include/linux/kobject.h

   1 /*
   2  * kobject.h - generic kernel object infrastructure.
   3  *
   4  * Copyright (c) 2002-2003 Patrick Mochel
   5  * Copyright (c) 2002-2003 Open Source Development Labs
   6  * Copyright (c) 2006-2008 Greg Kroah-Hartman <greg@kroah.com>
   7  * Copyright (c) 2006-2008 Novell Inc.
   8  *
   9  * This file is released under the GPLv2.
  10  *
  11  * Please read Documentation/kobject.txt before using the kobject
  12  * interface, ESPECIALLY the parts about reference counts and object
  13  * destructors.
  14  */
  15
  16 #ifndef _KOBJECT_H_
  17 #define _KOBJECT_H_
  18
  19 #include <linux/types.h>
  20 #include <linux/list.h>
  21 #include <linux/sysfs.h>
  22 #include <linux/compiler.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/kref.h>
  25 #include <linux/kobject_ns.h>
  26 #include <linux/kernel.h>
  27 #include <linux/wait.h>
  28 #include <linux/atomic.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/uidgid.h>
  31
  32 #define UEVENT_HELPER_PATH_LEN          256
  33 #define UEVENT_NUM_ENVP                 32      /* number of env pointers */
  34 #define UEVENT_BUFFER_SIZE              2048    /* buffer for the variables */
  35
  36 #ifdef CONFIG_UEVENT_HELPER
  37 /* path to the userspace helper executed on an event */
  38 extern char uevent_helper[];
  39 #endif
  40
  41 /* counter to tag the uevent, read only except for the kobject core */
  42 extern u64 uevent_seqnum;
  43
  44 /*
  45  * The actions here must match the index to the string array
  46  * in lib/kobject_uevent.c
  47  *
  48  * Do not add new actions here without checking with the driver-core
  49  * maintainers. Action strings are not meant to express subsystem
  50  * or device specific properties. In most cases you want to send a
  51  * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
  52  * specific variables added to the event environment.
  53  */
  54 enum kobject_action {
  55         KOBJ_ADD,
  56         KOBJ_REMOVE,
  57         KOBJ_CHANGE,
  58         KOBJ_MOVE,
  59         KOBJ_ONLINE,
  60         KOBJ_OFFLINE,
  61         KOBJ_BIND,
  62         KOBJ_UNBIND,
  63         KOBJ_MAX
  64 };
  65
  66 struct kobject {
  67         const char              *name;
  68         struct list_head        entry;
  69         struct kobject          *parent;
  70         struct kset             *kset;
  71         struct kobj_type        *ktype;
  72         struct kernfs_node      *sd; /* sysfs directory entry */
  73         struct kref             kref;
  74 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
  75         struct delayed_work     release;
  76 #endif
  77         unsigned int state_initialized:1;
  78         unsigned int state_in_sysfs:1;
  79         unsigned int state_add_uevent_sent:1;
  80         unsigned int state_remove_uevent_sent:1;
  81         unsigned int uevent_suppress:1;
  82 };
  83
  84 extern __printf(2, 3)
  85 int kobject_set_name(struct kobject *kobj, const char *name, ...);
  86 extern __printf(2, 0)
  87 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  88                            va_list vargs);
  89
  90 static inline const char *kobject_name(const struct kobject *kobj)
  91 {
  92         return kobj->name;
  93 }
  94
  95 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  96 extern __printf(3, 4) __must_check
  97 int kobject_add(struct kobject *kobj, struct kobject *parent,
  98                 const char *fmt, ...);
  99 extern __printf(4, 5) __must_check
 100 int kobject_init_and_add(struct kobject *kobj,
 101                          struct kobj_type *ktype, struct kobject *parent,
 102                          const char *fmt, ...);
 103
 104 extern void kobject_del(struct kobject *kobj);
 105
 106 extern struct kobject * __must_check kobject_create(void);
 107 extern struct kobject * __must_check kobject_create_and_add(const char *name,
 108                                                 struct kobject *parent);
 109
 110 extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 111 extern int __must_check kobject_move(struct kobject *, struct kobject *);
 112
 113 extern struct kobject *kobject_get(struct kobject *kobj);
 114 extern struct kobject * __must_check kobject_get_unless_zero(
 115                                                 struct kobject *kobj);
 116 extern void kobject_put(struct kobject *kobj);
 117
 118 extern const void *kobject_namespace(struct kobject *kobj);
 119 extern void kobject_get_ownership(struct kobject *kobj,
 120                                   kuid_t *uid, kgid_t *gid);
 121 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 122
 123 struct kobj_type {
 124         void (*release)(struct kobject *kobj);
 125         const struct sysfs_ops *sysfs_ops;
 126         struct attribute **default_attrs;
 127         const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 128         const void *(*namespace)(struct kobject *kobj);
 129         void (*get_ownership)(struct kobject *kobj, kuid_t *uid, kgid_t *gid);
 130 };
 131
 132 struct kobj_uevent_env {
 133         char *argv[3];
 134         char *envp[UEVENT_NUM_ENVP];
 135         int envp_idx;
 136         char buf[UEVENT_BUFFER_SIZE];
 137         int buflen;
 138 };
 139
 140 struct kset_uevent_ops {
 141         int (* const filter)(struct kset *kset, struct kobject *kobj);
 142         const char *(* const name)(struct kset *kset, struct kobject *kobj);
 143         int (* const uevent)(struct kset *kset, struct kobject *kobj,
 144                       struct kobj_uevent_env *env);
 145 };
 146
 147 struct kobj_attribute {
 148         struct attribute attr;
 149         ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 150                         char *buf);
 151         ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 152                          const char *buf, size_t count);
 153 };
 154
 155 extern const struct sysfs_ops kobj_sysfs_ops;
 156
 157 struct sock;
 158
 159 /**
 160  * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 161  *
 162  * A kset defines a group of kobjects.  They can be individually
 163  * different "types" but overall these kobjects all want to be grouped
 164  * together and operated on in the same manner.  ksets are used to
 165  * define the attribute callbacks and other common events that happen to
 166  * a kobject.
 167  *
 168  * @list: the list of all kobjects for this kset
 169  * @list_lock: a lock for iterating over the kobjects
 170  * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 171  * @uevent_ops: the set of uevent operations for this kset.  These are
 172  * called whenever a kobject has something happen to it so that the kset
 173  * can add new environment variables, or filter out the uevents if so
 174  * desired.
 175  */
 176 struct kset {
 177         struct list_head list;
 178         spinlock_t list_lock;
 179         struct kobject kobj;
 180         const struct kset_uevent_ops *uevent_ops;
 181 } __randomize_layout;
 182
 183 extern void kset_init(struct kset *kset);
 184 extern int __must_check kset_register(struct kset *kset);
 185 extern void kset_unregister(struct kset *kset);
 186 extern struct kset * __must_check kset_create_and_add(const char *name,
 187                                                 const struct kset_uevent_ops *u,
 188                                                 struct kobject *parent_kobj);
 189
 190 static inline struct kset *to_kset(struct kobject *kobj)
 191 {
 192         return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 193 }
 194
 195 static inline struct kset *kset_get(struct kset *k)
 196 {
 197         return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 198 }
 199
 200 static inline void kset_put(struct kset *k)
 201 {
 202         kobject_put(&k->kobj);
 203 }
 204
 205 static inline struct kobj_type *get_ktype(struct kobject *kobj)
 206 {
 207         return kobj->ktype;
 208 }
 209
 210 extern struct kobject *kset_find_obj(struct kset *, const char *);
 211
 212 /* The global /sys/kernel/ kobject for people to chain off of */
 213 extern struct kobject *kernel_kobj;
 214 /* The global /sys/kernel/mm/ kobject for people to chain off of */
 215 extern struct kobject *mm_kobj;
 216 /* The global /sys/hypervisor/ kobject for people to chain off of */
 217 extern struct kobject *hypervisor_kobj;
 218 /* The global /sys/power/ kobject for people to chain off of */
 219 extern struct kobject *power_kobj;
 220 /* The global /sys/firmware/ kobject for people to chain off of */
 221 extern struct kobject *firmware_kobj;
 222
 223 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 224 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 225                         char *envp[]);
 226 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
 227
 228 __printf(2, 3)
 229 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 230
 231 #endif /* _KOBJECT_H_ */