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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 | 49 | |
45fcc70c | 50 | /* Flag bits for kernel_param.flags */ |
fddd5201 | 51 | #define KPARAM_ISBOOL 2 |
45fcc70c | 52 | |
1da177e4 LT |
53 | struct kernel_param { |
54 | const char *name; | |
9bbb9e5a | 55 | const struct kernel_param_ops *ops; |
45fcc70c RR |
56 | u16 perm; |
57 | u16 flags; | |
22e48eaf JB |
58 | union { |
59 | void *arg; | |
60 | const struct kparam_string *str; | |
61 | const struct kparam_array *arr; | |
62 | }; | |
1da177e4 LT |
63 | }; |
64 | ||
65 | /* Special one for strings we want to copy into */ | |
66 | struct kparam_string { | |
67 | unsigned int maxlen; | |
68 | char *string; | |
69 | }; | |
70 | ||
71 | /* Special one for arrays */ | |
72 | struct kparam_array | |
73 | { | |
74 | unsigned int max; | |
c5be0b2e | 75 | unsigned int elemsize; |
1da177e4 | 76 | unsigned int *num; |
9bbb9e5a | 77 | const struct kernel_param_ops *ops; |
1da177e4 LT |
78 | void *elem; |
79 | }; | |
80 | ||
546970bc RR |
81 | /** |
82 | * module_param - typesafe helper for a module/cmdline parameter | |
83 | * @value: the variable to alter, and exposed parameter name. | |
84 | * @type: the type of the parameter | |
85 | * @perm: visibility in sysfs. | |
86 | * | |
87 | * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a | |
88 | * ".") the kernel commandline parameter. Note that - is changed to _, so | |
89 | * the user can use "foo-bar=1" even for variable "foo_bar". | |
90 | * | |
91 | * @perm is 0 if the the variable is not to appear in sysfs, or 0444 | |
92 | * for world-readable, 0644 for root-writable, etc. Note that if it | |
93 | * is writable, you may need to use kparam_block_sysfs_write() around | |
94 | * accesses (esp. charp, which can be kfreed when it changes). | |
95 | * | |
96 | * The @type is simply pasted to refer to a param_ops_##type and a | |
97 | * param_check_##type: for convenience many standard types are provided but | |
98 | * you can create your own by defining those variables. | |
99 | * | |
100 | * Standard types are: | |
101 | * byte, short, ushort, int, uint, long, ulong | |
102 | * charp: a character pointer | |
103 | * bool: a bool, values 0/1, y/n, Y/N. | |
104 | * invbool: the above, only sense-reversed (N = true). | |
105 | */ | |
106 | #define module_param(name, type, perm) \ | |
107 | module_param_named(name, name, type, perm) | |
108 | ||
109 | /** | |
110 | * module_param_named - typesafe helper for a renamed module/cmdline parameter | |
111 | * @name: a valid C identifier which is the parameter name. | |
112 | * @value: the actual lvalue to alter. | |
113 | * @type: the type of the parameter | |
114 | * @perm: visibility in sysfs. | |
115 | * | |
116 | * Usually it's a good idea to have variable names and user-exposed names the | |
117 | * same, but that's harder if the variable must be non-static or is inside a | |
118 | * structure. This allows exposure under a different name. | |
119 | */ | |
120 | #define module_param_named(name, value, type, perm) \ | |
121 | param_check_##type(name, &(value)); \ | |
122 | module_param_cb(name, ¶m_ops_##type, &value, perm); \ | |
123 | __MODULE_PARM_TYPE(name, #type) | |
124 | ||
125 | /** | |
126 | * module_param_cb - general callback for a module/cmdline parameter | |
127 | * @name: a valid C identifier which is the parameter name. | |
128 | * @ops: the set & get operations for this parameter. | |
129 | * @perm: visibility in sysfs. | |
130 | * | |
131 | * The ops can have NULL set or get functions. | |
132 | */ | |
133 | #define module_param_cb(name, ops, arg, perm) \ | |
134 | __module_param_call(MODULE_PARAM_PREFIX, \ | |
a6de51b2 | 135 | name, ops, arg, __same_type((arg), bool *), perm) |
546970bc | 136 | |
91d35dd9 IK |
137 | /* On alpha, ia64 and ppc64 relocations to global data cannot go into |
138 | read-only sections (which is part of respective UNIX ABI on these | |
139 | platforms). So 'const' makes no sense and even causes compile failures | |
140 | with some compilers. */ | |
141 | #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64) | |
142 | #define __moduleparam_const | |
143 | #else | |
144 | #define __moduleparam_const const | |
145 | #endif | |
146 | ||
1da177e4 | 147 | /* This is the fundamental function for registering boot/module |
546970bc | 148 | parameters. */ |
9bbb9e5a | 149 | #define __module_param_call(prefix, name, ops, arg, isbool, perm) \ |
9774a1f5 AD |
150 | /* Default value instead of permissions? */ \ |
151 | static int __param_perm_check_##name __attribute__((unused)) = \ | |
730b69d2 RR |
152 | BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ |
153 | + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ | |
22e48eaf | 154 | static const char __param_str_##name[] = prefix #name; \ |
91d35dd9 | 155 | static struct kernel_param __moduleparam_const __param_##name \ |
3ff6eecc | 156 | __used \ |
1da177e4 | 157 | __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ |
9bbb9e5a RR |
158 | = { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0, \ |
159 | { arg } } | |
160 | ||
161 | /* Obsolete - use module_param_cb() */ | |
162 | #define module_param_call(name, set, get, arg, perm) \ | |
163 | static struct kernel_param_ops __param_ops_##name = \ | |
164 | { (void *)set, (void *)get }; \ | |
165 | __module_param_call(MODULE_PARAM_PREFIX, \ | |
166 | name, &__param_ops_##name, arg, \ | |
a6de51b2 | 167 | __same_type(arg, bool *), \ |
9bbb9e5a RR |
168 | (perm) + sizeof(__check_old_set_param(set))*0) |
169 | ||
170 | /* We don't get oldget: it's often a new-style param_get_uint, etc. */ | |
171 | static inline int | |
172 | __check_old_set_param(int (*oldset)(const char *, struct kernel_param *)) | |
173 | { | |
174 | return 0; | |
175 | } | |
1da177e4 | 176 | |
907b29eb RR |
177 | /** |
178 | * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs. | |
179 | * @name: the name of the parameter | |
180 | * | |
181 | * There's no point blocking write on a paramter that isn't writable via sysfs! | |
182 | */ | |
183 | #define kparam_block_sysfs_write(name) \ | |
184 | do { \ | |
185 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
186 | __kernel_param_lock(); \ | |
187 | } while (0) | |
188 | ||
189 | /** | |
190 | * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again. | |
191 | * @name: the name of the parameter | |
192 | */ | |
193 | #define kparam_unblock_sysfs_write(name) \ | |
194 | do { \ | |
195 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
196 | __kernel_param_unlock(); \ | |
197 | } while (0) | |
198 | ||
199 | /** | |
200 | * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs. | |
201 | * @name: the name of the parameter | |
202 | * | |
203 | * This also blocks sysfs writes. | |
204 | */ | |
205 | #define kparam_block_sysfs_read(name) \ | |
206 | do { \ | |
207 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
208 | __kernel_param_lock(); \ | |
209 | } while (0) | |
210 | ||
211 | /** | |
212 | * kparam_unblock_sysfs_read - allows sysfs to read a parameter again. | |
213 | * @name: the name of the parameter | |
214 | */ | |
215 | #define kparam_unblock_sysfs_read(name) \ | |
216 | do { \ | |
217 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
218 | __kernel_param_unlock(); \ | |
219 | } while (0) | |
220 | ||
221 | #ifdef CONFIG_SYSFS | |
222 | extern void __kernel_param_lock(void); | |
223 | extern void __kernel_param_unlock(void); | |
224 | #else | |
225 | static inline void __kernel_param_lock(void) | |
226 | { | |
227 | } | |
228 | static inline void __kernel_param_unlock(void) | |
229 | { | |
230 | } | |
231 | #endif | |
232 | ||
67e67cea RR |
233 | #ifndef MODULE |
234 | /** | |
235 | * core_param - define a historical core kernel parameter. | |
236 | * @name: the name of the cmdline and sysfs parameter (often the same as var) | |
237 | * @var: the variable | |
546970bc | 238 | * @type: the type of the parameter |
67e67cea RR |
239 | * @perm: visibility in sysfs |
240 | * | |
241 | * core_param is just like module_param(), but cannot be modular and | |
242 | * doesn't add a prefix (such as "printk."). This is for compatibility | |
243 | * with __setup(), and it makes sense as truly core parameters aren't | |
244 | * tied to the particular file they're in. | |
245 | */ | |
246 | #define core_param(name, var, type, perm) \ | |
247 | param_check_##type(name, &(var)); \ | |
9bbb9e5a | 248 | __module_param_call("", name, ¶m_ops_##type, \ |
fddd5201 | 249 | &var, __same_type(var, bool), perm) |
67e67cea RR |
250 | #endif /* !MODULE */ |
251 | ||
546970bc RR |
252 | /** |
253 | * module_param_string - a char array parameter | |
254 | * @name: the name of the parameter | |
255 | * @string: the string variable | |
256 | * @len: the maximum length of the string, incl. terminator | |
257 | * @perm: visibility in sysfs. | |
258 | * | |
259 | * This actually copies the string when it's set (unlike type charp). | |
260 | * @len is usually just sizeof(string). | |
261 | */ | |
1da177e4 | 262 | #define module_param_string(name, string, len, perm) \ |
22e48eaf | 263 | static const struct kparam_string __param_string_##name \ |
1da177e4 | 264 | = { len, string }; \ |
fddd5201 | 265 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 266 | ¶m_ops_string, \ |
fddd5201 | 267 | .str = &__param_string_##name, 0, perm); \ |
1da177e4 LT |
268 | __MODULE_PARM_TYPE(name, "string") |
269 | ||
b1e4d20c MS |
270 | /** |
271 | * parameq - checks if two parameter names match | |
272 | * @name1: parameter name 1 | |
273 | * @name2: parameter name 2 | |
274 | * | |
275 | * Returns true if the two parameter names are equal. | |
276 | * Dashes (-) are considered equal to underscores (_). | |
277 | */ | |
278 | extern bool parameq(const char *name1, const char *name2); | |
279 | ||
280 | /** | |
281 | * parameqn - checks if two parameter names match | |
282 | * @name1: parameter name 1 | |
283 | * @name2: parameter name 2 | |
284 | * @n: the length to compare | |
285 | * | |
286 | * Similar to parameq(), except it compares @n characters. | |
287 | */ | |
288 | extern bool parameqn(const char *name1, const char *name2, size_t n); | |
289 | ||
1da177e4 LT |
290 | /* Called on module insert or kernel boot */ |
291 | extern int parse_args(const char *name, | |
292 | char *args, | |
914dcaa8 | 293 | const struct kernel_param *params, |
1da177e4 LT |
294 | unsigned num, |
295 | int (*unknown)(char *param, char *val)); | |
296 | ||
e180a6b7 RR |
297 | /* Called by module remove. */ |
298 | #ifdef CONFIG_SYSFS | |
299 | extern void destroy_params(const struct kernel_param *params, unsigned num); | |
300 | #else | |
301 | static inline void destroy_params(const struct kernel_param *params, | |
302 | unsigned num) | |
303 | { | |
304 | } | |
305 | #endif /* !CONFIG_SYSFS */ | |
306 | ||
1da177e4 LT |
307 | /* All the helper functions */ |
308 | /* The macros to do compile-time type checking stolen from Jakub | |
309 | Jelinek, who IIRC came up with this idea for the 2.4 module init code. */ | |
310 | #define __param_check(name, p, type) \ | |
311 | static inline type *__check_##name(void) { return(p); } | |
312 | ||
9bbb9e5a RR |
313 | extern struct kernel_param_ops param_ops_byte; |
314 | extern int param_set_byte(const char *val, const struct kernel_param *kp); | |
315 | extern int param_get_byte(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
316 | #define param_check_byte(name, p) __param_check(name, p, unsigned char) |
317 | ||
9bbb9e5a RR |
318 | extern struct kernel_param_ops param_ops_short; |
319 | extern int param_set_short(const char *val, const struct kernel_param *kp); | |
320 | extern int param_get_short(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
321 | #define param_check_short(name, p) __param_check(name, p, short) |
322 | ||
9bbb9e5a RR |
323 | extern struct kernel_param_ops param_ops_ushort; |
324 | extern int param_set_ushort(const char *val, const struct kernel_param *kp); | |
325 | extern int param_get_ushort(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
326 | #define param_check_ushort(name, p) __param_check(name, p, unsigned short) |
327 | ||
9bbb9e5a RR |
328 | extern struct kernel_param_ops param_ops_int; |
329 | extern int param_set_int(const char *val, const struct kernel_param *kp); | |
330 | extern int param_get_int(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
331 | #define param_check_int(name, p) __param_check(name, p, int) |
332 | ||
9bbb9e5a RR |
333 | extern struct kernel_param_ops param_ops_uint; |
334 | extern int param_set_uint(const char *val, const struct kernel_param *kp); | |
335 | extern int param_get_uint(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
336 | #define param_check_uint(name, p) __param_check(name, p, unsigned int) |
337 | ||
9bbb9e5a RR |
338 | extern struct kernel_param_ops param_ops_long; |
339 | extern int param_set_long(const char *val, const struct kernel_param *kp); | |
340 | extern int param_get_long(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
341 | #define param_check_long(name, p) __param_check(name, p, long) |
342 | ||
9bbb9e5a RR |
343 | extern struct kernel_param_ops param_ops_ulong; |
344 | extern int param_set_ulong(const char *val, const struct kernel_param *kp); | |
345 | extern int param_get_ulong(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
346 | #define param_check_ulong(name, p) __param_check(name, p, unsigned long) |
347 | ||
9bbb9e5a RR |
348 | extern struct kernel_param_ops param_ops_charp; |
349 | extern int param_set_charp(const char *val, const struct kernel_param *kp); | |
350 | extern int param_get_charp(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
351 | #define param_check_charp(name, p) __param_check(name, p, char *) |
352 | ||
fddd5201 | 353 | /* For historical reasons "bool" parameters can be (unsigned) "int". */ |
9bbb9e5a RR |
354 | extern struct kernel_param_ops param_ops_bool; |
355 | extern int param_set_bool(const char *val, const struct kernel_param *kp); | |
356 | extern int param_get_bool(char *buffer, const struct kernel_param *kp); | |
fddd5201 RR |
357 | #define param_check_bool(name, p) \ |
358 | static inline void __check_##name(void) \ | |
359 | { \ | |
a6de51b2 RR |
360 | BUILD_BUG_ON(!__same_type((p), bool *) && \ |
361 | !__same_type((p), unsigned int *) && \ | |
362 | !__same_type((p), int *)); \ | |
fddd5201 | 363 | } |
1da177e4 | 364 | |
9bbb9e5a RR |
365 | extern struct kernel_param_ops param_ops_invbool; |
366 | extern int param_set_invbool(const char *val, const struct kernel_param *kp); | |
367 | extern int param_get_invbool(char *buffer, const struct kernel_param *kp); | |
9a71af2c | 368 | #define param_check_invbool(name, p) __param_check(name, p, bool) |
1da177e4 | 369 | |
546970bc RR |
370 | /** |
371 | * module_param_array - a parameter which is an array of some type | |
372 | * @name: the name of the array variable | |
373 | * @type: the type, as per module_param() | |
374 | * @nump: optional pointer filled in with the number written | |
375 | * @perm: visibility in sysfs | |
376 | * | |
377 | * Input and output are as comma-separated values. Commas inside values | |
378 | * don't work properly (eg. an array of charp). | |
379 | * | |
380 | * ARRAY_SIZE(@name) is used to determine the number of elements in the | |
381 | * array, so the definition must be visible. | |
382 | */ | |
383 | #define module_param_array(name, type, nump, perm) \ | |
384 | module_param_array_named(name, name, type, nump, perm) | |
385 | ||
386 | /** | |
387 | * module_param_array_named - renamed parameter which is an array of some type | |
388 | * @name: a valid C identifier which is the parameter name | |
389 | * @array: the name of the array variable | |
390 | * @type: the type, as per module_param() | |
391 | * @nump: optional pointer filled in with the number written | |
392 | * @perm: visibility in sysfs | |
393 | * | |
394 | * This exposes a different name than the actual variable name. See | |
395 | * module_param_named() for why this might be necessary. | |
396 | */ | |
1da177e4 | 397 | #define module_param_array_named(name, array, type, nump, perm) \ |
22e48eaf | 398 | static const struct kparam_array __param_arr_##name \ |
c5be0b2e RK |
399 | = { .max = ARRAY_SIZE(array), .num = nump, \ |
400 | .ops = ¶m_ops_##type, \ | |
401 | .elemsize = sizeof(array[0]), .elem = array }; \ | |
fddd5201 | 402 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 403 | ¶m_array_ops, \ |
fddd5201 RR |
404 | .arr = &__param_arr_##name, \ |
405 | __same_type(array[0], bool), perm); \ | |
1da177e4 LT |
406 | __MODULE_PARM_TYPE(name, "array of " #type) |
407 | ||
9bbb9e5a | 408 | extern struct kernel_param_ops param_array_ops; |
1da177e4 | 409 | |
9bbb9e5a RR |
410 | extern struct kernel_param_ops param_ops_string; |
411 | extern int param_set_copystring(const char *val, const struct kernel_param *); | |
412 | extern int param_get_string(char *buffer, const struct kernel_param *kp); | |
1da177e4 | 413 | |
1da177e4 LT |
414 | /* for exporting parameters in /sys/parameters */ |
415 | ||
416 | struct module; | |
417 | ||
ef665c1a | 418 | #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) |
1da177e4 | 419 | extern int module_param_sysfs_setup(struct module *mod, |
9bbb9e5a | 420 | const struct kernel_param *kparam, |
1da177e4 LT |
421 | unsigned int num_params); |
422 | ||
423 | extern void module_param_sysfs_remove(struct module *mod); | |
ef665c1a RD |
424 | #else |
425 | static inline int module_param_sysfs_setup(struct module *mod, | |
9bbb9e5a | 426 | const struct kernel_param *kparam, |
ef665c1a RD |
427 | unsigned int num_params) |
428 | { | |
429 | return 0; | |
430 | } | |
431 | ||
432 | static inline void module_param_sysfs_remove(struct module *mod) | |
433 | { } | |
434 | #endif | |
1da177e4 LT |
435 | |
436 | #endif /* _LINUX_MODULE_PARAMS_H */ |