kobject.h (7179B)
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 u64 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#ifdef CONFIG_DEBUG_KOBJECT_RELEASE 73 struct delayed_work release; 74#endif 75 unsigned int state_initialized:1; 76 unsigned int state_in_sysfs:1; 77 unsigned int state_add_uevent_sent:1; 78 unsigned int state_remove_uevent_sent:1; 79 unsigned int uevent_suppress:1; 80}; 81 82extern __printf(2, 3) 83int kobject_set_name(struct kobject *kobj, const char *name, ...); 84extern __printf(2, 0) 85int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, 86 va_list vargs); 87 88static inline const char *kobject_name(const struct kobject *kobj) 89{ 90 return kobj->name; 91} 92 93extern void kobject_init(struct kobject *kobj, const struct kobj_type *ktype); 94extern __printf(3, 4) __must_check 95int kobject_add(struct kobject *kobj, struct kobject *parent, 96 const char *fmt, ...); 97extern __printf(4, 5) __must_check 98int kobject_init_and_add(struct kobject *kobj, 99 const struct kobj_type *ktype, struct kobject *parent, 100 const char *fmt, ...); 101 102extern void kobject_del(struct kobject *kobj); 103 104extern struct kobject * __must_check kobject_create_and_add(const char *name, 105 struct kobject *parent); 106 107extern int __must_check kobject_rename(struct kobject *, const char *new_name); 108extern int __must_check kobject_move(struct kobject *, struct kobject *); 109 110extern struct kobject *kobject_get(struct kobject *kobj); 111extern struct kobject * __must_check kobject_get_unless_zero( 112 struct kobject *kobj); 113extern void kobject_put(struct kobject *kobj); 114 115extern const void *kobject_namespace(struct kobject *kobj); 116extern void kobject_get_ownership(struct kobject *kobj, 117 kuid_t *uid, kgid_t *gid); 118extern char *kobject_get_path(struct kobject *kobj, gfp_t flag); 119 120struct kobj_type { 121 void (*release)(struct kobject *kobj); 122 const struct sysfs_ops *sysfs_ops; 123 const struct attribute_group **default_groups; 124 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj); 125 const void *(*namespace)(struct kobject *kobj); 126 void (*get_ownership)(struct kobject *kobj, kuid_t *uid, kgid_t *gid); 127}; 128 129struct kobj_uevent_env { 130 char *argv[3]; 131 char *envp[UEVENT_NUM_ENVP]; 132 int envp_idx; 133 char buf[UEVENT_BUFFER_SIZE]; 134 int buflen; 135}; 136 137struct kset_uevent_ops { 138 int (* const filter)(struct kobject *kobj); 139 const char *(* const name)(struct kobject *kobj); 140 int (* const uevent)(struct kobject *kobj, struct kobj_uevent_env *env); 141}; 142 143struct kobj_attribute { 144 struct attribute attr; 145 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 146 char *buf); 147 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 148 const char *buf, size_t count); 149}; 150 151extern const struct sysfs_ops kobj_sysfs_ops; 152 153struct sock; 154 155/** 156 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 157 * 158 * A kset defines a group of kobjects. They can be individually 159 * different "types" but overall these kobjects all want to be grouped 160 * together and operated on in the same manner. ksets are used to 161 * define the attribute callbacks and other common events that happen to 162 * a kobject. 163 * 164 * @list: the list of all kobjects for this kset 165 * @list_lock: a lock for iterating over the kobjects 166 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 167 * @uevent_ops: the set of uevent operations for this kset. These are 168 * called whenever a kobject has something happen to it so that the kset 169 * can add new environment variables, or filter out the uevents if so 170 * desired. 171 */ 172struct kset { 173 struct list_head list; 174 spinlock_t list_lock; 175 struct kobject kobj; 176 const struct kset_uevent_ops *uevent_ops; 177} __randomize_layout; 178 179extern void kset_init(struct kset *kset); 180extern int __must_check kset_register(struct kset *kset); 181extern void kset_unregister(struct kset *kset); 182extern struct kset * __must_check kset_create_and_add(const char *name, 183 const struct kset_uevent_ops *u, 184 struct kobject *parent_kobj); 185 186static inline struct kset *to_kset(struct kobject *kobj) 187{ 188 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 189} 190 191static inline struct kset *kset_get(struct kset *k) 192{ 193 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 194} 195 196static inline void kset_put(struct kset *k) 197{ 198 kobject_put(&k->kobj); 199} 200 201static inline const struct kobj_type *get_ktype(struct kobject *kobj) 202{ 203 return kobj->ktype; 204} 205 206extern struct kobject *kset_find_obj(struct kset *, const char *); 207 208/* The global /sys/kernel/ kobject for people to chain off of */ 209extern struct kobject *kernel_kobj; 210/* The global /sys/kernel/mm/ kobject for people to chain off of */ 211extern struct kobject *mm_kobj; 212/* The global /sys/hypervisor/ kobject for people to chain off of */ 213extern struct kobject *hypervisor_kobj; 214/* The global /sys/power/ kobject for people to chain off of */ 215extern struct kobject *power_kobj; 216/* The global /sys/firmware/ kobject for people to chain off of */ 217extern struct kobject *firmware_kobj; 218 219int kobject_uevent(struct kobject *kobj, enum kobject_action action); 220int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 221 char *envp[]); 222int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count); 223 224__printf(2, 3) 225int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...); 226 227#endif /* _KOBJECT_H_ */