include/linux/moduleparam.h

   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   __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         __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 */