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#include <linux/rh_kabi.h>
  30
  31#define UEVENT_HELPER_PATH_LEN          256
  32#define UEVENT_NUM_ENVP                 32      /* 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        KOBJ_MAX
  63};
  64
  65struct kobject {
  66        const char              *name;
  67        struct list_head        entry;
  68        struct kobject          *parent;
  69        struct kset             *kset;
  70        struct kobj_type        *ktype;
  71        struct kernfs_node      *sd; /* sysfs directory entry */
  72        struct kref             kref;
  73#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
  74        struct delayed_work     release;
  75#endif
  76        unsigned int state_initialized:1;
  77        unsigned int state_in_sysfs:1;
  78        unsigned int state_add_uevent_sent:1;
  79        unsigned int state_remove_uevent_sent:1;
  80        unsigned int uevent_suppress:1;
  81        RH_KABI_RESERVE(1)
  82        RH_KABI_RESERVE(2)
  83        RH_KABI_RESERVE(3)
  84        RH_KABI_RESERVE(4)
  85};
  86
  87extern __printf(2, 3)
  88int kobject_set_name(struct kobject *kobj, const char *name, ...);
  89extern __printf(2, 0)
  90int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  91                           va_list vargs);
  92
  93static inline const char *kobject_name(const struct kobject *kobj)
  94{
  95        return kobj->name;
  96}
  97
  98extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  99extern __printf(3, 4) __must_check
 100int kobject_add(struct kobject *kobj, struct kobject *parent,
 101                const char *fmt, ...);
 102extern __printf(4, 5) __must_check
 103int kobject_init_and_add(struct kobject *kobj,
 104                         struct kobj_type *ktype, struct kobject *parent,
 105                         const char *fmt, ...);
 106
 107extern void kobject_del(struct kobject *kobj);
 108
 109extern struct kobject * __must_check kobject_create(void);
 110extern struct kobject * __must_check kobject_create_and_add(const char *name,
 111                                                struct kobject *parent);
 112
 113extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 114extern int __must_check kobject_move(struct kobject *, struct kobject *);
 115
 116extern struct kobject *kobject_get(struct kobject *kobj);
 117extern struct kobject * __must_check kobject_get_unless_zero(
 118                                                struct kobject *kobj);
 119extern void kobject_put(struct kobject *kobj);
 120
 121extern const void *kobject_namespace(struct kobject *kobj);
 122extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 123
 124struct kobj_type {
 125        void (*release)(struct kobject *kobj);
 126        const struct sysfs_ops *sysfs_ops;
 127        struct attribute **default_attrs;       /* use default_groups instead */
 128        const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 129        const void *(*namespace)(struct kobject *kobj);
 130        RH_KABI_USE(1, const struct attribute_group **default_groups)
 131        RH_KABI_RESERVE(2)
 132        RH_KABI_RESERVE(3)
 133        RH_KABI_RESERVE(4)
 134};
 135
 136struct kobj_uevent_env {
 137        char *argv[3];
 138        char *envp[UEVENT_NUM_ENVP];
 139        int envp_idx;
 140        char buf[UEVENT_BUFFER_SIZE];
 141        int buflen;
 142};
 143
 144struct kset_uevent_ops {
 145        int (* const filter)(struct kset *kset, struct kobject *kobj);
 146        const char *(* const name)(struct kset *kset, struct kobject *kobj);
 147        int (* const uevent)(struct kset *kset, struct kobject *kobj,
 148                      struct kobj_uevent_env *env);
 149};
 150
 151struct kobj_attribute {
 152        struct attribute attr;
 153        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 154                        char *buf);
 155        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 156                         const char *buf, size_t count);
 157};
 158
 159extern const struct sysfs_ops kobj_sysfs_ops;
 160
 161struct sock;
 162
 163/**
 164 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 165 *
 166 * A kset defines a group of kobjects.  They can be individually
 167 * different "types" but overall these kobjects all want to be grouped
 168 * together and operated on in the same manner.  ksets are used to
 169 * define the attribute callbacks and other common events that happen to
 170 * a kobject.
 171 *
 172 * @list: the list of all kobjects for this kset
 173 * @list_lock: a lock for iterating over the kobjects
 174 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 175 * @uevent_ops: the set of uevent operations for this kset.  These are
 176 * called whenever a kobject has something happen to it so that the kset
 177 * can add new environment variables, or filter out the uevents if so
 178 * desired.
 179 */
 180struct kset {
 181        struct list_head list;
 182        spinlock_t list_lock;
 183        struct kobject kobj;
 184        const struct kset_uevent_ops *uevent_ops;
 185        RH_KABI_RESERVE(1)
 186        RH_KABI_RESERVE(2)
 187        RH_KABI_RESERVE(3)
 188        RH_KABI_RESERVE(4)
 189} __randomize_layout;
 190
 191extern void kset_init(struct kset *kset);
 192extern int __must_check kset_register(struct kset *kset);
 193extern void kset_unregister(struct kset *kset);
 194extern struct kset * __must_check kset_create_and_add(const char *name,
 195                                                const struct kset_uevent_ops *u,
 196                                                struct kobject *parent_kobj);
 197
 198static inline struct kset *to_kset(struct kobject *kobj)
 199{
 200        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 201}
 202
 203static inline struct kset *kset_get(struct kset *k)
 204{
 205        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 206}
 207
 208static inline void kset_put(struct kset *k)
 209{
 210        kobject_put(&k->kobj);
 211}
 212
 213static inline struct kobj_type *get_ktype(struct kobject *kobj)
 214{
 215        return kobj->ktype;
 216}
 217
 218extern struct kobject *kset_find_obj(struct kset *, const char *);
 219
 220/* The global /sys/kernel/ kobject for people to chain off of */
 221extern struct kobject *kernel_kobj;
 222/* The global /sys/kernel/mm/ kobject for people to chain off of */
 223extern struct kobject *mm_kobj;
 224/* The global /sys/hypervisor/ kobject for people to chain off of */
 225extern struct kobject *hypervisor_kobj;
 226/* The global /sys/power/ kobject for people to chain off of */
 227extern struct kobject *power_kobj;
 228/* The global /sys/firmware/ kobject for people to chain off of */
 229extern struct kobject *firmware_kobj;
 230
 231int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 232int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 233                        char *envp[]);
 234int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
 235
 236__printf(2, 3)
 237int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 238
 239#endif /* _KOBJECT_H_ */
 240