LXR linux/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/* 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)                                    \
  23static 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
  32struct kernel_param;
  33
  34/* Returns 0, or -errno.  arg is in kp->arg. */
  35typedef int (*param_set_fn)(const char *val, struct kernel_param *kp);
  36/* Returns length written or -errno.  Buffer is 4k (ie. be short!) */
  37typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp);
  38
  39/* Flag bits for kernel_param.flags */
  40#define KPARAM_KMALLOCED        1
  41#define KPARAM_ISBOOL           2
  42
  43struct kernel_param {
  44        const char *name;
  45        u16 perm;
  46        u16 flags;
  47        param_set_fn set;
  48        param_get_fn get;
  49        union {
  50                void *arg;
  51                const struct kparam_string *str;
  52                const struct kparam_array *arr;
  53        };
  54};
  55
  56/* Special one for strings we want to copy into */
  57struct kparam_string {
  58        unsigned int maxlen;
  59        char *string;
  60};
  61
  62/* Special one for arrays */
  63struct 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
  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
  83/* This is the fundamental function for registering boot/module
  84   parameters.  perm sets the visibility in sysfs: 000 means it's
  85   not there, read bits mean it's readable, write bits mean it's
  86   writable. */
  87#define __module_param_call(prefix, name, set, get, arg, isbool, perm)  \
  88        /* Default value instead of permissions? */                     \
  89        static int __param_perm_check_##name __attribute__((unused)) =  \
  90        BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))  \
  91        + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN);   \
  92        static const char __param_str_##name[] = prefix #name;          \
  93        static struct kernel_param __moduleparam_const __param_##name   \
  94        __used                                                          \
  95    __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
  96        = { __param_str_##name, perm, isbool ? KPARAM_ISBOOL : 0,       \
  97            set, get, { arg } }
  98
  99#define module_param_call(name, set, get, arg, perm)                          \
 100        __module_param_call(MODULE_PARAM_PREFIX,                              \
 101                            name, set, get, arg,                              \
 102                            __same_type(*(arg), bool), perm)
 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
 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, \
 131                            &var, __same_type(var, bool), perm)
 132#endif /* !MODULE */
 133
 134/* Actually copy string: maxlen param is usually sizeof(string). */
 135#define module_param_string(name, string, len, perm)                    \
 136        static const struct kparam_string __param_string_##name         \
 137                = { len, string };                                      \
 138        __module_param_call(MODULE_PARAM_PREFIX, name,                  \
 139                            param_set_copystring, param_get_string,     \
 140                            .str = &__param_string_##name, 0, perm);    \
 141        __MODULE_PARM_TYPE(name, "string")
 142
 143/* Called on module insert or kernel boot */
 144extern 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
 150/* Called by module remove. */
 151#ifdef CONFIG_SYSFS
 152extern void destroy_params(const struct kernel_param *params, unsigned num);
 153#else
 154static inline void destroy_params(const struct kernel_param *params,
 155                                  unsigned num)
 156{
 157}
 158#endif /* !CONFIG_SYSFS */
 159
 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
 166extern int param_set_byte(const char *val, struct kernel_param *kp);
 167extern int param_get_byte(char *buffer, struct kernel_param *kp);
 168#define param_check_byte(name, p) __param_check(name, p, unsigned char)
 169
 170extern int param_set_short(const char *val, struct kernel_param *kp);
 171extern int param_get_short(char *buffer, struct kernel_param *kp);
 172#define param_check_short(name, p) __param_check(name, p, short)
 173
 174extern int param_set_ushort(const char *val, struct kernel_param *kp);
 175extern int param_get_ushort(char *buffer, struct kernel_param *kp);
 176#define param_check_ushort(name, p) __param_check(name, p, unsigned short)
 177
 178extern int param_set_int(const char *val, struct kernel_param *kp);
 179extern int param_get_int(char *buffer, struct kernel_param *kp);
 180#define param_check_int(name, p) __param_check(name, p, int)
 181
 182extern int param_set_uint(const char *val, struct kernel_param *kp);
 183extern int param_get_uint(char *buffer, struct kernel_param *kp);
 184#define param_check_uint(name, p) __param_check(name, p, unsigned int)
 185
 186extern int param_set_long(const char *val, struct kernel_param *kp);
 187extern int param_get_long(char *buffer, struct kernel_param *kp);
 188#define param_check_long(name, p) __param_check(name, p, long)
 189
 190extern int param_set_ulong(const char *val, struct kernel_param *kp);
 191extern int param_get_ulong(char *buffer, struct kernel_param *kp);
 192#define param_check_ulong(name, p) __param_check(name, p, unsigned long)
 193
 194extern int param_set_charp(const char *val, struct kernel_param *kp);
 195extern int param_get_charp(char *buffer, struct kernel_param *kp);
 196#define param_check_charp(name, p) __param_check(name, p, char *)
 197
 198/* For historical reasons "bool" parameters can be (unsigned) "int". */
 199extern int param_set_bool(const char *val, struct kernel_param *kp);
 200extern int param_get_bool(char *buffer, struct kernel_param *kp);
 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        }
 208
 209extern int param_set_invbool(const char *val, struct kernel_param *kp);
 210extern int param_get_invbool(char *buffer, struct kernel_param *kp);
 211#define param_check_invbool(name, p) __param_check(name, p, bool)
 212
 213/* Comma-separated array: *nump is set to number they actually specified. */
 214#define module_param_array_named(name, array, type, nump, perm)         \
 215        static const struct kparam_array __param_arr_##name             \
 216        = { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
 217            sizeof(array[0]), array };                                  \
 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);         \
 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
 227extern int param_array_set(const char *val, struct kernel_param *kp);
 228extern int param_array_get(char *buffer, struct kernel_param *kp);
 229
 230extern int param_set_copystring(const char *val, struct kernel_param *kp);
 231extern int param_get_string(char *buffer, struct kernel_param *kp);
 232
 233/* for exporting parameters in /sys/parameters */
 234
 235struct module;
 236
 237#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
 238extern int module_param_sysfs_setup(struct module *mod,
 239                                    struct kernel_param *kparam,
 240                                    unsigned int num_params);
 241
 242extern void module_param_sysfs_remove(struct module *mod);
 243#else
 244static 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
 251static inline void module_param_sysfs_remove(struct module *mod)
 252{ }
 253#endif
 254
 255#endif /* _LINUX_MODULE_PARAMS_H */
 256