1 /* -*- 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 49 struct module; 50 51 struct configfs_item_operations; 52 struct configfs_group_operations; 53 struct configfs_attribute; 54 struct configfs_subsystem; 55 56 struct 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 67 extern int config_item_set_name(struct config_item *, const char *, ...); 68 69 static inline char *config_item_name(struct config_item * item) 70 { 71 return item->ci_name; 72 } 73 74 extern void config_item_init(struct config_item *); 75 extern void config_item_init_type_name(struct config_item *item, 76 const char *name, 77 struct config_item_type *type); 78 extern void config_item_cleanup(struct config_item *); 79 80 extern struct config_item * config_item_get(struct config_item *); 81 extern void config_item_put(struct config_item *); 82 83 struct 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 96 struct 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 }; 102 103 104 extern void config_group_init(struct config_group *group); 105 extern void config_group_init_type_name(struct config_group *group, 106 const char *name, 107 struct config_item_type *type); 108 109 110 static 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 } 114 115 static 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 } 119 120 static inline void config_group_put(struct config_group *group) 121 { 122 config_item_put(&group->cg_item); 123 } 124 125 extern struct config_item *config_group_find_obj(struct config_group *, const char *); 126 127 128 struct configfs_attribute { 129 const 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 */ 148 struct 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 }; 155 156 struct 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 186 187 188 struct configfs_subsystem { 189 struct config_group su_group; 190 struct semaphore su_sem; 191 }; 192 193 static 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 } 199 200 int configfs_register_subsystem(struct configfs_subsystem *subsys); 201 void configfs_unregister_subsystem(struct configfs_subsystem *subsys); 202 203 #endif /* __KERNEL__ */ 204 205 #endif /* _CONFIGFS_H_ */ 206