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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
38#ifdef __KERNEL__
39
40#include <linux/types.h>
41#include <linux/list.h>
42#include <linux/kref.h>
43
44#include <asm/atomic.h>
45#include <asm/semaphore.h>
46
47#define CONFIGFS_ITEM_NAME_LEN 20
48
49struct module;
50
51struct configfs_item_operations;
52struct configfs_group_operations;
53struct configfs_attribute;
54struct configfs_subsystem;
55
56struct config_item {
57 char *ci_name;
58 char ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
59 struct kref ci_kref;
60 struct list_head ci_entry;
61 struct config_item *ci_parent;
62 struct config_group *ci_group;
63 struct config_item_type *ci_type;
64 struct dentry *ci_dentry;
65};
66
67extern int config_item_set_name(struct config_item *, const char *, ...);
68
69static inline char *config_item_name(struct config_item * item)
70{
71 return item->ci_name;
72}
73
74extern void config_item_init(struct config_item *);
75extern void config_item_init_type_name(struct config_item *item,
76 const char *name,
77 struct config_item_type *type);
78extern void config_item_cleanup(struct config_item *);
79
80extern struct config_item * config_item_get(struct config_item *);
81extern void config_item_put(struct config_item *);
82
83struct config_item_type {
84 struct module *ct_owner;
85 struct configfs_item_operations *ct_item_ops;
86 struct configfs_group_operations *ct_group_ops;
87 struct configfs_attribute **ct_attrs;
88};
89
90
91/**
92 * group - a group of config_items of a specific type, belonging
93 * to a specific subsystem.
94 */
95
96struct config_group {
97 struct config_item cg_item;
98 struct list_head cg_children;
99 struct configfs_subsystem *cg_subsys;
100 struct config_group **default_groups;
101};
102
103
104extern void config_group_init(struct config_group *group);
105extern void config_group_init_type_name(struct config_group *group,
106 const char *name,
107 struct config_item_type *type);
108
109
110static inline struct config_group *to_config_group(struct config_item *item)
111{
112 return item ? container_of(item,struct config_group,cg_item) : NULL;
113}
114
115static inline struct config_group *config_group_get(struct config_group *group)
116{
117 return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
118}
119
120static inline void config_group_put(struct config_group *group)
121{
122 config_item_put(&group->cg_item);
123}
124
125extern struct config_item *config_group_find_obj(struct config_group *, const char *);
126
127
128struct configfs_attribute {
129 char *ca_name;
130 struct module *ca_owner;
131 mode_t ca_mode;
132};
133
134
135/*
136 * If allow_link() exists, the item can symlink(2) out to other
137 * items. If the item is a group, it may support mkdir(2).
138 * Groups supply one of make_group() and make_item(). If the
139 * group supports make_group(), one can create group children. If it
140 * supports make_item(), one can create config_item children. If it has
141 * default_groups on group->default_groups, it has automatically created
142 * group children. default_groups may coexist alongsize make_group() or
143 * make_item(), but if the group wishes to have only default_groups
144 * children (disallowing mkdir(2)), it need not provide either function.
145 * If the group has commit(), it supports pending and commited (active)
146 * items.
147 */
148struct configfs_item_operations {
149 void (*release)(struct config_item *);
150 ssize_t (*show_attribute)(struct config_item *, struct configfs_attribute *,char *);
151 ssize_t (*store_attribute)(struct config_item *,struct configfs_attribute *,const char *, size_t);
152 int (*allow_link)(struct config_item *src, struct config_item *target);
153 int (*drop_link)(struct config_item *src, struct config_item *target);
154};
155
156struct configfs_group_operations {
157 struct config_item *(*make_item)(struct config_group *group, const char *name);
158 struct config_group *(*make_group)(struct config_group *group, const char *name);
159 int (*commit_item)(struct config_item *item);
160 void (*drop_item)(struct config_group *group, struct config_item *item);
161};
162
163
164
165/**
166 * Use these macros to make defining attributes easier. See include/linux/device.h
167 * for examples..
168 */
169
170#if 0
171#define __ATTR(_name,_mode,_show,_store) { \
172 .attr = {.ca_name = __stringify(_name), .ca_mode = _mode, .ca_owner = THIS_MODULE }, \
173 .show = _show, \
174 .store = _store, \
175}
176
177#define __ATTR_RO(_name) { \
178 .attr = { .ca_name = __stringify(_name), .ca_mode = 0444, .ca_owner = THIS_MODULE }, \
179 .show = _name##_show, \
180}
181
182#define __ATTR_NULL { .attr = { .name = NULL } }
183
184#define attr_name(_attr) (_attr).attr.name
185#endif
186
187
188struct configfs_subsystem {
189 struct config_group su_group;
190 struct semaphore su_sem;
191};
192
193static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
194{
195 return group ?
196 container_of(group, struct configfs_subsystem, su_group) :
197 NULL;
198}
199
200int configfs_register_subsystem(struct configfs_subsystem *subsys);
201void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
202
203#endif /* __KERNEL__ */
204
205#endif /* _CONFIGFS_H_ */