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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 | #ifdef MODULE |
20 | #define ___module_cat(a,b) __mod_ ## a ## b | |
21 | #define __module_cat(a,b) ___module_cat(a,b) | |
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 LT |
26 | #else /* !MODULE */ |
27 | #define __MODULE_INFO(tag, name, info) | |
28 | #endif | |
29 | #define __MODULE_PARM_TYPE(name, _type) \ | |
30 | __MODULE_INFO(parmtype, name##type, #name ":" _type) | |
31 | ||
32 | struct kernel_param; | |
33 | ||
9bbb9e5a RR |
34 | struct kernel_param_ops { |
35 | /* Returns 0, or -errno. arg is in kp->arg. */ | |
36 | int (*set)(const char *val, const struct kernel_param *kp); | |
37 | /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ | |
38 | int (*get)(char *buffer, const struct kernel_param *kp); | |
e6df34a4 RR |
39 | /* Optional function to free kp->arg when module unloaded. */ |
40 | void (*free)(void *arg); | |
9bbb9e5a | 41 | }; |
1da177e4 | 42 | |
45fcc70c | 43 | /* Flag bits for kernel_param.flags */ |
fddd5201 | 44 | #define KPARAM_ISBOOL 2 |
45fcc70c | 45 | |
1da177e4 LT |
46 | struct kernel_param { |
47 | const char *name; | |
9bbb9e5a | 48 | const struct kernel_param_ops *ops; |
45fcc70c RR |
49 | u16 perm; |
50 | u16 flags; | |
22e48eaf JB |
51 | union { |
52 | void *arg; | |
53 | const struct kparam_string *str; | |
54 | const struct kparam_array *arr; | |
55 | }; | |
1da177e4 LT |
56 | }; |
57 | ||
58 | /* Special one for strings we want to copy into */ | |
59 | struct kparam_string { | |
60 | unsigned int maxlen; | |
61 | char *string; | |
62 | }; | |
63 | ||
64 | /* Special one for arrays */ | |
65 | struct kparam_array | |
66 | { | |
67 | unsigned int max; | |
68 | unsigned int *num; | |
9bbb9e5a | 69 | const struct kernel_param_ops *ops; |
1da177e4 LT |
70 | unsigned int elemsize; |
71 | void *elem; | |
72 | }; | |
73 | ||
546970bc RR |
74 | /** |
75 | * module_param - typesafe helper for a module/cmdline parameter | |
76 | * @value: the variable to alter, and exposed parameter name. | |
77 | * @type: the type of the parameter | |
78 | * @perm: visibility in sysfs. | |
79 | * | |
80 | * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a | |
81 | * ".") the kernel commandline parameter. Note that - is changed to _, so | |
82 | * the user can use "foo-bar=1" even for variable "foo_bar". | |
83 | * | |
84 | * @perm is 0 if the the variable is not to appear in sysfs, or 0444 | |
85 | * for world-readable, 0644 for root-writable, etc. Note that if it | |
86 | * is writable, you may need to use kparam_block_sysfs_write() around | |
87 | * accesses (esp. charp, which can be kfreed when it changes). | |
88 | * | |
89 | * The @type is simply pasted to refer to a param_ops_##type and a | |
90 | * param_check_##type: for convenience many standard types are provided but | |
91 | * you can create your own by defining those variables. | |
92 | * | |
93 | * Standard types are: | |
94 | * byte, short, ushort, int, uint, long, ulong | |
95 | * charp: a character pointer | |
96 | * bool: a bool, values 0/1, y/n, Y/N. | |
97 | * invbool: the above, only sense-reversed (N = true). | |
98 | */ | |
99 | #define module_param(name, type, perm) \ | |
100 | module_param_named(name, name, type, perm) | |
101 | ||
102 | /** | |
103 | * module_param_named - typesafe helper for a renamed module/cmdline parameter | |
104 | * @name: a valid C identifier which is the parameter name. | |
105 | * @value: the actual lvalue to alter. | |
106 | * @type: the type of the parameter | |
107 | * @perm: visibility in sysfs. | |
108 | * | |
109 | * Usually it's a good idea to have variable names and user-exposed names the | |
110 | * same, but that's harder if the variable must be non-static or is inside a | |
111 | * structure. This allows exposure under a different name. | |
112 | */ | |
113 | #define module_param_named(name, value, type, perm) \ | |
114 | param_check_##type(name, &(value)); \ | |
115 | module_param_cb(name, ¶m_ops_##type, &value, perm); \ | |
116 | __MODULE_PARM_TYPE(name, #type) | |
117 | ||
118 | /** | |
119 | * module_param_cb - general callback for a module/cmdline parameter | |
120 | * @name: a valid C identifier which is the parameter name. | |
121 | * @ops: the set & get operations for this parameter. | |
122 | * @perm: visibility in sysfs. | |
123 | * | |
124 | * The ops can have NULL set or get functions. | |
125 | */ | |
126 | #define module_param_cb(name, ops, arg, perm) \ | |
127 | __module_param_call(MODULE_PARAM_PREFIX, \ | |
a6de51b2 | 128 | name, ops, arg, __same_type((arg), bool *), perm) |
546970bc | 129 | |
91d35dd9 IK |
130 | /* On alpha, ia64 and ppc64 relocations to global data cannot go into |
131 | read-only sections (which is part of respective UNIX ABI on these | |
132 | platforms). So 'const' makes no sense and even causes compile failures | |
133 | with some compilers. */ | |
134 | #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64) | |
135 | #define __moduleparam_const | |
136 | #else | |
137 | #define __moduleparam_const const | |
138 | #endif | |
139 | ||
1da177e4 | 140 | /* This is the fundamental function for registering boot/module |
546970bc | 141 | parameters. */ |
9bbb9e5a | 142 | #define __module_param_call(prefix, name, ops, arg, isbool, perm) \ |
9774a1f5 AD |
143 | /* Default value instead of permissions? */ \ |
144 | static int __param_perm_check_##name __attribute__((unused)) = \ | |
730b69d2 RR |
145 | BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ |
146 | + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ | |
22e48eaf | 147 | static const char __param_str_##name[] = prefix #name; \ |
91d35dd9 | 148 | static struct kernel_param __moduleparam_const __param_##name \ |
3ff6eecc | 149 | __used \ |
1da177e4 | 150 | __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ |
9bbb9e5a RR |
151 | = { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0, \ |
152 | { arg } } | |
153 | ||
154 | /* Obsolete - use module_param_cb() */ | |
155 | #define module_param_call(name, set, get, arg, perm) \ | |
156 | static struct kernel_param_ops __param_ops_##name = \ | |
157 | { (void *)set, (void *)get }; \ | |
158 | __module_param_call(MODULE_PARAM_PREFIX, \ | |
159 | name, &__param_ops_##name, arg, \ | |
a6de51b2 | 160 | __same_type(arg, bool *), \ |
9bbb9e5a RR |
161 | (perm) + sizeof(__check_old_set_param(set))*0) |
162 | ||
163 | /* We don't get oldget: it's often a new-style param_get_uint, etc. */ | |
164 | static inline int | |
165 | __check_old_set_param(int (*oldset)(const char *, struct kernel_param *)) | |
166 | { | |
167 | return 0; | |
168 | } | |
1da177e4 | 169 | |
907b29eb RR |
170 | /** |
171 | * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs. | |
172 | * @name: the name of the parameter | |
173 | * | |
174 | * There's no point blocking write on a paramter that isn't writable via sysfs! | |
175 | */ | |
176 | #define kparam_block_sysfs_write(name) \ | |
177 | do { \ | |
178 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
179 | __kernel_param_lock(); \ | |
180 | } while (0) | |
181 | ||
182 | /** | |
183 | * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again. | |
184 | * @name: the name of the parameter | |
185 | */ | |
186 | #define kparam_unblock_sysfs_write(name) \ | |
187 | do { \ | |
188 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
189 | __kernel_param_unlock(); \ | |
190 | } while (0) | |
191 | ||
192 | /** | |
193 | * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs. | |
194 | * @name: the name of the parameter | |
195 | * | |
196 | * This also blocks sysfs writes. | |
197 | */ | |
198 | #define kparam_block_sysfs_read(name) \ | |
199 | do { \ | |
200 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
201 | __kernel_param_lock(); \ | |
202 | } while (0) | |
203 | ||
204 | /** | |
205 | * kparam_unblock_sysfs_read - allows sysfs to read a parameter again. | |
206 | * @name: the name of the parameter | |
207 | */ | |
208 | #define kparam_unblock_sysfs_read(name) \ | |
209 | do { \ | |
210 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
211 | __kernel_param_unlock(); \ | |
212 | } while (0) | |
213 | ||
214 | #ifdef CONFIG_SYSFS | |
215 | extern void __kernel_param_lock(void); | |
216 | extern void __kernel_param_unlock(void); | |
217 | #else | |
218 | static inline void __kernel_param_lock(void) | |
219 | { | |
220 | } | |
221 | static inline void __kernel_param_unlock(void) | |
222 | { | |
223 | } | |
224 | #endif | |
225 | ||
67e67cea RR |
226 | #ifndef MODULE |
227 | /** | |
228 | * core_param - define a historical core kernel parameter. | |
229 | * @name: the name of the cmdline and sysfs parameter (often the same as var) | |
230 | * @var: the variable | |
546970bc | 231 | * @type: the type of the parameter |
67e67cea RR |
232 | * @perm: visibility in sysfs |
233 | * | |
234 | * core_param is just like module_param(), but cannot be modular and | |
235 | * doesn't add a prefix (such as "printk."). This is for compatibility | |
236 | * with __setup(), and it makes sense as truly core parameters aren't | |
237 | * tied to the particular file they're in. | |
238 | */ | |
239 | #define core_param(name, var, type, perm) \ | |
240 | param_check_##type(name, &(var)); \ | |
9bbb9e5a | 241 | __module_param_call("", name, ¶m_ops_##type, \ |
fddd5201 | 242 | &var, __same_type(var, bool), perm) |
67e67cea RR |
243 | #endif /* !MODULE */ |
244 | ||
546970bc RR |
245 | /** |
246 | * module_param_string - a char array parameter | |
247 | * @name: the name of the parameter | |
248 | * @string: the string variable | |
249 | * @len: the maximum length of the string, incl. terminator | |
250 | * @perm: visibility in sysfs. | |
251 | * | |
252 | * This actually copies the string when it's set (unlike type charp). | |
253 | * @len is usually just sizeof(string). | |
254 | */ | |
1da177e4 | 255 | #define module_param_string(name, string, len, perm) \ |
22e48eaf | 256 | static const struct kparam_string __param_string_##name \ |
1da177e4 | 257 | = { len, string }; \ |
fddd5201 | 258 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 259 | ¶m_ops_string, \ |
fddd5201 | 260 | .str = &__param_string_##name, 0, perm); \ |
1da177e4 LT |
261 | __MODULE_PARM_TYPE(name, "string") |
262 | ||
263 | /* Called on module insert or kernel boot */ | |
264 | extern int parse_args(const char *name, | |
265 | char *args, | |
914dcaa8 | 266 | const struct kernel_param *params, |
1da177e4 LT |
267 | unsigned num, |
268 | int (*unknown)(char *param, char *val)); | |
269 | ||
e180a6b7 RR |
270 | /* Called by module remove. */ |
271 | #ifdef CONFIG_SYSFS | |
272 | extern void destroy_params(const struct kernel_param *params, unsigned num); | |
273 | #else | |
274 | static inline void destroy_params(const struct kernel_param *params, | |
275 | unsigned num) | |
276 | { | |
277 | } | |
278 | #endif /* !CONFIG_SYSFS */ | |
279 | ||
1da177e4 LT |
280 | /* All the helper functions */ |
281 | /* The macros to do compile-time type checking stolen from Jakub | |
282 | Jelinek, who IIRC came up with this idea for the 2.4 module init code. */ | |
283 | #define __param_check(name, p, type) \ | |
284 | static inline type *__check_##name(void) { return(p); } | |
285 | ||
9bbb9e5a RR |
286 | extern struct kernel_param_ops param_ops_byte; |
287 | extern int param_set_byte(const char *val, const struct kernel_param *kp); | |
288 | extern int param_get_byte(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
289 | #define param_check_byte(name, p) __param_check(name, p, unsigned char) |
290 | ||
9bbb9e5a RR |
291 | extern struct kernel_param_ops param_ops_short; |
292 | extern int param_set_short(const char *val, const struct kernel_param *kp); | |
293 | extern int param_get_short(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
294 | #define param_check_short(name, p) __param_check(name, p, short) |
295 | ||
9bbb9e5a RR |
296 | extern struct kernel_param_ops param_ops_ushort; |
297 | extern int param_set_ushort(const char *val, const struct kernel_param *kp); | |
298 | extern int param_get_ushort(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
299 | #define param_check_ushort(name, p) __param_check(name, p, unsigned short) |
300 | ||
9bbb9e5a RR |
301 | extern struct kernel_param_ops param_ops_int; |
302 | extern int param_set_int(const char *val, const struct kernel_param *kp); | |
303 | extern int param_get_int(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
304 | #define param_check_int(name, p) __param_check(name, p, int) |
305 | ||
9bbb9e5a RR |
306 | extern struct kernel_param_ops param_ops_uint; |
307 | extern int param_set_uint(const char *val, const struct kernel_param *kp); | |
308 | extern int param_get_uint(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
309 | #define param_check_uint(name, p) __param_check(name, p, unsigned int) |
310 | ||
9bbb9e5a RR |
311 | extern struct kernel_param_ops param_ops_long; |
312 | extern int param_set_long(const char *val, const struct kernel_param *kp); | |
313 | extern int param_get_long(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
314 | #define param_check_long(name, p) __param_check(name, p, long) |
315 | ||
9bbb9e5a RR |
316 | extern struct kernel_param_ops param_ops_ulong; |
317 | extern int param_set_ulong(const char *val, const struct kernel_param *kp); | |
318 | extern int param_get_ulong(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
319 | #define param_check_ulong(name, p) __param_check(name, p, unsigned long) |
320 | ||
9bbb9e5a RR |
321 | extern struct kernel_param_ops param_ops_charp; |
322 | extern int param_set_charp(const char *val, const struct kernel_param *kp); | |
323 | extern int param_get_charp(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
324 | #define param_check_charp(name, p) __param_check(name, p, char *) |
325 | ||
fddd5201 | 326 | /* For historical reasons "bool" parameters can be (unsigned) "int". */ |
9bbb9e5a RR |
327 | extern struct kernel_param_ops param_ops_bool; |
328 | extern int param_set_bool(const char *val, const struct kernel_param *kp); | |
329 | extern int param_get_bool(char *buffer, const struct kernel_param *kp); | |
fddd5201 RR |
330 | #define param_check_bool(name, p) \ |
331 | static inline void __check_##name(void) \ | |
332 | { \ | |
a6de51b2 RR |
333 | BUILD_BUG_ON(!__same_type((p), bool *) && \ |
334 | !__same_type((p), unsigned int *) && \ | |
335 | !__same_type((p), int *)); \ | |
fddd5201 | 336 | } |
1da177e4 | 337 | |
9bbb9e5a RR |
338 | extern struct kernel_param_ops param_ops_invbool; |
339 | extern int param_set_invbool(const char *val, const struct kernel_param *kp); | |
340 | extern int param_get_invbool(char *buffer, const struct kernel_param *kp); | |
9a71af2c | 341 | #define param_check_invbool(name, p) __param_check(name, p, bool) |
1da177e4 | 342 | |
546970bc RR |
343 | /** |
344 | * module_param_array - a parameter which is an array of some type | |
345 | * @name: the name of the array variable | |
346 | * @type: the type, as per module_param() | |
347 | * @nump: optional pointer filled in with the number written | |
348 | * @perm: visibility in sysfs | |
349 | * | |
350 | * Input and output are as comma-separated values. Commas inside values | |
351 | * don't work properly (eg. an array of charp). | |
352 | * | |
353 | * ARRAY_SIZE(@name) is used to determine the number of elements in the | |
354 | * array, so the definition must be visible. | |
355 | */ | |
356 | #define module_param_array(name, type, nump, perm) \ | |
357 | module_param_array_named(name, name, type, nump, perm) | |
358 | ||
359 | /** | |
360 | * module_param_array_named - renamed parameter which is an array of some type | |
361 | * @name: a valid C identifier which is the parameter name | |
362 | * @array: the name of the array variable | |
363 | * @type: the type, as per module_param() | |
364 | * @nump: optional pointer filled in with the number written | |
365 | * @perm: visibility in sysfs | |
366 | * | |
367 | * This exposes a different name than the actual variable name. See | |
368 | * module_param_named() for why this might be necessary. | |
369 | */ | |
1da177e4 | 370 | #define module_param_array_named(name, array, type, nump, perm) \ |
22e48eaf | 371 | static const struct kparam_array __param_arr_##name \ |
9bbb9e5a | 372 | = { ARRAY_SIZE(array), nump, ¶m_ops_##type, \ |
1da177e4 | 373 | sizeof(array[0]), array }; \ |
fddd5201 | 374 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 375 | ¶m_array_ops, \ |
fddd5201 RR |
376 | .arr = &__param_arr_##name, \ |
377 | __same_type(array[0], bool), perm); \ | |
1da177e4 LT |
378 | __MODULE_PARM_TYPE(name, "array of " #type) |
379 | ||
9bbb9e5a | 380 | extern struct kernel_param_ops param_array_ops; |
1da177e4 | 381 | |
9bbb9e5a RR |
382 | extern struct kernel_param_ops param_ops_string; |
383 | extern int param_set_copystring(const char *val, const struct kernel_param *); | |
384 | extern int param_get_string(char *buffer, const struct kernel_param *kp); | |
1da177e4 | 385 | |
1da177e4 LT |
386 | /* for exporting parameters in /sys/parameters */ |
387 | ||
388 | struct module; | |
389 | ||
ef665c1a | 390 | #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) |
1da177e4 | 391 | extern int module_param_sysfs_setup(struct module *mod, |
9bbb9e5a | 392 | const struct kernel_param *kparam, |
1da177e4 LT |
393 | unsigned int num_params); |
394 | ||
395 | extern void module_param_sysfs_remove(struct module *mod); | |
ef665c1a RD |
396 | #else |
397 | static inline int module_param_sysfs_setup(struct module *mod, | |
9bbb9e5a | 398 | const struct kernel_param *kparam, |
ef665c1a RD |
399 | unsigned int num_params) |
400 | { | |
401 | return 0; | |
402 | } | |
403 | ||
404 | static inline void module_param_sysfs_remove(struct module *mod) | |
405 | { } | |
406 | #endif | |
1da177e4 LT |
407 | |
408 | #endif /* _LINUX_MODULE_PARAMS_H */ |