1208 spin_lock_irq(&epfile->ffs->eps_lock);
1209 if (likely(epfile->ep)) {
1211 case FUNCTIONFS_FIFO_STATUS:
1212 ret = usb_ep_fifo_status(epfile->ep->ep);
1214 case FUNCTIONFS_FIFO_FLUSH:
1215 usb_ep_fifo_flush(epfile->ep->ep);
1218 case FUNCTIONFS_CLEAR_HALT:
1219 ret = usb_ep_clear_halt(epfile->ep->ep);
1221 case FUNCTIONFS_ENDPOINT_REVMAP:
1222 ret = epfile->ep->num;
1224 case FUNCTIONFS_ENDPOINT_DESC:
1227 struct usb_endpoint_descriptor desc1, *desc;
1229 switch (epfile->ffs->gadget->speed) {
1230 case USB_SPEED_SUPER:
1231 case USB_SPEED_SUPER_PLUS:
1234 case USB_SPEED_HIGH:
1241 desc = epfile->ep->descs[desc_idx];
1242 memcpy(&desc1, desc, desc->bLength);
1244 spin_unlock_irq(&epfile->ffs->eps_lock);
1245 ret = copy_to_user((void *)value, &desc1, desc1.bLength);
1256 spin_unlock_irq(&epfile->ffs->eps_lock);
1261 static const struct file_operations ffs_epfile_operations = {
1262 .llseek = no_llseek,
1264 .open = ffs_epfile_open,
1265 .write_iter = ffs_epfile_write_iter,
1266 .read_iter = ffs_epfile_read_iter,
1267 .release = ffs_epfile_release,
1268 .unlocked_ioctl = ffs_epfile_ioctl,
1272 /* File system and super block operations ***********************************/
1275 * Mounting the file system creates a controller file, used first for
1276 * function configuration then later for event monitoring.
1279 static struct inode *__must_check
1280 ffs_sb_make_inode(struct super_block *sb, void *data,
1281 const struct file_operations *fops,
1282 const struct inode_operations *iops,
1283 struct ffs_file_perms *perms)
1285 struct inode *inode;
1289 inode = new_inode(sb);
1291 if (likely(inode)) {
1292 struct timespec ts = current_time(inode);
1294 inode->i_ino = get_next_ino();
1295 inode->i_mode = perms->mode;
1296 inode->i_uid = perms->uid;
1297 inode->i_gid = perms->gid;
1298 inode->i_atime = ts;
1299 inode->i_mtime = ts;
1300 inode->i_ctime = ts;
1301 inode->i_private = data;
1303 inode->i_fop = fops;
1311 /* Create "regular" file */
1312 static struct dentry *ffs_sb_create_file(struct super_block *sb,
1313 const char *name, void *data,
1314 const struct file_operations *fops)
1316 struct ffs_data *ffs = sb->s_fs_info;
1317 struct dentry *dentry;
1318 struct inode *inode;
1322 dentry = d_alloc_name(sb->s_root, name);
1323 if (unlikely(!dentry))
1326 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
1327 if (unlikely(!inode)) {
1332 d_add(dentry, inode);
1337 static const struct super_operations ffs_sb_operations = {
1338 .statfs = simple_statfs,
1339 .drop_inode = generic_delete_inode,
1342 struct ffs_sb_fill_data {
1343 struct ffs_file_perms perms;
1345 const char *dev_name;
1347 struct ffs_data *ffs_data;
1350 static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
1352 struct ffs_sb_fill_data *data = _data;
1353 struct inode *inode;
1354 struct ffs_data *ffs = data->ffs_data;
1359 data->ffs_data = NULL;
1360 sb->s_fs_info = ffs;
1361 sb->s_blocksize = PAGE_SIZE;
1362 sb->s_blocksize_bits = PAGE_SHIFT;
1363 sb->s_magic = FUNCTIONFS_MAGIC;
1364 sb->s_op = &ffs_sb_operations;
1365 sb->s_time_gran = 1;
1368 data->perms.mode = data->root_mode;
1369 inode = ffs_sb_make_inode(sb, NULL,
1370 &simple_dir_operations,
1371 &simple_dir_inode_operations,
1373 sb->s_root = d_make_root(inode);
1374 if (unlikely(!sb->s_root))
1378 if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
1379 &ffs_ep0_operations)))
1385 static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
1389 if (!opts || !*opts)
1393 unsigned long value;
1397 comma = strchr(opts, ',');
1402 eq = strchr(opts, '=');
1403 if (unlikely(!eq)) {
1404 pr_err("'=' missing in %s\n", opts);
1410 if (kstrtoul(eq + 1, 0, &value)) {
1411 pr_err("%s: invalid value: %s\n", opts, eq + 1);
1415 /* Interpret option */
1416 switch (eq - opts) {
1418 if (!memcmp(opts, "no_disconnect", 13))
1419 data->no_disconnect = !!value;
1424 if (!memcmp(opts, "rmode", 5))
1425 data->root_mode = (value & 0555) | S_IFDIR;
1426 else if (!memcmp(opts, "fmode", 5))
1427 data->perms.mode = (value & 0666) | S_IFREG;
1433 if (!memcmp(opts, "mode", 4)) {
1434 data->root_mode = (value & 0555) | S_IFDIR;
1435 data->perms.mode = (value & 0666) | S_IFREG;
1442 if (!memcmp(opts, "uid", 3)) {
1443 data->perms.uid = make_kuid(current_user_ns(), value);
1444 if (!uid_valid(data->perms.uid)) {
1445 pr_err("%s: unmapped value: %lu\n", opts, value);
1448 } else if (!memcmp(opts, "gid", 3)) {
1449 data->perms.gid = make_kgid(current_user_ns(), value);
1450 if (!gid_valid(data->perms.gid)) {
1451 pr_err("%s: unmapped value: %lu\n", opts, value);
1461 pr_err("%s: invalid option\n", opts);
1465 /* Next iteration */
1474 /* "mount -t functionfs dev_name /dev/function" ends up here */
1476 static struct dentry *
1477 ffs_fs_mount(struct file_system_type *t, int flags,
1478 const char *dev_name, void *opts)
1480 struct ffs_sb_fill_data data = {
1482 .mode = S_IFREG | 0600,
1483 .uid = GLOBAL_ROOT_UID,
1484 .gid = GLOBAL_ROOT_GID,
1486 .root_mode = S_IFDIR | 0500,
1487 .no_disconnect = false,
1492 struct ffs_data *ffs;
1496 ret = ffs_fs_parse_opts(&data, opts);
1497 if (unlikely(ret < 0))
1498 return ERR_PTR(ret);
1500 ffs = ffs_data_new();
1502 return ERR_PTR(-ENOMEM);
1503 ffs->file_perms = data.perms;
1504 ffs->no_disconnect = data.no_disconnect;
1506 ffs->dev_name = kstrdup(dev_name, GFP_KERNEL);
1507 if (unlikely(!ffs->dev_name)) {
1509 return ERR_PTR(-ENOMEM);
1512 ffs_dev = ffs_acquire_dev(dev_name);
1513 if (IS_ERR(ffs_dev)) {
1515 return ERR_CAST(ffs_dev);
1517 ffs->private_data = ffs_dev;
1518 data.ffs_data = ffs;
1520 rv = mount_nodev(t, flags, &data, ffs_sb_fill);
1521 if (IS_ERR(rv) && data.ffs_data) {
1522 ffs_release_dev(data.ffs_data);
1523 ffs_data_put(data.ffs_data);
1529 ffs_fs_kill_sb(struct super_block *sb)
1533 kill_litter_super(sb);
1534 if (sb->s_fs_info) {
1535 ffs_release_dev(sb->s_fs_info);
1536 ffs_data_closed(sb->s_fs_info);
1540 static struct file_system_type ffs_fs_type = {
1541 .owner = THIS_MODULE,
1542 .name = "functionfs",
1543 .mount = ffs_fs_mount,
1544 .kill_sb = ffs_fs_kill_sb,
1546 MODULE_ALIAS_FS("functionfs");
1549 /* Driver's main init/cleanup functions *************************************/
1551 static int functionfs_init(void)
1557 ret = register_filesystem(&ffs_fs_type);
1559 pr_info("file system registered\n");
1561 pr_err("failed registering file system (%d)\n", ret);
1566 static void functionfs_cleanup(void)
1570 pr_info("unloading\n");
1571 unregister_filesystem(&ffs_fs_type);
1575 /* ffs_data and ffs_function construction and destruction code **************/
1577 static void ffs_data_clear(struct ffs_data *ffs);
1578 static void ffs_data_reset(struct ffs_data *ffs);
1580 static void ffs_data_get(struct ffs_data *ffs)
1584 atomic_inc(&ffs->ref);
1587 static void ffs_data_opened(struct ffs_data *ffs)
1591 atomic_inc(&ffs->ref);
1592 if (atomic_add_return(1, &ffs->opened) == 1 &&
1593 ffs->state == FFS_DEACTIVATED) {
1594 ffs->state = FFS_CLOSING;
1595 ffs_data_reset(ffs);
1599 static void ffs_data_put(struct ffs_data *ffs)
1603 if (unlikely(atomic_dec_and_test(&ffs->ref))) {
1604 pr_info("%s(): freeing\n", __func__);
1605 ffs_data_clear(ffs);
1606 BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
1607 waitqueue_active(&ffs->ep0req_completion.wait));
1608 kfree(ffs->dev_name);
1613 static void ffs_data_closed(struct ffs_data *ffs)
1617 if (atomic_dec_and_test(&ffs->opened)) {
1618 if (ffs->no_disconnect) {
1619 ffs->state = FFS_DEACTIVATED;
1621 ffs_epfiles_destroy(ffs->epfiles,
1623 ffs->epfiles = NULL;
1625 if (ffs->setup_state == FFS_SETUP_PENDING)
1626 __ffs_ep0_stall(ffs);
1628 ffs->state = FFS_CLOSING;
1629 ffs_data_reset(ffs);
1632 if (atomic_read(&ffs->opened) < 0) {
1633 ffs->state = FFS_CLOSING;
1634 ffs_data_reset(ffs);
1640 static struct ffs_data *ffs_data_new(void)
1642 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
1648 atomic_set(&ffs->ref, 1);
1649 atomic_set(&ffs->opened, 0);
1650 ffs->state = FFS_READ_DESCRIPTORS;
1651 mutex_init(&ffs->mutex);
1652 spin_lock_init(&ffs->eps_lock);
1653 init_waitqueue_head(&ffs->ev.waitq);
1654 init_completion(&ffs->ep0req_completion);
1656 /* XXX REVISIT need to update it in some places, or do we? */
1657 ffs->ev.can_stall = 1;
1662 static void ffs_data_clear(struct ffs_data *ffs)
1668 BUG_ON(ffs->gadget);
1671 ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
1672 ffs->epfiles = NULL;
1675 if (ffs->ffs_eventfd) {
1676 eventfd_ctx_put(ffs->ffs_eventfd);
1677 ffs->ffs_eventfd = NULL;
1680 kfree(ffs->raw_descs_data);
1681 kfree(ffs->raw_strings);
1682 kfree(ffs->stringtabs);
1685 static void ffs_data_reset(struct ffs_data *ffs)
1689 ffs_data_clear(ffs);
1691 ffs->raw_descs_data = NULL;
1692 ffs->raw_descs = NULL;
1693 ffs->raw_strings = NULL;
1694 ffs->stringtabs = NULL;
1696 ffs->raw_descs_length = 0;
1697 ffs->fs_descs_count = 0;
1698 ffs->hs_descs_count = 0;
1699 ffs->ss_descs_count = 0;
1701 ffs->strings_count = 0;
1702 ffs->interfaces_count = 0;
1707 ffs->state = FFS_READ_DESCRIPTORS;
1708 ffs->setup_state = FFS_NO_SETUP;
1711 ffs->ms_os_descs_ext_prop_count = 0;
1712 ffs->ms_os_descs_ext_prop_name_len = 0;
1713 ffs->ms_os_descs_ext_prop_data_len = 0;
1717 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
1719 struct usb_gadget_strings **lang;
1724 if (WARN_ON(ffs->state != FFS_ACTIVE
1725 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
1728 first_id = usb_string_ids_n(cdev, ffs->strings_count);
1729 if (unlikely(first_id < 0))
1732 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
1733 if (unlikely(!ffs->ep0req))
1735 ffs->ep0req->complete = ffs_ep0_complete;
1736 ffs->ep0req->context = ffs;
1738 lang = ffs->stringtabs;
1740 for (; *lang; ++lang) {
1741 struct usb_string *str = (*lang)->strings;
1743 for (; str->s; ++id, ++str)
1748 ffs->gadget = cdev->gadget;
1753 static void functionfs_unbind(struct ffs_data *ffs)
1757 if (!WARN_ON(!ffs->gadget)) {
1758 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
1761 clear_bit(FFS_FL_BOUND, &ffs->flags);
1766 static int ffs_epfiles_create(struct ffs_data *ffs)
1768 struct ffs_epfile *epfile, *epfiles;
1773 count = ffs->eps_count;
1774 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
1779 for (i = 1; i <= count; ++i, ++epfile) {
1781 mutex_init(&epfile->mutex);
1782 init_waitqueue_head(&epfile->wait);
1783 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
1784 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
1786 sprintf(epfile->name, "ep%u", i);
1787 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
1789 &ffs_epfile_operations);
1790 if (unlikely(!epfile->dentry)) {
1791 ffs_epfiles_destroy(epfiles, i - 1);
1796 ffs->epfiles = epfiles;
1800 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
1802 struct ffs_epfile *epfile = epfiles;
1806 for (; count; --count, ++epfile) {
1807 BUG_ON(mutex_is_locked(&epfile->mutex) ||
1808 waitqueue_active(&epfile->wait));
1809 if (epfile->dentry) {
1810 d_delete(epfile->dentry);
1811 dput(epfile->dentry);
1812 epfile->dentry = NULL;
1819 static void ffs_func_eps_disable(struct ffs_function *func)
1821 struct ffs_ep *ep = func->eps;
1822 struct ffs_epfile *epfile = func->ffs->epfiles;
1823 unsigned count = func->ffs->eps_count;
1824 unsigned long flags;
1826 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1828 /* pending requests get nuked */
1830 usb_ep_disable(ep->ep);
1835 __ffs_epfile_read_buffer_free(epfile);
1839 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1842 static int ffs_func_eps_enable(struct ffs_function *func)
1844 struct ffs_data *ffs = func->ffs;
1845 struct ffs_ep *ep = func->eps;
1846 struct ffs_epfile *epfile = ffs->epfiles;
1847 unsigned count = ffs->eps_count;
1848 unsigned long flags;
1851 spin_lock_irqsave(&func->ffs->eps_lock, flags);
1853 struct usb_endpoint_descriptor *ds;
1854 struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
1855 int needs_comp_desc = false;
1858 if (ffs->gadget->speed == USB_SPEED_SUPER) {
1860 needs_comp_desc = true;
1861 } else if (ffs->gadget->speed == USB_SPEED_HIGH)
1866 /* fall-back to lower speed if desc missing for current speed */
1868 ds = ep->descs[desc_idx];
1869 } while (!ds && --desc_idx >= 0);
1876 ep->ep->driver_data = ep;
1879 if (needs_comp_desc) {
1880 comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
1881 USB_DT_ENDPOINT_SIZE);
1882 ep->ep->maxburst = comp_desc->bMaxBurst + 1;
1883 ep->ep->comp_desc = comp_desc;
1886 ret = usb_ep_enable(ep->ep);
1889 epfile->in = usb_endpoint_dir_in(ds);
1890 epfile->isoc = usb_endpoint_xfer_isoc(ds);
1895 wake_up(&epfile->wait);
1900 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
1906 /* Parsing and building descriptors and strings *****************************/
1909 * This validates if data pointed by data is a valid USB descriptor as
1910 * well as record how many interfaces, endpoints and strings are
1911 * required by given configuration. Returns address after the
1912 * descriptor or NULL if data is invalid.
1915 enum ffs_entity_type {
1916 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
1919 enum ffs_os_desc_type {
1920 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
1923 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
1925 struct usb_descriptor_header *desc,
1928 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
1929 struct usb_os_desc_header *h, void *data,
1930 unsigned len, void *priv);
1932 static int __must_check ffs_do_single_desc(char *data, unsigned len,
1933 ffs_entity_callback entity,
1936 struct usb_descriptor_header *_ds = (void *)data;
1942 /* At least two bytes are required: length and type */
1944 pr_vdebug("descriptor too short\n");
1948 /* If we have at least as many bytes as the descriptor takes? */
1949 length = _ds->bLength;
1951 pr_vdebug("descriptor longer then available data\n");
1955 #define __entity_check_INTERFACE(val) 1
1956 #define __entity_check_STRING(val) (val)
1957 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
1958 #define __entity(type, val) do { \
1959 pr_vdebug("entity " #type "(%02x)\n", (val)); \
1960 if (unlikely(!__entity_check_ ##type(val))) { \
1961 pr_vdebug("invalid entity's value\n"); \
1964 ret = entity(FFS_ ##type, &val, _ds, priv); \
1965 if (unlikely(ret < 0)) { \
1966 pr_debug("entity " #type "(%02x); ret = %d\n", \
1972 /* Parse descriptor depending on type. */
1973 switch (_ds->bDescriptorType) {
1977 case USB_DT_DEVICE_QUALIFIER:
1978 /* function can't have any of those */
1979 pr_vdebug("descriptor reserved for gadget: %d\n",
1980 _ds->bDescriptorType);
1983 case USB_DT_INTERFACE: {
1984 struct usb_interface_descriptor *ds = (void *)_ds;
1985 pr_vdebug("interface descriptor\n");
1986 if (length != sizeof *ds)
1989 __entity(INTERFACE, ds->bInterfaceNumber);
1991 __entity(STRING, ds->iInterface);
1995 case USB_DT_ENDPOINT: {
1996 struct usb_endpoint_descriptor *ds = (void *)_ds;
1997 pr_vdebug("endpoint descriptor\n");
1998 if (length != USB_DT_ENDPOINT_SIZE &&
1999 length != USB_DT_ENDPOINT_AUDIO_SIZE)
2001 __entity(ENDPOINT, ds->bEndpointAddress);
2006 pr_vdebug("hid descriptor\n");
2007 if (length != sizeof(struct hid_descriptor))
2012 if (length != sizeof(struct usb_otg_descriptor))
2016 case USB_DT_INTERFACE_ASSOCIATION: {
2017 struct usb_interface_assoc_descriptor *ds = (void *)_ds;
2018 pr_vdebug("interface association descriptor\n");
2019 if (length != sizeof *ds)
2022 __entity(STRING, ds->iFunction);
2026 case USB_DT_SS_ENDPOINT_COMP:
2027 pr_vdebug("EP SS companion descriptor\n");
2028 if (length != sizeof(struct usb_ss_ep_comp_descriptor))
2032 case USB_DT_OTHER_SPEED_CONFIG:
2033 case USB_DT_INTERFACE_POWER:
2035 case USB_DT_SECURITY:
2036 case USB_DT_CS_RADIO_CONTROL:
2038 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
2042 /* We should never be here */
2043 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
2047 pr_vdebug("invalid length: %d (descriptor %d)\n",
2048 _ds->bLength, _ds->bDescriptorType);
2053 #undef __entity_check_DESCRIPTOR
2054 #undef __entity_check_INTERFACE
2055 #undef __entity_check_STRING
2056 #undef __entity_check_ENDPOINT
2061 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
2062 ffs_entity_callback entity, void *priv)
2064 const unsigned _len = len;
2065 unsigned long num = 0;
2075 /* Record "descriptor" entity */
2076 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
2077 if (unlikely(ret < 0)) {
2078 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
2086 ret = ffs_do_single_desc(data, len, entity, priv);
2087 if (unlikely(ret < 0)) {
2088 pr_debug("%s returns %d\n", __func__, ret);
2098 static int __ffs_data_do_entity(enum ffs_entity_type type,
2099 u8 *valuep, struct usb_descriptor_header *desc,
2102 struct ffs_desc_helper *helper = priv;
2103 struct usb_endpoint_descriptor *d;
2108 case FFS_DESCRIPTOR:
2113 * Interfaces are indexed from zero so if we
2114 * encountered interface "n" then there are at least
2117 if (*valuep >= helper->interfaces_count)
2118 helper->interfaces_count = *valuep + 1;
2123 * Strings are indexed from 1 (0 is magic ;) reserved
2124 * for languages list or some such)
2126 if (*valuep > helper->ffs->strings_count)
2127 helper->ffs->strings_count = *valuep;
2132 helper->eps_count++;
2133 if (helper->eps_count >= 15)
2135 /* Check if descriptors for any speed were already parsed */
2136 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
2137 helper->ffs->eps_addrmap[helper->eps_count] =
2138 d->bEndpointAddress;
2139 else if (helper->ffs->eps_addrmap[helper->eps_count] !=
2140 d->bEndpointAddress)
2148 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
2149 struct usb_os_desc_header *desc)
2151 u16 bcd_version = le16_to_cpu(desc->bcdVersion);
2152 u16 w_index = le16_to_cpu(desc->wIndex);
2154 if (bcd_version != 1) {
2155 pr_vdebug("unsupported os descriptors version: %d",
2161 *next_type = FFS_OS_DESC_EXT_COMPAT;
2164 *next_type = FFS_OS_DESC_EXT_PROP;
2167 pr_vdebug("unsupported os descriptor type: %d", w_index);
2171 return sizeof(*desc);
2175 * Process all extended compatibility/extended property descriptors
2176 * of a feature descriptor
2178 static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
2179 enum ffs_os_desc_type type,
2181 ffs_os_desc_callback entity,
2183 struct usb_os_desc_header *h)
2186 const unsigned _len = len;
2190 /* loop over all ext compat/ext prop descriptors */
2191 while (feature_count--) {
2192 ret = entity(type, h, data, len, priv);
2193 if (unlikely(ret < 0)) {
2194 pr_debug("bad OS descriptor, type: %d\n", type);
2203 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
2204 static int __must_check ffs_do_os_descs(unsigned count,
2205 char *data, unsigned len,
2206 ffs_os_desc_callback entity, void *priv)
2208 const unsigned _len = len;
2209 unsigned long num = 0;
2213 for (num = 0; num < count; ++num) {
2215 enum ffs_os_desc_type type;
2217 struct usb_os_desc_header *desc = (void *)data;
2219 if (len < sizeof(*desc))
2223 * Record "descriptor" entity.
2224 * Process dwLength, bcdVersion, wIndex, get b/wCount.
2225 * Move the data pointer to the beginning of extended
2226 * compatibilities proper or extended properties proper
2227 * portions of the data
2229 if (le32_to_cpu(desc->dwLength) > len)
2232 ret = __ffs_do_os_desc_header(&type, desc);
2233 if (unlikely(ret < 0)) {
2234 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
2239 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
2241 feature_count = le16_to_cpu(desc->wCount);
2242 if (type == FFS_OS_DESC_EXT_COMPAT &&
2243 (feature_count > 255 || desc->Reserved))
2249 * Process all function/property descriptors
2250 * of this Feature Descriptor
2252 ret = ffs_do_single_os_desc(data, len, type,
2253 feature_count, entity, priv, desc);
2254 if (unlikely(ret < 0)) {
2255 pr_debug("%s returns %d\n", __func__, ret);
2266 * Validate contents of the buffer from userspace related to OS descriptors.
2268 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
2269 struct usb_os_desc_header *h, void *data,
2270 unsigned len, void *priv)
2272 struct ffs_data *ffs = priv;
2278 case FFS_OS_DESC_EXT_COMPAT: {
2279 struct usb_ext_compat_desc *d = data;
2282 if (len < sizeof(*d) ||
2283 d->bFirstInterfaceNumber >= ffs->interfaces_count)
2285 if (d->Reserved1 != 1) {
2287 * According to the spec, Reserved1 must be set to 1
2288 * but older kernels incorrectly rejected non-zero
2289 * values. We fix it here to avoid returning EINVAL
2290 * in response to values we used to accept.
2292 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
2295 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
2296 if (d->Reserved2[i])
2299 length = sizeof(struct usb_ext_compat_desc);
2302 case FFS_OS_DESC_EXT_PROP: {
2303 struct usb_ext_prop_desc *d = data;
2307 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
2309 length = le32_to_cpu(d->dwSize);
2312 type = le32_to_cpu(d->dwPropertyDataType);
2313 if (type < USB_EXT_PROP_UNICODE ||
2314 type > USB_EXT_PROP_UNICODE_MULTI) {
2315 pr_vdebug("unsupported os descriptor property type: %d",
2319 pnl = le16_to_cpu(d->wPropertyNameLength);
2320 if (length < 14 + pnl) {
2321 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
2325 pdl = le32_to_cpu(*(u32 *)((u8 *)data + 10 + pnl));
2326 if (length != 14 + pnl + pdl) {
2327 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
2328 length, pnl, pdl, type);
2331 ++ffs->ms_os_descs_ext_prop_count;
2332 /* property name reported to the host as "WCHAR"s */
2333 ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
2334 ffs->ms_os_descs_ext_prop_data_len += pdl;
2338 pr_vdebug("unknown descriptor: %d\n", type);
2344 static int __ffs_data_got_descs(struct ffs_data *ffs,
2345 char *const _data, size_t len)
2347 char *data = _data, *raw_descs;
2348 unsigned os_descs_count = 0, counts[3], flags;
2349 int ret = -EINVAL, i;
2350 struct ffs_desc_helper helper;
2354 if (get_unaligned_le32(data + 4) != len)
2357 switch (get_unaligned_le32(data)) {
2358 case FUNCTIONFS_DESCRIPTORS_MAGIC:
2359 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
2363 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
2364 flags = get_unaligned_le32(data + 8);
2365 ffs->user_flags = flags;
2366 if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
2367 FUNCTIONFS_HAS_HS_DESC |
2368 FUNCTIONFS_HAS_SS_DESC |
2369 FUNCTIONFS_HAS_MS_OS_DESC |
2370 FUNCTIONFS_VIRTUAL_ADDR |
2371 FUNCTIONFS_EVENTFD |
2372 FUNCTIONFS_ALL_CTRL_RECIP |
2373 FUNCTIONFS_CONFIG0_SETUP)) {
2384 if (flags & FUNCTIONFS_EVENTFD) {
2388 eventfd_ctx_fdget((int)get_unaligned_le32(data));
2389 if (IS_ERR(ffs->ffs_eventfd)) {
2390 ret = PTR_ERR(ffs->ffs_eventfd);
2391 ffs->ffs_eventfd = NULL;
2398 /* Read fs_count, hs_count and ss_count (if present) */
2399 for (i = 0; i < 3; ++i) {
2400 if (!(flags & (1 << i))) {
2402 } else if (len < 4) {
2405 counts[i] = get_unaligned_le32(data);
2410 if (flags & (1 << i)) {
2414 os_descs_count = get_unaligned_le32(data);
2419 /* Read descriptors */
2422 for (i = 0; i < 3; ++i) {
2425 helper.interfaces_count = 0;
2426 helper.eps_count = 0;
2427 ret = ffs_do_descs(counts[i], data, len,
2428 __ffs_data_do_entity, &helper);
2431 if (!ffs->eps_count && !ffs->interfaces_count) {
2432 ffs->eps_count = helper.eps_count;
2433 ffs->interfaces_count = helper.interfaces_count;
2435 if (ffs->eps_count != helper.eps_count) {
2439 if (ffs->interfaces_count != helper.interfaces_count) {
2447 if (os_descs_count) {
2448 ret = ffs_do_os_descs(os_descs_count, data, len,
2449 __ffs_data_do_os_desc, ffs);
2456 if (raw_descs == data || len) {
2461 ffs->raw_descs_data = _data;
2462 ffs->raw_descs = raw_descs;
2463 ffs->raw_descs_length = data - raw_descs;
2464 ffs->fs_descs_count = counts[0];
2465 ffs->hs_descs_count = counts[1];
2466 ffs->ss_descs_count = counts[2];
2467 ffs->ms_os_descs_count = os_descs_count;
2476 static int __ffs_data_got_strings(struct ffs_data *ffs,
2477 char *const _data, size_t len)
2479 u32 str_count, needed_count, lang_count;
2480 struct usb_gadget_strings **stringtabs, *t;
2481 const char *data = _data;
2482 struct usb_string *s;
2486 if (unlikely(len < 16 ||
2487 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
2488 get_unaligned_le32(data + 4) != len))
2490 str_count = get_unaligned_le32(data + 8);
2491 lang_count = get_unaligned_le32(data + 12);
2493 /* if one is zero the other must be zero */
2494 if (unlikely(!str_count != !lang_count))
2497 /* Do we have at least as many strings as descriptors need? */
2498 needed_count = ffs->strings_count;
2499 if (unlikely(str_count < needed_count))
2503 * If we don't need any strings just return and free all
2506 if (!needed_count) {
2511 /* Allocate everything in one chunk so there's less maintenance. */
2515 vla_item(d, struct usb_gadget_strings *, stringtabs,
2517 vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
2518 vla_item(d, struct usb_string, strings,
2519 lang_count*(needed_count+1));
2521 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
2523 if (unlikely(!vlabuf)) {
2528 /* Initialize the VLA pointers */
2529 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2530 t = vla_ptr(vlabuf, d, stringtab);
2533 *stringtabs++ = t++;
2537 /* stringtabs = vlabuf = d_stringtabs for later kfree */
2538 stringtabs = vla_ptr(vlabuf, d, stringtabs);
2539 t = vla_ptr(vlabuf, d, stringtab);
2540 s = vla_ptr(vlabuf, d, strings);
2543 /* For each language */
2547 do { /* lang_count > 0 so we can use do-while */
2548 unsigned needed = needed_count;
2549 u32 str_per_lang = str_count;
2551 if (unlikely(len < 3))
2553 t->language = get_unaligned_le16(data);
2560 /* For each string */
2561 do { /* str_count > 0 so we can use do-while */
2562 size_t length = strnlen(data, len);
2564 if (unlikely(length == len))
2568 * User may provide more strings then we need,
2569 * if that's the case we simply ignore the
2572 if (likely(needed)) {
2574 * s->id will be set while adding
2575 * function to configuration so for
2576 * now just leave garbage here.
2585 } while (--str_per_lang);
2587 s->id = 0; /* terminator */
2591 } while (--lang_count);
2593 /* Some garbage left? */
2598 ffs->stringtabs = stringtabs;
2599 ffs->raw_strings = _data;
2611 /* Events handling and management *******************************************/
2613 static void __ffs_event_add(struct ffs_data *ffs,
2614 enum usb_functionfs_event_type type)
2616 enum usb_functionfs_event_type rem_type1, rem_type2 = type;
2620 * Abort any unhandled setup
2622 * We do not need to worry about some cmpxchg() changing value
2623 * of ffs->setup_state without holding the lock because when
2624 * state is FFS_SETUP_PENDING cmpxchg() in several places in
2625 * the source does nothing.
2627 if (ffs->setup_state == FFS_SETUP_PENDING)
2628 ffs->setup_state = FFS_SETUP_CANCELLED;
2631 * Logic of this function guarantees that there are at most four pending
2632 * evens on ffs->ev.types queue. This is important because the queue
2633 * has space for four elements only and __ffs_ep0_read_events function
2634 * depends on that limit as well. If more event types are added, those
2635 * limits have to be revisited or guaranteed to still hold.
2638 case FUNCTIONFS_RESUME:
2639 rem_type2 = FUNCTIONFS_SUSPEND;
2641 case FUNCTIONFS_SUSPEND:
2642 case FUNCTIONFS_SETUP:
2644 /* Discard all similar events */
2647 case FUNCTIONFS_BIND:
2648 case FUNCTIONFS_UNBIND:
2649 case FUNCTIONFS_DISABLE:
2650 case FUNCTIONFS_ENABLE:
2651 /* Discard everything other then power management. */
2652 rem_type1 = FUNCTIONFS_SUSPEND;
2653 rem_type2 = FUNCTIONFS_RESUME;
2658 WARN(1, "%d: unknown event, this should not happen\n", type);
2663 u8 *ev = ffs->ev.types, *out = ev;
2664 unsigned n = ffs->ev.count;
2665 for (; n; --n, ++ev)
2666 if ((*ev == rem_type1 || *ev == rem_type2) == neg)
2669 pr_vdebug("purging event %d\n", *ev);
2670 ffs->ev.count = out - ffs->ev.types;
2673 pr_vdebug("adding event %d\n", type);
2674 ffs->ev.types[ffs->ev.count++] = type;
2675 wake_up_locked(&ffs->ev.waitq);
2676 if (ffs->ffs_eventfd)
2677 eventfd_signal(ffs->ffs_eventfd, 1);
2680 static void ffs_event_add(struct ffs_data *ffs,
2681 enum usb_functionfs_event_type type)
2683 unsigned long flags;
2684 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
2685 __ffs_event_add(ffs, type);
2686 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
2689 /* Bind/unbind USB function hooks *******************************************/
2691 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
2695 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
2696 if (ffs->eps_addrmap[i] == endpoint_address)
2701 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
2702 struct usb_descriptor_header *desc,
2705 struct usb_endpoint_descriptor *ds = (void *)desc;
2706 struct ffs_function *func = priv;
2707 struct ffs_ep *ffs_ep;
2708 unsigned ep_desc_id;
2710 static const char *speed_names[] = { "full", "high", "super" };
2712 if (type != FFS_DESCRIPTOR)
2716 * If ss_descriptors is not NULL, we are reading super speed
2717 * descriptors; if hs_descriptors is not NULL, we are reading high
2718 * speed descriptors; otherwise, we are reading full speed
2721 if (func->function.ss_descriptors) {
2723 func->function.ss_descriptors[(long)valuep] = desc;
2724 } else if (func->function.hs_descriptors) {
2726 func->function.hs_descriptors[(long)valuep] = desc;
2729 func->function.fs_descriptors[(long)valuep] = desc;
2732 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
2735 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
2739 ffs_ep = func->eps + idx;
2741 if (unlikely(ffs_ep->descs[ep_desc_id])) {
2742 pr_err("two %sspeed descriptors for EP %d\n",
2743 speed_names[ep_desc_id],
2744 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2747 ffs_ep->descs[ep_desc_id] = ds;
2749 ffs_dump_mem(": Original ep desc", ds, ds->bLength);
2751 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
2752 if (!ds->wMaxPacketSize)
2753 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
2755 struct usb_request *req;
2757 u8 bEndpointAddress;
2760 * We back up bEndpointAddress because autoconfig overwrites
2761 * it with physical endpoint address.
2763 bEndpointAddress = ds->bEndpointAddress;
2764 pr_vdebug("autoconfig\n");
2765 ep = usb_ep_autoconfig(func->gadget, ds);
2768 ep->driver_data = func->eps + idx;
2770 req = usb_ep_alloc_request(ep, GFP_KERNEL);
2776 func->eps_revmap[ds->bEndpointAddress &
2777 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
2779 * If we use virtual address mapping, we restore
2780 * original bEndpointAddress value.
2782 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
2783 ds->bEndpointAddress = bEndpointAddress;
2785 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
2790 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
2791 struct usb_descriptor_header *desc,
2794 struct ffs_function *func = priv;
2800 case FFS_DESCRIPTOR:
2801 /* Handled in previous pass by __ffs_func_bind_do_descs() */
2806 if (func->interfaces_nums[idx] < 0) {
2807 int id = usb_interface_id(func->conf, &func->function);
2808 if (unlikely(id < 0))
2810 func->interfaces_nums[idx] = id;
2812 newValue = func->interfaces_nums[idx];
2816 /* String' IDs are allocated when fsf_data is bound to cdev */
2817 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
2822 * USB_DT_ENDPOINT are handled in
2823 * __ffs_func_bind_do_descs().
2825 if (desc->bDescriptorType == USB_DT_ENDPOINT)
2828 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
2829 if (unlikely(!func->eps[idx].ep))
2833 struct usb_endpoint_descriptor **descs;
2834 descs = func->eps[idx].descs;
2835 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
2840 pr_vdebug("%02x -> %02x\n", *valuep, newValue);
2845 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
2846 struct usb_os_desc_header *h, void *data,
2847 unsigned len, void *priv)
2849 struct ffs_function *func = priv;
2853 case FFS_OS_DESC_EXT_COMPAT: {
2854 struct usb_ext_compat_desc *desc = data;
2855 struct usb_os_desc_table *t;
2857 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
2858 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
2859 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
2860 ARRAY_SIZE(desc->CompatibleID) +
2861 ARRAY_SIZE(desc->SubCompatibleID));
2862 length = sizeof(*desc);
2865 case FFS_OS_DESC_EXT_PROP: {
2866 struct usb_ext_prop_desc *desc = data;
2867 struct usb_os_desc_table *t;
2868 struct usb_os_desc_ext_prop *ext_prop;
2869 char *ext_prop_name;
2870 char *ext_prop_data;
2872 t = &func->function.os_desc_table[h->interface];
2873 t->if_id = func->interfaces_nums[h->interface];
2875 ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
2876 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
2878 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
2879 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
2880 ext_prop->data_len = le32_to_cpu(*(u32 *)
2881 usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
2882 length = ext_prop->name_len + ext_prop->data_len + 14;
2884 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
2885 func->ffs->ms_os_descs_ext_prop_name_avail +=
2888 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
2889 func->ffs->ms_os_descs_ext_prop_data_avail +=
2891 memcpy(ext_prop_data,
2892 usb_ext_prop_data_ptr(data, ext_prop->name_len),
2893 ext_prop->data_len);
2894 /* unicode data reported to the host as "WCHAR"s */
2895 switch (ext_prop->type) {
2896 case USB_EXT_PROP_UNICODE:
2897 case USB_EXT_PROP_UNICODE_ENV:
2898 case USB_EXT_PROP_UNICODE_LINK:
2899 case USB_EXT_PROP_UNICODE_MULTI:
2900 ext_prop->data_len *= 2;
2903 ext_prop->data = ext_prop_data;
2905 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
2906 ext_prop->name_len);
2907 /* property name reported to the host as "WCHAR"s */
2908 ext_prop->name_len *= 2;
2909 ext_prop->name = ext_prop_name;
2911 t->os_desc->ext_prop_len +=
2912 ext_prop->name_len + ext_prop->data_len + 14;
2913 ++t->os_desc->ext_prop_count;
2914 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
2918 pr_vdebug("unknown descriptor: %d\n", type);
2924 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
2925 struct usb_configuration *c)
2927 struct ffs_function *func = ffs_func_from_usb(f);
2928 struct f_fs_opts *ffs_opts =
2929 container_of(f->fi, struct f_fs_opts, func_inst);
2935 * Legacy gadget triggers binding in functionfs_ready_callback,
2936 * which already uses locking; taking the same lock here would
2939 * Configfs-enabled gadgets however do need ffs_dev_lock.
2941 if (!ffs_opts->no_configfs)
2943 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
2944 func->ffs = ffs_opts->dev->ffs_data;
2945 if (!ffs_opts->no_configfs)
2948 return ERR_PTR(ret);
2951 func->gadget = c->cdev->gadget;
2954 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
2955 * configurations are bound in sequence with list_for_each_entry,
2956 * in each configuration its functions are bound in sequence
2957 * with list_for_each_entry, so we assume no race condition
2958 * with regard to ffs_opts->bound access
2960 if (!ffs_opts->refcnt) {
2961 ret = functionfs_bind(func->ffs, c->cdev);
2963 return ERR_PTR(ret);
2966 func->function.strings = func->ffs->stringtabs;
2971 static int _ffs_func_bind(struct usb_configuration *c,
2972 struct usb_function *f)
2974 struct ffs_function *func = ffs_func_from_usb(f);
2975 struct ffs_data *ffs = func->ffs;
2977 const int full = !!func->ffs->fs_descs_count;
2978 const int high = !!func->ffs->hs_descs_count;
2979 const int super = !!func->ffs->ss_descs_count;
2981 int fs_len, hs_len, ss_len, ret, i;
2982 struct ffs_ep *eps_ptr;
2984 /* Make it a single chunk, less management later on */
2986 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
2987 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
2988 full ? ffs->fs_descs_count + 1 : 0);
2989 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
2990 high ? ffs->hs_descs_count + 1 : 0);
2991 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
2992 super ? ffs->ss_descs_count + 1 : 0);
2993 vla_item_with_sz(d, short, inums, ffs->interfaces_count);
2994 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
2995 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2996 vla_item_with_sz(d, char[16], ext_compat,
2997 c->cdev->use_os_string ? ffs->interfaces_count : 0);
2998 vla_item_with_sz(d, struct usb_os_desc, os_desc,
2999 c->cdev->use_os_string ? ffs->interfaces_count : 0);
3000 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
3001 ffs->ms_os_descs_ext_prop_count);
3002 vla_item_with_sz(d, char, ext_prop_name,
3003 ffs->ms_os_descs_ext_prop_name_len);
3004 vla_item_with_sz(d, char, ext_prop_data,
3005 ffs->ms_os_descs_ext_prop_data_len);
3006 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
3011 /* Has descriptors only for speeds gadget does not support */
3012 if (unlikely(!(full | high | super)))
3015 /* Allocate a single chunk, less management later on */
3016 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
3017 if (unlikely(!vlabuf))
3020 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
3021 ffs->ms_os_descs_ext_prop_name_avail =
3022 vla_ptr(vlabuf, d, ext_prop_name);
3023 ffs->ms_os_descs_ext_prop_data_avail =
3024 vla_ptr(vlabuf, d, ext_prop_data);
3026 /* Copy descriptors */
3027 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
3028 ffs->raw_descs_length);
3030 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
3031 eps_ptr = vla_ptr(vlabuf, d, eps);
3032 for (i = 0; i < ffs->eps_count; i++)
3033 eps_ptr[i].num = -1;
3036 * d_eps == vlabuf, func->eps used to kfree vlabuf later
3038 func->eps = vla_ptr(vlabuf, d, eps);
3039 func->interfaces_nums = vla_ptr(vlabuf, d, inums);
3042 * Go through all the endpoint descriptors and allocate
3043 * endpoints first, so that later we can rewrite the endpoint
3044 * numbers without worrying that it may be described later on.
3047 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
3048 fs_len = ffs_do_descs(ffs->fs_descs_count,
3049 vla_ptr(vlabuf, d, raw_descs),
3051 __ffs_func_bind_do_descs, func);
3052 if (unlikely(fs_len < 0)) {
3061 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
3062 hs_len = ffs_do_descs(ffs->hs_descs_count,
3063 vla_ptr(vlabuf, d, raw_descs) + fs_len,
3064 d_raw_descs__sz - fs_len,
3065 __ffs_func_bind_do_descs, func);
3066 if (unlikely(hs_len < 0)) {
3074 if (likely(super)) {
3075 func->function.ss_descriptors = func->function.ssp_descriptors =
3076 vla_ptr(vlabuf, d, ss_descs);
3077 ss_len = ffs_do_descs(ffs->ss_descs_count,
3078 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
3079 d_raw_descs__sz - fs_len - hs_len,
3080 __ffs_func_bind_do_descs, func);
3081 if (unlikely(ss_len < 0)) {
3090 * Now handle interface numbers allocation and interface and
3091 * endpoint numbers rewriting. We can do that in one go
3094 ret = ffs_do_descs(ffs->fs_descs_count +
3095 (high ? ffs->hs_descs_count : 0) +
3096 (super ? ffs->ss_descs_count : 0),
3097 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
3098 __ffs_func_bind_do_nums, func);
3099 if (unlikely(ret < 0))
3102 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
3103 if (c->cdev->use_os_string) {
3104 for (i = 0; i < ffs->interfaces_count; ++i) {
3105 struct usb_os_desc *desc;
3107 desc = func->function.os_desc_table[i].os_desc =
3108 vla_ptr(vlabuf, d, os_desc) +
3109 i * sizeof(struct usb_os_desc);
3110 desc->ext_compat_id =
3111 vla_ptr(vlabuf, d, ext_compat) + i * 16;
3112 INIT_LIST_HEAD(&desc->ext_prop);
3114 ret = ffs_do_os_descs(ffs->ms_os_descs_count,
3115 vla_ptr(vlabuf, d, raw_descs) +
3116 fs_len + hs_len + ss_len,
3117 d_raw_descs__sz - fs_len - hs_len -
3119 __ffs_func_bind_do_os_desc, func);
3120 if (unlikely(ret < 0))
3123 func->function.os_desc_n =
3124 c->cdev->use_os_string ? ffs->interfaces_count : 0;
3126 /* And we're done */
3127 ffs_event_add(ffs, FUNCTIONFS_BIND);
3131 /* XXX Do we need to release all claimed endpoints here? */
3135 static int ffs_func_bind(struct usb_configuration *c,
3136 struct usb_function *f)
3138 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
3139 struct ffs_function *func = ffs_func_from_usb(f);
3142 if (IS_ERR(ffs_opts))
3143 return PTR_ERR(ffs_opts);
3145 ret = _ffs_func_bind(c, f);
3146 if (ret && !--ffs_opts->refcnt)
3147 functionfs_unbind(func->ffs);
3153 /* Other USB function hooks *************************************************/
3155 static void ffs_reset_work(struct work_struct *work)
3157 struct ffs_data *ffs = container_of(work,
3158 struct ffs_data, reset_work);
3159 ffs_data_reset(ffs);
3162 static int ffs_func_set_alt(struct usb_function *f,
3163 unsigned interface, unsigned alt)
3165 struct ffs_function *func = ffs_func_from_usb(f);
3166 struct ffs_data *ffs = func->ffs;
3169 if (alt != (unsigned)-1) {
3170 intf = ffs_func_revmap_intf(func, interface);
3171 if (unlikely(intf < 0))
3176 ffs_func_eps_disable(ffs->func);
3178 if (ffs->state == FFS_DEACTIVATED) {
3179 ffs->state = FFS_CLOSING;
3180 INIT_WORK(&ffs->reset_work, ffs_reset_work);
3181 schedule_work(&ffs->reset_work);
3185 if (ffs->state != FFS_ACTIVE)
3188 if (alt == (unsigned)-1) {
3190 ffs_event_add(ffs, FUNCTIONFS_DISABLE);
3195 ret = ffs_func_eps_enable(func);
3196 if (likely(ret >= 0))
3197 ffs_event_add(ffs, FUNCTIONFS_ENABLE);
3201 static void ffs_func_disable(struct usb_function *f)
3203 ffs_func_set_alt(f, 0, (unsigned)-1);
3206 static int ffs_func_setup(struct usb_function *f,
3207 const struct usb_ctrlrequest *creq)
3209 struct ffs_function *func = ffs_func_from_usb(f);
3210 struct ffs_data *ffs = func->ffs;
3211 unsigned long flags;
3216 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
3217 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
3218 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
3219 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
3220 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
3223 * Most requests directed to interface go through here
3224 * (notable exceptions are set/get interface) so we need to
3225 * handle them. All other either handled by composite or
3226 * passed to usb_configuration->setup() (if one is set). No
3227 * matter, we will handle requests directed to endpoint here
3228 * as well (as it's straightforward). Other request recipient
3229 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
3232 if (ffs->state != FFS_ACTIVE)
3235 switch (creq->bRequestType & USB_RECIP_MASK) {
3236 case USB_RECIP_INTERFACE:
3237 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
3238 if (unlikely(ret < 0))
3242 case USB_RECIP_ENDPOINT:
3243 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
3244 if (unlikely(ret < 0))
3246 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
3247 ret = func->ffs->eps_addrmap[ret];
3251 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
3252 ret = le16_to_cpu(creq->wIndex);
3257 spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
3258 ffs->ev.setup = *creq;
3259 ffs->ev.setup.wIndex = cpu_to_le16(ret);
3260 __ffs_event_add(ffs, FUNCTIONFS_SETUP);
3261 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
3263 return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
3266 static bool ffs_func_req_match(struct usb_function *f,
3267 const struct usb_ctrlrequest *creq,
3270 struct ffs_function *func = ffs_func_from_usb(f);
3272 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
3275 switch (creq->bRequestType & USB_RECIP_MASK) {
3276 case USB_RECIP_INTERFACE:
3277 return (ffs_func_revmap_intf(func,
3278 le16_to_cpu(creq->wIndex)) >= 0);
3279 case USB_RECIP_ENDPOINT:
3280 return (ffs_func_revmap_ep(func,
3281 le16_to_cpu(creq->wIndex)) >= 0);
3283 return (bool) (func->ffs->user_flags &
3284 FUNCTIONFS_ALL_CTRL_RECIP);
3288 static void ffs_func_suspend(struct usb_function *f)
3291 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
3294 static void ffs_func_resume(struct usb_function *f)
3297 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
3301 /* Endpoint and interface numbers reverse mapping ***************************/
3303 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
3305 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
3306 return num ? num : -EDOM;
3309 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
3311 short *nums = func->interfaces_nums;
3312 unsigned count = func->ffs->interfaces_count;
3314 for (; count; --count, ++nums) {
3315 if (*nums >= 0 && *nums == intf)
3316 return nums - func->interfaces_nums;
3323 /* Devices management *******************************************************/
3325 static LIST_HEAD(ffs_devices);
3327 static struct ffs_dev *_ffs_do_find_dev(const char *name)
3329 struct ffs_dev *dev;
3331 list_for_each_entry(dev, &ffs_devices, entry) {
3332 if (!dev->name || !name)
3334 if (strcmp(dev->name, name) == 0)
3342 * ffs_lock must be taken by the caller of this function
3344 static struct ffs_dev *_ffs_get_single_dev(void)
3346 struct ffs_dev *dev;
3348 if (list_is_singular(&ffs_devices)) {
3349 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
3358 * ffs_lock must be taken by the caller of this function
3360 static struct ffs_dev *_ffs_find_dev(const char *name)
3362 struct ffs_dev *dev;
3364 dev = _ffs_get_single_dev();
3368 return _ffs_do_find_dev(name);
3371 /* Configfs support *********************************************************/
3373 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
3375 return container_of(to_config_group(item), struct f_fs_opts,
3379 static void ffs_attr_release(struct config_item *item)
3381 struct f_fs_opts *opts = to_ffs_opts(item);
3383 usb_put_function_instance(&opts->func_inst);
3386 static struct configfs_item_operations ffs_item_ops = {
3387 .release = ffs_attr_release,
3390 static struct config_item_type ffs_func_type = {
3391 .ct_item_ops = &ffs_item_ops,
3392 .ct_owner = THIS_MODULE,
3396 /* Function registration interface ******************************************/
3398 static void ffs_free_inst(struct usb_function_instance *f)
3400 struct f_fs_opts *opts;
3402 opts = to_f_fs_opts(f);
3404 _ffs_free_dev(opts->dev);
3409 #define MAX_INST_NAME_LEN 40
3411 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
3413 struct f_fs_opts *opts;
3418 name_len = strlen(name) + 1;
3419 if (name_len > MAX_INST_NAME_LEN)
3420 return -ENAMETOOLONG;
3422 ptr = kstrndup(name, name_len, GFP_KERNEL);
3426 opts = to_f_fs_opts(fi);
3431 tmp = opts->dev->name_allocated ? opts->dev->name : NULL;
3432 ret = _ffs_name_dev(opts->dev, ptr);
3438 opts->dev->name_allocated = true;
3447 static struct usb_function_instance *ffs_alloc_inst(void)
3449 struct f_fs_opts *opts;
3450 struct ffs_dev *dev;
3452 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3454 return ERR_PTR(-ENOMEM);
3456 opts->func_inst.set_inst_name = ffs_set_inst_name;
3457 opts->func_inst.free_func_inst = ffs_free_inst;
3459 dev = _ffs_alloc_dev();
3463 return ERR_CAST(dev);
3468 config_group_init_type_name(&opts->func_inst.group, "",
3470 return &opts->func_inst;
3473 static void ffs_free(struct usb_function *f)
3475 kfree(ffs_func_from_usb(f));
3478 static void ffs_func_unbind(struct usb_configuration *c,
3479 struct usb_function *f)
3481 struct ffs_function *func = ffs_func_from_usb(f);
3482 struct ffs_data *ffs = func->ffs;
3483 struct f_fs_opts *opts =
3484 container_of(f->fi, struct f_fs_opts, func_inst);
3485 struct ffs_ep *ep = func->eps;
3486 unsigned count = ffs->eps_count;
3487 unsigned long flags;
3490 if (ffs->func == func) {
3491 ffs_func_eps_disable(func);
3495 if (!--opts->refcnt)
3496 functionfs_unbind(ffs);
3498 /* cleanup after autoconfig */
3499 spin_lock_irqsave(&func->ffs->eps_lock, flags);
3501 if (ep->ep && ep->req)
3502 usb_ep_free_request(ep->ep, ep->req);
3506 spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
3510 * eps, descriptors and interfaces_nums are allocated in the
3511 * same chunk so only one free is required.
3513 func->function.fs_descriptors = NULL;
3514 func->function.hs_descriptors = NULL;
3515 func->function.ss_descriptors = NULL;
3516 func->function.ssp_descriptors = NULL;
3517 func->interfaces_nums = NULL;
3519 ffs_event_add(ffs, FUNCTIONFS_UNBIND);
3522 static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
3524 struct ffs_function *func;
3528 func = kzalloc(sizeof(*func), GFP_KERNEL);
3529 if (unlikely(!func))
3530 return ERR_PTR(-ENOMEM);
3532 func->function.name = "Function FS Gadget";
3534 func->function.bind = ffs_func_bind;
3535 func->function.unbind = ffs_func_unbind;
3536 func->function.set_alt = ffs_func_set_alt;
3537 func->function.disable = ffs_func_disable;
3538 func->function.setup = ffs_func_setup;
3539 func->function.req_match = ffs_func_req_match;
3540 func->function.suspend = ffs_func_suspend;
3541 func->function.resume = ffs_func_resume;
3542 func->function.free_func = ffs_free;
3544 return &func->function;
3548 * ffs_lock must be taken by the caller of this function
3550 static struct ffs_dev *_ffs_alloc_dev(void)
3552 struct ffs_dev *dev;
3555 if (_ffs_get_single_dev())
3556 return ERR_PTR(-EBUSY);
3558 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3560 return ERR_PTR(-ENOMEM);
3562 if (list_empty(&ffs_devices)) {
3563 ret = functionfs_init();
3566 return ERR_PTR(ret);
3570 list_add(&dev->entry, &ffs_devices);
3576 * ffs_lock must be taken by the caller of this function
3577 * The caller is responsible for "name" being available whenever f_fs needs it
3579 static int _ffs_name_dev(struct ffs_dev *dev, const char *name)
3581 struct ffs_dev *existing;
3583 existing = _ffs_do_find_dev(name);
3593 * The caller is responsible for "name" being available whenever f_fs needs it
3595 int ffs_name_dev(struct ffs_dev *dev, const char *name)
3600 ret = _ffs_name_dev(dev, name);
3605 EXPORT_SYMBOL_GPL(ffs_name_dev);
3607 int ffs_single_dev(struct ffs_dev *dev)
3614 if (!list_is_singular(&ffs_devices))
3622 EXPORT_SYMBOL_GPL(ffs_single_dev);
3625 * ffs_lock must be taken by the caller of this function
3627 static void _ffs_free_dev(struct ffs_dev *dev)
3629 list_del(&dev->entry);
3630 if (dev->name_allocated)
3633 /* Clear the private_data pointer to stop incorrect dev access */
3635 dev->ffs_data->private_data = NULL;
3638 if (list_empty(&ffs_devices))
3639 functionfs_cleanup();
3642 static void *ffs_acquire_dev(const char *dev_name)
3644 struct ffs_dev *ffs_dev;
3649 ffs_dev = _ffs_find_dev(dev_name);
3651 ffs_dev = ERR_PTR(-ENOENT);
3652 else if (ffs_dev->mounted)
3653 ffs_dev = ERR_PTR(-EBUSY);
3654 else if (ffs_dev->ffs_acquire_dev_callback &&
3655 ffs_dev->ffs_acquire_dev_callback(ffs_dev))
3656 ffs_dev = ERR_PTR(-ENOENT);
3658 ffs_dev->mounted = true;
3664 static void ffs_release_dev(struct ffs_data *ffs_data)
3666 struct ffs_dev *ffs_dev;
3671 ffs_dev = ffs_data->private_data;
3673 ffs_dev->mounted = false;
3675 if (ffs_dev->ffs_release_dev_callback)
3676 ffs_dev->ffs_release_dev_callback(ffs_dev);
3682 static int ffs_ready(struct ffs_data *ffs)
3684 struct ffs_dev *ffs_obj;
3690 ffs_obj = ffs->private_data;
3695 if (WARN_ON(ffs_obj->desc_ready)) {
3700 ffs_obj->desc_ready = true;
3701 ffs_obj->ffs_data = ffs;
3703 if (ffs_obj->ffs_ready_callback) {
3704 ret = ffs_obj->ffs_ready_callback(ffs);
3709 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
3715 static void ffs_closed(struct ffs_data *ffs)
3717 struct ffs_dev *ffs_obj;
3718 struct f_fs_opts *opts;
3719 struct config_item *ci;
3724 ffs_obj = ffs->private_data;
3728 ffs_obj->desc_ready = false;
3729 ffs_obj->ffs_data = NULL;
3731 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
3732 ffs_obj->ffs_closed_callback)
3733 ffs_obj->ffs_closed_callback(ffs);
3736 opts = ffs_obj->opts;
3740 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
3741 || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount))
3744 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
3747 if (test_bit(FFS_FL_BOUND, &ffs->flags))
3748 unregister_gadget_item(ci);
3754 /* Misc helper functions ****************************************************/
3756 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
3759 ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
3760 : mutex_lock_interruptible(mutex);
3763 static char *ffs_prepare_buffer(const char __user *buf, size_t len)
3770 data = kmalloc(len, GFP_KERNEL);
3771 if (unlikely(!data))
3772 return ERR_PTR(-ENOMEM);
3774 if (unlikely(copy_from_user(data, buf, len))) {
3776 return ERR_PTR(-EFAULT);
3779 pr_vdebug("Buffer from user space:\n");
3780 ffs_dump_mem("", data, len);
3785 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
3786 MODULE_LICENSE("GPL");
3787 MODULE_AUTHOR("Michal Nazarewicz");