1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/devres.c - device resource management
4 *
5 * Copyright (c) 2006 SUSE Linux Products GmbH
6 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
7 */
8
9#include <linux/device.h>
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/percpu.h>
13
14#include <asm/sections.h>
15
16#include "base.h"
17
18struct devres_node {
19 struct list_head entry;
20 dr_release_t release;
21#ifdef CONFIG_DEBUG_DEVRES
22 const char *name;
23 size_t size;
24#endif
25};
26
27struct devres {
28 struct devres_node node;
29 /*
30 * Some archs want to perform DMA into kmalloc caches
31 * and need a guaranteed alignment larger than
32 * the alignment of a 64-bit integer.
33 * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
34 * buffer alignment as if it was allocated by plain kmalloc().
35 */
36 u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
37};
38
39struct devres_group {
40 struct devres_node node[2];
41 void *id;
42 int color;
43 /* -- 8 pointers */
44};
45
46#ifdef CONFIG_DEBUG_DEVRES
47static int log_devres = 0;
48module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
49
50static void set_node_dbginfo(struct devres_node *node, const char *name,
51 size_t size)
52{
53 node->name = name;
54 node->size = size;
55}
56
57static void devres_log(struct device *dev, struct devres_node *node,
58 const char *op)
59{
60 if (unlikely(log_devres))
61 dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
62 op, node, node->name, (unsigned long)node->size);
63}
64#else /* CONFIG_DEBUG_DEVRES */
65#define set_node_dbginfo(node, n, s) do {} while (0)
66#define devres_log(dev, node, op) do {} while (0)
67#endif /* CONFIG_DEBUG_DEVRES */
68
69/*
70 * Release functions for devres group. These callbacks are used only
71 * for identification.
72 */
73static void group_open_release(struct device *dev, void *res)
74{
75 /* noop */
76}
77
78static void group_close_release(struct device *dev, void *res)
79{
80 /* noop */
81}
82
83static struct devres_group * node_to_group(struct devres_node *node)
84{
85 if (node->release == &group_open_release)
86 return container_of(node, struct devres_group, node[0]);
87 if (node->release == &group_close_release)
88 return container_of(node, struct devres_group, node[1]);
89 return NULL;
90}
91
92static __always_inline struct devres * alloc_dr(dr_release_t release,
93 size_t size, gfp_t gfp, int nid)
94{
95 size_t tot_size;
96 struct devres *dr;
97
98 /* We must catch any near-SIZE_MAX cases that could overflow. */
99 if (unlikely(check_add_overflow(sizeof(struct devres), size,
100 &tot_size)))
101 return NULL;
102
103 dr = kmalloc_node_track_caller(tot_size, gfp, nid);
104 if (unlikely(!dr))
105 return NULL;
106
107 memset(dr, 0, offsetof(struct devres, data));
108
109 INIT_LIST_HEAD(&dr->node.entry);
110 dr->node.release = release;
111 return dr;
112}
113
114static void add_dr(struct device *dev, struct devres_node *node)
115{
116 devres_log(dev, node, "ADD");
117 BUG_ON(!list_empty(&node->entry));
118 list_add_tail(&node->entry, &dev->devres_head);
119}
120
121#ifdef CONFIG_DEBUG_DEVRES
122void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
123 const char *name)
124{
125 struct devres *dr;
126
127 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
128 if (unlikely(!dr))
129 return NULL;
130 set_node_dbginfo(&dr->node, name, size);
131 return dr->data;
132}
133EXPORT_SYMBOL_GPL(__devres_alloc_node);
134#else
135/**
136 * devres_alloc - Allocate device resource data
137 * @release: Release function devres will be associated with
138 * @size: Allocation size
139 * @gfp: Allocation flags
140 * @nid: NUMA node
141 *
142 * Allocate devres of @size bytes. The allocated area is zeroed, then
143 * associated with @release. The returned pointer can be passed to
144 * other devres_*() functions.
145 *
146 * RETURNS:
147 * Pointer to allocated devres on success, NULL on failure.
148 */
149void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
150{
151 struct devres *dr;
152
153 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
154 if (unlikely(!dr))
155 return NULL;
156 return dr->data;
157}
158EXPORT_SYMBOL_GPL(devres_alloc_node);
159#endif
160
161/**
162 * devres_for_each_res - Resource iterator
163 * @dev: Device to iterate resource from
164 * @release: Look for resources associated with this release function
165 * @match: Match function (optional)
166 * @match_data: Data for the match function
167 * @fn: Function to be called for each matched resource.
168 * @data: Data for @fn, the 3rd parameter of @fn
169 *
170 * Call @fn for each devres of @dev which is associated with @release
171 * and for which @match returns 1.
172 *
173 * RETURNS:
174 * void
175 */
176void devres_for_each_res(struct device *dev, dr_release_t release,
177 dr_match_t match, void *match_data,
178 void (*fn)(struct device *, void *, void *),
179 void *data)
180{
181 struct devres_node *node;
182 struct devres_node *tmp;
183 unsigned long flags;
184
185 if (!fn)
186 return;
187
188 spin_lock_irqsave(&dev->devres_lock, flags);
189 list_for_each_entry_safe_reverse(node, tmp,
190 &dev->devres_head, entry) {
191 struct devres *dr = container_of(node, struct devres, node);
192
193 if (node->release != release)
194 continue;
195 if (match && !match(dev, dr->data, match_data))
196 continue;
197 fn(dev, dr->data, data);
198 }
199 spin_unlock_irqrestore(&dev->devres_lock, flags);
200}
201EXPORT_SYMBOL_GPL(devres_for_each_res);
202
203/**
204 * devres_free - Free device resource data
205 * @res: Pointer to devres data to free
206 *
207 * Free devres created with devres_alloc().
208 */
209void devres_free(void *res)
210{
211 if (res) {
212 struct devres *dr = container_of(res, struct devres, data);
213
214 BUG_ON(!list_empty(&dr->node.entry));
215 kfree(dr);
216 }
217}
218EXPORT_SYMBOL_GPL(devres_free);
219
220/**
221 * devres_add - Register device resource
222 * @dev: Device to add resource to
223 * @res: Resource to register
224 *
225 * Register devres @res to @dev. @res should have been allocated
226 * using devres_alloc(). On driver detach, the associated release
227 * function will be invoked and devres will be freed automatically.
228 */
229void devres_add(struct device *dev, void *res)
230{
231 struct devres *dr = container_of(res, struct devres, data);
232 unsigned long flags;
233
234 spin_lock_irqsave(&dev->devres_lock, flags);
235 add_dr(dev, &dr->node);
236 spin_unlock_irqrestore(&dev->devres_lock, flags);
237}
238EXPORT_SYMBOL_GPL(devres_add);
239
240static struct devres *find_dr(struct device *dev, dr_release_t release,
241 dr_match_t match, void *match_data)
242{
243 struct devres_node *node;
244
245 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
246 struct devres *dr = container_of(node, struct devres, node);
247
248 if (node->release != release)
249 continue;
250 if (match && !match(dev, dr->data, match_data))
251 continue;
252 return dr;
253 }
254
255 return NULL;
256}
257
258/**
259 * devres_find - Find device resource
260 * @dev: Device to lookup resource from
261 * @release: Look for resources associated with this release function
262 * @match: Match function (optional)
263 * @match_data: Data for the match function
264 *
265 * Find the latest devres of @dev which is associated with @release
266 * and for which @match returns 1. If @match is NULL, it's considered
267 * to match all.
268 *
269 * RETURNS:
270 * Pointer to found devres, NULL if not found.
271 */
272void * devres_find(struct device *dev, dr_release_t release,
273 dr_match_t match, void *match_data)
274{
275 struct devres *dr;
276 unsigned long flags;
277
278 spin_lock_irqsave(&dev->devres_lock, flags);
279 dr = find_dr(dev, release, match, match_data);
280 spin_unlock_irqrestore(&dev->devres_lock, flags);
281
282 if (dr)
283 return dr->data;
284 return NULL;
285}
286EXPORT_SYMBOL_GPL(devres_find);
287
288/**
289 * devres_get - Find devres, if non-existent, add one atomically
290 * @dev: Device to lookup or add devres for
291 * @new_res: Pointer to new initialized devres to add if not found
292 * @match: Match function (optional)
293 * @match_data: Data for the match function
294 *
295 * Find the latest devres of @dev which has the same release function
296 * as @new_res and for which @match return 1. If found, @new_res is
297 * freed; otherwise, @new_res is added atomically.
298 *
299 * RETURNS:
300 * Pointer to found or added devres.
301 */
302void * devres_get(struct device *dev, void *new_res,
303 dr_match_t match, void *match_data)
304{
305 struct devres *new_dr = container_of(new_res, struct devres, data);
306 struct devres *dr;
307 unsigned long flags;
308
309 spin_lock_irqsave(&dev->devres_lock, flags);
310 dr = find_dr(dev, new_dr->node.release, match, match_data);
311 if (!dr) {
312 add_dr(dev, &new_dr->node);
313 dr = new_dr;
314 new_res = NULL;
315 }
316 spin_unlock_irqrestore(&dev->devres_lock, flags);
317 devres_free(new_res);
318
319 return dr->data;
320}
321EXPORT_SYMBOL_GPL(devres_get);
322
323/**
324 * devres_remove - Find a device resource and remove it
325 * @dev: Device to find resource from
326 * @release: Look for resources associated with this release function
327 * @match: Match function (optional)
328 * @match_data: Data for the match function
329 *
330 * Find the latest devres of @dev associated with @release and for
331 * which @match returns 1. If @match is NULL, it's considered to
332 * match all. If found, the resource is removed atomically and
333 * returned.
334 *
335 * RETURNS:
336 * Pointer to removed devres on success, NULL if not found.
337 */
338void * devres_remove(struct device *dev, dr_release_t release,
339 dr_match_t match, void *match_data)
340{
341 struct devres *dr;
342 unsigned long flags;
343
344 spin_lock_irqsave(&dev->devres_lock, flags);
345 dr = find_dr(dev, release, match, match_data);
346 if (dr) {
347 list_del_init(&dr->node.entry);
348 devres_log(dev, &dr->node, "REM");
349 }
350 spin_unlock_irqrestore(&dev->devres_lock, flags);
351
352 if (dr)
353 return dr->data;
354 return NULL;
355}
356EXPORT_SYMBOL_GPL(devres_remove);
357
358/**
359 * devres_destroy - Find a device resource and destroy it
360 * @dev: Device to find resource from
361 * @release: Look for resources associated with this release function
362 * @match: Match function (optional)
363 * @match_data: Data for the match function
364 *
365 * Find the latest devres of @dev associated with @release and for
366 * which @match returns 1. If @match is NULL, it's considered to
367 * match all. If found, the resource is removed atomically and freed.
368 *
369 * Note that the release function for the resource will not be called,
370 * only the devres-allocated data will be freed. The caller becomes
371 * responsible for freeing any other data.
372 *
373 * RETURNS:
374 * 0 if devres is found and freed, -ENOENT if not found.
375 */
376int devres_destroy(struct device *dev, dr_release_t release,
377 dr_match_t match, void *match_data)
378{
379 void *res;
380
381 res = devres_remove(dev, release, match, match_data);
382 if (unlikely(!res))
383 return -ENOENT;
384
385 devres_free(res);
386 return 0;
387}
388EXPORT_SYMBOL_GPL(devres_destroy);
389
390
391/**
392 * devres_release - Find a device resource and destroy it, calling release
393 * @dev: Device to find resource from
394 * @release: Look for resources associated with this release function
395 * @match: Match function (optional)
396 * @match_data: Data for the match function
397 *
398 * Find the latest devres of @dev associated with @release and for
399 * which @match returns 1. If @match is NULL, it's considered to
400 * match all. If found, the resource is removed atomically, the
401 * release function called and the resource freed.
402 *
403 * RETURNS:
404 * 0 if devres is found and freed, -ENOENT if not found.
405 */
406int devres_release(struct device *dev, dr_release_t release,
407 dr_match_t match, void *match_data)
408{
409 void *res;
410
411 res = devres_remove(dev, release, match, match_data);
412 if (unlikely(!res))
413 return -ENOENT;
414
415 (*release)(dev, res);
416 devres_free(res);
417 return 0;
418}
419EXPORT_SYMBOL_GPL(devres_release);
420
421static int remove_nodes(struct device *dev,
422 struct list_head *first, struct list_head *end,
423 struct list_head *todo)
424{
425 int cnt = 0, nr_groups = 0;
426 struct list_head *cur;
427
428 /* First pass - move normal devres entries to @todo and clear
429 * devres_group colors.
430 */
431 cur = first;
432 while (cur != end) {
433 struct devres_node *node;
434 struct devres_group *grp;
435
436 node = list_entry(cur, struct devres_node, entry);
437 cur = cur->next;
438
439 grp = node_to_group(node);
440 if (grp) {
441 /* clear color of group markers in the first pass */
442 grp->color = 0;
443 nr_groups++;
444 } else {
445 /* regular devres entry */
446 if (&node->entry == first)
447 first = first->next;
448 list_move_tail(&node->entry, todo);
449 cnt++;
450 }
451 }
452
453 if (!nr_groups)
454 return cnt;
455
456 /* Second pass - Scan groups and color them. A group gets
457 * color value of two iff the group is wholly contained in
458 * [cur, end). That is, for a closed group, both opening and
459 * closing markers should be in the range, while just the
460 * opening marker is enough for an open group.
461 */
462 cur = first;
463 while (cur != end) {
464 struct devres_node *node;
465 struct devres_group *grp;
466
467 node = list_entry(cur, struct devres_node, entry);
468 cur = cur->next;
469
470 grp = node_to_group(node);
471 BUG_ON(!grp || list_empty(&grp->node[0].entry));
472
473 grp->color++;
474 if (list_empty(&grp->node[1].entry))
475 grp->color++;
476
477 BUG_ON(grp->color <= 0 || grp->color > 2);
478 if (grp->color == 2) {
479 /* No need to update cur or end. The removed
480 * nodes are always before both.
481 */
482 list_move_tail(&grp->node[0].entry, todo);
483 list_del_init(&grp->node[1].entry);
484 }
485 }
486
487 return cnt;
488}
489
490static int release_nodes(struct device *dev, struct list_head *first,
491 struct list_head *end, unsigned long flags)
492 __releases(&dev->devres_lock)
493{
494 LIST_HEAD(todo);
495 int cnt;
496 struct devres *dr, *tmp;
497
498 cnt = remove_nodes(dev, first, end, &todo);
499
500 spin_unlock_irqrestore(&dev->devres_lock, flags);
501
502 /* Release. Note that both devres and devres_group are
503 * handled as devres in the following loop. This is safe.
504 */
505 list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
506 devres_log(dev, &dr->node, "REL");
507 dr->node.release(dev, dr->data);
508 kfree(dr);
509 }
510
511 return cnt;
512}
513
514/**
515 * devres_release_all - Release all managed resources
516 * @dev: Device to release resources for
517 *
518 * Release all resources associated with @dev. This function is
519 * called on driver detach.
520 */
521int devres_release_all(struct device *dev)
522{
523 unsigned long flags;
524
525 /* Looks like an uninitialized device structure */
526 if (WARN_ON(dev->devres_head.next == NULL))
527 return -ENODEV;
528 spin_lock_irqsave(&dev->devres_lock, flags);
529 return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
530 flags);
531}
532
533/**
534 * devres_open_group - Open a new devres group
535 * @dev: Device to open devres group for
536 * @id: Separator ID
537 * @gfp: Allocation flags
538 *
539 * Open a new devres group for @dev with @id. For @id, using a
540 * pointer to an object which won't be used for another group is
541 * recommended. If @id is NULL, address-wise unique ID is created.
542 *
543 * RETURNS:
544 * ID of the new group, NULL on failure.
545 */
546void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
547{
548 struct devres_group *grp;
549 unsigned long flags;
550
551 grp = kmalloc(sizeof(*grp), gfp);
552 if (unlikely(!grp))
553 return NULL;
554
555 grp->node[0].release = &group_open_release;
556 grp->node[1].release = &group_close_release;
557 INIT_LIST_HEAD(&grp->node[0].entry);
558 INIT_LIST_HEAD(&grp->node[1].entry);
559 set_node_dbginfo(&grp->node[0], "grp<", 0);
560 set_node_dbginfo(&grp->node[1], "grp>", 0);
561 grp->id = grp;
562 if (id)
563 grp->id = id;
564
565 spin_lock_irqsave(&dev->devres_lock, flags);
566 add_dr(dev, &grp->node[0]);
567 spin_unlock_irqrestore(&dev->devres_lock, flags);
568 return grp->id;
569}
570EXPORT_SYMBOL_GPL(devres_open_group);
571
572/* Find devres group with ID @id. If @id is NULL, look for the latest. */
573static struct devres_group * find_group(struct device *dev, void *id)
574{
575 struct devres_node *node;
576
577 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
578 struct devres_group *grp;
579
580 if (node->release != &group_open_release)
581 continue;
582
583 grp = container_of(node, struct devres_group, node[0]);
584
585 if (id) {
586 if (grp->id == id)
587 return grp;
588 } else if (list_empty(&grp->node[1].entry))
589 return grp;
590 }
591
592 return NULL;
593}
594
595/**
596 * devres_close_group - Close a devres group
597 * @dev: Device to close devres group for
598 * @id: ID of target group, can be NULL
599 *
600 * Close the group identified by @id. If @id is NULL, the latest open
601 * group is selected.
602 */
603void devres_close_group(struct device *dev, void *id)
604{
605 struct devres_group *grp;
606 unsigned long flags;
607
608 spin_lock_irqsave(&dev->devres_lock, flags);
609
610 grp = find_group(dev, id);
611 if (grp)
612 add_dr(dev, &grp->node[1]);
613 else
614 WARN_ON(1);
615
616 spin_unlock_irqrestore(&dev->devres_lock, flags);
617}
618EXPORT_SYMBOL_GPL(devres_close_group);
619
620/**
621 * devres_remove_group - Remove a devres group
622 * @dev: Device to remove group for
623 * @id: ID of target group, can be NULL
624 *
625 * Remove the group identified by @id. If @id is NULL, the latest
626 * open group is selected. Note that removing a group doesn't affect
627 * any other resources.
628 */
629void devres_remove_group(struct device *dev, void *id)
630{
631 struct devres_group *grp;
632 unsigned long flags;
633
634 spin_lock_irqsave(&dev->devres_lock, flags);
635
636 grp = find_group(dev, id);
637 if (grp) {
638 list_del_init(&grp->node[0].entry);
639 list_del_init(&grp->node[1].entry);
640 devres_log(dev, &grp->node[0], "REM");
641 } else
642 WARN_ON(1);
643
644 spin_unlock_irqrestore(&dev->devres_lock, flags);
645
646 kfree(grp);
647}
648EXPORT_SYMBOL_GPL(devres_remove_group);
649
650/**
651 * devres_release_group - Release resources in a devres group
652 * @dev: Device to release group for
653 * @id: ID of target group, can be NULL
654 *
655 * Release all resources in the group identified by @id. If @id is
656 * NULL, the latest open group is selected. The selected group and
657 * groups properly nested inside the selected group are removed.
658 *
659 * RETURNS:
660 * The number of released non-group resources.
661 */
662int devres_release_group(struct device *dev, void *id)
663{
664 struct devres_group *grp;
665 unsigned long flags;
666 int cnt = 0;
667
668 spin_lock_irqsave(&dev->devres_lock, flags);
669
670 grp = find_group(dev, id);
671 if (grp) {
672 struct list_head *first = &grp->node[0].entry;
673 struct list_head *end = &dev->devres_head;
674
675 if (!list_empty(&grp->node[1].entry))
676 end = grp->node[1].entry.next;
677
678 cnt = release_nodes(dev, first, end, flags);
679 } else {
680 WARN_ON(1);
681 spin_unlock_irqrestore(&dev->devres_lock, flags);
682 }
683
684 return cnt;
685}
686EXPORT_SYMBOL_GPL(devres_release_group);
687
688/*
689 * Custom devres actions allow inserting a simple function call
690 * into the teadown sequence.
691 */
692
693struct action_devres {
694 void *data;
695 void (*action)(void *);
696};
697
698static int devm_action_match(struct device *dev, void *res, void *p)
699{
700 struct action_devres *devres = res;
701 struct action_devres *target = p;
702
703 return devres->action == target->action &&
704 devres->data == target->data;
705}
706
707static void devm_action_release(struct device *dev, void *res)
708{
709 struct action_devres *devres = res;
710
711 devres->action(devres->data);
712}
713
714/**
715 * devm_add_action() - add a custom action to list of managed resources
716 * @dev: Device that owns the action
717 * @action: Function that should be called
718 * @data: Pointer to data passed to @action implementation
719 *
720 * This adds a custom action to the list of managed resources so that
721 * it gets executed as part of standard resource unwinding.
722 */
723int devm_add_action(struct device *dev, void (*action)(void *), void *data)
724{
725 struct action_devres *devres;
726
727 devres = devres_alloc(devm_action_release,
728 sizeof(struct action_devres), GFP_KERNEL);
729 if (!devres)
730 return -ENOMEM;
731
732 devres->data = data;
733 devres->action = action;
734
735 devres_add(dev, devres);
736 return 0;
737}
738EXPORT_SYMBOL_GPL(devm_add_action);
739
740/**
741 * devm_remove_action() - removes previously added custom action
742 * @dev: Device that owns the action
743 * @action: Function implementing the action
744 * @data: Pointer to data passed to @action implementation
745 *
746 * Removes instance of @action previously added by devm_add_action().
747 * Both action and data should match one of the existing entries.
748 */
749void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
750{
751 struct action_devres devres = {
752 .data = data,
753 .action = action,
754 };
755
756 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
757 &devres));
758
759}
760EXPORT_SYMBOL_GPL(devm_remove_action);
761
762/*
763 * Managed kmalloc/kfree
764 */
765static void devm_kmalloc_release(struct device *dev, void *res)
766{
767 /* noop */
768}
769
770static int devm_kmalloc_match(struct device *dev, void *res, void *data)
771{
772 return res == data;
773}
774
775/**
776 * devm_kmalloc - Resource-managed kmalloc
777 * @dev: Device to allocate memory for
778 * @size: Allocation size
779 * @gfp: Allocation gfp flags
780 *
781 * Managed kmalloc. Memory allocated with this function is
782 * automatically freed on driver detach. Like all other devres
783 * resources, guaranteed alignment is unsigned long long.
784 *
785 * RETURNS:
786 * Pointer to allocated memory on success, NULL on failure.
787 */
788void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
789{
790 struct devres *dr;
791
792 /* use raw alloc_dr for kmalloc caller tracing */
793 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
794 if (unlikely(!dr))
795 return NULL;
796
797 /*
798 * This is named devm_kzalloc_release for historical reasons
799 * The initial implementation did not support kmalloc, only kzalloc
800 */
801 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
802 devres_add(dev, dr->data);
803 return dr->data;
804}
805EXPORT_SYMBOL_GPL(devm_kmalloc);
806
807/**
808 * devm_kstrdup - Allocate resource managed space and
809 * copy an existing string into that.
810 * @dev: Device to allocate memory for
811 * @s: the string to duplicate
812 * @gfp: the GFP mask used in the devm_kmalloc() call when
813 * allocating memory
814 * RETURNS:
815 * Pointer to allocated string on success, NULL on failure.
816 */
817char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
818{
819 size_t size;
820 char *buf;
821
822 if (!s)
823 return NULL;
824
825 size = strlen(s) + 1;
826 buf = devm_kmalloc(dev, size, gfp);
827 if (buf)
828 memcpy(buf, s, size);
829 return buf;
830}
831EXPORT_SYMBOL_GPL(devm_kstrdup);
832
833/**
834 * devm_kstrdup_const - resource managed conditional string duplication
835 * @dev: device for which to duplicate the string
836 * @s: the string to duplicate
837 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
838 *
839 * Strings allocated by devm_kstrdup_const will be automatically freed when
840 * the associated device is detached.
841 *
842 * RETURNS:
843 * Source string if it is in .rodata section otherwise it falls back to
844 * devm_kstrdup.
845 */
846const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
847{
848 if (is_kernel_rodata((unsigned long)s))
849 return s;
850
851 return devm_kstrdup(dev, s, gfp);
852}
853EXPORT_SYMBOL_GPL(devm_kstrdup_const);
854
855/**
856 * devm_kvasprintf - Allocate resource managed space and format a string
857 * into that.
858 * @dev: Device to allocate memory for
859 * @gfp: the GFP mask used in the devm_kmalloc() call when
860 * allocating memory
861 * @fmt: The printf()-style format string
862 * @ap: Arguments for the format string
863 * RETURNS:
864 * Pointer to allocated string on success, NULL on failure.
865 */
866char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
867 va_list ap)
868{
869 unsigned int len;
870 char *p;
871 va_list aq;
872
873 va_copy(aq, ap);
874 len = vsnprintf(NULL, 0, fmt, aq);
875 va_end(aq);
876
877 p = devm_kmalloc(dev, len+1, gfp);
878 if (!p)
879 return NULL;
880
881 vsnprintf(p, len+1, fmt, ap);
882
883 return p;
884}
885EXPORT_SYMBOL(devm_kvasprintf);
886
887/**
888 * devm_kasprintf - Allocate resource managed space and format a string
889 * into that.
890 * @dev: Device to allocate memory for
891 * @gfp: the GFP mask used in the devm_kmalloc() call when
892 * allocating memory
893 * @fmt: The printf()-style format string
894 * @...: Arguments for the format string
895 * RETURNS:
896 * Pointer to allocated string on success, NULL on failure.
897 */
898char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
899{
900 va_list ap;
901 char *p;
902
903 va_start(ap, fmt);
904 p = devm_kvasprintf(dev, gfp, fmt, ap);
905 va_end(ap);
906
907 return p;
908}
909EXPORT_SYMBOL_GPL(devm_kasprintf);
910
911/**
912 * devm_kfree - Resource-managed kfree
913 * @dev: Device this memory belongs to
914 * @p: Memory to free
915 *
916 * Free memory allocated with devm_kmalloc().
917 */
918void devm_kfree(struct device *dev, const void *p)
919{
920 int rc;
921
922 /*
923 * Special case: pointer to a string in .rodata returned by
924 * devm_kstrdup_const().
925 */
926 if (unlikely(is_kernel_rodata((unsigned long)p)))
927 return;
928
929 rc = devres_destroy(dev, devm_kmalloc_release,
930 devm_kmalloc_match, (void *)p);
931 WARN_ON(rc);
932}
933EXPORT_SYMBOL_GPL(devm_kfree);
934
935/**
936 * devm_kmemdup - Resource-managed kmemdup
937 * @dev: Device this memory belongs to
938 * @src: Memory region to duplicate
939 * @len: Memory region length
940 * @gfp: GFP mask to use
941 *
942 * Duplicate region of a memory using resource managed kmalloc
943 */
944void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
945{
946 void *p;
947
948 p = devm_kmalloc(dev, len, gfp);
949 if (p)
950 memcpy(p, src, len);
951
952 return p;
953}
954EXPORT_SYMBOL_GPL(devm_kmemdup);
955
956struct pages_devres {
957 unsigned long addr;
958 unsigned int order;
959};
960
961static int devm_pages_match(struct device *dev, void *res, void *p)
962{
963 struct pages_devres *devres = res;
964 struct pages_devres *target = p;
965
966 return devres->addr == target->addr;
967}
968
969static void devm_pages_release(struct device *dev, void *res)
970{
971 struct pages_devres *devres = res;
972
973 free_pages(devres->addr, devres->order);
974}
975
976/**
977 * devm_get_free_pages - Resource-managed __get_free_pages
978 * @dev: Device to allocate memory for
979 * @gfp_mask: Allocation gfp flags
980 * @order: Allocation size is (1 << order) pages
981 *
982 * Managed get_free_pages. Memory allocated with this function is
983 * automatically freed on driver detach.
984 *
985 * RETURNS:
986 * Address of allocated memory on success, 0 on failure.
987 */
988
989unsigned long devm_get_free_pages(struct device *dev,
990 gfp_t gfp_mask, unsigned int order)
991{
992 struct pages_devres *devres;
993 unsigned long addr;
994
995 addr = __get_free_pages(gfp_mask, order);
996
997 if (unlikely(!addr))
998 return 0;
999
1000 devres = devres_alloc(devm_pages_release,
1001 sizeof(struct pages_devres), GFP_KERNEL);
1002 if (unlikely(!devres)) {
1003 free_pages(addr, order);
1004 return 0;
1005 }
1006
1007 devres->addr = addr;
1008 devres->order = order;
1009
1010 devres_add(dev, devres);
1011 return addr;
1012}
1013EXPORT_SYMBOL_GPL(devm_get_free_pages);
1014
1015/**
1016 * devm_free_pages - Resource-managed free_pages
1017 * @dev: Device this memory belongs to
1018 * @addr: Memory to free
1019 *
1020 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1021 * there is no need to supply the @order.
1022 */
1023void devm_free_pages(struct device *dev, unsigned long addr)
1024{
1025 struct pages_devres devres = { .addr = addr };
1026
1027 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1028 &devres));
1029}
1030EXPORT_SYMBOL_GPL(devm_free_pages);
1031
1032static void devm_percpu_release(struct device *dev, void *pdata)
1033{
1034 void __percpu *p;
1035
1036 p = *(void __percpu **)pdata;
1037 free_percpu(p);
1038}
1039
1040static int devm_percpu_match(struct device *dev, void *data, void *p)
1041{
1042 struct devres *devr = container_of(data, struct devres, data);
1043
1044 return *(void **)devr->data == p;
1045}
1046
1047/**
1048 * __devm_alloc_percpu - Resource-managed alloc_percpu
1049 * @dev: Device to allocate per-cpu memory for
1050 * @size: Size of per-cpu memory to allocate
1051 * @align: Alignment of per-cpu memory to allocate
1052 *
1053 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1054 * automatically freed on driver detach.
1055 *
1056 * RETURNS:
1057 * Pointer to allocated memory on success, NULL on failure.
1058 */
1059void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1060 size_t align)
1061{
1062 void *p;
1063 void __percpu *pcpu;
1064
1065 pcpu = __alloc_percpu(size, align);
1066 if (!pcpu)
1067 return NULL;
1068
1069 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1070 if (!p) {
1071 free_percpu(pcpu);
1072 return NULL;
1073 }
1074
1075 *(void __percpu **)p = pcpu;
1076
1077 devres_add(dev, p);
1078
1079 return pcpu;
1080}
1081EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1082
1083/**
1084 * devm_free_percpu - Resource-managed free_percpu
1085 * @dev: Device this memory belongs to
1086 * @pdata: Per-cpu memory to free
1087 *
1088 * Free memory allocated with devm_alloc_percpu().
1089 */
1090void devm_free_percpu(struct device *dev, void __percpu *pdata)
1091{
1092 WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1093 (void *)pdata));
1094}
1095EXPORT_SYMBOL_GPL(devm_free_percpu);
1096