base.h

  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(&sp->subsys);
 67	return sp;
 68}
 69
 70static inline void subsys_put(struct subsys_private *sp)
 71{
 72	if (sp)
 73		kset_put(&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#ifdef CONFIG_RUST
 89/**
 90 * struct driver_type - Representation of a Rust driver type.
 91 */
 92struct driver_type {
 93	/**
 94	 * @id: Representation of core::any::TypeId.
 95	 */
 96	u8 id[16];
 97} __packed;
 98#endif
 99
100/**
101 * struct device_private - structure to hold the private to the driver core portions of the device structure.
102 *
103 * @klist_children - klist containing all children of this device
104 * @knode_parent - node in sibling list
105 * @knode_driver - node in driver list
106 * @knode_bus - node in bus list
107 * @knode_class - node in class list
108 * @deferred_probe - entry in deferred_probe_list which is used to retry the
109 *	binding of drivers which were unable to get all the resources needed by
110 *	the device; typically because it depends on another driver getting
111 *	probed first.
112 * @async_driver - pointer to device driver awaiting probe via async_probe
113 * @device - pointer back to the struct device that this structure is
114 * associated with.
115 * @driver_type - The type of the bound Rust driver.
116 * @dead - This device is currently either in the process of or has been
117 *	removed from the system. Any asynchronous events scheduled for this
118 *	device should exit without taking any action.
119 *
120 * Nothing outside of the driver core should ever touch these fields.
121 */
122struct device_private {
123	struct klist klist_children;
124	struct klist_node knode_parent;
125	struct klist_node knode_driver;
126	struct klist_node knode_bus;
127	struct klist_node knode_class;
128	struct list_head deferred_probe;
129	const struct device_driver *async_driver;
130	char *deferred_probe_reason;
131	struct device *device;
132#ifdef CONFIG_RUST
133	struct driver_type driver_type;
134#endif
135	u8 dead:1;
136};
137#define to_device_private_parent(obj)	\
138	container_of(obj, struct device_private, knode_parent)
139#define to_device_private_driver(obj)	\
140	container_of(obj, struct device_private, knode_driver)
141#define to_device_private_bus(obj)	\
142	container_of(obj, struct device_private, knode_bus)
143#define to_device_private_class(obj)	\
144	container_of(obj, struct device_private, knode_class)
145
146/* initialisation functions */
147int devices_init(void);
148int buses_init(void);
149int classes_init(void);
150int firmware_init(void);
151#ifdef CONFIG_SYS_HYPERVISOR
152int hypervisor_init(void);
153#else
154static inline int hypervisor_init(void) { return 0; }
155#endif
156int platform_bus_init(void);
157int faux_bus_init(void);
158void cpu_dev_init(void);
159void container_dev_init(void);
160#ifdef CONFIG_AUXILIARY_BUS
161void auxiliary_bus_init(void);
162#else
163static inline void auxiliary_bus_init(void) { }
164#endif
165
166struct kobject *virtual_device_parent(void);
167
168int bus_add_device(struct device *dev);
169void bus_probe_device(struct device *dev);
170void bus_remove_device(struct device *dev);
171void bus_notify(struct device *dev, enum bus_notifier_event value);
172bool bus_is_registered(const struct bus_type *bus);
173
174int bus_add_driver(struct device_driver *drv);
175void bus_remove_driver(struct device_driver *drv);
176void device_release_driver_internal(struct device *dev, const struct device_driver *drv,
177				    struct device *parent);
178
179void driver_detach(const struct device_driver *drv);
180void driver_deferred_probe_del(struct device *dev);
181void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf);
182static inline int driver_match_device(const struct device_driver *drv,
183				      struct device *dev)
184{
185	return drv->bus->match ? drv->bus->match(dev, drv) : 1;
186}
187
188static inline void dev_sync_state(struct device *dev)
189{
190	if (dev->bus->sync_state)
191		dev->bus->sync_state(dev);
192	else if (dev->driver && dev->driver->sync_state)
193		dev->driver->sync_state(dev);
194}
195
196int driver_add_groups(const struct device_driver *drv, const struct attribute_group **groups);
197void driver_remove_groups(const struct device_driver *drv, const struct attribute_group **groups);
198void device_driver_detach(struct device *dev);
199
200static inline void device_set_driver(struct device *dev, const struct device_driver *drv)
201{
202	/*
203	 * Majority (all?) read accesses to dev->driver happens either
204	 * while holding device lock or in bus/driver code that is only
205	 * invoked when the device is bound to a driver and there is no
206	 * concern of the pointer being changed while it is being read.
207	 * However when reading device's uevent file we read driver pointer
208	 * without taking device lock (so we do not block there for
209	 * arbitrary amount of time). We use WRITE_ONCE() here to prevent
210	 * tearing so that READ_ONCE() can safely be used in uevent code.
211	 */
212	// FIXME - this cast should not be needed "soon"
213	WRITE_ONCE(dev->driver, (struct device_driver *)drv);
214}
215
216int devres_release_all(struct device *dev);
217void device_block_probing(void);
218void device_unblock_probing(void);
219void deferred_probe_extend_timeout(void);
220void driver_deferred_probe_trigger(void);
221const char *device_get_devnode(const struct device *dev, umode_t *mode,
222			       kuid_t *uid, kgid_t *gid, const char **tmp);
223
224/* /sys/devices directory */
225extern struct kset *devices_kset;
226void devices_kset_move_last(struct device *dev);
227
228#if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS)
229int module_add_driver(struct module *mod, const struct device_driver *drv);
230void module_remove_driver(const struct device_driver *drv);
231#else
232static inline int module_add_driver(struct module *mod,
233				    struct device_driver *drv)
234{
235	return 0;
236}
237static inline void module_remove_driver(struct device_driver *drv) { }
238#endif
239
240#ifdef CONFIG_DEVTMPFS
241int devtmpfs_init(void);
242#else
243static inline int devtmpfs_init(void) { return 0; }
244#endif
245
246#ifdef CONFIG_BLOCK
247extern const struct class block_class;
248static inline bool is_blockdev(struct device *dev)
249{
250	return dev->class == &block_class;
251}
252#else
253static inline bool is_blockdev(struct device *dev) { return false; }
254#endif
255
256/* Device links support */
257int device_links_read_lock(void);
258void device_links_read_unlock(int idx);
259int device_links_read_lock_held(void);
260int device_links_check_suppliers(struct device *dev);
261void device_links_force_bind(struct device *dev);
262void device_links_driver_bound(struct device *dev);
263void device_links_driver_cleanup(struct device *dev);
264void device_links_no_driver(struct device *dev);
265bool device_links_busy(struct device *dev);
266void device_links_unbind_consumers(struct device *dev);
267bool device_link_flag_is_sync_state_only(u32 flags);
268void fw_devlink_drivers_done(void);
269void fw_devlink_probing_done(void);
270
271#define dev_for_each_link_to_supplier(__link, __dev)	\
272	list_for_each_entry_srcu(__link, &(__dev)->links.suppliers, c_node, \
273				 device_links_read_lock_held())
274
275#define dev_for_each_link_to_consumer(__link, __dev)	\
276	list_for_each_entry_srcu(__link, &(__dev)->links.consumers, s_node, \
277				 device_links_read_lock_held())
278
279/* device pm support */
280void device_pm_move_to_tail(struct device *dev);
281
282#ifdef CONFIG_DEVTMPFS
283int devtmpfs_create_node(struct device *dev);
284int devtmpfs_delete_node(struct device *dev);
285#else
286static inline int devtmpfs_create_node(struct device *dev) { return 0; }
287static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
288#endif
289
290void software_node_notify(struct device *dev);
291void software_node_notify_remove(struct device *dev);