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 * This file is released under the GPLv2. 11 * 12 * Please read Documentation/kobject.txt before using the kobject 13 * interface, ESPECIALLY the parts about reference counts and object 14 * destructors. 15 */ 16 17 #ifndef _KOBJECT_H_ 18 #define _KOBJECT_H_ 19 20 #include <linux/types.h> 21 #include <linux/list.h> 22 #include <linux/sysfs.h> 23 #include <linux/compiler.h> 24 #include <linux/spinlock.h> 25 #include <linux/kref.h> 26 #include <linux/kobject_ns.h> 27 #include <linux/kernel.h> 28 #include <linux/wait.h> 29 #include <linux/atomic.h> 30 #include <linux/workqueue.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 char *kobject_get_path(struct kobject *kobj, gfp_t flag); 120 121 struct kobj_type { 122 void (*release)(struct kobject *kobj); 123 const struct sysfs_ops *sysfs_ops; 124 struct attribute **default_attrs; 125 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj); 126 const void *(*namespace)(struct kobject *kobj); 127 }; 128 129 struct kobj_uevent_env { 130 char *argv[3]; 131 char *envp[UEVENT_NUM_ENVP]; 132 int envp_idx; 133 char buf[UEVENT_BUFFER_SIZE]; 134 int buflen; 135 }; 136 137 struct kset_uevent_ops { 138 int (* const filter)(struct kset *kset, struct kobject *kobj); 139 const char *(* const name)(struct kset *kset, struct kobject *kobj); 140 int (* const uevent)(struct kset *kset, struct kobject *kobj, 141 struct kobj_uevent_env *env); 142 }; 143 144 struct kobj_attribute { 145 struct attribute attr; 146 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 147 char *buf); 148 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 149 const char *buf, size_t count); 150 }; 151 152 extern const struct sysfs_ops kobj_sysfs_ops; 153 154 struct sock; 155 156 /** 157 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 158 * 159 * A kset defines a group of kobjects. They can be individually 160 * different "types" but overall these kobjects all want to be grouped 161 * together and operated on in the same manner. ksets are used to 162 * define the attribute callbacks and other common events that happen to 163 * a kobject. 164 * 165 * @list: the list of all kobjects for this kset 166 * @list_lock: a lock for iterating over the kobjects 167 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 168 * @uevent_ops: the set of uevent operations for this kset. These are 169 * called whenever a kobject has something happen to it so that the kset 170 * can add new environment variables, or filter out the uevents if so 171 * desired. 172 */ 173 struct kset { 174 struct list_head list; 175 spinlock_t list_lock; 176 struct kobject kobj; 177 const struct kset_uevent_ops *uevent_ops; 178 } __randomize_layout; 179 180 extern void kset_init(struct kset *kset); 181 extern int __must_check kset_register(struct kset *kset); 182 extern void kset_unregister(struct kset *kset); 183 extern struct kset * __must_check kset_create_and_add(const char *name, 184 const struct kset_uevent_ops *u, 185 struct kobject *parent_kobj); 186 187 static inline struct kset *to_kset(struct kobject *kobj) 188 { 189 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 190 } 191 192 static inline struct kset *kset_get(struct kset *k) 193 { 194 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 195 } 196 197 static inline void kset_put(struct kset *k) 198 { 199 kobject_put(&k->kobj); 200 } 201 202 static inline struct kobj_type *get_ktype(struct kobject *kobj) 203 { 204 return kobj->ktype; 205 } 206 207 extern struct kobject *kset_find_obj(struct kset *, const char *); 208 209 /* The global /sys/kernel/ kobject for people to chain off of */ 210 extern struct kobject *kernel_kobj; 211 /* The global /sys/kernel/mm/ kobject for people to chain off of */ 212 extern struct kobject *mm_kobj; 213 /* The global /sys/hypervisor/ kobject for people to chain off of */ 214 extern struct kobject *hypervisor_kobj; 215 /* The global /sys/power/ kobject for people to chain off of */ 216 extern struct kobject *power_kobj; 217 /* The global /sys/firmware/ kobject for people to chain off of */ 218 extern struct kobject *firmware_kobj; 219 220 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 221 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 222 char *envp[]); 223 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count); 224 225 __printf(2, 3) 226 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...); 227 228 #endif /* _KOBJECT_H_ */ 229