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>
8 /* You can override this manually, but generally this should match the
11 #define MODULE_PARAM_PREFIX /* empty */
13 #define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
16 /* Chosen so that structs with an unsigned long line up. */
17 #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
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__)[] \
25 __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
27 #define __MODULE_INFO(tag, name, info)
29 #define __MODULE_PARM_TYPE(name, _type) \
30 __MODULE_INFO(parmtype, name##type, #name ":" _type)
34 struct kernel_param_ops
{
35 /* Returns 0, or -errno. arg is in kp->arg. */
36 int (*set
)(const char *val
, const struct kernel_param
*kp
);
37 /* Returns length written or -errno. Buffer is 4k (ie. be short!) */
38 int (*get
)(char *buffer
, const struct kernel_param
*kp
);
39 /* Optional function to free kp->arg when module unloaded. */
40 void (*free
)(void *arg
);
43 /* Flag bits for kernel_param.flags */
44 #define KPARAM_ISBOOL 2
48 const struct kernel_param_ops
*ops
;
53 const struct kparam_string
*str
;
54 const struct kparam_array
*arr
;
58 /* Special one for strings we want to copy into */
59 struct kparam_string
{
64 /* Special one for arrays */
69 const struct kernel_param_ops
*ops
;
70 unsigned int elemsize
;
74 /* On alpha, ia64 and ppc64 relocations to global data cannot go into
75 read-only sections (which is part of respective UNIX ABI on these
76 platforms). So 'const' makes no sense and even causes compile failures
77 with some compilers. */
78 #if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
79 #define __moduleparam_const
81 #define __moduleparam_const const
84 /* This is the fundamental function for registering boot/module
85 parameters. perm sets the visibility in sysfs: 000 means it's
86 not there, read bits mean it's readable, write bits mean it's
88 #define __module_param_call(prefix, name, ops, arg, isbool, perm) \
89 /* Default value instead of permissions? */ \
90 static int __param_perm_check_##name __attribute__((unused)) = \
91 BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \
92 + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \
93 static const char __param_str_##name[] = prefix #name; \
94 static struct kernel_param __moduleparam_const __param_##name \
96 __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
97 = { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0, \
100 /* Obsolete - use module_param_cb() */
101 #define module_param_call(name, set, get, arg, perm) \
102 static struct kernel_param_ops __param_ops_##name = \
103 { (void *)set, (void *)get }; \
104 __module_param_call(MODULE_PARAM_PREFIX, \
105 name, &__param_ops_##name, arg, \
106 __same_type(*(arg), bool), \
107 (perm) + sizeof(__check_old_set_param(set))*0)
109 /* We don't get oldget: it's often a new-style param_get_uint, etc. */
111 __check_old_set_param(int (*oldset
)(const char *, struct kernel_param
*))
116 #define module_param_cb(name, ops, arg, perm) \
117 __module_param_call(MODULE_PARAM_PREFIX, \
118 name, ops, arg, __same_type(*(arg), bool), perm)
121 * Helper functions: type is byte, short, ushort, int, uint, long,
122 * ulong, charp, bool or invbool, or XXX if you define param_ops_XXX
123 * and param_check_XXX.
125 #define module_param_named(name, value, type, perm) \
126 param_check_##type(name, &(value)); \
127 module_param_cb(name, ¶m_ops_##type, &value, perm); \
128 __MODULE_PARM_TYPE(name, #type)
130 #define module_param(name, type, perm) \
131 module_param_named(name, name, type, perm)
134 * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs.
135 * @name: the name of the parameter
137 * There's no point blocking write on a paramter that isn't writable via sysfs!
139 #define kparam_block_sysfs_write(name) \
141 BUG_ON(!(__param_##name.perm & 0222)); \
142 __kernel_param_lock(); \
146 * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again.
147 * @name: the name of the parameter
149 #define kparam_unblock_sysfs_write(name) \
151 BUG_ON(!(__param_##name.perm & 0222)); \
152 __kernel_param_unlock(); \
156 * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs.
157 * @name: the name of the parameter
159 * This also blocks sysfs writes.
161 #define kparam_block_sysfs_read(name) \
163 BUG_ON(!(__param_##name.perm & 0444)); \
164 __kernel_param_lock(); \
168 * kparam_unblock_sysfs_read - allows sysfs to read a parameter again.
169 * @name: the name of the parameter
171 #define kparam_unblock_sysfs_read(name) \
173 BUG_ON(!(__param_##name.perm & 0444)); \
174 __kernel_param_unlock(); \
178 extern void __kernel_param_lock(void);
179 extern void __kernel_param_unlock(void);
181 static inline void __kernel_param_lock(void)
184 static inline void __kernel_param_unlock(void)
191 * core_param - define a historical core kernel parameter.
192 * @name: the name of the cmdline and sysfs parameter (often the same as var)
194 * @type: the type (for param_set_##type and param_get_##type)
195 * @perm: visibility in sysfs
197 * core_param is just like module_param(), but cannot be modular and
198 * doesn't add a prefix (such as "printk."). This is for compatibility
199 * with __setup(), and it makes sense as truly core parameters aren't
200 * tied to the particular file they're in.
202 #define core_param(name, var, type, perm) \
203 param_check_##type(name, &(var)); \
204 __module_param_call("", name, ¶m_ops_##type, \
205 &var, __same_type(var, bool), perm)
208 /* Actually copy string: maxlen param is usually sizeof(string). */
209 #define module_param_string(name, string, len, perm) \
210 static const struct kparam_string __param_string_##name \
212 __module_param_call(MODULE_PARAM_PREFIX, name, \
214 .str = &__param_string_##name, 0, perm); \
215 __MODULE_PARM_TYPE(name, "string")
217 /* Called on module insert or kernel boot */
218 extern int parse_args(const char *name
,
220 const struct kernel_param
*params
,
222 int (*unknown
)(char *param
, char *val
));
224 /* Called by module remove. */
226 extern void destroy_params(const struct kernel_param
*params
, unsigned num
);
228 static inline void destroy_params(const struct kernel_param
*params
,
232 #endif /* !CONFIG_SYSFS */
234 /* All the helper functions */
235 /* The macros to do compile-time type checking stolen from Jakub
236 Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
237 #define __param_check(name, p, type) \
238 static inline type *__check_##name(void) { return(p); }
240 extern struct kernel_param_ops param_ops_byte
;
241 extern int param_set_byte(const char *val
, const struct kernel_param
*kp
);
242 extern int param_get_byte(char *buffer
, const struct kernel_param
*kp
);
243 #define param_check_byte(name, p) __param_check(name, p, unsigned char)
245 extern struct kernel_param_ops param_ops_short
;
246 extern int param_set_short(const char *val
, const struct kernel_param
*kp
);
247 extern int param_get_short(char *buffer
, const struct kernel_param
*kp
);
248 #define param_check_short(name, p) __param_check(name, p, short)
250 extern struct kernel_param_ops param_ops_ushort
;
251 extern int param_set_ushort(const char *val
, const struct kernel_param
*kp
);
252 extern int param_get_ushort(char *buffer
, const struct kernel_param
*kp
);
253 #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
255 extern struct kernel_param_ops param_ops_int
;
256 extern int param_set_int(const char *val
, const struct kernel_param
*kp
);
257 extern int param_get_int(char *buffer
, const struct kernel_param
*kp
);
258 #define param_check_int(name, p) __param_check(name, p, int)
260 extern struct kernel_param_ops param_ops_uint
;
261 extern int param_set_uint(const char *val
, const struct kernel_param
*kp
);
262 extern int param_get_uint(char *buffer
, const struct kernel_param
*kp
);
263 #define param_check_uint(name, p) __param_check(name, p, unsigned int)
265 extern struct kernel_param_ops param_ops_long
;
266 extern int param_set_long(const char *val
, const struct kernel_param
*kp
);
267 extern int param_get_long(char *buffer
, const struct kernel_param
*kp
);
268 #define param_check_long(name, p) __param_check(name, p, long)
270 extern struct kernel_param_ops param_ops_ulong
;
271 extern int param_set_ulong(const char *val
, const struct kernel_param
*kp
);
272 extern int param_get_ulong(char *buffer
, const struct kernel_param
*kp
);
273 #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
275 extern struct kernel_param_ops param_ops_charp
;
276 extern int param_set_charp(const char *val
, const struct kernel_param
*kp
);
277 extern int param_get_charp(char *buffer
, const struct kernel_param
*kp
);
278 #define param_check_charp(name, p) __param_check(name, p, char *)
280 /* For historical reasons "bool" parameters can be (unsigned) "int". */
281 extern struct kernel_param_ops param_ops_bool
;
282 extern int param_set_bool(const char *val
, const struct kernel_param
*kp
);
283 extern int param_get_bool(char *buffer
, const struct kernel_param
*kp
);
284 #define param_check_bool(name, p) \
285 static inline void __check_##name(void) \
287 BUILD_BUG_ON(!__same_type(*(p), bool) && \
288 !__same_type(*(p), unsigned int) && \
289 !__same_type(*(p), int)); \
292 extern struct kernel_param_ops param_ops_invbool
;
293 extern int param_set_invbool(const char *val
, const struct kernel_param
*kp
);
294 extern int param_get_invbool(char *buffer
, const struct kernel_param
*kp
);
295 #define param_check_invbool(name, p) __param_check(name, p, bool)
297 /* Comma-separated array: *nump is set to number they actually specified. */
298 #define module_param_array_named(name, array, type, nump, perm) \
299 static const struct kparam_array __param_arr_##name \
300 = { ARRAY_SIZE(array), nump, ¶m_ops_##type, \
301 sizeof(array[0]), array }; \
302 __module_param_call(MODULE_PARAM_PREFIX, name, \
304 .arr = &__param_arr_##name, \
305 __same_type(array[0], bool), perm); \
306 __MODULE_PARM_TYPE(name, "array of " #type)
308 #define module_param_array(name, type, nump, perm) \
309 module_param_array_named(name, name, type, nump, perm)
311 extern struct kernel_param_ops param_array_ops
;
313 extern struct kernel_param_ops param_ops_string
;
314 extern int param_set_copystring(const char *val
, const struct kernel_param
*);
315 extern int param_get_string(char *buffer
, const struct kernel_param
*kp
);
317 /* for exporting parameters in /sys/parameters */
321 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
322 extern int module_param_sysfs_setup(struct module
*mod
,
323 const struct kernel_param
*kparam
,
324 unsigned int num_params
);
326 extern void module_param_sysfs_remove(struct module
*mod
);
328 static inline int module_param_sysfs_setup(struct module
*mod
,
329 const struct kernel_param
*kparam
,
330 unsigned int num_params
)
335 static inline void module_param_sysfs_remove(struct module
*mod
)
339 #endif /* _LINUX_MODULE_PARAMS_H */