260 lines
8.6 KiB
C
260 lines
8.6 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
|
|
* vim: noexpandtab sw=8 ts=8 sts=0:
|
|
*
|
|
* configfs.h - definitions for the device driver filesystem
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public
|
|
* License along with this program; if not, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 021110-1307, USA.
|
|
*
|
|
* Based on sysfs:
|
|
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
|
|
*
|
|
* Based on kobject.h:
|
|
* Copyright (c) 2002-2003 Patrick Mochel
|
|
* Copyright (c) 2002-2003 Open Source Development Labs
|
|
*
|
|
* configfs Copyright (C) 2005 Oracle. All rights reserved.
|
|
*
|
|
* Please read Documentation/filesystems/configfs/configfs.txt before using
|
|
* the configfs interface, ESPECIALLY the parts about reference counts and
|
|
* item destructors.
|
|
*/
|
|
|
|
#ifndef _CONFIGFS_H_
|
|
#define _CONFIGFS_H_
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/list.h>
|
|
#include <linux/kref.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/err.h>
|
|
|
|
#include <linux/atomic.h>
|
|
|
|
#define CONFIGFS_ITEM_NAME_LEN 20
|
|
|
|
struct module;
|
|
|
|
struct configfs_item_operations;
|
|
struct configfs_group_operations;
|
|
struct configfs_attribute;
|
|
struct configfs_subsystem;
|
|
|
|
struct config_item {
|
|
char *ci_name;
|
|
char ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
|
|
struct kref ci_kref;
|
|
struct list_head ci_entry;
|
|
struct config_item *ci_parent;
|
|
struct config_group *ci_group;
|
|
struct config_item_type *ci_type;
|
|
struct dentry *ci_dentry;
|
|
};
|
|
|
|
extern int config_item_set_name(struct config_item *, const char *, ...);
|
|
|
|
static inline char *config_item_name(struct config_item * item)
|
|
{
|
|
return item->ci_name;
|
|
}
|
|
|
|
extern void config_item_init(struct config_item *);
|
|
extern void config_item_init_type_name(struct config_item *item,
|
|
const char *name,
|
|
struct config_item_type *type);
|
|
|
|
extern struct config_item * config_item_get(struct config_item *);
|
|
extern void config_item_put(struct config_item *);
|
|
|
|
struct config_item_type {
|
|
struct module *ct_owner;
|
|
struct configfs_item_operations *ct_item_ops;
|
|
struct configfs_group_operations *ct_group_ops;
|
|
struct configfs_attribute **ct_attrs;
|
|
};
|
|
|
|
/**
|
|
* group - a group of config_items of a specific type, belonging
|
|
* to a specific subsystem.
|
|
*/
|
|
struct config_group {
|
|
struct config_item cg_item;
|
|
struct list_head cg_children;
|
|
struct configfs_subsystem *cg_subsys;
|
|
struct config_group **default_groups;
|
|
};
|
|
|
|
extern void config_group_init(struct config_group *group);
|
|
extern void config_group_init_type_name(struct config_group *group,
|
|
const char *name,
|
|
struct config_item_type *type);
|
|
|
|
static inline struct config_group *to_config_group(struct config_item *item)
|
|
{
|
|
return item ? container_of(item,struct config_group,cg_item) : NULL;
|
|
}
|
|
|
|
static inline struct config_group *config_group_get(struct config_group *group)
|
|
{
|
|
return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
|
|
}
|
|
|
|
static inline void config_group_put(struct config_group *group)
|
|
{
|
|
config_item_put(&group->cg_item);
|
|
}
|
|
|
|
extern struct config_item *config_group_find_item(struct config_group *,
|
|
const char *);
|
|
|
|
|
|
struct configfs_attribute {
|
|
const char *ca_name;
|
|
struct module *ca_owner;
|
|
umode_t ca_mode;
|
|
};
|
|
|
|
/*
|
|
* Users often need to create attribute structures for their configurable
|
|
* attributes, containing a configfs_attribute member and function pointers
|
|
* for the show() and store() operations on that attribute. If they don't
|
|
* need anything else on the extended attribute structure, they can use
|
|
* this macro to define it The argument _item is the name of the
|
|
* config_item structure.
|
|
*/
|
|
#define CONFIGFS_ATTR_STRUCT(_item) \
|
|
struct _item##_attribute { \
|
|
struct configfs_attribute attr; \
|
|
ssize_t (*show)(struct _item *, char *); \
|
|
ssize_t (*store)(struct _item *, const char *, size_t); \
|
|
}
|
|
|
|
/*
|
|
* With the extended attribute structure, users can use this macro
|
|
* (similar to sysfs' __ATTR) to make defining attributes easier.
|
|
* An example:
|
|
* #define MYITEM_ATTR(_name, _mode, _show, _store) \
|
|
* struct myitem_attribute childless_attr_##_name = \
|
|
* __CONFIGFS_ATTR(_name, _mode, _show, _store)
|
|
*/
|
|
#define __CONFIGFS_ATTR(_name, _mode, _show, _store) \
|
|
{ \
|
|
.attr = { \
|
|
.ca_name = __stringify(_name), \
|
|
.ca_mode = _mode, \
|
|
.ca_owner = THIS_MODULE, \
|
|
}, \
|
|
.show = _show, \
|
|
.store = _store, \
|
|
}
|
|
/* Here is a readonly version, only requiring a show() operation */
|
|
#define __CONFIGFS_ATTR_RO(_name, _show) \
|
|
{ \
|
|
.attr = { \
|
|
.ca_name = __stringify(_name), \
|
|
.ca_mode = 0444, \
|
|
.ca_owner = THIS_MODULE, \
|
|
}, \
|
|
.show = _show, \
|
|
}
|
|
|
|
/*
|
|
* With these extended attributes, the simple show_attribute() and
|
|
* store_attribute() operations need to call the show() and store() of the
|
|
* attributes. This is a common pattern, so we provide a macro to define
|
|
* them. The argument _item is the name of the config_item structure.
|
|
* This macro expects the attributes to be named "struct <name>_attribute"
|
|
* and the function to_<name>() to exist;
|
|
*/
|
|
#define CONFIGFS_ATTR_OPS(_item) \
|
|
static ssize_t _item##_attr_show(struct config_item *item, \
|
|
struct configfs_attribute *attr, \
|
|
char *page) \
|
|
{ \
|
|
struct _item *_item = to_##_item(item); \
|
|
struct _item##_attribute *_item##_attr = \
|
|
container_of(attr, struct _item##_attribute, attr); \
|
|
ssize_t ret = 0; \
|
|
\
|
|
if (_item##_attr->show) \
|
|
ret = _item##_attr->show(_item, page); \
|
|
return ret; \
|
|
} \
|
|
static ssize_t _item##_attr_store(struct config_item *item, \
|
|
struct configfs_attribute *attr, \
|
|
const char *page, size_t count) \
|
|
{ \
|
|
struct _item *_item = to_##_item(item); \
|
|
struct _item##_attribute *_item##_attr = \
|
|
container_of(attr, struct _item##_attribute, attr); \
|
|
ssize_t ret = -EINVAL; \
|
|
\
|
|
if (_item##_attr->store) \
|
|
ret = _item##_attr->store(_item, page, count); \
|
|
return ret; \
|
|
}
|
|
|
|
/*
|
|
* If allow_link() exists, the item can symlink(2) out to other
|
|
* items. If the item is a group, it may support mkdir(2).
|
|
* Groups supply one of make_group() and make_item(). If the
|
|
* group supports make_group(), one can create group children. If it
|
|
* supports make_item(), one can create config_item children. make_group()
|
|
* and make_item() return ERR_PTR() on errors. If it has
|
|
* default_groups on group->default_groups, it has automatically created
|
|
* group children. default_groups may coexist alongsize make_group() or
|
|
* make_item(), but if the group wishes to have only default_groups
|
|
* children (disallowing mkdir(2)), it need not provide either function.
|
|
* If the group has commit(), it supports pending and committed (active)
|
|
* items.
|
|
*/
|
|
struct configfs_item_operations {
|
|
void (*release)(struct config_item *);
|
|
ssize_t (*show_attribute)(struct config_item *, struct configfs_attribute *,char *);
|
|
ssize_t (*store_attribute)(struct config_item *,struct configfs_attribute *,const char *, size_t);
|
|
int (*allow_link)(struct config_item *src, struct config_item *target);
|
|
int (*drop_link)(struct config_item *src, struct config_item *target);
|
|
};
|
|
|
|
struct configfs_group_operations {
|
|
struct config_item *(*make_item)(struct config_group *group, const char *name);
|
|
struct config_group *(*make_group)(struct config_group *group, const char *name);
|
|
int (*commit_item)(struct config_item *item);
|
|
void (*disconnect_notify)(struct config_group *group, struct config_item *item);
|
|
void (*drop_item)(struct config_group *group, struct config_item *item);
|
|
};
|
|
|
|
struct configfs_subsystem {
|
|
struct config_group su_group;
|
|
struct mutex su_mutex;
|
|
};
|
|
|
|
static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
|
|
{
|
|
return group ?
|
|
container_of(group, struct configfs_subsystem, su_group) :
|
|
NULL;
|
|
}
|
|
|
|
int configfs_register_subsystem(struct configfs_subsystem *subsys);
|
|
void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
|
|
|
|
/* These functions can sleep and can alloc with GFP_KERNEL */
|
|
/* WARNING: These cannot be called underneath configfs callbacks!! */
|
|
int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item *target);
|
|
void configfs_undepend_item(struct configfs_subsystem *subsys, struct config_item *target);
|
|
|
|
#endif /* _CONFIGFS_H_ */
|