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1da177e4 LT |
1 | /* |
2 | * file.c - part of debugfs, a tiny little debug file system | |
3 | * | |
4 | * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> | |
5 | * Copyright (C) 2004 IBM Inc. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License version | |
9 | * 2 as published by the Free Software Foundation. | |
10 | * | |
11 | * debugfs is for people to use instead of /proc or /sys. | |
12 | * See Documentation/DocBook/kernel-api for more details. | |
13 | * | |
14 | */ | |
15 | ||
1da177e4 LT |
16 | #include <linux/module.h> |
17 | #include <linux/fs.h> | |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/debugfs.h> | |
20 | ||
21 | static ssize_t default_read_file(struct file *file, char __user *buf, | |
22 | size_t count, loff_t *ppos) | |
23 | { | |
24 | return 0; | |
25 | } | |
26 | ||
27 | static ssize_t default_write_file(struct file *file, const char __user *buf, | |
28 | size_t count, loff_t *ppos) | |
29 | { | |
30 | return count; | |
31 | } | |
32 | ||
33 | static int default_open(struct inode *inode, struct file *file) | |
34 | { | |
8e18e294 TT |
35 | if (inode->i_private) |
36 | file->private_data = inode->i_private; | |
1da177e4 LT |
37 | |
38 | return 0; | |
39 | } | |
40 | ||
4b6f5d20 | 41 | const struct file_operations debugfs_file_operations = { |
1da177e4 LT |
42 | .read = default_read_file, |
43 | .write = default_write_file, | |
44 | .open = default_open, | |
45 | }; | |
46 | ||
acaefc25 AB |
47 | static void debugfs_u8_set(void *data, u64 val) |
48 | { | |
49 | *(u8 *)data = val; | |
50 | } | |
51 | static u64 debugfs_u8_get(void *data) | |
52 | { | |
53 | return *(u8 *)data; | |
54 | } | |
55 | DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); | |
1da177e4 LT |
56 | |
57 | /** | |
6468b3af | 58 | * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value |
1da177e4 LT |
59 | * @name: a pointer to a string containing the name of the file to create. |
60 | * @mode: the permission that the file should have | |
61 | * @parent: a pointer to the parent dentry for this file. This should be a | |
6468b3af | 62 | * directory dentry if set. If this parameter is %NULL, then the |
1da177e4 LT |
63 | * file will be created in the root of the debugfs filesystem. |
64 | * @value: a pointer to the variable that the file should read to and write | |
65 | * from. | |
66 | * | |
67 | * This function creates a file in debugfs with the given name that | |
68 | * contains the value of the variable @value. If the @mode variable is so | |
69 | * set, it can be read from, and written to. | |
70 | * | |
71 | * This function will return a pointer to a dentry if it succeeds. This | |
72 | * pointer must be passed to the debugfs_remove() function when the file is | |
73 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 74 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 75 | * |
6468b3af | 76 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
1da177e4 | 77 | * returned. It is not wise to check for this value, but rather, check for |
6468b3af | 78 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
1da177e4 LT |
79 | * code. |
80 | */ | |
81 | struct dentry *debugfs_create_u8(const char *name, mode_t mode, | |
82 | struct dentry *parent, u8 *value) | |
83 | { | |
84 | return debugfs_create_file(name, mode, parent, value, &fops_u8); | |
85 | } | |
86 | EXPORT_SYMBOL_GPL(debugfs_create_u8); | |
87 | ||
acaefc25 AB |
88 | static void debugfs_u16_set(void *data, u64 val) |
89 | { | |
90 | *(u16 *)data = val; | |
91 | } | |
92 | static u64 debugfs_u16_get(void *data) | |
93 | { | |
94 | return *(u16 *)data; | |
95 | } | |
96 | DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); | |
97 | ||
1da177e4 | 98 | /** |
6468b3af | 99 | * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value |
1da177e4 LT |
100 | * @name: a pointer to a string containing the name of the file to create. |
101 | * @mode: the permission that the file should have | |
102 | * @parent: a pointer to the parent dentry for this file. This should be a | |
6468b3af | 103 | * directory dentry if set. If this parameter is %NULL, then the |
1da177e4 LT |
104 | * file will be created in the root of the debugfs filesystem. |
105 | * @value: a pointer to the variable that the file should read to and write | |
106 | * from. | |
107 | * | |
108 | * This function creates a file in debugfs with the given name that | |
109 | * contains the value of the variable @value. If the @mode variable is so | |
110 | * set, it can be read from, and written to. | |
111 | * | |
112 | * This function will return a pointer to a dentry if it succeeds. This | |
113 | * pointer must be passed to the debugfs_remove() function when the file is | |
114 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 115 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 116 | * |
6468b3af | 117 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
1da177e4 | 118 | * returned. It is not wise to check for this value, but rather, check for |
6468b3af | 119 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
1da177e4 LT |
120 | * code. |
121 | */ | |
122 | struct dentry *debugfs_create_u16(const char *name, mode_t mode, | |
123 | struct dentry *parent, u16 *value) | |
124 | { | |
125 | return debugfs_create_file(name, mode, parent, value, &fops_u16); | |
126 | } | |
127 | EXPORT_SYMBOL_GPL(debugfs_create_u16); | |
128 | ||
acaefc25 AB |
129 | static void debugfs_u32_set(void *data, u64 val) |
130 | { | |
131 | *(u32 *)data = val; | |
132 | } | |
133 | static u64 debugfs_u32_get(void *data) | |
134 | { | |
135 | return *(u32 *)data; | |
136 | } | |
137 | DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); | |
138 | ||
1da177e4 | 139 | /** |
6468b3af | 140 | * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value |
1da177e4 LT |
141 | * @name: a pointer to a string containing the name of the file to create. |
142 | * @mode: the permission that the file should have | |
143 | * @parent: a pointer to the parent dentry for this file. This should be a | |
6468b3af | 144 | * directory dentry if set. If this parameter is %NULL, then the |
1da177e4 LT |
145 | * file will be created in the root of the debugfs filesystem. |
146 | * @value: a pointer to the variable that the file should read to and write | |
147 | * from. | |
148 | * | |
149 | * This function creates a file in debugfs with the given name that | |
150 | * contains the value of the variable @value. If the @mode variable is so | |
151 | * set, it can be read from, and written to. | |
152 | * | |
153 | * This function will return a pointer to a dentry if it succeeds. This | |
154 | * pointer must be passed to the debugfs_remove() function when the file is | |
155 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 156 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 157 | * |
6468b3af | 158 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
1da177e4 | 159 | * returned. It is not wise to check for this value, but rather, check for |
6468b3af | 160 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
1da177e4 LT |
161 | * code. |
162 | */ | |
163 | struct dentry *debugfs_create_u32(const char *name, mode_t mode, | |
164 | struct dentry *parent, u32 *value) | |
165 | { | |
166 | return debugfs_create_file(name, mode, parent, value, &fops_u32); | |
167 | } | |
168 | EXPORT_SYMBOL_GPL(debugfs_create_u32); | |
169 | ||
170 | static ssize_t read_file_bool(struct file *file, char __user *user_buf, | |
171 | size_t count, loff_t *ppos) | |
172 | { | |
173 | char buf[3]; | |
174 | u32 *val = file->private_data; | |
175 | ||
176 | if (*val) | |
177 | buf[0] = 'Y'; | |
178 | else | |
179 | buf[0] = 'N'; | |
180 | buf[1] = '\n'; | |
181 | buf[2] = 0x00; | |
182 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); | |
183 | } | |
184 | ||
185 | static ssize_t write_file_bool(struct file *file, const char __user *user_buf, | |
186 | size_t count, loff_t *ppos) | |
187 | { | |
188 | char buf[32]; | |
189 | int buf_size; | |
190 | u32 *val = file->private_data; | |
191 | ||
192 | buf_size = min(count, (sizeof(buf)-1)); | |
193 | if (copy_from_user(buf, user_buf, buf_size)) | |
194 | return -EFAULT; | |
195 | ||
196 | switch (buf[0]) { | |
197 | case 'y': | |
198 | case 'Y': | |
199 | case '1': | |
200 | *val = 1; | |
201 | break; | |
202 | case 'n': | |
203 | case 'N': | |
204 | case '0': | |
205 | *val = 0; | |
206 | break; | |
207 | } | |
208 | ||
209 | return count; | |
210 | } | |
211 | ||
4b6f5d20 | 212 | static const struct file_operations fops_bool = { |
1da177e4 LT |
213 | .read = read_file_bool, |
214 | .write = write_file_bool, | |
215 | .open = default_open, | |
216 | }; | |
217 | ||
218 | /** | |
6468b3af | 219 | * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value |
1da177e4 LT |
220 | * @name: a pointer to a string containing the name of the file to create. |
221 | * @mode: the permission that the file should have | |
222 | * @parent: a pointer to the parent dentry for this file. This should be a | |
6468b3af | 223 | * directory dentry if set. If this parameter is %NULL, then the |
1da177e4 LT |
224 | * file will be created in the root of the debugfs filesystem. |
225 | * @value: a pointer to the variable that the file should read to and write | |
226 | * from. | |
227 | * | |
228 | * This function creates a file in debugfs with the given name that | |
229 | * contains the value of the variable @value. If the @mode variable is so | |
230 | * set, it can be read from, and written to. | |
231 | * | |
232 | * This function will return a pointer to a dentry if it succeeds. This | |
233 | * pointer must be passed to the debugfs_remove() function when the file is | |
234 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 235 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 236 | * |
6468b3af | 237 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
1da177e4 | 238 | * returned. It is not wise to check for this value, but rather, check for |
6468b3af | 239 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
1da177e4 LT |
240 | * code. |
241 | */ | |
242 | struct dentry *debugfs_create_bool(const char *name, mode_t mode, | |
243 | struct dentry *parent, u32 *value) | |
244 | { | |
245 | return debugfs_create_file(name, mode, parent, value, &fops_bool); | |
246 | } | |
247 | EXPORT_SYMBOL_GPL(debugfs_create_bool); | |
248 | ||
dd308bc3 ME |
249 | static ssize_t read_file_blob(struct file *file, char __user *user_buf, |
250 | size_t count, loff_t *ppos) | |
251 | { | |
252 | struct debugfs_blob_wrapper *blob = file->private_data; | |
253 | return simple_read_from_buffer(user_buf, count, ppos, blob->data, | |
254 | blob->size); | |
255 | } | |
256 | ||
00977a59 | 257 | static const struct file_operations fops_blob = { |
dd308bc3 ME |
258 | .read = read_file_blob, |
259 | .open = default_open, | |
260 | }; | |
261 | ||
262 | /** | |
6468b3af | 263 | * debugfs_create_blob - create a debugfs file that is used to read and write a binary blob |
dd308bc3 ME |
264 | * @name: a pointer to a string containing the name of the file to create. |
265 | * @mode: the permission that the file should have | |
266 | * @parent: a pointer to the parent dentry for this file. This should be a | |
6468b3af | 267 | * directory dentry if set. If this parameter is %NULL, then the |
dd308bc3 ME |
268 | * file will be created in the root of the debugfs filesystem. |
269 | * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer | |
270 | * to the blob data and the size of the data. | |
271 | * | |
272 | * This function creates a file in debugfs with the given name that exports | |
273 | * @blob->data as a binary blob. If the @mode variable is so set it can be | |
274 | * read from. Writing is not supported. | |
275 | * | |
276 | * This function will return a pointer to a dentry if it succeeds. This | |
277 | * pointer must be passed to the debugfs_remove() function when the file is | |
278 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 279 | * you are responsible here.) If an error occurs, %NULL will be returned. |
dd308bc3 | 280 | * |
6468b3af | 281 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
dd308bc3 | 282 | * returned. It is not wise to check for this value, but rather, check for |
6468b3af | 283 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
dd308bc3 ME |
284 | * code. |
285 | */ | |
286 | struct dentry *debugfs_create_blob(const char *name, mode_t mode, | |
287 | struct dentry *parent, | |
288 | struct debugfs_blob_wrapper *blob) | |
289 | { | |
290 | return debugfs_create_file(name, mode, parent, blob, &fops_blob); | |
291 | } | |
292 | EXPORT_SYMBOL_GPL(debugfs_create_blob); |