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
  39struct 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 */
  52struct kparam_string {
  53        unsigned int maxlen;
  54        char *string;
  55};
  56
  57/* Special one for arrays */
  58struct 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 */
 135extern 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
 147extern int param_set_byte(const char *val, struct kernel_param *kp);
 148extern int param_get_byte(char *buffer, struct kernel_param *kp);
 149#define param_check_byte(name, p) __param_check(name, p, unsigned char)
 150
 151extern int param_set_short(const char *val, struct kernel_param *kp);
 152extern int param_get_short(char *buffer, struct kernel_param *kp);
 153#define param_check_short(name, p) __param_check(name, p, short)
 154
 155extern int param_set_ushort(const char *val, struct kernel_param *kp);
 156extern int param_get_ushort(char *buffer, struct kernel_param *kp);
 157#define param_check_ushort(name, p) __param_check(name, p, unsigned short)
 158
 159extern int param_set_int(const char *val, struct kernel_param *kp);
 160extern int param_get_int(char *buffer, struct kernel_param *kp);
 161#define param_check_int(name, p) __param_check(name, p, int)
 162
 163extern int param_set_uint(const char *val, struct kernel_param *kp);
 164extern int param_get_uint(char *buffer, struct kernel_param *kp);
 165#define param_check_uint(name, p) __param_check(name, p, unsigned int)
 166
 167extern int param_set_long(const char *val, struct kernel_param *kp);
 168extern int param_get_long(char *buffer, struct kernel_param *kp);
 169#define param_check_long(name, p) __param_check(name, p, long)
 170
 171extern int param_set_ulong(const char *val, struct kernel_param *kp);
 172extern int param_get_ulong(char *buffer, struct kernel_param *kp);
 173#define param_check_ulong(name, p) __param_check(name, p, unsigned long)
 174
 175extern int param_set_charp(const char *val, struct kernel_param *kp);
 176extern int param_get_charp(char *buffer, struct kernel_param *kp);
 177#define param_check_charp(name, p) __param_check(name, p, char *)
 178
 179extern int param_set_bool(const char *val, struct kernel_param *kp);
 180extern int param_get_bool(char *buffer, struct kernel_param *kp);
 181#define param_check_bool(name, p) __param_check(name, p, int)
 182
 183extern int param_set_invbool(const char *val, struct kernel_param *kp);
 184extern 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
 199extern int param_array_set(const char *val, struct kernel_param *kp);
 200extern int param_array_get(char *buffer, struct kernel_param *kp);
 201
 202extern int param_set_copystring(const char *val, struct kernel_param *kp);
 203extern int param_get_string(char *buffer, struct kernel_param *kp);
 204
 205/* for exporting parameters in /sys/parameters */
 206
 207struct module;
 208
 209#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
 210extern int module_param_sysfs_setup(struct module *mod,
 211                                    struct kernel_param *kparam,
 212                                    unsigned int num_params);
 213
 214extern void module_param_sysfs_remove(struct module *mod);
 215#else
 216static 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
 223static inline void module_param_sysfs_remove(struct module *mod)
 224{ }
 225#endif
 226
 227#endif /* _LINUX_MODULE_PARAMS_H */
 228