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_INFO(tag, name, info) \ 21 static const char __UNIQUE_ID(name)[] \ 22 __used __attribute__((section(".modinfo"), unused, aligned(1))) \ 23 = __stringify(tag) "=" info 24 #else /* !MODULE */ 25 /* This struct is here for syntactic coherency, it is not used */ 26 #define __MODULE_INFO(tag, name, info) \ 27 struct __UNIQUE_ID(name) {} 28 #endif 29 #define __MODULE_PARM_TYPE(name, _type) \ 30 __MODULE_INFO(parmtype, name##type, #name ":" _type) 31 32 /* One for each parameter, describing how to use it. Some files do 33 multiple of these per line, so can't just use MODULE_INFO. */ 34 #define MODULE_PARM_DESC(_parm, desc) \ 35 __MODULE_INFO(parm, _parm, #_parm ":" desc) 36 37 struct kernel_param; 38 39 /* 40 * Flags available for kernel_param_ops 41 * 42 * NOARG - the parameter allows for no argument (foo instead of foo=1) 43 */ 44 enum { 45 KERNEL_PARAM_OPS_FL_NOARG = (1 << 0) 46 }; 47 48 struct kernel_param_ops { 49 /* How the ops should behave */ 50 unsigned int flags; 51 /* Returns 0, or -errno. arg is in kp->arg. */ 52 int (*set)(const char *val, const struct kernel_param *kp); 53 /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ 54 int (*get)(char *buffer, const struct kernel_param *kp); 55 /* Optional function to free kp->arg when module unloaded. */ 56 void (*free)(void *arg); 57 }; 58 59 /* 60 * Flags available for kernel_param 61 * 62 * UNSAFE - the parameter is dangerous and setting it will taint the kernel 63 * HWPARAM - Hardware param not permitted in lockdown mode 64 */ 65 enum { 66 KERNEL_PARAM_FL_UNSAFE = (1 << 0), 67 KERNEL_PARAM_FL_HWPARAM = (1 << 1), 68 }; 69 70 struct kernel_param { 71 const char *name; 72 struct module *mod; 73 const struct kernel_param_ops *ops; 74 const u16 perm; 75 s8 level; 76 u8 flags; 77 union { 78 void *arg; 79 const struct kparam_string *str; 80 const struct kparam_array *arr; 81 }; 82 }; 83 84 extern const struct kernel_param __start___param[], __stop___param[]; 85 86 /* Special one for strings we want to copy into */ 87 struct kparam_string { 88 unsigned int maxlen; 89 char *string; 90 }; 91 92 /* Special one for arrays */ 93 struct kparam_array 94 { 95 unsigned int max; 96 unsigned int elemsize; 97 unsigned int *num; 98 const struct kernel_param_ops *ops; 99 void *elem; 100 }; 101 102 /** 103 * module_param - typesafe helper for a module/cmdline parameter 104 * @value: the variable to alter, and exposed parameter name. 105 * @type: the type of the parameter 106 * @perm: visibility in sysfs. 107 * 108 * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a 109 * ".") the kernel commandline parameter. Note that - is changed to _, so 110 * the user can use "foo-bar=1" even for variable "foo_bar". 111 * 112 * @perm is 0 if the the variable is not to appear in sysfs, or 0444 113 * for world-readable, 0644 for root-writable, etc. Note that if it 114 * is writable, you may need to use kernel_param_lock() around 115 * accesses (esp. charp, which can be kfreed when it changes). 116 * 117 * The @type is simply pasted to refer to a param_ops_##type and a 118 * param_check_##type: for convenience many standard types are provided but 119 * you can create your own by defining those variables. 120 * 121 * Standard types are: 122 * byte, short, ushort, int, uint, long, ulong 123 * charp: a character pointer 124 * bool: a bool, values 0/1, y/n, Y/N. 125 * invbool: the above, only sense-reversed (N = true). 126 */ 127 #define module_param(name, type, perm) \ 128 module_param_named(name, name, type, perm) 129 130 /** 131 * module_param_unsafe - same as module_param but taints kernel 132 */ 133 #define module_param_unsafe(name, type, perm) \ 134 module_param_named_unsafe(name, name, type, perm) 135 136 /** 137 * module_param_named - typesafe helper for a renamed module/cmdline parameter 138 * @name: a valid C identifier which is the parameter name. 139 * @value: the actual lvalue to alter. 140 * @type: the type of the parameter 141 * @perm: visibility in sysfs. 142 * 143 * Usually it's a good idea to have variable names and user-exposed names the 144 * same, but that's harder if the variable must be non-static or is inside a 145 * structure. This allows exposure under a different name. 146 */ 147 #define module_param_named(name, value, type, perm) \ 148 param_check_##type(name, &(value)); \ 149 module_param_cb(name, ¶m_ops_##type, &value, perm); \ 150 __MODULE_PARM_TYPE(name, #type) 151 152 /** 153 * module_param_named_unsafe - same as module_param_named but taints kernel 154 */ 155 #define module_param_named_unsafe(name, value, type, perm) \ 156 param_check_##type(name, &(value)); \ 157 module_param_cb_unsafe(name, ¶m_ops_##type, &value, perm); \ 158 __MODULE_PARM_TYPE(name, #type) 159 160 /** 161 * module_param_cb - general callback for a module/cmdline parameter 162 * @name: a valid C identifier which is the parameter name. 163 * @ops: the set & get operations for this parameter. 164 * @perm: visibility in sysfs. 165 * 166 * The ops can have NULL set or get functions. 167 */ 168 #define module_param_cb(name, ops, arg, perm) \ 169 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0) 170 171 #define module_param_cb_unsafe(name, ops, arg, perm) \ 172 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \ 173 KERNEL_PARAM_FL_UNSAFE) 174 175 /** 176 * <level>_param_cb - general callback for a module/cmdline parameter 177 * to be evaluated before certain initcall level 178 * @name: a valid C identifier which is the parameter name. 179 * @ops: the set & get operations for this parameter. 180 * @perm: visibility in sysfs. 181 * 182 * The ops can have NULL set or get functions. 183 */ 184 #define __level_param_cb(name, ops, arg, perm, level) \ 185 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0) 186 187 #define core_param_cb(name, ops, arg, perm) \ 188 __level_param_cb(name, ops, arg, perm, 1) 189 190 #define postcore_param_cb(name, ops, arg, perm) \ 191 __level_param_cb(name, ops, arg, perm, 2) 192 193 #define arch_param_cb(name, ops, arg, perm) \ 194 __level_param_cb(name, ops, arg, perm, 3) 195 196 #define subsys_param_cb(name, ops, arg, perm) \ 197 __level_param_cb(name, ops, arg, perm, 4) 198 199 #define fs_param_cb(name, ops, arg, perm) \ 200 __level_param_cb(name, ops, arg, perm, 5) 201 202 #define device_param_cb(name, ops, arg, perm) \ 203 __level_param_cb(name, ops, arg, perm, 6) 204 205 #define late_param_cb(name, ops, arg, perm) \ 206 __level_param_cb(name, ops, arg, perm, 7) 207 208 /* On alpha, ia64 and ppc64 relocations to global data cannot go into 209 read-only sections (which is part of respective UNIX ABI on these 210 platforms). So 'const' makes no sense and even causes compile failures 211 with some compilers. */ 212 #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64) 213 #define __moduleparam_const 214 #else 215 #define __moduleparam_const const 216 #endif 217 218 /* This is the fundamental function for registering boot/module 219 parameters. */ 220 #define __module_param_call(prefix, name, ops, arg, perm, level, flags) \ 221 /* Default value instead of permissions? */ \ 222 static const char __param_str_##name[] = prefix #name; \ 223 static struct kernel_param __moduleparam_const __param_##name \ 224 __used \ 225 __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ 226 = { __param_str_##name, THIS_MODULE, ops, \ 227 VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } } 228 229 /* Obsolete - use module_param_cb() */ 230 #define module_param_call(name, _set, _get, arg, perm) \ 231 static const struct kernel_param_ops __param_ops_##name = \ 232 { .flags = 0, .set = _set, .get = _get }; \ 233 __module_param_call(MODULE_PARAM_PREFIX, \ 234 name, &__param_ops_##name, arg, perm, -1, 0) 235 236 #ifdef CONFIG_SYSFS 237 extern void kernel_param_lock(struct module *mod); 238 extern void kernel_param_unlock(struct module *mod); 239 #else 240 static inline void kernel_param_lock(struct module *mod) 241 { 242 } 243 static inline void kernel_param_unlock(struct module *mod) 244 { 245 } 246 #endif 247 248 #ifndef MODULE 249 /** 250 * core_param - define a historical core kernel parameter. 251 * @name: the name of the cmdline and sysfs parameter (often the same as var) 252 * @var: the variable 253 * @type: the type of the parameter 254 * @perm: visibility in sysfs 255 * 256 * core_param is just like module_param(), but cannot be modular and 257 * doesn't add a prefix (such as "printk."). This is for compatibility 258 * with __setup(), and it makes sense as truly core parameters aren't 259 * tied to the particular file they're in. 260 */ 261 #define core_param(name, var, type, perm) \ 262 param_check_##type(name, &(var)); \ 263 __module_param_call("", name, ¶m_ops_##type, &var, perm, -1, 0) 264 265 /** 266 * core_param_unsafe - same as core_param but taints kernel 267 */ 268 #define core_param_unsafe(name, var, type, perm) \ 269 param_check_##type(name, &(var)); \ 270 __module_param_call("", name, ¶m_ops_##type, &var, perm, \ 271 -1, KERNEL_PARAM_FL_UNSAFE) 272 273 #endif /* !MODULE */ 274 275 /** 276 * module_param_string - a char array parameter 277 * @name: the name of the parameter 278 * @string: the string variable 279 * @len: the maximum length of the string, incl. terminator 280 * @perm: visibility in sysfs. 281 * 282 * This actually copies the string when it's set (unlike type charp). 283 * @len is usually just sizeof(string). 284 */ 285 #define module_param_string(name, string, len, perm) \ 286 static const struct kparam_string __param_string_##name \ 287 = { len, string }; \ 288 __module_param_call(MODULE_PARAM_PREFIX, name, \ 289 ¶m_ops_string, \ 290 .str = &__param_string_##name, perm, -1, 0);\ 291 __MODULE_PARM_TYPE(name, "string") 292 293 /** 294 * parameq - checks if two parameter names match 295 * @name1: parameter name 1 296 * @name2: parameter name 2 297 * 298 * Returns true if the two parameter names are equal. 299 * Dashes (-) are considered equal to underscores (_). 300 */ 301 extern bool parameq(const char *name1, const char *name2); 302 303 /** 304 * parameqn - checks if two parameter names match 305 * @name1: parameter name 1 306 * @name2: parameter name 2 307 * @n: the length to compare 308 * 309 * Similar to parameq(), except it compares @n characters. 310 */ 311 extern bool parameqn(const char *name1, const char *name2, size_t n); 312 313 /* Called on module insert or kernel boot */ 314 extern char *parse_args(const char *name, 315 char *args, 316 const struct kernel_param *params, 317 unsigned num, 318 s16 level_min, 319 s16 level_max, 320 void *arg, 321 int (*unknown)(char *param, char *val, 322 const char *doing, void *arg)); 323 324 /* Called by module remove. */ 325 #ifdef CONFIG_SYSFS 326 extern void destroy_params(const struct kernel_param *params, unsigned num); 327 #else 328 static inline void destroy_params(const struct kernel_param *params, 329 unsigned num) 330 { 331 } 332 #endif /* !CONFIG_SYSFS */ 333 334 /* All the helper functions */ 335 /* The macros to do compile-time type checking stolen from Jakub 336 Jelinek, who IIRC came up with this idea for the 2.4 module init code. */ 337 #define __param_check(name, p, type) \ 338 static inline type __always_unused *__check_##name(void) { return(p); } 339 340 extern const struct kernel_param_ops param_ops_byte; 341 extern int param_set_byte(const char *val, const struct kernel_param *kp); 342 extern int param_get_byte(char *buffer, const struct kernel_param *kp); 343 #define param_check_byte(name, p) __param_check(name, p, unsigned char) 344 345 extern const struct kernel_param_ops param_ops_short; 346 extern int param_set_short(const char *val, const struct kernel_param *kp); 347 extern int param_get_short(char *buffer, const struct kernel_param *kp); 348 #define param_check_short(name, p) __param_check(name, p, short) 349 350 extern const struct kernel_param_ops param_ops_ushort; 351 extern int param_set_ushort(const char *val, const struct kernel_param *kp); 352 extern int param_get_ushort(char *buffer, const struct kernel_param *kp); 353 #define param_check_ushort(name, p) __param_check(name, p, unsigned short) 354 355 extern const struct kernel_param_ops param_ops_int; 356 extern int param_set_int(const char *val, const struct kernel_param *kp); 357 extern int param_get_int(char *buffer, const struct kernel_param *kp); 358 #define param_check_int(name, p) __param_check(name, p, int) 359 360 extern const struct kernel_param_ops param_ops_uint; 361 extern int param_set_uint(const char *val, const struct kernel_param *kp); 362 extern int param_get_uint(char *buffer, const struct kernel_param *kp); 363 #define param_check_uint(name, p) __param_check(name, p, unsigned int) 364 365 extern const struct kernel_param_ops param_ops_long; 366 extern int param_set_long(const char *val, const struct kernel_param *kp); 367 extern int param_get_long(char *buffer, const struct kernel_param *kp); 368 #define param_check_long(name, p) __param_check(name, p, long) 369 370 extern const struct kernel_param_ops param_ops_ulong; 371 extern int param_set_ulong(const char *val, const struct kernel_param *kp); 372 extern int param_get_ulong(char *buffer, const struct kernel_param *kp); 373 #define param_check_ulong(name, p) __param_check(name, p, unsigned long) 374 375 extern const struct kernel_param_ops param_ops_ullong; 376 extern int param_set_ullong(const char *val, const struct kernel_param *kp); 377 extern int param_get_ullong(char *buffer, const struct kernel_param *kp); 378 #define param_check_ullong(name, p) __param_check(name, p, unsigned long long) 379 380 extern const struct kernel_param_ops param_ops_charp; 381 extern int param_set_charp(const char *val, const struct kernel_param *kp); 382 extern int param_get_charp(char *buffer, const struct kernel_param *kp); 383 extern void param_free_charp(void *arg); 384 #define param_check_charp(name, p) __param_check(name, p, char *) 385 386 /* We used to allow int as well as bool. We're taking that away! */ 387 extern const struct kernel_param_ops param_ops_bool; 388 extern int param_set_bool(const char *val, const struct kernel_param *kp); 389 extern int param_get_bool(char *buffer, const struct kernel_param *kp); 390 #define param_check_bool(name, p) __param_check(name, p, bool) 391 392 extern const struct kernel_param_ops param_ops_bool_enable_only; 393 extern int param_set_bool_enable_only(const char *val, 394 const struct kernel_param *kp); 395 /* getter is the same as for the regular bool */ 396 #define param_check_bool_enable_only param_check_bool 397 398 extern const struct kernel_param_ops param_ops_invbool; 399 extern int param_set_invbool(const char *val, const struct kernel_param *kp); 400 extern int param_get_invbool(char *buffer, const struct kernel_param *kp); 401 #define param_check_invbool(name, p) __param_check(name, p, bool) 402 403 /* An int, which can only be set like a bool (though it shows as an int). */ 404 extern const struct kernel_param_ops param_ops_bint; 405 extern int param_set_bint(const char *val, const struct kernel_param *kp); 406 #define param_get_bint param_get_int 407 #define param_check_bint param_check_int 408 409 /** 410 * module_param_array - a parameter which is an array of some type 411 * @name: the name of the array variable 412 * @type: the type, as per module_param() 413 * @nump: optional pointer filled in with the number written 414 * @perm: visibility in sysfs 415 * 416 * Input and output are as comma-separated values. Commas inside values 417 * don't work properly (eg. an array of charp). 418 * 419 * ARRAY_SIZE(@name) is used to determine the number of elements in the 420 * array, so the definition must be visible. 421 */ 422 #define module_param_array(name, type, nump, perm) \ 423 module_param_array_named(name, name, type, nump, perm) 424 425 /** 426 * module_param_array_named - renamed parameter which is an array of some type 427 * @name: a valid C identifier which is the parameter name 428 * @array: the name of the array variable 429 * @type: the type, as per module_param() 430 * @nump: optional pointer filled in with the number written 431 * @perm: visibility in sysfs 432 * 433 * This exposes a different name than the actual variable name. See 434 * module_param_named() for why this might be necessary. 435 */ 436 #define module_param_array_named(name, array, type, nump, perm) \ 437 param_check_##type(name, &(array)[0]); \ 438 static const struct kparam_array __param_arr_##name \ 439 = { .max = ARRAY_SIZE(array), .num = nump, \ 440 .ops = ¶m_ops_##type, \ 441 .elemsize = sizeof(array[0]), .elem = array }; \ 442 __module_param_call(MODULE_PARAM_PREFIX, name, \ 443 ¶m_array_ops, \ 444 .arr = &__param_arr_##name, \ 445 perm, -1, 0); \ 446 __MODULE_PARM_TYPE(name, "array of " #type) 447 448 enum hwparam_type { 449 hwparam_ioport, /* Module parameter configures an I/O port */ 450 hwparam_iomem, /* Module parameter configures an I/O mem address */ 451 hwparam_ioport_or_iomem, /* Module parameter could be either, depending on other option */ 452 hwparam_irq, /* Module parameter configures an IRQ */ 453 hwparam_dma, /* Module parameter configures a DMA channel */ 454 hwparam_dma_addr, /* Module parameter configures a DMA buffer address */ 455 hwparam_other, /* Module parameter configures some other value */ 456 }; 457 458 /** 459 * module_param_hw_named - A parameter representing a hw parameters 460 * @name: a valid C identifier which is the parameter name. 461 * @value: the actual lvalue to alter. 462 * @type: the type of the parameter 463 * @hwtype: what the value represents (enum hwparam_type) 464 * @perm: visibility in sysfs. 465 * 466 * Usually it's a good idea to have variable names and user-exposed names the 467 * same, but that's harder if the variable must be non-static or is inside a 468 * structure. This allows exposure under a different name. 469 */ 470 #define module_param_hw_named(name, value, type, hwtype, perm) \ 471 param_check_##type(name, &(value)); \ 472 __module_param_call(MODULE_PARAM_PREFIX, name, \ 473 ¶m_ops_##type, &value, \ 474 perm, -1, \ 475 KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0)); \ 476 __MODULE_PARM_TYPE(name, #type) 477 478 #define module_param_hw(name, type, hwtype, perm) \ 479 module_param_hw_named(name, name, type, hwtype, perm) 480 481 /** 482 * module_param_hw_array - A parameter representing an array of hw parameters 483 * @name: the name of the array variable 484 * @type: the type, as per module_param() 485 * @hwtype: what the value represents (enum hwparam_type) 486 * @nump: optional pointer filled in with the number written 487 * @perm: visibility in sysfs 488 * 489 * Input and output are as comma-separated values. Commas inside values 490 * don't work properly (eg. an array of charp). 491 * 492 * ARRAY_SIZE(@name) is used to determine the number of elements in the 493 * array, so the definition must be visible. 494 */ 495 #define module_param_hw_array(name, type, hwtype, nump, perm) \ 496 param_check_##type(name, &(name)[0]); \ 497 static const struct kparam_array __param_arr_##name \ 498 = { .max = ARRAY_SIZE(name), .num = nump, \ 499 .ops = ¶m_ops_##type, \ 500 .elemsize = sizeof(name[0]), .elem = name }; \ 501 __module_param_call(MODULE_PARAM_PREFIX, name, \ 502 ¶m_array_ops, \ 503 .arr = &__param_arr_##name, \ 504 perm, -1, \ 505 KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0)); \ 506 __MODULE_PARM_TYPE(name, "array of " #type) 507 508 509 extern const struct kernel_param_ops param_array_ops; 510 511 extern const struct kernel_param_ops param_ops_string; 512 extern int param_set_copystring(const char *val, const struct kernel_param *); 513 extern int param_get_string(char *buffer, const struct kernel_param *kp); 514 515 /* for exporting parameters in /sys/module/.../parameters */ 516 517 struct module; 518 519 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) 520 extern int module_param_sysfs_setup(struct module *mod, 521 const struct kernel_param *kparam, 522 unsigned int num_params); 523 524 extern void module_param_sysfs_remove(struct module *mod); 525 #else 526 static inline int module_param_sysfs_setup(struct module *mod, 527 const struct kernel_param *kparam, 528 unsigned int num_params) 529 { 530 return 0; 531 } 532 533 static inline void module_param_sysfs_remove(struct module *mod) 534 { } 535 #endif 536 537 #endif /* _LINUX_MODULE_PARAMS_H */ 538