inet: frag: enforce memory limits earlier
[linux/fpc-iii.git] / drivers / usb / gadget / function / u_fs.h
blob60139854e0b1b320d66f15b5b1f0d954e72e634d
1 /*
2 * u_fs.h
4 * Utility definitions for the FunctionFS
6 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
7 * http://www.samsung.com
9 * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #ifndef U_FFS_H
17 #define U_FFS_H
19 #include <linux/usb/composite.h>
20 #include <linux/list.h>
21 #include <linux/mutex.h>
22 #include <linux/workqueue.h>
24 #ifdef VERBOSE_DEBUG
25 #ifndef pr_vdebug
26 # define pr_vdebug pr_debug
27 #endif /* pr_vdebug */
28 # define ffs_dump_mem(prefix, ptr, len) \
29 print_hex_dump_bytes(pr_fmt(prefix ": "), DUMP_PREFIX_NONE, ptr, len)
30 #else
31 #ifndef pr_vdebug
32 # define pr_vdebug(...) do { } while (0)
33 #endif /* pr_vdebug */
34 # define ffs_dump_mem(prefix, ptr, len) do { } while (0)
35 #endif /* VERBOSE_DEBUG */
37 #define ENTER() pr_vdebug("%s()\n", __func__)
39 struct f_fs_opts;
41 struct ffs_dev {
42 const char *name;
43 bool name_allocated;
44 bool mounted;
45 bool desc_ready;
46 bool single;
47 struct ffs_data *ffs_data;
48 struct f_fs_opts *opts;
49 struct list_head entry;
51 int (*ffs_ready_callback)(struct ffs_data *ffs);
52 void (*ffs_closed_callback)(struct ffs_data *ffs);
53 void *(*ffs_acquire_dev_callback)(struct ffs_dev *dev);
54 void (*ffs_release_dev_callback)(struct ffs_dev *dev);
57 extern struct mutex ffs_lock;
59 static inline void ffs_dev_lock(void)
61 mutex_lock(&ffs_lock);
64 static inline void ffs_dev_unlock(void)
66 mutex_unlock(&ffs_lock);
69 int ffs_name_dev(struct ffs_dev *dev, const char *name);
70 int ffs_single_dev(struct ffs_dev *dev);
72 struct ffs_epfile;
73 struct ffs_function;
75 enum ffs_state {
77 * Waiting for descriptors and strings.
79 * In this state no open(2), read(2) or write(2) on epfiles
80 * may succeed (which should not be the problem as there
81 * should be no such files opened in the first place).
83 FFS_READ_DESCRIPTORS,
84 FFS_READ_STRINGS,
87 * We've got descriptors and strings. We are or have called
88 * functionfs_ready_callback(). functionfs_bind() may have
89 * been called but we don't know.
91 * This is the only state in which operations on epfiles may
92 * succeed.
94 FFS_ACTIVE,
97 * Function is visible to host, but it's not functional. All
98 * setup requests are stalled and transfers on another endpoints
99 * are refused. All epfiles, except ep0, are deleted so there
100 * is no way to perform any operations on them.
102 * This state is set after closing all functionfs files, when
103 * mount parameter "no_disconnect=1" has been set. Function will
104 * remain in deactivated state until filesystem is umounted or
105 * ep0 is opened again. In the second case functionfs state will
106 * be reset, and it will be ready for descriptors and strings
107 * writing.
109 * This is useful only when functionfs is composed to gadget
110 * with another function which can perform some critical
111 * operations, and it's strongly desired to have this operations
112 * completed, even after functionfs files closure.
114 FFS_DEACTIVATED,
117 * All endpoints have been closed. This state is also set if
118 * we encounter an unrecoverable error. The only
119 * unrecoverable error is situation when after reading strings
120 * from user space we fail to initialise epfiles or
121 * functionfs_ready_callback() returns with error (<0).
123 * In this state no open(2), read(2) or write(2) (both on ep0
124 * as well as epfile) may succeed (at this point epfiles are
125 * unlinked and all closed so this is not a problem; ep0 is
126 * also closed but ep0 file exists and so open(2) on ep0 must
127 * fail).
129 FFS_CLOSING
132 enum ffs_setup_state {
133 /* There is no setup request pending. */
134 FFS_NO_SETUP,
136 * User has read events and there was a setup request event
137 * there. The next read/write on ep0 will handle the
138 * request.
140 FFS_SETUP_PENDING,
142 * There was event pending but before user space handled it
143 * some other event was introduced which canceled existing
144 * setup. If this state is set read/write on ep0 return
145 * -EIDRM. This state is only set when adding event.
147 FFS_SETUP_CANCELLED
150 struct ffs_data {
151 struct usb_gadget *gadget;
154 * Protect access read/write operations, only one read/write
155 * at a time. As a consequence protects ep0req and company.
156 * While setup request is being processed (queued) this is
157 * held.
159 struct mutex mutex;
162 * Protect access to endpoint related structures (basically
163 * usb_ep_queue(), usb_ep_dequeue(), etc. calls) except for
164 * endpoint zero.
166 spinlock_t eps_lock;
169 * XXX REVISIT do we need our own request? Since we are not
170 * handling setup requests immediately user space may be so
171 * slow that another setup will be sent to the gadget but this
172 * time not to us but another function and then there could be
173 * a race. Is that the case? Or maybe we can use cdev->req
174 * after all, maybe we just need some spinlock for that?
176 struct usb_request *ep0req; /* P: mutex */
177 struct completion ep0req_completion; /* P: mutex */
179 /* reference counter */
180 atomic_t ref;
181 /* how many files are opened (EP0 and others) */
182 atomic_t opened;
184 /* EP0 state */
185 enum ffs_state state;
188 * Possible transitions:
189 * + FFS_NO_SETUP -> FFS_SETUP_PENDING -- P: ev.waitq.lock
190 * happens only in ep0 read which is P: mutex
191 * + FFS_SETUP_PENDING -> FFS_NO_SETUP -- P: ev.waitq.lock
192 * happens only in ep0 i/o which is P: mutex
193 * + FFS_SETUP_PENDING -> FFS_SETUP_CANCELLED -- P: ev.waitq.lock
194 * + FFS_SETUP_CANCELLED -> FFS_NO_SETUP -- cmpxchg
196 * This field should never be accessed directly and instead
197 * ffs_setup_state_clear_cancelled function should be used.
199 enum ffs_setup_state setup_state;
201 /* Events & such. */
202 struct {
203 u8 types[4];
204 unsigned short count;
205 /* XXX REVISIT need to update it in some places, or do we? */
206 unsigned short can_stall;
207 struct usb_ctrlrequest setup;
209 wait_queue_head_t waitq;
210 } ev; /* the whole structure, P: ev.waitq.lock */
212 /* Flags */
213 unsigned long flags;
214 #define FFS_FL_CALL_CLOSED_CALLBACK 0
215 #define FFS_FL_BOUND 1
217 /* Active function */
218 struct ffs_function *func;
221 * Device name, write once when file system is mounted.
222 * Intended for user to read if she wants.
224 const char *dev_name;
225 /* Private data for our user (ie. gadget). Managed by user. */
226 void *private_data;
228 /* filled by __ffs_data_got_descs() */
230 * raw_descs is what you kfree, real_descs points inside of raw_descs,
231 * where full speed, high speed and super speed descriptors start.
232 * real_descs_length is the length of all those descriptors.
234 const void *raw_descs_data;
235 const void *raw_descs;
236 unsigned raw_descs_length;
237 unsigned fs_descs_count;
238 unsigned hs_descs_count;
239 unsigned ss_descs_count;
240 unsigned ms_os_descs_count;
241 unsigned ms_os_descs_ext_prop_count;
242 unsigned ms_os_descs_ext_prop_name_len;
243 unsigned ms_os_descs_ext_prop_data_len;
244 void *ms_os_descs_ext_prop_avail;
245 void *ms_os_descs_ext_prop_name_avail;
246 void *ms_os_descs_ext_prop_data_avail;
248 unsigned user_flags;
250 u8 eps_addrmap[15];
252 unsigned short strings_count;
253 unsigned short interfaces_count;
254 unsigned short eps_count;
255 unsigned short _pad1;
257 /* filled by __ffs_data_got_strings() */
258 /* ids in stringtabs are set in functionfs_bind() */
259 const void *raw_strings;
260 struct usb_gadget_strings **stringtabs;
263 * File system's super block, write once when file system is
264 * mounted.
266 struct super_block *sb;
268 /* File permissions, written once when fs is mounted */
269 struct ffs_file_perms {
270 umode_t mode;
271 kuid_t uid;
272 kgid_t gid;
273 } file_perms;
275 struct eventfd_ctx *ffs_eventfd;
276 bool no_disconnect;
277 struct work_struct reset_work;
280 * The endpoint files, filled by ffs_epfiles_create(),
281 * destroyed by ffs_epfiles_destroy().
283 struct ffs_epfile *epfiles;
287 struct f_fs_opts {
288 struct usb_function_instance func_inst;
289 struct ffs_dev *dev;
290 unsigned refcnt;
291 bool no_configfs;
294 static inline struct f_fs_opts *to_f_fs_opts(struct usb_function_instance *fi)
296 return container_of(fi, struct f_fs_opts, func_inst);
299 #endif /* U_FFS_H */