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review.shift-gmbh.com / SHIFTPHONES / mainline / linux / 13765de8148f71fa795e0a6607de37c49ea5915a / . / drivers / usb / gadget / function / f_fs.c
blob: 25ad1e97a458589363eb67fe15b1688faa171f0e [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* f_fs.c -- user mode file system API for USB composite function controllers
*
* Copyright (C) 2010 Samsung Electronics
* Author: Michal Nazarewicz <mina86@mina86.com>
*
* Based on inode.c (GadgetFS) which was:
* Copyright (C) 2003-2004 David Brownell
* Copyright (C) 2003 Agilent Technologies
*/
/* #define DEBUG */
/* #define VERBOSE_DEBUG */
#include <linux/blkdev.h>
#include <linux/pagemap.h>
#include <linux/export.h>
#include <linux/fs_parser.h>
#include <linux/hid.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/sched/signal.h>
#include <linux/uio.h>
#include <linux/vmalloc.h>
#include <asm/unaligned.h>
#include <linux/usb/ccid.h>
#include <linux/usb/composite.h>
#include <linux/usb/functionfs.h>
#include <linux/aio.h>
#include <linux/kthread.h>
#include <linux/poll.h>
#include <linux/eventfd.h>
#include "u_fs.h"
#include "u_f.h"
#include "u_os_desc.h"
#include "configfs.h"
#define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
/* Reference counter handling */
static void ffs_data_get(struct ffs_data *ffs);
static void ffs_data_put(struct ffs_data *ffs);
/* Creates new ffs_data object. */
static struct ffs_data *__must_check ffs_data_new(const char *dev_name)
__attribute__((malloc));
/* Opened counter handling. */
static void ffs_data_opened(struct ffs_data *ffs);
static void ffs_data_closed(struct ffs_data *ffs);
/* Called with ffs->mutex held; take over ownership of data. */
static int __must_check
__ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len);
static int __must_check
__ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len);
/* The function structure ***************************************************/
struct ffs_ep;
struct ffs_function {
struct usb_configuration *conf;
struct usb_gadget *gadget;
struct ffs_data *ffs;
struct ffs_ep *eps;
u8 eps_revmap[16];
short *interfaces_nums;
struct usb_function function;
};
static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
{
return container_of(f, struct ffs_function, function);
}
static inline enum ffs_setup_state
ffs_setup_state_clear_cancelled(struct ffs_data *ffs)
{
return (enum ffs_setup_state)
cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP);
}
static void ffs_func_eps_disable(struct ffs_function *func);
static int __must_check ffs_func_eps_enable(struct ffs_function *func);
static int ffs_func_bind(struct usb_configuration *,
struct usb_function *);
static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);
static void ffs_func_disable(struct usb_function *);
static int ffs_func_setup(struct usb_function *,
const struct usb_ctrlrequest *);
static bool ffs_func_req_match(struct usb_function *,
const struct usb_ctrlrequest *,
bool config0);
static void ffs_func_suspend(struct usb_function *);
static void ffs_func_resume(struct usb_function *);
static int ffs_func_revmap_ep(struct ffs_function *func, u8 num);
static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf);
/* The endpoints structures *************************************************/
struct ffs_ep {
struct usb_ep *ep; /* P: ffs->eps_lock */
struct usb_request *req; /* P: epfile->mutex */
/* [0]: full speed, [1]: high speed, [2]: super speed */
struct usb_endpoint_descriptor *descs[3];
u8 num;
int status; /* P: epfile->mutex */
};
struct ffs_epfile {
/* Protects ep->ep and ep->req. */
struct mutex mutex;
struct ffs_data *ffs;
struct ffs_ep *ep; /* P: ffs->eps_lock */
struct dentry *dentry;
/*
* Buffer for holding data from partial reads which may happen since
* we’re rounding user read requests to a multiple of a max packet size.
*
* The pointer is initialised with NULL value and may be set by
* __ffs_epfile_read_data function to point to a temporary buffer.
*
* In normal operation, calls to __ffs_epfile_read_buffered will consume
* data from said buffer and eventually free it. Importantly, while the
* function is using the buffer, it sets the pointer to NULL. This is
* all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
* can never run concurrently (they are synchronised by epfile->mutex)
* so the latter will not assign a new value to the pointer.
*
* Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
* valid) and sets the pointer to READ_BUFFER_DROP value. This special
* value is crux of the synchronisation between ffs_func_eps_disable and
* __ffs_epfile_read_data.
*
* Once __ffs_epfile_read_data is about to finish it will try to set the
* pointer back to its old value (as described above), but seeing as the
* pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
* the buffer.
*
* == State transitions ==
*
* • ptr == NULL: (initial state)
* ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
* ◦ __ffs_epfile_read_buffered: nop
* ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
* ◦ reading finishes: n/a, not in ‘and reading’ state
* • ptr == DROP:
* ◦ __ffs_epfile_read_buffer_free: nop
* ◦ __ffs_epfile_read_buffered: go to ptr == NULL
* ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
* ◦ reading finishes: n/a, not in ‘and reading’ state
* • ptr == buf:
* ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
* ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading
* ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered
* is always called first
* ◦ reading finishes: n/a, not in ‘and reading’ state
* • ptr == NULL and reading:
* ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
* ◦ __ffs_epfile_read_buffered: n/a, mutex is held
* ◦ __ffs_epfile_read_data: n/a, mutex is held
* ◦ reading finishes and …
* … all data read: free buf, go to ptr == NULL
* … otherwise: go to ptr == buf and reading
* • ptr == DROP and reading:
* ◦ __ffs_epfile_read_buffer_free: nop
* ◦ __ffs_epfile_read_buffered: n/a, mutex is held
* ◦ __ffs_epfile_read_data: n/a, mutex is held
* ◦ reading finishes: free buf, go to ptr == DROP
*/
struct ffs_buffer *read_buffer;
#define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
char name[5];
unsigned char in; /* P: ffs->eps_lock */
unsigned char isoc; /* P: ffs->eps_lock */
unsigned char _pad;
};
struct ffs_buffer {
size_t length;
char *data;
char storage[];
};
/* ffs_io_data structure ***************************************************/
struct ffs_io_data {
bool aio;
bool read;
struct kiocb *kiocb;
struct iov_iter data;
const void *to_free;
char *buf;
struct mm_struct *mm;
struct work_struct work;
struct usb_ep *ep;
struct usb_request *req;
struct sg_table sgt;
bool use_sg;
struct ffs_data *ffs;
};
struct ffs_desc_helper {
struct ffs_data *ffs;
unsigned interfaces_count;
unsigned eps_count;
};
static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
static struct dentry *
ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
const struct file_operations *fops);
/* Devices management *******************************************************/
DEFINE_MUTEX(ffs_lock);
EXPORT_SYMBOL_GPL(ffs_lock);
static struct ffs_dev *_ffs_find_dev(const char *name);
static struct ffs_dev *_ffs_alloc_dev(void);
static void _ffs_free_dev(struct ffs_dev *dev);
static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data);
static void ffs_release_dev(struct ffs_dev *ffs_dev);
static int ffs_ready(struct ffs_data *ffs);
static void ffs_closed(struct ffs_data *ffs);
/* Misc helper functions ****************************************************/
static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
__attribute__((warn_unused_result, nonnull));
static char *ffs_prepare_buffer(const char __user *buf, size_t len)
__attribute__((warn_unused_result, nonnull));
/* Control file aka ep0 *****************************************************/
static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
{
struct ffs_data *ffs = req->context;
complete(&ffs->ep0req_completion);
}
static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
__releases(&ffs->ev.waitq.lock)
{
struct usb_request *req = ffs->ep0req;
int ret;
req->zero = len < le16_to_cpu(ffs->ev.setup.wLength);
spin_unlock_irq(&ffs->ev.waitq.lock);
req->buf = data;
req->length = len;
/*
* UDC layer requires to provide a buffer even for ZLP, but should
* not use it at all. Let's provide some poisoned pointer to catch
* possible bug in the driver.
*/
if (req->buf == NULL)
req->buf = (void *)0xDEADBABE;
reinit_completion(&ffs->ep0req_completion);
ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
if (ret < 0)
return ret;
ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
if (ret) {
usb_ep_dequeue(ffs->gadget->ep0, req);
return -EINTR;
}
ffs->setup_state = FFS_NO_SETUP;
return req->status ? req->status : req->actual;
}
static int __ffs_ep0_stall(struct ffs_data *ffs)
{
if (ffs->ev.can_stall) {
pr_vdebug("ep0 stall\n");
usb_ep_set_halt(ffs->gadget->ep0);
ffs->setup_state = FFS_NO_SETUP;
return -EL2HLT;
} else {
pr_debug("bogus ep0 stall!\n");
return -ESRCH;
}
}
static ssize_t ffs_ep0_write(struct file *file, const char __user *buf,
size_t len, loff_t *ptr)
{
struct ffs_data *ffs = file->private_data;
ssize_t ret;
char *data;
ENTER();
/* Fast check if setup was canceled */
if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
return -EIDRM;
/* Acquire mutex */
ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
if (ret < 0)
return ret;
/* Check state */
switch (ffs->state) {
case FFS_READ_DESCRIPTORS:
case FFS_READ_STRINGS:
/* Copy data */
if (len < 16) {
ret = -EINVAL;
break;
}
data = ffs_prepare_buffer(buf, len);
if (IS_ERR(data)) {
ret = PTR_ERR(data);
break;
}
/* Handle data */
if (ffs->state == FFS_READ_DESCRIPTORS) {
pr_info("read descriptors\n");
ret = __ffs_data_got_descs(ffs, data, len);
if (ret < 0)
break;
ffs->state = FFS_READ_STRINGS;
ret = len;
} else {
pr_info("read strings\n");
ret = __ffs_data_got_strings(ffs, data, len);
if (ret < 0)
break;
ret = ffs_epfiles_create(ffs);
if (ret) {
ffs->state = FFS_CLOSING;
break;
}
ffs->state = FFS_ACTIVE;
mutex_unlock(&ffs->mutex);
ret = ffs_ready(ffs);
if (ret < 0) {
ffs->state = FFS_CLOSING;
return ret;
}
return len;
}
break;
case FFS_ACTIVE:
data = NULL;
/*
* We're called from user space, we can use _irq
* rather then _irqsave
*/
spin_lock_irq(&ffs->ev.waitq.lock);
switch (ffs_setup_state_clear_cancelled(ffs)) {
case FFS_SETUP_CANCELLED:
ret = -EIDRM;
goto done_spin;
case FFS_NO_SETUP:
ret = -ESRCH;
goto done_spin;
case FFS_SETUP_PENDING:
break;
}
/* FFS_SETUP_PENDING */
if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) {
spin_unlock_irq(&ffs->ev.waitq.lock);
ret = __ffs_ep0_stall(ffs);
break;
}
/* FFS_SETUP_PENDING and not stall */
len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
spin_unlock_irq(&ffs->ev.waitq.lock);
data = ffs_prepare_buffer(buf, len);
if (IS_ERR(data)) {
ret = PTR_ERR(data);
break;
}
spin_lock_irq(&ffs->ev.waitq.lock);
/*
* We are guaranteed to be still in FFS_ACTIVE state
* but the state of setup could have changed from
* FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need
* to check for that. If that happened we copied data
* from user space in vain but it's unlikely.
*
* For sure we are not in FFS_NO_SETUP since this is
* the only place FFS_SETUP_PENDING -> FFS_NO_SETUP
* transition can be performed and it's protected by
* mutex.
*/
if (ffs_setup_state_clear_cancelled(ffs) ==
FFS_SETUP_CANCELLED) {
ret = -EIDRM;
done_spin:
spin_unlock_irq(&ffs->ev.waitq.lock);
} else {
/* unlocks spinlock */
ret = __ffs_ep0_queue_wait(ffs, data, len);
}
kfree(data);
break;
default:
ret = -EBADFD;
break;
}
mutex_unlock(&ffs->mutex);
return ret;
}
/* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */
static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
size_t n)
__releases(&ffs->ev.waitq.lock)
{
/*
* n cannot be bigger than ffs->ev.count, which cannot be bigger than
* size of ffs->ev.types array (which is four) so that's how much space
* we reserve.
*/
struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)];
const size_t size = n * sizeof *events;
unsigned i = 0;
memset(events, 0, size);
do {
events[i].type = ffs->ev.types[i];
if (events[i].type == FUNCTIONFS_SETUP) {
events[i].u.setup = ffs->ev.setup;
ffs->setup_state = FFS_SETUP_PENDING;
}
} while (++i < n);
ffs->ev.count -= n;
if (ffs->ev.count)
memmove(ffs->ev.types, ffs->ev.types + n,
ffs->ev.count * sizeof *ffs->ev.types);
spin_unlock_irq(&ffs->ev.waitq.lock);
mutex_unlock(&ffs->mutex);
return copy_to_user(buf, events, size) ? -EFAULT : size;
}
static ssize_t ffs_ep0_read(struct file *file, char __user *buf,
size_t len, loff_t *ptr)
{
struct ffs_data *ffs = file->private_data;
char *data = NULL;
size_t n;
int ret;
ENTER();
/* Fast check if setup was canceled */
if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED)
return -EIDRM;
/* Acquire mutex */
ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
if (ret < 0)
return ret;
/* Check state */
if (ffs->state != FFS_ACTIVE) {
ret = -EBADFD;
goto done_mutex;
}
/*
* We're called from user space, we can use _irq rather then
* _irqsave
*/
spin_lock_irq(&ffs->ev.waitq.lock);
switch (ffs_setup_state_clear_cancelled(ffs)) {
case FFS_SETUP_CANCELLED:
ret = -EIDRM;
break;
case FFS_NO_SETUP:
n = len / sizeof(struct usb_functionfs_event);
if (!n) {
ret = -EINVAL;
break;
}
if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
ret = -EAGAIN;
break;
}
if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq,
ffs->ev.count)) {
ret = -EINTR;
break;
}
/* unlocks spinlock */
return __ffs_ep0_read_events(ffs, buf,
min(n, (size_t)ffs->ev.count));
case FFS_SETUP_PENDING:
if (ffs->ev.setup.bRequestType & USB_DIR_IN) {
spin_unlock_irq(&ffs->ev.waitq.lock);
ret = __ffs_ep0_stall(ffs);
goto done_mutex;
}
len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength));
spin_unlock_irq(&ffs->ev.waitq.lock);
if (len) {
data = kmalloc(len, GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
goto done_mutex;
}
}
spin_lock_irq(&ffs->ev.waitq.lock);
/* See ffs_ep0_write() */
if (ffs_setup_state_clear_cancelled(ffs) ==
FFS_SETUP_CANCELLED) {
ret = -EIDRM;
break;
}
/* unlocks spinlock */
ret = __ffs_ep0_queue_wait(ffs, data, len);
if ((ret > 0) && (copy_to_user(buf, data, len)))
ret = -EFAULT;
goto done_mutex;
default:
ret = -EBADFD;
break;
}
spin_unlock_irq(&ffs->ev.waitq.lock);
done_mutex:
mutex_unlock(&ffs->mutex);
kfree(data);
return ret;
}
static int ffs_ep0_open(struct inode *inode, struct file *file)
{
struct ffs_data *ffs = inode->i_private;
ENTER();
if (ffs->state == FFS_CLOSING)
return -EBUSY;
file->private_data = ffs;
ffs_data_opened(ffs);
return stream_open(inode, file);
}
static int ffs_ep0_release(struct inode *inode, struct file *file)
{
struct ffs_data *ffs = file->private_data;
ENTER();
ffs_data_closed(ffs);
return 0;
}
static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value)
{
struct ffs_data *ffs = file->private_data;
struct usb_gadget *gadget = ffs->gadget;
long ret;
ENTER();
if (code == FUNCTIONFS_INTERFACE_REVMAP) {
struct ffs_function *func = ffs->func;
ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV;
} else if (gadget && gadget->ops->ioctl) {
ret = gadget->ops->ioctl(gadget, code, value);
} else {
ret = -ENOTTY;
}
return ret;
}
static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait)
{
struct ffs_data *ffs = file->private_data;
__poll_t mask = EPOLLWRNORM;
int ret;
poll_wait(file, &ffs->ev.waitq, wait);
ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
if (ret < 0)
return mask;
switch (ffs->state) {
case FFS_READ_DESCRIPTORS:
case FFS_READ_STRINGS:
mask |= EPOLLOUT;
break;
case FFS_ACTIVE:
switch (ffs->setup_state) {
case FFS_NO_SETUP:
if (ffs->ev.count)
mask |= EPOLLIN;
break;
case FFS_SETUP_PENDING:
case FFS_SETUP_CANCELLED:
mask |= (EPOLLIN | EPOLLOUT);
break;
}
break;
case FFS_CLOSING:
break;
case FFS_DEACTIVATED:
break;
}
mutex_unlock(&ffs->mutex);
return mask;
}
static const struct file_operations ffs_ep0_operations = {
.llseek = no_llseek,
.open = ffs_ep0_open,
.write = ffs_ep0_write,
.read = ffs_ep0_read,
.release = ffs_ep0_release,
.unlocked_ioctl = ffs_ep0_ioctl,
.poll = ffs_ep0_poll,
};
/* "Normal" endpoints operations ********************************************/
static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
{
ENTER();
if (req->context) {
struct ffs_ep *ep = _ep->driver_data;
ep->status = req->status ? req->status : req->actual;
complete(req->context);
}
}
static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter)
{
ssize_t ret = copy_to_iter(data, data_len, iter);
if (ret == data_len)
return ret;
if (iov_iter_count(iter))
return -EFAULT;
/*
* Dear user space developer!
*
* TL;DR: To stop getting below error message in your kernel log, change
* user space code using functionfs to align read buffers to a max
* packet size.
*
* Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max
* packet size. When unaligned buffer is passed to functionfs, it
* internally uses a larger, aligned buffer so that such UDCs are happy.
*
* Unfortunately, this means that host may send more data than was
* requested in read(2) system call. f_fs doesn’t know what to do with
* that excess data so it simply drops it.
*
* Was the buffer aligned in the first place, no such problem would
* happen.
*
* Data may be dropped only in AIO reads. Synchronous reads are handled
* by splitting a request into multiple parts. This splitting may still
* be a problem though so it’s likely best to align the buffer
* regardless of it being AIO or not..
*
* This only affects OUT endpoints, i.e. reading data with a read(2),
* aio_read(2) etc. system calls. Writing data to an IN endpoint is not
* affected.
*/
pr_err("functionfs read size %d > requested size %zd, dropping excess data. "
"Align read buffer size to max packet size to avoid the problem.\n",
data_len, ret);
return ret;
}
/*
* allocate a virtually contiguous buffer and create a scatterlist describing it
* @sg_table - pointer to a place to be filled with sg_table contents
* @size - required buffer size
*/
static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz)
{
struct page **pages;
void *vaddr, *ptr;
unsigned int n_pages;
int i;
vaddr = vmalloc(sz);
if (!vaddr)
return NULL;
n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL);
if (!pages) {
vfree(vaddr);
return NULL;
}
for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE)
pages[i] = vmalloc_to_page(ptr);
if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) {
kvfree(pages);
vfree(vaddr);
return NULL;
}
kvfree(pages);
return vaddr;
}
static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data,
size_t data_len)
{
if (io_data->use_sg)
return ffs_build_sg_list(&io_data->sgt, data_len);
return kmalloc(data_len, GFP_KERNEL);
}
static inline void ffs_free_buffer(struct ffs_io_data *io_data)
{
if (!io_data->buf)
return;
if (io_data->use_sg) {
sg_free_table(&io_data->sgt);
vfree(io_data->buf);
} else {
kfree(io_data->buf);
}
}
static void ffs_user_copy_worker(struct work_struct *work)
{
struct ffs_io_data *io_data = container_of(work, struct ffs_io_data,
work);
int ret = io_data->req->status ? io_data->req->status :
io_data->req->actual;
bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
if (io_data->read && ret > 0) {
kthread_use_mm(io_data->mm);
ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data);
kthread_unuse_mm(io_data->mm);
}
io_data->kiocb->ki_complete(io_data->kiocb, ret);
if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
eventfd_signal(io_data->ffs->ffs_eventfd, 1);
usb_ep_free_request(io_data->ep, io_data->req);
if (io_data->read)
kfree(io_data->to_free);
ffs_free_buffer(io_data);
kfree(io_data);
}
static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
struct usb_request *req)
{
struct ffs_io_data *io_data = req->context;
struct ffs_data *ffs = io_data->ffs;
ENTER();
INIT_WORK(&io_data->work, ffs_user_copy_worker);
queue_work(ffs->io_completion_wq, &io_data->work);
}
static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
{
/*
* See comment in struct ffs_epfile for full read_buffer pointer
* synchronisation story.
*/
struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
if (buf && buf != READ_BUFFER_DROP)
kfree(buf);
}
/* Assumes epfile->mutex is held. */
static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
struct iov_iter *iter)
{
/*
* Null out epfile->read_buffer so ffs_func_eps_disable does not free
* the buffer while we are using it. See comment in struct ffs_epfile
* for full read_buffer pointer synchronisation story.
*/
struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
ssize_t ret;
if (!buf || buf == READ_BUFFER_DROP)
return 0;
ret = copy_to_iter(buf->data, buf->length, iter);
if (buf->length == ret) {
kfree(buf);
return ret;
}
if (iov_iter_count(iter)) {
ret = -EFAULT;
} else {
buf->length -= ret;
buf->data += ret;
}
if (cmpxchg(&epfile->read_buffer, NULL, buf))
kfree(buf);
return ret;
}
/* Assumes epfile->mutex is held. */
static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
void *data, int data_len,
struct iov_iter *iter)
{
struct ffs_buffer *buf;
ssize_t ret = copy_to_iter(data, data_len, iter);
if (data_len == ret)
return ret;
if (iov_iter_count(iter))
return -EFAULT;
/* See ffs_copy_to_iter for more context. */
pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.",
data_len, ret);
data_len -= ret;
buf = kmalloc(sizeof(*buf) + data_len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
buf->length = data_len;
buf->data = buf->storage;
memcpy(buf->storage, data + ret, data_len);
/*
* At this point read_buffer is NULL or READ_BUFFER_DROP (if
* ffs_func_eps_disable has been called in the meanwhile). See comment
* in struct ffs_epfile for full read_buffer pointer synchronisation
* story.
*/
if (cmpxchg(&epfile->read_buffer, NULL, buf))
kfree(buf);
return ret;
}
static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
{
struct ffs_epfile *epfile = file->private_data;
struct usb_request *req;
struct ffs_ep *ep;
char *data = NULL;
ssize_t ret, data_len = -EINVAL;
int halt;
/* Are we still active? */
if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
return -ENODEV;
/* Wait for endpoint to be enabled */
ep = epfile->ep;
if (!ep) {
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = wait_event_interruptible(
epfile->ffs->wait, (ep = epfile->ep));
if (ret)
return -EINTR;
}
/* Do we halt? */
halt = (!io_data->read == !epfile->in);
if (halt && epfile->isoc)
return -EINVAL;
/* We will be using request and read_buffer */
ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
if (ret)
goto error;
/* Allocate & copy */
if (!halt) {
struct usb_gadget *gadget;
/*
* Do we have buffered data from previous partial read? Check
* that for synchronous case only because we do not have
* facility to ‘wake up’ a pending asynchronous read and push
* buffered data to it which we would need to make things behave
* consistently.
*/
if (!io_data->aio && io_data->read) {
ret = __ffs_epfile_read_buffered(epfile, &io_data->data);
if (ret)
goto error_mutex;
}
/*
* if we _do_ wait above, the epfile->ffs->gadget might be NULL
* before the waiting completes, so do not assign to 'gadget'
* earlier
*/
gadget = epfile->ffs->gadget;
spin_lock_irq(&epfile->ffs->eps_lock);
/* In the meantime, endpoint got disabled or changed. */
if (epfile->ep != ep) {
ret = -ESHUTDOWN;
goto error_lock;
}
data_len = iov_iter_count(&io_data->data);
/*
* Controller may require buffer size to be aligned to
* maxpacketsize of an out endpoint.
*/
if (io_data->read)
data_len = usb_ep_align_maybe(gadget, ep->ep, data_len);
io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE;
spin_unlock_irq(&epfile->ffs->eps_lock);
data = ffs_alloc_buffer(io_data, data_len);
if (!data) {
ret = -ENOMEM;
goto error_mutex;
}
if (!io_data->read &&
!copy_from_iter_full(data, data_len, &io_data->data)) {
ret = -EFAULT;
goto error_mutex;
}
}
spin_lock_irq(&epfile->ffs->eps_lock);
if (epfile->ep != ep) {
/* In the meantime, endpoint got disabled or changed. */
ret = -ESHUTDOWN;
} else if (halt) {
ret = usb_ep_set_halt(ep->ep);
if (!ret)
ret = -EBADMSG;
} else if (data_len == -EINVAL) {
/*
* Sanity Check: even though data_len can't be used
* uninitialized at the time I write this comment, some
* compilers complain about this situation.
* In order to keep the code clean from warnings, data_len is
* being initialized to -EINVAL during its declaration, which
* means we can't rely on compiler anymore to warn no future
* changes won't result in data_len being used uninitialized.
* For such reason, we're adding this redundant sanity check
* here.
*/
WARN(1, "%s: data_len == -EINVAL\n", __func__);
ret = -EINVAL;
} else if (!io_data->aio) {
DECLARE_COMPLETION_ONSTACK(done);
bool interrupted = false;
req = ep->req;
if (io_data->use_sg) {
req->buf = NULL;
req->sg = io_data->sgt.sgl;
req->num_sgs = io_data->sgt.nents;
} else {
req->buf = data;
req->num_sgs = 0;
}
req->length = data_len;
io_data->buf = data;
req->context = &done;
req->complete = ffs_epfile_io_complete;
ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
if (ret < 0)
goto error_lock;
spin_unlock_irq(&epfile->ffs->eps_lock);
if (wait_for_completion_interruptible(&done)) {
/*
* To avoid race condition with ffs_epfile_io_complete,
* dequeue the request first then check
* status. usb_ep_dequeue API should guarantee no race
* condition with req->complete callback.
*/
usb_ep_dequeue(ep->ep, req);
wait_for_completion(&done);
interrupted = ep->status < 0;
}
if (interrupted)
ret = -EINTR;
else if (io_data->read && ep->status > 0)
ret = __ffs_epfile_read_data(epfile, data, ep->status,
&io_data->data);
else
ret = ep->status;
goto error_mutex;
} else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) {
ret = -ENOMEM;
} else {
if (io_data->use_sg) {
req->buf = NULL;
req->sg = io_data->sgt.sgl;
req->num_sgs = io_data->sgt.nents;
} else {
req->buf = data;
req->num_sgs = 0;
}
req->length = data_len;
io_data->buf = data;
io_data->ep = ep->ep;
io_data->req = req;
io_data->ffs = epfile->ffs;
req->context = io_data;
req->complete = ffs_epfile_async_io_complete;
ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
if (ret) {
io_data->req = NULL;
usb_ep_free_request(ep->ep, req);
goto error_lock;
}
ret = -EIOCBQUEUED;
/*
* Do not kfree the buffer in this function. It will be freed
* by ffs_user_copy_worker.
*/
data = NULL;
}
error_lock:
spin_unlock_irq(&epfile->ffs->eps_lock);
error_mutex:
mutex_unlock(&epfile->mutex);
error:
if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */
ffs_free_buffer(io_data);
return ret;
}
static int
ffs_epfile_open(struct inode *inode, struct file *file)
{
struct ffs_epfile *epfile = inode->i_private;
ENTER();
if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
return -ENODEV;
file->private_data = epfile;
ffs_data_opened(epfile->ffs);
return stream_open(inode, file);
}
static int ffs_aio_cancel(struct kiocb *kiocb)
{
struct ffs_io_data *io_data = kiocb->private;
struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
unsigned long flags;
int value;
ENTER();
spin_lock_irqsave(&epfile->ffs->eps_lock, flags);
if (io_data && io_data->ep && io_data->req)
value = usb_ep_dequeue(io_data->ep, io_data->req);
else
value = -EINVAL;
spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);
return value;
}
static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from)
{
struct ffs_io_data io_data, *p = &io_data;
ssize_t res;
ENTER();
if (!is_sync_kiocb(kiocb)) {
p = kzalloc(sizeof(io_data), GFP_KERNEL);
if (!p)
return -ENOMEM;
p->aio = true;
} else {
memset(p, 0, sizeof(*p));
p->aio = false;
}
p->read = false;
p->kiocb = kiocb;
p->data = *from;
p->mm = current->mm;
kiocb->private = p;
if (p->aio)
kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
res = ffs_epfile_io(kiocb->ki_filp, p);
if (res == -EIOCBQUEUED)
return res;
if (p->aio)
kfree(p);
else
*from = p->data;
return res;
}
static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to)
{
struct ffs_io_data io_data, *p = &io_data;
ssize_t res;
ENTER();
if (!is_sync_kiocb(kiocb)) {
p = kzalloc(sizeof(io_data), GFP_KERNEL);
if (!p)
return -ENOMEM;
p->aio = true;
} else {
memset(p, 0, sizeof(*p));
p->aio = false;
}
p->read = true;
p->kiocb = kiocb;
if (p->aio) {
p->to_free = dup_iter(&p->data, to, GFP_KERNEL);
if (!p->to_free) {
kfree(p);
return -ENOMEM;
}
} else {
p->data = *to;
p->to_free = NULL;
}
p->mm = current->mm;
kiocb->private = p;
if (p->aio)
kiocb_set_cancel_fn(kiocb, ffs_aio_cancel);
res = ffs_epfile_io(kiocb->ki_filp, p);
if (res == -EIOCBQUEUED)
return res;
if (p->aio) {
kfree(p->to_free);
kfree(p);
} else {
*to = p->data;
}
return res;
}
static int
ffs_epfile_release(struct inode *inode, struct file *file)
{
struct ffs_epfile *epfile = inode->i_private;
ENTER();
__ffs_epfile_read_buffer_free(epfile);
ffs_data_closed(epfile->ffs);
return 0;
}
static long ffs_epfile_ioctl(struct file *file, unsigned code,
unsigned long value)
{
struct ffs_epfile *epfile = file->private_data;
struct ffs_ep *ep;
int ret;
ENTER();
if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
return -ENODEV;
/* Wait for endpoint to be enabled */
ep = epfile->ep;
if (!ep) {
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = wait_event_interruptible(
epfile->ffs->wait, (ep = epfile->ep));
if (ret)
return -EINTR;
}
spin_lock_irq(&epfile->ffs->eps_lock);
/* In the meantime, endpoint got disabled or changed. */
if (epfile->ep != ep) {
spin_unlock_irq(&epfile->ffs->eps_lock);
return -ESHUTDOWN;
}
switch (code) {
case FUNCTIONFS_FIFO_STATUS:
ret = usb_ep_fifo_status(epfile->ep->ep);
break;
case FUNCTIONFS_FIFO_FLUSH:
usb_ep_fifo_flush(epfile->ep->ep);
ret = 0;
break;
case FUNCTIONFS_CLEAR_HALT:
ret = usb_ep_clear_halt(epfile->ep->ep);
break;
case FUNCTIONFS_ENDPOINT_REVMAP:
ret = epfile->ep->num;
break;
case FUNCTIONFS_ENDPOINT_DESC:
{
int desc_idx;
struct usb_endpoint_descriptor desc1, *desc;
switch (epfile->ffs->gadget->speed) {
case USB_SPEED_SUPER:
case USB_SPEED_SUPER_PLUS:
desc_idx = 2;
break;
case USB_SPEED_HIGH:
desc_idx = 1;
break;
default:
desc_idx = 0;
}
desc = epfile->ep->descs[desc_idx];
memcpy(&desc1, desc, desc->bLength);
spin_unlock_irq(&epfile->ffs->eps_lock);
ret = copy_to_user((void __user *)value, &desc1, desc1.bLength);
if (ret)
ret = -EFAULT;
return ret;
}
default:
ret = -ENOTTY;
}
spin_unlock_irq(&epfile->ffs->eps_lock);
return ret;
}
static const struct file_operations ffs_epfile_operations = {
.llseek = no_llseek,
.open = ffs_epfile_open,
.write_iter = ffs_epfile_write_iter,
.read_iter = ffs_epfile_read_iter,
.release = ffs_epfile_release,
.unlocked_ioctl = ffs_epfile_ioctl,
.compat_ioctl = compat_ptr_ioctl,
};
/* File system and super block operations ***********************************/
/*
* Mounting the file system creates a controller file, used first for
* function configuration then later for event monitoring.
*/
static struct inode *__must_check
ffs_sb_make_inode(struct super_block *sb, void *data,
const struct file_operations *fops,
const struct inode_operations *iops,
struct ffs_file_perms *perms)
{
struct inode *inode;
ENTER();
inode = new_inode(sb);
if (inode) {
struct timespec64 ts = current_time(inode);
inode->i_ino = get_next_ino();
inode->i_mode = perms->mode;
inode->i_uid = perms->uid;
inode->i_gid = perms->gid;
inode->i_atime = ts;
inode->i_mtime = ts;
inode->i_ctime = ts;
inode->i_private = data;
if (fops)
inode->i_fop = fops;
if (iops)
inode->i_op = iops;
}
return inode;
}
/* Create "regular" file */
static struct dentry *ffs_sb_create_file(struct super_block *sb,
const char *name, void *data,
const struct file_operations *fops)
{
struct ffs_data *ffs = sb->s_fs_info;
struct dentry *dentry;
struct inode *inode;
ENTER();
dentry = d_alloc_name(sb->s_root, name);
if (!dentry)
return NULL;
inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
if (!inode) {
dput(dentry);
return NULL;
}
d_add(dentry, inode);
return dentry;
}
/* Super block */
static const struct super_operations ffs_sb_operations = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
};
struct ffs_sb_fill_data {
struct ffs_file_perms perms;
umode_t root_mode;
const char *dev_name;
bool no_disconnect;
struct ffs_data *ffs_data;
};
static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc)
{
struct ffs_sb_fill_data *data = fc->fs_private;
struct inode *inode;
struct ffs_data *ffs = data->ffs_data;
ENTER();
ffs->sb = sb;
data->ffs_data = NULL;
sb->s_fs_info = ffs;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = FUNCTIONFS_MAGIC;
sb->s_op = &ffs_sb_operations;
sb->s_time_gran = 1;
/* Root inode */
data->perms.mode = data->root_mode;
inode = ffs_sb_make_inode(sb, NULL,
&simple_dir_operations,
&simple_dir_inode_operations,
&data->perms);
sb->s_root = d_make_root(inode);
if (!sb->s_root)
return -ENOMEM;
/* EP0 file */
if (!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations))
return -ENOMEM;
return 0;
}
enum {
Opt_no_disconnect,
Opt_rmode,
Opt_fmode,
Opt_mode,
Opt_uid,
Opt_gid,
};
static const struct fs_parameter_spec ffs_fs_fs_parameters[] = {
fsparam_bool ("no_disconnect", Opt_no_disconnect),
fsparam_u32 ("rmode", Opt_rmode),
fsparam_u32 ("fmode", Opt_fmode),
fsparam_u32 ("mode", Opt_mode),
fsparam_u32 ("uid", Opt_uid),
fsparam_u32 ("gid", Opt_gid),
{}
};
static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct ffs_sb_fill_data *data = fc->fs_private;
struct fs_parse_result result;
int opt;
ENTER();
opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_no_disconnect:
data->no_disconnect = result.boolean;
break;
case Opt_rmode:
data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
break;
case Opt_fmode:
data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
break;
case Opt_mode:
data->root_mode = (result.uint_32 & 0555) | S_IFDIR;
data->perms.mode = (result.uint_32 & 0666) | S_IFREG;
break;
case Opt_uid:
data->perms.uid = make_kuid(current_user_ns(), result.uint_32);
if (!uid_valid(data->perms.uid))
goto unmapped_value;
break;
case Opt_gid:
data->perms.gid = make_kgid(current_user_ns(), result.uint_32);
if (!gid_valid(data->perms.gid))
goto unmapped_value;
break;
default:
return -ENOPARAM;
}
return 0;
unmapped_value:
return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32);
}
/*
* Set up the superblock for a mount.
*/
static int ffs_fs_get_tree(struct fs_context *fc)
{
struct ffs_sb_fill_data *ctx = fc->fs_private;
struct ffs_data *ffs;
int ret;
ENTER();
if (!fc->source)
return invalf(fc, "No source specified");
ffs = ffs_data_new(fc->source);
if (!ffs)
return -ENOMEM;
ffs->file_perms = ctx->perms;
ffs->no_disconnect = ctx->no_disconnect;
ffs->dev_name = kstrdup(fc->source, GFP_KERNEL);
if (!ffs->dev_name) {
ffs_data_put(ffs);
return -ENOMEM;
}
ret = ffs_acquire_dev(ffs->dev_name, ffs);
if (ret) {
ffs_data_put(ffs);
return ret;
}
ctx->ffs_data = ffs;
return get_tree_nodev(fc, ffs_sb_fill);
}
static void ffs_fs_free_fc(struct fs_context *fc)
{
struct ffs_sb_fill_data *ctx = fc->fs_private;
if (ctx) {
if (ctx->ffs_data) {
ffs_data_put(ctx->ffs_data);
}
kfree(ctx);
}
}
static const struct fs_context_operations ffs_fs_context_ops = {
.free = ffs_fs_free_fc,
.parse_param = ffs_fs_parse_param,
.get_tree = ffs_fs_get_tree,
};
static int ffs_fs_init_fs_context(struct fs_context *fc)
{
struct ffs_sb_fill_data *ctx;
ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->perms.mode = S_IFREG | 0600;
ctx->perms.uid = GLOBAL_ROOT_UID;
ctx->perms.gid = GLOBAL_ROOT_GID;
ctx->root_mode = S_IFDIR | 0500;
ctx->no_disconnect = false;
fc->fs_private = ctx;
fc->ops = &ffs_fs_context_ops;
return 0;
}
static void
ffs_fs_kill_sb(struct super_block *sb)
{
ENTER();
kill_litter_super(sb);
if (sb->s_fs_info)
ffs_data_closed(sb->s_fs_info);
}
static struct file_system_type ffs_fs_type = {
.owner = THIS_MODULE,
.name = "functionfs",
.init_fs_context = ffs_fs_init_fs_context,
.parameters = ffs_fs_fs_parameters,
.kill_sb = ffs_fs_kill_sb,
};
MODULE_ALIAS_FS("functionfs");
/* Driver's main init/cleanup functions *************************************/
static int functionfs_init(void)
{
int ret;
ENTER();
ret = register_filesystem(&ffs_fs_type);
if (!ret)
pr_info("file system registered\n");
else
pr_err("failed registering file system (%d)\n", ret);
return ret;
}
static void functionfs_cleanup(void)
{
ENTER();
pr_info("unloading\n");
unregister_filesystem(&ffs_fs_type);
}
/* ffs_data and ffs_function construction and destruction code **************/
static void ffs_data_clear(struct ffs_data *ffs);
static void ffs_data_reset(struct ffs_data *ffs);
static void ffs_data_get(struct ffs_data *ffs)
{
ENTER();
refcount_inc(&ffs->ref);
}
static void ffs_data_opened(struct ffs_data *ffs)
{
ENTER();
refcount_inc(&ffs->ref);
if (atomic_add_return(1, &ffs->opened) == 1 &&
ffs->state == FFS_DEACTIVATED) {
ffs->state = FFS_CLOSING;
ffs_data_reset(ffs);
}
}
static void ffs_data_put(struct ffs_data *ffs)
{
ENTER();
if (refcount_dec_and_test(&ffs->ref)) {
pr_info("%s(): freeing\n", __func__);
ffs_data_clear(ffs);
ffs_release_dev(ffs->private_data);
BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
swait_active(&ffs->ep0req_completion.wait) ||
waitqueue_active(&ffs->wait));
destroy_workqueue(ffs->io_completion_wq);
kfree(ffs->dev_name);
kfree(ffs);
}
}
static void ffs_data_closed(struct ffs_data *ffs)
{
ENTER();
if (atomic_dec_and_test(&ffs->opened)) {
if (ffs->no_disconnect) {
ffs->state = FFS_DEACTIVATED;
if (ffs->epfiles) {
ffs_epfiles_destroy(ffs->epfiles,
ffs->eps_count);
ffs->epfiles = NULL;
}
if (ffs->setup_state == FFS_SETUP_PENDING)
__ffs_ep0_stall(ffs);
} else {
ffs->state = FFS_CLOSING;
ffs_data_reset(ffs);
}
}
if (atomic_read(&ffs->opened) < 0) {
ffs->state = FFS_CLOSING;
ffs_data_reset(ffs);
}
ffs_data_put(ffs);
}
static struct ffs_data *ffs_data_new(const char *dev_name)
{
struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
if (!ffs)
return NULL;
ENTER();
ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name);
if (!ffs->io_completion_wq) {
kfree(ffs);
return NULL;
}
refcount_set(&ffs->ref, 1);
atomic_set(&ffs->opened, 0);
ffs->state = FFS_READ_DESCRIPTORS;
mutex_init(&ffs->mutex);
spin_lock_init(&ffs->eps_lock);
init_waitqueue_head(&ffs->ev.waitq);
init_waitqueue_head(&ffs->wait);
init_completion(&ffs->ep0req_completion);
/* XXX REVISIT need to update it in some places, or do we? */
ffs->ev.can_stall = 1;
return ffs;
}
static void ffs_data_clear(struct ffs_data *ffs)
{
ENTER();
ffs_closed(ffs);
BUG_ON(ffs->gadget);
if (ffs->epfiles) {
ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
ffs->epfiles = NULL;
}
if (ffs->ffs_eventfd) {
eventfd_ctx_put(ffs->ffs_eventfd);
ffs->ffs_eventfd = NULL;
}
kfree(ffs->raw_descs_data);
kfree(ffs->raw_strings);
kfree(ffs->stringtabs);
}
static void ffs_data_reset(struct ffs_data *ffs)
{
ENTER();
ffs_data_clear(ffs);
ffs->raw_descs_data = NULL;
ffs->raw_descs = NULL;
ffs->raw_strings = NULL;
ffs->stringtabs = NULL;
ffs->raw_descs_length = 0;
ffs->fs_descs_count = 0;
ffs->hs_descs_count = 0;
ffs->ss_descs_count = 0;
ffs->strings_count = 0;
ffs->interfaces_count = 0;
ffs->eps_count = 0;
ffs->ev.count = 0;
ffs->state = FFS_READ_DESCRIPTORS;
ffs->setup_state = FFS_NO_SETUP;
ffs->flags = 0;
ffs->ms_os_descs_ext_prop_count = 0;
ffs->ms_os_descs_ext_prop_name_len = 0;
ffs->ms_os_descs_ext_prop_data_len = 0;
}
static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
{
struct usb_gadget_strings **lang;
int first_id;
ENTER();
if (WARN_ON(ffs->state != FFS_ACTIVE
|| test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
return -EBADFD;
first_id = usb_string_ids_n(cdev, ffs->strings_count);
if (first_id < 0)
return first_id;
ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
if (!ffs->ep0req)
return -ENOMEM;
ffs->ep0req->complete = ffs_ep0_complete;
ffs->ep0req->context = ffs;
lang = ffs->stringtabs;
if (lang) {
for (; *lang; ++lang) {
struct usb_string *str = (*lang)->strings;
int id = first_id;
for (; str->s; ++id, ++str)
str->id = id;
}
}
ffs->gadget = cdev->gadget;
ffs_data_get(ffs);
return 0;
}
static void functionfs_unbind(struct ffs_data *ffs)
{
ENTER();
if (!WARN_ON(!ffs->gadget)) {
usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req);
ffs->ep0req = NULL;
ffs->gadget = NULL;
clear_bit(FFS_FL_BOUND, &ffs->flags);
ffs_data_put(ffs);
}
}
static int ffs_epfiles_create(struct ffs_data *ffs)
{
struct ffs_epfile *epfile, *epfiles;
unsigned i, count;
ENTER();
count = ffs->eps_count;
epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL);
if (!epfiles)
return -ENOMEM;
epfile = epfiles;
for (i = 1; i <= count; ++i, ++epfile) {
epfile->ffs = ffs;
mutex_init(&epfile->mutex);
if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
else
sprintf(epfile->name, "ep%u", i);
epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name,
epfile,
&ffs_epfile_operations);
if (!epfile->dentry) {
ffs_epfiles_destroy(epfiles, i - 1);
return -ENOMEM;
}
}
ffs->epfiles = epfiles;
return 0;
}
static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
{
struct ffs_epfile *epfile = epfiles;
ENTER();
for (; count; --count, ++epfile) {
BUG_ON(mutex_is_locked(&epfile->mutex));
if (epfile->dentry) {
d_delete(epfile->dentry);
dput(epfile->dentry);
epfile->dentry = NULL;
}
}
kfree(epfiles);
}
static void ffs_func_eps_disable(struct ffs_function *func)
{
struct ffs_ep *ep = func->eps;
struct ffs_epfile *epfile = func->ffs->epfiles;
unsigned count = func->ffs->eps_count;
unsigned long flags;
spin_lock_irqsave(&func->ffs->eps_lock, flags);
while (count--) {
/* pending requests get nuked */
if (ep->ep)
usb_ep_disable(ep->ep);
++ep;
if (epfile) {
epfile->ep = NULL;
__ffs_epfile_read_buffer_free(epfile);
++epfile;
}
}
spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
}
static int ffs_func_eps_enable(struct ffs_function *func)
{
struct ffs_data *ffs = func->ffs;
struct ffs_ep *ep = func->eps;
struct ffs_epfile *epfile = ffs->epfiles;
unsigned count = ffs->eps_count;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&func->ffs->eps_lock, flags);
while(count--) {
ep->ep->driver_data = ep;
ret = config_ep_by_speed(func->gadget, &func->function, ep->ep);
if (ret) {
pr_err("%s: config_ep_by_speed(%s) returned %d\n",
__func__, ep->ep->name, ret);
break;
}
ret = usb_ep_enable(ep->ep);
if (!ret) {
epfile->ep = ep;
epfile->in = usb_endpoint_dir_in(ep->ep->desc);
epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc);
} else {
break;
}
++ep;
++epfile;
}
wake_up_interruptible(&ffs->wait);
spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
return ret;
}
/* Parsing and building descriptors and strings *****************************/
/*
* This validates if data pointed by data is a valid USB descriptor as
* well as record how many interfaces, endpoints and strings are
* required by given configuration. Returns address after the
* descriptor or NULL if data is invalid.
*/
enum ffs_entity_type {
FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
};
enum ffs_os_desc_type {
FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP
};
typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
u8 *valuep,
struct usb_descriptor_header *desc,
void *priv);
typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity,
struct usb_os_desc_header *h, void *data,
unsigned len, void *priv);
static int __must_check ffs_do_single_desc(char *data, unsigned len,
ffs_entity_callback entity,
void *priv, int *current_class)
{
struct usb_descriptor_header *_ds = (void *)data;
u8 length;
int ret;
ENTER();
/* At least two bytes are required: length and type */
if (len < 2) {
pr_vdebug("descriptor too short\n");
return -EINVAL;
}
/* If we have at least as many bytes as the descriptor takes? */
length = _ds->bLength;
if (len < length) {
pr_vdebug("descriptor longer then available data\n");
return -EINVAL;
}
#define __entity_check_INTERFACE(val) 1
#define __entity_check_STRING(val) (val)
#define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK)
#define __entity(type, val) do { \
pr_vdebug("entity " #type "(%02x)\n", (val)); \
if (!__entity_check_ ##type(val)) { \
pr_vdebug("invalid entity's value\n"); \
return -EINVAL; \
} \
ret = entity(FFS_ ##type, &val, _ds, priv); \
if (ret < 0) { \
pr_debug("entity " #type "(%02x); ret = %d\n", \
(val), ret); \
return ret; \
} \
} while (0)
/* Parse descriptor depending on type. */
switch (_ds->bDescriptorType) {
case USB_DT_DEVICE:
case USB_DT_CONFIG:
case USB_DT_STRING:
case USB_DT_DEVICE_QUALIFIER:
/* function can't have any of those */
pr_vdebug("descriptor reserved for gadget: %d\n",
_ds->bDescriptorType);
return -EINVAL;
case USB_DT_INTERFACE: {
struct usb_interface_descriptor *ds = (void *)_ds;
pr_vdebug("interface descriptor\n");
if (length != sizeof *ds)
goto inv_length;
__entity(INTERFACE, ds->bInterfaceNumber);
if (ds->iInterface)
__entity(STRING, ds->iInterface);
*current_class = ds->bInterfaceClass;
}
break;
case USB_DT_ENDPOINT: {
struct usb_endpoint_descriptor *ds = (void *)_ds;
pr_vdebug("endpoint descriptor\n");
if (length != USB_DT_ENDPOINT_SIZE &&
length != USB_DT_ENDPOINT_AUDIO_SIZE)
goto inv_length;
__entity(ENDPOINT, ds->bEndpointAddress);
}
break;
case USB_TYPE_CLASS | 0x01:
if (*current_class == USB_INTERFACE_CLASS_HID) {
pr_vdebug("hid descriptor\n");
if (length != sizeof(struct hid_descriptor))
goto inv_length;
break;
} else if (*current_class == USB_INTERFACE_CLASS_CCID) {
pr_vdebug("ccid descriptor\n");
if (length != sizeof(struct ccid_descriptor))
goto inv_length;
break;
} else {
pr_vdebug("unknown descriptor: %d for class %d\n",
_ds->bDescriptorType, *current_class);
return -EINVAL;
}
case USB_DT_OTG:
if (length != sizeof(struct usb_otg_descriptor))
goto inv_length;
break;
case USB_DT_INTERFACE_ASSOCIATION: {
struct usb_interface_assoc_descriptor *ds = (void *)_ds;
pr_vdebug("interface association descriptor\n");
if (length != sizeof *ds)
goto inv_length;
if (ds->iFunction)
__entity(STRING, ds->iFunction);
}
break;
case USB_DT_SS_ENDPOINT_COMP:
pr_vdebug("EP SS companion descriptor\n");
if (length != sizeof(struct usb_ss_ep_comp_descriptor))
goto inv_length;
break;
case USB_DT_OTHER_SPEED_CONFIG:
case USB_DT_INTERFACE_POWER:
case USB_DT_DEBUG:
case USB_DT_SECURITY:
case USB_DT_CS_RADIO_CONTROL:
/* TODO */
pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType);
return -EINVAL;
default:
/* We should never be here */
pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType);
return -EINVAL;
inv_length:
pr_vdebug("invalid length: %d (descriptor %d)\n",
_ds->bLength, _ds->bDescriptorType);
return -EINVAL;
}
#undef __entity
#undef __entity_check_DESCRIPTOR
#undef __entity_check_INTERFACE
#undef __entity_check_STRING
#undef __entity_check_ENDPOINT
return length;
}
static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len,
ffs_entity_callback entity, void *priv)
{
const unsigned _len = len;
unsigned long num = 0;
int current_class = -1;
ENTER();
for (;;) {
int ret;
if (num == count)
data = NULL;
/* Record "descriptor" entity */
ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
if (ret < 0) {
pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n",
num, ret);
return ret;
}
if (!data)
return _len - len;
ret = ffs_do_single_desc(data, len, entity, priv,
&current_class);
if (ret < 0) {
pr_debug("%s returns %d\n", __func__, ret);
return ret;
}
len -= ret;
data += ret;
++num;
}
}
static int __ffs_data_do_entity(enum ffs_entity_type type,
u8 *valuep, struct usb_descriptor_header *desc,
void *priv)
{
struct ffs_desc_helper *helper = priv;
struct usb_endpoint_descriptor *d;
ENTER();
switch (type) {
case FFS_DESCRIPTOR:
break;
case FFS_INTERFACE:
/*
* Interfaces are indexed from zero so if we
* encountered interface "n" then there are at least
* "n+1" interfaces.
*/
if (*valuep >= helper->interfaces_count)
helper->interfaces_count = *valuep + 1;
break;
case FFS_STRING:
/*
* Strings are indexed from 1 (0 is reserved
* for languages list)
*/
if (*valuep > helper->ffs->strings_count)
helper->ffs->strings_count = *valuep;
break;
case FFS_ENDPOINT:
d = (void *)desc;
helper->eps_count++;
if (helper->eps_count >= FFS_MAX_EPS_COUNT)
return -EINVAL;
/* Check if descriptors for any speed were already parsed */
if (!helper->ffs->eps_count && !helper->ffs->interfaces_count)
helper->ffs->eps_addrmap[helper->eps_count] =
d->bEndpointAddress;
else if (helper->ffs->eps_addrmap[helper->eps_count] !=
d->bEndpointAddress)
return -EINVAL;
break;
}
return 0;
}
static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type,
struct usb_os_desc_header *desc)
{
u16 bcd_version = le16_to_cpu(desc->bcdVersion);
u16 w_index = le16_to_cpu(desc->wIndex);
if (bcd_version != 1) {
pr_vdebug("unsupported os descriptors version: %d",
bcd_version);
return -EINVAL;
}
switch (w_index) {
case 0x4:
*next_type = FFS_OS_DESC_EXT_COMPAT;
break;
case 0x5:
*next_type = FFS_OS_DESC_EXT_PROP;
break;
default:
pr_vdebug("unsupported os descriptor type: %d", w_index);
return -EINVAL;
}
return sizeof(*desc);
}
/*
* Process all extended compatibility/extended property descriptors
* of a feature descriptor
*/
static int __must_check ffs_do_single_os_desc(char *data, unsigned len,
enum ffs_os_desc_type type,
u16 feature_count,
ffs_os_desc_callback entity,
void *priv,
struct usb_os_desc_header *h)
{
int ret;
const unsigned _len = len;
ENTER();
/* loop over all ext compat/ext prop descriptors */
while (feature_count--) {
ret = entity(type, h, data, len, priv);
if (ret < 0) {
pr_debug("bad OS descriptor, type: %d\n", type);
return ret;
}
data += ret;
len -= ret;
}
return _len - len;
}
/* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */
static int __must_check ffs_do_os_descs(unsigned count,
char *data, unsigned len,
ffs_os_desc_callback entity, void *priv)
{
const unsigned _len = len;
unsigned long num = 0;
ENTER();
for (num = 0; num < count; ++num) {
int ret;
enum ffs_os_desc_type type;
u16 feature_count;
struct usb_os_desc_header *desc = (void *)data;
if (len < sizeof(*desc))
return -EINVAL;
/*
* Record "descriptor" entity.
* Process dwLength, bcdVersion, wIndex, get b/wCount.
* Move the data pointer to the beginning of extended
* compatibilities proper or extended properties proper
* portions of the data
*/
if (le32_to_cpu(desc->dwLength) > len)
return -EINVAL;
ret = __ffs_do_os_desc_header(&type, desc);
if (ret < 0) {
pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n",
num, ret);
return ret;
}
/*
* 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??"
*/
feature_count = le16_to_cpu(desc->wCount);
if (type == FFS_OS_DESC_EXT_COMPAT &&
(feature_count > 255 || desc->Reserved))
return -EINVAL;
len -= ret;
data += ret;
/*
* Process all function/property descriptors
* of this Feature Descriptor
*/
ret = ffs_do_single_os_desc(data, len, type,
feature_count, entity, priv, desc);
if (ret < 0) {
pr_debug("%s returns %d\n", __func__, ret);
return ret;
}
len -= ret;
data += ret;
}
return _len - len;
}
/*
* Validate contents of the buffer from userspace related to OS descriptors.
*/
static int __ffs_data_do_os_desc(enum ffs_os_desc_type type,
struct usb_os_desc_header *h, void *data,
unsigned len, void *priv)
{
struct ffs_data *ffs = priv;
u8 length;
ENTER();
switch (type) {
case FFS_OS_DESC_EXT_COMPAT: {
struct usb_ext_compat_desc *d = data;
int i;
if (len < sizeof(*d) ||
d->bFirstInterfaceNumber >= ffs->interfaces_count)
return -EINVAL;
if (d->Reserved1 != 1) {
/*
* According to the spec, Reserved1 must be set to 1
* but older kernels incorrectly rejected non-zero
* values. We fix it here to avoid returning EINVAL
* in response to values we used to accept.
*/
pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n");
d->Reserved1 = 1;
}
for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i)
if (d->Reserved2[i])
return -EINVAL;
length = sizeof(struct usb_ext_compat_desc);
}
break;
case FFS_OS_DESC_EXT_PROP: {
struct usb_ext_prop_desc *d = data;
u32 type, pdl;
u16 pnl;
if (len < sizeof(*d) || h->interface >= ffs->interfaces_count)
return -EINVAL;
length = le32_to_cpu(d->dwSize);
if (len < length)
return -EINVAL;
type = le32_to_cpu(d->dwPropertyDataType);
if (type < USB_EXT_PROP_UNICODE ||
type > USB_EXT_PROP_UNICODE_MULTI) {
pr_vdebug("unsupported os descriptor property type: %d",
type);
return -EINVAL;
}
pnl = le16_to_cpu(d->wPropertyNameLength);
if (length < 14 + pnl) {
pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n",
length, pnl, type);
return -EINVAL;
}
pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl));
if (length != 14 + pnl + pdl) {
pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n",
length, pnl, pdl, type);
return -EINVAL;
}
++ffs->ms_os_descs_ext_prop_count;
/* property name reported to the host as "WCHAR"s */
ffs->ms_os_descs_ext_prop_name_len += pnl * 2;
ffs->ms_os_descs_ext_prop_data_len += pdl;
}
break;
default:
pr_vdebug("unknown descriptor: %d\n", type);
return -EINVAL;
}
return length;
}
static int __ffs_data_got_descs(struct ffs_data *ffs,
char *const _data, size_t len)
{
char *data = _data, *raw_descs;
unsigned os_descs_count = 0, counts[3], flags;
int ret = -EINVAL, i;
struct ffs_desc_helper helper;
ENTER();
if (get_unaligned_le32(data + 4) != len)
goto error;
switch (get_unaligned_le32(data)) {
case FUNCTIONFS_DESCRIPTORS_MAGIC:
flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
data += 8;
len -= 8;
break;
case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
flags = get_unaligned_le32(data + 8);
ffs->user_flags = flags;
if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
FUNCTIONFS_HAS_HS_DESC |
FUNCTIONFS_HAS_SS_DESC |
FUNCTIONFS_HAS_MS_OS_DESC |
FUNCTIONFS_VIRTUAL_ADDR |
FUNCTIONFS_EVENTFD |
FUNCTIONFS_ALL_CTRL_RECIP |
FUNCTIONFS_CONFIG0_SETUP)) {
ret = -ENOSYS;
goto error;
}
data += 12;
len -= 12;
break;
default:
goto error;
}
if (flags & FUNCTIONFS_EVENTFD) {
if (len < 4)
goto error;
ffs->ffs_eventfd =
eventfd_ctx_fdget((int)get_unaligned_le32(data));
if (IS_ERR(ffs->ffs_eventfd)) {
ret = PTR_ERR(ffs->ffs_eventfd);
ffs->ffs_eventfd = NULL;
goto error;
}
data += 4;
len -= 4;
}
/* Read fs_count, hs_count and ss_count (if present) */
for (i = 0; i < 3; ++i) {
if (!(flags & (1 << i))) {
counts[i] = 0;
} else if (len < 4) {
goto error;
} else {
counts[i] = get_unaligned_le32(data);
data += 4;
len -= 4;
}
}
if (flags & (1 << i)) {
if (len < 4) {
goto error;
}
os_descs_count = get_unaligned_le32(data);
data += 4;
len -= 4;
}
/* Read descriptors */
raw_descs = data;
helper.ffs = ffs;
for (i = 0; i < 3; ++i) {
if (!counts[i])
continue;
helper.interfaces_count = 0;
helper.eps_count = 0;
ret = ffs_do_descs(counts[i], data, len,
__ffs_data_do_entity, &helper);
if (ret < 0)
goto error;
if (!ffs->eps_count && !ffs->interfaces_count) {
ffs->eps_count = helper.eps_count;
ffs->interfaces_count = helper.interfaces_count;
} else {
if (ffs->eps_count != helper.eps_count) {
ret = -EINVAL;
goto error;
}
if (ffs->interfaces_count != helper.interfaces_count) {
ret = -EINVAL;
goto error;
}
}
data += ret;
len -= ret;
}
if (os_descs_count) {
ret = ffs_do_os_descs(os_descs_count, data, len,
__ffs_data_do_os_desc, ffs);
if (ret < 0)
goto error;
data += ret;
len -= ret;
}
if (raw_descs == data || len) {
ret = -EINVAL;
goto error;
}
ffs->raw_descs_data = _data;
ffs->raw_descs = raw_descs;
ffs->raw_descs_length = data - raw_descs;
ffs->fs_descs_count = counts[0];
ffs->hs_descs_count = counts[1];
ffs->ss_descs_count = counts[2];
ffs->ms_os_descs_count = os_descs_count;
return 0;
error:
kfree(_data);
return ret;
}
static int __ffs_data_got_strings(struct ffs_data *ffs,
char *const _data, size_t len)
{
u32 str_count, needed_count, lang_count;
struct usb_gadget_strings **stringtabs, *t;
const char *data = _data;
struct usb_string *s;
ENTER();
if (len < 16 ||
get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC ||
get_unaligned_le32(data + 4) != len)
goto error;
str_count = get_unaligned_le32(data + 8);
lang_count = get_unaligned_le32(data + 12);
/* if one is zero the other must be zero */
if (!str_count != !lang_count)
goto error;
/* Do we have at least as many strings as descriptors need? */
needed_count = ffs->strings_count;
if (str_count < needed_count)
goto error;
/*
* If we don't need any strings just return and free all
* memory.
*/
if (!needed_count) {
kfree(_data);
return 0;
}
/* Allocate everything in one chunk so there's less maintenance. */
{
unsigned i = 0;
vla_group(d);
vla_item(d, struct usb_gadget_strings *, stringtabs,
lang_count + 1);
vla_item(d, struct usb_gadget_strings, stringtab, lang_count);
vla_item(d, struct usb_string, strings,
lang_count*(needed_count+1));
char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL);
if (!vlabuf) {
kfree(_data);
return -ENOMEM;
}
/* Initialize the VLA pointers */
stringtabs = vla_ptr(vlabuf, d, stringtabs);
t = vla_ptr(vlabuf, d, stringtab);
i = lang_count;
do {
*stringtabs++ = t++;
} while (--i);
*stringtabs = NULL;
/* stringtabs = vlabuf = d_stringtabs for later kfree */
stringtabs = vla_ptr(vlabuf, d, stringtabs);
t = vla_ptr(vlabuf, d, stringtab);
s = vla_ptr(vlabuf, d, strings);
}
/* For each language */
data += 16;
len -= 16;
do { /* lang_count > 0 so we can use do-while */
unsigned needed = needed_count;
u32 str_per_lang = str_count;
if (len < 3)
goto error_free;
t->language = get_unaligned_le16(data);
t->strings = s;
++t;
data += 2;
len -= 2;
/* For each string */
do { /* str_count > 0 so we can use do-while */
size_t length = strnlen(data, len);
if (length == len)
goto error_free;
/*
* User may provide more strings then we need,
* if that's the case we simply ignore the
* rest
*/
if (needed) {
/*
* s->id will be set while adding
* function to configuration so for
* now just leave garbage here.
*/
s->s = data;
--needed;
++s;
}
data += length + 1;
len -= length + 1;
} while (--str_per_lang);
s->id = 0; /* terminator */
s->s = NULL;
++s;
} while (--lang_count);
/* Some garbage left? */
if (len)
goto error_free;
/* Done! */
ffs->stringtabs = stringtabs;
ffs->raw_strings = _data;
return 0;
error_free:
kfree(stringtabs);
error:
kfree(_data);
return -EINVAL;
}
/* Events handling and management *******************************************/
static void __ffs_event_add(struct ffs_data *ffs,
enum usb_functionfs_event_type type)
{
enum usb_functionfs_event_type rem_type1, rem_type2 = type;
int neg = 0;
/*
* Abort any unhandled setup
*
* We do not need to worry about some cmpxchg() changing value
* of ffs->setup_state without holding the lock because when
* state is FFS_SETUP_PENDING cmpxchg() in several places in
* the source does nothing.
*/
if (ffs->setup_state == FFS_SETUP_PENDING)
ffs->setup_state = FFS_SETUP_CANCELLED;
/*
* Logic of this function guarantees that there are at most four pending
* evens on ffs->ev.types queue. This is important because the queue
* has space for four elements only and __ffs_ep0_read_events function
* depends on that limit as well. If more event types are added, those
* limits have to be revisited or guaranteed to still hold.
*/
switch (type) {
case FUNCTIONFS_RESUME:
rem_type2 = FUNCTIONFS_SUSPEND;
fallthrough;
case FUNCTIONFS_SUSPEND:
case FUNCTIONFS_SETUP:
rem_type1 = type;
/* Discard all similar events */
break;
case FUNCTIONFS_BIND:
case FUNCTIONFS_UNBIND:
case FUNCTIONFS_DISABLE:
case FUNCTIONFS_ENABLE:
/* Discard everything other then power management. */
rem_type1 = FUNCTIONFS_SUSPEND;
rem_type2 = FUNCTIONFS_RESUME;
neg = 1;
break;
default:
WARN(1, "%d: unknown event, this should not happen\n", type);
return;
}
{
u8 *ev = ffs->ev.types, *out = ev;
unsigned n = ffs->ev.count;
for (; n; --n, ++ev)
if ((*ev == rem_type1 || *ev == rem_type2) == neg)
*out++ = *ev;
else
pr_vdebug("purging event %d\n", *ev);
ffs->ev.count = out - ffs->ev.types;
}
pr_vdebug("adding event %d\n", type);
ffs->ev.types[ffs->ev.count++] = type;
wake_up_locked(&ffs->ev.waitq);
if (ffs->ffs_eventfd)
eventfd_signal(ffs->ffs_eventfd, 1);
}
static void ffs_event_add(struct ffs_data *ffs,
enum usb_functionfs_event_type type)
{
unsigned long flags;
spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
__ffs_event_add(ffs, type);
spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
}
/* Bind/unbind USB function hooks *******************************************/
static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address)
{
int i;
for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i)
if (ffs->eps_addrmap[i] == endpoint_address)
return i;
return -ENOENT;
}
static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
struct usb_descriptor_header *desc,
void *priv)
{
struct usb_endpoint_descriptor *ds = (void *)desc;
struct ffs_function *func = priv;
struct ffs_ep *ffs_ep;
unsigned ep_desc_id;
int idx;
static const char *speed_names[] = { "full", "high", "super" };
if (type != FFS_DESCRIPTOR)
return 0;
/*
* If ss_descriptors is not NULL, we are reading super speed
* descriptors; if hs_descriptors is not NULL, we are reading high
* speed descriptors; otherwise, we are reading full speed
* descriptors.
*/
if (func->function.ss_descriptors) {
ep_desc_id = 2;
func->function.ss_descriptors[(long)valuep] = desc;
} else if (func->function.hs_descriptors) {
ep_desc_id = 1;
func->function.hs_descriptors[(long)valuep] = desc;
} else {
ep_desc_id = 0;
func->function.fs_descriptors[(long)valuep] = desc;
}
if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
return 0;
idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1;
if (idx < 0)
return idx;
ffs_ep = func->eps + idx;
if (ffs_ep->descs[ep_desc_id]) {
pr_err("two %sspeed descriptors for EP %d\n",
speed_names[ep_desc_id],
ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
return -EINVAL;
}
ffs_ep->descs[ep_desc_id] = ds;
ffs_dump_mem(": Original ep desc", ds, ds->bLength);
if (ffs_ep->ep) {
ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress;
if (!ds->wMaxPacketSize)
ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize;
} else {
struct usb_request *req;
struct usb_ep *ep;
u8 bEndpointAddress;
u16 wMaxPacketSize;
/*
* We back up bEndpointAddress because autoconfig overwrites
* it with physical endpoint address.
*/
bEndpointAddress = ds->bEndpointAddress;
/*
* We back up wMaxPacketSize because autoconfig treats
* endpoint descriptors as if they were full speed.
*/
wMaxPacketSize = ds->wMaxPacketSize;
pr_vdebug("autoconfig\n");
ep = usb_ep_autoconfig(func->gadget, ds);
if (!ep)
return -ENOTSUPP;
ep->driver_data = func->eps + idx;
req = usb_ep_alloc_request(ep, GFP_KERNEL);
if (!req)
return -ENOMEM;
ffs_ep->ep = ep;
ffs_ep->req = req;
func->eps_revmap[ds->bEndpointAddress &
USB_ENDPOINT_NUMBER_MASK] = idx + 1;
/*
* If we use virtual address mapping, we restore
* original bEndpointAddress value.
*/
if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
ds->bEndpointAddress = bEndpointAddress;
/*
* Restore wMaxPacketSize which was potentially
* overwritten by autoconfig.
*/
ds->wMaxPacketSize = wMaxPacketSize;
}
ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength);
return 0;
}
static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
struct usb_descriptor_header *desc,
void *priv)
{
struct ffs_function *func = priv;
unsigned idx;
u8 newValue;
switch (type) {
default:
case FFS_DESCRIPTOR:
/* Handled in previous pass by __ffs_func_bind_do_descs() */
return 0;
case FFS_INTERFACE:
idx = *valuep;
if (func->interfaces_nums[idx] < 0) {
int id = usb_interface_id(func->conf, &func->function);
if (id < 0)
return id;
func->interfaces_nums[idx] = id;
}
newValue = func->interfaces_nums[idx];
break;
case FFS_STRING:
/* String' IDs are allocated when fsf_data is bound to cdev */
newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id;
break;
case FFS_ENDPOINT:
/*
* USB_DT_ENDPOINT are handled in
* __ffs_func_bind_do_descs().
*/
if (desc->bDescriptorType == USB_DT_ENDPOINT)
return 0;
idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1;
if (!func->eps[idx].ep)
return -EINVAL;
{
struct usb_endpoint_descriptor **descs;
descs = func->eps[idx].descs;
newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
}
break;
}
pr_vdebug("%02x -> %02x\n", *valuep, newValue);
*valuep = newValue;
return 0;
}
static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type,
struct usb_os_desc_header *h, void *data,
unsigned len, void *priv)
{
struct ffs_function *func = priv;
u8 length = 0;
switch (type) {
case FFS_OS_DESC_EXT_COMPAT: {
struct usb_ext_compat_desc *desc = data;
struct usb_os_desc_table *t;
t = &func->function.os_desc_table[desc->bFirstInterfaceNumber];
t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber];
memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID,
ARRAY_SIZE(desc->CompatibleID) +
ARRAY_SIZE(desc->SubCompatibleID));
length = sizeof(*desc);
}
break;
case FFS_OS_DESC_EXT_PROP: {
struct usb_ext_prop_desc *desc = data;
struct usb_os_desc_table *t;
struct usb_os_desc_ext_prop *ext_prop;
char *ext_prop_name;
char *ext_prop_data;
t = &func->function.os_desc_table[h->interface];
t->if_id = func->interfaces_nums[h->interface];
ext_prop = func->ffs->ms_os_descs_ext_prop_avail;
func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop);
ext_prop->type = le32_to_cpu(desc->dwPropertyDataType);
ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength);
ext_prop->data_len = le32_to_cpu(*(__le32 *)
usb_ext_prop_data_len_ptr(data, ext_prop->name_len));
length = ext_prop->name_len + ext_prop->data_len + 14;
ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail;
func->ffs->ms_os_descs_ext_prop_name_avail +=
ext_prop->name_len;
ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail;
func->ffs->ms_os_descs_ext_prop_data_avail +=
ext_prop->data_len;
memcpy(ext_prop_data,
usb_ext_prop_data_ptr(data, ext_prop->name_len),
ext_prop->data_len);
/* unicode data reported to the host as "WCHAR"s */
switch (ext_prop->type) {
case USB_EXT_PROP_UNICODE:
case USB_EXT_PROP_UNICODE_ENV:
case USB_EXT_PROP_UNICODE_LINK:
case USB_EXT_PROP_UNICODE_MULTI:
ext_prop->data_len *= 2;
break;
}
ext_prop->data = ext_prop_data;
memcpy(ext_prop_name, usb_ext_prop_name_ptr(data),
ext_prop->name_len);
/* property name reported to the host as "WCHAR"s */
ext_prop->name_len *= 2;
ext_prop->name = ext_prop_name;
t->os_desc->ext_prop_len +=
ext_prop->name_len + ext_prop->data_len + 14;
++t->os_desc->ext_prop_count;
list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop);
}
break;
default:
pr_vdebug("unknown descriptor: %d\n", type);
}
return length;
}
static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f,
struct usb_configuration *c)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct f_fs_opts *ffs_opts =
container_of(f->fi, struct f_fs_opts, func_inst);
struct ffs_data *ffs_data;
int ret;
ENTER();
/*
* Legacy gadget triggers binding in functionfs_ready_callback,
* which already uses locking; taking the same lock here would
* cause a deadlock.
*
* Configfs-enabled gadgets however do need ffs_dev_lock.
*/
if (!ffs_opts->no_configfs)
ffs_dev_lock();
ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV;
ffs_data = ffs_opts->dev->ffs_data;
if (!ffs_opts->no_configfs)
ffs_dev_unlock();
if (ret)
return ERR_PTR(ret);
func->ffs = ffs_data;
func->conf = c;
func->gadget = c->cdev->gadget;
/*
* in drivers/usb/gadget/configfs.c:configfs_composite_bind()
* configurations are bound in sequence with list_for_each_entry,
* in each configuration its functions are bound in sequence
* with list_for_each_entry, so we assume no race condition
* with regard to ffs_opts->bound access
*/
if (!ffs_opts->refcnt) {
ret = functionfs_bind(func->ffs, c->cdev);
if (ret)
return ERR_PTR(ret);
}
ffs_opts->refcnt++;
func->function.strings = func->ffs->stringtabs;
return ffs_opts;
}
static int _ffs_func_bind(struct usb_configuration *c,
struct usb_function *f)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct ffs_data *ffs = func->ffs;
const int full = !!func->ffs->fs_descs_count;
const int high = !!func->ffs->hs_descs_count;
const int super = !!func->ffs->ss_descs_count;
int fs_len, hs_len, ss_len, ret, i;
struct ffs_ep *eps_ptr;
/* Make it a single chunk, less management later on */
vla_group(d);
vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count);
vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs,
full ? ffs->fs_descs_count + 1 : 0);
vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs,
high ? ffs->hs_descs_count + 1 : 0);
vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
super ? ffs->ss_descs_count + 1 : 0);
vla_item_with_sz(d, short, inums, ffs->interfaces_count);
vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table,
c->cdev->use_os_string ? ffs->interfaces_count : 0);
vla_item_with_sz(d, char[16], ext_compat,
c->cdev->use_os_string ? ffs->interfaces_count : 0);
vla_item_with_sz(d, struct usb_os_desc, os_desc,
c->cdev->use_os_string ? ffs->interfaces_count : 0);
vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop,
ffs->ms_os_descs_ext_prop_count);
vla_item_with_sz(d, char, ext_prop_name,
ffs->ms_os_descs_ext_prop_name_len);
vla_item_with_sz(d, char, ext_prop_data,
ffs->ms_os_descs_ext_prop_data_len);
vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
char *vlabuf;
ENTER();
/* Has descriptors only for speeds gadget does not support */
if (!(full | high | super))
return -ENOTSUPP;
/* Allocate a single chunk, less management later on */
vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL);
if (!vlabuf)
return -ENOMEM;
ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop);
ffs->ms_os_descs_ext_prop_name_avail =
vla_ptr(vlabuf, d, ext_prop_name);
ffs->ms_os_descs_ext_prop_data_avail =
vla_ptr(vlabuf, d, ext_prop_data);
/* Copy descriptors */
memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
ffs->raw_descs_length);
memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
eps_ptr = vla_ptr(vlabuf, d, eps);
for (i = 0; i < ffs->eps_count; i++)
eps_ptr[i].num = -1;
/* Save pointers
* d_eps == vlabuf, func->eps used to kfree vlabuf later
*/
func->eps = vla_ptr(vlabuf, d, eps);
func->interfaces_nums = vla_ptr(vlabuf, d, inums);
/*
* Go through all the endpoint descriptors and allocate
* endpoints first, so that later we can rewrite the endpoint
* numbers without worrying that it may be described later on.
*/
if (full) {
func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs);
fs_len = ffs_do_descs(ffs->fs_descs_count,
vla_ptr(vlabuf, d, raw_descs),
d_raw_descs__sz,
__ffs_func_bind_do_descs, func);
if (fs_len < 0) {
ret = fs_len;
goto error;
}
} else {
fs_len = 0;
}
if (high) {
func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs);
hs_len = ffs_do_descs(ffs->hs_descs_count,
vla_ptr(vlabuf, d, raw_descs) + fs_len,
d_raw_descs__sz - fs_len,
__ffs_func_bind_do_descs, func);
if (hs_len < 0) {
ret = hs_len;
goto error;
}
} else {
hs_len = 0;
}
if (super) {
func->function.ss_descriptors = func->function.ssp_descriptors =
vla_ptr(vlabuf, d, ss_descs);
ss_len = ffs_do_descs(ffs->ss_descs_count,
vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len,
d_raw_descs__sz - fs_len - hs_len,
__ffs_func_bind_do_descs, func);
if (ss_len < 0) {
ret = ss_len;
goto error;
}
} else {
ss_len = 0;
}
/*
* Now handle interface numbers allocation and interface and
* endpoint numbers rewriting. We can do that in one go
* now.
*/
ret = ffs_do_descs(ffs->fs_descs_count +
(high ? ffs->hs_descs_count : 0) +
(super ? ffs->ss_descs_count : 0),
vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz,
__ffs_func_bind_do_nums, func);
if (ret < 0)
goto error;
func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table);
if (c->cdev->use_os_string) {
for (i = 0; i < ffs->interfaces_count; ++i) {
struct usb_os_desc *desc;
desc = func->function.os_desc_table[i].os_desc =
vla_ptr(vlabuf, d, os_desc) +
i * sizeof(struct usb_os_desc);
desc->ext_compat_id =
vla_ptr(vlabuf, d, ext_compat) + i * 16;
INIT_LIST_HEAD(&desc->ext_prop);
}
ret = ffs_do_os_descs(ffs->ms_os_descs_count,
vla_ptr(vlabuf, d, raw_descs) +
fs_len + hs_len + ss_len,
d_raw_descs__sz - fs_len - hs_len -
ss_len,
__ffs_func_bind_do_os_desc, func);
if (ret < 0)
goto error;
}
func->function.os_desc_n =
c->cdev->use_os_string ? ffs->interfaces_count : 0;
/* And we're done */
ffs_event_add(ffs, FUNCTIONFS_BIND);
return 0;
error:
/* XXX Do we need to release all claimed endpoints here? */
return ret;
}
static int ffs_func_bind(struct usb_configuration *c,
struct usb_function *f)
{
struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
struct ffs_function *func = ffs_func_from_usb(f);
int ret;
if (IS_ERR(ffs_opts))
return PTR_ERR(ffs_opts);
ret = _ffs_func_bind(c, f);
if (ret && !--ffs_opts->refcnt)
functionfs_unbind(func->ffs);
return ret;
}
/* Other USB function hooks *************************************************/
static void ffs_reset_work(struct work_struct *work)
{
struct ffs_data *ffs = container_of(work,
struct ffs_data, reset_work);
ffs_data_reset(ffs);
}
static int ffs_func_set_alt(struct usb_function *f,
unsigned interface, unsigned alt)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct ffs_data *ffs = func->ffs;
int ret = 0, intf;
if (alt != (unsigned)-1) {
intf = ffs_func_revmap_intf(func, interface);
if (intf < 0)
return intf;
}
if (ffs->func)
ffs_func_eps_disable(ffs->func);
if (ffs->state == FFS_DEACTIVATED) {
ffs->state = FFS_CLOSING;
INIT_WORK(&ffs->reset_work, ffs_reset_work);
schedule_work(&ffs->reset_work);
return -ENODEV;
}
if (ffs->state != FFS_ACTIVE)
return -ENODEV;
if (alt == (unsigned)-1) {
ffs->func = NULL;
ffs_event_add(ffs, FUNCTIONFS_DISABLE);
return 0;
}
ffs->func = func;
ret = ffs_func_eps_enable(func);
if (ret >= 0)
ffs_event_add(ffs, FUNCTIONFS_ENABLE);
return ret;
}
static void ffs_func_disable(struct usb_function *f)
{
ffs_func_set_alt(f, 0, (unsigned)-1);
}
static int ffs_func_setup(struct usb_function *f,
const struct usb_ctrlrequest *creq)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct ffs_data *ffs = func->ffs;
unsigned long flags;
int ret;
ENTER();
pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType);
pr_vdebug("creq->bRequest = %02x\n", creq->bRequest);
pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue));
pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex));
pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength));
/*
* Most requests directed to interface go through here
* (notable exceptions are set/get interface) so we need to
* handle them. All other either handled by composite or
* passed to usb_configuration->setup() (if one is set). No
* matter, we will handle requests directed to endpoint here
* as well (as it's straightforward). Other request recipient
* types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP
* is being used.
*/
if (ffs->state != FFS_ACTIVE)
return -ENODEV;
switch (creq->bRequestType & USB_RECIP_MASK) {
case USB_RECIP_INTERFACE:
ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex));
if (ret < 0)
return ret;
break;
case USB_RECIP_ENDPOINT:
ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
if (ret < 0)
return ret;
if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
ret = func->ffs->eps_addrmap[ret];
break;
default:
if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP)
ret = le16_to_cpu(creq->wIndex);
else
return -EOPNOTSUPP;
}
spin_lock_irqsave(&ffs->ev.waitq.lock, flags);
ffs->ev.setup = *creq;
ffs->ev.setup.wIndex = cpu_to_le16(ret);
__ffs_event_add(ffs, FUNCTIONFS_SETUP);
spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
}
static bool ffs_func_req_match(struct usb_function *f,
const struct usb_ctrlrequest *creq,
bool config0)
{
struct ffs_function *func = ffs_func_from_usb(f);
if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP))
return false;
switch (creq->bRequestType & USB_RECIP_MASK) {
case USB_RECIP_INTERFACE:
return (ffs_func_revmap_intf(func,
le16_to_cpu(creq->wIndex)) >= 0);
case USB_RECIP_ENDPOINT:
return (ffs_func_revmap_ep(func,
le16_to_cpu(creq->wIndex)) >= 0);
default:
return (bool) (func->ffs->user_flags &
FUNCTIONFS_ALL_CTRL_RECIP);
}
}
static void ffs_func_suspend(struct usb_function *f)
{
ENTER();
ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND);
}
static void ffs_func_resume(struct usb_function *f)
{
ENTER();
ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME);
}
/* Endpoint and interface numbers reverse mapping ***************************/
static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
{
num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
return num ? num : -EDOM;
}
static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf)
{
short *nums = func->interfaces_nums;
unsigned count = func->ffs->interfaces_count;
for (; count; --count, ++nums) {
if (*nums >= 0 && *nums == intf)
return nums - func->interfaces_nums;
}
return -EDOM;
}
/* Devices management *******************************************************/
static LIST_HEAD(ffs_devices);
static struct ffs_dev *_ffs_do_find_dev(const char *name)
{
struct ffs_dev *dev;
if (!name)
return NULL;
list_for_each_entry(dev, &ffs_devices, entry) {
if (strcmp(dev->name, name) == 0)
return dev;
}
return NULL;
}
/*
* ffs_lock must be taken by the caller of this function
*/
static struct ffs_dev *_ffs_get_single_dev(void)
{
struct ffs_dev *dev;
if (list_is_singular(&ffs_devices)) {
dev = list_first_entry(&ffs_devices, struct ffs_dev, entry);
if (dev->single)
return dev;
}
return NULL;
}
/*
* ffs_lock must be taken by the caller of this function
*/
static struct ffs_dev *_ffs_find_dev(const char *name)
{
struct ffs_dev *dev;
dev = _ffs_get_single_dev();
if (dev)
return dev;
return _ffs_do_find_dev(name);
}
/* Configfs support *********************************************************/
static inline struct f_fs_opts *to_ffs_opts(struct config_item *item)
{
return container_of(to_config_group(item), struct f_fs_opts,
func_inst.group);
}
static void ffs_attr_release(struct config_item *item)
{
struct f_fs_opts *opts = to_ffs_opts(item);
usb_put_function_instance(&opts->func_inst);
}
static struct configfs_item_operations ffs_item_ops = {
.release = ffs_attr_release,
};
static const struct config_item_type ffs_func_type = {
.ct_item_ops = &ffs_item_ops,
.ct_owner = THIS_MODULE,
};
/* Function registration interface ******************************************/
static void ffs_free_inst(struct usb_function_instance *f)
{
struct f_fs_opts *opts;
opts = to_f_fs_opts(f);
ffs_release_dev(opts->dev);
ffs_dev_lock();
_ffs_free_dev(opts->dev);
ffs_dev_unlock();
kfree(opts);
}
static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name)
{
if (strlen(name) >= sizeof_field(struct ffs_dev, name))
return -ENAMETOOLONG;
return ffs_name_dev(to_f_fs_opts(fi)->dev, name);
}
static struct usb_function_instance *ffs_alloc_inst(void)
{
struct f_fs_opts *opts;
struct ffs_dev *dev;
opts = kzalloc(sizeof(*opts), GFP_KERNEL);
if (!opts)
return ERR_PTR(-ENOMEM);
opts->func_inst.set_inst_name = ffs_set_inst_name;
opts->func_inst.free_func_inst = ffs_free_inst;
ffs_dev_lock();
dev = _ffs_alloc_dev();
ffs_dev_unlock();
if (IS_ERR(dev)) {
kfree(opts);
return ERR_CAST(dev);
}
opts->dev = dev;
dev->opts = opts;
config_group_init_type_name(&opts->func_inst.group, "",
&ffs_func_type);
return &opts->func_inst;
}
static void ffs_free(struct usb_function *f)
{
kfree(ffs_func_from_usb(f));
}
static void ffs_func_unbind(struct usb_configuration *c,
struct usb_function *f)
{
struct ffs_function *func = ffs_func_from_usb(f);
struct ffs_data *ffs = func->ffs;
struct f_fs_opts *opts =
container_of(f->fi, struct f_fs_opts, func_inst);
struct ffs_ep *ep = func->eps;
unsigned count = ffs->eps_count;
unsigned long flags;
ENTER();
if (ffs->func == func) {
ffs_func_eps_disable(func);
ffs->func = NULL;
}
/* Drain any pending AIO completions */
drain_workqueue(ffs->io_completion_wq);
if (!--opts->refcnt)
functionfs_unbind(ffs);
/* cleanup after autoconfig */
spin_lock_irqsave(&func->ffs->eps_lock, flags);
while (count--) {
if (ep->ep && ep->req)
usb_ep_free_request(ep->ep, ep->req);
ep->req = NULL;
++ep;
}
spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
kfree(func->eps);
func->eps = NULL;
/*
* eps, descriptors and interfaces_nums are allocated in the
* same chunk so only one free is required.
*/
func->function.fs_descriptors = NULL;
func->function.hs_descriptors = NULL;
func->function.ss_descriptors = NULL;
func->function.ssp_descriptors = NULL;
func->interfaces_nums = NULL;
ffs_event_add(ffs, FUNCTIONFS_UNBIND);
}
static struct usb_function *ffs_alloc(struct usb_function_instance *fi)
{
struct ffs_function *func;
ENTER();
func = kzalloc(sizeof(*func), GFP_KERNEL);
if (!func)
return ERR_PTR(-ENOMEM);
func->function.name = "Function FS Gadget";
func->function.bind = ffs_func_bind;
func->function.unbind = ffs_func_unbind;
func->function.set_alt = ffs_func_set_alt;
func->function.disable = ffs_func_disable;
func->function.setup = ffs_func_setup;
func->function.req_match = ffs_func_req_match;
func->function.suspend = ffs_func_suspend;
func->function.resume = ffs_func_resume;
func->function.free_func = ffs_free;
return &func->function;
}
/*
* ffs_lock must be taken by the caller of this function
*/
static struct ffs_dev *_ffs_alloc_dev(void)
{
struct ffs_dev *dev;
int ret;
if (_ffs_get_single_dev())
return ERR_PTR(-EBUSY);
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return ERR_PTR(-ENOMEM);
if (list_empty(&ffs_devices)) {
ret = functionfs_init();
if (ret) {
kfree(dev);
return ERR_PTR(ret);
}
}
list_add(&dev->entry, &ffs_devices);
return dev;
}
int ffs_name_dev(struct ffs_dev *dev, const char *name)
{
struct ffs_dev *existing;
int ret = 0;
ffs_dev_lock();
existing = _ffs_do_find_dev(name);
if (!existing)
strlcpy(dev->name, name, ARRAY_SIZE(dev->name));
else if (existing != dev)
ret = -EBUSY;
ffs_dev_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(ffs_name_dev);
int ffs_single_dev(struct ffs_dev *dev)
{
int ret;
ret = 0;
ffs_dev_lock();
if (!list_is_singular(&ffs_devices))
ret = -EBUSY;
else
dev->single = true;
ffs_dev_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(ffs_single_dev);
/*
* ffs_lock must be taken by the caller of this function
*/
static void _ffs_free_dev(struct ffs_dev *dev)
{
list_del(&dev->entry);
kfree(dev);
if (list_empty(&ffs_devices))
functionfs_cleanup();
}
static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data)
{
int ret = 0;
struct ffs_dev *ffs_dev;
ENTER();
ffs_dev_lock();
ffs_dev = _ffs_find_dev(dev_name);
if (!ffs_dev) {
ret = -ENOENT;
} else if (ffs_dev->mounted) {
ret = -EBUSY;
} else if (ffs_dev->ffs_acquire_dev_callback &&
ffs_dev->ffs_acquire_dev_callback(ffs_dev)) {
ret = -ENOENT;
} else {
ffs_dev->mounted = true;
ffs_dev->ffs_data = ffs_data;
ffs_data->private_data = ffs_dev;
}
ffs_dev_unlock();
return ret;
}
static void ffs_release_dev(struct ffs_dev *ffs_dev)
{
ENTER();
ffs_dev_lock();
if (ffs_dev && ffs_dev->mounted) {
ffs_dev->mounted = false;
if (ffs_dev->ffs_data) {
ffs_dev->ffs_data->private_data = NULL;
ffs_dev->ffs_data = NULL;
}
if (ffs_dev->ffs_release_dev_callback)
ffs_dev->ffs_release_dev_callback(ffs_dev);
}
ffs_dev_unlock();
}
static int ffs_ready(struct ffs_data *ffs)
{
struct ffs_dev *ffs_obj;
int ret = 0;
ENTER();
ffs_dev_lock();
ffs_obj = ffs->private_data;
if (!ffs_obj) {
ret = -EINVAL;
goto done;
}
if (WARN_ON(ffs_obj->desc_ready)) {
ret = -EBUSY;
goto done;
}
ffs_obj->desc_ready = true;
if (ffs_obj->ffs_ready_callback) {
ret = ffs_obj->ffs_ready_callback(ffs);
if (ret)
goto done;
}
set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
done:
ffs_dev_unlock();
return ret;
}
static void ffs_closed(struct ffs_data *ffs)
{
struct ffs_dev *ffs_obj;
struct f_fs_opts *opts;
struct config_item *ci;
ENTER();
ffs_dev_lock();
ffs_obj = ffs->private_data;
if (!ffs_obj)
goto done;
ffs_obj->desc_ready = false;
if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) &&
ffs_obj->ffs_closed_callback)
ffs_obj->ffs_closed_callback(ffs);
if (ffs_obj->opts)
opts = ffs_obj->opts;
else
goto done;
if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent
|| !kref_read(&opts->func_inst.group.cg_item.ci_kref))
goto done;
ci = opts->func_inst.group.cg_item.ci_parent->ci_parent;
ffs_dev_unlock();
if (test_bit(FFS_FL_BOUND, &ffs->flags))
unregister_gadget_item(ci);
return;
done:
ffs_dev_unlock();
}
/* Misc helper functions ****************************************************/
static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
{
return nonblock
? mutex_trylock(mutex) ? 0 : -EAGAIN
: mutex_lock_interruptible(mutex);
}
static char *ffs_prepare_buffer(const char __user *buf, size_t len)
{
char *data;
if (!len)
return NULL;
data = memdup_user(buf, len);
if (IS_ERR(data))
return data;
pr_vdebug("Buffer from user space:\n");
ffs_dump_mem("", data, len);
return data;
}
DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Nazarewicz");