moduleparam.h 9.2 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. /* Returns 0, or -errno. arg is in kp->arg. */
  30. typedef int (*param_set_fn)(const char *val, struct kernel_param *kp);
  31. /* Returns length written or -errno. Buffer is 4k (ie. be short!) */
  32. typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp);
  33. /* Flag bits for kernel_param.flags */
  34. #define KPARAM_ISBOOL 2
  35. struct kernel_param {
  36. const char *name;
  37. u16 perm;
  38. u16 flags;
  39. param_set_fn set;
  40. param_get_fn get;
  41. union {
  42. void *arg;
  43. const struct kparam_string *str;
  44. const struct kparam_array *arr;
  45. };
  46. };
  47. /* Special one for strings we want to copy into */
  48. struct kparam_string {
  49. unsigned int maxlen;
  50. char *string;
  51. };
  52. /* Special one for arrays */
  53. struct kparam_array
  54. {
  55. unsigned int max;
  56. unsigned int *num;
  57. param_set_fn set;
  58. param_get_fn get;
  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, set, get, 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, perm, isbool ? KPARAM_ISBOOL : 0, \
  85. set, get, { arg } }
  86. #define module_param_call(name, set, get, arg, perm) \
  87. __module_param_call(MODULE_PARAM_PREFIX, \
  88. name, set, get, arg, \
  89. __same_type(*(arg), bool), perm)
  90. /* Helper functions: type is byte, short, ushort, int, uint, long,
  91. ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
  92. param_set_XXX and param_check_XXX. */
  93. #define module_param_named(name, value, type, perm) \
  94. param_check_##type(name, &(value)); \
  95. module_param_call(name, param_set_##type, param_get_##type, &value, perm); \
  96. __MODULE_PARM_TYPE(name, #type)
  97. #define module_param(name, type, perm) \
  98. module_param_named(name, name, type, perm)
  99. #ifndef MODULE
  100. /**
  101. * core_param - define a historical core kernel parameter.
  102. * @name: the name of the cmdline and sysfs parameter (often the same as var)
  103. * @var: the variable
  104. * @type: the type (for param_set_##type and param_get_##type)
  105. * @perm: visibility in sysfs
  106. *
  107. * core_param is just like module_param(), but cannot be modular and
  108. * doesn't add a prefix (such as "printk."). This is for compatibility
  109. * with __setup(), and it makes sense as truly core parameters aren't
  110. * tied to the particular file they're in.
  111. */
  112. #define core_param(name, var, type, perm) \
  113. param_check_##type(name, &(var)); \
  114. __module_param_call("", name, param_set_##type, param_get_##type, \
  115. &var, __same_type(var, bool), perm)
  116. #endif /* !MODULE */
  117. /* Actually copy string: maxlen param is usually sizeof(string). */
  118. #define module_param_string(name, string, len, perm) \
  119. static const struct kparam_string __param_string_##name \
  120. = { len, string }; \
  121. __module_param_call(MODULE_PARAM_PREFIX, name, \
  122. param_set_copystring, param_get_string, \
  123. .str = &__param_string_##name, 0, perm); \
  124. __MODULE_PARM_TYPE(name, "string")
  125. /* Called on module insert or kernel boot */
  126. extern int parse_args(const char *name,
  127. char *args,
  128. struct kernel_param *params,
  129. unsigned num,
  130. int (*unknown)(char *param, char *val));
  131. /* Called by module remove. */
  132. #ifdef CONFIG_SYSFS
  133. extern void destroy_params(const struct kernel_param *params, unsigned num);
  134. #else
  135. static inline void destroy_params(const struct kernel_param *params,
  136. unsigned num)
  137. {
  138. }
  139. #endif /* !CONFIG_SYSFS */
  140. /* All the helper functions */
  141. /* The macros to do compile-time type checking stolen from Jakub
  142. Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
  143. #define __param_check(name, p, type) \
  144. static inline type *__check_##name(void) { return(p); }
  145. extern int param_set_byte(const char *val, struct kernel_param *kp);
  146. extern int param_get_byte(char *buffer, struct kernel_param *kp);
  147. #define param_check_byte(name, p) __param_check(name, p, unsigned char)
  148. extern int param_set_short(const char *val, struct kernel_param *kp);
  149. extern int param_get_short(char *buffer, struct kernel_param *kp);
  150. #define param_check_short(name, p) __param_check(name, p, short)
  151. extern int param_set_ushort(const char *val, struct kernel_param *kp);
  152. extern int param_get_ushort(char *buffer, struct kernel_param *kp);
  153. #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
  154. extern int param_set_int(const char *val, struct kernel_param *kp);
  155. extern int param_get_int(char *buffer, struct kernel_param *kp);
  156. #define param_check_int(name, p) __param_check(name, p, int)
  157. extern int param_set_uint(const char *val, struct kernel_param *kp);
  158. extern int param_get_uint(char *buffer, struct kernel_param *kp);
  159. #define param_check_uint(name, p) __param_check(name, p, unsigned int)
  160. extern int param_set_long(const char *val, struct kernel_param *kp);
  161. extern int param_get_long(char *buffer, struct kernel_param *kp);
  162. #define param_check_long(name, p) __param_check(name, p, long)
  163. extern int param_set_ulong(const char *val, struct kernel_param *kp);
  164. extern int param_get_ulong(char *buffer, struct kernel_param *kp);
  165. #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
  166. extern int param_set_charp(const char *val, struct kernel_param *kp);
  167. extern int param_get_charp(char *buffer, struct kernel_param *kp);
  168. #define param_check_charp(name, p) __param_check(name, p, char *)
  169. /* For historical reasons "bool" parameters can be (unsigned) "int". */
  170. extern int param_set_bool(const char *val, struct kernel_param *kp);
  171. extern int param_get_bool(char *buffer, struct kernel_param *kp);
  172. #define param_check_bool(name, p) \
  173. static inline void __check_##name(void) \
  174. { \
  175. BUILD_BUG_ON(!__same_type(*(p), bool) && \
  176. !__same_type(*(p), unsigned int) && \
  177. !__same_type(*(p), int)); \
  178. }
  179. extern int param_set_invbool(const char *val, struct kernel_param *kp);
  180. extern int param_get_invbool(char *buffer, struct kernel_param *kp);
  181. #define param_check_invbool(name, p) __param_check(name, p, bool)
  182. /* Comma-separated array: *nump is set to number they actually specified. */
  183. #define module_param_array_named(name, array, type, nump, perm) \
  184. static const struct kparam_array __param_arr_##name \
  185. = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
  186. sizeof(array[0]), array }; \
  187. __module_param_call(MODULE_PARAM_PREFIX, name, \
  188. param_array_set, param_array_get, \
  189. .arr = &__param_arr_##name, \
  190. __same_type(array[0], bool), perm); \
  191. __MODULE_PARM_TYPE(name, "array of " #type)
  192. #define module_param_array(name, type, nump, perm) \
  193. module_param_array_named(name, name, type, nump, perm)
  194. extern int param_array_set(const char *val, struct kernel_param *kp);
  195. extern int param_array_get(char *buffer, struct kernel_param *kp);
  196. extern int param_set_copystring(const char *val, struct kernel_param *kp);
  197. extern int param_get_string(char *buffer, struct kernel_param *kp);
  198. /* for exporting parameters in /sys/parameters */
  199. struct module;
  200. #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
  201. extern int module_param_sysfs_setup(struct module *mod,
  202. struct kernel_param *kparam,
  203. unsigned int num_params);
  204. extern void module_param_sysfs_remove(struct module *mod);
  205. #else
  206. static inline int module_param_sysfs_setup(struct module *mod,
  207. struct kernel_param *kparam,
  208. unsigned int num_params)
  209. {
  210. return 0;
  211. }
  212. static inline void module_param_sysfs_remove(struct module *mod)
  213. { }
  214. #endif
  215. #endif /* _LINUX_MODULE_PARAMS_H */