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 13 #define MODULE_PARAM_PREFIX KBUILD_MODNAME "." 14 #endif 15 16 /* Chosen so that structs with an unsigned long line up. */ 17 #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long)) 18 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__)[] \ 24 __used \ 25 __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info 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 34 /* Returns 0, or -errno. arg is in kp->arg. */ 35 typedef int (*param_set_fn)(const char *val, struct kernel_param *kp); 36 /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ 37 typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp); 38 39 /* Flag bits for kernel_param.flags */ 40 #define KPARAM_ISBOOL 2 41 42 struct kernel_param { 43 const char *name; 44 u16 perm; 45 u16 flags; 46 param_set_fn set; 47 param_get_fn get; 48 union { 49 void *arg; 50 const struct kparam_string *str; 51 const struct kparam_array *arr; 52 }; 53 }; 54 55 /* Special one for strings we want to copy into */ 56 struct kparam_string { 57 unsigned int maxlen; 58 char *string; 59 }; 60 61 /* Special one for arrays */ 62 struct kparam_array 63 { 64 unsigned int max; 65 unsigned int *num; 66 param_set_fn set; 67 param_get_fn get; 68 unsigned int elemsize; 69 void *elem; 70 }; 71 72 /* On alpha, ia64 and ppc64 relocations to global data cannot go into 73 read-only sections (which is part of respective UNIX ABI on these 74 platforms). So 'const' makes no sense and even causes compile failures 75 with some compilers. */ 76 #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64) 77 #define __moduleparam_const 78 #else 79 #define __moduleparam_const const 80 #endif 81 82 /* This is the fundamental function for registering boot/module 83 parameters. perm sets the visibility in sysfs: 000 means it's 84 not there, read bits mean it's readable, write bits mean it's 85 writable. */ 86 #define __module_param_call(prefix, name, set, get, arg, isbool, perm) \ 87 /* Default value instead of permissions? */ \ 88 static int __param_perm_check_##name __attribute__((unused)) = \ 89 BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ 90 + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ 91 static const char __param_str_##name[] = prefix #name; \ 92 static struct kernel_param __moduleparam_const __param_##name \ 93 __used \ 94 __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ 95 = { __param_str_##name, perm, isbool ? KPARAM_ISBOOL : 0, \ 96 set, get, { arg } } 97 98 #define module_param_call(name, set, get, arg, perm) \ 99 __module_param_call(MODULE_PARAM_PREFIX, \ 100 name, set, get, arg, \ 101 __same_type(*(arg), bool), perm) 102 103 /* Helper functions: type is byte, short, ushort, int, uint, long, 104 ulong, charp, bool or invbool, or XXX if you define param_get_XXX, 105 param_set_XXX and param_check_XXX. */ 106 #define module_param_named(name, value, type, perm) \ 107 param_check_##type(name, &(value)); \ 108 module_param_call(name, param_set_##type, param_get_##type, &value, perm); \ 109 __MODULE_PARM_TYPE(name, #type) 110 111 #define module_param(name, type, perm) \ 112 module_param_named(name, name, type, perm) 113 114 #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_set_##type, param_get_##type, \ 130 &var, __same_type(var, bool), perm) 131 #endif /* !MODULE */ 132 133 /* Actually copy string: maxlen param is usually sizeof(string). */ 134 #define module_param_string(name, string, len, perm) \ 135 static const struct kparam_string __param_string_##name \ 136 = { len, string }; \ 137 __module_param_call(MODULE_PARAM_PREFIX, name, \ 138 param_set_copystring, param_get_string, \ 139 .str = &__param_string_##name, 0, perm); \ 140 __MODULE_PARM_TYPE(name, "string") 141 142 /* Called on module insert or kernel boot */ 143 extern int parse_args(const char *name, 144 char *args, 145 struct kernel_param *params, 146 unsigned num, 147 int (*unknown)(char *param, char *val)); 148 149 /* Called by module remove. */ 150 #ifdef CONFIG_SYSFS 151 extern void destroy_params(const struct kernel_param *params, unsigned num); 152 #else 153 static inline void destroy_params(const struct kernel_param *params, 154 unsigned num) 155 { 156 } 157 #endif /* !CONFIG_SYSFS */ 158 159 /* All the helper functions */ 160 /* The macros to do compile-time type checking stolen from Jakub 161 Jelinek, who IIRC came up with this idea for the 2.4 module init code. */ 162 #define __param_check(name, p, type) \ 163 static inline type *__check_##name(void) { return(p); } 164 165 extern int param_set_byte(const char *val, struct kernel_param *kp); 166 extern int param_get_byte(char *buffer, struct kernel_param *kp); 167 #define param_check_byte(name, p) __param_check(name, p, unsigned char) 168 169 extern int param_set_short(const char *val, struct kernel_param *kp); 170 extern int param_get_short(char *buffer, struct kernel_param *kp); 171 #define param_check_short(name, p) __param_check(name, p, short) 172 173 extern int param_set_ushort(const char *val, struct kernel_param *kp); 174 extern int param_get_ushort(char *buffer, struct kernel_param *kp); 175 #define param_check_ushort(name, p) __param_check(name, p, unsigned short) 176 177 extern int param_set_int(const char *val, struct kernel_param *kp); 178 extern int param_get_int(char *buffer, struct kernel_param *kp); 179 #define param_check_int(name, p) __param_check(name, p, int) 180 181 extern int param_set_uint(const char *val, struct kernel_param *kp); 182 extern int param_get_uint(char *buffer, struct kernel_param *kp); 183 #define param_check_uint(name, p) __param_check(name, p, unsigned int) 184 185 extern int param_set_long(const char *val, struct kernel_param *kp); 186 extern int param_get_long(char *buffer, struct kernel_param *kp); 187 #define param_check_long(name, p) __param_check(name, p, long) 188 189 extern int param_set_ulong(const char *val, struct kernel_param *kp); 190 extern int param_get_ulong(char *buffer, struct kernel_param *kp); 191 #define param_check_ulong(name, p) __param_check(name, p, unsigned long) 192 193 extern int param_set_charp(const char *val, struct kernel_param *kp); 194 extern int param_get_charp(char *buffer, struct kernel_param *kp); 195 #define param_check_charp(name, p) __param_check(name, p, char *) 196 197 /* For historical reasons "bool" parameters can be (unsigned) "int". */ 198 extern int param_set_bool(const char *val, struct kernel_param *kp); 199 extern int param_get_bool(char *buffer, struct kernel_param *kp); 200 #define param_check_bool(name, p) \ 201 static inline void __check_##name(void) \ 202 { \ 203 BUILD_BUG_ON(!__same_type(*(p), bool) && \ 204 !__same_type(*(p), unsigned int) && \ 205 !__same_type(*(p), int)); \ 206 } 207 208 extern int param_set_invbool(const char *val, struct kernel_param *kp); 209 extern int param_get_invbool(char *buffer, struct kernel_param *kp); 210 #define param_check_invbool(name, p) __param_check(name, p, bool) 211 212 /* Comma-separated array: *nump is set to number they actually specified. */ 213 #define module_param_array_named(name, array, type, nump, perm) \ 214 static const struct kparam_array __param_arr_##name \ 215 = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\ 216 sizeof(array[0]), array }; \ 217 __module_param_call(MODULE_PARAM_PREFIX, name, \ 218 param_array_set, param_array_get, \ 219 .arr = &__param_arr_##name, \ 220 __same_type(array[0], bool), perm); \ 221 __MODULE_PARM_TYPE(name, "array of " #type) 222 223 #define module_param_array(name, type, nump, perm) \ 224 module_param_array_named(name, name, type, nump, perm) 225 226 extern int param_array_set(const char *val, struct kernel_param *kp); 227 extern int param_array_get(char *buffer, struct kernel_param *kp); 228 229 extern int param_set_copystring(const char *val, struct kernel_param *kp); 230 extern int param_get_string(char *buffer, struct kernel_param *kp); 231 232 /* for exporting parameters in /sys/parameters */ 233 234 struct module; 235 236 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) 237 extern int module_param_sysfs_setup(struct module *mod, 238 struct kernel_param *kparam, 239 unsigned int num_params); 240 241 extern void module_param_sysfs_remove(struct module *mod); 242 #else 243 static inline int module_param_sysfs_setup(struct module *mod, 244 struct kernel_param *kparam, 245 unsigned int num_params) 246 { 247 return 0; 248 } 249 250 static inline void module_param_sysfs_remove(struct module *mod) 251 { } 252 #endif 253 254 #endif /* _LINUX_MODULE_PARAMS_H */ 255