| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* -*- mode: c; c-basic-offset: 8; -*- |
| * vim: noexpandtab sw=8 ts=8 sts=0: |
| * |
| * configfs.h - definitions for the device driver filesystem |
| * |
| * 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.rst before using |
| * the configfs interface, ESPECIALLY the parts about reference counts and |
| * item destructors. |
| */ |
| |
| #ifndef _CONFIGFS_H_ |
| #define _CONFIGFS_H_ |
| |
| #include <linux/stat.h> /* S_IRUGO */ |
| #include <linux/types.h> /* ssize_t */ |
| #include <linux/list.h> /* struct list_head */ |
| #include <linux/kref.h> /* struct kref */ |
| #include <linux/mutex.h> /* struct mutex */ |
| |
| #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; |
| const 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, |
| const struct config_item_type *type); |
| |
| extern struct config_item *config_item_get(struct config_item *); |
| extern struct config_item *config_item_get_unless_zero(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, |
| const 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); |
| void (*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, |
| const 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_ */ |