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