LXR linux/include/linux/kobject.h

   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/kobject.txt 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/spinlock.h>
  23#include <linux/kref.h>
  24#include <linux/kobject_ns.h>
  25#include <linux/kernel.h>
  26#include <linux/wait.h>
  27#include <linux/atomic.h>
  28#include <linux/workqueue.h>
  29
  30#define UEVENT_HELPER_PATH_LEN          256
  31#define UEVENT_NUM_ENVP                 32      /* number of env pointers */
  32#define UEVENT_BUFFER_SIZE              2048    /* buffer for the variables */
  33
  34#ifdef CONFIG_UEVENT_HELPER
  35/* path to the userspace helper executed on an event */
  36extern char uevent_helper[];
  37#endif
  38
  39/* counter to tag the uevent, read only except for the kobject core */
  40extern u64 uevent_seqnum;
  41
  42/*
  43 * The actions here must match the index to the string array
  44 * in lib/kobject_uevent.c
  45 *
  46 * Do not add new actions here without checking with the driver-core
  47 * maintainers. Action strings are not meant to express subsystem
  48 * or device specific properties. In most cases you want to send a
  49 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
  50 * specific variables added to the event environment.
  51 */
  52enum kobject_action {
  53        KOBJ_ADD,
  54        KOBJ_REMOVE,
  55        KOBJ_CHANGE,
  56        KOBJ_MOVE,
  57        KOBJ_ONLINE,
  58        KOBJ_OFFLINE,
  59        KOBJ_BIND,
  60        KOBJ_UNBIND,
  61        KOBJ_MAX
  62};
  63
  64struct kobject {
  65        const char              *name;
  66        struct list_head        entry;
  67        struct kobject          *parent;
  68        struct kset             *kset;
  69        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, 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                         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(void);
 105extern struct kobject * __must_check kobject_create_and_add(const char *name,
 106                                                struct kobject *parent);
 107
 108extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 109extern int __must_check kobject_move(struct kobject *, struct kobject *);
 110
 111extern struct kobject *kobject_get(struct kobject *kobj);
 112extern struct kobject * __must_check kobject_get_unless_zero(
 113                                                struct kobject *kobj);
 114extern void kobject_put(struct kobject *kobj);
 115
 116extern const void *kobject_namespace(struct kobject *kobj);
 117extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 118
 119struct kobj_type {
 120        void (*release)(struct kobject *kobj);
 121        const struct sysfs_ops *sysfs_ops;
 122        struct attribute **default_attrs;
 123        const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 124        const void *(*namespace)(struct kobject *kobj);
 125};
 126
 127struct kobj_uevent_env {
 128        char *argv[3];
 129        char *envp[UEVENT_NUM_ENVP];
 130        int envp_idx;
 131        char buf[UEVENT_BUFFER_SIZE];
 132        int buflen;
 133};
 134
 135struct kset_uevent_ops {
 136        int (* const filter)(struct kset *kset, struct kobject *kobj);
 137        const char *(* const name)(struct kset *kset, struct kobject *kobj);
 138        int (* const uevent)(struct kset *kset, struct kobject *kobj,
 139                      struct kobj_uevent_env *env);
 140};
 141
 142struct kobj_attribute {
 143        struct attribute attr;
 144        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 145                        char *buf);
 146        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 147                         const char *buf, size_t count);
 148};
 149
 150extern const struct sysfs_ops kobj_sysfs_ops;
 151
 152struct sock;
 153
 154/**
 155 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 156 *
 157 * A kset defines a group of kobjects.  They can be individually
 158 * different "types" but overall these kobjects all want to be grouped
 159 * together and operated on in the same manner.  ksets are used to
 160 * define the attribute callbacks and other common events that happen to
 161 * a kobject.
 162 *
 163 * @list: the list of all kobjects for this kset
 164 * @list_lock: a lock for iterating over the kobjects
 165 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 166 * @uevent_ops: the set of uevent operations for this kset.  These are
 167 * called whenever a kobject has something happen to it so that the kset
 168 * can add new environment variables, or filter out the uevents if so
 169 * desired.
 170 */
 171struct kset {
 172        struct list_head list;
 173        spinlock_t list_lock;
 174        struct kobject kobj;
 175        const struct kset_uevent_ops *uevent_ops;
 176} __randomize_layout;
 177
 178extern void kset_init(struct kset *kset);
 179extern int __must_check kset_register(struct kset *kset);
 180extern void kset_unregister(struct kset *kset);
 181extern struct kset * __must_check kset_create_and_add(const char *name,
 182                                                const struct kset_uevent_ops *u,
 183                                                struct kobject *parent_kobj);
 184
 185static inline struct kset *to_kset(struct kobject *kobj)
 186{
 187        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 188}
 189
 190static inline struct kset *kset_get(struct kset *k)
 191{
 192        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 193}
 194
 195static inline void kset_put(struct kset *k)
 196{
 197        kobject_put(&k->kobj);
 198}
 199
 200static inline struct kobj_type *get_ktype(struct kobject *kobj)
 201{
 202        return kobj->ktype;
 203}
 204
 205extern struct kobject *kset_find_obj(struct kset *, const char *);
 206
 207/* The global /sys/kernel/ kobject for people to chain off of */
 208extern struct kobject *kernel_kobj;
 209/* The global /sys/kernel/mm/ kobject for people to chain off of */
 210extern struct kobject *mm_kobj;
 211/* The global /sys/hypervisor/ kobject for people to chain off of */
 212extern struct kobject *hypervisor_kobj;
 213/* The global /sys/power/ kobject for people to chain off of */
 214extern struct kobject *power_kobj;
 215/* The global /sys/firmware/ kobject for people to chain off of */
 216extern struct kobject *firmware_kobj;
 217
 218int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 219int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 220                        char *envp[]);
 221int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
 222
 223__printf(2, 3)
 224int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 225
 226#endif /* _KOBJECT_H_ */
 227