From 4b187fceec3c731815ff8e6a7317fd5ba50d1d5d Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Tue, 3 Dec 2013 15:15:32 +0100 Subject: [PATCH] usb: gadget: FunctionFS: add devices management code This will be required in order to use the new function interface (usb_get_function_instance/usb_put_function_instance) Signed-off-by: Andrzej Pietrasiewicz Signed-off-by: Kyunmgin Park Acked-by: Michal Nazarewicz Signed-off-by: Felipe Balbi --- drivers/usb/gadget/f_fs.c | 238 ++++++++++++++++++++++++++++++++- drivers/usb/gadget/g_ffs.c | 175 ++++++++---------------- drivers/usb/gadget/u_fs.h | 24 ++++ include/linux/usb/functionfs.h | 14 -- 4 files changed, 314 insertions(+), 137 deletions(-) diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c index c0b4cf808638..d17930d9a843 100644 --- a/drivers/usb/gadget/f_fs.c +++ b/drivers/usb/gadget/f_fs.c @@ -90,7 +90,7 @@ enum ffs_state { /* * We've got descriptors and strings. We are or have called - * functionfs_ready_callback(). functionfs_bind() may have + * ffs_ready(). functionfs_bind() may have * been called but we don't know. * * This is the only state in which operations on epfiles may @@ -103,7 +103,7 @@ enum ffs_state { * we encounter an unrecoverable error. The only * unrecoverable error is situation when after reading strings * from user space we fail to initialise epfiles or - * functionfs_ready_callback() returns with error (<0). + * 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 @@ -361,6 +361,15 @@ ffs_sb_create_file(struct super_block *sb, const char *name, void *data, const struct file_operations *fops, struct dentry **dentry_p); +/* Devices management *******************************************************/ + +DEFINE_MUTEX(ffs_lock); + +static struct ffs_dev *ffs_find_dev(const char *name); +static void *ffs_acquire_dev(const char *dev_name); +static void ffs_release_dev(struct ffs_data *ffs_data); +static int ffs_ready(struct ffs_data *ffs); +static void ffs_closed(struct ffs_data *ffs); /* Misc helper functions ****************************************************/ @@ -486,7 +495,7 @@ static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, ffs->state = FFS_ACTIVE; mutex_unlock(&ffs->mutex); - ret = functionfs_ready_callback(ffs); + ret = ffs_ready(ffs); if (unlikely(ret < 0)) { ffs->state = FFS_CLOSING; return ret; @@ -1218,7 +1227,7 @@ ffs_fs_mount(struct file_system_type *t, int flags, return ERR_PTR(-ENOMEM); } - ffs_dev = functionfs_acquire_dev_callback(dev_name); + ffs_dev = ffs_acquire_dev(dev_name); if (IS_ERR(ffs_dev)) { ffs_data_put(ffs); return ERR_CAST(ffs_dev); @@ -1228,7 +1237,7 @@ ffs_fs_mount(struct file_system_type *t, int flags, rv = mount_nodev(t, flags, &data, ffs_sb_fill); if (IS_ERR(rv) && data.ffs_data) { - functionfs_release_dev_callback(data.ffs_data); + ffs_release_dev(data.ffs_data); ffs_data_put(data.ffs_data); } return rv; @@ -1241,7 +1250,7 @@ ffs_fs_kill_sb(struct super_block *sb) kill_litter_super(sb); if (sb->s_fs_info) { - functionfs_release_dev_callback(sb->s_fs_info); + ffs_release_dev(sb->s_fs_info); ffs_data_put(sb->s_fs_info); } } @@ -1354,7 +1363,7 @@ 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); + ffs_closed(ffs); BUG_ON(ffs->gadget); @@ -2466,6 +2475,221 @@ static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) } +/* Devices management *******************************************************/ + +static LIST_HEAD(ffs_devices); + +static struct ffs_dev *_ffs_find_dev(const char *name) +{ + struct ffs_dev *dev; + + list_for_each_entry(dev, &ffs_devices, entry) { + if (!dev->name || !name) + continue; + 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_find_dev(name); +} + +/* + * ffs_lock must be taken by the caller of this function + */ +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; +} + +/* + * ffs_lock must be taken by the caller of this function + * The caller is responsible for "name" being available whenever f_fs needs it + */ +static int _ffs_name_dev(struct ffs_dev *dev, const char *name) +{ + struct ffs_dev *existing; + + existing = _ffs_find_dev(name); + if (existing) + return -EBUSY; + + dev->name = name; + + return 0; +} + +/* + * The caller is responsible for "name" being available whenever f_fs needs it + */ +int ffs_name_dev(struct ffs_dev *dev, const char *name) +{ + int ret; + + ffs_dev_lock(); + ret = _ffs_name_dev(dev, name); + ffs_dev_unlock(); + + return ret; +} + +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; +} + +/* + * ffs_lock must be taken by the caller of this function + */ +void ffs_free_dev(struct ffs_dev *dev) +{ + list_del(&dev->entry); + kfree(dev); + if (list_empty(&ffs_devices)) + functionfs_cleanup(); +} + +static void *ffs_acquire_dev(const char *dev_name) +{ + struct ffs_dev *ffs_dev; + + ENTER(); + ffs_dev_lock(); + + ffs_dev = ffs_find_dev(dev_name); + if (!ffs_dev) + ffs_dev = ERR_PTR(-ENODEV); + else if (ffs_dev->mounted) + ffs_dev = ERR_PTR(-EBUSY); + else + ffs_dev->mounted = true; + + ffs_dev_unlock(); + return ffs_dev; +} + +static void ffs_release_dev(struct ffs_data *ffs_data) +{ + struct ffs_dev *ffs_dev; + + ENTER(); + ffs_dev_lock(); + + ffs_dev = ffs_data->private_data; + if (ffs_dev) + ffs_dev->mounted = false; + + 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; + ffs_obj->ffs_data = ffs; + + if (ffs_obj->ffs_ready_callback) + ret = ffs_obj->ffs_ready_callback(ffs); + +done: + ffs_dev_unlock(); + return ret; +} + +static void ffs_closed(struct ffs_data *ffs) +{ + struct ffs_dev *ffs_obj; + + ENTER(); + ffs_dev_lock(); + + ffs_obj = ffs->private_data; + if (!ffs_obj) + goto done; + + ffs_obj->desc_ready = false; + + if (ffs_obj->ffs_closed_callback) + ffs_obj->ffs_closed_callback(ffs); +done: + ffs_dev_unlock(); +} + /* Misc helper functions ****************************************************/ static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) diff --git a/drivers/usb/gadget/g_ffs.c b/drivers/usb/gadget/g_ffs.c index 1aaa103e01c6..074df0d56255 100644 --- a/drivers/usb/gadget/g_ffs.c +++ b/drivers/usb/gadget/g_ffs.c @@ -157,6 +157,8 @@ struct gfs_configuration { #endif }; +static int functionfs_ready_callback(struct ffs_data *ffs); +static void functionfs_closed_callback(struct ffs_data *ffs); static int gfs_bind(struct usb_composite_dev *cdev); static int gfs_unbind(struct usb_composite_dev *cdev); static int gfs_do_config(struct usb_configuration *c); @@ -170,172 +172,113 @@ static __refdata struct usb_composite_driver gfs_driver = { .unbind = gfs_unbind, }; -static DEFINE_MUTEX(gfs_lock); static unsigned int missing_funcs; static bool gfs_registered; static bool gfs_single_func; -static struct ffs_dev *ffs_tab; +static struct ffs_dev **ffs_tab; static int __init gfs_init(void) { int i; + int ret = 0; ENTER(); - if (!func_num) { + if (func_num < 2) { gfs_single_func = true; func_num = 1; } - ffs_tab = kcalloc(func_num, sizeof *ffs_tab, GFP_KERNEL); + ffs_tab = kcalloc(func_num, sizeof(*ffs_tab), GFP_KERNEL); if (!ffs_tab) return -ENOMEM; - if (!gfs_single_func) - for (i = 0; i < func_num; i++) - ffs_tab[i].name = func_names[i]; + for (i = 0; i < func_num; i++) { + ffs_dev_lock(); + ffs_tab[i] = ffs_alloc_dev(); + ffs_dev_unlock(); + if (IS_ERR(ffs_tab[i])) { + ret = PTR_ERR(ffs_tab[i]); + --i; + goto no_dev; + } + if (gfs_single_func) + ret = ffs_single_dev(ffs_tab[i]); + else + ret = ffs_name_dev(ffs_tab[i], func_names[i]); + if (ret) + goto no_dev; + ffs_tab[i]->ffs_ready_callback = functionfs_ready_callback; + ffs_tab[i]->ffs_closed_callback = functionfs_closed_callback; + } missing_funcs = func_num; - return functionfs_init(); + return 0; +no_dev: + ffs_dev_lock(); + while (i >= 0) + ffs_free_dev(ffs_tab[i--]); + ffs_dev_unlock(); + kfree(ffs_tab); + return ret; } module_init(gfs_init); static void __exit gfs_exit(void) { + int i; + ENTER(); - mutex_lock(&gfs_lock); + ffs_dev_lock(); if (gfs_registered) usb_composite_unregister(&gfs_driver); gfs_registered = false; - functionfs_cleanup(); - - mutex_unlock(&gfs_lock); + for (i = 0; i < func_num; i++) + ffs_free_dev(ffs_tab[i]); + ffs_dev_unlock(); kfree(ffs_tab); } module_exit(gfs_exit); -static struct ffs_dev *gfs_find_dev(const char *dev_name) -{ - int i; - - ENTER(); - - if (gfs_single_func) - return &ffs_tab[0]; - - for (i = 0; i < func_num; i++) - if (strcmp(ffs_tab[i].name, dev_name) == 0) - return &ffs_tab[i]; - - return NULL; -} - +/* + * The caller of this function takes ffs_lock + */ static int functionfs_ready_callback(struct ffs_data *ffs) { - struct ffs_dev *ffs_obj; - int ret; - - ENTER(); - mutex_lock(&gfs_lock); + int ret = 0; - 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; - ffs_obj->ffs_data = ffs; + if (--missing_funcs) + return 0; - if (--missing_funcs) { - ret = 0; - goto done; - } + if (gfs_registered) + return -EBUSY; - if (gfs_registered) { - ret = -EBUSY; - goto done; - } gfs_registered = true; ret = usb_composite_probe(&gfs_driver); if (unlikely(ret < 0)) gfs_registered = false; - -done: - mutex_unlock(&gfs_lock); + return ret; } +/* + * The caller of this function takes ffs_lock + */ static void functionfs_closed_callback(struct ffs_data *ffs) { - struct ffs_dev *ffs_obj; - - ENTER(); - mutex_lock(&gfs_lock); - - ffs_obj = ffs->private_data; - if (!ffs_obj) - goto done; - - ffs_obj->desc_ready = false; missing_funcs++; if (gfs_registered) usb_composite_unregister(&gfs_driver); gfs_registered = false; - -done: - mutex_unlock(&gfs_lock); -} - -static void *functionfs_acquire_dev_callback(const char *dev_name) -{ - struct ffs_dev *ffs_dev; - - ENTER(); - mutex_lock(&gfs_lock); - - ffs_dev = gfs_find_dev(dev_name); - if (!ffs_dev) { - ffs_dev = ERR_PTR(-ENODEV); - goto done; - } - - if (ffs_dev->mounted) { - ffs_dev = ERR_PTR(-EBUSY); - goto done; - } - ffs_dev->mounted = true; - -done: - mutex_unlock(&gfs_lock); - return ffs_dev; -} - -static void functionfs_release_dev_callback(struct ffs_data *ffs_data) -{ - struct ffs_dev *ffs_dev; - - ENTER(); - mutex_lock(&gfs_lock); - - ffs_dev = ffs_data->private_data; - if (ffs_dev) - ffs_dev->mounted = false; - - mutex_unlock(&gfs_lock); } /* - * It is assumed that gfs_bind is called from a context where gfs_lock is held + * It is assumed that gfs_bind is called from a context where ffs_lock is held */ static int gfs_bind(struct usb_composite_dev *cdev) { @@ -422,10 +365,10 @@ static int gfs_bind(struct usb_composite_dev *cdev) gfs_dev_desc.iProduct = gfs_strings[USB_GADGET_PRODUCT_IDX].id; for (i = func_num; i--; ) { - ret = functionfs_bind(ffs_tab[i].ffs_data, cdev); + ret = functionfs_bind(ffs_tab[i]->ffs_data, cdev); if (unlikely(ret < 0)) { while (++i < func_num) - functionfs_unbind(ffs_tab[i].ffs_data); + functionfs_unbind(ffs_tab[i]->ffs_data); goto error_rndis; } } @@ -448,7 +391,7 @@ static int gfs_bind(struct usb_composite_dev *cdev) error_unbind: for (i = 0; i < func_num; i++) - functionfs_unbind(ffs_tab[i].ffs_data); + functionfs_unbind(ffs_tab[i]->ffs_data); error_rndis: #ifdef CONFIG_USB_FUNCTIONFS_RNDIS usb_put_function_instance(fi_rndis); @@ -464,7 +407,7 @@ error: } /* - * It is assumed that gfs_unbind is called from a context where gfs_lock is held + * It is assumed that gfs_unbind is called from a context where ffs_lock is held */ static int gfs_unbind(struct usb_composite_dev *cdev) { @@ -497,15 +440,15 @@ static int gfs_unbind(struct usb_composite_dev *cdev) * do...? */ for (i = func_num; i--; ) - if (ffs_tab[i].ffs_data) - functionfs_unbind(ffs_tab[i].ffs_data); + if (ffs_tab[i]->ffs_data) + functionfs_unbind(ffs_tab[i]->ffs_data); return 0; } /* * It is assumed that gfs_do_config is called from a context where - * gfs_lock is held + * ffs_lock is held */ static int gfs_do_config(struct usb_configuration *c) { @@ -529,7 +472,7 @@ static int gfs_do_config(struct usb_configuration *c) } for (i = 0; i < func_num; i++) { - ret = functionfs_bind_config(c->cdev, c, ffs_tab[i].ffs_data); + ret = functionfs_bind_config(c->cdev, c, ffs_tab[i]->ffs_data); if (unlikely(ret < 0)) return ret; } diff --git a/drivers/usb/gadget/u_fs.h b/drivers/usb/gadget/u_fs.h index 5d9229a01560..2d00f9d296a3 100644 --- a/drivers/usb/gadget/u_fs.h +++ b/drivers/usb/gadget/u_fs.h @@ -17,12 +17,36 @@ #define U_FFS_H #include +#include +#include struct ffs_dev { const char *name; bool mounted; bool desc_ready; + bool single; struct ffs_data *ffs_data; + struct list_head entry; + + int (*ffs_ready_callback)(struct ffs_data *ffs); + void (*ffs_closed_callback)(struct ffs_data *ffs); }; +extern struct mutex ffs_lock; + +static inline void ffs_dev_lock(void) +{ + mutex_lock(&ffs_lock); +} + +static inline void ffs_dev_unlock(void) +{ + mutex_unlock(&ffs_lock); +} + +struct ffs_dev *ffs_alloc_dev(void); +int ffs_name_dev(struct ffs_dev *dev, const char *name); +int ffs_single_dev(struct ffs_dev *dev); +void ffs_free_dev(struct ffs_dev *dev); + #endif /* U_FFS_H */ diff --git a/include/linux/usb/functionfs.h b/include/linux/usb/functionfs.h index 65d0a88dbc67..9c1e92620dfb 100644 --- a/include/linux/usb/functionfs.h +++ b/include/linux/usb/functionfs.h @@ -8,10 +8,6 @@ struct ffs_data; struct usb_composite_dev; struct usb_configuration; - -static int functionfs_init(void) __attribute__((warn_unused_result)); -static void functionfs_cleanup(void); - static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) __attribute__((warn_unused_result, nonnull)); static void functionfs_unbind(struct ffs_data *ffs) @@ -23,14 +19,4 @@ static int functionfs_bind_config(struct usb_composite_dev *cdev, __attribute__((warn_unused_result, nonnull)); -static int functionfs_ready_callback(struct ffs_data *ffs) - __attribute__((warn_unused_result, nonnull)); -static void functionfs_closed_callback(struct ffs_data *ffs) - __attribute__((nonnull)); -static void *functionfs_acquire_dev_callback(const char *dev_name) - __attribute__((warn_unused_result, nonnull)); -static void functionfs_release_dev_callback(struct ffs_data *ffs_data) - __attribute__((nonnull)); - - #endif -- 2.20.1