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Joel Becker7063fbf2005-12-15 14:29:43 -08001/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * configfs.h - definitions for the device driver filesystem
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
20 *
21 * Based on sysfs:
22 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
23 *
24 * Based on kobject.h:
25 * Copyright (c) 2002-2003 Patrick Mochel
26 * Copyright (c) 2002-2003 Open Source Development Labs
27 *
28 * configfs Copyright (C) 2005 Oracle. All rights reserved.
29 *
30 * Please read Documentation/filesystems/configfs.txt before using the
31 * configfs interface, ESPECIALLY the parts about reference counts and
32 * item destructors.
33 */
34
35#ifndef _CONFIGFS_H_
36#define _CONFIGFS_H_
37
Ben Nizette07783612008-02-14 19:31:31 -080038#include <linux/kernel.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080039#include <linux/types.h>
40#include <linux/list.h>
41#include <linux/kref.h>
Joel Beckere6bd07a2007-07-06 23:33:17 -070042#include <linux/mutex.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080043
44#include <asm/atomic.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080045
46#define CONFIGFS_ITEM_NAME_LEN 20
47
48struct module;
49
50struct configfs_item_operations;
51struct configfs_group_operations;
52struct configfs_attribute;
53struct configfs_subsystem;
54
55struct config_item {
56 char *ci_name;
57 char ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
58 struct kref ci_kref;
59 struct list_head ci_entry;
60 struct config_item *ci_parent;
61 struct config_group *ci_group;
62 struct config_item_type *ci_type;
63 struct dentry *ci_dentry;
64};
65
66extern int config_item_set_name(struct config_item *, const char *, ...);
67
68static inline char *config_item_name(struct config_item * item)
69{
70 return item->ci_name;
71}
72
73extern void config_item_init(struct config_item *);
74extern void config_item_init_type_name(struct config_item *item,
75 const char *name,
76 struct config_item_type *type);
Joel Becker7063fbf2005-12-15 14:29:43 -080077
78extern struct config_item * config_item_get(struct config_item *);
79extern void config_item_put(struct config_item *);
80
81struct config_item_type {
82 struct module *ct_owner;
83 struct configfs_item_operations *ct_item_ops;
84 struct configfs_group_operations *ct_group_ops;
85 struct configfs_attribute **ct_attrs;
86};
87
Joel Becker7063fbf2005-12-15 14:29:43 -080088/**
89 * group - a group of config_items of a specific type, belonging
90 * to a specific subsystem.
91 */
Joel Becker7063fbf2005-12-15 14:29:43 -080092struct config_group {
93 struct config_item cg_item;
94 struct list_head cg_children;
95 struct configfs_subsystem *cg_subsys;
96 struct config_group **default_groups;
97};
98
Joel Becker7063fbf2005-12-15 14:29:43 -080099extern void config_group_init(struct config_group *group);
100extern void config_group_init_type_name(struct config_group *group,
101 const char *name,
102 struct config_item_type *type);
103
Joel Becker7063fbf2005-12-15 14:29:43 -0800104static inline struct config_group *to_config_group(struct config_item *item)
105{
106 return item ? container_of(item,struct config_group,cg_item) : NULL;
107}
108
109static inline struct config_group *config_group_get(struct config_group *group)
110{
111 return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
112}
113
114static inline void config_group_put(struct config_group *group)
115{
116 config_item_put(&group->cg_item);
117}
118
Satyam Sharma3fe6c5c2007-07-04 16:37:16 +0530119extern struct config_item *config_group_find_item(struct config_group *,
120 const char *);
Joel Becker7063fbf2005-12-15 14:29:43 -0800121
122
123struct configfs_attribute {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800124 const char *ca_name;
Joel Becker7063fbf2005-12-15 14:29:43 -0800125 struct module *ca_owner;
126 mode_t ca_mode;
127};
128
Satyam Sharma9b1d9aa2007-07-04 16:37:06 +0530129/*
130 * Users often need to create attribute structures for their configurable
131 * attributes, containing a configfs_attribute member and function pointers
132 * for the show() and store() operations on that attribute. They can use
133 * this macro (similar to sysfs' __ATTR) to make defining attributes easier.
134 */
135#define __CONFIGFS_ATTR(_name, _mode, _show, _store) \
136{ \
137 .attr = { \
138 .ca_name = __stringify(_name), \
139 .ca_mode = _mode, \
140 .ca_owner = THIS_MODULE, \
141 }, \
142 .show = _show, \
143 .store = _store, \
144}
Joel Becker7063fbf2005-12-15 14:29:43 -0800145
146/*
147 * If allow_link() exists, the item can symlink(2) out to other
148 * items. If the item is a group, it may support mkdir(2).
149 * Groups supply one of make_group() and make_item(). If the
150 * group supports make_group(), one can create group children. If it
151 * supports make_item(), one can create config_item children. If it has
152 * default_groups on group->default_groups, it has automatically created
153 * group children. default_groups may coexist alongsize make_group() or
154 * make_item(), but if the group wishes to have only default_groups
155 * children (disallowing mkdir(2)), it need not provide either function.
156 * If the group has commit(), it supports pending and commited (active)
157 * items.
158 */
159struct configfs_item_operations {
160 void (*release)(struct config_item *);
161 ssize_t (*show_attribute)(struct config_item *, struct configfs_attribute *,char *);
162 ssize_t (*store_attribute)(struct config_item *,struct configfs_attribute *,const char *, size_t);
163 int (*allow_link)(struct config_item *src, struct config_item *target);
164 int (*drop_link)(struct config_item *src, struct config_item *target);
165};
166
167struct configfs_group_operations {
168 struct config_item *(*make_item)(struct config_group *group, const char *name);
169 struct config_group *(*make_group)(struct config_group *group, const char *name);
170 int (*commit_item)(struct config_item *item);
Joel Becker299894c2006-10-06 17:33:23 -0700171 void (*disconnect_notify)(struct config_group *group, struct config_item *item);
Joel Becker7063fbf2005-12-15 14:29:43 -0800172 void (*drop_item)(struct config_group *group, struct config_item *item);
173};
174
Joel Becker7063fbf2005-12-15 14:29:43 -0800175struct configfs_subsystem {
176 struct config_group su_group;
Joel Beckere6bd07a2007-07-06 23:33:17 -0700177 struct mutex su_mutex;
Joel Becker7063fbf2005-12-15 14:29:43 -0800178};
179
180static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
181{
182 return group ?
183 container_of(group, struct configfs_subsystem, su_group) :
184 NULL;
185}
186
187int configfs_register_subsystem(struct configfs_subsystem *subsys);
188void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
189
Joel Becker631d1fe2007-06-18 18:06:09 -0700190/* These functions can sleep and can alloc with GFP_KERNEL */
191/* WARNING: These cannot be called underneath configfs callbacks!! */
192int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item *target);
193void configfs_undepend_item(struct configfs_subsystem *subsys, struct config_item *target);
194
Joel Becker7063fbf2005-12-15 14:29:43 -0800195#endif /* _CONFIGFS_H_ */