1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_MODULE_PARAMS_H 3 #define _LINUX_MODULE_PARAMS_H 4 /* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */ 5 #include <linux/init.h> 6 #include <linux/stringify.h> 7 #include <linux/kernel.h> 8 9 /* You can override this manually, but generally this should match the 10 module name. */ 11 #ifdef MODULE 12 #define MODULE_PARAM_PREFIX /* empty */ 13 #define __MODULE_INFO_PREFIX /* empty */ 14 #else 15 #define MODULE_PARAM_PREFIX KBUILD_MODNAME "." 16 /* We cannot use MODULE_PARAM_PREFIX because some modules override it. */ 17 #define __MODULE_INFO_PREFIX KBUILD_MODNAME "." 18 #endif 19 20 /* Chosen so that structs with an unsigned long line up. */ 21 #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long)) 22 23 #define __MODULE_INFO(tag, name, info) \ 24 static const char __UNIQUE_ID(name)[] \ 25 __used __section(".modinfo") __aligned(1) \ 26 = __MODULE_INFO_PREFIX __stringify(tag) "=" info 27 28 #define __MODULE_PARM_TYPE(name, _type) \ 29 __MODULE_INFO(parmtype, name##type, #name ":" _type) 30 31 /* One for each parameter, describing how to use it. Some files do 32 multiple of these per line, so can't just use MODULE_INFO. */ 33 #define MODULE_PARM_DESC(_parm, desc) \ 34 __MODULE_INFO(parm, _parm, #_parm ":" desc) 35 36 struct kernel_param; 37 38 /* 39 * Flags available for kernel_param_ops 40 * 41 * NOARG - the parameter allows for no argument (foo instead of foo=1) 42 */ 43 enum { 44 KERNEL_PARAM_OPS_FL_NOARG = (1 << 0) 45 }; 46 47 struct kernel_param_ops { 48 /* How the ops should behave */ 49 unsigned int flags; 50 /* Returns 0, or -errno. arg is in kp->arg. */ 51 int (*set)(const char *val, const struct kernel_param *kp); 52 /* Returns length written or -errno. Buffer is 4k (ie. be short!) */ 53 int (*get)(char *buffer, const struct kernel_param *kp); 54 /* Optional function to free kp->arg when module unloaded. */ 55 void (*free)(void *arg); 56 }; 57 58 /* 59 * Flags available for kernel_param 60 * 61 * UNSAFE - the parameter is dangerous and setting it will taint the kernel 62 * HWPARAM - Hardware param not permitted in lockdown mode 63 */ 64 enum { 65 KERNEL_PARAM_FL_UNSAFE = (1 << 0), 66 KERNEL_PARAM_FL_HWPARAM = (1 << 1), 67 }; 68 69 struct kernel_param { 70 const char *name; 71 struct module *mod; 72 const struct kernel_param_ops *ops; 73 const u16 perm; 74 s8 level; 75 u8 flags; 76 union { 77 void *arg; 78 const struct kparam_string *str; 79 const struct kparam_array *arr; 80 }; 81 }; 82 83 extern const struct kernel_param __start___param[], __stop___param[]; 84 85 /* Special one for strings we want to copy into */ 86 struct kparam_string { 87 unsigned int maxlen; 88 char *string; 89 }; 90 91 /* Special one for arrays */ 92 struct kparam_array 93 { 94 unsigned int max; 95 unsigned int elemsize; 96 unsigned int *num; 97 const struct kernel_param_ops *ops; 98 void *elem; 99 }; 100 101 /** 102 * module_param - typesafe helper for a module/cmdline parameter 103 * @name: the variable to alter, and exposed parameter name. 104 * @type: the type of the parameter 105 * @perm: visibility in sysfs. 106 * 107 * @name becomes the module parameter, or (prefixed by KBUILD_MODNAME and a 108 * ".") the kernel commandline parameter. Note that - is changed to _, so 109 * the user can use "foo-bar=1" even for variable "foo_bar". 110 * 111 * @perm is 0 if the variable is not to appear in sysfs, or 0444 112 * for world-readable, 0644 for root-writable, etc. Note that if it 113 * is writable, you may need to use kernel_param_lock() around 114 * accesses (esp. charp, which can be kfreed when it changes). 115 * 116 * The @type is simply pasted to refer to a param_ops_##type and a 117 * param_check_##type: for convenience many standard types are provided but 118 * you can create your own by defining those variables. 119 * 120 * Standard types are: 121 * byte, hexint, short, ushort, int, uint, long, ulong 122 * charp: a character pointer 123 * bool: a bool, values 0/1, y/n, Y/N. 124 * invbool: the above, only sense-reversed (N = true). 125 */ 126 #define module_param(name, type, perm) \ 127 module_param_named(name, name, type, perm) 128 129 /** 130 * module_param_unsafe - same as module_param but taints kernel 131 * @name: the variable to alter, and exposed parameter name. 132 * @type: the type of the parameter 133 * @perm: visibility in sysfs. 134 */ 135 #define module_param_unsafe(name, type, perm) \ 136 module_param_named_unsafe(name, name, type, perm) 137 138 /** 139 * module_param_named - typesafe helper for a renamed module/cmdline parameter 140 * @name: a valid C identifier which is the parameter name. 141 * @value: the actual lvalue to alter. 142 * @type: the type of the parameter 143 * @perm: visibility in sysfs. 144 * 145 * Usually it's a good idea to have variable names and user-exposed names the 146 * same, but that's harder if the variable must be non-static or is inside a 147 * structure. This allows exposure under a different name. 148 */ 149 #define module_param_named(name, value, type, perm) \ 150 param_check_##type(name, &(value)); \ 151 module_param_cb(name, ¶m_ops_##type, &value, perm); \ 152 __MODULE_PARM_TYPE(name, #type) 153 154 /** 155 * module_param_named_unsafe - same as module_param_named but taints kernel 156 * @name: a valid C identifier which is the parameter name. 157 * @value: the actual lvalue to alter. 158 * @type: the type of the parameter 159 * @perm: visibility in sysfs. 160 */ 161 #define module_param_named_unsafe(name, value, type, perm) \ 162 param_check_##type(name, &(value)); \ 163 module_param_cb_unsafe(name, ¶m_ops_##type, &value, perm); \ 164 __MODULE_PARM_TYPE(name, #type) 165 166 /** 167 * module_param_cb - general callback for a module/cmdline parameter 168 * @name: a valid C identifier which is the parameter name. 169 * @ops: the set & get operations for this parameter. 170 * @arg: args for @ops 171 * @perm: visibility in sysfs. 172 * 173 * The ops can have NULL set or get functions. 174 */ 175 #define module_param_cb(name, ops, arg, perm) \ 176 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0) 177 178 #define module_param_cb_unsafe(name, ops, arg, perm) \ 179 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \ 180 KERNEL_PARAM_FL_UNSAFE) 181 182 #define __level_param_cb(name, ops, arg, perm, level) \ 183 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0) 184 /** 185 * core_param_cb - general callback for a module/cmdline parameter 186 * to be evaluated before core initcall level 187 * @name: a valid C identifier which is the parameter name. 188 * @ops: the set & get operations for this parameter. 189 * @arg: args for @ops 190 * @perm: visibility in sysfs. 191 * 192 * The ops can have NULL set or get functions. 193 */ 194 #define core_param_cb(name, ops, arg, perm) \ 195 __level_param_cb(name, ops, arg, perm, 1) 196 197 /** 198 * postcore_param_cb - general callback for a module/cmdline parameter 199 * to be evaluated before postcore initcall level 200 * @name: a valid C identifier which is the parameter name. 201 * @ops: the set & get operations for this parameter. 202 * @arg: args for @ops 203 * @perm: visibility in sysfs. 204 * 205 * The ops can have NULL set or get functions. 206 */ 207 #define postcore_param_cb(name, ops, arg, perm) \ 208 __level_param_cb(name, ops, arg, perm, 2) 209 210 /** 211 * arch_param_cb - general callback for a module/cmdline parameter 212 * to be evaluated before arch initcall level 213 * @name: a valid C identifier which is the parameter name. 214 * @ops: the set & get operations for this parameter. 215 * @arg: args for @ops 216 * @perm: visibility in sysfs. 217 * 218 * The ops can have NULL set or get functions. 219 */ 220 #define arch_param_cb(name, ops, arg, perm) \ 221 __level_param_cb(name, ops, arg, perm, 3) 222 223 /** 224 * subsys_param_cb - general callback for a module/cmdline parameter 225 * to be evaluated before subsys initcall level 226 * @name: a valid C identifier which is the parameter name. 227 * @ops: the set & get operations for this parameter. 228 * @arg: args for @ops 229 * @perm: visibility in sysfs. 230 * 231 * The ops can have NULL set or get functions. 232 */ 233 #define subsys_param_cb(name, ops, arg, perm) \ 234 __level_param_cb(name, ops, arg, perm, 4) 235 236 /** 237 * fs_param_cb - general callback for a module/cmdline parameter 238 * to be evaluated before fs initcall level 239 * @name: a valid C identifier which is the parameter name. 240 * @ops: the set & get operations for this parameter. 241 * @arg: args for @ops 242 * @perm: visibility in sysfs. 243 * 244 * The ops can have NULL set or get functions. 245 */ 246 #define fs_param_cb(name, ops, arg, perm) \ 247 __level_param_cb(name, ops, arg, perm, 5) 248 249 /** 250 * device_param_cb - general callback for a module/cmdline parameter 251 * to be evaluated before device initcall level 252 * @name: a valid C identifier which is the parameter name. 253 * @ops: the set & get operations for this parameter. 254 * @arg: args for @ops 255 * @perm: visibility in sysfs. 256 * 257 * The ops can have NULL set or get functions. 258 */ 259 #define device_param_cb(name, ops, arg, perm) \ 260 __level_param_cb(name, ops, arg, perm, 6) 261 262 /** 263 * late_param_cb - general callback for a module/cmdline parameter 264 * to be evaluated before late initcall level 265 * @name: a valid C identifier which is the parameter name. 266 * @ops: the set & get operations for this parameter. 267 * @arg: args for @ops 268 * @perm: visibility in sysfs. 269 * 270 * The ops can have NULL set or get functions. 271 */ 272 #define late_param_cb(name, ops, arg, perm) \ 273 __level_param_cb(name, ops, arg, perm, 7) 274 275 /* On alpha, ia64 and ppc64 relocations to global data cannot go into 276 read-only sections (which is part of respective UNIX ABI on these 277 platforms). So 'const' makes no sense and even causes compile failures 278 with some compilers. */ 279 #if defined(CONFIG_ALPHA) || defined(CONFIG_PPC64) 280 #define __moduleparam_const 281 #else 282 #define __moduleparam_const const 283 #endif 284 285 /* This is the fundamental function for registering boot/module 286 parameters. */ 287 #define __module_param_call(prefix, name, ops, arg, perm, level, flags) \ 288 /* Default value instead of permissions? */ \ 289 static const char __param_str_##name[] = prefix #name; \ 290 static struct kernel_param __moduleparam_const __param_##name \ 291 __used __section("__param") \ 292 __aligned(__alignof__(struct kernel_param)) \ 293 = { __param_str_##name, THIS_MODULE, ops, \ 294 VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } } 295 296 /* 297 * Useful for describing a set/get pair used only once (i.e. for this 298 * parameter). For repeated set/get pairs (i.e. the same struct 299 * kernel_param_ops), use module_param_cb() instead. 300 */ 301 #define module_param_call(name, _set, _get, arg, perm) \ 302 static const struct kernel_param_ops __param_ops_##name = \ 303 { .flags = 0, .set = _set, .get = _get }; \ 304 __module_param_call(MODULE_PARAM_PREFIX, \ 305 name, &__param_ops_##name, arg, perm, -1, 0) 306 307 #ifdef CONFIG_SYSFS 308 extern void kernel_param_lock(struct module *mod); 309 extern void kernel_param_unlock(struct module *mod); 310 #else 311 static inline void kernel_param_lock(struct module *mod) 312 { 313 } 314 static inline void kernel_param_unlock(struct module *mod) 315 { 316 } 317 #endif 318 319 #ifndef MODULE 320 /** 321 * core_param - define a historical core kernel parameter. 322 * @name: the name of the cmdline and sysfs parameter (often the same as var) 323 * @var: the variable 324 * @type: the type of the parameter 325 * @perm: visibility in sysfs 326 * 327 * core_param is just like module_param(), but cannot be modular and 328 * doesn't add a prefix (such as "printk."). This is for compatibility 329 * with __setup(), and it makes sense as truly core parameters aren't 330 * tied to the particular file they're in. 331 */ 332 #define core_param(name, var, type, perm) \ 333 param_check_##type(name, &(var)); \ 334 __module_param_call("", name, ¶m_ops_##type, &var, perm, -1, 0) 335 336 /** 337 * core_param_unsafe - same as core_param but taints kernel 338 * @name: the name of the cmdline and sysfs parameter (often the same as var) 339 * @var: the variable 340 * @type: the type of the parameter 341 * @perm: visibility in sysfs 342 */ 343 #define core_param_unsafe(name, var, type, perm) \ 344 param_check_##type(name, &(var)); \ 345 __module_param_call("", name, ¶m_ops_##type, &var, perm, \ 346 -1, KERNEL_PARAM_FL_UNSAFE) 347 348 #endif /* !MODULE */ 349 350 /** 351 * module_param_string - a char array parameter 352 * @name: the name of the parameter 353 * @string: the string variable 354 * @len: the maximum length of the string, incl. terminator 355 * @perm: visibility in sysfs. 356 * 357 * This actually copies the string when it's set (unlike type charp). 358 * @len is usually just sizeof(string). 359 */ 360 #define module_param_string(name, string, len, perm) \ 361 static const struct kparam_string __param_string_##name \ 362 = { len, string }; \ 363 __module_param_call(MODULE_PARAM_PREFIX, name, \ 364 ¶m_ops_string, \ 365 .str = &__param_string_##name, perm, -1, 0);\ 366 __MODULE_PARM_TYPE(name, "string") 367 368 /** 369 * parameq - checks if two parameter names match 370 * @name1: parameter name 1 371 * @name2: parameter name 2 372 * 373 * Returns true if the two parameter names are equal. 374 * Dashes (-) are considered equal to underscores (_). 375 */ 376 extern bool parameq(const char *name1, const char *name2); 377 378 /** 379 * parameqn - checks if two parameter names match 380 * @name1: parameter name 1 381 * @name2: parameter name 2 382 * @n: the length to compare 383 * 384 * Similar to parameq(), except it compares @n characters. 385 */ 386 extern bool parameqn(const char *name1, const char *name2, size_t n); 387 388 typedef int (*parse_unknown_fn)(char *param, char *val, const char *doing, void *arg); 389 390 /* Called on module insert or kernel boot */ 391 extern char *parse_args(const char *name, 392 char *args, 393 const struct kernel_param *params, 394 unsigned num, 395 s16 level_min, 396 s16 level_max, 397 void *arg, parse_unknown_fn unknown); 398 399 /* Called by module remove. */ 400 #ifdef CONFIG_SYSFS 401 extern void destroy_params(const struct kernel_param *params, unsigned num); 402 #else 403 static inline void destroy_params(const struct kernel_param *params, 404 unsigned num) 405 { 406 } 407 #endif /* !CONFIG_SYSFS */ 408 409 /* All the helper functions */ 410 /* The macros to do compile-time type checking stolen from Jakub 411 Jelinek, who IIRC came up with this idea for the 2.4 module init code. */ 412 #define __param_check(name, p, type) \ 413 static inline type __always_unused *__check_##name(void) { return(p); } 414 415 extern const struct kernel_param_ops param_ops_byte; 416 extern int param_set_byte(const char *val, const struct kernel_param *kp); 417 extern int param_get_byte(char *buffer, const struct kernel_param *kp); 418 #define param_check_byte(name, p) __param_check(name, p, unsigned char) 419 420 extern const struct kernel_param_ops param_ops_short; 421 extern int param_set_short(const char *val, const struct kernel_param *kp); 422 extern int param_get_short(char *buffer, const struct kernel_param *kp); 423 #define param_check_short(name, p) __param_check(name, p, short) 424 425 extern const struct kernel_param_ops param_ops_ushort; 426 extern int param_set_ushort(const char *val, const struct kernel_param *kp); 427 extern int param_get_ushort(char *buffer, const struct kernel_param *kp); 428 #define param_check_ushort(name, p) __param_check(name, p, unsigned short) 429 430 extern const struct kernel_param_ops param_ops_int; 431 extern int param_set_int(const char *val, const struct kernel_param *kp); 432 extern int param_get_int(char *buffer, const struct kernel_param *kp); 433 #define param_check_int(name, p) __param_check(name, p, int) 434 435 extern const struct kernel_param_ops param_ops_uint; 436 extern int param_set_uint(const char *val, const struct kernel_param *kp); 437 extern int param_get_uint(char *buffer, const struct kernel_param *kp); 438 int param_set_uint_minmax(const char *val, const struct kernel_param *kp, 439 unsigned int min, unsigned int max); 440 #define param_check_uint(name, p) __param_check(name, p, unsigned int) 441 442 extern const struct kernel_param_ops param_ops_long; 443 extern int param_set_long(const char *val, const struct kernel_param *kp); 444 extern int param_get_long(char *buffer, const struct kernel_param *kp); 445 #define param_check_long(name, p) __param_check(name, p, long) 446 447 extern const struct kernel_param_ops param_ops_ulong; 448 extern int param_set_ulong(const char *val, const struct kernel_param *kp); 449 extern int param_get_ulong(char *buffer, const struct kernel_param *kp); 450 #define param_check_ulong(name, p) __param_check(name, p, unsigned long) 451 452 extern const struct kernel_param_ops param_ops_ullong; 453 extern int param_set_ullong(const char *val, const struct kernel_param *kp); 454 extern int param_get_ullong(char *buffer, const struct kernel_param *kp); 455 #define param_check_ullong(name, p) __param_check(name, p, unsigned long long) 456 457 extern const struct kernel_param_ops param_ops_hexint; 458 extern int param_set_hexint(const char *val, const struct kernel_param *kp); 459 extern int param_get_hexint(char *buffer, const struct kernel_param *kp); 460 #define param_check_hexint(name, p) param_check_uint(name, p) 461 462 extern const struct kernel_param_ops param_ops_charp; 463 extern int param_set_charp(const char *val, const struct kernel_param *kp); 464 extern int param_get_charp(char *buffer, const struct kernel_param *kp); 465 extern void param_free_charp(void *arg); 466 #define param_check_charp(name, p) __param_check(name, p, char *) 467 468 /* We used to allow int as well as bool. We're taking that away! */ 469 extern const struct kernel_param_ops param_ops_bool; 470 extern int param_set_bool(const char *val, const struct kernel_param *kp); 471 extern int param_get_bool(char *buffer, const struct kernel_param *kp); 472 #define param_check_bool(name, p) __param_check(name, p, bool) 473 474 extern const struct kernel_param_ops param_ops_bool_enable_only; 475 extern int param_set_bool_enable_only(const char *val, 476 const struct kernel_param *kp); 477 /* getter is the same as for the regular bool */ 478 #define param_check_bool_enable_only param_check_bool 479 480 extern const struct kernel_param_ops param_ops_invbool; 481 extern int param_set_invbool(const char *val, const struct kernel_param *kp); 482 extern int param_get_invbool(char *buffer, const struct kernel_param *kp); 483 #define param_check_invbool(name, p) __param_check(name, p, bool) 484 485 /* An int, which can only be set like a bool (though it shows as an int). */ 486 extern const struct kernel_param_ops param_ops_bint; 487 extern int param_set_bint(const char *val, const struct kernel_param *kp); 488 #define param_get_bint param_get_int 489 #define param_check_bint param_check_int 490 491 /** 492 * module_param_array - a parameter which is an array of some type 493 * @name: the name of the array variable 494 * @type: the type, as per module_param() 495 * @nump: optional pointer filled in with the number written 496 * @perm: visibility in sysfs 497 * 498 * Input and output are as comma-separated values. Commas inside values 499 * don't work properly (eg. an array of charp). 500 * 501 * ARRAY_SIZE(@name) is used to determine the number of elements in the 502 * array, so the definition must be visible. 503 */ 504 #define module_param_array(name, type, nump, perm) \ 505 module_param_array_named(name, name, type, nump, perm) 506 507 /** 508 * module_param_array_named - renamed parameter which is an array of some type 509 * @name: a valid C identifier which is the parameter name 510 * @array: the name of the array variable 511 * @type: the type, as per module_param() 512 * @nump: optional pointer filled in with the number written 513 * @perm: visibility in sysfs 514 * 515 * This exposes a different name than the actual variable name. See 516 * module_param_named() for why this might be necessary. 517 */ 518 #define module_param_array_named(name, array, type, nump, perm) \ 519 param_check_##type(name, &(array)[0]); \ 520 static const struct kparam_array __param_arr_##name \ 521 = { .max = ARRAY_SIZE(array), .num = nump, \ 522 .ops = ¶m_ops_##type, \ 523 .elemsize = sizeof(array[0]), .elem = array }; \ 524 __module_param_call(MODULE_PARAM_PREFIX, name, \ 525 ¶m_array_ops, \ 526 .arr = &__param_arr_##name, \ 527 perm, -1, 0); \ 528 __MODULE_PARM_TYPE(name, "array of " #type) 529 530 enum hwparam_type { 531 hwparam_ioport, /* Module parameter configures an I/O port */ 532 hwparam_iomem, /* Module parameter configures an I/O mem address */ 533 hwparam_ioport_or_iomem, /* Module parameter could be either, depending on other option */ 534 hwparam_irq, /* Module parameter configures an IRQ */ 535 hwparam_dma, /* Module parameter configures a DMA channel */ 536 hwparam_dma_addr, /* Module parameter configures a DMA buffer address */ 537 hwparam_other, /* Module parameter configures some other value */ 538 }; 539 540 /** 541 * module_param_hw_named - A parameter representing a hw parameters 542 * @name: a valid C identifier which is the parameter name. 543 * @value: the actual lvalue to alter. 544 * @type: the type of the parameter 545 * @hwtype: what the value represents (enum hwparam_type) 546 * @perm: visibility in sysfs. 547 * 548 * Usually it's a good idea to have variable names and user-exposed names the 549 * same, but that's harder if the variable must be non-static or is inside a 550 * structure. This allows exposure under a different name. 551 */ 552 #define module_param_hw_named(name, value, type, hwtype, perm) \ 553 param_check_##type(name, &(value)); \ 554 __module_param_call(MODULE_PARAM_PREFIX, name, \ 555 ¶m_ops_##type, &value, \ 556 perm, -1, \ 557 KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0)); \ 558 __MODULE_PARM_TYPE(name, #type) 559 560 #define module_param_hw(name, type, hwtype, perm) \ 561 module_param_hw_named(name, name, type, hwtype, perm) 562 563 /** 564 * module_param_hw_array - A parameter representing an array of hw parameters 565 * @name: the name of the array variable 566 * @type: the type, as per module_param() 567 * @hwtype: what the value represents (enum hwparam_type) 568 * @nump: optional pointer filled in with the number written 569 * @perm: visibility in sysfs 570 * 571 * Input and output are as comma-separated values. Commas inside values 572 * don't work properly (eg. an array of charp). 573 * 574 * ARRAY_SIZE(@name) is used to determine the number of elements in the 575 * array, so the definition must be visible. 576 */ 577 #define module_param_hw_array(name, type, hwtype, nump, perm) \ 578 param_check_##type(name, &(name)[0]); \ 579 static const struct kparam_array __param_arr_##name \ 580 = { .max = ARRAY_SIZE(name), .num = nump, \ 581 .ops = ¶m_ops_##type, \ 582 .elemsize = sizeof(name[0]), .elem = name }; \ 583 __module_param_call(MODULE_PARAM_PREFIX, name, \ 584 ¶m_array_ops, \ 585 .arr = &__param_arr_##name, \ 586 perm, -1, \ 587 KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0)); \ 588 __MODULE_PARM_TYPE(name, "array of " #type) 589 590 591 extern const struct kernel_param_ops param_array_ops; 592 593 extern const struct kernel_param_ops param_ops_string; 594 extern int param_set_copystring(const char *val, const struct kernel_param *); 595 extern int param_get_string(char *buffer, const struct kernel_param *kp); 596 597 /* for exporting parameters in /sys/module/.../parameters */ 598 599 struct module; 600 601 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES) 602 extern int module_param_sysfs_setup(struct module *mod, 603 const struct kernel_param *kparam, 604 unsigned int num_params); 605 606 extern void module_param_sysfs_remove(struct module *mod); 607 #else 608 static inline int module_param_sysfs_setup(struct module *mod, 609 const struct kernel_param *kparam, 610 unsigned int num_params) 611 { 612 return 0; 613 } 614 615 static inline void module_param_sysfs_remove(struct module *mod) 616 { } 617 #endif 618 619 #endif /* _LINUX_MODULE_PARAMS_H */ 620