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 <[email protected]> 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 */ 36 extern char uevent_helper[]; 37 #endif 38 39 /* counter to tag the uevent, read only except for the kobject core */ 40 extern 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 */ 52 enum 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 64 struct 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 82 extern __printf(2, 3) 83 int kobject_set_name(struct kobject *kobj, const char *name, ...); 84 extern __printf(2, 0) 85 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, 86 va_list vargs); 87 88 static inline const char *kobject_name(const struct kobject *kobj) 89 { 90 return kobj->name; 91 } 92 93 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype); 94 extern __printf(3, 4) __must_check 95 int kobject_add(struct kobject *kobj, struct kobject *parent, 96 const char *fmt, ...); 97 extern __printf(4, 5) __must_check 98 int kobject_init_and_add(struct kobject *kobj, 99 struct kobj_type *ktype, struct kobject *parent, 100 const char *fmt, ...); 101 102 extern void kobject_del(struct kobject *kobj); 103 104 extern struct kobject * __must_check kobject_create(void); 105 extern struct kobject * __must_check kobject_create_and_add(const char *name, 106 struct kobject *parent); 107 108 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 109 extern int __must_check kobject_move(struct kobject *, struct kobject *); 110 111 extern struct kobject *kobject_get(struct kobject *kobj); 112 extern struct kobject * __must_check kobject_get_unless_zero( 113 struct kobject *kobj); 114 extern void kobject_put(struct kobject *kobj); 115 116 extern const void *kobject_namespace(struct kobject *kobj); 117 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag); 118 119 /** 120 * kobject_has_children - Returns whether a kobject has children. 121 * @kobj: the object to test 122 * 123 * This will return whether a kobject has other kobjects as children. 124 * 125 * It does NOT account for the presence of attribute files, only sub 126 * directories. It also assumes there is no concurrent addition or 127 * removal of such children, and thus relies on external locking. 128 */ 129 static inline bool kobject_has_children(struct kobject *kobj) 130 { 131 WARN_ON_ONCE(kref_read(&kobj->kref) == 0); 132 133 return kobj->sd && kobj->sd->dir.subdirs; 134 } 135 136 struct kobj_type { 137 void (*release)(struct kobject *kobj); 138 const struct sysfs_ops *sysfs_ops; 139 struct attribute **default_attrs; 140 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj); 141 const void *(*namespace)(struct kobject *kobj); 142 }; 143 144 struct kobj_uevent_env { 145 char *argv[3]; 146 char *envp[UEVENT_NUM_ENVP]; 147 int envp_idx; 148 char buf[UEVENT_BUFFER_SIZE]; 149 int buflen; 150 }; 151 152 struct kset_uevent_ops { 153 int (* const filter)(struct kset *kset, struct kobject *kobj); 154 const char *(* const name)(struct kset *kset, struct kobject *kobj); 155 int (* const uevent)(struct kset *kset, struct kobject *kobj, 156 struct kobj_uevent_env *env); 157 }; 158 159 struct kobj_attribute { 160 struct attribute attr; 161 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 162 char *buf); 163 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 164 const char *buf, size_t count); 165 }; 166 167 extern const struct sysfs_ops kobj_sysfs_ops; 168 169 struct sock; 170 171 /** 172 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 173 * 174 * A kset defines a group of kobjects. They can be individually 175 * different "types" but overall these kobjects all want to be grouped 176 * together and operated on in the same manner. ksets are used to 177 * define the attribute callbacks and other common events that happen to 178 * a kobject. 179 * 180 * @list: the list of all kobjects for this kset 181 * @list_lock: a lock for iterating over the kobjects 182 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 183 * @uevent_ops: the set of uevent operations for this kset. These are 184 * called whenever a kobject has something happen to it so that the kset 185 * can add new environment variables, or filter out the uevents if so 186 * desired. 187 */ 188 struct kset { 189 struct list_head list; 190 spinlock_t list_lock; 191 struct kobject kobj; 192 const struct kset_uevent_ops *uevent_ops; 193 } __randomize_layout; 194 195 extern void kset_init(struct kset *kset); 196 extern int __must_check kset_register(struct kset *kset); 197 extern void kset_unregister(struct kset *kset); 198 extern struct kset * __must_check kset_create_and_add(const char *name, 199 const struct kset_uevent_ops *u, 200 struct kobject *parent_kobj); 201 202 static inline struct kset *to_kset(struct kobject *kobj) 203 { 204 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 205 } 206 207 static inline struct kset *kset_get(struct kset *k) 208 { 209 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 210 } 211 212 static inline void kset_put(struct kset *k) 213 { 214 kobject_put(&k->kobj); 215 } 216 217 static inline struct kobj_type *get_ktype(struct kobject *kobj) 218 { 219 return kobj->ktype; 220 } 221 222 extern struct kobject *kset_find_obj(struct kset *, const char *); 223 224 /* The global /sys/kernel/ kobject for people to chain off of */ 225 extern struct kobject *kernel_kobj; 226 /* The global /sys/kernel/mm/ kobject for people to chain off of */ 227 extern struct kobject *mm_kobj; 228 /* The global /sys/hypervisor/ kobject for people to chain off of */ 229 extern struct kobject *hypervisor_kobj; 230 /* The global /sys/power/ kobject for people to chain off of */ 231 extern struct kobject *power_kobj; 232 /* The global /sys/firmware/ kobject for people to chain off of */ 233 extern struct kobject *firmware_kobj; 234 235 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 236 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 237 char *envp[]); 238 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count); 239 240 __printf(2, 3) 241 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...); 242 243 #endif /* _KOBJECT_H_ */ 244