1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
4 * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
5 * Copyright (c) 2008-2012 Novell Inc.
6 * Copyright (c) 2012-2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
7 * Copyright (c) 2012-2019 Linux Foundation
8 *
9 * Core driver model functions and structures that should not be
10 * shared outside of the drivers/base/ directory.
11 *
12 */
13#include <linux/notifier.h>
14
15/**
16 * struct subsys_private - structure to hold the private to the driver core portions of the bus_type/class structure.
17 *
18 * @subsys - the struct kset that defines this subsystem
19 * @devices_kset - the subsystem's 'devices' directory
20 * @interfaces - list of subsystem interfaces associated
21 * @mutex - protect the devices, and interfaces lists.
22 *
23 * @drivers_kset - the list of drivers associated
24 * @klist_devices - the klist to iterate over the @devices_kset
25 * @klist_drivers - the klist to iterate over the @drivers_kset
26 * @bus_notifier - the bus notifier list for anything that cares about things
27 * on this bus.
28 * @bus - pointer back to the struct bus_type that this structure is associated
29 * with.
30 * @dev_root: Default device to use as the parent.
31 *
32 * @glue_dirs - "glue" directory to put in-between the parent device to
33 * avoid namespace conflicts
34 * @class - pointer back to the struct class that this structure is associated
35 * with.
36 * @lock_key: Lock class key for use by the lock validator
37 *
38 * This structure is the one that is the actual kobject allowing struct
39 * bus_type/class to be statically allocated safely. Nothing outside of the
40 * driver core should ever touch these fields.
41 */
42struct subsys_private {
43 struct kset subsys;
44 struct kset *devices_kset;
45 struct list_head interfaces;
46 struct mutex mutex;
47
48 struct kset *drivers_kset;
49 struct klist klist_devices;
50 struct klist klist_drivers;
51 struct blocking_notifier_head bus_notifier;
52 unsigned int drivers_autoprobe:1;
53 const struct bus_type *bus;
54 struct device *dev_root;
55
56 struct kset glue_dirs;
57 const struct class *class;
58
59 struct lock_class_key lock_key;
60};
61#define to_subsys_private(obj) container_of_const(obj, struct subsys_private, subsys.kobj)
62
63static inline struct subsys_private *subsys_get(struct subsys_private *sp)
64{
65 if (sp)
66 kset_get(k: &sp->subsys);
67 return sp;
68}
69
70static inline void subsys_put(struct subsys_private *sp)
71{
72 if (sp)
73 kset_put(k: &sp->subsys);
74}
75
76struct subsys_private *bus_to_subsys(const struct bus_type *bus);
77struct subsys_private *class_to_subsys(const struct class *class);
78
79struct driver_private {
80 struct kobject kobj;
81 struct klist klist_devices;
82 struct klist_node knode_bus;
83 struct module_kobject *mkobj;
84 struct device_driver *driver;
85};
86#define to_driver(obj) container_of(obj, struct driver_private, kobj)
87
88/**
89 * struct device_private - structure to hold the private to the driver core portions of the device structure.
90 *
91 * @klist_children - klist containing all children of this device
92 * @knode_parent - node in sibling list
93 * @knode_driver - node in driver list
94 * @knode_bus - node in bus list
95 * @knode_class - node in class list
96 * @deferred_probe - entry in deferred_probe_list which is used to retry the
97 * binding of drivers which were unable to get all the resources needed by
98 * the device; typically because it depends on another driver getting
99 * probed first.
100 * @async_driver - pointer to device driver awaiting probe via async_probe
101 * @device - pointer back to the struct device that this structure is
102 * associated with.
103 * @dead - This device is currently either in the process of or has been
104 * removed from the system. Any asynchronous events scheduled for this
105 * device should exit without taking any action.
106 *
107 * Nothing outside of the driver core should ever touch these fields.
108 */
109struct device_private {
110 struct klist klist_children;
111 struct klist_node knode_parent;
112 struct klist_node knode_driver;
113 struct klist_node knode_bus;
114 struct klist_node knode_class;
115 struct list_head deferred_probe;
116 const struct device_driver *async_driver;
117 char *deferred_probe_reason;
118 struct device *device;
119 u8 dead:1;
120};
121#define to_device_private_parent(obj) \
122 container_of(obj, struct device_private, knode_parent)
123#define to_device_private_driver(obj) \
124 container_of(obj, struct device_private, knode_driver)
125#define to_device_private_bus(obj) \
126 container_of(obj, struct device_private, knode_bus)
127#define to_device_private_class(obj) \
128 container_of(obj, struct device_private, knode_class)
129
130/* initialisation functions */
131int devices_init(void);
132int buses_init(void);
133int classes_init(void);
134int firmware_init(void);
135#ifdef CONFIG_SYS_HYPERVISOR
136int hypervisor_init(void);
137#else
138static inline int hypervisor_init(void) { return 0; }
139#endif
140int platform_bus_init(void);
141int faux_bus_init(void);
142void cpu_dev_init(void);
143void container_dev_init(void);
144#ifdef CONFIG_AUXILIARY_BUS
145void auxiliary_bus_init(void);
146#else
147static inline void auxiliary_bus_init(void) { }
148#endif
149
150struct kobject *virtual_device_parent(void);
151
152int bus_add_device(struct device *dev);
153void bus_probe_device(struct device *dev);
154void bus_remove_device(struct device *dev);
155void bus_notify(struct device *dev, enum bus_notifier_event value);
156bool bus_is_registered(const struct bus_type *bus);
157
158int bus_add_driver(struct device_driver *drv);
159void bus_remove_driver(struct device_driver *drv);
160void device_release_driver_internal(struct device *dev, const struct device_driver *drv,
161 struct device *parent);
162
163void driver_detach(const struct device_driver *drv);
164void driver_deferred_probe_del(struct device *dev);
165void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf);
166static inline int driver_match_device(const struct device_driver *drv,
167 struct device *dev)
168{
169 return drv->bus->match ? drv->bus->match(dev, drv) : 1;
170}
171
172static inline void dev_sync_state(struct device *dev)
173{
174 if (dev->bus->sync_state)
175 dev->bus->sync_state(dev);
176 else if (dev->driver && dev->driver->sync_state)
177 dev->driver->sync_state(dev);
178}
179
180int driver_add_groups(const struct device_driver *drv, const struct attribute_group **groups);
181void driver_remove_groups(const struct device_driver *drv, const struct attribute_group **groups);
182void device_driver_detach(struct device *dev);
183
184static inline void device_set_driver(struct device *dev, const struct device_driver *drv)
185{
186 /*
187 * Majority (all?) read accesses to dev->driver happens either
188 * while holding device lock or in bus/driver code that is only
189 * invoked when the device is bound to a driver and there is no
190 * concern of the pointer being changed while it is being read.
191 * However when reading device's uevent file we read driver pointer
192 * without taking device lock (so we do not block there for
193 * arbitrary amount of time). We use WRITE_ONCE() here to prevent
194 * tearing so that READ_ONCE() can safely be used in uevent code.
195 */
196 // FIXME - this cast should not be needed "soon"
197 WRITE_ONCE(dev->driver, (struct device_driver *)drv);
198}
199
200int devres_release_all(struct device *dev);
201void device_block_probing(void);
202void device_unblock_probing(void);
203void deferred_probe_extend_timeout(void);
204void driver_deferred_probe_trigger(void);
205const char *device_get_devnode(const struct device *dev, umode_t *mode,
206 kuid_t *uid, kgid_t *gid, const char **tmp);
207
208/* /sys/devices directory */
209extern struct kset *devices_kset;
210void devices_kset_move_last(struct device *dev);
211
212#if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS)
213int module_add_driver(struct module *mod, const struct device_driver *drv);
214void module_remove_driver(const struct device_driver *drv);
215#else
216static inline int module_add_driver(struct module *mod,
217 struct device_driver *drv)
218{
219 return 0;
220}
221static inline void module_remove_driver(struct device_driver *drv) { }
222#endif
223
224#ifdef CONFIG_DEVTMPFS
225int devtmpfs_init(void);
226#else
227static inline int devtmpfs_init(void) { return 0; }
228#endif
229
230#ifdef CONFIG_BLOCK
231extern const struct class block_class;
232static inline bool is_blockdev(struct device *dev)
233{
234 return dev->class == &block_class;
235}
236#else
237static inline bool is_blockdev(struct device *dev) { return false; }
238#endif
239
240/* Device links support */
241int device_links_read_lock(void);
242void device_links_read_unlock(int idx);
243int device_links_read_lock_held(void);
244int device_links_check_suppliers(struct device *dev);
245void device_links_force_bind(struct device *dev);
246void device_links_driver_bound(struct device *dev);
247void device_links_driver_cleanup(struct device *dev);
248void device_links_no_driver(struct device *dev);
249bool device_links_busy(struct device *dev);
250void device_links_unbind_consumers(struct device *dev);
251void fw_devlink_drivers_done(void);
252void fw_devlink_probing_done(void);
253
254/* device pm support */
255void device_pm_move_to_tail(struct device *dev);
256
257#ifdef CONFIG_DEVTMPFS
258int devtmpfs_create_node(struct device *dev);
259int devtmpfs_delete_node(struct device *dev);
260#else
261static inline int devtmpfs_create_node(struct device *dev) { return 0; }
262static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
263#endif
264
265void software_node_notify(struct device *dev);
266void software_node_notify_remove(struct device *dev);
267

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source code of linux/drivers/base/base.h