// 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 <[email protected]> * * 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/dma-buf.h> #include <linux/dma-fence.h> #include <linux/dma-resv.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 <linux/unaligned.h> #include <linux/usb/ccid.h> #include <linux/usb/composite.h> #include <linux/usb/functionfs.h> #include <linux/usb/func_utils.h> #include <linux/aio.h> #include <linux/kthread.h> #include <linux/poll.h> #include <linux/eventfd.h> #include "u_fs.h" #include "u_os_desc.h" #include "configfs.h" #define FUNCTIONFS_MAGIC … #define MAX_ALT_SETTINGS … #define DMABUF_ENQUEUE_TIMEOUT_MS … MODULE_IMPORT_NS(…); /* 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 { … }; static struct ffs_function *ffs_func_from_usb(struct usb_function *f) { … } static inline enum ffs_setup_state ffs_setup_state_clear_cancelled(struct ffs_data *ffs) { … } 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 int ffs_func_get_alt(struct usb_function *f, unsigned int intf); 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 ffs_dmabuf_priv { … }; struct ffs_dma_fence { … }; struct ffs_epfile { … }; struct ffs_buffer { … }; /* ffs_io_data structure ***************************************************/ struct ffs_io_data { … }; struct ffs_desc_helper { … }; 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(…) …; EXPORT_SYMBOL_GPL(…); 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) { … } static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) __releases(&ffs->ev.waitq.lock) { … } static int __ffs_ep0_stall(struct ffs_data *ffs) { … } static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, size_t len, loff_t *ptr) { … } /* 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) { … } static ssize_t ffs_ep0_read(struct file *file, char __user *buf, size_t len, loff_t *ptr) { … } static int ffs_ep0_open(struct inode *inode, struct file *file) { … } static int ffs_ep0_release(struct inode *inode, struct file *file) { … } static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) { … } static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait) { … } static const struct file_operations ffs_ep0_operations = …; /* "Normal" endpoints operations ********************************************/ static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) { … } static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) { … } /* * 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) { … } static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data, size_t data_len) { … } static inline void ffs_free_buffer(struct ffs_io_data *io_data) { … } static void ffs_user_copy_worker(struct work_struct *work) { … } static void ffs_epfile_async_io_complete(struct usb_ep *_ep, struct usb_request *req) { … } static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile) { … } /* Assumes epfile->mutex is held. */ static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile, struct iov_iter *iter) { … } /* 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) { … } static struct ffs_ep *ffs_epfile_wait_ep(struct file *file) { … } static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) { … } static int ffs_epfile_open(struct inode *inode, struct file *file) { … } static int ffs_aio_cancel(struct kiocb *kiocb) { … } static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) { … } static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) { … } static void ffs_dmabuf_release(struct kref *ref) { … } static void ffs_dmabuf_get(struct dma_buf_attachment *attach) { … } static void ffs_dmabuf_put(struct dma_buf_attachment *attach) { … } static int ffs_epfile_release(struct inode *inode, struct file *file) { … } static void ffs_dmabuf_cleanup(struct work_struct *work) { … } static void ffs_dmabuf_signal_done(struct ffs_dma_fence *dma_fence, int ret) { … } static void ffs_epfile_dmabuf_io_complete(struct usb_ep *ep, struct usb_request *req) { … } static const char *ffs_dmabuf_get_driver_name(struct dma_fence *fence) { … } static const char *ffs_dmabuf_get_timeline_name(struct dma_fence *fence) { … } static void ffs_dmabuf_fence_release(struct dma_fence *fence) { … } static const struct dma_fence_ops ffs_dmabuf_fence_ops = …; static int ffs_dma_resv_lock(struct dma_buf *dmabuf, bool nonblock) { … } static struct dma_buf_attachment * ffs_dmabuf_find_attachment(struct ffs_epfile *epfile, struct dma_buf *dmabuf) { … } static int ffs_dmabuf_attach(struct file *file, int fd) { … } static int ffs_dmabuf_detach(struct file *file, int fd) { … } static int ffs_dmabuf_transfer(struct file *file, const struct usb_ffs_dmabuf_transfer_req *req) { … } static long ffs_epfile_ioctl(struct file *file, unsigned code, unsigned long value) { … } static const struct file_operations ffs_epfile_operations = …; /* 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) { … } /* Create "regular" file */ static struct dentry *ffs_sb_create_file(struct super_block *sb, const char *name, void *data, const struct file_operations *fops) { … } /* Super block */ static const struct super_operations ffs_sb_operations = …; struct ffs_sb_fill_data { … }; static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc) { … } enum { … }; static const struct fs_parameter_spec ffs_fs_fs_parameters[] = …; static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param) { … } /* * Set up the superblock for a mount. */ static int ffs_fs_get_tree(struct fs_context *fc) { … } static void ffs_fs_free_fc(struct fs_context *fc) { … } static const struct fs_context_operations ffs_fs_context_ops = …; static int ffs_fs_init_fs_context(struct fs_context *fc) { … } static void ffs_fs_kill_sb(struct super_block *sb) { … } static struct file_system_type ffs_fs_type = …; MODULE_ALIAS_FS(…) …; /* Driver's main init/cleanup functions *************************************/ static int functionfs_init(void) { … } static void functionfs_cleanup(void) { … } /* 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) { … } static void ffs_data_opened(struct ffs_data *ffs) { … } static void ffs_data_put(struct ffs_data *ffs) { … } static void ffs_data_closed(struct ffs_data *ffs) { … } static struct ffs_data *ffs_data_new(const char *dev_name) { … } static void ffs_data_clear(struct ffs_data *ffs) { … } static void ffs_data_reset(struct ffs_data *ffs) { … } static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) { … } static void functionfs_unbind(struct ffs_data *ffs) { … } static int ffs_epfiles_create(struct ffs_data *ffs) { … } static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) { … } static void ffs_func_eps_disable(struct ffs_function *func) { … } static int ffs_func_eps_enable(struct ffs_function *func) { … } /* 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 { … }; enum ffs_os_desc_type { … }; ffs_entity_callback; ffs_os_desc_callback; static int __must_check ffs_do_single_desc(char *data, unsigned len, ffs_entity_callback entity, void *priv, int *current_class, int *current_subclass) { … } static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, ffs_entity_callback entity, void *priv) { … } static int __ffs_data_do_entity(enum ffs_entity_type type, u8 *valuep, struct usb_descriptor_header *desc, void *priv) { … } static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, struct usb_os_desc_header *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) { … } /* 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) { … } /* * 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) { … } static int __ffs_data_got_descs(struct ffs_data *ffs, char *const _data, size_t len) { … } static int __ffs_data_got_strings(struct ffs_data *ffs, char *const _data, size_t len) { … } /* Events handling and management *******************************************/ static void __ffs_event_add(struct ffs_data *ffs, enum usb_functionfs_event_type type) { … } static void ffs_event_add(struct ffs_data *ffs, enum usb_functionfs_event_type type) { … } /* Bind/unbind USB function hooks *******************************************/ static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) { … } static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, struct usb_descriptor_header *desc, void *priv) { … } static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, struct usb_descriptor_header *desc, void *priv) { … } 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) { … } static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, struct usb_configuration *c) { … } static int _ffs_func_bind(struct usb_configuration *c, struct usb_function *f) { … } static int ffs_func_bind(struct usb_configuration *c, struct usb_function *f) { … } /* Other USB function hooks *************************************************/ static void ffs_reset_work(struct work_struct *work) { … } static int ffs_func_get_alt(struct usb_function *f, unsigned int interface) { … } static int ffs_func_set_alt(struct usb_function *f, unsigned interface, unsigned alt) { … } static void ffs_func_disable(struct usb_function *f) { … } static int ffs_func_setup(struct usb_function *f, const struct usb_ctrlrequest *creq) { … } static bool ffs_func_req_match(struct usb_function *f, const struct usb_ctrlrequest *creq, bool config0) { … } static void ffs_func_suspend(struct usb_function *f) { … } static void ffs_func_resume(struct usb_function *f) { … } /* Endpoint and interface numbers reverse mapping ***************************/ static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) { … } static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) { … } /* Devices management *******************************************************/ static LIST_HEAD(ffs_devices); static struct ffs_dev *_ffs_do_find_dev(const char *name) { … } /* * ffs_lock must be taken by the caller of this function */ static struct ffs_dev *_ffs_get_single_dev(void) { … } /* * ffs_lock must be taken by the caller of this function */ static struct ffs_dev *_ffs_find_dev(const char *name) { … } /* Configfs support *********************************************************/ static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) { … } static ssize_t f_fs_opts_ready_show(struct config_item *item, char *page) { … } CONFIGFS_ATTR_RO(…); static struct configfs_attribute *ffs_attrs[] = …; static void ffs_attr_release(struct config_item *item) { … } static struct configfs_item_operations ffs_item_ops = …; static const struct config_item_type ffs_func_type = …; /* Function registration interface ******************************************/ static void ffs_free_inst(struct usb_function_instance *f) { … } static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) { … } static struct usb_function_instance *ffs_alloc_inst(void) { … } static void ffs_free(struct usb_function *f) { … } static void ffs_func_unbind(struct usb_configuration *c, struct usb_function *f) { … } static struct usb_function *ffs_alloc(struct usb_function_instance *fi) { … } /* * ffs_lock must be taken by the caller of this function */ static struct ffs_dev *_ffs_alloc_dev(void) { … } int ffs_name_dev(struct ffs_dev *dev, const char *name) { … } EXPORT_SYMBOL_GPL(…); int ffs_single_dev(struct ffs_dev *dev) { … } EXPORT_SYMBOL_GPL(…); /* * ffs_lock must be taken by the caller of this function */ 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) { … } static char *ffs_prepare_buffer(const char __user *buf, size_t len) { … } DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …;
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