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 */ 42 struct 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 63 static inline struct subsys_private *subsys_get(struct subsys_private *sp) 64 { 65 if (sp) 66 kset_get(&sp->subsys); 67 return sp; 68 } 69 70 static inline void subsys_put(struct subsys_private *sp) 71 { 72 if (sp) 73 kset_put(&sp->subsys); 74 } 75 76 struct subsys_private *bus_to_subsys(const struct bus_type *bus); 77 struct subsys_private *class_to_subsys(const struct class *class); 78 79 struct 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 */ 109 struct 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 */ 131 int devices_init(void); 132 int buses_init(void); 133 int classes_init(void); 134 int firmware_init(void); 135 #ifdef CONFIG_SYS_HYPERVISOR 136 int hypervisor_init(void); 137 #else 138 static inline int hypervisor_init(void) { return 0; } 139 #endif 140 int platform_bus_init(void); 141 int faux_bus_init(void); 142 void cpu_dev_init(void); 143 void container_dev_init(void); 144 #ifdef CONFIG_AUXILIARY_BUS 145 void auxiliary_bus_init(void); 146 #else 147 static inline void auxiliary_bus_init(void) { } 148 #endif 149 150 struct kobject *virtual_device_parent(void); 151 152 int bus_add_device(struct device *dev); 153 void bus_probe_device(struct device *dev); 154 void bus_remove_device(struct device *dev); 155 void bus_notify(struct device *dev, enum bus_notifier_event value); 156 bool bus_is_registered(const struct bus_type *bus); 157 158 int bus_add_driver(struct device_driver *drv); 159 void bus_remove_driver(struct device_driver *drv); 160 void device_release_driver_internal(struct device *dev, const struct device_driver *drv, 161 struct device *parent); 162 163 void driver_detach(const struct device_driver *drv); 164 void driver_deferred_probe_del(struct device *dev); 165 void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf); 166 static 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 } 171 172 static 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 } 179 180 int driver_add_groups(const struct device_driver *drv, const struct attribute_group **groups); 181 void driver_remove_groups(const struct device_driver *drv, const struct attribute_group **groups); 182 void device_driver_detach(struct device *dev); 183 184 static 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 } 199 200 int devres_release_all(struct device *dev); 201 void device_block_probing(void); 202 void device_unblock_probing(void); 203 void deferred_probe_extend_timeout(void); 204 void driver_deferred_probe_trigger(void); 205 const 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 */ 209 extern struct kset *devices_kset; 210 void devices_kset_move_last(struct device *dev); 211 212 #if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS) 213 int module_add_driver(struct module *mod, const struct device_driver *drv); 214 void module_remove_driver(const struct device_driver *drv); 215 #else 216 static inline int module_add_driver(struct module *mod, 217 struct device_driver *drv) 218 { 219 return 0; 220 } 221 static inline void module_remove_driver(struct device_driver *drv) { } 222 #endif 223 224 #ifdef CONFIG_DEVTMPFS 225 int devtmpfs_init(void); 226 #else 227 static inline int devtmpfs_init(void) { return 0; } 228 #endif 229 230 #ifdef CONFIG_BLOCK 231 extern const struct class block_class; 232 static inline bool is_blockdev(struct device *dev) 233 { 234 return dev->class == &block_class; 235 } 236 #else 237 static inline bool is_blockdev(struct device *dev) { return false; } 238 #endif 239 240 /* Device links support */ 241 int device_links_read_lock(void); 242 void device_links_read_unlock(int idx); 243 int device_links_read_lock_held(void); 244 int device_links_check_suppliers(struct device *dev); 245 void device_links_force_bind(struct device *dev); 246 void device_links_driver_bound(struct device *dev); 247 void device_links_driver_cleanup(struct device *dev); 248 void device_links_no_driver(struct device *dev); 249 bool device_links_busy(struct device *dev); 250 void device_links_unbind_consumers(struct device *dev); 251 void fw_devlink_drivers_done(void); 252 void fw_devlink_probing_done(void); 253 254 /* device pm support */ 255 void device_pm_move_to_tail(struct device *dev); 256 257 #ifdef CONFIG_DEVTMPFS 258 int devtmpfs_create_node(struct device *dev); 259 int devtmpfs_delete_node(struct device *dev); 260 #else 261 static inline int devtmpfs_create_node(struct device *dev) { return 0; } 262 static inline int devtmpfs_delete_node(struct device *dev) { return 0; } 263 #endif 264 265 void software_node_notify(struct device *dev); 266 void software_node_notify_remove(struct device *dev); 267