--- /dev/null
+/*
+ * f_fs.c -- user mode filesystem api for usb composite funtcion controllers
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
+ *
+ * Based on inode.c (GadgetFS):
+ * Copyright (C) 2003-2004 David Brownell
+ * Copyright (C) 2003 Agilent Technologies
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+
+/* #define DEBUG */
+/* #define VERBOSE_DEBUG */
+
+#include <linux/blkdev.h>
+#include <asm/unaligned.h>
+#include <linux/smp_lock.h>
+
+#include <linux/usb/composite.h>
+#include <linux/usb/functionfs.h>
+
+
+#define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */
+
+
+/* Debuging *****************************************************************/
+
+#define ffs_printk(level, fmt, args...) printk(level "f_fs: " fmt "\n", ## args)
+
+#define FERR(...) ffs_printk(KERN_ERR, __VA_ARGS__)
+#define FINFO(...) ffs_printk(KERN_INFO, __VA_ARGS__)
+
+#ifdef DEBUG
+# define FDBG(...) ffs_printk(KERN_DEBUG, __VA_ARGS__)
+#else
+# define FDBG(...) do { } while (0)
+#endif /* DEBUG */
+
+#ifdef VERBOSE_DEBUG
+# define FVDBG FDBG
+#else
+# define FVDBG(...) do { } while (0)
+#endif /* VERBOSE_DEBUG */
+
+#define ENTER() FVDBG("%s()", __func__)
+
+#ifdef VERBOSE_DEBUG
+# define ffs_dump_mem(prefix, ptr, len) \
+ print_hex_dump_bytes("f_fs" prefix ": ", DUMP_PREFIX_NONE, ptr, len)
+#else
+# define ffs_dump_mem(prefix, ptr, len) do { } while (0)
+#endif
+
+
+/* The data structure and setup file ****************************************/
+
+enum ffs_state {
+ /* Waiting for descriptors and strings. */
+ /* In this state no open(2), read(2) or write(2) on epfiles
+ * may succeed (which should not be the problem as there
+ * should be no such files opened in the firts place). */
+ FFS_READ_DESCRIPTORS,
+ FFS_READ_STRINGS,
+
+ /* We've got descriptors and strings. We are or have called
+ * functionfs_ready_callback(). functionfs_bind() may have
+ * been called but we don't know. */
+ /* This is the only state in which operations on epfiles may
+ * succeed. */
+ FFS_ACTIVE,
+
+ /* All endpoints have been closed. This state is also set if
+ * we encounter an unrecoverable error. The only
+ * unrecoverable error is situation when after reading strings
+ * from user space we fail to initialise EP files or
+ * functionfs_ready_callback() returns with error (<0). */
+ /* In this state no open(2), read(2) or write(2) (both on ep0
+ * as well as epfile) may succeed (at this point epfiles are
+ * unlinked and all closed so this is not a problem; ep0 is
+ * also closed but ep0 file exists and so open(2) on ep0 must
+ * fail). */
+ FFS_CLOSING
+};
+
+
+enum ffs_setup_state {
+ /* There is no setup request pending. */
+ FFS_NO_SETUP,
+ /* User has read events and there was a setup request event
+ * there. The next read/write on ep0 will handle the
+ * request. */
+ FFS_SETUP_PENDING,
+ /* There was event pending but before user space handled it
+ * some other event was introduced which canceled existing
+ * setup. If this state is set read/write on ep0 return
+ * -EIDRM. This state is only set when adding event. */
+ FFS_SETUP_CANCELED
+};
+
+
+
+struct ffs_epfile;
+struct ffs_function;
+
+struct ffs_data {
+ struct usb_gadget *gadget;
+
+ /* Protect access read/write operations, only one read/write
+ * at a time. As a consequence protects ep0req and company.
+ * While setup request is being processed (queued) this is
+ * held. */
+ struct mutex mutex;
+
+ /* Protect access to enpoint related structures (basically
+ * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
+ * endpint zero. */
+ spinlock_t eps_lock;
+
+ /* XXX REVISIT do we need our own request? Since we are not
+ * handling setup requests immidiatelly user space may be so
+ * slow that another setup will be sent to the gadget but this
+ * time not to us but another function and then there could be
+ * a race. Is taht the case? Or maybe we can use cdev->req
+ * after all, maybe we just need some spinlock for that? */
+ struct usb_request *ep0req; /* P: mutex */
+ struct completion ep0req_completion; /* P: mutex */
+ int ep0req_status; /* P: mutex */
+
+ /* reference counter */
+ atomic_t ref;
+ /* how many files are opened (EP0 and others) */
+ atomic_t opened;
+
+ /* EP0 state */
+ enum ffs_state state;
+
+ /*
+ * Possible transations:
+ * + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
+ * happens only in ep0 read which is P: mutex
+ * + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
+ * happens only in ep0 i/o which is P: mutex
+ * + FFS_SETUP_PENDING -> FFS_SETUP_CANCELED -- P: ev.waitq.lock
+ * + FFS_SETUP_CANCELED -> FFS_NO_SETUP -- cmpxchg
+ */
+ enum ffs_setup_state setup_state;
+
+#define FFS_SETUP_STATE(ffs) \
+ ((enum ffs_setup_state)cmpxchg(&(ffs)->setup_state, \
+ FFS_SETUP_CANCELED, FFS_NO_SETUP))
+
+ /* Events & such. */
+ struct {
+ u8 types[4];
+ unsigned short count;
+ /* XXX REVISIT need to update it in some places, or do we? */
+ unsigned short can_stall;
+ struct usb_ctrlrequest setup;
+
+ wait_queue_head_t waitq;
+ } ev; /* the whole structure, P: ev.waitq.lock */
+
+ /* Flags */
+ unsigned long flags;
+#define FFS_FL_CALL_CLOSED_CALLBACK 0
+#define FFS_FL_BOUND 1
+
+ /* Active function */
+ struct ffs_function *func;
+
+ /* Device name, write once when file system is mounted.
+ * Intendet for user to read if she wants. */
+ const char *dev_name;
+ /* Private data for our user (ie. gadget). Managed by
+ * user. */
+ void *private_data;
+
+ /* filled by __ffs_data_got_descs() */
+ /* real descriptors are 16 bytes after raw_descs (so you need
+ * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
+ * first full speed descriptor). raw_descs_length and
+ * raw_fs_descs_length do not have those 16 bytes added. */
+ const void *raw_descs;
+ unsigned raw_descs_length;
+ unsigned raw_fs_descs_length;
+ unsigned fs_descs_count;
+ unsigned hs_descs_count;
+
+ unsigned short strings_count;
+ unsigned short interfaces_count;
+ unsigned short eps_count;
+ unsigned short _pad1;
+
+ /* filled by __ffs_data_got_strings() */
+ /* ids in stringtabs are set in functionfs_bind() */
+ const void *raw_strings;
+ struct usb_gadget_strings **stringtabs;
+
+ /* File system's super block, write once when file system is mounted. */
+ struct super_block *sb;
+
+ /* File permissions, written once when fs is mounted*/
+ struct ffs_file_perms {
+ umode_t mode;
+ uid_t uid;
+ gid_t gid;
+ } file_perms;
+
+ /* The endpoint files, filled by ffs_epfiles_create(),
+ * destroyed by ffs_epfiles_destroy(). */
+ struct ffs_epfile *epfiles;
+};
+
+/* 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(void) __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 ownerrship 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 void ffs_func_free(struct ffs_function *func);
+
+
+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 void ffs_func_unbind(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 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 */
+ struct usb_endpoint_descriptor *descs[2];
+
+ u8 num;
+
+ int status; /* P: epfile->mutex */
+};
+
+struct ffs_epfile {
+ /* Protects ep->ep and ep->req. */
+ struct mutex mutex;
+ wait_queue_head_t wait;
+
+ struct ffs_data *ffs;
+ struct ffs_ep *ep; /* P: ffs->eps_lock */
+
+ struct dentry *dentry;
+
+ char name[5];
+
+ unsigned char in; /* P: ffs->eps_lock */
+ unsigned char isoc; /* P: ffs->eps_lock */
+
+ unsigned char _pad;
+};
+
+
+static int __must_check ffs_epfiles_create(struct ffs_data *ffs);
+static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count);
+
+static struct inode *__must_check
+ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
+ const struct file_operations *fops,
+ struct dentry **dentry_p);
+
+
+/* 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_all(&ffs->ep0req_completion);
+}
+
+
+static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
+{
+ 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;
+
+ INIT_COMPLETION(ffs->ep0req_completion);
+
+ ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
+ if (unlikely(ret < 0))
+ return ret;
+
+ ret = wait_for_completion_interruptible(&ffs->ep0req_completion);
+ if (unlikely(ret)) {
+ usb_ep_dequeue(ffs->gadget->ep0, req);
+ return -EINTR;
+ }
+
+ ffs->setup_state = FFS_NO_SETUP;
+ return ffs->ep0req_status;
+}
+
+static int __ffs_ep0_stall(struct ffs_data *ffs)
+{
+ if (ffs->ev.can_stall) {
+ FVDBG("ep0 stall\n");
+ usb_ep_set_halt(ffs->gadget->ep0);
+ ffs->setup_state = FFS_NO_SETUP;
+ return -EL2HLT;
+ } else {
+ FDBG("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(ffs) == FFS_SETUP_CANCELED)
+ return -EIDRM;
+
+ /* Acquire mutex */
+ ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
+ if (unlikely(ret < 0))
+ return ret;
+
+
+ /* Check state */
+ switch (ffs->state) {
+ case FFS_READ_DESCRIPTORS:
+ case FFS_READ_STRINGS:
+ /* Copy data */
+ if (unlikely(len < 16)) {
+ ret = -EINVAL;
+ break;
+ }
+
+ data = ffs_prepare_buffer(buf, len);
+ if (unlikely(IS_ERR(data))) {
+ ret = PTR_ERR(data);
+ break;
+ }
+
+ /* Handle data */
+ if (ffs->state == FFS_READ_DESCRIPTORS) {
+ FINFO("read descriptors");
+ ret = __ffs_data_got_descs(ffs, data, len);
+ if (unlikely(ret < 0))
+ break;
+
+ ffs->state = FFS_READ_STRINGS;
+ ret = len;
+ } else {
+ FINFO("read strings");
+ ret = __ffs_data_got_strings(ffs, data, len);
+ if (unlikely(ret < 0))
+ break;
+
+ ret = ffs_epfiles_create(ffs);
+ if (unlikely(ret)) {
+ ffs->state = FFS_CLOSING;
+ break;
+ }
+
+ ffs->state = FFS_ACTIVE;
+ mutex_unlock(&ffs->mutex);
+
+ ret = functionfs_ready_callback(ffs);
+ if (unlikely(ret < 0)) {
+ ffs->state = FFS_CLOSING;
+ return ret;
+ }
+
+ set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags);
+ 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(ffs)) {
+ case FFS_SETUP_CANCELED:
+ 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 (unlikely(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_CANCELED 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(ffs) == FFS_SETUP_CANCELED) {
+ 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;
+}
+
+
+
+static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
+ size_t n)
+{
+ /* We are holding ffs->ev.waitq.lock and ffs->mutex and we need
+ * to release them. */
+
+ struct usb_functionfs_event events[n];
+ unsigned i = 0;
+
+ memset(events, 0, sizeof events);
+
+ 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);
+
+ if (n < ffs->ev.count) {
+ ffs->ev.count -= n;
+ memmove(ffs->ev.types, ffs->ev.types + n,
+ ffs->ev.count * sizeof *ffs->ev.types);
+ } else {
+ ffs->ev.count = 0;
+ }
+
+ spin_unlock_irq(&ffs->ev.waitq.lock);
+ mutex_unlock(&ffs->mutex);
+
+ return unlikely(__copy_to_user(buf, events, sizeof events))
+ ? -EFAULT : sizeof events;
+}
+
+
+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(ffs) == FFS_SETUP_CANCELED)
+ return -EIDRM;
+
+ /* Acquire mutex */
+ ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK);
+ if (unlikely(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(ffs)) {
+ case FFS_SETUP_CANCELED:
+ ret = -EIDRM;
+ break;
+
+ case FFS_NO_SETUP:
+ n = len / sizeof(struct usb_functionfs_event);
+ if (unlikely(!n)) {
+ ret = -EINVAL;
+ break;
+ }
+
+ if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) {
+ ret = -EAGAIN;
+ break;
+ }
+
+ if (unlikely(wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, ffs->ev.count))) {
+ ret = -EINTR;
+ break;
+ }
+
+ 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 (likely(len)) {
+ data = kmalloc(len, GFP_KERNEL);
+ if (unlikely(!data)) {
+ ret = -ENOMEM;
+ goto done_mutex;
+ }
+ }
+
+ spin_lock_irq(&ffs->ev.waitq.lock);
+
+ /* See ffs_ep0_write() */
+ if (FFS_SETUP_STATE(ffs) == FFS_SETUP_CANCELED) {
+ ret = -EIDRM;
+ break;
+ }
+
+ /* unlocks spinlock */
+ ret = __ffs_ep0_queue_wait(ffs, data, len);
+ if (likely(ret > 0) && unlikely(__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 (unlikely(ffs->state == FFS_CLOSING))
+ return -EBUSY;
+
+ file->private_data = ffs;
+ ffs_data_opened(ffs);
+
+ return 0;
+}
+
+
+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->ops->ioctl) {
+ lock_kernel();
+ ret = gadget->ops->ioctl(gadget, code, value);
+ unlock_kernel();
+ } else {
+ ret = -ENOTTY;
+ }
+
+ return ret;
+}
+
+
+static const struct file_operations ffs_ep0_operations = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+
+ .open = ffs_ep0_open,
+ .write = ffs_ep0_write,
+ .read = ffs_ep0_read,
+ .release = ffs_ep0_release,
+ .unlocked_ioctl = ffs_ep0_ioctl,
+};
+
+
+/* "Normal" endpoints operations ********************************************/
+
+
+static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req)
+{
+ ENTER();
+ if (likely(req->context)) {
+ struct ffs_ep *ep = _ep->driver_data;
+ ep->status = req->status ? req->status : req->actual;
+ complete(req->context);
+ }
+}
+
+
+static ssize_t ffs_epfile_io(struct file *file,
+ char __user *buf, size_t len, int read)
+{
+ struct ffs_epfile *epfile = file->private_data;
+ struct ffs_ep *ep;
+ char *data = NULL;
+ ssize_t ret;
+ int halt;
+
+ goto first_try;
+ do {
+ spin_unlock_irq(&epfile->ffs->eps_lock);
+ mutex_unlock(&epfile->mutex);
+
+first_try:
+ /* Are we still active? */
+ if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
+ ret = -ENODEV;
+ goto error;
+ }
+
+ /* Wait for endpoint to be enabled */
+ ep = epfile->ep;
+ if (!ep) {
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ goto error;
+ }
+
+ if (unlikely(wait_event_interruptible
+ (epfile->wait, (ep = epfile->ep)))) {
+ ret = -EINTR;
+ goto error;
+ }
+ }
+
+ /* Do we halt? */
+ halt = !read == !epfile->in;
+ if (halt && epfile->isoc) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ /* Allocate & copy */
+ if (!halt && !data) {
+ data = kzalloc(len, GFP_KERNEL);
+ if (unlikely(!data))
+ return -ENOMEM;
+
+ if (!read &&
+ unlikely(__copy_from_user(data, buf, len))) {
+ ret = -EFAULT;
+ goto error;
+ }
+ }
+
+ /* We will be using request */
+ ret = ffs_mutex_lock(&epfile->mutex,
+ file->f_flags & O_NONBLOCK);
+ if (unlikely(ret))
+ goto error;
+
+ /* We're called from user space, we can use _irq rather then
+ * _irqsave */
+ spin_lock_irq(&epfile->ffs->eps_lock);
+
+ /* While we were acquiring mutex endpoint got disabled
+ * or changed? */
+ } while (unlikely(epfile->ep != ep));
+
+ /* Halt */
+ if (unlikely(halt)) {
+ if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
+ usb_ep_set_halt(ep->ep);
+ spin_unlock_irq(&epfile->ffs->eps_lock);
+ ret = -EBADMSG;
+ } else {
+ /* Fire the request */
+ DECLARE_COMPLETION_ONSTACK(done);
+
+ struct usb_request *req = ep->req;
+ req->context = &done;
+ req->complete = ffs_epfile_io_complete;
+ req->buf = data;
+ req->length = len;
+
+ ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
+
+ spin_unlock_irq(&epfile->ffs->eps_lock);
+
+ if (unlikely(ret < 0)) {
+ /* nop */
+ } else if (unlikely(wait_for_completion_interruptible(&done))) {
+ ret = -EINTR;
+ usb_ep_dequeue(ep->ep, req);
+ } else {
+ ret = ep->status;
+ if (read && ret > 0 &&
+ unlikely(copy_to_user(buf, data, ret)))
+ ret = -EFAULT;
+ }
+ }
+
+ mutex_unlock(&epfile->mutex);
+error:
+ kfree(data);
+ return ret;
+}
+
+
+static ssize_t
+ffs_epfile_write(struct file *file, const char __user *buf, size_t len,
+ loff_t *ptr)
+{
+ ENTER();
+
+ return ffs_epfile_io(file, (char __user *)buf, len, 0);
+}
+
+static ssize_t
+ffs_epfile_read(struct file *file, char __user *buf, size_t len, loff_t *ptr)
+{
+ ENTER();
+
+ return ffs_epfile_io(file, buf, len, 1);
+}
+
+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 0;
+}
+
+static int
+ffs_epfile_release(struct inode *inode, struct file *file)
+{
+ struct ffs_epfile *epfile = inode->i_private;
+
+ ENTER();
+
+ 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;
+ int ret;
+
+ ENTER();
+
+ if (WARN_ON(epfile->ffs->state != FFS_ACTIVE))
+ return -ENODEV;
+
+ spin_lock_irq(&epfile->ffs->eps_lock);
+ if (likely(epfile->ep)) {
+ 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;
+ default:
+ ret = -ENOTTY;
+ }
+ } else {
+ ret = -ENODEV;
+ }
+ spin_unlock_irq(&epfile->ffs->eps_lock);
+
+ return ret;
+}
+
+
+static const struct file_operations ffs_epfile_operations = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+
+ .open = ffs_epfile_open,
+ .write = ffs_epfile_write,
+ .read = ffs_epfile_read,
+ .release = ffs_epfile_release,
+ .unlocked_ioctl = ffs_epfile_ioctl,
+};
+
+
+
+/* File system and super block operations ***********************************/
+
+/*
+ * Mounting the filesystem 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 (likely(inode)) {
+ struct timespec current_time = CURRENT_TIME;
+
+ inode->i_mode = perms->mode;
+ inode->i_uid = perms->uid;
+ inode->i_gid = perms->gid;
+ inode->i_atime = current_time;
+ inode->i_mtime = current_time;
+ inode->i_ctime = current_time;
+ inode->i_private = data;
+ if (fops)
+ inode->i_fop = fops;
+ if (iops)
+ inode->i_op = iops;
+ }
+
+ return inode;
+}
+
+
+/* Create "regular" file */
+
+static struct inode *ffs_sb_create_file(struct super_block *sb,
+ const char *name, void *data,
+ const struct file_operations *fops,
+ struct dentry **dentry_p)
+{
+ struct ffs_data *ffs = sb->s_fs_info;
+ struct dentry *dentry;
+ struct inode *inode;
+
+ ENTER();
+
+ dentry = d_alloc_name(sb->s_root, name);
+ if (unlikely(!dentry))
+ return NULL;
+
+ inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms);
+ if (unlikely(!inode)) {
+ dput(dentry);
+ return NULL;
+ }
+
+ d_add(dentry, inode);
+ if (dentry_p)
+ *dentry_p = dentry;
+
+ return inode;
+}
+
+
+/* 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;
+};
+
+static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
+{
+ struct ffs_sb_fill_data *data = _data;
+ struct inode *inode;
+ struct dentry *d;
+ struct ffs_data *ffs;
+
+ ENTER();
+
+ /* Initialize data */
+ ffs = ffs_data_new();
+ if (unlikely(!ffs))
+ goto enomem0;
+
+ ffs->sb = sb;
+ ffs->dev_name = data->dev_name;
+ ffs->file_perms = data->perms;
+
+ sb->s_fs_info = ffs;
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_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);
+ if (unlikely(!inode))
+ goto enomem1;
+ d = d_alloc_root(inode);
+ if (unlikely(!d))
+ goto enomem2;
+ sb->s_root = d;
+
+ /* EP0 file */
+ if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
+ &ffs_ep0_operations, NULL)))
+ goto enomem3;
+
+ return 0;
+
+enomem3:
+ dput(d);
+enomem2:
+ iput(inode);
+enomem1:
+ ffs_data_put(ffs);
+enomem0:
+ return -ENOMEM;
+}
+
+
+static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
+{
+ ENTER();
+
+ if (!opts || !*opts)
+ return 0;
+
+ for (;;) {
+ char *end, *eq, *comma;
+ unsigned long value;
+
+ /* Option limit */
+ comma = strchr(opts, ',');
+ if (comma)
+ *comma = 0;
+
+ /* Value limit */
+ eq = strchr(opts, '=');
+ if (unlikely(!eq)) {
+ FERR("'=' missing in %s", opts);
+ return -EINVAL;
+ }
+ *eq = 0;
+
+ /* Parse value */
+ value = simple_strtoul(eq + 1, &end, 0);
+ if (unlikely(*end != ',' && *end != 0)) {
+ FERR("%s: invalid value: %s", opts, eq + 1);
+ return -EINVAL;
+ }
+
+ /* Interpret option */
+ switch (eq - opts) {
+ case 5:
+ if (!memcmp(opts, "rmode", 5))
+ data->root_mode = (value & 0555) | S_IFDIR;
+ else if (!memcmp(opts, "fmode", 5))
+ data->perms.mode = (value & 0666) | S_IFREG;
+ else
+ goto invalid;
+ break;
+
+ case 4:
+ if (!memcmp(opts, "mode", 4)) {
+ data->root_mode = (value & 0555) | S_IFDIR;
+ data->perms.mode = (value & 0666) | S_IFREG;
+ } else {
+ goto invalid;
+ }
+ break;
+
+ case 3:
+ if (!memcmp(opts, "uid", 3))
+ data->perms.uid = value;
+ else if (!memcmp(opts, "gid", 3))
+ data->perms.gid = value;
+ else
+ goto invalid;
+ break;
+
+ default:
+invalid:
+ FERR("%s: invalid option", opts);
+ return -EINVAL;
+ }
+
+ /* Next iteration */
+ if (!comma)
+ break;
+ opts = comma + 1;
+ }
+
+ return 0;
+}
+
+
+/* "mount -t functionfs dev_name /dev/function" ends up here */
+
+static int
+ffs_fs_get_sb(struct file_system_type *t, int flags,
+ const char *dev_name, void *opts, struct vfsmount *mnt)
+{
+ struct ffs_sb_fill_data data = {
+ .perms = {
+ .mode = S_IFREG | 0600,
+ .uid = 0,
+ .gid = 0
+ },
+ .root_mode = S_IFDIR | 0500,
+ };
+ int ret;
+
+ ENTER();
+
+ ret = functionfs_check_dev_callback(dev_name);
+ if (unlikely(ret < 0))
+ return ret;
+
+ ret = ffs_fs_parse_opts(&data, opts);
+ if (unlikely(ret < 0))
+ return ret;
+
+ data.dev_name = dev_name;
+ return get_sb_single(t, flags, &data, ffs_sb_fill, mnt);
+}
+
+static void
+ffs_fs_kill_sb(struct super_block *sb)
+{
+ void *ptr;
+
+ ENTER();
+
+ kill_litter_super(sb);
+ ptr = xchg(&sb->s_fs_info, NULL);
+ if (ptr)
+ ffs_data_put(ptr);
+}
+
+static struct file_system_type ffs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "functionfs",
+ .get_sb = ffs_fs_get_sb,
+ .kill_sb = ffs_fs_kill_sb,
+};
+
+
+
+/* Driver's main init/cleanup functions *************************************/
+
+
+static int functionfs_init(void)
+{
+ int ret;
+
+ ENTER();
+
+ ret = register_filesystem(&ffs_fs_type);
+ if (likely(!ret))
+ FINFO("file system registered");
+ else
+ FERR("failed registering file system (%d)", ret);
+
+ return ret;
+}
+
+static void functionfs_cleanup(void)
+{
+ ENTER();
+
+ FINFO("unloading");
+ 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();
+
+ atomic_inc(&ffs->ref);
+}
+
+static void ffs_data_opened(struct ffs_data *ffs)
+{
+ ENTER();
+
+ atomic_inc(&ffs->ref);
+ atomic_inc(&ffs->opened);
+}
+
+static void ffs_data_put(struct ffs_data *ffs)
+{
+ ENTER();
+
+ if (unlikely(atomic_dec_and_test(&ffs->ref))) {
+ FINFO("%s(): freeing", __func__);
+ ffs_data_clear(ffs);
+ BUG_ON(mutex_is_locked(&ffs->mutex) ||
+ spin_is_locked(&ffs->ev.waitq.lock) ||
+ waitqueue_active(&ffs->ev.waitq) ||
+ waitqueue_active(&ffs->ep0req_completion.wait));
+ kfree(ffs);
+ }
+}
+
+
+
+static void ffs_data_closed(struct ffs_data *ffs)
+{
+ ENTER();
+
+ if (atomic_dec_and_test(&ffs->opened)) {
+ ffs->state = FFS_CLOSING;
+ ffs_data_reset(ffs);
+ }
+
+ ffs_data_put(ffs);
+}
+
+
+static struct ffs_data *ffs_data_new(void)
+{
+ struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL);
+ if (unlikely(!ffs))
+ return 0;
+
+ ENTER();
+
+ atomic_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_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();
+
+ if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags))
+ functionfs_closed_callback(ffs);
+
+ BUG_ON(ffs->gadget);
+
+ if (ffs->epfiles)
+ ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
+
+ kfree(ffs->raw_descs);
+ kfree(ffs->raw_strings);
+ kfree(ffs->stringtabs);
+}
+
+
+static void ffs_data_reset(struct ffs_data *ffs)
+{
+ ENTER();
+
+ ffs_data_clear(ffs);
+
+ ffs->epfiles = NULL;
+ ffs->raw_descs = NULL;
+ ffs->raw_strings = NULL;
+ ffs->stringtabs = NULL;
+
+ ffs->raw_descs_length = 0;
+ ffs->raw_fs_descs_length = 0;
+ ffs->fs_descs_count = 0;
+ ffs->hs_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;
+}
+
+
+static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
+{
+ unsigned i, count;
+
+ ENTER();
+
+ if (WARN_ON(ffs->state != FFS_ACTIVE
+ || test_and_set_bit(FFS_FL_BOUND, &ffs->flags)))
+ return -EBADFD;
+
+ ffs_data_get(ffs);
+
+ ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL);
+ if (unlikely(!ffs->ep0req))
+ return -ENOMEM;
+ ffs->ep0req->complete = ffs_ep0_complete;
+ ffs->ep0req->context = ffs;
+
+ /* Get strings identifiers */
+ for (count = ffs->strings_count, i = 0; i < count; ++i) {
+ struct usb_gadget_strings **lang;
+
+ int id = usb_string_id(cdev);
+ if (unlikely(id < 0)) {
+ usb_ep_free_request(cdev->gadget->ep0, ffs->ep0req);
+ ffs->ep0req = NULL;
+ return id;
+ }
+
+ lang = ffs->stringtabs;
+ do {
+ (*lang)->strings[i].id = id;
+ ++lang;
+ } while (*lang);
+ }
+
+ ffs->gadget = cdev->gadget;
+ 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;
+ 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 = kzalloc(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);
+ init_waitqueue_head(&epfile->wait);
+ sprintf(epfiles->name, "ep%u", i);
+ if (!unlikely(ffs_sb_create_file(ffs->sb, epfiles->name, epfile,
+ &ffs_epfile_operations,
+ &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) ||
+ waitqueue_active(&epfile->wait));
+ if (epfile->dentry) {
+ d_delete(epfile->dentry);
+ dput(epfile->dentry);
+ epfile->dentry = NULL;
+ }
+ }
+
+ kfree(epfiles);
+}
+
+
+static int functionfs_add(struct usb_composite_dev *cdev,
+ struct usb_configuration *c,
+ struct ffs_data *ffs)
+{
+ struct ffs_function *func;
+ int ret;
+
+ ENTER();
+
+ func = kzalloc(sizeof *func, GFP_KERNEL);
+ if (unlikely(!func))
+ return -ENOMEM;
+
+ func->function.name = "Function FS Gadget";
+ func->function.strings = ffs->stringtabs;
+
+ func->function.bind = ffs_func_bind;
+ func->function.unbind = ffs_func_unbind;
+ func->function.set_alt = ffs_func_set_alt;
+ /*func->function.get_alt = ffs_func_get_alt;*/
+ func->function.disable = ffs_func_disable;
+ func->function.setup = ffs_func_setup;
+ func->function.suspend = ffs_func_suspend;
+ func->function.resume = ffs_func_resume;
+
+ func->conf = c;
+ func->gadget = cdev->gadget;
+ func->ffs = ffs;
+ ffs_data_get(ffs);
+
+ ret = usb_add_function(c, &func->function);
+ if (unlikely(ret))
+ ffs_func_free(func);
+
+ return ret;
+}
+
+static void ffs_func_free(struct ffs_function *func)
+{
+ ENTER();
+
+ ffs_data_put(func->ffs);
+
+ kfree(func->eps);
+ /* eps and interfaces_nums are allocated in the same chunk so
+ * only one free is required. Descriptors are also allocated
+ * in the same chunk. */
+
+ kfree(func);
+}
+
+
+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);
+ do {
+ /* pending requests get nuked */
+ if (likely(ep->ep))
+ usb_ep_disable(ep->ep);
+ epfile->ep = NULL;
+
+ ++ep;
+ ++epfile;
+ } while (--count);
+ 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);
+ do {
+ struct usb_endpoint_descriptor *ds;
+ ds = ep->descs[ep->descs[1] ? 1 : 0];
+
+ ep->ep->driver_data = ep;
+ ret = usb_ep_enable(ep->ep, ds);
+ if (likely(!ret)) {
+ epfile->ep = ep;
+ epfile->in = usb_endpoint_dir_in(ds);
+ epfile->isoc = usb_endpoint_xfer_isoc(ds);
+ } else {
+ break;
+ }
+
+ wake_up(&epfile->wait);
+
+ ++ep;
+ ++epfile;
+ } while (--count);
+ 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 afther the
+ * descriptor or NULL if data is invalid. */
+
+enum ffs_entity_type {
+ FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT
+};
+
+typedef int (*ffs_entity_callback)(enum ffs_entity_type entity,
+ u8 *valuep,
+ struct usb_descriptor_header *desc,
+ void *priv);
+
+static int __must_check ffs_do_desc(char *data, unsigned len,
+ ffs_entity_callback entity, void *priv)
+{
+ struct usb_descriptor_header *_ds = (void *)data;
+ u8 length;
+ int ret;
+
+ ENTER();
+
+ /* At least two bytes are required: length and type */
+ if (len < 2) {
+ FVDBG("descriptor too short");
+ return -EINVAL;
+ }
+
+ /* If we have at least as many bytes as the descriptor takes? */
+ length = _ds->bLength;
+ if (len < length) {
+ FVDBG("descriptor longer then available data");
+ 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 { \
+ FVDBG("entity " #type "(%02x)", (val)); \
+ if (unlikely(!__entity_check_ ##type(val))) { \
+ FVDBG("invalid entity's value"); \
+ return -EINVAL; \
+ } \
+ ret = entity(FFS_ ##type, &val, _ds, priv); \
+ if (unlikely(ret < 0)) { \
+ FDBG("entity " #type "(%02x); ret = %d", \
+ (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 */
+ FVDBG("descriptor reserved for gadget: %d", _ds->bDescriptorType);
+ return -EINVAL;
+
+ case USB_DT_INTERFACE: {
+ struct usb_interface_descriptor *ds = (void *)_ds;
+ FVDBG("interface descriptor");
+ if (length != sizeof *ds)
+ goto inv_length;
+
+ __entity(INTERFACE, ds->bInterfaceNumber);
+ if (ds->iInterface)
+ __entity(STRING, ds->iInterface);
+ }
+ break;
+
+ case USB_DT_ENDPOINT: {
+ struct usb_endpoint_descriptor *ds = (void *)_ds;
+ FVDBG("endpoint descriptor");
+ if (length != USB_DT_ENDPOINT_SIZE &&
+ length != USB_DT_ENDPOINT_AUDIO_SIZE)
+ goto inv_length;
+ __entity(ENDPOINT, ds->bEndpointAddress);
+ }
+ break;
+
+ 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;
+ FVDBG("interface association descriptor");
+ if (length != sizeof *ds)
+ goto inv_length;
+ if (ds->iFunction)
+ __entity(STRING, ds->iFunction);
+ }
+ 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 */
+ FVDBG("unimplemented descriptor: %d", _ds->bDescriptorType);
+ return -EINVAL;
+
+ default:
+ /* We should never be here */
+ FVDBG("unknown descriptor: %d", _ds->bDescriptorType);
+ return -EINVAL;
+
+ inv_length:
+ FVDBG("invalid length: %d (descriptor %d)",
+ _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;
+
+ ENTER();
+
+ for (;;) {
+ int ret;
+
+ if (num == count)
+ data = NULL;
+
+ /* Record "descriptor" entitny */
+ ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv);
+ if (unlikely(ret < 0)) {
+ FDBG("entity DESCRIPTOR(%02lx); ret = %d", num, ret);
+ return ret;
+ }
+
+ if (!data)
+ return _len - len;
+
+ ret = ffs_do_desc(data, len, entity, priv);
+ if (unlikely(ret < 0)) {
+ FDBG("%s returns %d", __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_data *ffs = priv;
+
+ 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 >= ffs->interfaces_count)
+ ffs->interfaces_count = *valuep + 1;
+ break;
+
+ case FFS_STRING:
+ /* Strings are indexed from 1 (0 is magic ;) reserved
+ * for languages list or some such) */
+ if (*valuep > ffs->strings_count)
+ ffs->strings_count = *valuep;
+ break;
+
+ case FFS_ENDPOINT:
+ /* Endpoints are indexed from 1 as well. */
+ if ((*valuep & USB_ENDPOINT_NUMBER_MASK) > ffs->eps_count)
+ ffs->eps_count = (*valuep & USB_ENDPOINT_NUMBER_MASK);
+ break;
+ }
+
+ return 0;
+}
+
+
+static int __ffs_data_got_descs(struct ffs_data *ffs,
+ char *const _data, size_t len)
+{
+ unsigned fs_count, hs_count;
+ int fs_len, ret = -EINVAL;
+ char *data = _data;
+
+ ENTER();
+
+ if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
+ get_unaligned_le32(data + 4) != len))
+ goto error;
+ fs_count = get_unaligned_le32(data + 8);
+ hs_count = get_unaligned_le32(data + 12);
+
+ if (!fs_count && !hs_count)
+ goto einval;
+
+ data += 16;
+ len -= 16;
+
+ if (likely(fs_count)) {
+ fs_len = ffs_do_descs(fs_count, data, len,
+ __ffs_data_do_entity, ffs);
+ if (unlikely(fs_len < 0)) {
+ ret = fs_len;
+ goto error;
+ }
+
+ data += fs_len;
+ len -= fs_len;
+ } else {
+ fs_len = 0;
+ }
+
+ if (likely(hs_count)) {
+ ret = ffs_do_descs(hs_count, data, len,
+ __ffs_data_do_entity, ffs);
+ if (unlikely(ret < 0))
+ goto error;
+ } else {
+ ret = 0;
+ }
+
+ if (unlikely(len != ret))
+ goto einval;
+
+ ffs->raw_fs_descs_length = fs_len;
+ ffs->raw_descs_length = fs_len + ret;
+ ffs->raw_descs = _data;
+ ffs->fs_descs_count = fs_count;
+ ffs->hs_descs_count = hs_count;
+
+ return 0;
+
+einval:
+ ret = -EINVAL;
+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;
+ struct usb_string *strings, *s;
+ const char *data = _data;
+
+ ENTER();
+
+ if (unlikely(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 (unlikely(!str_count != !lang_count))
+ goto error;
+
+ /* Do we have at least as many strings as descriptors need? */
+ needed_count = ffs->strings_count;
+ if (unlikely(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 */
+ {
+ /* Allocate everything in one chunk so there's less
+ * maintanance. */
+ struct {
+ struct usb_gadget_strings *stringtabs[lang_count + 1];
+ struct usb_gadget_strings stringtab[lang_count];
+ struct usb_string strings[lang_count*(needed_count+1)];
+ } *d;
+ unsigned i = 0;
+
+ d = kmalloc(sizeof *d, GFP_KERNEL);
+ if (unlikely(!d)) {
+ kfree(_data);
+ return -ENOMEM;
+ }
+
+ stringtabs = d->stringtabs;
+ t = d->stringtab;
+ i = lang_count;
+ do {
+ *stringtabs++ = t++;
+ } while (--i);
+ *stringtabs = NULL;
+
+ stringtabs = d->stringtabs;
+ t = d->stringtab;
+ s = d->strings;
+ strings = s;
+ }
+
+ /* For each language */
+ data += 16;
+ len -= 16;
+
+ do { /* lang_count > 0 so we can use do-while */
+ unsigned needed = needed_count;
+
+ if (unlikely(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 (unlikely(length == len))
+ goto error_free;
+
+ /* user may provide more strings then we need,
+ * if that's the case we simply ingore the
+ * rest */
+ if (likely(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_count);
+
+ s->id = 0; /* terminator */
+ s->s = NULL;
+ ++s;
+
+ } while (--lang_count);
+
+ /* Some garbage left? */
+ if (unlikely(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_CANCELED;
+
+ switch (type) {
+ case FUNCTIONFS_RESUME:
+ rem_type2 = FUNCTIONFS_SUSPEND;
+ /* FALL THGOUTH */
+ 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:
+ BUG();
+ }
+
+ {
+ 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
+ FVDBG("purging event %d", *ev);
+ ffs->ev.count = out - ffs->ev.types;
+ }
+
+ FVDBG("adding event %d", type);
+ ffs->ev.types[ffs->ev.count++] = type;
+ wake_up_locked(&ffs->ev.waitq);
+}
+
+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_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;
+
+ /* If hs_descriptors is not NULL then we are reading hs
+ * descriptors now */
+ const int isHS = func->function.hs_descriptors != NULL;
+ unsigned idx;
+
+ if (type != FFS_DESCRIPTOR)
+ return 0;
+
+ if (isHS)
+ func->function.hs_descriptors[(long)valuep] = desc;
+ else
+ func->function.descriptors[(long)valuep] = desc;
+
+ if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT)
+ return 0;
+
+ idx = (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) - 1;
+ ffs_ep = func->eps + idx;
+
+ if (unlikely(ffs_ep->descs[isHS])) {
+ FVDBG("two %sspeed descriptors for EP %d",
+ isHS ? "high" : "full",
+ ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
+ return -EINVAL;
+ }
+ ffs_ep->descs[isHS] = 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;
+
+ FVDBG("autoconfig");
+ ep = usb_ep_autoconfig(func->gadget, ds);
+ if (unlikely(!ep))
+ return -ENOTSUPP;
+ ep->driver_data = func->eps + idx;;
+
+ req = usb_ep_alloc_request(ep, GFP_KERNEL);
+ if (unlikely(!req))
+ return -ENOMEM;
+
+ ffs_ep->ep = ep;
+ ffs_ep->req = req;
+ func->eps_revmap[ds->bEndpointAddress &
+ USB_ENDPOINT_NUMBER_MASK] = idx + 1;
+ }
+ 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 (unlikely(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 (unlikely(!func->eps[idx].ep))
+ return -EINVAL;
+
+ {
+ struct usb_endpoint_descriptor **descs;
+ descs = func->eps[idx].descs;
+ newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress;
+ }
+ break;
+ }
+
+ FVDBG("%02x -> %02x", *valuep, newValue);
+ *valuep = newValue;
+ return 0;
+}
+
+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 = gadget_is_dualspeed(func->gadget) &&
+ func->ffs->hs_descs_count;
+
+ int ret;
+
+ /* Make it a single chunk, less management later on */
+ struct {
+ struct ffs_ep eps[ffs->eps_count];
+ struct usb_descriptor_header
+ *fs_descs[full ? ffs->fs_descs_count + 1 : 0];
+ struct usb_descriptor_header
+ *hs_descs[high ? ffs->hs_descs_count + 1 : 0];
+ short inums[ffs->interfaces_count];
+ char raw_descs[high ? ffs->raw_descs_length
+ : ffs->raw_fs_descs_length];
+ } *data;
+
+ ENTER();
+
+ /* Only high speed but not supported by gadget? */
+ if (unlikely(!(full | high)))
+ return -ENOTSUPP;
+
+ /* Allocate */
+ data = kmalloc(sizeof *data, GFP_KERNEL);
+ if (unlikely(!data))
+ return -ENOMEM;
+
+ /* Zero */
+ memset(data->eps, 0, sizeof data->eps);
+ memcpy(data->raw_descs, ffs->raw_descs + 16, sizeof data->raw_descs);
+ memset(data->inums, 0xff, sizeof data->inums);
+ for (ret = ffs->eps_count; ret; --ret)
+ data->eps[ret].num = -1;
+
+ /* Save pointers */
+ func->eps = data->eps;
+ func->interfaces_nums = data->inums;
+
+ /* Go throught all the endpoint descriptors and allocate
+ * endpoints first, so that later we can rewrite the endpoint
+ * numbers without worying that it may be described later on. */
+ if (likely(full)) {
+ func->function.descriptors = data->fs_descs;
+ ret = ffs_do_descs(ffs->fs_descs_count,
+ data->raw_descs,
+ sizeof data->raw_descs,
+ __ffs_func_bind_do_descs, func);
+ if (unlikely(ret < 0))
+ goto error;
+ } else {
+ ret = 0;
+ }
+
+ if (likely(high)) {
+ func->function.hs_descriptors = data->hs_descs;
+ ret = ffs_do_descs(ffs->hs_descs_count,
+ data->raw_descs + ret,
+ (sizeof data->raw_descs) - ret,
+ __ffs_func_bind_do_descs, func);
+ }
+
+ /* Now handle interface numbers allocation and interface and
+ * enpoint numbers rewritting. We can do that in one go
+ * now. */
+ ret = ffs_do_descs(ffs->fs_descs_count +
+ (high ? ffs->hs_descs_count : 0),
+ data->raw_descs, sizeof data->raw_descs,
+ __ffs_func_bind_do_nums, func);
+ if (unlikely(ret < 0))
+ goto error;
+
+ /* 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;
+}
+
+
+/* Other USB function hooks *************************************************/
+
+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;
+
+ ENTER();
+
+ if (ffs->func == func) {
+ ffs_func_eps_disable(func);
+ ffs->func = NULL;
+ }
+
+ ffs_event_add(ffs, FUNCTIONFS_UNBIND);
+
+ ffs_func_free(func);
+}
+
+
+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 (unlikely(intf < 0))
+ return intf;
+ }
+
+ if (ffs->func)
+ ffs_func_eps_disable(ffs->func);
+
+ 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 (likely(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();
+
+ FVDBG("creq->bRequestType = %02x", creq->bRequestType);
+ FVDBG("creq->bRequest = %02x", creq->bRequest);
+ FVDBG("creq->wValue = %04x", le16_to_cpu(creq->wValue));
+ FVDBG("creq->wIndex = %04x", le16_to_cpu(creq->wIndex));
+ FVDBG("creq->wLength = %04x", le16_to_cpu(creq->wLength));
+
+ /* Most requests directed to interface go throught 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) but what to do with any
+ * other request? */
+
+ 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 (unlikely(ret < 0))
+ return ret;
+ break;
+
+ case USB_RECIP_ENDPOINT:
+ ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex));
+ if (unlikely(ret < 0))
+ return ret;
+ break;
+
+ default:
+ 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 0;
+}
+
+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);
+}
+
+
+
+/* Enpoint 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;
+}
+
+
+/* Misc helper functions ****************************************************/
+
+static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock)
+{
+ return nonblock
+ ? likely(mutex_trylock(mutex)) ? 0 : -EAGAIN
+ : mutex_lock_interruptible(mutex);
+}
+
+
+static char *ffs_prepare_buffer(const char * __user buf, size_t len)
+{
+ char *data;
+
+ if (unlikely(!len))
+ return NULL;
+
+ data = kmalloc(len, GFP_KERNEL);
+ if (unlikely(!data))
+ return ERR_PTR(-ENOMEM);
+
+ if (unlikely(__copy_from_user(data, buf, len))) {
+ kfree(data);
+ return ERR_PTR(-EFAULT);
+ }
+
+ FVDBG("Buffer from user space:");
+ ffs_dump_mem("", data, len);
+
+ return data;
+}
projects / platform / kernel / linux-stable.git / commitdiff