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 /* Chosen so that structs with an unsigned long line up. */
17 #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
18
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__)[] \
24 __used \
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
39 struct kernel_param {
40 const char *name;
41 unsigned int perm;
42 param_set_fn set;
43 param_get_fn get;
44 union {
45 void *arg;
46 const struct kparam_string *str;
47 const struct kparam_array *arr;
48 };
49 };
50
51 /* Special one for strings we want to copy into */
52 struct kparam_string {
53 unsigned int maxlen;
54 char *string;
55 };
56
57 /* Special one for arrays */
58 struct kparam_array
59 {
60 unsigned int max;
61 unsigned int *num;
62 param_set_fn set;
63 param_get_fn get;
64 unsigned int elemsize;
65 void *elem;
66 };
67
68 /* On alpha, ia64 and ppc64 relocations to global data cannot go into
69 read-only sections (which is part of respective UNIX ABI on these
70 platforms). So 'const' makes no sense and even causes compile failures
71 with some compilers. */
72 #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
73 #define __moduleparam_const
74 #else
75 #define __moduleparam_const const
76 #endif
77
78 /* This is the fundamental function for registering boot/module
79 parameters. perm sets the visibility in sysfs: 000 means it's
80 not there, read bits mean it's readable, write bits mean it's
81 writable. */
82 #define __module_param_call(prefix, name, set, get, arg, perm) \
83 /* Default value instead of permissions? */ \
84 static int __param_perm_check_##name __attribute__((unused)) = \
85 BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \
86 + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \
87 static const char __param_str_##name[] = prefix #name; \
88 static struct kernel_param __moduleparam_const __param_##name \
89 __used \
90 __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
91 = { __param_str_##name, perm, set, get, { arg } }
92
93 #define module_param_call(name, set, get, arg, perm) \
94 __module_param_call(MODULE_PARAM_PREFIX, name, set, get, arg, perm)
95
96 /* Helper functions: type is byte, short, ushort, int, uint, long,
97 ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
98 param_set_XXX and param_check_XXX. */
99 #define module_param_named(name, value, type, perm) \
100 param_check_##type(name, &(value)); \
101 module_param_call(name, param_set_##type, param_get_##type, &value, perm); \
102 __MODULE_PARM_TYPE(name, #type)
103
104 #define module_param(name, type, perm) \
105 module_param_named(name, name, type, perm)
106
107 #ifndef MODULE
108 /**
109 * core_param - define a historical core kernel parameter.
110 * @name: the name of the cmdline and sysfs parameter (often the same as var)
111 * @var: the variable
112 * @type: the type (for param_set_##type and param_get_##type)
113 * @perm: visibility in sysfs
114 *
115 * core_param is just like module_param(), but cannot be modular and
116 * doesn't add a prefix (such as "printk."). This is for compatibility
117 * with __setup(), and it makes sense as truly core parameters aren't
118 * tied to the particular file they're in.
119 */
120 #define core_param(name, var, type, perm) \
121 param_check_##type(name, &(var)); \
122 __module_param_call("", name, param_set_##type, param_get_##type, \
123 &var, perm)
124 #endif /* !MODULE */
125
126 /* Actually copy string: maxlen param is usually sizeof(string). */
127 #define module_param_string(name, string, len, perm) \
128 static const struct kparam_string __param_string_##name \
129 = { len, string }; \
130 module_param_call(name, param_set_copystring, param_get_string, \
131 .str = &__param_string_##name, perm); \
132 __MODULE_PARM_TYPE(name, "string")
133
134 /* Called on module insert or kernel boot */
135 extern int parse_args(const char *name,
136 char *args,
137 struct kernel_param *params,
138 unsigned num,
139 int (*unknown)(char *param, char *val));
140
141 /* All the helper functions */
142 /* The macros to do compile-time type checking stolen from Jakub
143 Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
144 #define __param_check(name, p, type) \
145 static inline type *__check_##name(void) { return(p); }
146
147 extern int param_set_byte(const char *val, struct kernel_param *kp);
148 extern int param_get_byte(char *buffer, struct kernel_param *kp);
149 #define param_check_byte(name, p) __param_check(name, p, unsigned char)
150
151 extern int param_set_short(const char *val, struct kernel_param *kp);
152 extern int param_get_short(char *buffer, struct kernel_param *kp);
153 #define param_check_short(name, p) __param_check(name, p, short)
154
155 extern int param_set_ushort(const char *val, struct kernel_param *kp);
156 extern int param_get_ushort(char *buffer, struct kernel_param *kp);
157 #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
158
159 extern int param_set_int(const char *val, struct kernel_param *kp);
160 extern int param_get_int(char *buffer, struct kernel_param *kp);
161 #define param_check_int(name, p) __param_check(name, p, int)
162
163 extern int param_set_uint(const char *val, struct kernel_param *kp);
164 extern int param_get_uint(char *buffer, struct kernel_param *kp);
165 #define param_check_uint(name, p) __param_check(name, p, unsigned int)
166
167 extern int param_set_long(const char *val, struct kernel_param *kp);
168 extern int param_get_long(char *buffer, struct kernel_param *kp);
169 #define param_check_long(name, p) __param_check(name, p, long)
170
171 extern int param_set_ulong(const char *val, struct kernel_param *kp);
172 extern int param_get_ulong(char *buffer, struct kernel_param *kp);
173 #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
174
175 extern int param_set_charp(const char *val, struct kernel_param *kp);
176 extern int param_get_charp(char *buffer, struct kernel_param *kp);
177 #define param_check_charp(name, p) __param_check(name, p, char *)
178
179 extern int param_set_bool(const char *val, struct kernel_param *kp);
180 extern int param_get_bool(char *buffer, struct kernel_param *kp);
181 #define param_check_bool(name, p) __param_check(name, p, int)
182
183 extern int param_set_invbool(const char *val, struct kernel_param *kp);
184 extern int param_get_invbool(char *buffer, struct kernel_param *kp);
185 #define param_check_invbool(name, p) __param_check(name, p, int)
186
187 /* Comma-separated array: *nump is set to number they actually specified. */
188 #define module_param_array_named(name, array, type, nump, perm) \
189 static const struct kparam_array __param_arr_##name \
190 = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
191 sizeof(array[0]), array }; \
192 module_param_call(name, param_array_set, param_array_get, \
193 .arr = &__param_arr_##name, perm); \
194 __MODULE_PARM_TYPE(name, "array of " #type)
195
196 #define module_param_array(name, type, nump, perm) \
197 module_param_array_named(name, name, type, nump, perm)
198
199 extern int param_array_set(const char *val, struct kernel_param *kp);
200 extern int param_array_get(char *buffer, struct kernel_param *kp);
201
202 extern int param_set_copystring(const char *val, struct kernel_param *kp);
203 extern int param_get_string(char *buffer, struct kernel_param *kp);
204
205 /* for exporting parameters in /sys/parameters */
206
207 struct module;
208
209 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
210 extern int module_param_sysfs_setup(struct module *mod,
211 struct kernel_param *kparam,
212 unsigned int num_params);
213
214 extern void module_param_sysfs_remove(struct module *mod);
215 #else
module_param_sysfs_setup(struct module * mod,struct kernel_param * kparam,unsigned int num_params)216 static inline int module_param_sysfs_setup(struct module *mod,
217 struct kernel_param *kparam,
218 unsigned int num_params)
219 {
220 return 0;
221 }
222
module_param_sysfs_remove(struct module * mod)223 static inline void module_param_sysfs_remove(struct module *mod)
224 { }
225 #endif
226
227 #endif /* _LINUX_MODULE_PARAMS_H */
228