1// SPDX-License-Identifier: GPL-2.0 2/* 3 * kobject.h - generic kernel object infrastructure. 4 * 5 * Copyright (c) 2002-2003 Patrick Mochel 6 * Copyright (c) 2002-2003 Open Source Development Labs 7 * Copyright (c) 2006-2008 Greg Kroah-Hartman <greg@kroah.com> 8 * Copyright (c) 2006-2008 Novell Inc. 9 * 10 * Please read Documentation/core-api/kobject.rst before using the kobject 11 * interface, ESPECIALLY the parts about reference counts and object 12 * destructors. 13 */ 14 15#ifndef _KOBJECT_H_ 16#define _KOBJECT_H_ 17 18#include <linux/types.h> 19#include <linux/list.h> 20#include <linux/sysfs.h> 21#include <linux/compiler.h> 22#include <linux/container_of.h> 23#include <linux/spinlock.h> 24#include <linux/kref.h> 25#include <linux/kobject_ns.h> 26#include <linux/wait.h> 27#include <linux/atomic.h> 28#include <linux/workqueue.h> 29#include <linux/uidgid.h> 30 31#define UEVENT_HELPER_PATH_LEN 256 32#define UEVENT_NUM_ENVP 64 /* number of env pointers */ 33#define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */ 34 35#ifdef CONFIG_UEVENT_HELPER 36/* path to the userspace helper executed on an event */ 37extern char uevent_helper[]; 38#endif 39 40/* counter to tag the uevent, read only except for the kobject core */ 41extern atomic64_t uevent_seqnum; 42 43/* 44 * The actions here must match the index to the string array 45 * in lib/kobject_uevent.c 46 * 47 * Do not add new actions here without checking with the driver-core 48 * maintainers. Action strings are not meant to express subsystem 49 * or device specific properties. In most cases you want to send a 50 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event 51 * specific variables added to the event environment. 52 */ 53enum kobject_action { 54 KOBJ_ADD, 55 KOBJ_REMOVE, 56 KOBJ_CHANGE, 57 KOBJ_MOVE, 58 KOBJ_ONLINE, 59 KOBJ_OFFLINE, 60 KOBJ_BIND, 61 KOBJ_UNBIND, 62}; 63 64struct kobject { 65 const char *name; 66 struct list_head entry; 67 struct kobject *parent; 68 struct kset *kset; 69 const struct kobj_type *ktype; 70 struct kernfs_node *sd; /* sysfs directory entry */ 71 struct kref kref; 72 73 unsigned int state_initialized:1; 74 unsigned int state_in_sysfs:1; 75 unsigned int state_add_uevent_sent:1; 76 unsigned int state_remove_uevent_sent:1; 77 unsigned int uevent_suppress:1; 78 79#ifdef CONFIG_DEBUG_KOBJECT_RELEASE 80 struct delayed_work release; 81#endif 82}; 83 84__printf(2, 3) int kobject_set_name(struct kobject *kobj, const char *name, ...); 85__printf(2, 0) int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, va_list vargs); 86 87static inline const char *kobject_name(const struct kobject *kobj) 88{ 89 return kobj->name; 90} 91 92void kobject_init(struct kobject *kobj, const struct kobj_type *ktype); 93__printf(3, 4) __must_check int kobject_add(struct kobject *kobj, 94 struct kobject *parent, 95 const char *fmt, ...); 96__printf(4, 5) __must_check int kobject_init_and_add(struct kobject *kobj, 97 const struct kobj_type *ktype, 98 struct kobject *parent, 99 const char *fmt, ...); 100 101void kobject_del(struct kobject *kobj); 102 103struct kobject * __must_check kobject_create_and_add(const char *name, struct kobject *parent); 104 105int __must_check kobject_rename(struct kobject *, const char *new_name); 106int __must_check kobject_move(struct kobject *, struct kobject *); 107 108struct kobject *kobject_get(struct kobject *kobj); 109struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj); 110void kobject_put(struct kobject *kobj); 111 112const void *kobject_namespace(const struct kobject *kobj); 113void kobject_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid); 114char *kobject_get_path(const struct kobject *kobj, gfp_t flag); 115 116struct kobj_type { 117 void (*release)(struct kobject *kobj); 118 const struct sysfs_ops *sysfs_ops; 119 const struct attribute_group **default_groups; 120 const struct kobj_ns_type_operations *(*child_ns_type)(const struct kobject *kobj); 121 const void *(*namespace)(const struct kobject *kobj); 122 void (*get_ownership)(const struct kobject *kobj, kuid_t *uid, kgid_t *gid); 123}; 124 125struct kobj_uevent_env { 126 char *argv[3]; 127 char *envp[UEVENT_NUM_ENVP]; 128 int envp_idx; 129 char buf[UEVENT_BUFFER_SIZE]; 130 int buflen; 131}; 132 133struct kset_uevent_ops { 134 int (* const filter)(const struct kobject *kobj); 135 const char *(* const name)(const struct kobject *kobj); 136 int (* const uevent)(const struct kobject *kobj, struct kobj_uevent_env *env); 137}; 138 139struct kobj_attribute { 140 struct attribute attr; 141 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 142 char *buf); 143 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 144 const char *buf, size_t count); 145}; 146 147extern const struct sysfs_ops kobj_sysfs_ops; 148 149struct sock; 150 151/** 152 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 153 * 154 * A kset defines a group of kobjects. They can be individually 155 * different "types" but overall these kobjects all want to be grouped 156 * together and operated on in the same manner. ksets are used to 157 * define the attribute callbacks and other common events that happen to 158 * a kobject. 159 * 160 * @list: the list of all kobjects for this kset 161 * @list_lock: a lock for iterating over the kobjects 162 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 163 * @uevent_ops: the set of uevent operations for this kset. These are 164 * called whenever a kobject has something happen to it so that the kset 165 * can add new environment variables, or filter out the uevents if so 166 * desired. 167 */ 168struct kset { 169 struct list_head list; 170 spinlock_t list_lock; 171 struct kobject kobj; 172 const struct kset_uevent_ops *uevent_ops; 173} __randomize_layout; 174 175void kset_init(struct kset *kset); 176int __must_check kset_register(struct kset *kset); 177void kset_unregister(struct kset *kset); 178struct kset * __must_check kset_create_and_add(const char *name, const struct kset_uevent_ops *u, 179 struct kobject *parent_kobj); 180 181static inline struct kset *to_kset(struct kobject *kobj) 182{ 183 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 184} 185 186static inline struct kset *kset_get(struct kset *k) 187{ 188 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 189} 190 191static inline void kset_put(struct kset *k) 192{ 193 kobject_put(&k->kobj); 194} 195 196static inline const struct kobj_type *get_ktype(const struct kobject *kobj) 197{ 198 return kobj->ktype; 199} 200 201struct kobject *kset_find_obj(struct kset *, const char *); 202 203/* The global /sys/kernel/ kobject for people to chain off of */ 204extern struct kobject *kernel_kobj; 205/* The global /sys/kernel/mm/ kobject for people to chain off of */ 206extern struct kobject *mm_kobj; 207/* The global /sys/hypervisor/ kobject for people to chain off of */ 208extern struct kobject *hypervisor_kobj; 209/* The global /sys/power/ kobject for people to chain off of */ 210extern struct kobject *power_kobj; 211/* The global /sys/firmware/ kobject for people to chain off of */ 212extern struct kobject *firmware_kobj; 213 214int kobject_uevent(struct kobject *kobj, enum kobject_action action); 215int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 216 char *envp[]); 217int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count); 218 219__printf(2, 3) 220int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...); 221 222#endif /* _KOBJECT_H_ */ 223