xref: /freebsd/sys/compat/linuxkpi/common/include/linux/device.h (revision 3208d4ad2b8320a24af4a8293f7fd3ef9c35caa6)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  * Copyright (c) 2021-2022 The FreeBSD Foundation
8  *
9  * Portions of this software were developed by Björn Zeeb
10  * under sponsorship from the FreeBSD Foundation.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice unmodified, this list of conditions, and the following
17  *    disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #ifndef	_LINUXKPI_LINUX_DEVICE_H_
34 #define	_LINUXKPI_LINUX_DEVICE_H_
35 
36 #include <linux/err.h>
37 #include <linux/types.h>
38 #include <linux/kobject.h>
39 #include <linux/sysfs.h>
40 #include <linux/list.h>
41 #include <linux/compiler.h>
42 #include <linux/module.h>
43 #include <linux/workqueue.h>
44 #include <linux/kdev_t.h>
45 #include <linux/backlight.h>
46 #include <linux/pm.h>
47 #include <linux/idr.h>
48 #include <linux/overflow.h>
49 #include <linux/ratelimit.h>	/* via linux/dev_printk.h */
50 #include <linux/fwnode.h>
51 #include <asm/atomic.h>
52 
53 #include <sys/bus.h>
54 #include <sys/backlight.h>
55 
56 struct device;
57 
58 struct class {
59 	const char	*name;
60 	struct module	*owner;
61 	struct kobject	kobj;
62 	devclass_t	bsdclass;
63 	const struct dev_pm_ops *pm;
64 	const struct attribute_group **dev_groups;
65 	void		(*class_release)(struct class *class);
66 	void		(*dev_release)(struct device *dev);
67 	char *		(*devnode)(struct device *dev, umode_t *mode);
68 };
69 
70 struct dev_pm_ops {
71 	int (*prepare)(struct device *dev);
72 	void (*complete)(struct device *dev);
73 	int (*suspend)(struct device *dev);
74 	int (*suspend_late)(struct device *dev);
75 	int (*resume)(struct device *dev);
76 	int (*resume_early)(struct device *dev);
77 	int (*freeze)(struct device *dev);
78 	int (*freeze_late)(struct device *dev);
79 	int (*thaw)(struct device *dev);
80 	int (*thaw_early)(struct device *dev);
81 	int (*poweroff)(struct device *dev);
82 	int (*poweroff_late)(struct device *dev);
83 	int (*restore)(struct device *dev);
84 	int (*restore_early)(struct device *dev);
85 	int (*suspend_noirq)(struct device *dev);
86 	int (*runtime_suspend)(struct device *dev);
87 	int (*runtime_resume)(struct device *dev);
88 	int (*runtime_idle)(struct device *dev);
89 };
90 
91 struct device_driver {
92 	const char	*name;
93 	const struct dev_pm_ops *pm;
94 };
95 
96 struct device_type {
97 	const char	*name;
98 };
99 
100 struct device {
101 	struct device	*parent;
102 	struct list_head irqents;
103 	device_t	bsddev;
104 	/*
105 	 * The following flag is used to determine if the LinuxKPI is
106 	 * responsible for detaching the BSD device or not. If the
107 	 * LinuxKPI got the BSD device using devclass_get_device(), it
108 	 * must not try to detach or delete it, because it's already
109 	 * done somewhere else.
110 	 */
111 	bool		bsddev_attached_here;
112 	struct device_driver *driver;
113 	struct device_type *type;
114 	dev_t		devt;
115 	struct class	*class;
116 	void		(*release)(struct device *dev);
117 	struct kobject	kobj;
118 	void		*dma_priv;
119 	void		*driver_data;
120 	unsigned int	irq;
121 #define	LINUX_IRQ_INVALID	65535
122 	unsigned int	irq_start;
123 	unsigned int	irq_end;
124 	const struct attribute_group **groups;
125 	struct fwnode_handle *fwnode;
126 	struct cdev	*backlight_dev;
127 	struct backlight_device	*bd;
128 
129 	spinlock_t	devres_lock;
130 	struct list_head devres_head;
131 
132 	struct dev_pm_info	power;
133 };
134 
135 extern struct device linux_root_device;
136 extern struct kobject linux_class_root;
137 extern const struct kobj_type linux_dev_ktype;
138 extern const struct kobj_type linux_class_ktype;
139 
140 struct class_attribute {
141 	struct attribute attr;
142 	ssize_t (*show)(struct class *, struct class_attribute *, char *);
143 	ssize_t (*store)(struct class *, struct class_attribute *, const char *, size_t);
144 	const void *(*namespace)(struct class *, const struct class_attribute *);
145 };
146 
147 #define	CLASS_ATTR(_name, _mode, _show, _store)				\
148 	struct class_attribute class_attr_##_name =			\
149 	    { { #_name, NULL, _mode }, _show, _store }
150 
151 struct device_attribute {
152 	struct attribute	attr;
153 	ssize_t			(*show)(struct device *,
154 					struct device_attribute *, char *);
155 	ssize_t			(*store)(struct device *,
156 					struct device_attribute *, const char *,
157 					size_t);
158 };
159 
160 #define	DEVICE_ATTR(_name, _mode, _show, _store)			\
161 	struct device_attribute dev_attr_##_name =			\
162 	    __ATTR(_name, _mode, _show, _store)
163 #define	DEVICE_ATTR_RO(_name)						\
164 	struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
165 #define	DEVICE_ATTR_WO(_name)						\
166 	struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
167 #define	DEVICE_ATTR_RW(_name)						\
168 	struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
169 
170 /* Simple class attribute that is just a static string */
171 struct class_attribute_string {
172 	struct class_attribute attr;
173 	char *str;
174 };
175 
176 static inline ssize_t
177 show_class_attr_string(struct class *class,
178 				struct class_attribute *attr, char *buf)
179 {
180 	struct class_attribute_string *cs;
181 	cs = container_of(attr, struct class_attribute_string, attr);
182 	return snprintf(buf, PAGE_SIZE, "%s\n", cs->str);
183 }
184 
185 /* Currently read-only only */
186 #define _CLASS_ATTR_STRING(_name, _mode, _str) \
187 	{ __ATTR(_name, _mode, show_class_attr_string, NULL), _str }
188 #define CLASS_ATTR_STRING(_name, _mode, _str) \
189 	struct class_attribute_string class_attr_##_name = \
190 		_CLASS_ATTR_STRING(_name, _mode, _str)
191 
192 #define	dev_printk(lvl, dev, fmt, ...)					\
193     device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
194 
195 #define	dev_emerg(dev, fmt, ...)	device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
196 #define	dev_alert(dev, fmt, ...)	device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
197 #define	dev_crit(dev, fmt, ...)		device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
198 #define	dev_err(dev, fmt, ...)		device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
199 #define	dev_warn(dev, fmt, ...)		device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
200 #define	dev_notice(dev, fmt, ...)	device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
201 #define	dev_info(dev, fmt, ...)		device_printf((dev)->bsddev, fmt, ##__VA_ARGS__)
202 #define	dev_dbg(dev, fmt, ...)		do { } while (0)
203 
204 #define	dev_WARN(dev, fmt, ...)	\
205     device_printf((dev)->bsddev, "%s:%d: " fmt, __func__, __LINE__, ##__VA_ARGS__)
206 
207 #define	dev_WARN_ONCE(dev, condition, fmt, ...) do {		\
208 	static bool __dev_WARN_ONCE;				\
209 	bool __ret_warn_on = (condition);			\
210 	if (unlikely(__ret_warn_on)) {				\
211 		if (!__dev_WARN_ONCE) {				\
212 			__dev_WARN_ONCE = true;			\
213 			device_printf((dev)->bsddev, "%s:%d: " fmt, __func__, __LINE__, ##__VA_ARGS__); \
214 		}						\
215 	}							\
216 } while (0)
217 
218 #define dev_info_once(dev, ...) do {		\
219 	static bool __dev_info_once;		\
220 	if (!__dev_info_once) {			\
221 	__dev_info_once = true;			\
222 	dev_info(dev, __VA_ARGS__);		\
223 	}					\
224 } while (0)
225 
226 #define	dev_warn_once(dev, ...) do {		\
227 	static bool __dev_warn_once;		\
228 	if (!__dev_warn_once) {			\
229 		__dev_warn_once = 1;		\
230 		dev_warn(dev, __VA_ARGS__);	\
231 	}					\
232 } while (0)
233 
234 #define	dev_err_once(dev, ...) do {		\
235 	static bool __dev_err_once;		\
236 	if (!__dev_err_once) {			\
237 		__dev_err_once = 1;		\
238 		dev_err(dev, __VA_ARGS__);	\
239 	}					\
240 } while (0)
241 
242 #define	dev_dbg_once(dev, ...) do {		\
243 	static bool __dev_dbg_once;		\
244 	if (!__dev_dbg_once) {			\
245 		__dev_dbg_once = 1;		\
246 		dev_dbg(dev, __VA_ARGS__);	\
247 	}					\
248 } while (0)
249 
250 #define	dev_err_ratelimited(dev, ...) do {	\
251 	static linux_ratelimit_t __ratelimited;	\
252 	if (linux_ratelimited(&__ratelimited))	\
253 		dev_err(dev, __VA_ARGS__);	\
254 } while (0)
255 
256 #define	dev_warn_ratelimited(dev, ...) do {	\
257 	static linux_ratelimit_t __ratelimited;	\
258 	if (linux_ratelimited(&__ratelimited))	\
259 		dev_warn(dev, __VA_ARGS__);	\
260 } while (0)
261 
262 #define	dev_dbg_ratelimited(dev, ...) do {	\
263 	static linux_ratelimit_t __ratelimited;	\
264 	if (linux_ratelimited(&__ratelimited))	\
265 		dev_dbg(dev, __VA_ARGS__);	\
266 } while (0)
267 
268 /* Public and LinuxKPI internal devres functions. */
269 void *lkpi_devres_alloc(void(*release)(struct device *, void *), size_t, gfp_t);
270 void lkpi_devres_add(struct device *, void *);
271 void lkpi_devres_free(void *);
272 void *lkpi_devres_find(struct device *, void(*release)(struct device *, void *),
273     int (*match)(struct device *, void *, void *), void *);
274 int lkpi_devres_destroy(struct device *, void(*release)(struct device *, void *),
275     int (*match)(struct device *, void *, void *), void *);
276 #define	devres_alloc(_r, _s, _g)	lkpi_devres_alloc(_r, _s, _g)
277 #define	devres_add(_d, _p)		lkpi_devres_add(_d, _p)
278 #define	devres_free(_p)			lkpi_devres_free(_p)
279 #define	devres_find(_d, _rfn, _mfn, _mp) \
280 					lkpi_devres_find(_d, _rfn, _mfn, _mp)
281 #define	devres_destroy(_d, _rfn, _mfn, _mp) \
282 					lkpi_devres_destroy(_d, _rfn, _mfn, _mp)
283 void lkpi_devres_release_free_list(struct device *);
284 void lkpi_devres_unlink(struct device *, void *);
285 void lkpi_devm_kmalloc_release(struct device *, void *);
286 
287 static inline const char *
288 dev_driver_string(const struct device *dev)
289 {
290 	driver_t *drv;
291 	const char *str = "";
292 
293 	if (dev->bsddev != NULL) {
294 		drv = device_get_driver(dev->bsddev);
295 		if (drv != NULL)
296 			str = drv->name;
297 	}
298 
299 	return (str);
300 }
301 
302 static inline void *
303 dev_get_drvdata(const struct device *dev)
304 {
305 
306 	return dev->driver_data;
307 }
308 
309 static inline void
310 dev_set_drvdata(struct device *dev, void *data)
311 {
312 
313 	dev->driver_data = data;
314 }
315 
316 static inline struct device *
317 get_device(struct device *dev)
318 {
319 
320 	if (dev)
321 		kobject_get(&dev->kobj);
322 
323 	return (dev);
324 }
325 
326 static inline char *
327 dev_name(const struct device *dev)
328 {
329 
330 	return kobject_name(&dev->kobj);
331 }
332 
333 #define	dev_set_name(_dev, _fmt, ...)					\
334 	kobject_set_name(&(_dev)->kobj, (_fmt), ##__VA_ARGS__)
335 
336 static inline void
337 put_device(struct device *dev)
338 {
339 
340 	if (dev)
341 		kobject_put(&dev->kobj);
342 }
343 
344 struct class *class_create(struct module *owner, const char *name);
345 
346 static inline int
347 class_register(struct class *class)
348 {
349 
350 	class->bsdclass = devclass_create(class->name);
351 	kobject_init(&class->kobj, &linux_class_ktype);
352 	kobject_set_name(&class->kobj, class->name);
353 	kobject_add(&class->kobj, &linux_class_root, class->name);
354 
355 	return (0);
356 }
357 
358 static inline void
359 class_unregister(struct class *class)
360 {
361 
362 	kobject_put(&class->kobj);
363 }
364 
365 static inline struct device *kobj_to_dev(struct kobject *kobj)
366 {
367 	return container_of(kobj, struct device, kobj);
368 }
369 
370 struct device *device_create(struct class *class, struct device *parent,
371 	    dev_t devt, void *drvdata, const char *fmt, ...);
372 struct device *device_create_groups_vargs(struct class *class, struct device *parent,
373     dev_t devt, void *drvdata, const struct attribute_group **groups,
374     const char *fmt, va_list args);
375 
376 /*
377  * Devices are registered and created for exporting to sysfs. Create
378  * implies register and register assumes the device fields have been
379  * setup appropriately before being called.
380  */
381 static inline void
382 device_initialize(struct device *dev)
383 {
384 	device_t bsddev = NULL;
385 	int unit = -1;
386 
387 	if (dev->devt) {
388 		unit = MINOR(dev->devt);
389 		bsddev = devclass_get_device(dev->class->bsdclass, unit);
390 		dev->bsddev_attached_here = false;
391 	} else if (dev->parent == NULL) {
392 		bsddev = devclass_get_device(dev->class->bsdclass, 0);
393 		dev->bsddev_attached_here = false;
394 	} else {
395 		dev->bsddev_attached_here = true;
396 	}
397 
398 	if (bsddev == NULL && dev->parent != NULL) {
399 		bsddev = device_add_child(dev->parent->bsddev,
400 		    dev->class->kobj.name, unit);
401 	}
402 
403 	if (bsddev != NULL)
404 		device_set_softc(bsddev, dev);
405 
406 	dev->bsddev = bsddev;
407 	MPASS(dev->bsddev != NULL);
408 	kobject_init(&dev->kobj, &linux_dev_ktype);
409 
410 	spin_lock_init(&dev->devres_lock);
411 	INIT_LIST_HEAD(&dev->devres_head);
412 }
413 
414 static inline int
415 device_add(struct device *dev)
416 {
417 	if (dev->bsddev != NULL) {
418 		if (dev->devt == 0)
419 			dev->devt = makedev(0, device_get_unit(dev->bsddev));
420 	}
421 	kobject_add(&dev->kobj, &dev->class->kobj, dev_name(dev));
422 
423 	if (dev->groups)
424 		return (sysfs_create_groups(&dev->kobj, dev->groups));
425 
426 	return (0);
427 }
428 
429 static inline void
430 device_create_release(struct device *dev)
431 {
432 	kfree(dev);
433 }
434 
435 static inline struct device *
436 device_create_with_groups(struct class *class,
437     struct device *parent, dev_t devt, void *drvdata,
438     const struct attribute_group **groups, const char *fmt, ...)
439 {
440 	va_list vargs;
441 	struct device *dev;
442 
443 	va_start(vargs, fmt);
444 	dev = device_create_groups_vargs(class, parent, devt, drvdata,
445 	    groups, fmt, vargs);
446 	va_end(vargs);
447 	return dev;
448 }
449 
450 static inline bool
451 device_is_registered(struct device *dev)
452 {
453 
454 	return (dev->bsddev != NULL);
455 }
456 
457 static inline int
458 device_register(struct device *dev)
459 {
460 	device_t bsddev = NULL;
461 	int unit = -1;
462 
463 	if (device_is_registered(dev))
464 		goto done;
465 
466 	if (dev->devt) {
467 		unit = MINOR(dev->devt);
468 		bsddev = devclass_get_device(dev->class->bsdclass, unit);
469 		dev->bsddev_attached_here = false;
470 	} else if (dev->parent == NULL) {
471 		bsddev = devclass_get_device(dev->class->bsdclass, 0);
472 		dev->bsddev_attached_here = false;
473 	} else {
474 		dev->bsddev_attached_here = true;
475 	}
476 	if (bsddev == NULL && dev->parent != NULL) {
477 		bsddev = device_add_child(dev->parent->bsddev,
478 		    dev->class->kobj.name, unit);
479 	}
480 	if (bsddev != NULL) {
481 		if (dev->devt == 0)
482 			dev->devt = makedev(0, device_get_unit(bsddev));
483 		device_set_softc(bsddev, dev);
484 	}
485 	dev->bsddev = bsddev;
486 done:
487 	kobject_init(&dev->kobj, &linux_dev_ktype);
488 	kobject_add(&dev->kobj, &dev->class->kobj, dev_name(dev));
489 
490 	sysfs_create_groups(&dev->kobj, dev->class->dev_groups);
491 
492 	return (0);
493 }
494 
495 static inline void
496 device_unregister(struct device *dev)
497 {
498 	device_t bsddev;
499 
500 	sysfs_remove_groups(&dev->kobj, dev->class->dev_groups);
501 
502 	bsddev = dev->bsddev;
503 	dev->bsddev = NULL;
504 
505 	if (bsddev != NULL && dev->bsddev_attached_here) {
506 		bus_topo_lock();
507 		device_delete_child(device_get_parent(bsddev), bsddev);
508 		bus_topo_unlock();
509 	}
510 	put_device(dev);
511 }
512 
513 static inline void
514 device_del(struct device *dev)
515 {
516 	device_t bsddev;
517 
518 	bsddev = dev->bsddev;
519 	dev->bsddev = NULL;
520 
521 	if (bsddev != NULL && dev->bsddev_attached_here) {
522 		bus_topo_lock();
523 		device_delete_child(device_get_parent(bsddev), bsddev);
524 		bus_topo_unlock();
525 	}
526 }
527 
528 static inline void
529 device_destroy(struct class *class, dev_t devt)
530 {
531 	device_t bsddev;
532 	int unit;
533 
534 	unit = MINOR(devt);
535 	bsddev = devclass_get_device(class->bsdclass, unit);
536 	if (bsddev != NULL)
537 		device_unregister(device_get_softc(bsddev));
538 }
539 
540 static inline void
541 device_release_driver(struct device *dev)
542 {
543 
544 #if 0
545 	/* This leads to panics. Disable temporarily. Keep to rework. */
546 
547 	/* We also need to cleanup LinuxKPI bits. What else? */
548 	lkpi_devres_release_free_list(dev);
549 	dev_set_drvdata(dev, NULL);
550 	/* Do not call dev->release! */
551 
552 	bus_topo_lock();
553 	if (device_is_attached(dev->bsddev))
554 		device_detach(dev->bsddev);
555 	bus_topo_unlock();
556 #endif
557 }
558 
559 static inline int
560 device_reprobe(struct device *dev)
561 {
562 	int error;
563 
564 	device_release_driver(dev);
565 	bus_topo_lock();
566 	error = device_probe_and_attach(dev->bsddev);
567 	bus_topo_unlock();
568 
569 	return (-error);
570 }
571 
572 static inline void
573 device_set_wakeup_enable(struct device *dev __unused, bool enable __unused)
574 {
575 
576 	/*
577 	 * XXX-BZ TODO This is used by wireless drivers supporting WoWLAN which
578 	 * we currently do not support.
579 	 */
580 }
581 
582 static inline int
583 device_wakeup_enable(struct device *dev)
584 {
585 
586 	device_set_wakeup_enable(dev, true);
587 	return (0);
588 }
589 
590 static inline bool
591 device_iommu_mapped(struct device *dev __unused)
592 {
593 	return (false);
594 }
595 
596 #define	dev_pm_set_driver_flags(dev, flags) do { \
597 } while (0)
598 
599 static inline void
600 linux_class_kfree(struct class *class)
601 {
602 
603 	kfree(class);
604 }
605 
606 static inline void
607 class_destroy(struct class *class)
608 {
609 
610 	if (class == NULL)
611 		return;
612 	class_unregister(class);
613 }
614 
615 static inline int
616 device_create_file(struct device *dev, const struct device_attribute *attr)
617 {
618 
619 	if (dev)
620 		return sysfs_create_file(&dev->kobj, &attr->attr);
621 	return -EINVAL;
622 }
623 
624 static inline void
625 device_remove_file(struct device *dev, const struct device_attribute *attr)
626 {
627 
628 	if (dev)
629 		sysfs_remove_file(&dev->kobj, &attr->attr);
630 }
631 
632 static inline int
633 class_create_file(struct class *class, const struct class_attribute *attr)
634 {
635 
636 	if (class)
637 		return sysfs_create_file(&class->kobj, &attr->attr);
638 	return -EINVAL;
639 }
640 
641 static inline void
642 class_remove_file(struct class *class, const struct class_attribute *attr)
643 {
644 
645 	if (class)
646 		sysfs_remove_file(&class->kobj, &attr->attr);
647 }
648 
649 #define	dev_to_node(dev) linux_dev_to_node(dev)
650 #define	of_node_to_nid(node) -1
651 int linux_dev_to_node(struct device *);
652 
653 char *kvasprintf(gfp_t, const char *, va_list);
654 char *kasprintf(gfp_t, const char *, ...);
655 char *lkpi_devm_kasprintf(struct device *, gfp_t, const char *, ...);
656 
657 #define	devm_kasprintf(_dev, _gfp, _fmt, ...)			\
658     lkpi_devm_kasprintf(_dev, _gfp, _fmt, ##__VA_ARGS__)
659 
660 static __inline void *
661 devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
662 {
663 	void *p;
664 
665 	p = lkpi_devres_alloc(lkpi_devm_kmalloc_release, size, gfp);
666 	if (p != NULL)
667 		lkpi_devres_add(dev, p);
668 
669 	return (p);
670 }
671 
672 static inline void *
673 devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
674 {
675 	void *dst;
676 
677 	if (len == 0)
678 		return (NULL);
679 
680 	dst = devm_kmalloc(dev, len, gfp);
681 	if (dst != NULL)
682 		memcpy(dst, src, len);
683 
684 	return (dst);
685 }
686 
687 #define	devm_kzalloc(_dev, _size, _gfp)				\
688     devm_kmalloc((_dev), (_size), (_gfp) | __GFP_ZERO)
689 
690 #define	devm_kcalloc(_dev, _sizen, _size, _gfp)			\
691     devm_kmalloc((_dev), ((_sizen) * (_size)), (_gfp) | __GFP_ZERO)
692 
693 int lkpi_devm_add_action(struct device *dev, void (*action)(void *), void *data);
694 #define	devm_add_action(dev, action, data)	\
695 	lkpi_devm_add_action(dev, action, data);
696 int lkpi_devm_add_action_or_reset(struct device *dev, void (*action)(void *), void *data);
697 #define	devm_add_action_or_reset(dev, action, data)	\
698 	lkpi_devm_add_action_or_reset(dev, action, data)
699 
700 #endif	/* _LINUXKPI_LINUX_DEVICE_H_ */
701