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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 | ||
34 | struct kernel_param; | |
35 | ||
9bbb9e5a RR |
36 | struct kernel_param_ops { |
37 | /* Returns 0, or -errno. arg is in kp->arg. */ | |
38 | int (*set)(const char *val, const struct kernel_param *kp); | |
39 | /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ | |
40 | int (*get)(char *buffer, const struct kernel_param *kp); | |
e6df34a4 RR |
41 | /* Optional function to free kp->arg when module unloaded. */ |
42 | void (*free)(void *arg); | |
9bbb9e5a | 43 | }; |
1da177e4 | 44 | |
45fcc70c | 45 | /* Flag bits for kernel_param.flags */ |
fddd5201 | 46 | #define KPARAM_ISBOOL 2 |
45fcc70c | 47 | |
1da177e4 LT |
48 | struct kernel_param { |
49 | const char *name; | |
9bbb9e5a | 50 | const struct kernel_param_ops *ops; |
45fcc70c RR |
51 | u16 perm; |
52 | u16 flags; | |
22e48eaf JB |
53 | union { |
54 | void *arg; | |
55 | const struct kparam_string *str; | |
56 | const struct kparam_array *arr; | |
57 | }; | |
1da177e4 LT |
58 | }; |
59 | ||
60 | /* Special one for strings we want to copy into */ | |
61 | struct kparam_string { | |
62 | unsigned int maxlen; | |
63 | char *string; | |
64 | }; | |
65 | ||
66 | /* Special one for arrays */ | |
67 | struct kparam_array | |
68 | { | |
69 | unsigned int max; | |
c5be0b2e | 70 | unsigned int elemsize; |
1da177e4 | 71 | unsigned int *num; |
9bbb9e5a | 72 | const struct kernel_param_ops *ops; |
1da177e4 LT |
73 | void *elem; |
74 | }; | |
75 | ||
546970bc RR |
76 | /** |
77 | * module_param - typesafe helper for a module/cmdline parameter | |
78 | * @value: the variable to alter, and exposed parameter name. | |
79 | * @type: the type of the parameter | |
80 | * @perm: visibility in sysfs. | |
81 | * | |
82 | * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a | |
83 | * ".") the kernel commandline parameter. Note that - is changed to _, so | |
84 | * the user can use "foo-bar=1" even for variable "foo_bar". | |
85 | * | |
86 | * @perm is 0 if the the variable is not to appear in sysfs, or 0444 | |
87 | * for world-readable, 0644 for root-writable, etc. Note that if it | |
88 | * is writable, you may need to use kparam_block_sysfs_write() around | |
89 | * accesses (esp. charp, which can be kfreed when it changes). | |
90 | * | |
91 | * The @type is simply pasted to refer to a param_ops_##type and a | |
92 | * param_check_##type: for convenience many standard types are provided but | |
93 | * you can create your own by defining those variables. | |
94 | * | |
95 | * Standard types are: | |
96 | * byte, short, ushort, int, uint, long, ulong | |
97 | * charp: a character pointer | |
98 | * bool: a bool, values 0/1, y/n, Y/N. | |
99 | * invbool: the above, only sense-reversed (N = true). | |
100 | */ | |
101 | #define module_param(name, type, perm) \ | |
102 | module_param_named(name, name, type, perm) | |
103 | ||
104 | /** | |
105 | * module_param_named - typesafe helper for a renamed module/cmdline parameter | |
106 | * @name: a valid C identifier which is the parameter name. | |
107 | * @value: the actual lvalue to alter. | |
108 | * @type: the type of the parameter | |
109 | * @perm: visibility in sysfs. | |
110 | * | |
111 | * Usually it's a good idea to have variable names and user-exposed names the | |
112 | * same, but that's harder if the variable must be non-static or is inside a | |
113 | * structure. This allows exposure under a different name. | |
114 | */ | |
115 | #define module_param_named(name, value, type, perm) \ | |
116 | param_check_##type(name, &(value)); \ | |
117 | module_param_cb(name, ¶m_ops_##type, &value, perm); \ | |
118 | __MODULE_PARM_TYPE(name, #type) | |
119 | ||
120 | /** | |
121 | * module_param_cb - general callback for a module/cmdline parameter | |
122 | * @name: a valid C identifier which is the parameter name. | |
123 | * @ops: the set & get operations for this parameter. | |
124 | * @perm: visibility in sysfs. | |
125 | * | |
126 | * The ops can have NULL set or get functions. | |
127 | */ | |
128 | #define module_param_cb(name, ops, arg, perm) \ | |
129 | __module_param_call(MODULE_PARAM_PREFIX, \ | |
a6de51b2 | 130 | name, ops, arg, __same_type((arg), bool *), perm) |
546970bc | 131 | |
91d35dd9 IK |
132 | /* On alpha, ia64 and ppc64 relocations to global data cannot go into |
133 | read-only sections (which is part of respective UNIX ABI on these | |
134 | platforms). So 'const' makes no sense and even causes compile failures | |
135 | with some compilers. */ | |
136 | #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64) | |
137 | #define __moduleparam_const | |
138 | #else | |
139 | #define __moduleparam_const const | |
140 | #endif | |
141 | ||
1da177e4 | 142 | /* This is the fundamental function for registering boot/module |
546970bc | 143 | parameters. */ |
9bbb9e5a | 144 | #define __module_param_call(prefix, name, ops, arg, isbool, perm) \ |
9774a1f5 AD |
145 | /* Default value instead of permissions? */ \ |
146 | static int __param_perm_check_##name __attribute__((unused)) = \ | |
730b69d2 RR |
147 | BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ |
148 | + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ | |
22e48eaf | 149 | static const char __param_str_##name[] = prefix #name; \ |
91d35dd9 | 150 | static struct kernel_param __moduleparam_const __param_##name \ |
3ff6eecc | 151 | __used \ |
1da177e4 | 152 | __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ |
9bbb9e5a RR |
153 | = { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0, \ |
154 | { arg } } | |
155 | ||
156 | /* Obsolete - use module_param_cb() */ | |
157 | #define module_param_call(name, set, get, arg, perm) \ | |
158 | static struct kernel_param_ops __param_ops_##name = \ | |
159 | { (void *)set, (void *)get }; \ | |
160 | __module_param_call(MODULE_PARAM_PREFIX, \ | |
161 | name, &__param_ops_##name, arg, \ | |
a6de51b2 | 162 | __same_type(arg, bool *), \ |
9bbb9e5a RR |
163 | (perm) + sizeof(__check_old_set_param(set))*0) |
164 | ||
165 | /* We don't get oldget: it's often a new-style param_get_uint, etc. */ | |
166 | static inline int | |
167 | __check_old_set_param(int (*oldset)(const char *, struct kernel_param *)) | |
168 | { | |
169 | return 0; | |
170 | } | |
1da177e4 | 171 | |
907b29eb RR |
172 | /** |
173 | * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs. | |
174 | * @name: the name of the parameter | |
175 | * | |
176 | * There's no point blocking write on a paramter that isn't writable via sysfs! | |
177 | */ | |
178 | #define kparam_block_sysfs_write(name) \ | |
179 | do { \ | |
180 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
181 | __kernel_param_lock(); \ | |
182 | } while (0) | |
183 | ||
184 | /** | |
185 | * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again. | |
186 | * @name: the name of the parameter | |
187 | */ | |
188 | #define kparam_unblock_sysfs_write(name) \ | |
189 | do { \ | |
190 | BUG_ON(!(__param_##name.perm & 0222)); \ | |
191 | __kernel_param_unlock(); \ | |
192 | } while (0) | |
193 | ||
194 | /** | |
195 | * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs. | |
196 | * @name: the name of the parameter | |
197 | * | |
198 | * This also blocks sysfs writes. | |
199 | */ | |
200 | #define kparam_block_sysfs_read(name) \ | |
201 | do { \ | |
202 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
203 | __kernel_param_lock(); \ | |
204 | } while (0) | |
205 | ||
206 | /** | |
207 | * kparam_unblock_sysfs_read - allows sysfs to read a parameter again. | |
208 | * @name: the name of the parameter | |
209 | */ | |
210 | #define kparam_unblock_sysfs_read(name) \ | |
211 | do { \ | |
212 | BUG_ON(!(__param_##name.perm & 0444)); \ | |
213 | __kernel_param_unlock(); \ | |
214 | } while (0) | |
215 | ||
216 | #ifdef CONFIG_SYSFS | |
217 | extern void __kernel_param_lock(void); | |
218 | extern void __kernel_param_unlock(void); | |
219 | #else | |
220 | static inline void __kernel_param_lock(void) | |
221 | { | |
222 | } | |
223 | static inline void __kernel_param_unlock(void) | |
224 | { | |
225 | } | |
226 | #endif | |
227 | ||
67e67cea RR |
228 | #ifndef MODULE |
229 | /** | |
230 | * core_param - define a historical core kernel parameter. | |
231 | * @name: the name of the cmdline and sysfs parameter (often the same as var) | |
232 | * @var: the variable | |
546970bc | 233 | * @type: the type of the parameter |
67e67cea RR |
234 | * @perm: visibility in sysfs |
235 | * | |
236 | * core_param is just like module_param(), but cannot be modular and | |
237 | * doesn't add a prefix (such as "printk."). This is for compatibility | |
238 | * with __setup(), and it makes sense as truly core parameters aren't | |
239 | * tied to the particular file they're in. | |
240 | */ | |
241 | #define core_param(name, var, type, perm) \ | |
242 | param_check_##type(name, &(var)); \ | |
9bbb9e5a | 243 | __module_param_call("", name, ¶m_ops_##type, \ |
fddd5201 | 244 | &var, __same_type(var, bool), perm) |
67e67cea RR |
245 | #endif /* !MODULE */ |
246 | ||
546970bc RR |
247 | /** |
248 | * module_param_string - a char array parameter | |
249 | * @name: the name of the parameter | |
250 | * @string: the string variable | |
251 | * @len: the maximum length of the string, incl. terminator | |
252 | * @perm: visibility in sysfs. | |
253 | * | |
254 | * This actually copies the string when it's set (unlike type charp). | |
255 | * @len is usually just sizeof(string). | |
256 | */ | |
1da177e4 | 257 | #define module_param_string(name, string, len, perm) \ |
22e48eaf | 258 | static const struct kparam_string __param_string_##name \ |
1da177e4 | 259 | = { len, string }; \ |
fddd5201 | 260 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 261 | ¶m_ops_string, \ |
fddd5201 | 262 | .str = &__param_string_##name, 0, perm); \ |
1da177e4 LT |
263 | __MODULE_PARM_TYPE(name, "string") |
264 | ||
265 | /* Called on module insert or kernel boot */ | |
266 | extern int parse_args(const char *name, | |
267 | char *args, | |
914dcaa8 | 268 | const struct kernel_param *params, |
1da177e4 LT |
269 | unsigned num, |
270 | int (*unknown)(char *param, char *val)); | |
271 | ||
e180a6b7 RR |
272 | /* Called by module remove. */ |
273 | #ifdef CONFIG_SYSFS | |
274 | extern void destroy_params(const struct kernel_param *params, unsigned num); | |
275 | #else | |
276 | static inline void destroy_params(const struct kernel_param *params, | |
277 | unsigned num) | |
278 | { | |
279 | } | |
280 | #endif /* !CONFIG_SYSFS */ | |
281 | ||
1da177e4 LT |
282 | /* All the helper functions */ |
283 | /* The macros to do compile-time type checking stolen from Jakub | |
284 | Jelinek, who IIRC came up with this idea for the 2.4 module init code. */ | |
285 | #define __param_check(name, p, type) \ | |
286 | static inline type *__check_##name(void) { return(p); } | |
287 | ||
9bbb9e5a RR |
288 | extern struct kernel_param_ops param_ops_byte; |
289 | extern int param_set_byte(const char *val, const struct kernel_param *kp); | |
290 | extern int param_get_byte(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
291 | #define param_check_byte(name, p) __param_check(name, p, unsigned char) |
292 | ||
9bbb9e5a RR |
293 | extern struct kernel_param_ops param_ops_short; |
294 | extern int param_set_short(const char *val, const struct kernel_param *kp); | |
295 | extern int param_get_short(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
296 | #define param_check_short(name, p) __param_check(name, p, short) |
297 | ||
9bbb9e5a RR |
298 | extern struct kernel_param_ops param_ops_ushort; |
299 | extern int param_set_ushort(const char *val, const struct kernel_param *kp); | |
300 | extern int param_get_ushort(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
301 | #define param_check_ushort(name, p) __param_check(name, p, unsigned short) |
302 | ||
9bbb9e5a RR |
303 | extern struct kernel_param_ops param_ops_int; |
304 | extern int param_set_int(const char *val, const struct kernel_param *kp); | |
305 | extern int param_get_int(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
306 | #define param_check_int(name, p) __param_check(name, p, int) |
307 | ||
9bbb9e5a RR |
308 | extern struct kernel_param_ops param_ops_uint; |
309 | extern int param_set_uint(const char *val, const struct kernel_param *kp); | |
310 | extern int param_get_uint(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
311 | #define param_check_uint(name, p) __param_check(name, p, unsigned int) |
312 | ||
9bbb9e5a RR |
313 | extern struct kernel_param_ops param_ops_long; |
314 | extern int param_set_long(const char *val, const struct kernel_param *kp); | |
315 | extern int param_get_long(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
316 | #define param_check_long(name, p) __param_check(name, p, long) |
317 | ||
9bbb9e5a RR |
318 | extern struct kernel_param_ops param_ops_ulong; |
319 | extern int param_set_ulong(const char *val, const struct kernel_param *kp); | |
320 | extern int param_get_ulong(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
321 | #define param_check_ulong(name, p) __param_check(name, p, unsigned long) |
322 | ||
9bbb9e5a RR |
323 | extern struct kernel_param_ops param_ops_charp; |
324 | extern int param_set_charp(const char *val, const struct kernel_param *kp); | |
325 | extern int param_get_charp(char *buffer, const struct kernel_param *kp); | |
1da177e4 LT |
326 | #define param_check_charp(name, p) __param_check(name, p, char *) |
327 | ||
fddd5201 | 328 | /* For historical reasons "bool" parameters can be (unsigned) "int". */ |
9bbb9e5a RR |
329 | extern struct kernel_param_ops param_ops_bool; |
330 | extern int param_set_bool(const char *val, const struct kernel_param *kp); | |
331 | extern int param_get_bool(char *buffer, const struct kernel_param *kp); | |
fddd5201 RR |
332 | #define param_check_bool(name, p) \ |
333 | static inline void __check_##name(void) \ | |
334 | { \ | |
a6de51b2 RR |
335 | BUILD_BUG_ON(!__same_type((p), bool *) && \ |
336 | !__same_type((p), unsigned int *) && \ | |
337 | !__same_type((p), int *)); \ | |
fddd5201 | 338 | } |
1da177e4 | 339 | |
9bbb9e5a RR |
340 | extern struct kernel_param_ops param_ops_invbool; |
341 | extern int param_set_invbool(const char *val, const struct kernel_param *kp); | |
342 | extern int param_get_invbool(char *buffer, const struct kernel_param *kp); | |
9a71af2c | 343 | #define param_check_invbool(name, p) __param_check(name, p, bool) |
1da177e4 | 344 | |
546970bc RR |
345 | /** |
346 | * module_param_array - a parameter which is an array of some type | |
347 | * @name: the name of the array variable | |
348 | * @type: the type, as per module_param() | |
349 | * @nump: optional pointer filled in with the number written | |
350 | * @perm: visibility in sysfs | |
351 | * | |
352 | * Input and output are as comma-separated values. Commas inside values | |
353 | * don't work properly (eg. an array of charp). | |
354 | * | |
355 | * ARRAY_SIZE(@name) is used to determine the number of elements in the | |
356 | * array, so the definition must be visible. | |
357 | */ | |
358 | #define module_param_array(name, type, nump, perm) \ | |
359 | module_param_array_named(name, name, type, nump, perm) | |
360 | ||
361 | /** | |
362 | * module_param_array_named - renamed parameter which is an array of some type | |
363 | * @name: a valid C identifier which is the parameter name | |
364 | * @array: the name of the array variable | |
365 | * @type: the type, as per module_param() | |
366 | * @nump: optional pointer filled in with the number written | |
367 | * @perm: visibility in sysfs | |
368 | * | |
369 | * This exposes a different name than the actual variable name. See | |
370 | * module_param_named() for why this might be necessary. | |
371 | */ | |
1da177e4 | 372 | #define module_param_array_named(name, array, type, nump, perm) \ |
22e48eaf | 373 | static const struct kparam_array __param_arr_##name \ |
c5be0b2e RK |
374 | = { .max = ARRAY_SIZE(array), .num = nump, \ |
375 | .ops = ¶m_ops_##type, \ | |
376 | .elemsize = sizeof(array[0]), .elem = array }; \ | |
fddd5201 | 377 | __module_param_call(MODULE_PARAM_PREFIX, name, \ |
9bbb9e5a | 378 | ¶m_array_ops, \ |
fddd5201 RR |
379 | .arr = &__param_arr_##name, \ |
380 | __same_type(array[0], bool), perm); \ | |
1da177e4 LT |
381 | __MODULE_PARM_TYPE(name, "array of " #type) |
382 | ||
9bbb9e5a | 383 | extern struct kernel_param_ops param_array_ops; |
1da177e4 | 384 | |
9bbb9e5a RR |
385 | extern struct kernel_param_ops param_ops_string; |
386 | extern int param_set_copystring(const char *val, const struct kernel_param *); | |
387 | extern int param_get_string(char *buffer, const struct kernel_param *kp); | |
1da177e4 | 388 | |
1da177e4 LT |
389 | /* for exporting parameters in /sys/parameters */ |
390 | ||
391 | struct module; | |
392 | ||
ef665c1a | 393 | #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) |
1da177e4 | 394 | extern int module_param_sysfs_setup(struct module *mod, |
9bbb9e5a | 395 | const struct kernel_param *kparam, |
1da177e4 LT |
396 | unsigned int num_params); |
397 | ||
398 | extern void module_param_sysfs_remove(struct module *mod); | |
ef665c1a RD |
399 | #else |
400 | static inline int module_param_sysfs_setup(struct module *mod, | |
9bbb9e5a | 401 | const struct kernel_param *kparam, |
ef665c1a RD |
402 | unsigned int num_params) |
403 | { | |
404 | return 0; | |
405 | } | |
406 | ||
407 | static inline void module_param_sysfs_remove(struct module *mod) | |
408 | { } | |
409 | #endif | |
1da177e4 LT |
410 | |
411 | #endif /* _LINUX_MODULE_PARAMS_H */ |