xref: /linux/include/linux/moduleparam.h (revision c84d574698bad2c02aad506dfe712f83cbe3b771)
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 /*
10  * The maximum module name length, including the NUL byte.
11  * Chosen so that structs with an unsigned long line up, specifically
12  * modversion_info.
13  */
14 #define __MODULE_NAME_LEN (64 - sizeof(unsigned long))
15 
16 /* You can override this manually, but generally this should match the
17    module name. */
18 #ifdef MODULE
19 #define MODULE_PARAM_PREFIX /* empty */
20 #define __MODULE_INFO_PREFIX /* empty */
21 #else
22 #define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
23 /* We cannot use MODULE_PARAM_PREFIX because some modules override it. */
24 #define __MODULE_INFO_PREFIX KBUILD_MODNAME "."
25 #endif
26 
27 /* Generic info of form tag = "info" */
28 #define MODULE_INFO(tag, info)					  \
29 	static_assert(						  \
30 		sizeof(info) - 1 == __builtin_strlen(info),	  \
31 		"MODULE_INFO(" #tag ", ...) contains embedded NUL byte"); \
32 	static const char __UNIQUE_ID(modinfo)[]			  \
33 		__used __section(".modinfo") __aligned(1)		  \
34 		= __MODULE_INFO_PREFIX __stringify(tag) "=" info
35 
36 #define __MODULE_PARM_TYPE(name, _type)					  \
37 	MODULE_INFO(parmtype, #name ":" _type)
38 
39 /* One for each parameter, describing how to use it.  Some files do
40    multiple of these per line, so can't just use MODULE_INFO. */
41 #define MODULE_PARM_DESC(_parm, desc) \
42 	MODULE_INFO(parm, #_parm ":" desc)
43 
44 struct kernel_param;
45 
46 /*
47  * Flags available for kernel_param_ops
48  *
49  * NOARG - the parameter allows for no argument (foo instead of foo=1)
50  */
51 enum {
52 	KERNEL_PARAM_OPS_FL_NOARG = (1 << 0)
53 };
54 
55 struct kernel_param_ops {
56 	/* How the ops should behave */
57 	unsigned int flags;
58 	/* Returns 0, or -errno.  arg is in kp->arg. */
59 	int (*set)(const char *val, const struct kernel_param *kp);
60 	/* Returns length written or -errno.  Buffer is 4k (ie. be short!) */
61 	int (*get)(char *buffer, const struct kernel_param *kp);
62 	/* Optional function to free kp->arg when module unloaded. */
63 	void (*free)(void *arg);
64 };
65 
66 /*
67  * Flags available for kernel_param
68  *
69  * UNSAFE - the parameter is dangerous and setting it will taint the kernel
70  * HWPARAM - Hardware param not permitted in lockdown mode
71  */
72 enum {
73 	KERNEL_PARAM_FL_UNSAFE	= (1 << 0),
74 	KERNEL_PARAM_FL_HWPARAM	= (1 << 1),
75 };
76 
77 struct kernel_param {
78 	const char *name;
79 	struct module *mod;
80 	const struct kernel_param_ops *ops;
81 	const u16 perm;
82 	s8 level;
83 	u8 flags;
84 	union {
85 		void *arg;
86 		const struct kparam_string *str;
87 		const struct kparam_array *arr;
88 	};
89 };
90 
91 extern const struct kernel_param __start___param[], __stop___param[];
92 
93 /* Special one for strings we want to copy into */
94 struct kparam_string {
95 	unsigned int maxlen;
96 	char *string;
97 };
98 
99 /* Special one for arrays */
100 struct kparam_array
101 {
102 	unsigned int max;
103 	unsigned int elemsize;
104 	unsigned int *num;
105 	const struct kernel_param_ops *ops;
106 	void *elem;
107 };
108 
109 /**
110  * module_param - typesafe helper for a module/cmdline parameter
111  * @name: the variable to alter, and exposed parameter name.
112  * @type: the type of the parameter
113  * @perm: visibility in sysfs.
114  *
115  * @name becomes the module parameter, or (prefixed by KBUILD_MODNAME and a
116  * ".") the kernel commandline parameter.  Note that - is changed to _, so
117  * the user can use "foo-bar=1" even for variable "foo_bar".
118  *
119  * @perm is 0 if the variable is not to appear in sysfs, or 0444
120  * for world-readable, 0644 for root-writable, etc.  Note that if it
121  * is writable, you may need to use kernel_param_lock() around
122  * accesses (esp. charp, which can be kfreed when it changes).
123  *
124  * The @type is simply pasted to refer to a param_ops_##type and a
125  * param_check_##type: for convenience many standard types are provided but
126  * you can create your own by defining those variables.
127  *
128  * Standard types are:
129  *	byte, hexint, short, ushort, int, uint, long, ulong
130  *	charp: a character pointer
131  *	bool: a bool, values 0/1, y/n, Y/N.
132  *	invbool: the above, only sense-reversed (N = true).
133  */
134 #define module_param(name, type, perm)				\
135 	module_param_named(name, name, type, perm)
136 
137 /**
138  * module_param_unsafe - same as module_param but taints kernel
139  * @name: the variable to alter, and exposed parameter name.
140  * @type: the type of the parameter
141  * @perm: visibility in sysfs.
142  */
143 #define module_param_unsafe(name, type, perm)			\
144 	module_param_named_unsafe(name, name, type, perm)
145 
146 /**
147  * module_param_named - typesafe helper for a renamed module/cmdline parameter
148  * @name: a valid C identifier which is the parameter name.
149  * @value: the actual lvalue to alter.
150  * @type: the type of the parameter
151  * @perm: visibility in sysfs.
152  *
153  * Usually it's a good idea to have variable names and user-exposed names the
154  * same, but that's harder if the variable must be non-static or is inside a
155  * structure.  This allows exposure under a different name.
156  */
157 #define module_param_named(name, value, type, perm)			   \
158 	param_check_##type(name, &(value));				   \
159 	module_param_cb(name, &param_ops_##type, &value, perm);		   \
160 	__MODULE_PARM_TYPE(name, #type)
161 
162 /**
163  * module_param_named_unsafe - same as module_param_named but taints kernel
164  * @name: a valid C identifier which is the parameter name.
165  * @value: the actual lvalue to alter.
166  * @type: the type of the parameter
167  * @perm: visibility in sysfs.
168  */
169 #define module_param_named_unsafe(name, value, type, perm)		\
170 	param_check_##type(name, &(value));				\
171 	module_param_cb_unsafe(name, &param_ops_##type, &value, perm);	\
172 	__MODULE_PARM_TYPE(name, #type)
173 
174 /**
175  * module_param_cb - general callback for a module/cmdline parameter
176  * @name: a valid C identifier which is the parameter name.
177  * @ops: the set & get operations for this parameter.
178  * @arg: args for @ops
179  * @perm: visibility in sysfs.
180  *
181  * The ops can have NULL set or get functions.
182  */
183 #define module_param_cb(name, ops, arg, perm)				      \
184 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0)
185 
186 #define module_param_cb_unsafe(name, ops, arg, perm)			      \
187 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1,    \
188 			    KERNEL_PARAM_FL_UNSAFE)
189 
190 #define __level_param_cb(name, ops, arg, perm, level)			\
191 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
192 /**
193  * core_param_cb - general callback for a module/cmdline parameter
194  *                 to be evaluated before core initcall level
195  * @name: a valid C identifier which is the parameter name.
196  * @ops: the set & get operations for this parameter.
197  * @arg: args for @ops
198  * @perm: visibility in sysfs.
199  *
200  * The ops can have NULL set or get functions.
201  */
202 #define core_param_cb(name, ops, arg, perm)		\
203 	__level_param_cb(name, ops, arg, perm, 1)
204 
205 /**
206  * postcore_param_cb - general callback for a module/cmdline parameter
207  *                     to be evaluated before postcore initcall level
208  * @name: a valid C identifier which is the parameter name.
209  * @ops: the set & get operations for this parameter.
210  * @arg: args for @ops
211  * @perm: visibility in sysfs.
212  *
213  * The ops can have NULL set or get functions.
214  */
215 #define postcore_param_cb(name, ops, arg, perm)		\
216 	__level_param_cb(name, ops, arg, perm, 2)
217 
218 /**
219  * arch_param_cb - general callback for a module/cmdline parameter
220  *                 to be evaluated before arch initcall level
221  * @name: a valid C identifier which is the parameter name.
222  * @ops: the set & get operations for this parameter.
223  * @arg: args for @ops
224  * @perm: visibility in sysfs.
225  *
226  * The ops can have NULL set or get functions.
227  */
228 #define arch_param_cb(name, ops, arg, perm)		\
229 	__level_param_cb(name, ops, arg, perm, 3)
230 
231 /**
232  * subsys_param_cb - general callback for a module/cmdline parameter
233  *                   to be evaluated before subsys initcall level
234  * @name: a valid C identifier which is the parameter name.
235  * @ops: the set & get operations for this parameter.
236  * @arg: args for @ops
237  * @perm: visibility in sysfs.
238  *
239  * The ops can have NULL set or get functions.
240  */
241 #define subsys_param_cb(name, ops, arg, perm)		\
242 	__level_param_cb(name, ops, arg, perm, 4)
243 
244 /**
245  * fs_param_cb - general callback for a module/cmdline parameter
246  *               to be evaluated before fs initcall level
247  * @name: a valid C identifier which is the parameter name.
248  * @ops: the set & get operations for this parameter.
249  * @arg: args for @ops
250  * @perm: visibility in sysfs.
251  *
252  * The ops can have NULL set or get functions.
253  */
254 #define fs_param_cb(name, ops, arg, perm)		\
255 	__level_param_cb(name, ops, arg, perm, 5)
256 
257 /**
258  * device_param_cb - general callback for a module/cmdline parameter
259  *                   to be evaluated before device initcall level
260  * @name: a valid C identifier which is the parameter name.
261  * @ops: the set & get operations for this parameter.
262  * @arg: args for @ops
263  * @perm: visibility in sysfs.
264  *
265  * The ops can have NULL set or get functions.
266  */
267 #define device_param_cb(name, ops, arg, perm)		\
268 	__level_param_cb(name, ops, arg, perm, 6)
269 
270 /**
271  * late_param_cb - general callback for a module/cmdline parameter
272  *                 to be evaluated before late initcall level
273  * @name: a valid C identifier which is the parameter name.
274  * @ops: the set & get operations for this parameter.
275  * @arg: args for @ops
276  * @perm: visibility in sysfs.
277  *
278  * The ops can have NULL set or get functions.
279  */
280 #define late_param_cb(name, ops, arg, perm)		\
281 	__level_param_cb(name, ops, arg, perm, 7)
282 
283 /* On alpha, ia64 and ppc64 relocations to global data cannot go into
284    read-only sections (which is part of respective UNIX ABI on these
285    platforms). So 'const' makes no sense and even causes compile failures
286    with some compilers. */
287 #if defined(CONFIG_ALPHA) || defined(CONFIG_PPC64)
288 #define __moduleparam_const
289 #else
290 #define __moduleparam_const const
291 #endif
292 
293 /* This is the fundamental function for registering boot/module parameters. */
294 #define __module_param_call(prefix, name, ops, arg, perm, level, flags)	\
295 	static_assert(sizeof(""prefix) - 1 <= __MODULE_NAME_LEN);	\
296 	static const char __param_str_##name[] = prefix #name;		\
297 	static struct kernel_param __moduleparam_const __param_##name	\
298 	__used __section("__param")					\
299 	__aligned(__alignof__(struct kernel_param))			\
300 	= { __param_str_##name, THIS_MODULE, ops,			\
301 	    VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } }
302 
303 /*
304  * Useful for describing a set/get pair used only once (i.e. for this
305  * parameter). For repeated set/get pairs (i.e. the same struct
306  * kernel_param_ops), use module_param_cb() instead.
307  */
308 #define module_param_call(name, _set, _get, arg, perm)			\
309 	static const struct kernel_param_ops __param_ops_##name =	\
310 		{ .flags = 0, .set = _set, .get = _get };		\
311 	__module_param_call(MODULE_PARAM_PREFIX,			\
312 			    name, &__param_ops_##name, arg, perm, -1, 0)
313 
314 #ifdef CONFIG_SYSFS
315 extern void kernel_param_lock(struct module *mod);
316 extern void kernel_param_unlock(struct module *mod);
317 #else
kernel_param_lock(struct module * mod)318 static inline void kernel_param_lock(struct module *mod)
319 {
320 }
kernel_param_unlock(struct module * mod)321 static inline void kernel_param_unlock(struct module *mod)
322 {
323 }
324 #endif
325 
326 #ifndef MODULE
327 /**
328  * core_param - define a historical core kernel parameter.
329  * @name: the name of the cmdline and sysfs parameter (often the same as var)
330  * @var: the variable
331  * @type: the type of the parameter
332  * @perm: visibility in sysfs
333  *
334  * core_param is just like module_param(), but cannot be modular and
335  * doesn't add a prefix (such as "printk.").  This is for compatibility
336  * with __setup(), and it makes sense as truly core parameters aren't
337  * tied to the particular file they're in.
338  */
339 #define core_param(name, var, type, perm)				\
340 	param_check_##type(name, &(var));				\
341 	__module_param_call("", name, &param_ops_##type, &var, perm, -1, 0)
342 
343 /**
344  * core_param_unsafe - same as core_param but taints kernel
345  * @name: the name of the cmdline and sysfs parameter (often the same as var)
346  * @var: the variable
347  * @type: the type of the parameter
348  * @perm: visibility in sysfs
349  */
350 #define core_param_unsafe(name, var, type, perm)		\
351 	param_check_##type(name, &(var));				\
352 	__module_param_call("", name, &param_ops_##type, &var, perm,	\
353 			    -1, KERNEL_PARAM_FL_UNSAFE)
354 
355 /**
356  * __core_param_cb - similar like core_param, with a set/get ops instead of type.
357  * @name: the name of the cmdline and sysfs parameter (often the same as var)
358  * @var: the variable
359  * @ops: the set & get operations for this parameter.
360  * @perm: visibility in sysfs
361  *
362  * Ideally this should be called 'core_param_cb', but the name has been
363  * used for module core parameter, so add the '__' prefix
364  */
365 #define __core_param_cb(name, ops, arg, perm) \
366 	__module_param_call("", name, ops, arg, perm, -1, 0)
367 
368 #endif /* !MODULE */
369 
370 /**
371  * module_param_string - a char array parameter
372  * @name: the name of the parameter
373  * @string: the string variable
374  * @len: the maximum length of the string, incl. terminator
375  * @perm: visibility in sysfs.
376  *
377  * This actually copies the string when it's set (unlike type charp).
378  * @len is usually just sizeof(string).
379  */
380 #define module_param_string(name, string, len, perm)			\
381 	static const struct kparam_string __param_string_##name		\
382 		= { len, string };					\
383 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
384 			    &param_ops_string,				\
385 			    .str = &__param_string_##name, perm, -1, 0);\
386 	__MODULE_PARM_TYPE(name, "string")
387 
388 /**
389  * parameq - checks if two parameter names match
390  * @name1: parameter name 1
391  * @name2: parameter name 2
392  *
393  * Returns true if the two parameter names are equal.
394  * Dashes (-) are considered equal to underscores (_).
395  */
396 extern bool parameq(const char *name1, const char *name2);
397 
398 /**
399  * parameqn - checks if two parameter names match
400  * @name1: parameter name 1
401  * @name2: parameter name 2
402  * @n: the length to compare
403  *
404  * Similar to parameq(), except it compares @n characters.
405  */
406 extern bool parameqn(const char *name1, const char *name2, size_t n);
407 
408 typedef int (*parse_unknown_fn)(char *param, char *val, const char *doing, void *arg);
409 
410 /* Called on module insert or kernel boot */
411 extern char *parse_args(const char *name,
412 		      char *args,
413 		      const struct kernel_param *params,
414 		      unsigned num,
415 		      s16 level_min,
416 		      s16 level_max,
417 		      void *arg, parse_unknown_fn unknown);
418 
419 /* Called by module remove. */
420 #ifdef CONFIG_SYSFS
421 extern void destroy_params(const struct kernel_param *params, unsigned num);
422 #else
destroy_params(const struct kernel_param * params,unsigned num)423 static inline void destroy_params(const struct kernel_param *params,
424 				  unsigned num)
425 {
426 }
427 #endif /* !CONFIG_SYSFS */
428 
429 /* All the helper functions */
430 /* The macros to do compile-time type checking stolen from Jakub
431    Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
432 #define __param_check(name, p, type) \
433 	static inline type __always_unused *__check_##name(void) { return(p); }
434 
435 extern const struct kernel_param_ops param_ops_byte;
436 extern int param_set_byte(const char *val, const struct kernel_param *kp);
437 extern int param_get_byte(char *buffer, const struct kernel_param *kp);
438 #define param_check_byte(name, p) __param_check(name, p, unsigned char)
439 
440 extern const struct kernel_param_ops param_ops_short;
441 extern int param_set_short(const char *val, const struct kernel_param *kp);
442 extern int param_get_short(char *buffer, const struct kernel_param *kp);
443 #define param_check_short(name, p) __param_check(name, p, short)
444 
445 extern const struct kernel_param_ops param_ops_ushort;
446 extern int param_set_ushort(const char *val, const struct kernel_param *kp);
447 extern int param_get_ushort(char *buffer, const struct kernel_param *kp);
448 #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
449 
450 extern const struct kernel_param_ops param_ops_int;
451 extern int param_set_int(const char *val, const struct kernel_param *kp);
452 extern int param_get_int(char *buffer, const struct kernel_param *kp);
453 #define param_check_int(name, p) __param_check(name, p, int)
454 
455 extern const struct kernel_param_ops param_ops_uint;
456 extern int param_set_uint(const char *val, const struct kernel_param *kp);
457 extern int param_get_uint(char *buffer, const struct kernel_param *kp);
458 int param_set_uint_minmax(const char *val, const struct kernel_param *kp,
459 		unsigned int min, unsigned int max);
460 #define param_check_uint(name, p) __param_check(name, p, unsigned int)
461 
462 extern const struct kernel_param_ops param_ops_long;
463 extern int param_set_long(const char *val, const struct kernel_param *kp);
464 extern int param_get_long(char *buffer, const struct kernel_param *kp);
465 #define param_check_long(name, p) __param_check(name, p, long)
466 
467 extern const struct kernel_param_ops param_ops_ulong;
468 extern int param_set_ulong(const char *val, const struct kernel_param *kp);
469 extern int param_get_ulong(char *buffer, const struct kernel_param *kp);
470 #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
471 
472 extern const struct kernel_param_ops param_ops_ullong;
473 extern int param_set_ullong(const char *val, const struct kernel_param *kp);
474 extern int param_get_ullong(char *buffer, const struct kernel_param *kp);
475 #define param_check_ullong(name, p) __param_check(name, p, unsigned long long)
476 
477 extern const struct kernel_param_ops param_ops_hexint;
478 extern int param_set_hexint(const char *val, const struct kernel_param *kp);
479 extern int param_get_hexint(char *buffer, const struct kernel_param *kp);
480 #define param_check_hexint(name, p) param_check_uint(name, p)
481 
482 extern const struct kernel_param_ops param_ops_charp;
483 extern int param_set_charp(const char *val, const struct kernel_param *kp);
484 extern int param_get_charp(char *buffer, const struct kernel_param *kp);
485 extern void param_free_charp(void *arg);
486 #define param_check_charp(name, p) __param_check(name, p, char *)
487 
488 /* We used to allow int as well as bool.  We're taking that away! */
489 extern const struct kernel_param_ops param_ops_bool;
490 extern int param_set_bool(const char *val, const struct kernel_param *kp);
491 extern int param_get_bool(char *buffer, const struct kernel_param *kp);
492 #define param_check_bool(name, p) __param_check(name, p, bool)
493 
494 extern const struct kernel_param_ops param_ops_bool_enable_only;
495 extern int param_set_bool_enable_only(const char *val,
496 				      const struct kernel_param *kp);
497 /* getter is the same as for the regular bool */
498 #define param_check_bool_enable_only param_check_bool
499 
500 extern const struct kernel_param_ops param_ops_invbool;
501 extern int param_set_invbool(const char *val, const struct kernel_param *kp);
502 extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
503 #define param_check_invbool(name, p) __param_check(name, p, bool)
504 
505 /* An int, which can only be set like a bool (though it shows as an int). */
506 extern const struct kernel_param_ops param_ops_bint;
507 extern int param_set_bint(const char *val, const struct kernel_param *kp);
508 #define param_get_bint param_get_int
509 #define param_check_bint param_check_int
510 
511 /**
512  * module_param_array - a parameter which is an array of some type
513  * @name: the name of the array variable
514  * @type: the type, as per module_param()
515  * @nump: optional pointer filled in with the number written
516  * @perm: visibility in sysfs
517  *
518  * Input and output are as comma-separated values.  Commas inside values
519  * don't work properly (eg. an array of charp).
520  *
521  * ARRAY_SIZE(@name) is used to determine the number of elements in the
522  * array, so the definition must be visible.
523  */
524 #define module_param_array(name, type, nump, perm)		\
525 	module_param_array_named(name, name, type, nump, perm)
526 
527 /**
528  * module_param_array_named - renamed parameter which is an array of some type
529  * @name: a valid C identifier which is the parameter name
530  * @array: the name of the array variable
531  * @type: the type, as per module_param()
532  * @nump: optional pointer filled in with the number written
533  * @perm: visibility in sysfs
534  *
535  * This exposes a different name than the actual variable name.  See
536  * module_param_named() for why this might be necessary.
537  */
538 #define module_param_array_named(name, array, type, nump, perm)		\
539 	param_check_##type(name, &(array)[0]);				\
540 	static const struct kparam_array __param_arr_##name		\
541 	= { .max = ARRAY_SIZE(array), .num = nump,                      \
542 	    .ops = &param_ops_##type,					\
543 	    .elemsize = sizeof(array[0]), .elem = array };		\
544 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
545 			    &param_array_ops,				\
546 			    .arr = &__param_arr_##name,			\
547 			    perm, -1, 0);				\
548 	__MODULE_PARM_TYPE(name, "array of " #type)
549 
550 enum hwparam_type {
551 	hwparam_ioport,		/* Module parameter configures an I/O port */
552 	hwparam_iomem,		/* Module parameter configures an I/O mem address */
553 	hwparam_ioport_or_iomem, /* Module parameter could be either, depending on other option */
554 	hwparam_irq,		/* Module parameter configures an IRQ */
555 	hwparam_dma,		/* Module parameter configures a DMA channel */
556 	hwparam_dma_addr,	/* Module parameter configures a DMA buffer address */
557 	hwparam_other,		/* Module parameter configures some other value */
558 };
559 
560 /**
561  * module_param_hw_named - A parameter representing a hw parameters
562  * @name: a valid C identifier which is the parameter name.
563  * @value: the actual lvalue to alter.
564  * @type: the type of the parameter
565  * @hwtype: what the value represents (enum hwparam_type)
566  * @perm: visibility in sysfs.
567  *
568  * Usually it's a good idea to have variable names and user-exposed names the
569  * same, but that's harder if the variable must be non-static or is inside a
570  * structure.  This allows exposure under a different name.
571  */
572 #define module_param_hw_named(name, value, type, hwtype, perm)		\
573 	param_check_##type(name, &(value));				\
574 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
575 			    &param_ops_##type, &value,			\
576 			    perm, -1,					\
577 			    KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0));	\
578 	__MODULE_PARM_TYPE(name, #type)
579 
580 #define module_param_hw(name, type, hwtype, perm)		\
581 	module_param_hw_named(name, name, type, hwtype, perm)
582 
583 /**
584  * module_param_hw_array - A parameter representing an array of hw parameters
585  * @name: the name of the array variable
586  * @type: the type, as per module_param()
587  * @hwtype: what the value represents (enum hwparam_type)
588  * @nump: optional pointer filled in with the number written
589  * @perm: visibility in sysfs
590  *
591  * Input and output are as comma-separated values.  Commas inside values
592  * don't work properly (eg. an array of charp).
593  *
594  * ARRAY_SIZE(@name) is used to determine the number of elements in the
595  * array, so the definition must be visible.
596  */
597 #define module_param_hw_array(name, type, hwtype, nump, perm)		\
598 	param_check_##type(name, &(name)[0]);				\
599 	static const struct kparam_array __param_arr_##name		\
600 	= { .max = ARRAY_SIZE(name), .num = nump,			\
601 	    .ops = &param_ops_##type,					\
602 	    .elemsize = sizeof(name[0]), .elem = name };		\
603 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
604 			    &param_array_ops,				\
605 			    .arr = &__param_arr_##name,			\
606 			    perm, -1,					\
607 			    KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0));	\
608 	__MODULE_PARM_TYPE(name, "array of " #type)
609 
610 
611 extern const struct kernel_param_ops param_array_ops;
612 
613 extern const struct kernel_param_ops param_ops_string;
614 extern int param_set_copystring(const char *val, const struct kernel_param *);
615 extern int param_get_string(char *buffer, const struct kernel_param *kp);
616 
617 /* for exporting parameters in /sys/module/.../parameters */
618 
619 struct module;
620 
621 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
622 extern int module_param_sysfs_setup(struct module *mod,
623 				    const struct kernel_param *kparam,
624 				    unsigned int num_params);
625 
626 extern void module_param_sysfs_remove(struct module *mod);
627 #else
module_param_sysfs_setup(struct module * mod,const struct kernel_param * kparam,unsigned int num_params)628 static inline int module_param_sysfs_setup(struct module *mod,
629 			     const struct kernel_param *kparam,
630 			     unsigned int num_params)
631 {
632 	return 0;
633 }
634 
module_param_sysfs_remove(struct module * mod)635 static inline void module_param_sysfs_remove(struct module *mod)
636 { }
637 #endif
638 
639 #endif /* _LINUX_MODULE_PARAMS_H */
640