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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _LINUX_MODULE_PARAMS_H3#define _LINUX_MODULE_PARAMS_H4/* (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 the10 module name. */11#ifdef MODULE12#define MODULE_PARAM_PREFIX /* empty */13#define __MODULE_INFO_PREFIX /* empty */14#else15#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#endif19 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) "=" info27 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 do32 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 36struct kernel_param;37 38/*39 * Flags available for kernel_param_ops40 *41 * NOARG - the parameter allows for no argument (foo instead of foo=1)42 */43enum {44 KERNEL_PARAM_OPS_FL_NOARG = (1 << 0)45};46 47struct 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_param60 *61 * UNSAFE - the parameter is dangerous and setting it will taint the kernel62 * HWPARAM - Hardware param not permitted in lockdown mode63 */64enum {65 KERNEL_PARAM_FL_UNSAFE = (1 << 0),66 KERNEL_PARAM_FL_HWPARAM = (1 << 1),67};68 69struct 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 83extern const struct kernel_param __start___param[], __stop___param[];84 85/* Special one for strings we want to copy into */86struct kparam_string {87 unsigned int maxlen;88 char *string;89};90 91/* Special one for arrays */92struct kparam_array93{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 parameter103 * @name: the variable to alter, and exposed parameter name.104 * @type: the type of the parameter105 * @perm: visibility in sysfs.106 *107 * @name becomes the module parameter, or (prefixed by KBUILD_MODNAME and a108 * ".") the kernel commandline parameter. Note that - is changed to _, so109 * 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 0444112 * for world-readable, 0644 for root-writable, etc. Note that if it113 * is writable, you may need to use kernel_param_lock() around114 * 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 a117 * param_check_##type: for convenience many standard types are provided but118 * you can create your own by defining those variables.119 *120 * Standard types are:121 * byte, hexint, short, ushort, int, uint, long, ulong122 * charp: a character pointer123 * 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 kernel131 * @name: the variable to alter, and exposed parameter name.132 * @type: the type of the parameter133 * @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 parameter140 * @name: a valid C identifier which is the parameter name.141 * @value: the actual lvalue to alter.142 * @type: the type of the parameter143 * @perm: visibility in sysfs.144 *145 * Usually it's a good idea to have variable names and user-exposed names the146 * same, but that's harder if the variable must be non-static or is inside a147 * 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 kernel156 * @name: a valid C identifier which is the parameter name.157 * @value: the actual lvalue to alter.158 * @type: the type of the parameter159 * @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 parameter168 * @name: a valid C identifier which is the parameter name.169 * @ops: the set & get operations for this parameter.170 * @arg: args for @ops171 * @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 parameter186 * to be evaluated before core initcall level187 * @name: a valid C identifier which is the parameter name.188 * @ops: the set & get operations for this parameter.189 * @arg: args for @ops190 * @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 parameter199 * to be evaluated before postcore initcall level200 * @name: a valid C identifier which is the parameter name.201 * @ops: the set & get operations for this parameter.202 * @arg: args for @ops203 * @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 parameter212 * to be evaluated before arch initcall level213 * @name: a valid C identifier which is the parameter name.214 * @ops: the set & get operations for this parameter.215 * @arg: args for @ops216 * @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 parameter225 * to be evaluated before subsys initcall level226 * @name: a valid C identifier which is the parameter name.227 * @ops: the set & get operations for this parameter.228 * @arg: args for @ops229 * @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 parameter238 * to be evaluated before fs initcall level239 * @name: a valid C identifier which is the parameter name.240 * @ops: the set & get operations for this parameter.241 * @arg: args for @ops242 * @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 parameter251 * to be evaluated before device initcall level252 * @name: a valid C identifier which is the parameter name.253 * @ops: the set & get operations for this parameter.254 * @arg: args for @ops255 * @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 parameter264 * to be evaluated before late initcall level265 * @name: a valid C identifier which is the parameter name.266 * @ops: the set & get operations for this parameter.267 * @arg: args for @ops268 * @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 into276 read-only sections (which is part of respective UNIX ABI on these277 platforms). So 'const' makes no sense and even causes compile failures278 with some compilers. */279#if defined(CONFIG_ALPHA) || defined(CONFIG_PPC64)280#define __moduleparam_const281#else282#define __moduleparam_const const283#endif284 285/* This is the fundamental function for registering boot/module286 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 this298 * parameter). For repeated set/get pairs (i.e. the same struct299 * 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_SYSFS308extern void kernel_param_lock(struct module *mod);309extern void kernel_param_unlock(struct module *mod) HWJS_SUSPENDS;310#else311static inline void kernel_param_lock(struct module *mod)312{313}314static inline void kernel_param_unlock(struct module *mod)315{316}317#endif318 319#ifndef MODULE320/**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 variable324 * @type: the type of the parameter325 * @perm: visibility in sysfs326 *327 * core_param is just like module_param(), but cannot be modular and328 * doesn't add a prefix (such as "printk."). This is for compatibility329 * with __setup(), and it makes sense as truly core parameters aren't330 * 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 kernel338 * @name: the name of the cmdline and sysfs parameter (often the same as var)339 * @var: the variable340 * @type: the type of the parameter341 * @perm: visibility in sysfs342 */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 parameter352 * @name: the name of the parameter353 * @string: the string variable354 * @len: the maximum length of the string, incl. terminator355 * @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 match370 * @name1: parameter name 1371 * @name2: parameter name 2372 *373 * Returns true if the two parameter names are equal.374 * Dashes (-) are considered equal to underscores (_).375 */376extern bool parameq(const char *name1, const char *name2);377 378/**379 * parameqn - checks if two parameter names match380 * @name1: parameter name 1381 * @name2: parameter name 2382 * @n: the length to compare383 *384 * Similar to parameq(), except it compares @n characters.385 */386extern bool parameqn(const char *name1, const char *name2, size_t n);387 388typedef int (*parse_unknown_fn)(char *param, char *val, const char *doing, void *arg);389 390/* Called on module insert or kernel boot */391extern 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) HWJS_SUSPENDS;398 399/* Called by module remove. */400#ifdef CONFIG_SYSFS401extern void destroy_params(const struct kernel_param *params, unsigned num);402#else403static 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 Jakub411 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 415extern const struct kernel_param_ops param_ops_byte;416extern int param_set_byte(const char *val, const struct kernel_param *kp);417extern 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 420extern const struct kernel_param_ops param_ops_short;421extern int param_set_short(const char *val, const struct kernel_param *kp);422extern int param_get_short(char *buffer, const struct kernel_param *kp);423#define param_check_short(name, p) __param_check(name, p, short)424 425extern const struct kernel_param_ops param_ops_ushort;426extern int param_set_ushort(const char *val, const struct kernel_param *kp);427extern 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 430extern const struct kernel_param_ops param_ops_int;431extern int param_set_int(const char *val, const struct kernel_param *kp);432extern int param_get_int(char *buffer, const struct kernel_param *kp);433#define param_check_int(name, p) __param_check(name, p, int)434 435extern const struct kernel_param_ops param_ops_uint;436extern int param_set_uint(const char *val, const struct kernel_param *kp);437extern int param_get_uint(char *buffer, const struct kernel_param *kp);438int 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 442extern const struct kernel_param_ops param_ops_long;443extern int param_set_long(const char *val, const struct kernel_param *kp);444extern int param_get_long(char *buffer, const struct kernel_param *kp);445#define param_check_long(name, p) __param_check(name, p, long)446 447extern const struct kernel_param_ops param_ops_ulong;448extern int param_set_ulong(const char *val, const struct kernel_param *kp);449extern 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 452extern const struct kernel_param_ops param_ops_ullong;453extern int param_set_ullong(const char *val, const struct kernel_param *kp);454extern 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 457extern const struct kernel_param_ops param_ops_hexint;458extern int param_set_hexint(const char *val, const struct kernel_param *kp);459extern int param_get_hexint(char *buffer, const struct kernel_param *kp);460#define param_check_hexint(name, p) param_check_uint(name, p)461 462extern const struct kernel_param_ops param_ops_charp;463extern int param_set_charp(const char *val, const struct kernel_param *kp);464extern int param_get_charp(char *buffer, const struct kernel_param *kp);465extern 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! */469extern const struct kernel_param_ops param_ops_bool;470extern int param_set_bool(const char *val, const struct kernel_param *kp);471extern int param_get_bool(char *buffer, const struct kernel_param *kp);472#define param_check_bool(name, p) __param_check(name, p, bool)473 474extern const struct kernel_param_ops param_ops_bool_enable_only;475extern 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_bool479 480extern const struct kernel_param_ops param_ops_invbool;481extern int param_set_invbool(const char *val, const struct kernel_param *kp);482extern 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). */486extern const struct kernel_param_ops param_ops_bint;487extern int param_set_bint(const char *val, const struct kernel_param *kp);488#define param_get_bint param_get_int489#define param_check_bint param_check_int490 491/**492 * module_param_array - a parameter which is an array of some type493 * @name: the name of the array variable494 * @type: the type, as per module_param()495 * @nump: optional pointer filled in with the number written496 * @perm: visibility in sysfs497 *498 * Input and output are as comma-separated values. Commas inside values499 * don't work properly (eg. an array of charp).500 *501 * ARRAY_SIZE(@name) is used to determine the number of elements in the502 * 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 type509 * @name: a valid C identifier which is the parameter name510 * @array: the name of the array variable511 * @type: the type, as per module_param()512 * @nump: optional pointer filled in with the number written513 * @perm: visibility in sysfs514 *515 * This exposes a different name than the actual variable name. See516 * 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 530enum 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 parameters542 * @name: a valid C identifier which is the parameter name.543 * @value: the actual lvalue to alter.544 * @type: the type of the parameter545 * @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 the549 * same, but that's harder if the variable must be non-static or is inside a550 * 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 parameters565 * @name: the name of the array variable566 * @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 written569 * @perm: visibility in sysfs570 *571 * Input and output are as comma-separated values. Commas inside values572 * don't work properly (eg. an array of charp).573 *574 * ARRAY_SIZE(@name) is used to determine the number of elements in the575 * 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 591extern const struct kernel_param_ops param_array_ops;592 593extern const struct kernel_param_ops param_ops_string;594extern int param_set_copystring(const char *val, const struct kernel_param *);595extern int param_get_string(char *buffer, const struct kernel_param *kp);596 597/* for exporting parameters in /sys/module/.../parameters */598 599struct module;600 601#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)602extern int module_param_sysfs_setup(struct module *mod,603 const struct kernel_param *kparam,604 unsigned int num_params);605 606extern void module_param_sysfs_remove(struct module *mod);607#else608static 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 615static inline void module_param_sysfs_remove(struct module *mod)616{ }617#endif618 619#endif /* _LINUX_MODULE_PARAMS_H */620