summaryrefslogtreecommitdiff
path: root/include/linux/moduleparam.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/moduleparam.h')
-rw-r--r--include/linux/moduleparam.h508
1 files changed, 508 insertions, 0 deletions
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
new file mode 100644
index 000000000..1c9effa25
--- /dev/null
+++ b/include/linux/moduleparam.h
@@ -0,0 +1,508 @@
+#ifndef _LINUX_MODULE_PARAMS_H
+#define _LINUX_MODULE_PARAMS_H
+/* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */
+#include <linux/init.h>
+#include <linux/stringify.h>
+#include <linux/kernel.h>
+
+/* You can override this manually, but generally this should match the
+ module name. */
+#ifdef MODULE
+#define MODULE_PARAM_PREFIX /* empty */
+#else
+#define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
+#endif
+
+/* Chosen so that structs with an unsigned long line up. */
+#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
+
+#ifdef MODULE
+#define __MODULE_INFO(tag, name, info) \
+static const char __UNIQUE_ID(name)[] \
+ __used __attribute__((section(".modinfo"), unused, aligned(1))) \
+ = __stringify(tag) "=" info
+#else /* !MODULE */
+/* This struct is here for syntactic coherency, it is not used */
+#define __MODULE_INFO(tag, name, info) \
+ struct __UNIQUE_ID(name) {}
+#endif
+#define __MODULE_PARM_TYPE(name, _type) \
+ __MODULE_INFO(parmtype, name##type, #name ":" _type)
+
+/* One for each parameter, describing how to use it. Some files do
+ multiple of these per line, so can't just use MODULE_INFO. */
+#define MODULE_PARM_DESC(_parm, desc) \
+ __MODULE_INFO(parm, _parm, #_parm ":" desc)
+
+struct kernel_param;
+
+/*
+ * Flags available for kernel_param_ops
+ *
+ * NOARG - the parameter allows for no argument (foo instead of foo=1)
+ */
+enum {
+ KERNEL_PARAM_OPS_FL_NOARG = (1 << 0)
+};
+
+struct kernel_param_ops {
+ /* How the ops should behave */
+ unsigned int flags;
+ /* Returns 0, or -errno. arg is in kp->arg. */
+ int (*set)(const char *val, const struct kernel_param *kp);
+ /* Returns length written or -errno. Buffer is 4k (ie. be short!) */
+ int (*get)(char *buffer, const struct kernel_param *kp);
+ /* Optional function to free kp->arg when module unloaded. */
+ void (*free)(void *arg);
+};
+
+/*
+ * Flags available for kernel_param
+ *
+ * UNSAFE - the parameter is dangerous and setting it will taint the kernel
+ */
+enum {
+ KERNEL_PARAM_FL_UNSAFE = (1 << 0)
+};
+
+struct kernel_param {
+ const char *name;
+ const struct kernel_param_ops *ops;
+ u16 perm;
+ s8 level;
+ u8 flags;
+ union {
+ void *arg;
+ const struct kparam_string *str;
+ const struct kparam_array *arr;
+ };
+};
+
+extern const struct kernel_param __start___param[], __stop___param[];
+
+/* Special one for strings we want to copy into */
+struct kparam_string {
+ unsigned int maxlen;
+ char *string;
+};
+
+/* Special one for arrays */
+struct kparam_array
+{
+ unsigned int max;
+ unsigned int elemsize;
+ unsigned int *num;
+ const struct kernel_param_ops *ops;
+ void *elem;
+};
+
+/**
+ * module_param - typesafe helper for a module/cmdline parameter
+ * @value: the variable to alter, and exposed parameter name.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
+ *
+ * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a
+ * ".") the kernel commandline parameter. Note that - is changed to _, so
+ * the user can use "foo-bar=1" even for variable "foo_bar".
+ *
+ * @perm is 0 if the the variable is not to appear in sysfs, or 0444
+ * for world-readable, 0644 for root-writable, etc. Note that if it
+ * is writable, you may need to use kparam_block_sysfs_write() around
+ * accesses (esp. charp, which can be kfreed when it changes).
+ *
+ * The @type is simply pasted to refer to a param_ops_##type and a
+ * param_check_##type: for convenience many standard types are provided but
+ * you can create your own by defining those variables.
+ *
+ * Standard types are:
+ * byte, short, ushort, int, uint, long, ulong
+ * charp: a character pointer
+ * bool: a bool, values 0/1, y/n, Y/N.
+ * invbool: the above, only sense-reversed (N = true).
+ */
+#define module_param(name, type, perm) \
+ module_param_named(name, name, type, perm)
+
+/**
+ * module_param_unsafe - same as module_param but taints kernel
+ */
+#define module_param_unsafe(name, type, perm) \
+ module_param_named_unsafe(name, name, type, perm)
+
+/**
+ * module_param_named - typesafe helper for a renamed module/cmdline parameter
+ * @name: a valid C identifier which is the parameter name.
+ * @value: the actual lvalue to alter.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
+ *
+ * Usually it's a good idea to have variable names and user-exposed names the
+ * same, but that's harder if the variable must be non-static or is inside a
+ * structure. This allows exposure under a different name.
+ */
+#define module_param_named(name, value, type, perm) \
+ param_check_##type(name, &(value)); \
+ module_param_cb(name, &param_ops_##type, &value, perm); \
+ __MODULE_PARM_TYPE(name, #type)
+
+/**
+ * module_param_named_unsafe - same as module_param_named but taints kernel
+ */
+#define module_param_named_unsafe(name, value, type, perm) \
+ param_check_##type(name, &(value)); \
+ module_param_cb_unsafe(name, &param_ops_##type, &value, perm); \
+ __MODULE_PARM_TYPE(name, #type)
+
+/**
+ * module_param_cb - general callback for a module/cmdline parameter
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
+#define module_param_cb(name, ops, arg, perm) \
+ __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0)
+
+#define module_param_cb_unsafe(name, ops, arg, perm) \
+ __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \
+ KERNEL_PARAM_FL_UNSAFE)
+
+/**
+ * <level>_param_cb - general callback for a module/cmdline parameter
+ * to be evaluated before certain initcall level
+ * @name: a valid C identifier which is the parameter name.
+ * @ops: the set & get operations for this parameter.
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
+#define __level_param_cb(name, ops, arg, perm, level) \
+ __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
+
+#define core_param_cb(name, ops, arg, perm) \
+ __level_param_cb(name, ops, arg, perm, 1)
+
+#define postcore_param_cb(name, ops, arg, perm) \
+ __level_param_cb(name, ops, arg, perm, 2)
+
+#define arch_param_cb(name, ops, arg, perm) \
+ __level_param_cb(name, ops, arg, perm, 3)
+
+#define subsys_param_cb(name, ops, arg, perm) \
+ __level_param_cb(name, ops, arg, perm, 4)
+
+#define fs_param_cb(name, ops, arg, perm) \
+ __level_param_cb(name, ops, arg, perm, 5)
+
+#define device_param_cb(name, ops, arg, perm) \
+ __level_param_cb(name, ops, arg, perm, 6)
+
+#define late_param_cb(name, ops, arg, perm) \
+ __level_param_cb(name, ops, arg, perm, 7)
+
+/* On alpha, ia64 and ppc64 relocations to global data cannot go into
+ read-only sections (which is part of respective UNIX ABI on these
+ platforms). So 'const' makes no sense and even causes compile failures
+ with some compilers. */
+#if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
+#define __moduleparam_const
+#else
+#define __moduleparam_const const
+#endif
+
+/* This is the fundamental function for registering boot/module
+ parameters. */
+#define __module_param_call(prefix, name, ops, arg, perm, level, flags) \
+ /* Default value instead of permissions? */ \
+ static const char __param_str_##name[] = prefix #name; \
+ static struct kernel_param __moduleparam_const __param_##name \
+ __used \
+ __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
+ = { __param_str_##name, ops, VERIFY_OCTAL_PERMISSIONS(perm), \
+ level, flags, { arg } }
+
+/* Obsolete - use module_param_cb() */
+#define module_param_call(name, set, get, arg, perm) \
+ static struct kernel_param_ops __param_ops_##name = \
+ { .flags = 0, (void *)set, (void *)get }; \
+ __module_param_call(MODULE_PARAM_PREFIX, \
+ name, &__param_ops_##name, arg, \
+ (perm) + sizeof(__check_old_set_param(set))*0, -1, 0)
+
+/* We don't get oldget: it's often a new-style param_get_uint, etc. */
+static inline int
+__check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
+{
+ return 0;
+}
+
+/**
+ * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs.
+ * @name: the name of the parameter
+ *
+ * There's no point blocking write on a paramter that isn't writable via sysfs!
+ */
+#define kparam_block_sysfs_write(name) \
+ do { \
+ BUG_ON(!(__param_##name.perm & 0222)); \
+ __kernel_param_lock(); \
+ } while (0)
+
+/**
+ * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again.
+ * @name: the name of the parameter
+ */
+#define kparam_unblock_sysfs_write(name) \
+ do { \
+ BUG_ON(!(__param_##name.perm & 0222)); \
+ __kernel_param_unlock(); \
+ } while (0)
+
+/**
+ * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs.
+ * @name: the name of the parameter
+ *
+ * This also blocks sysfs writes.
+ */
+#define kparam_block_sysfs_read(name) \
+ do { \
+ BUG_ON(!(__param_##name.perm & 0444)); \
+ __kernel_param_lock(); \
+ } while (0)
+
+/**
+ * kparam_unblock_sysfs_read - allows sysfs to read a parameter again.
+ * @name: the name of the parameter
+ */
+#define kparam_unblock_sysfs_read(name) \
+ do { \
+ BUG_ON(!(__param_##name.perm & 0444)); \
+ __kernel_param_unlock(); \
+ } while (0)
+
+#ifdef CONFIG_SYSFS
+extern void __kernel_param_lock(void);
+extern void __kernel_param_unlock(void);
+#else
+static inline void __kernel_param_lock(void)
+{
+}
+static inline void __kernel_param_unlock(void)
+{
+}
+#endif
+
+#ifndef MODULE
+/**
+ * core_param - define a historical core kernel parameter.
+ * @name: the name of the cmdline and sysfs parameter (often the same as var)
+ * @var: the variable
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs
+ *
+ * core_param is just like module_param(), but cannot be modular and
+ * doesn't add a prefix (such as "printk."). This is for compatibility
+ * with __setup(), and it makes sense as truly core parameters aren't
+ * tied to the particular file they're in.
+ */
+#define core_param(name, var, type, perm) \
+ param_check_##type(name, &(var)); \
+ __module_param_call("", name, &param_ops_##type, &var, perm, -1, 0)
+#endif /* !MODULE */
+
+/**
+ * module_param_string - a char array parameter
+ * @name: the name of the parameter
+ * @string: the string variable
+ * @len: the maximum length of the string, incl. terminator
+ * @perm: visibility in sysfs.
+ *
+ * This actually copies the string when it's set (unlike type charp).
+ * @len is usually just sizeof(string).
+ */
+#define module_param_string(name, string, len, perm) \
+ static const struct kparam_string __param_string_##name \
+ = { len, string }; \
+ __module_param_call(MODULE_PARAM_PREFIX, name, \
+ &param_ops_string, \
+ .str = &__param_string_##name, perm, -1, 0);\
+ __MODULE_PARM_TYPE(name, "string")
+
+/**
+ * parameq - checks if two parameter names match
+ * @name1: parameter name 1
+ * @name2: parameter name 2
+ *
+ * Returns true if the two parameter names are equal.
+ * Dashes (-) are considered equal to underscores (_).
+ */
+extern bool parameq(const char *name1, const char *name2);
+
+/**
+ * parameqn - checks if two parameter names match
+ * @name1: parameter name 1
+ * @name2: parameter name 2
+ * @n: the length to compare
+ *
+ * Similar to parameq(), except it compares @n characters.
+ */
+extern bool parameqn(const char *name1, const char *name2, size_t n);
+
+/* Called on module insert or kernel boot */
+extern char *parse_args(const char *name,
+ char *args,
+ const struct kernel_param *params,
+ unsigned num,
+ s16 level_min,
+ s16 level_max,
+ int (*unknown)(char *param, char *val,
+ const char *doing));
+
+/* Called by module remove. */
+#ifdef CONFIG_SYSFS
+extern void destroy_params(const struct kernel_param *params, unsigned num);
+#else
+static inline void destroy_params(const struct kernel_param *params,
+ unsigned num)
+{
+}
+#endif /* !CONFIG_SYSFS */
+
+/* All the helper functions */
+/* The macros to do compile-time type checking stolen from Jakub
+ Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
+#define __param_check(name, p, type) \
+ static inline type __always_unused *__check_##name(void) { return(p); }
+
+extern struct kernel_param_ops param_ops_byte;
+extern int param_set_byte(const char *val, const struct kernel_param *kp);
+extern int param_get_byte(char *buffer, const struct kernel_param *kp);
+#define param_check_byte(name, p) __param_check(name, p, unsigned char)
+
+extern struct kernel_param_ops param_ops_short;
+extern int param_set_short(const char *val, const struct kernel_param *kp);
+extern int param_get_short(char *buffer, const struct kernel_param *kp);
+#define param_check_short(name, p) __param_check(name, p, short)
+
+extern struct kernel_param_ops param_ops_ushort;
+extern int param_set_ushort(const char *val, const struct kernel_param *kp);
+extern int param_get_ushort(char *buffer, const struct kernel_param *kp);
+#define param_check_ushort(name, p) __param_check(name, p, unsigned short)
+
+extern struct kernel_param_ops param_ops_int;
+extern int param_set_int(const char *val, const struct kernel_param *kp);
+extern int param_get_int(char *buffer, const struct kernel_param *kp);
+#define param_check_int(name, p) __param_check(name, p, int)
+
+extern struct kernel_param_ops param_ops_uint;
+extern int param_set_uint(const char *val, const struct kernel_param *kp);
+extern int param_get_uint(char *buffer, const struct kernel_param *kp);
+#define param_check_uint(name, p) __param_check(name, p, unsigned int)
+
+extern struct kernel_param_ops param_ops_long;
+extern int param_set_long(const char *val, const struct kernel_param *kp);
+extern int param_get_long(char *buffer, const struct kernel_param *kp);
+#define param_check_long(name, p) __param_check(name, p, long)
+
+extern struct kernel_param_ops param_ops_ulong;
+extern int param_set_ulong(const char *val, const struct kernel_param *kp);
+extern int param_get_ulong(char *buffer, const struct kernel_param *kp);
+#define param_check_ulong(name, p) __param_check(name, p, unsigned long)
+
+extern struct kernel_param_ops param_ops_ullong;
+extern int param_set_ullong(const char *val, const struct kernel_param *kp);
+extern int param_get_ullong(char *buffer, const struct kernel_param *kp);
+#define param_check_ullong(name, p) __param_check(name, p, unsigned long long)
+
+extern struct kernel_param_ops param_ops_charp;
+extern int param_set_charp(const char *val, const struct kernel_param *kp);
+extern int param_get_charp(char *buffer, const struct kernel_param *kp);
+#define param_check_charp(name, p) __param_check(name, p, char *)
+
+/* We used to allow int as well as bool. We're taking that away! */
+extern struct kernel_param_ops param_ops_bool;
+extern int param_set_bool(const char *val, const struct kernel_param *kp);
+extern int param_get_bool(char *buffer, const struct kernel_param *kp);
+#define param_check_bool(name, p) __param_check(name, p, bool)
+
+extern struct kernel_param_ops param_ops_invbool;
+extern int param_set_invbool(const char *val, const struct kernel_param *kp);
+extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
+#define param_check_invbool(name, p) __param_check(name, p, bool)
+
+/* An int, which can only be set like a bool (though it shows as an int). */
+extern struct kernel_param_ops param_ops_bint;
+extern int param_set_bint(const char *val, const struct kernel_param *kp);
+#define param_get_bint param_get_int
+#define param_check_bint param_check_int
+
+/**
+ * module_param_array - a parameter which is an array of some type
+ * @name: the name of the array variable
+ * @type: the type, as per module_param()
+ * @nump: optional pointer filled in with the number written
+ * @perm: visibility in sysfs
+ *
+ * Input and output are as comma-separated values. Commas inside values
+ * don't work properly (eg. an array of charp).
+ *
+ * ARRAY_SIZE(@name) is used to determine the number of elements in the
+ * array, so the definition must be visible.
+ */
+#define module_param_array(name, type, nump, perm) \
+ module_param_array_named(name, name, type, nump, perm)
+
+/**
+ * module_param_array_named - renamed parameter which is an array of some type
+ * @name: a valid C identifier which is the parameter name
+ * @array: the name of the array variable
+ * @type: the type, as per module_param()
+ * @nump: optional pointer filled in with the number written
+ * @perm: visibility in sysfs
+ *
+ * This exposes a different name than the actual variable name. See
+ * module_param_named() for why this might be necessary.
+ */
+#define module_param_array_named(name, array, type, nump, perm) \
+ param_check_##type(name, &(array)[0]); \
+ static const struct kparam_array __param_arr_##name \
+ = { .max = ARRAY_SIZE(array), .num = nump, \
+ .ops = &param_ops_##type, \
+ .elemsize = sizeof(array[0]), .elem = array }; \
+ __module_param_call(MODULE_PARAM_PREFIX, name, \
+ &param_array_ops, \
+ .arr = &__param_arr_##name, \
+ perm, -1, 0); \
+ __MODULE_PARM_TYPE(name, "array of " #type)
+
+extern struct kernel_param_ops param_array_ops;
+
+extern struct kernel_param_ops param_ops_string;
+extern int param_set_copystring(const char *val, const struct kernel_param *);
+extern int param_get_string(char *buffer, const struct kernel_param *kp);
+
+/* for exporting parameters in /sys/module/.../parameters */
+
+struct module;
+
+#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
+extern int module_param_sysfs_setup(struct module *mod,
+ const struct kernel_param *kparam,
+ unsigned int num_params);
+
+extern void module_param_sysfs_remove(struct module *mod);
+#else
+static inline int module_param_sysfs_setup(struct module *mod,
+ const struct kernel_param *kparam,
+ unsigned int num_params)
+{
+ return 0;
+}
+
+static inline void module_param_sysfs_remove(struct module *mod)
+{ }
+#endif
+
+#endif /* _LINUX_MODULE_PARAMS_H */