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
  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 */
  37 extern char uevent_helper[];
  38 #endif
  39
  40 /* counter to tag the uevent, read only except for the kobject core */
  41 extern 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  */
  53 enum 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
  65 struct 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 };
  82
  83 extern __printf(2, 3)
  84 int kobject_set_name(struct kobject *kobj, const char *name, ...);
  85 extern __printf(2, 0)
  86 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  87                            va_list vargs);
  88
  89 static inline const char *kobject_name(const struct kobject *kobj)
  90 {
  91         return kobj->name;
  92 }
  93
  94 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  95 extern __printf(3, 4) __must_check
  96 int kobject_add(struct kobject *kobj, struct kobject *parent,
  97                 const char *fmt, ...);
  98 extern __printf(4, 5) __must_check
  99 int kobject_init_and_add(struct kobject *kobj,
 100                          struct kobj_type *ktype, struct kobject *parent,
 101                          const char *fmt, ...);
 102
 103 extern void kobject_del(struct kobject *kobj);
 104
 105 extern struct kobject * __must_check kobject_create(void);
 106 extern struct kobject * __must_check kobject_create_and_add(const char *name,
 107                                                 struct kobject *parent);
 108
 109 extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 110 extern int __must_check kobject_move(struct kobject *, struct kobject *);
 111
 112 extern struct kobject *kobject_get(struct kobject *kobj);
 113 extern struct kobject * __must_check kobject_get_unless_zero(
 114                                                 struct kobject *kobj);
 115 extern void kobject_put(struct kobject *kobj);
 116
 117 extern const void *kobject_namespace(struct kobject *kobj);
 118 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 119
 120 struct kobj_type {
 121         void (*release)(struct kobject *kobj);
 122         const struct sysfs_ops *sysfs_ops;
 123         struct attribute **default_attrs;
 124         const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 125         const void *(*namespace)(struct kobject *kobj);
 126 };
 127
 128 struct kobj_uevent_env {
 129         char *argv[3];
 130         char *envp[UEVENT_NUM_ENVP];
 131         int envp_idx;
 132         char buf[UEVENT_BUFFER_SIZE];
 133         int buflen;
 134 };
 135
 136 struct kset_uevent_ops {
 137         int (* const filter)(struct kset *kset, struct kobject *kobj);
 138         const char *(* const name)(struct kset *kset, struct kobject *kobj);
 139         int (* const uevent)(struct kset *kset, struct kobject *kobj,
 140                       struct kobj_uevent_env *env);
 141 };
 142
 143 struct 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
 151 extern const struct sysfs_ops kobj_sysfs_ops;
 152
 153 struct 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  */
 172 struct 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
 179 extern void kset_init(struct kset *kset);
 180 extern int __must_check kset_register(struct kset *kset);
 181 extern void kset_unregister(struct kset *kset);
 182 extern struct kset * __must_check kset_create_and_add(const char *name,
 183                                                 const struct kset_uevent_ops *u,
 184                                                 struct kobject *parent_kobj);
 185
 186 static inline struct kset *to_kset(struct kobject *kobj)
 187 {
 188         return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 189 }
 190
 191 static inline struct kset *kset_get(struct kset *k)
 192 {
 193         return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 194 }
 195
 196 static inline void kset_put(struct kset *k)
 197 {
 198         kobject_put(&k->kobj);
 199 }
 200
 201 static inline struct kobj_type *get_ktype(struct kobject *kobj)
 202 {
 203         return kobj->ktype;
 204 }
 205
 206 extern struct kobject *kset_find_obj(struct kset *, const char *);
 207
 208 /* The global /sys/kernel/ kobject for people to chain off of */
 209 extern struct kobject *kernel_kobj;
 210 /* The global /sys/kernel/mm/ kobject for people to chain off of */
 211 extern struct kobject *mm_kobj;
 212 /* The global /sys/hypervisor/ kobject for people to chain off of */
 213 extern struct kobject *hypervisor_kobj;
 214 /* The global /sys/power/ kobject for people to chain off of */
 215 extern struct kobject *power_kobj;
 216 /* The global /sys/firmware/ kobject for people to chain off of */
 217 extern struct kobject *firmware_kobj;
 218
 219 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 220 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 221                         char *envp[]);
 222 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
 223
 224 __printf(2, 3)
 225 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 226
 227 #endif /* _KOBJECT_H_ */