1/*
  2 * drivers/base/devres.c - device resource management
  3 *
  4 * Copyright (c) 2006  SUSE Linux Products GmbH
  5 * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
  6 *
  7 * This file is released under the GPLv2.
  8 */
  9
 10#include <linux/device.h>
 11#include <linux/module.h>
 12#include <linux/slab.h>
 13
 14#include "base.h"
 15
 16struct devres_node {
 17	struct list_head		entry;
 18	dr_release_t			release;
 19#ifdef CONFIG_DEBUG_DEVRES
 20	const char			*name;
 21	size_t				size;
 22#endif
 23};
 24
 25struct devres {
 26	struct devres_node		node;
 27	/* -- 3 pointers */
 28	unsigned long long		data[];	/* guarantee ull alignment */
 29};
 30
 31struct devres_group {
 32	struct devres_node		node[2];
 33	void				*id;
 34	int				color;
 35	/* -- 8 pointers */
 36};
 37
 38#ifdef CONFIG_DEBUG_DEVRES
 39static int log_devres = 0;
 40module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
 41
 42static void set_node_dbginfo(struct devres_node *node, const char *name,
 43			     size_t size)
 44{
 45	node->name = name;
 46	node->size = size;
 47}
 48
 49static void devres_log(struct device *dev, struct devres_node *node,
 50		       const char *op)
 51{
 52	if (unlikely(log_devres))
 53		dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
 54			op, node, node->name, (unsigned long)node->size);
 55}
 56#else /* CONFIG_DEBUG_DEVRES */
 57#define set_node_dbginfo(node, n, s)	do {} while (0)
 58#define devres_log(dev, node, op)	do {} while (0)
 59#endif /* CONFIG_DEBUG_DEVRES */
 60
 61/*
 62 * Release functions for devres group.  These callbacks are used only
 63 * for identification.
 64 */
 65static void group_open_release(struct device *dev, void *res)
 66{
 67	/* noop */
 68}
 69
 70static void group_close_release(struct device *dev, void *res)
 71{
 72	/* noop */
 73}
 74
 75static struct devres_group * node_to_group(struct devres_node *node)
 76{
 77	if (node->release == &group_open_release)
 78		return container_of(node, struct devres_group, node[0]);
 79	if (node->release == &group_close_release)
 80		return container_of(node, struct devres_group, node[1]);
 81	return NULL;
 82}
 83
 84static __always_inline struct devres * alloc_dr(dr_release_t release,
 85						size_t size, gfp_t gfp, int nid)
 86{
 87	size_t tot_size = sizeof(struct devres) + size;
 88	struct devres *dr;
 89
 90	dr = kmalloc_node_track_caller(tot_size, gfp, nid);
 91	if (unlikely(!dr))
 92		return NULL;
 93
 94	memset(dr, 0, offsetof(struct devres, data));
 95
 96	INIT_LIST_HEAD(&dr->node.entry);
 97	dr->node.release = release;
 98	return dr;
 99}
100
101static void add_dr(struct device *dev, struct devres_node *node)
102{
103	devres_log(dev, node, "ADD");
104	BUG_ON(!list_empty(&node->entry));
105	list_add_tail(&node->entry, &dev->devres_head);
106}
107
108#ifdef CONFIG_DEBUG_DEVRES
109void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
110		      const char *name)
111{
112	struct devres *dr;
113
114	dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
115	if (unlikely(!dr))
116		return NULL;
117	set_node_dbginfo(&dr->node, name, size);
118	return dr->data;
119}
120EXPORT_SYMBOL_GPL(__devres_alloc_node);
121#else
122/**
123 * devres_alloc - Allocate device resource data
124 * @release: Release function devres will be associated with
125 * @size: Allocation size
126 * @gfp: Allocation flags
127 * @nid: NUMA node
128 *
129 * Allocate devres of @size bytes.  The allocated area is zeroed, then
130 * associated with @release.  The returned pointer can be passed to
131 * other devres_*() functions.
132 *
133 * RETURNS:
134 * Pointer to allocated devres on success, NULL on failure.
135 */
136void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
137{
138	struct devres *dr;
139
140	dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
141	if (unlikely(!dr))
142		return NULL;
143	return dr->data;
144}
145EXPORT_SYMBOL_GPL(devres_alloc_node);
146#endif
147
148/**
149 * devres_for_each_res - Resource iterator
150 * @dev: Device to iterate resource from
151 * @release: Look for resources associated with this release function
152 * @match: Match function (optional)
153 * @match_data: Data for the match function
154 * @fn: Function to be called for each matched resource.
155 * @data: Data for @fn, the 3rd parameter of @fn
156 *
157 * Call @fn for each devres of @dev which is associated with @release
158 * and for which @match returns 1.
159 *
160 * RETURNS:
161 * 	void
162 */
163void devres_for_each_res(struct device *dev, dr_release_t release,
164			dr_match_t match, void *match_data,
165			void (*fn)(struct device *, void *, void *),
166			void *data)
167{
168	struct devres_node *node;
169	struct devres_node *tmp;
170	unsigned long flags;
171
172	if (!fn)
173		return;
174
175	spin_lock_irqsave(&dev->devres_lock, flags);
176	list_for_each_entry_safe_reverse(node, tmp,
177			&dev->devres_head, entry) {
178		struct devres *dr = container_of(node, struct devres, node);
179
180		if (node->release != release)
181			continue;
182		if (match && !match(dev, dr->data, match_data))
183			continue;
184		fn(dev, dr->data, data);
185	}
186	spin_unlock_irqrestore(&dev->devres_lock, flags);
187}
188EXPORT_SYMBOL_GPL(devres_for_each_res);
189
190/**
191 * devres_free - Free device resource data
192 * @res: Pointer to devres data to free
193 *
194 * Free devres created with devres_alloc().
195 */
196void devres_free(void *res)
197{
198	if (res) {
199		struct devres *dr = container_of(res, struct devres, data);
200
201		BUG_ON(!list_empty(&dr->node.entry));
202		kfree(dr);
203	}
204}
205EXPORT_SYMBOL_GPL(devres_free);
206
207/**
208 * devres_add - Register device resource
209 * @dev: Device to add resource to
210 * @res: Resource to register
211 *
212 * Register devres @res to @dev.  @res should have been allocated
213 * using devres_alloc().  On driver detach, the associated release
214 * function will be invoked and devres will be freed automatically.
215 */
216void devres_add(struct device *dev, void *res)
217{
218	struct devres *dr = container_of(res, struct devres, data);
219	unsigned long flags;
220
221	spin_lock_irqsave(&dev->devres_lock, flags);
222	add_dr(dev, &dr->node);
223	spin_unlock_irqrestore(&dev->devres_lock, flags);
224}
225EXPORT_SYMBOL_GPL(devres_add);
226
227static struct devres *find_dr(struct device *dev, dr_release_t release,
228			      dr_match_t match, void *match_data)
229{
230	struct devres_node *node;
231
232	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
233		struct devres *dr = container_of(node, struct devres, node);
234
235		if (node->release != release)
236			continue;
237		if (match && !match(dev, dr->data, match_data))
238			continue;
239		return dr;
240	}
241
242	return NULL;
243}
244
245/**
246 * devres_find - Find device resource
247 * @dev: Device to lookup resource from
248 * @release: Look for resources associated with this release function
249 * @match: Match function (optional)
250 * @match_data: Data for the match function
251 *
252 * Find the latest devres of @dev which is associated with @release
253 * and for which @match returns 1.  If @match is NULL, it's considered
254 * to match all.
255 *
256 * RETURNS:
257 * Pointer to found devres, NULL if not found.
258 */
259void * devres_find(struct device *dev, dr_release_t release,
260		   dr_match_t match, void *match_data)
261{
262	struct devres *dr;
263	unsigned long flags;
264
265	spin_lock_irqsave(&dev->devres_lock, flags);
266	dr = find_dr(dev, release, match, match_data);
267	spin_unlock_irqrestore(&dev->devres_lock, flags);
268
269	if (dr)
270		return dr->data;
271	return NULL;
272}
273EXPORT_SYMBOL_GPL(devres_find);
274
275/**
276 * devres_get - Find devres, if non-existent, add one atomically
277 * @dev: Device to lookup or add devres for
278 * @new_res: Pointer to new initialized devres to add if not found
279 * @match: Match function (optional)
280 * @match_data: Data for the match function
281 *
282 * Find the latest devres of @dev which has the same release function
283 * as @new_res and for which @match return 1.  If found, @new_res is
284 * freed; otherwise, @new_res is added atomically.
285 *
286 * RETURNS:
287 * Pointer to found or added devres.
288 */
289void * devres_get(struct device *dev, void *new_res,
290		  dr_match_t match, void *match_data)
291{
292	struct devres *new_dr = container_of(new_res, struct devres, data);
293	struct devres *dr;
294	unsigned long flags;
295
296	spin_lock_irqsave(&dev->devres_lock, flags);
297	dr = find_dr(dev, new_dr->node.release, match, match_data);
298	if (!dr) {
299		add_dr(dev, &new_dr->node);
300		dr = new_dr;
301		new_res = NULL;
302	}
303	spin_unlock_irqrestore(&dev->devres_lock, flags);
304	devres_free(new_res);
305
306	return dr->data;
307}
308EXPORT_SYMBOL_GPL(devres_get);
309
310/**
311 * devres_remove - Find a device resource and remove it
312 * @dev: Device to find resource from
313 * @release: Look for resources associated with this release function
314 * @match: Match function (optional)
315 * @match_data: Data for the match function
316 *
317 * Find the latest devres of @dev associated with @release and for
318 * which @match returns 1.  If @match is NULL, it's considered to
319 * match all.  If found, the resource is removed atomically and
320 * returned.
321 *
322 * RETURNS:
323 * Pointer to removed devres on success, NULL if not found.
324 */
325void * devres_remove(struct device *dev, dr_release_t release,
326		     dr_match_t match, void *match_data)
327{
328	struct devres *dr;
329	unsigned long flags;
330
331	spin_lock_irqsave(&dev->devres_lock, flags);
332	dr = find_dr(dev, release, match, match_data);
333	if (dr) {
334		list_del_init(&dr->node.entry);
335		devres_log(dev, &dr->node, "REM");
336	}
337	spin_unlock_irqrestore(&dev->devres_lock, flags);
338
339	if (dr)
340		return dr->data;
341	return NULL;
342}
343EXPORT_SYMBOL_GPL(devres_remove);
344
345/**
346 * devres_destroy - Find a device resource and destroy it
347 * @dev: Device to find resource from
348 * @release: Look for resources associated with this release function
349 * @match: Match function (optional)
350 * @match_data: Data for the match function
351 *
352 * Find the latest devres of @dev associated with @release and for
353 * which @match returns 1.  If @match is NULL, it's considered to
354 * match all.  If found, the resource is removed atomically and freed.
355 *
356 * Note that the release function for the resource will not be called,
357 * only the devres-allocated data will be freed.  The caller becomes
358 * responsible for freeing any other data.
359 *
360 * RETURNS:
361 * 0 if devres is found and freed, -ENOENT if not found.
362 */
363int devres_destroy(struct device *dev, dr_release_t release,
364		   dr_match_t match, void *match_data)
365{
366	void *res;
367
368	res = devres_remove(dev, release, match, match_data);
369	if (unlikely(!res))
370		return -ENOENT;
371
372	devres_free(res);
373	return 0;
374}
375EXPORT_SYMBOL_GPL(devres_destroy);
376
377
378/**
379 * devres_release - Find a device resource and destroy it, calling release
380 * @dev: Device to find resource from
381 * @release: Look for resources associated with this release function
382 * @match: Match function (optional)
383 * @match_data: Data for the match function
384 *
385 * Find the latest devres of @dev associated with @release and for
386 * which @match returns 1.  If @match is NULL, it's considered to
387 * match all.  If found, the resource is removed atomically, the
388 * release function called and the resource freed.
389 *
390 * RETURNS:
391 * 0 if devres is found and freed, -ENOENT if not found.
392 */
393int devres_release(struct device *dev, dr_release_t release,
394		   dr_match_t match, void *match_data)
395{
396	void *res;
397
398	res = devres_remove(dev, release, match, match_data);
399	if (unlikely(!res))
400		return -ENOENT;
401
402	(*release)(dev, res);
403	devres_free(res);
404	return 0;
405}
406EXPORT_SYMBOL_GPL(devres_release);
407
408static int remove_nodes(struct device *dev,
409			struct list_head *first, struct list_head *end,
410			struct list_head *todo)
411{
412	int cnt = 0, nr_groups = 0;
413	struct list_head *cur;
414
415	/* First pass - move normal devres entries to @todo and clear
416	 * devres_group colors.
417	 */
418	cur = first;
419	while (cur != end) {
420		struct devres_node *node;
421		struct devres_group *grp;
422
423		node = list_entry(cur, struct devres_node, entry);
424		cur = cur->next;
425
426		grp = node_to_group(node);
427		if (grp) {
428			/* clear color of group markers in the first pass */
429			grp->color = 0;
430			nr_groups++;
431		} else {
432			/* regular devres entry */
433			if (&node->entry == first)
434				first = first->next;
435			list_move_tail(&node->entry, todo);
436			cnt++;
437		}
438	}
439
440	if (!nr_groups)
441		return cnt;
442
443	/* Second pass - Scan groups and color them.  A group gets
444	 * color value of two iff the group is wholly contained in
445	 * [cur, end).  That is, for a closed group, both opening and
446	 * closing markers should be in the range, while just the
447	 * opening marker is enough for an open group.
448	 */
449	cur = first;
450	while (cur != end) {
451		struct devres_node *node;
452		struct devres_group *grp;
453
454		node = list_entry(cur, struct devres_node, entry);
455		cur = cur->next;
456
457		grp = node_to_group(node);
458		BUG_ON(!grp || list_empty(&grp->node[0].entry));
459
460		grp->color++;
461		if (list_empty(&grp->node[1].entry))
462			grp->color++;
463
464		BUG_ON(grp->color <= 0 || grp->color > 2);
465		if (grp->color == 2) {
466			/* No need to update cur or end.  The removed
467			 * nodes are always before both.
468			 */
469			list_move_tail(&grp->node[0].entry, todo);
470			list_del_init(&grp->node[1].entry);
471		}
472	}
473
474	return cnt;
475}
476
477static int release_nodes(struct device *dev, struct list_head *first,
478			 struct list_head *end, unsigned long flags)
479	__releases(&dev->devres_lock)
480{
481	LIST_HEAD(todo);
482	int cnt;
483	struct devres *dr, *tmp;
484
485	cnt = remove_nodes(dev, first, end, &todo);
486
487	spin_unlock_irqrestore(&dev->devres_lock, flags);
488
489	/* Release.  Note that both devres and devres_group are
490	 * handled as devres in the following loop.  This is safe.
491	 */
492	list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
493		devres_log(dev, &dr->node, "REL");
494		dr->node.release(dev, dr->data);
495		kfree(dr);
496	}
497
498	return cnt;
499}
500
501/**
502 * devres_release_all - Release all managed resources
503 * @dev: Device to release resources for
504 *
505 * Release all resources associated with @dev.  This function is
506 * called on driver detach.
507 */
508int devres_release_all(struct device *dev)
509{
510	unsigned long flags;
511
512	/* Looks like an uninitialized device structure */
513	if (WARN_ON(dev->devres_head.next == NULL))
514		return -ENODEV;
515	spin_lock_irqsave(&dev->devres_lock, flags);
516	return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
517			     flags);
518}
519
520/**
521 * devres_open_group - Open a new devres group
522 * @dev: Device to open devres group for
523 * @id: Separator ID
524 * @gfp: Allocation flags
525 *
526 * Open a new devres group for @dev with @id.  For @id, using a
527 * pointer to an object which won't be used for another group is
528 * recommended.  If @id is NULL, address-wise unique ID is created.
529 *
530 * RETURNS:
531 * ID of the new group, NULL on failure.
532 */
533void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
534{
535	struct devres_group *grp;
536	unsigned long flags;
537
538	grp = kmalloc(sizeof(*grp), gfp);
539	if (unlikely(!grp))
540		return NULL;
541
542	grp->node[0].release = &group_open_release;
543	grp->node[1].release = &group_close_release;
544	INIT_LIST_HEAD(&grp->node[0].entry);
545	INIT_LIST_HEAD(&grp->node[1].entry);
546	set_node_dbginfo(&grp->node[0], "grp<", 0);
547	set_node_dbginfo(&grp->node[1], "grp>", 0);
548	grp->id = grp;
549	if (id)
550		grp->id = id;
551
552	spin_lock_irqsave(&dev->devres_lock, flags);
553	add_dr(dev, &grp->node[0]);
554	spin_unlock_irqrestore(&dev->devres_lock, flags);
555	return grp->id;
556}
557EXPORT_SYMBOL_GPL(devres_open_group);
558
559/* Find devres group with ID @id.  If @id is NULL, look for the latest. */
560static struct devres_group * find_group(struct device *dev, void *id)
561{
562	struct devres_node *node;
563
564	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
565		struct devres_group *grp;
566
567		if (node->release != &group_open_release)
568			continue;
569
570		grp = container_of(node, struct devres_group, node[0]);
571
572		if (id) {
573			if (grp->id == id)
574				return grp;
575		} else if (list_empty(&grp->node[1].entry))
576			return grp;
577	}
578
579	return NULL;
580}
581
582/**
583 * devres_close_group - Close a devres group
584 * @dev: Device to close devres group for
585 * @id: ID of target group, can be NULL
586 *
587 * Close the group identified by @id.  If @id is NULL, the latest open
588 * group is selected.
589 */
590void devres_close_group(struct device *dev, void *id)
591{
592	struct devres_group *grp;
593	unsigned long flags;
594
595	spin_lock_irqsave(&dev->devres_lock, flags);
596
597	grp = find_group(dev, id);
598	if (grp)
599		add_dr(dev, &grp->node[1]);
600	else
601		WARN_ON(1);
602
603	spin_unlock_irqrestore(&dev->devres_lock, flags);
604}
605EXPORT_SYMBOL_GPL(devres_close_group);
606
607/**
608 * devres_remove_group - Remove a devres group
609 * @dev: Device to remove group for
610 * @id: ID of target group, can be NULL
611 *
612 * Remove the group identified by @id.  If @id is NULL, the latest
613 * open group is selected.  Note that removing a group doesn't affect
614 * any other resources.
615 */
616void devres_remove_group(struct device *dev, void *id)
617{
618	struct devres_group *grp;
619	unsigned long flags;
620
621	spin_lock_irqsave(&dev->devres_lock, flags);
622
623	grp = find_group(dev, id);
624	if (grp) {
625		list_del_init(&grp->node[0].entry);
626		list_del_init(&grp->node[1].entry);
627		devres_log(dev, &grp->node[0], "REM");
628	} else
629		WARN_ON(1);
630
631	spin_unlock_irqrestore(&dev->devres_lock, flags);
632
633	kfree(grp);
634}
635EXPORT_SYMBOL_GPL(devres_remove_group);
636
637/**
638 * devres_release_group - Release resources in a devres group
639 * @dev: Device to release group for
640 * @id: ID of target group, can be NULL
641 *
642 * Release all resources in the group identified by @id.  If @id is
643 * NULL, the latest open group is selected.  The selected group and
644 * groups properly nested inside the selected group are removed.
645 *
646 * RETURNS:
647 * The number of released non-group resources.
648 */
649int devres_release_group(struct device *dev, void *id)
650{
651	struct devres_group *grp;
652	unsigned long flags;
653	int cnt = 0;
654
655	spin_lock_irqsave(&dev->devres_lock, flags);
656
657	grp = find_group(dev, id);
658	if (grp) {
659		struct list_head *first = &grp->node[0].entry;
660		struct list_head *end = &dev->devres_head;
661
662		if (!list_empty(&grp->node[1].entry))
663			end = grp->node[1].entry.next;
664
665		cnt = release_nodes(dev, first, end, flags);
666	} else {
667		WARN_ON(1);
668		spin_unlock_irqrestore(&dev->devres_lock, flags);
669	}
670
671	return cnt;
672}
673EXPORT_SYMBOL_GPL(devres_release_group);
674
675/*
676 * Custom devres actions allow inserting a simple function call
677 * into the teadown sequence.
678 */
679
680struct action_devres {
681	void *data;
682	void (*action)(void *);
683};
684
685static int devm_action_match(struct device *dev, void *res, void *p)
686{
687	struct action_devres *devres = res;
688	struct action_devres *target = p;
689
690	return devres->action == target->action &&
691	       devres->data == target->data;
692}
693
694static void devm_action_release(struct device *dev, void *res)
695{
696	struct action_devres *devres = res;
697
698	devres->action(devres->data);
699}
700
701/**
702 * devm_add_action() - add a custom action to list of managed resources
703 * @dev: Device that owns the action
704 * @action: Function that should be called
705 * @data: Pointer to data passed to @action implementation
706 *
707 * This adds a custom action to the list of managed resources so that
708 * it gets executed as part of standard resource unwinding.
709 */
710int devm_add_action(struct device *dev, void (*action)(void *), void *data)
711{
712	struct action_devres *devres;
713
714	devres = devres_alloc(devm_action_release,
715			      sizeof(struct action_devres), GFP_KERNEL);
716	if (!devres)
717		return -ENOMEM;
718
719	devres->data = data;
720	devres->action = action;
721
722	devres_add(dev, devres);
723	return 0;
724}
725EXPORT_SYMBOL_GPL(devm_add_action);
726
727/**
728 * devm_remove_action() - removes previously added custom action
729 * @dev: Device that owns the action
730 * @action: Function implementing the action
731 * @data: Pointer to data passed to @action implementation
732 *
733 * Removes instance of @action previously added by devm_add_action().
734 * Both action and data should match one of the existing entries.
735 */
736void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
737{
738	struct action_devres devres = {
739		.data = data,
740		.action = action,
741	};
742
743	WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
744			       &devres));
745
746}
747EXPORT_SYMBOL_GPL(devm_remove_action);
748
749/*
750 * Managed kmalloc/kfree
751 */
752static void devm_kmalloc_release(struct device *dev, void *res)
753{
754	/* noop */
755}
756
757static int devm_kmalloc_match(struct device *dev, void *res, void *data)
758{
759	return res == data;
760}
761
762/**
763 * devm_kmalloc - Resource-managed kmalloc
764 * @dev: Device to allocate memory for
765 * @size: Allocation size
766 * @gfp: Allocation gfp flags
767 *
768 * Managed kmalloc.  Memory allocated with this function is
769 * automatically freed on driver detach.  Like all other devres
770 * resources, guaranteed alignment is unsigned long long.
771 *
772 * RETURNS:
773 * Pointer to allocated memory on success, NULL on failure.
774 */
775void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
776{
777	struct devres *dr;
778
779	/* use raw alloc_dr for kmalloc caller tracing */
780	dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
781	if (unlikely(!dr))
782		return NULL;
783
784	/*
785	 * This is named devm_kzalloc_release for historical reasons
786	 * The initial implementation did not support kmalloc, only kzalloc
787	 */
788	set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
789	devres_add(dev, dr->data);
790	return dr->data;
791}
792EXPORT_SYMBOL_GPL(devm_kmalloc);
793
794/**
795 * devm_kstrdup - Allocate resource managed space and
796 *                copy an existing string into that.
797 * @dev: Device to allocate memory for
798 * @s: the string to duplicate
799 * @gfp: the GFP mask used in the devm_kmalloc() call when
800 *       allocating memory
801 * RETURNS:
802 * Pointer to allocated string on success, NULL on failure.
803 */
804char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
805{
806	size_t size;
807	char *buf;
808
809	if (!s)
810		return NULL;
811
812	size = strlen(s) + 1;
813	buf = devm_kmalloc(dev, size, gfp);
814	if (buf)
815		memcpy(buf, s, size);
816	return buf;
817}
818EXPORT_SYMBOL_GPL(devm_kstrdup);
819
820/**
821 * devm_kvasprintf - Allocate resource managed space and format a string
822 *		     into that.
823 * @dev: Device to allocate memory for
824 * @gfp: the GFP mask used in the devm_kmalloc() call when
825 *       allocating memory
826 * @fmt: The printf()-style format string
827 * @ap: Arguments for the format string
828 * RETURNS:
829 * Pointer to allocated string on success, NULL on failure.
830 */
831char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
832		      va_list ap)
833{
834	unsigned int len;
835	char *p;
836	va_list aq;
837
838	va_copy(aq, ap);
839	len = vsnprintf(NULL, 0, fmt, aq);
840	va_end(aq);
841
842	p = devm_kmalloc(dev, len+1, gfp);
843	if (!p)
844		return NULL;
845
846	vsnprintf(p, len+1, fmt, ap);
847
848	return p;
849}
850EXPORT_SYMBOL(devm_kvasprintf);
851
852/**
853 * devm_kasprintf - Allocate resource managed space and format a string
854 *		    into that.
855 * @dev: Device to allocate memory for
856 * @gfp: the GFP mask used in the devm_kmalloc() call when
857 *       allocating memory
858 * @fmt: The printf()-style format string
859 * @...: Arguments for the format string
860 * RETURNS:
861 * Pointer to allocated string on success, NULL on failure.
862 */
863char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
864{
865	va_list ap;
866	char *p;
867
868	va_start(ap, fmt);
869	p = devm_kvasprintf(dev, gfp, fmt, ap);
870	va_end(ap);
871
872	return p;
873}
874EXPORT_SYMBOL_GPL(devm_kasprintf);
875
876/**
877 * devm_kfree - Resource-managed kfree
878 * @dev: Device this memory belongs to
879 * @p: Memory to free
880 *
881 * Free memory allocated with devm_kmalloc().
882 */
883void devm_kfree(struct device *dev, void *p)
884{
885	int rc;
886
887	rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
888	WARN_ON(rc);
889}
890EXPORT_SYMBOL_GPL(devm_kfree);
891
892/**
893 * devm_kmemdup - Resource-managed kmemdup
894 * @dev: Device this memory belongs to
895 * @src: Memory region to duplicate
896 * @len: Memory region length
897 * @gfp: GFP mask to use
898 *
899 * Duplicate region of a memory using resource managed kmalloc
900 */
901void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
902{
903	void *p;
904
905	p = devm_kmalloc(dev, len, gfp);
906	if (p)
907		memcpy(p, src, len);
908
909	return p;
910}
911EXPORT_SYMBOL_GPL(devm_kmemdup);
912
913struct pages_devres {
914	unsigned long addr;
915	unsigned int order;
916};
917
918static int devm_pages_match(struct device *dev, void *res, void *p)
919{
920	struct pages_devres *devres = res;
921	struct pages_devres *target = p;
922
923	return devres->addr == target->addr;
924}
925
926static void devm_pages_release(struct device *dev, void *res)
927{
928	struct pages_devres *devres = res;
929
930	free_pages(devres->addr, devres->order);
931}
932
933/**
934 * devm_get_free_pages - Resource-managed __get_free_pages
935 * @dev: Device to allocate memory for
936 * @gfp_mask: Allocation gfp flags
937 * @order: Allocation size is (1 << order) pages
938 *
939 * Managed get_free_pages.  Memory allocated with this function is
940 * automatically freed on driver detach.
941 *
942 * RETURNS:
943 * Address of allocated memory on success, 0 on failure.
944 */
945
946unsigned long devm_get_free_pages(struct device *dev,
947				  gfp_t gfp_mask, unsigned int order)
948{
949	struct pages_devres *devres;
950	unsigned long addr;
951
952	addr = __get_free_pages(gfp_mask, order);
953
954	if (unlikely(!addr))
955		return 0;
956
957	devres = devres_alloc(devm_pages_release,
958			      sizeof(struct pages_devres), GFP_KERNEL);
959	if (unlikely(!devres)) {
960		free_pages(addr, order);
961		return 0;
962	}
963
964	devres->addr = addr;
965	devres->order = order;
966
967	devres_add(dev, devres);
968	return addr;
969}
970EXPORT_SYMBOL_GPL(devm_get_free_pages);
971
972/**
973 * devm_free_pages - Resource-managed free_pages
974 * @dev: Device this memory belongs to
975 * @addr: Memory to free
976 *
977 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
978 * there is no need to supply the @order.
979 */
980void devm_free_pages(struct device *dev, unsigned long addr)
981{
982	struct pages_devres devres = { .addr = addr };
983
984	WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
985			       &devres));
986}
987EXPORT_SYMBOL_GPL(devm_free_pages);