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 #ifdef CONFIG_RUST 89 /** 90 * struct driver_type - Representation of a Rust driver type. 91 */ 92 struct 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 */ 122 struct 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 */ 147 int devices_init(void); 148 int buses_init(void); 149 int classes_init(void); 150 int firmware_init(void); 151 #ifdef CONFIG_SYS_HYPERVISOR 152 int hypervisor_init(void); 153 #else 154 static inline int hypervisor_init(void) { return 0; } 155 #endif 156 int platform_bus_init(void); 157 int faux_bus_init(void); 158 void cpu_dev_init(void); 159 void container_dev_init(void); 160 #ifdef CONFIG_AUXILIARY_BUS 161 void auxiliary_bus_init(void); 162 #else 163 static inline void auxiliary_bus_init(void) { } 164 #endif 165 166 struct kobject *virtual_device_parent(void); 167 168 int bus_add_device(struct device *dev); 169 void bus_probe_device(struct device *dev); 170 void bus_remove_device(struct device *dev); 171 void bus_notify(struct device *dev, enum bus_notifier_event value); 172 bool bus_is_registered(const struct bus_type *bus); 173 174 int bus_add_driver(struct device_driver *drv); 175 void bus_remove_driver(struct device_driver *drv); 176 void device_release_driver_internal(struct device *dev, const struct device_driver *drv, 177 struct device *parent); 178 179 void driver_detach(const struct device_driver *drv); 180 void driver_deferred_probe_del(struct device *dev); 181 void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf); 182 static inline int driver_match_device_locked(const struct device_driver *drv, 183 struct device *dev) 184 { 185 device_lock_assert(dev); 186 187 return drv->bus->match ? drv->bus->match(dev, drv) : 1; 188 } 189 190 static inline int driver_match_device(const struct device_driver *drv, 191 struct device *dev) 192 { 193 guard(device)(dev); 194 return driver_match_device_locked(drv, dev); 195 } 196 197 static inline void dev_sync_state(struct device *dev) 198 { 199 if (dev->bus->sync_state) 200 dev->bus->sync_state(dev); 201 else if (dev->driver && dev->driver->sync_state) 202 dev->driver->sync_state(dev); 203 } 204 205 int driver_add_groups(const struct device_driver *drv, const struct attribute_group **groups); 206 void driver_remove_groups(const struct device_driver *drv, const struct attribute_group **groups); 207 void device_driver_detach(struct device *dev); 208 209 static inline void device_set_driver(struct device *dev, const struct device_driver *drv) 210 { 211 /* 212 * Majority (all?) read accesses to dev->driver happens either 213 * while holding device lock or in bus/driver code that is only 214 * invoked when the device is bound to a driver and there is no 215 * concern of the pointer being changed while it is being read. 216 * However when reading device's uevent file we read driver pointer 217 * without taking device lock (so we do not block there for 218 * arbitrary amount of time). We use WRITE_ONCE() here to prevent 219 * tearing so that READ_ONCE() can safely be used in uevent code. 220 */ 221 // FIXME - this cast should not be needed "soon" 222 WRITE_ONCE(dev->driver, (struct device_driver *)drv); 223 } 224 225 void devres_for_each_res(struct device *dev, dr_release_t release, 226 dr_match_t match, void *match_data, 227 void (*fn)(struct device *, void *, void *), 228 void *data); 229 int devres_release_all(struct device *dev); 230 void device_block_probing(void); 231 void device_unblock_probing(void); 232 void deferred_probe_extend_timeout(void); 233 void driver_deferred_probe_trigger(void); 234 const char *device_get_devnode(const struct device *dev, umode_t *mode, 235 kuid_t *uid, kgid_t *gid, const char **tmp); 236 237 /* /sys/devices directory */ 238 extern struct kset *devices_kset; 239 void devices_kset_move_last(struct device *dev); 240 241 #if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS) 242 int module_add_driver(struct module *mod, const struct device_driver *drv); 243 void module_remove_driver(const struct device_driver *drv); 244 #else 245 static inline int module_add_driver(struct module *mod, 246 struct device_driver *drv) 247 { 248 return 0; 249 } 250 static inline void module_remove_driver(struct device_driver *drv) { } 251 #endif 252 253 #ifdef CONFIG_DEVTMPFS 254 int devtmpfs_init(void); 255 #else 256 static inline int devtmpfs_init(void) { return 0; } 257 #endif 258 259 #ifdef CONFIG_BLOCK 260 extern const struct class block_class; 261 static inline bool is_blockdev(struct device *dev) 262 { 263 return dev->class == &block_class; 264 } 265 #else 266 static inline bool is_blockdev(struct device *dev) { return false; } 267 #endif 268 269 /* Device links support */ 270 int device_links_read_lock(void); 271 void device_links_read_unlock(int idx); 272 int device_links_read_lock_held(void); 273 int device_links_check_suppliers(struct device *dev); 274 void device_links_force_bind(struct device *dev); 275 void device_links_driver_bound(struct device *dev); 276 void device_links_driver_cleanup(struct device *dev); 277 void device_links_no_driver(struct device *dev); 278 bool device_links_busy(struct device *dev); 279 void device_links_unbind_consumers(struct device *dev); 280 bool device_link_flag_is_sync_state_only(u32 flags); 281 void fw_devlink_drivers_done(void); 282 void fw_devlink_probing_done(void); 283 284 #define dev_for_each_link_to_supplier(__link, __dev) \ 285 list_for_each_entry_srcu(__link, &(__dev)->links.suppliers, c_node, \ 286 device_links_read_lock_held()) 287 288 #define dev_for_each_link_to_consumer(__link, __dev) \ 289 list_for_each_entry_srcu(__link, &(__dev)->links.consumers, s_node, \ 290 device_links_read_lock_held()) 291 292 /* device pm support */ 293 void device_pm_move_to_tail(struct device *dev); 294 295 #ifdef CONFIG_DEVTMPFS 296 int devtmpfs_create_node(struct device *dev); 297 int devtmpfs_delete_node(struct device *dev); 298 #else 299 static inline int devtmpfs_create_node(struct device *dev) { return 0; } 300 static inline int devtmpfs_delete_node(struct device *dev) { return 0; } 301 #endif 302 303 void software_node_notify(struct device *dev); 304 void software_node_notify_remove(struct device *dev); 305