/* -*- 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;	mode_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_ */