[mirror_ubuntu-bionic-kernel.git] / include / linux / moduleparam.h

#ifndef _LINUX_MODULE_PARAMS_H
#define _LINUX_MODULE_PARAMS_H
/* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */
#include <linux/init.h>
#include <linux/stringify.h>
#include <linux/kernel.h>

/* You can override this manually, but generally this should match the
   module name. */
#ifdef MODULE
#define MODULE_PARAM_PREFIX /* empty */
#else
#define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
#endif

/* Chosen so that structs with an unsigned long line up. */
#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))

#ifdef MODULE
#define ___module_cat(a,b) __mod_ ## a ## b
#define __module_cat(a,b) ___module_cat(a,b)
#define __MODULE_INFO(tag, name, info)					  \
static const char __module_cat(name,__LINE__)[]				  \
  __used								  \
  __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
#else  /* !MODULE */
#define __MODULE_INFO(tag, name, info)
#endif
#define __MODULE_PARM_TYPE(name, _type)					  \
  __MODULE_INFO(parmtype, name##type, #name ":" _type)

struct kernel_param;

/* Returns 0, or -errno.  arg is in kp->arg. */
typedef int (*param_set_fn)(const char *val, struct kernel_param *kp);
/* Returns length written or -errno.  Buffer is 4k (ie. be short!) */
typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp);

/* Flag bits for kernel_param.flags */
#define KPARAM_KMALLOCED	1
#define KPARAM_ISBOOL		2

struct kernel_param {
	const char *name;
	u16 perm;
	u16 flags;
	param_set_fn set;
	param_get_fn get;
	union {
		void *arg;
		const struct kparam_string *str;
		const struct kparam_array *arr;
	};
};

/* Special one for strings we want to copy into */
struct kparam_string {
	unsigned int maxlen;
	char *string;
};

/* Special one for arrays */
struct kparam_array
{
	unsigned int max;
	unsigned int *num;
	param_set_fn set;
	param_get_fn get;
	unsigned int elemsize;
	void *elem;
};

/* On alpha, ia64 and ppc64 relocations to global data cannot go into
   read-only sections (which is part of respective UNIX ABI on these
   platforms). So 'const' makes no sense and even causes compile failures
   with some compilers. */
#if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
#define __moduleparam_const
#else
#define __moduleparam_const const
#endif

/* This is the fundamental function for registering boot/module
   parameters.  perm sets the visibility in sysfs: 000 means it's
   not there, read bits mean it's readable, write bits mean it's
   writable. */
#define __module_param_call(prefix, name, set, get, arg, isbool, perm)	\
	/* Default value instead of permissions? */			\
	static int __param_perm_check_##name __attribute__((unused)) =	\
	BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))	\
	+ BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN);	\
	static const char __param_str_##name[] = prefix #name;		\
	static struct kernel_param __moduleparam_const __param_##name	\
	__used								\
    __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
	= { __param_str_##name, perm, isbool ? KPARAM_ISBOOL : 0,	\
	    set, get, { arg } }

#define module_param_call(name, set, get, arg, perm)			      \
	__module_param_call(MODULE_PARAM_PREFIX,			      \
			    name, set, get, arg,			      \
			    __same_type(*(arg), bool), perm)

/* Helper functions: type is byte, short, ushort, int, uint, long,
   ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
   param_set_XXX and param_check_XXX. */
#define module_param_named(name, value, type, perm)			   \
	param_check_##type(name, &(value));				   \
	module_param_call(name, param_set_##type, param_get_##type, &value, perm); \
	__MODULE_PARM_TYPE(name, #type)

#define module_param(name, type, perm)				\
	module_param_named(name, name, type, perm)

#ifndef MODULE
/**
 * core_param - define a historical core kernel parameter.
 * @name: the name of the cmdline and sysfs parameter (often the same as var)
 * @var: the variable
 * @type: the type (for param_set_##type and param_get_##type)
 * @perm: visibility in sysfs
 *
 * core_param is just like module_param(), but cannot be modular and
 * doesn't add a prefix (such as "printk.").  This is for compatibility
 * with __setup(), and it makes sense as truly core parameters aren't
 * tied to the particular file they're in.
 */
#define core_param(name, var, type, perm)				\
	param_check_##type(name, &(var));				\
	__module_param_call("", name, param_set_##type, param_get_##type, \
			    &var, __same_type(var, bool), perm)
#endif /* !MODULE */

/* Actually copy string: maxlen param is usually sizeof(string). */
#define module_param_string(name, string, len, perm)			\
	static const struct kparam_string __param_string_##name		\
		= { len, string };					\
	__module_param_call(MODULE_PARAM_PREFIX, name,			\
			    param_set_copystring, param_get_string,	\
			    .str = &__param_string_##name, 0, perm);	\
	__MODULE_PARM_TYPE(name, "string")

/* Called on module insert or kernel boot */
extern int parse_args(const char *name,
		      char *args,
		      struct kernel_param *params,
		      unsigned num,
		      int (*unknown)(char *param, char *val));

/* Called by module remove. */
#ifdef CONFIG_SYSFS
extern void destroy_params(const struct kernel_param *params, unsigned num);
#else
static inline void destroy_params(const struct kernel_param *params,
				  unsigned num)
{
}
#endif /* !CONFIG_SYSFS */

/* All the helper functions */
/* The macros to do compile-time type checking stolen from Jakub
   Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
#define __param_check(name, p, type) \
	static inline type *__check_##name(void) { return(p); }

extern int param_set_byte(const char *val, struct kernel_param *kp);
extern int param_get_byte(char *buffer, struct kernel_param *kp);
#define param_check_byte(name, p) __param_check(name, p, unsigned char)

extern int param_set_short(const char *val, struct kernel_param *kp);
extern int param_get_short(char *buffer, struct kernel_param *kp);
#define param_check_short(name, p) __param_check(name, p, short)

extern int param_set_ushort(const char *val, struct kernel_param *kp);
extern int param_get_ushort(char *buffer, struct kernel_param *kp);
#define param_check_ushort(name, p) __param_check(name, p, unsigned short)

extern int param_set_int(const char *val, struct kernel_param *kp);
extern int param_get_int(char *buffer, struct kernel_param *kp);
#define param_check_int(name, p) __param_check(name, p, int)

extern int param_set_uint(const char *val, struct kernel_param *kp);
extern int param_get_uint(char *buffer, struct kernel_param *kp);
#define param_check_uint(name, p) __param_check(name, p, unsigned int)

extern int param_set_long(const char *val, struct kernel_param *kp);
extern int param_get_long(char *buffer, struct kernel_param *kp);
#define param_check_long(name, p) __param_check(name, p, long)

extern int param_set_ulong(const char *val, struct kernel_param *kp);
extern int param_get_ulong(char *buffer, struct kernel_param *kp);
#define param_check_ulong(name, p) __param_check(name, p, unsigned long)

extern int param_set_charp(const char *val, struct kernel_param *kp);
extern int param_get_charp(char *buffer, struct kernel_param *kp);
#define param_check_charp(name, p) __param_check(name, p, char *)

/* For historical reasons "bool" parameters can be (unsigned) "int". */
extern int param_set_bool(const char *val, struct kernel_param *kp);
extern int param_get_bool(char *buffer, struct kernel_param *kp);
#define param_check_bool(name, p)					\
	static inline void __check_##name(void)				\
	{								\
		BUILD_BUG_ON(!__same_type(*(p), bool) &&		\
			     !__same_type(*(p), unsigned int) &&	\
			     !__same_type(*(p), int));			\
	}

extern int param_set_invbool(const char *val, struct kernel_param *kp);
extern int param_get_invbool(char *buffer, struct kernel_param *kp);
#define param_check_invbool(name, p) __param_check(name, p, bool)

/* Comma-separated array: *nump is set to number they actually specified. */
#define module_param_array_named(name, array, type, nump, perm)		\
	static const struct kparam_array __param_arr_##name		\
	= { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
	    sizeof(array[0]), array };					\
	__module_param_call(MODULE_PARAM_PREFIX, name,			\
			    param_array_set, param_array_get,		\
			    .arr = &__param_arr_##name,			\
			    __same_type(array[0], bool), perm);		\
	__MODULE_PARM_TYPE(name, "array of " #type)

#define module_param_array(name, type, nump, perm)		\
	module_param_array_named(name, name, type, nump, perm)

extern int param_array_set(const char *val, struct kernel_param *kp);
extern int param_array_get(char *buffer, struct kernel_param *kp);

extern int param_set_copystring(const char *val, struct kernel_param *kp);
extern int param_get_string(char *buffer, struct kernel_param *kp);

/* for exporting parameters in /sys/parameters */

struct module;

#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
extern int module_param_sysfs_setup(struct module *mod,
				    struct kernel_param *kparam,
				    unsigned int num_params);

extern void module_param_sysfs_remove(struct module *mod);
#else
static inline int module_param_sysfs_setup(struct module *mod,
			     struct kernel_param *kparam,
			     unsigned int num_params)
{
	return 0;
}

static inline void module_param_sysfs_remove(struct module *mod)
{ }
#endif

#endif /* _LINUX_MODULE_PARAMS_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_MODULE_PARAMS_H
	2	#define _LINUX_MODULE_PARAMS_H
	3	/* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */
	4	#include <linux/init.h>
	5	#include <linux/stringify.h>
	6	#include <linux/kernel.h>
	7
	8	/* You can override this manually, but generally this should match the
	9	module name. */
	10	#ifdef MODULE
	11	#define MODULE_PARAM_PREFIX /* empty */
	12	#else
367cb704	13	#define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
1da177e4 LT	14	#endif
1da177e4 LT	15
730b69d2 RR	16	/* Chosen so that structs with an unsigned long line up. */
	17	#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
	18
1da177e4 LT	19	#ifdef MODULE
	20	#define ___module_cat(a,b) __mod_ ## a ## b
	21	#define __module_cat(a,b) ___module_cat(a,b)
	22	#define __MODULE_INFO(tag, name, info) \
	23	static const char __module_cat(name,__LINE__)[] \
3ff6eecc	24	__used \
1da177e4 LT	25	__attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
	26	#else /* !MODULE */
	27	#define __MODULE_INFO(tag, name, info)
	28	#endif
	29	#define __MODULE_PARM_TYPE(name, _type) \
	30	__MODULE_INFO(parmtype, name##type, #name ":" _type)
	31
	32	struct kernel_param;
	33
	34	/* Returns 0, or -errno. arg is in kp->arg. */
	35	typedef int (param_set_fn)(const char val, struct kernel_param *kp);
	36	/* Returns length written or -errno. Buffer is 4k (ie. be short!) */
	37	typedef int (param_get_fn)(char buffer, struct kernel_param *kp);
	38
45fcc70c RR	39	/* Flag bits for kernel_param.flags */
45fcc70c RR	40	#define KPARAM_KMALLOCED 1
fddd5201	41	#define KPARAM_ISBOOL 2
45fcc70c	42
1da177e4 LT	43	struct kernel_param {
1da177e4 LT	44	const char *name;
45fcc70c RR	45	u16 perm;
45fcc70c RR	46	u16 flags;
1da177e4 LT	47	param_set_fn set;
1da177e4 LT	48	param_get_fn get;
22e48eaf JB	49	union {
	50	void *arg;
	51	const struct kparam_string *str;
	52	const struct kparam_array *arr;
	53	};
1da177e4 LT	54	};
	55
	56	/* Special one for strings we want to copy into */
	57	struct kparam_string {
	58	unsigned int maxlen;
	59	char *string;
	60	};
	61
	62	/* Special one for arrays */
	63	struct kparam_array
	64	{
	65	unsigned int max;
	66	unsigned int *num;
	67	param_set_fn set;
	68	param_get_fn get;
	69	unsigned int elemsize;
	70	void *elem;
	71	};
	72
91d35dd9 IK	73	/* On alpha, ia64 and ppc64 relocations to global data cannot go into
	74	read-only sections (which is part of respective UNIX ABI on these
	75	platforms). So 'const' makes no sense and even causes compile failures
	76	with some compilers. */
	77	#if defined(CONFIG_ALPHA) \|\| defined(CONFIG_IA64) \|\| defined(CONFIG_PPC64)
	78	#define __moduleparam_const
	79	#else
	80	#define __moduleparam_const const
	81	#endif
	82
1da177e4	83	/* This is the fundamental function for registering boot/module
405ae7d3	84	parameters. perm sets the visibility in sysfs: 000 means it's
1da177e4 LT	85	not there, read bits mean it's readable, write bits mean it's
1da177e4 LT	86	writable. */
fddd5201	87	#define __module_param_call(prefix, name, set, get, arg, isbool, perm) \
9774a1f5 AD	88	/* Default value instead of permissions? */ \
9774a1f5 AD	89	static int __param_perm_check_##name __attribute__((unused)) = \
730b69d2 RR	90	BUILD_BUG_ON_ZERO((perm) < 0 \|\| (perm) > 0777 \|\| ((perm) & 2)) \
730b69d2 RR	91	+ BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \
22e48eaf	92	static const char __param_str_##name[] = prefix #name; \
91d35dd9	93	static struct kernel_param __moduleparam_const __param_##name \
3ff6eecc	94	__used \
1da177e4	95	__attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
fddd5201 RR	96	= { __param_str_##name, perm, isbool ? KPARAM_ISBOOL : 0, \
fddd5201 RR	97	set, get, { arg } }
1da177e4 LT	98
1da177e4 LT	99	#define module_param_call(name, set, get, arg, perm) \
fddd5201 RR	100	__module_param_call(MODULE_PARAM_PREFIX, \
	101	name, set, get, arg, \
	102	__same_type(*(arg), bool), perm)
1da177e4 LT	103
	104	/* Helper functions: type is byte, short, ushort, int, uint, long,
	105	ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
	106	param_set_XXX and param_check_XXX. */
	107	#define module_param_named(name, value, type, perm) \
	108	param_check_##type(name, &(value)); \
	109	module_param_call(name, param_set_##type, param_get_##type, &value, perm); \
	110	__MODULE_PARM_TYPE(name, #type)
	111
	112	#define module_param(name, type, perm) \
	113	module_param_named(name, name, type, perm)
	114
67e67cea RR	115	#ifndef MODULE
	116	/**
	117	* core_param - define a historical core kernel parameter.
	118	* @name: the name of the cmdline and sysfs parameter (often the same as var)
	119	* @var: the variable
	120	* @type: the type (for param_set_##type and param_get_##type)
	121	* @perm: visibility in sysfs
	122	*
	123	* core_param is just like module_param(), but cannot be modular and
	124	* doesn't add a prefix (such as "printk."). This is for compatibility
	125	* with __setup(), and it makes sense as truly core parameters aren't
	126	* tied to the particular file they're in.
	127	*/
	128	#define core_param(name, var, type, perm) \
	129	param_check_##type(name, &(var)); \
	130	__module_param_call("", name, param_set_##type, param_get_##type, \
fddd5201	131	&var, __same_type(var, bool), perm)
67e67cea RR	132	#endif /* !MODULE */
67e67cea RR	133
1da177e4 LT	134	/* Actually copy string: maxlen param is usually sizeof(string). */
1da177e4 LT	135	#define module_param_string(name, string, len, perm) \
22e48eaf	136	static const struct kparam_string __param_string_##name \
1da177e4	137	= { len, string }; \
fddd5201 RR	138	__module_param_call(MODULE_PARAM_PREFIX, name, \
	139	param_set_copystring, param_get_string, \
	140	.str = &__param_string_##name, 0, perm); \
1da177e4 LT	141	__MODULE_PARM_TYPE(name, "string")
	142
	143	/* Called on module insert or kernel boot */
	144	extern int parse_args(const char *name,
	145	char *args,
	146	struct kernel_param *params,
	147	unsigned num,
	148	int (unknown)(char param, char *val));
	149
e180a6b7 RR	150	/* Called by module remove. */
	151	#ifdef CONFIG_SYSFS
	152	extern void destroy_params(const struct kernel_param *params, unsigned num);
	153	#else
	154	static inline void destroy_params(const struct kernel_param *params,
	155	unsigned num)
	156	{
	157	}
	158	#endif /* !CONFIG_SYSFS */
	159
1da177e4 LT	160	/* All the helper functions */
	161	/* The macros to do compile-time type checking stolen from Jakub
	162	Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
	163	#define __param_check(name, p, type) \
	164	static inline type *__check_##name(void) { return(p); }
	165
	166	extern int param_set_byte(const char val, struct kernel_param kp);
	167	extern int param_get_byte(char buffer, struct kernel_param kp);
	168	#define param_check_byte(name, p) __param_check(name, p, unsigned char)
	169
	170	extern int param_set_short(const char val, struct kernel_param kp);
	171	extern int param_get_short(char buffer, struct kernel_param kp);
	172	#define param_check_short(name, p) __param_check(name, p, short)
	173
	174	extern int param_set_ushort(const char val, struct kernel_param kp);
	175	extern int param_get_ushort(char buffer, struct kernel_param kp);
	176	#define param_check_ushort(name, p) __param_check(name, p, unsigned short)
	177
	178	extern int param_set_int(const char val, struct kernel_param kp);
	179	extern int param_get_int(char buffer, struct kernel_param kp);
	180	#define param_check_int(name, p) __param_check(name, p, int)
	181
	182	extern int param_set_uint(const char val, struct kernel_param kp);
	183	extern int param_get_uint(char buffer, struct kernel_param kp);
	184	#define param_check_uint(name, p) __param_check(name, p, unsigned int)
	185
	186	extern int param_set_long(const char val, struct kernel_param kp);
	187	extern int param_get_long(char buffer, struct kernel_param kp);
	188	#define param_check_long(name, p) __param_check(name, p, long)
	189
	190	extern int param_set_ulong(const char val, struct kernel_param kp);
	191	extern int param_get_ulong(char buffer, struct kernel_param kp);
	192	#define param_check_ulong(name, p) __param_check(name, p, unsigned long)
	193
	194	extern int param_set_charp(const char val, struct kernel_param kp);
	195	extern int param_get_charp(char buffer, struct kernel_param kp);
	196	#define param_check_charp(name, p) __param_check(name, p, char *)
	197
fddd5201	198	/* For historical reasons "bool" parameters can be (unsigned) "int". */
1da177e4 LT	199	extern int param_set_bool(const char val, struct kernel_param kp);
1da177e4 LT	200	extern int param_get_bool(char buffer, struct kernel_param kp);
fddd5201 RR	201	#define param_check_bool(name, p) \
	202	static inline void __check_##name(void) \
	203	{ \
	204	BUILD_BUG_ON(!__same_type(*(p), bool) && \
	205	!__same_type(*(p), unsigned int) && \
	206	!__same_type(*(p), int)); \
	207	}
1da177e4 LT	208
	209	extern int param_set_invbool(const char val, struct kernel_param kp);
	210	extern int param_get_invbool(char buffer, struct kernel_param kp);
9a71af2c	211	#define param_check_invbool(name, p) __param_check(name, p, bool)
1da177e4 LT	212
	213	/* Comma-separated array: nump is set to number they actually specified. /
	214	#define module_param_array_named(name, array, type, nump, perm) \
22e48eaf	215	static const struct kparam_array __param_arr_##name \
1da177e4 LT	216	= { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
1da177e4 LT	217	sizeof(array[0]), array }; \
fddd5201 RR	218	__module_param_call(MODULE_PARAM_PREFIX, name, \
	219	param_array_set, param_array_get, \
	220	.arr = &__param_arr_##name, \
	221	__same_type(array[0], bool), perm); \
1da177e4 LT	222	__MODULE_PARM_TYPE(name, "array of " #type)
	223
	224	#define module_param_array(name, type, nump, perm) \
	225	module_param_array_named(name, name, type, nump, perm)
	226
	227	extern int param_array_set(const char val, struct kernel_param kp);
	228	extern int param_array_get(char buffer, struct kernel_param kp);
	229
	230	extern int param_set_copystring(const char val, struct kernel_param kp);
	231	extern int param_get_string(char buffer, struct kernel_param kp);
	232
1da177e4 LT	233	/* for exporting parameters in /sys/parameters */
	234
	235	struct module;
	236
ef665c1a	237	#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
1da177e4 LT	238	extern int module_param_sysfs_setup(struct module *mod,
	239	struct kernel_param *kparam,
	240	unsigned int num_params);
	241
	242	extern void module_param_sysfs_remove(struct module *mod);
ef665c1a RD	243	#else
	244	static inline int module_param_sysfs_setup(struct module *mod,
	245	struct kernel_param *kparam,
	246	unsigned int num_params)
	247	{
	248	return 0;
	249	}
	250
	251	static inline void module_param_sysfs_remove(struct module *mod)
	252	{ }
	253	#endif
1da177e4 LT	254
1da177e4 LT	255	#endif /* _LINUX_MODULE_PARAMS_H */