LXR linux/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/kernel.h>
  26#include <linux/wait.h>
  27#include <asm/atomic.h>
  28
  29#define UEVENT_HELPER_PATH_LEN          256
  30#define UEVENT_NUM_ENVP                 32      /* number of env pointers */
  31#define UEVENT_BUFFER_SIZE              2048    /* buffer for the variables */
  32
  33/* path to the userspace helper executed on an event */
  34extern char uevent_helper[];
  35
  36/* counter to tag the uevent, read only except for the kobject core */
  37extern u64 uevent_seqnum;
  38
  39/*
  40 * The actions here must match the index to the string array
  41 * in lib/kobject_uevent.c
  42 *
  43 * Do not add new actions here without checking with the driver-core
  44 * maintainers. Action strings are not meant to express subsystem
  45 * or device specific properties. In most cases you want to send a
  46 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
  47 * specific variables added to the event environment.
  48 */
  49enum kobject_action {
  50        KOBJ_ADD,
  51        KOBJ_REMOVE,
  52        KOBJ_CHANGE,
  53        KOBJ_MOVE,
  54        KOBJ_ONLINE,
  55        KOBJ_OFFLINE,
  56        KOBJ_MAX
  57};
  58
  59struct kobject {
  60        const char              *name;
  61        struct list_head        entry;
  62        struct kobject          *parent;
  63        struct kset             *kset;
  64        struct kobj_type        *ktype;
  65        struct sysfs_dirent     *sd;
  66        struct kref             kref;
  67        unsigned int state_initialized:1;
  68        unsigned int state_in_sysfs:1;
  69        unsigned int state_add_uevent_sent:1;
  70        unsigned int state_remove_uevent_sent:1;
  71        unsigned int uevent_suppress:1;
  72};
  73
  74extern int kobject_set_name(struct kobject *kobj, const char *name, ...)
  75                            __attribute__((format(printf, 2, 3)));
  76extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  77                                  va_list vargs);
  78
  79static inline const char *kobject_name(const struct kobject *kobj)
  80{
  81        return kobj->name;
  82}
  83
  84extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
  85extern int __must_check kobject_add(struct kobject *kobj,
  86                                    struct kobject *parent,
  87                                    const char *fmt, ...);
  88extern int __must_check kobject_init_and_add(struct kobject *kobj,
  89                                             struct kobj_type *ktype,
  90                                             struct kobject *parent,
  91                                             const char *fmt, ...);
  92
  93extern void kobject_del(struct kobject *kobj);
  94
  95extern struct kobject * __must_check kobject_create(void);
  96extern struct kobject * __must_check kobject_create_and_add(const char *name,
  97                                                struct kobject *parent);
  98
  99extern int __must_check kobject_rename(struct kobject *, const char *new_name);
 100extern int __must_check kobject_move(struct kobject *, struct kobject *);
 101
 102extern struct kobject *kobject_get(struct kobject *kobj);
 103extern void kobject_put(struct kobject *kobj);
 104
 105extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
 106
 107struct kobj_type {
 108        void (*release)(struct kobject *kobj);
 109        const struct sysfs_ops *sysfs_ops;
 110        struct attribute **default_attrs;
 111        const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
 112        const void *(*namespace)(struct kobject *kobj);
 113};
 114
 115struct kobj_uevent_env {
 116        char *envp[UEVENT_NUM_ENVP];
 117        int envp_idx;
 118        char buf[UEVENT_BUFFER_SIZE];
 119        int buflen;
 120};
 121
 122struct kset_uevent_ops {
 123        int (* const filter)(struct kset *kset, struct kobject *kobj);
 124        const char *(* const name)(struct kset *kset, struct kobject *kobj);
 125        int (* const uevent)(struct kset *kset, struct kobject *kobj,
 126                      struct kobj_uevent_env *env);
 127};
 128
 129struct kobj_attribute {
 130        struct attribute attr;
 131        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
 132                        char *buf);
 133        ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 134                         const char *buf, size_t count);
 135};
 136
 137extern const struct sysfs_ops kobj_sysfs_ops;
 138
 139/*
 140 * Namespace types which are used to tag kobjects and sysfs entries.
 141 * Network namespace will likely be the first.
 142 */
 143enum kobj_ns_type {
 144        KOBJ_NS_TYPE_NONE = 0,
 145        KOBJ_NS_TYPE_NET,
 146        KOBJ_NS_TYPES
 147};
 148
 149struct sock;
 150
 151/*
 152 * Callbacks so sysfs can determine namespaces
 153 *   @current_ns: return calling task's namespace
 154 *   @netlink_ns: return namespace to which a sock belongs (right?)
 155 *   @initial_ns: return the initial namespace (i.e. init_net_ns)
 156 */
 157struct kobj_ns_type_operations {
 158        enum kobj_ns_type type;
 159        const void *(*current_ns)(void);
 160        const void *(*netlink_ns)(struct sock *sk);
 161        const void *(*initial_ns)(void);
 162};
 163
 164int kobj_ns_type_register(const struct kobj_ns_type_operations *ops);
 165int kobj_ns_type_registered(enum kobj_ns_type type);
 166const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent);
 167const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj);
 168
 169const void *kobj_ns_current(enum kobj_ns_type type);
 170const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk);
 171const void *kobj_ns_initial(enum kobj_ns_type type);
 172void kobj_ns_exit(enum kobj_ns_type type, const void *ns);
 173
 174
 175/**
 176 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
 177 *
 178 * A kset defines a group of kobjects.  They can be individually
 179 * different "types" but overall these kobjects all want to be grouped
 180 * together and operated on in the same manner.  ksets are used to
 181 * define the attribute callbacks and other common events that happen to
 182 * a kobject.
 183 *
 184 * @list: the list of all kobjects for this kset
 185 * @list_lock: a lock for iterating over the kobjects
 186 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
 187 * @uevent_ops: the set of uevent operations for this kset.  These are
 188 * called whenever a kobject has something happen to it so that the kset
 189 * can add new environment variables, or filter out the uevents if so
 190 * desired.
 191 */
 192struct kset {
 193        struct list_head list;
 194        spinlock_t list_lock;
 195        struct kobject kobj;
 196        const struct kset_uevent_ops *uevent_ops;
 197};
 198
 199extern void kset_init(struct kset *kset);
 200extern int __must_check kset_register(struct kset *kset);
 201extern void kset_unregister(struct kset *kset);
 202extern struct kset * __must_check kset_create_and_add(const char *name,
 203                                                const struct kset_uevent_ops *u,
 204                                                struct kobject *parent_kobj);
 205
 206static inline struct kset *to_kset(struct kobject *kobj)
 207{
 208        return kobj ? container_of(kobj, struct kset, kobj) : NULL;
 209}
 210
 211static inline struct kset *kset_get(struct kset *k)
 212{
 213        return k ? to_kset(kobject_get(&k->kobj)) : NULL;
 214}
 215
 216static inline void kset_put(struct kset *k)
 217{
 218        kobject_put(&k->kobj);
 219}
 220
 221static inline struct kobj_type *get_ktype(struct kobject *kobj)
 222{
 223        return kobj->ktype;
 224}
 225
 226extern struct kobject *kset_find_obj(struct kset *, const char *);
 227
 228/* The global /sys/kernel/ kobject for people to chain off of */
 229extern struct kobject *kernel_kobj;
 230/* The global /sys/kernel/mm/ kobject for people to chain off of */
 231extern struct kobject *mm_kobj;
 232/* The global /sys/hypervisor/ kobject for people to chain off of */
 233extern struct kobject *hypervisor_kobj;
 234/* The global /sys/power/ kobject for people to chain off of */
 235extern struct kobject *power_kobj;
 236/* The global /sys/firmware/ kobject for people to chain off of */
 237extern struct kobject *firmware_kobj;
 238
 239#if defined(CONFIG_HOTPLUG)
 240int kobject_uevent(struct kobject *kobj, enum kobject_action action);
 241int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 242                        char *envp[]);
 243
 244int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 245        __attribute__((format (printf, 2, 3)));
 246
 247int kobject_action_type(const char *buf, size_t count,
 248                        enum kobject_action *type);
 249#else
 250static inline int kobject_uevent(struct kobject *kobj,
 251                                 enum kobject_action action)
 252{ return 0; }
 253static inline int kobject_uevent_env(struct kobject *kobj,
 254                                      enum kobject_action action,
 255                                      char *envp[])
 256{ return 0; }
 257
 258static inline int add_uevent_var(struct kobj_uevent_env *env,
 259                                 const char *format, ...)
 260{ return 0; }
 261
 262static inline int kobject_action_type(const char *buf, size_t count,
 263                                      enum kobject_action *type)
 264{ return -EINVAL; }
 265#endif
 266
 267#endif /* _KOBJECT_H_ */
 268