xref: /linux/include/linux/moduleparam.h (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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
13 #define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
14 #endif
15 
16 #ifdef MODULE
17 #define ___module_cat(a,b) __mod_ ## a ## b
18 #define __module_cat(a,b) ___module_cat(a,b)
19 #define __MODULE_INFO(tag, name, info)					  \
20 static const char __module_cat(name,__LINE__)[]				  \
21   __attribute_used__							  \
22   __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
23 #else  /* !MODULE */
24 #define __MODULE_INFO(tag, name, info)
25 #endif
26 #define __MODULE_PARM_TYPE(name, _type)					  \
27   __MODULE_INFO(parmtype, name##type, #name ":" _type)
28 
29 struct kernel_param;
30 
31 /* Returns 0, or -errno.  arg is in kp->arg. */
32 typedef int (*param_set_fn)(const char *val, struct kernel_param *kp);
33 /* Returns length written or -errno.  Buffer is 4k (ie. be short!) */
34 typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp);
35 
36 struct kernel_param {
37 	const char *name;
38 	unsigned int perm;
39 	param_set_fn set;
40 	param_get_fn get;
41 	union {
42 		void *arg;
43 		const struct kparam_string *str;
44 		const struct kparam_array *arr;
45 	};
46 };
47 
48 /* Special one for strings we want to copy into */
49 struct kparam_string {
50 	unsigned int maxlen;
51 	char *string;
52 };
53 
54 /* Special one for arrays */
55 struct kparam_array
56 {
57 	unsigned int max;
58 	unsigned int *num;
59 	param_set_fn set;
60 	param_get_fn get;
61 	unsigned int elemsize;
62 	void *elem;
63 };
64 
65 /* This is the fundamental function for registering boot/module
66    parameters.  perm sets the visibility in sysfs: 000 means it's
67    not there, read bits mean it's readable, write bits mean it's
68    writable. */
69 #define __module_param_call(prefix, name, set, get, arg, perm)		\
70 	/* Default value instead of permissions? */			\
71 	static int __param_perm_check_##name __attribute__((unused)) =	\
72 	BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2));	\
73 	static const char __param_str_##name[] = prefix #name;		\
74 	static struct kernel_param const __param_##name			\
75 	__attribute_used__						\
76     __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
77 	= { __param_str_##name, perm, set, get, { arg } }
78 
79 #define module_param_call(name, set, get, arg, perm)			      \
80 	__module_param_call(MODULE_PARAM_PREFIX, name, set, get, arg, perm)
81 
82 /* Helper functions: type is byte, short, ushort, int, uint, long,
83    ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
84    param_set_XXX and param_check_XXX. */
85 #define module_param_named(name, value, type, perm)			   \
86 	param_check_##type(name, &(value));				   \
87 	module_param_call(name, param_set_##type, param_get_##type, &value, perm); \
88 	__MODULE_PARM_TYPE(name, #type)
89 
90 #define module_param(name, type, perm)				\
91 	module_param_named(name, name, type, perm)
92 
93 /* Actually copy string: maxlen param is usually sizeof(string). */
94 #define module_param_string(name, string, len, perm)			\
95 	static const struct kparam_string __param_string_##name		\
96 		= { len, string };					\
97 	module_param_call(name, param_set_copystring, param_get_string,	\
98 			  .str = &__param_string_##name, perm);		\
99 	__MODULE_PARM_TYPE(name, "string")
100 
101 /* Called on module insert or kernel boot */
102 extern int parse_args(const char *name,
103 		      char *args,
104 		      struct kernel_param *params,
105 		      unsigned num,
106 		      int (*unknown)(char *param, char *val));
107 
108 /* All the helper functions */
109 /* The macros to do compile-time type checking stolen from Jakub
110    Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
111 #define __param_check(name, p, type) \
112 	static inline type *__check_##name(void) { return(p); }
113 
114 extern int param_set_byte(const char *val, struct kernel_param *kp);
115 extern int param_get_byte(char *buffer, struct kernel_param *kp);
116 #define param_check_byte(name, p) __param_check(name, p, unsigned char)
117 
118 extern int param_set_short(const char *val, struct kernel_param *kp);
119 extern int param_get_short(char *buffer, struct kernel_param *kp);
120 #define param_check_short(name, p) __param_check(name, p, short)
121 
122 extern int param_set_ushort(const char *val, struct kernel_param *kp);
123 extern int param_get_ushort(char *buffer, struct kernel_param *kp);
124 #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
125 
126 extern int param_set_int(const char *val, struct kernel_param *kp);
127 extern int param_get_int(char *buffer, struct kernel_param *kp);
128 #define param_check_int(name, p) __param_check(name, p, int)
129 
130 extern int param_set_uint(const char *val, struct kernel_param *kp);
131 extern int param_get_uint(char *buffer, struct kernel_param *kp);
132 #define param_check_uint(name, p) __param_check(name, p, unsigned int)
133 
134 extern int param_set_long(const char *val, struct kernel_param *kp);
135 extern int param_get_long(char *buffer, struct kernel_param *kp);
136 #define param_check_long(name, p) __param_check(name, p, long)
137 
138 extern int param_set_ulong(const char *val, struct kernel_param *kp);
139 extern int param_get_ulong(char *buffer, struct kernel_param *kp);
140 #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
141 
142 extern int param_set_charp(const char *val, struct kernel_param *kp);
143 extern int param_get_charp(char *buffer, struct kernel_param *kp);
144 #define param_check_charp(name, p) __param_check(name, p, char *)
145 
146 extern int param_set_bool(const char *val, struct kernel_param *kp);
147 extern int param_get_bool(char *buffer, struct kernel_param *kp);
148 #define param_check_bool(name, p) __param_check(name, p, int)
149 
150 extern int param_set_invbool(const char *val, struct kernel_param *kp);
151 extern int param_get_invbool(char *buffer, struct kernel_param *kp);
152 #define param_check_invbool(name, p) __param_check(name, p, int)
153 
154 /* Comma-separated array: *nump is set to number they actually specified. */
155 #define module_param_array_named(name, array, type, nump, perm)		\
156 	static const struct kparam_array __param_arr_##name		\
157 	= { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
158 	    sizeof(array[0]), array };					\
159 	module_param_call(name, param_array_set, param_array_get, 	\
160 			  .arr = &__param_arr_##name, perm);		\
161 	__MODULE_PARM_TYPE(name, "array of " #type)
162 
163 #define module_param_array(name, type, nump, perm)		\
164 	module_param_array_named(name, name, type, nump, perm)
165 
166 extern int param_array_set(const char *val, struct kernel_param *kp);
167 extern int param_array_get(char *buffer, struct kernel_param *kp);
168 
169 extern int param_set_copystring(const char *val, struct kernel_param *kp);
170 extern int param_get_string(char *buffer, struct kernel_param *kp);
171 
172 /* for exporting parameters in /sys/parameters */
173 
174 struct module;
175 
176 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
177 extern int module_param_sysfs_setup(struct module *mod,
178 				    struct kernel_param *kparam,
179 				    unsigned int num_params);
180 
181 extern void module_param_sysfs_remove(struct module *mod);
182 #else
183 static inline int module_param_sysfs_setup(struct module *mod,
184 			     struct kernel_param *kparam,
185 			     unsigned int num_params)
186 {
187 	return 0;
188 }
189 
190 static inline void module_param_sysfs_remove(struct module *mod)
191 { }
192 #endif
193 
194 #endif /* _LINUX_MODULE_PARAMS_H */
195