/* -*- 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_bin_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 __printf(2, 3) 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_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; struct configfs_bin_attribute **ct_bin_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 list_head default_groups; struct list_head group_entry; }; 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 *); static inline void configfs_add_default_group(struct config_group *new_group, struct config_group *group) { list_add_tail(&new_group->group_entry, &group->default_groups); } struct configfs_attribute { const char *ca_name; struct module *ca_owner; umode_t ca_mode; ssize_t (*show)(struct config_item *, char *); ssize_t (*store)(struct config_item *, const char *, size_t); }; #define CONFIGFS_ATTR(_pfx, _name) \ static struct configfs_attribute _pfx##attr_##_name = { \ .ca_name = __stringify(_name), \ .ca_mode = S_IRUGO | S_IWUSR, \ .ca_owner = THIS_MODULE, \ .show = _pfx##_name##_show, \ .store = _pfx##_name##_store, \ } #define CONFIGFS_ATTR_RO(_pfx, _name) \ static struct configfs_attribute _pfx##attr_##_name = { \ .ca_name = __stringify(_name), \ .ca_mode = S_IRUGO, \ .ca_owner = THIS_MODULE, \ .show = _pfx##_name##_show, \ } #define CONFIGFS_ATTR_WO(_pfx, _name) \ static struct configfs_attribute _pfx##attr_##_name = { \ .ca_name = __stringify(_name), \ .ca_mode = S_IWUSR, \ .ca_owner = THIS_MODULE, \ .store = _pfx##_name##_store, \ } struct file; struct vm_area_struct; struct configfs_bin_attribute { struct configfs_attribute cb_attr; /* std. attribute */ void *cb_private; /* for user */ size_t cb_max_size; /* max core size */ ssize_t (*read)(struct config_item *, void *, size_t); ssize_t (*write)(struct config_item *, const void *, size_t); }; #define CONFIGFS_BIN_ATTR(_pfx, _name, _priv, _maxsz) \ static struct configfs_bin_attribute _pfx##attr_##_name = { \ .cb_attr = { \ .ca_name = __stringify(_name), \ .ca_mode = S_IRUGO | S_IWUSR, \ .ca_owner = THIS_MODULE, \ }, \ .cb_private = _priv, \ .cb_max_size = _maxsz, \ .read = _pfx##_name##_read, \ .write = _pfx##_name##_write, \ } #define CONFIGFS_BIN_ATTR_RO(_pfx, _name, _priv, _maxsz) \ static struct configfs_bin_attribute _pfx##attr_##_name = { \ .cb_attr = { \ .ca_name = __stringify(_name), \ .ca_mode = S_IRUGO, \ .ca_owner = THIS_MODULE, \ }, \ .cb_private = _priv, \ .cb_max_size = _maxsz, \ .read = _pfx##_name##_read, \ } #define CONFIGFS_BIN_ATTR_WO(_pfx, _name, _priv, _maxsz) \ static struct configfs_bin_attribute _pfx##attr_##_name = { \ .cb_attr = { \ .ca_name = __stringify(_name), \ .ca_mode = S_IWUSR, \ .ca_owner = THIS_MODULE, \ }, \ .cb_private = _priv, \ .cb_max_size = _maxsz, \ .write = _pfx##_name##_write, \ } /* * 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 *); 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); int configfs_register_group(struct config_group *parent_group, struct config_group *group); void configfs_unregister_group(struct config_group *group); void configfs_remove_default_groups(struct config_group *group); struct config_group * configfs_register_default_group(struct config_group *parent_group, const char *name, struct config_item_type *item_type); void configfs_unregister_default_group(struct config_group *group); /* 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 config_item *target); /* * These functions can sleep and can alloc with GFP_KERNEL * NOTE: These should be called only underneath configfs callbacks. * NOTE: First parameter is a caller's subsystem, not target's. * WARNING: These cannot be called on newly created item * (in make_group()/make_item() callback) */ int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys, struct config_item *target); static inline void configfs_undepend_item_unlocked(struct config_item *target) { configfs_undepend_item(target); } #endif /* _CONFIGFS_H_ */