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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)
86{
87 size_t tot_size = sizeof(struct devres) + size;
88 struct devres *dr;
89
90 dr = kmalloc_track_caller(tot_size, gfp);
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(dr_release_t release, size_t size, gfp_t gfp,
110 const char *name)
111{
112 struct devres *dr;
113
114 dr = alloc_dr(release, size, gfp | __GFP_ZERO);
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);
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 *
128 * Allocate devres of @size bytes. The allocated area is zeroed, then
129 * associated with @release. The returned pointer can be passed to
130 * other devres_*() functions.
131 *
132 * RETURNS:
133 * Pointer to allocated devres on success, NULL on failure.
134 */
135void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
136{
137 struct devres *dr;
138
139 dr = alloc_dr(release, size, gfp | __GFP_ZERO);
140 if (unlikely(!dr))
141 return NULL;
142 return dr->data;
143}
144EXPORT_SYMBOL_GPL(devres_alloc);
145#endif
146
147/**
148 * devres_for_each_res - Resource iterator
149 * @dev: Device to iterate resource from
150 * @release: Look for resources associated with this release function
151 * @match: Match function (optional)
152 * @match_data: Data for the match function
153 * @fn: Function to be called for each matched resource.
154 * @data: Data for @fn, the 3rd parameter of @fn
155 *
156 * Call @fn for each devres of @dev which is associated with @release
157 * and for which @match returns 1.
158 *
159 * RETURNS:
160 * void
161 */
162void devres_for_each_res(struct device *dev, dr_release_t release,
163 dr_match_t match, void *match_data,
164 void (*fn)(struct device *, void *, void *),
165 void *data)
166{
167 struct devres_node *node;
168 struct devres_node *tmp;
169 unsigned long flags;
170
171 if (!fn)
172 return;
173
174 spin_lock_irqsave(&dev->devres_lock, flags);
175 list_for_each_entry_safe_reverse(node, tmp,
176 &dev->devres_head, entry) {
177 struct devres *dr = container_of(node, struct devres, node);
178
179 if (node->release != release)
180 continue;
181 if (match && !match(dev, dr->data, match_data))
182 continue;
183 fn(dev, dr->data, data);
184 }
185 spin_unlock_irqrestore(&dev->devres_lock, flags);
186}
187EXPORT_SYMBOL_GPL(devres_for_each_res);
188
189/**
190 * devres_free - Free device resource data
191 * @res: Pointer to devres data to free
192 *
193 * Free devres created with devres_alloc().
194 */
195void devres_free(void *res)
196{
197 if (res) {
198 struct devres *dr = container_of(res, struct devres, data);
199
200 BUG_ON(!list_empty(&dr->node.entry));
201 kfree(dr);
202 }
203}
204EXPORT_SYMBOL_GPL(devres_free);
205
206/**
207 * devres_add - Register device resource
208 * @dev: Device to add resource to
209 * @res: Resource to register
210 *
211 * Register devres @res to @dev. @res should have been allocated
212 * using devres_alloc(). On driver detach, the associated release
213 * function will be invoked and devres will be freed automatically.
214 */
215void devres_add(struct device *dev, void *res)
216{
217 struct devres *dr = container_of(res, struct devres, data);
218 unsigned long flags;
219
220 spin_lock_irqsave(&dev->devres_lock, flags);
221 add_dr(dev, &dr->node);
222 spin_unlock_irqrestore(&dev->devres_lock, flags);
223}
224EXPORT_SYMBOL_GPL(devres_add);
225
226static struct devres *find_dr(struct device *dev, dr_release_t release,
227 dr_match_t match, void *match_data)
228{
229 struct devres_node *node;
230
231 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
232 struct devres *dr = container_of(node, struct devres, node);
233
234 if (node->release != release)
235 continue;
236 if (match && !match(dev, dr->data, match_data))
237 continue;
238 return dr;
239 }
240
241 return NULL;
242}
243
244/**
245 * devres_find - Find device resource
246 * @dev: Device to lookup resource from
247 * @release: Look for resources associated with this release function
248 * @match: Match function (optional)
249 * @match_data: Data for the match function
250 *
251 * Find the latest devres of @dev which is associated with @release
252 * and for which @match returns 1. If @match is NULL, it's considered
253 * to match all.
254 *
255 * RETURNS:
256 * Pointer to found devres, NULL if not found.
257 */
258void * devres_find(struct device *dev, dr_release_t release,
259 dr_match_t match, void *match_data)
260{
261 struct devres *dr;
262 unsigned long flags;
263
264 spin_lock_irqsave(&dev->devres_lock, flags);
265 dr = find_dr(dev, release, match, match_data);
266 spin_unlock_irqrestore(&dev->devres_lock, flags);
267
268 if (dr)
269 return dr->data;
270 return NULL;
271}
272EXPORT_SYMBOL_GPL(devres_find);
273
274/**
275 * devres_get - Find devres, if non-existent, add one atomically
276 * @dev: Device to lookup or add devres for
277 * @new_res: Pointer to new initialized devres to add if not found
278 * @match: Match function (optional)
279 * @match_data: Data for the match function
280 *
281 * Find the latest devres of @dev which has the same release function
282 * as @new_res and for which @match return 1. If found, @new_res is
283 * freed; otherwise, @new_res is added atomically.
284 *
285 * RETURNS:
286 * Pointer to found or added devres.
287 */
288void * devres_get(struct device *dev, void *new_res,
289 dr_match_t match, void *match_data)
290{
291 struct devres *new_dr = container_of(new_res, struct devres, data);
292 struct devres *dr;
293 unsigned long flags;
294
295 spin_lock_irqsave(&dev->devres_lock, flags);
296 dr = find_dr(dev, new_dr->node.release, match, match_data);
297 if (!dr) {
298 add_dr(dev, &new_dr->node);
299 dr = new_dr;
300 new_dr = NULL;
301 }
302 spin_unlock_irqrestore(&dev->devres_lock, flags);
303 devres_free(new_dr);
304
305 return dr->data;
306}
307EXPORT_SYMBOL_GPL(devres_get);
308
309/**
310 * devres_remove - Find a device resource and remove it
311 * @dev: Device to find resource from
312 * @release: Look for resources associated with this release function
313 * @match: Match function (optional)
314 * @match_data: Data for the match function
315 *
316 * Find the latest devres of @dev associated with @release and for
317 * which @match returns 1. If @match is NULL, it's considered to
318 * match all. If found, the resource is removed atomically and
319 * returned.
320 *
321 * RETURNS:
322 * Pointer to removed devres on success, NULL if not found.
323 */
324void * devres_remove(struct device *dev, dr_release_t release,
325 dr_match_t match, void *match_data)
326{
327 struct devres *dr;
328 unsigned long flags;
329
330 spin_lock_irqsave(&dev->devres_lock, flags);
331 dr = find_dr(dev, release, match, match_data);
332 if (dr) {
333 list_del_init(&dr->node.entry);
334 devres_log(dev, &dr->node, "REM");
335 }
336 spin_unlock_irqrestore(&dev->devres_lock, flags);
337
338 if (dr)
339 return dr->data;
340 return NULL;
341}
342EXPORT_SYMBOL_GPL(devres_remove);
343
344/**
345 * devres_destroy - Find a device resource and destroy it
346 * @dev: Device to find resource from
347 * @release: Look for resources associated with this release function
348 * @match: Match function (optional)
349 * @match_data: Data for the match function
350 *
351 * Find the latest devres of @dev associated with @release and for
352 * which @match returns 1. If @match is NULL, it's considered to
353 * match all. If found, the resource is removed atomically and freed.
354 *
355 * Note that the release function for the resource will not be called,
356 * only the devres-allocated data will be freed. The caller becomes
357 * responsible for freeing any other data.
358 *
359 * RETURNS:
360 * 0 if devres is found and freed, -ENOENT if not found.
361 */
362int devres_destroy(struct device *dev, dr_release_t release,
363 dr_match_t match, void *match_data)
364{
365 void *res;
366
367 res = devres_remove(dev, release, match, match_data);
368 if (unlikely(!res))
369 return -ENOENT;
370
371 devres_free(res);
372 return 0;
373}
374EXPORT_SYMBOL_GPL(devres_destroy);
375
376
377/**
378 * devres_release - Find a device resource and destroy it, calling release
379 * @dev: Device to find resource from
380 * @release: Look for resources associated with this release function
381 * @match: Match function (optional)
382 * @match_data: Data for the match function
383 *
384 * Find the latest devres of @dev associated with @release and for
385 * which @match returns 1. If @match is NULL, it's considered to
386 * match all. If found, the resource is removed atomically, the
387 * release function called and the resource freed.
388 *
389 * RETURNS:
390 * 0 if devres is found and freed, -ENOENT if not found.
391 */
392int devres_release(struct device *dev, dr_release_t release,
393 dr_match_t match, void *match_data)
394{
395 void *res;
396
397 res = devres_remove(dev, release, match, match_data);
398 if (unlikely(!res))
399 return -ENOENT;
400
401 (*release)(dev, res);
402 devres_free(res);
403 return 0;
404}
405EXPORT_SYMBOL_GPL(devres_release);
406
407static int remove_nodes(struct device *dev,
408 struct list_head *first, struct list_head *end,
409 struct list_head *todo)
410{
411 int cnt = 0, nr_groups = 0;
412 struct list_head *cur;
413
414 /* First pass - move normal devres entries to @todo and clear
415 * devres_group colors.
416 */
417 cur = first;
418 while (cur != end) {
419 struct devres_node *node;
420 struct devres_group *grp;
421
422 node = list_entry(cur, struct devres_node, entry);
423 cur = cur->next;
424
425 grp = node_to_group(node);
426 if (grp) {
427 /* clear color of group markers in the first pass */
428 grp->color = 0;
429 nr_groups++;
430 } else {
431 /* regular devres entry */
432 if (&node->entry == first)
433 first = first->next;
434 list_move_tail(&node->entry, todo);
435 cnt++;
436 }
437 }
438
439 if (!nr_groups)
440 return cnt;
441
442 /* Second pass - Scan groups and color them. A group gets
443 * color value of two iff the group is wholly contained in
444 * [cur, end). That is, for a closed group, both opening and
445 * closing markers should be in the range, while just the
446 * opening marker is enough for an open group.
447 */
448 cur = first;
449 while (cur != end) {
450 struct devres_node *node;
451 struct devres_group *grp;
452
453 node = list_entry(cur, struct devres_node, entry);
454 cur = cur->next;
455
456 grp = node_to_group(node);
457 BUG_ON(!grp || list_empty(&grp->node[0].entry));
458
459 grp->color++;
460 if (list_empty(&grp->node[1].entry))
461 grp->color++;
462
463 BUG_ON(grp->color <= 0 || grp->color > 2);
464 if (grp->color == 2) {
465 /* No need to update cur or end. The removed
466 * nodes are always before both.
467 */
468 list_move_tail(&grp->node[0].entry, todo);
469 list_del_init(&grp->node[1].entry);
470 }
471 }
472
473 return cnt;
474}
475
476static int release_nodes(struct device *dev, struct list_head *first,
477 struct list_head *end, unsigned long flags)
478 __releases(&dev->devres_lock)
479{
480 LIST_HEAD(todo);
481 int cnt;
482 struct devres *dr, *tmp;
483
484 cnt = remove_nodes(dev, first, end, &todo);
485
486 spin_unlock_irqrestore(&dev->devres_lock, flags);
487
488 /* Release. Note that both devres and devres_group are
489 * handled as devres in the following loop. This is safe.
490 */
491 list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
492 devres_log(dev, &dr->node, "REL");
493 dr->node.release(dev, dr->data);
494 kfree(dr);
495 }
496
497 return cnt;
498}
499
500/**
501 * devres_release_all - Release all managed resources
502 * @dev: Device to release resources for
503 *
504 * Release all resources associated with @dev. This function is
505 * called on driver detach.
506 */
507int devres_release_all(struct device *dev)
508{
509 unsigned long flags;
510
511 /* Looks like an uninitialized device structure */
512 if (WARN_ON(dev->devres_head.next == NULL))
513 return -ENODEV;
514 spin_lock_irqsave(&dev->devres_lock, flags);
515 return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
516 flags);
517}
518
519/**
520 * devres_open_group - Open a new devres group
521 * @dev: Device to open devres group for
522 * @id: Separator ID
523 * @gfp: Allocation flags
524 *
525 * Open a new devres group for @dev with @id. For @id, using a
526 * pointer to an object which won't be used for another group is
527 * recommended. If @id is NULL, address-wise unique ID is created.
528 *
529 * RETURNS:
530 * ID of the new group, NULL on failure.
531 */
532void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
533{
534 struct devres_group *grp;
535 unsigned long flags;
536
537 grp = kmalloc(sizeof(*grp), gfp);
538 if (unlikely(!grp))
539 return NULL;
540
541 grp->node[0].release = &group_open_release;
542 grp->node[1].release = &group_close_release;
543 INIT_LIST_HEAD(&grp->node[0].entry);
544 INIT_LIST_HEAD(&grp->node[1].entry);
545 set_node_dbginfo(&grp->node[0], "grp<", 0);
546 set_node_dbginfo(&grp->node[1], "grp>", 0);
547 grp->id = grp;
548 if (id)
549 grp->id = id;
550
551 spin_lock_irqsave(&dev->devres_lock, flags);
552 add_dr(dev, &grp->node[0]);
553 spin_unlock_irqrestore(&dev->devres_lock, flags);
554 return grp->id;
555}
556EXPORT_SYMBOL_GPL(devres_open_group);
557
558/* Find devres group with ID @id. If @id is NULL, look for the latest. */
559static struct devres_group * find_group(struct device *dev, void *id)
560{
561 struct devres_node *node;
562
563 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
564 struct devres_group *grp;
565
566 if (node->release != &group_open_release)
567 continue;
568
569 grp = container_of(node, struct devres_group, node[0]);
570
571 if (id) {
572 if (grp->id == id)
573 return grp;
574 } else if (list_empty(&grp->node[1].entry))
575 return grp;
576 }
577
578 return NULL;
579}
580
581/**
582 * devres_close_group - Close a devres group
583 * @dev: Device to close devres group for
584 * @id: ID of target group, can be NULL
585 *
586 * Close the group identified by @id. If @id is NULL, the latest open
587 * group is selected.
588 */
589void devres_close_group(struct device *dev, void *id)
590{
591 struct devres_group *grp;
592 unsigned long flags;
593
594 spin_lock_irqsave(&dev->devres_lock, flags);
595
596 grp = find_group(dev, id);
597 if (grp)
598 add_dr(dev, &grp->node[1]);
599 else
600 WARN_ON(1);
601
602 spin_unlock_irqrestore(&dev->devres_lock, flags);
603}
604EXPORT_SYMBOL_GPL(devres_close_group);
605
606/**
607 * devres_remove_group - Remove a devres group
608 * @dev: Device to remove group for
609 * @id: ID of target group, can be NULL
610 *
611 * Remove the group identified by @id. If @id is NULL, the latest
612 * open group is selected. Note that removing a group doesn't affect
613 * any other resources.
614 */
615void devres_remove_group(struct device *dev, void *id)
616{
617 struct devres_group *grp;
618 unsigned long flags;
619
620 spin_lock_irqsave(&dev->devres_lock, flags);
621
622 grp = find_group(dev, id);
623 if (grp) {
624 list_del_init(&grp->node[0].entry);
625 list_del_init(&grp->node[1].entry);
626 devres_log(dev, &grp->node[0], "REM");
627 } else
628 WARN_ON(1);
629
630 spin_unlock_irqrestore(&dev->devres_lock, flags);
631
632 kfree(grp);
633}
634EXPORT_SYMBOL_GPL(devres_remove_group);
635
636/**
637 * devres_release_group - Release resources in a devres group
638 * @dev: Device to release group for
639 * @id: ID of target group, can be NULL
640 *
641 * Release all resources in the group identified by @id. If @id is
642 * NULL, the latest open group is selected. The selected group and
643 * groups properly nested inside the selected group are removed.
644 *
645 * RETURNS:
646 * The number of released non-group resources.
647 */
648int devres_release_group(struct device *dev, void *id)
649{
650 struct devres_group *grp;
651 unsigned long flags;
652 int cnt = 0;
653
654 spin_lock_irqsave(&dev->devres_lock, flags);
655
656 grp = find_group(dev, id);
657 if (grp) {
658 struct list_head *first = &grp->node[0].entry;
659 struct list_head *end = &dev->devres_head;
660
661 if (!list_empty(&grp->node[1].entry))
662 end = grp->node[1].entry.next;
663
664 cnt = release_nodes(dev, first, end, flags);
665 } else {
666 WARN_ON(1);
667 spin_unlock_irqrestore(&dev->devres_lock, flags);
668 }
669
670 return cnt;
671}
672EXPORT_SYMBOL_GPL(devres_release_group);
673
674/*
675 * Custom devres actions allow inserting a simple function call
676 * into the teadown sequence.
677 */
678
679struct action_devres {
680 void *data;
681 void (*action)(void *);
682};
683
684static int devm_action_match(struct device *dev, void *res, void *p)
685{
686 struct action_devres *devres = res;
687 struct action_devres *target = p;
688
689 return devres->action == target->action &&
690 devres->data == target->data;
691}
692
693static void devm_action_release(struct device *dev, void *res)
694{
695 struct action_devres *devres = res;
696
697 devres->action(devres->data);
698}
699
700/**
701 * devm_add_action() - add a custom action to list of managed resources
702 * @dev: Device that owns the action
703 * @action: Function that should be called
704 * @data: Pointer to data passed to @action implementation
705 *
706 * This adds a custom action to the list of managed resources so that
707 * it gets executed as part of standard resource unwinding.
708 */
709int devm_add_action(struct device *dev, void (*action)(void *), void *data)
710{
711 struct action_devres *devres;
712
713 devres = devres_alloc(devm_action_release,
714 sizeof(struct action_devres), GFP_KERNEL);
715 if (!devres)
716 return -ENOMEM;
717
718 devres->data = data;
719 devres->action = action;
720
721 devres_add(dev, devres);
722 return 0;
723}
724EXPORT_SYMBOL_GPL(devm_add_action);
725
726/**
727 * devm_remove_action() - removes previously added custom action
728 * @dev: Device that owns the action
729 * @action: Function implementing the action
730 * @data: Pointer to data passed to @action implementation
731 *
732 * Removes instance of @action previously added by devm_add_action().
733 * Both action and data should match one of the existing entries.
734 */
735void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
736{
737 struct action_devres devres = {
738 .data = data,
739 .action = action,
740 };
741
742 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
743 &devres));
744
745}
746EXPORT_SYMBOL_GPL(devm_remove_action);
747
748/*
749 * Managed kmalloc/kfree
750 */
751static void devm_kmalloc_release(struct device *dev, void *res)
752{
753 /* noop */
754}
755
756static int devm_kmalloc_match(struct device *dev, void *res, void *data)
757{
758 return res == data;
759}
760
761/**
762 * devm_kmalloc - Resource-managed kmalloc
763 * @dev: Device to allocate memory for
764 * @size: Allocation size
765 * @gfp: Allocation gfp flags
766 *
767 * Managed kmalloc. Memory allocated with this function is
768 * automatically freed on driver detach. Like all other devres
769 * resources, guaranteed alignment is unsigned long long.
770 *
771 * RETURNS:
772 * Pointer to allocated memory on success, NULL on failure.
773 */
774void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
775{
776 struct devres *dr;
777
778 /* use raw alloc_dr for kmalloc caller tracing */
779 dr = alloc_dr(devm_kmalloc_release, size, gfp);
780 if (unlikely(!dr))
781 return NULL;
782
783 /*
784 * This is named devm_kzalloc_release for historical reasons
785 * The initial implementation did not support kmalloc, only kzalloc
786 */
787 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
788 devres_add(dev, dr->data);
789 return dr->data;
790}
791EXPORT_SYMBOL_GPL(devm_kmalloc);
792
793/**
794 * devm_kstrdup - Allocate resource managed space and
795 * copy an existing string into that.
796 * @dev: Device to allocate memory for
797 * @s: the string to duplicate
798 * @gfp: the GFP mask used in the devm_kmalloc() call when
799 * allocating memory
800 * RETURNS:
801 * Pointer to allocated string on success, NULL on failure.
802 */
803char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
804{
805 size_t size;
806 char *buf;
807
808 if (!s)
809 return NULL;
810
811 size = strlen(s) + 1;
812 buf = devm_kmalloc(dev, size, gfp);
813 if (buf)
814 memcpy(buf, s, size);
815 return buf;
816}
817EXPORT_SYMBOL_GPL(devm_kstrdup);
818
819/**
820 * devm_kfree - Resource-managed kfree
821 * @dev: Device this memory belongs to
822 * @p: Memory to free
823 *
824 * Free memory allocated with devm_kmalloc().
825 */
826void devm_kfree(struct device *dev, void *p)
827{
828 int rc;
829
830 rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
831 WARN_ON(rc);
832}
833EXPORT_SYMBOL_GPL(devm_kfree);
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#include "trace.h"
18
19struct devres_node {
20 struct list_head entry;
21 dr_release_t release;
22 const char *name;
23 size_t size;
24};
25
26struct devres {
27 struct devres_node node;
28 /*
29 * Some archs want to perform DMA into kmalloc caches
30 * and need a guaranteed alignment larger than
31 * the alignment of a 64-bit integer.
32 * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
33 * buffer alignment as if it was allocated by plain kmalloc().
34 */
35 u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
36};
37
38struct devres_group {
39 struct devres_node node[2];
40 void *id;
41 int color;
42 /* -- 8 pointers */
43};
44
45static void set_node_dbginfo(struct devres_node *node, const char *name,
46 size_t size)
47{
48 node->name = name;
49 node->size = size;
50}
51
52#ifdef CONFIG_DEBUG_DEVRES
53static int log_devres = 0;
54module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
55
56static void devres_dbg(struct device *dev, struct devres_node *node,
57 const char *op)
58{
59 if (unlikely(log_devres))
60 dev_err(dev, "DEVRES %3s %p %s (%zu bytes)\n",
61 op, node, node->name, node->size);
62}
63#else /* CONFIG_DEBUG_DEVRES */
64#define devres_dbg(dev, node, op) do {} while (0)
65#endif /* CONFIG_DEBUG_DEVRES */
66
67static void devres_log(struct device *dev, struct devres_node *node,
68 const char *op)
69{
70 trace_devres_log(dev, op, node, node->name, node->size);
71 devres_dbg(dev, node, op);
72}
73
74/*
75 * Release functions for devres group. These callbacks are used only
76 * for identification.
77 */
78static void group_open_release(struct device *dev, void *res)
79{
80 /* noop */
81}
82
83static void group_close_release(struct device *dev, void *res)
84{
85 /* noop */
86}
87
88static struct devres_group * node_to_group(struct devres_node *node)
89{
90 if (node->release == &group_open_release)
91 return container_of(node, struct devres_group, node[0]);
92 if (node->release == &group_close_release)
93 return container_of(node, struct devres_group, node[1]);
94 return NULL;
95}
96
97static bool check_dr_size(size_t size, size_t *tot_size)
98{
99 /* We must catch any near-SIZE_MAX cases that could overflow. */
100 if (unlikely(check_add_overflow(sizeof(struct devres),
101 size, tot_size)))
102 return false;
103
104 /* Actually allocate the full kmalloc bucket size. */
105 *tot_size = kmalloc_size_roundup(*tot_size);
106
107 return true;
108}
109
110static __always_inline struct devres * alloc_dr(dr_release_t release,
111 size_t size, gfp_t gfp, int nid)
112{
113 size_t tot_size;
114 struct devres *dr;
115
116 if (!check_dr_size(size, &tot_size))
117 return NULL;
118
119 dr = kmalloc_node_track_caller(tot_size, gfp, nid);
120 if (unlikely(!dr))
121 return NULL;
122
123 /* No need to clear memory twice */
124 if (!(gfp & __GFP_ZERO))
125 memset(dr, 0, offsetof(struct devres, data));
126
127 INIT_LIST_HEAD(&dr->node.entry);
128 dr->node.release = release;
129 return dr;
130}
131
132static void add_dr(struct device *dev, struct devres_node *node)
133{
134 devres_log(dev, node, "ADD");
135 BUG_ON(!list_empty(&node->entry));
136 list_add_tail(&node->entry, &dev->devres_head);
137}
138
139static void replace_dr(struct device *dev,
140 struct devres_node *old, struct devres_node *new)
141{
142 devres_log(dev, old, "REPLACE");
143 BUG_ON(!list_empty(&new->entry));
144 list_replace(&old->entry, &new->entry);
145}
146
147/**
148 * __devres_alloc_node - Allocate device resource data
149 * @release: Release function devres will be associated with
150 * @size: Allocation size
151 * @gfp: Allocation flags
152 * @nid: NUMA node
153 * @name: Name of the resource
154 *
155 * Allocate devres of @size bytes. The allocated area is zeroed, then
156 * associated with @release. The returned pointer can be passed to
157 * other devres_*() functions.
158 *
159 * RETURNS:
160 * Pointer to allocated devres on success, NULL on failure.
161 */
162void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
163 const char *name)
164{
165 struct devres *dr;
166
167 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
168 if (unlikely(!dr))
169 return NULL;
170 set_node_dbginfo(&dr->node, name, size);
171 return dr->data;
172}
173EXPORT_SYMBOL_GPL(__devres_alloc_node);
174
175/**
176 * devres_for_each_res - Resource iterator
177 * @dev: Device to iterate resource from
178 * @release: Look for resources associated with this release function
179 * @match: Match function (optional)
180 * @match_data: Data for the match function
181 * @fn: Function to be called for each matched resource.
182 * @data: Data for @fn, the 3rd parameter of @fn
183 *
184 * Call @fn for each devres of @dev which is associated with @release
185 * and for which @match returns 1.
186 *
187 * RETURNS:
188 * void
189 */
190void devres_for_each_res(struct device *dev, dr_release_t release,
191 dr_match_t match, void *match_data,
192 void (*fn)(struct device *, void *, void *),
193 void *data)
194{
195 struct devres_node *node;
196 struct devres_node *tmp;
197 unsigned long flags;
198
199 if (!fn)
200 return;
201
202 spin_lock_irqsave(&dev->devres_lock, flags);
203 list_for_each_entry_safe_reverse(node, tmp,
204 &dev->devres_head, entry) {
205 struct devres *dr = container_of(node, struct devres, node);
206
207 if (node->release != release)
208 continue;
209 if (match && !match(dev, dr->data, match_data))
210 continue;
211 fn(dev, dr->data, data);
212 }
213 spin_unlock_irqrestore(&dev->devres_lock, flags);
214}
215EXPORT_SYMBOL_GPL(devres_for_each_res);
216
217/**
218 * devres_free - Free device resource data
219 * @res: Pointer to devres data to free
220 *
221 * Free devres created with devres_alloc().
222 */
223void devres_free(void *res)
224{
225 if (res) {
226 struct devres *dr = container_of(res, struct devres, data);
227
228 BUG_ON(!list_empty(&dr->node.entry));
229 kfree(dr);
230 }
231}
232EXPORT_SYMBOL_GPL(devres_free);
233
234/**
235 * devres_add - Register device resource
236 * @dev: Device to add resource to
237 * @res: Resource to register
238 *
239 * Register devres @res to @dev. @res should have been allocated
240 * using devres_alloc(). On driver detach, the associated release
241 * function will be invoked and devres will be freed automatically.
242 */
243void devres_add(struct device *dev, void *res)
244{
245 struct devres *dr = container_of(res, struct devres, data);
246 unsigned long flags;
247
248 spin_lock_irqsave(&dev->devres_lock, flags);
249 add_dr(dev, &dr->node);
250 spin_unlock_irqrestore(&dev->devres_lock, flags);
251}
252EXPORT_SYMBOL_GPL(devres_add);
253
254static struct devres *find_dr(struct device *dev, dr_release_t release,
255 dr_match_t match, void *match_data)
256{
257 struct devres_node *node;
258
259 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
260 struct devres *dr = container_of(node, struct devres, node);
261
262 if (node->release != release)
263 continue;
264 if (match && !match(dev, dr->data, match_data))
265 continue;
266 return dr;
267 }
268
269 return NULL;
270}
271
272/**
273 * devres_find - Find device resource
274 * @dev: Device to lookup resource from
275 * @release: Look for resources associated with this release function
276 * @match: Match function (optional)
277 * @match_data: Data for the match function
278 *
279 * Find the latest devres of @dev which is associated with @release
280 * and for which @match returns 1. If @match is NULL, it's considered
281 * to match all.
282 *
283 * RETURNS:
284 * Pointer to found devres, NULL if not found.
285 */
286void * devres_find(struct device *dev, dr_release_t release,
287 dr_match_t match, void *match_data)
288{
289 struct devres *dr;
290 unsigned long flags;
291
292 spin_lock_irqsave(&dev->devres_lock, flags);
293 dr = find_dr(dev, release, match, match_data);
294 spin_unlock_irqrestore(&dev->devres_lock, flags);
295
296 if (dr)
297 return dr->data;
298 return NULL;
299}
300EXPORT_SYMBOL_GPL(devres_find);
301
302/**
303 * devres_get - Find devres, if non-existent, add one atomically
304 * @dev: Device to lookup or add devres for
305 * @new_res: Pointer to new initialized devres to add if not found
306 * @match: Match function (optional)
307 * @match_data: Data for the match function
308 *
309 * Find the latest devres of @dev which has the same release function
310 * as @new_res and for which @match return 1. If found, @new_res is
311 * freed; otherwise, @new_res is added atomically.
312 *
313 * RETURNS:
314 * Pointer to found or added devres.
315 */
316void * devres_get(struct device *dev, void *new_res,
317 dr_match_t match, void *match_data)
318{
319 struct devres *new_dr = container_of(new_res, struct devres, data);
320 struct devres *dr;
321 unsigned long flags;
322
323 spin_lock_irqsave(&dev->devres_lock, flags);
324 dr = find_dr(dev, new_dr->node.release, match, match_data);
325 if (!dr) {
326 add_dr(dev, &new_dr->node);
327 dr = new_dr;
328 new_res = NULL;
329 }
330 spin_unlock_irqrestore(&dev->devres_lock, flags);
331 devres_free(new_res);
332
333 return dr->data;
334}
335EXPORT_SYMBOL_GPL(devres_get);
336
337/**
338 * devres_remove - Find a device resource and remove it
339 * @dev: Device to find resource from
340 * @release: Look for resources associated with this release function
341 * @match: Match function (optional)
342 * @match_data: Data for the match function
343 *
344 * Find the latest devres of @dev associated with @release and for
345 * which @match returns 1. If @match is NULL, it's considered to
346 * match all. If found, the resource is removed atomically and
347 * returned.
348 *
349 * RETURNS:
350 * Pointer to removed devres on success, NULL if not found.
351 */
352void * devres_remove(struct device *dev, dr_release_t release,
353 dr_match_t match, void *match_data)
354{
355 struct devres *dr;
356 unsigned long flags;
357
358 spin_lock_irqsave(&dev->devres_lock, flags);
359 dr = find_dr(dev, release, match, match_data);
360 if (dr) {
361 list_del_init(&dr->node.entry);
362 devres_log(dev, &dr->node, "REM");
363 }
364 spin_unlock_irqrestore(&dev->devres_lock, flags);
365
366 if (dr)
367 return dr->data;
368 return NULL;
369}
370EXPORT_SYMBOL_GPL(devres_remove);
371
372/**
373 * devres_destroy - Find a device resource and destroy it
374 * @dev: Device to find resource from
375 * @release: Look for resources associated with this release function
376 * @match: Match function (optional)
377 * @match_data: Data for the match function
378 *
379 * Find the latest devres of @dev associated with @release and for
380 * which @match returns 1. If @match is NULL, it's considered to
381 * match all. If found, the resource is removed atomically and freed.
382 *
383 * Note that the release function for the resource will not be called,
384 * only the devres-allocated data will be freed. The caller becomes
385 * responsible for freeing any other data.
386 *
387 * RETURNS:
388 * 0 if devres is found and freed, -ENOENT if not found.
389 */
390int devres_destroy(struct device *dev, dr_release_t release,
391 dr_match_t match, void *match_data)
392{
393 void *res;
394
395 res = devres_remove(dev, release, match, match_data);
396 if (unlikely(!res))
397 return -ENOENT;
398
399 devres_free(res);
400 return 0;
401}
402EXPORT_SYMBOL_GPL(devres_destroy);
403
404
405/**
406 * devres_release - Find a device resource and destroy it, calling release
407 * @dev: Device to find resource from
408 * @release: Look for resources associated with this release function
409 * @match: Match function (optional)
410 * @match_data: Data for the match function
411 *
412 * Find the latest devres of @dev associated with @release and for
413 * which @match returns 1. If @match is NULL, it's considered to
414 * match all. If found, the resource is removed atomically, the
415 * release function called and the resource freed.
416 *
417 * RETURNS:
418 * 0 if devres is found and freed, -ENOENT if not found.
419 */
420int devres_release(struct device *dev, dr_release_t release,
421 dr_match_t match, void *match_data)
422{
423 void *res;
424
425 res = devres_remove(dev, release, match, match_data);
426 if (unlikely(!res))
427 return -ENOENT;
428
429 (*release)(dev, res);
430 devres_free(res);
431 return 0;
432}
433EXPORT_SYMBOL_GPL(devres_release);
434
435static int remove_nodes(struct device *dev,
436 struct list_head *first, struct list_head *end,
437 struct list_head *todo)
438{
439 struct devres_node *node, *n;
440 int cnt = 0, nr_groups = 0;
441
442 /* First pass - move normal devres entries to @todo and clear
443 * devres_group colors.
444 */
445 node = list_entry(first, struct devres_node, entry);
446 list_for_each_entry_safe_from(node, n, end, entry) {
447 struct devres_group *grp;
448
449 grp = node_to_group(node);
450 if (grp) {
451 /* clear color of group markers in the first pass */
452 grp->color = 0;
453 nr_groups++;
454 } else {
455 /* regular devres entry */
456 if (&node->entry == first)
457 first = first->next;
458 list_move_tail(&node->entry, todo);
459 cnt++;
460 }
461 }
462
463 if (!nr_groups)
464 return cnt;
465
466 /* Second pass - Scan groups and color them. A group gets
467 * color value of two iff the group is wholly contained in
468 * [current node, end). That is, for a closed group, both opening
469 * and closing markers should be in the range, while just the
470 * opening marker is enough for an open group.
471 */
472 node = list_entry(first, struct devres_node, entry);
473 list_for_each_entry_safe_from(node, n, end, entry) {
474 struct devres_group *grp;
475
476 grp = node_to_group(node);
477 BUG_ON(!grp || list_empty(&grp->node[0].entry));
478
479 grp->color++;
480 if (list_empty(&grp->node[1].entry))
481 grp->color++;
482
483 BUG_ON(grp->color <= 0 || grp->color > 2);
484 if (grp->color == 2) {
485 /* No need to update current node or end. The removed
486 * nodes are always before both.
487 */
488 list_move_tail(&grp->node[0].entry, todo);
489 list_del_init(&grp->node[1].entry);
490 }
491 }
492
493 return cnt;
494}
495
496static void release_nodes(struct device *dev, struct list_head *todo)
497{
498 struct devres *dr, *tmp;
499
500 /* Release. Note that both devres and devres_group are
501 * handled as devres in the following loop. This is safe.
502 */
503 list_for_each_entry_safe_reverse(dr, tmp, todo, node.entry) {
504 devres_log(dev, &dr->node, "REL");
505 dr->node.release(dev, dr->data);
506 kfree(dr);
507 }
508}
509
510/**
511 * devres_release_all - Release all managed resources
512 * @dev: Device to release resources for
513 *
514 * Release all resources associated with @dev. This function is
515 * called on driver detach.
516 */
517int devres_release_all(struct device *dev)
518{
519 unsigned long flags;
520 LIST_HEAD(todo);
521 int cnt;
522
523 /* Looks like an uninitialized device structure */
524 if (WARN_ON(dev->devres_head.next == NULL))
525 return -ENODEV;
526
527 /* Nothing to release if list is empty */
528 if (list_empty(&dev->devres_head))
529 return 0;
530
531 spin_lock_irqsave(&dev->devres_lock, flags);
532 cnt = remove_nodes(dev, dev->devres_head.next, &dev->devres_head, &todo);
533 spin_unlock_irqrestore(&dev->devres_lock, flags);
534
535 release_nodes(dev, &todo);
536 return cnt;
537}
538
539/**
540 * devres_open_group - Open a new devres group
541 * @dev: Device to open devres group for
542 * @id: Separator ID
543 * @gfp: Allocation flags
544 *
545 * Open a new devres group for @dev with @id. For @id, using a
546 * pointer to an object which won't be used for another group is
547 * recommended. If @id is NULL, address-wise unique ID is created.
548 *
549 * RETURNS:
550 * ID of the new group, NULL on failure.
551 */
552void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
553{
554 struct devres_group *grp;
555 unsigned long flags;
556
557 grp = kmalloc(sizeof(*grp), gfp);
558 if (unlikely(!grp))
559 return NULL;
560
561 grp->node[0].release = &group_open_release;
562 grp->node[1].release = &group_close_release;
563 INIT_LIST_HEAD(&grp->node[0].entry);
564 INIT_LIST_HEAD(&grp->node[1].entry);
565 set_node_dbginfo(&grp->node[0], "grp<", 0);
566 set_node_dbginfo(&grp->node[1], "grp>", 0);
567 grp->id = grp;
568 if (id)
569 grp->id = id;
570
571 spin_lock_irqsave(&dev->devres_lock, flags);
572 add_dr(dev, &grp->node[0]);
573 spin_unlock_irqrestore(&dev->devres_lock, flags);
574 return grp->id;
575}
576EXPORT_SYMBOL_GPL(devres_open_group);
577
578/* Find devres group with ID @id. If @id is NULL, look for the latest. */
579static struct devres_group * find_group(struct device *dev, void *id)
580{
581 struct devres_node *node;
582
583 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
584 struct devres_group *grp;
585
586 if (node->release != &group_open_release)
587 continue;
588
589 grp = container_of(node, struct devres_group, node[0]);
590
591 if (id) {
592 if (grp->id == id)
593 return grp;
594 } else if (list_empty(&grp->node[1].entry))
595 return grp;
596 }
597
598 return NULL;
599}
600
601/**
602 * devres_close_group - Close a devres group
603 * @dev: Device to close devres group for
604 * @id: ID of target group, can be NULL
605 *
606 * Close the group identified by @id. If @id is NULL, the latest open
607 * group is selected.
608 */
609void devres_close_group(struct device *dev, void *id)
610{
611 struct devres_group *grp;
612 unsigned long flags;
613
614 spin_lock_irqsave(&dev->devres_lock, flags);
615
616 grp = find_group(dev, id);
617 if (grp)
618 add_dr(dev, &grp->node[1]);
619 else
620 WARN_ON(1);
621
622 spin_unlock_irqrestore(&dev->devres_lock, flags);
623}
624EXPORT_SYMBOL_GPL(devres_close_group);
625
626/**
627 * devres_remove_group - Remove a devres group
628 * @dev: Device to remove group for
629 * @id: ID of target group, can be NULL
630 *
631 * Remove the group identified by @id. If @id is NULL, the latest
632 * open group is selected. Note that removing a group doesn't affect
633 * any other resources.
634 */
635void devres_remove_group(struct device *dev, void *id)
636{
637 struct devres_group *grp;
638 unsigned long flags;
639
640 spin_lock_irqsave(&dev->devres_lock, flags);
641
642 grp = find_group(dev, id);
643 if (grp) {
644 list_del_init(&grp->node[0].entry);
645 list_del_init(&grp->node[1].entry);
646 devres_log(dev, &grp->node[0], "REM");
647 } else
648 WARN_ON(1);
649
650 spin_unlock_irqrestore(&dev->devres_lock, flags);
651
652 kfree(grp);
653}
654EXPORT_SYMBOL_GPL(devres_remove_group);
655
656/**
657 * devres_release_group - Release resources in a devres group
658 * @dev: Device to release group for
659 * @id: ID of target group, can be NULL
660 *
661 * Release all resources in the group identified by @id. If @id is
662 * NULL, the latest open group is selected. The selected group and
663 * groups properly nested inside the selected group are removed.
664 *
665 * RETURNS:
666 * The number of released non-group resources.
667 */
668int devres_release_group(struct device *dev, void *id)
669{
670 struct devres_group *grp;
671 unsigned long flags;
672 LIST_HEAD(todo);
673 int cnt = 0;
674
675 spin_lock_irqsave(&dev->devres_lock, flags);
676
677 grp = find_group(dev, id);
678 if (grp) {
679 struct list_head *first = &grp->node[0].entry;
680 struct list_head *end = &dev->devres_head;
681
682 if (!list_empty(&grp->node[1].entry))
683 end = grp->node[1].entry.next;
684
685 cnt = remove_nodes(dev, first, end, &todo);
686 spin_unlock_irqrestore(&dev->devres_lock, flags);
687
688 release_nodes(dev, &todo);
689 } else {
690 WARN_ON(1);
691 spin_unlock_irqrestore(&dev->devres_lock, flags);
692 }
693
694 return cnt;
695}
696EXPORT_SYMBOL_GPL(devres_release_group);
697
698/*
699 * Custom devres actions allow inserting a simple function call
700 * into the teardown sequence.
701 */
702
703struct action_devres {
704 void *data;
705 void (*action)(void *);
706};
707
708static int devm_action_match(struct device *dev, void *res, void *p)
709{
710 struct action_devres *devres = res;
711 struct action_devres *target = p;
712
713 return devres->action == target->action &&
714 devres->data == target->data;
715}
716
717static void devm_action_release(struct device *dev, void *res)
718{
719 struct action_devres *devres = res;
720
721 devres->action(devres->data);
722}
723
724/**
725 * devm_add_action() - add a custom action to list of managed resources
726 * @dev: Device that owns the action
727 * @action: Function that should be called
728 * @data: Pointer to data passed to @action implementation
729 *
730 * This adds a custom action to the list of managed resources so that
731 * it gets executed as part of standard resource unwinding.
732 */
733int devm_add_action(struct device *dev, void (*action)(void *), void *data)
734{
735 struct action_devres *devres;
736
737 devres = devres_alloc(devm_action_release,
738 sizeof(struct action_devres), GFP_KERNEL);
739 if (!devres)
740 return -ENOMEM;
741
742 devres->data = data;
743 devres->action = action;
744
745 devres_add(dev, devres);
746 return 0;
747}
748EXPORT_SYMBOL_GPL(devm_add_action);
749
750/**
751 * devm_remove_action() - removes previously added custom action
752 * @dev: Device that owns the action
753 * @action: Function implementing the action
754 * @data: Pointer to data passed to @action implementation
755 *
756 * Removes instance of @action previously added by devm_add_action().
757 * Both action and data should match one of the existing entries.
758 */
759void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
760{
761 struct action_devres devres = {
762 .data = data,
763 .action = action,
764 };
765
766 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
767 &devres));
768}
769EXPORT_SYMBOL_GPL(devm_remove_action);
770
771/**
772 * devm_release_action() - release previously added custom action
773 * @dev: Device that owns the action
774 * @action: Function implementing the action
775 * @data: Pointer to data passed to @action implementation
776 *
777 * Releases and removes instance of @action previously added by
778 * devm_add_action(). Both action and data should match one of the
779 * existing entries.
780 */
781void devm_release_action(struct device *dev, void (*action)(void *), void *data)
782{
783 struct action_devres devres = {
784 .data = data,
785 .action = action,
786 };
787
788 WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
789 &devres));
790
791}
792EXPORT_SYMBOL_GPL(devm_release_action);
793
794/*
795 * Managed kmalloc/kfree
796 */
797static void devm_kmalloc_release(struct device *dev, void *res)
798{
799 /* noop */
800}
801
802static int devm_kmalloc_match(struct device *dev, void *res, void *data)
803{
804 return res == data;
805}
806
807/**
808 * devm_kmalloc - Resource-managed kmalloc
809 * @dev: Device to allocate memory for
810 * @size: Allocation size
811 * @gfp: Allocation gfp flags
812 *
813 * Managed kmalloc. Memory allocated with this function is
814 * automatically freed on driver detach. Like all other devres
815 * resources, guaranteed alignment is unsigned long long.
816 *
817 * RETURNS:
818 * Pointer to allocated memory on success, NULL on failure.
819 */
820void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
821{
822 struct devres *dr;
823
824 if (unlikely(!size))
825 return ZERO_SIZE_PTR;
826
827 /* use raw alloc_dr for kmalloc caller tracing */
828 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
829 if (unlikely(!dr))
830 return NULL;
831
832 /*
833 * This is named devm_kzalloc_release for historical reasons
834 * The initial implementation did not support kmalloc, only kzalloc
835 */
836 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
837 devres_add(dev, dr->data);
838 return dr->data;
839}
840EXPORT_SYMBOL_GPL(devm_kmalloc);
841
842/**
843 * devm_krealloc - Resource-managed krealloc()
844 * @dev: Device to re-allocate memory for
845 * @ptr: Pointer to the memory chunk to re-allocate
846 * @new_size: New allocation size
847 * @gfp: Allocation gfp flags
848 *
849 * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
850 * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
851 * it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
852 * previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
853 * change the order in which the release callback for the re-alloc'ed devres
854 * will be called (except when falling back to devm_kmalloc() or when freeing
855 * resources when new_size is zero). The contents of the memory are preserved
856 * up to the lesser of new and old sizes.
857 */
858void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
859{
860 size_t total_new_size, total_old_size;
861 struct devres *old_dr, *new_dr;
862 unsigned long flags;
863
864 if (unlikely(!new_size)) {
865 devm_kfree(dev, ptr);
866 return ZERO_SIZE_PTR;
867 }
868
869 if (unlikely(ZERO_OR_NULL_PTR(ptr)))
870 return devm_kmalloc(dev, new_size, gfp);
871
872 if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
873 /*
874 * We cannot reliably realloc a const string returned by
875 * devm_kstrdup_const().
876 */
877 return NULL;
878
879 if (!check_dr_size(new_size, &total_new_size))
880 return NULL;
881
882 total_old_size = ksize(container_of(ptr, struct devres, data));
883 if (total_old_size == 0) {
884 WARN(1, "Pointer doesn't point to dynamically allocated memory.");
885 return NULL;
886 }
887
888 /*
889 * If new size is smaller or equal to the actual number of bytes
890 * allocated previously - just return the same pointer.
891 */
892 if (total_new_size <= total_old_size)
893 return ptr;
894
895 /*
896 * Otherwise: allocate new, larger chunk. We need to allocate before
897 * taking the lock as most probably the caller uses GFP_KERNEL.
898 */
899 new_dr = alloc_dr(devm_kmalloc_release,
900 total_new_size, gfp, dev_to_node(dev));
901 if (!new_dr)
902 return NULL;
903
904 /*
905 * The spinlock protects the linked list against concurrent
906 * modifications but not the resource itself.
907 */
908 spin_lock_irqsave(&dev->devres_lock, flags);
909
910 old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
911 if (!old_dr) {
912 spin_unlock_irqrestore(&dev->devres_lock, flags);
913 kfree(new_dr);
914 WARN(1, "Memory chunk not managed or managed by a different device.");
915 return NULL;
916 }
917
918 replace_dr(dev, &old_dr->node, &new_dr->node);
919
920 spin_unlock_irqrestore(&dev->devres_lock, flags);
921
922 /*
923 * We can copy the memory contents after releasing the lock as we're
924 * no longer modifying the list links.
925 */
926 memcpy(new_dr->data, old_dr->data,
927 total_old_size - offsetof(struct devres, data));
928 /*
929 * Same for releasing the old devres - it's now been removed from the
930 * list. This is also the reason why we must not use devm_kfree() - the
931 * links are no longer valid.
932 */
933 kfree(old_dr);
934
935 return new_dr->data;
936}
937EXPORT_SYMBOL_GPL(devm_krealloc);
938
939/**
940 * devm_kstrdup - Allocate resource managed space and
941 * copy an existing string into that.
942 * @dev: Device to allocate memory for
943 * @s: the string to duplicate
944 * @gfp: the GFP mask used in the devm_kmalloc() call when
945 * allocating memory
946 * RETURNS:
947 * Pointer to allocated string on success, NULL on failure.
948 */
949char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
950{
951 size_t size;
952 char *buf;
953
954 if (!s)
955 return NULL;
956
957 size = strlen(s) + 1;
958 buf = devm_kmalloc(dev, size, gfp);
959 if (buf)
960 memcpy(buf, s, size);
961 return buf;
962}
963EXPORT_SYMBOL_GPL(devm_kstrdup);
964
965/**
966 * devm_kstrdup_const - resource managed conditional string duplication
967 * @dev: device for which to duplicate the string
968 * @s: the string to duplicate
969 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
970 *
971 * Strings allocated by devm_kstrdup_const will be automatically freed when
972 * the associated device is detached.
973 *
974 * RETURNS:
975 * Source string if it is in .rodata section otherwise it falls back to
976 * devm_kstrdup.
977 */
978const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
979{
980 if (is_kernel_rodata((unsigned long)s))
981 return s;
982
983 return devm_kstrdup(dev, s, gfp);
984}
985EXPORT_SYMBOL_GPL(devm_kstrdup_const);
986
987/**
988 * devm_kvasprintf - Allocate resource managed space and format a string
989 * into that.
990 * @dev: Device to allocate memory for
991 * @gfp: the GFP mask used in the devm_kmalloc() call when
992 * allocating memory
993 * @fmt: The printf()-style format string
994 * @ap: Arguments for the format string
995 * RETURNS:
996 * Pointer to allocated string on success, NULL on failure.
997 */
998char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
999 va_list ap)
1000{
1001 unsigned int len;
1002 char *p;
1003 va_list aq;
1004
1005 va_copy(aq, ap);
1006 len = vsnprintf(NULL, 0, fmt, aq);
1007 va_end(aq);
1008
1009 p = devm_kmalloc(dev, len+1, gfp);
1010 if (!p)
1011 return NULL;
1012
1013 vsnprintf(p, len+1, fmt, ap);
1014
1015 return p;
1016}
1017EXPORT_SYMBOL(devm_kvasprintf);
1018
1019/**
1020 * devm_kasprintf - Allocate resource managed space and format a string
1021 * into that.
1022 * @dev: Device to allocate memory for
1023 * @gfp: the GFP mask used in the devm_kmalloc() call when
1024 * allocating memory
1025 * @fmt: The printf()-style format string
1026 * @...: Arguments for the format string
1027 * RETURNS:
1028 * Pointer to allocated string on success, NULL on failure.
1029 */
1030char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
1031{
1032 va_list ap;
1033 char *p;
1034
1035 va_start(ap, fmt);
1036 p = devm_kvasprintf(dev, gfp, fmt, ap);
1037 va_end(ap);
1038
1039 return p;
1040}
1041EXPORT_SYMBOL_GPL(devm_kasprintf);
1042
1043/**
1044 * devm_kfree - Resource-managed kfree
1045 * @dev: Device this memory belongs to
1046 * @p: Memory to free
1047 *
1048 * Free memory allocated with devm_kmalloc().
1049 */
1050void devm_kfree(struct device *dev, const void *p)
1051{
1052 int rc;
1053
1054 /*
1055 * Special cases: pointer to a string in .rodata returned by
1056 * devm_kstrdup_const() or NULL/ZERO ptr.
1057 */
1058 if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
1059 return;
1060
1061 rc = devres_destroy(dev, devm_kmalloc_release,
1062 devm_kmalloc_match, (void *)p);
1063 WARN_ON(rc);
1064}
1065EXPORT_SYMBOL_GPL(devm_kfree);
1066
1067/**
1068 * devm_kmemdup - Resource-managed kmemdup
1069 * @dev: Device this memory belongs to
1070 * @src: Memory region to duplicate
1071 * @len: Memory region length
1072 * @gfp: GFP mask to use
1073 *
1074 * Duplicate region of a memory using resource managed kmalloc
1075 */
1076void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
1077{
1078 void *p;
1079
1080 p = devm_kmalloc(dev, len, gfp);
1081 if (p)
1082 memcpy(p, src, len);
1083
1084 return p;
1085}
1086EXPORT_SYMBOL_GPL(devm_kmemdup);
1087
1088struct pages_devres {
1089 unsigned long addr;
1090 unsigned int order;
1091};
1092
1093static int devm_pages_match(struct device *dev, void *res, void *p)
1094{
1095 struct pages_devres *devres = res;
1096 struct pages_devres *target = p;
1097
1098 return devres->addr == target->addr;
1099}
1100
1101static void devm_pages_release(struct device *dev, void *res)
1102{
1103 struct pages_devres *devres = res;
1104
1105 free_pages(devres->addr, devres->order);
1106}
1107
1108/**
1109 * devm_get_free_pages - Resource-managed __get_free_pages
1110 * @dev: Device to allocate memory for
1111 * @gfp_mask: Allocation gfp flags
1112 * @order: Allocation size is (1 << order) pages
1113 *
1114 * Managed get_free_pages. Memory allocated with this function is
1115 * automatically freed on driver detach.
1116 *
1117 * RETURNS:
1118 * Address of allocated memory on success, 0 on failure.
1119 */
1120
1121unsigned long devm_get_free_pages(struct device *dev,
1122 gfp_t gfp_mask, unsigned int order)
1123{
1124 struct pages_devres *devres;
1125 unsigned long addr;
1126
1127 addr = __get_free_pages(gfp_mask, order);
1128
1129 if (unlikely(!addr))
1130 return 0;
1131
1132 devres = devres_alloc(devm_pages_release,
1133 sizeof(struct pages_devres), GFP_KERNEL);
1134 if (unlikely(!devres)) {
1135 free_pages(addr, order);
1136 return 0;
1137 }
1138
1139 devres->addr = addr;
1140 devres->order = order;
1141
1142 devres_add(dev, devres);
1143 return addr;
1144}
1145EXPORT_SYMBOL_GPL(devm_get_free_pages);
1146
1147/**
1148 * devm_free_pages - Resource-managed free_pages
1149 * @dev: Device this memory belongs to
1150 * @addr: Memory to free
1151 *
1152 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1153 * there is no need to supply the @order.
1154 */
1155void devm_free_pages(struct device *dev, unsigned long addr)
1156{
1157 struct pages_devres devres = { .addr = addr };
1158
1159 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1160 &devres));
1161}
1162EXPORT_SYMBOL_GPL(devm_free_pages);
1163
1164static void devm_percpu_release(struct device *dev, void *pdata)
1165{
1166 void __percpu *p;
1167
1168 p = *(void __percpu **)pdata;
1169 free_percpu(p);
1170}
1171
1172static int devm_percpu_match(struct device *dev, void *data, void *p)
1173{
1174 struct devres *devr = container_of(data, struct devres, data);
1175
1176 return *(void **)devr->data == p;
1177}
1178
1179/**
1180 * __devm_alloc_percpu - Resource-managed alloc_percpu
1181 * @dev: Device to allocate per-cpu memory for
1182 * @size: Size of per-cpu memory to allocate
1183 * @align: Alignment of per-cpu memory to allocate
1184 *
1185 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1186 * automatically freed on driver detach.
1187 *
1188 * RETURNS:
1189 * Pointer to allocated memory on success, NULL on failure.
1190 */
1191void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1192 size_t align)
1193{
1194 void *p;
1195 void __percpu *pcpu;
1196
1197 pcpu = __alloc_percpu(size, align);
1198 if (!pcpu)
1199 return NULL;
1200
1201 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1202 if (!p) {
1203 free_percpu(pcpu);
1204 return NULL;
1205 }
1206
1207 *(void __percpu **)p = pcpu;
1208
1209 devres_add(dev, p);
1210
1211 return pcpu;
1212}
1213EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1214
1215/**
1216 * devm_free_percpu - Resource-managed free_percpu
1217 * @dev: Device this memory belongs to
1218 * @pdata: Per-cpu memory to free
1219 *
1220 * Free memory allocated with devm_alloc_percpu().
1221 */
1222void devm_free_percpu(struct device *dev, void __percpu *pdata)
1223{
1224 WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1225 (__force void *)pdata));
1226}
1227EXPORT_SYMBOL_GPL(devm_free_percpu);