xref: /linux/include/linux/moduleparam.h (revision 6086f349a30232f3119ec647356cd191087b1333)
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 
6 #include <linux/array_size.h>
7 #include <linux/build_bug.h>
8 #include <linux/compiler.h>
9 #include <linux/init.h>
10 #include <linux/stringify.h>
11 #include <linux/sysfs.h>
12 #include <linux/types.h>
13 
14 /*
15  * The maximum module name length, including the NUL byte.
16  * Chosen so that structs with an unsigned long line up, specifically
17  * modversion_info.
18  */
19 #define __MODULE_NAME_LEN (64 - sizeof(unsigned long))
20 
21 /* You can override this manually, but generally this should match the
22    module name. */
23 #ifdef MODULE
24 #define MODULE_PARAM_PREFIX /* empty */
25 #define __MODULE_INFO_PREFIX /* empty */
26 #else
27 #define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
28 /* We cannot use MODULE_PARAM_PREFIX because some modules override it. */
29 #define __MODULE_INFO_PREFIX KBUILD_MODNAME "."
30 #endif
31 
32 /* Generic info of form tag = "info" */
33 #define MODULE_INFO(tag, info)					  \
34 	static_assert(						  \
35 		sizeof(info) - 1 == __builtin_strlen(info),	  \
36 		"MODULE_INFO(" #tag ", ...) contains embedded NUL byte"); \
37 	static const char __UNIQUE_ID(modinfo)[]			  \
38 		__used __section(".modinfo") __aligned(1)		  \
39 		= __MODULE_INFO_PREFIX __stringify(tag) "=" info
40 
41 #define __MODULE_PARM_TYPE(name, _type)					  \
42 	MODULE_INFO(parmtype, #name ":" _type)
43 
44 /* One for each parameter, describing how to use it.  Some files do
45    multiple of these per line, so can't just use MODULE_INFO. */
46 #define MODULE_PARM_DESC(_parm, desc) \
47 	MODULE_INFO(parm, #_parm ":" desc)
48 
49 struct kernel_param;
50 
51 /*
52  * Flags available for kernel_param_ops
53  *
54  * NOARG - the parameter allows for no argument (foo instead of foo=1)
55  */
56 enum {
57 	KERNEL_PARAM_OPS_FL_NOARG = (1 << 0)
58 };
59 
60 struct kernel_param_ops {
61 	/* How the ops should behave */
62 	unsigned int flags;
63 	/* Returns 0, or -errno.  arg is in kp->arg. */
64 	int (*set)(const char *val, const struct kernel_param *kp);
65 	/* Returns length written or -errno.  Buffer is 4k (ie. be short!) */
66 	int (*get)(char *buffer, const struct kernel_param *kp);
67 	/* Optional function to free kp->arg when module unloaded. */
68 	void (*free)(void *arg);
69 };
70 
71 /*
72  * Flags available for kernel_param
73  *
74  * UNSAFE - the parameter is dangerous and setting it will taint the kernel
75  * HWPARAM - Hardware param not permitted in lockdown mode
76  */
77 enum {
78 	KERNEL_PARAM_FL_UNSAFE	= (1 << 0),
79 	KERNEL_PARAM_FL_HWPARAM	= (1 << 1),
80 };
81 
82 struct kernel_param {
83 	const char *name;
84 	struct module *mod;
85 	const struct kernel_param_ops *ops;
86 	const u16 perm;
87 	s8 level;
88 	u8 flags;
89 	union {
90 		void *arg;
91 		const struct kparam_string *str;
92 		const struct kparam_array *arr;
93 	};
94 };
95 
96 extern const struct kernel_param __start___param[], __stop___param[];
97 
98 /* Special one for strings we want to copy into */
99 struct kparam_string {
100 	unsigned int maxlen;
101 	char *string;
102 };
103 
104 /* Special one for arrays */
105 struct kparam_array
106 {
107 	unsigned int max;
108 	unsigned int elemsize;
109 	unsigned int *num;
110 	const struct kernel_param_ops *ops;
111 	void *elem;
112 };
113 
114 /**
115  * module_param - typesafe helper for a module/cmdline parameter
116  * @name: the variable to alter, and exposed parameter name.
117  * @type: the type of the parameter
118  * @perm: visibility in sysfs.
119  *
120  * @name becomes the module parameter, or (prefixed by KBUILD_MODNAME and a
121  * ".") the kernel commandline parameter.  Note that - is changed to _, so
122  * the user can use "foo-bar=1" even for variable "foo_bar".
123  *
124  * @perm is 0 if the variable is not to appear in sysfs, or 0444
125  * for world-readable, 0644 for root-writable, etc.  Note that if it
126  * is writable, you may need to use kernel_param_lock() around
127  * accesses (esp. charp, which can be kfreed when it changes).
128  *
129  * The @type is simply pasted to refer to a param_ops_##type and a
130  * param_check_##type: for convenience many standard types are provided but
131  * you can create your own by defining those variables.
132  *
133  * Standard types are:
134  *	byte, hexint, short, ushort, int, uint, long, ulong
135  *	charp: a character pointer
136  *	bool: a bool, values 0/1, y/n, Y/N.
137  *	invbool: the above, only sense-reversed (N = true).
138  */
139 #define module_param(name, type, perm)				\
140 	module_param_named(name, name, type, perm)
141 
142 /**
143  * module_param_unsafe - same as module_param but taints kernel
144  * @name: the variable to alter, and exposed parameter name.
145  * @type: the type of the parameter
146  * @perm: visibility in sysfs.
147  */
148 #define module_param_unsafe(name, type, perm)			\
149 	module_param_named_unsafe(name, name, type, perm)
150 
151 /**
152  * module_param_named - typesafe helper for a renamed module/cmdline parameter
153  * @name: a valid C identifier which is the parameter name.
154  * @value: the actual lvalue to alter.
155  * @type: the type of the parameter
156  * @perm: visibility in sysfs.
157  *
158  * Usually it's a good idea to have variable names and user-exposed names the
159  * same, but that's harder if the variable must be non-static or is inside a
160  * structure.  This allows exposure under a different name.
161  */
162 #define module_param_named(name, value, type, perm)			   \
163 	param_check_##type(name, &(value));				   \
164 	module_param_cb(name, &param_ops_##type, &value, perm);		   \
165 	__MODULE_PARM_TYPE(name, #type)
166 
167 /**
168  * module_param_named_unsafe - same as module_param_named but taints kernel
169  * @name: a valid C identifier which is the parameter name.
170  * @value: the actual lvalue to alter.
171  * @type: the type of the parameter
172  * @perm: visibility in sysfs.
173  */
174 #define module_param_named_unsafe(name, value, type, perm)		\
175 	param_check_##type(name, &(value));				\
176 	module_param_cb_unsafe(name, &param_ops_##type, &value, perm);	\
177 	__MODULE_PARM_TYPE(name, #type)
178 
179 /**
180  * module_param_cb - general callback for a module/cmdline parameter
181  * @name: a valid C identifier which is the parameter name.
182  * @ops: the set & get operations for this parameter.
183  * @arg: args for @ops
184  * @perm: visibility in sysfs.
185  *
186  * The ops can have NULL set or get functions.
187  */
188 #define module_param_cb(name, ops, arg, perm)				      \
189 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0)
190 
191 #define module_param_cb_unsafe(name, ops, arg, perm)			      \
192 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1,    \
193 			    KERNEL_PARAM_FL_UNSAFE)
194 
195 #define __level_param_cb(name, ops, arg, perm, level)			\
196 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
197 /**
198  * core_param_cb - general callback for a module/cmdline parameter
199  *                 to be evaluated before core 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 core_param_cb(name, ops, arg, perm)		\
208 	__level_param_cb(name, ops, arg, perm, 1)
209 
210 /**
211  * postcore_param_cb - general callback for a module/cmdline parameter
212  *                     to be evaluated before postcore 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 postcore_param_cb(name, ops, arg, perm)		\
221 	__level_param_cb(name, ops, arg, perm, 2)
222 
223 /**
224  * arch_param_cb - general callback for a module/cmdline parameter
225  *                 to be evaluated before arch 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 arch_param_cb(name, ops, arg, perm)		\
234 	__level_param_cb(name, ops, arg, perm, 3)
235 
236 /**
237  * subsys_param_cb - general callback for a module/cmdline parameter
238  *                   to be evaluated before subsys 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 subsys_param_cb(name, ops, arg, perm)		\
247 	__level_param_cb(name, ops, arg, perm, 4)
248 
249 /**
250  * fs_param_cb - general callback for a module/cmdline parameter
251  *               to be evaluated before fs 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 fs_param_cb(name, ops, arg, perm)		\
260 	__level_param_cb(name, ops, arg, perm, 5)
261 
262 /**
263  * device_param_cb - general callback for a module/cmdline parameter
264  *                   to be evaluated before device 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 device_param_cb(name, ops, arg, perm)		\
273 	__level_param_cb(name, ops, arg, perm, 6)
274 
275 /**
276  * late_param_cb - general callback for a module/cmdline parameter
277  *                 to be evaluated before late initcall level
278  * @name: a valid C identifier which is the parameter name.
279  * @ops: the set & get operations for this parameter.
280  * @arg: args for @ops
281  * @perm: visibility in sysfs.
282  *
283  * The ops can have NULL set or get functions.
284  */
285 #define late_param_cb(name, ops, arg, perm)		\
286 	__level_param_cb(name, ops, arg, perm, 7)
287 
288 /* On alpha, ia64 and ppc64 relocations to global data cannot go into
289    read-only sections (which is part of respective UNIX ABI on these
290    platforms). So 'const' makes no sense and even causes compile failures
291    with some compilers. */
292 #if defined(CONFIG_ALPHA) || defined(CONFIG_PPC64)
293 #define __moduleparam_const
294 #else
295 #define __moduleparam_const const
296 #endif
297 
298 /* This is the fundamental function for registering boot/module parameters. */
299 #define __module_param_call(prefix, name, ops, arg, perm, level, flags)	\
300 	static_assert(sizeof(""prefix) - 1 <= __MODULE_NAME_LEN);	\
301 	static const char __param_str_##name[] = prefix #name;		\
302 	static struct kernel_param __moduleparam_const __param_##name	\
303 	__used __section("__param")					\
304 	__aligned(__alignof__(struct kernel_param))			\
305 	= { __param_str_##name, THIS_MODULE, ops,			\
306 	    VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } }
307 
308 /*
309  * Useful for describing a set/get pair used only once (i.e. for this
310  * parameter). For repeated set/get pairs (i.e. the same struct
311  * kernel_param_ops), use module_param_cb() instead.
312  */
313 #define module_param_call(name, _set, _get, arg, perm)			\
314 	static const struct kernel_param_ops __param_ops_##name =	\
315 		{ .flags = 0, .set = _set, .get = _get };		\
316 	__module_param_call(MODULE_PARAM_PREFIX,			\
317 			    name, &__param_ops_##name, arg, perm, -1, 0)
318 
319 #ifdef CONFIG_SYSFS
320 extern void kernel_param_lock(struct module *mod);
321 extern void kernel_param_unlock(struct module *mod);
322 #else
323 static inline void kernel_param_lock(struct module *mod)
324 {
325 }
326 static inline void kernel_param_unlock(struct module *mod)
327 {
328 }
329 #endif
330 
331 #ifndef MODULE
332 /**
333  * core_param - define a historical core kernel parameter.
334  * @name: the name of the cmdline and sysfs parameter (often the same as var)
335  * @var: the variable
336  * @type: the type of the parameter
337  * @perm: visibility in sysfs
338  *
339  * core_param is just like module_param(), but cannot be modular and
340  * doesn't add a prefix (such as "printk.").  This is for compatibility
341  * with __setup(), and it makes sense as truly core parameters aren't
342  * tied to the particular file they're in.
343  */
344 #define core_param(name, var, type, perm)				\
345 	param_check_##type(name, &(var));				\
346 	__module_param_call("", name, &param_ops_##type, &var, perm, -1, 0)
347 
348 /**
349  * core_param_unsafe - same as core_param but taints kernel
350  * @name: the name of the cmdline and sysfs parameter (often the same as var)
351  * @var: the variable
352  * @type: the type of the parameter
353  * @perm: visibility in sysfs
354  */
355 #define core_param_unsafe(name, var, type, perm)		\
356 	param_check_##type(name, &(var));				\
357 	__module_param_call("", name, &param_ops_##type, &var, perm,	\
358 			    -1, KERNEL_PARAM_FL_UNSAFE)
359 
360 /**
361  * __core_param_cb - similar like core_param, with a set/get ops instead of type.
362  * @name: the name of the cmdline and sysfs parameter (often the same as var)
363  * @ops: the set & get operations for this parameter.
364  * @arg: the variable
365  * @perm: visibility in sysfs
366  *
367  * Ideally this should be called 'core_param_cb', but the name has been
368  * used for module core parameter, so add the '__' prefix
369  */
370 #define __core_param_cb(name, ops, arg, perm) \
371 	__module_param_call("", name, ops, arg, perm, -1, 0)
372 
373 #endif /* !MODULE */
374 
375 /**
376  * module_param_string - a char array parameter
377  * @name: the name of the parameter
378  * @string: the string variable
379  * @len: the maximum length of the string, incl. terminator
380  * @perm: visibility in sysfs.
381  *
382  * This actually copies the string when it's set (unlike type charp).
383  * @len is usually just sizeof(string).
384  */
385 #define module_param_string(name, string, len, perm)			\
386 	static const struct kparam_string __param_string_##name		\
387 		= { len, string };					\
388 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
389 			    &param_ops_string,				\
390 			    .str = &__param_string_##name, perm, -1, 0);\
391 	__MODULE_PARM_TYPE(name, "string")
392 
393 /**
394  * parameq - checks if two parameter names match
395  * @name1: parameter name 1
396  * @name2: parameter name 2
397  *
398  * Returns: true if the two parameter names are equal.
399  * Dashes (-) are considered equal to underscores (_).
400  */
401 extern bool parameq(const char *name1, const char *name2);
402 
403 /**
404  * parameqn - checks if two parameter names match
405  * @name1: parameter name 1
406  * @name2: parameter name 2
407  * @n: the length to compare
408  *
409  * Similar to parameq(), except it compares @n characters.
410  *
411  * Returns: true if the first @n characters of the two parameter names
412  * are equal.
413  * Dashes (-) are considered equal to underscores (_).
414  */
415 extern bool parameqn(const char *name1, const char *name2, size_t n);
416 
417 typedef int (*parse_unknown_fn)(char *param, char *val, const char *doing, void *arg);
418 
419 /* Called on module insert or kernel boot */
420 extern char *parse_args(const char *name,
421 		      char *args,
422 		      const struct kernel_param *params,
423 		      unsigned num,
424 		      s16 level_min,
425 		      s16 level_max,
426 		      void *arg, parse_unknown_fn unknown);
427 
428 /* Called by module remove. */
429 #ifdef CONFIG_SYSFS
430 extern void destroy_params(const struct kernel_param *params, unsigned num);
431 #else
432 static inline void destroy_params(const struct kernel_param *params,
433 				  unsigned num)
434 {
435 }
436 #endif /* !CONFIG_SYSFS */
437 
438 /* All the helper functions */
439 /* The macros to do compile-time type checking stolen from Jakub
440    Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
441 #define __param_check(name, p, type) \
442 	static inline type __always_unused *__check_##name(void) { return(p); }
443 
444 extern const struct kernel_param_ops param_ops_byte;
445 extern int param_set_byte(const char *val, const struct kernel_param *kp);
446 extern int param_get_byte(char *buffer, const struct kernel_param *kp);
447 #define param_check_byte(name, p) __param_check(name, p, unsigned char)
448 
449 extern const struct kernel_param_ops param_ops_short;
450 extern int param_set_short(const char *val, const struct kernel_param *kp);
451 extern int param_get_short(char *buffer, const struct kernel_param *kp);
452 #define param_check_short(name, p) __param_check(name, p, short)
453 
454 extern const struct kernel_param_ops param_ops_ushort;
455 extern int param_set_ushort(const char *val, const struct kernel_param *kp);
456 extern int param_get_ushort(char *buffer, const struct kernel_param *kp);
457 #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
458 
459 extern const struct kernel_param_ops param_ops_int;
460 extern int param_set_int(const char *val, const struct kernel_param *kp);
461 extern int param_get_int(char *buffer, const struct kernel_param *kp);
462 #define param_check_int(name, p) __param_check(name, p, int)
463 
464 extern const struct kernel_param_ops param_ops_uint;
465 extern int param_set_uint(const char *val, const struct kernel_param *kp);
466 extern int param_get_uint(char *buffer, const struct kernel_param *kp);
467 int param_set_uint_minmax(const char *val, const struct kernel_param *kp,
468 		unsigned int min, unsigned int max);
469 #define param_check_uint(name, p) __param_check(name, p, unsigned int)
470 
471 extern const struct kernel_param_ops param_ops_long;
472 extern int param_set_long(const char *val, const struct kernel_param *kp);
473 extern int param_get_long(char *buffer, const struct kernel_param *kp);
474 #define param_check_long(name, p) __param_check(name, p, long)
475 
476 extern const struct kernel_param_ops param_ops_ulong;
477 extern int param_set_ulong(const char *val, const struct kernel_param *kp);
478 extern int param_get_ulong(char *buffer, const struct kernel_param *kp);
479 #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
480 
481 extern const struct kernel_param_ops param_ops_ullong;
482 extern int param_set_ullong(const char *val, const struct kernel_param *kp);
483 extern int param_get_ullong(char *buffer, const struct kernel_param *kp);
484 #define param_check_ullong(name, p) __param_check(name, p, unsigned long long)
485 
486 extern const struct kernel_param_ops param_ops_hexint;
487 extern int param_set_hexint(const char *val, const struct kernel_param *kp);
488 extern int param_get_hexint(char *buffer, const struct kernel_param *kp);
489 #define param_check_hexint(name, p) param_check_uint(name, p)
490 
491 extern const struct kernel_param_ops param_ops_charp;
492 extern int param_set_charp(const char *val, const struct kernel_param *kp);
493 extern int param_get_charp(char *buffer, const struct kernel_param *kp);
494 extern void param_free_charp(void *arg);
495 #define param_check_charp(name, p) __param_check(name, p, char *)
496 
497 /* We used to allow int as well as bool.  We're taking that away! */
498 extern const struct kernel_param_ops param_ops_bool;
499 extern int param_set_bool(const char *val, const struct kernel_param *kp);
500 extern int param_get_bool(char *buffer, const struct kernel_param *kp);
501 #define param_check_bool(name, p) __param_check(name, p, bool)
502 
503 extern const struct kernel_param_ops param_ops_bool_enable_only;
504 extern int param_set_bool_enable_only(const char *val,
505 				      const struct kernel_param *kp);
506 /* getter is the same as for the regular bool */
507 #define param_check_bool_enable_only param_check_bool
508 
509 extern const struct kernel_param_ops param_ops_invbool;
510 extern int param_set_invbool(const char *val, const struct kernel_param *kp);
511 extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
512 #define param_check_invbool(name, p) __param_check(name, p, bool)
513 
514 /* An int, which can only be set like a bool (though it shows as an int). */
515 extern const struct kernel_param_ops param_ops_bint;
516 extern int param_set_bint(const char *val, const struct kernel_param *kp);
517 #define param_get_bint param_get_int
518 #define param_check_bint param_check_int
519 
520 /**
521  * module_param_array - a parameter which is an array of some type
522  * @name: the name of the array variable
523  * @type: the type, as per module_param()
524  * @nump: optional pointer filled in with the number written
525  * @perm: visibility in sysfs
526  *
527  * Input and output are as comma-separated values.  Commas inside values
528  * don't work properly (eg. an array of charp).
529  *
530  * ARRAY_SIZE(@name) is used to determine the number of elements in the
531  * array, so the definition must be visible.
532  */
533 #define module_param_array(name, type, nump, perm)		\
534 	module_param_array_named(name, name, type, nump, perm)
535 
536 /**
537  * module_param_array_named - renamed parameter which is an array of some type
538  * @name: a valid C identifier which is the parameter name
539  * @array: the name of the array variable
540  * @type: the type, as per module_param()
541  * @nump: optional pointer filled in with the number written
542  * @perm: visibility in sysfs
543  *
544  * This exposes a different name than the actual variable name.  See
545  * module_param_named() for why this might be necessary.
546  */
547 #define module_param_array_named(name, array, type, nump, perm)		\
548 	param_check_##type(name, &(array)[0]);				\
549 	static const struct kparam_array __param_arr_##name		\
550 	= { .max = ARRAY_SIZE(array), .num = nump,                      \
551 	    .ops = &param_ops_##type,					\
552 	    .elemsize = sizeof(array[0]), .elem = array };		\
553 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
554 			    &param_array_ops,				\
555 			    .arr = &__param_arr_##name,			\
556 			    perm, -1, 0);				\
557 	__MODULE_PARM_TYPE(name, "array of " #type)
558 
559 enum hwparam_type {
560 	hwparam_ioport,		/* Module parameter configures an I/O port */
561 	hwparam_iomem,		/* Module parameter configures an I/O mem address */
562 	hwparam_ioport_or_iomem, /* Module parameter could be either, depending on other option */
563 	hwparam_irq,		/* Module parameter configures an IRQ */
564 	hwparam_dma,		/* Module parameter configures a DMA channel */
565 	hwparam_dma_addr,	/* Module parameter configures a DMA buffer address */
566 	hwparam_other,		/* Module parameter configures some other value */
567 };
568 
569 /**
570  * module_param_hw_named - A parameter representing a hw parameters
571  * @name: a valid C identifier which is the parameter name.
572  * @value: the actual lvalue to alter.
573  * @type: the type of the parameter
574  * @hwtype: what the value represents (enum hwparam_type)
575  * @perm: visibility in sysfs.
576  *
577  * Usually it's a good idea to have variable names and user-exposed names the
578  * same, but that's harder if the variable must be non-static or is inside a
579  * structure.  This allows exposure under a different name.
580  */
581 #define module_param_hw_named(name, value, type, hwtype, perm)		\
582 	param_check_##type(name, &(value));				\
583 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
584 			    &param_ops_##type, &value,			\
585 			    perm, -1,					\
586 			    KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0));	\
587 	__MODULE_PARM_TYPE(name, #type)
588 
589 #define module_param_hw(name, type, hwtype, perm)		\
590 	module_param_hw_named(name, name, type, hwtype, perm)
591 
592 /**
593  * module_param_hw_array - A parameter representing an array of hw parameters
594  * @name: the name of the array variable
595  * @type: the type, as per module_param()
596  * @hwtype: what the value represents (enum hwparam_type)
597  * @nump: optional pointer filled in with the number written
598  * @perm: visibility in sysfs
599  *
600  * Input and output are as comma-separated values.  Commas inside values
601  * don't work properly (eg. an array of charp).
602  *
603  * ARRAY_SIZE(@name) is used to determine the number of elements in the
604  * array, so the definition must be visible.
605  */
606 #define module_param_hw_array(name, type, hwtype, nump, perm)		\
607 	param_check_##type(name, &(name)[0]);				\
608 	static const struct kparam_array __param_arr_##name		\
609 	= { .max = ARRAY_SIZE(name), .num = nump,			\
610 	    .ops = &param_ops_##type,					\
611 	    .elemsize = sizeof(name[0]), .elem = name };		\
612 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
613 			    &param_array_ops,				\
614 			    .arr = &__param_arr_##name,			\
615 			    perm, -1,					\
616 			    KERNEL_PARAM_FL_HWPARAM | (hwparam_##hwtype & 0));	\
617 	__MODULE_PARM_TYPE(name, "array of " #type)
618 
619 
620 extern const struct kernel_param_ops param_array_ops;
621 
622 extern const struct kernel_param_ops param_ops_string;
623 extern int param_set_copystring(const char *val, const struct kernel_param *);
624 extern int param_get_string(char *buffer, const struct kernel_param *kp);
625 
626 /* for exporting parameters in /sys/module/.../parameters */
627 
628 struct module;
629 
630 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
631 extern int module_param_sysfs_setup(struct module *mod,
632 				    const struct kernel_param *kparam,
633 				    unsigned int num_params);
634 
635 extern void module_param_sysfs_remove(struct module *mod);
636 #else
637 static inline int module_param_sysfs_setup(struct module *mod,
638 			     const struct kernel_param *kparam,
639 			     unsigned int num_params)
640 {
641 	return 0;
642 }
643 
644 static inline void module_param_sysfs_remove(struct module *mod)
645 { }
646 #endif
647 
648 #endif /* _LINUX_MODULE_PARAMS_H */
649