1 files changed, 213 insertions, 209 deletions

diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index d17930d9a843..8d318eaaaf20 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -22,6 +22,7 @@
 #include <linux/pagemap.h>
 #include <linux/export.h>
 #include <linux/hid.h>
+#include <linux/module.h>
 #include <asm/unaligned.h>
 
 #include <linux/usb/composite.h>
@@ -57,210 +58,6 @@
 #define vla_ptr(ptr, groupname, name) \
         ((void *) ((char *)ptr + groupname##_##name##__offset))
 
-/* Debugging ****************************************************************/
-
-#ifdef VERBOSE_DEBUG
-#ifndef pr_vdebug
-#  define pr_vdebug pr_debug
-#endif /* pr_vdebug */
-#  define ffs_dump_mem(prefix, ptr, len) \
-        print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
-#else
-#ifndef pr_vdebug
-#  define pr_vdebug(...)                 do { } while (0)
-#endif /* pr_vdebug */
-#  define ffs_dump_mem(prefix, ptr, len) do { } while (0)
-#endif /* VERBOSE_DEBUG */
-
-#define ENTER()    pr_vdebug("%s()\n", __func__)
-
-
-/* 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 first place).
-         */
-        FFS_READ_DESCRIPTORS,
-        FFS_READ_STRINGS,
-
-        /*
-         * We've got descriptors and strings.  We are or have called
-         * ffs_ready().  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 epfiles or
-         * ffs_ready() 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 endpoint related structures (basically
-         * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
-         * endpoint zero.
-         */
-        spinlock_t                      eps_lock;
-
-        /*
-         * XXX REVISIT do we need our own request? Since we are not
-         * handling setup requests immediately 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 that 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 transitions:
-         * + 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.
-         * Intended 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;
-                kuid_t                          uid;
-                kgid_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);
@@ -300,15 +97,19 @@ static struct ffs_function *ffs_func_from_usb(struct usb_function *f)
         return container_of(f, struct ffs_function, function);
 }
 
+#ifdef USB_FFS_INCLUDED
 static void ffs_func_free(struct ffs_function *func);
+#endif
 
 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 *,
+#ifdef USB_FFS_INCLUDED
+static void old_ffs_func_unbind(struct usb_configuration *,
                             struct usb_function *);
+#endif
 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 *,
@@ -364,6 +165,9 @@ ffs_sb_create_file(struct super_block *sb, const char *name, void *data,
 /* Devices management *******************************************************/
 
 DEFINE_MUTEX(ffs_lock);
+#ifndef USB_FFS_INCLUDED
+EXPORT_SYMBOL(ffs_lock);
+#endif
 
 static struct ffs_dev *ffs_find_dev(const char *name);
 static void *ffs_acquire_dev(const char *dev_name);
@@ -1499,6 +1303,8 @@ static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count)
         kfree(epfiles);
 }
 
+#ifdef USB_FFS_INCLUDED
+
 static int functionfs_bind_config(struct usb_composite_dev *cdev,
                                   struct usb_configuration *c,
                                   struct ffs_data *ffs)
@@ -1516,7 +1322,7 @@ static int functionfs_bind_config(struct usb_composite_dev *cdev,
         func->function.strings = ffs->stringtabs;
 
         func->function.bind    = ffs_func_bind;
-        func->function.unbind  = ffs_func_unbind;
+        func->function.unbind  = old_ffs_func_unbind;
         func->function.set_alt = ffs_func_set_alt;
         func->function.disable = ffs_func_disable;
         func->function.setup   = ffs_func_setup;
@@ -1565,6 +1371,8 @@ static void ffs_func_free(struct ffs_function *func)
         kfree(func);
 }
 
+#endif
+
 static void ffs_func_eps_disable(struct ffs_function *func)
 {
         struct ffs_ep *ep         = func->eps;
@@ -2227,8 +2035,59 @@ static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep,
         return 0;
 }
 
-static int ffs_func_bind(struct usb_configuration *c,
-                         struct usb_function *f)
+#ifndef USB_FFS_INCLUDED
+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);
+        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;
+        func->ffs = ffs_opts->dev->ffs_data;
+        if (!ffs_opts->no_configfs)
+                ffs_dev_unlock();
+        if (ret)
+                return ERR_PTR(ret);
+
+        func->conf = c;
+        func->gadget = c->cdev->gadget;
+
+        ffs_data_get(func->ffs);
+
+        /*
+         * 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;
+}
+#endif
+
+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;
@@ -2328,10 +2187,25 @@ error:
         return ret;
 }
 
+static int ffs_func_bind(struct usb_configuration *c,
+                         struct usb_function *f)
+{
+#ifndef USB_FFS_INCLUDED
+        struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
+
+        if (IS_ERR(ffs_opts))
+                return PTR_ERR(ffs_opts);
+#endif
+
+        return _ffs_func_bind(c, f);
+}
+
 
 /* Other USB function hooks *************************************************/
 
-static void ffs_func_unbind(struct usb_configuration *c,
+#ifdef USB_FFS_INCLUDED
+
+static void old_ffs_func_unbind(struct usb_configuration *c,
                             struct usb_function *f)
 {
         struct ffs_function *func = ffs_func_from_usb(f);
@@ -2349,6 +2223,8 @@ static void ffs_func_unbind(struct usb_configuration *c,
         ffs_func_free(func);
 }
 
+#endif
+
 static int ffs_func_set_alt(struct usb_function *f,
                             unsigned interface, unsigned alt)
 {
@@ -2523,6 +2399,116 @@ static struct ffs_dev *ffs_find_dev(const char *name)
         return _ffs_find_dev(name);
 }
 
+/* Function registration interface ******************************************/
+
+#ifndef USB_FFS_INCLUDED
+
+static void ffs_free_inst(struct usb_function_instance *f)
+{
+        struct f_fs_opts *opts;
+
+        opts = to_f_fs_opts(f);
+        ffs_dev_lock();
+        ffs_free_dev(opts->dev);
+        ffs_dev_unlock();
+        kfree(opts);
+}
+
+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.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;
+
+        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;
+        }
+
+        if (!--opts->refcnt)
+                functionfs_unbind(ffs);
+
+        /* cleanup after autoconfig */
+        spin_lock_irqsave(&func->ffs->eps_lock, flags);
+        do {
+                if (ep->ep && ep->req)
+                        usb_ep_free_request(ep->ep, ep->req);
+                ep->req = NULL;
+                ++ep;
+        } while (--count);
+        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->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 (unlikely(!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.suspend = ffs_func_suspend;
+        func->function.resume  = ffs_func_resume;
+        func->function.free_func = ffs_free;
+
+        return &func->function;
+}
+
+#endif
+
 /*
  * ffs_lock must be taken by the caller of this function
  */
@@ -2581,6 +2567,9 @@ int ffs_name_dev(struct ffs_dev *dev, const char *name)
 
         return ret;
 }
+#ifndef USB_FFS_INCLUDED
+EXPORT_SYMBOL(ffs_name_dev);
+#endif
 
 int ffs_single_dev(struct ffs_dev *dev)
 {
@@ -2597,6 +2586,9 @@ int ffs_single_dev(struct ffs_dev *dev)
         ffs_dev_unlock();
         return ret;
 }
+#ifndef USB_FFS_INCLUDED
+EXPORT_SYMBOL(ffs_single_dev);
+#endif
 
 /*
  * ffs_lock must be taken by the caller of this function
@@ -2621,6 +2613,9 @@ static void *ffs_acquire_dev(const char *dev_name)
                 ffs_dev = ERR_PTR(-ENODEV);
         else if (ffs_dev->mounted)
                 ffs_dev = ERR_PTR(-EBUSY);
+        else if (ffs_dev->ffs_acquire_dev_callback &&
+            ffs_dev->ffs_acquire_dev_callback(ffs_dev))
+                ffs_dev = ERR_PTR(-ENODEV);
         else
                 ffs_dev->mounted = true;
 
@@ -2638,6 +2633,9 @@ static void ffs_release_dev(struct ffs_data *ffs_data)
         ffs_dev = ffs_data->private_data;
         if (ffs_dev)
                 ffs_dev->mounted = false;
+        
+        if (ffs_dev->ffs_release_dev_callback)
+                ffs_dev->ffs_release_dev_callback(ffs_dev);
 
         ffs_dev_unlock();
 }
@@ -2720,3 +2718,9 @@ static char *ffs_prepare_buffer(const char __user *buf, size_t len)
 
         return data;
 }
+
+#ifndef USB_FFS_INCLUDED
+DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michal Nazarewicz");
+#endif