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1da177e4 LT |
1 | #ifndef _LINUX_MODULE_PARAMS_H |
2 | #define _LINUX_MODULE_PARAMS_H | |
3 | /* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */ | |
4 | #include <linux/init.h> | |
5 | #include <linux/stringify.h> | |
6 | #include <linux/kernel.h> | |
7 | ||
8 | /* You can override this manually, but generally this should match the | |
9 | module name. */ | |
10 | #ifdef MODULE | |
11 | #define MODULE_PARAM_PREFIX /* empty */ | |
12 | #else | |
367cb704 | 13 | #define MODULE_PARAM_PREFIX KBUILD_MODNAME "." |
1da177e4 LT |
14 | #endif |
15 | ||
730b69d2 RR |
16 | /* Chosen so that structs with an unsigned long line up. */ |
17 | #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long)) | |
18 | ||
1da177e4 LT |
19 | #define ___module_cat(a,b) __mod_ ## a ## b |
20 | #define __module_cat(a,b) ___module_cat(a,b) | |
b75be420 | 21 | #ifdef MODULE |
1da177e4 LT |
22 | #define __MODULE_INFO(tag, name, info) \ |
23 | static const char __module_cat(name,__LINE__)[] \ | |
b6472776 JB |
24 | __used __attribute__((section(".modinfo"), unused, aligned(1))) \ |
25 | = __stringify(tag) "=" info | |
1da177e4 | 26 | #else /* !MODULE */ |
b75be420 LW |
27 | /* This struct is here for syntactic coherency, it is not used */ |
28 | #define __MODULE_INFO(tag, name, info) \ | |
29 | struct __module_cat(name,__LINE__) {} | |
1da177e4 LT |
30 | #endif |
31 | #define __MODULE_PARM_TYPE(name, _type) \ | |
32 | __MODULE_INFO(parmtype, name##type, #name ":" _type) | |
33 | ||
639938eb PG |
34 | /* One for each parameter, describing how to use it. Some files do |
35 | multiple of these per line, so can't just use MODULE_INFO. */ | |
36 | #define MODULE_PARM_DESC(_parm, desc) \ | |
37 | __MODULE_INFO(parm, _parm, #_parm ":" desc) | |
38 | ||
1da177e4 LT |
39 | struct kernel_param; |
40 | ||
9bbb9e5a RR |
41 | struct kernel_param_ops { |
42 | /* Returns 0, or -errno. arg is in kp->arg. */ | |
43 | int (*set)(const char *val, const struct kernel_param *kp); | |
44 | /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ | |
45 | int (*get)(char *buffer, const struct kernel_param *kp); | |
e6df34a4 RR |
46 | /* Optional function to free kp->arg when module unloaded. */ |
47 | void (*free)(void *arg); | |
9bbb9e5a | 48 | }; |
1da177e4 LT |
49 | |
50 | struct kernel_param { | |
51 | const char *name; | |
9bbb9e5a | 52 | const struct kernel_param_ops *ops; |
45fcc70c | 53 | u16 perm; |
026cee00 | 54 | s16 level; |
22e48eaf JB |
55 | union { |
56 | void *arg; | |
57 | const struct kparam_string *str; | |
58 | const struct kparam_array *arr; | |
59 | }; | |
1da177e4 LT |
60 | }; |
61 | ||
62 | /* Special one for strings we want to copy into */ | |
63 | struct kparam_string { | |
64 | unsigned int maxlen; | |
65 | char *string; | |
66 | }; | |
67 | ||
68 | /* Special one for arrays */ | |
69 | struct kparam_array | |
70 | { | |
71 | unsigned int max; | |
c5be0b2e | 72 | unsigned int elemsize; |
1da177e4 | 73 | unsigned int *num; |
9bbb9e5a | 74 | const struct kernel_param_ops *ops; |
1da177e4 LT |
75 | void *elem; |
76 | }; | |
77 | ||
546970bc RR |
78 | /** |
79 | * module_param - typesafe helper for a module/cmdline parameter | |
80 | * @value: the variable to alter, and exposed parameter name. | |
81 | * @type: the type of the parameter | |
82 | * @perm: visibility in sysfs. | |
83 | * | |
84 | * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a | |
85 | * ".") the kernel commandline parameter. Note that - is changed to _, so | |
86 | * the user can use "foo-bar=1" even for variable "foo_bar". | |
87 | * | |
88 | * @perm is 0 if the the variable is not to appear in sysfs, or 0444 | |
89 | * for world-readable, 0644 for root-writable, etc. Note that if it | |
90 | * is writable, you may need to use kparam_block_sysfs_write() around | |
91 | * accesses (esp. charp, which can be kfreed when it changes). | |
92 | * | |
93 | * The @type is simply pasted to refer to a param_ops_##type and a | |
94 | * param_check_##type: for convenience many standard types are provided but | |
95 | * you can create your own by defining those variables. | |
96 | * | |
97 | * Standard types are: | |
98 | * byte, short, ushort, int, uint, long, ulong | |
99 | * charp: a character pointer | |
100 | * bool: a bool, values 0/1, y/n, Y/N. | |
101 | * invbool: the above, only sense-reversed (N = true). | |
102 | */ | |
103 | #define module_param(name, type, perm) \ | |
104 | module_param_named(name, name, type, perm) | |
105 | ||
106 | /** | |
107 | * module_param_named - typesafe helper for a renamed module/cmdline parameter | |
108 | * @name: a valid C identifier which is the parameter name. | |
109 | * @value: the actual lvalue to alter. | |
110 | * @type: the type of the parameter | |
111 | * @perm: visibility in sysfs. | |
112 | * | |
113 | * Usually it's a good idea to have variable names and user-exposed names the | |
114 | * same, but that's harder if the variable must be non-static or is inside a | |
115 | * structure. This allows exposure under a different name. | |
116 | */ | |
117 | #define module_param_named(name, value, type, perm) \ | |
118 | param_check_##type(name, &(value)); \ | |
119 | module_param_cb(name, ¶m_ops_##type, &value, perm); \ | |
120 | __MODULE_PARM_TYPE(name, #type) | |
121 | ||
122 | /** | |
123 | * module_param_cb - general callback for a module/cmdline parameter | |
124 | * @name: a valid C identifier which is the parameter name. | |
125 | * @ops: the set & get operations for this parameter. | |
126 | * @perm: visibility in sysfs. | |
127 | * | |
128 | * The ops can have NULL set or get functions. | |
129 | */ | |
130 | #define module_param_cb(name, ops, arg, perm) \ | |
ae82fdb1 | 131 | __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1) |
026cee00 PM |
132 | |
133 | /** | |
134 | * <level>_param_cb - general callback for a module/cmdline parameter | |
135 | * to be evaluated before certain initcall level | |
136 | * @name: a valid C identifier which is the parameter name. | |
137 | * @ops: the set & get operations for this parameter. | |
138 | * @perm: visibility in sysfs. | |
139 | * | |
140 | * The ops can have NULL set or get functions. | |
141 | */ | |
142 | #define __level_param_cb(name, ops, arg, perm, level) \ | |
143 | __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level) | |
144 | ||
145 | #define core_param_cb(name, ops, arg, perm) \ | |
146 | __level_param_cb(name, ops, arg, perm, 1) | |
147 | ||
148 | #define postcore_param_cb(name, ops, arg, perm) \ | |
149 | __level_param_cb(name, ops, arg, perm, 2) | |
150 | ||
151 | #define arch_param_cb(name, ops, arg, perm) \ | |
152 | __level_param_cb(name, ops, arg, perm, 3) | |
153 | ||
154 | #define subsys_param_cb(name, ops, arg, perm) \ | |
155 | __level_param_cb(name, ops, arg, perm, 4) | |
156 | ||
157 | #define fs_param_cb(name, ops, arg, perm) \ | |
158 | __level_param_cb(name, ops, arg, perm, 5) | |
159 | ||
160 | #define device_param_cb(name, ops, arg, perm) \ | |
161 | __level_param_cb(name, ops, arg, perm, 6) | |
162 | ||
163 | #define late_param_cb(name, ops, arg, perm) \ | |
164 | __level_param_cb(name, ops, arg, perm, 7) | |
546970bc | 165 | |
91d35dd9 IK |
166 | /* On alpha, ia64 and ppc64 relocations to global data cannot go into |
167 | read-only sections (which is part of respective UNIX ABI on these | |
168 | platforms). So 'const' makes no sense and even causes compile failures | |
169 | with some compilers. */ | |
170 | #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64) | |
171 | #define __moduleparam_const | |
172 | #else | |
173 | #define __moduleparam_const const | |
174 | #endif | |
175 | ||
1da177e4 | 176 | /* This is the fundamental function for registering boot/module |
546970bc | 177 | parameters. */ |
026cee00 | 178 | #define __module_param_call(prefix, name, ops, arg, perm, level) \ |
9774a1f5 AD |
179 | /* Default value instead of permissions? */ \ |
180 | static int __param_perm_check_##name __attribute__((unused)) = \ | |
730b69d2 RR |
181 | BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ |
182 | + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ | |
22e48eaf | 183 | static const char __param_str_##name[] = prefix #name; \ |
91d35dd9 | 184 | static struct kernel_param __moduleparam_const __param_##name \ |
3ff6eecc | 185 | __used \ |
1da177e4 | 186 | __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ |
026cee00 | 187 | = { __param_str_##name, ops, perm, level, { arg } } |
9bbb9e5a RR |
188 | |
189 | /* Obsolete - use module_param_cb() */ | |
190 | #define module_param_call(name, set, get, arg, perm) \ | |
191 | static struct kernel_param_ops __param_ops_##name = \ | |
192 | { (void *)set, (void *)get }; \ | |
193 | __module_param_call(MODULE_PARAM_PREFIX, \ | |
194 | name, &__param_ops_##name, arg, \ | |
ae82fdb1 | 195 | (perm) + sizeof(__check_old_set_param(set))*0, -1) |
9bbb9e5a RR |
196 | |
197 | /* We don't get oldget: it's often a new-style param_get_uint, etc. */ | |
198 | static inline int | |
199 | __check_old_set_param(int (*oldset)(const char *, struct kernel_param *)) | |
200 | { | |
201 | return 0; | |
202 | } | |
1da177e4 | 203 | |
907b29eb RR |
204 | /** |
205 | * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs. | |
206 | * @name: the name of the parameter | |
207 | * | |
208 | * There's no point blocking write on a paramter that isn't writable via sysfs! | |
209 | */ | |
210 | #define kparam_block_sysfs_write(name) \ | |
211 | do { \ | |
212 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
213 | __kernel_param_lock(); \ | |
214 | } while (0) | |
215 | ||
216 | /** | |
217 | * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again. | |
218 | * @name: the name of the parameter | |
219 | */ | |
220 | #define kparam_unblock_sysfs_write(name) \ | |
221 | do { \ | |
222 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
223 | __kernel_param_unlock(); \ | |
224 | } while (0) | |
225 | ||
226 | /** | |
227 | * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs. | |
228 | * @name: the name of the parameter | |
229 | * | |
230 | * This also blocks sysfs writes. | |
231 | */ | |
232 | #define kparam_block_sysfs_read(name) \ | |
233 | do { \ | |
234 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
235 | __kernel_param_lock(); \ | |
236 | } while (0) | |
237 | ||
238 | /** | |
239 | * kparam_unblock_sysfs_read - allows sysfs to read a parameter again. | |
240 | * @name: the name of the parameter | |
241 | */ | |
242 | #define kparam_unblock_sysfs_read(name) \ | |
243 | do { \ | |
244 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
245 | __kernel_param_unlock(); \ | |
246 | } while (0) | |
247 | ||
248 | #ifdef CONFIG_SYSFS | |
249 | extern void __kernel_param_lock(void); | |
250 | extern void __kernel_param_unlock(void); | |
251 | #else | |
252 | static inline void __kernel_param_lock(void) | |
253 | { | |
254 | } | |
255 | static inline void __kernel_param_unlock(void) | |
256 | { | |
257 | } | |
258 | #endif | |
259 | ||
67e67cea RR |
260 | #ifndef MODULE |
261 | /** | |
262 | * core_param - define a historical core kernel parameter. | |
263 | * @name: the name of the cmdline and sysfs parameter (often the same as var) | |
264 | * @var: the variable | |
546970bc | 265 | * @type: the type of the parameter |
67e67cea RR |
266 | * @perm: visibility in sysfs |
267 | * | |
268 | * core_param is just like module_param(), but cannot be modular and | |
269 | * doesn't add a prefix (such as "printk."). This is for compatibility | |
270 | * with __setup(), and it makes sense as truly core parameters aren't | |
271 | * tied to the particular file they're in. | |
272 | */ | |
273 | #define core_param(name, var, type, perm) \ | |
274 | param_check_##type(name, &(var)); \ | |
ae82fdb1 | 275 | __module_param_call("", name, ¶m_ops_##type, &var, perm, -1) |
67e67cea RR |
276 | #endif /* !MODULE */ |
277 | ||
546970bc RR |
278 | /** |
279 | * module_param_string - a char array parameter | |
280 | * @name: the name of the parameter | |
281 | * @string: the string variable | |
282 | * @len: the maximum length of the string, incl. terminator | |
283 | * @perm: visibility in sysfs. | |
284 | * | |
285 | * This actually copies the string when it's set (unlike type charp). | |
286 | * @len is usually just sizeof(string). | |
287 | */ | |
1da177e4 | 288 | #define module_param_string(name, string, len, perm) \ |
22e48eaf | 289 | static const struct kparam_string __param_string_##name \ |
1da177e4 | 290 | = { len, string }; \ |
fddd5201 | 291 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 292 | ¶m_ops_string, \ |
ae82fdb1 | 293 | .str = &__param_string_##name, perm, -1); \ |
1da177e4 LT |
294 | __MODULE_PARM_TYPE(name, "string") |
295 | ||
b1e4d20c MS |
296 | /** |
297 | * parameq - checks if two parameter names match | |
298 | * @name1: parameter name 1 | |
299 | * @name2: parameter name 2 | |
300 | * | |
301 | * Returns true if the two parameter names are equal. | |
302 | * Dashes (-) are considered equal to underscores (_). | |
303 | */ | |
304 | extern bool parameq(const char *name1, const char *name2); | |
305 | ||
306 | /** | |
307 | * parameqn - checks if two parameter names match | |
308 | * @name1: parameter name 1 | |
309 | * @name2: parameter name 2 | |
310 | * @n: the length to compare | |
311 | * | |
312 | * Similar to parameq(), except it compares @n characters. | |
313 | */ | |
314 | extern bool parameqn(const char *name1, const char *name2, size_t n); | |
315 | ||
1da177e4 LT |
316 | /* Called on module insert or kernel boot */ |
317 | extern int parse_args(const char *name, | |
318 | char *args, | |
914dcaa8 | 319 | const struct kernel_param *params, |
1da177e4 | 320 | unsigned num, |
026cee00 PM |
321 | s16 level_min, |
322 | s16 level_max, | |
9fb48c74 JC |
323 | int (*unknown)(char *param, char *val, |
324 | const char *doing)); | |
1da177e4 | 325 | |
e180a6b7 RR |
326 | /* Called by module remove. */ |
327 | #ifdef CONFIG_SYSFS | |
328 | extern void destroy_params(const struct kernel_param *params, unsigned num); | |
329 | #else | |
330 | static inline void destroy_params(const struct kernel_param *params, | |
331 | unsigned num) | |
332 | { | |
333 | } | |
334 | #endif /* !CONFIG_SYSFS */ | |
335 | ||
1da177e4 LT |
336 | /* All the helper functions */ |
337 | /* The macros to do compile-time type checking stolen from Jakub | |
338 | Jelinek, who IIRC came up with this idea for the 2.4 module init code. */ | |
339 | #define __param_check(name, p, type) \ | |
340 | static inline type *__check_##name(void) { return(p); } | |
341 | ||
9bbb9e5a RR |
342 | extern struct kernel_param_ops param_ops_byte; |
343 | extern int param_set_byte(const char *val, const struct kernel_param *kp); | |
344 | extern int param_get_byte(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
345 | #define param_check_byte(name, p) __param_check(name, p, unsigned char) |
346 | ||
9bbb9e5a RR |
347 | extern struct kernel_param_ops param_ops_short; |
348 | extern int param_set_short(const char *val, const struct kernel_param *kp); | |
349 | extern int param_get_short(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
350 | #define param_check_short(name, p) __param_check(name, p, short) |
351 | ||
9bbb9e5a RR |
352 | extern struct kernel_param_ops param_ops_ushort; |
353 | extern int param_set_ushort(const char *val, const struct kernel_param *kp); | |
354 | extern int param_get_ushort(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
355 | #define param_check_ushort(name, p) __param_check(name, p, unsigned short) |
356 | ||
9bbb9e5a RR |
357 | extern struct kernel_param_ops param_ops_int; |
358 | extern int param_set_int(const char *val, const struct kernel_param *kp); | |
359 | extern int param_get_int(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
360 | #define param_check_int(name, p) __param_check(name, p, int) |
361 | ||
9bbb9e5a RR |
362 | extern struct kernel_param_ops param_ops_uint; |
363 | extern int param_set_uint(const char *val, const struct kernel_param *kp); | |
364 | extern int param_get_uint(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
365 | #define param_check_uint(name, p) __param_check(name, p, unsigned int) |
366 | ||
9bbb9e5a RR |
367 | extern struct kernel_param_ops param_ops_long; |
368 | extern int param_set_long(const char *val, const struct kernel_param *kp); | |
369 | extern int param_get_long(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
370 | #define param_check_long(name, p) __param_check(name, p, long) |
371 | ||
9bbb9e5a RR |
372 | extern struct kernel_param_ops param_ops_ulong; |
373 | extern int param_set_ulong(const char *val, const struct kernel_param *kp); | |
374 | extern int param_get_ulong(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
375 | #define param_check_ulong(name, p) __param_check(name, p, unsigned long) |
376 | ||
9bbb9e5a RR |
377 | extern struct kernel_param_ops param_ops_charp; |
378 | extern int param_set_charp(const char *val, const struct kernel_param *kp); | |
379 | extern int param_get_charp(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
380 | #define param_check_charp(name, p) __param_check(name, p, char *) |
381 | ||
72db395f | 382 | /* We used to allow int as well as bool. We're taking that away! */ |
9bbb9e5a RR |
383 | extern struct kernel_param_ops param_ops_bool; |
384 | extern int param_set_bool(const char *val, const struct kernel_param *kp); | |
385 | extern int param_get_bool(char *buffer, const struct kernel_param *kp); | |
72db395f | 386 | #define param_check_bool(name, p) __param_check(name, p, bool) |
1da177e4 | 387 | |
9bbb9e5a RR |
388 | extern struct kernel_param_ops param_ops_invbool; |
389 | extern int param_set_invbool(const char *val, const struct kernel_param *kp); | |
390 | extern int param_get_invbool(char *buffer, const struct kernel_param *kp); | |
9a71af2c | 391 | #define param_check_invbool(name, p) __param_check(name, p, bool) |
1da177e4 | 392 | |
69116f27 RR |
393 | /* An int, which can only be set like a bool (though it shows as an int). */ |
394 | extern struct kernel_param_ops param_ops_bint; | |
395 | extern int param_set_bint(const char *val, const struct kernel_param *kp); | |
396 | #define param_get_bint param_get_int | |
397 | #define param_check_bint param_check_int | |
398 | ||
546970bc RR |
399 | /** |
400 | * module_param_array - a parameter which is an array of some type | |
401 | * @name: the name of the array variable | |
402 | * @type: the type, as per module_param() | |
403 | * @nump: optional pointer filled in with the number written | |
404 | * @perm: visibility in sysfs | |
405 | * | |
406 | * Input and output are as comma-separated values. Commas inside values | |
407 | * don't work properly (eg. an array of charp). | |
408 | * | |
409 | * ARRAY_SIZE(@name) is used to determine the number of elements in the | |
410 | * array, so the definition must be visible. | |
411 | */ | |
412 | #define module_param_array(name, type, nump, perm) \ | |
413 | module_param_array_named(name, name, type, nump, perm) | |
414 | ||
415 | /** | |
416 | * module_param_array_named - renamed parameter which is an array of some type | |
417 | * @name: a valid C identifier which is the parameter name | |
418 | * @array: the name of the array variable | |
419 | * @type: the type, as per module_param() | |
420 | * @nump: optional pointer filled in with the number written | |
421 | * @perm: visibility in sysfs | |
422 | * | |
423 | * This exposes a different name than the actual variable name. See | |
424 | * module_param_named() for why this might be necessary. | |
425 | */ | |
1da177e4 | 426 | #define module_param_array_named(name, array, type, nump, perm) \ |
bafeafea | 427 | param_check_##type(name, &(array)[0]); \ |
22e48eaf | 428 | static const struct kparam_array __param_arr_##name \ |
c5be0b2e RK |
429 | = { .max = ARRAY_SIZE(array), .num = nump, \ |
430 | .ops = ¶m_ops_##type, \ | |
431 | .elemsize = sizeof(array[0]), .elem = array }; \ | |
fddd5201 | 432 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 433 | ¶m_array_ops, \ |
fddd5201 | 434 | .arr = &__param_arr_##name, \ |
ae82fdb1 | 435 | perm, -1); \ |
1da177e4 LT |
436 | __MODULE_PARM_TYPE(name, "array of " #type) |
437 | ||
9bbb9e5a | 438 | extern struct kernel_param_ops param_array_ops; |
1da177e4 | 439 | |
9bbb9e5a RR |
440 | extern struct kernel_param_ops param_ops_string; |
441 | extern int param_set_copystring(const char *val, const struct kernel_param *); | |
442 | extern int param_get_string(char *buffer, const struct kernel_param *kp); | |
1da177e4 | 443 | |
1da177e4 LT |
444 | /* for exporting parameters in /sys/parameters */ |
445 | ||
446 | struct module; | |
447 | ||
ef665c1a | 448 | #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) |
1da177e4 | 449 | extern int module_param_sysfs_setup(struct module *mod, |
9bbb9e5a | 450 | const struct kernel_param *kparam, |
1da177e4 LT |
451 | unsigned int num_params); |
452 | ||
453 | extern void module_param_sysfs_remove(struct module *mod); | |
ef665c1a RD |
454 | #else |
455 | static inline int module_param_sysfs_setup(struct module *mod, | |
9bbb9e5a | 456 | const struct kernel_param *kparam, |
ef665c1a RD |
457 | unsigned int num_params) |
458 | { | |
459 | return 0; | |
460 | } | |
461 | ||
462 | static inline void module_param_sysfs_remove(struct module *mod) | |
463 | { } | |
464 | #endif | |
1da177e4 LT |
465 | |
466 | #endif /* _LINUX_MODULE_PARAMS_H */ |