xref: /linux-6.15/include/linux/device.h (revision c131bd0b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * device.h - generic, centralized driver model
4  *
5  * Copyright (c) 2001-2003 Patrick Mochel <[email protected]>
6  * Copyright (c) 2004-2009 Greg Kroah-Hartman <[email protected]>
7  * Copyright (c) 2008-2009 Novell Inc.
8  *
9  * See Documentation/driver-api/driver-model/ for more information.
10  */
11 
12 #ifndef _DEVICE_H_
13 #define _DEVICE_H_
14 
15 #include <linux/dev_printk.h>
16 #include <linux/energy_model.h>
17 #include <linux/ioport.h>
18 #include <linux/kobject.h>
19 #include <linux/klist.h>
20 #include <linux/list.h>
21 #include <linux/lockdep.h>
22 #include <linux/compiler.h>
23 #include <linux/types.h>
24 #include <linux/mutex.h>
25 #include <linux/pm.h>
26 #include <linux/atomic.h>
27 #include <linux/uidgid.h>
28 #include <linux/gfp.h>
29 #include <linux/overflow.h>
30 #include <linux/device/bus.h>
31 #include <linux/device/class.h>
32 #include <linux/device/driver.h>
33 #include <asm/device.h>
34 
35 struct device;
36 struct device_private;
37 struct device_driver;
38 struct driver_private;
39 struct module;
40 struct class;
41 struct subsys_private;
42 struct device_node;
43 struct fwnode_handle;
44 struct iommu_ops;
45 struct iommu_group;
46 struct dev_pin_info;
47 struct dev_iommu;
48 
49 /**
50  * struct subsys_interface - interfaces to device functions
51  * @name:       name of the device function
52  * @subsys:     subsytem of the devices to attach to
53  * @node:       the list of functions registered at the subsystem
54  * @add_dev:    device hookup to device function handler
55  * @remove_dev: device hookup to device function handler
56  *
57  * Simple interfaces attached to a subsystem. Multiple interfaces can
58  * attach to a subsystem and its devices. Unlike drivers, they do not
59  * exclusively claim or control devices. Interfaces usually represent
60  * a specific functionality of a subsystem/class of devices.
61  */
62 struct subsys_interface {
63 	const char *name;
64 	struct bus_type *subsys;
65 	struct list_head node;
66 	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
67 	void (*remove_dev)(struct device *dev, struct subsys_interface *sif);
68 };
69 
70 int subsys_interface_register(struct subsys_interface *sif);
71 void subsys_interface_unregister(struct subsys_interface *sif);
72 
73 int subsys_system_register(struct bus_type *subsys,
74 			   const struct attribute_group **groups);
75 int subsys_virtual_register(struct bus_type *subsys,
76 			    const struct attribute_group **groups);
77 
78 /*
79  * The type of device, "struct device" is embedded in. A class
80  * or bus can contain devices of different types
81  * like "partitions" and "disks", "mouse" and "event".
82  * This identifies the device type and carries type-specific
83  * information, equivalent to the kobj_type of a kobject.
84  * If "name" is specified, the uevent will contain it in
85  * the DEVTYPE variable.
86  */
87 struct device_type {
88 	const char *name;
89 	const struct attribute_group **groups;
90 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
91 	char *(*devnode)(struct device *dev, umode_t *mode,
92 			 kuid_t *uid, kgid_t *gid);
93 	void (*release)(struct device *dev);
94 
95 	const struct dev_pm_ops *pm;
96 };
97 
98 /* interface for exporting device attributes */
99 struct device_attribute {
100 	struct attribute	attr;
101 	ssize_t (*show)(struct device *dev, struct device_attribute *attr,
102 			char *buf);
103 	ssize_t (*store)(struct device *dev, struct device_attribute *attr,
104 			 const char *buf, size_t count);
105 };
106 
107 struct dev_ext_attribute {
108 	struct device_attribute attr;
109 	void *var;
110 };
111 
112 ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
113 			  char *buf);
114 ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
115 			   const char *buf, size_t count);
116 ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
117 			char *buf);
118 ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
119 			 const char *buf, size_t count);
120 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
121 			char *buf);
122 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
123 			 const char *buf, size_t count);
124 
125 #define DEVICE_ATTR(_name, _mode, _show, _store) \
126 	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
127 #define DEVICE_ATTR_PREALLOC(_name, _mode, _show, _store) \
128 	struct device_attribute dev_attr_##_name = \
129 		__ATTR_PREALLOC(_name, _mode, _show, _store)
130 #define DEVICE_ATTR_RW(_name) \
131 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
132 #define DEVICE_ATTR_ADMIN_RW(_name) \
133 	struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
134 #define DEVICE_ATTR_RO(_name) \
135 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
136 #define DEVICE_ATTR_ADMIN_RO(_name) \
137 	struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
138 #define DEVICE_ATTR_WO(_name) \
139 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
140 #define DEVICE_ULONG_ATTR(_name, _mode, _var) \
141 	struct dev_ext_attribute dev_attr_##_name = \
142 		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
143 #define DEVICE_INT_ATTR(_name, _mode, _var) \
144 	struct dev_ext_attribute dev_attr_##_name = \
145 		{ __ATTR(_name, _mode, device_show_int, device_store_int), &(_var) }
146 #define DEVICE_BOOL_ATTR(_name, _mode, _var) \
147 	struct dev_ext_attribute dev_attr_##_name = \
148 		{ __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) }
149 #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
150 	struct device_attribute dev_attr_##_name =		\
151 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
152 
153 int device_create_file(struct device *device,
154 		       const struct device_attribute *entry);
155 void device_remove_file(struct device *dev,
156 			const struct device_attribute *attr);
157 bool device_remove_file_self(struct device *dev,
158 			     const struct device_attribute *attr);
159 int __must_check device_create_bin_file(struct device *dev,
160 					const struct bin_attribute *attr);
161 void device_remove_bin_file(struct device *dev,
162 			    const struct bin_attribute *attr);
163 
164 /* device resource management */
165 typedef void (*dr_release_t)(struct device *dev, void *res);
166 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
167 
168 #ifdef CONFIG_DEBUG_DEVRES
169 void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
170 			  int nid, const char *name) __malloc;
171 #define devres_alloc(release, size, gfp) \
172 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
173 #define devres_alloc_node(release, size, gfp, nid) \
174 	__devres_alloc_node(release, size, gfp, nid, #release)
175 #else
176 void *devres_alloc_node(dr_release_t release, size_t size,
177 			gfp_t gfp, int nid) __malloc;
178 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
179 {
180 	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
181 }
182 #endif
183 
184 void devres_for_each_res(struct device *dev, dr_release_t release,
185 			 dr_match_t match, void *match_data,
186 			 void (*fn)(struct device *, void *, void *),
187 			 void *data);
188 void devres_free(void *res);
189 void devres_add(struct device *dev, void *res);
190 void *devres_find(struct device *dev, dr_release_t release,
191 		  dr_match_t match, void *match_data);
192 void *devres_get(struct device *dev, void *new_res,
193 		 dr_match_t match, void *match_data);
194 void *devres_remove(struct device *dev, dr_release_t release,
195 		    dr_match_t match, void *match_data);
196 int devres_destroy(struct device *dev, dr_release_t release,
197 		   dr_match_t match, void *match_data);
198 int devres_release(struct device *dev, dr_release_t release,
199 		   dr_match_t match, void *match_data);
200 
201 /* devres group */
202 void * __must_check devres_open_group(struct device *dev, void *id, gfp_t gfp);
203 void devres_close_group(struct device *dev, void *id);
204 void devres_remove_group(struct device *dev, void *id);
205 int devres_release_group(struct device *dev, void *id);
206 
207 /* managed devm_k.alloc/kfree for device drivers */
208 void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
209 void *devm_krealloc(struct device *dev, void *ptr, size_t size,
210 		    gfp_t gfp) __must_check;
211 __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
212 				     const char *fmt, va_list ap) __malloc;
213 __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
214 				    const char *fmt, ...) __malloc;
215 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
216 {
217 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
218 }
219 static inline void *devm_kmalloc_array(struct device *dev,
220 				       size_t n, size_t size, gfp_t flags)
221 {
222 	size_t bytes;
223 
224 	if (unlikely(check_mul_overflow(n, size, &bytes)))
225 		return NULL;
226 
227 	return devm_kmalloc(dev, bytes, flags);
228 }
229 static inline void *devm_kcalloc(struct device *dev,
230 				 size_t n, size_t size, gfp_t flags)
231 {
232 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
233 }
234 void devm_kfree(struct device *dev, const void *p);
235 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
236 const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
237 void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);
238 
239 unsigned long devm_get_free_pages(struct device *dev,
240 				  gfp_t gfp_mask, unsigned int order);
241 void devm_free_pages(struct device *dev, unsigned long addr);
242 
243 void __iomem *devm_ioremap_resource(struct device *dev,
244 				    const struct resource *res);
245 void __iomem *devm_ioremap_resource_wc(struct device *dev,
246 				       const struct resource *res);
247 
248 void __iomem *devm_of_iomap(struct device *dev,
249 			    struct device_node *node, int index,
250 			    resource_size_t *size);
251 
252 /* allows to add/remove a custom action to devres stack */
253 int devm_add_action(struct device *dev, void (*action)(void *), void *data);
254 void devm_remove_action(struct device *dev, void (*action)(void *), void *data);
255 void devm_release_action(struct device *dev, void (*action)(void *), void *data);
256 
257 static inline int devm_add_action_or_reset(struct device *dev,
258 					   void (*action)(void *), void *data)
259 {
260 	int ret;
261 
262 	ret = devm_add_action(dev, action, data);
263 	if (ret)
264 		action(data);
265 
266 	return ret;
267 }
268 
269 /**
270  * devm_alloc_percpu - Resource-managed alloc_percpu
271  * @dev: Device to allocate per-cpu memory for
272  * @type: Type to allocate per-cpu memory for
273  *
274  * Managed alloc_percpu. Per-cpu memory allocated with this function is
275  * automatically freed on driver detach.
276  *
277  * RETURNS:
278  * Pointer to allocated memory on success, NULL on failure.
279  */
280 #define devm_alloc_percpu(dev, type)      \
281 	((typeof(type) __percpu *)__devm_alloc_percpu((dev), sizeof(type), \
282 						      __alignof__(type)))
283 
284 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
285 				   size_t align);
286 void devm_free_percpu(struct device *dev, void __percpu *pdata);
287 
288 struct device_dma_parameters {
289 	/*
290 	 * a low level driver may set these to teach IOMMU code about
291 	 * sg limitations.
292 	 */
293 	unsigned int max_segment_size;
294 	unsigned long segment_boundary_mask;
295 };
296 
297 /**
298  * enum device_link_state - Device link states.
299  * @DL_STATE_NONE: The presence of the drivers is not being tracked.
300  * @DL_STATE_DORMANT: None of the supplier/consumer drivers is present.
301  * @DL_STATE_AVAILABLE: The supplier driver is present, but the consumer is not.
302  * @DL_STATE_CONSUMER_PROBE: The consumer is probing (supplier driver present).
303  * @DL_STATE_ACTIVE: Both the supplier and consumer drivers are present.
304  * @DL_STATE_SUPPLIER_UNBIND: The supplier driver is unbinding.
305  */
306 enum device_link_state {
307 	DL_STATE_NONE = -1,
308 	DL_STATE_DORMANT = 0,
309 	DL_STATE_AVAILABLE,
310 	DL_STATE_CONSUMER_PROBE,
311 	DL_STATE_ACTIVE,
312 	DL_STATE_SUPPLIER_UNBIND,
313 };
314 
315 /*
316  * Device link flags.
317  *
318  * STATELESS: The core will not remove this link automatically.
319  * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind.
320  * PM_RUNTIME: If set, the runtime PM framework will use this link.
321  * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation.
322  * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind.
323  * AUTOPROBE_CONSUMER: Probe consumer driver automatically after supplier binds.
324  * MANAGED: The core tracks presence of supplier/consumer drivers (internal).
325  * SYNC_STATE_ONLY: Link only affects sync_state() behavior.
326  * INFERRED: Inferred from data (eg: firmware) and not from driver actions.
327  */
328 #define DL_FLAG_STATELESS		BIT(0)
329 #define DL_FLAG_AUTOREMOVE_CONSUMER	BIT(1)
330 #define DL_FLAG_PM_RUNTIME		BIT(2)
331 #define DL_FLAG_RPM_ACTIVE		BIT(3)
332 #define DL_FLAG_AUTOREMOVE_SUPPLIER	BIT(4)
333 #define DL_FLAG_AUTOPROBE_CONSUMER	BIT(5)
334 #define DL_FLAG_MANAGED			BIT(6)
335 #define DL_FLAG_SYNC_STATE_ONLY		BIT(7)
336 #define DL_FLAG_INFERRED		BIT(8)
337 
338 /**
339  * enum dl_dev_state - Device driver presence tracking information.
340  * @DL_DEV_NO_DRIVER: There is no driver attached to the device.
341  * @DL_DEV_PROBING: A driver is probing.
342  * @DL_DEV_DRIVER_BOUND: The driver has been bound to the device.
343  * @DL_DEV_UNBINDING: The driver is unbinding from the device.
344  */
345 enum dl_dev_state {
346 	DL_DEV_NO_DRIVER = 0,
347 	DL_DEV_PROBING,
348 	DL_DEV_DRIVER_BOUND,
349 	DL_DEV_UNBINDING,
350 };
351 
352 /**
353  * struct dev_links_info - Device data related to device links.
354  * @suppliers: List of links to supplier devices.
355  * @consumers: List of links to consumer devices.
356  * @defer_sync: Hook to global list of devices that have deferred sync_state.
357  * @status: Driver status information.
358  */
359 struct dev_links_info {
360 	struct list_head suppliers;
361 	struct list_head consumers;
362 	struct list_head defer_sync;
363 	enum dl_dev_state status;
364 };
365 
366 /**
367  * struct device - The basic device structure
368  * @parent:	The device's "parent" device, the device to which it is attached.
369  * 		In most cases, a parent device is some sort of bus or host
370  * 		controller. If parent is NULL, the device, is a top-level device,
371  * 		which is not usually what you want.
372  * @p:		Holds the private data of the driver core portions of the device.
373  * 		See the comment of the struct device_private for detail.
374  * @kobj:	A top-level, abstract class from which other classes are derived.
375  * @init_name:	Initial name of the device.
376  * @type:	The type of device.
377  * 		This identifies the device type and carries type-specific
378  * 		information.
379  * @mutex:	Mutex to synchronize calls to its driver.
380  * @lockdep_mutex: An optional debug lock that a subsystem can use as a
381  * 		peer lock to gain localized lockdep coverage of the device_lock.
382  * @bus:	Type of bus device is on.
383  * @driver:	Which driver has allocated this
384  * @platform_data: Platform data specific to the device.
385  * 		Example: For devices on custom boards, as typical of embedded
386  * 		and SOC based hardware, Linux often uses platform_data to point
387  * 		to board-specific structures describing devices and how they
388  * 		are wired.  That can include what ports are available, chip
389  * 		variants, which GPIO pins act in what additional roles, and so
390  * 		on.  This shrinks the "Board Support Packages" (BSPs) and
391  * 		minimizes board-specific #ifdefs in drivers.
392  * @driver_data: Private pointer for driver specific info.
393  * @links:	Links to suppliers and consumers of this device.
394  * @power:	For device power management.
395  *		See Documentation/driver-api/pm/devices.rst for details.
396  * @pm_domain:	Provide callbacks that are executed during system suspend,
397  * 		hibernation, system resume and during runtime PM transitions
398  * 		along with subsystem-level and driver-level callbacks.
399  * @em_pd:	device's energy model performance domain
400  * @pins:	For device pin management.
401  *		See Documentation/driver-api/pinctl.rst for details.
402  * @msi_list:	Hosts MSI descriptors
403  * @msi_domain: The generic MSI domain this device is using.
404  * @numa_node:	NUMA node this device is close to.
405  * @dma_ops:    DMA mapping operations for this device.
406  * @dma_mask:	Dma mask (if dma'ble device).
407  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
408  * 		hardware supports 64-bit addresses for consistent allocations
409  * 		such descriptors.
410  * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller
411  *		DMA limit than the device itself supports.
412  * @dma_range_map: map for DMA memory ranges relative to that of RAM
413  * @dma_parms:	A low level driver may set these to teach IOMMU code about
414  * 		segment limitations.
415  * @dma_pools:	Dma pools (if dma'ble device).
416  * @dma_mem:	Internal for coherent mem override.
417  * @cma_area:	Contiguous memory area for dma allocations
418  * @archdata:	For arch-specific additions.
419  * @of_node:	Associated device tree node.
420  * @fwnode:	Associated device node supplied by platform firmware.
421  * @devt:	For creating the sysfs "dev".
422  * @id:		device instance
423  * @devres_lock: Spinlock to protect the resource of the device.
424  * @devres_head: The resources list of the device.
425  * @knode_class: The node used to add the device to the class list.
426  * @class:	The class of the device.
427  * @groups:	Optional attribute groups.
428  * @release:	Callback to free the device after all references have
429  * 		gone away. This should be set by the allocator of the
430  * 		device (i.e. the bus driver that discovered the device).
431  * @iommu_group: IOMMU group the device belongs to.
432  * @iommu:	Per device generic IOMMU runtime data
433  *
434  * @offline_disabled: If set, the device is permanently online.
435  * @offline:	Set after successful invocation of bus type's .offline().
436  * @of_node_reused: Set if the device-tree node is shared with an ancestor
437  *              device.
438  * @state_synced: The hardware state of this device has been synced to match
439  *		  the software state of this device by calling the driver/bus
440  *		  sync_state() callback.
441  * @dma_coherent: this particular device is dma coherent, even if the
442  *		architecture supports non-coherent devices.
443  * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the
444  *		streaming DMA operations (->map_* / ->unmap_* / ->sync_*),
445  *		and optionall (if the coherent mask is large enough) also
446  *		for dma allocations.  This flag is managed by the dma ops
447  *		instance from ->dma_supported.
448  *
449  * At the lowest level, every device in a Linux system is represented by an
450  * instance of struct device. The device structure contains the information
451  * that the device model core needs to model the system. Most subsystems,
452  * however, track additional information about the devices they host. As a
453  * result, it is rare for devices to be represented by bare device structures;
454  * instead, that structure, like kobject structures, is usually embedded within
455  * a higher-level representation of the device.
456  */
457 struct device {
458 	struct kobject kobj;
459 	struct device		*parent;
460 
461 	struct device_private	*p;
462 
463 	const char		*init_name; /* initial name of the device */
464 	const struct device_type *type;
465 
466 	struct bus_type	*bus;		/* type of bus device is on */
467 	struct device_driver *driver;	/* which driver has allocated this
468 					   device */
469 	void		*platform_data;	/* Platform specific data, device
470 					   core doesn't touch it */
471 	void		*driver_data;	/* Driver data, set and get with
472 					   dev_set_drvdata/dev_get_drvdata */
473 #ifdef CONFIG_PROVE_LOCKING
474 	struct mutex		lockdep_mutex;
475 #endif
476 	struct mutex		mutex;	/* mutex to synchronize calls to
477 					 * its driver.
478 					 */
479 
480 	struct dev_links_info	links;
481 	struct dev_pm_info	power;
482 	struct dev_pm_domain	*pm_domain;
483 
484 #ifdef CONFIG_ENERGY_MODEL
485 	struct em_perf_domain	*em_pd;
486 #endif
487 
488 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
489 	struct irq_domain	*msi_domain;
490 #endif
491 #ifdef CONFIG_PINCTRL
492 	struct dev_pin_info	*pins;
493 #endif
494 #ifdef CONFIG_GENERIC_MSI_IRQ
495 	struct list_head	msi_list;
496 #endif
497 #ifdef CONFIG_DMA_OPS
498 	const struct dma_map_ops *dma_ops;
499 #endif
500 	u64		*dma_mask;	/* dma mask (if dma'able device) */
501 	u64		coherent_dma_mask;/* Like dma_mask, but for
502 					     alloc_coherent mappings as
503 					     not all hardware supports
504 					     64 bit addresses for consistent
505 					     allocations such descriptors. */
506 	u64		bus_dma_limit;	/* upstream dma constraint */
507 	const struct bus_dma_region *dma_range_map;
508 
509 	struct device_dma_parameters *dma_parms;
510 
511 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
512 
513 #ifdef CONFIG_DMA_DECLARE_COHERENT
514 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
515 					     override */
516 #endif
517 #ifdef CONFIG_DMA_CMA
518 	struct cma *cma_area;		/* contiguous memory area for dma
519 					   allocations */
520 #endif
521 	/* arch specific additions */
522 	struct dev_archdata	archdata;
523 
524 	struct device_node	*of_node; /* associated device tree node */
525 	struct fwnode_handle	*fwnode; /* firmware device node */
526 
527 #ifdef CONFIG_NUMA
528 	int		numa_node;	/* NUMA node this device is close to */
529 #endif
530 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
531 	u32			id;	/* device instance */
532 
533 	spinlock_t		devres_lock;
534 	struct list_head	devres_head;
535 
536 	struct class		*class;
537 	const struct attribute_group **groups;	/* optional groups */
538 
539 	void	(*release)(struct device *dev);
540 	struct iommu_group	*iommu_group;
541 	struct dev_iommu	*iommu;
542 
543 	bool			offline_disabled:1;
544 	bool			offline:1;
545 	bool			of_node_reused:1;
546 	bool			state_synced:1;
547 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
548     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
549     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
550 	bool			dma_coherent:1;
551 #endif
552 #ifdef CONFIG_DMA_OPS_BYPASS
553 	bool			dma_ops_bypass : 1;
554 #endif
555 };
556 
557 /**
558  * struct device_link - Device link representation.
559  * @supplier: The device on the supplier end of the link.
560  * @s_node: Hook to the supplier device's list of links to consumers.
561  * @consumer: The device on the consumer end of the link.
562  * @c_node: Hook to the consumer device's list of links to suppliers.
563  * @link_dev: device used to expose link details in sysfs
564  * @status: The state of the link (with respect to the presence of drivers).
565  * @flags: Link flags.
566  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
567  * @kref: Count repeated addition of the same link.
568  * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
569  * @supplier_preactivated: Supplier has been made active before consumer probe.
570  */
571 struct device_link {
572 	struct device *supplier;
573 	struct list_head s_node;
574 	struct device *consumer;
575 	struct list_head c_node;
576 	struct device link_dev;
577 	enum device_link_state status;
578 	u32 flags;
579 	refcount_t rpm_active;
580 	struct kref kref;
581 #ifdef CONFIG_SRCU
582 	struct rcu_head rcu_head;
583 #endif
584 	bool supplier_preactivated; /* Owned by consumer probe. */
585 };
586 
587 static inline struct device *kobj_to_dev(struct kobject *kobj)
588 {
589 	return container_of(kobj, struct device, kobj);
590 }
591 
592 /**
593  * device_iommu_mapped - Returns true when the device DMA is translated
594  *			 by an IOMMU
595  * @dev: Device to perform the check on
596  */
597 static inline bool device_iommu_mapped(struct device *dev)
598 {
599 	return (dev->iommu_group != NULL);
600 }
601 
602 /* Get the wakeup routines, which depend on struct device */
603 #include <linux/pm_wakeup.h>
604 
605 static inline const char *dev_name(const struct device *dev)
606 {
607 	/* Use the init name until the kobject becomes available */
608 	if (dev->init_name)
609 		return dev->init_name;
610 
611 	return kobject_name(&dev->kobj);
612 }
613 
614 /**
615  * dev_bus_name - Return a device's bus/class name, if at all possible
616  * @dev: struct device to get the bus/class name of
617  *
618  * Will return the name of the bus/class the device is attached to.  If it is
619  * not attached to a bus/class, an empty string will be returned.
620  */
621 static inline const char *dev_bus_name(const struct device *dev)
622 {
623 	return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "");
624 }
625 
626 __printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
627 
628 #ifdef CONFIG_NUMA
629 static inline int dev_to_node(struct device *dev)
630 {
631 	return dev->numa_node;
632 }
633 static inline void set_dev_node(struct device *dev, int node)
634 {
635 	dev->numa_node = node;
636 }
637 #else
638 static inline int dev_to_node(struct device *dev)
639 {
640 	return NUMA_NO_NODE;
641 }
642 static inline void set_dev_node(struct device *dev, int node)
643 {
644 }
645 #endif
646 
647 static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
648 {
649 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
650 	return dev->msi_domain;
651 #else
652 	return NULL;
653 #endif
654 }
655 
656 static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
657 {
658 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
659 	dev->msi_domain = d;
660 #endif
661 }
662 
663 static inline void *dev_get_drvdata(const struct device *dev)
664 {
665 	return dev->driver_data;
666 }
667 
668 static inline void dev_set_drvdata(struct device *dev, void *data)
669 {
670 	dev->driver_data = data;
671 }
672 
673 static inline struct pm_subsys_data *dev_to_psd(struct device *dev)
674 {
675 	return dev ? dev->power.subsys_data : NULL;
676 }
677 
678 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
679 {
680 	return dev->kobj.uevent_suppress;
681 }
682 
683 static inline void dev_set_uevent_suppress(struct device *dev, int val)
684 {
685 	dev->kobj.uevent_suppress = val;
686 }
687 
688 static inline int device_is_registered(struct device *dev)
689 {
690 	return dev->kobj.state_in_sysfs;
691 }
692 
693 static inline void device_enable_async_suspend(struct device *dev)
694 {
695 	if (!dev->power.is_prepared)
696 		dev->power.async_suspend = true;
697 }
698 
699 static inline void device_disable_async_suspend(struct device *dev)
700 {
701 	if (!dev->power.is_prepared)
702 		dev->power.async_suspend = false;
703 }
704 
705 static inline bool device_async_suspend_enabled(struct device *dev)
706 {
707 	return !!dev->power.async_suspend;
708 }
709 
710 static inline bool device_pm_not_required(struct device *dev)
711 {
712 	return dev->power.no_pm;
713 }
714 
715 static inline void device_set_pm_not_required(struct device *dev)
716 {
717 	dev->power.no_pm = true;
718 }
719 
720 static inline void dev_pm_syscore_device(struct device *dev, bool val)
721 {
722 #ifdef CONFIG_PM_SLEEP
723 	dev->power.syscore = val;
724 #endif
725 }
726 
727 static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
728 {
729 	dev->power.driver_flags = flags;
730 }
731 
732 static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
733 {
734 	return !!(dev->power.driver_flags & flags);
735 }
736 
737 static inline void device_lock(struct device *dev)
738 {
739 	mutex_lock(&dev->mutex);
740 }
741 
742 static inline int device_lock_interruptible(struct device *dev)
743 {
744 	return mutex_lock_interruptible(&dev->mutex);
745 }
746 
747 static inline int device_trylock(struct device *dev)
748 {
749 	return mutex_trylock(&dev->mutex);
750 }
751 
752 static inline void device_unlock(struct device *dev)
753 {
754 	mutex_unlock(&dev->mutex);
755 }
756 
757 static inline void device_lock_assert(struct device *dev)
758 {
759 	lockdep_assert_held(&dev->mutex);
760 }
761 
762 static inline struct device_node *dev_of_node(struct device *dev)
763 {
764 	if (!IS_ENABLED(CONFIG_OF) || !dev)
765 		return NULL;
766 	return dev->of_node;
767 }
768 
769 static inline bool dev_has_sync_state(struct device *dev)
770 {
771 	if (!dev)
772 		return false;
773 	if (dev->driver && dev->driver->sync_state)
774 		return true;
775 	if (dev->bus && dev->bus->sync_state)
776 		return true;
777 	return false;
778 }
779 
780 /*
781  * High level routines for use by the bus drivers
782  */
783 int __must_check device_register(struct device *dev);
784 void device_unregister(struct device *dev);
785 void device_initialize(struct device *dev);
786 int __must_check device_add(struct device *dev);
787 void device_del(struct device *dev);
788 int device_for_each_child(struct device *dev, void *data,
789 			  int (*fn)(struct device *dev, void *data));
790 int device_for_each_child_reverse(struct device *dev, void *data,
791 				  int (*fn)(struct device *dev, void *data));
792 struct device *device_find_child(struct device *dev, void *data,
793 				 int (*match)(struct device *dev, void *data));
794 struct device *device_find_child_by_name(struct device *parent,
795 					 const char *name);
796 int device_rename(struct device *dev, const char *new_name);
797 int device_move(struct device *dev, struct device *new_parent,
798 		enum dpm_order dpm_order);
799 int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
800 const char *device_get_devnode(struct device *dev, umode_t *mode, kuid_t *uid,
801 			       kgid_t *gid, const char **tmp);
802 int device_is_dependent(struct device *dev, void *target);
803 
804 static inline bool device_supports_offline(struct device *dev)
805 {
806 	return dev->bus && dev->bus->offline && dev->bus->online;
807 }
808 
809 void lock_device_hotplug(void);
810 void unlock_device_hotplug(void);
811 int lock_device_hotplug_sysfs(void);
812 int device_offline(struct device *dev);
813 int device_online(struct device *dev);
814 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
815 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
816 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
817 
818 static inline int dev_num_vf(struct device *dev)
819 {
820 	if (dev->bus && dev->bus->num_vf)
821 		return dev->bus->num_vf(dev);
822 	return 0;
823 }
824 
825 /*
826  * Root device objects for grouping under /sys/devices
827  */
828 struct device *__root_device_register(const char *name, struct module *owner);
829 
830 /* This is a macro to avoid include problems with THIS_MODULE */
831 #define root_device_register(name) \
832 	__root_device_register(name, THIS_MODULE)
833 
834 void root_device_unregister(struct device *root);
835 
836 static inline void *dev_get_platdata(const struct device *dev)
837 {
838 	return dev->platform_data;
839 }
840 
841 /*
842  * Manual binding of a device to driver. See drivers/base/bus.c
843  * for information on use.
844  */
845 int __must_check device_bind_driver(struct device *dev);
846 void device_release_driver(struct device *dev);
847 int  __must_check device_attach(struct device *dev);
848 int __must_check driver_attach(struct device_driver *drv);
849 void device_initial_probe(struct device *dev);
850 int __must_check device_reprobe(struct device *dev);
851 
852 bool device_is_bound(struct device *dev);
853 
854 /*
855  * Easy functions for dynamically creating devices on the fly
856  */
857 __printf(5, 6) struct device *
858 device_create(struct class *cls, struct device *parent, dev_t devt,
859 	      void *drvdata, const char *fmt, ...);
860 __printf(6, 7) struct device *
861 device_create_with_groups(struct class *cls, struct device *parent, dev_t devt,
862 			  void *drvdata, const struct attribute_group **groups,
863 			  const char *fmt, ...);
864 void device_destroy(struct class *cls, dev_t devt);
865 
866 int __must_check device_add_groups(struct device *dev,
867 				   const struct attribute_group **groups);
868 void device_remove_groups(struct device *dev,
869 			  const struct attribute_group **groups);
870 
871 static inline int __must_check device_add_group(struct device *dev,
872 					const struct attribute_group *grp)
873 {
874 	const struct attribute_group *groups[] = { grp, NULL };
875 
876 	return device_add_groups(dev, groups);
877 }
878 
879 static inline void device_remove_group(struct device *dev,
880 				       const struct attribute_group *grp)
881 {
882 	const struct attribute_group *groups[] = { grp, NULL };
883 
884 	return device_remove_groups(dev, groups);
885 }
886 
887 int __must_check devm_device_add_groups(struct device *dev,
888 					const struct attribute_group **groups);
889 void devm_device_remove_groups(struct device *dev,
890 			       const struct attribute_group **groups);
891 int __must_check devm_device_add_group(struct device *dev,
892 				       const struct attribute_group *grp);
893 void devm_device_remove_group(struct device *dev,
894 			      const struct attribute_group *grp);
895 
896 /*
897  * Platform "fixup" functions - allow the platform to have their say
898  * about devices and actions that the general device layer doesn't
899  * know about.
900  */
901 /* Notify platform of device discovery */
902 extern int (*platform_notify)(struct device *dev);
903 
904 extern int (*platform_notify_remove)(struct device *dev);
905 
906 
907 /*
908  * get_device - atomically increment the reference count for the device.
909  *
910  */
911 struct device *get_device(struct device *dev);
912 void put_device(struct device *dev);
913 bool kill_device(struct device *dev);
914 
915 #ifdef CONFIG_DEVTMPFS
916 int devtmpfs_mount(void);
917 #else
918 static inline int devtmpfs_mount(void) { return 0; }
919 #endif
920 
921 /* drivers/base/power/shutdown.c */
922 void device_shutdown(void);
923 
924 /* debugging and troubleshooting/diagnostic helpers. */
925 const char *dev_driver_string(const struct device *dev);
926 
927 /* Device links interface. */
928 struct device_link *device_link_add(struct device *consumer,
929 				    struct device *supplier, u32 flags);
930 void device_link_del(struct device_link *link);
931 void device_link_remove(void *consumer, struct device *supplier);
932 void device_links_supplier_sync_state_pause(void);
933 void device_links_supplier_sync_state_resume(void);
934 
935 extern __printf(3, 4)
936 int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
937 
938 /* Create alias, so I can be autoloaded. */
939 #define MODULE_ALIAS_CHARDEV(major,minor) \
940 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
941 #define MODULE_ALIAS_CHARDEV_MAJOR(major) \
942 	MODULE_ALIAS("char-major-" __stringify(major) "-*")
943 
944 #ifdef CONFIG_SYSFS_DEPRECATED
945 extern long sysfs_deprecated;
946 #else
947 #define sysfs_deprecated 0
948 #endif
949 
950 #endif /* _DEVICE_H_ */
951