moduleparam.h 10 KB

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  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. /* You can override this manually, but generally this should match the
  8. module name. */
  9. #ifdef MODULE
  10. #define MODULE_PARAM_PREFIX /* empty */
  11. #else
  12. #define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
  13. #endif
  14. /* Chosen so that structs with an unsigned long line up. */
  15. #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
  16. #ifdef MODULE
  17. #define ___module_cat(a,b) __mod_ ## a ## b
  18. #define __module_cat(a,b) ___module_cat(a,b)
  19. #define __MODULE_INFO(tag, name, info) \
  20. static const char __module_cat(name,__LINE__)[] \
  21. __used \
  22. __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
  23. #else /* !MODULE */
  24. #define __MODULE_INFO(tag, name, info)
  25. #endif
  26. #define __MODULE_PARM_TYPE(name, _type) \
  27. __MODULE_INFO(parmtype, name##type, #name ":" _type)
  28. struct kernel_param;
  29. struct kernel_param_ops {
  30. /* Returns 0, or -errno. arg is in kp->arg. */
  31. int (*set)(const char *val, const struct kernel_param *kp);
  32. /* Returns length written or -errno. Buffer is 4k (ie. be short!) */
  33. int (*get)(char *buffer, const struct kernel_param *kp);
  34. /* Optional function to free kp->arg when module unloaded. */
  35. void (*free)(void *arg);
  36. };
  37. /* Flag bits for kernel_param.flags */
  38. #define KPARAM_ISBOOL 2
  39. struct kernel_param {
  40. const char *name;
  41. const struct kernel_param_ops *ops;
  42. u16 perm;
  43. u16 flags;
  44. union {
  45. void *arg;
  46. const struct kparam_string *str;
  47. const struct kparam_array *arr;
  48. };
  49. };
  50. /* Special one for strings we want to copy into */
  51. struct kparam_string {
  52. unsigned int maxlen;
  53. char *string;
  54. };
  55. /* Special one for arrays */
  56. struct kparam_array
  57. {
  58. unsigned int max;
  59. unsigned int *num;
  60. const struct kernel_param_ops *ops;
  61. unsigned int elemsize;
  62. void *elem;
  63. };
  64. /* On alpha, ia64 and ppc64 relocations to global data cannot go into
  65. read-only sections (which is part of respective UNIX ABI on these
  66. platforms). So 'const' makes no sense and even causes compile failures
  67. with some compilers. */
  68. #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
  69. #define __moduleparam_const
  70. #else
  71. #define __moduleparam_const const
  72. #endif
  73. /* This is the fundamental function for registering boot/module
  74. parameters. perm sets the visibility in sysfs: 000 means it's
  75. not there, read bits mean it's readable, write bits mean it's
  76. writable. */
  77. #define __module_param_call(prefix, name, ops, arg, isbool, perm) \
  78. /* Default value instead of permissions? */ \
  79. static int __param_perm_check_##name __attribute__((unused)) = \
  80. BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \
  81. + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \
  82. static const char __param_str_##name[] = prefix #name; \
  83. static struct kernel_param __moduleparam_const __param_##name \
  84. __used \
  85. __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
  86. = { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0, \
  87. { arg } }
  88. /* Obsolete - use module_param_cb() */
  89. #define module_param_call(name, set, get, arg, perm) \
  90. static struct kernel_param_ops __param_ops_##name = \
  91. { (void *)set, (void *)get }; \
  92. __module_param_call(MODULE_PARAM_PREFIX, \
  93. name, &__param_ops_##name, arg, \
  94. __same_type(*(arg), bool), \
  95. (perm) + sizeof(__check_old_set_param(set))*0)
  96. /* We don't get oldget: it's often a new-style param_get_uint, etc. */
  97. static inline int
  98. __check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
  99. {
  100. return 0;
  101. }
  102. #define module_param_cb(name, ops, arg, perm) \
  103. __module_param_call(MODULE_PARAM_PREFIX, \
  104. name, ops, arg, __same_type(*(arg), bool), perm)
  105. /*
  106. * Helper functions: type is byte, short, ushort, int, uint, long,
  107. * ulong, charp, bool or invbool, or XXX if you define param_ops_XXX
  108. * and param_check_XXX.
  109. */
  110. #define module_param_named(name, value, type, perm) \
  111. param_check_##type(name, &(value)); \
  112. module_param_cb(name, &param_ops_##type, &value, perm); \
  113. __MODULE_PARM_TYPE(name, #type)
  114. #define module_param(name, type, perm) \
  115. module_param_named(name, name, type, perm)
  116. #ifndef MODULE
  117. /**
  118. * core_param - define a historical core kernel parameter.
  119. * @name: the name of the cmdline and sysfs parameter (often the same as var)
  120. * @var: the variable
  121. * @type: the type (for param_set_##type and param_get_##type)
  122. * @perm: visibility in sysfs
  123. *
  124. * core_param is just like module_param(), but cannot be modular and
  125. * doesn't add a prefix (such as "printk."). This is for compatibility
  126. * with __setup(), and it makes sense as truly core parameters aren't
  127. * tied to the particular file they're in.
  128. */
  129. #define core_param(name, var, type, perm) \
  130. param_check_##type(name, &(var)); \
  131. __module_param_call("", name, &param_ops_##type, \
  132. &var, __same_type(var, bool), perm)
  133. #endif /* !MODULE */
  134. /* Actually copy string: maxlen param is usually sizeof(string). */
  135. #define module_param_string(name, string, len, perm) \
  136. static const struct kparam_string __param_string_##name \
  137. = { len, string }; \
  138. __module_param_call(MODULE_PARAM_PREFIX, name, \
  139. &param_ops_string, \
  140. .str = &__param_string_##name, 0, perm); \
  141. __MODULE_PARM_TYPE(name, "string")
  142. /* Called on module insert or kernel boot */
  143. extern int parse_args(const char *name,
  144. char *args,
  145. const struct kernel_param *params,
  146. unsigned num,
  147. int (*unknown)(char *param, char *val));
  148. /* Called by module remove. */
  149. #ifdef CONFIG_SYSFS
  150. extern void destroy_params(const struct kernel_param *params, unsigned num);
  151. #else
  152. static inline void destroy_params(const struct kernel_param *params,
  153. unsigned num)
  154. {
  155. }
  156. #endif /* !CONFIG_SYSFS */
  157. /* All the helper functions */
  158. /* The macros to do compile-time type checking stolen from Jakub
  159. Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
  160. #define __param_check(name, p, type) \
  161. static inline type *__check_##name(void) { return(p); }
  162. extern struct kernel_param_ops param_ops_byte;
  163. extern int param_set_byte(const char *val, const struct kernel_param *kp);
  164. extern int param_get_byte(char *buffer, const struct kernel_param *kp);
  165. #define param_check_byte(name, p) __param_check(name, p, unsigned char)
  166. extern struct kernel_param_ops param_ops_short;
  167. extern int param_set_short(const char *val, const struct kernel_param *kp);
  168. extern int param_get_short(char *buffer, const struct kernel_param *kp);
  169. #define param_check_short(name, p) __param_check(name, p, short)
  170. extern struct kernel_param_ops param_ops_ushort;
  171. extern int param_set_ushort(const char *val, const struct kernel_param *kp);
  172. extern int param_get_ushort(char *buffer, const struct kernel_param *kp);
  173. #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
  174. extern struct kernel_param_ops param_ops_int;
  175. extern int param_set_int(const char *val, const struct kernel_param *kp);
  176. extern int param_get_int(char *buffer, const struct kernel_param *kp);
  177. #define param_check_int(name, p) __param_check(name, p, int)
  178. extern struct kernel_param_ops param_ops_uint;
  179. extern int param_set_uint(const char *val, const struct kernel_param *kp);
  180. extern int param_get_uint(char *buffer, const struct kernel_param *kp);
  181. #define param_check_uint(name, p) __param_check(name, p, unsigned int)
  182. extern struct kernel_param_ops param_ops_long;
  183. extern int param_set_long(const char *val, const struct kernel_param *kp);
  184. extern int param_get_long(char *buffer, const struct kernel_param *kp);
  185. #define param_check_long(name, p) __param_check(name, p, long)
  186. extern struct kernel_param_ops param_ops_ulong;
  187. extern int param_set_ulong(const char *val, const struct kernel_param *kp);
  188. extern int param_get_ulong(char *buffer, const struct kernel_param *kp);
  189. #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
  190. extern struct kernel_param_ops param_ops_charp;
  191. extern int param_set_charp(const char *val, const struct kernel_param *kp);
  192. extern int param_get_charp(char *buffer, const struct kernel_param *kp);
  193. #define param_check_charp(name, p) __param_check(name, p, char *)
  194. /* For historical reasons "bool" parameters can be (unsigned) "int". */
  195. extern struct kernel_param_ops param_ops_bool;
  196. extern int param_set_bool(const char *val, const struct kernel_param *kp);
  197. extern int param_get_bool(char *buffer, const struct kernel_param *kp);
  198. #define param_check_bool(name, p) \
  199. static inline void __check_##name(void) \
  200. { \
  201. BUILD_BUG_ON(!__same_type(*(p), bool) && \
  202. !__same_type(*(p), unsigned int) && \
  203. !__same_type(*(p), int)); \
  204. }
  205. extern struct kernel_param_ops param_ops_invbool;
  206. extern int param_set_invbool(const char *val, const struct kernel_param *kp);
  207. extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
  208. #define param_check_invbool(name, p) __param_check(name, p, bool)
  209. /* Comma-separated array: *nump is set to number they actually specified. */
  210. #define module_param_array_named(name, array, type, nump, perm) \
  211. static const struct kparam_array __param_arr_##name \
  212. = { ARRAY_SIZE(array), nump, &param_ops_##type, \
  213. sizeof(array[0]), array }; \
  214. __module_param_call(MODULE_PARAM_PREFIX, name, \
  215. &param_array_ops, \
  216. .arr = &__param_arr_##name, \
  217. __same_type(array[0], bool), perm); \
  218. __MODULE_PARM_TYPE(name, "array of " #type)
  219. #define module_param_array(name, type, nump, perm) \
  220. module_param_array_named(name, name, type, nump, perm)
  221. extern struct kernel_param_ops param_array_ops;
  222. extern struct kernel_param_ops param_ops_string;
  223. extern int param_set_copystring(const char *val, const struct kernel_param *);
  224. extern int param_get_string(char *buffer, const struct kernel_param *kp);
  225. /* for exporting parameters in /sys/parameters */
  226. struct module;
  227. #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
  228. extern int module_param_sysfs_setup(struct module *mod,
  229. const struct kernel_param *kparam,
  230. unsigned int num_params);
  231. extern void module_param_sysfs_remove(struct module *mod);
  232. #else
  233. static inline int module_param_sysfs_setup(struct module *mod,
  234. const struct kernel_param *kparam,
  235. unsigned int num_params)
  236. {
  237. return 0;
  238. }
  239. static inline void module_param_sysfs_remove(struct module *mod)
  240. { }
  241. #endif
  242. #endif /* _LINUX_MODULE_PARAMS_H */