/* * f_fs.c -- user mode file system API for USB composite function controllers * * Copyright (C) 2010 Samsung Electronics * Author: Michal Nazarewicz <mina86@mina86.com> * * Based on inode.c (GadgetFS) which was: * Copyright (C) 2003-2004 David Brownell * Copyright (C) 2003 Agilent Technologies * * 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. */ /* #define DEBUG */ /* #define VERBOSE_DEBUG */ #include <linux/blkdev.h> #include <linux/pagemap.h> #include <linux/export.h> #include <asm/unaligned.h> #include <linux/usb/composite.h> #include <linux/usb/functionfs.h> #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ /* Debugging ****************************************************************/ #ifdef VERBOSE_DEBUG # define pr_vdebug pr_debug # define ffs_dump_mem(prefix, ptr, len) \ print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len) #else # define pr_vdebug(...) do { } while (0) # 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 * 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 epfiles 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 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; 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 ownership of data. */ static int __must_check __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); static int __must_check __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); /* The function structure ***************************************************/ struct ffs_ep; struct ffs_function { struct usb_configuration *conf; struct usb_gadget *gadget; struct ffs_data *ffs; struct ffs_ep *eps; u8 eps_revmap[16]; short *interfaces_nums; struct usb_function function; }; static struct ffs_function *ffs_func_from_usb(struct usb_function *f) { return container_of(f, struct ffs_function, function); } static 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; /* * UDC layer requires to provide a buffer even for ZLP, but should * not use it at all. Let's provide some poisoned pointer to catch * possible bug in the driver. */ if (req->buf == NULL) req->buf = (void *)0xDEADBABE; 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) { pr_vdebug("ep0 stall\n"); usb_ep_set_halt(ffs->gadget->ep0); ffs->setup_state = FFS_NO_SETUP; return -EL2HLT; } else { pr_debug("bogus ep0 stall!\n"); return -ESRCH; } } static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, size_t len, loff_t *ptr) { struct ffs_data *ffs = file->private_data; ssize_t ret; char *data; ENTER(); /* Fast check if setup was canceled */ if (FFS_SETUP_STATE(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 (IS_ERR(data)) { ret = PTR_ERR(data); break; } /* Handle data */ if (ffs->state == FFS_READ_DESCRIPTORS) { pr_info("read descriptors\n"); ret = __ffs_data_got_descs(ffs, data, len); if (unlikely(ret < 0)) break; ffs->state = FFS_READ_STRINGS; ret = len; } else { pr_info("read strings\n"); ret = __ffs_data_got_strings(ffs, data, len); if (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 (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 (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) { ret = gadget->ops->ioctl(gadget, code, value); } 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 (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 file system creates a controller file, used first for * function configuration then later for event monitoring. */ static struct inode *__must_check ffs_sb_make_inode(struct super_block *sb, void *data, const struct file_operations *fops, const struct inode_operations *iops, struct ffs_file_perms *perms) { struct inode *inode; ENTER(); inode = new_inode(sb); if (likely(inode)) { struct timespec current_time = CURRENT_TIME; inode->i_ino = get_next_ino(); 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 ffs_data *ffs; ENTER(); /* Initialise data */ ffs = ffs_data_new(); if (unlikely(!ffs)) goto Enomem; 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); sb->s_root = d_make_root(inode); if (unlikely(!sb->s_root)) goto Enomem; /* EP0 file */ if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations, NULL))) goto Enomem; return 0; Enomem: 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)) { pr_err("'=' missing in %s\n", opts); return -EINVAL; } *eq = 0; /* Parse value */ value = simple_strtoul(eq + 1, &end, 0); if (unlikely(*end != ',' && *end != 0)) { pr_err("%s: invalid value: %s\n", 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: pr_err("%s: invalid option\n", opts); return -EINVAL; } /* Next iteration */ if (!comma) break; opts = comma + 1; } return 0; } /* "mount -t functionfs dev_name /dev/function" ends up here */ static struct dentry * ffs_fs_mount(struct file_system_type *t, int flags, const char *dev_name, void *opts) { 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 ERR_PTR(ret); ret = ffs_fs_parse_opts(&data, opts); if (unlikely(ret < 0)) return ERR_PTR(ret); data.dev_name = dev_name; return mount_single(t, flags, &data, ffs_sb_fill); } static void ffs_fs_kill_sb(struct super_block *sb) { ENTER(); kill_litter_super(sb); if (sb->s_fs_info) ffs_data_put(sb->s_fs_info); } static struct file_system_type ffs_fs_type = { .owner = THIS_MODULE, .name = "functionfs", .mount = ffs_fs_mount, .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)) pr_info("file system registered\n"); else pr_err("failed registering file system (%d)\n", ret); return ret; } static void functionfs_cleanup(void) { ENTER(); pr_info("unloading\n"); unregister_filesystem(&ffs_fs_type); } /* ffs_data and ffs_function construction and destruction code **************/ static void ffs_data_clear(struct ffs_data *ffs); static void ffs_data_reset(struct ffs_data *ffs); static void ffs_data_get(struct ffs_data *ffs) { ENTER(); 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))) { pr_info("%s(): freeing\n", __func__); ffs_data_clear(ffs); BUG_ON(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) { struct usb_gadget_strings **lang; int first_id; ENTER(); if (WARN_ON(ffs->state != FFS_ACTIVE || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) return -EBADFD; first_id = usb_string_ids_n(cdev, ffs->strings_count); if (unlikely(first_id < 0)) return first_id; 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; lang = ffs->stringtabs; for (lang = ffs->stringtabs; *lang; ++lang) { struct usb_string *str = (*lang)->strings; int id = first_id; for (; str->s; ++id, ++str) str->id = id; } ffs->gadget = cdev->gadget; ffs_data_get(ffs); return 0; } static void functionfs_unbind(struct ffs_data *ffs) { ENTER(); if (!WARN_ON(!ffs->gadget)) { usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); ffs->ep0req = NULL; ffs->gadget = NULL; ffs_data_put(ffs); } } static int ffs_epfiles_create(struct ffs_data *ffs) { struct ffs_epfile *epfile, *epfiles; unsigned i, count; ENTER(); count = ffs->eps_count; epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); if (!epfiles) return -ENOMEM; epfile = epfiles; for (i = 1; i <= count; ++i, ++epfile) { epfile->ffs = ffs; mutex_init(&epfile->mutex); 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_bind_config(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.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; ep->ep->desc = ds; ret = usb_ep_enable(ep->ep); 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 after 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) { pr_vdebug("descriptor too short\n"); return -EINVAL; } /* If we have at least as many bytes as the descriptor takes? */ length = _ds->bLength; if (len < length) { pr_vdebug("descriptor longer then available data\n"); return -EINVAL; } #define __entity_check_INTERFACE(val) 1 #define __entity_check_STRING(val) (val) #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) #define __entity(type, val) do { \ pr_vdebug("entity " #type "(%02x)\n", (val)); \ if (unlikely(!__entity_check_ ##type(val))) { \ pr_vdebug("invalid entity's value\n"); \ return -EINVAL; \ } \ ret = entity(FFS_ ##type, &val, _ds, priv); \ if (unlikely(ret < 0)) { \ pr_debug("entity " #type "(%02x); ret = %d\n", \ (val), ret); \ return ret; \ } \ } while (0) /* Parse descriptor depending on type. */ switch (_ds->bDescriptorType) { case USB_DT_DEVICE: case USB_DT_CONFIG: case USB_DT_STRING: case USB_DT_DEVICE_QUALIFIER: /* function can't have any of those */ pr_vdebug("descriptor reserved for gadget: %d\n", _ds->bDescriptorType); return -EINVAL; case USB_DT_INTERFACE: { struct usb_interface_descriptor *ds = (void *)_ds; pr_vdebug("interface descriptor\n"); if (length != sizeof *ds) goto inv_length; __entity(INTERFACE, ds->bInterfaceNumber); if (ds->iInterface) __entity(STRING, ds->iInterface); } break; case USB_DT_ENDPOINT: { struct usb_endpoint_descriptor *ds = (void *)_ds; pr_vdebug("endpoint descriptor\n"); if (length != USB_DT_ENDPOINT_SIZE && length != USB_DT_ENDPOINT_AUDIO_SIZE) goto inv_length; __entity(ENDPOINT, ds->bEndpointAddress); } break; case USB_DT_OTG: if (length != sizeof(struct usb_otg_descriptor)) goto inv_length; break; case USB_DT_INTERFACE_ASSOCIATION: { struct usb_interface_assoc_descriptor *ds = (void *)_ds; pr_vdebug("interface association descriptor\n"); if (length != sizeof *ds) goto inv_length; if (ds->iFunction) __entity(STRING, ds->iFunction); } break; case USB_DT_OTHER_SPEED_CONFIG: case USB_DT_INTERFACE_POWER: case USB_DT_DEBUG: case USB_DT_SECURITY: case USB_DT_CS_RADIO_CONTROL: /* TODO */ pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); return -EINVAL; default: /* We should never be here */ pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); return -EINVAL; inv_length: pr_vdebug("invalid length: %d (descriptor %d)\n", _ds->bLength, _ds->bDescriptorType); return -EINVAL; } #undef __entity #undef __entity_check_DESCRIPTOR #undef __entity_check_INTERFACE #undef __entity_check_STRING #undef __entity_check_ENDPOINT return length; } static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, ffs_entity_callback entity, void *priv) { const unsigned _len = len; unsigned long num = 0; ENTER(); for (;;) { int ret; if (num == count) data = NULL; /* Record "descriptor" entity */ ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); if (unlikely(ret < 0)) { pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", num, ret); return ret; } if (!data) return _len - len; ret = ffs_do_desc(data, len, entity, priv); if (unlikely(ret < 0)) { pr_debug("%s returns %d\n", __func__, ret); return ret; } len -= ret; data += ret; ++num; } } static int __ffs_data_do_entity(enum ffs_entity_type type, u8 *valuep, struct usb_descriptor_header *desc, void *priv) { struct ffs_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 everything in one chunk so there's less maintenance. */ { 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 ignore 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 THROUGH */ 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 pr_vdebug("purging event %d\n", *ev); ffs->ev.count = out - ffs->ev.types; } pr_vdebug("adding event %d\n", type); ffs->ev.types[ffs->ev.count++] = type; wake_up_locked(&ffs->ev.waitq); } 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])) { pr_vdebug("two %sspeed descriptors for EP %d\n", 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; pr_vdebug("autoconfig\n"); 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; } pr_vdebug("%02x -> %02x\n", *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 through all the endpoint descriptors and allocate * endpoints first, so that later we can rewrite the endpoint * numbers without worrying that it may be described later on. */ if (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 * endpoint numbers rewriting. We can do that in one go * now. */ ret = ffs_do_descs(ffs->fs_descs_count + (high ? ffs->hs_descs_count : 0), 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(); pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); /* * Most requests directed to interface go through here * (notable exceptions are set/get interface) so we need to * handle them. All other either handled by composite or * passed to usb_configuration->setup() (if one is set). No * matter, we will handle requests directed to endpoint here * as well (as it's straightforward) 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); } /* Endpoint and interface numbers reverse mapping ***************************/ static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) { num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; return num ? num : -EDOM; } static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) { short *nums = func->interfaces_nums; unsigned count = func->ffs->interfaces_count; for (; count; --count, ++nums) { if (*nums >= 0 && *nums == intf) return nums - func->interfaces_nums; } return -EDOM; } /* 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); } pr_vdebug("Buffer from user space:\n"); ffs_dump_mem("", data, len); return data; }